As one of the high-quality organic trace elements, polysaccharide trace element complexes have attracted the attention of domestic and foreign researchers because of their excellent biological functions of polysaccharides, and can significantly increase the utilization of trace elements and reduce environmental pollution. This review outlines the state-of-art research advances in plant, alga, and microbial polysaccharide trace element complexes. We emphasized the influence of molecular structure of the polysaccharide on the process conditions for complex synthesis and the potential application of polysaccharide trace element complexes in the feed industry. Meanwhile, challenges faced by polysaccharide trace element complexes and corresponding solutions are discussed. Overall, this review is intended to provide valuable insights for the synthesis of polysaccharide trace element complexes from a biochemical engineering standpoint, promoting the combination of green agricultural development and green livestock products.

Materials with high permeability, high selectivity and high stability are the critical factors to efficient membrane separation processes. Organic framework membranes (OFMs) hold great prospects in gas separation, owing to their high porosity, long-range regular structure, facilely-tailored functionality, and high stability. This review summarized the chemical compositions, structures, fabrications of OFMs and their applications in carbon dioxide capture and separation, olefin/paraffin separation and noble gas separation. Finally, the major challenges and brief perspectives of OFMs in gas separation are tentatively identified.

As a reserve battery that heats the electrolyte to melt when applied to use, thermal batteries are mostly used in military and aerospace fields. At room temperature, its electrolyte is in a solid state without ionic conduction, so that the battery does not self-discharge, which is a necessary condition for its long-term storage. The molten salt electrolyte of the thermal battery is one of the key elements that determine its performance. In recent years, the application of a new system of component-controlled molten salt electrolyte to reduce the melting point and increase the ionic conductivity has become one of the research hotspots such as adding low-melting component salts to lower the melting point of the molten salt system, or using the entropy increase principle to optimize the performance of molten salt by adding new components. Combining with theoretical calculations and simulations, the ternary or even quaternary molten salt is developed to improve thermal battery performance, especially to extend battery life. In order to make the use of thermal batteries more common, the molten salt of the low melting point system is utilized. The introduction of some precious metal cations and the use of nitrates can reduce the melting temperature of the molten salt system to below 300℃, which is the standard for its common use. The addition of functional components such as MgO binder can reduce the probability of electrolyte molten salt leakage, but its dosage and structure need to be optimized to reduce the internal resistance of the battery and improve the retention of molten salt, which can improve the electrochemical performance of thermal batteries. Further, the introduction of inorganic fiber separators can reduce or eliminate the use of MgO binder to a greater extent and improve the safety and reliability of the battery, which also provides guidance for miniaturization of thermal battery.

Peptide is composed of amino acid through dehydration condensation, which is a compound molecule that has specific biological activity, and thus peptide-based drugs became an important direction of pharmaceutical engineering. Peptide drugs are the frontier of modern medical research and have important social and economic values. This paper reviews the research progress of peptide biosynthesis methods (natural raw material extraction, enzymatic solution, fermentation, gene recombination) and chemical synthesis methods (liquid-phase peptide synthesis and solid-phase peptide synthesis), focusing on the solid-phase peptide synthesis among chemical synthesis methods. This paper also introduces the application of reverse-phase high-performance chromatography, capillary electrophoresis, and ion exchange chromatography, gel filtration chromatography, and affinity chromatography. Finally, the future development of peptide pharmaceutical technology is prospected.

White LED (light-emitting diode) is known as the fourth-generation solid-state lighting source due to its excellent luminous performance. By taking quantum efficiency as the core parameter and warm white light as the ultimate goal, this paper reviews and summarizes the research on rare earth doped tricolor (red, green and blue) inorganic phosphors and single matrix single doped, co-doped and multi-doped warm white phosphors. The results show that Eu²⁺ and Ce³⁺ are the main active ions of high quantum efficiency near UV excited blue phosphor, Tb³⁺ and Eu²⁺ are the main active ions of green phosphor, and Eu³⁺ and Eu²⁺ are the main active ions of red phosphor. The existing single substrate warm white phosphors still have many technical bottlenecks, such as insufficient red light, low color rendering index, low quantum efficiency and so on. Based on the literatures, it is proposed to prepare a single matrix white phosphor from the existing high-efficiency red powder, so as to eliminate the lack of red component in the spectrum, and appropriately introduce transition metal elements other than Mn. At the same time, strengthen the research on the kinetic theory of the matrix and the kinetic theory of the electronic coupling between the matrix and the rare earth. It is hoped that the design calculation and controllable preparation of rare earth doped inorganic phosphors can be realized.

Transition metal carbides (TMCs) are formed by carburizing reaction of parent metal compounds. They have variable structure and noble metal like electronic properties. They are a kind of inexpensive but important materials in heterogeneous catalysis, providing great potential for large-scale industrial applications. Integrating carbon atoms into the parent metals leads to the expansion of metal lattice and structural rearrangement, which then broadens the metal d band with a greater density of state and alters the electronic properties. They are used in catalytic hydrogenation, hydrodeoxygenation(HDO) and hydrogenolysis and other important catalytic reactions showed excellent performance. In recent years, significant progress has been achieved in developing efficient and highly-stable TMCs in catalytic reactions. However, it remains great challenging to investigate the surface properties and understand the structure-activity relationship in these materials due to their inherent complexity of carbides involving phase purity, surface defects, surface termination and surface oxides. In this review, we firstly give a brief introduction on the current status and then summarize the recent progress in the development of TMCs towards HDO of representative oxygenates in pyrolysis bio-oil. Based on the analysis of the reaction pathway of representative oxygenates in pyrolysis bio-oil, the design and preparation strategy of TMCs, and the relationship between their structure and HDO catalytic performance are emphatically discussed. Finally, the R&D direction and prospect of TMCs as catalytic materials for HDO of biomass-derived oxygenates are proposed.

The process of microbial extracellular electron transfer (EET) is widespread in nature and has broad application prospects in energy utilization and environmental remediation. However, inefficient electron transfer has always been a key bottleneck in practical applications. Nanomaterials have unique properties such as surface effect, volume effect, quantum size, and macro-quantum tunneling effect. The combination of nanomaterials and electroactive microorganisms can achieve complementary advantages, which can shorten the charge transfer path and increase the rate of EET. This review introduces the pathways of EET, as well as the factors affecting the interface EET such as the electron transfer ability, redox potential, surface structure and biocompatibility of nanomaterials, with a focus on various strategies for constructing the interface between nanomaterials and electroactive microorganisms, and the applicability and limitations of these strategies are summarized. Finally, the future research direction of nanomaterials to enhance electroactive microorganism EET is prospected.

Based on 4-methylthiazole, a two-step method was used to synthesize four sulfonic acid functionalized ionic liquids with different anions to catalyze the transesterification reaction of soapberry oil with methanol to produce biodiesel. The characterization results of Fourier transform infrared spectroscopy, nuclear magnetic resonance, and thermogravimetric analysis suggested that ionic liquids are successfully prepared with high thermal stability. Among the ionic liquids investigated, 3-(3-sulfonic) propyl-4-methylthiazole trifluoromethane sulfonate ([Ps-MTH][CF₃SO₃]) performs the highest catalytic activity. In particular, catalyzed by [Ps-MTH][CF₃SO₃], the optimum operating conditions of transesterification of soapberry oil and methanol are 128℃ (temperature), 28.10∶1 (molar ratio of alcohol to oil), 0.62 mmol/g (catalyst amount, based on the mass of oil) and 8 h (reaction time), leading to a high biodiesel yield of 92.78%±0.47%. Besides, [Ps-MTH][CF₃SO₃] also possesses good reusability and universality. This study will provide basic data for the industrial production of biodiesel from soapberry oil catalyzed by ionic liquids.

Developing highly efficient stable Au-Ti bifunctional catalysts is scientific and technological challenge for direct propylene epoxidation with H₂ and O₂. This work describes a novel strategy of employing tetrapropylammonium hydroxide (TPAOH) to modify uncalcined titanium silicalite-1 (TS-1-B) by secondary crystallization. Urea is used as the precipitation agent to immobilize gold nanoparticles onto the modified TS-1-B by deposition-precipitation method, aiming at allowing high gold capture efficiency as well as avoiding the introduction of residual alkaline cations to the catalyst. Compared with the reference Au/TS-1-B catalyst, the nano-gold particles immobilized on the modified TS-1 delivers significantly enhanced stability (> 36 h), propylene oxide (PO) formation rate (about 120 g/(h·kg)), PO selectivity (about 92.1%) and hydrogen efficiency (about 33.3%). The Fourier transform infrared spectroscopy (FT-IR) spectra demonstrates that the strength of the hydrogen-bonded silanols and trapped water in the TS-1-B decreased remarkably after secondary crystallization, indicating that the hydrophobic of TS-1-B is increased, which can be responsible for the improved stability and activity of the modified TS-1-B immobilized nano-gold catalyst. Moreover, the analysis of kinetic characteristic demonstrates that the propylene conversion and PO formation rate increase with increasing reaction temperature, while the PO selectivity and hydrogen efficiency decrease monotonously, and the apparent activation energies of by-products are much higher than the PO, indicating that higher reaction temperature favours the formation of by-products. In addition, the kinetic behavior of the catalyst was also studied, and the activation energy for the formation of main/by-products was calculated.

Photofluidics can combine photocatalytic reaction with microfluidic technology, greatly improve light utilization and reaction rate, and achieve efficient enhancement of photocatalytic water treatment. The design and optimization of microreactor structure is one of the research focuses. In this work, we first use computational fluid dynamics simulation to optimize the number of channels, and design a 5-level tree-shaped microfluidic planar reactor. The planar microreactor has a 12 mm × 12 mm reaction chamber enclosed by TiO₂ coated glass slide as bottom substrate and polydimethylsiloxane board as the top cover, and a microstructured UV-cured NOA-81 layer is as the sealant and flow input/output. Subsequently, photocatalytic performance is investigated by tuning the microreactor overall height. This is evidenced by our findings in this paper that the degradation and continuous operation performance of the 50 μm microreactor is better than that of 100 μm microreactor. In the photocatalysis experiment, the methylene blue is used as a simulated wastewater to study the performance of planar microreactors and tank reactors, including reaction kinetics, microreactor pollution problems and continuous operation performance. It is shown that when the microreactors operate at different flow rates, the methylene blue can achieve continuous and high-efficiency photocatalytic degradation, and the degradation rate is much higher than the tank reactor. When the flow rate is 55 μl/min, the degradation rate of 5×10^-5 mol/L methylene blue can reach 95%, which means that the planar microreactors can maintain good continuous operation performance and reusability. Planar micreactor inherits the merits of microfluidics, such as huge specific surface area, efficient and stable reaction, and easy control, and offers an efficient and feasible scheme for water treatment.

The supported PdCu/N-CB catalysts were prepared by using nitrogen-modified carbon black as support. Compared with the catalysts without nitrogen modification, their catalytic performance in terms of hydrogen production from formic acid was significantly improved. Among them, Pd₈Cu₂/N-CB catalyst demonstrated the highest activity with TOF of 718.56 h^-1 and satisfying stability. XRD, TEM, FTIR and XPS analysis confirm that the N-CB support modified by APTMS can promote the particle size of PdCu alloy to become smaller, which allows better dispersion. The strong interaction between the active phase PdCu alloy and the N-CB support improved the chemical state of PdCu alloy and thereby enhanced the catalytic performance for hydrogen production from formic acid. The method of improving the catalytic performance of supported noble metal catalysts by introducing transition metals and nitrogen modified supports is helpful to the development of low-cost and high-performance hydrogen production catalysts.

Fischer-Tropsch (F-T) synthesis is an important way to produce clean fuels and other chemicals from syngas. The traditional F-T synthesis follows Anderson-Schulz-Flory distribution, except for methane and heavy hydrocarbons, where its selectivity has no limit. Therefore, maximizing the yields of heavy hydrocarbons to further obtain high quality diesel and aviation kerosene by hydrocracking and hydroisomerization has been the research focus for F-T synthesis. The present work compared the effects of different supports (SiO₂, Al₂O₃ and SiC) on the catalytic performance of cobalt-based catalysts for F-T synthesis, in which SiC showed the highest activity (83.5%) and C₅₊ selectivity (80.3%). Compared to impregnation method, introducing Ru promoter by in-situ reduction method is more effective, with C₅₊ selectivity being further increased to 90.1%. Ru promoter could improve the C₅₊ selectivity while maintaining a high catalytic performance of Co/SiC catalyst. The characterization (XRD, H₂-TPR, XPS, H₂-chemisorption and TEM) results demonstrated the interaction between Ru and Co, thereby enhancing the reducibility and dispersion of active components and improved the selectivity for heavy hydrocarbons of Co/SiC catalyst.

This work designs a tandem route for the production of ethylbenzene (EB) directly from ethane and benzene via the ethylene intermediate. The tandem reaction consists of chlorine oxidation of ethane to form ethylene and the alkylation reaction between ethylene and benzene. In this paper, cerium-based oxide was selected as the catalyst for activating ethane to produce ethylene, and the H-ZSM-5 zeolite was used to be further alkylated with benzene to produce ethylbenzene. We investigate the optimization of the selected oxides, and the effects of the ratio of oxides and zeolites, acidity of zeolite on catalytic performances of tandem reaction over Mn/CeO₂-H-ZSM-5 bifunctional catalyst. The stability of catalyst is also investigated. Combining X-ray diffraction (XRD), NH₃ temperature programmed desorption (NH₃-TPD), transmission electron microscopy (TEM), and X-ray fluorescence spectroscopy (XRF) techniques, the structure of catalyst and the relationship of structure and performances are further studied. The research suggests that the key to subsequent catalyst research lies in the improvement of zeolite alkylation ability and anti-loss ability.

Rape pollen was used as a biological template to prepare ZnO with a multi-layered pore structure, and Cu/ZnO supported catalysts (bio-CZ-500) with different structures were prepared by dipping and reducing Cu on ZnO. The obtained Cu/ZnO catalyst (namely, bio-CZ-500 upon calcination under 500℃) exhibited a high methanol selectivity of 81% in CO₂ hydrogenation and the activity could remain almost unchanged over 100 h on stream. However, the Cu/ZnO catalyst prepared by a conventional deposition-precipitation method exhibited much lower methanol selectivity (50%) and a rapid deactivation within 12 h under the same operation conditions. Based on series of characterization results, including TEM, SEM, N₂ physisorption, FTIR, XRD, XPS, contact angle analysis, and temperature-programmed techniques, etc., it was revealed that the bio-CZ-500 catalyst had a hierarchically porous carbon structure, abundant Cu-ZnO active interfaces, and a relatively larger water contact angle. The relative hydrophobicity of the bio-CZ-500 catalyst surface could accelerate the desorption of the by-product H₂O, promote the transformation of reaction intermediates to methanol, and also inhibit the sintering of copper, which led to the enhancement of both methanol selectivity and catalyst stability. It is believed that this work will provide a novel synthetic strategy to fabricate highly efficient and stable Cu-based catalysts for industrial application.

This work proposes a method for supercritical carbon dioxide to intervene α-terpineol to synthesize 1,8-cineole. In addition, the diode-array detector was employed to measure the maximum absorption wavelength of the α-terpineol/cyclohexane mixture in supercritical carbon dioxide for analysis of the relationship between the amount of carbon dioxide and the polarity of the system. The catalytic isomerization was studied by considering the effects of polarity, solvent amount, and carbon dioxide pressure. The plausible mechanism for isomerization of α-terpineol to 1,8-cineole by phosphotungstic acid/poly(ionic liquid) (PW/PIL) in supercritical carbon dioxide was proposed. This work offers a novel green and efficient supercritical technique for the synthesis of 1,8-cineole. In supercritical carbon dioxide, 89.3% conversion of α-terpineol and 54.6% selectivity to 1,8-cineole were obtained with the mass ratio of cyclohexane to α-terpineol 10∶1 and the molar ratio of PW/PIL catalyst to α-terpineol 0.0163∶1, at 19.0 MPa, 50℃ for 8 h. The results showed that supercritical carbon dioxide as co-solvent expanded the applied solvent as well as reducing the polarity of the system; therefore, the catalyst aggregation was alleviated obviously, and as a result the selectivity of 1,8-cineole was increased.

N-Rich metal organic framework materials (MOFs) have good CO₂ capture performance, but their CO₂ catalytic performance often requires the addition of co-catalysts with hydrogen bonds or nucleophilic groups. In this work, a stable Zn(NO₃)₂-Ad-Int-DMF (Ad=adenine, Int=isonicotinic acid) framework was constructed, and showed low activity (<2%) on propylene carbonate (PC) synthesis. Zinc halide precursors were selected to bring in nucleophilic halogen, only ZnI₂-Ad-Int-DMF was crystallized in DMF solvent, and its activity reached 19.5%. Then, the solvent was modulated from DMF to H₂O-DMFmixed solvent, MOFs could be constructed from all of ZnCl₂,ZnBr₂ and ZnI₂. After the introduction of H₂O, metal could be coordinated with organic ligands without halogen interference. These MOFs grown in H₂O-DMF showed an obviously higher initial decomposing temperature (Tonset, 434℃) and smaller BET (<14 m²/g) than the one in DMF (280℃,571 m²/g), consequently with lower activity. Then, it was speculated that iodine was adsorbed uniformly on alkaline Zn in the framework according to the CO₂ pulse adsorption and UV-Vis diffuse reflectance spectra. The activity evaluation was tested on CO₂ cycloaddition under no cocatalyst and no solvent. The activity was promoted significantly with temperature increasing, the yield for ZnI₂-Ad-Int-DMF could reach 98.5% at 140℃. The halogen would fall from the framework under high temperature and solvent environment, which lead to the decrease of activity in the repeatability test. Nonetheless, the framework kept stable before and after reaction, no collapse and remarkable pore blocking were happened. If the halogen adsorption could be strengthened or reaction condition got milder, it would exhibit a good application potential.

Stable CO₂ has to be activated by high-energy chemicals, such as epoxide. Nucleophilic reagents are acted as the trigger for the ring-opening of epoxides and CO₂ insertion. In this work, a series of polystyrene-supported N-heterocycles were tested for their difference on CO₂ cycloaddition. It is found that five-membered heterocyclic compounds exhibited higher activity than six-membered ones. A weak interaction between five-membered heterocycles and substrates is the key point to promote the ring-opening of epoxide and the activation of CO₂ insertion. By comparison, the introduction of ZnCl₂ and_{alkyl amine boosted the reaction rate, but decreased the selectivity. As a simple, cost-effective, stable and reusable material, polystyrene-supported imidazole without metal, halide, co-catalyst and solvent, is considered as a suitable catalyst for industrial application.}

The low-temperature plasma combined with catalyst technology (NTP-CAT) has feature of convenience in operation and relatively low energy consumption. It can be applied to industrial elimination of low concentration VOCs both continuous or batch. It was found the 13X supported CeO₂ catalyst has higher efficiency to decompose toluene in NTP-CAT system, and then it is further explored the effect of CeO₂ content on toluene degradation. The results showed that 30% CeO₂/13X was the best for toluene degradation using NTP-CAT, and around 85% of toluene can be decomposed with about 55% CO₂ selectivity. The characterization results demonstrated that Ce component was dispersed relatively evenly on the surface of 13X for 30% CeO₂/13X. Specially, the maximum amount of Ce³⁺ was found on its surface, and the Ce³⁺ was originated from the Ce⁴⁺ species as deduced from the results of O₂-TPD. Moreover, the increased amount of Ce³⁺ was beneficial for producing more active oxygen species, which can react with the NTP-treated toluene adsorbed on the 13X. Therefore, it can be concluded that the NTP-CAT system has synergic effect for toluene degradation.

In this study, to improve the selectivity separation performance of polyether block amide (PEBA) membrane for phenol in water, dibenzo-18-crown ether-6 (CE) was used to modify the PEBA membrane. FT-IR and SEM characterization confirmed that the CE was closely combined with PEBA and the CE was evenly distributed on the membrane surface. AFM characterization showed that CE modification effectively improved the contact area between the membrane surface and phenol. Water contact angle test showed that CE modification greatly improved the hydrophobicity of PEBA /CE membrane. At the same time, the effects of CE content, feed phenol concentration and feed temperature on pervaporation performance of PEBA/CE were systematically studied. The results show that CE can significantly improve the selectivity of PEBA/CE membrane to phenol in water. When the feed phenol concentration is 0.8%(mass) and the operating temperature is 70℃, the separation factor and permeation flux of PEBA/CE-6 membrane (CE content 6%(mass) of PEBA) are 23.34 and 494.40 g/(m²·h), which is far exceeding pure PEBA membrane performance (separation factor 8.46, total permeation flux 547.48 g/(m²·h). The prepared PEBA/CE-6 membranes have good stability and potential industrial application value.

Using C18 as the stationary phase and methanol/water=70/30 (volume ratio) as the mobile phase, the three-zone simulated moving bed was used to separate two alkaloids, evodiamine and rutaecarpine. The isotherms of the two alkaloids were determined by frontal analysis, which can be described by linear isotherms with the Henry coefficients of 3.11 for evodiamine and 5.25 for rutaecarpine. The axial diffusion coefficient and mass-transfer coefficients of the two alkaloids were estimated by empirical equations. The operation conditions were designed by triangle theory and optimization method based on the mathematical model. Through optimization, the maximum feed flow rate was 0.55 ml?min^-1. The experimental purities of two products were both higher than 99%. By asynchronous switching, the feed flow rate was increased to 0.62 ml?min^-1 without additional investment and product purity loss.

The κ-carrageenase gene from Pseudoalteromonas sp. JMUZ2 was expressed heterologously in Escherichia coli. After the recombinant κ-carrageenase was purified, the properties of the recombinant enzyme were characterized and the antioxidant activity was explored for the enzymatic hydrolysis products of κ-carrageenan. The results showed that the κ-carrageenase from Pseudoalteromonas sp. JMUZ2 belonged to GH16 family. The recombinant enzyme could specifically degrade κ-carrageenan. The optimal reaction temperature and pH of the recombinant κ-carrageenase were 50℃ and 8.0, respectively. The recombinant κ-carrageenase maintained the residual activity of about 80% after incubation at 40℃ for 1 h. The recombinant enzyme had good tolerance to the detergents of Tween 20, Tween 80 and Triton X-100. LC-MS analysis showed that the final products of κ-carrageenan hydrolyzed by recombinant enzyme were disaccharides and tetrasaccharides. The hydrolysates had scavenging effects on ·OH, DPPH and ABTS radicals, and also had good reducing ability. The enzymatic properties of the recombinant κ-carrageenase and the analysis of the enzymatic hydrolysates lay a theoretical foundation for the application of the enzyme in the green preparation of κ-carrageenan oligosaccharides.

The widely distributed genus Shewanella is famous for its capacity of reducing iron. The aim of this study is to decipher the behavioral change on Shewanella xiamenensis BC01 (SXM) under stress of organic solvents. The tolerance of SXM to organic solvents is related to the hydrophilicity of solvents. For methanol, ethanol, acetone and DMSO, the tolerance concentration for SXM is 5%, for n-propanol, isopropanol and tert-butanol, the tolerance concentration is 2%, while for n-butanol, the tolerance concentration is only 1%. The scanning electron microscopy revealed that cells were obviously stretched to at least 5 μm under n-propanol stress, and cells were shrunk to an average of less than 1 μm under n-butanol stress. Protein identification implied that TonB receptor, IucA family protein and iron containing dehydrogenase were down-regulating under propanol and butanol stress, and the enzymatic assay of ferric reductase was obviously dropped down. At the genetic level, the expression of mtrC gene related to electron transport increased by 147.6% under the stimulation of propanol. It would provide practical information on environmental stress and accelerate mechanism of stress in Shewanella geneus.

The oxidoreductase, which can efficiently catalyze asymmetric reduction reactions to prepare chiral compounds in non-aqueous systems, has important scientific significance and industrial application prospects. Based on gene mining technology, 17 salt-tolerant amino acid dehydrogenase genes were obtained, and their evolutionary homology and protein stability thermodynamic parameters were further analyzed. Bioinformatic identification combined with structure classification and thermodynamic parameters calculation led to a promising phenylalanine dehydrogenase from Natranaerobius thermophiles. Catalytic characteristics of phenylalanine dehydrogenase in the non-aqueous system were studied. This PheDH was highly stable for oxidative deamination of phenylalanine with optimal temperature of 60℃ and optimal pH of 12, which is rarely reported in such alkaline environment. Enzyme activity was enhanced by 1.2 folds with 30% dimethylsulfoxide. For biosynthesis of L-homophenylalanine by reductive ammoniation,the optimal reaction condition is 70℃ and pH 8.5. With 30% methyl tert-butyl ether and dimethylsulfoxide,the relative activity is 101.3% and 99.2%, respectively. The results indicated that this halotolerant PheDH has better resistance to heat and organic solvents. This paper offers a novel strategy for mining of halotolerant amino acid dehydrogenase based on sequenced-driven approaches, and thus provides robust key enzymes to biochemists.

Eicosapentaenoic acid (EPA) is widely used in the fields of food, medical treatment, cosmetics and feed additives because of its physiological functions of regulating blood lipids, reducing fibrin, preventing cardiovascular diseases, anti-inflammatory and anti-allergic. At present, the supply of EPA cannot meet the market demand, due to the natural resources such as fish oil rich in polyunsaturated fatty acids (PUFAs) are gradually scarce. Therefore, more and more research focus on using the modified microbial strains to produce EPA. In this study, homologous recombination technology was used to knock the enoyl-reductase gene (sh-ER) of Shewanella sp.SCRC2738 into the ORFB-ER and ORFC-ER domains of Schizochytrium limacinum SR21, in order to regulate the preference for polyunsaturated fatty acid synthesis to increase the yield of EPA. The results showed that the EPA content of the B-sh-ER strain increased by 85.7% and the transcriptional level of polyketide synthases (PKS) pathway related genes were significantly up-regulated. The synthesis of PUFAs in C-sh-ER strains presented little change. In 5 L fed-batch fermentation, total lipids yield of the B-sh-ER strains increased by 28.7% reaching to 73.2 g/L; the EPA yield increased by 71.6% reaching to 732.4 mg/L. This study supplies a new strategy for promoting the high production of PUFAs and provides a novel perspective for regulating the synthesis of EPA in Schizochytrium sp.

Organic Rankine cycle (ORC) has been widely used as the primary choice to realize power generation from low temperature waste-heat, and the combination of zeotropic mixture and dual-pressure evaporation has been evidenced their potential to significantly improve the thermal efficiency of ORC. However, it is still unclear how the multiple stages of evaporation affect the performance. In this study, a multi-pressure evaporation ORC based on zeotropic mixture (MZORC) was proposed, a heat transfer limit model was developed based on the entransy analysis, and the processes of ORC (BORC), dual-pressure evaporation MZORC and tri-pressure evaporation MZORC were simulated with Aspen Plus. The results show that MZORC can improve the performance by reducing both the heat loss and entransy dissipation caused by the evaporation. When the heat source is 423.15 K and the ambient temperature is 298.15 K, the net output power of tri-pressure evaporation MZORC can be improved by 38.6% compared with BORC, and those of BORC, dual-pressure evaporation MZORC, and tri-pressure evaporation MZORC can reach 65.0%, 79.0% and 90.1% of the theoretical limit, respectively, i.e., increasing the number of evaporation units will result in performance enhancement, approaching the theoretical limit.

TG-FTIR-MS was used to study the mass loss characteristics and the evolution of small molecule gas during the pyrolysis of binary mixtures, which were mixed by biomass three-component. The results showed that the initial pyrolysis temperature decreased in the co-pyrolysis process. During the co-pyrolysis of cellulose and hemicellulose, the pyrolysis reaction was inhibited and the mass loss rate was reduced. Additionally, the yield of H₂, CH₄ and H₂O decreased, while the yield of CO and CO₂ increased. Synergistic effect was found in the co-pyrolysis of lignin and hemicellulose, which promoted the pyrolysis reaction process. For the volatile products, the formation of H₂O was promoted and its yield increased, however, the production of other small molecule gas products was inhibited. This synergistic effect was mainly conducive to the formation of condensable volatile products. Moreover, this effect decreased as the proportion of hemicellulose increased. The entire pyrolysis process of hemicellulose and cellulose exhibited mutual inhibition effects, and the production of small molecule gas products decreased, but the influence decreased with the increase of cellulose ratio.

Biomethane system can produce methane from organic wastes, which has developed rapidly in the past twenty years. However, biomethane system has some disadvantages, such as complex raw material source, low utilization rate of organic matter, high output of biogas slurry and biogas residue. Therefore, it is very important to clarify and evaluate the composition of raw materials, biogas slurry and biogas residue during the process of biomethane system, and then optimize the biomethane system and reduce pollutant emissions. In present study, the biomethane system of typical raw materials was established. The component of raw materials, biogas, biogas slurry and biogas residue were analyzed. Moreover, the comprehensive evaluation system of biomethane system with green degree, methane yield, contamination degree of heavy metals and potential ecological risk was constructed. The advantages and disadvantages of the biomethane system with five different raw materials were obtained. The green degree and methane yield were the highest in the biomethane system of swine manure with 0.222 and 212 ml·g^-1, respectively, whereas the contamination degree of heavy metals of biogas residue was the highest. The green degree was 0.200 in the biomethane system of cattle manure, and the contamination degree of heavy metals of biogas residue was the lowest, but the methane yield was only 116 ml·g^-1. The potential ecological risk and contamination degree of heavy metals of biogas slurry were the lowest in the biomethane system of straw, whereas the green degree and methane yield was low. The methane yield was 183 ml·g^-1 in the biomethane system of chicken manure, however the contamination degree of heavy metals and potential ecological risk of biogas slurry were the highest, and the green degree was low. The biomethane system of food waste raw materials has the worst performance, the lowest green degree and methane yield, and the highest potential ecological risk of biogas residue.

Super-hydrophobic coatings have great application potential in the fields of surface self-cleaning, fluid drag reduction, anti-fog and anti-icing, and microfluidic control. The controls of morphologies for the super-hydrophobic coating inside a circular tube have not been investigated. In this paper, the polydopamine (PDA) was coated on the inner wall of stainless-steel cylinder by electrochemical deposition under different values of shear stress, and n-dodecyl mercaptan (NDM) was used to modify the PDA surface. This PDA/NDM coating shows super-hydrophobic behavior. Scanning electron microscopy (SEM), contact angle tester (CA), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction tester (XRD) were used to analyze the characterization of the coating. The results show that PDA deposition can be divided into two stages under the effect of shear stress. The first stage is the agglomeration of PDA particles on the stainless steel substrate. The second stage is PDA in-situ growth based on PDA particles aggregate, and the growth process is controlled by shear stress. When the shear stress is 1.85 mPa, the coating surface shows coral shaped balls with about 15—24 μm. When the shear stress is 7.41 mPa, the coating surface has a flaky structure with a particle size of about 1—4 μm. The wetting angles of the prepared PDA/NDM coating are greater than 150°, belongs to super-hydrophobic properties. And the coating has good chemical stability and heat resistance wear resistance and corrosion resistance. The work has certain guiding for the regulation and control of the surface nano/microstructure during the preparation of the inner surface coating of the pipe.

Gold nanoparticles have characteristic ultraviolet-visible absorption spectra, and they are widely used in the field of analysis and detection. In order to break through the technical limitations of batch stirring reaction to prepare gold nanoparticles, a continuous-flow microreaction method was proposed. This method implemented rapid and uniform mixing of HAuCl₄ and Na₃Ct aqueous solutions under acidic conditions with the help of threaded pipes, introduced an inert solvent to avoid particle deposition in the reactor, and used a membrane phase separator to complete the oil-water online phase separation, achieving continuous and stable preparation of gold nanoparticles. The influences of the reactant molar ratio, concentration, residence time, water-oil volume ratio, pH and other factors on the particle size distribution and absorption spectrum were investigated, and the narrow size distributed gold nanoparticles with average sizes of 20—24 nm and dispersion factors of <10% were successfully prepared.

The di-imine matter synthesized from methyl isobutyl ketone(MIBK) and m-xylylenediamine (MXDA), abbreviated as MIBKDI, is a frequently-utilized latent curing agent for one-component epoxy adhesive. The remained MXDA in the curing agent, due to its direct cross-linking with epoxy resin, would significantly impair epoxy_{adhesive's stability in storage. In industrial synthesis processes, ultrahigh molar proportion between MIBK and MXDA (>10∶1) is applied to enhance MXDA conversion as much as possible; nevertheless, MIBK loss and energy consumption for its recovery would result in extensive cost. In this research, the orthogonal experiments were used at first to make weight analysis and factorial effect analysis for reaction temperature, time and reagent ratio; and the single-factor experiments were carried through systematically to investigate the effects of reaction time and reagent ratio on MXDA conversion ratio. It is resulted that the epoxy adhesives could be stable enough for sale with the curing agent synthesized with the MIBK/MXDA molar ratio higher than 5∶1, while the reaction was sustained for 4 h under 170℃. Under the typical condition for adhesion, the cured epoxy resin behaved excellent with shear strength up to 12.9 MPa and tensile strength equal to 19.2 MPa, which can meet the demand defined in National Standard GB/T 2567—2008. When the MIBK/MXDA molar ratio was optimized to be 5∶1 for curing agent synthesis, energy consumption is greatly reduced, while MIBK consumption is effectively saved, and the total cost is reduced considerably.}

Joule-heating studies of different electric-conducting nanocarbon aerogels have been extensively exploited, however, there are no systematic investigations on the Joule-heating characteristics of reduced graphene oxide (rGO) aerogels prepared via the hydrothermal approach. Therefore, this work adopted the hydrothermal and freeze-drying methods, followed by thermal reduction to fabricate three-dimensional, cylindrical, and electric-conducting reduced hydrothermal graphene oxide aerogel, i.e., rHT-GO aerogel. Electron microscopic analysis showed that the aerogel interior presented a high density of nanocarbon interconnectivity and multiscale porosity, providing numerous paths for electrons to transport, hence available for systematic Joule-heating studies. The results demonstrated that the power input and Joule-heating temperature exhibited a good linear correlation with R² > 0.999, high electrothermal transformation efficiency (reaching up to 128℃ with only 2 W energy consumption), ultrafast heating/cooling capacities, long-duration electrothermal performance and excellent cycling capability. The 3D variable range hopping (3D VRH) model elucidated that the Joule-heating effects can reach the entire rHT-GO aerogel. The high electrical conductivity (9.0 S?m^-1) was originated from the small bandgap (E_a = 0.015 eV). Additionally, the radial temperature gradient fitting results corroborated that the as-prepared rHT-GO aerogels also displayed distinct thermal conductivity (0.222 W?m^-1?K^-1), resulting in their ultrafast cooling rates (456 K?min^-1) and consequently outperforming traditional external radiative heating modes. Importantly, the as-prepared cylindrical rHT-GO aerogels in this study can also be potentially utilized as Joule-heating-assisted adsorption/desorption agents, energy-efficient heaters, temperature-controllable catalyst supports, highly accurate sensors, and solar water evaporators.

In this work, the nano-molecule C₆₀(EDA)₈ was synthesized by the fullerene C₆₀ and ethylenediamine, which was used as rigid crosslinking agent to crosslink polyphenylene oxide (PPO) with triple quaternary ammonium groups for the preparation of high-performance anion exchange membranes. With the rigid structure of C₆₀ in C₆₀(EDA)₈, it effectively supports the polymer chain segment and builds a wider ion channel, thereby reducing membrane swelling and improving conductivity. The experimental results show that with the increase of C₆₀(EDA)₈ input, the ion exchange capacity(IEC) of the cross-linked membrane decreases, but the conductivity gradually increases. When the crosslinking agent C₆₀(EDA)₈ is added at 5%, the conductivity of the membrane increases 34%. In addition, the prepared crosslinked membranes all show good swelling resistance, mechanical properties and alkaline stability.

As a common polymer material, epoxy resin (EP) is flammable. Traditional EP usually loses its transparency after flame retardant incorporated. Besides, it is hard to obtain the satisfying flame-retardant efficiency with low loading amount. In this work, two kinds of flame retardant with organophosphorus/boron hybrid were successfully synthesized (abbreviated as: DPC-1B and PDS-2B) by simple reaction between diphenylphosphinyl chloride/phenylphosphoryl dichloride and 4-hydroxyphenylboric acid. After introduced 2.0%(mass) of DPC- 1B or PDS-2B, the EP composite reached V-0 rating in the UL-94 vertical burning test and the limited oxygen index (LOI) values increased from 25.7% to 31.8% and 31.5% respectively. Interestingly, the EP composite still presented excellent transparency. Furthermore, the peak heat release rate of the flame retardant EP decreased 26.5% and 21.8%. Due to the combination of boron and phosphorus, a dense carbon layer was formed, which insulated the heat and achieves the flame retardant effect. Accordingly, the two novel flame retardant demonstrate promising applications in the flame retardant of EP without sacrifice of transparency.

Graphene is a special two-dimensional material with excellent conductivity. However, graphene sheets would easily agglomerate, leading to a large decrease in its conductivity and capacitance. In this study, a three-dimensional activated sludge graphene hydrogel (SGH) was formed by mixing the suspension of graphene oxide (GO) and domesticated waste activated sludge, due to the biocompatibility of GO and the colloidal properties of bacteria. GO was reduced to conductive reduced graphene oxide (rGO) during the formation of hydrogel. SGH can be lyophilized to obtain a porous O and N self-doped porous material with good hydrophilicity and conductivity, namely activated sludge graphene aerogel (SGA). The annealing process in high temperature was found a crucial factor in improving the electrochemical properties of SGA. The specific capacitance of the modified SGA (ANSGA) was increased to 174 F/g at a current density of 2 A/g, after annealing in argon gas with 700℃, 2 h. In addition, the excellent rate capability, ion transport properties and cycling stability make ANSGA a promising material for the probable use of processing electrode materials, which points to a green and dual-beneficial way to produce graphene-based materials and reuse waste activated sludge.

Biomass polyols were obtained from coconut fiber (CF) by solvent-catalyzed liquefaction technology directly, and the liquefied products (BP) were used to prepare polyurethane foams (BPUF). Firstly, the influence of liquefaction conditions on the liquefaction process and liquefaction products was analyzed, and the optimal liquefaction reaction conditions were determined as: 2% concentrated sulfuric acid catalyst, liquid-solid ratio 6∶1 (liquid reagent and coconut fiber mass ratio), 160℃ atmospheric pressure reaction for 80 min. And then the products liquefied in these liquefaction conditions were used as raw materials to replace partial petroleum-based polyols to synthesize the BPUF. The mechanical property test, thermogravimetric (TGA), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR) were carried out to research the influence of BP content on BPUF. The results show the BPUF prepared with 35% BP have excellent comprehensive performance with an average pore diameter of 427 μm uniformly, a density of 20.3 kg/m³, a compressive strength of 40.2 kPa, a compression modulus of 766 kPa, and a minimum cushioning coefficient of 2.27. The biomass polyols obtained from CF are promising and environment friendly in polyurethane foams buffer packaging materials, and also giving a new approach to the integrated use of CF.