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Comparison and Selection of Process of Hydrogen Production
LIU Yi-ming(Hubei Research and Design Institute of Chemical Industry,Wuhan 430074,China)The process and technology for hydrogen production from steam reforming of natural gas,steam reforming of methanol,electrolysis of water were introduced.Three processes of hydrogen production were compared and selected.The principle of these was put forward.
Research Progress of Bioremediation of Heavy Metal Cadmium Pollution
XIAO Chun-wen1,2,LUO Xiu-yun1,2,TIAN Yun1,2,LU Xiang-yang1,2(1.College of Bioscience and Biotechnology,Hunan Agricultural University,Changsha 410128,China; 2.Hunan Agricultural Bioengineering Research Institute,Changsha 410128,China)The present situation and main harm of cadmium pollution are overviewed,and then the research progress of bioremediation of cadmium pollution is summarized.The latest research progress of cadmium hyperaccumulation plants and microorganisms for adsorbing cadmium are especially reviewed.The bioremediation application prospect and the future research direction for bioremediation of cadmium pollution are systemtically elaborated.
Purification of Tuckahoe Polysaccharide and Determination of Its Molecular Weight
YAN Jun1,TAO Tao1,SUN Xiao-chun2,HE Gang1,YI Yong1,GOU Xiao-jun1,2(1.The Key Laboratory of Medicinal and Edible Plants Resources Exploitation,Chengdu University,Chengdu 610106,China;2.Sichuan Industrial Institute of Antibiotic,Chengdu,610052,China)Tuckahoe polysaccharide was extracted by boiling water and precipitated by alcohol,and purified using ion-exchange column chromatography,and its molecular weight was determined by high performance gel filtration chromatography(HPGFC).The results showed that Sevag method was effective for removing proteins from crude polysaccharide to obtain refined tuckahoe polysaccharide(TAP);two components,neutral polysaccharide TAP1 and acidic polysaccharide TAP2,were got through DEAE-650C column chromatography purification,whose molecular weight were determined by HPGFC as 11 721 and 44 065,respectively.
Experimental Exploration on Styrene Suspension Polymerization
TANG Xiao-hong,WANG Jin,ZHENG Hui-qin,LI Cheng-wei,LI Yong(Department of Chemistry,Henan Institute of Education,Zhengzhou 450046,China)The effects of initiator dosage,suspension agent dosage,stirring speed and reaction temperature on styrene suspension polymerization were investigated.The optimum conditions were obtained as follows:styrene amount 16 mL,deionized water amount 130 mL,initiator(benzoyl peroxide) dosage 0.3 g,suspension agent(0.3% polyvinyl alcohol solution) dosage 7～8 mL,stirring speed 300 r·min-1,reaction temperature 85～90 ℃.Under above conditions,the polystyrene with appropriate particle size,good transparency and high yield of about 98.60% could be obtained.
Preparation and Properties of Injectable Sodium Glycerophosphate-Chitosan/Sodium Alginate Composite Hydrogel
ZHANG Guoguang;DENG Chunmei;KANG Xinhuang;HE Lanzhen;ZHENG Guanhao;BAI Hao;Using sodium alginate(SA)and sodium glycerophosphate-chitosan(GP-CS)as raw materials,we prepared injectable GP-CS/SA composite hydrogel by aphysical crossing method.Meanwhile,we investigated the effects of material ratio(the mass ratio of GP-CS and SA)on gelation time,sol content,micromorphology,thermal stability,and equilibrium swelling of composite hydrogel.The results show that the larger the SA proportion in the composite hydrogel is,the shorter the gelation time and the less the sol content will be.The SEM image and FTIR spectrum indicate that GP-CS/SA composite hydrogel has three-dimensional network structure through the physical crossing reaction of GP-CS with SA.Moreover,the thermogravimetric analysis shows that there is no significant difference between the thermal stability of composite hydrogel and GP-CS hydrogel.Furthermore,the equilibrium swelling experiment indicates that the swelling rate and the equilibrium swelling rate increase with the increase of SA proportion.The GP-CS/SA composite hydrogel has higher mechanical strength than single GP-CS hydrogel,and has better water absorption and equilibrium swelling property.
Research Progress of Targeted Protein Degradation Technology
HAO Yafeng;WANG Hanjie;Targeted protein degradation technology is a subversive biological technology developed in recent years.The core principle is that,through the introduction of proteins or small molecular substances,the inherent protein degradation system in cells is induced to directly knockdown of target protein at the post-translational protein level.Compared with traditional interfering protein expression technologies,the targeted protein degradation technology has specific advantages such as specific recognition of target proteins,direct regulation at the post-translational protein level,rapid degradation,and no intermediate effects,and has shown broad scopes in biomedical field.In this article,we mainly review the inherent protein degradation pathways in cells,the development and application of targeted protein degradation technology,and the opportunities and challenges of targeted protein degradation technology.With the deepening of research,the targeted protein degradation technology is expected to be further optimized and developed,and plays a more important role in biomedicine and clinical application research.
Research Progress in Biodegradation of Perfluorinated Compounds
ZU Lei;Baoji University of Arts and Sciences;Perfluorinated compounds(PFCs) are widely used in industrial production due to their special hydrophobicity and lipophobicity and chemical inertness.The resulting environmental and ecological pollution has become a global environmental problem.Compared with chemical and physical degradation methods, biodegradation possesses the advantages of green and low energy consumption, which has become one of the most commonly used methods for the treatment of persistent organic pollutants.In this paper, we analyze three biodegradation mechanisms of PFCs based on the mechanism of carbon-fluorine bond breaking.Then, according to the degree of biological defluorination, we introduce the pathway, products, mechanism of fluorotelomer biodegradation, and the mechanism and degradation strains of two typical PFCs, such as perfluorooctanoic acid(PFOA) and perfluorooctane sulfonate(PFOS).Although, the reports on the biodegradation of PFCs are rarely available in the literature so far, the feasibility of biodegradation has been shown in the related studies.The screening of the potential strains and the co-metabolic degradation will contribute to the improvement of degradation rate.
Optimization in Extraction Process of Total Polyphenols from Hippophae rhamnoides L. Fruits and Its Stability
GE Liang;LI Qi;LI Sen;GONG Haiyan;TIAN Shuge;We optimized the ultrasonic extraction process of total polyphenols from Hippophae rhamnoides L.fruits by orthogonal experiments, and investigated the effects of pH value, carbohydrate, light, temperature, oxidant, reducing agent, and preservative on the stability of total polyphenols from Hippophae rhamnoides L.fruits.The results show that the optimum extraction process can be determined as follows: the solid-liquid ratio of 1∶12(g∶mL),the ethanol volume fraction of 60%,the ultrasonic time of 45 min, and the ultrasonic temperature of 60 ℃.The total polyphenols from Hippophae rhamnoides L.fruits is stable under meta-acidic and low temperature conditions, carbohydrate and light have no effect on its stability, while oxidant, reducing agent, and preservative have great effect on its stability, indicating that the total polyphenols from Hippophae rhamnoides L.fruits needs to be preserved in meta-acidic and low temperature conditions without the use of related additives.The extraction method is simple and fast, which is suitable for the extraction of total polyphenols from Hippophae rhamnoides L.fruits.
Research and Development of Hindered Phenolic Antioxidants
WANG Jun, YANG Hong-jun, LI Cui-qin(Daqing Petroleum Institute, Daqing 163318,China)In this article, the current progress of hindered phenolic antioxidants, its classification, mechanism of action, influence factor on efficiency and mechanism of discoloration are reviewed. In the end, typical products of phenolic antioxidant are introduced and the developing trend of hindered phenolic antioxidants in the future have also been presented.
Modification and Photocatalytic Degradation Performance of Bismuth Vanadate Photocatalyst
CHEN Yaqian;PENG Meng;YUAN Hua;Taking bismuth nitrate and ammonium vanadate as raw materials, we prepared photocatalyst bismuth vanadate(BiVO4) by surfactant-assisted hydrothermal(alcohol-thermal) method, and characterized the morphology and structure of the photocatalyst by XRD,IR,and SEM.Moreover, we investigated the photocatalytic performance of the photocatalyst for the degradation of organic pollutants(Rhodamine B,tetracycline hydrochloride) under visible light irradiation.The results show that the addition of surfactants can improve the morphology and structure of the photocatalysts.Among them, the BiVO4/SDS photocatalyst with the addition of anionic surfactant sodium dodecyl sulfonate(SDS) has the best morphology and catalytic performance, of which the structure is homogeneous solid microspheres with smooth surface.The photocatalytic degradation rates of Rhodamine B at the initial concentration of 20 mg·L-1 and tetracycline hydrochloride at the initial concentration of 10 mg·L-1 can reach 83% and 86%,respectively, within 180 min.