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High-throughput Screening of the Enantioselectivity of Hyperthermophilic Mutant Esterases from Archaeon Aeropyrum pernix K1 for Resolution of (R,S)-2-Octanol Acetate

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Chemical Research in Chinese Universities 2007年第3期23卷 319-324页

作者： zhang Gui-rong GAO Ren-jun zhang Ai-jun RAO Lang CAO Shu-gui Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education Jilin University Changchun 130021 P. R. China

To identify the desired hypertherrnophilic variants within a mutant esterase library for the resolution of （R, S）-2- octanol acetate, a simple, reliable, and versatile method was developed in this study. We built a screening strategy including two steps, first we selected agar plate with substrate to screen the enzymatic activity; secondly we used a pH indicator to screen the enantioselectivity. This method could rapidly detect favorable mutants with high activity and enantioselectivity. A total of 96. 2% of tedious screening work can be precluded using this screening strategy. It is an effective screening for alkyl ester and can be applied to relative screening researches. The four improved mutants were screened from the mutant esterase library. Their enantioselectivities, activities, and structures were investigated at different temperatures.

关键词： High-throughput screening Enantioselectivity Hyperthermophilic esterase Directed evolution

OIL-WATER TWO-PHASE FLOW INSIDE T-junCTION

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Journal of Hydrodynamics 2008年第2期20卷 147-153页

作者： WANG Li-yang WU Ying-xiang ZHENG Zhi-chu GUO jun zhang jun TANG Chi Laboratory of Applied Fluid Dynamics Department of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

The oil / water two-phase flow inside T-junctions was numerically simulated with a 3-D two-fluid model, and the turbulence was described using the mixture k- ε model. Some experiments of oil / water flow inside a single T-junction were conducted in the laboratory. The results show that the separating performance of T-junction largely depends on the inlet volumetric fraction and flow patterns. A reasonable agreement is reached between the numerical simulation and the experiments for both the oil fraction distribution and the separation efficiency.

关键词： T-junction two-phase flow liquid / liquid separation numerical simulation

Dispersion of ZnO Nanocrytals in Co-solvent and Its Application in Photovoltaic Material

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Chemical Research in Chinese Universities 2011年第6期27卷 906-909页

作者： CHEN Shao-jie zhang Qiu-yu zhang jun-ping GU jun-wei ZHOU Jian SHI You-qiang Key Laboratory of Space Materials Science and Technology Ministry of Education School of Science Northwestern Polytechnical University Xi＇an 710129 P. R. China

To overcome the aggregation of nanocrystals in a blend of inorganic material with conjugated polymers to prepare photovoltaic material, we used a co-solvent blend of CHCl3 with MeOH at a certain volume fraction to disperse inorganic nanocrystals. The results show that when the volume fraction of MeOH is 50%, ZnO nanocrystals with an average diameter of 30 nm disperse well in the co-solvent solution. Its application in photovoltaic material was investigated in this work, and the photoluminescence（PL） spectra show that when ZnO was 50%（volume fraction） in solution and 25%（volume fraction） in film, the fluorescence quenching reached the maximum values 83.34% and 64.4%, respectively, indicating that electron could transfer from conjugated polymer to electron-acceptor ZnO effectively.

关键词： ZnO nanocrystal Dispersion Co-solvent Photovoltaic material

Treatment of polycystic liver disease with resection-fenestration and a new classification

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World Journal of Gastroenterology 2008年第32期14卷 5066-5072页

作者： Tuan-Jie Li Hai-Bin zhang jun-Hua Lu jun Zhao Ning Yang Guang-Shun Yang Eastern Hepatobiliary Hospital Second Military Medical University Shanghai 200438 China

AIM: To evaluate outcomes in patients with autosomal dominant polycyst liver disease (APLD) treated by combined hepatic resection and fenestration. A new classification was recommended to presume postoperative complications and long outcome of patients. METHODS: Twenty-one patients with APLD were treated by a combined hepatic resection and fenestration technique. All patients were reviewed retrospectively, and clinical symptoms, performance status and morbidity were recorded. A new classifi cation of APLD is recommended here. RESULTS: All patients were discharged when free of symptoms. The mean follow-up time was 55.7 mo and three patients had a recurrence of symptoms at 81, 68 and 43 mo after operation, respectively. The overall morbidity rate was 76.2%. Two patients with Type B-Ⅱ and Type B-Ⅰ developed biliary leakage. Four patients had severe ascites, including three with Type B-Ⅲ and one with Type B-Ⅱ, Nine patients had pleural effusion, including one with Type A-Ⅰ; one with Type B-Ⅰ; fi ve with Type B-Ⅱ; one with Type A-Ⅲ and one with Type B-Ⅲ. Three patients with Type B had recurrence of symptoms, while none with Type A had severe complications. CONCLUSION: Combined hepatic resection and fenestration is an acceptable procedure for treatment of APLD. According to our classifi cation, postoperative complications and long outcome can be predicted before surgery.

关键词： Autosomal dominant polycyst liverdisease Autosomal dominant polycyst kidney disease Fenestration

NUMERICAL AND EXPERIMENTAL STUDY ON LIQUID-SOLID FLOW IN A HYDROCYCLONE

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Journal of Hydrodynamics 2009年第3期21卷 408-414页

作者： WANG Li-yang ZHENG Zhi-chu WU Ying-xiang GUO jun zhang jun TANG Chi Laboratory of Applied Fluid Dynamics Division of Engineering Sciences Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

Hydrocyclones are widely used in industry, of which the geometrical design using CFD techniques is gaining more popularity in recent years. In this study, the Euler-Euler approach and the Reynolds stress model are applied to simulate the liquid-solid flowfield in a hydrocyclone. The methodology is validated by a good agreement between experimental data and numerical results. Within the research range, the simulation indicates that the liquid-solid separation mainly occurs in the conical segment, and increasing conical height or decreasing cylindrical height helps to improve the grade efficiencies of solid particles. Based on these results, two of the same hydrocyclones are designed and installed in series to establish a liquid-solid separation system. Many experiments are then conducted under different conditions, in which the effects of the water cut and the second hydrocyclone on the separation are investigated. The results also confirm that smaller solid particles are more susceptible to the inlet conditions, and the second hydrocyclone plays a more important role as the water cut reduces.

关键词： hydrocyclone liquid-solid flow model efficiency

Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun zhang Shengtao Gao Xingzhao zhang Dacheng Ma Chuanlei Zhu jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)

Alteration of the Specificity of PstⅠ Restriction Endonuclease

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Wuhan University Journal of Natural Sciences 2000年第3期5卷 361-365页

作者： Zou Guo-lin, Gao Cheng-zhuo, Pi Xin-chun, zhang jun-jun College of Life Sciences, Wuhan University, Wuhan 430072, C hina College of Life Sciences Wuhan University Wuhan China

The influence of factors on the subst rate-specificity of Pst Ⅰ restric tion endonuclease has been studied with the method of electrophoresis. The resu lts show that, the specificity of Pst Ⅰ almost can not be influenced by th e sin gle alteration of the concentration of Tris·HCl, Mg 2+ or Na+ in the rea ction s ystem, but it can be altered by the reduction of any two of them. The specificit y can not be altered by the single alteration of pH or the replacement of Mg 2+ w ith Mn 2+. The addition of glycerol or dimethylsulphoxide (DMSO) to the rea ction system results in the relaxation of the substrate-specificity of Pst Ⅰ , b ut dim ethylmethylformide, glycol and ethyl alcohol can not bring about the alteration of Pst Ⅰ specificity. Through the method of cloning and sequencing, the nuc leot ides of No.1 and 6 in the recognition sequence of Pst Ⅰ have changed (1C→A or 6 G→T). Used with the enzyme analysis of an artificially synthetic DNA segment co ntaining a special sequence, the nucleotides of No.1 and 6 have both changed (1C →A and 6G→T). The recognition sequence of Pst Ⅰ is speculated to be chan ged from CTGCA↓G to TGCA↓.

关键词： restriction endonuclease specificity star activity

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常温时添加剂对Ce-Mn转化膜的影响

华南理工大学学报（自然科学版） 2010年第4期38卷 76-82页

作者：张军军李文芳杜军华南理工大学材料科学与工程学院广东广州510640

为了提高常温下Ce-Mn转化膜在铝合金表面的成膜速度和耐腐蚀性能,在室温、pH=2的Ce(NO3)3和KMnO4的混合溶液中分别添加H3BO3、Zr(SO4)2、NaF、HF、NaBF4和Na2ZrF66种添加剂,研究添加剂对Ce-Mn转化膜的影响.通过光学显微镜、涡流测厚仪... 详细信息

为了提高常温下Ce-Mn转化膜在铝合金表面的成膜速度和耐腐蚀性能,在室温、pH=2的Ce(NO3)3和KMnO4的混合溶液中分别添加H3BO3、Zr(SO4)2、NaF、HF、NaBF4和Na2ZrF66种添加剂,研究添加剂对Ce-Mn转化膜的影响.通过光学显微镜、涡流测厚仪、点滴腐蚀法、Tafel极化曲线和交流阻抗等研究了膜的金相组织、厚度及耐腐蚀性能等;同时,通过SEM和EDS研究了氟化钠对膜的形貌和成分的影响.结果表明:氟化钠是较佳的常温成膜促进剂,常温下9 min就能成膜,相对于无添加剂的Ce-Mn转化膜,膜厚增加2.3倍,耐点滴腐蚀时间延长2.0倍,腐蚀电流密度降低至原来的1/3,膜电阻提高3.9倍:添加NaF后膜的铈含量从5.14%提高到8.59%,锰含量从7.70%提高到14.42%.

关键词：铝合金成膜促进剂 Ce-Mn转化膜硝酸铈高锰酸钾耐蚀性能

直列泵柴油机燃用二甲醚(DME)的燃烧排放特性分析

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内燃机工程 2006年第6期27卷 36-39页

作者：鲁骏黄震乔信起吴君华张俊军张亮上海交通大学机械与动力工程学院上海200030

在一台增压直列泵柴油机进行了燃用柴油和二甲醚的试验,实测了缸内压力,并据此计算了燃烧放热率,对动力性及排放特性进行了对比分析。结果表明:发动机燃用二甲醚后,功率和扭矩都有所提升,选用9°CA和12°CA供油提前角时,在不同转速下的... 详细信息

在一台增压直列泵柴油机进行了燃用柴油和二甲醚的试验,实测了缸内压力,并据此计算了燃烧放热率,对动力性及排放特性进行了对比分析。结果表明:发动机燃用二甲醚后,功率和扭矩都有所提升,选用9°CA和12°CA供油提前角时,在不同转速下的NOx排放均低于柴油;在全负荷情况下的最高燃烧压力和峰值放热率均低于柴油;二甲醚的喷油量是柴油的两倍,但二甲醚的燃烧速度高于柴油,所以二者的燃烧持续期相差不大;选用6孔的喷嘴比5孔喷嘴燃烧更加充分,但是较高的最高燃烧压力和燃烧放热律也使得NOx排放增加。

关键词：内燃机柴油机直列泵二甲醚代用燃料