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Analysis of bacterial community structures in two sewage treatment plants with different sludge properties and treatment performance by nested PCR-DGGE method

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Journal of Environmental Sciences 2007年第1期19卷 60-66页

作者： LIU Xin-chun zhang yu YANG min WANG Zhen-yu LV Wen-zhou State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beifing 100085 China

The bacterial community structures in two sewage treatment plants with different processes and performance were investigated by denaturing gradient gel electrophoresis （DGGE） of nested polymerase chain reaction （nested PCR） amplified 16S rRNA gene fragments with group-specific primers. Samples of raw sewage and treated effluents were amplified using the whole-cell PCR method, and the activated sludge samples were amplified using the extracted genomic DNA before the PCR products were loaded on the same DGGE gel for bacterial community analysis. Ammonia-oxidizing bacterial and actinomycetic community analysis were also carried out to investigate the relationship between specific population structures and system or sludge performance. The two plants demonstrated a similarity in bacterial community structures of raw sewage and activated sludge, but they had different effluent populations. Many dominant bacterial populations of raw sewage did not appear in the activated sludge samples, suggesting that the dominant bacterial populations in raw sewage might not play an important role during wastewater treatment. Although the two plants had different sludge properties in terms of settleability and foam forming ability, they demonstrated similar actinomycetic community structures. For activated sludge with bad settling performance, the treated water presented a similar DGGE pattern with that of activated sludge, indicating the nonselective washout of bacteria from the system. The plant with better ammonium removal efficiency showed higher ammonia-oxidizing bacteria species richness. Analysis of sequencing results showed that the major populations in raw sewage were uncultured bacterium, while in activated sludge the predominant populations were beta proteobacteria.

关键词： activated sludge wastewater treatment sewage community analysis PCR-DGGE

Electrooxidation of Hydroxypivalaldehyde in an Undivided Cell

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Chemical Research in Chinese Universities 2006年第5期22卷 626-630页

作者： yu Jian-guo CAO Xue-jing zhang Heng-bin zhang yu-min LI Ke-chang College of Chemistry Jilin University Changchun 130021 P. R. China

The factors affecting the electrooxidation of hydroxypivalaldehyde（HPAL） in an undivided cell were studied by using cyclic voltammetry（CV）, linear scan voltammetry（ LSV）, and potentiostatic electrolysis. The electrocatalytic activity and stability of a PbO2 electrode in sulfuric acid, acetic acid, and phosphoric acid were studied. The selectivity and the current efficiency for producing hydroxypivalic acid were explored with different supporting electrolytes, concentrations of HPAL, and pH values. The results show that higher selectivity and current efficiency for producing hydroxypivalic acid can be achieved when sulfuric acid with a high concentration is used as the supporting electrolyte and the selectivity and the current efficiency can reach 80% and 60%. resvectively.

关键词： Hydroxypivalaldehyde Hydroxypivalic acid Electrooxidation Electrosynthesis

NUMERICAL AND EXPERIMENTAL STUDIES OF INFLUENCE OF THE CAUDAL FIN SHAPE ON THE PROPULSION PERFORMANCE OF A FLAPPING CAUDAL FIN

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Journal of Hydrodynamics 2011年第3期23卷 325-332页

作者： zhang Xi SU yu-min WANG Zhao-li State Key Laboratory of Autonomous Underwater Vehicle Harbin Engineering University Harbin 150001 China

This article presents a comprehensive study of the effects of the caudal fin shape on the propulsion performance of a candal fin in harmonic heaving and pitching. A numerical simulation based on an unsteady panel method was carried out to analyze the hydrodynamic performance of flapping caudal fins of three shapes （the whale caudal fin with the largest projected area, the dolphin caudal fin with the median projected area, and the tuna caudal fin with the smallest projected area）. Then, a series of hydrodynamic experiments for three caudal fin shapes were performed. Both computational and experimental results indicate that the tuna caudal fin produces the highest efficiency. However the mean thrust coefficient of the tuna caudal fin is the smallest. It is found that although the mean thrust coefficient for the tuna caudal fin is not large, the input power of the tuna caudal fin is also quite small. So the tuna caudal fin achieves a high efficiency.

关键词： flapping caudal fin caudal fin shape numerical simulations hydrodynamic experiments hydrodynamic performance

Effect Factors in Synthesis of Nicotinic Acid by Electrooxidation of 3-Picoline

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Chemical Research in Chinese Universities 2005年第6期21卷 692-696页

作者： SUN Xiu-yun zhang yu-min CAO Xue-jing zhang Heng-bin LI Fei XU yu-ling College of Chemistry Jilin University Changchun 130021 P. R. China Department of Applied Chemistry Jilin Institute of Chemical Technology Jilin 132022 P. R. China

In an electrolytic cell with a proton exchange membrane, nicotinic acid was synthesized at the PbO2 anode. The relationship between the current density and the potential at different concentrations of 3-picoline and sulfuric acid as well as at different temperatures was studied with polarization curves. The effects of the concentrations of sulfuric acid and 3-picoline, the anode potential and the reaction temperature on the selectivity and the current efficiency were explored. The optimum conditions were determined by orthogonal experiments. Under optimum conditions the selectivity and the current efficiency for the synthesis of nicotinic acid might reach 89% and 65%, respectively. The, concentrations of 3-picoline and nicotinic acid were analyzed with high performance liquid chromatography and the product was characterized with elemental analysis, chromatography-mass spectrometry and IR spectrometry.

关键词： 3-Picoline Nicotinic acid Electrooxidation Electroorganic synthesis

Design and Coupled Thermo-Mechanical Analysis of Silicon Carbide Primary Mirror Assembly

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Chinese Journal of Aeronautics 2006年第B12期19卷 62-65页

作者： HAN yuan-yuan zhang yu-min HAN Jie-cai Center for Composite Materials Harbin Institute of Technology Harbin 150080 China

Based on the principle that the thermal expansion coefficient of the support structure should match that of the mirror, three schemes of primary mirror assembly were designed. Of them, the first is fused silica mirror plus 4J32 flexible support plus ZTC4 support back plate, the second K9 mirror plus 4J45 flexible support plus ZTC4 support back plate, and the third SiC mirror plus SiC rigid support back plate. A coupled thermo-mechanical analysis of the three primary mirror assemblies was made with finite element method. The results show that the SiC assembly is the best of all schemes in terms of their combination properties due to its elimination of the thermal expansion mismatch between the materials. The analytical results on the cryogenic property of the SiC primary mirror assembly show a higher surface finish of the SiC mirror even under the cryogenic condition.

关键词： silicon carbide primary mirror assembly design coupled thermo-mechanical analysis

Research on Ultrasonic Vibration Grinding of the Hard and Brittle Materials

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Chinese Journal of Aeronautics 2006年第B12期19卷 9-13页

作者： YANG Xin-hong HAN Jie-cai zhang yu-min ZUO Hong-bo zhang Xue-jun Research Station on Material Science and Engineering for Postdoctoral Fellows Harbin Institute of Technology Harbin 150001 China Centre for Composite Materials Harbin Institute of Technology Harbin 150001 China

It is well known that grinding techniques are main methods to machine hard and brittle materials such as engineering ceramics. But the conventional grinding has many shortcomings such as poorer surface finish, quicker wear and tear of grinding tools, lower efficiency and so on. Ultrasonic vibration grinding （UVG） which combines ultrasonic machining and grinding emerged as a developing and promising technique in recent years. In this paper, experimental studies on UVG were conducted on several kinds of hard and brittle material by altering processing parameters such as vibration frequency and its amplitude, diamond abrasive grit size, cutting depth, feeding speed and rotary speed of tools. The experimental results show that alteration in any of above mentioned parameters will bring effects on the processed surface finish of these materials. Of them, the diamond abrasive grit size has the greatest. Moreover, conventional grinding experiments were also carried out on these materials. By comparison, it was found that the UVG is superior to the conventional method in terms of the ground surface quality, the working efficiency and the wear rate of tools.

关键词： ultrasonic vibration grinding (UVG) hard and brittle materials surface roughness wear extent

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保温叠合剪力墙FRP连接件力学性能

华北理工大学学报（自然科学版） 2025年第1期47卷 70-78页

作者：徐海东张玉敏徐振华华北理工大学建筑工程学院河北唐山063210 河北省地震工程研究中心河北唐山063009

以夹心保温叠合剪力墙为研究对象,研究螺纹型、矩形和六芒星状3种纤维增强复合材料连接件(FRP)在施工阶段和使用阶段下的抗剪力学性能,并且对三种FRP连接件在两个阶段下的破坏形态、抗拔承载力和荷载-位移曲线进行分析,结果表明:试件的... 详细信息

以夹心保温叠合剪力墙为研究对象,研究螺纹型、矩形和六芒星状3种纤维增强复合材料连接件(FRP)在施工阶段和使用阶段下的抗剪力学性能,并且对三种FRP连接件在两个阶段下的破坏形态、抗拔承载力和荷载-位移曲线进行分析,结果表明:试件的破坏形态主要有混凝土锚固破坏,层间剪切破坏和断裂破坏。施工阶段下单根FRP连接件最终抗剪承载力在1.41~3.91 kN之间,使用阶段下单根FRP连接件最终的抗剪承载力在3.19~6.02 kN之间,根据理论公式得到的计算值与试验值对比可知,在两个阶段情况下3种连接件的安全系数均大于1,均有较大的安全储备,可以应用到实际工程中。

关键词：叠合剪力墙纤维增强复合连接件夹芯保温剪切承载力

Mutations in surface and polymerase gene of chronic hepatitis B patients with coexisting HBsAg and anti-HBs

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World Journal of Gastroenterology 2006年第26期12卷 4219-4223页

作者： Hai-Ying Lu Zheng Zeng Xiao-yuan Xu Nai-Lin zhang min yu Wei-Bo Gong Department of Infectious Diseases Peking University First Hospital Beijing 100034 China

AIM： To investigate the clinical significance and presence of mutations in the surface （S） and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS： Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, i i were both positive for hepatitis B virus （HBV） surface antigen （HBsAg） and antibody to HBV surface antigen （anti-HBs）, 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS： Forty-one mutations were found within the surface gene protein of HBV in 15 patients （10 with coexisting HBsAg and anti-HBs）. Six （14.6%） out of 41 mutations were located at ＂α＂ determinant region in 5 patients （4 positive for HBsAg and anti-HBs）. Eleven mutations （26.8%） occurred in the downstream or upstream of ＂α＂ determinant region. Lamivudine （LMV）- selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions （196, 198, 199） of the surface protein and in YMDD motif （M204I/V） of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA ***： Besides mutations in the ＂α＂ determinant region, mutations at downstream or upstream of the ＂α＂ determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.

关键词： Hepatitis B virus surface antigen Antibody to hepatitis B virus surface Mutation

Poly(ethylene glycol)-supported Piperazine——Synthesis and Application in Knoevenagel Condensation

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Chemical Research in Chinese Universities 2010年第2期26卷 263-267页

作者： WANG Cui-e JIN Jie zhang min yu Shu-yan SHANG Yong-jia HU Jin-song College of Chemistry and Materials Science Anhui Key Laboratory of Functional Molecular SolidsAnhui Key Laboratory of Molecular Based Materials Anhui Normal University Wuhu 241000 P. R. China

A soluble, poly（ethylene glycol）-supported piperazine catalyst was prepared. This soluble catalyst efficiently catalyzes the Knoevenagel condensation of various aromatic aldehydes with diethyl malonate or ethyl acetoacetate in a homogeneous phase to afford the desired alkenes in good purity and yield with a facile work-up process. It was found that the polymer reagent could be repeatedly used at least four times without the too much loss of activity. The catalyst has shown a good activity, stability, and recycling capability.

关键词： Piperazine Polymer-supported catalyst Knoevenagel condensation