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Molecular Weight Dependence of Associative Behavior in Polyimide/DMF Solutions

Chinese Journal of Polymer Science 2020年第6期38卷 629-637页

作者： hong-xiang chen En-Song Zhang Mei hong Wei Liu Xue-Min Dai Quan chen Xue-Peng Qiu xiang-Ling Ji State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China Laboratory of Polymer Composites and Engineering Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Eight 6FDA-TFDB polyimide(PI)samples with absolute molecular weights ranging from 1.25 × 10^5 g mol^-1 to 3.11 × 10^5 g mol^-1 are obtained by precipitation *** experiments are conducted to determine the influence of molecular weight on the associating behavior of PI in A/X-dimethylformamide(DMF)solutions in a broad volume fraction,including abnormal steady shear flow,solution heterogeneity,and scaling *** flow behaviors,i.e.,multi-region shear thinning and weak shear thickening,are studied,and these behaviors have not been reported in *** heterogeneity of PI/DMF solutions is examined by dynamic rheological *** plotting qsp versus four concentration regions of l-IV can be distinguished for all PI samples with various molecular *** scaling results in different concentration regions are in good agreement with the associative polymer theory proposed by Rubinstein and *** scaling exponents do not show molecular weight dependence in concentration regions I and *** concentration regions Ⅲ and Ⅳ,the scaling exponents change little when the molecular weight is below 242 k but increase when the molecular weight increases from 242 k to 311 *** work can help us to understand polyimide solution properties from dilute to semidilute entangled solutions,and will guide the polyimide solution preparation for different processing.

关键词： Soluble polyimide Molecular weight Rheology Associative polymer Scaling behavior

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Numerical simulation and method study of X-ray litho-density logging

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Nuclear Science and Techniques 2020年第12期31卷 129-138页

作者： Hua-Wei Yu Yu-Xin Zhang xiang-hong chen Wen-Ding Wang Chao-Zhuo Liu Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China School of Geosciences China University of Petroleum(East China)Qingdao 266580China College of Science China University of Petroleum(East China)Qingdao 266580China

To effectively replace the isotope radiation source in litho-density logging,this study presents a method for measuring the formation density and photoelectric absorption index(Pe)using a switchable X-ray ***,the gamma-ray litho-density logging(GLD)method for measuring formation density and Pe using chemical sources is ***,a benchmark verification based on the X-ray litho-density logging tool prototype and data published by Simon(In:Paper presented at the SPWLA 59th annual logging symposium,London,UK,2018)was carried out using Monte Carlo numerical ***,the impacts of the photoelectric effect and detector statistical error on the GLD method were ***,based on a theoretical analysis,the formation density and Pe measurement algorithm(double energy window(DEW)method)was improved,which was found to be suitable for X-ray litho-density ***,the results obtained using this algorithm were compared with those obtained using the GLD *** results indicate that owing to the impact of photoelectric effect and detector statistical error on the density energy window,the accuracy of formation density and Pe measurement using the GLD method is relatively low,with the uncertainty in formation density and Pe measurement reaching 2.620±0.047 g/cm3 and 4.090±0.580 b/e,*** comparison,the DEW method can improve the accuracy of density and Pe measurement to 0.006 g/cm3 and 0.065 b/e,respectively,as the photoelectric effect in the density window is corrected using the counts in the lithology window of the energy *** study aims to provide a new theoretical foundation for processing X-ray litho-density logs in the future.

关键词： X-ray controllable source Litho-density logging Monte Carlo simulation

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High performance lithium oxygen batteries based on a phosphorous-doped holey graphene cathode

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Rare Metals 2022年第12期41卷 4027-4033页

作者： Ying Meng Jia-Kui Zhang Hai-Ying Lu xiang-hong chen Jian-Tie Xu National Engineering Laboratory for VOCs Pollution Control Technology and Equipment Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution ControlSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510640China

The sluggish electrochemical kinetics of cathode is one of the critical issues for the development of high performance lithium oxygen batteries(LOBs).Graphene-based materials have attracted great attentions as advance... 详细信息

关键词： lithium performance kinetics

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Clinical features and therapeutic strategies of obstructive azoospermia in patients treated by bilateral inguinal hernia repair in childhood

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Asian Journal of Andrology 2014年第5期16卷 745-748,I0010页

作者： xiang-Feng chen hong-xiang Wang Yi-Dong Liu Kai Sun Li-Xin Zhou Yi-Ran Huang Zheng Li Ping Ping Department of Urology Ren Ji Hospital School of Medicine Shanghai Jiao Tong University Shanghai Institute of Andrology Shanghai China

Childhood inguinal herniorrhaphy is one common cause of seminal tract obstruction. Vasovasostomy （VV） can reconstruct seminal deferens and result in appearance of sperm and natural pregnancy in some patients. Secondary epididymal obstruction caused by a relatively long-term vasal obstruction is a common cause of lower patency compared with VV due to vasectomy in adults. From July 2007 to June 2012, a total of 62 patients, with history of childhood inguinal herniorrhaphy and diagnosed as obstructive azoospermia were treated in our center. The overall patency rate and natural pregnancy rate were 56.5% （35/62） and 25.8% （16/62）, respectively. 48.4% （30/62） of the patients underwent bilateral VV in the inguinal region, with a patency rate of 76.7% （23/30） and a natural pregnancy rate of 36.7% （11/30）, respectively. 30.6% （19/62） of the patients underwent bilateral VV and unilateral or bilateral vasoepididymostomies due to ipsilateral epididymal obstruction with the patency and natural pregnancy rate decreasing to 63.2% （12/19） and 26.3% （5/19）. 21.0% （13/62） of the patients merely underwent vasal exploration without reconstruction due to failure to find distal vasal stump, etc. Our study indicate that microsurgical reanastomosis is an effective treatment for some patients with seminal tract obstruction caused by childhood inguinal herniorrhaphy.

关键词： azoospermia inguinal herniorrhaphy microsurgical reanastomosis

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A new monosaccharide from Swertia punicea Hemsl

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Chinese Chemical Letters 2009年第6期20卷 684-686页

作者： Luan Yuan Tian Jia Chun chen Jin Bo Fang Qun Zhou Xue Bai Jian Qiu Zhou xiang hong chen Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation Tongji School of Pharmaceutical Sciences Huazhong University of Science and Technology Wuhan 430030 China

A new compound named 1-hydrate, 3-deoxy-α-D-tagatofuranose was isolated from Swertia punicea Hemsl. The structure of compound was determined by 1D and 2D NMR, HRESIMS techniques.

关键词： Swertia punicea Hemsl. Monosaccharide 1-Hydrate 3-Deoxy -α-D-tagatofuranose

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The Prokaryotic Expression and Bioactivity of the Recombinant Red Fire Ant Venom Allergen Sol i 4

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Agricultural Sciences in China 2009年第2期8卷 182-187页

作者： HAN Xue-qing LIN xiang-mei chen hong-jun ZHANG Yong-guo YE Gui-sheng WU Shao-qiang LI Jian chen Nai-zhong chen Yan ZHU Shui-fang Chinese Academy of Inspection and Quarantine Beijing 100029 P.R.China

The sting of red imported fire ant （RIFA） could cause serious allergic response in fraction of people. These allergic reactions are mainly caused by its venom, especially venom allergen Sol i 1-4. To produce large amount of RIFA venom allergen Sol i 4 for diagnosis of RIFA allergy and allergen-specific immunotherapy, the gene encoding this protein was amplified and cloned into the prokaryotic expression vector pET43, la. The recombinant plasmid was used to transform competent cells and the recombinant proteins were expressed in E. coll. SDS-PAGE and Western blotting analysis indicated that high-level expression of Sol i 4 protein was successfully achieved. Allergenic activity analysis of the recombinant allergen Sol i 4 was then performed on rabbit. The result showed that the recombinant protein obtained had significant allergenic activity. It indicated that the recombinant allergen Sol i 4 of RIFA venom was successfully expressed in E. coli, which provided foundation for further developing therapeutic and diagnosis reagents of RIFA allergy.

关键词： red imported fire ant recombinant allergen Sol i 4 expression activity

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Synthesis of Novel Non-Nucleoside HIV-1 Reverse Transcriptase Inhibitors-1-(3-Phthalimido-2-oxobutyl)-4-Substituted-phenylpiperazines

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Chinese Chemical Letters 2000年第7期11卷 571-572页

作者： Xin chen Lin WANG Zhi Zhong ZHAO Xing Quan ZHANG xiang hong chen hong Shan chen(Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050 Institute of Medicinal Biotechnology, Chinese Academy of M Institute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100050 China Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100050 China

We have designed and synthesized a series of new phthalimidopiperazines, biological activity test show that the target compounds(Ic, Ie, ii) can inhibit HIV-I RT with IC50 20.0, 43.8, and 63.7 mu M, respectively.

关键词： piperazine phthalimide HIV1-RT inhibitor

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Total Synthesis of (±)-Calanolide A and Its Anti-HIV Activity

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Chinese Chemical Letters 1998年第5期9卷 433-434页

作者： Chun Mei ZHOU Lin WANG Ming Long ZHANG Zhi Zhong ZHAO (Institute of Materia Medica, Peking Union Medical College &Chinese Academy of Medical Sciences, Beijing 100050)Xing Quan ZHANG xiang hong chen hong Shan chen (Institute of Medicinal Biotechno Institute of Materia Medica Peking Union Medical College Chinese Academy of Medical Sciences Beijing 100050 China Institute of Medicinal Biotechnology Peking Union Medical College Chinese Academy of Medical Sciences Beijing 100050 China

Anti-HIV agent (±)-calanolide A has been synthesized by a four-step approach startingfrom phloroglucinol, including the Pechmann reaction, Friedel-Crafts acylation, cyclization,chromenylation and Luche reduction.

关键词： total synthesis (±)-calanolide A anti-HIV activity

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Measurement of Apex Offsets for Fiber Connector End Faces

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Semiconductor Photonics and Technology 2006年第4期12卷 270-275页

作者： XU Yong-xiang ZHU Ri-hong chen Lei College of Opto-electronic Technology Nanjing University of Science and Technology Nanjing 210094 CHN

As one of the most important geometric parameters for a PC-type fiber connector end face, apex offset can contribute to high insertion loss and high back-reflection reading. A novel measurement method for the parameter, connector rotating-π method, is proposed. With the method, the apex offset of a common connector end face is measured. The result is compared with that measured by a Norland 3000 fiber connector end face interferometer. It is found that the difference between two results is 1.8μm. Meantime, the influences of relevant error resources on apex offset measurement under rotating-π method and apex-core method are respectively analyzed, and two error equations are derived. The analytical result shows that, compared with apex-core method, if two additional sub-tilts of axis within and in the direction perpendicular to principal plane caused by its rotation are not bigger than the original axis tilt angle, the max. measurement error will then be reduced by at least 22.5% with rotating-π method. The practicability of the method is confirmed by the experiments.

关键词： Apex offset Fiber connector Phase shifting interferometry Algorithm

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Preliminary studies on the mechanism of blistering cupping therapy

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TMR Non-Drug Therapy 2018年第2期1卷 26-31页

作者： xiang-hong chen Bo chen Ze-Lin chen Meng-dan Li Qin Long College of Acupuncture and Massage Tianjin University of Traditional Chinese Medicine Tianjin China Research Center of Experimental Acupuncture Science Tianjin University of Traditional Chinese Medicine Tianjin China.

Blistering cupping therapy, as a new type of cupping therapy, has attracted more and more attention of clinical doctor and scholars in home and abroad. Blistering cupping therapy achieves better effects through the formation of blistering fluid after suction. However, it is still controversial whether cupping induced blisters are beneficial to recovery of diseases, and the mechanism is still not completely clear. Here on the basis of the traditional cupping method, we aimed to identify the mechanism of blistering cupping from the levels of biomechanics and molecular biology. The negative pressure attraction induced by cupping suck should be of value in increasing pain threshold and relieving pain as well as improving the blood circulation and metabolism. Furthermore, the blistering fluid induced by cupping was the inflammatory substance actually that discharged through the superficial lymphatic vessels, including immunoglobulin, lysozyme, erythrocytes, etc. which could cause the autogenetic inflammatory reaction of selected cupping area, and further activated certain immune pathways including anti-oxidation, anti-apoptosis, tissue repairing and metabolic regulation. Besides, the formation of scar induced by blistering cupping was not only the result of excessive inflammatory response, but also involved in mobilizing the immune response.

关键词： Cupping Blistering cupping Mechanism Biomechanics Molecular biology Inflammation Immunity.

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