检索结果-南通市图书馆

Chinese Journal of Polymer Science 2017年第2期35卷 249-260页

作者： Xiao-peng Xu guang-jun zhang Yun-zhe Zhao 刘江 Ying Li 彭强 Key Laboratory of Green Chemistry and Technology of Ministry of Education College of ChemistryState Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610064China Chengdu Green Energy and Green Manufacturing Technology R&D Center Chengdu 610207China

A series of copolymers, based on benzo[1,2-b：4,5-b＇]dithiophene （BDT） as the electron donor and 2,1,3- benzothiadiazole （BT）/diketopyrrolo[3,4-c]pyrrole （DPP） as the electron acceptors, were synthesized for highly efficient polymer solar cells. By changing the BT/DPP ratio in the conjugated backbone, the absorption, energy levels, molecular aggregation and carrier mobility could be finely tuned. With increased DPP content, the absorption range was extended to the longer wavelength region with narrower bandgaps. The highest occupied molecular orbital （HOMO） levels were also raised up and the molecular aggregation was enhanced. The balance of these factors would afford a remarkable device performance enhancement. Polymer P3 with BT：DPP = 0.7：0.3 （molar ratio） exhibited the highest power conversion efficiency （PCE） of 9.01%, with open circuit voltage （Voc） = 0.73 V, short current density （Jsc） = 18.45 ***-2, and fill factor （FF） - 66.9%. The PCE value was improved by 48.7% compared to P1 and by 117.6% compared to P7, respectively, indicating a great potential in photovoltaic application.

关键词： Polymer solar cells Terpolymers Complementary absorption Molecular aggregation

Mechanical Properties of QFP Joints Soldered with SnAgCu and SnPb Solders

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2011年第4期24卷 596-600页

作者： XUE Peng XUE Songbai ZENG guang zhang Liang DAI Wei College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

With the development of lead-free solder alloys, the investiagtion focusing on the relibility of lead-free solders are essential. Since the reliability database of lead-free solder joints needs to be further supplied, the creep behavior of SnAgCu soldered joints on Quad Flat Package （QFP） devices under thermo cycling load are studied in this paper, compared to conventional SnPb solder, by finite element simulation based on Garofalo-Arrhenius creep model. Meanwhile, the mechanical properties of SnAgCu and SnPb soldered joints in the pitches of QFP devices are also carried out by means of tensile test. The results indicate that the values of strain and stress of SnAgCu soldered joints were all smaller than those of SnPb under thermal cycling, and the tensile strength of the joints soldered with SnAgCu solder was higher than that of SnPb, which means the reliability of the joints soldered with SnAgCu solder is better than SnPb soldered joints. As the fracture surface morphology of the soldered joints compared, SnAgCu soldered joint presented ductile fracture, while the fracture mechanism of SnPb solder joints displayed both brittle and ductile fracture. Above all, the experimental results is in accord with that of simulation, which will provide guidance for reliability study and application of lead-free solders.

关键词： creep model finite element analysis Quad flat package (QFP) devices mechanical properties

Mutation of cytotoxin-associated gene A affects expressions of antioxidant proteins of Helicobacter pylori

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第5期15卷 599-606页

作者： Zhi-Gang Huang guang-Cai Duan Qing-Tang Fan Wei-Dong zhang Chun-Hua Song Xue-Yong Huang Rong-guang zhang Department of Epidemiology College of Public HealthZhengzhou University Zhengzhou 450001 Henan ProvinceChina Department of Epidemiology School of Public Health Guangdong Medical College Dongguan 523808Guangdong Province China

AIM: To determine if disruption of the cagA gene of Helicobacter pylori (H pylori) has an effect on the expression of other proteins at proteome level. METHODS: Construction of a cagA knock out mutant Hp27 _△cagA (cagA -) via homologous recombination with the wild-type strain Hp27 (cagA+) as a recipient was performed. The method of sonication-urea-CHAPS-DTT was employed to extract bacterial proteins from both strains. Soluble proteins were analyzed by two-dimensional electrophoresis (2-DE). Images of 2-DE gels were digitalized and analyzed. Only spots that had a statistical signif icance in differential expression were selected and analyzed by matrix-assisted laser desorption/ionizationtime of flight mass spectrometry (MALDI-TOF-MS). Biological information was used to search protein database and identify the biological function of proteins. RESULTS: The proteome expressions between wild-type strain and isogenic mutant with the cagA gene knocked-out were compared. Five protein spots with high abundance in bacteria proteins of wild-type strains, down-regulated or absently expressed in bacteria proteins of mutants, were identified and analyzed. From a quantitative point of view, the identified proteins are related to the cagA gene and important antioxidant proteins of H pylori , including alkyl hydroperoxide reductase (Ahp), superoxide dismutase (SOD) and modulator of drug activity (Mda66), respectively, suggesting that cagA is important to maintain the normal activity of antioxidative stress and ensure H pylori persistent colonization in the host. CONCLUSION: cagA gene is relevant to the expressions of antioxidant proteins of H pylori, which may be a novel mechanism involved in H pylori cagA pathogenesis.

关键词： Helicobacter pylorr, Cytotoxin-associatedgene A Knock-out Antioxidant protein Two-dimensional electrophoresis

Effect of temperature and mating pair on tribological properties of DLC and GLC coatings under high pressure lubricated by MoDTC and ZDDP

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2021年第6期9卷 1390-1405页

作者： Kang LIU Jia-jie KANG guang-an zhang Zhi-bin LU Wen YUE School of Engineering and Technology China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Deep GeoDrilling Technology of Ministry of Natural Resources Beijing 100083China Zhengzhou Institute China University of Geosciences(Beijing)Zhengzhou 451283China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Diamond-like carbon(DLC)and graphite-like carbon(GLC)coatings have good prospects for improving the surface properties of engine ***,further understanding is needed on the effect of working conditions on tribological *** this study,GLC and two types of DLC coatings were deposited on GCr15 substrate for *** friction and wear properties of self-mated and steel-mated pairs were *** temperatures(25 and 90℃),three lubrication conditions(base oil,molybdenum dithiocarbamate(MoDTC)-containing oil,MoDTC+zinc dialkyldithiophosphate(ZDDP)-containing oil),and high Hertz contact stress(2.41 GPa)were applied in the *** results showed that high temperature promoted the effect of ZDDP on steel-mated pairs,but increased wear under base oil *** increased wear for steel-mated pairs lubricated by MoDTC-containing oil was due to abrasive wear probably caused by MoO_(3) andβ-FeMoO_(4).It was also found that in most cases,the tribological properties of self-mated pairs were better than those of steel-mated pairs.

关键词： diamond-like carbon(DLC) graphite-like carbon(GLC) mating pair temperature oil additives

Orientational growth behavior and mechanism of delta(δ)phase precipitation in cold-rolled Inconel 718 alloy during heat treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第1期31卷 264-274页

作者： Neng-yong Ye guang-liang zhang Tian-yue Huang Ming Cheng Shi-hong zhang Lei Wang School of Materials Science&Engineering Taizhou UniversityTaizhou318000ZhejiangChina Institute of Metal Research Chinese Academy of SciencesShenyang110016LiaoningChina

Due to the important role ofδphase's quantity and morphology in the mechanical and fatigue properties of Inconel 718 alloy and its components,it is necessary to renew insights into the effect of cold deformation on theδphase precipitation,especially on the morphology ***,the nucleation and growth behavior ofδphase in cold-rolled Inconel 718 alloy during aging were *** results show that the precipitation rate and volume fraction ofδphase increase with increasing the cold rolling reduction from 10%to 50%.The volume fraction ofδphase reaches equilibrium after 5 h,remaining at 5.98%,6.52%,and 6.79%under different rolling reductions(10%,30%,and 50%),*** nucleation ofδphase mainly occurs on different sites(grain boundaries,new twin boundaries and old twin boundaries)under 10%rolling reduction,whileδphase mainly nucleates on the new grain boundaries of static recrystallization due to 50%rolling *** the growth ofδphase undergoes a process of alternate orientation growth from spherical(nucleation)→short rod(longitudinal orientation growth)→short rod(radial orientation growth)→dynamic *** 10%rolling reduction,δphase tends to grow into the matrix,while under 50%rolling reduction,the orientation grows faster and is easily affected by the grain boundary curvature.

关键词： Inconel 718 alloy Cold rolling δphase Orientation growth Morphology evolution

Organocatalytic Copolymerization of Mixed Type Monomers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2017年第5期35卷 581-581,582-601页

作者： Qi-lei Song Shuang-yan Hu 赵俊鹏 guang-zhao zhang Faculty of Materials Science and Engineering South China University of Technology

Triggered by environmental concerns and the rising demands for metal-free polymers in e.g. bio-related and microelectronic applications, studies on organocatalytic polymerization have been launched and developed unprecedentedly during the last 15 years. A wide range of organic molecules are now available in polymer chemists＇ toolbox to choose from as catalysts for polymerization of （hetero）cyclic and polar vinyl monomers. Apart from the intrinsic merits such as lower toxicity and better solubility compared with （transition） metal catalysts/initiators, organocatalysts have also shown, in many cases, excellence to achieve high polymerization rates and/or good control （selectivity）. In addition, particular natures and catalytic/activating mechanisms of organocatalysts have led to new opportunities for rational design and efficient synthesis of macromolecular architectures, i.e. chain structures, topological structures and functionalities. This mini-review is specially themed on pathways to construct copolymer chain structures by organocatalytic copolymerization of mixed type monomers （comonomers bearing different polymerizing moieties） and will be sectioned by different comonomer combinations, including cyclic monoesters of different sizes, cyclic monoesters and lactides, cyclic esters and cyclic carbonates or epoxides, heterocycles and vinyl monomers.

关键词： Chain structure Copolymer Organocatalytic polymerization

Effect of End Shape on Flow and Heat Transfer Characteristics of Two Parallel Plates

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 815-832页

作者： zhang guang HONG Tianxiao WANG Dongrui XIN Jialin TAO Junyu LIN Zhe Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou310018China

Flow around a pair of flat plates is a basic hydrodynamics *** this paper,the flow and heat transfer characteristics of two parallel plates with different edge shapes are numerically *** different inclined angles,the influence of chamfered and rounded structures with different sizes at the end-edge on unsteady flow and heat transfer characteristics of two parallel plates are *** is found that the instability and unsteadiness of flow decrease with the increase of end-edge size,and the non-uniformity of wake velocity of both rounded and chamfered plates decreases *** non-uniformity of wake temperature increases firstly and then decreases at a small inclined angle,and the amplitude becomes the largest when S_(rou)(S_(cha))=3,while it basically keeps monotonically increasing at a large inclined ***,the global heat transfer performance of the flat plate is obviously affected by the end-edge modification,especially the chamfered *** the increase of chamfered size,the global Nusselt number basically shows the decreasing *** study provides a theoretical basis for the application of plate-shape structure in engineering fields.

关键词： two parallel plates end shape flow characteristic heat transfer numerical simulation

Direct pore engineering of 2D imine covalent organic frameworks via sub-stoichiometric synthesis

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2022年第1期65卷 190-196页

作者： Xiao Yang Zhen Xie Ting zhang guang zhang Ziqiang Zhao Yong Wang Guolong Xing Long Chen Department of Chemistry Tianjin Key Laboratory of Molecular Optoelectronic ScienceTianjin UniversityTianjin 300072China

Two-dimensional covalent organic frameworks(2D COFs)bearing various topologies can be precisely designed based on the symmetry of *** pore environment can be further regulated via either pre-functionalization of the monomers or post-modification of the *** them,sub-stoichiometric synthesis is an efficient method which can mediate uncondensed functional moieties periodically arranged in the COF ***,a series of imine-linked 2D COFs with specifically decorated formyl or amino groups were selectively synthesized via sub-stoichiometric formyl *** molar ratios of the monomers directly determine the structures of the resulting COFs with periodic vertex *** COF with polar amino sites could efficiently capture CO_(2) and H_(2)*** work demonstrates tuning the stoichiometry of the monomers could facilely modulate the functions of the pore *** also provides insights into constructing novel COFs with complex structures for targeted applications.

关键词： covalent organic frameworks sub-stoichiometric periodic vertex vacancies

Photorefractive Spatial Dark-Soliton Stripes in LiNbO_(3):Fe Crystal and Their Application

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1996年第2期13卷 101-104页

作者： zhang Guo-quan LIU Si-min XU Jing-jun zhang guang-yin SUN Qian Department of Physics Nankai UniversityTianjin 300071

We observed the photorefractive spatial dark-soliton stripes In LiNbO3:Fe crystal,and demonsirate the planar waveguide property of refractive index proiile induced by these spatial dark-soli ton *** suggest a new moth... 详细信息

关键词： technique waveguide Photorefractive

Sphingosine kinase 1 knockout alleviates hepatic ischemia/reperfusion injury by attenuating inflammation and oxidative stress in mice

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2019年第3期18卷 255-265页

作者： guang-Hui Qiang Zhong-Xia Wang An-Lai Ji Jun-Yi Wu Yin Cao guang zhang Yi-Yang zhang Chun-Ping Jiang Department of Hepatobiliary Surgery Nanjing Drum Tower Hospital Drum Tower Clinical College of Nanjing Medical University Nanjing 210008 China Department of Hepatobiliary Surgery the Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing 210008 China Department of Gastroenterology Nanjing Drum Tower Hospital Drum Tower Clinical College of Nanjing Medical University Nanjing 210008 China

Background: Hepatic ischemia/reperfusion(I/R) injury remains a significant problem in clinical practice. Sphingosine kinase 1(Sph K1) phosphorylates sphingosine to sphingosine-1-phosphate(S1 P) which participates in multiple bioactive processes. However, little is known about the role of Sph K1 in hepatic I/R injury. This study aimed to investigate the effect of Sph K1 knockout on liver I/R injury and to explore underlying mechanisms. Methods: Sph K1 knockout and wild type mice were subjected to 70% partial hepatic I/R. Serum alanine aminotransferase was determined to indicate the degree of liver damage. Hematoxylin-eosin staining and TUNEL assay were used to assess histological changes and hepatocellular apoptosis, respectively. Immunohistochemistry was performed to detect the expression and translocation of phosphorylated p65 and signal transducer and activator of transcription 3(STAT3). Western blotting was used to determine the expression of S1 P receptor 1(S1 PR1), phosphorylated p65 and STAT3. Real-time PCR was used to demonstrate the changes of proinflammatory cytokines. Oxidative stress markers were also determined through biochemical assays. Results: Sph K1 knockout significantly ameliorated I/R-induced liver damage, mitigated liver tissue necrosis and apoptosis compared with wild type control. I/R associated inflammation was alleviated in Sph K1 knockout mice as demonstrated by attenuated expression of S1 PR1 and reduced phosphorylation of nuclear factor kappa B p65 and STAT3. The proinflammatory cytokines interleukin-1 β, interleukin-6 and tumor necrosis factor-α were also inhibited by Sph K1 genetic deletion. The oxidative stress markers were lower in Sph K1 knockout mice after I/R injury than wild type mice. Conclusions: Knockout of Sph K1 significantly alleviated damage after hepatic I/R injury, possibly through inhibiting inflammation and oxidative stress. Sph K1 may be a novel and potent target in clinical practice in I/R-related liver injury.

关键词： Ischemia/reperfusion injury Sphingosine kinase 1 Inflammation Oxidative stress