检索结果-南通市图书馆

Flux enhancement during ultrafiltration of produced water using turbulence promoter

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2006年第6期18卷 1077-1081页

作者： ZHEN Xiang-hua YU Shui-li WANg Bei-fu ZHENg Hai-feng School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

Concentration polarization and membrane fouling remain one of the major hurdles for the implementation of ultrafiltration of produced water. Although many applications for ultrafiltration were already suggested, only few were implemented on an industrial scale. Among those techniques, turbulence promoter can be more simple and effective in overcoming membrane fouling and enhancing membrane flux. As for the result that turbulence promoter increase fluid velocity, wall shear rates and produce secondary flows or instabilities, the influence of turbulence promoter was investigated on permeate flux during produced water ultrafiltration and the potential application of this arrangement for an industrial development. Experimental investigations were performed on 100 KDa molecular weight cut-off PVDF single-channel tubular membrane module using four kinds of turbulence promoters. It is observed that the significant flux enhancement in the range of 83%--164% was achieved while the hydraulic dissipated power per unit volume of permeate decreased from 31%--42%, which indicated that the using of turbulence promoter is more efficient than operation without the turbulence promoter. The effects of transmembrane pressure and cross-flow velocity with and without turbulence promoter were studied as well. Among the four kinds of turbulence promoters, winding inserts with 20.0 mm pitch and 1.0 mm wire diameter showed better performances than the others did.

关键词： hydraulic dissipated power flux enhancement turbulence promoter produced water ultrafiltration

Modeling of friction stir welding process for tools design

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2011年第2期5卷 236-245页

作者： San-Bao LIN Yan-hua ZHAO Zi-Qiu HE Lin WU State Key Lab of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China

A three-dimensional friction stir welding （FSW） process model has been developed based on fluid mechanics. The material transport in the welding process has been regarded as a laminar, viscous, and non-Newtonian liquid that flows past a rotating pin. A criterion to divide the weld zone has been given on the basis of cooperation of velocity field and viscosity field. That is, the η0-easy-flow zone that existed near the tool pin corresponded to the weld nugget zone; the area between the η0-easy-flow zone and η1-viscosity band is corresponded to the thermal-mechanical affected zone （TMAZ）. The model gives some useful information to improve the understanding of material flow in FSW through the simulation result of velocity distribution. In order to appraise the friction stir pin design, three kinds of pin geometry, one is column pin, the second is taper pin, and the last one is screw threaded taper pin, were used in the model. The pin geometry seriously affected the simulation result of velocity distribution in the η0-easy-flow zone. The velocity distribution in the η0-easy-flow zone can be considered as the criterion of optimizing friction stir tool design. This study will benefit to direct the friction stir tool design.

关键词： friction stir welding (FSM) 2014Al alloy, model, flow, fdction stir pin

Experiment and finite element method analysis mass erosion and transfer of Ag/La_2NiO_4-based electrical contacts during operation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2013年第1期32卷 93-99页

作者： Song Chen Wei-Ming guan Kun-hua Zhang Zhi-Long Tan Ming Xie Kunming Institute of Precious Metals State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals

A uniform transient temperature field model of electrical contacts operation was found by analyzing the process of closing arc constriction resistance Joule heat ~ breaking arc. Essential parameters of Ag/La2NiO4 electrical contact material for transient temperature field calculation were obtained through tests of electrical contact experimental instrument under 18 V DC in different cur- rents, other correlation experiments, and calculation anal- ysis. The finite element method was applied to solve the transient temperature field, and the features and distribution of the transient temperature field were obtained. The condition of material erosion and mass transfer can be forecasted by those calculation results. It is beneficial to research about the lifetime of Ag/La2NiO4 electrical material.

关键词： Electrical contact Finite element Mass transfer Erosion Temperature field model

gut microbial dysbiosis associates hepatocellular carcinoma via the gut-liver axis

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2019年第1期18卷 19-27页

作者： Jian-Wen Jiang Xin-hua Chen Zhigang Ren Shu-Sen Zheng Department of Hepatobiliary and Pancreatic Surgery Key Laboratory of Combined Multi-organ Transplantation Ministry of Public Health First Affiliated Hospital Zhejiang University School of Medicine Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases Zhejiang University Health Management Center First Affiliated Hospital Zhejiang University School of Medicine Department of Infectious Disease Precision Medicine Center the First Affiliated Hospital of Zhengzhou University

Background: Hepatocellular carcinoma(HCC) is one of the most common malignancies in the world. gut microbiota has been demonstrated to play a critical role in liver inflammation, chronic fibrosis, liver cirrhosis, and HCC development through the gut-liver axis. Data sources: Recently there have been several innovative studies investigating gut microbial dysbiosismediated enhancement of HCC through the gut-liver axis. Literatures from January 1998 to January 2018 were searched in the Pub Med database using the keywords "gut microbiota" and "hepatocellular carcinoma" or "liver cancer", and the results of experimental and clinical studies were analyzed. Results: gut microbial dysbiosis accompanies the progression of alcoholic liver disease, non-alcoholic fatty liver disease and liver cirrhosis, and promotes HCC progression in an experimental mouse model. The immune system and key factors such as Toll-like receptor 4 are involved in the process. There is evidence for gut microbial dysbiosis in hepatitis virus-related HCC patients. Conclusions: gut microbial dysbiosis is closely associated with hepatic inflammation disease and HCC through the gut-liver axis. With the enhanced understanding of the interactions between gut microbiota and liver through the gut-liver axis, new treatment strategies for HCC are being developed.

关键词： gut-liver axis gut microbiota Hepatocellular carcinoma Lipopolysaccharide Toll-like receptor 4

Synthesis of Tribolure,the Common Aggregation Pheromone of Four Tribolium Flour Beetles

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2015年第6期33卷 627-631页

作者： Chao Wang Chengyu He Yong Shi hua Xiang Weisheng Tian Department of Medicinal Chemistry School of PharmacyChinese Pharmaceutical UniversityNanjingJiangsu 210009China CAS Key Laboratory of Synthetic Chemistry of Natural Substances Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Herein we report a synthesis of the natural tribolure,an aggregation pheromone which consists of(4R,8S)-,(4R,8R)-,(4S,8S)-,and(4S,8R)-4,8-dimethyldecanals in a ratio of 4/4/1/1,from(R)-4-methyl-δ-valerolactone,a by-product of the degradation of steroidal *** the stereoisomers of the same ratios into one synthetic target and using the same chiron for the construction of the C4 stereocenters are notable features of this synthesis.

关键词： aggregation pheromone tribolure synthesis Tribolium flour beetle (R)-4-methyl-δ-valerolactone

Stereoselective Palladium-catalyzed Cross-coupling of （2-Amido-l-phenylpropyl）zinc Compounds with Aryl Bromides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2013年第4期29卷 678-681页

作者： TANg Shi ZHOU Dong LI Shu-hua WANg Nai-xing College of Chemistry and Chemical Engineering Jishou University Jishou 416000 P. R. China Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 P R. China

A controllable diastereoselective C（sp2）-C（sp3） Negishi coupling reaction of secondary benzylic zinc reagents with aryl bromides to form medicinally important 2-arylphenylethylamines was *** the presence of Pd（OAc）2 and 2-dicyclohexylphosphino-2＇,6＇-dimethoxybiphenyl（S-phos）,open-chain（2-amido-1-phenylethyl）zinc reagent bearing a β-NHAc or NHCHO group undergoes coupling reaction to give syn-1-arylphenylethylamine mainly,whereas the zinc reagent bearing a sterically hindered β-amido group,for example NHCOC（CH3）2OTBS undergoes the coupling reaction to yield anti-1-arylphenylethylamines with a configuration *** addition,a working mechanism for the stereoselective Negishi cross-coupling was also proposed.

关键词： Palladium Stereoselective Negishi coupling Benzylic zinc 2-Arylphenylethylamine

Terpenoid glucosides fromAster Smithianus

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2005年第5期21卷 531-535页

作者： gUO Shou-jun ZHAO Xin-hua YANg Yong-li CHENg Dong-liang Department of Chemistry National Laboratory of Appied Organic Chemistry Lanzhou University Lanzhou 730000 P. R. China Department of Biology Hanshan Normal University Chaozhou 521041 P. R. China

A diterpenoid trisaccharide, smithoside A, and a saponin, smithoside B, as well as six known compounds, apigenin, apigenin-7-O-glucoside, daucosterol, shanzhiside methyl ester, 8-acetylshanzhiside methyl ester and acteoside, were isolated from Aster smithianus. On the basis of spectral evidence and chemical analytical results, smithosides A and B were identified as pimar-1 5 （ 16 ） -β-ene-8β, 11 α-diol-3β-O-β-D-glucopyranosyl （ 1→3 ） - [ β-glucopyranosyl（ 1 →2 ） ] -β-D-glucopyranoside and 2β,3β, 16β,21β,23-pentahydroxy-12-ene-28 oleanoic acid lactone-3-O-β-D- glucopyranosyl （ 1→3 ） -β-D-glucopyranoside, respectively.

关键词： Aster smithianus Pimarene-type diterpenoid glucoside Triterpenoid glucoside Oleanolic acid lactone

Smoc2 potentiates proliferation of hepatocellular carcinoma cells via promotion of cell cycle progression

在线全文

学校读者我要写书评

暂无评论

World Journal of gastroenterology 2016年第45期22卷 10053-10063页

作者： Jing-Ran Su Jing-hua Kuai Yan-Qing Li Department of gastroenterology Laboratory of Translational Gastroenterology Shandong University Qilu Hospital Department of gastroenterology Shandong University Qilu Hospital of Shandong University (Qingdao)

AIM To determine the influence of Smoc2 on hepatocellular carcinoma(HCC) cell proliferation and to find a possible new therapeutic target for preventing HCC *** We detected expression of Smoc2 in HCC tissues and corresponding non-tumor liver(CNL) tissues using PCR, western blot, and immunohistochemistry methods. Subsequently, we down-regulated and upregulated Smoc2 expression using siR NA and lentivirus transfection assay, respectively. Then, we identified the effect of Smoc2 on cell proliferation and cell cycle using CCK-8 and flow cytometry, respectively. The common cell growth signaling influenced by Smoc2 was detected by western blot assay. RESULTS The expression of Smoc2 was significantly higher in HCC tissues compared with CNL tissues. Overexpression of Smoc2 promoted HCC cell proliferation and cell cycle progression. Down-regulation of Smoc2 led to inhibition of cell proliferation and cell cycle progression. Smoc2 had positive effect on ERK and AKT *** Smoc2 promotes the proliferation of HCC cells through accelerating cell cycle progression and might act as an anti-cancer therapeutic target in the future.

关键词： Smoc2 Hepatocellular carcinoma Cell cycle Proliferation

Hierarchical micro-mobility management in high-speed multihop access networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2006年第4期13卷 7-12页

作者： TANg Bi-hua MA Xiao-lei LIU Yuan-an gAO Jin-chun School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

This article integrates the hierarchical micro-mobility management and the high-speed multihop access networks （HMAN）, to accomplish the smooth handover between different access reuters. The proposed soft handover scheme in the high-speed HMAN can solve the micro-mobility management problem in the access network. This article also proposes the hybrid access muter （AR） advertisement scheme and AR selection algorithm, which uses the time delay and stable route to the AR as the gateway selection parameters. By simulation, the proposed micro-mobility,management scheme can achieve high packet delivery fraction and improve the lifetime of network.

关键词： Ad-hoc networks hierarchical micro-mobility management wireless multihop access network