检索结果-南通市图书馆

Effects of the Recombination of Nucleons into α-Particles on the R-process in Proto-magnetar Wind

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第6期29卷 303-306页

作者： chen yan-jun YUAN Ye-Fei Department of Physics and Electronic Science Changsha University of Science and TechnologyChangsha 410114 Center for Astrophysics University of Science and Technology of ChinaHefei 230026

We take the recombination of nucleons to α-particles into account in proto-magnetar winds and evaluate its effects on r-process *** proto-magnetar winds are described in the time-independent Newtonian magnetohydrodynamic wind *** is found that stellar rotation and strong magnetic fields significantly affect the properties of the ***,the fact that the recombination of nucleons can enhance the wind entropy by approximately twenty percent and somewhat reduce the expansion timescale indicates that the effects of this recombination on the r-process can not be ignored.

关键词： process rotation Newtonian

Solid phase extraction of methomyl and thiodicarb from environmental water with an activated carbon cartridge and their determination by HPLC

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

Journal of Environmental Sciences 2000年第1期12卷 100-104页

作者： chen, yan-jun Lu, Ying-Hua Liu, jun chen, Ya-Min Department of Chemistry Jining Medical College Shandong Jining 272113 China

A solid phase extraction procedure of methomyl and thiodicarb from environmental water was presented. This method utilizes a 40—60 mesh activated carbon cartridge and high performance liquid chromatography (HPLC). The 40—60 mesh activated carbon works faster and yield higher adsorption efficiency. Detection limits of methomyl and thiodicarb in environmental water are 0 1 μg/L and 0 2 μg/L, respectively. Average recoveries of fortified methomyl and thiodicarb in water are in the range of 90 7%—98 8% and 88 9%—103 6%, respectively. The relative standard deviations are lower than 7%. This method is simple, rapid, accurate and precise.

关键词： HPLC solid phase extraction activated carbon methomyl thiodicarb CLC number: X592 Document code: A

Standing Shocks in the Inner Slow Solar Wind

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第5期28卷 296-299页

作者： LI Bo chen yan-jun LI Xing Shandong Provincial Key Laboratory of Optical Astronomy&Solar-Terrestrial Environment School of Space Science and PhysicsShandong University at WeihaiWeihai 264209 State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190 Institute of Mathematics and Physics Aberystwyth UniversityAberystwyth SY233BZUK

We examine whether the flow tube along the edge of a coronal streamer supports standing shocks in the inner slow wind by solving an isothermal wind model in terms of the Lambert W *** is shown that solutions with standing shocks do exist and they exist in a broad area in the parameter space characterizing the wind temperature and flow *** particular,streamers with cusps located at a heliocentric distance(≥)3.2R⊙can readily support discontinuous slow winds with temperatures barely higher than 1 MK.

关键词： function flow readily

Lentivirus-mediated shRNA interference targeting STAT3 inhibits human pancreatic cancer cell invasion

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

World Journal of Gastroenterology 2009年第30期15卷 3757-3766页

作者： Guang yan chen Huang jun Cao Ke-Jian Huang Tao Jiang Zheng-jun Qiu Department of General Surgery Affiliated First People's Hospital Shanghai Jiao Tong University Shanghai 200080 China

AIM： To investigate RNA interference targeting signal transducer and activator of transcription-3 （STAT3） on invasion of human pancreatic cancer cells.METHODS： We constructed three plasmids of RNA interference targeting the STAT3 gene. After LV （lentivirus）-STAT3siRNA （STAT3 small interfering RNA） the vector was transfected into the human pancreatic cell line, SW1990 and cell proliferation was measured by the MTT assay. Flow cytometry was used to assess cell cycle. Vascular endothelial growth favor （VEGF） and matrix metalloproteinase-2 （MMP-2） mRNA and protein expression were examined by quantitative PCR and western blotting, respectively. The invasion ability of SW1990 cells was determined by cell invasion assay.RESULTS： We successfully constructed the LVSTAT3siRNA lentivirus vector and proved that it can suppress expression of STAT3 gene in SW1990 cells. RNA interference of STAT3 by the LV-STAT3siRNA construct significantly inhibited the growth of SW1990 cells, in addition to significantly decreasing both VEGF and MMP-2 mRNA and protein expression. Moreover, suppression of STAT3 by LV-STAT3siRNA decreased the invasion ability of SW1990 cells.CONCLUSION： The STAT3 signaling pathway may provide a novel therapeutic target for the treatment of pancreatic cancer since it inhibits the invasion ability of pancreatic cancer cells.

关键词： Signal transducer and activator of transcription3 RNA interference Lentivirus vector Pancreatic cancercells Invasion

A CSCW SYSTEM FOR BUILDING REVIEWING BY INTEGRATING GIS WITH OA

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

Geo-Spatial Information Science 2000年第1期3卷 45-49页

作者： JIANG Jie chen jun yan Ronghua XU Lilin Belling Graduate School China University of Mining and Technology Belling China

The process of urban building reviewing is a collaborative work by a group of urban planning staffs and land managers who are working with different departments of a organization. There are three ingredients for improving the work efficiency, i.e., agile communication and interactive mechanisms, good information, effective processing and visualizing tools. In order to build a computer supported collaborative work (CSCW) system in Urban Planning and Land Administration Bureau in Changzhou Municapality, GIS was integrated with office automation (OA). The workflow and organizational structure had been re-engineered to meet the requirement of application of the new technology. Federated databases were constructed by assembling disparate sources of heterogeneous spatial and attribute data. Easy access to the data by contents was developed for promoting information sharing within the organization. Specific desktop spatial data handling tools were provided for delineating land lots or building layouts on large-scale digital maps. Office automation functions, including applications registering, reasonableness checking, opinions giving and exchanging, were developed and they permit printing and documents filing. The work efficiency in the organization has been improved by introducing the computer-based collaborative building reviewing system.

关键词： CSCW System office automation

A Hybrid Genetic Algorithm for Vehicle Routing Problem with Complex Constraints

在线全文

学校读者我要写书评

暂无评论

International Journal of Plant Engineering and Management 2006年第2期11卷 88-96页

作者： chen yan LU jun LI Zeng-zhi School of Electronics and Information Engineering Xi＇an Jiaotong University Xi＇an 710049 P. R. China

Most research on the Vehicle Routing Problem （VRP） is focused on standard conditions, which is not suitable for specific cases. A Hybrid Genetic Algorithm is proposed to solve a Vehicle Routing Problem （VRP） with complex side constraints. A novel coding method is designed especially for side constraints. A greedy algorithm combined with a random algorithm is introduced to enable the diversity of the initial population, as well as a local optimization algorithm employed to improve the searching efficiency. In order to evaluate the performance, this mechanism has been implemented in an oil distribution center, the experimental and executing results show that the near global optimal solution can be easily and quickly obtained by this method, and the solution is definitely satisfactory in the VRP application.

关键词： genetic algorithm vehicle routing problem greedy algorithm complex constraints

抗癌药物α,β不饱和羰基化合物3D-QSAR研究

在线全文

学校读者我要写书评

暂无评论

四川大学学报（自然科学版） 2018年第1期55卷 141-146页

作者：陈研君广西师范学院广西530001

采用CoMFA和CoMSIA方法对31个α,β不饱和羰基化合物进行了三维定量构效关系研究,所得模型都具有良好统计学意义.CoMFA:q^2=0.687,R^2=0.956,N=9,SEE=0.090;CoMSIA:q^2=0.756,R2=0.954,N=9,SEE=0.093.通过三维等值图分析其影响抑制剂分... 详细信息

关键词：构效关系 CoMFA CoMSIA α β不饱和羰基化合物

STUDY ON METHANE STEAM REFORMING IN MEMBRANE REACTORS

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 1994年第4期 442-452页

作者： CUN cheng-yan chen Yi-jun QU Mei-Zheng AN Wei-Zhuchengdu Institute of Organic Chemistry, Academia Sinica chengdu, Sichuan 610015

The steam reforming of methane was carried out in two types ofmembrane reactor and in a conventional fixed-bed reactor packed with acatalyst of Rh/*** membranes were a neat anodic alumina membraneand a Pd-anodic alumina composite *** conditions wereas follows:reaction temperature 573-723 K,operating pressure 1 atm,HO/CH=3.0 （molar ratio）,methane space velocity 453 *** was shown thatthe attainable conversion of methane in membrane reactors were greater thanthat in the conventional fixed-bed reactor as a result of selective removal ofhydrogen from the reaction *** the same experimental conditions thecomposite membrane exhibited much more effective in increasing methaneconversion than the neat *** was attributed to their hydrogenpermselectivity.

关键词： In STUDY ON METHANE STEAM REFORMING IN MEMBRANE REACTORS rate

不同碳源对Na_(3)V_(2)(PO_(4))_(3)正极材料储钠性能的影响

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

新型炭材料 2021年第6期36卷 1118-1127页

作者：陈彦俊程军孙式琦王延忠郭丽中北大学先进能源材料与系统研究院材料科学与工程学院山西太原030051

具有独特三维框架结构的钠超离子导体型磷酸钒钠是非常具有前景的钠电正极材料。在本工作中,两种碳源被选择作为原材料,通过溶胶凝胶法制备了碳包覆的磷酸钒钠。深入研究了不同炭材料对晶体结构、形貌特征、动力学特性以及电化学储钠特... 详细信息

具有独特三维框架结构的钠超离子导体型磷酸钒钠是非常具有前景的钠电正极材料。在本工作中,两种碳源被选择作为原材料,通过溶胶凝胶法制备了碳包覆的磷酸钒钠。深入研究了不同炭材料对晶体结构、形貌特征、动力学特性以及电化学储钠特性的影响。结果表明柠檬酸作为碳源制备得到的磷酸钒钠,具有更大的晶胞体积和更小的粒子尺寸,导致了拓宽的离子迁移通道和缩短的离子迁移路径,进而提高动力学特性。该材料表现出优异的电化学特性,在0.1 C下可以释放112.3 mAh g^(−1)的容量。在1 C循环200圈下容量保持率接近100%。由于快速的粒子导电特性,在2 C和5 C的大倍率循环下,该材料可以释放90.0和89.1 mAh g^(−1)的初始容量,循环200圈后保持率分别为92.7%和90%。因此,这种改性的磷酸钒钠电极材料可以作为优异的正极材料应用在钠电池领域。

关键词：磷酸钒钠正极材料碳源储钠特性