检索结果-南通市图书馆

On power allocation for a cognitive radio network with hybrid spectrum sharing

在线全文

学校读者我要写书评

暂无评论

Science china(Information sciences) 2011年第11期54卷 2425-2434页

作者： ZHANG Jing 1,2.3 & ZHU HongBo 1 1 Key laboratory of Wireless Communications of Jiangsu Province,Nanjing University of Posts & Telecommunications,Nanjing 2.0003,china 2.College of Electronic Science & Engineering,Nanjing University of Posts & Telecommunications,Nanjing 2.0003,china 3 State Key laboratory of Millimeter Waves,Nanjing 2.0096,china 1. Key laboratory of Wireless Communications of Jiangsu Province Nanjing University of Posts & Telecommunications Nanjing 210003 China2. College of Electronic Science & Engineering Nanjing University of Posts & Telecommunications Nanjing 210003 China3. State Key Laboratory of Millimeter Waves Nanjing 210096 China

In this study we propose a hybrid spectrum sharing scheme based on power control by combining Overlay with Underlay schemes,to improve radio spectrum *** the scheme,the secondary users dynamically switch their operational states between Overlay and Underlay according to the spectrum *** the dynamics of the primary network is first modeled with a discrete-state Markov process to find the time fraction of secondary users in the Overlay state and that in the Underlay state,which leads to the capacity model of the hybrid spectrum sharing *** the criterion of maximizing capacity,the power allocation of the cognitive network is researched and the optimum power allocation for secondary users is *** a result,the maximum achievable capacity of the cognitive network is *** are given to prove the analysis *** and simulated results indicate that hybrid spectrum sharing based on power control provides a higher capacity than single Overlay and Underlay systems for the cognitive network,i.e.,hybrid spectrum sharing can further improve radio spectrum efficiency.

关键词： cognitive radio network hybrid spectrum sharing primary network dynamics power allocation achievable capacity

Role of surface evaporation in surface rainfall processes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Role of surface evaporation in surface rainfall processes

DIET COMPARISONS OF THE THREE GEOGRAPHICAL POPULATIONS OF THE SICHUAN SNUB-NOSED MONKEY

“2.10年北京气象学会中青年优秀论文评选”学术研讨会

作者： Xiaopeng Cui and Xiaofan Li 1 laboratory of Cloud-Precipitation physics and Severe Storms,{2. of Atmospheric physics,chinese Academy of sciences,beijing,china. 2.Joint Center for Satellite Data Assimilation and national Oceanic and Atmospheric Administration/national Environmental Satellite,Data,and Information Service Center for Satellite Applications and Research,Camp Springs,Maryland,USA.

The roles of surface evaporation in tropical surface rainfall processes in rainfall regions(raining stratiform and convective regions) and rainfall-free regions(nonraining stratiform and clear-sky regions) are investigated on the basis of the data from a series of two-dimensional cloud-resolving *** model is integrated for 2. days with imposed zonally uniform vertical velocity,zonal wind,horizontal temperature,and vapor advection,as well as sea surface temperature from the Tropical Ocean-Global Atmosphere Coupled Ocean-Atmosphere Response Experiment(TOGA COARE).The model is also integrated to equilibrium states for 40 days with imposed zero vertical velocity,constant zonal wind,and sea surface temperatures of 31℃and 2.℃for two separate *** time- and zonal-mean surface evaporation mainly comes from rainfall-free regions,where the surface evaporation is largely balanced by the vapor divergence associated with the *** rainfall regions the vapor convergence determines the convective rainfall while the surface evaporation plays a negligible role. Thus surface evaporation pumps water vapor into rainfall-free regions,and the divergence transports the vapor from rainfall-free regions to rainfall regions,which supports the *** forcing and sea surface temperature do not change the role of surface evaporation in rainfall processes.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

DIET COMPARISONS OF THE THREE GEOGRAPHICAL POPULATIONS OF TH...

Purification and Characterization of Two Endo-β-1,4-glucanases from Mollusca,Ampullaria crossean

灵长类资源的保护与利用——中国扶绥国际灵长类研讨会

作者： Ren Baoping~1 Li Baoguo~2.Li Ming~1 Wei Fuwen~1 ~1Key laboratory of Animal Ecology and Conservation Biology institute of Zoology {2. Academy of sciences 100080 beijing china ~2.ollege of Life sciences Northwest University 710069 Xi’an china

＜正＞Diets from the three geographical groups of Rhinopithecus roxellana live in Shaaxi. Sichuan and Gansu,and Hubei provinces were *** results showed that 13. plant species,belonged to 37 families,were eaten by this... 详细信息

关键词： Rhinopithecus roxellana Geographical groups Dietary comparison

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2005年第10期37卷 702-708页

作者： Yan-Hong LI~(1#) Rui GUO~(3#) Qiu-Yu YIN~1 Ming DING~1 Si-Liang ZHANG~3 Gen-Jun XU~(1,2. Fu-Kun ZHAO~(1,2.) 1 Key laboratory of Proteomics,institute of Biochemistry and Cell Biology,Shanghai institutes for Biological sciences.Graduate School of the chinese Academy of sciences,chinese Academy of sciences,Shanghai 2.0031,china 2.College of Life Science,Zhejiang Sci-Tech University,Hangzhou 310018,china 3 Bioengineering institute,East china University of Science and Technology,Shanghai 2.02.3,china KeylaboratoryofProteomics InstituteofBiochemistryandCellBiologyShanghaiInstitutesforBiologicalSciencesGrad

Two novel endo-β-1,4-glucanases,EG45 and EG2.,were isolated from the gastric juice ofmollusca,Ampullaria crossean,by anion exchange,hydrophobic interaction,gel filtration and a secondround of anion exchange *** purified proteins EG45 and EG2. appeared as a single bandon sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 2. kDa,*** optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for *** optimumtemperature range for EG2. was broad,between 50℃ and 60℃;for EG45 it was 50℃.The analysis on thestability of these two endo-β-1,4-glucanases showed that EG2. was acceptably stable at pH 3.0-11.0 evenwhen the incubation time was prolonged to 2. h at 30℃,whereas EG45 remained relatively stable at *** 85% of the activity of EG2. could be retained upon incubation at 60℃ for 2. ***,less than 10% residual activity of EG45 was detected at 50℃.Among different kinds of substrates,bothenzymes showed a high preference for carboxymethyl ***45,in particular,showed a carboxymethylcellulose hydrolytic activity of 146.5 IU/mg *** enzymes showed low activities to xylan (from oatspelt) and Sigmacell 101,and they were inactive to p-nitrophenyl-β-D-cellobioside,salicin and starch.

关键词： cellulase endo-β-1,4-glucanase Ampullaria crossean purification substrate specificity

A General Algorithm of Rotating/tilting Positioner Inverse Kinematics for Robotic Arc Welding Off-line Programming

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第1期17卷 161-162页

作者： Jinsong TIAN Lin WU Ming DAI and Yu KONG national Key laboratory of Advanced Welding Production Technology, Harbin {2. of Technology, Harbin 150001, china Harbin Inst Technol Natl Key Lab Adv Welding Prod Technol Harbin 150001 Peoples R China

Off-line programming provides an essential link between CAD and CAM, whose development should result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is a major application area, where manual programming is a very tedious job. Off-line programming is a constructive way to solve the problem. The inverse kinematics algorithm of robot and positioner is the foundation of the off-line programming system. Although previously there were some researchers who studied the positioner inverse kinematics algorithm, they only focused on a special solution of the positioner inverse kinematics, which is the solution at down-hand welding position. However, in welding production, welding position other than down-hand position is also needed. A method for representing welding position was introduced. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented.

关键词： inverse kinematics welding position robotic arc welding

Endogenous leptin fluctuates in hepatic ischemia/reperfusion injury and represents a potential therapeutic target

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第43期16卷 5424-5434页

作者： Ji Lin, Guang-Tao Yan, Hui Xue, Xiu-Hua Hao, Lu-Huan Wang, Research laboratory of Biochemistry, Basic Medical institute, {2. PLA General Hospital, 2. Fuxing Road, beijing 100853, china Xiao-Ning Gao, Department of Hematology, Clinical Division of Internal Medicine, {2. PLA General Hospital, 2. Fuxing Road, beijing 100853, china Research laboratory of Biochemistry Basic Medical Institute Chinese PLA General Hospital 28 Fuxing Road Beijing 100853 China. yan301@***

AIM: To evaluate the role of leptin in the internal disorders during hepatic ischemia/reperfusion injury. METHODS: A rat model of 70% hepatic ischemia/reperfusion injury was established, with groups of shamoperation (Sham), 60 min ischemia/60 min reperfusion (I60'R60'), I60'R150', I60'R2.0' and I60'R360'. Serum leptin was detected by a self-produced radioimmunoassay; serum glucose, total anti-oxidation capacity, myeloperoxidase, alanine transaminase and diamine oxidase were determined by relevant kits, while histologicalalterations and protein levels of leptin in the lung, liver and duodenum were examined by hematoxylin-eosin staining and immunohistochemistry. Spearman's rank correlation between leptin and other variables or grading of tissue impairment were analyzed simultaneously. RESULTS: Serum leptin in I60'R360' was significantly higher than in Sham and I60'R2.0' groups (both P 2.0' and I60'R360' were higher than in Sham (both P 2.0' and I60'R360' were lower than in I60'R150'group (both P 2.0'; the levels in the liver in I60'R60' and I60'R2.0' were higher than in the Sham group (both P 2.0' and I60'R360' were lower than in I60'R60' (both P < 0.01); the levels in

关键词： Leptin Reperfusion injury Liver Lung Duodenum Recovery of function

Development and characterization of a cell line from the embryos of half smooth tongue sole (Cynoglossus semilaevis)

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

Acta Oceanologica Sinica 2010年第2期29卷 81-87页

作者： SHA Zhenxia REN Guocheng WANG Xianli WANG Na CHEN Songlin Key laboratory of Sustainable Development of Marine Fisheries Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fisheries Sciences Qingdao 266071 China College of Biology Shandong Normal University Jinan 250014 China College of Marine Life Ocean University of China Qingdao 266003 China

A new cell line, CSEC, has been successfully established from embryos at gastrula stage of a cultured marine fish, half smooth tongue sole （Cynoglossus sernilaevis）. CSEC cells grow actively and stably more than 50 passages for over 2.0 d in DMEM medium supplemented with 15% FBS （fetal bovine serum）, 2.5 ng/cm^3 bFGF （basic fibroblast growth factor）, 1 ng/cm^3 LIF （leukemia inhibitory factor） and 50 mmol/dm^3 2.ME （2.mecaptoethanol）. The cells grew well in the temperature range of 2.-30 ℃ and the optimal growth temperature was 2. ℃. FBS and bFGF concentrations are the two key components for CSEC cells proliferation. Chromosome analysis reveals that CSEC cells have a normal diploid karyotype with 2.=42.. The significant fluorescent signals were observed in CSEC after transfection with the GFP reporter gene, suggesting that the CSEC cell line can be used as a useful tool for transgenic and genetic manipulation studies. CSEC cells showed the cytopathic effect （CPE） after infection with lymphosystis disease virus （LCDV） in 2.d. Moreover, the LCDV particles can be observed in the cytoplasm of virus-infected cells by electron microscopy. It suggests that CSEC could be potentially used for the study of aquatic virus.

关键词： embryonic cell line half smooth tongue sole karyotype GFP LCDV CSEC

Crystal and Molecular Structure of Quinide

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Structural Chemistry 1996年第5期15卷 400-403页

作者： WANG Gang-Li ZHAO Shu-Jie CHEN De-Chang(national institute for the Control of Pharmaceutical and Biological Product, {2., 100050)LU Yang WU Nan ZHENG Qi-Tai(institute of Material Medical,the chinese Academy of Medical sciences, {2., 100050) Natl. Inst. Contr. Pharmaceut./B.P. Beijing 100050 institute of Material Medical Chinese Academy of Medical Sciences Beijing 100050

A pure title compound was isolated from water soluble extraction of the fruits of Gardenia sootepensis Hutch.,and its crystal structure was determined by X-ray diffraction. The crystal, chemical formula C_7H_(10)O_5 and Mr 174. 15, is colorless,transparent and belongs to monoclinic system, space group P2.1. The crystal data are as follows:a=6.467(4), b=18.349(4), c=7. 041(4), β= 116. 2. (5)°,V=749.7(6), Z=4,Dx=1.543 g/cm￣3,F(000)=368,μ=0.08 mm-1,λ(MoKα) =0. 7106,R=0.063. It is weak hydrobonds that result in slight conformation difference between the intermolecular H-bond associated molecules.

关键词： gardenia sootepensis quinide crystal structure

SHRIMP U-Pb zircon geochronology and its implications on the Xilin Gol Complex,Inner Mongolia,china

在线全文

学校读者我要写书评

暂无评论

SHRIMP U-Pb zircon geochronology and its implications on the...