OALib Journal期刊

ISSN: 2333-9721



匹配条件: “<br>张旭杰” ,找到相关结果约262501条。
Image-Processing System Based on TMS320C80

Zhang Xudong,Guan Hongjie,Wang Desheng,<br>张旭,关鸿
中国图象图形学报 , 1997,
Abstract: 概述了TMS320C80MVP并行处理器的系统结构与主要特点,介绍了TMS320C80软件开发板SDB的主要功能单元,最后给出了基于TMS320C80的图象处理产品的列表。
Effect of agitation on hyaluronic acid produced by Streptococcus zooepidemicus by using computational fluid dynamics

Xiaohua Gu,Xujie Duan,Wensong Tan,Xu Zhang,<br>顾小华,段须,谭文松,张旭
生物工程学报 , 2009,
Abstract: Agitation plays an important role in the hyaluronic acid(HA) fermentation process.However,views about the effect of agitation on HA production remain controversial.We investigated the effect of agitation on cell growth and HA synthesis during HA fermentation process by using Computational Fluid Dynamics(CFD) technology.The results showed that the biomass and HA yield changed a little with the increase of impeller speed,but the HA molecular weight firstly increased and then decreased.The results of phase agi...
一类奇异非线性两点边值问题的 Galerkin 解的误差估计

Zhang Xu,<br>张旭
计算数学 , 2010,
Abstract: This paper is concerned with the application of the symmetric Galerkin method to the numerical solution of a kind of singular boundary value problems in one space. With the aid of Green function, we derive the desired error estimates in the maximum norm for the linear problem. Furthermore, we extend these results to the nonlinear problem. Finally, we present some numerical results which illustrate and support our theoretical results.
A suggestion on the estimation method of population sizes of Niviventer confucianus in Land-bridge island

ZHANG Xu,BAO Yixin,LIU Jun,LIN Jiejun,SHEN Liangliang,WANG Yanni,<br>张旭,鲍毅新,刘军,,沈良良,王艳妮
生态学报 , 2012,
Abstract: We live-trapped two Niviventer confucianus populations from March to November of 2010 in Thousand Island Lake region using the capture-mark-recapture (CMR) method. We used Jolly-Seber method, modified Lincoln index method, Schnabel method and minimum number of animals alive (MNA) method to estimate population sizes of Niviventer confucianus, and discussed the applicability of these estimators in white-bellied rats on land-bridge island. Our results showed that there was no significant difference between Jolly-Seber method and modified Lincoln index method. We considered that modified Lincoln index method was more suitable for estimating the population quantity of Niviventer confucianus in the land-bridge island. The study can provide basic data for the future study of population ecology of rodent in the land-bridge island.
Population genetics of Niviventer confucianus and its relationships with habitat area in Thousand Island Lake region

LIU Jun,BAO Yixin,ZHANG Xu,LIN Jiejun,YE Bin,WANG Yanni,<br>刘军,鲍毅新,张旭,,叶彬,王艳妮
生态学报 , 2012,
Abstract: Island is a special kind of fence for rodent populations on islands. Island rodents may face increased risk of inbreeding and population decline due to isolation among islands and mainland. We investigated the population genetics of Chinese white-bellied rat (Niviventer confucianus) populations on 13 islands in the Thousand Island Lake region in 2008. These islands included 8 small (Chawuling S Island, CS; Zhongdao Island, ZD; Dengta Island, DT; Wushi S Island, WS; Qiaowuping Island, Q; Chawuling F Island, CF; Lanwang Island, LW; Zhusiwu Island, Z) and 5 large islands (Jieshou Island, JS; Dafanlong Island, D; Gaoxiange Island, G; Wushi T Island, WT; Dongmen Island, DM). Of them, JS was the largest one. One hundred ninety two individuals were captured, and the muscle samples were used to extract the genomic DNA. Thirteen microsatellite markers were selected to analyze the population genetics. Five to ten microsatellite loci deviated from Hardy-Weinberg equilibrium (HWE) significantly in the four populations on the small islands (DT, Q, CF, Z), but no significant deviations from HWE were found at any locus on the large islands. Our results showed that the mean numbers of observed alleles (Na) and effective alleles (Ne) were 7.385 and 5.952, respectively. Mean expected heterozygosity (He) and observed heterozygosity (Ho) were 0.819 and 0.930, respectively. Mean polymorphic information content (PIC) was 0.760, and mean Shannon's Information index (I) was 1.780. Based on these results, we concluded that the white-bellied rat populations on 13 islands had a high genetic diversity. The F-statistic (Fst) value of the 13 populations was 0.053; thus, mild genetic differentiation was found among these populations. Additionally, the Fst values among 3 populations on larger islands (G, WT and DM) were less than 0.05, and we considered that there was little genetic differentiation among the populations on 3 larger islands. However, the genetic differentiation of white-bellied rat populations between smaller and larger islands was conspicuous. We also detected relationships between genetic diversity and island area. Significantly positive correlations were found between PIC and island area (P = 0.023), as well as between I and island area (P = 0.009). Therefore, rat populations on the larger islands had higher genetic diversity, but relatively lower genetic diversity on the smaller islands. Furthermore, the level of genetic differentiation between populations on the small and large islands presented some difference to some extent. We considered that the reduction of habitat area might result in not only variation in genetic component during the evolutionary process, but also the rapid evolution of animal populations. That is, rodent populations with different habitat areas might face different survival pressures. For instance, populations on small islands might be subjected to increased mortality and high turnover of individuals, and thus experienced more varia
Quantitative analysis on the influences of the precursor and annealing temperature on Nd2O3 film composition

Zhang Xu-Jie,Liu Hong-Xia,Fan Xiao-Jiao,Fan Ji-Bin,<br>张旭,刘红侠,范小娇,樊继斌
物理学报 , 2013,
Abstract: 采用Nd(thd)3和O3作为反应前驱体, 利用先进的原子层淀积方法在P型硅(100)衬底上制备了超薄Nd2O3介质膜, 并在N2气氛下进行了退火处理. 采用X射线光电子能谱仪对薄膜样品组分进行分析. 研究结果表明, 淀积过程中将前驱体温度从175 ℃提高到185 ℃后, 薄膜的质量得到提高, O/Nd 原子比达到1.82, 更接近理想的化学计量比, 介电常数也从6.85升高到10.32.
Oat-agar culture and rDNA-ITS sequence analyses of the plasmodium of Physarum melleum in Myxomycetes

PAN Jing-Zhi,ZHANG Xu,LIU Fu-Jie,WANG Qi,LI Yu,<br>潘景芝,张旭,刘福,王琦,李玉
菌物学报 , 2010,
Abstract: Plasmodium of Physarum melleum in myxomycetes was cultured in oat-agar medium, and rDNA-ITS from the plasmodia was amplified and sequenced. The culture condition of the plasmodia was described. DNA preparation method and PCR amplification conditions from the plasmodia were provided. The molecular phylogenetic relationships among P. melleum and related species were analyzed based on rDNA-ITS sequences using Neighbor-joining method.
公路交通科技 , 1996,
Abstract: 针对交通量分配中的路阻函数问题,把行驶时间、行驶费用和交通量等综合在一起建立了路阻函数模型,在具有OD调查数据的基础上,应用最大似然估计法标定了路阻函数,并通过简单的例子说明了该方法的可行性。
力学进展 , 2010, DOI: 10.6052/1000-0992-2010-5-lxjzJ2009-023
Abstract: CO2地质埋存是温室气体资源化利用及减少大气温室气体排放量的有效途径之一,埋存后CO2的逃逸会引起地表的隆起或凹陷、污染水源、破坏海洋生态系统、加剧温室气体效应等。本文重点对CO2埋存问题以及埋存后逃逸问题的研究现状作综述。重点阐述了CO2埋存后的逃逸方式以及重要的控制参数。通过分析,认为进一步需要研究的问题有在CO2逃逸方面除要考虑扩散、渗流效应外,还要考虑井口分布的影响、高气压引起的劈裂导致的渗透性急剧增加的效应等因素的影响。
兵工学报 , 2012,
Abstract: ?针对固体火箭发动机在舰船运动影响下损伤难以评估的问题,以某固体火箭发动机为例,建立了摇摆载荷作用下发动机药柱粘接界面的疲劳损伤评估方法。通过推进剂粘接界面定应力往复剪切试验获得了其粘接界面的疲劳损伤特性;利用有限元分析方法计算得到了发动机界面剪切应力较大部位的应力谱;运用雨流计数法和Miner线性累积损伤原理对发动机粘接界面的疲劳损伤进行了评估。试验与仿真结果表明,推进剂粘接界面应力幅值和疲劳破坏次数的自然对数满足指数型方程,并且在给定舰载条件下发动机海上战备值班一年的寿命比仓库贮存时至少降低8.62%.针对固体火箭发动机在舰船运动影响下损伤难以评估的问题,以某固体火箭发动机为例,建立了摇摆载荷作用下发动机药柱粘接界面的疲劳损伤评估方法。通过推进剂粘接界面定应力往复剪切试验获得了其粘接界面的疲劳损伤特性;利用有限元分析方法计算得到了发动机界面剪切应力较大部位的应力谱;运用雨流计数法和Miner线性累积损伤原理对发动机粘接界面的疲劳损伤进行了评估。试验与仿真结果表明,推进剂粘接界面应力幅值和疲劳破坏次数的自然对数满足指数型方程,并且在给定舰载条件下发动机海上战备值班一年的寿命比仓库贮存时至少降低8.62%.

Copyright © 2008-2017 Open Access Library. All rights reserved.