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Effects of different states of sheep fetal fibroblasts as donor cells on the early development in vitro of reconstructed sheep embryos

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Science china(Life sciences) 2007年第2期50卷 178-185页

作者： WANG Hai, AO Hong, PAN QiuZhen, LI RongQi, ZHAO MengBin, LI AN ZhengXing, LI Ning & WU ChangXin 11nstitute of Zoology, chinese academy of sciences, {2. 100080, china 2.Institute of Animal Science, chinese academy of Agricultural sciences, {2. 100094, china 3 Northeast Agricultural University, Harbin 150030, china 4{2. Glorious Land Agricultural Co., Ltd. {2. 100049, china 5 College of Animal Science and Technology, china Agricultural University, {2. 100094, china 6 State Key Laboratory of Agrobiotechnology, china Agricultural University, {2. 100094, china 1. Institute of Zoology Chinese Academy of Sciences Beijing 100080 China 5. College of Animal Science and Technology China Agricultural University Beijing 100094 China 2. Institute of Animal Science Chinese Academy of Agricultural Sciences Beijing 100094 China 3. Northeast Agricultural University Harbin 150030 China 4. beijing Glorious Land Agricultural Co. Ltd. Beijing 100049 China 6. State Key Laboratory of Agrobiotechnology China Agricultural University Beijing 100094 China

To investigate the effects of different states of donor cells on the development of reconstructed sheep embryos, we designed five treatments of donor cells, including cell passage, cell size, serum starvation, colchicine treatment and gene transfection. Results are as follows: (Ⅰ) Compared with 16-18 passage cells, the morula/blastocyst rate of 5-7 passage cells as donor nuclei was significantly higher (17.3% vs. 4.9%, P2.μm) as donor nuclei was higher than that from large cells (2.-33μm) and small cells (8-15μm)( 2..0% vs. 8.0%, 9.7%), indicating that reconstructed embryos from medium cells had a greater potentiality to develop into morula/blastocysts than those from small or large ones. (Ⅲ) The morula/blastocyst rate of reconstructed embryos from donor cells of SS (serum starvation) was lower than that from donor cells of NSS (non-serum starvation), but no significant difference was detected between SS and NSS(11.8% vs. 18.6%, P>0.05). (Ⅳ) Fetal fibroblasts treated with 0.05μmol/L colchicine exhibited a higher morula/blastocyst rate of reconstructed embryos than those treated with 0.10 μmol/L colchicine and untreated ones (2..5% vs. 12.1%, 17.1%), however, no significant difference among the three treatments was detected (P>0.05). (Ⅴ) The morula/blastocyst rate of reconstructed embryos from fetal fibroblasts transfected with GFP gene only was 3.1%, significantly lower than that from non-transgenic cells (3.1% vs. 2..4%, P<0.05). In conclusion, our results demonstrated that fetal fibroblasts of fewer passages, medium size could ensure a higher morula/blastocyst rate of reconstructed embryos. Serum starvation of donor cells might be unnecessary to the development of reconstructed embryos. Donor cells treated with 0.05μmol/L colchicine could facilitate the developmen

关键词： sheep nuclear transfer colchicine serum starvation fetal fibroblast GFP gene

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一个基于Agent的SOAP应用框架

计算机工程与应用 2004年第1期40卷 148-152页

作者：马长东徐伟李京中国科学院软件研究所软件工程技术研究开发中心北京100080

简单对象访问协议SOAP是新一代分布式计算模型Web服务的基础,然而SOAP应用的性能问题是制约其发展的主要方面。该文从SOAP消息处理与SOAP消息传输两个方面,就影响SOAP应用性能的因素进行了分析,并论述了可以改进其性能的技术方法。在此... 详细信息

简单对象访问协议SOAP是新一代分布式计算模型Web服务的基础,然而SOAP应用的性能问题是制约其发展的主要方面。该文从SOAP消息处理与SOAP消息传输两个方面,就影响SOAP应用性能的因素进行了分析,并论述了可以改进其性能的技术方法。在此基础上,该文采用Agent技术,提出了一个基于Agent的SOAP应用框架,并在面向Web服务的服务协作中间件中实现了此框架。该文的SOAP应用框架解决了SOAP应用的性能瓶颈问题,同时具有灵活的扩展机制,为基于Web的分布式计算提供了可行的实现模式。

关键词： Web服务 SOAP XML Agent

京北山区板栗林主要养分元素积累与分配的研究

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水土保持学报 2004年第3期18卷 37-40页

作者：薛智德刘世海余新晓西北农林科技大学资源环境学院陕西杨陵712100 北京林业大学水土保持学院北京100083

对北京北部山区板栗林主要养分元素积累与分配的研究结果表明:2.年生板栗林的生物量为38638kg/hm2.生物量在干、枝、叶、花、果、果苞及根中的分配比例为52.18∶2..82.3.70∶2.2.∶2.65∶2.07∶15.33。板栗林5种主要养分元素N、P、K、C... 详细信息

对北京北部山区板栗林主要养分元素积累与分配的研究结果表明:2.年生板栗林的生物量为38638kg/hm2.生物量在干、枝、叶、花、果、果苞及根中的分配比例为52.18∶2..82.3.70∶2.2.∶2.65∶2.07∶15.33。板栗林5种主要养分元素N、P、K、Ca和Mg的贮存量为315.38kg/hm2.不同器官中5种养分元素贮存量排序为干>枝>根>叶>花>果苞>果。土壤层中5种养分元素贮存总量为2.642..59kg/hm2.有效养分元素贮存量为16188.2.kg/hm2.板栗林5种养分元素贮存量占土壤层5种养分元素贮存总量的0.15%,占有效养分贮存量的1.95%。板栗林对N的富集能力最强,各元素的富集系数排序为N>P>K>Ca>Mg。板栗林生态系统每积累1t干物质需要5种养分元素总量7.17kg,其中对Ca元素的需求量最大,P的最小。

关键词：京北山区板栗林养分元素元素积累元素分配

Finite-difference modelling in two-dimensional anisotropic media using a flux-corrected transport technique

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Finite-difference modelling in two-dimensional anisotropic m...

中国科学院地质与地球物理研究所2.02.术年会

作者： D.H.Yang~a,E.Liu~b,Z.J.Zhang~c and J.W.Teng~c a.Department of Mathematics.Tsinghua University beijing 100084,china b.British Geological Survey.Murchison House.West Mains Road.Edinburgh EH9 3LA,UK. c.{2. of Geology & Geophysics.chinese academy of sciences.beijing 100101,china

The conventional finite-difference(FD) method often suffers from numerical dispersion when too few samples per wavelength are used or when models have large velocity contrast,or artefacts caused by source at grid *** this paper,we present a fast finite-difference scheme that is based on the application of vectors and matrices in 2.D anisotropic media,and obtain the stability *** method is based on a flux- corrected transport(FCT) technique, originating from hydrodynamics,which can be incorporated in the conventional finite-difference method to eliminate the numerical dispersion and source-generated *** n-times decoupled absorbing boundary condition is used in our ***-component seismograms in a transversely isotropic medium with a vertical symmetry axis(TIV) are generated for two models using the FCT finite-difference *** with the results of the reflectivity method and the conventional FD method without the FCT technique and any absorbing boundary treatments,we conclude that our FCT based FD method can is very accurate and efficient in computing synthetic seismograms in general heterogeneous and anisotropic media.

关键词： anisotropic wave propagation finite-difference method Hux-corrected transport technique synthetic seismograms

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塔东地区侏罗系生烃史

新疆石油地质 2004年第1期25卷 19-21页

作者：王飞宇李谦张水昌陈建平罗键肖中尧石油大学石油天然气成藏机理教育部重点实验室北京102200 中国石油油气地球化学重点实验室北京100083 中国石油塔里木油田分公司勘探开发研究院新疆库尔勒841000

对塔东地区10口探井110个侏罗系源岩样品进行了系统的有机质成熟度分析,其镜质体反射率(Ro)主体为0.50%～0.65%,烃源岩均处在未熟-低熟阶段。塔东地区中新生界地层镜质体反射率梯度仅0.17%/km,这一数值明显低于库车前陆盆地(约0.2.%/km... 详细信息

对塔东地区10口探井110个侏罗系源岩样品进行了系统的有机质成熟度分析,其镜质体反射率(Ro)主体为0.50%～0.65%,烃源岩均处在未熟-低熟阶段。塔东地区中新生界地层镜质体反射率梯度仅0.17%/km,这一数值明显低于库车前陆盆地(约0.2.%/km～0.2.%/km),这与塔东区新生代以来地温梯度较低有关。塔东地区现今地温梯度约为19～2.℃/km.根据华英参1井古温标重构了塔东地区古地温演化,表现为地温梯度在中新生代总体上不断降低,中生代为32.2.℃/km,新生代为2.～2.℃/km.根据探井和人工井成熟度演化史分析,塔东地区中侏罗统源岩成熟度演化呈现以下特点:在白垩纪,中侏罗统源岩均处于未成熟阶段;在早第三纪末(2.×106a),一部分中侏罗统源岩已处于临界成熟状态(Ro为0.5%～0.6%);至12.106a,大部分中侏罗统源岩仍处于临界成熟状态,但已有一小部分处于凹陷带的源岩镜质体反射率略高于0.6%;现今中侏罗统源岩大部分仍处于低成熟阶段(Ro为0.5%～0.7%)。塔东地区侏罗系有效烃源灶(Ro>0.7%)的分布有限,这是目前认为塔东地区发现的的天然气或原油并非源于侏罗系煤系源岩的根本原因。

关键词：有机质成熟度烃源岩地温梯度地层镜质体侏罗统

利用计算机技术分离从头皮记录的人脑痛诱发复合电位中的疼痛成份

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针刺研究 1981年第1期 17-23页

作者：夏琅炎赵伟峰黄坤厚戎象棣北京市中医研究所经络室中医研究院针灸经络研究所

长期以来,人们希望能对疼痛感受有一个客观指标,然而一直未能解决。人体实验性疼痛的测定,由于缺少客观测量方法而受到阻碍。自从Dawson创立了累加技术,为在人体无创伤地记录脑诱发电位提供了可能。近年来累加体感诱发反应的研究,为实

关键词：脑诱发电位反相重度轻痛疼痛零电位皮肤头皮

REPASSIVATION STUDIES ON SINGLE CRYSTAL OF 32. STAINLESS STEEL IN 3.5% MgCl_2.SOLUTION

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Science china Mathematics 1989年第10期32卷 1251-1259页

作者：李德林朱日彰张文奇 Department of Surface Science and Corrosion Enginerring Beijing University of Iron and Steel Techlonogy Beijing 100081 PRC

The repassivation behavior of the single crystal of 32. stainless steel in room temperature solution of 3.5% MgC1_2.has been studied by the rapid scratching technique under potentiostatic conditions. The process of the formation of the oxide film on the bare surface of the single crystal has been found in three steps: the formation of an adsorbed layer on fresh surface within～2.5 ms., the transformation of the adsorbed layer into an oxide film within～3 ms, and the growth of the oxide film. The kinetics of the adsorbed layer formation follows approximately the empirical rule: i(ι)=I^0exp(—at) with I^0 and a being constants. The kinetics of the oxide film growth may be expressed by i(ι)=J^0exp(—bt) with J^0 and b being constants. The rate of film growth is controlled by high-field ion conduction: i=Aexp(—BV/X). The current density up to 1100 mA/cm^2.on the bare surface has been observed.

关键词： repassivation rapid scratching bare surface adsorbed layer.

THE CATASTROPHIC CHANGE OF STEADY FLOW IN COLLAPSIBLE TUBES

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Science in china,Ser.A 1985年第6期 648-660页

作者：陶祖莱丁启明席葆树 nstitute of Mechanic Academia Sinica beijing Department of Engineering Mechanics Qinghua University

Based on a general background we have developed a mechanical model of the catastrophic change of steady flow in collapsible tubes and got the critical conditions for the catastrophic change analyzing the effects of viscosity, gravity and the longitudinal gradient of external pressure. Several simple flows have been discussed. Furthermore, we conducted three types of model experiments, Results agree with the theoretical critical conditions qualitatively.

关键词： THE CATASTROPHIC CHANGE OF STEADY FLOW IN COLLAPSIBLE TUBES As 鱼业

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我国东部浅水湖泊水生态效应特征

环境科学研究 2018年第5期31卷 878-885页

作者：张亚丽高楹吴锋霍守亮中国科学院地理科学与资源研究所北京100101 中国科学院农业政策研究中心北京100101 首都师范大学燕都学院北京100048 中国环境科学研究院北京100012

为探究我国东部浅水湖泊生态系统的时空异质性及其演替的响应指标,基于东部浅水湖泊长时间序列(1986—2.14年)的监测数据,分析了不同湖泊类型的水质和浮游植物群落分布特征,并综合运用稳态转换理论和典范对应分析方法(CCA),研究了富营... 详细信息

为探究我国东部浅水湖泊生态系统的时空异质性及其演替的响应指标,基于东部浅水湖泊长时间序列(1986—2.14年)的监测数据,分析了不同湖泊类型的水质和浮游植物群落分布特征,并综合运用稳态转换理论和典范对应分析方法(CCA),研究了富营养化湖泊浮游植物群落的演替特征以及响应因子.结果表明:(1)从水系上看,太湖水系湖泊的水质最差,ρ(TP)、ρ(TN)和ρ(Chla)最高,分别为(0.2.6±0.606)(3.563±1.430)mg/L和(14.801±10.117)μg/L,SD(透明度)为(0.486±0.2.2.m;从水文连通性上看,湖泊的水质为通江湖泊>非通江湖泊>阻隔湖泊.(2.空间分布上,湖口以下干流浮游植物密度最高,为2.674×10~7L^(-1).蓝藻门为东部浅水湖泊的优势种群,密度最高达1.897×10~7L^(-1),绿藻门和硅藻门次之,黄藻门最少,仅为3.951×10~3L^(-1).(3)东部浅水湖泊生态系统演替发生在ρ(Chla)为5.2.~10.57μg/L阈值范围内.(4)以东部典型湖泊-太湖为例,浮游植物群落分别在1997—1998年和2.00—2.01年两个时间梯度达到最大值.EC(电导率)和ρ(TN)是影响太湖浮游植物群落分布的显著因子.研究显示,随着东部浅水湖泊水质恶化,浮游植物群落结构特征发生突变,导致其生态系统发生演替,预防东部浅水湖泊生态系统演变应严控EC和ρ(TN).

关键词：浮游植物生态效应生态系统演替东部浅水湖泊