29 research outputs found

    基于LabVIEW的电滞回线测试系统的开发

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    测量铁电材料的电滞回线是确定铁电参数、检验材料性能好坏的一个重要手段,目前采用的主要测量手段是示波器法。但是,这种传统的方法无法在测量的过程中对误差进行修正、对数据进行处理和分析。为了克服这种不足,研究和开发了一种基于美国N I公司最新推出的L abV IEW 7.1Express虚拟仪器开发平台的电滞回线测试系统,通过介绍该系统的数据接口、数据处理、数据库链接以及多种语言联合作业的方法,提出了一种新的电滞回线测量方案,并获得了初步的实验结果

    透皮促进剂对白花前胡甲素体外经皮渗透的影响

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    目的:考察透皮促进剂对白花前胡甲素(dl-praeruptorin A,Pd-Ia)体外经皮渗透的影响。方法:采用改进的Franz扩散池,以大鼠离体皮肤为渗透屏障,用高效液相色谱法对Pd-Ia进行含量测定,考察月桂氮酮(Azone)及1%Azone与不同浓度丙二醇(PG)混合物对Pd-Ia透皮吸收的影响。结果:使用Azone对Pd-Ia有促透作用,1%Azone效果较好,平均渗透速率达到4.064μg.cm-2.h-1;1%Azone与15%PG合用促透效果最好,平均渗透速率达到4.889μg.cm-2.h-1,且与单用1%Azone有显著性差异(P<0.05)。结论:1%Azone与15%PG合用时,含0.5%Pd-Ia溶液体外渗透具有最大促透效果,体现出协同作用

    分子筛修饰电极中内电子传输机理的研究

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    【中文摘要】用电化学方法聚合分子筛孔道内的苯胺 , 以聚苯胺分子筛修饰电极为模型研究分子筛修饰电极的内电子传输机理 . NaY分子筛的离子交换点位被苯胺修饰后 , 通过电聚合制得聚苯胺分子筛修饰电极 ( Pan+Y-ZM E ),该电极通过聚苯胺链自身的电子跳跃来实现电子传输 , 且只有通过阴极富集后对溶液中Cd 2+才有响应 ,并能用于测定抗坏血酸。【Abstract】This paper is concerned with the mechanism of intrazeolite electron transfer in zeolite-modified electrodes (ZMEs) where the zeolite have been modified with polyaniline, First, data were obtained from ZMEs prepared with zeolite-Y loading aniline and the electropolymerizing of anilines was performed by cyclic voltammery, Polyaniline might not leak out from zeolite due to the bulk size of polyaniline being bigger than the channel of zeolite-Y. At the absence of electron transfer mediators, the Pan(+)Y-ZME showed the expected presence of electron hopping of adjacent polyaniline cations, Second, the data were obtained for the determining Cd2+ and ascorbic acid using Pan+Y-ZME. The Cd2+ might not be preconcentrated at open circuit and could be done at constant potential. At the absence of ion exchange between zeolite and surrounding electrolyte the electron transfer was performed via the electron hopping, i. e. by an intrazeolite mechanism; rather than by an extrazeolite mechanism. In addition, the ascorbic acid molecule and its anion could not cross zeolite film to base electrode therefore, its current was conducted also by the electron hopping between the chains of polyaniline, Experimental results indicate that the electron transfer of Pan(+)Y-ZME was dominated by intrazeolite processes

    社会系统工程与国家治理体系现代化

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    2014年3月30日,中国人民大学国家发展与战略研究院社会系统工程研究中心成立暨“社会系统工程与国家治理体系现代化“学术研讨会在中国人民大学逸夫会堂第一会议室举行,来自十余所高校和学术团体的专家、学者和一些媒体的代表参加了会议。现把会议主要发言内容选载如下

    An Efficient Approachto Defend DoS Attack Against Mapping Cache Under Identifier-Based Universal Network

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    为了抵御一体化标识网络中接人路由器可能遭受的映射缓存DoS攻击,本文提出了一种基于双门限机制的映射缓存DoS攻击防范方法.该方法设计了一种基于迭代思想的谜题机制降低映射缓存中映射信息条目的增加速率,并采用了映射信息可信度算法识别和过滤映射缓存中恶意的映射信息条目.仿真实验与性能分析表明,该方法能够有效地抵御映射缓存DoS攻击,防止映射缓存溢出

    Influence of winding pattern on failure of filament wound composite pipe under axial tension

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    采用细观刚度模型的有限元分析(fEA)与改进的逐渐累积损伤方法相结合,建立了缠绕复合材料圆管轴向拉伸失效的分析方法与流程,以揭示缠绕线型对缠绕复合材料损伤失效的影响。对沿圆周方向分布有1个、3个和5个单胞的3种不同线型的缠绕复合材料圆管试件进行轴向拉伸破坏实验,获得其失效形式、平均拉伸强度及其随缠绕线型的变化规律。研究表明:缠绕复合材料圆管轴向拉伸失效主要以丧失承载能力的功能失效为主,缠绕线型对其拉伸强度有一定的影响;数值分析结果表明,轴向拉伸过程中,主要损伤为基体开裂与基纤剪切,纤维交叉容易引起损伤起始与扩展。The analytical procedure of filament wound composite pipe under axial tension was built up with finite element analysis(FEA),which adopted micro stiffness model and improved progressing damage method for displaying the influence of filament winding pattern on propagation of damage in filament wound composite and its failure.The axial tensile experiments were performed for three kinds of winding pattern such as one,three and five represent volume element along the circumferential direction of filament wound composite pipe and failure model,average tensile strength and regulation of strength with winding pattern were obtained.The experiments show that the tensile failure of filament wound composite pipe under axial tension is mainly function failure with loss of bearing capacity.Winding pattern has some effect on the tensile strength of filament wound composite.The numerical simulation demonstrates that main damage are matrix crack and fiber/matrix debonding and fiber crossing can result in damage initiation and propagation more easily in the process of axial tension.高等学校博士学科点专项科研基金(20120121110026

    姜黄素对小鼠腹水型肝癌高淋巴道转移细胞株(HCa—F)生物学行为的影响

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    目的 研究姜黄索对小鼠腹水型肝癌高淋巴道转移细胞株(HCa—F)生长和转移行为的影响。方法 体外实验中用15~250μmol/L姜黄素分别处理HCa—F细胞48h,以MTT法检测HCa—F细胞的生长活性;以生长曲线评估姜黄素对细胞增殖的影响;以流式细胞仪检测姜黄素对细胞周期分布的影响。体内实验中,于615小鼠腹腔、足垫接种HCa—F细胞,通过ip给药的方法,观察姜黄素对腹腔接种HCa—F细胞的615小鼠生存率的影响和对HCa—F细胞在615小鼠淋巴道转移的影响。结果 姜黄素可抑制HCa—F细胞的生长,对HCa—F细胞生长抑制率为7.23%~82.23%,呈剂量依赖性,IC50为51.48μmol/L。以非细胞毒性最大剂量15μmol/L姜黄素作用48h后,HCa—F细胞的群体倍增时间增加,生长速度受到抑制,细胞周期被重新分布,阻滞于S期。姜黄素ip给药50mg/kg抑制小鼠腹水瘤的生长,延长荷瘤小鼠的生存期,使瘤细胞淋巴道转移率从70%下降到40%。结论 姜黄素可抑制小鼠腹水型肝癌高淋巴道转移细胞株(HCa—F)的增殖与转移

    analysis of timing constraints in workflow based on event-condition-action (eca) rules

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    本文着重研究了工作流中各活动间的定量时序关系,提出了一种分析工作流中时间约束的方法。该方法针对基于ECA规则的工作流,通过建立及分析工作流的约束图,对工作流中活动间定量时序约束的一致性进行了分析,从而保证了工作流的正常运行

    姜黄素对小鼠腹水型肝癌高淋巴道转移细胞株(HCa—F)生物学行为的影响

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    目的 研究姜黄索对小鼠腹水型肝癌高淋巴道转移细胞株(HCa—F)生长和转移行为的影响。方法 体外实验中用15~250μmol/L姜黄素分别处理HCa—F细胞48h,以MTT法检测HCa—F细胞的生长活性;以生长曲线评估姜黄素对细胞增殖的影响;以流式细胞仪检测姜黄素对细胞周期分布的影响。体内实验中,于615小鼠腹腔、足垫接种HCa—F细胞,通过ip给药的方法,观察姜黄素对腹腔接种HCa—F细胞的615小鼠生存率的影响和对HCa—F细胞在615小鼠淋巴道转移的影响。结果 姜黄素可抑制HCa—F细胞的生长,对HCa—F细胞生长抑制率为7.23%~82.23%,呈剂量依赖性,IC50为51.48μmol/L。以非细胞毒性最大剂量15μmol/L姜黄素作用48h后,HCa—F细胞的群体倍增时间增加,生长速度受到抑制,细胞周期被重新分布,阻滞于S期。姜黄素ip给药50mg/kg抑制小鼠腹水瘤的生长,延长荷瘤小鼠的生存期,使瘤细胞淋巴道转移率从70%下降到40%。结论 姜黄素可抑制小鼠腹水型肝癌高淋巴道转移细胞株(HCa—F)的增殖与转移
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