201 resultados para 153-923A


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Application server provides a platform that helps users to create,deploy,execute,integrate and maintainmulti-tier enterprise applications. This paper analyzes a variety of implementation strategies of application servers,th eh gives evaluating features for J2EE application server and compares the 4 representative products.

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介绍了一种MPI程序死锁检测的静态方法以及该方法所处理的程序模型.为实现该方法,提出了比例方程组(一种特殊线性方程组)的概念并设计了求解方程组最简解的线性时空复杂度的高效算法.算法由一个四遍扫描过程与一个主控程序构成.主控程序用来处理并行计算节点计算机构成的划分.四遍扫描过程采用深度优先搜索方法确定方程组中各变元之间的比例关系.通过该算法所获得的最简解,任意多个变元之间的比例关系能在常数时间内获得.证明了该算法的正确性,并采用Java语言实现了该算法的标准程序库.该程序库目前已运行于MPI同步通信静态死锁检测的软件框架中.

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随着卫星组网技术的发展,卫星网络安全防护技术日益受到人们的关注,安全认证是其中一项关键技术。本文在建立卫星网络安全认证模型的基础上,设计了入网认证协议和端到端认证协议,并构建了安全认证仿真系统,以语音和视频业务为例对协议进行了仿真验证。本文取得的成果主要包括: (1)建立了卫星网络安全认证模型。分析了典型卫星网络的组成、特点及对安全协议设计的影响,构建了包括节点安全系统、安全通信过程和安全认证过程在内的卫星网络安全认证模型。 (2)设计了卫星网络入网认证协议。该协议主要基于散列函数和异或运算,具有计算量小的优点,能够抵抗冒充、篡改、重放等常见攻击。 (3)设计了卫星网络端到端认证协议。该协议基于ECC密码系统,能够实现节点之间的双向认证,同时还会协商出具有完全前向私密性的共享会话密钥。该协议具有较好的计算性能,适于计算资源受限的环境,能够抵抗冒充、篡改、重放、未知密钥共享等常见攻击。 (4)设计了安全认证仿真系统。对入网认证协议和端到端认证协议进行了仿真实现,建立了星间链路、上下行链路的传输信道模型、及语音和视频业务模型,实现了业务过程仿真。 (5)以语音和视频业务为例,对卫星网络安全认证协议进行了仿真验证。结果表明,部署安全认证和加密服务后,业务启动存在秒级延迟,但服务质量基本不会受到影响。

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针对退耕态势差异较大的陕西省吴起县和米脂县在3个不同退耕阶段农地资源生态服务价值进行评估的基础上,分析了两个区域各阶段农地资源生态服务价值的变化,探讨了在不同退耕态势下退耕还林(草)工程的实施对两个区域农地资源生态服务价值的影响。结果表明:退耕前后两个区域农地资源直接经济价值分别增长了11576.46万元和3754.42万元,间接生态服务价值分别增加了107946.19万元和4624.11万元。两个区域在3个不同阶段直接经济产出价值与间接生态服务价值之比分别为1∶0.84,1∶2.63,1∶3.56和1∶0.41,1∶0.65,1∶0.56。

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试验研究了不同施肥处理对小麦产量及肥料、水分利用率的影响。结果表明:氮磷配施对产量的贡献率最高,产量达5 099.8 kg/hm2,增产率达21.5%,较氮、磷肥单施产量分别增产14.0%和18.4%,具有正交互效应;单施有机肥较NM、PM、NPM增产率分别达到6.63%、4.12%、11.3%。化肥配施可显著提高旱地小麦的肥料利用率和水分利用效率,氮磷有机肥配施肥料氮、磷肥的利用率分别较氮、磷肥单施提高1.71和12.55个百分点;氮磷配施可同时提高氮肥、磷肥肥效,此时氮贡献率为15.53%,磷贡献率达12.26%,且水分利用率提高了24.1%,耗水系数降低了17.57%。

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在离心机模拟不同水吸力条件下,研究了聚丙烯酸钠(sodium polyacrylate记作SP)5种使用浓度(占干土质量0,0.01%,0.08%,0.2%与1%)对3种土壤(砂土、壤土、黏土)持水能力的影响;采用大田试验研究了地表撒施2 g/m2SP对冬小麦与下季玉米产量及WUE影响。结果表明:3种土壤在0.01 MPa至1.5 MPa水吸力下的持水能力随着SP用量的增加而增加,砂土的作用效果较壤土、黏土更显著;3种土壤适宜浓度为0.08%~0.2%,最佳用量为0.2%,此用量条件下砂土、壤土、黏土的最大毛管持水量分别较对照增加了138.61%,7.22%,62.70%;不灌水条件下,SP处理较不施用SP冬小麦增产4%,WUE增加5.7%,灌浆期灌水28.5 mm条件下SP处理较不施用SP增产1%,WUE降低1%;SP处理的玉米产量较对照降低0.5%,WUE提高3%,效果明显低于对冬小麦效果。

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Albumin, the most abundant protein components of blood plasma, is synthesized and secreted by liver cells in vertebrates. Recently, it was demonstrated that frog Bombina maxima albumin is also expressed in skin. Both B. maxima albumins from skin and serum (BmA-skin and BmAserum) have similar biochemical characteristics except that the former contains haem b. Present studies showed that BmA-skin exhibited cytotoxic activity on H9 and C8166 cells. Pretreated with hemin to induce erythroid differentiation, K562 cells lost their resistance to cytotoxicity of BmAskin. After treating cells with BmA-skin for 48 h, 50 percentage cytotoxic concentrations (CC50) of BmA-skin on H9, C8166 and hemin-treated K562 cells were 1.31±0.09, 1.59±0.08 and 2.28±0.06 μM, respectively. The cell death induced by BmA-skin was mediated by apoptosis of the tested cell lines, as demonstrated by nuclear morphological changes, DNA fragmentation and DNA hypodiploidy of apoptosis cells. At BmA-skin concentration of 2 μM, 27.3%, 19.7% and 17.8% of H9, C8166 and hemin-treated K562 cells were found to be apoptotic. In contrast, BmA-serum possessed no cytotoxic and apoptosis-inducing activity on all the cell lines tested, even with concentration used up to 15 μM. These results indicated that bound haem b in BmA-skin contributed significantly to its cytotoxic and apoptosis-inducing activity on the cell lines assayed.