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排序方式: 共有7149条查询结果,搜索用时 62 毫秒
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智能交通的出现使得车辆自组织网络受到越来越多的关注。车辆自组织网络的动态拓扑结构变化非常剧烈,这对网络的吞吐率、传输速率等性能提出了很高的要求。提出1种具有握手机制协议的自适应多通道双时钟NP-CSMA随机多址接入协议。该协议首先区分2种P-CSMA协议,握手机制成功解决了隐藏的终端问题,双时钟机制减少了平均空闲时间,多通道机制增加通道数量和划分用户优先级的同时提高了系统吞吐率,自适应机制能够使系统在高负载下保持稳定吞吐率。还对该协议的传输速率进行了分析,得出该协议的传输速率相对较高的结论。通过平均周期方法推导吞吐率和传输速率的计算公式,仿真结果与理论推导一致。 相似文献
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Xing Wang Yuxin Zhang Qing Liu Zhixin Ai Yanling Zhang Yuhong Xiang Yanjiang Qiao 《International journal of molecular sciences》2016,17(3)
Endothelin-1 receptors (ETAR and ETBR) act as a pivotal regulator in the biological effects of ET-1 and represent a potential drug target for the treatment of multiple cardiovascular diseases. The purpose of the study is to discover dual ETA/ETB receptor antagonists from traditional Chinese herbs. Ligand- and structure-based virtual screening was performed to screen an in-house database of traditional Chinese herbs, followed by a series of in vitro bioassay evaluation. Aristolochic acid A (AAA) was first confirmed to be a dual ETA/ETB receptor antagonist based intracellular calcium influx assay and impedance-based assay. Dose-response curves showed that AAA can block both ETAR and ETBR with IC50 of 7.91 and 7.40 μM, respectively. Target specificity and cytotoxicity bioassay proved that AAA is a selective dual ETA/ETB receptor antagonist and has no significant cytotoxicity on HEK293/ETAR and HEK293/ETBR cells within 24 h. It is a feasible and effective approach to discover bioactive compounds from traditional Chinese herbs using in silico screening combined with in vitro bioassay evaluation. The structural characteristic of AAA for its activity was especially interpreted, which could provide valuable reference for the further structural modification of AAA. 相似文献
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《International Journal of Hydrogen Energy》2019,44(47):25277-25286
The different methods for the generation of hydrogen are well known, as well as their applications, advantages and complications for their use. Every day it is essential to replace fossil fuels, so it is necessary to improve and take advantage of the different devices that we already have. The alkaline electrolyser is one of the best options, due to the simplicity of its components and its simple assembling; it is a relatively inexpensive device for the production of hydrogen. In this article, three different alkaline electrolyser stacks are presented, ECH-001 model. The difference between them lies in the fact that the configuration of the electrode changes with the number of drill holes. This has the purpose of optimizing the maximum productivity of the oxyhydrogen gas (OH2G) with respect to input power and the performance with different operation parameters, like the number of serial plates, geometry and the distance between them. The performance curves of parallel and serial arrangements are shown. The performance of a DEKTM diesel engine (monocylinder of 406 cc) with and without OH2G was evaluated, with flows of one, two and three sL min-1. Tests for CO, CO2, HC and NOx emissions were measured using the exhaust gas analyzer and varying the engine speed. The results show that the electrolyser assembly with four holes electrodes achieved the best performance with an OH2G productivity of 2 sL min-1 when using; 7 serial plates at the anode (which is called arrangement 1, 5–10), 3 mm gap and a 5% solution of NaOH. The results also shows a 14% reduction in fuel consumption, 22% reduction in HC, 23% reduction in CO, 7% reduction in CO2 and 15.5% NOx reduction with 2 sL min-1 of OH2G all this for 2500 rpm. The obtained results show a great advantage for the use of dual combustion with the diesel-hydrogen combination. 相似文献
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卢晓丽 《网络安全技术与应用》2014,(1):10-10,12
IPv6过渡技术广泛应用在Internet上,技术发展相对成熟。为了给内部网的升级换代提供有效的参考,实现内部网的平稳过渡。本文首先对常用的双栈技术、隧道技术和协议转换技术的基本原理进行分析研究。 相似文献
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噢易机房BOSS系统提供Dos和Windows双模式操作,教学可能需要很多个不同类的操作系统,不同的系统里面安装不同的教学软件,安装第一个系统的时候从这个系统中创建多个频道,频道和真实的系统完全一样。这样的话可以减少磁盘的使用空间,方便维护与管理,可快速搭建个人私密的开放系统环境,方便学生在机房保存学习资料、完成作业或进行课程设计、毕业设计等任务。 相似文献
98.
Abstract In this study, the numerical scheme of dual reciprocity boundary element method (DRBEM) is adopted to investigate the resonant problem in a harbor while considering the effect of energy dissipation. The numerical model employed the mild slope equation as a basic equation. To avoid complicated procedures for solving the equation, DRBEM is used to improve numerical efficiency. Computation results are compared with the existing experimental data and other theoretical results. It shows that the present model is valid and effective to solve the harbor oscillation problem. 相似文献
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