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791.
简述ATP软件国产化科研项目pcsam软件的背景。针对法国CSEE版pcsam软件存在的较多不足,提出一种新解析方法——模型驱动解析。模型驱动解析首先借助xml模型驱动思想灵活处理sam文件的解析结构和定义;其次设计按比特方式的解析函数并采用工厂方法模式架构软件以实现软件的开闭原则;最后利用多种计算机技术例如二进制文件存储数据、控制I/O次数、多数据流以及多线程等提高解析速度。采用模型驱动解析使国产pcsam软件实现了正确、快速的数据解析,论文给出基于VC6.0平台的实现方法。 相似文献
792.
在地震勘探中,尤其在浅层地震勘探、层析成像和地震波法超前探测中初至时间拾取精度直接影响勘探区域地质结构的反演结果,初至时间的自动拾取也是隧道超前地质预报地震数据处理的一个关键环节。介绍4种初至自动拾取算法--最大振幅法、能量比法、STA/LTA(长短时窗比)法和AIC(峰度赤池信息量准则)法,利用云南某隧道超前地质预报采集到的1组地震数据,对4种初至自动拾取算法进行对比分析,结果显示SLA/LTA算法拾取的初至时间更为精确,AIC法、能量比法次之。进一步利用其他隧道超前地质预报采集到的几组数据进行对比分析,获得相同结论。 相似文献
793.
对凿岩用中空六角形钎杆的断裂事故进行了分析,结果表明,断裂主要是钎杆硬度过低造成的(其表面硬度为132HV0.1)而硬度低的原因是金相组织为粗状贝氏体。 相似文献
794.
795.
IntroductionInprocesscontrol,morethan95%ofthecontrolloopsareofPIDtype[1].Themainreasonisitsrelativelysimplestructure,whichcanbeeasilyunderstoodandimplementedinpractice,andthatmanysophisticatedcontrolstrategies,suchasmodelpredictivecontrol,arebasedoni… 相似文献
796.
Ying Wang 《Maritime Policy and Management》2013,40(6):701-714
ABSTRACTThis paper investigates the factors affecting transshipment (T/S) hub port selection by a feeder port and helps shipping carriers make a decision about T/S hub port selection in a dual hub-port system. By employing established evaluation factors, a case study is conducted to weigh the priority of factors and to select an alternative T/S hub port, such as between the Shanghai and Ningbo ports from the Nanjing feeder port in the Yangtze River delta (YRD). A combined multi-criteria decision-making (MCDM) framework utilizing the analytic hierarchy process (AHP) and the consistent fuzzy preference relations (CFPR) method is employed to both reduce the number of pairwise comparisons by AHP and to obtain experts’ knowledge in the decision-making process. The result indicates that the cost, availability of hub port’s space allocation, and the connectivity between feeder port and hub port are crucial factors for T/S hub port selection by shipping carriers. In the case study, Shanghai is selected as the T/S hub port from the Nanjing feeder port. Nevertheless, Ningbo port has the advantage of cost, and if the relationship with feeder port can be improved, Ningbo port would be preferred over Shanghai as a T/S hub port for shipping carriers in a dual hub-port system. 相似文献
797.
The swarm parametes for c-C4F8/CF4 mixtures, including the density-normalized effective ionization coefficient, drift velocity and mean energy were calculated using Monte-Carlo method with the null collision technique. The overall density-reduced electric field strength could be varied between 150 and 500 Td,while the c-C4F8 content in gas mixtures is varied in the range of 0-100%. The value of the density-normalize deffective ionization coefficient shows a strong dependence on the c-C4F8 content, becoming more electronegative as the content of c-C4F8 is increased. The drift velocity of c-C4F4/CF4 mixtures is more affected by CF4. The calculated limiting field strength for c-C4F8/CF4 mixtures is higher than that of SF6/CF4. 相似文献
798.
ERTMS is the standard railway control-command and signaling system which aims to ensure railway interoperability throughout Europe while enhancing safety and competitiveness. ERTMS is composed of two main subsystems which include GSM-R, a radio system for enabling communication between the train and the traffic management center and ETCS, an automatic train protection system (ATP) to replace the existing national ATP systems. The ERTMS specifications are defined by means of standard documents which set out the requirements ensuring interoperability. These documents evolve regularly to give rise to successive versions. The ERTMS/ETCS standard defines different levels and operation modes according to various trackside and onboard setups and some operational conditions. Given the complexity and the high criticality of railway operation, verification and validation (V&V) are crucial tasks in railway application development.In this paper, after setting the background and the motivations, a mechanizable formalization of a subset of ERTMS/ETCS specifications relative to ETCS modes and transitions is developed. The present work aims to offer a readily available model for formal V&V. Using formal techniques to check SRS is highly recommended to tackle the complexity of the defined requirements and prevent specification errors. Model-checking technique, which is targeted here, offers exhaustive analysis of the system behavior based on its model and is highly automated, since it is supported by software tools. Based on the last available version of SRS specifications, a progressive process is undertaken to get a formal model which makes explicit the various modes characterized by their respective active functions, as well as the numerous combinations of conditions for switching between modes. The various steps guiding the translation of the SRS literal specifications into a formal model are explained. As will be shown through different examples, the obtained model is a convenient basis to check safety, interoperability and liveness properties. 相似文献
799.
800.
为科学管理共享停车资源,构建一种共享停车泊位的分配-定价-收益分配机制。首先,以存在多个地块的区域为对象,根据出行者对不同地块及停车时间模式的选择偏好构建停车许可证的最优分配-定价模型,其中,最优分配模型为组合拍卖竞胜标确定问题(NP困难问题)。其次,利用Benders分解原理、对偶理论及新型升价拍卖代理系统构建调优法对停车许可证进行拍卖。最后,为调动共享泊位提供者的积极性,利用沙普利值法构建基于对社会福利贡献程度的停车收益分配模型。由理论分析及数值试验可知,运用上述机制可精确实现社会福利最优状态,最小竞争均衡价格与公平的收益分配。结果表明:①相较VCG机制与Leonard机制,调优法不仅可精确求解停车许可证的最优分配-定价,而且在算法最坏时间复杂度方面拥有更高效率;②在调优法的每个步骤中,即使停车许可证的分配并非最优,通过机制所实现的收费定价依然具有防止策略性操作的重要性质;③调优法可在较少的步骤之内实现较高的社会福利;④新型升价拍卖代理系统拥有多项式型的最坏时间复杂度;⑤通过最优分配-定价机制可获得每位出行者的选择偏好,进而可计算不同泊位提供者组合条件下的社会福利,实现沙普利值法在现实应用中的可计算性。 相似文献