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91.
Angsuman Sarkar Swapnadip De Chandan Kumar Sarkar 《International Journal of Numerical Modelling》2013,26(1):41-55
This paper presents an analytical subthreshold surface potential model of novel structures called asymmetric pocket‐implanted Double‐Halo Dual‐Material Gate (DHDMG) and Single‐Halo Dual‐Material Gate (SHDMG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET), which combines the advantages of both the channel engineering (halo) and the gate engineering techniques (dual‐material gate) to effectively suppress the short‐channel effects (SCEs). The model is derived using the pseudo‐2D analysis by applying the Gauss's law to an elementary rectangular box in the channel depletion region, considering the surface potential variation with the channel depletion layer depth. The asymmetric pocket‐implanted model takes into account the effective doping concentration of the two linear pocket profiles at the source and the drain ends. The inner fringing field capacitances are also considered in the model for accurate estimation of the subthreshold surface potential at the two ends of the MOSFET. The same model is used to find the characteristic parameters for dual‐material gate with single‐halo and double‐halo implantations. It is concluded that the DHDMG device structure exhibits better suppression of the SCEs and the threshold voltage roll‐off than a pocket‐implanted and SHDMG MOSFET after investigating the characteristics parameter improvement. In order to validate our model, the modeled expressions have been extensively compared with the simulated characteristics obtained from the 2D device simulator DESSIS. A nice agreement is achieved with a reasonable accuracy over a wide range of device parameter and bias condition. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
92.
致密油可划分为页岩油、互层或夹层型致密油和邻源型致密油3种,根据它们的地质特点和成藏机理建立成藏模型。结果认为:页岩油的成藏过程很特殊,既没有经历二次运移也没有进行初次运移,只发生原始运移:互层或夹层型致密油属于自生自储型,是初次运移的结果;邻源型致密油是一种过渡型油藏,介于初次运移与二次运移之间。是“膨胀力”驱动的结果,.基于这种认识,提出“膨胀流”驱动论,并以此为基础建立了邻源型致密油数值模型、互层或夹层型致密油的自生自储数值模型及页岩油数值计算的容积法模型。应用实例证明,该技术具有较好的应用前景.. 相似文献
93.
94.
李萍 《湖南工业大学学报》2005,19(2)
公平或不公平的问题常常受到人们的关注,但很少有人从实证的角度给出具有说服力的描述与说明.依据某国家课题的问卷统计数据对此问题进行评述.总体上说,普通中国人对不公平的感受还是比较强烈的,但也存在个体和阶层差别. 相似文献
95.
中性点不接地系统常会遇到一些电压输出不平衡的情况。若对这方面认识不足,一方面会因电压不平衡而误认为接地情况,找不到真正的问题所在,将做许多无用功;另一方面,也可能会因未能及时找到接地点及故障原因,而给设备安全稳定运行埋下隐患或引起扩大事故。结合我厂10kV系统一次单相接地故障的处理经过,就此问题进行一些分析探讨。 相似文献
97.
Kenji Morita Takashi Imakoma Morio Nishikawa Hiroshi Nozaki 《Electrical Engineering in Japan》1995,115(2):21-31
Transmission and distribution lines are sometimes struck by lightning and there is some risk of electrical puncture of suspension insulators due to high and steep lightning surge voltage. When the insulators suffer from steep lightning surge voltages, the solid insulating body of the insulators sometimes is punctured before external flashover in the air occurs. These characteristics were investigated on the insulators in the laboratory by using different steep impulse voltages. From the investigation results, both V-t characteristics of external flashover and internal puncture were obtained on the insulators. It was found that the puncture of the insulators is a matter of probability, depending on the dimensions of the insulators, steep impulse voltages and number of impulse voltage applications. Especially, the effect of number of voltage applications on puncture probability was clarified and partial damage by a small number of voltage applications was verified before complete puncture occurred. Based on the study results, an empirical equation relating to probability of puncture (P), impulse voltage (V) and number of voltage applications (N) was established. 相似文献
98.
99.
Fourier spectral method can achieve exponential accuracy both on the approximation level and for solving partial differential equations if the solutions are analytic. For a linear PDE with discontinuous solutions, Fourier spectral method will produce poor point-wise accuracy without post-processing, but still maintains exponential accuracy for all moments against analytic functions. In this note we assess the accuracy of Fourier spectral method applied to nonlinear conservation laws through a numerical case study. We have found out that the moments against analytic functions are no longer very accurate. However the numerical solution does contain accurate information which can be extracted by a Gegenbauer polynomial based post-processing.Research supported by ARO Grant DAAL03-91-G-0123 and DAAH04-94-G-0205, NSF Grant DMS-9211820, NASA Grant NAG1-1145 and contract NAS1-19480 while the first author was in residence at ICASE, NASA Langley Research Center, Hampton, Virginia 23681-0001, and AFOSR Grant 93-0090. 相似文献
100.
本文用传输线理论和数值计算分析研究了在用H_(011)圆柱型腔测介质时由于杂模干扰而引起的异常现象。提出了用该法测量介质时应注意的问题,及避免杂模干扰的方法。 相似文献