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81.
介绍一种使用傅里叶全息滤波器的光电图像形态学处理系统,其中关于图像结构元的扩张,侵蚀及开和闭等基本运算于傅里叶全息光学方法产生的图像与结构元的卷积结果,其迭代过程使用了计算机控制的电寻址空间光调制器,该系统具有结构简单、能反复迭代、易于根据图像设计、更换及使用计算机制全息图产生结构元等优点。 相似文献
82.
本文基于近年来的工作,对高功率二极管泵浦固体激光器的一些关键技术问题进行了分析,提出了向更高功率水平发展可行的技术方案,并讨论了应解决的关键问题,最后展望了高功率二极管泵浦固体激光器的应用前景。 相似文献
83.
以四川省长宁县双河镇燕子村龙马溪组页岩为研究对象,采用自行研制的三轴渗流装置,开展了考虑注入压力和体积应力影响的页岩中超临界CO2渗流及增透规律实验研究。结果表明:页岩中超临界CO2渗透率随着孔隙压力增大呈现先减小后增大趋势,当孔隙压力较小时存在Klinkenberg效应;随体积应力的增大渗透率逐渐减小,曲线基本呈现负指数变化规律。开展不同增透条件下页岩中CH4渗流实验,宏观量化分析超临界CO2注入压力对于页岩增透效果的影响,可以得出随着超临界CO2注入压力的增加,CH4渗透率呈现上升趋势,但增长幅度先上升后下降,即超临界CO2注入压力为9.5MPa时增透效果最为明显。通过微观分析页岩元素含量得出超临界CO2可以萃取和溶解页岩中的O、Ca、Mg等矿物元素,有效促进页岩内部微孔隙的发育,致使页岩渗透能力增强。 相似文献
84.
To reduce the viscosity of viscous crude oil and flow resistance, the effect of a ternary compound system including organic alkali, n-alkanol, and nonionic surfactants on viscous crude oil viscosity reduction was studied. The results showed that n-alkanol effectively reduced the droplet size of an emulsion and the viscosity of viscous crude oil and improved the fluidity of viscous crude oil. Of the low-carbon n-alkanols, n-pentanol has the best viscosity-reducing effect. The organic alkali avoids the phenomenon of fouling and corrosion caused by inorganic alkali and reacts with the acidic macromolecular components in viscous crude oil to generate alkanolamides, which produce synergistic effects with nonionic surfactants and reduce the interfacial tension between oil and water. In the ternary compound of organic alkali, n-alkanol, and nonionic surfactant, the viscosity reduction effect of viscous crude oil is significantly enhanced compared with that of a single reagent. The viscosity reduction rate of viscous crude oil of the diethanolamine ternary compound system reached 98.1% and was the best choice by experimental validation. It is shown that a reasonable formula of compound system and dosage can significantly reduce the viscosity of viscous crude oil. 相似文献
85.
86.
超宽带信道建模中基于压缩感知的解卷积算法 总被引:1,自引:0,他引:1
针对频域测量方式下的超宽带(UWB)信道测量数据后处理,该文提出了用具有高斯滚降特性过渡带的类高斯窗,提取符合中国UWB频谱规范的信道测量数据,并将类高斯窗对应的时域脉冲作为先验信息,使用基于压缩感知(CS)的算法对时域信道测量信号解卷积,使得解卷积后的信道冲激响应具有高分辨率特性。利用频域加窗补零,以及改变解卷积算法中参数化波形字典原子的步长,可以得到不同分辨率的解卷积结果。采用匹配追踪(Matching Pursuit,MP)算法作为CS的重构算法。针对一间办公室的视距(LOS)与非视距(NLOS)信道测量数据处理结果表明,基于压缩感知的解卷积算法可以用较少的观测值获得和CLEAN算法相近的解卷积性能。 相似文献
87.
88.
Jingyi Qiu Long Zhao Maolin Zhai Jiangfeng Ni Henghui Zhou Jing Peng Jiuqiang Li Genshuan Wei 《Journal of power sources》2008
A poly(vinylidene difluoride) (PVDF) membrane was grafted with styrene (St) and maleic anhydride (MAn) using an electron-beam-induced pre-irradiation grafting technique. The grafted membrane (PVDF-g-PS-co-PMAn) was then sulfonated and hydrolyzed to give an ion exchange membrane (denoted as PVDF-g-PSSA-co-PMAc) for vanadium redox flow batteries (VRB) use. Micro-FTIR analysis indicated that PVDF was successfully grafted and sulfonated at the above condition, and the membrane with a high grafting yield (GY) can be easily prepared in a St/MAn binary system at low dose due to a synergistic effect. The water uptake and ion exchange capacity (IEC) of the PVDF-g-PSSA-co-PMAc membrane increased with GY, so too did the conductivity. At a GY of 33.6%, the resulting PVDF-g-PSSA-co-PMAc membrane showed a much higher IEC and conductivity than a conventional Nafion117 membrane, and a much lower permeability of vanadium ions: ca. 1/11 to 1/16 of that through Nafion117. Open circuit voltage measurements showed that the VRB assembled with the PVDF-g-PSSA-co-PMAc membrane maintained values above 1.3 V after a period of 33 h, which was much longer than that with the Nafion117 membrane. It is expected that this work provides a new approach for the fabrication of ion exchange membranes for VRB. 相似文献
89.
A solar-powered adsorption air-conditioning system was designed and installed in the green building of Shanghai Research Institute of Building Science. The system contained 150 m2 solar collectors and two adsorption chillers with nominal refrigeration capacity of 8.5 kW. Based on performance characteristics of the adsorption chiller, the operation mode of the solar-powered air-conditioning system was optimized by maintaining a phase shift of 540 s between the two adsorption chillers. Thereafter, the whole system realized stable operation by the balance of heat consumption and refrigeration output. From June to August of 2005, the solar-powered air-conditioning system continuously ran between 9:00 and 17:00. The operation performance of the system under representative working condition showed that the average refrigeration output of the solar-powered air-conditioning system was 15.3 kW during an 8 h operation and the maximum value exceeded 20 kW. Solar fraction for the system in summer was 71.7%, which corresponded to the designed cooling load (15 kW). Compared with the ambient temperature, it was deduced that solar radiant intensity had a more distinct influence on the performance of solar-powered air-conditioning system. 相似文献
90.
3G工程的启动为我国电信业的发展带来全新的、巨大的驱动力,而电信业重组后形成的失衡的竞争格局又使3G建设成为新一轮的竞争焦点。弱势运营商为抢夺市场份额、强势运营商为进一步巩固行业龙头地位,均不断加大对3G网络的投资,因此也为国内射频同轴连接器及电缆组件生产企业带来了巨大的需求市场。 相似文献