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81.
Participants (N = 216) were administered a differential implicit learning task during which they were trained and tested on 3 maximally distinct 2nd-order visuomotor sequences, with sequence color serving as discriminative stimulus. During training, 1 sequence each was followed by an emotional face, a neutral face, and no face, using backward masking. Emotion (joy, surprise, anger), face gender, and exposure duration (12 ms, 209 ms) were varied between participants; implicit motives were assessed with a picture-story exercise. For power-motivated individuals, low-dominance facial expressions enhanced and high-dominance expressions impaired learning. For affiliation-motivated individuals, learning was impaired in the context of hostile faces. These findings did not depend on explicit learning of fixed sequences or on awareness of sequence-face contingencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
82.
介绍了关于含有B、Ti、Sr等合金及复合盐对抗磨白口铸铁变质效果的研究情况。并通过实验结果表明,采用复合盐类变质处理可以改善高铬铸铁的碳化物形貌,同时大大提高了冲击韧性。  相似文献   
83.
Laser surface alloying of Mo, WC and Mo–WC powders on the surface of Ti6Al4V alloys using a 2 kW Nd-YAG laser was performed. The dilution effect upon the microstructure, microhardness and wear resistance of the surface metal matrix composite (MMC) coating was investigated. With a constant thickness of pre-placed powder, the dilution levels of the alloyed layers were found to increase with the incident laser power. The fabricated surface MMC layer was metallurgically bonded to the Ti6Al4V substrate. The microhardness of the fabricated surface layer was found to be inversely proportional to the dilution level. The EDAX and XRD spectra results show that new intermetallic compounds and alloy phases were formed in the MMC layer. With the existence of Mo content in the pre-placed powder, the β-phase of Ti in the MMC coating can be retained at the quenching process. With increasing weight percentage content of WC particles in the Mo–WC pre-pasted powder, the microhardness and sliding wear resistance of the laser surface coating were increased by 87% and 150 times, respectively, as compared with the Ti6Al4V alloy. The surface friction of the laser-fabricated MMC coatings was also decreased as compared with the worn Ti6Al4V substrate.  相似文献   
84.
A frontside-release etch-diffusion process has been developed to create released single-crystalline Si microstructures without the need for wafer bonding. This frontside-release process is simple and requires only a single mask. A deep dry etch in an electron cyclotron resonance source is used to define the structures, followed by a short boron diffusion to convert them to p++ Si. A short etch in ethylenediamine pyrocatechol (EDP) is then used to undercut and release the structures from the frontside of the Si wafer. The structures are isolated from the substrate using a reverse-biased p++/n junction. Since the structures have a high aspect ratio, beams longer than 1 mm can be released without sticking to the substrate, and thick resonators are flat with no bending due to stresses. Resonant microstructures with thicknesses ranging from 10 to 55 μm thick have been fabricated using this process and their resonant frequency has been measured. For typical clamped-clamped beam resonators that were 24 μm thick, 5 μm wide, and 400 μm long, with 2-μm comb gaps, a resonant frequency of 90.6 kHz and a quality factor of 362 were measured in air  相似文献   
85.
A novel principle “electret” microphone, i.e., floating electrode electret microphone, is proposed and implemented in this study. Single-chip fabrication and corrugation technique are used in the design and fabrication of the microphone. The floating electrode is encapsulated by highly insulated materials to ensure that there is no electric-leakage passage between the floating electrode and the electrodes of the microphone. Net-free electronic charges (not “bonded” charges as in traditional electret) in the floating electrode can excite the electric field, which is similar to that of the traditional electret. The floating electrode can be easily charged by use of the “hot” electron technique, available using the avalanche breakdown of the p+-n junction. Therefore, the electret microphone is rechargeable, which can greatly increase the lifetime of the device. The preamplifier has been on-chip integrated in a junction-field-effect transistor (JFET) source-follower type with resistors by use of ion implantation. Electret charges are banded in a deep potential trap, thus, this microphone can operate at a high temperature (as high as 300°C) and has high stability and reliability. Experiments show that the prototype has a 3-mV/Pa sensitivity and a larger than 21-kHz frequency bandwidth in a 1 mm ×1-mm diaphragm area. Microphone performance can be further improved by optimized process and design. The fabrication is completely integrated-circuit (IC) compatible, hence, the microphone shows promise in integrated acoustic systems  相似文献   
86.
一种智能加速度传感器的设计与实现   总被引:1,自引:0,他引:1  
针对目前加速度传感器智能化程度较低的现状,详细介绍了一种智能加速度传感器的信号调理、串行接口等硬件电路设计和软件实现方案,并采用系统自检和数字滤波技术以增强系统的抗干扰性。试验结果证明,该传感器性能稳定,灵敏度可达到0.28mV/g,具有测量精度高、价格较低、灵活可靠的特点,克服了传统加速度传感器测量精度低、元器件精度要求较高、测试系统复杂昂贵、应用范围具有局限性的缺陷,大大提高了加速度测量的自动化水平,具有重要的应用价值。  相似文献   
87.
Capturing the appearance of objects under different lighting conditions is useful in texture acquisition, bidirectional reflectance distribution function (BRDF) measurement, and image-based data acquisition. With the acquired data, we can render virtual objects realistically. During the data capture, we must record both the radiance and the light vector. Measuring the light vector is not necessarily easy. We propose a capturing system that estimates the light vector by applying a vision-based technique. It lets the user freely position a handheld light source during capture. The system estimates light-source orientation in real time through a Web cam mounted on the light source. Software running on an ordinary PC analyzes images from the Web cam to recognize the light source direction (the light vector). Our goal is to design a low-cost, portable, and adaptable system. Vision-based approaches offer such characteristics. We use a pose-estimation system to acquire image-based data for relighting.  相似文献   
88.
探讨了开展发电企业向大用户直接供电的条件,提出了一种输电网络开放环境下的电力市场运营模式,即中长期金融合的交易和实时平衡市场相结合的电能交易模式。这种模式使市场竞争主体能够有效规避市场风险但又不降低市场竞争力度,而且市场主体之间的合约履行又不制约电网的安全可靠运行,市场运作简单、高效、透明。  相似文献   
89.
介绍了三钢天车钢水自动跟踪计量系统的功能、实现原理、硬件构成和软件设计 ,阐述了提高这一计量系统的准确度的方法及实施效果。  相似文献   
90.
电力系统一般都很复杂且变量又多,实现二阶负载-频率自动控制也相应变得很困难.对此,把误差和误差变化率作为模糊控制器的输入,使得模糊控制器对较小误差具有较强的敏感性,这样有利于消除稳态误差,以适应误差的快速调节和精确调节.仿真结果表明这种模糊控制的策略对于存在扰动且并不是很大的情况是很适用的,提高了系统的稳态性能,减小了响应的超调.  相似文献   
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