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941.
采用化学气相淀积淀积SiC薄膜中SiH4、CH4的分解产物种属进行数学建模,并结合相关热力学数据进行计算机模拟,得出SiH4分解产物中以SiH2为最多,CH4以CH2为最多,表明它们在淀积薄膜中是主要因素。  相似文献   
942.
带状图像交叉区域的骨架求解算法   总被引:4,自引:2,他引:2  
交叉区域的求解技术是图像骨架化中的难点,在基于无向图的图像整体骨架表示模型及算法的基础上,提出了图像交叉区域(如X形、K形等)的骨架求解算法,它根据图像交叉区域在无向图中的位置和邻接关系确定图像交叉区域的形状,并根据几何近似原理,用多边形近似方法对不同形状的交叉区域进行求解,算法充分利用图像的拓扑信息,具有速度快,了等优点,并得到了实际应用。  相似文献   
943.
本文介绍的大电流热保护器参数自动测量系统.其控制系统以PLC为核心,配备触摸屏、微型打印机等.系统采用恒流电子负载提供稳定的大电流(100A),利用霍尔元件检测电流的有无,精确记录热保护器断开或闭合的时间;同时可测试其绝缘电阻是否合格,对于热保护器动作时产生抖动(振颤)的情况亦可进行检测.该系统具备多参数的测试功能,测试精度高.操作简便,并提供数据统计、打印和产品分选等功能,提高了工作效率.  相似文献   
944.
AD7656与LPC2210的并行采集接口设计   总被引:1,自引:0,他引:1  
引言在电力系统三相信号处理应用中,常需要同时对A、B、C三相电压和电流信号进行数据采集和处理。如三相功率、电能测量及谐波分析等。美国ADI公司的AD7656是16位6通道同时采样的模/数转换器,内部含有6个16位A/D转换器,具有转换精度高、速度快、功耗低、输入模拟信号幅度大、信噪比高等特点。Philips公司出品的LPC2210,是一款工业级的ARM控制器,处理速度快,性能稳定,与AD7656共同组成的6通道数据采集系统能在很大程度上提高系统的信号采集和处理能力。1AD7656的特点及工作原理1.1AD7656的特点图1为AD7656的内部功能框图。其主要特性为:◆6个16位独立的ADC通道。◆输入模拟信号的范围为±(10~15V)。◆最大转换速率为250ksps。◆低功耗,5V供电时在250ksps下功耗为140mW。◆片上2.5V参考电压和参考缓冲器。◆8/16位并行接口模式和串行接口模式。1.2工作原理AD7656是6通道16位逐次逼近型ADC,有2种接口模式:串行接口模式和高速的并行接口模式,并行接口模式又分为8位和16位传送方式。在数据转换时,3个转换信号CONVSTA/B/C,用来控制每对或每4...  相似文献   
945.
This paper develops a novel microcontact printing system for printing tens of protein solutions into an array with batch filling and parallel printing. This printing system consists of micro filling and micros tamp chips. The micro filling chip can simultaneously transfer numerous protein solutions into the micros tamp chip in seconds by capillary force without cross contamination while preserving the functionality of proteins. Different proteins can be dispensed into the corresponding channels and driven into the tips of the microstamps. The microstamp can then be brought to contact with the substrate to produce bio fluid spot arrays. Teflon patterns are applied on both micro filling and microstamp chips to prevent cross contamination during filling. Thirty-six proteins can be printed in parallel with a spot size variation of less than 5%. This device has a potential to be expanded to a passive and high-throughput system for simultaneously printing hundreds of bio fluid spots to form dense arrays for diagnosing disease or screening for drugs.  相似文献   
946.
In this paper, we propose a new robust output feedback control approach for flexible-joint electrically driven (FJED) robots via the observer dynamic surface design technique. The proposed method only requires position measurements of the FJED robots. To estimate the link and actuator velocity information of the FJED robots with model uncertainties, we develop an adaptive observer using self-recurrent wavelet neural networks (SRWNNs). The SRWNNs are used to approximate model uncertainties in both robot (link) dynamics and actuator dynamics, and all their weights are trained online. Based on the designed observer, the link position tracking controller using the estimated states is induced from the dynamic surface design procedure. Therefore, the proposed controller can be designed more simply than the observer backstepping controller. From the Lyapunov stability analysis, it is shown that all signals in a closed-loop adaptive system are uniformly ultimately bounded. Finally, the simulation results on a three-link FJED robot are presented to validate the good position tracking performance and robustness of the proposed control system against payload uncertainties and external disturbances.  相似文献   
947.
In this paper, a navigation system is developed. The system includes path tracking and obstacle avoidance apparatus for a car-like wheeled robot (CLWR) within an Internet-based smart-space (IBSS) using fuzzy-neural adaptive control (FNAC). Two distributed charge-coupled device (CCD) cameras are installed to capture both the dynamic pose of the CLWR and the obstacle. Based on the control authority of these two CCD cameras, a suitable reference command that contains the desired steering angle and angular velocity for the FNAC built into the client computer is planned. Because of the delay encountered by the transmission through the Internet network (IN) and the wireless local area network (WLAN) and the nonlinear coupling features of the CLWR, a weighted combination of $N$ linear subsystems that are described by a state-space model with average-delay is implemented to approximate the dynamics of an IBSS-CLWR. The proposed FNAC contains a neural network consisting of a radial basis function (RBFNN) to learn the uncertainties due to the fuzzy-model error (e.g., the random time-varying delays and the slippage of the CLWR) and the interactions caused by other subsystems. The stability of the overall system is then investigated by adopting the Lyapunov stability theory. Finally, a sequence of experiments including the control of the off-ground CLWR (i.e., the CLWR does not make contact with the ground) and the navigation of the IBSS-CLWR as compared with the conventional proportional-integral-derivative (PID) control is performed to demonstrate the advantage of the proposed control system.   相似文献   
948.
Fuzzy interpolative reasoning is an inference technique for dealing with the sparse rules problem in sparse fuzzy-rule-based systems. In this paper, we present a new fuzzy interpolative reasoning method for sparse fuzzy-rule-based systems based on the areas of fuzzy sets. The proposed method uses the weighted average method to infer the fuzzy interpolative reasoning results and has the following advantages: 1) it holds the normality and the convexity of the fuzzy interpolative reasoning result, 2) it can deal with fuzzy interpolative reasoning with complicated membership functions, 3) it can deal with fuzzy interpolative reasoning when the fuzzy sets of the antecedents and the consequents of the fuzzy rules have different kinds of membership functions, 4) it can handle fuzzy interpolative reasoning with multiple antecedent variables, 5) it can handle fuzzy interpolative reasoning with multiple fuzzy rules, and 6) it can handle fuzzy interpolative reasoning with logically consistent properties with respect to the ratios of fuzziness. We use some examples to compare the fuzzy interpolative reasoning results of the proposed method with those of the existing fuzzy interpolative reasoning methods. In terms of the six evaluation indices, the experimental results show that the proposed method performs more reasonably than the existing methods. The proposed method provides us a useful way to deal with fuzzy interpolative reasoning in sparse fuzzy-rule-based systems.   相似文献   
949.
Abstract— A 2.0‐in. a‐Si:H TFT‐LCD with embedded TFT sensors for the control of the backlight intensity according to the ambient light intensity has been developed. Two types of a‐Si:H TFT sensors with various channel widths were embedded into a TFT backplane with bottom‐ and top‐gate structures for measuring the ambient light and backlight illumination, respectively. The output signal, measured by a readout IC, increased with backlight intensity until 20,000 lux.  相似文献   
950.
Abstract— This study is intended to explore the legibility and visual fatigue of different age users under various surface treatments and reflectance of electronic paper. Through the method of character‐search task, the results indicated that compared with single types of treatment [anti‐reflection (AR) 0.8%, anti‐glare, 43% haze), the compound treatment of anti‐reflection and anti‐glare (ARC) exhibited the same legibility, and it showed superior properties to effectively reduce visual fatigue. Hence, it is suggested that electronic‐paper manufacturers should choose the compound surface treatment for better visual performance. On the other hand, the findings also validated that enhancing the reflectance of electronic paper to the same level as regular paper (about 80%) is worthy to be practically implemented. Based on the results of this study, electronic‐paper manufacturers can take useful information to fulfill ergonomic requirements on product design.  相似文献   
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