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排序方式: 共有1271条查询结果,搜索用时 671 毫秒
31.
遗传算法在跨超声速风洞总压控制中的应用 总被引:2,自引:0,他引:2
总压作为风洞控制中的重要流场参数,其调节性能是风洞控制系统能否满足试验要求的重要指标,为提高跨超声速风洞的总压控制水平,需对总压控制策略进行设计。针对某跨超声速风洞对总压控制系统提出的快速性和精确性要求,提出串级控制、智能PID控制和总压分段控制等方法,并利用MATLAB系统辨识工具箱对流场调节阶段的总压系统模型进行了辨识。提出将遗传算法应用于风洞流场调节阶段的PID控制器参数整定中,重点对基于遗传算法的PID控制原理和参数整定步骤进行介绍,并针对遗传算法的遗传算子进行了设计。系统仿真和风洞实际运行情况表明:该方法较常规PID参数整定与优化方法,具有更好的控制性能指标,满足总压控制系统精确性、快速性、鲁棒性等要求,为后续风洞建设和设备改造提供了新方法。 相似文献
32.
合理设置、调整核心网、无线网参数是提高GSM网络整体性能的必要手段。随着GSM网络优化工作的深入开展,核心网的参数设置对全网用户接入、寻呼、增值业务使用等方面的广泛影响而日渐得到重视;无线网参数对网络中小区的覆盖、信令流程的分布、网络的业务性能等也具有至关重要的影响;同时周期性位置更新、隐含用户关机等参数,必须核心网与无线网的定时器、参数值关联设置才能起到良好的作用。本文结合多年网络优化经验,对核心网、无线网关键参数的合理设置及调整,逐一进行阐述。 相似文献
33.
迭代函数系IFS吸引子的参数控制与树木的模拟 总被引:1,自引:0,他引:1
文章讨论了迭代函数系IFS吸引子的参数控制,讨论了IFS参数控制实现模拟树木的方法。 相似文献
34.
Yahya H. Zweiri 《国际自动化与计算杂志》2008,5(2):185-192
Parameter identification is a key requirement in the field of automated control of unmanned excavators (UEs). Furthermore, the UE operates in unstructured, often hazardous environments, and requires a robust parameter identification scheme for field applications. This paper presents the results of a research study on parameter identification for UE. Three identification methods, the Newton-Raphson method, the generalized Newton method, and the least squares method are used and compared for prediction accuracy, robustness to noise and computational speed. The techniques are used to identify the link parameters (mass, inertia, and length) and friction coefficients of the full-scale UE. Using experimental data from a full-scale field UE, the values of link parameters and the friction coefficient are identified. Some of the identified parameters are compared with measured physical values. Furthermore, the joint torques and positions computed by the proposed model using the identified parameters are validated against measured data. The comparison shows that both the Newton-Raphson method and the generalized Newton method are better in terms of prediction accuracy. The Newton-Raphson method is computationally efficient and has potential for real time application, but the generalized Newton method is slightly more robust to measurement noise. The experimental data were obtained in collaboration with QinetiQ Ltd. 相似文献
35.
Ping Yang Fuyun Liu Yong Liu Ningbo Liao Binghao Bao 《Structural and Multidisciplinary Optimization》2008,35(5):489-498
Electronic equipment’s system is always manufactured as a superprecision system. However, it will be used in harsh environment.
For example, the computer in moving vehicles will be acted by vibrations. The objective of this paper is to provide a systematic
investigation to test and computer-aided design of the vibration isolator for protection of electronic equipment’s system
in harsh vibration environment. A micro-oil damping vibration isolator is designed and manufactured through coupling the oil
and spring by ingenious tactics. The structure of the oil damping vibration isolator can achieve circulating oil damping function
with an inner tube and an outer tube (some orifices are manufactured on upside and underside of the inner tube). The dynamics
of the key model machine is systematically investigated. Based on the test, a nonlinear dynamic model for the vibration isolator
is presented by analyzing the internal fluid dynamic phenomenon with respect to the vibration isolator. The model considers
all the physical parameters of the structure. Comparisons with experimental data confirm the validity of the model. In the
other, the model is integrated by introducing normalization measure. The normalization model shows the actual physical characteristics
of the oil damping vibration isolator by considering quadratic damping, viscous damping, Coulomb damping, and nonlinear spring
forces. An approximate solution is deduced by introducing harmonic transform method and Fourier transform method. Therefore,
a parameter-matching optimal model for computer-aided design of the vibration isolator is build based on approximate solution.
An example confirms the validity of the computer-aided design integration.
相似文献
Ping YangEmail: |
36.
本文介绍了射频传输线及LTCC技术的概念和特点,建立了基于LTCC技术的射频传输线模型,推导了传输线模型特征参数提取公式;并对传输线模型进行三维电磁仿真,得到了仿真参数。通过分析传输线性能,提出了优化设计的一定方法 相似文献
37.
38.
Choosing the Right Parameter for Single-Duct Constant Air Volume System Supply Air Temperature Reset
To improve system efficiency under part-load conditions, the supply air temperature set point for a single-duct constant air volume air handling unit (AHU) system is often reset based on either return air temperature or outside air temperature. Both reset strategies make engineering sense as long as the reset schedules are reasonable. Quite often the decision to use one over the other is made with the assumption that they will both achieve some energy savings. However, the impact of these two strategies on AHU energy consumption could be very different. An in-depth analysis and comparison of these two commonly used supply air temperature reset strategies for a single-duct constant air volume system is presented in this paper. It is shown that the reset strategy based on outside air temperature is inherently better than that based on return air temperature, with lower energy consumption and improved building comfort level. 相似文献
39.
The finite element procedures are extremely useful in gaining insights into the behavior of reinforced soil retaining walls. In this study, a validated finite element procedure was used for conducting a series of parametric studies on the behavior of reinforced soil walls under construction and subject to earthquake loading. The procedure utilized a nonlinear numerical algorithms that incorporated a generalized plasticity soil model and a bounding surface geosynthetic model. The reinforcement layouts, soil properties under monotonic and cyclic loadings, block interaction properties, and earthquake motions were among major variables of investigation. The performance of the wall was presented for the facing deformation and crest surface settlement, lateral earth pressure, tensile force in the reinforcement layers, and acceleration amplification. The effects of soil properties, earthquake motions, and reinforcement layouts are issues of major design concern under earthquake loading. The deformation, reinforcement force, and earth pressure increased drastically under earthquake loading compared to end of construction. 相似文献
40.
断路器电容器参数的选择 总被引:2,自引:1,他引:2
断路器电容器与断路器的断口相并联,用以改善断口上的电压分布及降低恢复电压的上升率。本文介绍了选择断路器电容器的额定电压和额定电容量的方法。 相似文献