全文获取类型
收费全文 | 322篇 |
免费 | 10篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 76篇 |
金属工艺 | 5篇 |
机械仪表 | 6篇 |
建筑科学 | 8篇 |
能源动力 | 17篇 |
轻工业 | 25篇 |
石油天然气 | 2篇 |
无线电 | 47篇 |
一般工业技术 | 92篇 |
冶金工业 | 19篇 |
原子能技术 | 6篇 |
自动化技术 | 27篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 11篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 19篇 |
2012年 | 14篇 |
2011年 | 15篇 |
2010年 | 15篇 |
2009年 | 18篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 13篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 3篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 5篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有332条查询结果,搜索用时 15 毫秒
71.
Concept of Functionally Graded Materials for Advanced Thermal Barrier Coating Applications 总被引:4,自引:0,他引:4
Woo Y. Lee David P. Stinton Christopher C. Berndt Fazil Erdogan Yi-Der Lee Zaher Mutasim 《Journal of the American Ceramic Society》1996,79(12):3003-3012
This feature article explores the concept of creating functionally graded metal-ceramic composite microstructures for thermal barrier coatings used in gas-turbine applications. From a thermomechanical perspective, this concept offers the possibility of significantly improving the life and reliability of thermal barrier coatings. However, prior research reveals that progress has been somewhat limited because of the oxidative instability exhibited by some metal-ceramic composite microstructures. The present study addresses some of the materials criteria and research issues associated with preparing chemically stable, yet mechanically durable, graded metal-ceramic microstructures for realistic application environments. 相似文献
72.
We approach the multiple input multiple output (MIMO) decision feedback equalization (DFE) problem in digital communications from an H/sup /spl infin// estimation point of view. Using the standard (and simplifying) assumption that all previous decisions are correct, we obtain an explicit parameterization of all H/sup /spl infin// optimal DFEs. In particular, we show that, under the above assumption, minimum mean square error (MMSE) DFEs are H/sup /spl infin// optimal. The H/sup /spl infin// approach also suggests a method for dealing with errors in previous decisions. 相似文献
73.
Field experiments show that Weibull distribution can be considered as the most suitable distribution to model weak to high signal power levels in indoor and outdoor environments. Recently, Exponentiated Weibull which is a special case of Weibull fading, have been widely adopted in free-space optical communication systems to model weak and high levels of turbulence effects. Motivated from the increasing use of Weibull distribution, this paper studies the popular dual-hop amplify-and-forward relay network with joint transmit and receive antenna selection where closed form ergodic capacity, symbol error rate and outage probability expressions are derived for Weibull fading channels. With the help of high SNR analysis, diversity gain, array gain and optimum relay location are obtained. Finally, theoretical findings are validated by simulation results. 相似文献
74.
Multimedia Tools and Applications - Noise level estimation is a required step for many preprocessing algorithms in computer vision such as image denoising. In this paper, a model-based technique... 相似文献
75.
Solubility of polyethylene molecular weight standards (Mw = 2150, 16,400, 108,000, and 420,000 and Mw/Mn = 1.14, 1.16, 1.32, and 2.66, respectively) has been studied in near- and supercritical n-butane and n-butane/CO2 mixtures at pressures up to 70 MPa. For each polyethylene/solvent system at selected compositions, demixing pressures have been determined using a high-pressure variable-volume view-cell at temperatures up to 200°C. Solutions in pure n-butane are found to display LCST (lower critical solution temperature)-type behavior. The behavior of the solutions in n-butane/CO2 mixtures are observed to change from the LCST to the UCST (upper critical solution temperature) with increasing CO2 content in the binary solvent. Sanchez–Lacombe theory has been used to model these systems. The predictions correctly describe the nature of the phase diagrams for both binary and ternary systems and the calculations are in reasonable agreement with experimental data. © 1994 John Wiley & Sons, Inc. 相似文献
76.
Gencer Erdogan Yan Li Ragnhild Kobro Runde Fredrik Seehusen Ketil Stølen 《International Journal on Software Tools for Technology Transfer (STTT)》2014,16(5):627-642
Risk analysis and testing are conducted for different purposes. Risk analysis and testing nevertheless involve processes that may be combined to the benefit of both. We may use testing to support risk analysis and risk analysis to support testing. This paper surveys literature on the combined use of risk analysis and testing. First, the existing approaches are identified through a systematic literature review. The identified approaches are then classified and discussed with respect to main goal, context of use and maturity level. The survey highlights the need for more structure and rigor in the definition and presentation of approaches. Evaluations are missing in most cases. The paper may serve as a basis for examining approaches for the combined use of risk analysis and testing, or as a resource for identifying the adequate approach to use. 相似文献
77.
Yildirim Serhat Erdogan Pelin Gundes Bakir 《Engineering Applications of Artificial Intelligence》2013,26(1):357-367
A fuzzy finite element model updating (FFEMU) method is presented in this study for the damage detection problem. The uncertainty caused by the measurement noise in modal parameters is described by fuzzy numbers. Inverse analysis is formulated as a constrained optimization problem at each α-cut level. Membership functions of each updating parameter which correspond to reduction in bending stiffness of the finite elements is determined by minimizing an objective function using a hybrid version of genetic algorithms (GA) and particle swarm optimization method (PSO) which is very efficient in terms of accuracy and robustness. Practical evaluation of the approximate bounds of the interval modal parameters in FFEMU iterations is addressed. A probabilistic analysis is performed using Monte Carlo simulation (MCS) and the results are compared with presented FFEMU method. It is apparent from numerical simulations that the proposed method is well capable in finding the membership functions of the updating parameters within reasonable accuracy. It is also shown that the results obtained by FFEMU are in good agreement with the MCS results while FFEMU is not as computationally expensive as the MCS method. Nevertheless, the proposed FFEMU do not required derivatives of the objective function like existing methods except in the deterministic case. 相似文献
78.
Use of input power information for load sharing in parallel connected boost converters 总被引:1,自引:1,他引:0
A. D. Erdogan Mehmet Timur Aydemir 《Electrical Engineering (Archiv fur Elektrotechnik)》2009,91(4-5):229-250
Parallel operation of several small rated converters may be preferred for various reasons instead of using a single, high power converter. Sharing of the load among the converters is a serious problem of parallel operation. There are basically two kinds of algorithms for sharing: systems using communication and systems using droop characteristics without communication. This paper investigates these concepts, and then proposes modifications for each method. Basic suggestion is the use of input power as the control parameter, a technique which is especially useful for the converters designed for renewable energy systems. Another modification is to utilize an offset voltage in the droop method while determining the set values. This technique has been shown to improve the voltage regulation. Simulation and experimental results are provided to verify the concepts. 相似文献
79.
Exact distribution of edge-preserving MAP estimators for linearsignal models with Gaussian measurement noise 总被引:1,自引:0,他引:1
We derive the exact statistical distribution of maximum a posteriori (MAP) estimators having edge-preserving nonGaussian priors. Such estimators have been widely advocated for image restoration and reconstruction problems. Previous investigations of these image recovery methods have been primarily empirical; the distribution we derive enables theoretical analysis. The signal model is linear with Gaussian measurement noise. We assume that the energy function of the prior distribution is chosen to ensure a unimodal posterior distribution (for which convexity of the energy function is sufficient), and that the energy function satisfies a uniform Lipschitz regularity condition. The regularity conditions are sufficiently general to encompass popular priors such as the generalized Gaussian Markov random field prior and the Huber prior, even though those priors are not everywhere twice continuously differentiable. 相似文献
80.
An analog queue-based architecture and an adaptive digital-calibration algorithm calibrate a 12-b algorithmic analog-to-digital converter in the background. At a sampling rate of 125 ksample/s and with monolithic background calibration, the peak signal-to-(noise+distortion) ratio is 71 dB, and the spurious-free dynamic range is 95 dB. The total power dissipation is 16 mW from 5 V. The active area is 5.9 mm2 in 1.5-μm CMOS 相似文献