全文获取类型
收费全文 | 6871篇 |
免费 | 610篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 98篇 |
综合类 | 5篇 |
化学工业 | 1808篇 |
金属工艺 | 218篇 |
机械仪表 | 487篇 |
建筑科学 | 114篇 |
矿业工程 | 5篇 |
能源动力 | 310篇 |
轻工业 | 563篇 |
水利工程 | 17篇 |
石油天然气 | 3篇 |
无线电 | 1230篇 |
一般工业技术 | 1549篇 |
冶金工业 | 299篇 |
原子能技术 | 85篇 |
自动化技术 | 704篇 |
出版年
2024年 | 6篇 |
2023年 | 86篇 |
2022年 | 108篇 |
2021年 | 214篇 |
2020年 | 190篇 |
2019年 | 238篇 |
2018年 | 233篇 |
2017年 | 272篇 |
2016年 | 277篇 |
2015年 | 267篇 |
2014年 | 351篇 |
2013年 | 426篇 |
2012年 | 539篇 |
2011年 | 582篇 |
2010年 | 443篇 |
2009年 | 421篇 |
2008年 | 367篇 |
2007年 | 306篇 |
2006年 | 272篇 |
2005年 | 246篇 |
2004年 | 210篇 |
2003年 | 213篇 |
2002年 | 176篇 |
2001年 | 141篇 |
2000年 | 121篇 |
1999年 | 123篇 |
1998年 | 144篇 |
1997年 | 119篇 |
1996年 | 71篇 |
1995年 | 65篇 |
1994年 | 30篇 |
1993年 | 37篇 |
1992年 | 32篇 |
1991年 | 28篇 |
1990年 | 28篇 |
1989年 | 27篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 16篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有7495条查询结果,搜索用时 15 毫秒
31.
Zirconia-rich subsolidus phase relationships in the ZrO2 –Sc2 O3 and ZrO2 –In2 O3 systems were investigated. Phase inconsistencies in the ZrO2 –Sc2 O3 system resulted from a diffusionless cubic-to-tetragonal ( t' ) phase transformation not being recognized in the past. Through three different measuring techniques, along with microstructural observations, the solubility limits of the tetragonal and cubic phases were determined. 相似文献
32.
Hyun-Seob?Song Joo?Sung?Lee Jae?Chun?HyunEmail author 《Korean Journal of Chemical Engineering》2002,19(6):949-953
A mathematical model for the pyrolysis reaction of polystyrene (PS) in a semi-batch reactor has been presented. The thermal
degradation of PS was flexibly modeled by a combination of random and specific chain-end scissions. Numerical simulation was
used to investigate the effect of operating conditions on the PS products spectrum, the results of which were validated by
the experimental data. It was found that as the reaction temperature increased (decreased), the monomer fraction in the products
became lower (higher) while the trimer higher (lower). No significant variation in the product composition was, however, observed
while constant temperature was maintained. These results indicate the reaction temperature is an effective manipulated variable
for the control of products composition of PS pyrolysis. The calculation of the optimum temperature trajectories through the
optimization study can thus be of interest for achieving productivity enhancement in plastics pyrolysis processes.
This paper is dedicated to Professor Dong Sup Doh on the occasion of his retirement from Korea University. 相似文献
33.
Defect detection is an important technology for the quality control in the production process of wafer, TFT-LCD and PCB. Inspection is performed using the finished product’s image. The images are classified into two different groups—images with a repetitive pattern on a regular cycle and images without a repetitive pattern. A standard object for comparison is required, because manual defect detection is not possible for areas without repetitive patterns. In such areas, defect detection occurs through contrasting a reference pattern to the pattern being inspected. Methods of inspection using reference image have been researched but have limitations due to their requirement of precise alignment of the images. This paper proposes a method of defect detection to overcome such limitation using feature point matching. Feature points are extracted using a corner detector and detects defect by finding a correspondence between two feature point sets. Performance of the proposed method is evaluated by using Wafer SEM images and compared with conventional methods. Experiment results demonstrate the proposed method achieves higher detection accuracy than conventional methods and is less sensitive to alignment error and noise. 相似文献
34.
Yoon -Suk Choi Sung -Joon Kim Ik -Min Park Kwang -Woo Kwon In -Suk Yoo 《Metals and Materials International》1997,3(2):118-124
Boron distribution in a low-alloy steel (15B26:0.25C-0.29Cr-0.03Ti-0.028Al-0.0016B) has been characterized employing Fission
Track Etching (FTE) method. The characteristics of boron distribution with variation of cooling rate after austenitization
and through case-hardened depth after carburization were analyzed. Hardenability of 15B26 steel was also evaluated through
Jominy-end-quench test and the results are as follows: It was observed that, in austenitized 15B26 steel, boron was distributed
uniformly over the whole area of specimen with a little segregation along the austenite grain boundaries at higher cooling
rates and boron precipitates were formed in the intergranular as well as transgranular regions at lower cooling rates. Jominy
equivalents (HRC 35) of 15B26 steel were fairly increased between the Jominy temperatures of 820°C and 850°C, which might
result from the increase of the amount of soluble boron in austenite due to the dissolution of borocarbides between 820°C
and 850°C. In carburized 15B26 steel, the different through thickness features of boron distribution from the carburized surface
were found; coarse nodular boron precipitates up to the depth of 150 μm; uniform distribution of dissolved boron between 150~650
μm; and segregation of boron atoms along grain boundaries in the regions deeper than 650 μm. 相似文献
35.
A timing controller embedded driver IC with 3.24‐Gbps eDP interface for chip‐on‐glass TFT‐LCD applications 下载免费PDF全文
Tae‐Jin Kim Changhoon Baek Sengsub Chun Kil‐Hoon Lee Jong‐Il Hwang Kyeonghwan Kwon Yong‐Hun Kim Hyun‐Sang Park Youngmin Shin Seong‐young Ryu Jae‐Youl Lee Gyoocheol Hwang Gyeongnam Kim 《Journal of the Society for Information Display》2016,24(5):299-306
This paper presents a timing controller embedded driver (TED) IC with 3.24‐Gbps embedded display port (eDP), which is implemented using a 45‐nm high‐voltage CMOS process for the chip‐on‐glass (COG) TFT‐LCD applications. The proposed TED‐IC employs the input offset calibration scheme, the zero‐adjustable equalizer, and the phase locked loop‐based bang‐bang clock and data recovery to enhance the maximum data rate. Also, the proposed TED‐IC provides efficient power management by supporting advanced link power management feature of eDP standard v1.4. Additionally, the smart charge sharing is proposed to reduce the dynamic power consumption of output buffers. Measured result demonstrates the maximum data rate of 3.24 Gbps from a 1.1 V supply voltage with a 7.9‐inch QXGA 60‐Hz COG‐LCD prototype panel and 44% power saving from the display system. 相似文献
36.
Observer‐based decentralized adaptive control for large‐scale pure‐feedback systems with unknown time‐delayed nonlinear interactions 下载免费PDF全文
Sung Jin Yoo 《国际强度与非线性控制杂志
》2015,25(8):1107-1125
》2015,25(8):1107-1125
This paper presents an approximation design for a decentralized adaptive output‐feedback control of large‐scale pure‐feedback nonlinear systems with unknown time‐varying delayed interconnections. The interaction terms are bounded by unknown nonlinear bounding functions including unmeasurable state variables of subsystems. These bounding functions together with the algebraic loop problem of virtual and actual control inputs in the pure‐feedback form make the output‐feedback controller design difficult and challenging. To overcome the design difficulties, the observer‐based dynamic surface memoryless local controller for each subsystem is designed using appropriate Lyapunov‐Krasovskii functionals, the function approximation technique based on neural networks, and the additional first‐order low‐pass filter for the actual control input. It is shown that all signals in the total controlled closed‐loop system are semiglobally uniformly bounded and control errors converge to an adjustable neighborhood of the origin. Finally, simulation examples are provided to illustrate the effectiveness of the proposed decentralized control scheme. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
37.
Yongmin Park Jang Jin Yoo Dongwoo Kang Sungjin Kim 《Journal of the Society for Information Display》2015,23(9):391-396
We present a feasible modeling method to estimate the proper curvature for large‐sized curved TVs. We especially focused on two factors – preference and perceived distortion – to be considered to determine the proper curvature. The preference includes a number of advantages that people expect to fulfill the possibilities of a more immersive image and sense of realism from curved display. On the other hand, the perceived distortion means the side effects that people can notice uncomfortable feeling caused by the shape of a curved one. In order to find out how two factors would be different as a number of conditions like curvature, size, and viewing angle change, a series of subjective assessments were conducted. The evaluation results show that both the preference and perceived distortion vary with the conditions considerably. We performed the statistical analysis based on the results and proposed the quantification model of proper curvature, which has higher preference and less perceived distortion, for various‐sized curved TVs. 相似文献
38.
Exploring the Relationship Between Green Consumption Value,Satisfaction, and Loyalty to Hybrid Car in Elderly Consumers 下载免费PDF全文
The study aimed to examine the relationship between green consumption value, satisfaction, and loyalty of driving hybrid cars among elderly consumers. Data were collected from a cross‐sectional survey of 314 elderly consumers who purchased hybrid cars in the United States. A partial least squares analysis revealed that elderly consumers’ social, price, and quality values positively influenced the satisfaction of their hybrid car experience, and their satisfaction significantly influenced their loyalty of hybrid car. The relationship between green consumption value, satisfaction, and loyalty toward driving hybrid cars among elderly consumers revealed insight into their value orientations toward the hybrid car. Special efforts are suggested in promoting hybrid car use to elderly consumer groups. Marketers should pay attention to changing beliefs and increasing perceived values of driving a hybrid car for consumers to encourage them to use green products. 相似文献
39.
Jae Sundaram 《Information & Communications Technology Law》2015,24(2):121-163
The entry of the Trade-Related Aspects of Intellectual Property Rights (TRIPS) Agreement has seen the developing countries and the least developed countries (LDCs) suffer from the excessive burden of obligations imposed under the Agreement to embrace and implement a higher standard of intellectual property (IP) protection. One of the areas where the impact of the measures is most felt is on accessibility to affordable medicines for frontline treatment of diseases in developing countries and LDCs, where the majority of the HIV/AIDS sufferers come from. This inevitable plight, although well known, and posited by the developing countries and LDCs during the Uruguay round of negotiations, was overlooked. This also necessitated the Doha Deceleration, which does not seem to have addressed the problem. The developed countries have also successfully utilised the TRIPS Agreement's IP rights protection criteria as a benchmark, to develop a much higher IP rights protection agenda through the introduction of TRIPS-plus provisions in bilateral and other multilateral agreements entered into with developing countries. The winners in the game are the patent-holding pharmaceutical corporations, software corporations, media corporations, and the developed countries where they are incorporated. The ones at the receiving end are the developing countries and the LDCs who were promised technology transfer to build a modern economy by the developed countries, but are faced with multiple problems of non-availability of affordable medicines for health care, besides others. This article seeks to study the justification for an extended IP rights protection under the TRIPS Agreement through an analysis of the philosophical underpinnings of the IP rights and the patent regime. It will be argued that the TRIPS Agreement is a major obstacle that the developing countries and the LDCs have been made to face as Members of the WTO (World Trade Organisation), with no end in sight for their miseries, and that the only possible solution is a review or an amendment of the TRIPS Agreement. 相似文献
40.
Seung Jin Chang Jae Young Lee Jin Bae Park Yoon Ho Choi 《International Journal of Control, Automation and Systems》2015,13(2):311-318
In this paper, we propose an actor-critic neuro-control for a class of continuous-time nonlinear systems under nonlinear abrupt faults, which is combined with an adaptive fault diagnosis observer (AFDO). Together with its estimation laws, an AFDO scheme, which estimates the faults in real time, is designed based on Lyapunov analysis. Then, based on the designed AFDO, a fault tolerant actor- critic control scheme is proposed where the critic neural network (NN) is used to approximate the value function and the actor NN updates the fault tolerant policy based on the approximated value function in the critic NN. The weight update laws for critic NN and actor NN are designed using the gradient descent method. By Lyapunov analysis, we prove the uniform ultimately boundedness (UUB) of all the states, their estimation errors, and NN weights of the fault tolerant system under the unpredictable faults. Finally, we verify the effectiveness of the proposed method through numerical simulations. 相似文献