全文获取类型
收费全文 | 5110篇 |
免费 | 149篇 |
国内免费 | 39篇 |
专业分类
电工技术 | 93篇 |
综合类 | 5篇 |
化学工业 | 992篇 |
金属工艺 | 122篇 |
机械仪表 | 199篇 |
建筑科学 | 97篇 |
能源动力 | 193篇 |
轻工业 | 231篇 |
水利工程 | 27篇 |
石油天然气 | 4篇 |
无线电 | 906篇 |
一般工业技术 | 913篇 |
冶金工业 | 564篇 |
原子能技术 | 25篇 |
自动化技术 | 927篇 |
出版年
2024年 | 9篇 |
2023年 | 31篇 |
2022年 | 111篇 |
2021年 | 108篇 |
2020年 | 35篇 |
2019年 | 56篇 |
2018年 | 66篇 |
2017年 | 76篇 |
2016年 | 101篇 |
2015年 | 102篇 |
2014年 | 177篇 |
2013年 | 375篇 |
2012年 | 269篇 |
2011年 | 323篇 |
2010年 | 232篇 |
2009年 | 266篇 |
2008年 | 271篇 |
2007年 | 241篇 |
2006年 | 229篇 |
2005年 | 197篇 |
2004年 | 162篇 |
2003年 | 157篇 |
2002年 | 126篇 |
2001年 | 116篇 |
2000年 | 86篇 |
1999年 | 99篇 |
1998年 | 250篇 |
1997年 | 150篇 |
1996年 | 114篇 |
1995年 | 72篇 |
1994年 | 96篇 |
1993年 | 61篇 |
1992年 | 45篇 |
1991年 | 54篇 |
1990年 | 36篇 |
1989年 | 45篇 |
1988年 | 53篇 |
1987年 | 39篇 |
1986年 | 32篇 |
1985年 | 24篇 |
1984年 | 28篇 |
1983年 | 24篇 |
1982年 | 11篇 |
1981年 | 16篇 |
1980年 | 15篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 18篇 |
1976年 | 34篇 |
1974年 | 7篇 |
排序方式: 共有5298条查询结果,搜索用时 15 毫秒
101.
In this paper, the electric-discharge machining (EDM) of non-contact seal grooves was studied. Two types of material, namely: tungsten carbide and silicon carbide were tested by EDM due to their hard machining behaviors. The geometry of seal grooves is another reason why grinding or other precision machining processes cannot be applied. Four parameters of EDM processes were studied, namely: electrode material, pulse duration, discharge current, and polarity. According to experimental results, the optimal process parameters were obtained based on the specimen’s qualities, such as surface roughness and depth of cut. An industrial example was also studied in the final stage of the proposed paper. 相似文献
102.
Michael J. McNallan Ph.D. Pei Pei Hsu Ph.D. Soo Young Lee Ph.D. 《JOM Journal of the Minerals, Metals and Materials Society》1993,45(12):22-25
Nonoxide silicon-based ceramics owe their oxidation resistance to the formation of a thin silica film that separates the ceramic from oxidizing environments. This silica film can be fluxed by alkali oxides to form low-melting alkali silicate corrosion products that do not provide protection. Alkali chlorides and other halides have sufficiently high vapor pressures that silica fluxing can occur without the formation of a condensed halide salt. The rates of oxidation of Si, SiC, and Si3N4 are influenced by the composition of gas mixtures containing these species. 相似文献
103.
Hualong Li Emilie Hsu Jerzy Szpunar Ravi Verma Jon. T. Carter 《Journal of Materials Engineering and Performance》2007,16(3):321-326
In order to determine the deformation modes in AZ31 magnesium alloy at room temperature, computer simulations of deformation
texture development and calculation of formability have been carried out. The simulation results were compared with the measured
texture results. Based on agreement between the experiments and simulations the active deformation modes were determined.
A Visco Plastic Self Consistent model was employed for the simulation of plastic deformation. Simulations and experiments
were performed for different initial textures. The goal of the study was to develop the understanding of deformation texture
evolution and its effects on mechanical properties of magnesium, with an ultimate goal of improving room temperature formability
of magnesium alloys.
This article was presented at Materials Science & Technology 2006, Innovations in Metal Forming symposium held in Cincinnati,
OH, October 15-19, 2006. 相似文献
104.
This paper studies the adoption and diffusion of a cross-cultural Interorganizational Information System (IOS), which is used to streamline the processing of financial transactions between European investment fund companies and Taiwanese banks. Drawing from institutional and organizational legitimacy theory, we argue that the adoption and implementation of technological innovation is contingent upon its alignment with three institutional pillars in different countries and the deployment of legitimation strategies by stakeholders. Departing from classical innovation diffusion theory, our empirical investigation reveals that the implementation of a cross-cultural IOS is a dynamic process involving the recognition, understanding, and management of the regulative, normative, and cognitive challenges arising in two different institutional settings. This paper contributes to the growing body of research that highlights the significance of social and institutional influences on the adoption of IOS in a global environment. 相似文献
105.
From Job Characteristics to Job Satisfaction of Foreign Workers in Taiwan's Construction Industry: The Mediating Role of Organizational Commitment 下载免费PDF全文
The purpose of this study was to investigate the relationships among job characteristics, organizational commitment, and job satisfaction of foreign workers in Taiwan. Overall, 440 Thailand foreign workers were recruited and structural equation modeling was used to test the research hypotheses. The results of this study supported all proposed hypotheses. Job characteristics had a positive effect on job satisfaction of foreign workers. However, the results showed an indirect effect of job characteristics on job satisfaction via organizational commitment. Moreover, the findings suggested that job autonomy is better compared to other job characteristics. This study contributes to the existing literature by stressing the importance of such relationships in the cross‐cultural management enterprises, particularly those concerning foreign workers. 相似文献
106.
Ao Zhou Shangguang Wang Ching-Hsien Hsu Qibo Sun Fangchun Yang 《Multimedia Tools and Applications》2016,75(20):12901-12917
An increasing number of big-data services are being deployed in a cloud computing environment, attracted by the on-demand service, rapid elasticity, and low maintenance costs. As a result, ensuring the quality of service has become an important research problem. Traditionally, task rescheduling is used to ensure a consistent quality of service in the event of failure of a virtual machine. However, the network resource consumption of different rescheduling methods varies. To address this problem, we propose a task rescheduling method that minimizes network resource consumption.The method includes three algorithms. The first obtains a set of good virtual machines from the large quantity of service-providing virtual machines using the skyline operation. A ranking algorithm then fuses the data size and the task emergency to identify significant tasks. Finally, we present an algorithm that automatically determines the optimal insertion point for each task. To verify the effectiveness of the proposed method, we extend the renowned simulator CloudSim and conduct a series of experiments. The results show that our method is more efficient than other methods in terms of network resource consumption. 相似文献
107.
Boris Hudec Chung-Wei Hsu I-Ting Wang Wei-Li Lai Che-Chia Chang Taifang Wang Karol Fröhlich Chia-Hua Ho Chen-Hsi Lin Tuo-Hung Hou 《中国科学:信息科学(英文版)》2016,59(6):061403
In this article, we comprehensively review recent progress in the ReRAM cell technology for 3D integration focusing on a material/device level. First we briefly mention pioneering work on high-density crossbar ReRAM arrays which paved the way to 3D integration. We discuss the two main proposed 3D integration schemes—3D horizontally stacked ReRAM vs 3D Vertical ReRAM and their respective advantages and disadvantages. We follow with the detailed memory cell design on important work in both areas, utilizing either filamentary or interface-limited switching mechanisms. We also discuss our own contributions on HfO2-based filamentary 3D Vertical ReRAM as well as TaOx/TiO2 bilayer-based self-rectifying 3D Vertical ReRAM. Finally, we summarize the present status and provide an outlook for the nearterm future. 相似文献
108.
Liu Hsu Marcelo Carvalho Minhoto Teixeira Ramon Romankevicius Costa Edvaldo Assunção 《Asian journal of control》2015,17(5):1484-1497
A Lyapunov design of multiple input, multiple output (MIMO) model‐reference adaptive control (MRAC) systems is proposed using new generalized passivity concepts based on WSPR and WASPR properties. The new design avoids control overparameterization and leads to the simplest unnormalized gradient algorithm by means of a passivating multiplier. To this end, a necessary and sufficient condition on the high frequency gain matrix to achieve the WASPR property is established. This condition is referred to as Positive Diagonal Jordan (PDJ) form. Based on the robustness WSPR and WASPR properties, a systematic determination of a robust passivating matrix multiplier is then presented. The advantages of the new design are illustrated by numerical simulation including a robotics adaptive visual servoing problem and a 4‐input‐4‐output dynamic system. © 2014 Chinese Automatic Control Society and Wiley Publishing Asia Pty Ltd 相似文献
109.
Dong-Her Shih Sheng-Fei Hsu Chia-Chia Lin 《International journal of human-computer interaction》2013,29(10):627-645
Even though the ubiquity of technology can make many aspects of life more convenient, it may simultaneously raise some concerns about the privacy issues related to personal information. This research focused on the individual's behavior toward self-disclosure online and his or her cognition on personal privacy that was affected by not only the personal psychological factors but also the individual's computer knowledge and associated skills. To study how technological and psychological factors can simultaneously affect one's privacy concern and restrain behavior on disclosure, this study applied both perceived privacy and privacy concern to assess such factors as personal subjective attitude, computer self-efficacy, and perceived behavioral control to investigate the technological influence. A hypothesized model was proposed to describe the relationships among these constructs. After structural equation modeling is utilized to analyze the proposed hypotheses, the research findings showed that, although the perceived behavioral control had a negative effect on self-disclosure online, all the other hypotheses indicated a positive casual effect. 相似文献
110.
Kuo‐Chung Huang Yi‐Heng Chou Lang‐chin Lin Hoang Yan Lin Fu‐Hao Chen Ching‐Chiu Liao Yi‐Han Chen Kuen Lee Wan‐Hsuan Hsu 《Journal of the Society for Information Display》2013,21(6):263-270
The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement. 相似文献