全文获取类型
收费全文 | 994篇 |
免费 | 22篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 130篇 |
化学工业 | 211篇 |
金属工艺 | 15篇 |
机械仪表 | 23篇 |
建筑科学 | 15篇 |
矿业工程 | 2篇 |
能源动力 | 35篇 |
轻工业 | 100篇 |
石油天然气 | 2篇 |
无线电 | 110篇 |
一般工业技术 | 148篇 |
冶金工业 | 132篇 |
原子能技术 | 26篇 |
自动化技术 | 68篇 |
出版年
2023年 | 5篇 |
2022年 | 14篇 |
2021年 | 20篇 |
2020年 | 6篇 |
2019年 | 14篇 |
2018年 | 14篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2015年 | 21篇 |
2014年 | 15篇 |
2013年 | 57篇 |
2012年 | 35篇 |
2011年 | 48篇 |
2010年 | 47篇 |
2009年 | 41篇 |
2008年 | 47篇 |
2007年 | 47篇 |
2006年 | 48篇 |
2005年 | 29篇 |
2004年 | 23篇 |
2003年 | 42篇 |
2002年 | 27篇 |
2001年 | 19篇 |
2000年 | 24篇 |
1999年 | 23篇 |
1998年 | 68篇 |
1997年 | 33篇 |
1996年 | 28篇 |
1995年 | 26篇 |
1994年 | 9篇 |
1993年 | 19篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 3篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1972年 | 4篇 |
排序方式: 共有1017条查询结果,搜索用时 15 毫秒
21.
Yoshiyuki Sakamoto Tomoyoshi Motohiro Shinichi Matsunaga Kohei Okumura Tomoyuki Kayama Kiyoshi Yamazaki Toshiyuki Tanaka Yoshimi Kizaki Naoki Takahashi Hirofumi Shinjoh 《Catalysis Today》2007,121(3-4):217-225
The release and reduction of NOx in a NOx storage-reduction (NSR) catalyst were studied with a transient reaction analysis in the millisecond range, which was made possible by the combination of pulsed injection of gases and time resolved time-of-flight mass spectrometry. After an O2 pulse and a subsequent NO pulse were injected into a pellet of the Pt/Ba/Al2O3 catalyst, the time profiles of several gas products, NO, N2, NH3 and H2O, were obtained as a result of the release and reduction of NOx caused by H2 injection. Comparing the time profiles in another analysis, which were obtained using a model catalyst consisting of a flat 5 nmPt/Ba(NO3)2/cordierite plate, the release and reduction of NOx on Pt/Ba/Al2O3 catalyst that stored NOx took the following two steps; in the first step NO molecules were released from Ba and in the second step the released NO was reduced into N2 by H2 pulse injection. When this H2 pulse was injected in a large amount, NO was reduced to NH3 instead of N2.
A only small amount of H2O was detected because of the strong affinity for alumina support. We can analyze the NOx regeneration process to separate two steps of the NOx release and reduction by a detailed analysis of the time profiles using a two-step reaction model. From the result of the analysis, it is found that the rate constant for NOx release increased as temperature increase. 相似文献
22.
A new procedure has been developed to measure the temperature distribution of the polymer melts along the screw axis during injection by using a small sheath thermocouple. At the same time, the effects of molding conditions on temperature distribution has been studied. The temperature distribution of the polymer melt along the screw axis during injection can be obtained from the difference between the standard temperature profile and the temperature profile of the polymer melt with unknown and non-uniform temperature measured under the same rate of injection. The temperature of a polymer melt within a shot is not uniform. The difference between the maximum and the minimum temperature within a shot may exceed 10°C in some cases. There are two major factors which govern the effects of molding conditions on the temperature distribution of the polymer melts during injection. The first is the amount of shear heating in the metering zone. The second is the amount of heat absorbed into the polymer in the compression and feed zones. 相似文献
23.
Kazunori Sakata Kosuke Nakano Hirofumi Miyahara Yasuhiro Matsubara Keisaku Ogi 《Journal of Thermal Spray Technology》2007,16(5-6):991-997
This article describes microstructure control aimed for wear-resistance improvement of Co-based (Co-Cr-W-B-Si) self-fluxing
alloy coating by diffusion treatment. The diffusion treatments of thermally sprayed Co-based self-fluxing alloy coating on
steel substrate were carried out at 1370-1450 K for 600-6000 s under an Ar gas atmosphere. Microstructural variations of the
coating and the interface between the substrate and the coating were investigated in detail. A proper diffusion treatment
precipitates two kinds of fine compounds in Co-based matrix. X-ray diffractometer (XRD) and electron probe microanalyzer (EPMA)
analysis revealed these precipitates to be a chromium boride dissolving cobalt and a tungsten boride containing cobalt and
chromium. The size of each precipitate became larger with increasing treatment temperature and time. A coating with the proper
size borides showed a superior wear-resistance.
This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been
expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain
Montavon, Ed., ASM International, Materials Park, OH, 2007. 相似文献
24.
Recently, we revealed a standard pattern of a macroscopic molecular network for controlling morphogenetic processes such as the development of organs, including blast, mesoderm, heart, and hands during about sevenfold cell divisions and a standard bio-chemical clock like the circadian one (Naitoh in Artif Life Robot 13, 2008; Japan J Ind Appl Math 28(1), 2011; J Phys Conf Ser 344, 2012; Artif Life Robot 17, 2012) A network model derived logically based on experimental observations is described by a nonlinear differential equation for predicting time evolutions of six macroscopic molecular groups: three gene groups and three enzyme groups, which include promoting and suppressing factors. Here, the macroscopic model extended for also describing aging processes shows various types of cycles and reveals the physical condition for determining whether or not living beings such as humans can survive after getting ill. It is stressed that, after becoming ill, living systems with overly fast generation of information molecules such as various genes end in death, whereas relatively fast production of enzymes leads to recovery. This may also explain an essential feature underlying carcinogenic processes. 相似文献
25.
Yoshihisa Shinya Kenji Kamiya Tomoyuki Toyoda Yasumi Endo Nelly Soudakova Hirofumi Kondo 《Journal of the Society for Information Display》2009,17(4):331-336
Abstract— The display used in current cell phones has an air gap between the cover glass and the liquid‐crystal‐display (LCD) module to prevent the LCD glass from being damaged. Reflections at the boundaries of the air gap cause a reduction in the LCD luminance and contrast. To address this problem, a newly proposed LCD structure has been investigated. The “Super View Resin (SVR),” a transparent elastic resin which improves the shock resistance and visibility of the LCD, has been developed. Filling the air gap between the cover glass and LCD module with a refractive‐index‐matching resin solves the light‐reflection problem inherent in the use of a reinforced cover‐glass lens. Moreover, the elastic filler works as a damper, reducing any external shock, which prevents not only the cover glass and LCD module from being damaged, but also the glass from being shattered when it is broken. 相似文献
26.
Yuko Kizu Ray Hasegawa Isao Amemiya Shuichi Uchikoga Hirofumi Wakemoto 《Journal of the Society for Information Display》2009,17(8):647-658
Abstract— A 9‐in. full‐color polymer‐stabilized OCB TFT‐LCD with stable bend alignment in the absence of an electric field was developed. The condition of the polymer stabilization, the characteristics of UV‐curable monomers, and their influence on the configurations of the polymer network in the cell were studied. Possible models of the configuration were proposed and their relationship to the electro‐optical properties was analyzed using a novel simulation method considering the distribution of anchoring effects from both alignment surfaces and the polymer network. It was suggested that a good performance such as high contrast ratio and fast response could be expected in the polymer network originating from newly developed monomers composed of multifunctional LC acrylates due to a relatively weak‐anchoring effect and presumably its localization near the alignment surfaces. By using the newly developed monomers under the optimized polymer‐stabilizing process, a high contrast ratio of 250:1 and fast response nearly equal to that of a conventional OCB cell were achieved. 相似文献
27.
Yoshifumi Morita Norihiro Toya Ryosuke Takeichi Hitomi Hattori Hirofumi Tanabe Yoshiaki Takagi 《Advanced Robotics》2016,30(21):1406-1414
We developed a new training system, called ‘UR-System 2’, for the recovery of motor function of a plegic upper limb after stroke. UR-System 2, which was redesigned based on knowledge gained from clinical tests using UR-System 1, was newly equipped with a function for testing the motor function of patients, such as isolated movement. In order to verify the effectiveness of UR-System 2, we conducted the following procedures: we verified the safety of training in healthy persons; we gathered standard data on pronation and supination of healthy forearms during tests; and, we verified that the test function was effective in evaluating the recovery effect of isolated movement in two hemiplegic patients. 相似文献
28.
Yukio Yokoyama Hirofumi Kawashima Hisashi Kanie 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2006,53(5):847-852
Rectangular X-cut quartz crystal resonators with cut angles theta > 5.0 degrees and aspect ratios Rzy (= width 2z0/length 2y0) from 0.3 to 0.5 are investigated. The resonators oscillate mode is a length-extensional mode. A semiempirical frequency equation was derived from the stress expressed in terms of the trigonometric and the hyperbolic transcendental functions with constants estimated by the regression curve fit to the stress simulated by the finite-element method (FEM). Contours on which a point satisfies a zero first order temperature coefficient condition are shown in a cut angle theta and Rzy diagram. We proved that a fabricated resonator with Rzy = 0.400 and theta = 16.0 degrees, whose design parameter is located in the area of the contour, had a zero temperature coefficient. 相似文献
29.
Nakano Hirofumi Ishizaka Kazuhisa Obata Motoki Kimura Keiji Kasahara Hironori 《International journal of parallel programming》2003,31(3):211-223
Effective use of cache memory is getting more important with increasing gap between the processor speed and memory access speed. Also, use of multigrain parallelism is getting more important to improve effective performance beyond the limitation of loop iteration level parallelism. Considering these factors, this paper proposes a coarse grain task static scheduling scheme considering cache optimization. The proposed scheme schedules coarse grain tasks to threads so that shared data among coarse grain tasks can be passed via cache after task and data decomposition considering cache size at compile time. It is implemented on OSCAR Fortran multigrain parallelizing compiler and evaluated on Sun Ultra80 four-processor SMP workstation using Swim and Tomcatv from the SPEC fp 95. As the results, the proposed scheme gives us 4.56 times speedup for Swim and 2.37 times on 4 processors for Tomcatv respectively against the Sun Forte HPC Ver. 6 update 1 loop parallelizing compiler. 相似文献
30.
We developed a dual-probe (DP) atomic force microscopy (AFM) system that has two independently controlled probes. The deflection of each cantilever is measured by the optical beam deflection (OBD) method. In order to keep a large space over the two probes for an objective lens with a large numerical aperture, we employed the OBD sensors with obliquely incident laser beams. In this paper, we describe the details of our developed DP-AFM system, including analysis of the sensitivity of the OBD sensor for detection of the cantilever deflection. We also describe a method to eliminate the crosstalk caused by the vertical translation of the cantilever. In addition, we demonstrate simultaneous topographic imaging of a test sample by the two probes and surface potential measurement on an α-sexithiophene (α-6T) thin film by one probe while electrical charges were injected by the other probe. 相似文献