全文获取类型
收费全文 | 1174篇 |
免费 | 23篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 43篇 |
化学工业 | 262篇 |
金属工艺 | 28篇 |
机械仪表 | 25篇 |
建筑科学 | 14篇 |
能源动力 | 29篇 |
轻工业 | 214篇 |
水利工程 | 2篇 |
石油天然气 | 4篇 |
无线电 | 55篇 |
一般工业技术 | 206篇 |
冶金工业 | 179篇 |
原子能技术 | 23篇 |
自动化技术 | 114篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 21篇 |
2021年 | 37篇 |
2020年 | 18篇 |
2019年 | 16篇 |
2018年 | 9篇 |
2017年 | 17篇 |
2016年 | 16篇 |
2015年 | 17篇 |
2014年 | 27篇 |
2013年 | 50篇 |
2012年 | 39篇 |
2011年 | 56篇 |
2010年 | 55篇 |
2009年 | 63篇 |
2008年 | 57篇 |
2007年 | 48篇 |
2006年 | 52篇 |
2005年 | 42篇 |
2004年 | 42篇 |
2003年 | 35篇 |
2002年 | 28篇 |
2001年 | 18篇 |
2000年 | 19篇 |
1999年 | 33篇 |
1998年 | 72篇 |
1997年 | 39篇 |
1996年 | 37篇 |
1995年 | 24篇 |
1994年 | 30篇 |
1993年 | 24篇 |
1992年 | 8篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1963年 | 1篇 |
排序方式: 共有1198条查询结果,搜索用时 15 毫秒
11.
The electron-microscopic visualization of acrylic rubber dispersed in a heterogeneous structural resin composition consisting of a rubber-modified two-phase plastic comprising essentially a butyl acrylate rubber phase and an acrylonitrile–styrene copolymer phase, respectively, has been accomplished. This procedure consists of the following: The molded resin specimen is treated with hydrazine hydrate solution to produce the acrylic acid hydrazides. Allow the treated specimen to soak in osmium tetroxide solution. The acrylic rubber may be indirectly fixed and stained. Some micrographs of ultrathin sections of two or three resin compositions, cut by an ultramicrotome, are presented. 相似文献
12.
Sun-Chan Jeong Ichiro Katayama Hirokane Kawakami Yutaka Watanabe Hironobu Ishiyama Nobuaki Imai Yoshikazu Hirayama Hiroari Miyatake Masao Sataka Satoru Okayasu Hiroyuki Sugai Shin-Ichi Ichikawa Katsuhisa Nishio Shinichi Mitsuoka Takamitsu Nakanoya Masahito Yahagi Takanori Hashimoto Kazunori Takada Mamoru Watanabe Tomoko Ishikawa Akihiro Iwase 《Journal of Phase Equilibria and Diffusion》2005,26(5):472-476
For the effective use of short-lived radioactive beams, soon to be available at the Tokai Radioactive Ion Accelerator Complex, the authors have developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound βLiAl using an α-emitting radiotracer of 8Li (T1/2=0.84 s). It was found that the time-dependent yields of the α particles from the diffusing 8Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in βLiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects (i.e., the existence of the atomic vacancies of Li and the defects in Ga sites that are replaced by Li). 相似文献
13.
This paper proposes a synthesis method of gain‐scheduled control systems that switch linear time‐invariant controllers according to hysteresis of the scheduling parameter. Stability and L2‐gain analysis and synthesis methods for switched systems are applied to the switched gain‐scheduled control synthesis using reset of the controller state, where also the reset law is computed via linear matrix inequalities (LMIs). In addition to optimization of an upper bound of L2‐gain, we reduce jumps of control input via an auxiliary optimization. Numerical examples are presented to illustrate the switched gain‐scheduled controller. 相似文献
14.
Nobuhiko Yabu Kouhei Nagano Nozomu Izumi 《Journal of the Society for Information Display》2015,23(6):246-252
Using shorter wavelength for exposure light is one way to achieve high resolution while keeping sufficient depth of focus. We show exposure results for high resolution to confirm the effect of deep UV exposure light. With deep UV light, 1.2‐µm line and space pattern and 1.8‐µm contact hole pattern are resolved while keeping sufficient depth of focus. 相似文献
15.
Izumi Kuroishi 《Nexus Network Journal》2009,11(2):201-216
This paper presents an examination of the process of the development of module in the works and theories of Japanese architect
Ikebe Kiyoshi (1920-79). Ikebe based his idea of module on the belief that “Beauty is Mathematics.” He applied his ideas of
module in various ways from the 1940s to the 1970s. Analyzing his ideas and works against their historical background, the
social and creative meanings of the idea of module and of mathematics in architecture will be re-examined. This allows us
to see how Ikebe developed his ideas of module from a characteristic mathematical approach, and how he developed his idea
of mathematical logic into his creative theories based on the flexible nature of people’s lifestyles and social conditions.
Going beyond the cultural and social differences and the limitations of Le Corbusier’s Modulor, the idea of module as the
method for organizing human space in a harmonious manner was reframed in Ikebe’s works, and was developed in a more flexible
mathematical way. 相似文献
16.
H Toyoshima S Hayashi N Tanabe K Miyanishi T Satoh Y Aizawa T Izumi 《Canadian Metallurgical Quarterly》1996,59(3-4):81-95
Epidemiological features, risk factors and preventive methods of sudden death (SD) derived from studies the authors have performed since 1987 together with colleagues in Niigata University School of Medicine were reviewed. When SD was defined as death occurring within 24 hours of the onset of symptoms, the annual incidence was 145/100,000 for people aged 15 years and older in Niigata Prefecture. The incidence increased sharply along with the advance of age, while the proportion of SD to natural death due to circulatory diseases was higher in younger people. Though diseases of the circulatory system made up approximately 90 percent of all causes of death, SD due to ischemic heart disease was less frequent in Japan than in western countries. SD showed various patterns in seasonal and "within-a-day" occurrences according to sex, age and cause of death. The months of the highest SD occurrence differed by occupation and matched the busiest work periods. A decrease in sleeping hours and mental stress experienced during the preceding week were related to the occurrence of both sudden death and non-fatal acute myocardial infarction. People having structural circulatory diseases were shown to be predisposed to SD when stress occurred, because fatal arrhythmia is easily induced by the above factors in such people. Health examinations were shown to have preventive effects, though limited, against SD. Differences in the resuscitated rates in cases where a witness was present and where one was not indicates that educating people about correct resuscitation methods is important to minimizing SD. 相似文献
17.
Tomoko Watanabe Traphagan Yueh-hui Vanessa Chiang Hyeseung Maria Chang Benjaporn Wattanawaha Haekyung Lee Michael Charles Mayrath Jeongwon Woo Hyo-Jin Yoon Min Jung Jee Paul E. Resta 《Computers & Education》2010
Using a framework of cognitive, social, and teaching presence, the nature of learning experiences in a three-dimensional virtual world environment (Second Life) and a text-chat learning environment without visuals (TeachNet) were investigated. A mixed method of code frequencies, coherence graphs, interviews, and a survey was used. The results revealed that the TeachNet debates included more cognitive presence codes that indicate higher levels of cognitive processing than in SL debates. The teams were significantly different from each other in the collaboration style for developing arguments and in the ways to use utterances associated with cognitive, social, and teaching presences, and the groups’ collaboration style became more established with more experience with the tasks. The three critical factors–tool, tasks and group cohesion–that affect cognitive, teaching, and social presence are discussed. 相似文献
18.
Yang Yang Shigeo Hirose Paulo Debenest Michele Guarnieri Norimitsu Izumi Koichi Suzumori 《Advanced Robotics》2016,30(21):1415-1429
To avert potential crisis from Japan’s aging infrastructure and declining birth rate, the Japanese Government is planning to introduce robotic technology for the inspection of social infrastructure (such as pipes, dams, and bridges). Recording underwater positions is a difficult task for human divers who undertake conventional dam inspections. This study presents the Anchor Diver 5.2 system for efficient and effectual dam inspection. Anchor Diver 5.2 is based on an extended-tether-maneuvered remotely operated vehicle (ROV) equipped with cameras. The ROV is lowered into water by a hoist system from a boat and implements a visual survey of the concrete underwater structure. To improve the visibility of the ROV in murky and cloudy water, a novel concept named Water Loupe is proposed. In addition, a simple boat-fixing method is proposed to provide a stable base on the water surface, and the underwater position of the ROV, which cannot be accessed by global positioning systems, is recorded using a feasible localization method. Finally, the developed system was evaluated in field experiments conducted in the Amagase Dam, Japan, and its merits and problems are discussed. 相似文献
19.
Keisuke Ichida Kiyotaka Izumi Keigo Watanabe Nobuhiro Uchida 《Artificial Life and Robotics》2008,12(1-2):258-263
In general, manipulators used for industry and in academic laboratories have actuators to drive each joint. On the other hand,
underactuated manipulators handled by our research have some passive or free joints without actuators and brakes. We recently
developed a switching method of fuzzy energy regions to control such manipulators. In such a method, it is necessary to design
parameters related to energy regions and the gains of some partly stable controllers based on the computed torque method.
Here, the switching method is applied for a three-link underactuated manipulator. We optimize such design parameters related
to fuzzy energy regions by a genetic algorithm. The effectiveness of the present method is illustrated with some simulations.
This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January
25–27, 2007 相似文献
20.
Akihiko Nagata Osamu Izumi Kōshichi Noto Hiroshi Hirayama 《Journal of Materials Science》1978,13(4):731-738
The dilute Cu-Nb-Sn alloys containing small amounts of Nb and Sn less than 1 at % exhibited superconductivity after quenching from the liquid state and ageing. The best superconducting properties (
andJ
c=130 A cm–2) in a Cu-0.30 at % Nb 0.15 at % Sn alloy were obtained when the sample was aged at 550° C for 384 h. This sample exhibited a structure of fine Nb3Sn precipitates of 200 to 500Å diameter distributed homogeneously in the Cu matrix, and therefore it was concluded that superconductivity in these alloys resulted from the proximity effect of Nb3Sn particles. In spite of the similar structure obtained by ageing at 800° C, the Cu-Nb-Sn alloys showed inferior superconducting properties compared to the Cu-0.4 at % Nb alloy and this would be explained qualitatively by the difference in the mean free path in the two alloys. 相似文献