全文获取类型
收费全文 | 1786篇 |
免费 | 36篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 41篇 |
综合类 | 3篇 |
化学工业 | 290篇 |
金属工艺 | 51篇 |
机械仪表 | 55篇 |
建筑科学 | 25篇 |
矿业工程 | 1篇 |
能源动力 | 37篇 |
轻工业 | 152篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
武器工业 | 1篇 |
无线电 | 212篇 |
一般工业技术 | 269篇 |
冶金工业 | 538篇 |
原子能技术 | 41篇 |
自动化技术 | 108篇 |
出版年
2023年 | 9篇 |
2022年 | 23篇 |
2021年 | 22篇 |
2020年 | 11篇 |
2019年 | 18篇 |
2018年 | 23篇 |
2017年 | 17篇 |
2016年 | 23篇 |
2015年 | 15篇 |
2014年 | 16篇 |
2013年 | 52篇 |
2012年 | 46篇 |
2011年 | 71篇 |
2010年 | 50篇 |
2009年 | 57篇 |
2008年 | 59篇 |
2007年 | 60篇 |
2006年 | 50篇 |
2005年 | 52篇 |
2004年 | 50篇 |
2003年 | 66篇 |
2002年 | 50篇 |
2001年 | 35篇 |
2000年 | 41篇 |
1999年 | 54篇 |
1998年 | 210篇 |
1997年 | 118篇 |
1996年 | 115篇 |
1995年 | 59篇 |
1994年 | 41篇 |
1993年 | 60篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 15篇 |
1989年 | 19篇 |
1988年 | 16篇 |
1987年 | 14篇 |
1986年 | 14篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 23篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1977年 | 13篇 |
1976年 | 17篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1970年 | 4篇 |
排序方式: 共有1828条查询结果,搜索用时 13 毫秒
51.
52.
Immersion ultrasonic probes for measurements and imaging at high temperature are presented. The probes consist of sol-gel-sprayed thick films as piezoelectric ultrasonic transducers (UTs) directly deposited onto steel buffer rods. They operate in pulse-echo mode at temperatures up to 500/spl deg/C. The operating ultrasonic frequency is between 5 MHz and 20 MHz, controlled by the film thickness. The ultrasonic thickness measurement of a steel plate with the probe fully immersed in molten zinc at 450/spl deg/C was demonstrated using ultrasonic plane waves. For imaging purposes, the probing end of the steel buffer rod was machined into a semispherical concave shape to form an ultrasonic lens and achieve high spatial resolution with focused ultrasound in liquids. Ultrasonic surface and subsurface imaging using a mechanical raster scan of the focused probe in silicone oil at 200/spl deg/C was also carried out. The importance of the signal-to-noise ratio (SNR) in the pulse-echo measurement is discussed. 相似文献
53.
Small crack behavior and fracture of nickel-based superalloy under ultrasonic fatigue 总被引:1,自引:0,他引:1
Q. Chen N. Kawagoishi Q.Y. Wang N. Yan T. Ono G. Hashiguchi 《International Journal of Fatigue》2005,27(10-12):1227
Fracture and small crack behavior in the very high cycle domain of 109 cycles were investigated with a nickel-based superalloy under ultrasonic fatigue in ambient air at room temperature. The influence of ultrasonic frequency is examined by comparing the results with those in conventional low frequency fatigue. It is found that fatigue strength increases as frequency is raised up to 19.5 kHz and the most of fatigue life is consumed in nucleating and propagating small cracks up to 100 μm. Transition of fracture mode from transgranular ductile fracture to cleavage-dominated fracture occurs beyond a critical stress intensity factor range of approximately , leading to the catastrophic failure under ultrasonic fatigue. 相似文献
54.
55.
Hirofumi Takano Daiyu Kamikihara Daisuke Ono Shinichiro Nakao Hideki Yamamoto Yoshiaki Miyazato 《热科学学报(英文版)》2016,25(1):78-83
The rainbow schlieren deflectometry has been combined with the computed tomography to obtain three-dimensional density fields of shock containing free jets and we call the method the schlieren CT. Experiments on the schlieren CT have been performed at a nozzle pressure ratio of 4.0 by using an axisymmetric convergent nozzle with an inner diameter of 10 mm at the exit where the nozzle was operated at an underexpanded condition. Multidirectional rainbow schlieren pictures of an underexpanded sonic jet can be acquired by rotating the nozzle about its longitudinal axis in equal angular intervals and the three-dimensional density fields are reconstructed by the schlieren CT. The validity of the schlieren CT is verified by a comparison with the density fields reconstructed by the Abel inversion method. As a result, it is found that excellent quantitative agreement is reached between the three-dimensional jet density fields reconstructed from both methods. 相似文献
56.
In vivo measurement of swallowing by monitoring thyroid cartilage movement in healthy subjects using thickened liquid samples and its comparison with sensory evaluation 下载免费PDF全文
57.
E.-A. Reinecke K. Takenaka H. Ono T. Kita M. Taniguchi Y. Nishihata R. Hino H. Tanaka 《International Journal of Hydrogen Energy》2021,46(23):12511-12521
The safe decommissioning as well as decontamination of the radioactive waste resulting from the nuclear accident in Fukushima Daiichi represents a huge task for the next decade. At present, research and development on long-term safe storage containers has become an urgent task with international cooperation in Japan. One challenge is the generation of hydrogen and oxygen in significant amounts by means of radiolysis inside the containers, as the nuclear waste contains a large portion of sea water. The generation of radiolysis gases may lead to a significant pressure build-up inside the containers and to the formation of flammable gases with the risk of ignition and the loss of integrity.In the framework of the project “R&D on technology for reducing concentration of flammable gases generated in long-term waste storage containers” funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), the potential application of catalytic recombiner devices inside the storage containers is investigated. In this context, a suitable catalyst based on the so-called intelligent automotive catalyst for use in a recombiner is under consideration. The catalyst is originally developed and mass-produced for automotive exhaust gas purification, and is characterized by having a self-healing function of precious metals (Pd, Pt and Rh) dissolved as a solid solution in the perovskite type oxides. The basic features of this catalyst have been tested in an experimental program. The test series in the REKO-4 facility has revealed the basic characteristics of the catalyst required for designing the recombiner system. 相似文献
58.
Kunihiro Ogata Tokio Umino Tsuyoshi Nakayama Eiichi Ono Toshiaki Tsuji 《Advanced Robotics》2017,31(6):303-310
Development of clothing in consideration of the shape and body function of a person with spinal cord injury is an important task. Then, a dummy robot with a deformation mechanism was developed in this study for evaluating the comfortable level of clothings. Specifically, a trunk joint mechanism and an abdominal mechanism that can realize various deformations of the abdominal area and various trunk poses were developed. The trunk joint mechanism was implemented in order to simulate the seated posture of persons with spinal cord injury. The abdominal deformation mechanism was implemented using linear actuators and rotating servomotors in order to simulate abdominal obesity of persons with spinal cord injury. Further, a tactile sensor system was developed for measuring the clothing pressure on the abdominal area and evaluating the comfort or discomfort of clothing. 相似文献
59.
Kazuo Nakajima Satoshi Ono Ryota Murai Yuzuru Kaneko 《Journal of Electronic Materials》2016,45(6):2837-2846
60.
Shiho Suzuki Mariko Ono Toshiya Toda Shinichi Kitamura 《Journal of Applied Glycoscience》2016,63(1):1
We studied the structure of alginates extracted from five commercial Saccharina (Laminaria) species including three varieties (eight samples in all) harvested in Hokkaido, Japan. The algae used were Saccharina japonica, S. japonica var. diabolica, S. japonica var. ochotensis, S. japonica var. religiosa, S. longissima, S. coriacea, S. angustata, and S. sculpera (Kjellmaniella crassiforia). These alginates have molar fractions of mannuronic acid (FM) ranging from 0.68 to 0.76 and weight average molecular weights (Mws) ranging from 511,000 to 616,000. Alginate samples from both S. angustata (FM = 0.76) and S. longissima (FM = 0.68) showed intestinal immunological activity through Peyer’s patch cells of C3H/HeJ mice. Low molecular weight S. angustata alginate (FM = 0.75, Mw = 70,000) degraded using a wet pulverizing system showed higher activity than the native one. 相似文献