全文获取类型
收费全文 | 701篇 |
免费 | 27篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 49篇 |
综合类 | 1篇 |
化学工业 | 195篇 |
金属工艺 | 31篇 |
机械仪表 | 39篇 |
建筑科学 | 5篇 |
能源动力 | 25篇 |
轻工业 | 51篇 |
水利工程 | 4篇 |
石油天然气 | 4篇 |
无线电 | 24篇 |
一般工业技术 | 169篇 |
冶金工业 | 53篇 |
原子能技术 | 27篇 |
自动化技术 | 53篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 18篇 |
2014年 | 25篇 |
2013年 | 46篇 |
2012年 | 33篇 |
2011年 | 43篇 |
2010年 | 23篇 |
2009年 | 33篇 |
2008年 | 31篇 |
2007年 | 31篇 |
2006年 | 29篇 |
2005年 | 24篇 |
2004年 | 19篇 |
2003年 | 26篇 |
2002年 | 22篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 19篇 |
1998年 | 18篇 |
1997年 | 15篇 |
1996年 | 14篇 |
1995年 | 7篇 |
1994年 | 16篇 |
1993年 | 12篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 2篇 |
排序方式: 共有730条查询结果,搜索用时 693 毫秒
91.
92.
93.
Masaki Saito Nobuo Yamaoka Keiji Miyazaki Masahiko Kinoshita Yoshihito Abe 《Nuclear Engineering and Design》1994,146(1-3)
To study the effects of reduced gravity on the flow regime and the heat transfer characteristics of a boiling two-phase horizontal flow, parabolic flight experiments were performed by using an aircraft. The gravity level during the parabolic flight and the duration time were about −0.01ge +0.01ge and 20 s, respectively. Under earth gravity, many small bubbles are detached very frequently from the heater rod surface, flowing into the upper stream due to the buoyancy and resulting in a stratified flow in the cases of lower inlet fluid velocity and higher heat flux. Under microgravity conditions, bubbles are hardly detached from the heater rod, growing and coalescing to become much larger along the heater rod, surrounding the heater rod in the downstream. This tendency was more noticeable in the cases of lower inlet fluid velocity, higher heat flux and lower inlet fluid subcooling. The local heat transfer coefficients at the bottom of the heater rod tend to decrease slightly under microgravity compared with those under earth gravity because of the reduction of the heat removal due to natural convection. On the other hand, the local heat transfer coefficients at the top of the heater rod tend to increase slightly under microgravity. However, the differences of the local heat transfer coefficients are very small in spite of large differences of the flow regimes under earth gravity and microgravity. 相似文献
94.
Keiji Katsuno Akihiro Nishioka Tomonori Koda Ken Miyata Go Murasawa Yoshiko Nakaura Naoyoshi Inouchi 《Starch - St?rke》2010,62(9):475-479
The present study investigated a novel milling method for producing amorphous rice starch without adding water. A new type of milling machine was developed (termed the shear and heat milling machine (SHMM)), which is capable of applying mechanical shear and heat during the milling process. The SHMM consisted of a pair of rice mortars attached to a servomotor and a ring heater. The heater was installed on the upper mortar; the temperature of the upper mortar was monitored and controlled by a thermal controller. Wide‐angle X‐ray diffraction (WAXD) analysis was used to determine the crystallinities of starch in rice flour samples produced using the SHMM at different milling temperatures. The WAXD data for milled rice flour that had been heated exhibited no diffraction peaks. This experimental result demonstrates that the developed SHMM produces amorphous rice starch easily by milling with heating without the addition of water. The milling conditions such as the shear and heat applied can be used to control the crystallinity of starch in rice. 相似文献
95.
Terry Wall Yinghui Liu Chris Spero Liza Elliott Sameer Khare Renu Rathnam Farida Zeenathal Behdad Moghtaderi Bart Buhre Changdong Sheng Raj Gupta Toshihiko Yamada Keiji Makino Jianglong Yu 《Chemical Engineering Research and Design》2009,87(8):1003-1016
Oxyfuel combustion is seen as one of the major options for CO2 capture for future clean coal technologies. The paper provides an overview on research activities and technology development through a fundamental research underpinning the Australia/Japan Oxyfuel Feasibility Project. Studies on oxyfuel combustion on a pilot-scale furnace and a laboratory scale drop tube furnace are presented and compared with computational fluid dynamics (CFD) predictions. The research has made several contributions to current knowledge, including; comprehensive assessment on oxyfuel combustion in a pilot-scale oxyfuel furnace, modifying the design criterion for an oxy retrofit by matching heat transfer, a new 4-grey gas model which accurately predicts emissivity of the gases in oxy-fired furnaces has been developed for furnace modelling, the first measurements of coal reactivity comparisons in air and oxyfuel at laboratory and pilot-scale; and predictions of observed delays in flame ignition in oxy-firing. 相似文献
96.
Yukari Totsuka Takashi Higuchi Toshio Imai Akiyoshi Nishikawa Takehiko Nohmi Tatsuya Kato Shuich Masuda Naohide Kinae Kyoko Hiyoshi Sayaka Ogo Masanobu Kawanishi Takashi Yagi Takamichi Ichinose Nobutaka Fukumori Masatoshi Watanabe Takashi Sugimura Keiji Wakabayashi 《Particle and fibre toxicology》2009,6(1):1-11
Background
Recently, manufactured nano/microparticles such as fullerenes (C60), carbon black (CB) and ceramic fiber are being widely used because of their desirable properties in industrial, medical and cosmetic fields. However, there are few data on these particles in mammalian mutagenesis and carcinogenesis. To examine genotoxic effects by C60, CB and kaolin, an in vitro micronuclei (MN) test was conducted with human lung cancer cell line, A549 cells. In addition, DNA damage and mutations were analyzed by in vivo assay systems using male C57BL/6J or gpt delta transgenic mice which were intratracheally instilled with single or multiple doses of 0.2 mg per animal of particles.Results
In in vitro genotoxic analysis, increased MN frequencies were observed in A549 cells treated with C60, CB and kaolin in a dose-dependent manner. These three nano/microparticles also induced DNA damage in the lungs of C57BL/6J mice measured by comet assay. Moreover, single or multiple instillations of C60 and kaolin, increased either or both of gpt and Spi- mutant frequencies in the lungs of gpt delta transgenic mice. Mutation spectra analysis showed transversions were predominant, and more than 60% of the base substitutions occurred at G:C base pairs in the gpt genes. The G:C to C:G transversion was commonly increased by these particle instillations.Conclusion
Manufactured nano/microparticles, CB, C60 and kaolin, were shown to be genotoxic in in vitro and in vivo assay systems. 相似文献97.
Kenta Inagaki Takatoshi Hijikata Takeshi Tsukada Tadafumi Koyama Keiji Ishikawa Shoichi Ono 《Journal of Nuclear Science and Technology》2014,51(7-8):906-915
A simulation code was developed to evaluate the performance of the cesium adsorption instrument operating in Fukushima Daiichi Nuclear Power Station. Since contaminated water contains seawater whose salinity is not constant, a new model was introduced to the conventional zeolite column simulation code to deal with the variable salinity of the seawater. Another feature of the cesium adsorption instrument is that it consists of several columns arranged in both series and parallel. The spent columns are replaced in a unique manner using a merry-go-round system. The code is designed by taking those factors into account. Consequently, it enables the evaluation of the performance characteristics of the cesium adsorption instrument, such as the time history of the decontamination factor, the cesium adsorption amount in each column, and the axial distribution of the adsorbed cesium in the spent columns. The simulation is conducted for different operation patterns and its results are given to Tokyo Electric Power Company (TEPCO) to support the optimization of the operation schedule. The code is also used to investigate the cause of some events that actually occurred in the operation of the cesium adsorption instrument. 相似文献
98.
YanXin Dan Takashi Costa Atsushi Nakamura Keiji Komatsu Hidetoshi Saitoh 《Ceramics International》2021,47(9):11862-11869
The morphology and microstructure of splats impact the comprehensive capability of a new coating methodology called chelate flame spraying (CFS). This study addresses the quantitative characterization of the spread morphologies of flame sprayed Er2O3 splats directly deposited under different spray conditions on aluminum alloy substrates with a mirror finish. The influence of the in-flight particle temperature and velocity, carrier gas type, and carrier gas ratio on the solidification mechanism of molten droplets was investigated. Image analysis methods were employed to identify single splats from the morphology observed with field-emission scanning electron microscopy (FE-SEM). In addition, Er2O3 films were synthesized on an Al–Mg alloy (A5052) substrate using N2 or O2 as the carrier gas. When O2 was used as the carrier gas, 109-μm-thick films were deposited on the A5052 substrate. The cross-sectional porosity of the films was 3.8%. In contrast, films with 101-μm thickness were synthesized on the A5052 substrate when N2 was used as the carrier gas. The cross-sectional porosity of these films was 13.8%. The results showed that the carrier gas type (N2) and carrier gas ratio had a significant effect on the flattening behavior of the molten droplets. A spraying method combined with multidimensional modes is proposed to control the morphology of the splats. 相似文献
99.
100.
The dissolution of refrigerant into a lubricant causes a decrease in viscosity of the oil and it gives a large effect on the lubrication of sliding parts in a refrigerant compressor. This paper describes an application of micro FT-IR to measure the two-dimensional concentration distribution of refrigerant held in solution in the EHL film surrounded by the refrigerant gas and discusses the refrigerant concentration variation in the vicinity of the Hertzian contact area. In order to measure the concentration distribution, an apparatus which can observe the EHL film in a point contact in the refrigerant atmosphere was developed. The refrigerant concentration was measured using micro FT-IR through a CaF2 window from outside of the apparatus with polyol ester as a base oil in an atmosphere pressurized with HFC-134a refrigerant gas. The results indicate that the concentration of HFC-134a refrigerant reduces in the inlet boost region of EHL contact and the Hertzian contact area but in the side region of Hertzian contact area it is greater than that in the bulk fluid. In addition, the effect of the variation on the oil film thickness is discussed. 相似文献