全文获取类型
收费全文 | 250篇 |
免费 | 8篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 69篇 |
金属工艺 | 2篇 |
机械仪表 | 6篇 |
建筑科学 | 4篇 |
能源动力 | 14篇 |
轻工业 | 30篇 |
水利工程 | 3篇 |
无线电 | 31篇 |
一般工业技术 | 53篇 |
冶金工业 | 13篇 |
原子能技术 | 8篇 |
自动化技术 | 11篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 17篇 |
2012年 | 13篇 |
2011年 | 26篇 |
2010年 | 23篇 |
2009年 | 8篇 |
2008年 | 11篇 |
2007年 | 7篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 12篇 |
2002年 | 12篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有258条查询结果,搜索用时 15 毫秒
1.
Tatsuya Hanaoka Hisashi Ishitani Ryuji Matsuhashi Yoshikuni Yoshida 《Applied Energy》2002,72(3-4):705-721
The objective of this study is to evaluate the potential for recovering fluorocarbons as measures for the abatement of global warming. In this study, we focused on the three different kinds of fluorocarbons: CFCs, HCFCs and HFCs, and targeted refrigerant use because of the availability of relevant data. We first estimated future fluorocarbon emissions from the targeted appliances; we next compared those emissions in the units of CO2 equivalent to the level of CO2 emissions in 1990 from a quantitative point of view. As the result of this study, it was found that fluorocarbon emissions in 1999 and 2010 would be equal to approximately 7 and 3% of the level of CO2 emissions in 1990 respectively. Moreover, if we implement a 100% recovery rate in every recovery route, we can reduce a large amount of emissions which correspond to approximately 2–5% of the level of CO2 emissions in 1990, even if we take into account the energy-related CO2 emissions by the transportation and decomposition of fluorocarbons. 相似文献
2.
M Matsuhashi 《Canadian Metallurgical Quarterly》1994,85(2):251-260
One approach to the treatment of obstructive azoospermic cases in whom either vasovasostomy cannot be performed or the vas deferens is absent is to construct an artificial spermatocele in the epididymis. By using this method to recover sperms for use in AIH, we have succeeded in achieving pregnancy in only 2 of 35 cases, leading us to investigate the fertility of the recovered sperms. Sperm fertility was investigated by the hypoosmotic swelling (HOS) test, observation by confocal laser-scanning microscope (CLSM), flow cytometry and hamster egg sperm penetration test. The percentage of swollen sperm determined by the HOS test was 15.0-83.3%, with a mean of 47.6 +/- 16.1%, significantly lower than the values of the normal group and the infertile male group, excluding cases of obstructed azoospermia. Examination by confocal laser-scanning microscope of samples stained with PI and FITC-PSA or PI and FITC-Con A stain revealed viable and dead spermatozoa as well as viable and dead acrosome-reacted spermatozoa. In addition, fertility was evaluated from the distribution of spermatozoa in each area from the flow cytometry percentage. This method was shown previously to be useful for the evaluation of fertility as it demonstrated the presence of numerous spermatozoa in the fertile area of cases who did not succeeded in pregnancy. The hamster egg sperm penetration test yielded a fertility rate of 0-25% with a mean of 8.2 +/- 10.0%, which was significantly lower than the value of the normal group, but was not significantly different from the infertile group. The findings of this study indicated that the fertility of epididymal sperms is low, thereby pointing to the need for studies to improve the materials used in the artificial spermatocele as well as the method of sperm recovery. Furthermore, our findings suggest that flow cytometry may be used to select the epididymal sperms with the highest fertility for sperm recovery. 相似文献
3.
A Novel UWB Pulse Shape Modulation System 总被引:5,自引:1,他引:4
Ghavami Mohammad Michael Lachlan B. Haruyama Shinichiro Kohno Ryuji 《Wireless Personal Communications》2002,23(1):105-120
In this paper novel modified Hermite polynomial functions for use in impulse radio (ultra-wideband) communications are proposed. With these functions pulse shapes which are orthogonal and have nearly constant pulse width regardless of the pulse order are generated. These properties hold under the effects of differentiation. An M-ary communication system is constructed using these pulse shapes. A Matlab model for generating the pulses is designed and the effect of timing jitter on the performance of the system is investigated by computer simulation. 相似文献
4.
Yoshio Yamashita Hideyuki Jinbo Ryuji Kawazu Takateru Asano Hiroshi Umehara 《Polymer Engineering and Science》1991,31(12):855-859
LMR-UV (“low molecular weight resist for uv lithography”), a naphthoquinone-diazide sulfonic acid ester of a novolak resin, is a negative working resist. The mechanism of insolubilization of LMR-UV is based on the facts that the naphthoquinone-diazide moiety is decomposed to indenecarboxylic acid (polar compound) by photolysis upon UV irradiation and that the irradiated resist film insolubilizes in a non-polar developer. LMR-UV reliably forms 0.6 μm lines and spaces over a reflective substrate with steps by using a g-line stepper having a 0.35 NA lens. 0.6 μm-wide aluminum patterns over topography are obtained by use of g-line exposure and reactive ion etching. By use of an i-line aligner (NA = 0.42), LMR-UV resolves 0.25 μm space patterns with overhang profiles. The profiles are due to the large absorption coefficient of 3.8 μm?1. 0.3 μm wide aluminum patterns are formed by i-line exposure and lift-off metallization. 相似文献
5.
Kiyoshi Itatani Ryuji Tsukamoto Anne C. A. Delsing Hubertus T. Hintzen Isao Okada 《Journal of the American Ceramic Society》2002,85(7):1894-1896
Aluminum nitride (AlN)–silicon carbide (SiC) nanocomposite powders were prepared by the nitridation of aluminum-silicon carbide (Al4 SiC4 ) with the specific surface area of 15.5 m2 ·g−1 . The powders nitrided at and above 1400°C for 3 h contained the 2H-phases which consisted of AlN-rich and SiC-rich phases. The formation of homogeneous solid solution proceeded with increasing nitridation temperature from 1400° up to 1500°C. The specific surface area of the AlN–SiC powder nitrided at 1500°C for 3 h was 19.5 m2 ·g−1 , whereas the primary particle size (assuming spherical particles) was estimated to be ∼100 nm. 相似文献
6.
Control of the Metal–Insulator Transition at Complex Oxide Heterointerfaces through Visible Light
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
8.
Atsushi Yoshida Sho Ohata Tatsuhiro Mori Ryuji Tada Pavla Dagsson-Waldhauserová 《Aerosol science and technology》2016,50(3):1-4
Copyright © 2016 American Association for Aerosol Research 相似文献
9.
Shoji Eita Takahashi Ryuji Isogai Shosei Ito Naoto Kubo Masaki Tsukada Takao Fukuyama Hiroyuki 《Metallurgical and Materials Transactions B》2019,50(5):2454-2458
Metallurgical and Materials Transactions B - Normal spectral emissivity of molten Cu-Fe alloy with different compositions was measured at the wavelength of 807 nm using an electromagnetic... 相似文献
10.
Mutational analysis of structure--activity relationships in human tumor necrosis factor-alpha 总被引:1,自引:0,他引:1
Yamagishi Jun-ichi; Kawashima Hitoshi; Matsuo Noriyuki; Ohue Mayumi; Yamayoshi Michiko; Fukui Toshikazu; Kotani Hirotada; Furuta Ryuji; Nakano Katsuji; Yamada Masaaki 《Protein engineering, design & selection : PEDS》1990,3(8):713-719
To determine the region of human tumor necrosis factor-alpha(TNF-), essential for cytotoxic activity against mouse L-M cells,single amino-acid-substituted TNF- mutant proteins (muteins)were produced in Escherichia coli by protein engineering techniques.An expression plasmid for TNF- was mutagenized by passage throughan E.coli mutD5 mutator strain and by oligonucleotide-directedmutagenesis. Approximately 100 single amino-acid-substitutedTNF- muteins were produced and assayed for cytotoxic activity.The cytotoxic activities of purified TNF- muteins, e.g. TNF-31T,-32Y, -82D, -85H, -115L, -141Y, -144K and -146E, were < 1%of that of parent TNF-. These results indicate that the integrityof at least four distinct regions of the TNF- molecule is requiredfor full biological activity. These regions are designated asfollows: region I, from position 30 to 32; region II, from position82 to 89; region III, from position 115 to 117; region FV, fromposition 141 to 146. In addition, TNF-141Y could not completelycompete with parent TNF- for binding to the receptor. This demonstratesthat region IV, and at least aspartk acid at position 141, mustbe involved in the TNF receptor binding site. 相似文献