全文获取类型
收费全文 | 692篇 |
免费 | 27篇 |
学科分类
工业技术 | 719篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 22篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 13篇 |
2015年 | 11篇 |
2014年 | 26篇 |
2013年 | 31篇 |
2012年 | 15篇 |
2011年 | 38篇 |
2010年 | 33篇 |
2009年 | 28篇 |
2008年 | 24篇 |
2007年 | 26篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 25篇 |
2002年 | 21篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 53篇 |
1997年 | 38篇 |
1996年 | 34篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 16篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1986年 | 1篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 8篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有719条查询结果,搜索用时 15 毫秒
1.
In order to investigate the influence of puffer volume V/sub P/ and operating force to dielectric performance of GCB at current interruption, we calculated the prospective dielectric withstand voltage V/sub W/ between arcing contacts. The withstand voltage was calculated by the electric field strength appeared on arcing contacts and the allowable electric field strength E/sub W//sup */ of hot gas due to thermal puffer action. We could clarify that large initial puffer volume V/sub P/ can increase withstand voltage V/sub W/ at current breaking point and also that an optimum point exists in operating force F. For example, it was found that in case of the operating force of 1000 kgf, the puffer volume V/sub P/ of 1.2 liter would be best choice in the interrupting condition of i=50 kA and arcing time of 1.35 cycle. 相似文献
2.
Tetsuya Ikuta Yuki Miyanami Hayato Iwamoto Takayoshi Shimura Kiyoshi Yasutake 《Science and Technology of Advanced Materials》2007,8(3):142-145
Selective epitaxial Si with a high arsenic concentration of 2.2×1019 atoms/cm3 was deposited at a high growth rate of 3.3 nm/min under atmospheric pressure. It was confirmed that this method had excellent selectivity and produced films having good crystalline quality, abrupt dopant profiles at the interfaces, and smooth surfaces. The growth mechanism is discussed in terms of the relationship between the effects of arsenic surface segregation and etching by hydrogen chloride. 相似文献
3.
4.
M Miyata E Fukaya T Takagi K Watanabe H Saito M Ito R Yoshioka Y Kazuta Y Yusa A Irisawa Y Sato T Nishimaki H Kumakawa R Kasukawa 《Canadian Metallurgical Quarterly》1998,37(12):1058-1063
Two patients with polymyositis (PM) or dermatomyositis (DM) complicated with massive pleural effusion are reported here. Both patients presented a high-grade fever, pleural effusion prominent on the right, and good response to steroid therapy. In a 50-year-old woman with PM, combined process of pleural inflammation, cardiomyopathy and coexisting hypothyroidism were considered to be responsible for the accumulation of the massive pleural effusion. However, in a 34-year-old man with DM, pleural inflammation associated with interstitial pneumonia or pleural microvasculopathy in DM was considered to be responsible for the accumulation of the massive pleural effusion. 相似文献
5.
A unique substrate MCPM (Mitsubishi Copper Polyimide Metal-base) technology has been developed by applying our basic copper/polyimide
technology.1 This new substrate technology MCPM is suited for a high-density, multi-layer, multi-chip, high-power module/package, such
as used for a computer. The new MCPM was processed using a copper metal base (110 × 110 mm), full copper system (all layers)
with 50-μm fine lines. As for pad metallizations for the IC assembly, we evaluated both Ni/Au for chip and wire ICs and solder
for TAB ICs. The total number of assembled ICs is 25. To improve the thermal dispersion, copper thermal vias are simultaneously
formed by electro-plating. This thermal via is located between the IC chip and copper metal base, and promotes heat dispersion.
We employed one large thermal via (4.5 mm?) and four small vias (1.0 mm?) for each IC pad. The effect of thermal vias and/or base metal is simulated by a computer analysis and compared with an alumina
base substrate. The results show that the thermal vias are effective at lowering the temperature difference between the IC
and base substrate, and also lowering the temperature rise of the IC chip. We also evaluated the substrate’s reliability by
adhesion test, pressure cooker test, etc. 相似文献
6.
Tomohito Kameda Kazuya Horikoshi Shogo Kumagai Yuko Saito Toshiaki Yoshioka 《中国化学工程学报》2021,28(12):2993-3001
In this paper, we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis. We studied the adsorption of artificial waste dialysate, which is a mixed solution of urea, creatinine, and uric acid, and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical. The amount of adsorption was approximately 1.4 mg·g-1 for urea, 18 mg·g-1 for creatinine, and 20 mg·g-1 for uric acid. The urea, creatinine, and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃, and the adsorption capacity of the spherical activated carbon was regenerated. Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process. 相似文献
7.
A significant bulk flow is thought to occur if a part of the body of a suspension, which has a different density from the density of the remainder of the suspension, is large enough in space however slight the difference may be. As a typical case, the slow motion of a swarm of particles in a viscous fluid was studied both theoretically and experimentally. Under a certain condition, the suspended particles formed a drop of suspension, in which the suspended particles and fluid moved as one body in the same way. The falling velocity of a spherical swarm of particles, which was called a drop of suspension, was measured and compared with a new theoretical prediction presented in this paper.It may be also noted that the theoretical model may be applicable to the flow due to density difference by means of replacement of the continuous mass by the damped mass which is regarded as consisting of particles. 相似文献
8.
Tsugio Sato Kenji Dosaka Toshiaki Yoshioka Akitsugu Okuwaki Kazuo Torii Yoshiro Onodera 《Journal of the American Ceramic Society》1992,75(3):552-556
Amorphous CeO2 –ZrO2 gels were prepared by coprecipitation in ammonia solutions. The onset of crystallization of the gels, from calcining in air, was 420°C, while 200° to 250°C in the presence of water and organic solvents such as methanol and ethanol. The sintering behaviors of CeO2 –ZrO2 powders were sensitive to the crystallizing conditions, since hard agglomerates formed when the precipitated gels were crystallized by normal calcination in air, whereas soft agglomerates formed when they were crystallized in water or organic solvents. CeO2 –ZrO2 powders crystallized in methanol and water at 250°C were sintered to full theoretical density at 1150° and 1400°C, respectively, whereas that crystallized by calcination in air at 450°C was sintered to only 95.2% of theoretical density, even at 1500°C. 相似文献
9.
Uniaxially oriented thin films of poly(ethylene terephthalate) (PET), poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) and their blends were prepared by applying shear strain to their respective melts, and the resulting morphologies were studied by transmission electron microscopy. Selected-area electron diffraction of each film revealed well-defined uniaxial orientation of polymer chains in the shearing direction. In the uniaxially oriented thin film of PEN, stacked-lamellar structure with the average long period of 27 nm consisting of a crystalline region about 15 nm thick and an amorphous one about 12 nm thick was found here and there in the dark-field image: PEN-type. On the other hand, stacked-lamellar structure was rarely observed in the case of PET: PET-type. In PET/PEN blends, the morphologies changed from the PET-type to the PEN-type with increasing content of PEN. 相似文献
10.