全文获取类型
收费全文 | 582篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 23篇 |
综合类 | 1篇 |
化学工业 | 77篇 |
金属工艺 | 17篇 |
机械仪表 | 4篇 |
建筑科学 | 11篇 |
矿业工程 | 1篇 |
能源动力 | 19篇 |
轻工业 | 36篇 |
水利工程 | 1篇 |
无线电 | 118篇 |
一般工业技术 | 79篇 |
冶金工业 | 155篇 |
原子能技术 | 7篇 |
自动化技术 | 46篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 15篇 |
2012年 | 11篇 |
2011年 | 24篇 |
2010年 | 11篇 |
2009年 | 20篇 |
2008年 | 25篇 |
2007年 | 14篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 19篇 |
2002年 | 8篇 |
2001年 | 10篇 |
2000年 | 8篇 |
1999年 | 13篇 |
1998年 | 69篇 |
1997年 | 56篇 |
1996年 | 34篇 |
1995年 | 25篇 |
1994年 | 13篇 |
1993年 | 19篇 |
1992年 | 12篇 |
1991年 | 16篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 13篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有595条查询结果,搜索用时 531 毫秒
91.
K. Tanabe H. Sasaki H. Hattori K. Ouchi K. Makino H. Itoh G. Takeya 《Fuel Processing Technology》1979,2(4):253-259
The activities of fourteen kinds of catalysts for the hydrocracking of Taiheiyo coal were examined by a high pressure differential thermal analytical method. Exothermic peaks appeared at low temperatures (420–430°C) when MoO3TiO2, NiY zeolite and CoY zeolite were used as catalysts, indicating that these catalysts are highly active compared with other catalysts including MoO3CoOAl2O3. The qualitative analysis of gas and liquid products revealed that MoO3TiO2 and CoY are good catalysts for the liquefaction reaction. The hydrogenation ability of the catalyst is concluded to be more important than its acidic property. 相似文献
92.
A dynamic model for partly gain-coupled 1.55 μm MQW DFB lasers consisting of etched strained-layer multiquantum wells is presented. For the modulation and noise characteristics of DFB lasers, analytical expressions which take into account both the longitudinal distribution of laser parameters and carrier transport effects are derived for the first time using the transfer-matrix method. As a numerical example, the relaxation oscillation frequency is compared to experimental results, and reasonable agreements are obtained between the theory and experiment 相似文献
93.
94.
95.
E.s.r. spectra of peroxy radicals trapped in isotactic and atactic polypropylenes have been observed at various temperatures. The spectrum observed at 77 K was shown to be composed of one component by comparing it with that at 4 K. The spectra observed at higher temperatures comprised of two spectra arising from the rigid peroxy radicals and the mobile peroxy radicals. All of the observed spectra have been reconstructed by means of computer simulation and the changes in anisotropic g-values with temperature were estimated. The motion of the mobile fraction was shown to be rotation or rotatory vibration of the radicals around the chain axis both in the isotactic polypropylene and in the atactic polypropylene as well as in polyethylene and poly(tetrafluoroethylene) although the structures of the polymers are different, that is helical (polypropylene) or planar zigzag (polyethylene, poly(tetrafluoroethylene)). 相似文献
96.
M. Nagase H. Namatsu K. Kurihara K. Iwadate K. Murase T. Makino 《Microelectronic Engineering》1996,30(1-4):419-422
The resist pattern fluctuations on the nano-scale are successfully observed using a dynamic force mode AFM. A scaling analysis based on the fractals applies to the AFM images for quantitative evaluation of the fluctuations. The standard deviation of width fluctuations in a ZEP resist pattern is 2.8 nm. The scaling analysis confirms that the surface morphology of the pattern sidewall is almost the same as that of the resist film lightly exposed by an electron beam. The main cause of the fluctuation is structures with a diameter of 20–30 nm which are composed of large groups of molecules. 相似文献
97.
T Mano K Iwase R Hayashi N Hayakawa K Uchimura M Makino M Nagata Y Sawai N Oda M Hamada T Aono A Nakai A Nagasaka M Itoh 《Canadian Metallurgical Quarterly》1998,315(4):230-232
Chylous fistula complicates 1.1% of all radical neck dissections, and 2.4% of left-sided dissections. The standard treatment of established chylous leak in the reported cases is a pressure dressing applied to the lower neck. Here we present a case of chylous fistula, where conservative methods failed to cope with this complication. The additional application of a fibrin adhesive set was a successful modality of treatment. 相似文献
98.
High-speed performance of partly gain-coupled 1.55-μmstrained-layer multiple-quantum-well DFB lasers
A partly-gain-coupled 1.55-μm distributed feedback (DFB) laser with a strained-layer multiple-quantum-well (MQW) active region with high relaxation oscillation frequency and maximum intrinsic bandwidth of 28 GHz is reported. An effective differential gain of 1.80×10-15 cm2 was achieved, which may be attributed to the strain effect in the MQW active region as well as the combination of the longitudinal gain/index coupling mechanism and fast lateral carrier injection from the cladding layers into the wells 相似文献
99.
Y Morita M Yamamura M Kawashima S Harada K Tsuji K Shibuya K Maruyama H Makino 《Canadian Metallurgical Quarterly》1998,41(9):1669-1676
BACKGROUND AND PURPOSE: To detect areas of cerebral perfusion from bypass arteries after vascular reconstruction, we administered selective intraarterial microsphere tracer into the external carotid arteries and determined (via single-photon emission computed tomography [IA-SPECT]) whether the distribution of radiotracer matched the arteriographic distribution of contrast material as shown on external carotid angiograms. METHODS: We compared the extent of regional distribution of tracer after external carotid artery injection of 20 to 40 MBq of 99mTc-HMPAO or 99mTc-ECD with that of contrast medium on the external carotid angiograms in 582 cortical regions in 12 patients with atherosclerotic occlusive disease and in 18 patients with moyamoya disease. RESULTS: Marked accumulation of tracer was found only in the expected, specific, newly developed areas of cerebral perfusion from bypass arteries. The regional distribution of tracer corresponded to that of contrast medium in 523 regions (90%) and did not correspond in 59 regions (10%). Significant overestimation of the distribution of contrast material relative to that of tracer was observed in the patients with moyamoya disease. CONCLUSION: SPECT showed slightly different distribution of tracer from that predicted by conventional angiography. IA-SPECT should enhance the analysis of newly developed areas of cerebral perfusion from the bypass arteries. 相似文献
100.
N. Araki D. W. Tang A. Makino M. Hashimoto T. Sano 《International Journal of Thermophysics》1998,19(4):1239-1251
The effective thermal conductivity of dispersed composites with a hot-melt-adhesive matrix, measured using the steady-state method, is compared with the apparent thermal conductivity calculated from the average heat capacity and from the thermal diffusivity measured by the laser-flash method. The transient effect has been observed obviously at higher volume percentages for various dispersed particle sizes and ratios of the thermal conductivity values of dispersed and continuous phases. All of the experimental results are compared with those calculated by existing models and by the finite element method (FEM). An attempt has been made to show how the criterion for the homogeneity of dispersed composites under transient conditions is affected by the percentages of dispersed phase, dispersed particle size, and ratio of the thermal conductivity values of dispersed and continuous phases. 相似文献