全文获取类型
收费全文 | 292篇 |
免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 43篇 |
金属工艺 | 3篇 |
机械仪表 | 9篇 |
建筑科学 | 4篇 |
能源动力 | 4篇 |
轻工业 | 23篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 114篇 |
一般工业技术 | 43篇 |
冶金工业 | 31篇 |
原子能技术 | 3篇 |
自动化技术 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 20篇 |
2011年 | 13篇 |
2010年 | 12篇 |
2009年 | 14篇 |
2008年 | 7篇 |
2007年 | 22篇 |
2006年 | 7篇 |
2005年 | 17篇 |
2004年 | 12篇 |
2003年 | 11篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 12篇 |
1999年 | 20篇 |
1998年 | 19篇 |
1997年 | 20篇 |
1996年 | 3篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1970年 | 1篇 |
1923年 | 1篇 |
1909年 | 2篇 |
1899年 | 1篇 |
排序方式: 共有295条查询结果,搜索用时 15 毫秒
1.
Polycrystalline Cu(In,Ga)Se2 (CIGS) films with various ratios of Cu, In, and Ga were grown by codeposition of all elements in vacuum. The X-ray diffraction
study showed that the films are single-phase and possess a chalcopyrite structure with predominant [112] orientation. The
films exhibited a mirror smooth surface and had a close-packed structure composed of crystallites with clear faceting and
a transverse size of 0.1–0.3 μm. Related surface barrier structures of the (In,Ag)/Cu(In,Ga)Se2 type were obtained and their spectra of the quantum efficiency of photoconversion were studied. The obtained structures can
be used for optimization of the CIGS film technology. 相似文献
2.
E. V. Astrova V. V. Ratnikov R. F. Vitman A. A. Lebedev A. D. Remenyuk Yu. V. Rud’ 《Semiconductors》1997,31(10):1084-1090
The results of an investigation of layers of porous silicon (PS), which was obtained by electrochemical etching of p-Si under different illumination conditions — natural light, incandescent light, and light from a mercury lamp with and without
a filter — are reported. The structure of the layers was studied by double-crystal x-ray diffractometry, the composition was
monitored by means of the IR absorption spectra, and the radiative properties were monitored according to the photoluminescence
(PL) spectra. It was established that electrochemical etching under illumination produces PS with a higher porosity and more
intense PL whose maximum is shifted into the short-wavelength region. These changes are accompanied by a large disordering
of the structure and an increase in the oxygen content in the layer. It is concluded that illumination accelerates the chemical
interaction of PS with the electrolyte due to oxidation. High-porosity porous silicon stored in air exhibits quenching of
PL. Conversely, PL is excited in layers with a lower porosity. Aging of PS is characterized by an increase in the microdeformation
of the layers, a decrease in the crystallite sizes with a partial loss of coherence between the crystallites and the substrate,
and an increase in the fraction of the amorphous phase.
Fiz. Tekh. Poluprovodn. 31, 1261–1268 (October 1997) 相似文献
3.
A. A. Vaipolin Yu. A. Nikolaev V. Yu. Rud’ Yu. V. Rud’ E. I. Terukov 《Semiconductors》2003,37(4):414-416
Photosensitive structures of surface-barrier and homojunction types have been fabricated for the first time on the basis of ZnIn2Se4 single crystals. The spectral dependence of the quantum efficiency of photoconversion has been studied and discussed. It is concluded that the structures are promising for commercial applications. 相似文献
4.
After designing a method of handling cattle so that they reproducibly developed DFD meat, pH and temperature in cattle developing DFD and normal meat, respectively were studied. The influence of low voltage stimulation on both groups was also investigated. Depending on final pH and other characteristics of the meat, the carcasses could be assigned to subgroups representing pronounced DFD, slight DFD and normal meat, with and without electrical stimulation. In normal and in pronounced DFD carcasses electrical stimulation speeded up the pH drop but did not affect the final state of the meat. In stressed animals the pH values are variable for the first few hours post mortem. This effect is enhanced by electrical stimulation which, in carcasses with slight DFD (from stressed but not exhausted animals), may produce extremely fast pH drop and PSE-like meat. There is no evidence that electrical stimulation would influence the incidence of DFD in cattle slaughtered under commercial conditions. In normal animals electrical stimulation raised the carcass temperature during the first few hours post mortem by approximately 2°C. Carcasses from stressed animals had a higher temperature, independent of stimulation. 相似文献
5.
Helen M. Snaith Corresponding author Martin Gade Gordon W. Jolly Antoine Mangin Vittorio Barale Ove Rud 《International journal of remote sensing》2013,34(7-8):1341-1347
The Clean Seas project focused on the role that existing Earth observing satellites might play in monitoring marine pollution. Results are presented here from August 1997, for the North Sea test site, using sea surface temperature (SST), colour and synthetic aperture radar (SAR) images in conjunction with a hydrodynamic model. There was good correlation between data sources, e.g. between SST and ERS-2 SAR images. Both datasets showed the development of fine plume structures close to the Rhine outflow, apparently associated with the outflow, and possibly caused by tidal pulsing of the Rhine Plume. The model reproduced general temperature and sediment distributions well, but fine structures were not reproduced. Model sediment distribution patterns were verified using ‘chlorophyll concentration’ data from colour sensors, representative of sediment concentration in turbid water. In conjunction with the visible channels of the Advanced Very High Resolution Radiometer and Along-Track Scanning Radiometer, they give an uncalibrated measure of the sediment load. The model gives a more complete picture of the temporal dispersion of the Rhine Plume over time than is evident from the remotely sensed data alone. 相似文献
6.
V. Yu. Rud’ Yu. V. Rud’ E. I. Terukov T. N. Ushakova G. A. Il’chuk 《Semiconductors》2014,48(4):455-458
A new non-vacuum technology is proposed and anisotype photosensitive heterojunctions (native oxide of a narrow-gap III–V semiconductor)-(binary compound) p-GaSb(Ox)/n-GaSb are fabricated for the first time. The developed technological process is based on the surface thermal interaction of a GaSb crystal with components of the normal Earth atmosphere. Based on original physical-technological studies of interaction in the GaSb/(air medium) system, it is found that p-GaSb(Ox) native-oxide films obtained in such a way exhibit high adhesion to the surface of the initial gallium antimonide n-GaSb. The steady-state current-voltage characteristics and spectral dependences of the relative photoconversion quantum efficiency of the obtained p-GaSb(Ox)/n-GaSb heterojunctions are first measured. On this basis, the systematic features of charge transport and photosensitivity are discussed. A new possible application of the non-vacuum thermal oxidation of GaSb films in the development of optical radiation photodetectors on substrates of homogeneous gallium antimonide n-GaSb crystals is first detected and implemented. 相似文献
7.
8.
9.
10.