全文获取类型
收费全文 | 1528篇 |
免费 | 12篇 |
专业分类
电工技术 | 8篇 |
综合类 | 1篇 |
化学工业 | 95篇 |
金属工艺 | 11篇 |
机械仪表 | 2篇 |
建筑科学 | 27篇 |
能源动力 | 8篇 |
轻工业 | 20篇 |
水利工程 | 7篇 |
石油天然气 | 1篇 |
无线电 | 34篇 |
一般工业技术 | 66篇 |
冶金工业 | 1225篇 |
自动化技术 | 35篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 9篇 |
2018年 | 3篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 15篇 |
2011年 | 11篇 |
2010年 | 12篇 |
2009年 | 9篇 |
2008年 | 15篇 |
2007年 | 13篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 36篇 |
1998年 | 337篇 |
1997年 | 190篇 |
1996年 | 142篇 |
1995年 | 73篇 |
1994年 | 77篇 |
1993年 | 77篇 |
1992年 | 18篇 |
1991年 | 32篇 |
1990年 | 22篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1987年 | 27篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 2篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 15篇 |
1980年 | 10篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 30篇 |
1976年 | 94篇 |
1975年 | 6篇 |
1930年 | 1篇 |
排序方式: 共有1540条查询结果,搜索用时 31 毫秒
91.
TA Serel G Akhan HR Koyuncuo?lu A Oztürk K Do?ruer S Unal K Celik 《Canadian Metallurgical Quarterly》1997,31(6):537-539
The treatment and favorable outcome of a bitch with uterine torsion and two retained fetuses are described. The condition was corrected surgically by ovariohysterectomy. Complications (i.e., septic shock, peritonitis, and hemostatic abnormalities) were managed with aggressive medical therapy. Torsion of the gravid uterus in dogs is a life-threatening condition which can have a successful outcome if medical complications encountered in the pre- and postoperative periods are treated quickly and effectively. 相似文献
92.
J. E. Epperson B. A. Loomis J. Faber J. S. Lin R. W. Hendricks 《Metallurgical and Materials Transactions A》1987,18(12):2027-2035
The phase separation at 550 °C in a Ni-12.7 at. pct Al alloy was investigated by means of small angle X-ray scattering, large
angle X-ray scattering, electrical resistivity, and transmission electron microscopy. It was found that an abrupt change in
the electrical resistivity and small angle scattering occurred within 15 seconds at 550 °C, following quenching from 1060
°C, and transmission electron microscopy confirmed the presence of small nuclei. However, after this period of rapid change,
there was an incubation period of about ten hours in which there was minimal net growth of the nuclei. After the incubation
period, growth was accelerated. High angle side bands were observed after a few minutes annealing, and their development closely
paralleled the growth of the nuclei and precipitate particles at this temperature. For times beyond the incubation period,
small angle X-ray scattering diagrams from single crystals became markedly anisotropic, indicating a quasi-regular spatial
distribution of particles. The large and rapid change, in both electrical resistivity and in X-ray small angle scattering,
observed after annealing at 550 °C of samples quenched from 1060 °C was attributed to the formation of tiny regions of short
range ordered Ni3Al which constitute subcritical nuclei. 相似文献
93.
Tove Faber Frandsen 《Scientometrics》2008,74(3):439-451
This paper presents a study of possible changes in patterns of document types in economics journals since the mid-1980s. Furthermore,
the study includes an analysis of a possible relation between the profile of a journal concerning composition of document
types and factors such as place of publication and JIF. The results provide little evidence that the journal editors have
succeeded in manipulating the distribution of document types. Furthermore, there is little support for the hypothesis that
journal editors decrease the number of publications included in the calculation of JIF or for that matter for the hypothesis
that journal editors increase the number of publications not included in the calculation of JIF. The results of the analyses
show that there is a clear distinction of journals based on place of publication and JIF 相似文献
94.
95.
96.
97.
C.-H.H. Hsiung A.J. Pyzik F. De Carlo X. Xiao S.R. Stock K.T. Faber 《Journal of the European Ceramic Society》2013,33(3):503-513
Porous acicular mullite (ACM) ceramics are known to be mechanically robust even at high porosities. This study was undertaken to better understand what aspects of acicular mullite's needle-like microstructure affect the overall mechanical properties and how the microstructure might be modified to improve mechanical performance. ACMs with a variety of porosities, pore sizes, and needle diameters were produced, and their elastic moduli, flexure strengths, and fracture toughnesses were measured. Three-dimensional image analysis was an invaluable tool in determining the needle diameters of these complex 3D network structures. It was found that porosity was the most dominant factor in determining the mechanical properties of ACM and that its behavior could be described using the Gibson–Ashby foam model. 相似文献
98.
Nadja Straue Martin Rauscher Sabine Walther Hendrik Faber Andreas Roosen 《Journal of Materials Science》2009,44(22):6011-6019
The production of printed electronics exhibits an enormous economical potential due to the possibility to manufacture innovative
products at low cost. At the moment, one of the major challenges for the fabrication of printed electronics is the controllability
of the material properties during processing and the miniaturization of the deposited structures. In this context, the application
of soft lithographic techniques appears promising, because they allow a defined patterning of the materials in the range of
few nanometers, which is far below the limits of other printing techniques like inkjet-printing or screen printing. This work
proves the applicability of the soft lithographic technique micro-molding in capillaries (MIMIC) for the manufacture of conductive
indium tin oxide (ITO) electrodes. For the creation of stable dispersions of ITO nano-sized particles, steric as well as electrostatic
stabilization concepts are applied. The prepared dispersions are characterized with regard to the later processing via MIMIC.
The geometry and the electrical properties of the soft lithographically deposited structures are determined to prove their
functionality. Special attention is paid to the influence of the wetting behavior of the dispersions on the resulting geometry
of the structures. Finally, the applicability of the optimized structures is demonstrated by the assembly of a thin film transistor
(TFT), in which the deposited structures serve as source and drain electrodes. 相似文献
99.
An electrodeposition technique has been adapted to produce copper–silicon carbide composites with honeycomb-like microstructures. The detrimental Cu–SiC reaction was avoided by using this room temperature processing technique. The wood-derived silicon carbide phase allows for tailorable microstructures due to the variety of available wood precursors. Plating efficiency for each wood type was determined using image analysis. This processing method results in the successful filling of pores with aspect ratios of up to 100. 相似文献
100.
Jorge Henrique Faber Boog 《Fuel》2011,90(2):905-907
A simple low cost method is proposed for the quantitative analysis of residual alcohol in biodiesel through determination of the flash point, with which it is correlated. Methyl ester biodiesels from vegetable oils such as corn, soy and sunflower were prepared. The ethyl ester was obtained from soy oil and methyl biodiesel was also synthesized from bovine fat. In all cases it became very evident that there is a direct correlation between the flash point and the residual alcohol content in the prepared biodiesel. Therefore this parameter can be used to directly determine the residual alcohol content of the product. 相似文献