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151.
A kinetics of the chemical vapor deposition (CVD) of copper using novel unfluorinated precursor, copper(I)(N(1(dimethylvinylsiloxy)-1-methylethano)-2-imino-4-pentanoate), namely Cu-KI5, was studied. Since its great thermal stability, Cu-KI5 allowed high source temperature to provide high vapor pressure, for example Cu-KI5 has a vapor pressure of 0.2-2.2 Torr at the temperature range of 100-140 °C. Furthermore, copper could be deposited by direct reduction from Cu-KI5 instead of disproportionation. By using formic acid (HCOOH) as a reducing agent, copper films were deposited on ruthenium substrate at temperature range of 150-350 °C. The activation energy was 48.9 kJ/mol in surface reaction limited region (<210 °C) and 1.9 kJ/mol in diffusion limited region (>210 °C) at the total pressure of 5 Torr. Secondary ion mass spectroscopy (SIMS) analysis showed that CVD copper film of high purity (>99.99%) was deposited at 250 °C. The as-deposited copper films grown at 150-300 °C exhibited strong 〈111〉 preferred orientation. The minimum resistivity of the copper film was 1.77 μΩ cm obtained at the deposition temperature of 250 °C. In the surface reaction limited region, kinetic data extracted from experiments enabled 2-D computational simulation to predict copper deposition into trench structures. Simulation results showed excellent step coverage, which was larger than 90% for aspect ratio of 10:1. Cu-KI5 is a promising Cu-CVD precursor for the fabrication of ultra large scale integration (ULSI) or through silicon via (TSV) copper interconnects. 相似文献
152.
阐述金刚石切削工具在机加工中的重要作用和CVD金刚石的优异性能以及CVD金刚石切削工具的形式。对CVD金刚石薄膜切削工具和CVD金刚石厚膜切削工具的特点和应用范围进行了分析对比,并指出存在问题和发展前景。 相似文献
153.
石墨烯因具备宽波段高透光性和良好的导电性而有望成为光学窗口的电磁屏蔽材料。采用AuCl3掺杂方式增加少层石墨烯薄膜的载流子浓度,降低表面电阻值。并通过拉曼光谱对掺杂前后石墨烯薄膜进行表征、对比,得到石墨烯薄膜层数、缺陷、掺杂类型及连续性方面的信息。利用各向异性介质的平面波传输线模型,着重考虑化学势对石墨烯电导率的影响,得到宽波段掺杂石墨烯的屏蔽效能曲线。实验采用屏蔽室法对转移在PET表面的石墨烯薄膜进行屏蔽效能测试,结果表明寡层(1~2层)掺杂石墨烯的平均屏蔽效能在6.7dB左右,与计算值符合较好。 相似文献
154.
干法刻蚀图形化CVD金刚石膜研究进展 总被引:1,自引:0,他引:1
CVD金刚石膜因其极高的强度和耐磨特性在微机电系统(MEMS)领域具有极好的应用前景,然而其极高的硬度和化学惰性又使其很难被加工成型,这极大地限制了CVD金刚石膜在MEMS领域的应用。本文主要介绍了近年来干法刻蚀图形化CVD金刚石膜的研究进展,系统地分析了激光刻蚀,等离子体刻蚀,等离子体辅助固体刻蚀的原理及其各自优缺点,着重论述了国内外采用等离子体刻蚀CVD金刚石膜的研究现状。 相似文献
155.
Fracture in CVD diamond 总被引:1,自引:0,他引:1
R.H. Telling J.E. Field 《International Journal of Refractory Metals and Hard Materials》1998,16(4-6):269-276
The fracture behaviour of thick, textured films of chemical-vapour-deposited diamond is discussed with particular emphasis on the influences asserted by the polycrystalline microstructure. Cracking is investigated on two different scales, firstly where it is large in that it traverses many grains and pertains to the fracture of the bulk. The second is where the fractures are localised, resulting from repeated small particle impacts and the mechanisms of material removal at the grain-size-scale are elucidated. The behaviour at this smaller level can be rationalised in terms intermediate to bulk fracture and that observed in single crystal diamond. The effects of grain size, grain boundaries, crystallographic orientation, twinning, internal stresses and pre-existing flaws are discussed. A new value for the fracture toughness is calculated and the gravimetric erosion rate for different surface orientations measured. 相似文献
156.
C. Barbatti J. Garcia R. Pitonak A. Kostka M.H. Staia 《Surface & coatings technology》2009,203(24):3708-3717
Cemented carbides coated with CVD multilayers are commonly used in metal cutting turning and milling operations. For many applications, a micro-blasting finishing procedure based on an impact treatment of the surfaces is carried out in order to smooth the coated surface and reduce sharp cutting edges. In this work, micro-blasting with corundum in aqueous solution at pressures between 0.05 and 0.3 MPa was applied to CVD TiN/Ti(C,N)/κ-Al2O3 multilayer coatings deposited onto cemented carbides in order to investigate its influence on the micro-topography, microstructure and residual stresses. The results showed that the micro-blasting reduces the surface roughness and affects the coating thickness. TEM investigations revealed no significant changes on the microstructure of the κ-Al2O3 top layer. Synchrotron X-ray investigations showed that the residual stress state of the as-deposited κ-Al2O3 top layer is not affected by the micro-blasting treatment under the conditions investigated. 相似文献
157.
In this work, a new deposition method for coating Cr2O3 and Al2O3 forming alloys has been set up. This is a modified CVD deposition method based on the pyrolisis of an aerosol produced by an ultrasonic wave focussed on the surface of a solution containing a reactive element soluble salt that will later transform to an oxide. The deposition takes place in a reaction chamber maintained at 473 K. To test the efficiency of the deposition method, commercial AISI-304 stainless steel samples were coated directly on the mill finish surface and on a pre-formed oxide layer with lanthanum nitrate. Specimens were then oxidised at 1173 K in synthetic air atmosphere during 25 h in a thermobalance. Oxidation kinetics of coated samples was compared with that of untreated ones. The results show that coated samples improve their high temperature oxidation resistance by decreasing their parabolic rate constant by one order of magnitude. The deposition method developed proves to be an easy, cheap and efficient way of increasing the service temperature of conventional stainless steel. 相似文献
158.
S. Bolognini D. Mari T. Viatte W. Benoit 《International Journal of Refractory Metals and Hard Materials》2001,19(4-6):285-292
Mixed TiCN–WC–Co cermets are developed to improve at the same time toughness and resistance to deformation of materials for cutting tool applications. Moreover, graded materials joining optimum properties according to the functional part of the tool are elaborated. To this end, TiCN–WC–Co cermets are interesting because they develop a WC–Co layer at the surface during the sintering. This tough layer at the surface limits the crack propagation that can lead to the rupture of the tool. Such materials show a good resistance to the deformation in the bulk and a good toughness at the surface, where the cracks are initiated upon machining. Cutting tools are often coated by CVD to improve the wear resistance. This paper proposes a method to measure the toughness KIC at high temperature by using this CVD coating for initial crack formation. The coating thickness is the precrack length of traditional KIC measurements. Samples are fractured by three point bend tests. The rupture stress is measured by Weibull statistics. This method is particularly interesting for graded structure materials where the influence of surface layers on toughness must be estimated. The comparison between cermets with and without WC–Co layer shows an improvement of 28% of the toughness when the layer is present. The possible bias of internal stresses on the results is discussed. 相似文献
159.
160.
Norberto Hernández-ComoArturo Morales-Acevedo Y. Matsumoto 《Solar Energy Materials & Solar Cells》2011,95(8):1996-2000
p-Type hydrogenated amorphous silicon (a-Si:H) was deposited on n-type crystalline silicon (c-Si) substrates to obtain hetero-junction diodes. Additionally, a thin intrinsic a-Si:H layer was inserted between both the p-type film and the n-type substrate to study its passivation effect on the c-Si surface. The amorphous films were obtained by the hot wire chemical vapor deposition (HWCVD) technique, using a tungsten filament and silane (SiH4), hydrogen (H2) and diborane (B2H6) gases, where the deposition parameters such as gas flow, substrate temperature and filament temperature were varied. Optical band gap, deposition rate and conductivity were measured for all the films. We studied the influence of the quality of the amorphous films upon the performance of the hetero-junction diodes. In particular, the diode ideality factor (n) and the saturation current density (J0) were determined by measuring the current-voltage characteristics in dark conditions. It is shown that the presence of the intrinsic layer is fundamental for making good diodes, since devices made without this film cause the diodes to have high saturation current density and ideality factor (J0>10×10−6 A/cm2, n>4) as compared to diodes with a good intrinsic layer (J0=5×10−9 A/cm2, n=1.39). The results obtained are encouraging, but the quality of the intrinsic films still should be improved for applying them to HIT solar cells. 相似文献