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991.
Kazuto Yamauchi Kikuji Hirose Hidekazu Goto Kazuhisa Sugiyama Koji Inagaki Kazuya Yamamura Yasuhisa Sano Yuzo Mori 《Computational Materials Science》1999,14(1-4):232-235
Interactions between ultra-fine powder [SiO2] and work [Si (1 0 0) surface] in EEM (Elastic Emission Machining) has been investigated by employing first-principles molecular dynamics (MD) simulations. Calculated results show the possibilities of the atomic removal through the solid phase chemical interaction between surfaces of ultra-fine powders and works. 相似文献
992.
为了研究重离子射线照射后家蚕造血器官的修复再生作用,用碳离子射线局部照射家蚕接近孵化时紧贴翅原基内侧的胚胎造血器官,局部细微手术损伤造血器官,观察了对幼虫造血功能的影响,了解了造血器官的修复程度。100Gy以上剂量照射,家蚕出现变态困难,幼虫和蛹的生存率下降,眠中、化蛹或羽化时期出现死亡个体等缺血生理障碍,其影响程度随射线剂量增加而加重。200Gy照射组5龄存活幼虫血细胞含量下降,但其中部分个体的血细胞含量接近对照未照射处理,其体内出现了再生的造血器官。家蚕幼虫有很强的修复再生造血器官功能。 相似文献
993.
Hydrogen diffusion in steels was examined by both a high sensitivity hydrogen microprint technique (HMT) and an electrochemical hydrogen permeation method. The main diffusion path in an extremely low carbon steel was lattice within grains; grain boundaries were not accelerated diffusion paths. In the case of a hypo-eutectoid steel, hydrogen diffused through proeutectoid ferrite and ferrite in pearlite under steady-state of hydrogen diffusion. The diffusion paths, however, were carbide/ferrite interfaces when hydrogen charging was interrupted before achievement of the steady state. This is probably ascribable to the reversible trapping effect of the interface. The detection efficiency of the high sensitivity HMT was 75% for the low carbon steel and 40% for the hypo-eutectoid steel. 相似文献
994.
Hemispherical and specular transmittance in visible wavelength region and small-angle neutron-scattering of silica aerogels were measured to investigate the effects of supercritical drying media and heat treatment on the optical properties and structure of them. Silica aerogels were prepared by using methanol, ethanol, 2-propanol and carbon dioxide as supercritical drying medium. The analysis of transmission spectra suggested that a reduction of transmittance in visible light can be attributed to Rayleigh scattering, and the scattering intensity depended on the supercritical drying medium. The difference of the scattering intensity among the samples was related to the difference of the cluster size of aerogels from the results of small angle neutron scattering. Heat treatment affected the scattering intensity, but the change of the cluster size was not observed. 相似文献
995.
The results of an unsteady stirring method staged, used in the suspension polymerization of styrene in a lab‐scale batch reactor, are presented. Variation of droplet size during the whole polymerization process under the unsteady stirring condition, compared with that under a steady stirring condition, was found to be small. According to the variable droplet size character, two methods were used to divide the polymerization process into four stages and the unsteady stirring method was used in only one stage of each experimental run. By these operations, the optimum operation of obtaining large particle product with uniform particle size distribution was achieved. The results suggest that controlling the droplet coalescence process is more important than controlling the initial droplet size distribution to obtain uniform final particle products. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1873–1881, 2001 相似文献
996.
Koji Tsunokawa Dinh Van Hiep & Riaz Ul-Islam 《Computer-Aided Civil and Infrastructure Engineering》2006,21(3):193-204
Abstract: A prototypical problem road agencies are faced with is to find the optimal application schedule of maintenance works for a given road section. To solve such problems what-if models such as the road transport investment model (RTIM), the highway economic requirements system (HERS), and the highway development and management tool (HDM-4) are widely used to predict the consequences of different maintenance options. With these models maintenance options to be compared must be exogenously specified by an analyst, and the "optimization" with these routines simply chooses the best among those compared. As there are usually infinite numbers of options, it is impossible to exhaust all of them and only suboptimal optimizers may be found with this approach. The present article proposes the use of gradient search methods with what-if models to find the true optima without requiring exogenously specified alternatives. It demonstrates through a case study the feasibility of the use of the steepest descent method and the conjugate gradient method along with HDM-4 to find the true optimum maintenance options. 相似文献
997.
The status and prospects of the development of Japanese nuclear power are controversial and uncertain. Many deem that nuclear power can play key roles in both supplying energy and abating CO2 emissions; however, due to severe nuclear accidents, public acceptance of nuclear power in Japan has not been fully obtained. Moreover, deregulation and liberalization of the electricity market impose pressure on large Japanese electric power companies with regard to both the operation of nuclear power plants and the development of the nuclear fuel cycle. Long-term Japanese CO2 reduction strategies up to 2100 are of environmental concern and are socially demanded under the circumstances described above. Taking these factors into account, we set the following two objectives for this study. One is to estimate lifecycle CO2 (LCCO2) emissions from Japanese nuclear power, and the other is to evaluate CO2 emissions from the Japanese electric power sector in the 21st century by quantifying the relationship between LCCO2 emissions and scenarios for the adoption of nuclear power. In the pursuit of the above objectives, we first create four scenarios of Japanese adoption of nuclear power, that range from nuclear power promotion to phase-out. Next, we formulate four scenarios describing the mix of the total electricity supply in Japan till the year 2100 corresponding to each of these nuclear power scenarios. CO2 emissions from the electric power sector in Japan till the year 2100 are estimated by summing those generated by each respective electric power technology and LCCO2 emission intensity. The LCCO2 emission intensity of nuclear power for both light water reactors (LWR) and fast breeder reactors (FBR) includes the uranium fuel production chain, facility construction/operation/decommission, and spent fuel processing/disposal. From our investigations, we conclude that the promotion of nuclear power is clearly a strong option for reducing CO2 emissions by the electric power sector. The introduction of FBR has the effect of further reducing CO2 emissions in the nuclear power sector. Meeting energy demand and reducing CO2 emissions while phasing out nuclear power appears challenging given its importance in the Japanese energy supply. 相似文献
998.
Poly(styrene‐co‐N‐maleimide) precursor and poly(styrene‐co‐N‐maleimide)‐block‐polystyrene have been synthesized by quasiliving radical polymerization. Low molecular weight compounds with the sites specific for the complementary binding to the maleimide moieties via triple hydrogen bonds, 2,4‐diamino‐6‐n‐alkoxy(C‐4, C‐8, and C‐12)‐s‐triazines, have been prepared. Hydrogen bonding between diaminotriazine and maleimide units in the copolymer–diaminotriazine mixtures has been investigated by FTIR. Microphase separated structure in the block copolymer‐diaminotriazine mixtures has been confirmed by DSC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2338–2346, 2006 相似文献
999.
1000.
A pair of spins is the most simple quantum system that can exhibit entanglement: a nonclassical property that plays an essential role in quantum information technologies. In this paper, feedback control problems of a symmetric two-spin system conditioned on a continuous measurement are investigated. In order to make some useful formulas in stochastic control theory directly applicable, we first derive a two-dimensional representation of the system. We then prove that a feedback controller stabilizes an entangled state of the two spins almost globally with probability one. Furthermore, it is demonstrated that some entangled states, which correspond to nonequilibrium points of the dynamics, are globally stabilized via feedback in the sense that the mean distance from a target can be reduced to an arbitrarily small value. 相似文献