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991.
992.
Kellie Vella Madison Klarkowski Selen Turkay Daniel Johnson 《Behaviour & Information Technology》2020,39(8):917-934
ABSTRACT While online multiplayer games provide an opportunity for players to both maintain and establish new connections, male and female players have been found to experience these environments differently. Interviews (n?=?22) and focus groups (n?=?14) were used to explore these differences as they impact on creating new social connections, as well as to provide recommendations for the development of new social tools and features that account for these differences. While all participants experienced toxicity and performance pressure as barriers to forming new connections, female players uniquely reported the impacts of misogynistic targeting and stereotype threat. In turn, female players wishing to avoid these stresses would often mask their gender. The common practice of gender misrepresentation by both male and female players impacted female players’ ability to create social connections through voice technology, as well as building their distrust of unknown others. Recommendations are made to build social connectedness between players taking into account the specific constraints faced by female players. These include establishing mentoring opportunities as well as profiling players beyond their immediate skill or rank. Additionally, the desire for control of one’s online identity presents practical challenges that may be overcome through thoughtful design. 相似文献
993.
Quanhu Zhang Xianghua Su Suxia Hou Sufen Li Jianqing Yang Linjun Hou 《Journal of Nuclear Science and Technology》2020,57(6):678-688
ABSTRACTThe analysis method of Fast Neutron Multiplicity Counting (FNMC) plays an increasingly important role in the measurement of nuclear material properties. Based on the assumption of point model, fast neutron multiplicity measurement equation is derived which can be used to measure the mass of Pu sample. However, the deviation of the simulated measurement of 1 kg Pu sample reaches 16.6% and increases with mass. Because nonpoint source samples of different shapes do not fully satify the hypothesis. To correct this deviation, a set of fast neutron multiplicity counters was built by Geant4 to simulate and study the mass attribute of Pu samples.The cylindrical sources of different shapes and different masses were simulated, the self-multiplication factor and α coefficient were corrected.And the corresponding third-order polynomial fitting equation was obtained, the goodness of fit was greater than 0.970. In the same way, the spherical and spherical shell source samples in the mass range of 0–5 kg were analyzed, the corrected mass deviation of samples was less than 10% in this interval. The results show that the combination of the fast neutron multiplicity counter and parameter correction can accurately measure the sample mass attribute. 相似文献
994.
ABSTRACT Governing the rate of heat transport by condenser tubes in the passive containment cooling system (PCCS), the steam condensation over a vertical cylinder in the presence of air was investigated experimentally. The main objective of this study was to explore if the condensation heat transfer coefficient relies on the tube dimension, which has been a variable missed in most condensation models or has been embraced without experimental demonstration under phase change environments. The mean heat transfer coefficient was measured in the condensation test facility named JERICHO (JNU Experimental Rig for Investigation of Condensation Heat transfer On tube). The outer diameter of the condenser tube used in this study was set to 21.5 mm. The measured heat transfer coefficients were compared to those obtained from the 40-mm-O.D. tube, and a multiplier to correct the variation of the heat transfer coefficient with the tube diameter was proposed for its application to Lee correlation. The proposed correlation was further validated against another set of experimental data obtained from a separate test facility housing the 31.8-mm-O.D. tube. 相似文献
995.
996.
Adam Morawiec 《Centaurus; international magazine of the history of science and medicine》2020,62(3):465-478
In the present paper, I present and discuss some new information about the life of Paul Wittich from Wrocław, Poland (formerly Breslau, Germany), an elusive mathematician and astronomer of the late 16th century. Wittich seems to have played a significant role in the emergence of two important, though short-lived, developments of late 16th-century science: the so-called prosthaphaeresis calculating method, and the geoheliocentric model of the universe usually attributed to Tycho Brahe. His role in both achievements, however, has not been sufficiently explained so far, and it is my belief that one of the main obstacles to that endeavor has been our scarce knowledge about the details of Wittich's life. Thus, I attempt to reconstruct his life with aim of being able to evaluate, eventually, his involvement in the development of mathematics and astronomy towards the end of the 16th century, primarily with the use of whatever scant sources can be found concerning Wittich. The source that I present here—a notebook of Bartholomäus Scultetus, an astronomer from Görlitz—is known and has already been used, but only to a limited extent by the community of historians of science, or by those of astronomy and mathematics. By presenting the information about Wittich from Scultetus's notebook, I aim to bring this source to the attention of those communities, clarify some hitherto unclear details from Wittich's life, and set out new paths for further investigation into his biography. 相似文献
997.
Modular reconfigurable machines offer the possibility to efficiently produce a family of different parts. This paper formalises a cost optimisation problem for flow lines equipped with reconfigurable machines which carry turrets, machining modules and single spindles. The proposed models take into account constraints related to: (i) design of machining modules, turrets, and machines, (ii) part locations, and (iii) precedence relations among operations. The goal is to minimise equipment cost while reaching a given output and satisfying all the constraints. A mixed integer programming model is developed for the considered optimisation problem. The approach is validated through an industrial case study and extensive numerical experiments. 相似文献
998.
随着社会的发展,物联网已成为社会发展的重要新兴产业,在各个领域中广泛应用。物联网是基于互联网技术产生的,在物联网的运行过程中势必会产生大量数据,这些数据都是客户的隐私,切实保护好客户隐私是物联网进一步发展的首要条件。在面向物联网的隐私数据安全问题时,相关技术人员一定要清楚威胁物联网隐私数据安全的主要途径,加大安全防护力度,保护人们的隐私。文章从信息获取、信息传输以及信息处理3个途径,对隐私数据安全问题进行探讨,并提出一些加大隐私安全防护的举措。 相似文献
999.
为了研究三维圆弧型井眼轨道设计方程组是否存在解析解以及如何有效求解,使用消去法从多元非线性方程组中推导出其中的某个未知数满足一个特征多项式方程,并且证明了该方程组的拟解析解可以由特征多项式方程的实数根和已知设计参数构成的解析公式计算得到;如果极点多项式非恒等于0,则当特征多项式次数不超过5时,如果有解则为解析解,否则为数值解。通过使用C++类实现多项式加减法、乘法的计算方法,提出了多项式实数根的分隔算法、并用二分法快速求解出多项式全部实数根的计算方案。该方法在数学上经严格推导,计算方案简洁、稳健,在三维井眼轨道设计、智能钻井定向控制中具有应用价值。 相似文献
1000.
M.A. Abbas M.A. Lajis D.R. Abbas O.M. Merzah M.H. Kadhim A.A. Shamran 《Materialwissenschaft und Werkstofftechnik》2020,51(6):719-724
The quality of the machined surface resulted from the electrical discharge machining (EDM) environment is not efficient according to the previous studies. One of the significant problems is the impedance of dielectric fluid, where it is contributing to focusing the plasma channel in a limited area. Hence, this behavior leads to appearing deep craters on the machined zone. The researchers have attempted to enhance the average of surface roughness by employing powder particles or surfactant as the additive materials in the dielectric fluid. Unfortunately, these studies did not present a comparison between these additive materials in this environment. Therefore, the present study aims to compare the performance of the average of surface roughness (Ra) for AISI D2 steel by utilizing Nano chromium powder (NCP) and Span-20. The present work has proved that the behavior of the average of surface roughness for this steel is dropping at the maximum level of Nano chromium powder concentration and pulse duration as compared to the behavior with the Span-20. Moreover, the best roughness was produced by this steel with Nano chromium powder at 2 g/L and 20 μs for this powder and the pulse duration. 相似文献