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41.
A self‐consistent texture model is implemented in the finite‐element code ABAQUS/Explicit®. Hardening of the slip systems is described by evolution laws for dislocation densities, and the Bauschinger effect is included. With these ingredients the cold rolling of an IF‐steel is simulated and the evolution of texture and anisotropy is examined. The use of the dislocation based hardening law is found to have a significant effect on the evolution of the anisotropic yield surface, but only very little influence on the texture. Furthermore, the hardening model is used to investigate the evolution of dislocation densities in differently oriented grains during plane strain compression. It is found that the dislocation density varies greatly depending on orientation, an observation which can help to explain the orientation dependence of recrystallization. 相似文献
42.
在薄板坯连铸连轧流程上,经过对Ti微合金化技术研究,有效解决了Ti微合金化强度性能波动大的问题,开发出屈服强度450~700MPa高强钢。对试制钢组织性能和工业应用分析研究,表明该产品通板性能良好,通板强度差30MPa左右;成形性能良好,d=0时冷弯测试全部合格;同时还具有良好焊接性能,焊接后,强度波动较小,均在母材部位断开;试制钢显微组织为珠光体和铁素体,晶粒均匀细小,平均尺寸为4~8/μm;实物质量满足集装箱和汽车制造行业要求,具有广阔市场前景。 相似文献
43.
Total simulation model of the thermo-mechanical process in shape rolling of steel rods 总被引:2,自引:0,他引:2
The production of steel reinforcing bars for civil engineering is investigated by means of FEM-simulation. An integrated system for computing appropriate thermo-mechanical parameters of the rolling process is proposed. Generalized plane strain approach and coupled thermal-mechanical solution are applied. The microstructural model combines both the effect of the recrystallization mechanisms (static, dynamic and metadynamic) upon the austenite grain forming in hot rolling and that of phase transformation upon the final microstructure. The phases are created during interrupted below the temperature of martensite transition cooling. Thus a typical industrial process for thermo-mechanical strengthening of reinforcing bars, known as Tempcor-process is considered. Computational results are validated to experimental measured mechanical properties of the steel. By means of computer simulation the system can perform different solutions, giving the possibility to obtain a reasonable choice of different thermo-mechanical rolling conditions. 相似文献
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46.
热镀锌工艺对Ti-IF钢光整热镀锌板组织和性能的影响 总被引:3,自引:1,他引:2
在连续热镀锌线上研究了RTH带钢温度和光整延伸率对Ti—IF钢光整热镀锌板组织和性能的影响。试验表明,当RTH带钢温度在830℃以下时,成品铁素体晶粒度为10.0级,织构类型以{332}、{114}为主,随着带钢温度的进一步提高,热镀锌板的晶粒逐渐粗化,织构成为典型的{111}织构,且取向密度增加,r值随之提高,但当带钢温度在900℃以上时,织构又趋于无规则分布,r值显著降低;光整延伸率对Ti—IF钢光整热镀锌板力学性能的影响很大,随着光整延伸率的提高,屈服强度明显提高,n值明显降低,延伸率降低,抗拉强度变化较小,且光整延伸率对性能的影响与成品铁素体晶粒尺寸有关,成品晶粒越粗,光整延伸率的影响越大。因此对于Ti—IF钢光整热镀锌板而言,n、r值是一对矛盾体,在制订热镀锌工艺时,需根据使用条件的不同,对其n、r值进行综合考虑。 相似文献
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48.
乳化型轧制液的质量标准研究 总被引:4,自引:0,他引:4
对国内目前所使用的冷轧薄钢板(汽车钢板)轧制液母液和乳化液的质量指标及常用试验评定方法进行了考察,并对产品的性能要求进行了研究与分析,制订出一套标准以供参考,包括乳化液稳定性、润滑性、防锈性、抗泡性、使用周期及粘度、闪点等性能。 相似文献
49.
Per Hovstad Liching Sung 《International Journal of Satellite Communications and Networking》2005,23(2):91-110
The 1977 Broadcasting‐Satellite Service (BSS) Plan for Region 1 & 3 had been widely acknowledged to be out‐of‐date by the late 1980s. Development of digital modulation in the early 1990s provided an opportunity to update the technical provisions of the Plan to make it more economically viable. After a decade of work and three World Radiocommunication Conferences (WRCs), the revision of Region 1 & 3 BSS Plan was finally completed in 2003. The new Plan increased channel assignments from 5 to 10 analog‐equivalent channels for each country in Region 1, and from 4 to 12 channels for each country in Region 3. Yet, despite the increase in capacity, the new Plan is surprisingly similar to the original one in terms of the technical parameters. It is still based on national coverage, and the channel plan, orbital location, orbital spacing, and polarization are also the same. As a result, the new Plan is no more economically viable to implement than the old. To create economically viable BSS systems would most likely require modifications to the assignment in the Plan. Yet, modification procedures were made more difficult to apply after replanning. Less future implementation of BSS networks than would otherwise have occurred can be expected, and an inefficient usage of these frequency bands will likely result. On the other hand, less implemented systems will mean more capacity set aside for future use. This is important for countries that currently do not have satellite operations. In the end, BSS replanning reflects the eternal conflict between efficient usage and guaranteed future access. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
50.
控轧技术在H型钢生产中的应用 总被引:2,自引:0,他引:2
根据钢板的控轧经验,结合H型钢轧制的特点分析控轧在轧制中运用的具体问题,制定H型钢控轧工艺方案。介绍了实际应用情况,并提出改进的措施。 相似文献