全文获取类型
收费全文 | 30179篇 |
免费 | 1794篇 |
国内免费 | 1608篇 |
专业分类
电工技术 | 897篇 |
技术理论 | 1篇 |
综合类 | 1441篇 |
化学工业 | 8078篇 |
金属工艺 | 7217篇 |
机械仪表 | 1585篇 |
建筑科学 | 2036篇 |
矿业工程 | 432篇 |
能源动力 | 879篇 |
轻工业 | 1552篇 |
水利工程 | 328篇 |
石油天然气 | 1500篇 |
武器工业 | 380篇 |
无线电 | 959篇 |
一般工业技术 | 4404篇 |
冶金工业 | 1333篇 |
原子能技术 | 193篇 |
自动化技术 | 366篇 |
出版年
2024年 | 134篇 |
2023年 | 521篇 |
2022年 | 814篇 |
2021年 | 905篇 |
2020年 | 844篇 |
2019年 | 794篇 |
2018年 | 782篇 |
2017年 | 992篇 |
2016年 | 926篇 |
2015年 | 982篇 |
2014年 | 1610篇 |
2013年 | 1597篇 |
2012年 | 2087篇 |
2011年 | 2352篇 |
2010年 | 1825篇 |
2009年 | 1747篇 |
2008年 | 1445篇 |
2007年 | 1841篇 |
2006年 | 1860篇 |
2005年 | 1549篇 |
2004年 | 1418篇 |
2003年 | 1110篇 |
2002年 | 1011篇 |
2001年 | 807篇 |
2000年 | 749篇 |
1999年 | 583篇 |
1998年 | 471篇 |
1997年 | 396篇 |
1996年 | 332篇 |
1995年 | 272篇 |
1994年 | 211篇 |
1993年 | 175篇 |
1992年 | 150篇 |
1991年 | 73篇 |
1990年 | 59篇 |
1989年 | 59篇 |
1988年 | 29篇 |
1987年 | 18篇 |
1986年 | 15篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1959年 | 3篇 |
1951年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
911.
《Journal of the European Ceramic Society》2017,37(2):811-821
Sintering neck is a featured microstructure that may have significant effect on the sintering behaviour of air-plasma-sprayed thermal barrier coating system (APS TBCs). Based on experimental observations, a multi-necking wedge-shaped model for the sintering of APS TBCs was proposed by considering the sintering stress as surface tension and by employing the thermal-elasto-viscoplastic constitutive relation. Deformation pattern, stress distribution, sintering induced shrinkage, stiffening behaviour and temperature field were analysed by using finite element method. It is shown that the formation of sintering neck significantly affects thermal and mechanical properties related to sintering. Mechanisms of thermal and mechanical degradation induced by sintering were further elucidated. 相似文献
912.
913.
《Materials at High Temperatures》2013,30(4):475-480
AbstractIN100 blades and CMSX-4 samples with NiCoCrAlY bond coats manufactured via LPPS and EB-PVD were cyclically tested in a burner rig at 1120°C and a furnace at 1100°C. Two different TBC chemistries were deposited by EB-PVD techniques: PYSZ and CeSZ. In all cases the performance of the CeSZ coated variances was superior to the PYSZ coated counterparts. TGO growth kinetics were slightly slower for the CeSZ coated samples. The benefits in lifetime are mainly attributed to the mixed zone oxides that tolerate spinel phase formation due to their ability to “wet” each other. Pore formation in the mixed zone is hereby suppressed favoring crack blunting mechanisms. 相似文献
914.
This paper describes the synthesis of phosphorus‐containing polyester‐urethanes and their applications in nanoclay composites and coatings. Polyester was prepared by the reaction of bis(bisphenol‐A) monophenyl phosphonate, maleic anhydride and phthalic anhydride. The polyester was reacted with various diols such as ethylene glycol, diethylene glycol and propylene glycol to obtain polyester polyols. Synthesized polyester polyols were characterized by chemical analysis and instrumental analysis and was used further to react with different isocyanates to develop polyester‐urethanes. The synthesized polyester‐urethanes were blended with organo‐modified montmorillonite nanoclay (1 wt%, 3 wt% and 5 wt%) and were cast in a mold and coated on mild steel panels. The thermal stability of neat polyester‐urethane and the nanoclay composites was determined by thermogravimetric analysis. The flame retardant properties of cast films and their composites were determined by the limiting oxygen index and UL‐94 test methods. The physical and mechanical properties of coatings such as pot life, drying properties, scratch hardness, pencil hardness, impact resistance, adhesion and flexibility were investigated. The chemical resistance properties of the coatings were also determined in different reagents. The data reveal that the polyester‐urethane nanoclay composites with 3 wt% clay hold promise for use in effective flame retardant coatings. © 2013 Society of Chemical Industry 相似文献
915.
Zi-xi WANG Jing-hui ZHAO Xiao-hong JIA Jian-guo FANG Bo ZHANG Guo-qing DING 《钢铁研究学报(英文版)》2013,20(11):85-89
The effect of seawater after ultraviolet inactivation on corrosion of a shipbuilding steel plate was investigated by means of natural corrosion potential experiments and immersion corrosion test. The effects of natural seawater and treated seawater after ultraviolet inactivation on corrosion of the selected steel plate samples were compared with each other. The results showed that there was no obvious change in the chemical composition of treated seawater compared with natural seawater. The corrosion potential slightly increased by 10 mV, whereas the corrosion rate rose significantly by 20%. The experiments verified the naturally formed biofilm in the natural seawater for the inhibition of corrosion on the shipbuilding steel plate. The possible influences of ballast water treatment on biofilm by ultraviolet and electrolysis inactivation under the condition of practical usage were also investigated. And it was found that ballast water treatment methods with no continuous disinfection could protect original tank biofilm structure, reducing the intensity of tank corrosion. 相似文献
916.
对卫生间硅酸钙板轻质隔墙上采用瓷砖饰面系统进行了相关应用性研究,讨论了硅酸钙板厚度、界面处理、防水处理以及粘贴材料等对系统粘结力的影响,提出了在硅酸钙板轻质墙体上进行瓷砖饰面的可靠施工方案。 相似文献
917.
ABSTRACTThe versatility of polymer matrix composites in industrial applications has gained reputation and adaptability among advanced materials. Still, treatment of reinforcement for these composites has emerged as a vital domain to be explored. With a continuance to this fact, the present paper aims to analyze the effect of reinforced electroless coated silicon carbide particulates on mechanical properties of composites. The composite is developed using epoxy polymer as matrix and glass fibers as primary reinforcement. The electroless coated and uncoated silicon carbide particulates were used as secondary reinforcement. The phase identification of copper on secondary reinforcement was identified using X-ray powder diffraction technique. Fracture analysis during tensile testing and bonding behavior between matrix and reinforcement is examined using field emission scanning electron microscopy with energy dispersive spectroscopy. The presence of copper particles on secondary reinforcement results in improved interfacial bonding and resistance against fracture during loading. 相似文献
918.
919.
Jianfeng Li Ben Freireich Carl Wassgren James D. Litster 《American Institute of Chemical Engineers》2012,58(5):1397-1408
In this work, a general multidimensional population balance (PB) model is developed to predict the coating volume distribution on polydisperse particles as a function of time during particle coating in a paddle mixer. The model adopts a compartmental approach to account for coating variation caused by particle flow heterogeneity. Simulations show that for a realistic range of seed particle size polydispersity and coating mass applied, the coating volume distribution depends on the growth rate exponent and seed particle size distribute on, with the coating volume coefficient of variance (CoV) approaching an asymptotic value as the coating‐to‐particle volume ratio increases. These effects cannot be predicted by simpler one‐dimensional models. However, the full two‐dimensional PB and simpler one‐dimensional models such as Mann's equation do predict similar sensitivity of coating volume CoV to the variation in the compartment model parameters, i.e., to changes in the particle mixing behavior in the vessel. © 2011 American Institute of Chemical Engineers AIChE J, 2012 相似文献
920.