全文获取类型
收费全文 | 2192篇 |
免费 | 11篇 |
国内免费 | 27篇 |
专业分类
电工技术 | 10篇 |
综合类 | 21篇 |
化学工业 | 730篇 |
金属工艺 | 218篇 |
机械仪表 | 112篇 |
建筑科学 | 6篇 |
矿业工程 | 6篇 |
能源动力 | 26篇 |
轻工业 | 5篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
武器工业 | 1篇 |
无线电 | 39篇 |
一般工业技术 | 1009篇 |
冶金工业 | 17篇 |
原子能技术 | 15篇 |
自动化技术 | 13篇 |
出版年
2023年 | 32篇 |
2022年 | 44篇 |
2021年 | 50篇 |
2020年 | 56篇 |
2019年 | 45篇 |
2018年 | 55篇 |
2017年 | 60篇 |
2016年 | 54篇 |
2015年 | 30篇 |
2014年 | 77篇 |
2013年 | 108篇 |
2012年 | 75篇 |
2011年 | 261篇 |
2010年 | 137篇 |
2009年 | 169篇 |
2008年 | 176篇 |
2007年 | 124篇 |
2006年 | 61篇 |
2005年 | 98篇 |
2004年 | 76篇 |
2003年 | 94篇 |
2002年 | 87篇 |
2001年 | 47篇 |
2000年 | 32篇 |
1999年 | 23篇 |
1998年 | 25篇 |
1997年 | 27篇 |
1996年 | 20篇 |
1995年 | 28篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 12篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有2230条查询结果,搜索用时 504 毫秒
31.
长期以来我国陶瓷产业仍以手工为主,工业化、自动化、信息化程度较低。本文力图在陶瓷物流领域,结合物联网概念和技术,提出打造“陶瓷物流装备物联网”的理念,本文阐述了陶瓷物流装备物联网的整体构想、应用前景等,并且有针对性地阐述了打造该物联网所需要解决的关键技术,并提出陶瓷二维码花纸底款、智能I-Box物联网终端等解决方案,取得了一定的前期开发与应用成果,为今后进一步打造围绕陶瓷生产全过程的物联网建设做了有益的探索。 相似文献
32.
钛酸铝陶瓷及其研究现状 总被引:3,自引:1,他引:3
本文简述了钛酸铝陶瓷的制备及性能,论述了钛酸铝陶瓷的稳定性、微裂纹、低热膨胀性,讨论了工艺条件及外加剂对钛酸铝材料性能的影响,最后提出了改善钛酸铝陶瓷性能的技术途径。 相似文献
33.
34.
运用高分辨透射电镜显微技术观察到PFN中B位离子呈无序排列,不易形成有序结构,在性能上,PFN的介电常数ε和介电损耗tgδ均很大,相变扩散度小;相应时的介电行为,热容和热膨胀的变化比较特殊。 相似文献
35.
在以原料作为配料计算的基础之上,提出了“元配料”的概念,并指出了在坯釉料配方计算、配合料制备、建立预报性能的数学模型以及寻优等方面应用的可能性。元配料概念的提出及其应用将可简化以上工作,使之更加迅捷有效,并夏容易实现程式化电算,从而成为陶瓷工艺人员的有用工具。而且,还可望简化生产组织和提高管理水平,并对构建我国的陶瓷原料加工工业、早日实现坯料商品化起到一定的促进和推动作用。 相似文献
36.
Characterization and microstructure of highly preferred oriented lead barium titanate thin films on MgO (100) by sol-gel process 总被引:1,自引:0,他引:1
Highly preferred oriented lead barium titanate (Pb1−x,Bax)TiO3 thin film, with particular emphasis on (Pb0.5,Ba0.5)TiO3, can be obtained by spin-coating on MgO (100) substrate by using the precursor sol, which was synthesized from acetylacetone chelating with titanium isopropoxide and ethylene glycol as a solvent, in the sol-gel process. Film thickness, pyrolysis temperature and heating rate were studied systemically to investigate their influences on the formation of preferred oriented thin films. The highly preferred (001)/(100) oriented thin film could be obtained by the pyrolysis of wet film at 500 °C and annealing at 600 °C at a slow heating rate of 5 °C/min. It is confirmed that the tetragonal perovskite structure of the titanate ceramic decreases with an increase of Ba content in (Pb1−x,Bax)TiO3. The (001)/(100) oriented films were synthesized from all compositions between x = 0.2 and x = 0.8, at a crystallization temperature of 600 °C. In particular, for the Ba content in the range of x = 0.50.6, highly preferred (001)/(100) planes were observed. 相似文献
37.
This paper was prepared in response to being awarded the Hypervelocity Impact Society's Distinguished Scientist Award at HVIS 2003 held in Noordwijk, The Netherlands. It is traditional that the paper associated with the HVIS Distinguished Scientist Award is a retrospective on the recipient's career. This paper is in that tradition. 相似文献
38.
本文介绍了一种新型的逻辑控制器九点控制器,它具有控制规则简单,对被控对象无严格的限制等特点,在稳定控制和延时控制方面有很好的控制效果。文章对它用于陶瓷材料微波烧结温度控制系统进行仿真研究,实际表明此控制方法具有可行性。 相似文献
39.
Yi Wang Lei Sun Ling-Gang Kong Jin-Feng Kang Xing Zhang Ru-Qi Han 《Journal of Electroceramics》2006,16(4):389-391
Effects of Co
x
Ti
1−x
O
2−δ on the sinterability and the ferromagnetism properties of Co
2sO
3/TiO
2 (0.0 < x < 0.06) ceramics are investigated in this paper. It is found that the Co-doped Ti
O
2 ceramics transform from paramagnetism to room-temperature ferromagnetism (RTFM) after hydrogenation. With annealing temperatures
at 600∘
C and 1000∘
C, these as-prepared samples present anatase and rutile structures respectively, which are analyzed with X-ray diffraction
(XRD). After hydrogenation, the relation between temperature variations and the magnetic susceptibility for the hydrogenated
samples were measured under zero-field-cooled and field-cooled conditions by using SQUID magnetometer. And the hysteresis
loops are observed. These ferromagnetism resonance data suggest that the observed RTFM is at least partly due to the Cobalt
nano-particles in our hydrogenated samples. 相似文献
40.
Laser surface treatment of Al2O3-based refractory ceramics, by melting and re-solidification, can be successfully applied to producing surfaces that are pore-free, homogeneous and crack-free. Such treated surfaces can lead to an increase in the corrosion and erosion resistances of the materials, due to lower permeability to corrosive species and higher surface hardness, respectively. Furthermore, the corrosion resistance can be influenced by the wetting characteristics of the treated surfaces in service environment. Therefore, it is important to investigate the effect of laser treatment of ceramic materials on the interaction of the surface with the various environmental elements. This work is concerned with an experimental investigation of the effects of laser surface treatment, by melting and re-solidification, on the fluid contact angles of Al2O3-based refractory ceramics. These effects are examined by the modification of the surface roughness characteristics induced by laser treatment. Laser-treated surfaces, both containing cracks and crack-free, are compared with untreated surfaces and the results are reported. The untreated surfaces demonstrated considerable non-uniformity in wetting, in contrast to the treated surfaces. The extent of wetting of the laser-treated surfaces containing cracks was proportional to laser power density. This is due to wetting being enhanced, among other factors, by surface roughness, which increased with power density. The crack-free surfaces were the most smooth and, thereby, exhibited the smallest extent of wettability variations. The reduction in wettability after the laser treatment (crack-free) may have an advantage for corrosion resistance. 相似文献