全文获取类型
收费全文 | 95882篇 |
免费 | 5924篇 |
国内免费 | 3519篇 |
专业分类
电工技术 | 4612篇 |
技术理论 | 27篇 |
综合类 | 8392篇 |
化学工业 | 9858篇 |
金属工艺 | 3757篇 |
机械仪表 | 5018篇 |
建筑科学 | 15778篇 |
矿业工程 | 5502篇 |
能源动力 | 2111篇 |
轻工业 | 9118篇 |
水利工程 | 2391篇 |
石油天然气 | 7621篇 |
武器工业 | 2187篇 |
无线电 | 8894篇 |
一般工业技术 | 5444篇 |
冶金工业 | 3965篇 |
原子能技术 | 428篇 |
自动化技术 | 10222篇 |
出版年
2024年 | 288篇 |
2023年 | 925篇 |
2022年 | 2084篇 |
2021年 | 2684篇 |
2020年 | 2892篇 |
2019年 | 1783篇 |
2018年 | 1662篇 |
2017年 | 2289篇 |
2016年 | 2704篇 |
2015年 | 2982篇 |
2014年 | 7305篇 |
2013年 | 5231篇 |
2012年 | 7306篇 |
2011年 | 7753篇 |
2010年 | 5779篇 |
2009年 | 5960篇 |
2008年 | 5361篇 |
2007年 | 6515篇 |
2006年 | 5889篇 |
2005年 | 5193篇 |
2004年 | 4355篇 |
2003年 | 3980篇 |
2002年 | 3212篇 |
2001年 | 2681篇 |
2000年 | 2040篇 |
1999年 | 1598篇 |
1998年 | 1089篇 |
1997年 | 803篇 |
1996年 | 666篇 |
1995年 | 535篇 |
1994年 | 441篇 |
1993年 | 295篇 |
1992年 | 239篇 |
1991年 | 182篇 |
1990年 | 162篇 |
1989年 | 111篇 |
1988年 | 70篇 |
1987年 | 46篇 |
1986年 | 44篇 |
1985年 | 29篇 |
1984年 | 24篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 39篇 |
1979年 | 14篇 |
1978年 | 4篇 |
1975年 | 5篇 |
1964年 | 6篇 |
1959年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
文章首先对智能化电子信息技术进行了深入的研究,而后分析了该技术在应用过程中出现的问题,最后结合该技术的相关特点给出了相应的问题解决措施,希望能够对智能化电子信息技术的发展提供帮助。 相似文献
3.
4.
《Ceramics International》2022,48(12):16877-16884
Oxygen selective membrane on the base of cermet δ-Bi2O3/Ag with an interpenetrating structure has the maximum potential efficiency of air separation. However, the degradation processes, including the phase degradation of fluorite δ-Bi2O3, do not make it possible to create a membrane with the required perfection and durability. In this work, the ordering of oxygen vacancies with the transformation of fluorite into the rhombohedral phase (S.G. R-3) was studied by powder HT XRD in situ at 600 °C on dense Bi0.78Er0.2Hf0.02O1.51 ceramics. Fast regeneration of disordered fluorite occurs at T = 640–700 °C. The phase degradation of fluorite due to the segregation of dopants at the second stage leads into stable phases - sillenite, tetragonal or rhombohedral phase (S.G. R-3m), depending on the composition of δ-Bi2O3. Fast regeneration of fluorite occurs when heated to 820 °C, which is unacceptable for membranes. Analysis of all available data allows us to propose approaches to optimize the composition of δ-Bi2O3 and technical solutions for creating durable oxygen selective membranes with promising use in distributed multigeneration. As a result of the analysis, a new solid electrolyte with better parameters was obtained. 相似文献
5.
《Ceramics International》2022,48(8):10921-10931
Coatings were obtained by vacuum electro-spark alloying (VESA), pulsed cathodic arc evaporation (PCAE), magnetron sputtering (MS) techniques and VESA-PCAE-MS hybrid technology using Cr3C2–NiAl electrodes. The structure of the coatings was analyzed using scanning and transmission electron microscopy, X-ray diffraction and energy-dispersive spectroscopy. Mechanical properties were determined by nanoindentation, while tribological properties were assessed using pin-on-disk tribometer. Corrosion resistance was estimated by voltammetry in 1 N H2SO4 and 3.5%NaCl solutions. Oxidation resistance tests were performed at 800°С in air. The VESA coating had the highest thickness, low friction coefficient and high wear resistance. PCAE coating demonstrated the highest hardness (24 GPa) and elastic recovery (59%), oxidation resistance and superior corrosion resistance both in 1 N H2SO4 (icorr = 70 μА/cm2) and 3.5%NaCl (icorr = 0.74 μА/cm2) solutions. The MS coating had average mechanical properties and low corrosion current density (71 μА/cm2) in 1 N H2SO4. Deposition of coatings using VESA-PCAE-MS hybrid technology led to an increase in corrosion and oxidation resistance at least by 1.5 times in comparison with the VESA coating. 相似文献
6.
7.
8.
9.
现今国内的数字集群网络发展存在局限性、差异性,还远没有达到“网”状分布的程度,因此,共网数字集群发展空间巨大、前景广阔。通过列举共网数字集群系统在龙嘉国际机场和长春雷锋车队的成功应用案例,探讨了我国共网数字集群系统应用的可行性和必要性。 相似文献
10.
A small handful of recent studies have addressed a phenomenon known as “phantom vibration syndrome”. This refers to when phone users perceive their device to vibrate, indicating that a call or text is incoming, when in fact the phone did not vibrate at all. Though these studies show that most users do not find phantom vibration hallucinations to be very bothersome, they also find that a large majority of users experience this phenomenon. This paper explores what the striking prevalence of phantom vibration syndrome means for our contemporary relationships with technology. I begin with a review of the theories purporting to explain these data, which largely rely on particular understandings of the brain. Next I develop an alternative theory of phantom vibration syndrome based on insights from the philosophical tradition of phenomenology. This account considers the ways users develop bodily and perceptual habits regarding how the phone is understood and used. By critically contrasting these different theories, we can refine our questions about what the high prevalence of phantom vibration syndrome implies about our contemporary technological situation. 相似文献