全文获取类型
收费全文 | 1139篇 |
免费 | 48篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
化学工业 | 239篇 |
金属工艺 | 44篇 |
机械仪表 | 28篇 |
建筑科学 | 9篇 |
能源动力 | 60篇 |
轻工业 | 58篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 202篇 |
一般工业技术 | 237篇 |
冶金工业 | 70篇 |
原子能技术 | 11篇 |
自动化技术 | 208篇 |
出版年
2023年 | 12篇 |
2022年 | 14篇 |
2021年 | 37篇 |
2020年 | 39篇 |
2019年 | 34篇 |
2018年 | 41篇 |
2017年 | 42篇 |
2016年 | 29篇 |
2015年 | 24篇 |
2014年 | 45篇 |
2013年 | 79篇 |
2012年 | 61篇 |
2011年 | 59篇 |
2010年 | 52篇 |
2009年 | 59篇 |
2008年 | 61篇 |
2007年 | 62篇 |
2006年 | 45篇 |
2005年 | 40篇 |
2004年 | 34篇 |
2003年 | 26篇 |
2002年 | 20篇 |
2001年 | 18篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1998年 | 16篇 |
1997年 | 24篇 |
1996年 | 20篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1992年 | 15篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 14篇 |
1988年 | 10篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1977年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有1188条查询结果,搜索用时 15 毫秒
1.
Prashant Thapliyal Alok S. Kandari Vijendra Lingwal N.S. Panwar G. Mohan Rao 《Ceramics International》2021,47(9):12066-12071
(Ta2O5)1-x- (TiO2)x (TTOx) thin films, with x = 0, 0.03, 0.06, 0.08, and 0.11, were deposited using magnetron direct current (DC) sputtering method onto the P/boron-silicon (1 0 0) substrates by varying areas of Tantalum and Titanium metallic targets, in oxygen environment at ambient temperature. The as-deposited thin films were annealed at temperatures ranging from 500 to 800 °C. Generally, the formation of the Ta2O5 structure was observed from the X-ray diffraction measurements of the annealed films. The capacitance of prepared metal– oxide– semiconductor (MOS) structures of Ag/TTOx/p-Si was measured at 1 MHz. The dielectric constant of the deposited films was observed altering with varying composition and annealing temperature, showing the highest value 71, at 1 MHz, for the TTOx films, x = 0.06, annealed at 700 °C. With increasing annealing temperature, from 700 to 800 °C, the leakage current density was observed, generally decreasing, from 10?5 to 10?8 A cm?2, for the prepared compositions. Among the prepared compositions, films with x = 0.06, annealed at 800 °C, having the observed value of dielectric constant 48, at 1 MHz; and the leakage current density 2.7 × 10?8 A cm?2, at the electric field of 3.5 × 105 V cm?1, show preferred potential as a dielectric for high-density silicon memory devices. 相似文献
2.
Pahlavan Kaveh Krishnamurthy Prashant 《International Journal of Wireless Information Networks》2021,28(1):3-19
International Journal of Wireless Information Networks - The IEEE 802.11 standard for wireless local area networking (WLAN), commercially known as Wi-Fi, has become a necessity in our day-to-day... 相似文献
3.
Prasad Ravi Kumar Madhu Santanoo Ramotra Prashant Edla Damodar Reddy 《Wireless Networks》2021,27(6):4111-4122
Wireless Networks - In Wireless Sensor Networks (WSNs), where power consumption is a huge concern, the improvement of the network’s lifetime is an area of constant study and innovation. The... 相似文献
4.
Metal injection moulding (MIM) is an established process for high volume production of complex shaped metallic parts using commercially available feedstocks. The characteristics of parts after moulding, debinding, and sintering cannot be simply predictable from raw materials because the properties get altered with the process parameters and the corresponding levels of porosity during processing steps. In this study, physical properties, microstructure, and mechanical properties of the MIM parts have been characterised to understand the evolution of strength during various steps in MIM processing. Feedstocks with different binder loading show a considerable difference in physical as well as mechanical characteristics. During sintering of parts which have solid loading of grinding sludge, simultaneous in situ reduction and densification takes place, whereas only densification occurs in carbonyl iron parts. It is, therefore, possible to make complex shaped parts of different levels of porosity from downgraded shop floor metallic waste. 相似文献
5.
Faustino Bisaccia Prashant Koshal Vittorio Abruzzese Maria Antonietta Castiglione Morelli Angela Ostuni 《International journal of molecular sciences》2021,22(6)
Pseudoxanthoma elasticum (PXE) is a complex autosomal recessive disease caused by mutations of ABCC6 transporter and characterized by ectopic mineralization of soft connective tissues. Compared to the other ABC transporters, very few studies are available to explain the structural components and working of a full ABCC6 transporter, which may provide some idea about its physiological role in humans. Some studies suggest that mutations of ABCC6 in the liver lead to a decrease in some circulating factor and indicate that PXE is a metabolic disease. It has been reported that ABCC6 mediates the efflux of ATP, which is hydrolyzed in PPi and AMP; in the extracellular milieu, PPi gives potent anti-mineralization effect, whereas AMP is hydrolyzed to Pi and adenosine which affects some cellular properties by modulating the purinergic pathway. Structural and functional studies have demonstrated that silencing or inhibition of ABCC6 with probenecid changed the expression of several genes and proteins such as NT5E and TNAP, as well as Lamin, and CDK1, which are involved in cell motility and cell cycle. Furthermore, a change in cytoskeleton rearrangement and decreased motility of HepG2 cells makes ABCC6 a potential target for anti-cancer therapy. Collectively, these findings suggested that ABCC6 transporter performs functions that modify both the external and internal compartments of the cells. 相似文献
6.
The Journal of Supercomputing - In this paper, physical layer impairment (PLI)-aware shared path protection (SPP) scheme for single-link failures in transparent optical WDM mesh networks is... 相似文献
7.
Wireless Networks - One of the biggest challenges in political mayhem is visible during the election process where no stone is kept unturned in order to gain the power. Further, due to poll... 相似文献
8.
Prashant S. Salimath Ivar S. Ertesvåg 《International Journal of Hydrogen Energy》2021,46(52):26616-26630
Premixed H2-air flames are studied in a one-dimensional wall-bounded configuration. The laminar flame propagates towards and quenches at a wall that is either solid or permeable. Entropy generation by each of 19 elementary reactions is evaluated. Their total contribution remains the most important up to the quenching instance. Close to quenching, the conduction entropy generation grows considerable. Mass diffusion has a modest contribution, which decreases towards quenching. Viscous forces are negligible as a source of entropy. Effects of unburnt-mixture temperature and fuel-air ratio are investigated, and also dilution with nitrogen (inert) and water vapour. The diffusive entropy flux changed direction away from the permeating wall compared that of the solid wall. A major finding is that fuel permeation through the wall tends to decrease the entropy generation per unit of converted fuel, in particular for initially lean mixtures. 相似文献
9.
10.