全文获取类型
收费全文 | 81846篇 |
免费 | 7000篇 |
国内免费 | 3588篇 |
专业分类
电工技术 | 4671篇 |
技术理论 | 11篇 |
综合类 | 5730篇 |
化学工业 | 13931篇 |
金属工艺 | 4203篇 |
机械仪表 | 4613篇 |
建筑科学 | 6215篇 |
矿业工程 | 2129篇 |
能源动力 | 2297篇 |
轻工业 | 7429篇 |
水利工程 | 1557篇 |
石油天然气 | 4120篇 |
武器工业 | 620篇 |
无线电 | 9438篇 |
一般工业技术 | 9914篇 |
冶金工业 | 3905篇 |
原子能技术 | 821篇 |
自动化技术 | 10830篇 |
出版年
2024年 | 364篇 |
2023年 | 1374篇 |
2022年 | 2583篇 |
2021年 | 3558篇 |
2020年 | 2755篇 |
2019年 | 2153篇 |
2018年 | 2481篇 |
2017年 | 2643篇 |
2016年 | 2530篇 |
2015年 | 3401篇 |
2014年 | 4257篇 |
2013年 | 4990篇 |
2012年 | 5529篇 |
2011年 | 5982篇 |
2010年 | 4990篇 |
2009年 | 4805篇 |
2008年 | 4689篇 |
2007年 | 4325篇 |
2006年 | 3994篇 |
2005年 | 3265篇 |
2004年 | 2378篇 |
2003年 | 2042篇 |
2002年 | 1850篇 |
2001年 | 1622篇 |
2000年 | 1756篇 |
1999年 | 2060篇 |
1998年 | 1754篇 |
1997年 | 1443篇 |
1996年 | 1405篇 |
1995年 | 1173篇 |
1994年 | 1020篇 |
1993年 | 711篇 |
1992年 | 556篇 |
1991年 | 403篇 |
1990年 | 349篇 |
1989年 | 314篇 |
1988年 | 225篇 |
1987年 | 156篇 |
1986年 | 117篇 |
1985年 | 84篇 |
1984年 | 63篇 |
1983年 | 44篇 |
1982年 | 54篇 |
1981年 | 38篇 |
1980年 | 40篇 |
1979年 | 14篇 |
1977年 | 12篇 |
1976年 | 14篇 |
1974年 | 12篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Neural Computing and Applications - In this paper, an adaptive neural network (NN) output feedback control is investigated for incommensurate fractional-order permanent magnet synchronous motors... 相似文献
42.
43.
Zhao Hongliang Lu Tingting Liu Fengqin Yin Pan Wang Sen 《JOM Journal of the Minerals, Metals and Materials Society》2019,71(5):1643-1649
JOM - The Isa/Ausmelt smelting technology with a top submerged lance (TSL) has been extensively used in copper smelting processes. However, the TSL is extremely vulnerable to damage and failure... 相似文献
44.
Park Sangwon Nam Hyunbin Na Youngsang Kim Hyoungseop Moon Younghoon Kang Namhyun 《Metals and Materials International》2020,26(5):641-649
Metals and Materials International - This study investigated the influence of the initial grain size on the plastic deformation and tunnel defects that occurred from friction stir welding of... 相似文献
45.
Machine Learning - Recently, the $${ Tensor}~{ Nuclear}~{ Norm}~{ (TNN)}$$ regularization based on t-SVD has been widely used in various low tubal-rank tensor recovery tasks. However, these models... 相似文献
46.
47.
The flame front deformation instability of low-velocity filtration combustion within an inert packed bed is studied based on the initial preheating non-uniformity. Based on the experimental phenomena, an initial thermal perturbation model is numerically proposed so as to predict the deformation behaviors of the flame front instabilities. The numerical prediction indicates that the assumption of an initial thermal perturbation is a feasible explanation as the cause of the flame front inclination instability. As the initial thermal perturbation increases, the phenomena of the flame front break and shrinking instabilities could easily occur at high filtration velocity or low equivalence ratio. Moreover, the evolutions of the flame front break rate and the shrinking rate are quantitatively analyzed. 相似文献
48.
The synthesis of BaMgAl10O17∶ Eu2 (BAM) phosphors using the sol-gel method and their luminescence properties were reported. The blue-light emitting BAM was synthesized using citric acid and ethylene glycol as chelating materials. Emission of blue-light was obtained from these phosphors. The luminescent intensity increases as the temperature of heat treatment is increased. This study investigated the effects of the molar ratio of ethylene glycol to citric acid (Φ value), with respect to the phase formation and luminescence properties of BAM. The variation of the Φ value resulted in the change of the sol-gel reaction mechanism and the microstructures of the resultant powders. An increase in Φ value leads to an increase in the rate of BAM phase formation. The photoluminescent intensity of the prepared phosphors increases with heating temperatures because of enhanced crystallization. 相似文献
49.
Performance study of iSCSI-based storage subsystems 总被引:9,自引:0,他引:9
iISCSI is emerging as an end-to-end protocol for transporting storage I/O block data over IP networks. By exploiting the ubiquitous Internet infrastructure, iSCSI greatly facilitates remote storage, remote backup, and data mirroring. This article evaluates the performance of two typical iSCSI storage subsystems by measuring and analyzing block-level I/O access performance and file-level access performance. In the file-level performance study, we compare file access performance in an NAS scheme with that in an iSCSI-based SAN scheme. Our test results show that Gigabit Ethernet-based iSCSI can reach very high bandwidth, close to that of a direct FC disk access in block I/O access. However, when the iSCSI traverses through longer distance, throughput relies heavily on the available bandwidth between the initiator and the target. On the other hand, the file-level performance shows that iSCSI-based file access (SAN scheme) provides higher performance than using NFS protocol in Linux and SMB protocol in Windows (NAS scheme). However, the advantage of using iSCSI-based file accesses decreases as the file size increases. The obtained experimental results shed some light on the performance of applications based on iSCSI storage. 相似文献
50.
自2005年全球电信业提出“向综合信息服务提供商转型”的观念后,国内各电信企业已经纷纷行动起来.经过长达一年时间的策划和筹备,目前已进入具体实施阶段。但是,转型不是推倒重来,而是要兼顾效益和成本,这是各运营商成功实施转型所必须遵从的一个基本原则。 相似文献