全文获取类型
收费全文 | 152143篇 |
免费 | 26480篇 |
国内免费 | 6985篇 |
专业分类
电工技术 | 9434篇 |
技术理论 | 1篇 |
综合类 | 9467篇 |
化学工业 | 33992篇 |
金属工艺 | 7496篇 |
机械仪表 | 8526篇 |
建筑科学 | 11209篇 |
矿业工程 | 3890篇 |
能源动力 | 4008篇 |
轻工业 | 15697篇 |
水利工程 | 2903篇 |
石油天然气 | 5728篇 |
武器工业 | 1366篇 |
无线电 | 20371篇 |
一般工业技术 | 23336篇 |
冶金工业 | 5030篇 |
原子能技术 | 1534篇 |
自动化技术 | 21620篇 |
出版年
2024年 | 505篇 |
2023年 | 1853篇 |
2022年 | 4024篇 |
2021年 | 5822篇 |
2020年 | 5420篇 |
2019年 | 6233篇 |
2018年 | 6446篇 |
2017年 | 7161篇 |
2016年 | 7229篇 |
2015年 | 9200篇 |
2014年 | 10106篇 |
2013年 | 12376篇 |
2012年 | 11299篇 |
2011年 | 11410篇 |
2010年 | 10960篇 |
2009年 | 10623篇 |
2008年 | 9829篇 |
2007年 | 9181篇 |
2006年 | 8224篇 |
2005年 | 7029篇 |
2004年 | 5160篇 |
2003年 | 4539篇 |
2002年 | 4438篇 |
2001年 | 3890篇 |
2000年 | 3210篇 |
1999年 | 2364篇 |
1998年 | 1287篇 |
1997年 | 1142篇 |
1996年 | 981篇 |
1995年 | 801篇 |
1994年 | 657篇 |
1993年 | 491篇 |
1992年 | 358篇 |
1991年 | 308篇 |
1990年 | 241篇 |
1989年 | 199篇 |
1988年 | 154篇 |
1987年 | 103篇 |
1986年 | 96篇 |
1985年 | 38篇 |
1984年 | 34篇 |
1983年 | 17篇 |
1982年 | 27篇 |
1981年 | 19篇 |
1980年 | 33篇 |
1979年 | 13篇 |
1978年 | 9篇 |
1976年 | 7篇 |
1959年 | 12篇 |
1951年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 859 毫秒
151.
152.
Alfredo M. Gravagnuolo Eden Morales‐Narváez Charlene Regina Santos Matos Sara Longobardi Paola Giardina Arben Merkoçi 《Advanced functional materials》2015,25(38):6084-6092
Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self‐assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self‐assembling of Vmh2 at liquid–solid interfaces is achieved (in 2 min). The Vmh2‐coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti‐immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self‐assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications. 相似文献
153.
Mohammad Reza Gaeeni Morteza Sasani Ghamsari Abbas Majd Abadi Mohammad Hossein Majles Ara Wooje Han Hyung‐Ho Park 《Journal of the American Ceramic Society》2015,98(6):1818-1822
A facile sol–gel procedure has been developed for the synthesis of colloidal alumina nanocrystals. For the first time, optical characterization procedures were employed to study the quantum confinement effects in optical properties of the prepared Al2O3 sol. Accordingly, the hyperbolic band model was used to determine the optical band gap of colloidal alumina nanocrystals. X‐Ray diffraction pattern was used to study the crystallographic phase of the dried gel. Morphological characterization was performed using scanning electron microscopy (SEM). Inductively Coupled Plasma (ICP) emission spectroscopy was used to determination purity of the Al2O3 powder. High‐resolution TEM showed that the diameter of colloidal nanocrystals is about 10 nm. Photoluminescence spectroscopy demonstrated that quantum yields for colloidal nanocrystals are 68% with 300 nm excitation wavelength. The experimental observations confirm that highly stable alumina sol with strong UV emission was synthesized. The mentioned optical properties have not been reported before. 相似文献
154.
155.
该文针对当前矿井炮掘巷道大断面掘进普遍存在掘进施工较慢的实际,结合公司实际情况,有针对性地提出了解决的办法。 相似文献
156.
Seong‐Hee Kim 《Quality and Reliability Engineering International》2015,31(6):923-934
We present a distribution‐free tabular cumulative sum chart for monitoring the variability of an autocorrelated process. A quantity known as the asymptotic variance parameter is employed as a measure of the variability, and a distribution‐free tabular cumulative sum chart is applied to variance estimates calculated from batches of nonoverlapping samples. The proposed chart is applicable to a stationary process with a general marginal distribution and a general autocorrelation structure. It also determines control limits analytically without trial‐and‐error simulations. The performance of the proposed chart is tested on stationary processes with both normal and nonnormal marginals with various autocorrelation structures. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
157.
Xiangrong Ma Rui Dang Ning Yang Xiao Li Ya zhang Ying Gong Zhipan Liu Wei Guo Yuanyuan Zhang Chunyan Li 《International Journal of Hydrogen Energy》2021,46(44):22842-22851
The high cost of noble metal catalysts has been a great bottleneck for the catalyst industry. Using the noble metal at a single-atom level for catalytic applications could dramatically decrease the cost. The impacts of single Pt atoms on the photocatalytic performance of Ag3VO4 have been investigated and reported. In this report, single Pt atoms were anchored on the surface of Ag3VO4 (AVO) as a cocatalyst, and the resultant composite photocatalyst has been studied for photocatalytic H2 production from water driven by visible light. The as-prepared AVO particles are hollow nanospheres in the monoclinic phase with a bandgap of 2.20 eV. The light absorption edge of AVO/Pt is slightly red-shifted compared to that of the pristine AVO, indicating more visible light absorption of AVO/Pt. The XPS peaks of Ag, V, and Pt exhibit a significant shift after AVO and Pt get into contact, suggesting the strong interaction between the surface Ag and V atoms, and single Pt atoms. After 3-h illumination, the photocatalytic H2 evolution amount from AVO/Pt is improved up to 1400 μmol, which is 2.8 times that on the bare AVO. Such efficient photocatalytic H2 evolution on AVO/Pt is still maintained after five reaction cycles. The better photocatalytic performance of AVO/Pt has been attributed to the more efficient visible light utilization and the lower interfacial charge transfer resistance, as demonstrated in the DRS and EIS spectra. The presence of the surface Pt atoms also leads to a higher amount of reactive radicals, which could efficiently promote the surface redox reactions. 相似文献
158.
159.
Tian Xiaoying Peng Hui Luo Xuguang Nie Shiyuan Zhou Feng Peng Xiaoyan 《International Journal of Control, Automation and Systems》2020,18(4):897-910
International Journal of Control, Automation and Systems - There is a class of typical nonlinear industrial process, which can be characterized by a first-order inertia plus pure delay model in an... 相似文献
160.
Xu Zhi-Zheng Jiang Feng Zhong Chong-Quan Gou Yong-Jie Teng Hong-Fei 《Structural and Multidisciplinary Optimization》2020,61(1):207-223
Structural and Multidisciplinary Optimization - The overall layout optimization design of an orbital propellant depot involves the optimization of shape, size, and positions of propellant tanks in... 相似文献