全文获取类型
收费全文 | 741篇 |
免费 | 15篇 |
国内免费 | 3篇 |
学科分类
工业技术 | 759篇 |
出版年
2023年 | 6篇 |
2022年 | 23篇 |
2021年 | 20篇 |
2020年 | 20篇 |
2019年 | 21篇 |
2018年 | 20篇 |
2017年 | 30篇 |
2016年 | 23篇 |
2015年 | 11篇 |
2014年 | 27篇 |
2013年 | 57篇 |
2012年 | 31篇 |
2011年 | 32篇 |
2010年 | 35篇 |
2009年 | 36篇 |
2008年 | 31篇 |
2007年 | 32篇 |
2006年 | 28篇 |
2005年 | 19篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 12篇 |
1998年 | 17篇 |
1997年 | 9篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 15篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1957年 | 1篇 |
1955年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有759条查询结果,搜索用时 0 毫秒
1.
2.
3.
Haemangiopericytoma of nose and paranasal sinuses is relatively uncommon tumour. It occurs in adults in sixth and seventh decades of life. In view of paucity of intranasal haemangiopericytoma old in Indian literature and young age of patient, we are reporting one case in 28-year-old female who presented with recurrent, profuse epistaxis. 相似文献
4.
5.
We have utilized a variable energy positron beam and infrared transmission spectroscopy to study defects in GaAs epilayers
grown at low temperatures (LT-GaAs) by molecular beam epitaxy. We have measured the Doppler broadening of the positron-electron
annihilation gamma ray spectra as a function of positron implantation energy. From these measurements, we have obtained results
for the depth profiles of Ga monovacancies in unannealed LT-GaAs and Ga monovacancies and arsenic cluster related defects
in annealed LT-GaAs. We have also studied the effects of the Si impurities in annealed LT-GaAs. The infrared transmission
measurements on unannealed LT-GaAs furnish a broad defect band, related to As antisites, centered at 0.370 eV below the conduction
band. 相似文献
6.
Electrochemical impedance measurements have been used to characterize zinc selenide films prepared by electrochemical co-deposition at a platinum rotating disk electrode. Estimations of capacitance and polarization resistance of variously prepared electrodeposits have been carried out to determine charge carrier density and corrosion rates. 相似文献
7.
In the past several years, various ontologies and terminologies such as the Gene Ontology have been developed to enable interoperability across multiple diverse medical information systems. They provide a standard way of representing terms and concepts thereby supporting easy transmission and interpretation of data for various applications. However, with their growing utilization, not only has the number of available ontologies increased considerably, but they are also becoming larger and more complex to manage. Toward this end, a growing body of work is emerging in the area of modular ontologies where the emphasis is on either extracting and managing "modules" of an ontology relevant to a particular application scenario (ontology decomposition) or developing them independently and integrating into a larger ontology (ontology composition). In this paper, we investigate state-of-the-art approaches in modular ontologies focusing on techniques that are based on rigorous logical formalisms as well as well-studied graph theories. We analyze and compare how such approaches can be leveraged in developing tools and applications in the biomedical domain. We conclude by highlighting some of the limitations of the modular ontology formalisms and put forward additional requirements to steer their future development. 相似文献
8.
Mahajan Nitish Chauhan Amita Kumar Harish Kaushal Sakshi Sangaiah Arun Kumar 《Mobile Networks and Applications》2022,27(4):1423-1443
Mobile Networks and Applications - In the era of Internet of Things (IoT) powered by 5G technologies, Automobile Industry is headed towards a revolution. In Intelligent Transport Systems (ITS),... 相似文献
9.
S. K. Mishra L. C. Pathak V. Rao D. Bhattacharya K. L. Chopra 《Journal of Superconductivity》1996,9(2):211-216
Critical current densities of the superconducting Y-Ba-Cu-O (YBCO) films have been observed to decrease with the increase of power of microwave radiation. Presence of Josephson type of junctions in the microbridges has been established from the microwave irradiation and magnetic field studies. BCS energy gap parameter (2/kT
c
) has been calculated from thedI/dV characteristics and found to be 3.7 at 13 K. 相似文献
10.
K. K. Pathak S. Lomash A. K. Jha N. Ramakrishnan 《Structural and Multidisciplinary Optimization》2010,40(1-6):491-496
This study is related to material modeling and die and process design of tube extrusion of γ iron. Strain dependent rate power law is used for material modeling whose coefficients are arrived at through genetic algorithm (GA). Die profile of the tube extrusion process is optimized to produce microstructurally sound product at maximum production speed and minimum left out material in the die. The design problem is formulated as a nonlinear programming problem which is solved using GA. Selection of the processing parameters is carried out using dynamic material modeling (DMM). Using this approach tube extrusion process of γ iron is successfully designed. 相似文献