全文获取类型
收费全文 | 607篇 |
免费 | 18篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 137篇 |
金属工艺 | 14篇 |
机械仪表 | 7篇 |
建筑科学 | 14篇 |
能源动力 | 61篇 |
轻工业 | 47篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 77篇 |
一般工业技术 | 124篇 |
冶金工业 | 58篇 |
自动化技术 | 67篇 |
出版年
2023年 | 12篇 |
2022年 | 25篇 |
2021年 | 22篇 |
2020年 | 19篇 |
2019年 | 38篇 |
2018年 | 23篇 |
2017年 | 31篇 |
2016年 | 20篇 |
2015年 | 14篇 |
2014年 | 20篇 |
2013年 | 44篇 |
2012年 | 30篇 |
2011年 | 29篇 |
2010年 | 22篇 |
2009年 | 27篇 |
2008年 | 16篇 |
2007年 | 19篇 |
2006年 | 10篇 |
2005年 | 17篇 |
2004年 | 10篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 15篇 |
1997年 | 13篇 |
1996年 | 14篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有627条查询结果,搜索用时 15 毫秒
81.
Rathee Geetanjali Sandhu Rajinder Saini Hemraj Sivaram M. Dhasarathan Vigneswaran 《Wireless Networks》2020,26(4):2339-2351
Wireless Networks - In this paper, we have demoralized the transmission processing concerns of fog nodes and IoT device layer attack during the handoff (mobility) of IoT devices in the fog... 相似文献
82.
In this endeavor, a new multiple‐input‐multiple‐output antenna with a sharp rejection at wireless local area network (WLAN) band is designed and practically examined for portable wireless ultra‐wideband applications. The intended diversity antenna possess a small size of 15 mm × 26 mm and two inverted L‐strip are loaded over the conventional rectangular patch antenna to form protrudent‐shaped radiator that acts as a radiating element. The sharp band‐rejection capability at WLAN is established by incising the L‐shaped slits at the decoupling structure. More than ?21 dB isolation is accomplished for the complete working band (ie, 2.87 ‐17 GHz). Degradation in the antenna efficiency at the center frequency of band rejection corroborates the good interference rejection capability. The working capabilities of the intended antenna are tested by using the isolation between the ports, total efficiency, gain, envelope correlation coefficient, radiation pattern, mean effective gain, and total active reflection coefficient. 相似文献
83.
Chauhan Digvijay Singh Singh Amit Kumar Kumar Basant Saini J. P. 《Multimedia Tools and Applications》2019,78(4):3911-3923
Multimedia Tools and Applications - In this paper, an improved wavelet based medical image watermarking algorithm is proposed. Initially, the proposed technique decomposes the cover medical image... 相似文献
84.
Vandita Kakkar Indu Pal Kaur Amrit Pal Kaur Komal Saini Kamalinder K. Singh 《Drug development and industrial pharmacy》2018,44(10):1701-1712
Tetrahydrocurcumin (THC) also referred to as ‘white curcumin’, is a stable colorless hydrogenated product of curcumin with superior antioxidant and anti-inflammatory properties. The present study is an attempt to elevate the topical bioavailability of THC, post-incorporation into a nano-carrier system with its final dosage as a hydrogel. Lipid nanoparticles of THC (THC-SLNs) prepared by microemulsification technique were ellipsoidal in shape (revealed in transmission electron microscopy) with a mean particle size of 96.6?nm and zeta potential of ?22?mV. Total drug content and entrapment efficiency of THC-SLNs was 94.51%?±?2.15% and 69.56%?±?1.35%, respectively. Differential scanning calorimetry and X-ray diffraction studies confirmed the formation of THC-SLNs. In vitro drug release studies showed the drug release from THC-SLNs gel to follow Higuchi’s equation revealing a Fickian diffusion. Ex vivo permeation studies indicated a 17 times (approximately) higher skin permeation of THC-SLNs gel as compared with the free THC gel. Skin irritation, occlusion, and stability studies indicated the formulation to be nonirritating, and stable with a desired occlusivity. Pharmacodynamic evaluation in an excision wound mice model clearly revealed the enhanced anti-inflammatory activity of THC-SLNs gel and was further confirmed using biochemical and histopathological studies. It is noteworthy to report here that THC-SLNs gel showed significantly better (p?≤?0.001) activity than free THC in gel. As inflammation is innate to all the skin disorders, the developed product opens up new therapeutic avenues for several skin diseases. To the best of our knowledge, this is the first paper elaborating the therapeutic usefulness of white curcumin-loaded lipidic nanoparticles for skin inflammation. 相似文献
85.
Wireless Personal Communications - Camera placement is very important for surveillance applications. Proposed work presents a new method of optimum placement of visual sensors for maximum coverage... 相似文献
86.
Kumar Pradeep Saini Rajkumar Roy Partha Pratim Dogra Debi Prosad 《Multimedia Tools and Applications》2018,77(7):8823-8846
Multimedia Tools and Applications - Sign language is the only means of communication for speech and hearing impaired people. Using machine translation, Sign Language Recognition (SLR) systems... 相似文献
87.
Tripurari Saran Indu B. Paul Deb S. Chatterjee Lakshminarayanapuram V. Ramachandran Phanindra N. Mukherjee 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1978,28(9):633-637
The effect of washing on the texture of silica gel has been investigated in terms of parameters such as porosity, pore size distribution, surface area and absorption of moisture. It was observed that if silica gel (before activation) is washed with water containing dissolved ions such as Ca and Mg wider pores are formed at the expense of smaller ones. This phenomenon has been explained in terms of change in the size distribution of gel particles which is brought about by solution of very fine particles followed by growth, through condensation, of larger particles. The experimental observations have been interpreted to suggest guidelines to control the texture of gels by washing with solutions comaining different cations. 相似文献
88.
The need for recycling of polymeric waste has been well recogmized as a result of the escalating prices of the petrochemical feedstocks and the growing awareness to curtail solid waste that causes environmental pollution. During processing, the molecular weight of the polymer is reduced due to thermal and shear degradation. Since the melt rheology of the processed material is sensitive to the changes in molecular structure, knowledge of the complete flow curve depicting the variation of melt viscosity with shear rate at processing temperatures is a useful tool for assessing the reprocessibility of waste material and for specifying the conditions of reprocessing. In the present paper, an effective method is proposed to generate the melt flow curves of polymer waste from knowledge of its melt flow index. The method makes use of a master curve that can be obtained by plotting the available viscosity data in terms of modified functions based on the melt flow index. The master curves characteristic of the particular generic resin type are presented for low-density polyethylene, polypropylene and polystyrene. 相似文献
89.
Wireless Personal Communications - Now-a-days the most common pretentious disease is the lung cancer, which has become more prevalent in the world that primarily infects the pulmonary nodules of... 相似文献
90.