全文获取类型
收费全文 | 2115篇 |
免费 | 72篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 36篇 |
综合类 | 2篇 |
化学工业 | 491篇 |
金属工艺 | 87篇 |
机械仪表 | 49篇 |
建筑科学 | 38篇 |
矿业工程 | 2篇 |
能源动力 | 112篇 |
轻工业 | 95篇 |
水利工程 | 18篇 |
石油天然气 | 8篇 |
无线电 | 277篇 |
一般工业技术 | 414篇 |
冶金工业 | 216篇 |
原子能技术 | 23篇 |
自动化技术 | 322篇 |
出版年
2023年 | 17篇 |
2022年 | 29篇 |
2021年 | 32篇 |
2020年 | 24篇 |
2019年 | 39篇 |
2018年 | 55篇 |
2017年 | 42篇 |
2016年 | 51篇 |
2015年 | 38篇 |
2014年 | 49篇 |
2013年 | 122篇 |
2012年 | 78篇 |
2011年 | 112篇 |
2010年 | 94篇 |
2009年 | 93篇 |
2008年 | 86篇 |
2007年 | 90篇 |
2006年 | 76篇 |
2005年 | 65篇 |
2004年 | 38篇 |
2003年 | 52篇 |
2002年 | 49篇 |
2001年 | 37篇 |
2000年 | 36篇 |
1999年 | 42篇 |
1998年 | 79篇 |
1997年 | 64篇 |
1996年 | 42篇 |
1995年 | 43篇 |
1994年 | 45篇 |
1993年 | 29篇 |
1992年 | 38篇 |
1991年 | 42篇 |
1990年 | 25篇 |
1989年 | 28篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 16篇 |
1985年 | 32篇 |
1984年 | 32篇 |
1983年 | 31篇 |
1982年 | 25篇 |
1981年 | 22篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1975年 | 17篇 |
1974年 | 11篇 |
1973年 | 11篇 |
排序方式: 共有2190条查询结果,搜索用时 15 毫秒
81.
82.
Allister Yingwei Tham Chinnasamy Gandhimathi Jayaraman Praveena Jayarama Reddy Venugopal Seeram Ramakrishna Srinivasan Dinesh Kumar 《International journal of molecular sciences》2016,17(8)
Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering. 相似文献
83.
Lipid carriers for delivery of celecoxib: In vitro,in vivo assessment of nanomedicine in rheumatoid arthritis
下载免费PDF全文
![点击此处可从《European Journal of Lipid Science and Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
84.
Ansari Tariq Anwar Srinivasan Vinoth Singh T. N. Das Abhinab 《Bulletin of Engineering Geology and the Environment》2019,78(8):5695-5706
Bulletin of Engineering Geology and the Environment - The numerical methods for slope stability problems always have a serious concern related to their continuum and discontinuum nature. In... 相似文献
85.
Wang Lifei Zhang Zhengyong Cao Miao Zhang Hua Han Tingzhuang Wang Hongxia Arthanari Srinivasan Cheng Weili Jinlong Lyu 《JOM Journal of the Minerals, Metals and Materials Society》2019,71(5):1705-1713
JOM - Prestretch deformation of 6.48% with various initial speeds (1 mm/min, 101 mm/min, and 100 mm/min) was carried out at 723 K to improve the formability of... 相似文献
86.
Ajith Kumar K. K. Srinivasan A. Pillai U. T. S. Pai B. C. Chakraborty M. 《SILICON》2022,14(15):9499-9515
Silicon - The present work aims at understanding the microstructure and mechanical property correlation of hypo (Mg-0.5, 0.7, 1.15 wt% Si) and hyper (Mg-2, 4, 6, 8 and 10 wt% Si) eutectic binary... 相似文献
87.
Silicon - In this paper, electrical and microwave characteristics of Al0.1Ga0.9 N channel HEMTs was reported. The device performance were evaluated for conventional gate, field plate gate,... 相似文献
88.
Influence of High-k Passivation Layer on Gate Field Plate AlGaN/GaN/AlGaN Double Heterojunction HEMT
Silicon - In this work, we have analysed the influence of passivation material such as Silicon dioxide (SiO2), Silicon Nitride (Si3N4), Aluminium oxide (Al2O3), Hafnium Silicon Oxide (HfSiO4),... 相似文献
89.
Saurabh Chaudhary Surekha Parthasarathy Devendra Kumar Chitra Rajagopal Prasun Kumar Roy 《应用聚合物科学杂志》2014,131(4)
The potential of poly(ethyleneterephthalate) glycolysates toward improving the energy absorption characteristics of cycloaliphatic epoxy resins has been explored. Microwave‐assisted glycolytic depolymerization of PET was performed in the presence of polyether diols of different molecular weights. The obtained glycolysates were blended with epoxy, and their mechanical properties were studied under both quasi‐static and dynamic conditions. Significant improvements were observed, which were found to depend both on the amount as well as nature of glycolysate. Amine functionalities were introduced at the terminal positions of glycolysates to improve the compatibility between the two phases. The amine derivatives exhibited superior performance and the Mode I fracture toughness (KIC) of epoxy increased by ~18% in optimized compositions, which is indicative of its improved notch sensitivity. Neat epoxy specimens fractured in a brittle fashion, but all the blends exhibited ductile failure, as evidenced by surface morphological investigations. The mechanical properties of epoxy blends prepared with analogous aliphatic polyols, both before and after amine functionalization, were also studied which clearly reveal the beneficial role of aromatic groups toward improving the toughness of the base cycloaliphatic epoxy resin without compromising on the material stiffness. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39941. 相似文献
90.
A. Amala Jeya Ranchani V. Parthasarathy Chechia Hu Yi-Feng Lin 《Chemical Engineering Communications》2020,207(6):871-886
AbstractAn eco-friendly catalyst system was synthesized using three step reaction. The Cu nanoparticles bridged aminoclay catalyst was analyzed using various analytical techniques. The structure of the catalyst was confirmed by FTIR and XRD. The synthesized catalyst system was used for the reduction of p-nitrophenol (NP), Cr(VI), and fluorescein (Flur) dye individually, as well as in their mixture forms. The kapp value was computed to access the efficiency of the catalyst. The results indicated that the kapp value of the individual system is higher than that of the mixture systems due to the absence of the complex formation reaction. The catalytic performance of the catalyst was also tested for the Schiff base (SB) formation between poly(ethyleneglycol) (PEG) and aniline (ANI) in an oxygen atmosphere. The 1H-NMR spectroscopy result indicates that the present catalyst system produced 86% yield. 相似文献