全文获取类型
收费全文 | 2239篇 |
免费 | 111篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 25篇 |
综合类 | 5篇 |
化学工业 | 542篇 |
金属工艺 | 68篇 |
机械仪表 | 86篇 |
建筑科学 | 35篇 |
矿业工程 | 3篇 |
能源动力 | 77篇 |
轻工业 | 142篇 |
水利工程 | 17篇 |
石油天然气 | 12篇 |
无线电 | 218篇 |
一般工业技术 | 511篇 |
冶金工业 | 223篇 |
原子能技术 | 18篇 |
自动化技术 | 375篇 |
出版年
2024年 | 6篇 |
2023年 | 35篇 |
2022年 | 50篇 |
2021年 | 90篇 |
2020年 | 59篇 |
2019年 | 66篇 |
2018年 | 94篇 |
2017年 | 77篇 |
2016年 | 86篇 |
2015年 | 60篇 |
2014年 | 96篇 |
2013年 | 183篇 |
2012年 | 93篇 |
2011年 | 109篇 |
2010年 | 105篇 |
2009年 | 96篇 |
2008年 | 116篇 |
2007年 | 84篇 |
2006年 | 67篇 |
2005年 | 53篇 |
2004年 | 54篇 |
2003年 | 41篇 |
2002年 | 48篇 |
2001年 | 34篇 |
2000年 | 33篇 |
1999年 | 33篇 |
1998年 | 66篇 |
1997年 | 42篇 |
1996年 | 32篇 |
1995年 | 20篇 |
1994年 | 32篇 |
1993年 | 23篇 |
1992年 | 25篇 |
1991年 | 14篇 |
1990年 | 26篇 |
1989年 | 18篇 |
1988年 | 12篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 19篇 |
1984年 | 14篇 |
1983年 | 22篇 |
1982年 | 9篇 |
1981年 | 14篇 |
1980年 | 19篇 |
1979年 | 9篇 |
1978年 | 10篇 |
1977年 | 6篇 |
1975年 | 4篇 |
1974年 | 5篇 |
排序方式: 共有2357条查询结果,搜索用时 468 毫秒
91.
Dextrin crosslinked with poly(lactic acid): A novel hydrogel for controlled drug release application 下载免费PDF全文
A new class of biodegradable crosslinked hydrogel, consisting of hydrophobic polylactic acid (PLA) and hydrophilic dextrin in presence of crosslinker N,N‐methylene bisacrylamide (MBA) has been synthesized by free‐radical polymerization technique using potassium persulfate (KPS) as initiator. By variation of crosslinker concentration, a series of hydrogels have been prepared and the optimized grade has been selected on the basis of higher crosslinking efficiency as well as lower equilibrium swelling characteristics, XRD analysis. The hydrogels have been characterized by FTIR spectra, 13C‐NMR spectra, CHN analysis, SEM analysis, swelling characteristics, and toxicity study. In vitro release study of model drugs (ciprofloxacin and ornidazole) from hydrogel matrix has been performed in various buffer solutions at 37°C. The drug release kinetics and mechanism have been studied using zero order, first‐order kinetic models, Korsemeyar–Peppas model, Higuchi model, Hixson–Crowell model, and nonlinear Kopcha model. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40039. 相似文献
92.
Since 2009, numerous failures of the working rollers in the 5000 mill at OAO MMK have been observed, on account of fracture of the drive pins. Efforts to resolve this problem are described. 相似文献
93.
94.
Gaurav Kumar Pal S. Bharath Kumar P. Prabhasankar P. V. Suresh 《Sensing and Instrumentation for Food Quality and Safety》2017,11(3):939-947
Incorporating exogenous proteins into food products is a better practice for improving nutritional attributes of food commodities. In the search for a way to improve the product and nutritional quality of noodles, this study was aimed to evaluate the impact of the incorporation of poultry based ingredients egg yolk powder (EYP) and chicken mincemeat (CMM) in noodles at different levels (5, 10 and 15%, w/w). The incorporated noodles were subjected to evaluation of the cooking, texture, colour, sensory and microstructure properties. The results showed that the incorporation of poultry based food ingredient types and amount influence the nutritional content of noodles. Simultaneously, poultry based ingredients incorporated noodles showed the acceptable firmness and colour charatertistics. Scanning electron micrograph of the incorporated noodles showed the gelatinized starch granules enveloped by protein matrix, and also indicating a better structure as compared to the control. The sensory profile of incorporated noodles was showed significant (p?≤?0.05) high overall quality. The result of this study showed that 10% (w/w) EYP and 15% (w/w) CMM incorporated noodles showed a better overall noodles quality attributes (texture, colour, sensory and microstructure). The results also provide ideas about the inclusion of the appropriate levels of poultry based ingredients (EYP and CMM) with a better sensory and nutritional profile. Therefore, this study may be useful in the food industry for the production of poultry based ingredients noodles with enhanced quality characteristics. 相似文献
95.
Despite of substantial advancement, the effect of grain boundary (GB) complexions on high temperature creep deformation process has not been fully understood. In this paper, we have studied the high temperature bending creep deformation of copper bicrystal with various GB complexions under different loads using molecular dynamics simulation. It has been found that specimen with normal kite GB complexion have better creep resistance properties when subjected to comparatively lower applied load. In case of monolayer Zr segregation, a drastic decrease in creep strength as well as creep plasticity is observed due to inhibition of GB migration. On the other hand, deviation between creep properties for specimen with split-kite GB complexion and split-kite bilayer Zr segregation GB complexion is minimal. Enhanced creep plasticity is observed in case of split-kite bilayer Zr segregation GB complexion, which is due to formation of interpenetrating icosahedral clusters in the necking region. Fracture in specimen with monolayer Zr segregation GB complexion has occurred by means of slip phenomenon at lower deformation load whereas amorphization and necking is observed at higher deformation load. In case of specimen with bilayer Zr segregation GB complexion, it is found that fracture has occurred through amorphization and necking at all deformation loads due to higher GB thickness. 相似文献
96.
Colour of light modulates the appearance of displayed artifacts in exhibition. To understand the effect of light on appearance of paintings, few studies have experimented to establish a relation between pleasantness with the correlated colour temperature (CCT) of light. However, some studies have found that CCT has no significant effect on pleasant appearance of painting. Therefore, in this article, an experiment with a qualitative (questionnaire on semantic differential scale, N = 30) approach was designed to understand the effect of CCT on appearance of paintings exhibited under LED lights. The findings from the experimental result depict that the appearance of paintings changes due to different CCTs of LEDs having the same illuminance. In addition, the result reveals that for both mediums of paintings considered in this study, in comparison to warm white LED and artificial daylight LED, cool white LED has appeared to be more pleasant having moderately warm feelings to the viewers. 相似文献
97.
Physicochemical characterisation of corn extrudates prepared with varying levels of beetroot (Beta vulgaris) at different extrusion temperatures 下载免费PDF全文
Jatinder Pal Singh Amritpal Kaur Khetan Shevkani Narpinder Singh Baljit Singh 《International Journal of Food Science & Technology》2016,51(4):911-919
This study examines the effect of beetroot powder (BRP) incorporation (0%, 5%, 10% and 15%) at different extrusion temperatures (125, 150 and 175 °C) on the physicochemical, antioxidant and sensory properties of corn grit (CG) extrudates. BRP showed higher values of total phenolic content (TPC = 9095 μg GAE g?1) and free radical inhibition (ABTS = 6.5 μm trolox mg?1 and DPPH = 7.9 μm trolox mg?1) than CG (1346 μg GAE g?1, 1.5 μm trolox mg?1 and 2.2 μm trolox mg?1, respectively). Pasting viscosity (peak, breakdown and final) decreased, while pasting temperature of CG increased with the level of BRP incorporation. Analyses of the extrudates showed an increase in redness, bulk density, hardness, TPC, free radical inhibition, total dietary fibre (TDF) and a decrease in water absorption index (WAI), water solubility index (WSI), expansion ratio and oil uptake with the increase in the level of BRP incorporation. On the other hand, higher extrusion temperature increased porosity, WAI, WSI, oil uptake but decreased redness, bulk density, hardness and TPC. 相似文献
98.
Bola Yoon Devinder Yadav Sanjit Ghose Rishi Raj 《Journal of the American Ceramic Society》2019,102(5):2294-2303
We show that flash experiments with three phase mixed-powders of yttria-stabilized zirconia (8YSZ), MgO, and α-Al2O3 not only produce polycrystals of high density, but also the transformation of magnesia and alumina into single-phase spinel. The presence of zirconia facilitates the onset of the flash. The sintering experiments in the laboratory were extended to live experiments at the National Synchrotron Light Source II at Brookhaven National Laboratory in order to measure the time-dependent evolution of single-phase spinel. The phase transformation occurred in <3 seconds during Stage II. Later, during Stage III the cubic zirconia transformed partly into the monoclinic phase, which reverted back to the cubic phase when the flash was extinguished by turning off the current to the specimen. The results underpin a recent report on the synthesis of single-phase bismuth ferrite from constituent oxides in reactive flash experiments, raising the specter of flash as a method for synthesis as well as sintering of complex oxide ceramics. The role of zirconia in catalyzing the flash in the present study is discussed. 相似文献
99.
Rajesh K. Gangwar Vinayak A. Dhumale Dimple Kumari Umesh T. Nakate S.W. Gosavi Rishi B. Sharma S.N. Kale Suwarna Datar 《Materials science & engineering. C, Materials for biological applications》2012,32(8):2659-2663
Curcumin, a natural polyphenolic compound, has astounding therapeutic applications but lacks in bioavailability mainly due to its poor solubility in water. Polyvinyl pyrrolidone (PVP) which is a proven drug carrier has been used to facilitate the conjugation of curcumin with gold nanoparticles and to improve the solubility of curcumin in water. In this conjugate diaryl heptanoid chromophore group of curcumin which is a much needed group in biomedical applications remains intact as observed from FTIR and UV–vis spectroscopy analysis. The work shows good promise for such conjugates as therapeutic-cum-imaging materials in biomedical field. 相似文献
100.
Neural Computing and Applications - In the present situation, the sustainable development goal on “Gender Equality” (SDG 5) is a challenging problem over the entire globe, also in... 相似文献