全文获取类型
收费全文 | 391篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 28篇 |
金属工艺 | 23篇 |
机械仪表 | 23篇 |
建筑科学 | 8篇 |
能源动力 | 23篇 |
轻工业 | 86篇 |
水利工程 | 1篇 |
武器工业 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 134篇 |
冶金工业 | 2篇 |
原子能技术 | 6篇 |
自动化技术 | 43篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 15篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 21篇 |
2013年 | 125篇 |
2012年 | 34篇 |
2011年 | 33篇 |
2010年 | 19篇 |
2009年 | 12篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有395条查询结果,搜索用时 15 毫秒
91.
ARUN KUMAR DARSHAN LAL RAMAN SETH VIVEK SHARMA 《International Journal of Dairy Technology》2010,63(3):457-462
A fractionation technique followed by the apparent solidification time (AST) test was adopted for detecting the admixture of foreign oils and fats in milk fat. The AST values of the solid fraction obtained at 20°C, and solid and liquid fractions obtained at 18°C for pure cow milk fat, were 2 min 30 s, and 3 min 21 s and 3 min 31 s, while for buffalo milk fat they were 1 min 58 s, and 2 min 47 s and 3 min 10 s respectively. This new approach can detect some mixtures of foreign oils and fats in cow milk fat but not in buffalo milk fat. 相似文献
92.
PURUSHOTTAM KUMAR SINGH PANKAJ KUMAR MANOWAR HUSSAIN ALOK KUMAR DAS GANESH CHANDRA NAYAK 《Bulletin of Materials Science》2016,39(2):469-478
In the present study, cupric oxide (CuO) nanoparticles were synthesized by electrochemical discharge process using strong base electrolytes. The experiments were carried out separately using NaOH and KOH electrolytes. The mass output rate and the crystal size were obtained with variation of the rotation speed of magnetic stirrer for both types of electrolytes. The mass output rate of CuO nanoparticles increased with the increase in the speed of rotation, and, after an optimum speed, it started decreasing. However, the size of the particles reduced with the increase of the rotation speed. The crystal plane of the obtained CuO nanoparticles was similar for both the electrolytes whereas the yield of nanoparticles was higher in KOH as compared with NaOH under the same experiment conditions. In this set of experiments, the maximum output rates obtained were 21.66 mg h?1 for NaOH and 24.66 mg h?1 for KOH at 200 rpm for a single discharge arrangement. The average crystal size of CuO particles obtained was in the range of 13–18 nm for KOH electrolyte and 15–20 nm for NaOH electrolyte. Scanning electron microscopy images revealed that flower-like and caddice clew-shaped CuO nanocrystalline particles were synthesized by the electrochemical discharge process. Fourier transform infrared spectrum showed that the CuO nanoparticles have a pure and monolithic phase. UV–vis–NIR spectroscopy was used to monitor oxidation course of Cu → CuO and the band gap energy was measured as 2 and 2.6 eV for CuO nanoparticle synthesized in NaOH and KOH solutions, respectively. 相似文献
93.
The reflectivity dependence, of the lasing photon energy in GaAs junction lasers at 77° K is studied. It is found that the lasing photon energy decreases with increasing values of the laser reflectivity. 相似文献
94.
The selection of parts and machines poses an important problem in the design and planning phases of cellular manufacturing and flexible manufacturing systems. In most real-life situations, this grouping invariably leads to 'bottleneck’ parts and machines. This paper discusses a method of identifying the minimal number of bottle-neck cells (machines or parts) which, when dealt with through either duplication of machines or subcontracting of parts, will result in perfect part-machine groupings with no overlap. The polynomially bounded algorithms used in the analysis are oriented towards finding minimal cut-nodes in either partition of the bipartite part-machine graph. 相似文献
95.
96.
MOHAN KUMAR KUNTUMALLA HARISH OJHA VADALI VENKATA SATYA SIVA SRIKANTH 《Bulletin of Materials Science》2013,36(6):1087-1090
It is difficult to detect β-SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, β-SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/β-SiC nanocomposite thin film system is considered in which nanosized β-SiC crystallites are surrounded by a relatable nanodiamond medium that leads to the appearance of a weak Raman surface phonon band at about 855 cm???1. Change in the nature of the surrounding material structure and its volume content when relatable, will affect the resultant Raman response of β-SiC phase as seen in the present case of diamond/β-SiC nanocomposite thin films. 相似文献
97.
The aim of this paper is to investigate the effect of sintering temperature and time on the properties of Fe–Al2O3 composite (5 wt% Al2O3; 95 wt% Fe) prepared by powder metallurgy process. X-ray diffraction, microstructure, density, hardness and compressive strength of prepared samples have been investigated. XRD studies show the presence of Fe and Al2O3 along with iron aluminate phase. Iron aluminate is formed as a result of reactive sintering between iron and alumina particles. Microstructural examination of the specimen showed a dense structure with nanosize dispersion of the reinforcement of ceramic phase. Density as well as hardness of specimens depend on the formation of iron aluminate phase, which in turn depends on sintering temperature and time. 相似文献
98.
SANDEEP ARYA SALEEM KHAN SALEEM KUMAR RAJNIKANT VERMA PARVEEN LEHANA 《Bulletin of Materials Science》2013,36(4):535-539
Copper telluride (CuTe) nanowires were synthesized electrochemically from aqueous acidic solution of copper (II) sulphate (CuSO4·5H2O) and tellurium oxide (TeO2) on a copper substrate by template-assisted electrodeposition method. The electrodeposition was conducted at 30 °C and the length of nanowires was controlled by adjusting deposition time. Structural characteristics were examined using X-ray diffraction and scanning electron microscope which confirm the formation of CuTe nanowires. Investigation for chemical sensing was carried out using air and chloroform, acetone, ethanol, glycerol, distilled water as liquids having dielectric constants 1, 4·81, 8·93, 21, 24· 55, 42·5 and 80·1, respectively. The results unequivocally prove that copper telluride nanowires can be fabricated as chemical sensors with enhanced sensitivity and reliability. 相似文献
99.
M SATYA KISHORE P SRIMATHI SUNDEEP KUMAR SWARNAGOWRI ADDEPALLI SRINIVASAN SWAMINATHAN VINAYAK TILAK ROBERT COLBORN 《Bulletin of Materials Science》2013,36(4):667-672
Graphene sheets are synthesized by a simple method starting from graphitic oxide as a precursor. Reaction of graphitic oxide at 250 °C with a combustion mixture of urea and ammonium nitrate results in the formation of thin graphene sheets. Graphene formation is characterized by XRD, TGA, XPS and TEM. Graphene materials synthesized by this method are investigated as an ultracapacitor material. Specific capacitance values of about 70 F/g are obtained at a current density of 100 mA/g by using KOH as an electrolyte. 相似文献
100.
Asphaltenes separated from two different crude oils from upper Assam, India, having different geological origins, viz. DK (eocene) and JN (oligocene–miocene) were pyrolysed at 600 °C and the products were analysed by gas chromatography–mass spectrometry (GC/MS) especially for the generated alkylnaphthalenes and alkylphenanthrenes. Both the asphaltenes produce aliphatic as well as aromatic compound classes. Alkylnaphthalenes and alkylphenanthrenes were identified by using reference chromatograms and literature data and the distributions used to assess thermal maturity of the asphaltenes. The ratios of β -substituted to α -substituted isomers of both alkylnaphthalenes and alkylphenanthrenes revealed higher maturity of the JN asphaltenes than the DK asphaltenes. For both the asphaltenes, the abundance of 1-methylphenanthrene dominates over that of 9-methylphenanthrene showing the terrestrial nature of the organic matter. 相似文献