全文获取类型
收费全文 | 338篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 17篇 |
化学工业 | 57篇 |
金属工艺 | 11篇 |
机械仪表 | 5篇 |
建筑科学 | 5篇 |
能源动力 | 16篇 |
轻工业 | 17篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 55篇 |
一般工业技术 | 81篇 |
冶金工业 | 59篇 |
自动化技术 | 20篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 25篇 |
2012年 | 7篇 |
2011年 | 22篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 19篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2001年 | 13篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 9篇 |
1997年 | 15篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有346条查询结果,搜索用时 234 毫秒
61.
Rui WANG Song YANG Shitao YIN Baoan SONG Pinaki S. BHADURY Wei XUE Shuwei TAO Zhaohui JIA Da LIU Liang GAO 《Frontiers of Chemical Engineering in China》2008,2(4):468-472
The preparation and regeneration conditions of the identified catalyst X/Y/MgO/γ-Al2O3 with high catalytic activity were studied and optimized. The biodiesel was prepared by transesterification of Jatropha curcas seed oil produced in Guizhou with methanol at its reflux temoerature in the presence of X/Y/MgO/γ-Al2O3. The pilot plant tests were carried out in a 100 L reaction vessel. Both average yield and fatty acid methyl esters (FAME)
content reached more than 96.50% under the optimum reaction conditions of the pilot plant tests designed withan oil/methanol
molar ratio of 1: 10, catalyst concentration of 1.00%, and reaction time of 3 h at reflux temperature. In addition, analysis
shows that the quality of biodiesel meets the standard EN 14214.
__________
Translated from Modern Chemical Industry, 2007, 27(Suppl. 2): 452–455 [译自: 现代化工] 相似文献
62.
We propose a microsphere array device with microspheres having controllable positions for error-free target identification. We conduct a statistical design analysis to select the optimal distance between the microspheres as well as the optimal temperature. Our design simplifies the imaging and ensures a desired statistical performance for a given sensor cost. Specifically, we compute the posterior Cramér-Rao bound on the errors in estimating the unknown target concentrations. We use this performance bound to compute the optimal design variables. We discuss both uniform and sparse concentration levels of targets, and replace the unknown imaging parameters with their maximum likelihood estimates. We illustrate our design concept using numerical examples. The proposed microarray has high sensitivity, efficient packing, and guaranteed imaging performance. It simplifies the imaging analysis significantly by identifying targets based on the known positions of the microspheres. Potential applications include molecular recognition, specificity of targeting molecules, protein-protein dimerization, high throughput screening assays for enzyme inhibitors, drug discovery, and gene sequencing. 相似文献
63.
Fan H Song B Bhadury PS Jin L Hu D Yang S 《International journal of molecular sciences》2011,12(7):4522-4535
Using half-leaf method O,O'-diisopropyl (3-(L-1-(benzylamino)-1-oxo-3- phenylpropan-2-yl)thioureido)(phenyl)methyl phosphonate (2009104) was studied for its activity on tobacco mosaic virus (TMV). It showed good curative activity in vivo and the curative activity at 500 μg/mL was found to be 53.3%. In vivo treatment with the control agent Ningnanmycin at 500 μg/mL resulted in 51.2% inhibition and curative inhibition rates respectively. Dot-ELISA test was employed to verify the efficacy of activity of compound 200910 for anti-TMV activity. The mechanism of action of compound 2009104 to resist TMV was also studied. The results showed that the resistance enzymes PAL, POD, SOD activity and chlorophyll content after TMV inoculation K(326) (Nicotiana tabacum K(326)) of tobacco plants followed by treatment with compound 2009104 were significantly enhanced. The study of the effect of compound 2009104 on TMV capsid protein (CP) showed that it inhibited the polymerization process of TMV-CP in vitro. 相似文献
64.
Arshad Khan D. Sen P. Kothalkar B. K. Sapra S. Mazumder Y. S. Mayya 《Drying Technology》2013,31(6):679-686
This work discusses the design, development, and performance of an indigenous laboratory spray dryer with a relatively slow drying rate. The drying time of droplets of colloidal silica (5 wt%) and sodium chloride solution (20 wt%) in this spray dryer was nearly 10 s. The present system was composed of a four-jet compressed air nebulizer that generates a droplet size of 2–5 µm with a nebulization rate of nearly 60 mL/h. The generated powder can be collected using a cyclone or a wire mesh collector. Design and characterization of this system as well as characterization of the micrometric self-assembled powder grains obtained by this spray dryer are discussed. 相似文献
65.
A study of the effects of the breaker-card-cylinder speed and delivery-roller speed on jute-yarn properties is reported. Though machine makers recommend a cylinder speed of 200 rev/min, a speed of 150 rev/min is shown to give a better yarn, even when the production is kept at the same level. Finer fibres absorb more power and yield yarn of higher strength. The strength realization of the fibre is also higher at a lower cylinder speed. 相似文献
66.
67.
The mechanism and chemical nature of uranium and thorium sequestration by a Pseudomonas strain was investigated by transmission electron microscopy, energy dispersive X-ray (EDX) analysis, FTIR spectroscopy and X-ray diffractometry. Atomic force microscopy (AFM) used in the tapping mode elucidated the morphological changes in bacterial cells following uranium and thorium binding. Transmission electron microscopy revealed intracellular sequestration of uranium and thorium throughout the cell cytoplasm with electron dense microprecipitations of accumulated metals. Energy dispersive X-ray analysis confirmed the cellular deposition of uranium and thorium. EDX and elemental analysis of sorption solution indicated the binding of uranium and thorium by the bacterial biomass via displacement of cellular potassium and calcium. The strong involvement of cellular phosphate, carboxyl and amide groups in radionuclide binding was ascertained by FTIR spectroscopy. X-ray powder diffraction (XRD) analyses confirmed cellular sequestration of crystalline uranium and thorium phosphates. Overall results indicate that a combined ion-exchange-complexation-microprecipitation mechanism could be involved in uranium and thorium sequestration by this bacterium. Atomic force microscopy and topography analysis revealed an undamaged cell surface with an increase in cell length, width and height following radionuclide accumulation. The arithmetic average roughness (R(a)) and root mean square (RMS) roughness (R(q)) values indicated an increase in surface roughness following uranium and thorium sequestration. 相似文献
68.
69.
Amrita Mazumder Jagannath Chanda Sanjay Bhattacharyya Saikat Dasgupta Rabindra Mukhopadhyay Anil K. Bhowmick 《应用聚合物科学杂志》2021,138(42):51236
Automotive industry is currently looking for an eco-friendly tire with low rolling resistance coefficient (RRc), better traction, wear resistance, and fatigue properties. Presently, solution styrene-butadiene rubber (SSBR)-silica systems are pursued for balancing between traction and RRc. However, the interaction between SSBR and silica is not enough to give satisfactory results. Functionalized-SSBR (FSSBR) leads to better rubber-silica interaction due to introduction of polar groups in the polymer chain. The present study investigates the influence of FSSBR, highly dispersible (HD) silica, and its hybrid filler systems with organically modified nanoclay (ONC) and exfoliated graphene nanoplatelet (xGnP). Both MH, and Δtorque were higher for the FSSBR-HD silica compound (S1) with the lowest change in storage modulus (∆G') value, due to higher polymer-filler interaction. S1 exhibited 16% ice traction and 12% wet traction improvement with 29% lower rolling resistance over SSBR-silica compound. S1 showed the best wet traction rating and wear resistance. Replacing small portion of silica by ONC and xGnP improved the properties further. At 5 phr of nanofiller, TEM images revealed well-dispersed nanofillers in the FSSBR matrix. The xGnP compound showed the least crack growth. For both the cases, abradability decreased with higher nanofiller amount, due to better reinforcement of the rubber. 相似文献
70.
Chandrakanta Sen Pinaki Ranjan Ray Mahasweta Bhattacharyya 《International Journal of Dairy Technology》2021,74(1):17-31
Metabolomics deals with the identification and quantification of the small molecules involved in metabolic reactions. It has recently been used to understand the nutritional quality and authenticity of milk and milk products. Various analytical techniques such as nuclear magnetic resonance spectroscopy, liquid chromatography–mass spectrometry, gas chromatography–mass spectrometry and ultra‐performance liquid chromatography–quadrupole time‐of‐flight mass spectrometry have been successfully employed to identify and quantify the metabolites present in milk and milk products. This review focuses on the recent advances in metabolomics for quality and safety analyses of milk and milk products. 相似文献