全文获取类型
收费全文 | 193篇 |
免费 | 14篇 |
专业分类
电工技术 | 4篇 |
综合类 | 1篇 |
化学工业 | 58篇 |
金属工艺 | 1篇 |
机械仪表 | 4篇 |
建筑科学 | 6篇 |
能源动力 | 6篇 |
轻工业 | 43篇 |
无线电 | 13篇 |
一般工业技术 | 30篇 |
冶金工业 | 11篇 |
自动化技术 | 30篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 16篇 |
2019年 | 22篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 6篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 27篇 |
2012年 | 12篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 9篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1992年 | 1篇 |
排序方式: 共有207条查询结果,搜索用时 250 毫秒
61.
62.
Elena Binkauskiene Albinas Lugauskas Malle Krunks Ilona Oja Acik Vitalija Jasulaitiene Gintautas Saduikis 《Synthetic Metals》2010,160(9-10):906-910
The growth of Chrysosporium merdarium on TiO2 (rutile, anatase) and its possibility to deteriorate the surface were investigated. Treated with fungi and untreated samples of deteriorated TiO2 surfaces were studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Microbial deterioration of TiO2 is also discussed. The attachment to the TiO2 surface via metabolic products resulted in the formation of cryptand [2,2,2] complex with Ca2+ ions. According to water contact angle (CA) measurements microbial growth increases the wettability of TiO2 film surfaces. A much more intensive fungal action during microbial treatment on rutile in comparison with that of anatase was observed. A chemical deterioration product, the volatile trimethyl borate, on rutile in exudation of C. merdarium was detected by gas chromatographic–mass spectrometric analysis. 相似文献
63.
Infrared heating for dry-roasting and pasteurization of almonds 总被引:1,自引:0,他引:1
The use of infrared (IR) heating for improving the microbial safety and processing efficiency of dry-roasted almonds was investigated. Almonds were roasted at 130, 140 and 150 °C with three different methods: IR roasting, sequential infrared and hot air (SIRHA) roasting, and traditional hot air (HA) roasting. The heating rate and pasteurization efficacy of almonds under different roasting methods and temperatures were evaluated. Pediococcus sp. NRRL B-2354 was used as a surrogate for Salmonella enterica Enteriditis PT 30 for evaluating the pasteurization efficacy of different processing methods and conditions. When SIRHA roasting at 130, 140 and 150 °C roasting temperatures was used to produce medium roasted almonds, 4.10-, 5.82- and 6.96-log, bacterial reductions were achieved with 38%, 39% and 62% time saving compared to HA roasting at each temperatures, respectively. The decimal reduction time of the bacteria at all roasting temperatures were calculated for SIRHA roasting as 8.68, 3.72 and 1.42 min, respectively, with a correlation coefficient greater than 0.92 and the thermal resistance constant was found as 25.4 °C. The total color change followed zero-order reaction kinetics and the activation energies were 73.58, 52.15 and 67.60 kJ/mol for HA, IR and SIRHA roasting, respectively. No significant difference (p > 0.05) was observed in sensory quality of medium roasted almonds processed with different roasting methods. We conclude that the SIRHA roasting is a promising new method for the production of dry-roasted pasteurized almonds. 相似文献
64.
A procedure for the determination of trace amounts of chromium(III), iron(III), lead(II) and manganese(II) is described, that combines atomic absorption spectrometry-europium hydroxide coprecipitation. The influences of analytical parameters including amount of europium(III), amount of ammonia, sample volume, etc. were investigated on the recoveries of analyte ions. The effects of concomitant ions were also examined. The recoveries of the analyte ions were in the range of 95-104%. The detection limits (3 s) were in the range of 1.7-17.1 microg/L. The validation of the presented coprecipitation procedure was performed by the analysis of Bovine Liver 1577-b and BCR-144R Sewage Sludge (domestic origin) standard reference materials. The method was applied to the determination of analytes in real samples including natural waters and some food, soil and fertilizer samples, etc. and good results were obtained (relative standard deviations < 10%, recoveries > 95%). 相似文献
65.
It has been shown that the following three substituted α-aminoalcohols, 2-(N-methyl-N-phenylamino-1-phenyl) ethanol (1), 2-methyl-1-[4-(methylthio) phenyl-2-morpholino]propane-1-ol (2) and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-ol (3) fragment upon irradiation to give radicals which initiate polymerisation of trimethylolpropane triacrylate (TMPTA). The effectiveness of aminoalcohol (1) as an amelioration of oxygen inhibition was investigated and found to be less effective than N-methyldiethanolamine. Aminoalcohol (1) is a good synergist for isopropylthioxanthone, but due to the absorption characteristic of benzophenone, which absorbs poorly above 300 nm, it is not a suitable initiator. 相似文献
66.
CO2 emissions in the atmosphere are increasing continually, which are mainly originated from burning of fossil fuels. The fossil fuels are expected to remain a major component of the world’s energy supply in the near future, because of their inherent advantages. Therefore, various measures have to be considered to reduce anthropogenic CO2 emissions. Increasing the efficiency of energy usage and/or developing lower carbon or non-carbon energies to replace high carbon fuels may bring the result of the reduction of the accumulation of CO2 in the atmosphere. The other alternative to reduce CO2 concentrations in atmosphere include gaseous storage in various deep geological formations, liquid storage in the ocean, and solid storage by reaction of CO2 with metal oxides to produce stable carbonates. In this article, the geological storage options of CO2 are examined. They are discussed in terms of applicability, cost, storage capacity and safety. 相似文献
67.
In supply chain management process, the firm select best supplier takes the competitive advantage to other companies. Thus, supplier selection is an important issue and with the multiple criteria decision-making approach, the supplier selection problem includes both tangible and intangible factors. This paper is aimed to present an integrated fuzzy and linear programming approach to the problem. Firstly, linguistic values expressed in trapezoidal fuzzy numbers are applied to assess weights and ratings of supplier selection criteria. Then a hierarchy multiple model based on fuzzy set theory is expressed and fuzzy positive and negative ideal solutions are used to find each supplier’s closeness coefficient. Finally, a linear programming model based on the coefficients of suppliers, buyer’s budgeting, suppliers’ quality and capacity constraints is developed and order quantities assigned to each supplier according to the linear programming model. The integrated model is illustrated by an example in a textile firm. 相似文献
68.
Zhongli Pan Gokhan Bingol Maria T. Brandl Tara H. McHugh 《Food and Bioprocess Technology》2012,5(6):2046-2057
After the 2001 and 2004 Salmonellosis outbreaks that were associated with raw almonds, ensuring the microbial safety of almonds by treating them to achieve a minimum 4-log reduction of Salmonella population became mandatory in California, the world??s largest almond producer. In this paper, we summarize potential pathways of microbial contamination during almond production and manufacturing. Furthermore, we review sanitization technologies, including chemical, thermal, and non-thermal methods, as well as proprietary systems with regard to microbial and sensory quality of almonds and compare various aspects of their use during almond processing. 相似文献
69.
70.
Serkan Gunal Omer Nezih Gerek Dogan Gokhan Ece Rifat Edizkan 《Expert systems with applications》2009,36(7):10266-10273
The significance of detection and classification of power quality (PQ) events that disturbs the voltage and/or current waveforms in the electrical power distribution networks is well known. Consequently, in spite of a large number of research reports in this area, the problem of PQ event classification remains to be an important engineering problem. Several feature construction, pattern recognition, analysis, and classification methods were proposed for this purpose. In spite of the extensive number of such alternatives, a research on the comparison of “how useful these features with respect to each other using specific classifiers” was omitted. In this work, a thorough analysis is carried out regarding the classification strengths of an ensemble of celebrated features. The feature items were selected from well-known tools such as spectral information, wavelet extrema across several decomposition levels, and local statistical variations of the waveform. The tests are repeated for classification of several types of real-life data acquired during line-to-ground arcing faults and voltage sags due to the induction motor starting under different load conditions. In order to avoid specificity in classifier strength determination, eight different approaches are applied, including the computationally costly “exhaustive search” together with the leave-one-out technique. To further avoid specificity of the feature for a given classifier, two classifiers (Bayes and SVM) are tested. As a result of these analyses, the more useful set among a wider set of features for each classifier is obtained. It is observed that classification accuracy improves by eliminating relatively useless feature items for both classifiers. Furthermore, the feature selection results somewhat change according to the classifier used. This observation shows that when a new analysis tool or a feature is developed and claimed to perform “better” than another, one should always indicate the matching classifier for the feature because that feature may prove comparably inefficient with other classifiers. 相似文献