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排序方式: 共有368条查询结果,搜索用时 31 毫秒
101.
This paper examines the possibility of modifying the surface of carbon fibers with tantalum carbide via reactive chemical vapor deposition at temperatures from 800 to 1000°C. We have studied the surface morphology and topography of the coatings on carbon fibers and determined their phase composition by a variety of physicochemical characterization techniques, including X-ray diffraction, high-resolution scanning electron microscopy, and atomic force microscopy. The strength of the modified fibers has been measured at room temperature. The results demonstrate that the coatings are continuous and uniform in thick-ness along and across the monofilaments, with good surface adhesion. The microstructure and surface topography of the coatings depend on the deposition time and temperature. 相似文献
102.
Aneta Masternak-Janus 《Papers in Regional Science》2022,101(3):603-618
This paper examines the applicability of DEA (Data Envelopment Analysis) to measure and evaluate the efficiency of materials management at the regional level. The research has been conducted for Polish regions as a case study. The basis for the calculation of the efficiency scores was a statistically selected set of materials used in a given region and the Gross Domestic Product (GDP). The results of the analysis reveal that 4 (Łódzkie, Śląskie, Warmińsko-Mazurskie, and Zachodniopomorskie) out of 16 Polish regions are relatively efficient. The remaining regions consume too many material resources in the process of generating goods and services. 相似文献
103.
104.
ABSTRACTOwing to the ability of electrodialysis to produce highly concentrated solutions from dilute stream, in this paper, the possibility of nickel recovery and concentration from real electroplating industrial waste was discussed. The results showed that the nickel content in solutions after electrodialysis was approximately two times higher than in the initial working solutions, and the nickel recovery exceeded 85%. The nickel electric current efficiency (CENi) depended upon the type of electroplating bath and its acidic behaviour. The CENi was in the range of 52.3–70.6%. Moreover, high boron and the total organic carbon retention coefficients equal to 88.92% and 93.93% respectively, were observed. 相似文献
105.
Sheng-Han Lo Hsin-Kuan Liu Jun-Xiang Zhan Wei-Cheng Lin Ching-Che Kao Chia-Her Lin Vítězslav Zima 《Inorganic chemistry communications》2011,14(10):1602-1605
A new strontium metal–organic framework, [Sr2(BTEC)(H2O)4]?2H2O (1) (H4BTEC = benzene-1,2,4,5-tetracarboxylic acid), has been successfully synthesized by mixing the starting reagents. The single-crystal structure analysis showed that compound 1 displayed three-dimensional structures containing inorganic motifs with two-dimensional layers pillar-connected through organic linkers and forming water-coordinated neutral framework. Further studies revealed that compound 1 was insoluble in water and that it emitted strong luminescence at approximately 437 nm after dehydration. 相似文献
106.
Aneta Hapka Wlodzimierz JankeJaroslaw Krasniewski 《Materials Science and Engineering: B》2012,177(15):1310-1313
The paper presents the exemplary electro-thermal models of merged PiN Schottky diode – a diode with the parallel PiN junction, protecting the device against the uncontrolled voltage rise, causing so-called thermal runaway. In the presented models, the conductivity modulation effect in the PiN junction is taken into account. The influence of the PiN junction on the non-isothermal I–V characteristics of MPS diodes, for various cooling conditions, is discussed. It is shown, that the thermal runaway is possible, in spite of presence of protecting PiN junction. 相似文献
107.
Effect of production season on protein fraction content in milk of various breeds of goats in Poland
Aneta Brodziak Jolanta Król Joanna Barłowska Zygmunt Litwińczuk 《International Journal of Dairy Technology》2014,67(3):410-419
Milk of various goat breeds was analysed to assess the effect of production season on content of basic chemical components, with regard to whey proteins. Milk of goats in the productive herds (white and coloured coat) contained significantly (P < 0.01) more total protein, casein, fat, dry matter and functional whey proteins. The production season significantly determined the content of total protein (P < 0.01), casein (P < 0.01) and whey proteins (P < 0.05), including α‐lactalbumin (P < 0.01) and lactoferrin (P < 0.01). A higher content of total protein and casein was found in the autumn–winter season and the content of whey proteins was higher in the spring–summer period. 相似文献
108.
Gordana Kocic Dusan Sokolovic Tatjana Jevtovic Tatjana Cvetkovic Andrej Veljkovic Hristina Kocic Svetlana Stojanovic Aneta Jovanovic Jelena Jovanovic Petar Zivkovic 《Journal of dairy science》2014
Cardiovascular repair and myocardial contractility may be improved by migration of bone marrow stem cells (BMSC) and their delivery to the site of injury, a process known as BMSC homing. The aim of our study was to examine the dietary effect of a newly patented depurinized milk (DP) that is almost free of uric acid and purine and pyrimidine compounds compared with a standard commercial 1.5% fat UHT milk diet or allopurinol therapy in rat experimental hyperuricemia. Bone marrow stem cell potential (BMCD34+, CD34-postive bone marrow cells), plasma oxidative stress parameters [advanced oxidation protein products, AOPP) and thiobarbituric acid reactive substances (TBARS)], myocardial damage markers [creatine phosphokinase (CPK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH)], plasma cholesterol, and high-density lipoprotein cholesterol were investigated. The DP milk diet significantly increased the number of BMCD34+ stem cells compared with commercial UHT milk. Allopurinol given alone also increased the number of BMCD34+. Hyperuricemia caused a significant increase in all plasma enzyme markers for myocardial damage (CPK, LDH, and AST). A cardioprotective effect was achieved with allopurinol but almost equally with DP milk and more than with commercial milk. Regarding plasma AOPP, TBARS, and cholesterol levels, the most effective treatment was DP milk. In conclusion, the protective role of a milk diet on cardiovascular function may be enhanced through the new depurinized milk diet, which may improve cardiovascular system function via increased bone marrow stem cell regenerative potential, decreased plasma oxidative stress parameters, and decreased levels of myocardial damage markers and cholesterol. New dairy technology strategies focused on eliminating harmful milk compounds should be completely nontoxic. Novel milk products should be tested for their ability to improve tissue repair and function. 相似文献
109.
110.
VL Zima 《Canadian Metallurgical Quarterly》1998,70(3):23-38
Recent data about the structural and functional features of protein motors (myosin, dynein, kinesin) are presented. The mechanism by which the chemical energy of ATP is transduced into mechanical work is discussed. 相似文献