首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   43篇
  免费   4篇
电工技术   2篇
化学工业   11篇
建筑科学   2篇
矿业工程   1篇
能源动力   2篇
轻工业   8篇
一般工业技术   6篇
冶金工业   6篇
自动化技术   9篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   2篇
  2012年   4篇
  2011年   4篇
  2010年   2篇
  2009年   2篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  2001年   2篇
  1999年   1篇
  1998年   2篇
  1996年   1篇
  1990年   1篇
  1985年   1篇
  1983年   1篇
  1980年   1篇
  1959年   2篇
排序方式: 共有47条查询结果,搜索用时 15 毫秒
1.
IN 2008, a nuclear event occurred at Kr?ko nuclear power plant in Slovenia. Even though it was classified as level 0 on International Nuclear Event Scale, the transparency policy of the Slovenian nuclear safety authorities prompted it to notify the international community. This was the first time that the European Community Urgent Radiological Information Exchange (ECURIE) notification system was used outside the exercise framework. The event was reported in all major European. In this contribution, we report on a content analysis of media articles related to this event. The main research question was if a nuclear emergency generates significant media coverage, even in the case of a minor event and a transparent communication policy. The analysis included more than 200 articles from printed and spoken media in Slovenia and other countries. The analysis revealed a high‐intensity media coverage, emotional reactions and heated political discussion. The main media sources in countries with open political discussions on nuclear energy end up being the politicians, rather than resident experts.  相似文献   
2.
The methylation of phosphatidylethanolamine is an auxiliary pathway for phosphatidylcholine biosynthesis in liver. Two forms of the enzyme, phosphatidylethanolamine N-methyltransferase, which catalyses this reaction, are located on the endoplasmic reticulum and mitochondria-associated membranes. Both forms are encoded by a single murine gene, Pempt, located on chromosome 11. The expression of the gene begins at birth. An inverse relationship exists between the rate of liver growth and the expression of phosphatidylethanolamine N-methyltransferase. However, disruption of the Pempt gene does not alter liver growth in mice or cause any other obvious phenotype.  相似文献   
3.
Fate of ivermectin residues in ewes' milk and derived products   总被引:1,自引:0,他引:1  
The fate of ivermectin (IVM) residues was studied throughout the processing of daily bulk milk from 30 ewes (taken up to 33 d following subcutaneous administration of 0.2 mg IVM/kg b.w.) in the following milk products: yoghurt made from raw and pasteurized milk; cheese after pressing; 30- and 60-day ripened cheese; and whey, secondary whey and whey proteins obtained after cheese-making (albumin cheese). The concentration of the H2B1a component of IVM was analysed in these dairy products using an HPLC method with fluorescence detection. The mean recovery of the method was, depending on the matrix, between 87 and 100%. Limits of detection in the order of only 0.1 microg H2B1a/kg of product were achieved. Maximum concentrations of IVM were detected mostly at 2 d after drug administration to the ewes. The highest concentration of IVM was found on day 2 in 60-day ripened cheese (96 microg H2B1a/kg cheese). Secondary whey was the matrix with the lowest concentration of IVM (<0.6 microg H2B1a/ kg). Residue levels fell below the limits of detection between day 5 (for secondary whey) and day 25 (for all cheese samples). In the matrices investigated, linear correlations between daily concentrations of IVM, milk fat and solid content were evident. During yoghurt production, fermentation and thermal stability of IVM was observed. During cheese production, approximately 35% of the IVM, present in the raw (bulk) milk samples, was lost. From the results it was concluded that the processing of ewes' milk did not eliminate the drug residues under investigation. The consequences of IVM in the human diet were discussed. Milk from treated animals should be excluded from production of fat products like cheese for longer after treatment with IVM than for lower fat products.  相似文献   
4.
Polymer processing is typically done via the melt state. Plastic pellets are conveyed with a screw, melted, transformed into the desired shape and finally cooled down to ambient temperature. From this process chain, several simulation targets can be derived, such as the conveying characteristics of solid polymer pellets in a screw, analysis of the melt flow, temperature distribution and development in the melt and the mould, phase change between solid and melt state, and shrinkage and warpage due to the cooling process. The material data used for simulation are an important factor strongly affecting the quality of the results. In this paper four examples of simulation in polymer processing are shown: simulation of microstructured injection moulded parts, influence of material data on simulation results, modelling of heat development in converging flows, and modelling of the solid conveying characteristics of single screw extruders.  相似文献   
5.
Surface Cleanliness Effect on Lunar Soil Shear Strength   总被引:1,自引:0,他引:1  
Lunar soil consists of dry silty sand. Observations and measurements conducted during Surveyor, Apollo, and Luna missions indicated that the lunar soil is unusually cohesive. This is attributable to the fact that thick layers of adsorbed gases, which coat and lubricate soil particles on Earth, are absent in the ultrahigh vacuum on the Moon. “Surface cleanliness” is introduced as a new parameter for describing soils in different planetary environments. It is defined as the dimensionless inverse of adsorbate thickness on solid surfaces. By this definition, the ultrahigh vacuum on the Moon is associated with high surface cleanliness, while Earth's atmosphere is associated with low surface cleanliness. A model is developed to calculate surface cleanliness and its effect on shear strength in any planetary environment. Results obtained from the model compare well with data from previous ultrahigh vacuum and variable temperature laboratory experiments on Earth soils. It is shown that surface cleanliness is an important parameter with respect to lunar soil shear strength.  相似文献   
6.
In this study the densification behavior of bimodal Y-TZP powder compacts consisting of nano/sub-micron-sized particles was studied and an explanation for their improved flexural strength while biscuit-sintered is provided. An in situ-heating TEM analysis revealed that up to 800 °C only the nanoparticles sinter in a bimodal mixture without any densification. By increasing the temperature to 900 °C the densification of the nanoparticles begins and partially densified nanoparticle clusters migrate into the contact area between the core particles. Consequently, the driving force for the sintering of the powder-blend compacts is reduced and this is reflected in a slower densification compared to that of the core material. At 1000 °C the sintered nanoparticle clusters begin to incorporate into the core material, resulting in a sharp increase in the strength due to the increased neck area. Biscuit-sintered powder-blend compacts reached a plateau of strength at 670 MPa, which was reached at a relative density of 70%.  相似文献   
7.
Typical and atypical carcinoids (TC, ATC) and small (SCLC) and large cell neuroendocrine carcinomas (LCNEC) constitute the spectrum of neuroendocrine lung tumors. Chromosomal aberrations have not been studied in LCNEC and only rarely in carcinoids. Only SCLCs have been investigated frequently for chromosomal aberrations. We compared three typical and four atypical carcinoids, one atypical carcinoid/SCLC mixed type, three SCLC, and three LCNEC for chromosomal gains and losses using comparative genomic hybridization. Typical carcinoids showed either no changes or only few chromosomal gains. Atypical carcinoids appeared genetically heterogeneous: One case had no aberrations, and three cases had few aberrations; two of them showed a deletion of 11q. SCLC and LCNEC were characterized by many gains and losses, especially similar changes of 3p, 5q, 5p, and 13q. Although ATC resemble LCNEC morphologically, there were no similarities at the genetic level. We have found a reciprocal relationship of prognosis and the amount of aberrations. TCs and ATCs with few chromosomal changes have the best prognosis, whereas SCLCs and LCNECs were generally characterized by a great amount of aberrations and worst prognosis. There was no unbalanced aberration common in all types of neuroendocrine tumors of the lung.  相似文献   
8.
A. Perko 《Software》1985,15(1):55-57
Certain implicit data structures for priority queues are implemented and compared with a simple linked structure. Timing experiments show that implicit structures are rather slow.  相似文献   
9.
    
Zusammenfassung Ätherextrakte von erhitzten wäßrigen Glucose-Glykokoll-Lösungen wurden auf papierchromatographischem Wege untersucht und in einfachen, eindimensionalen Chromatogrammen eine Auftrennung vorgenommen. Mit einer einzigen Ausnahme konnte jedoch — insbesondere auf Grund der ermitteltenR F-Werte — keine Übereinstimmung mit den vonChichester, Stadtman undMackinney angegebenen Verbindungen festgestellt werden. Die von verschiedenen Autoren beschriebene Bildung von Hydroxymethylfurfurol im Verlauf der Maillard-Reaktion konnte bestätigt werden.Eine Verbindung von reduktonähnlichem Verhalten konnte nachgewiesen werden. Ihr könnte die Struktur eines Kondensationsproduktes von Hydroxymethylfurfurol mit Glykokoll zugeschrieben werden. Ein solches wurde vonGottschalk undPartridge papierchromatographisch bei der Maillard-Reaktion in alkalischem Medium nachgewiesen. Der Beweis für seine Bildung in schwach saurem Bereich kann durch vorliegende Untersuchungen als erbracht gelten. Ob diese Verbindung sekundär durch Umlagerung von vorhandenem Glucosid oder jedoch bevorzugt durch Kondensation aus primär entstandenem Hydroxymethylfurfurol mit Glykokoll gebildet wird, wurde im Rahmen vorliegender Untersuchung noch nicht geklärt.Herrn Professor Dr.A. Janke, dem Vorstand des Instituts für Biochemische Technologie und Mikrobiologie, zur Vollendung des 70. Lebensjahres in Verehrung gewidmet.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号