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   832篇
  免费   15篇
  国内免费   4篇
电工技术   33篇
化学工业   221篇
金属工艺   8篇
机械仪表   15篇
建筑科学   55篇
矿业工程   4篇
能源动力   19篇
轻工业   133篇
水利工程   12篇
无线电   31篇
一般工业技术   103篇
冶金工业   108篇
原子能技术   6篇
自动化技术   103篇
  2019年   8篇
  2018年   7篇
  2016年   15篇
  2015年   14篇
  2014年   13篇
  2013年   24篇
  2012年   32篇
  2011年   31篇
  2010年   22篇
  2009年   22篇
  2008年   29篇
  2007年   37篇
  2006年   25篇
  2005年   26篇
  2004年   28篇
  2003年   20篇
  2002年   15篇
  2001年   12篇
  2000年   14篇
  1999年   21篇
  1998年   14篇
  1997年   12篇
  1996年   11篇
  1995年   15篇
  1993年   8篇
  1992年   8篇
  1991年   15篇
  1990年   17篇
  1989年   7篇
  1988年   7篇
  1986年   9篇
  1985年   7篇
  1984年   15篇
  1983年   10篇
  1982年   9篇
  1981年   10篇
  1980年   7篇
  1979年   10篇
  1978年   12篇
  1977年   13篇
  1976年   7篇
  1975年   14篇
  1974年   11篇
  1973年   18篇
  1972年   11篇
  1971年   10篇
  1970年   16篇
  1969年   9篇
  1968年   7篇
  1967年   7篇
排序方式: 共有851条查询结果,搜索用时 15 毫秒
41.
Zusammenfassung Die isoelektrische Fokussierung einer wasserlöslichen Proteinfraktion von Hart- und Weichweizen aus Teigwarenprodukten wird mit der bisher üblichen disk-elektrophoretischen Trennmethode verglichen. Die Elektrofokussierung liefert im Gegensatz zur Disk-Elektrophorese auch bei Anwesenheit von Ei-Proteinen sowie nach vorgängiger Hitzedenaturierung der Proteine zuverlässige und genaue Resultate. Im weiteren wird zur besseren Auftrennung und Charakterisierung der wasserlöslichen Proteinfraktion eine zweidimensionale Trennmethode (isoelektrische Fokussierung und anschließende Elektrophorese) beschrieben.
Isoelectric focusing and two-dimensional separation of watersoluble protein fraction of hard and soft wheat from macaroni
Summary The isoelectric focusing of water-soluble protein fraction of hard and soft wheat from macaroni are compared with the disc electrophoresic separation methods. Electrofocusing produced more trustworthy and exacter results in the presence of egg proteins as well for heat-denaturated proteins. Further is described a better separation and characterisation of a water-soluble protein fraction using a two-dimensional system involving isoelectric focusing in the first dimension followed by electrophoresis in the second.
  相似文献   
42.
43.
In the COLLATE project, we aim to design and implement a Web-based collaboratory for archives, scientists, and end users working with digitized cultural material. Our example domain is the historic film documentation comprising digitized material about European films of the early 20th century. Designed as a content- and context-based knowledge working environment for distributed user groups, the COLLATE system supports both individual work and collaboration of domain experts who are analyzing, evaluating, indexing, and annotating material in the data repository. The system provides appropriate task-based interfaces for indexing and annotating. As a multifunctional means of in-depth analysis, annotations can be made individually but also collaboratively, for example in the form of annotation of annotations. Combining results from manual and automatic indexing procedures, elaborate content- and context-based information retrieval mechanisms can be applied.  相似文献   
44.
Since 1993 we compile and publish twice a year a list of the most powerful supercomputers in the world. In this article we analyze some major trends in High-Performance Computing (HPC) based on the quantitative data gathered over the years in this TOP500 project (see www.top500.org for a complete access to all data). We start with an overview of the project, including the motivation and rationale behind it. We present the results of the TOP500 project as of November 2003 focusing on the changes over time with respect to the performance levels, the overall dynamics in this market, the manufacturers active in this market-segment, the architectures, and technologies used for these systems, and the major centers using such systems.  相似文献   
45.
46.
47.
Zusammenfassung Ein Nachweis für Carbamat-Pesticide mittels Enzym-Inhibition auf imprägnierten Cellulose-Schichten wurde ausgearbeitet. Bei Celluloseschichten, die mit Äthylglykol, Triäthylglykol und,-Ogydipropionitril imprägniert waren, erwies sich die Kombination Schweineleberesterase/Indophenylacetat (als chromogenes Substrat) als besonders empfindlicher Nachweis. Die Nachweisempfindlichkeit wurde in Abhängigkeit von der Art des Enzympräparates, des Substrates, des pH, der Inhibitionszeit und -temperatur, der Schichtdicke und des Impriignierungsmittels untersucht.
Enzymatic detection of carbamate pesticides on impregnated cellulose plates
Summary The detection of carbamate pesticides by an enzyme-inhibition method on impregnated (ethylene glycol, triethylene glycol,,-ogydipropionitrile) cellulose thin layer plates is described. The enzyme-substrate combination: pig liver esterase-indophenylacetate (chromogenic substrate) was the most sensitive. The following parameters concerning the sensitivity of the method were investigated: enzyme source, substrate, pH, inhibition time, inhibition temperature, thickness of the cellulose layer, stationary phase.


Herrn o.Univ.-Prof. Dr. O. Hoffmann-Ostenhof, Vorstand des Instituts für Allgemeine Biochemie, Universität Wien, zum 60. Geburtstag gewidmet.

Wir danken dem Fonds zur Förderung der wissenschaftlichen Forschung, der uns die Durchführung dieser Arbeit (Projekt Nr. 2161) ermöglichte.

Ing. B. Rapié dankt der SEA-Stiftung (Scientific Exchange Agreement) für die Gewährung eines Stipendiums.  相似文献   
48.
We investigated which structural components are responsible for maintaining interstitial fluid equilibrium in the pulpal tissue, for which the existence of an effective lymph drainage is postulated. There have been only a small number of investigations on pulpal lymph tissue. Therefore, we decided to perform a detailed structural analysis. Twenty vital, healthy teeth that had to be extracted for orthodontic reasons were immersed in Patent Blue for 10 to 15 minutes after opening the pulpal cavity. They were then extracted and the dental pulps were opened by cleavage of the surrounding hard tooth structure. Subsequently, the specimens were prepared for light and electron microscopic investigation. A clear blue ring of stain was detected by light microscopy in Weil's zone in the coronal region of the pulp, the cell-rarefied layer surrounded by the odontoblasts. No dye deposition was observed in the apical part. However, using transmission electron microscopy, capillary structures with typical morphological characteristics of lymphatic vessels were found apically. The coronal part of the pulp did not reveal any such vascular structures. It may be concluded from these findings that the lymph in the coronal region is collected in interstitial tissue clefts and drained towards the apex, whence it is further transported via lymph capillaries.  相似文献   
49.
50.
The combination of SGML and database technology allows to refine both declarative and navigational access mechanisms for structured document collection: with regard to declarative access, the user can formulate complex information needs without knowing a query language, the respective document type definition (DTD) or the underlying modelling. Navigational access is eased by hyperlink-rendition mechanisms going beyond plain link-integrity checking. With our approach, the database-internal representation of documents is configurable. It allows for an efficient implementation of operations, because DTD knowledge is not needed for document structure recognition. We show how the number of method invocations and the cost of parsing can be significantly reduced. Edited by Y.C. Tay. Received April 22, 1996 / Accepted March 16, 1997  相似文献   
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