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   158篇
  免费   5篇
电工技术   3篇
综合类   10篇
化学工业   21篇
机械仪表   1篇
建筑科学   11篇
能源动力   12篇
轻工业   59篇
水利工程   2篇
石油天然气   3篇
无线电   1篇
一般工业技术   11篇
冶金工业   8篇
自动化技术   21篇
  2022年   1篇
  2021年   4篇
  2020年   3篇
  2019年   5篇
  2018年   4篇
  2017年   2篇
  2016年   5篇
  2015年   3篇
  2014年   6篇
  2013年   9篇
  2012年   8篇
  2011年   12篇
  2010年   9篇
  2009年   10篇
  2008年   8篇
  2007年   8篇
  2006年   7篇
  2005年   6篇
  2004年   8篇
  2003年   4篇
  2002年   10篇
  2001年   1篇
  2000年   4篇
  1999年   5篇
  1998年   3篇
  1996年   2篇
  1995年   5篇
  1993年   2篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1987年   1篇
  1984年   1篇
  1964年   1篇
排序方式: 共有163条查询结果,搜索用时 15 毫秒
91.
The antioxidant reaction of carnosol, a phenolic diterpene of sage and rosemary, produced ortho‐ and para‐quinone derivatives. Although the orthoquinone derivative of carnosol (CARQ) is stable in a lipophilic solution and has a very weak antioxidant activity, the thermal treatment of CARQ in lipid restored strong antioxidant activity. HPLC analysis of the thermal recovery reaction clarified that the strong activity was mainly due to the reproduced carnosol. A possible mechanism for the production of carnosol from CARQ is the self‐redox reaction of CARQ. Two of the oxidation products from CARQ in the thermal recovery reaction were identified to be rosmariquinone and dehydrorosmariquinone. Copyright © 2004 Society of Chemical Industry  相似文献   
92.
The volatiles of five samples of Greek propolis from various geographic origin (A–E) were analyzed by capillary gas chromatography, using flame ionization GC and mass spectrometric detection. Ninety-four components were identified from the oils. The major components from each sample were found to be: junipene (11.7%), α-pinene (7.9%), manoyl oxide (7.1%) (sample A), α-pinene (45.8%), trans-β-terpineol (6.6%) (sample B), α-pinene (17.7%), α-eudesmol (12.1%), n-decanal (6.2%), guaiol (5.0%) (sample C), α-pinene (18.2%), δ-cadinene (8.4%) and α-muurolene (5.0%) (sample D), α-pinene (10.9%), n-decanal (10.3%), cedrol (6.3%), n-nonanal (5.4%), and manool (5.2%) (sample E). The total profile of the volatile constituents of all samples reveals the predominance of terpenoids, especially of α-pinene. The in vitro antimicrobial activity of the volatiles from all five studied samples against six bacteria and three fungi is also assayed and reported.  相似文献   
93.
The increasing spread of photovoltaic (PV) systems occurring nowadays does not always keep pace with respective legislative initiatives, especially those regarding a specific relation between PV systems, the natural environment and landscape. As a result of this differentiation, the existence of legislative gaps or omissions is noticed. Thus, while the development of Renewable Energy Sources (RES) is actively promoted by the government in general, from a legal point of view there are no equivalent preventive measures for the protection and preservation of physical environment and landscape aesthetics, at least in all types of RES, with the exception of wind farms. In fact, in the case of PV systems, there is no specific legal framework, which would regulate their integration in the environment, and in particular into landscape.The work analyzes a method for assessment of aesthetic impact caused by PV plants. The method is developed in MATLAB and based on the use of a PV plant photo and the quantification of three parameters: visibility, color and fractality. Purpose of this work is to propose this method as an applicable integration rule of PV systems into landscape, aiming to reduce its aesthetic downgrading, contributing thereby to sustainability.Additionally, in an interdisciplinary approach, the suggested method restores the issue of the explicit legislative provision of specific rules and criteria regarding the PV systems integration into landscape.  相似文献   
94.
ABSTRACT: Musts from 3 grape varieties were used to elucidate the effect of the presence of grape solids in must on the volatile composition of the resultant white wines. Volatile compounds were analyzed by GC/MS and GC/FPD except H2S, which was measured spectrophotometrically. Increasing quantities of grape insoluble material decreased the substances that enhanced aroma of Savatiano and Batiki wines. Simultaneously, the levels of compounds that degrade wine aroma, when formed in large amounts, were increased. However, in Muscat of Hamburg wines, the levels of some volatiles were not influenced by must turbidity in the same way as in wines of the other cultivars.  相似文献   
95.
96.
新闻(英文)     
正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to  相似文献   
97.
Robert Harbison defines the Baroque in the 17th and early 18th centuries, which is so often characterised in contrast with the Renaissance by its excess and drama. In doing so, he challenges the reader to consider whether this artful style of subversion, tension, movement, gravity-defying feats and freedom was really one of whimsical frivolity or subversive disquiet. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
98.
以新鲜羊奶为主要原料,添加羊乳清粉,研究了希腊式酸羊奶的工艺条件。 通过单因素试验和正交试验,以感官评分及酸度 为评价指标,确定希腊式酸羊奶的最佳发酵工艺条件。 结果表明,希腊式酸羊奶的最佳发酵工艺条件为羊乳清粉添加量1.0%,接种 量6%,发酵温度42 ℃,发酵时间8 h。 在此最佳条件下,感官评分达到87分,酸度为97 °T。 希腊式酸羊奶质地均匀,口感细腻浓郁,酸甜 适中,发酵乳香味明显,羊膻味不明显,其理化及微生物指标均符合相关国家标准。  相似文献   
99.
Scott Olsen examines the philosophy of Plato to bring to light the nature of Plato’s Second Principle, known as the Indefinite Dyad, sometimes called the Greater and the Lesser, and its relation to the Golden Section, ϕ . He responds to the challenge posed in 1983 by Kenneth Sayre, and explains how the the Indefinite Dyad can be used to derive the square roots of 2 and 3.  相似文献   
100.
The increasing competition in the national and international banking markets, the changeover towards monetary union and the new technological innovations herald major changes in the banking environment, and challenge all banks to make timely preparations in order to enter into the new competitive monetary and financial environment. Therefore, it is interesting to investigate the effectiveness of Greek banks, as it is valued by the financial markets, i.e. the greater the efficacy the higher the competitiveness and vice versa. Taking into consideration the bank assets, we distinguish banks into small and large ones. Finding factors that make the differences in such effectiveness may explain the effective advantage of these two types of financial institutions and help us understand the 'financial intermediation' industry in Greece better. Based on their size, a classification of Greek banks, in a multivariate environment, according to the return and operation factors for the years 1990–1999 takes place. In order to investigate the differences of profitability and efficiency between small and large Greek banks, as well as the factors of profitability and operation related with the size of banks, a multicriteria methodology has been used. The results of this paper may help us determine the key success (or failure) factors of these two categories of Greek banks as well as the responsible banking decision–makers for future readjustments.  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