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   616篇
  免费   24篇
  国内免费   1篇
电工技术   5篇
化学工业   153篇
金属工艺   9篇
机械仪表   21篇
建筑科学   20篇
能源动力   23篇
轻工业   91篇
水利工程   5篇
无线电   67篇
一般工业技术   86篇
冶金工业   70篇
原子能技术   4篇
自动化技术   87篇
  2024年   2篇
  2023年   5篇
  2022年   22篇
  2021年   25篇
  2020年   7篇
  2019年   12篇
  2018年   16篇
  2017年   12篇
  2016年   14篇
  2015年   14篇
  2014年   25篇
  2013年   33篇
  2012年   33篇
  2011年   40篇
  2010年   21篇
  2009年   22篇
  2008年   27篇
  2007年   24篇
  2006年   36篇
  2005年   23篇
  2004年   13篇
  2003年   17篇
  2002年   11篇
  2001年   17篇
  2000年   12篇
  1999年   15篇
  1998年   15篇
  1997年   21篇
  1996年   13篇
  1995年   6篇
  1994年   5篇
  1993年   6篇
  1992年   8篇
  1991年   4篇
  1990年   6篇
  1989年   3篇
  1987年   6篇
  1986年   4篇
  1985年   4篇
  1984年   6篇
  1983年   6篇
  1982年   5篇
  1981年   7篇
  1980年   5篇
  1979年   2篇
  1978年   4篇
  1976年   2篇
  1974年   2篇
  1971年   1篇
  1968年   1篇
排序方式: 共有641条查询结果,搜索用时 15 毫秒
81.
A regression model composed of two sigmoid functions with variable asymptotes was developed and used to analyse the dietary fibre supplement behaviour during bread dough mixing. Using eight commercial dietary fibres of different botanical origin and model wheat starch-gluten flour, farinograph curves for fibre-flour blends and for the flour only were performed. After smoothing of the curves with the regression model, difference farinograms as the fibre supplementation effects were determined. The results showed that the difference farinograms had two peaks, whose shape was strongly differentiated by the studied supplements. The presence of both peaks allowed distinguishing two kinds of the rheological activity of each fibre supplement: weakening and strengthening of the consistency of bread dough during its development. The carrot, oat, cranberry, and cacao fibres exhibited dominance of strengthening over weakening action. While chokeberry, carob, apple, and flax fibres were characterised by dominance of weakening over strengthening action. The analysis of both position and height of the peaks in the difference farinogram can be also helpful for determination of hydration kinetics of the fibres used for bread supplementation.  相似文献   
82.
83.
The drying behaviour of kiwi fruits at different stage of ripeness has been evaluated. A diffusional model solved by a finite difference method has been proposed to simulate the drying kinetics at different temperatures. Drying curves of ripe kiwis exhibited only one diffusional period, whereas two different diffusional periods could be observed on the drying curves of green and half‐ripe kiwis. Furthermore, the drying curves of green and half‐ripe kiwis were coincident. The effective diffusional coefficient, which was identified at different temperatures (from 40 to 80 °C) from experimental data, varied with temperature according to the Arrhenius equation. An adequate simulation of the drying curves using the proposed model was achieved. Thus, the percentage of explained variance for the drying curves of green and half‐ripe kiwis (considering two diffusional periods) was 99.7 and 99.3% for the ripe kiwis (only one diffusional period). Regarding to the characteristics of the dried kiwis, it was observed that the colour of the samples was mainly affected by the drying temperature, whereas functional properties such as hydration and fat retention capacities were mostly influenced by the stage of ripeness of the fruit. Copyright © 2004 Society of Chemical Industry  相似文献   
84.
Velarde A  Dalmau A 《Meat science》2012,92(3):244-251
Producers, retailers and other food chain actors increasingly recognize that consumer concerns for good animal welfare represent a business opportunity that could be profitably incorporated into their commercial strategies. Therefore, during the last decade, numerous trade groups (producers, processors, retailers and restaurant chains) have developed certification systems with their suppliers which include elements of animal welfare. The Welfare Quality® project has developed an integrated and standardised welfare assessment system based on twelve welfare criteria grouped into four main principles (good feeding, good housing, good health and appropriate behaviour) according to how they are experienced by animals. One of the innovations of the Welfare Quality® assessment system is that it focuses more on outcome measures (e.g. directly related to animal body condition, health aspects, injuries, behaviour, etc.). This paper has the objective to discuss the rationale behind the welfare assessment and to describe the Welfare Quality® assessment of pigs and cattle at the slaughterhouse.  相似文献   
85.
A semi‐industrial spray drying process of chokeberry juice concentrate using maltodextrin was analysed. The influence of the content and dextrose equivalent (DE) of maltodextrin, inlet air temperature and rotary disc atomiser speed was studied on the physicochemical properties of the obtained powders. The size and structure of the powder particles, bulk density, moisture content, flowability, yield and total polyphenol content were analysed. An increase in carrier content from 50% to 70% caused a 4.9% increase in total polyphenol retention, better flowability (Hausner ratio decrease of 0.17) and greater yield of the powder (60%). An increase in the drying temperature (150–170 °C) caused larger particle size and improved powder flowability but also resulted in greater loss of total polyphenols. A decrease in rotary atomiser speed (11 000–15 000 rpm) had a moderate influence on particle size and improvement in flowability but had no effect on polyphenol retention. Changes in the DE (8–22) of maltodextrin as a carrier indicated a moderate growing dependence on particle size and worse flowability.  相似文献   
86.
87.
88.
A case of phlebothrombosis with recurrent pulmonary and cerebral embolism is presented which occurred in a 42 year old patient two weeks after treatment of a traumatic crural fracture despite of prophylaxis with low molecular heparin. By means of transthoracic echocardiography a large intracardiac thrombus was detected, entrapped in an patent foramen ovale (PFO) and prolapsing through both atrioventricular valves into both ventricles. This was found after systemic thrombolysis with rtPA had been performed because of fulminant pulmonary embolism. Subsequently the intracardiac thrombus was surgically removed and the PFO closed. The importance of an PFO for paradoxical embolism is discussed as well as the various therapeutical paths to treat an "embolus-in-transit" (cardiac surgery, thrombolytic therapy or anti-coagulation).  相似文献   
89.
The Authors, through a review of their vascular surgery experience in the treatment of PAOD at the III General Surgery Institute directed by Prof. G. Di Matteo (University, of Rome), focus their attention on endovascular surgery. Initially considered as an effective complement to "traditional surgery" rapidly its role has grown as an effective alternative for a number of vascular patients.  相似文献   
90.
This paper takes Franco's Spain to be a powerful case study for analyzing the ways in which power shapes science and technology and is shaped by them in return. Spain was the last country in Western Europe to establish closer links with any of the international cooperative institutions emerging after WWII. As such, developments internal to Spanish society were quite autonomous and relatively free from foreign influences. The paper focuses first on the brand new, powerful institution that the Francoist regime created to promote scientific research under tight political control, the Consejo Superior de Investigaciones Científicas. Next it turns to applied science and technology, top priorities for the regime's state‐supported programs of industrialization. They were implemented through the politically and financially powerful Instituto Nacional de Industria. Using diplomatic sources, the paper next argues that, until the late 1950s, Spain maintained substantial political and economic isolation essentially because the regime bet on autarkic policies and a model of largely isolated development. In this model, it was crucial for the regime to develop its own technological and scientific resources. Finally, the paper examines how the regime fostered a new Spanish identity in which science had a new role.  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