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   224篇
  免费   9篇
电工技术   1篇
化学工业   37篇
金属工艺   1篇
机械仪表   9篇
建筑科学   4篇
能源动力   7篇
轻工业   17篇
石油天然气   3篇
无线电   31篇
一般工业技术   43篇
冶金工业   11篇
原子能技术   3篇
自动化技术   66篇
  2023年   11篇
  2022年   21篇
  2021年   16篇
  2020年   13篇
  2019年   7篇
  2018年   20篇
  2017年   8篇
  2016年   10篇
  2015年   3篇
  2014年   7篇
  2013年   19篇
  2012年   10篇
  2011年   9篇
  2010年   4篇
  2009年   5篇
  2008年   9篇
  2007年   11篇
  2006年   5篇
  2005年   2篇
  2004年   3篇
  2003年   1篇
  2002年   3篇
  2001年   3篇
  2000年   2篇
  1998年   7篇
  1996年   1篇
  1995年   2篇
  1993年   2篇
  1992年   4篇
  1990年   2篇
  1989年   2篇
  1987年   1篇
  1985年   2篇
  1984年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1965年   1篇
排序方式: 共有233条查询结果,搜索用时 31 毫秒
61.
There is little information available about incidences and causes of foodborne illnesses that can help the government develop policies, which prevent them in the UAE. This study includes a group of multinational subjects (males and females), residing in Al Ain, UAE, and of an age ranging between 15 and 55 years. A questionnaire designed to assess “Knowledge” and “Practice” of public hygiene measures was piloted in a group of subjects from the public (n = 600). Data shows that 100% of highly educated subjects with postgraduate degrees (Master and PhD) have the proper information about food safety. However, only 70% of them always wash their hands before and after eating, while 80% always wash their hands after using toilets and frequently using warm water and soap. 29% of the total participants were inflicted with foodborne illness, and 85% read articles about food safety and personal hygiene. Most of the subjects in this study are Muslims, and they mainly depended on their daily attitude, which affects their personal hygiene because they must wash before praying. Data generally referred that awareness programs or training are needed, even for the highly educated members of the public. Further research is needed to explain the differences between reports of actual and usual behaviors.  相似文献   
62.
Wireless Networks - Maintaining durable connectivity during data forwarding in Vehicular Ad hoc Networks has witnessed significant attention in the past few decades with the aim of supporting most...  相似文献   
63.
The densities and kinematic viscosities of 10 binary subsystems of the regular quinary system, benzene (1) + toluene (2) + ethylbenzene (3) + heptane (4) + cyclooctane (5), were measured at 308.15 K and 313.15 K over the entire composition range. The viscosity-composition data reported herein were utilized to examine the predictive capability of some viscosity models, namely, the predictive version of the McAllister model, a group contribution method (GC-UNIMOD), a generalized corresponding states principle (GCSP), and the Allan and Teja correlation. The results of testing showed that the McAllister model outperformed all other models except for systems containing cyclooctane. The results also showed an overall average absolute deviation (%AAD) of 1.25% for systems that did not contain cyclooctane.  相似文献   
64.
A substantial amount of textual data is present electronically in several languages. These texts directed the gear to information redundancy. It is essential to remove this redundancy and decrease the reading time of these data. Therefore, we need a computerized text summarization technique to extract relevant information from group of text documents with correlated subjects. This paper proposes a language-independent extractive summarization technique. The proposed technique presents a clustering-based optimization technique. The clustering technique determines the main subjects of the text, while the proposed optimization technique minimizes redundancy, and maximizes significance. Experiments are devised and evaluated using BillSum dataset for the English language, MLSUM for German and Russian and Mawdoo3 for the Arabic language. The experiments are evaluated using ROUGE metrics. The results showed the effectiveness of the proposed technique compared to other language-dependent and language-independent summarization techniques. Our technique achieved better ROUGE metrics for all the utilized datasets. The technique accomplished an F-measure of 41.9% for Rouge-1, 18.7% for Rouge-2, 39.4% for Rouge-3, and 16.8% for Rouge-4 on average for all the dataset using all three objectives. Our system also exhibited an improvement of 26.6%, 35.5%, 34.65%, and 31.54% w.r.t. The recent model contributed in the summarization of BillSum in terms of ROUGE metric evaluation. Our model’s performance is higher than the compared models, especially in the metric results of ROUGE_2 which is bi-gram matching.  相似文献   
65.
We discuss robust M‐estimation of INARCH models for count time series. These models assume the observation at each point in time to follow a Poisson distribution conditionally on the past, with the conditional mean being a linear function of previous observations. This simple linear structure allows us to transfer M‐estimators for autoregressive models to this situation, with some simplifications being possible because the conditional variance given the past equals the conditional mean. We investigate the performance of the resulting generalized M‐estimators using simulations. The usefulness of the proposed methods is illustrated by real data examples.  相似文献   
66.
In desert sunny clear-sky regions solar penetration can become excessive. This can cause non-uniform daylight distribution, glare and high solar heat gain, affecting both visual and thermal comfort. Shading devices, such as solar screens, were usually used to diffuse and prevent direct solar penetration into spaces. This paper investigates the impact of changing solar screen axial rotation angle and screen opening aspect ratio on daylighting performance in a typical residential living room space under the desert sunny clear-sky. The larger aim is to arrive at efficient solar screen designs that suit the different orientations.The study was divided into three consecutive phases. In phase one, the effect of the two parameters on Daylight Availability was tested. The solar screen was axially rotated by three different angles at 10° increments. Also, the aspect ratio of the screen opening in both horizontal and vertical directions was changed systematically. Simulation was conducted using the annual Daylight Dynamic Performance Metrics (DDPMs). In phase two, the Annual Daylight Glare Probability (DGP) metric was evaluated for the cases that were found adequate in phase one. In the third phase, the annual solar energy transmittance through the screen was calculated for the cases that achieved acceptable performance in the two previous phases in order to identify the more energy efficient screens.Solar screens with openings having horizontal aspect ratios were found to be the most effective, while those with vertical aspect ratios were achieved the lowest performance. In the North orientation, since almost all the cases that were tested in this research provided acceptable daylighting performance, the designer now have a variety of options to choose from. Preference should be given to screen openings of horizontal aspect ratios, especially the 12:1 and 18:1 (H:V) screens that achieved the best performance where 92% of the space was “daylit” in comparison with only 53% of the base case. In the East orientation, it is advisable to use the 12:1 (H:V) screen opening ratio, as it was found acceptable in the two daylighting testing phases and achieved the best performance in regards to annual transmittance of solar radiation. For the South orientation, there were also many acceptable choices. However, the 3:1 screen aspect ratio is recommended as it assists in saving energy by reducing the annual transmitted solar radiation (60% reduction) while achieving acceptable daylighting performance.  相似文献   
67.
68.
69.
Clustering has been used as one of energy-efficient mechanisms for data routing in wireless sensor networks. In hierarchical routing approaches, cluster heads are responsible for management (e.g. data aggregation, queries dispatch) and transmission of the collected data in the region controlled by them. For efficient data delivery, several researches have proposed various mechanisms for cluster organization and cluster head selection. However, less focus is given in the area of data transmission associated with Base Station (BS). In such a situation, any failure or packet loss may lead to considerable packet loss. For solving this problem, we propose an efficient data routing scheme for controlling data delivery from nodes to BS. In our proposed approach every node is aware about the link quality of all nodes and is able to deliver data to the BS through the most reliable and energy-efficient route.  相似文献   
70.
In the study, the authors examined the effects of smoking deprivation, anticipation of smoking, and actual smoking on the craving to smoke. Flight attendants who were light to heavy smokers rated their craving to smoke at predetermined time points during a 2-way short flight (each leg 3–5.5 hr) and a 1-way long flight (8–13 hr). In both short and long flights, craving increased gradually and peaked as landing approached. Craving levels at the end of the 1st leg of the short flights were equal to those at the end of the long flight and were much higher than those at the parallel time point in the long flight. In the short flight, craving levels at the beginning of the 2nd leg dropped relative to the end of the 1st leg, both for participants who smoked during the intermission and for those who did not, though the drop was steeper for the former. The results provide additional evidence for the role of psychological factors in determining the craving to smoke in a naturalistic setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  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