全文获取类型
收费全文 | 3510篇 |
免费 | 209篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 41篇 |
化学工业 | 862篇 |
金属工艺 | 47篇 |
机械仪表 | 86篇 |
建筑科学 | 140篇 |
矿业工程 | 6篇 |
能源动力 | 114篇 |
轻工业 | 636篇 |
水利工程 | 31篇 |
石油天然气 | 21篇 |
无线电 | 239篇 |
一般工业技术 | 498篇 |
冶金工业 | 165篇 |
原子能技术 | 13篇 |
自动化技术 | 828篇 |
出版年
2024年 | 10篇 |
2023年 | 45篇 |
2022年 | 130篇 |
2021年 | 151篇 |
2020年 | 120篇 |
2019年 | 135篇 |
2018年 | 132篇 |
2017年 | 119篇 |
2016年 | 155篇 |
2015年 | 120篇 |
2014年 | 158篇 |
2013年 | 300篇 |
2012年 | 253篇 |
2011年 | 290篇 |
2010年 | 220篇 |
2009年 | 205篇 |
2008年 | 191篇 |
2007年 | 166篇 |
2006年 | 134篇 |
2005年 | 105篇 |
2004年 | 84篇 |
2003年 | 72篇 |
2002年 | 74篇 |
2001年 | 37篇 |
2000年 | 35篇 |
1999年 | 31篇 |
1998年 | 49篇 |
1997年 | 30篇 |
1996年 | 29篇 |
1995年 | 24篇 |
1994年 | 13篇 |
1993年 | 20篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1945年 | 1篇 |
排序方式: 共有3727条查询结果,搜索用时 8 毫秒
111.
Fernando Araya Robert Dell Pedro Donoso Vladimir Marianov Francisco Martínez Andrés Weintraub 《International Transactions in Operational Research》2012,19(5):695-710
The Chilean Ministry of Education oversees preschool, primary, and secondary education in both urban and rural areas. Many parts of Chile are sparsely populated and there are currently over 4,000 rural schools (almost 38% of all schools in Chile) educating 9.5% of the students in the country. Many of the rural schools are small with only one teacher responsible for instruction of all local students (multigrade schools). The geographical distribution of the rural schools has not been coordinated and this has resulted in unequal utilization of existing schools and some unreasonably long travel distances by students. Good management of the rural schools is fundamental to meeting Chile's goal of providing quality education to its citizens. Seeking to improve the situation, the Ministry of Education ordered a study of the optimal location and size of rural schools with the general goals of reducing the number of lesser quality multigrade schools and reducing student travel distances while maintaining reasonable costs. This paper presents results of this study obtained using an integer linear program that has been embedded in a geographical information system. We present computational results for the entire country. Recommendations include where to open new rural schools as well as where to expand, reduce, close, or leave unchanged existing schools. We show how recommendations are sensitive to key parameters such as the cost of transportation. 相似文献
112.
André C. Santos João M. P. Cardoso Pedro C. Diniz Diogo R. Ferreira Zlatko Petrov 《The Journal of supercomputing》2014,70(3):1218-1248
The traditional approach for specifying adaptive behavior in embedded applications requires developers to engage in error-prone programming tasks. This results in long design cycles and in the inherent inability to explore and evaluate a wide variety of alternative adaptation behaviors, critical for systems exposed to dynamic operational and situational environments. In this paper, we introduce a domain-specific language (DSL) for specifying and implementing run-time adaptable application behavior. We illustrate our approach using a real-life stereo navigation application as a case study, highlighting the impact and benefits of dynamically adapting algorithm parameters. The experiments reveal our approach effective, as such run-time adaptations are easily specified in a higher level by the DSL, and thus at a lower programming effort than when using a general-purpose language such as C. 相似文献
113.
Daniel Ortiz Morales Simon Westerberg Pedro X. La Hera Uwe Mettin Leonid Freidovich Anton S. Shiriaev 《野外机器人技术杂志》2014,31(3):343-363
Working with forestry machines requires a great deal of training to be sufficiently skilled to operate forestry cranes. In view of this, it would be desirable within the forestry industry to introduce automated motions, such as those seen in robotic arms, to shorten the training time and make the work of the operator easier. Motivated by this fact, we have developed two experimental platforms for testing control systems and motion‐planning algorithms in real time. They correspond to a laboratory setup and a commercial version of a hydraulic manipulator used in forwarder machines. The aim of this article is to present the results of this development by providing an overview of our trajectory‐planning algorithm and motion‐control method, with a subsequent view of the experimental results. For motion control, we design feedback controllers that are able to track reference trajectories based on sensor measurements. Likewise, we provide arguments to design controllers in an open‐loop for machines that lack sensing devices. Relying on the tracking efficiency of these controllers, we design time‐efficient reference trajectories of motions that correspond to logging tasks. To demonstrate performance, we provide an overview of extensive testing done on these machines. 相似文献
114.
de Matos Pedro André Pinto Jorge Sousa Pereira David Pinho Luís Miguel 《International Journal on Software Tools for Technology Transfer (STTT)》2018,20(4):379-395
International Journal on Software Tools for Technology Transfer - Current real-time embedded systems development frameworks lack support for the verification of properties using explicit time where... 相似文献
115.
Hugh E. Lippman Jehan-François Desjeux Zong-Yi Ding Kraisid Tontisirin Ricardo Uauy Regina A. Pedro 《Critical reviews in food science and nutrition》2016,56(1):141-145
Utilization of expert recommendations in the development of food and beverage nutritional profiles represents an opportunity to merge science and food manufacturing to deliver nutritionally optimized products into the marketplace. This report details expert panel guidelines for the design of a nutritional product for children one to six years of age. This interaction demonstrates the essential synergy between academia and food manufacturers in translating nutrient recommendations to food for their delivery to a population. Important factors for such translation are the identification of applicable nutrient recommendations and selection of an appropriate delivery matrix. This report demonstrates the translation of expert nutritional recommendations to a milk-based product for children—one to six years of age. 相似文献
116.
José M. León Blanco Pedro L. González-R Carmen Martina Arroyo García María José Cózar-Bernal Marcos Calle Suárez David Canca Ortiz 《Drug development and industrial pharmacy》2018,44(1):135-143
This work was aimed at determining the feasibility of artificial neural networks (ANN) by implementing backpropagation algorithms with default settings to generate better predictive models than multiple linear regression (MLR) analysis. The study was hypothesized on timolol-loaded liposomes. As tutorial data for ANN, causal factors were used, which were fed into the computer program. The number of training cycles has been identified in order to optimize the performance of the ANN. The optimization was performed by minimizing the error between the predicted and real response values in the training step. The results showed that training was stopped at 10?000 training cycles with 80% of the pattern values, because at this point the ANN generalizes better. Minimum validation error was achieved at 12 hidden neurons in a single layer. MLR has great prediction ability, with errors between predicted and real values lower than 1% in some of the parameters evaluated. Thus, the performance of this model was compared to that of the MLR using a factorial design. Optimal formulations were identified by minimizing the distance among measured and theoretical parameters, by estimating the prediction errors. Results indicate that the ANN shows much better predictive ability than the MLR model. These findings demonstrate the increased efficiency of the combination of ANN and design of experiments, compared to the conventional MLR modeling techniques. 相似文献
117.
118.
In this paper we present the use of static temperature measurements as process variation observable. Contrary to previously published thermal testing methods, the proposed methodology does not need an excitation signal, thus reducing test cost and improving built-in capabilities of thermal monitoring. The feasibility of the technique and a complete test methodology is presented using a narrowband LNA as example. Finally, a complete electro-thermal co-simulation test bench between the LNA and a differential temperature sensor embedded in the same silicon die is presented in order to validate the results. Results prove that RF figures of merit can be extracted from DC temperature measurements done without loading or exciting the RF circuit under test. 相似文献
119.
120.