全文获取类型
收费全文 | 51594篇 |
免费 | 4263篇 |
国内免费 | 2158篇 |
专业分类
电工技术 | 2752篇 |
技术理论 | 10篇 |
综合类 | 3192篇 |
化学工业 | 9058篇 |
金属工艺 | 2824篇 |
机械仪表 | 3362篇 |
建筑科学 | 3880篇 |
矿业工程 | 1750篇 |
能源动力 | 1506篇 |
轻工业 | 3155篇 |
水利工程 | 846篇 |
石油天然气 | 3939篇 |
武器工业 | 462篇 |
无线电 | 5556篇 |
一般工业技术 | 6232篇 |
冶金工业 | 2559篇 |
原子能技术 | 521篇 |
自动化技术 | 6411篇 |
出版年
2024年 | 267篇 |
2023年 | 1012篇 |
2022年 | 1674篇 |
2021年 | 2220篇 |
2020年 | 1733篇 |
2019年 | 1438篇 |
2018年 | 1600篇 |
2017年 | 1795篇 |
2016年 | 1578篇 |
2015年 | 2096篇 |
2014年 | 2554篇 |
2013年 | 3071篇 |
2012年 | 3140篇 |
2011年 | 3481篇 |
2010年 | 2891篇 |
2009年 | 2819篇 |
2008年 | 2891篇 |
2007年 | 2608篇 |
2006年 | 2668篇 |
2005年 | 2356篇 |
2004年 | 1466篇 |
2003年 | 1379篇 |
2002年 | 1249篇 |
2001年 | 1114篇 |
2000年 | 1225篇 |
1999年 | 1437篇 |
1998年 | 1137篇 |
1997年 | 955篇 |
1996年 | 851篇 |
1995年 | 765篇 |
1994年 | 635篇 |
1993年 | 473篇 |
1992年 | 361篇 |
1991年 | 264篇 |
1990年 | 220篇 |
1989年 | 154篇 |
1988年 | 136篇 |
1987年 | 87篇 |
1986年 | 63篇 |
1985年 | 35篇 |
1984年 | 29篇 |
1983年 | 31篇 |
1982年 | 24篇 |
1981年 | 15篇 |
1980年 | 12篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Neural Computing and Applications - Existing data race detection approaches based on deep learning are suffering from the problems of unique feature extraction and low accuracy. To this end, this... 相似文献
72.
Ren Wuyang Li Handong Gao Lei Li Yong Zhang Zhongyang Long Chengjia Ji Haining Niu Xiaobin Lin Yuan Wang Zhiming 《Nano Research》2017,10(1):247-254
Nano Research - Thermal transport in superlattices is governed by various phonon-scattering processes. For extracting the phonon-scattering contribution of hetero-interfaces in chalcogenide... 相似文献
73.
74.
75.
简述了复合型导电高分子材料的研究及发展,并对其导电机理、基体树脂、导电填料的研究概况进行了述评,介绍了其在各领域中的应用. 相似文献
76.
This study presents a novel weight-based multiobjective artificial immune system (WBMOAIS) based on opt-aiNET, the artificial immune system algorithm for multi-modal optimization. The proposed algorithm follows the elementary structure of opt-aiNET, but has the following distinct characteristics: (1) a randomly weighted sum of multiple objectives is used as a fitness function. The fitness assignment has a much lower computational complexity than that based on Pareto ranking, (2) the individuals of the population are chosen from the memory, which is a set of elite solutions, and a local search procedure is utilized to facilitate the exploitation of the search space, and (3) in addition to the clonal suppression algorithm similar to that used in opt-aiNET, a new truncation algorithm with similar individuals (TASI) is presented in order to eliminate similar individuals in memory and obtain a well-distributed spread of non-dominated solutions. The proposed algorithm, WBMOAIS, is compared with the vector immune algorithm (VIS) and the elitist non-dominated sorting genetic system (NSGA-II) that are representative of the state-of-the-art in multiobjective optimization metaheuristics. Simulation results on seven standard problems (ZDT6, SCH2, DEB, KUR, POL, FON, and VNT) show WBMOAIS outperforms VIS and NSGA-II and can become a valid alternative to standard algorithms for solving multiobjective optimization problems. 相似文献
77.
Tian Y Shumway BR Gao W Youngbull C Holl MR Johnson RH Meldrum DR 《Sensors and actuators. B, Chemical》2010,150(2):579-587
Oxygen sensing films were synthesized by a chemical conjugation of functional platinum porphyrin probes in silica gel, polystyrene (PS), and poly(2-hydroxyethyl methacrylate) (PHEMA) matrices. Responses of the sensing films to gaseous oxygen and dissolved oxygen were studied and the influence of the matrices on the sensing behaviors was investigated. Silica gel films had the highest fluorescence intensity ratio from deoxygenated to oxygenated environments and the fastest response time to oxygen. PHEMA films had no response to gaseous oxygen, but had greater sensitivity and a faster response time for dissolved oxygen than those of PS films. The influence of matrices on oxygen response, sensitivity and response time was discussed. The influence is most likely attributed to the oxygen diffusion abilities of the matrices. Since the probes were chemically immobilized in the matrices, no leaching of the probes was observed from the sensing films when applied in aqueous environment. One sensing film made from the PHEMA matrix was used to preliminarily monitor the oxygen consumption of Escherichia coli (E. coli) bacteria. E. coli cell density and antibiotics ampicillin concentration dependent oxygen consumption was observed, indicating the potential application of the oxygen sensing film for biological application. 相似文献
78.
介绍数字通信系统的广泛应用和Monte Carlo算法的基本思想,重点分析数字通信系统中的差错概率和应用Monte Carlo仿真对存在噪声和干扰的数字通信系统的性能进行评估。 相似文献
79.
Partner selection is a major issue in the formation of a virtual enterprise. In practice, in the partner selection process, the information about the candidates and their performances are incomplete and uncertain. Vague sets theory is one of the methods used to deal with uncertain information. In this paper, a new method based on vague sets is proposed to deal with the partner selection problem in the formation of a virtual enterprise while the factors of satisfaction degree, due date, cost and the precedence of tasks are taken into account. On the basis of the agreement index of satisfaction degree, the formulated partner selection problems are interpreted so as to maximize the minimum agreement index. To solve the problem, an improved particle swarm optimization (PSO) algorithm is proposed. Finally, the simulation of a numerical example demonstrates that the method is effective. 相似文献
80.