全文获取类型
收费全文 | 4898篇 |
免费 | 589篇 |
国内免费 | 436篇 |
专业分类
电工技术 | 740篇 |
综合类 | 479篇 |
化学工业 | 378篇 |
金属工艺 | 80篇 |
机械仪表 | 199篇 |
建筑科学 | 69篇 |
矿业工程 | 45篇 |
能源动力 | 75篇 |
轻工业 | 82篇 |
水利工程 | 34篇 |
石油天然气 | 86篇 |
武器工业 | 45篇 |
无线电 | 1767篇 |
一般工业技术 | 424篇 |
冶金工业 | 106篇 |
原子能技术 | 31篇 |
自动化技术 | 1283篇 |
出版年
2024年 | 12篇 |
2023年 | 80篇 |
2022年 | 70篇 |
2021年 | 92篇 |
2020年 | 153篇 |
2019年 | 155篇 |
2018年 | 127篇 |
2017年 | 181篇 |
2016年 | 173篇 |
2015年 | 173篇 |
2014年 | 247篇 |
2013年 | 435篇 |
2012年 | 295篇 |
2011年 | 296篇 |
2010年 | 287篇 |
2009年 | 271篇 |
2008年 | 273篇 |
2007年 | 312篇 |
2006年 | 316篇 |
2005年 | 261篇 |
2004年 | 234篇 |
2003年 | 201篇 |
2002年 | 174篇 |
2001年 | 162篇 |
2000年 | 142篇 |
1999年 | 125篇 |
1998年 | 99篇 |
1997年 | 73篇 |
1996年 | 78篇 |
1995年 | 81篇 |
1994年 | 52篇 |
1993年 | 61篇 |
1992年 | 42篇 |
1991年 | 29篇 |
1990年 | 30篇 |
1989年 | 24篇 |
1988年 | 21篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1977年 | 8篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1963年 | 3篇 |
排序方式: 共有5923条查询结果,搜索用时 843 毫秒
41.
42.
Jorge Soriano-Santos† Setsuko Iwabuchi Kenshiro Fujimoto 《International Journal of Food Science & Technology》1992,27(3):337-346
Nitrogen was extracted more efficiently from amaranth seed with 0.04 M Na2 SO4 (5% w/v) than with either 0.09 M or 0.17 M NaCl (5% or 10% w/v), despite both solutions having the same ionic strength (μ= 1). Solubility of saline soluble proteins (albumin ± globulin) was very poor in either water or 1M NaCl, but increased in 0.4M NaCl at alkaline pH between 7 and 10. Globulins were very soluble in 0.4M NaCl at a pH 9. Albumin was the main storage protein. Saline soluble proteins formed very weak gels. 相似文献
43.
128×128红外焦平面阵列时序分析与温控电路设计 总被引:8,自引:0,他引:8
介绍了微测辐射热计的 12 8× 12 8凝视型非致冷红外热像仪的系统框图 ,论述了一种新型的红外焦平面阵列温控电路设计方案以及读出电路时序的FPGA实现方法 .该方案具有高集成度、高精度、低成本、布线简单等优点 ,为热像仪系统的研制开发提供了设计思想 . 相似文献
44.
集成电路芯片级的热分析方法 总被引:2,自引:2,他引:0
文章在研究分析了集成电路中功耗的主要来源以及温度对集成电路性能的影响后,详细总结了近年来集成电路芯片级的几种热分析方法。并从实际应用角度对这几种方法进行了分析和比较,讨论了各个方法的优点及其适用范围。 相似文献
45.
46.
47.
Reports an error in "Learning myopia: An adaptive recency effect in category learning" by Matt Jones and Winston R. Sieck (Journal of Experimental Psychology: Learning, Memory, and Cognition, 2003[Jul], Vol 29[4], 626-640). On page 633, Table 2, the values in columns (T, P) and (P, T) in the dual condition row incorrectly read .10 and .90, respectively. The correct values are .90 and .10, respectively. (The following abstract of the original article appeared in record 2003-06626-013.) Recency effects (REs) have been well established in memory and probability learning paradigms but have received little attention in category learning research. Extant categorization models predict REs to be unaffected by learning, whereas a functional interpretation of REs, suggested by results in other domains, predicts that people are able to learn sequential dependencies and incorporate this information into their responses. These contrasting predictions were tested in 2 experiments involving a classification task in which outcome sequences were autocorrelated. Experiment 1 showed that reliance on recent outcomes adapts to the structure of the task, in contrast to models' predictions. Experiment 2 provided constraints on how sequential information is learned and suggested possible extensions to current models to account for this learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
48.
A technique for designing efficient checkers for conventional Berger code is proposed in this paper. The check bits are derived by partitioning the information bits into two blocks, and then using an addition array to sum the number of 1's in each block. The check bit generator circuit uses a specially designed 4-input 1's counter. Two other types of 1's counters having 2 and 3 inputs are also used to realize checkers for variable length information bits. Several variations of 2-bit adder circuits are used to add the number of 1's. The check bit generator circuit uses gates with fan-in of less than or equal to 4 to simplify implementation in CMOS. The technique achieves significant improvement in gate count as well as speed over existing approaches. 相似文献
49.
50.
V. Székely M. Rencz J.M. Karam M. Lubaszewski B. Courtois 《Journal of Electronic Testing》1998,12(1-2):81-92
With the increasing power density in integrated systems resulting from scaling down, the occurrence of field failures due to overheating has considerably increased. Faulty operation can be prevented by on-line temperature monitoring. This paper deals with questions of on-line temperature monitoring in safety-critical systems. First the possible temperature sensors are reviewed and basic principles of self-checking systems including such sensors are detailed, then a new temperature sensor cell with extremely good parameters designed especially for DfTT applications is presented. The basic questions of integrating thermal sensors into self-checking systems are also discussed. 相似文献