全文获取类型
收费全文 | 56489篇 |
免费 | 5170篇 |
国内免费 | 2597篇 |
专业分类
电工技术 | 1459篇 |
技术理论 | 3篇 |
综合类 | 4273篇 |
化学工业 | 5069篇 |
金属工艺 | 2604篇 |
机械仪表 | 3419篇 |
建筑科学 | 964篇 |
矿业工程 | 1513篇 |
能源动力 | 503篇 |
轻工业 | 16048篇 |
水利工程 | 457篇 |
石油天然气 | 1558篇 |
武器工业 | 875篇 |
无线电 | 7318篇 |
一般工业技术 | 4390篇 |
冶金工业 | 2164篇 |
原子能技术 | 381篇 |
自动化技术 | 11258篇 |
出版年
2024年 | 350篇 |
2023年 | 1027篇 |
2022年 | 1434篇 |
2021年 | 2002篇 |
2020年 | 2031篇 |
2019年 | 1684篇 |
2018年 | 1579篇 |
2017年 | 1811篇 |
2016年 | 1949篇 |
2015年 | 2192篇 |
2014年 | 3044篇 |
2013年 | 3305篇 |
2012年 | 3707篇 |
2011年 | 3983篇 |
2010年 | 2845篇 |
2009年 | 2838篇 |
2008年 | 2810篇 |
2007年 | 3542篇 |
2006年 | 3248篇 |
2005年 | 2846篇 |
2004年 | 2363篇 |
2003年 | 2177篇 |
2002年 | 1777篇 |
2001年 | 1388篇 |
2000年 | 1332篇 |
1999年 | 1031篇 |
1998年 | 892篇 |
1997年 | 816篇 |
1996年 | 700篇 |
1995年 | 561篇 |
1994年 | 531篇 |
1993年 | 455篇 |
1992年 | 359篇 |
1991年 | 284篇 |
1990年 | 253篇 |
1989年 | 217篇 |
1988年 | 153篇 |
1987年 | 99篇 |
1986年 | 91篇 |
1985年 | 105篇 |
1984年 | 79篇 |
1983年 | 81篇 |
1982年 | 67篇 |
1981年 | 42篇 |
1980年 | 37篇 |
1979年 | 29篇 |
1978年 | 20篇 |
1977年 | 24篇 |
1976年 | 13篇 |
1959年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Review: Modified Atmosphere Packaging and its effects on the microbiological quality and safety of produce 总被引:10,自引:0,他引:10
Carol A. Phillips 《International Journal of Food Science & Technology》1996,31(6):463-479
Modified Atmosphere Packaging and related technologies are increasingly used to extend shelf-life of fresh produce. This paper reviews the effect of such technology on the spoilage microbiological flora and food-borne pathogens which may be present in produce and also on the organoleptic properties of the product. 相似文献
82.
利用小波变换具有的多时频分辨率特性,对地震勘探和测井信号这类非平衡信号进行分析,可以充分利用信号的时间-频率特性。文中介绍了小波变换的基本概念及其在地震勘探信号的时变滤波和声波全波列测井信号的信号分离中的应用,实例表明,小波变换在地球物理信号中具有广阔的应用前景。图5参7 相似文献
83.
Nourh ne Boudhrioua Bertrand Broyart Catherine Bonazzi Jean-Dominique Daudin 《Drying Technology》2005,23(12):2313-2335
A method is presented for computing the values of apparent diffusivity in solids with respect to the concentration of the diffusing substance (water or sodium chloride). This method does not require any assumption upon the mathematical relationship between diffusivity and concentration. It can be applied to experimental measurements of local concentration versus position within the solid (profiles) with relatively few measurements (circa 10) and a mathematical smoothing of the experimental data by using an artificial neural network model. The method was first validated on simulated data obtained by using a constant diffusivity value and on experimental profiles when the relation between diffusivity and concentration was given. It was then applied to original experimental moisture profiles obtained by putting gelatin gels with different initial moisture contents into contact for up to 14 days. The method was also successfully applied to five sets of experimental moisture and sodium chloride profiles taken from the literature and obtained from different food products. Apparent diffusivities calculated by our method were found in agreement with those obtained by authors using different numerical methods to compute the diffusivity values. 相似文献
84.
85.
Enhanced Image Detection on an ARM based Embedded System 总被引:2,自引:0,他引:2
This paper presents a new technique for thedetection of Integrated Circuits within images of Printed Circuit Boards autonomouslyand without the need to be assisted by CAD data. The technique is a key partof a suite of algorithms targeted for an embedded System On Chip architecturebased on the ARM7 platform for real time detection of PCB images for diagnosticpurposes. The technique has a significant reduction in complexity when comparedto conventional approaches such as the Hough Transform. The reduction in complexitymakes the approach ideal for an embedded vision application suchas the one described in this paper. This paper presents the technique, thetarget embedded architecture and results showing the reduction in complexitywhen compared to a Hough Transform. 相似文献
86.
87.
R. GRAY† M. HILARY STEVENSON‡ 《International Journal of Food Science & Technology》1991,26(6):669-672
One hundred and twenty-five pairs of chicken drumsticks were randomly allocated to one of five dose rates: 5, 10, 15, 20 or 600 kGyh-. The highest dose rate was obtained using a linear accelerator whilst the remaining dose rates were provided using a 60 Co gamma source. Each batch of 25 pairs was further divided into groups five of which were stored at 4°C for 0, 7, 14, 21 or 28 days. ESR spectroscopy was used to measure the intensity of the radiation-induced signal. There was a quadratic relationship between ESR signal strength and dose rate, which although statistically significant is unlikely to be of practical importance. The magnitude of the ESR signal declined by about 20% over the first 14 days of storage at 4°C and thereafter the decrease was minimal. 相似文献
88.
Staub Adrian; Rayner Keith; Pollatsek Alexander; Hy?n? Jukka; Majewski Helen 《Canadian Metallurgical Quarterly》2007,33(6):1162
Readers' eye movements were monitored as they read sentences containing noun-noun compounds that varied in frequency (e.g., elevator mechanic, mountain lion). The left constituent of the compound was either plausible or implausible as a head noun at the point at which it appeared, whereas the compound as a whole was always plausible. When the head noun analysis of the left constituent was implausible, reading times on this word were inflated, beginning with the first fixation. This finding is consistent with previous demonstrations of very rapid effects of plausibility on eye movements. Compound frequency did not modulate the plausibility effect, and all disruption was resolved by the time readers' eyes moved to the next word. These findings suggest (contra Kennison, 2005) that the parser initially analyzes a singular noun as a head instead of a modifier. In addition, the findings confirm that the very rapid effect of plausibility on eye movements is not due to strategic factors, because in the present experiment, unlike in previous demonstrations, this effect appeared in sentences that were globally plausible. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
89.
E.J. Widjaja G. Delporte F. Vandevelde B. Vanterwyngen 《Solar Energy Materials & Solar Cells》2008,92(2):97-100
As electrochromic device (ECD) emerges into the market, the necessity of cost reduction via high-throughput manufacturing is unavoidable. Inorganic monolithic ECD has compatibility in its manufacturing steps, allows continuous processing and hence low-cost ECD. A roll-to-roll (R2R) production is the industrial standard for high-throughput processing and was chosen to synthesize ECD on polymeric substrates. Preliminary success by implementing methods compatible to the aforementioned R2R processing has been achieved; however, continuous test-runs on an R2R machine are still limited. 相似文献
90.
I. Egli L. Davidsson M.-A. Juillerat D. Barclay R. Hurrell 《Journal of food science》2003,68(5):1855-1859
Complementary foods based on cereals and legumes often contain high amounts of phytic acid, a potent inhibitor of mineral and trace element absorption. The possibility to degrade phytic acid during the production of complementary foods by using whole grain cereals as the phytase source was investigated. Whole grain rye, wheat, or buckwheat (10%) were added to cereal‐legume‐based complementary food mixtures, and phytic acid was shown to be completely degraded in a relatively short time (1.5 to 3 h) when incubated at optimal conditions for cereal phytase. The potential usefulness of the method for industrial production was demonstrated with a complementary food based on wheat and soybean. 相似文献