全文获取类型
收费全文 | 429篇 |
免费 | 28篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 154篇 |
金属工艺 | 6篇 |
机械仪表 | 10篇 |
建筑科学 | 17篇 |
矿业工程 | 2篇 |
能源动力 | 9篇 |
轻工业 | 60篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 22篇 |
一般工业技术 | 74篇 |
冶金工业 | 63篇 |
原子能技术 | 2篇 |
自动化技术 | 30篇 |
出版年
2023年 | 7篇 |
2022年 | 17篇 |
2021年 | 32篇 |
2020年 | 14篇 |
2019年 | 11篇 |
2018年 | 12篇 |
2017年 | 24篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 33篇 |
2012年 | 22篇 |
2011年 | 32篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 21篇 |
2007年 | 21篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1974年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有457条查询结果,搜索用时 218 毫秒
1.
Nicolas Guerda; DeSilva Angela M.; Grey Kathleen S.; Gonzalez-Eastep Diana 《Canadian Metallurgical Quarterly》2006,37(6):702
Currently, ethnic and racial minority individuals represent a large proportion of the U.S. population, and researchers expect that they will represent the majority of the population by 2050. This shift in U.S. demographics calls for a greater awareness and integration of cultural issues into the assessment and treatment of ethnically and linguistically diverse clients. This article examines the unique beliefs and manifestations of illnesses among Haitians in connection with the American Psychological Association's (APA, 2002) Multicultural Guidelines. The authors use a common culture-bound syndrome, Séizisman, to illustrate the cultural beliefs, assessment, and treatment of illnesses among Haitians. In so doing, they demonstrate how to incorporate the APA Multicultural Guidelines into treatment with clients of diverse cultural and racial backgrounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
3.
A multitemporal sequence of ERS interferometric coherence data acquired between 1993 and 1999 are utilised for automatically mapping urban change within South Wales, UK. Validation of the change map derived from the coherence data is performed using independent, multidate, digital survey data of the city of Cardiff, UK. All major building developments that have occurred within the study area are located. There is evidence to suggest that this approach is generalisable for a wide range of coherence data and to other regions with similar landscapes. 相似文献
4.
5.
The excitonic properties in two (111)B-grown In0·15Ga0·85As/GaAs multiple quantum well p-i-n diodes are investigated by thermally-detected optical absorption and electroreflectance rneasurements. The lineshape of the electroreflectance spectra is analysed by means of a multilayer model enabling the energies and the oscillator strengths of excitonic transitions to be deduced. The excitonic characteristic values are calculated by using a variational method. The determination of the variation of the binding energy with in-well field leads to an accurate value of the piezoelectric field in the InGaAs layers. The theoretical oscillator strengths are compared to those obtained from electroreflectance for different excitonic transitions. 相似文献
6.
Machine Translation - Existing work on the animation of signing avatars often relies on pure procedural techniques or on the playback of Motion Capture (MoCap) data. While the first solution... 相似文献
7.
Claude Leger Lucie Fremont Didier Marion Ibrahim Nassour Marie-Françoise Desfarges 《Lipids》1981,16(8):593-600
This paper describes evidence of (n−3) and particularly of 22∶6 (n−3) fatty acid enrichment in trout lipoproteins as well
as in vitellogenin, egg lipovitellin and oil globule. Among the lipoproteins, HDL and LDL were the main forms of blood lipid
transport, whereas phospholipids and cholesteryl esters are the preferential chemical carriers for (n−3) fatty acid transport.
However, cholesteryl esters were less important as esterified fatty acid carriers than in man. Taken together with the data
obtained in mammals, our results suggest that there may be a relationship between EFA activity and the distribution of the
EFA among the lipoprotein lipid fractions in vertebrates, irrespective of the EFA series. Administration of an (n−3) fatty
acid deficient diet for three months prior to trout spawning produced a significant increase in egg lipid content, primarily
as a result of the increase of the oil globule composed almost exclusively of triacylglycerols. This diet decreased the 22∶6
(n−3), as well as the (n−3) fatty acid contents of lipoproteins, lipovitellin, vitellogenin and the oil globule. In contrast,
the (n−3) fatty acid level was always higher in lipoproteins and lipovitellin than in the vitellogenin and the oil globule.
Moreover, the relative levels of 22∶6 (n−3) and total (n−3) fatty acids were quite similar in lipoproteins and lipovitellin
on the one hand, and in vitellogenin and the oil globule on the other. These findings suggest a direct relationship between
the two forms of plasma lipid transport and the two egg compartments. During ovogenesis, dietary lipids seemed to be diverted
from the adipose tissue and essentially deposited in the egg. 相似文献
8.
Virginie Boy Wajdi Ben Khalifa Lucie Drvillon Yves Leme Thomas Lendormi Jean‐Louis Lanoisell 《加拿大化工杂志》2021,99(1):120-134
An original drying process combining air impingement and intermittent drying was studied on apple slices and mango cubes. The influence of four operating parameters (air velocity, drying/tempering periods, upper height, and air temperature) on the drying time and on the drying rate was evaluated. Continuous and intermittent drying were compared. The intermittency α = 1/7 (τon = 10 seconds and τoff = 60 seconds) gave the best results. A time savings of 54% for apple and 67% for mango was reached. In continuous drying, a time savings of 4620 seconds was observed by increasing the air velocity from 6 to 40 m s?1 for apple. Air temperatures of 328 K for apple and of 328 K or 338 K for mango were determined as optimum to prevent case‐hardening. Experimental results were fitted with the analytical solution of Fick's second law and the modified Page equation (average values R2 = 0.985 and 0.961, for apple and mango, respectively). For both products, the apparent moisture diffusivity Dapp, the drying constant k, the drying coefficient n, and the activation energy Ea, were identified. Activation energies calculated from the analytical solution were 30.3 and 36.8 kJ mol?1 and were 25.4 and 30.0 kJ mol?1 using the modified Page equation for apple and mango, respectively. Mango has an increased temperature sensitivity and thus will need less energy for drying than apple. 相似文献
9.
Flow profile measurement in microchannel using the optical feedback interferometry sensing technique 总被引:1,自引:1,他引:0
Lucie Campagnolo Milan Nikolić Julien Perchoux Yah Leng Lim Karl Bertling Karine Loubière Laurent Prat Aleksandar D. Rakić Thierry Bosch 《Microfluidics and nanofluidics》2013,14(1-2):113-119
The need to accurately measure flow profiles in microfluidic channels is well recognised. In this work, we present a new optical feedback interferometry (OFI) flow sensor that accurately measures local velocity in fluids and enables reconstruction of a velocity profile inside a microchannel. OFI is a self-aligned interferometric technique that uses the laser as both the transmitter and the receiver thus offering high sensitivity, fast response, and a simple and compact optical design. The system described here is based on a commercial semiconductor laser and has been designed to achieve a micrometer-range spatial resolution. The sensor performance was validated by reconstructing the velocity profile inside a circular cross-section flow-channel with 320 $\upmu $ m internal diameter, with a relative error smaller than 1.8 %. The local flow velocity is directly measured, thus avoiding the need for model based profile calculation and uncertainties inherent to this approach. The system was validated by successfully extracting the flow profiles in both Newtonian and shear-thinning liquids. 相似文献
10.
Luis TruebaJr Monica A. Torres Lucie B. Johannes Daniel Rybicki 《International Journal of Material Forming》2018,11(4):559-570
Self-reacting friction stir welding (SR-FSW), also called bobbin-tool friction stir welding (BT-FSW), is a solid state welding process similar to friction stir welding (FSW) except that the tool has two opposing shoulders instead of the shoulder and a backing plate found in FSW. The tool configuration results in greater heat input and a symmetrical weld macrostructure. A significant amount of information has been published in the literature concerning traditional FSW while little has been published about SR-FSW. An optimization experiment was performed using a factorial design to evaluate the effect of process parameters on the weld temperature, surface and internal quality, and mechanical properties of self-reacting friction stir welded aluminum alloy 6061-T6 butt joints. The parameters evaluated were tool rotational speed, traverse speed, and tool plunge force. A correlation between weld temperature, defect formation (specifically galling and void formation), and mechanical properties was found. Optimum parameters were determined for the welding of 8-mm-thick 6061-T6 plate. 相似文献