全文获取类型
收费全文 | 25437篇 |
免费 | 921篇 |
国内免费 | 85篇 |
专业分类
电工技术 | 324篇 |
综合类 | 45篇 |
化学工业 | 5462篇 |
金属工艺 | 506篇 |
机械仪表 | 507篇 |
建筑科学 | 1816篇 |
矿业工程 | 160篇 |
能源动力 | 727篇 |
轻工业 | 2367篇 |
水利工程 | 198篇 |
石油天然气 | 60篇 |
武器工业 | 1篇 |
无线电 | 1697篇 |
一般工业技术 | 4508篇 |
冶金工业 | 3646篇 |
原子能技术 | 172篇 |
自动化技术 | 4247篇 |
出版年
2023年 | 163篇 |
2022年 | 338篇 |
2021年 | 588篇 |
2020年 | 330篇 |
2019年 | 360篇 |
2018年 | 530篇 |
2017年 | 455篇 |
2016年 | 565篇 |
2015年 | 502篇 |
2014年 | 742篇 |
2013年 | 1597篇 |
2012年 | 1163篇 |
2011年 | 1648篇 |
2010年 | 1178篇 |
2009年 | 1146篇 |
2008年 | 1382篇 |
2007年 | 1193篇 |
2006年 | 1010篇 |
2005年 | 945篇 |
2004年 | 844篇 |
2003年 | 755篇 |
2002年 | 718篇 |
2001年 | 443篇 |
2000年 | 423篇 |
1999年 | 468篇 |
1998年 | 735篇 |
1997年 | 580篇 |
1996年 | 449篇 |
1995年 | 366篇 |
1994年 | 373篇 |
1993年 | 374篇 |
1992年 | 278篇 |
1991年 | 230篇 |
1990年 | 224篇 |
1989年 | 253篇 |
1988年 | 207篇 |
1987年 | 193篇 |
1986年 | 191篇 |
1985年 | 261篇 |
1984年 | 233篇 |
1983年 | 195篇 |
1982年 | 181篇 |
1981年 | 204篇 |
1980年 | 135篇 |
1979年 | 153篇 |
1978年 | 149篇 |
1977年 | 139篇 |
1976年 | 151篇 |
1975年 | 126篇 |
1974年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 23 毫秒
991.
提出可以增加集合住宅受欢迎度的共鸣设计方法策略,这些策略不仅考虑到建筑本身的一些可能性,同时考虑到在空间和社会环境方面的要求,涵盖了物理的、心理的以及社会的因素;指出这类策略的应用带来了高度的用户接受度并使得适应性建筑在一个长时期内可以保持其价值.阐释在设计方法的帮助下,建筑物被记录和相互比较. 相似文献
992.
Peter Williams 《Urban Policy and Research》2013,31(3):291-310
Abstract Focus in this paper is placed on the issue of inclusionary zoning and developer contributions to provide affordable housing in the City West and Green Square urban redevelopment projects. Both are ambitious inner city urban renewal projects which form key parts of the New South Wales government's urban consolidation policy and also seek to maintain a social mix through the provision of social (i.e. affordable) housing. 相似文献
993.
Local communities with good stocks of social capital nurture and support the families residing within. This qualitative study explored through the perspectives of mothers, how families with children aged 0–5 years build social capital in newer residential areas in Perth, Western Australia. Parenthood generally increased the desire to connect to one's local community, which activated and enhanced social capital. Two themes appear to drive this desire: an increased need for social support and an increased vested interest in the local community. However, newer residential areas commonly have a lag of community infrastructure needed to provide opportunities for families with young children to interact with other families. Urban planning and community sectors need to coordinate to provide infrastructure and opportunities for families with young children to connect and build social capital within their local communities. 相似文献
994.
Peter H. Nash James F. Shurtleff 《Journal of the American Planning Association. American Planning Association》2013,79(3):153-172
Abstract PLAN FOR REZONING THE CITY OF NEW YORK. A Report by Harrison, Ballard &; Allen. City Planning Commission. New York. 1950. 290 pp. maps, illustrations. $2.00. CONTROLLED ACCESS EXPRESSWAYS IN URBAN AREAS—A symposium. Highway Research Board Bulletin No. 25. Washington, D. C., 1950. 45 pages, illustrated. 60 cents. SOCIAL PRESSURES IN INFORMAL GROUPS. By Leon Festinger, Stanley Schachter and Kurt Back. Harper Bros., New York, 1950. x-930 pp. $3.00. PRODUCTION OF NEW HOUSING. A Research Monograph on Efficiency in Production. By Leo Grebler. Social Science Research Council. New York 1950. ix+ 186 pp. $1.75. 相似文献
995.
996.
Hendrick Berlage is known to architectural history mainly for his Amsterdam Stock Exchange of 1903. This is often celebrated as a proto-modernist work in a rationalist spirit, an oversimplified view, for the building had a conventionally eclectic start and was the fruit of long struggle and many revisions. The development of Berlage's architectural ideas during the period of its gestation is chronicled in a fascinating way by a series of private villas built for friends who were artists and intellectuals. Completed year by year, they run right through the 1890s, showing Berlage's changing concerns with the articulation of content, the expression of construction, the application of controlling geometry, and the development of architectural space. 相似文献
997.
Relevance of the acid–base approach in prediction of adhesion properties in two‐component injection moulding
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Eduard Kraus Sonja Horvat Christian Deubel Christian Staudigel Benjamin Baudrit Peter Heidemeyer Martin Bastian Irina Starostina Oleg Stoyanov 《应用聚合物科学杂志》2016,133(8)
We demonstrate the use of innovative wetting method in prediction of the adhesion properties of biobased polymers for two‐component injection moulding, taking into account the acid–base surface properties of joined materials. The measurements were carried out in accordance with modified Berger method by calculation of the difference in shortened acidity parameter ΔDshort between hard and soft component. Correlation factors up to 0.99 were observed between ΔDshort and peel force. In comparison to results obtained by conventional wetting methods, high potential for the selection of components with high interface adhesion and for prediction of the functionality by the acid–base approach was demonstrated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43048. 相似文献
998.
A comparison of partially acetylated nanocellulose,nanocrystalline cellulose,and nanoclay as fillers for high‐performance polylactide nanocomposites
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jon Trifol David Plackett Cecile Sillard Ole Hassager Anders Egede Daugaard Julien Bras Peter Szabo 《应用聚合物科学杂志》2016,133(14)
Partially acetylated cellulose nanofibers (CNF) were chemically extracted from sisal fibers and the performance of those CNF as nanofillers for polylactide (PLA) for food packaging applications was evaluated. Three PLA nanocomposites; PLA/CNF (cellulose nanofibers), PLA/CNC (nanocrystalline cellulose), and PLA/C30B (CloisiteTM 30B, an organically modified montmorillonite clay) were prepared and their properties were evaluated. It was found that CNF reinforced composites showed a larger decrease on oxygen transmission rate (OTR) than the clay‐based composites; (PLA/CNF 1% nanocomposite showed a 63% of reduction at 23°C and 50% RH while PLA/C30B 1% showed a 26% decrease) and similar behavior on terms of water vapor barrier properties with 46 and 43%, respectively of decrease on water vapor transmission rate at 23°C and 50% RH (relative humidity). In terms of mechanical and thermomechanical properties, CNF‐based nanocomposites showed better performance than clay‐based composites without affecting significantly the optical transparency. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43257. 相似文献
999.
1000.
Changes in Retinal N-Acylethanolamines and their Oxylipin Derivatives During the Development of Visual Impairment in a Mouse Model for Glaucoma
下载免费PDF全文
![点击此处可从《Lipids》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Christa L. Montgomery Jantana Keereetaweep Heather M. Johnson Stephanie L. Grillo Kent D. Chapman Peter Koulen 《Lipids》2016,51(7):857-866
Neurons are especially susceptible to oxidative damage, which is increasingly implicated in neurodegenerative disease. Certain N‐acylethanolamines (NAEs) have been shown to protect neurons from oxidative stress. Since glaucoma may be considered a neurodegenerative disorder and the survival of retinal neurons could also be influenced by N‐acylethanolamines, our goal was to quantify changes in certain N‐acylethanolamine species and their oxylipin derivatives in the retina of a mouse model for glaucoma. We also sought to identify relationships between these and parameters of glaucoma disease development, specifically intraocular pressure, visual acuity, and contrast sensitivity. Five N‐acylethanolamine species and three NAE oxylipin derivatives were quantified in retina from young and aged DBA/2Crl mice. N‐Acylethanolamines and NAE‐oxylipins in retinal extracts were quantified against deuterated standards by isotope dilution gas chromatography–mass spectrometry. Levels (nmol/g dry weight) of N‐arachidonoylethanolamine (anandamide; NAE 20:4) were significantly (p = 0.008) decreased in aged (2.875 ± 0.6702) compared to young animals (5.175 ± 0.971). Conversely, the anandamide oxylipin, 15(S)‐HETE ethanolamide (15(S)‐HETE EA), was significantly (p = 0.042) increased in aged (0.063 ± 0.009) compared to young animals (0.039 ± 0.011). Enzymatic depletion of the anandamide pool by 15‐lipoxygenase and consequent accumulation of 15(S)‐HETE ethanolamine may contribute to decreased visual function in glaucomatous mice. Since N‐acylethanolamines effectively attenuate glaucoma pathogenesis and associated visual impairment, our data provides additional rationale and novel targets for glaucoma therapies. 相似文献