全文获取类型
收费全文 | 1612篇 |
免费 | 43篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 247篇 |
金属工艺 | 20篇 |
机械仪表 | 20篇 |
建筑科学 | 101篇 |
矿业工程 | 11篇 |
能源动力 | 22篇 |
轻工业 | 224篇 |
水利工程 | 21篇 |
石油天然气 | 4篇 |
无线电 | 43篇 |
一般工业技术 | 153篇 |
冶金工业 | 626篇 |
原子能技术 | 3篇 |
自动化技术 | 160篇 |
出版年
2022年 | 19篇 |
2021年 | 23篇 |
2020年 | 18篇 |
2019年 | 19篇 |
2018年 | 19篇 |
2017年 | 24篇 |
2016年 | 35篇 |
2015年 | 18篇 |
2014年 | 23篇 |
2013年 | 99篇 |
2012年 | 50篇 |
2011年 | 80篇 |
2010年 | 60篇 |
2009年 | 42篇 |
2008年 | 62篇 |
2007年 | 66篇 |
2006年 | 74篇 |
2005年 | 59篇 |
2004年 | 60篇 |
2003年 | 58篇 |
2002年 | 49篇 |
2001年 | 33篇 |
2000年 | 38篇 |
1999年 | 35篇 |
1998年 | 22篇 |
1997年 | 34篇 |
1996年 | 32篇 |
1995年 | 30篇 |
1994年 | 24篇 |
1993年 | 35篇 |
1992年 | 30篇 |
1991年 | 12篇 |
1990年 | 32篇 |
1989年 | 23篇 |
1988年 | 19篇 |
1987年 | 24篇 |
1986年 | 22篇 |
1985年 | 19篇 |
1984年 | 24篇 |
1983年 | 21篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 10篇 |
1977年 | 13篇 |
1976年 | 14篇 |
1975年 | 16篇 |
1974年 | 9篇 |
1973年 | 9篇 |
排序方式: 共有1657条查询结果,搜索用时 296 毫秒
41.
Margaret Rangecroft 《Behaviour & Information Technology》2003,22(6):421-426
3-D or perspective pie charts are popular graphical displays, especially now that they are so easy to produce on computers, but they are problematical because they distort the very features that communicate the information about the data. This paper presents evidence to support the hypothesis that such distortions can lead to mis-information being obtained from such graphs. In particular the orientation of the segments is crucial to the interpretation of the data. This evidence comes from an experiment on a large number of subjects from varied backgrounds and ages who were asked to identify the largest and smallest segments in a 3-D pie chart. For some graphs the numbers of respondents who identified the segments incorrectly far exceeded those who identified them correctly. A control group who carried out the same task for 2-D pie charts were all able to correctly identify the largest and smallest segments in each graph. 相似文献
42.
John P. Schroeter J. P. Bretaudiere Margaret A. Goldstein 《Microscopy research and technique》1991,18(3):296-304
We have shown previously that the small square (ss) and basket weave (bw) states of the Z band lattice in cardiac and skeletal muscle are related to the contractile state of the muscle. We have used two-dimensional image processing techniques on digitized electron micrographs to enhance the structural features of each projected lattice form in cardiac and skeletal muscle. Four different processing techniques were employed to assess the effect of enhancement artifacts on the resulting Z band images. We observed only slight differences between enhanced images of a particular Z band form produced by the four different techniques. Every enhanced image showed an approximate four-fold symmetry independent of muscle type or Z band lattice form. Each enhanced image showed four cross-connecting Z-filaments which appeared to connect each axial filament to the four nearest axial filaments. In bw images from both cardiac and skeletal muscle, axial filaments had a greater apparent diameter and a greater interaxial filament spacing than in the ss images. In both muscle types, the cross-connecting Z-filaments appeared to overlap half-way between axial filaments in the ss images while the bw images showed no such overlap. These structural features are consistent with a dynamic Z band lattice that participates in muscle contraction. 相似文献
43.
Yanqiao Zhao Khanh Tran Margaret Brennan Charles Brennan 《International Journal of Food Science & Technology》2021,56(6):2687-2695
Polyphenols were extracted from five kinds of New Zealand grape pomace (Sauvignon Blanc, Pinot Gris, Gerwurztraminer, Merlot and Pinot Noir) at 30, 50 and 70 °C in an ultrasonic generator. The extraction kinetics for total phenol, anthocyanin and tannin were determined. The results of dynamics study showed that the extraction of total polyphenols, anthocyanin and tannin followed first-order reaction kinetics during the extraction at 30, 50 and 70 °C. The total phenolic content, anthocyanin conten, and tannin content of water–ethanol extracts from grape pomaces were compared, and the parameters in the extraction kinetics equations were determined. The extraction results showed that the Pinot Noir pomace extract had the highest total phenolic content of 59.95 mg GAE g−1 pomace and tannin content of 79.93 mg EE g−1 pomace. The anthocyanin content in Merlot pomace extract was the highest, which was 4.50 CE g−1 pomace. The results might be of great significance for the development of grape pomace or its polyphenol and/or anthocyanin components as an antioxidant source with natural and inexpensive benefits. 相似文献
44.
Margaret H. Kurth Jesse M. Keenan Mehrdad Sasani 《Building Research & Information》2019,47(4):480-492
ABSTRACTInitiatives to operationalize the concept of resilience in the building industry are rapidly emerging. The concept of resilience has introduced a way to explore solutions to some important problems in the building industry. However, much of the work that has taken place to date represents activities generally assigned to risk management, which is discussed as being inherently insufficient for sustaining the functions of the built environment under stresses. This commentary considers the opportunities and limitations for mainstreaming resilience into building industry processes and actors. Barriers include indeterminate analytical meaning, event and performance uncertainty, immature regulatory standards setting, and untested enterprise economics. Further, the multiple outcomes of recovery and the relationship between building recovery and adaptation are discussed and, along with economics of resilience investments, a research need highlighted. A simple heuristic is presented to illustrate the complement of resilience to risk management and advance the integration of resilience into existing industry workflows. 相似文献
45.
46.
Benjamin W. Riblett Nicola L. Francis Margaret A. Wheatley Ulrike G. K. Wegst 《Advanced functional materials》2012,22(23):4920-4923
Successful spinal cord repair is thought to be promoted with hierarchically structured scaffolds. These should combine aligned porosity with additional linear features on the micrometer scale to guide axons across multiple length scales. Such scaffolds are generated through the carefully controlled directional solidification of an aqueous biopolymer solution, followed by lyophilization. Under specific freezing conditions this yields a highly regular and aligned lamellar architecture. This architecture exhibits uniform ridges of controlled height and width on the lamellar surface. These ridges run parallel to the pore axis, serving as secondary guidance features. The ridges are capable of linearly aligning 62.4% of chick dorsal root ganglia neurites to within ±10° of the ridge direction. Notably, neurites sprouting perpendicular to the ridge are guided into alignment with these microridged features. 相似文献
47.
48.
49.
Effect of clove extract pretreatment and drying conditions on lipid oxidation and sensory discrimination of dried omena (Rastrineobola argentea) fish
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Margaret Slavin Mengyi Dong Constance Gewa 《International Journal of Food Science & Technology》2016,51(11):2376-2385
Sun‐drying is a low‐cost, low‐technology fish preservation method frequently employed in developing areas. However, the process promotes lipid oxidation and its associated undesired flavours and odours. This study investigated low‐technology solutions for impact on lipid oxidation and sensory attributes of oven‐dried omena fish (Rastrineobola argentea). Two oven‐drying conditions and four doses of clove water extract ‘dip’ pretreatments were studied in a complete factorial design. Lipid oxidation in dried fish was assessed by TBARS, peroxide value and fatty acid analysis by GC‐FID. Results showed that soaking in 10 g L?1 clove water extract for 1 h and oven‐drying at 150 °C × 30 min significantly reduced TBARS and peroxide values in omena fish by 77% and 79%, respectively, and polyene index showed improved retention of long‐chain polyunsaturated fats, compared to original drying condition. Lastly, panellists of a triangle test were able to discriminate between biscuits made with the modified and original dried fish. 相似文献
50.