全文获取类型
收费全文 | 19326篇 |
免费 | 580篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 255篇 |
综合类 | 9篇 |
化学工业 | 3949篇 |
金属工艺 | 295篇 |
机械仪表 | 340篇 |
建筑科学 | 1149篇 |
矿业工程 | 111篇 |
能源动力 | 549篇 |
轻工业 | 1590篇 |
水利工程 | 170篇 |
石油天然气 | 201篇 |
武器工业 | 1篇 |
无线电 | 1174篇 |
一般工业技术 | 3060篇 |
冶金工业 | 4346篇 |
原子能技术 | 169篇 |
自动化技术 | 2556篇 |
出版年
2022年 | 183篇 |
2021年 | 264篇 |
2020年 | 203篇 |
2019年 | 253篇 |
2018年 | 307篇 |
2017年 | 294篇 |
2016年 | 365篇 |
2015年 | 264篇 |
2014年 | 432篇 |
2013年 | 1168篇 |
2012年 | 730篇 |
2011年 | 970篇 |
2010年 | 744篇 |
2009年 | 734篇 |
2008年 | 906篇 |
2007年 | 912篇 |
2006年 | 725篇 |
2005年 | 754篇 |
2004年 | 588篇 |
2003年 | 606篇 |
2002年 | 537篇 |
2001年 | 355篇 |
2000年 | 317篇 |
1999年 | 321篇 |
1998年 | 376篇 |
1997年 | 342篇 |
1996年 | 344篇 |
1995年 | 357篇 |
1994年 | 289篇 |
1993年 | 316篇 |
1992年 | 279篇 |
1991年 | 171篇 |
1990年 | 244篇 |
1989年 | 288篇 |
1988年 | 210篇 |
1987年 | 217篇 |
1986年 | 214篇 |
1985年 | 266篇 |
1984年 | 260篇 |
1983年 | 229篇 |
1982年 | 220篇 |
1981年 | 217篇 |
1980年 | 174篇 |
1979年 | 191篇 |
1978年 | 176篇 |
1977年 | 178篇 |
1976年 | 154篇 |
1975年 | 179篇 |
1974年 | 167篇 |
1973年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Molecular structure and granule morphology of native and heat‐moisture‐treated pinhão starch 下载免费PDF全文
Vania Z. Pinto Khalid Moomand Nathan L. Vanier Rosana Colussi Franciene A. Villanova Elessandra R. Zavareze Loong‐Tak Lim Alvaro R. G. Dias 《International Journal of Food Science & Technology》2015,50(2):282-289
Pinhão seed is an unconventional source of starch and the pines grow up in native forests of southern Latin America. In this study, pinhão starch was adjusted at 15, 20 and 25% moisture content and heated to 100, 110 and 120 °C for 1 h. A decrease in λ max (starch/iodine complex) was observed as a result of increase in temperature and moisture content of HMT. The ratio of crystalline to amorphous phase in pinhão starch was determined via Fourier transform infra red by taking 1045/1022 band ratio. A decrease in crystallinity occurred as a result of HMT. Polarised light microscopy indicated a loss of birefringence of starch granules under 120 °C at 25% moisture content. Granule size distribution was further confirmed via scanning electron microscopy which showed the HMT effects. These results increased the understanding on molecular and structural properties of HMT pinhão starch and broadened its food and nonfood industrial applications. 相似文献
3.
4.
5.
6.
<正>悉尼理工大学工程和计算机系系馆位于市区的显赫地段,旨在重新给大学城市校区注入活力,成为悉尼商务中心南端的门户。建筑本体如同一件雕塑作品,迥然和周围的传统建筑风格相异。建筑地上14层,地下4层,设有先进的演讲厅、学术办公室、会议室、学习和研究实验室、营业咖啡厅、娱乐区、停车场,并在隔壁建筑旁设计自行车停靠处。 相似文献
7.
Few jurisdictions have translated internationally agreed social impact assessment (SIA) principles into statutory provisions. Governments and regulatory bodies tend to provide developers with high-level frameworks, or require that social impacts be ‘considered’, without specifying how this is to be done. In Australia, this lack of clarity leaves all parties uncertain about requirements for SIA. The New South Wales (NSW) Government’s 2017 release of the SIA guideline for State-significant mining, petroleum and extractive industry development represents an attempt to clarify requirements and provide guidance. In this paper, we describe the process of bringing this guideline to fruition from the perspective of being directly involved in its development, and highlight the challenges involved in integrating leading-practice principles into the state’s pre-existing policy framework. While the guideline represents a significant advance in policy-based SIA guidance, some aspects leave room for improvement. The real test of the guideline’s impact will lie in its influence on SIA practice in NSW, and ultimately in social outcomes for communities affected by resources projects. 相似文献
8.
9.
10.
The Intellectual Development of Science and Engineering Students. Part 2: Teaching to Promote Growth
As college students experience the challenges of their classes and extracurricular activities, they undergo a developmental progression in which they gradually relinquish their belief in the certainty of knowledge and the omniscience of authorities and take increasing responsibility for their own learning. At the highest developmental level normally seen in college students (which few attain before graduation), they display attitudes and thinking patterns resembling those of expert scientists and engineers, including habitually and skillfully gathering and analyzing evidence to support their judgments. This paper proposes an instructional model designed to provide a suitable balance of challenge and support to advance students to that level. The model components are (1) variety and choice of learning tasks; (2) explicit communication and explanation of expectations; (3) modeling, practice, and constructive feedback on high‐level tasks; (4) a student‐centered instructional environment; and (5) respect for students at all levels of development. 相似文献