全文获取类型
收费全文 | 1184篇 |
免费 | 25篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 43篇 |
化学工业 | 269篇 |
金属工艺 | 39篇 |
机械仪表 | 28篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 31篇 |
轻工业 | 92篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 114篇 |
一般工业技术 | 244篇 |
冶金工业 | 237篇 |
原子能技术 | 12篇 |
自动化技术 | 88篇 |
出版年
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 21篇 |
2017年 | 18篇 |
2016年 | 35篇 |
2015年 | 12篇 |
2014年 | 25篇 |
2013年 | 71篇 |
2012年 | 43篇 |
2011年 | 65篇 |
2010年 | 53篇 |
2009年 | 60篇 |
2008年 | 66篇 |
2007年 | 54篇 |
2006年 | 36篇 |
2005年 | 31篇 |
2004年 | 27篇 |
2003年 | 29篇 |
2002年 | 21篇 |
2001年 | 21篇 |
2000年 | 23篇 |
1999年 | 22篇 |
1998年 | 86篇 |
1997年 | 61篇 |
1996年 | 43篇 |
1995年 | 37篇 |
1994年 | 15篇 |
1993年 | 23篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1988年 | 7篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 10篇 |
1975年 | 3篇 |
1974年 | 6篇 |
1972年 | 3篇 |
排序方式: 共有1212条查询结果,搜索用时 31 毫秒
51.
Network environments give computer users the option of employing distributed information and services to complete a task. However, gathering information and using services distributed in networks requires knowing exactly what kinds of information and services are required for a task, where they are, and how they can be obtained or utilized. Tracking down the answers to these questions can be difficult, time consuming tasks for users. Mobile agent technology is expected to release them from having to do so. Instead, “intelligent” mobile agents will comprehend the user's requirements, search network nodes autonomously for appropriate information and services, and return with the answers. But several problems must be solved before we can expect agents to perform such actions effectively. We focus on the question of intelligence as a prerequisite for agent functions. What sort of intelligence is expected of agents? We have adopted a model based on the ability to make flexible plans. Specifically, we think mobile agents must be able to: understand user requirements; plan actions that will satisfy the requirements act according to the plan; modify the plan according to actual conditions when they differ from those initially expected; and execute the modified plan. We have implemented these functions in the Plangent system and validated their effectiveness in several example applications. We describe how we combined these planning functions with mobile agent facilities, and show how the agents behave intelligently in an example application of personal travel assistance 相似文献
52.
Reiji Hattori Shuhei Yamada Yoshitomo Masuda Norio Nihei 《Journal of the Society for Information Display》2004,12(1):75-80
Abstract— We have developed new powder materials that exhibit liquid behavior, which can lead to the realization of novel bistable and reflective displays having paper‐white appearance, high contrast, and quick response. Two types of display were demonstrated, one had 160 × 160 array of pixels and the other had 320 × 320 in a 3.1‐in.‐diagonal viewable image size corresponding to 66 and 132 dpi, respectively. These displays were driven by passive‐matrix addressing. The displays showed a reflectivity of more than 41%, a contrast more than 1:10, and a pixel response time of less than 0.2 msec. The seven‐segment display for use in clocks was also demonstrated. 相似文献
53.
Yoshihiko Hangai Hiroaki Yoshida Nobuhiro Yoshikawa 《Metallurgical and Materials Transactions A》2012,43(3):802-805
A new friction powder compaction (FPC) process by the sintering and dissolution process (SDP) route for fabricating open-cell
aluminum (Al) foam, which requires no external heat sources, was developed. Foams with porosities of 74 and 83 pct were successfully
fabricated and their compressive responses were investigated. The sintered mixture during the removal process was observed
nondestructively by X-ray computed tomography (CT) to reveal the progress of the removal of soluble particles and to confirm
that they were completely dissolved. 相似文献
54.
Ya-Li Wang Zhi-Jun Liu Qiang Liu Jian-Nan Ma Masao Hattori Chao-Mei Ma 《Food Analytical Methods》2014,7(7):1526-1529
Two cyanogenic glycosides (linustatin and neolinustatin) and sucrose were isolated from defatted flaxseed, and their structures were determined by NMR spectral analysis and comparison with existing data. Using secoisolariciresinol diglucoside (SDG) and the cyanogenic glycosides as standards, we developed a method to quantify the three compounds simultaneously by ultrahigh-performance liquid chromatography (UHPLC)-MS in selected reaction monitoring (SRM) mode. Using this tool, flaxseed powder—processed by various methods—was analyzed with regard to the contents of the beneficial compound, SDG, and the toxic compounds, cyanogenic glycosides. The levels of SDG in samples treated with alkaline solution are much higher than in samples without treatment, and in general, the levels of linustatin and neolinustatin in flaxseed powder decreased progressively as heating time is prolonged after treatment with alkaline solutions. 相似文献
55.
56.
57.
58.
59.
Katsuki Hirabayashi Yoshiya Tashiro Nobuhiro Kondo Sachio Hayashi 《Journal of Applied Glycoscience》2017,64(2):33
We report production of the functional disaccharide gentiobiose β-D-Glcp-(1→6)-D-Glc by a hydrolysis reaction of hydrothermally treated Aureobasidium pullulans β-1,3-1,6-glucan as the substrate and Kitalase as the enzyme. Gentiobiose was produced over the pH range 4−6 and the concentration of gentiobiose produced decreased above pH 7. The maximum value of gentiobiose production was unaffected by the enzyme concentration. The maximum concentration of gentiobiose produced was dependent on the substrate concentration whereas the maximum ratio of gentiobiose to glucose was not. The production of gentiobiose from yeast β-1,3-1,6-glucan was lower than that from A. pullulans β-1,3-1,6-glucan. 相似文献
60.
Jomjai Peerapattana Kuniko Otsuka Yusuke Hattori 《Drug development and industrial pharmacy》2015,41(3):515-521
The objective of this research was to quantify the α-mangostin content in mangosteen pericarp (MP) ointment as a colloidal dispersion using near-infrared (NIR) spectroscopy. Various concentrations of MP (IP and EP) ointments containing both internal and external pericarps were prepared and the NIR spectra of these ointments were measured. The NIR spectrum of each ointment was correlated with α-mangostin concentration by partial least square (PLS) regression. Validation of the models was performed and their predictive ability was also investigated. The equation and R2 value for the prediction of α-mangostin concentration in IP ointment were y?=?0.9843x?+?0.4441 and 0.9730 and those in EP ointment were y?=?0.9569x?+?0.1142 and 0.9136, respectively. The biases of the IP and EP ointment models were 0.23 and 0.00, respectively. The results showed that NIR could be a useful tool for the quality control of herbal medicine in hydrophilic ointment without any sample preparation. It could predict α-mangostin content in hydrophilic ointment at very low concentration with sufficient accuracy. 相似文献