全文获取类型
收费全文 | 5919篇 |
免费 | 187篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 76篇 |
综合类 | 21篇 |
化学工业 | 1568篇 |
金属工艺 | 154篇 |
机械仪表 | 100篇 |
建筑科学 | 306篇 |
矿业工程 | 33篇 |
能源动力 | 104篇 |
轻工业 | 446篇 |
水利工程 | 26篇 |
石油天然气 | 11篇 |
无线电 | 383篇 |
一般工业技术 | 922篇 |
冶金工业 | 1274篇 |
原子能技术 | 63篇 |
自动化技术 | 623篇 |
出版年
2022年 | 45篇 |
2021年 | 67篇 |
2020年 | 62篇 |
2019年 | 73篇 |
2018年 | 84篇 |
2017年 | 65篇 |
2016年 | 109篇 |
2015年 | 107篇 |
2014年 | 137篇 |
2013年 | 174篇 |
2012年 | 213篇 |
2011年 | 238篇 |
2010年 | 204篇 |
2009年 | 193篇 |
2008年 | 218篇 |
2007年 | 198篇 |
2006年 | 179篇 |
2005年 | 194篇 |
2004年 | 147篇 |
2003年 | 121篇 |
2002年 | 135篇 |
2001年 | 140篇 |
2000年 | 131篇 |
1999年 | 134篇 |
1998年 | 349篇 |
1997年 | 216篇 |
1996年 | 169篇 |
1995年 | 151篇 |
1994年 | 120篇 |
1993年 | 114篇 |
1992年 | 92篇 |
1991年 | 95篇 |
1990年 | 85篇 |
1989年 | 95篇 |
1988年 | 64篇 |
1987年 | 65篇 |
1986年 | 52篇 |
1985年 | 60篇 |
1984年 | 49篇 |
1983年 | 58篇 |
1982年 | 63篇 |
1981年 | 59篇 |
1980年 | 55篇 |
1979年 | 70篇 |
1978年 | 56篇 |
1977年 | 75篇 |
1976年 | 116篇 |
1975年 | 54篇 |
1974年 | 51篇 |
1973年 | 47篇 |
排序方式: 共有6110条查询结果,搜索用时 31 毫秒
1.
Nazir Kizzie‐Hayford Doris Jaros Yvonne Schneider Harald Rohm 《International Journal of Food Science & Technology》2015,50(2):381-388
A standard method for the extraction of tiger nut milk has been introduced. It has been shown that, although milling duration improves the yield of tiger nut milk solids and its nutrient composition, there is a quantifiable loss of nutrient in the pressing residue during milk extraction. Milling duration improved the colloidal stability of the milk against creaming during 16 h of storage. A higher milling intensity resulted in the aggregation of biological polymers which resulted in colloidal destabilisation. Milling improved the lightness and stability and reduced browning rate of the tiger nut milk during storage. This report is important for the production of tiger nut milk of consistent and comparable characteristics. Milling has been introduced as a processing method for the qualitative and quantitative modulation of the properties of tiger nut milk. It is recommended to develop further strategies to improve the colloidal stability of tiger nut milk as a beverage. 相似文献
2.
3.
Dr. Kathrin Schindl Dr. Deepika Sharma Prof. Dr. Dieter Spiteller 《Chembiochem : a European journal of chemical biology》2020,21(21):3151-3157
When Streptomyces violaceoruber grows together with Streptomyces sp. MG7-G1, it reacts with strongly induced droplet production on its aerial mycelium. Initially the metabolite profile of droplets from S. violaceoruber in co-culture with Streptomyces sp. MG7-G1 was compared to samples from S. violaceoruber in single-culture by using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Then, the exudate from agar plates of co-cultures and single cultures (after freezing and thawing) was also analysed. Several compounds were only observed when S. violaceoruber was grown in co-culture. Based on their high-resolution ESI mass spectra and their comparable retention times to the calcium-dependent antibiotics (CDAs) produced by S. violaceoruber, the new compounds were suspected to be deacylated calcium-dependent antibiotics (daCDAs), lacking the 2,3-epoxyhexanoyl residue of CDAs. This was verified by detailed analysis of the MS/MS spectra of the daCDAs in comparison to the CDAs. The major CDA compounds present in calcium ion-supplemented agar medium of co-cultures were daCDAs, thus suggesting that Streptomyces sp. MG7-G1 expresses a deacylase that degrades CDAs. 相似文献
4.
Daniel Biedermann Jan Schneider Hendrik Drachsler 《Journal of Computer Assisted Learning》2021,37(5):1217-1231
Digital distractions can interfere with goal attainment and lead to undesirable habits that are hard to get red rid of. Various digital self-control interventions promise support to alleviate the negative impact of digital distractions. These interventions use different approaches, such as the blocking of apps and websites, goal setting, or visualizations of device usage statistics. While many apps and browser extensions make use of these features, little is known about their effectiveness. This systematic review synthesizes the current research to provide insights into the effectiveness of the different kinds of interventions. From a search of the ‘ACM’, ‘Springer Link’, ‘Web of Science’, ’IEEE Xplore’ and ‘Pubmed’ databases, we identified 28 digital self-control interventions. We categorized these interventions according to their features and their outcomes. The interventions showed varying degrees of effectiveness, and especially interventions that relied purely on increasing the participants' awareness were barely effective. For those interventions that sanctioned the use of distractions, the current literature indicates that the sanctions have to be sufficiently difficult to overcome, as they will otherwise be quickly dismissed. The overall confidence in the results is low, with small sample sizes, short study duration, and unclear study contexts. From these insights, we highlight research gaps and close with suggestions for future research. 相似文献
5.
6.
这幢位于瑞士比尔郊区的公寓高三层,由8套大小不同的住宅单元所构成,所处位置能够俯瞰整个小镇,具有极佳的视野。下面的部分是跃层式的二层公寓,上面一层则是普通公寓。楼顶为公共活动区域,设有孩子们的游戏室,其屋顶形式与相邻的建筑风格颇为近似。基地东南向的陡坡非常理想地 相似文献
7.
8.
Butyl, hexyl, and 2-ethylhexyl diesters of 1,1-bis(5-carboxyl-2-furyl)-2,2-dichloroethene, hexyl and 2-ethylhexyl diesters of 1,1-bis(5-carboxyl-2-furyl) ketone, and the hexyl diester of 1,1-bis(5-carboxyl-2-furyl)methane were synthesized from furfural and evaluated for their plasticizing abilities toward PVC, by the application of dynamic mechanical thermal analysis and [di(2-ethylhexyl) phthalate] as a standard of reference. © 1995 John Wiley & Sons, Inc. 相似文献
9.
T Reck F K?ckerling C Schneider W Hohenberger 《Canadian Metallurgical Quarterly》1997,122(10):914-918
Morgagni hernias are the least common form of diaphragmatic hernias. Although they are congenital, most of them are not diagnosed until later in life. The indication for surgery is based on the patient's symptoms or on the radiological evidence of incarcerated tissue, and until quite recently involved a laparotomy or thoracotomy. Laparoscopy not only permits the suspected diagnosis to be confirmed--which is otherwise often difficult--but also makes it possible to close the hernia site by suturing. For improved security, the hernia site is augmented by fixing in place a non-absorbable mesh. The operative technique employed is described. 相似文献
10.
Robotica is a computer-aided design package for robotic nmanipulators developed at the Coordinated Science Laboratory at the University of Illinois at Urbana- Champaign. The package is a collection of function definitions for the Mathematica symbolic mathematics program. Robotica can be used either with an X- Windows graphical user interface (GUI) on a Sun Workstation or as an included function definition file within Mathematica. The primary feature of Robotica is the ability to compute, symbolically or numerically, the kinematic and dynamic equations of arbitrary robot systems utilizing the standard Denevit-Hartenburg (DH) kinematic convention. Robotica also provides the ability to visualize these arbitrary manipulators using the X- Windows graphical interface to the Mathematica graphics routines. The paper looks at the usage of Robotica at the Air Force Institute of Technology, comments on the features of Robotica, and needs for improvement and suggestions for future development 相似文献