全文获取类型
收费全文 | 1042篇 |
免费 | 61篇 |
国内免费 | 8篇 |
学科分类
工业技术 | 1111篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 28篇 |
2021年 | 64篇 |
2020年 | 30篇 |
2019年 | 27篇 |
2018年 | 39篇 |
2017年 | 36篇 |
2016年 | 37篇 |
2015年 | 42篇 |
2014年 | 37篇 |
2013年 | 99篇 |
2012年 | 63篇 |
2011年 | 66篇 |
2010年 | 41篇 |
2009年 | 42篇 |
2008年 | 35篇 |
2007年 | 54篇 |
2006年 | 38篇 |
2005年 | 39篇 |
2004年 | 35篇 |
2003年 | 20篇 |
2002年 | 18篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 15篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 11篇 |
1991年 | 3篇 |
1990年 | 10篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1973年 | 3篇 |
1972年 | 4篇 |
排序方式: 共有1111条查询结果,搜索用时 15 毫秒
951.
Yu. S. Zaslavsky A. A. Berlin R. N. Zaslavsky M. I. Cherkashin K. E. Beloserova V. A. Rusakova 《Wear》1972,20(3):287-297
A new type of additive for oils and fuels has been developed. These additives, ashless organic compounds forming friction polymers, provide simultaneous antiwear, extreme pressure and antifriction action. The results of four-ball testing of antiwear, extreme pressure and antifriction action of the additives are presented. Their ability to form friction polymers on rubbing metal surfaces was confirmed by radiotracer investigations. 相似文献
952.
Ana C.F. Ribeiro A.J.F.N. Sobral S.M.N. Simões Marisa C.F. Barros Victor M.M. Lobo Ana M.T.D.P.V. Cabral Francisco J.B. Veiga Cecilia I.A.V. Santos Miguel A. Esteso 《Food chemistry》2011
Mutual diffusion coefficients (interdiffusion coefficients) of sodium alginate in aqueous dilute solutions, at concentrations from 0.001 to 0.500 g mL−1 and at 298.15 K, alone and in combination with caffeine, using an open-ended conductimetric capillary cell, have been measured. These results are discussed in the light of structural analysis conducted by means of theoretical calculations (molecular mechanics). 相似文献
953.
Residential thermostats control a substantial portion of both fuel and electrical energy—9% of the total energy consumption in the U.S. Consumers install programmable thermostats to save energy, yet numerous recent studies found that homes with programmable thermostats can use more energy than those controlled manually depending on how—or if—they are used. At the same time, thermostats are undergoing a dramatic increase in capability and features, including control of ventilation, responding to electricity price signals, and interacting with a home area network. These issues warrant a review of the current state of thermostats, evaluating their effectiveness in providing thermal comfort and energy savings, and identifying areas for further improvement or research. 相似文献
954.
Cecilia Cagliero Barbara Sgorbini Chiara Cordero Erica Liberto Patrizia Rubiolo Carlo Bicchi 《Israel journal of chemistry》2016,56(11-12):925-939
This article deals with enantioselective gas chromatography (Es-GC) utilizing cyclodextrin derivatives as chiral stationary phases (CSPs) for chiral recognition in the flavour and fragrance field. It consists of two main parts. The first one concerns cyclodextrins and their use in Es-GC, and it deals with their introduction and evolution as CSPs in GC, together with some theoretical aspects involved with enantiomeric separation and their consequent influence on routine chiral recognition. The second part reports on the strategy of chiral recognition in routine analysis with cyclodextrin derivatives as CSP, illustrated with examples from the authors’ everyday experiences. This part describes how to identify enantiomers or to measure their excess or ratio determination in complex mixtures; in particular, it discusses the opportunities offered by multidimensional and fast GC techniques, the role of mass spectrometry, and the application of total analysis systems to chiral recognition. 相似文献
955.
956.
957.
958.
959.
960.
Cecilia Wallin Dr. Jinghui Luo Dr. Jüri Jarvet Dr. Sebastian K. T. S. Wärmländer Prof. Astrid Gräslund 《Israel journal of chemistry》2017,57(7-8):674-685
This review describes interactions between the amyloid-β peptide (Aβ) involved in Alzheimer's disease (AD) and endogenous metal ions and proteins, with an emphasis on future potential drug therapies and targets. AD is characterised by loss of neurons, memory, and cognitive functions, and by formation of cerebral senile plaque deposits. These plaques consist mainly of aggregated Aβ peptides. AD pathology includes a) on the molecular level imbalanced concentrations of Aβ peptides and metal ions, and formation of amyloid structures, and b) on the physiological level a combination of inflammatory responses and oxidative stress effects causing neuronal death. Interestingly, certain blood proteins and metal ions can affect the Aβ amyloid aggregation process. These interactions are the topics of the present review. A deeper understanding of these interactions could facilitate new therapeutic strategies against AD. Previous therapeutic approaches and trials are also briefly described. 相似文献