全文获取类型
收费全文 | 679篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
化学 | 328篇 |
晶体学 | 2篇 |
力学 | 40篇 |
数学 | 94篇 |
物理学 | 232篇 |
出版年
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 14篇 |
2014年 | 10篇 |
2013年 | 21篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 10篇 |
2009年 | 18篇 |
2008年 | 26篇 |
2007年 | 33篇 |
2006年 | 29篇 |
2005年 | 30篇 |
2004年 | 16篇 |
2003年 | 18篇 |
2002年 | 20篇 |
2001年 | 11篇 |
2000年 | 15篇 |
1999年 | 7篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 17篇 |
1995年 | 12篇 |
1994年 | 16篇 |
1993年 | 23篇 |
1992年 | 24篇 |
1991年 | 17篇 |
1990年 | 18篇 |
1989年 | 11篇 |
1988年 | 10篇 |
1986年 | 6篇 |
1985年 | 17篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1938年 | 4篇 |
1867年 | 6篇 |
1863年 | 4篇 |
排序方式: 共有696条查询结果,搜索用时 15 毫秒
571.
Thomas Carey Christopher D. Williams Daniel J. McArthur Tammie Malkinson Olivia R. Thompson Aliaksandr Baidak Laura Murtagh Gyorgyi Glodan Sean P. Morgan Anthony W. Banford 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):93-102
This article reports the findings from a series of radioactive experimental trials which have examined the sorption properties of graphene oxide focused on four key radionuclides commonly linked to effluent challenges in the nuclear industry—Cs, Sr, U and Pu. Unlike previous experimental studies, simulated effluent waste solutions were utilised with compositions typical of those found at the Sellafield nuclear site, UK. Molecular dynamics simulations were performed in parallel to elucidate the functional groups to which radionuclides preferentially adsorb. 相似文献
572.
573.
574.
OBJECTIVES: To examine whether being a BRCA1/2 mutation carrier affects a wide array of aspects of life, and if so, how. METHODS: Participants were grouped according to their carrier status (carrier and noncarrier status), health status (affected or unaffected by cancer), and their enrollment at the counseling service (probands and other family members). One hundred and sixty-five women completed a self-administered questionnaire following their genetic consultation session. RESULTS: Probands/nonprobands and carriers/noncarriers did not differ with regard to demographic characteristics, health behaviors including medical checkups, the distress they experience or their resources (sense of coherence, social integration, religiosity). Individuals affected by cancer did differ on some of these aspects from participants without cancer. CONCLUSIONS: From the results of this study, being a carrier could not be considered a psychosocial risk factor, nor does it seem to have an effect on carriers' resources and lifestyle. 相似文献
575.
Peter D. Friedman Vidya D. Vadakoot William J. MeyerJr Steven Carey 《Experiments in fluids》2007,42(5):751-759
Experimental simulations were carried out to investigate the onset of instability in negatively buoyant fountains by injecting
glycerin–water mixtures into silicon oil. The transition from a stable to an unstable fountain structure is primarily governed
by the Richardson number, and to a lesser extent, Reynolds number, viscosity ratio, Weber number and vent geometry. Transition
nominally occurs at a Ri = 1.0. For a fountain issuing from a cylindrical pipe, the major effect of the Reynolds number is in determining whether
or not the fountain is laminar or turbulent. The Reynolds number effect can be largely accounted for by basing a corrected
Richardson number on the root mean square of the mean velocity. Viscosity ratio deviating from unity has the effect of stabilizing
the flow structure and thereby reducing the transition Richardson number. Similarly, interfacial tension stabilizes the flow
pattern resulting in a trend of increasing transition Richardson number with increasing Weber number. The results are valid
in rectangular vents if the Richardson number and Reynolds number are based on the hydraulic diameter. 相似文献
576.
An experimental methodology is proposed in which localized convective boiling heat transfer coefficients inside the tubes of compact evaporators are determined by testing of full evaporator cores. The proposed technique makes use of a special test system having two main flow circuits. One of these flow loops is a conventional vapor compression system, which provides a steady, low-quality, two-phase flow of refrigerant to the tube side of the evaporator. The second primary flow loop provides a steady flow of the vapor of a second working fluid, which condenses on the finned side of the evaporator. Measured data from this system are analyzed using an iterative scheme. Trends in the variation of the refrigerant-side heat transfer coefficient determined by this method throughout a typical evaporator core are described, and the differences and similarities relative to previously published results for single round tubes are discussed. 相似文献
577.
The liquid-to-air membrane energy exchanger is a novel membrane base energy exchanger that allows both heat and moisture transfer between air and a salt solution using a membrane. The heat and mass transfer performance of a single one is significantly dependent on two dimensionless parameters: number of heat transfer units and the ratio of heat capacity rates between solution flow and airflow (Cr*). In this study, the effectiveness of a small-scale liquid-to-air membrane energy exchanger under low Cr* conditions (i.e., Cr* < 1) that has been not investigated previously is experimentally and numerically tested. 相似文献
578.
C. Lea 《Fresenius' Journal of Analytical Chemistry》1875,14(1):370
Ohne Zusammenfassung 相似文献
579.
Carey Lea 《Fresenius' Journal of Analytical Chemistry》1874,13(1):453
Ohne Zusammenfassung 相似文献
580.
Carey Lea 《Fresenius' Journal of Analytical Chemistry》1863,2(1):81-82
Ohne Zusammenfassung 相似文献