全文获取类型
收费全文 | 1445篇 |
免费 | 40篇 |
国内免费 | 10篇 |
专业分类
化学 | 1033篇 |
晶体学 | 13篇 |
力学 | 62篇 |
数学 | 116篇 |
物理学 | 271篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 13篇 |
2020年 | 22篇 |
2019年 | 29篇 |
2018年 | 27篇 |
2017年 | 16篇 |
2016年 | 31篇 |
2015年 | 26篇 |
2014年 | 35篇 |
2013年 | 68篇 |
2012年 | 100篇 |
2011年 | 89篇 |
2010年 | 49篇 |
2009年 | 31篇 |
2008年 | 80篇 |
2007年 | 87篇 |
2006年 | 55篇 |
2005年 | 79篇 |
2004年 | 51篇 |
2003年 | 67篇 |
2002年 | 52篇 |
2001年 | 33篇 |
2000年 | 35篇 |
1999年 | 26篇 |
1998年 | 20篇 |
1997年 | 15篇 |
1996年 | 23篇 |
1995年 | 10篇 |
1994年 | 19篇 |
1993年 | 15篇 |
1992年 | 24篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 22篇 |
1983年 | 10篇 |
1982年 | 17篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 11篇 |
1978年 | 14篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1974年 | 7篇 |
1973年 | 17篇 |
排序方式: 共有1495条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
M.J. Grosskopf R.P. Drake C.C. Kuranz E.M. Rutter J.S. Ross N.L. Kugland C. Plechaty B.A. Remington A. Spitkovsky L. Gargate G. Gregori A. Bell C.D. Murphy J. Meinecke B. Reville Y. Sakawa Y. Kuramitsu H. Takabe H.-S. Park 《High Energy Density Physics》2013,9(1):192-197
Experiments investigating the physics of interpenetrating, collisionless, ablated plasma flows have become an important area of research in the high-energy-density field. In order to evaluate the feasibility of designing experiments that will generate a collisionless shock mediated by the Weibel instability on the National Ignition Facility (NIF) laser, computer simulations using the Center for Radiative Shock Hydrodynamics (CRASH) radiation-hydrodynamics model have been carried out. This paper reports assessment of whether the experiment can reach the required scale size while maintaining the low interflow collisionality necessary for the collisionless shock to form. Comparison of simulation results with data from Omega experiments shows the ability of the CRASH code to model these ablated systems. The combined results indicate that experiments on the NIF are capable of reaching the regimes necessary for the formation of a collisionless shock in a laboratory experiment. 相似文献
55.
Justin J. Maresh Sean O. CroweArthur A. Ralko Mark D. ApareceCasey M. Murphy Mark KrzeszowiecMichael W. Mullowney 《Tetrahedron letters》2014
A convenient method for oxidative decarboxylation of α-amino acids is presented. The aldehyde products may be isolated or converted to tetrahydroisoquinolines by addition of dopamine via Pictet–Spengler reaction. Racemic products are generated by phosphate buffer >300 mM to maximize regioselectivity. (S)-Enantiomer products are generated by norcoclaurine synthase reaction in maleic acid buffer to minimize chemical background reaction. 相似文献
56.
Dr. Aron J. Huckaba Dr. Aswani Yella Dr. Louis E. McNamara April E. Steen J. Scott Murphy Casey A. Carpenter George D. Puneky Prof. Nathan I. Hammer Prof. Mohammad Khaja Nazeeruddin Prof. Michael Grätzel Prof. Jared H. Delcamp 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15536-15542
Desirable components for dye‐sensitzed solar cell (DSC) sensitizers and fluorescent imaging dyes include strong donating building blocks coupled with well‐balanced acceptor functionalities for absorption beyond the visible range. We have evaluated the effects of increasing acceptor strengths and incorporation of dye morphology controlling groups on molar absorptivity and absorption breadth with indolizine donor‐based dyes. Indolizine‐based D –A and D –π–A sensitizers incorporating bis‐rhodanine, tricyanofuran (TCF), and cyanoacrylic acid functionalities were analyzed for performance in DSC devices. The TCF derivatives were also evaluated as near‐infrared (NIR)‐emissive materials with the AH25 emissions extending past 1000 nm. 相似文献
57.
58.
Peter C. Griffiths Nicolo Mauro Damien M. Murphy Emma Carter Simon C. W. Richardson Paul Dyer Paolo Ferruti 《Macromolecular bioscience》2013,13(5):641-649
A series of nanoparticles is prepared via layer‐by‐layer assembly of oppositely charged, synthetic biocompatible polyamidoamine polymers as potential carriers. Particle size, surface charge and internal chain mobility are quantified as a function of the polymer type and number of layers. The effect of addition of surfactant is examined to simulate the effects of nanoparticle dissolution. The cyctotoxicity of these particles (in epithelia and murine cell lines) are orders of magnitude lower than polyethyleneimine controls. Stable nanoparticles may be prepared from mixtures of strongly, oppositely charged polymers, but less successfully from weakly charged polymers, and, given their acceptable toxicity characteristics, such modularly designed constructs show promise for drug and gene delivery.
59.
60.
Brian Murphy Peter Mcloughlin 《International journal of environmental analytical chemistry》2013,93(7-8):653-662
The potential of an optical sensor based on mid-infrared spectroscopy, utilising a zinc selenide (ZnSe) attenuated total reflectance (ATR) element coated with an amorphous Teflon polymer, to determine chlorinated hydrocarbon species (CHC) in an aqueous environment is examined. The polymer coating concentrates the analytes within the penetration depth of the Fourier transform infrared (FTIR) evanescent wave and excludes water from the region. Teflon AF (Amorphous Fluoropolymer) is a family of amorphous copolymers based on polytetrafluoroethylene (PTFE), and is commercially available in two polymeric grades. Teflon AF is highly amorphous in nature with a large 'void volume', exhibits excellent chemical resistance and low water absorption. Such properties identify it as an excellent candidate for enrichment coating on an ATR/FTIR sensor. The potential of both polymeric grades of Teflon AF as enrichment membranes for ATR/FTIR analysis of CHC species was examined and contrasted. A rapid, repeatable, reversible response was observed with both grades to a range of CHC species. Linear responses in the mg/L region, with detection limits in the low mg/L region were achieved with the system used. 相似文献