全文获取类型
收费全文 | 855篇 |
免费 | 8篇 |
专业分类
化学 | 346篇 |
晶体学 | 3篇 |
力学 | 10篇 |
数学 | 59篇 |
物理学 | 445篇 |
出版年
2018年 | 5篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 28篇 |
2011年 | 38篇 |
2010年 | 19篇 |
2009年 | 16篇 |
2008年 | 37篇 |
2007年 | 37篇 |
2006年 | 33篇 |
2005年 | 46篇 |
2004年 | 29篇 |
2003年 | 26篇 |
2002年 | 23篇 |
2001年 | 20篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 20篇 |
1993年 | 18篇 |
1992年 | 33篇 |
1991年 | 15篇 |
1990年 | 24篇 |
1989年 | 24篇 |
1988年 | 26篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 26篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 16篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1977年 | 11篇 |
1976年 | 15篇 |
1975年 | 7篇 |
1974年 | 10篇 |
1973年 | 8篇 |
1968年 | 5篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1937年 | 3篇 |
1934年 | 3篇 |
1931年 | 3篇 |
排序方式: 共有863条查询结果,搜索用时 31 毫秒
31.
Dominick J Lambrecht M Sanghera S Shelkov V Skwarnicki T Stroynowski R Volobouev I Wei G Zadorozhny P Artuso M Goldberg M He D Horwitz N Kennett R Mountain R Moneti GC Muheim F Mukhin Y Playfer S Rozen Y Stone S Thulasidas M Vasseur G Zhu G Bartelt J Csorna SE Egyed Z Jain V Kinoshita K Edwards KW Ogg M Britton DI Hyatt ER MacFarlane DB Patel PM Akerib DS Barish B Chadha M Chan S Cowen DF Eigen G Miller JS O'Grady C Urheim J Weinstein AJ Acosta D Athanas M Masek G Paar HP Sivertz M Gronberg J 《Physical review D: Particles and fields》1994,50(5):3027-3037
32.
33.
We show that classical chaotic scattering has experimentally measurable consequences for the quantum conductance of semiconductor microstructures. These include the existence of conductance fluctuations-a sensitivity of the conductance to either Fermi energy or magnetic field-and weak-localization-a change in the average conductance upon applying a magnetic field. We develop a semiclassical theory and present numerical results for these two effects in which we model the microstructures by billiards attached to leads. We find that the difference between chaotic and regular classical scattering produces a qualitative difference in the fluctuation spectrum and weak-localization lineshape of chaotic and nonchaotic structures. While the semiclassical theory within the diagonal approximation accounts well for the weak-localization lineshape and for the spectrum of the fluctuations, we uncover a surprising failure of the semiclassical diagonal-approximation theory in describing the magnitude of these quantum transport effects. 相似文献
34.
Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Malchow R Morrow F Skovpen Y Sung M White C Whitmore J Wilson P Butler F Fu X Kalbfleisch G Lambrecht M Ross WR Skubic P Snow J Wang PL Wood M Bortoletto D Brown DN Fast J McIlwain RL Miao T Miller DH Modesitt M Schaffner SF Shibata EI Shipsey IP Wang PN Battle M Ernst J Kroha H Roberts S Sparks K Thorndike EH Wang CH Dominick J Sanghera S Skwarnicki T Stoynowski R Artuso M He D Goldberg M Horwitz N Kennett R 《Physical review letters》1993,71(20):3259-3262
35.
36.
Haas P Hempstead M Jensen T Kagan H Kass R Behrends S Gentile T Guida JM Guida JA Morrow F Poling R Rosenfeld C Thorndike EH Tipton P Besson D Green J Namjoshi R Sannes F Skubic P Stone R Bortoletto D Chen A Goldberg M Horwitz N Jawahery A Lubrano P Moneti GC Trahern CG van Hecke H Csorna SE Garren L Mestayer MD Panvini RS Word GB Yi X Alam MS Bean A Ferguson T Avery P Bebek C Berkelman K Blucher E Cassel DG Copie T DeSalvo R DeWire JW Ehrlich R Galik RS Gilchriese MG Gittelman B Gray SW 《Physical review letters》1985,55(12):1248-1251
37.
38.
39.
LoSecco JM Bionta RM Biewitt G Bratton CB Casper D Chrysicopoulou P Claus R Cortez BG Errede S Foster GW Gajewski W Ganezer KS Goldhaber M Haines TJ Jones TW Kielczewska D Kropp WR Learned JG Lehmann E Park HS Reines F Schultz J Seidel S Shumard E Sinclair D Sobel HW Stone JL Sulak L Svoboda R van der Velde JC Wuest C 《Physical review letters》1985,54(21):2299-2301
40.
Barnes JH Schilling GD Stone SF Sperline RP Denton MB Young ET Barinaga CJ Koppenaal DW Hieftje GM 《Analytical and bioanalytical chemistry》2004,380(2):227-234
The use of a separation step, such as liquid chromatography, prior to inductively coupled plasma mass spectrometry (ICP–MS) has become a common tool for highly selective and sensitive analyses. This type of coupling has several benefits including the ability to perform speciation analysis or to remove isobaric interferences. Several limitations of conventional instruments result from the necessity to scan or pulse the mass spectrometer to obtain a complete mass spectrum. When the instrument is operated in such a non-continuous manner, duty cycle is reduced, resulting in poorer absolute limits of detection. Additionally, with scanning instruments, spectral skew can be introduced into the measurement, limiting quantitation accuracy. To address these shortcomings, a high-performance liquid chromatograph has been coupled to an ICP–MS capable of continuous sample introduction and simultaneous multimass detection. These features have been realized with a novel detector array, the focal plane camera. Instrument performance has been tested for both speciation analysis and for the elimination of isobaric interferences. Absolute limits of detection in the sub picogram to tens of picograms regime are obtainable, while the added mass dimension introduced by simultaneous detection dramatically increases chromatographic peak capacity. 相似文献