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51.
52.
High-spectral-resolution rayleigh-mie lidar measurement of vertical aerosol and atmospheric profiles 总被引:1,自引:0,他引:1
C. Y. She R. J. Alvarez II L. M. Caldwell D. A. Krueger 《Applied physics. B, Lasers and optics》1992,55(2):154-158
A new two-channel ground-based high-spectral-resolution Rayleigh-Mie lidar and its operation is described. Upon the inversion of data collected during the night of August 14–15, 1990, with this unique lidar system (553.7 nm), vertical profiles of atmospheric parameters including temperature, potential temperature, pressure and density, as well as aerosol parameters including backscatter-ratio, extinction coefficient and backscatter phase function are determined. 相似文献
53.
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55.
E. Kuchta R. J. Alvarez II Y. H. Li D. A. Krueger C. Y. She 《Applied physics. B, Lasers and optics》1990,50(2):129-132
The Doppler-free line shape of the 6s
2
1
S
0 – 6s
16p
1
1
P
1 transition at 553.5 nm in natural Ba in the presence of an argon or helium buffer gas has been measured at 744 K for gas pressures from 0.2 to 100 Torr. Using the measured data for pressures above 5 Torr, the broadening rate coefficients for the half width at half maximum (HWHM) are determined to be (4.9±0.5)10–9 and (5.0±0.5)10–9 s–1 cm–3 for helium and argon respectively. 相似文献
56.
ter Steege DH Smits M de Lange CA Westwood NP Peel JB Visscher L 《Faraday discussions》2000,(115):259-69; discussion 303-30
A (2 + 1) one-colour resonance-enhanced multiphoton ionisation study is carried out on the C 2 sigma- state of the ClO radical in the one-photon energy range 29,500-31,250 cm-1. The ClO radical is produced by one-photon photolysis of ClO2 employing 359.2 nm photons derived from a separate laser. In this way a significant concentration of vibrationally excited ClO in its spin-orbit split X 2 pi omega (omega = 3/2 or 1/2) electronic ground state is produced. In addition to mass-resolved excitation spectra, kinetic-energy resolved photoelectron spectra for the X 3 sigma-(v+)<--C 2 sigma-(v' = 3-5) transitions are measured. These transitions are not completely Frank-Condon diagonal, and indicate a decrease in bond length on removal of the Rydberg electron from the C 2 sigma- state. In addition to an unambiguous assignment of the C 2 sigma- state, valuable information is obtained on the degree of vibrational excitation with which the nascent ClO radical is formed in the photolysis of ClO2. Analysis of the photoelectron spectra is supported by Franck-Condon calculations based on potential energy curves either from experimental spectroscopic parameters, or obtained by theoretical ab initio methods. 相似文献
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58.
Dr. Suresh S. Pujari Caitlin C. Jokipii Krueger Christopher Chao Spencer Hutchins Alexander K. Hurben Dr. Gunnar Boysen Dr. Natalia Tretyakova 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(3):e202103245
Metabolic activation of the human carcinogen 1,3-butadiene (BD) by cytochrome 450 monooxygenases gives rise to a genotoxic diepoxide, 1,2,3,4-diepoxybutane (DEB). This reactive electrophile alkylates guanine bases in DNA to produce N7-(2-hydroxy-3,4-epoxy-1-yl)-dG (N7-DE-dG) adducts. Because of the positive charge at the N7 position of the purine heterocycle, N7-DEB-dG adducts are inherently unstable and can undergo spontaneous depurination or base-catalyzed imidazole ring opening to give N6-[2-deoxy-D-erythro-pentofuranosyl]-2,6-diamino-3,4-dihydro-4-oxo-5-N-1-(oxiran-2-yl)propan-1-ol-formamidopyrimidine (DEB-FAPy-dG) adducts. Here we report the first synthesis and structural characterization of DEB-FAPy-dG adducts. Authentic standards of DEB-FAPy-dG and its 15N3-labeled analogue were used for the development of a quantitative nanoLC-ESI+-HRMS/MS method, allowing for adduct detection in DEB-treated calf thymus DNA. DEB-FAPy-dG formation in DNA was dependent on DEB concentration and pH, with higher numbers observed under alkaline conditions. 相似文献
59.
Manuel W. Thesen Bianca Höfer Marc Debeaux Silvia Janietz Armin Wedel Anna Köhler Hans‐Hermann Johannes Hartmut Krueger 《Journal of polymer science. Part A, Polymer chemistry》2010,48(15):3417-3430
A series of novel styrene derived monomers with triphenylamine‐based units, and their polymers have been synthesized and compared with the well‐known structure of polymer of N,N′‐bis(3‐methylphenyl)‐N,N′‐diphenylbenzidine with respect to their hole‐transporting behavior in phosphorescent polymer light‐emitting diodes (PLEDs). A vinyltriphenylamine structure was selected as a basic unit, functionalized at the para positions with the following side groups: diphenylamine, 3‐methylphenyl‐aniline, 1‐ and 2‐naphthylamine, carbazole, and phenothiazine. The polymers are used in PLEDs as host polymers for blend systems with the following device configuration: glass/indium–tin–oxide/PEDOT:PSS/polymer‐blend/CsF/Ca/Ag. In addition to the hole‐transporting host polymer, the polymer blend includes a phosphorescent dopant [Ir(Me‐ppy)3] and an electron‐transporting molecule (2‐(4‐biphenyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole). We demonstrate that two polymers are excellent hole‐transporting matrix materials for these blend systems because of their good overall electroluminescent performances and their comparatively high glass transition temperatures. For the carbazole‐substituted polymer (Tg = 246 °C), a luminous efficiency of 35 cd A?1 and a brightness of 6700 cd m?2 at 10 V is accessible. The phenothiazine‐functionalized polymer (Tg = 220 °C) shows nearly the same outstanding PLED behavior. Hence, both these polymers outperform the well‐known polymer of N,N′‐bis(3‐methylphenyl)‐N,N′‐diphenylbenzidine, showing only a luminous efficiency of 7.9 cd A?1 and a brightness of 2500 cd m?2 (10 V). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3417–3430, 2010 相似文献
60.
Clinton A. Krueger Christopher K. Hilton Mark Osgood Jianglin Wu Ching Wu 《International Journal for Ion Mobility Spectrometry》2009,12(1):33-37
Current commercially available ion mobility spectrometers are intended for the analysis of chemicals in the gas phase. Sample
introduction methods, such as direct air sampling, a GC injector or a thermal desorber, are commonly an integral part of these
instruments. This paper describes an electrospray ionization ion mobility spectrometer system that allows direct introduction
samples in solution phase. This allows direct analysis of non-volatile organic and biological samples, and avoids decomposition
of thermally liable samples, providing reliable chemical identification. In addition, the new ion mobility spectrometer allows
mobility analysis with high resolving power. Commonly used commercial IMS systems provide resolving powers between 10 and
30; this new ion mobility spectrometer has resolving power greater than 60 for routine analysis. A high resolution instrument
is necessary for many applications where a complex mixture needs to be separated and quantified. This paper demonstrates the
advantages of using a high resolution ion mobility spectrometer and an electrospray ionization source for the analysis of
non-volatile pharmaceuticals as well as dissolved explosive in solution phase. 相似文献