全文获取类型
收费全文 | 310篇 |
免费 | 10篇 |
国内免费 | 9篇 |
专业分类
化学 | 149篇 |
晶体学 | 7篇 |
力学 | 11篇 |
数学 | 73篇 |
物理学 | 89篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 7篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 19篇 |
2012年 | 9篇 |
2011年 | 21篇 |
2010年 | 16篇 |
2009年 | 14篇 |
2008年 | 19篇 |
2007年 | 17篇 |
2006年 | 21篇 |
2005年 | 15篇 |
2004年 | 15篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有329条查询结果,搜索用时 29 毫秒
1.
Gunes Sibel Senyigit Ercan Karakaya Ersin Ozceyhan Veysel 《Journal of Thermal Analysis and Calorimetry》2019,136(4):1795-1806
Journal of Thermal Analysis and Calorimetry - This work introduces the determination of the optimum values of the design parameters in a tube with loose-fit perforated twisted tapes. The effects of... 相似文献
2.
Alp E. E. Sturhahn W. Toellner T. S. Zhao J. Hu M. Brown D. E. 《Hyperfine Interactions》2002,144(1-4):3-20
Nuclear resonant inelastic X-ray scattering of synchrotron radiation is being applied to ever widening areas ranging from
geophysics to biophysics and materials science. Since its first demonstration in 1995 using the 57Fe resonance, the technique has now been applied to materials containing 83Kr, 151Eu, 119Sn, and 161Dy isotopes. The energy resolution has been reduced to under a millielectronvolt. This, in turn, has enabled new types of
measurements like Debye velocity of sound, as well as the study of origins of non-Debye behavior in presence of other low-energy
excitations. The effect of atomic disorder on phonon density of states has been studied in detail. The flux increase due to
the improved X-ray sources, crystal monochromators, and time-resolved detectors has been exploited for reducing sample sizes
to nano-gram levels, or using samples with dilute resonant nuclei like myoglobin, or even monolayers. Incorporation of micro-focusing
optics to the existing experimental setup enables experiments under high pressure using diamond-anvil cells. In this article,
we will review these developments.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
Z. Ercan 《Proceedings of the American Mathematical Society》2006,134(3):917-920
We give a characterization of realcompact spaces in terms of nets. By using the technique of this characterization we give easy proofs of the Tychonoff Theorem and the Alaoglu Theorem.
4.
B. Sahoo W. Keune E. Schuster W. Sturhahn T. S. Toellner E. E. Alp 《Hyperfine Interactions》2006,168(1-3):1185-1190
Amorphous (a-) Fe x Mg1?x alloys are interesting materials for the investigation of non-Debye-like low-energy vibrational excitations. We have prepared a-Fe x Mg1?x alloy thin films (0.3 ≤ × ≤0.7) by vapour quenching. The amorphous state was confirmed by conversion electron Mössbauer spectroscopy between 4.2–300 K, and the x- and temperature-dependence of the isomer shift and hyperfine magnetic field was measured. For x= 0.6 and 0.7, magnetic ordering occurs below ~150 K. The atomic vibrational density of states, g(E), was determined by nuclear resonant inelastic scattering, providing clear evidence for the non-Debye-like low-energy vibrational excitations. 相似文献
5.
S. Alpay E. Yu. Emel'yanov Z. Ercan 《Proceedings of the American Mathematical Society》2004,132(12):3627-3628
In this paper we give a characterization of order ideals in Riesz spaces.
6.
J. Odeurs R. Coussement C. L'abbé G. Neyens G.R. Hoy E.E. Alp W. Sturhahn T. Toellner C. Johnson 《Hyperfine Interactions》1998,113(1-4):455-463
A new time integrated method for the study of resonant nuclear scattering of synchrotron radiation in the forward direction
or in Bragg directions is introduced. This method gives in principle similar information as the well known time differential
method. A brief comparison of both methods is presented. The idea is to excite coherently the nuclei incorporated in two absorbers,
one moving with respect to the other. The fields radiated by the nuclei from both absorbers interfere and each time the nuclear
energy in one absorber matches, by Doppler modulation, the nuclear energy of the other, an extremum in the time integrated
intensity is observed. The results of the first experiments at the Advanced Photon Source at the Argonne National Laboratory
will be presented.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
A. Konjhodzic A. Adamczyk F. Vagizov Z. Hasan E E. Alp W. Sturhahn Jiyong Zhao J J. Carroll 《Hyperfine Interactions》2006,170(1-3):83-89
With the decrease in size of devices, rapid characterization of nano-devices is an inevitable necessity. It is shown that Mössbauer spectroscopy using synchrotron radiation from the advanced photon source provides such a tool of investigation. Results are presented and compared for conventional Mössbauer and Nuclear Forward Scattering for 151Eu-doped magnesium sulfide as an example, especially at low concentrations. 相似文献
8.
K. Özker A. Sungur M. Ercan N. Ardagil N. Aydin 《Journal of Radioanalytical and Nuclear Chemistry》1987,118(3):201-208
The labelling of human serum albumin /HSA/ with99mTc has been investigated using a chemical method /stannous citrate/ and electrolytically generated tin/II/ ions. A comparative study of various chemical parameters and current intensities has been carried out in order to find the optimal conditions for labelling. The labelling yield was over 95%, for the chemical and electrolytical methods. 相似文献
9.
F. Soramel-Stanco R. Julin J. Styczen P. T. Prokofjev A. Ercan P. Kleinheinz 《Zeitschrift für Physik A Hadrons and Nuclei》1983,314(2):127-133
In the doubly odd 63 150 Eu87 nucleus a 45 ns 8+ isomer at 589 keV excitation has been identified through (p, 3n) in beamγ ande ? measurements. The low lying negative parity levels populated in its decay show great similarity to analogous states in the lighter odd-odd Eu neighbours suggesting a spherical shape for150Eu. A spherical shape is also proposed for the isomer which is assigned as (πh 11/2 vf 7 2/?3 )8+ state analogous to the 9+ isomers known in148Eu and146Eu. The spin change is attributed to the crossing of the half-filledf 7/2 neutron shell atN=86. 相似文献
10.
Rai BK Durbin SM Prohofsky EW Sage JT Ellison MK Roth A Scheidt WR Sturhahn W Alp EE 《Journal of the American Chemical Society》2003,125(23):6927-6936
Detailed Fe vibrational spectra have been obtained for the heme model complex [Fe(TPP)(CO)(1-MeIm)] using a new, highly selective and quantitative technique, Nuclear Resonance Vibrational Spectroscopy (NRVS). This spectroscopy measures the complete vibrational density of states for iron atoms, from which normal modes can be calculated via refinement of the force constants. These data and mode assignments can reveal previously undetected vibrations and are useful for validating predictions based on optical spectroscopies and density functional theory, for example. Vibrational modes of the iron porphyrin-imidazole compound [Fe(TPP)(CO)(1-MeIm)] have been determined by refining normal mode calculations to NRVS data obtained at an X-ray synchrotron source. Iron dynamics of this compound, which serves as a useful model for the active site in the six-coordinate heme protein, carbonmonoxy-myoglobin, are discussed in relation to recently determined dynamics of a five-coordinate deoxy-myoglobin model, [Fe(TPP)(2-MeHIm)]. For the first time in a six-coordinate heme system, the iron-imidazole stretch mode has been observed, at 226 cm(-)(1). The heme in-plane modes with large contributions from the nu(42), nu(49), nu(50), and nu(53) modes of the core porphyrin are identified. In general, the iron modes can be attributed to coupling with the porphyrin core, the CO ligand, the imidazole ring, and/or the phenyl rings. Other significant findings are the observation that the porphyrin ring peripheral substituents are strongly coupled to the iron doming mode and that the Fe-C-O tilting and bending modes are related by a negative interaction force constant. 相似文献