全文获取类型
收费全文 | 527篇 |
免费 | 17篇 |
专业分类
化学 | 386篇 |
晶体学 | 10篇 |
力学 | 5篇 |
数学 | 19篇 |
物理学 | 124篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 8篇 |
2013年 | 33篇 |
2012年 | 35篇 |
2011年 | 37篇 |
2010年 | 24篇 |
2009年 | 11篇 |
2008年 | 37篇 |
2007年 | 27篇 |
2006年 | 38篇 |
2005年 | 27篇 |
2004年 | 30篇 |
2003年 | 14篇 |
2002年 | 31篇 |
2001年 | 7篇 |
2000年 | 10篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有544条查询结果,搜索用时 31 毫秒
1.
J. Fujimoto T. Ishikawa M. Jimbo T. Kaneko T. Kon Y. Kurihara M. Kuroda Y. Shimizu Y. Yasui 《Pramana》2007,69(5):943-946
We report the recent development on the SUSY calculations with the help of GRACE system. GRACE/SUSY/1LOOP is the computer
code which can generate Feynman diagrams in the MSSM automatically and compute one-loop amplitudes in the numerical way. We
present new results of various two-body decay widths and chargino pair production at ILC (international linear collider) at
one-loop level.
相似文献
2.
We demonstrate the potential of femtosecond two-color pulse interferometry for in vitro optical glucose monitoring, by dispersion of the group refractive index in a glucose solution sample with respect to a red-color
light and a blue-color light. By comparison with femtosecond one-color pulse interferometry, the basic performance of the
present system with regard to sensitivity, quantitativeness, and tolerance to surrounding disturbances, is evaluated. The
resulting accuracy and precision of glucose determination are 77 and 118mg/dl for 10-mm-sample-thickness, respectively. This
near-common-path configuration of the two-color pulse light provides good stability to fluctuations of sample temperature,
which is important in clinical applications. Considering the performance of femtosecond two-color pulse interferometry as
an optical glucose sensor, a suitable measurement site for in vivo optical glucose monitoring is discussed. 相似文献
3.
This paper considers two models of BASIC mode data transmission: When we transmit data with length l
- 1. (1) data are divided into N blocks and each block is transmitted individually
- 2. (2) data are divided into N sub-blocks and all sub-blocks are transmitted together.
4.
Eiko Yasui 《Tetrahedron letters》2006,47(5):743-746
A novel method for synthesizing arylhydrazones, the precursor for Fischer indole synthesis, using aryllithium reagents and α-diazo esters that are easily obtained from α-amino acid esters, is described. 相似文献
5.
Reduction of dislocation density and improvement of optical quality in ZnO layers by MgO-buffer annealing 总被引:1,自引:0,他引:1
Hiroki Goto Hisao Makino Agus Setiawan Takuma Suzuki Chihiro Harada Tsutomu Minegishi Meoung-Whan Cho Takafumi Yao 《Current Applied Physics》2004,4(6):637-639
Optical properties of ZnO thin films with/without MgO-buffer annealing were investigated by low and room temperature photoluminescence measurements. The ZnO films were grown on c-sapphire substrates by plasma-assisted molecular-beam epitaxy employing a thin MgO-buffer layer. Dislocation density of ZnO layer was reduced from 5.3 × 109 to 1.9 × 109 cm−2 by annealing MgO-buffer prior to the growth of ZnO. The intensity of free exciton emission from the sample with MgO-buffer annealing was almost twice of that from the sample without annealing, while the deep level emission from the sample with MgO-buffer annealing was about 1/3 of that without annealing. The MgO-buffer annealing improves optical quality of overgrown ZnO films. 相似文献
6.
Takanari Yasui Takeshi Ohtsuka Tetsu Suzuki Shigeki Okajima Kazuya Nakayama Mitsuru Tomioka Katsuhiro Kamimura Takeo Namekata Hiroaki Minamide Hiromasa Ito 《International Journal of Infrared and Millimeter Waves》2006,27(2):199-210
A new, wide-band, high-speed and high-sensitivity THz detector has been developed. The prototype detector consists of a parabolic
cylindrical mirror, a long wire antenna and a Schottky barrier diode. Direct detection measurements have shown a stable sensitivity
of 150 ± 50 V/W for 1–2 THz without any adjustments. The long wire antenna was fixed at the focus of parabolic cylindrical
mirror then it has been realized less operation steps, easy coupling to the external THz signals and a dramatic enhancement
in the practicality of this system. The optically polished mirror and frosted surface one showed comparable sensitivities,
thus easy polishing and less cost mirror fabrication can be applied for this system. The radiation pattern showed a maximum
radiation angle of approximately 23° with its dominant main lobe, which was attributed to the wire antenna character and confirmed
good agreements with classical antenna theory. 相似文献
7.
Sonochemistry and its dosimetry 总被引:3,自引:0,他引:3
The effects of ultrasound originate primarily in acoustic cavitation. The cavitation bubbles collapse violently enough to lead to interesting chemical effects, known as sonochemistry. There is a great need to relate the efficiency of sonochemical reaction to the energy of ultrasonic irradiation used to produce them. In this paper, three OH radical dosimeters, Fricke dosimeter, terephthalate dosimeter, and iodide dosimeter, are compared from the analytical point of view. The dosimeters based on photometry, i.e., Fricke and iodide, produced reliable and reproducible results, but the sensitivity is not enough for special applications, such as chemical monitoring of single bubble cavitation. The dosimeter based on fluorometry, terephthalate dosimeter, offered high sensitivity, 1.2×1011 molecules ml−1. The effects of some experimental parameters in sonochemistry, i.e., solution temperature and the dissolved gas species, were evaluated with the dosimeters. 相似文献
8.
9.
10.
Chihiro Kachi‐Terajima Dr. Takamasa Akatsuka Masa‐aki Kohbara Satoshi Takamizawa Dr. 《化学:亚洲杂志》2007,2(1):40-50
The crystalline one‐dimensional compound, [RhII2(bza)4(pyz)]n ( 1 ) (bza=benzoate, pyz=pyrazine) demonstrates gas adsorbency for N2, NO, NO2, and SO2. These gas‐inclusion crystal structures were characterized by single‐crystal X‐ray crystallography as 1 ?1.5 N2 (298 K), 1 ?2.5 N2 (90 K), and 1 ?1.95 NO (90 K) under forcible adsorption conditions and 1 ?2 NO2 (90 K) and 1 ?3 SO2 (90 K) under ambient pressure. Crystal‐phase transition to the P space group that correlates with gas adsorption was observed under N2, NO, and SO2 conditions. The C2/c space group was observed under NO2 conditions without phase transition. All adsorbed gases were stabilized by the host lattice. In the N2, NO, and SO2 inclusion crystals at 90 K, short interatomic distances within van der Waals contacts were found among the neighboring guest molecules along the channel. The adsorbed NO molecules generated the trans‐NO???NO associated dimer with short intermolecular contacts but without the conventional chemical bond. The magnetic susceptibility of the NO inclusion crystal indicated antiferromagnetic interaction between the NO molecules and paramagnetism arising from the NO monomer. The NO2 inclusion crystal structure revealed that the gas molecules were adsorbed in the crystal in dimeric form, N2O4. 相似文献