全文获取类型
收费全文 | 327篇 |
免费 | 3篇 |
专业分类
化学 | 231篇 |
晶体学 | 2篇 |
力学 | 2篇 |
数学 | 1篇 |
物理学 | 94篇 |
出版年
2021年 | 2篇 |
2020年 | 5篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 21篇 |
2012年 | 14篇 |
2011年 | 15篇 |
2010年 | 3篇 |
2009年 | 6篇 |
2008年 | 17篇 |
2007年 | 30篇 |
2006年 | 16篇 |
2005年 | 20篇 |
2004年 | 12篇 |
2003年 | 18篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有330条查询结果,搜索用时 15 毫秒
61.
Analysis of antimony around the abandoned Tsugu mine in Aichi Prefecture by neutron activation analysis 总被引:1,自引:0,他引:1
Y. Katayama A. Misawa N. Yamada S. Yachi H. Muto T. Aoki Y. Kawabata M. Nagai 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(2):283-286
At Tsugu mine in Aichi Prefecture, antimony was mined and smelted until 1956. The amounts of antimony present in the soil
of the abandoned mine were measured to enable us to detect any traces of the operation of the mine and to measure the level
of environmental contamination with antimony. The quantity of antimony in rings of hinoki and sugi was also measured to obtain
information about chronological changes in environmental conditions. The quantity of antimony in the samples was determined
by INAA. The antimony concentrations in eight soil samples at different points in the Tsugu mine area were 8–17,000 ppm. 相似文献
62.
M. Yosoi H. Akimune I. Daito H. Ejiri H. Fujimura M. Fujiwara K. Hara K. Y. Hara T. Ishikawa M. Itoh Y. Itow T. Kawabata K. Kobayashi M. Nakamura T. Noro E. Obayashi H. Sakaguchi Y. Sakemi M. Shiozawa H. Takeda T. Taki A. Tamii H. Toyokawa N. Tsukahara M. Uchida T. Yamada Y. Yasuda H. P. Yoshida R. G. T. Zegers 《Physics of Atomic Nuclei》2004,67(10):1810-1817
Decay particles from the s-hole states in 11B and 15N have been measured in coincidence with the quasifree 12C(p, 2p) and 16O(p, 2p) reactions at E p =392 MeV. Triton decay is found to be dominant for the 11B(s-hole) state and also found to be larger than α decay for the 15N(s-hole) state despite its smaller Q value compared to α decay. Measured decay branching ratios are discussed in comparison with the results of statistical-model, SU(3)-model, and shell-model calculations. The energy spectra around the s-hole states in both 11B and 15N exhibit some bumplike structures, which can be qualitatively explained by recent shell-model calculations for both nuclei. 相似文献
63.
The cobalt(II) complex is detected spectrophotometrically by its catalysis of a photochromic isomerism of norbornadiene (NBD). NBD is immobilized on porous glass beads, and is isomerized to quadricyclane (QC) by UV irradiation. The beads are then immersed in a solution containing tetraphenylporphinecobalt(II) [TPPCo(II)], and the QC is converted back to NBD by a catalytic reaction with TPPCo(II). The rate constant, measured spectrophotometrically, is proportional to the concentration of TPPCo(II). The detection limit of TPPCo(II) is 60 μM for a reaction period of 1 h. This spectrophotometric detection can be applied repetitively without any supply of the chemical reagent, as NBD immobilized on the porous glass beads can be re-isomerized to QC by UV irradiation. 相似文献
64.
Ryuji Furuta Shunsuke Naruto Atsushi Tamura Kanae Yokogawa 《Tetrahedron letters》1979,20(19):1701-1704
A new indole-N-glycoside, neosidomycin (I), is produced by a strain belonging to Streptomyces hygroscopicus. The structure of I has been deduced from physico-chemical data obtained using the natural compound, its derivatives and products of degradation reactions. 相似文献
65.
H. Hasegawa N. Akata H. Kawabata Y. Chikuchi T. Sato K. Kondo J. Inaba 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):171-175
7Be deposition fluxes and atmospheric concentrations were measured at Rokkasho Village, Aomori Prefecture, Japan, from 2000
to 2005. It was confirmed that the 7Be deposition fluxes were minimum in summer, and the fallout maximizes in winter. The atmospheric concentration of 7Be was especially low in summer, and high in the other three seasons. A positive correlation was observed between the amount
of precipitation and 7Be deposition. Clear seasonal differences were evident among the ratios of 7Be deposition flux to precipitation amounts in the four seasons. The ratios were especially high in winter, higher than those
in the other three seasons. 7Be deposition flux was estimated by a simple simulation model using atmospheric 7Be concentrations and local meteorological data. As a result, the estimated deposition value was relatively lower than the
measured value in winter. 相似文献
66.
67.
68.
Nitrogen heterocycles with contiguous quaternary and tertiary stereocenters have been prepared in high enantiomeric purity by intramolecular conjugate addition of enolates generated from alpha-amino acid derivatives via memory of chirality. 相似文献
69.
Kawabata E Kikuchi K Urano Y Kojima H Odani A Nagano T 《Journal of the American Chemical Society》2005,127(3):818-819
Zinc (Zn2+) is found in every cell in human bodies. A few millimolar of free Zn2+ exists in the vesicles of presynaptic neurons in the mammalian brain and is released by synaptic activity or depolarization, modulating the function of certain ion channels and receptors. Although various chemical tools for measuring Zn2+ in biological samples, such as fluorescent probes for Zn2+, have been developed, Zn2+-selective chelators have room to be improved. Research on Zn2+ signals in the brain has traditionally employed several chelators, which have several shortcomings for biological applications. Here we report the design, synthesis, and properties of new membrane-impermeable chelators selective for Zn2+ and describe biological applications in hippocampal slices. As a result, our newly designed chelator revealed the first biological implication that presynaptic Zn2+ can be released in the CA1 region. This confirms the utility of these new chelatotrs as extracellular Zn2+ chelators for biological applications. 相似文献
70.
Okamoto Y Kawano M Kawabata T Kubota T Hiromitsu I 《The journal of physical chemistry. B》2005,109(1):288-296
The elucidation of a molecular structure of the active sites (i.e., the Co-Mo-S phase) of Co-Mo hydrodesulfurization catalysts has received extensive attention. In the present study, we unambiguously determined, for the first time, the NO adsorption behavior and magnetic property of the Co-Mo-S phase by preparing unique Co-Mo/Al(2)O(3) catalysts (CVD-Co/MoS(2)/Al(2)O(3)), in which all the Co atoms are present as the Co-Mo-S phase. The catalysts were characterized by NO adsorption (pulse technique and FTIR), Co K-edge XANES, and the magnetic susceptibility and effective magnetic moment of Co. Nitric oxide molecules were adsorbed on 33% of the Co atoms in CVD-Co/MoS(2)/Al(2)O(3) after sulfidation and on only half of the Co atoms even after an H(2)-treatment of the sulfided catalyst at 573-673 K. The Co atoms in CVD-Co/MoS(2)/Al(2)O(3) exclusively exhibited an antiferromagnetic property, indicating that even-numbered Co atoms are interacting with each other in the Co-Mo-S phase. A Co-Mo/Al(2)O(3) catalyst, prepared by a conventional impregnation technique, was composed of the antiferromagnetic Co sulfide species as observed in CVD-Co/MoS(2)/Al(2)O(3) in addition to Co(9)S(8). On the basis of the NO adsorption behavior and magnetic property, it is empirically proposed that the structure of the Co-Mo-S phase is represented as a Co sulfide dinuclear cluster located on the edge of MoS(2) particles. The magnetic property of Co/Al(2)O(3) sulfide catalysts depended on the preparation method. 相似文献