全文获取类型
收费全文 | 256篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
化学 | 86篇 |
数学 | 10篇 |
物理学 | 169篇 |
出版年
2021年 | 4篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 6篇 |
2008年 | 10篇 |
2007年 | 14篇 |
2006年 | 14篇 |
2005年 | 3篇 |
2004年 | 11篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 10篇 |
1994年 | 10篇 |
1993年 | 11篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1964年 | 1篇 |
1958年 | 1篇 |
1956年 | 2篇 |
1955年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有265条查询结果,搜索用时 865 毫秒
1.
2.
V. Hnatowicz J. Kvítek V. Švorčík V. Rybka V. Popok 《Czechoslovak Journal of Physics》1994,44(6):621-627
Samples of polyethylene (PE) loaded with carbon black up to 8 wt.% and implanted with 150 keV Sb+ ions to the doses from 2×1013–2×1015 cm–2 were studied using standard Rutherford Back Scattering (RBS) technique. On the PE samples implanted to the doses above 2×1014 cm–2, a considerable surface carbonization is observed. The measured parameters of the Sb depth profile are compared with theoretical TRIM estimations. The projected range is by 25% lower than the theoretical one and the range straggling is about twice of that predicted. The differences are explained by stepwise polymer degradation during the ion bombardment. Strong oxidation of the ion implanted polymers is also observed. The oxygen depth profiles from the sample surface up to the depth comparable with Sb+ ion range evolve from nearly uniform one for low ion doses to highly non-uniform one for doses above 1×1015 cm–2. The total oxygen content in the sample surface layer 300 nm thick reaches a maximum for the doses of (1–2)×1014 cm–2.On leave from Belorussian State University, 220050 Minsk, Belarus.The authors thank the member of electrostatic accelerator group at INP for help during RBS measurements. The work was partly (V.H. and J.K.) supported by the Internal Grant Agency of the Academy of Sciences of Czech Republic under the grant No. 14805 and by the Internal Grant Agency of the Ministry of Education of Czech Republic under the grant No. 1002 (V.., V.R., V.H. and J.K.). In the final stage, the work was also supported by the Grant Agency of Czech Republic under the grant No. 202/93/0121. 相似文献
3.
4.
5.
6.
Kopel Pavel Trávníček Zdeněk Kvítek Libor Biler Martin Pavlíček Marek Šindelář Zdeněk Marek Jaromír 《Transition Metal Chemistry》2001,26(3):282-286
NiII mixed-ligand complexes of compositions [Ni(pmdien)(ttcH)] (1), [Ni(baphen)2(ttcH)] · 4H2O (2), [Ni-(dpa)(ttcH)(H2O)] (3), [Ni(cyclam)(ttcH)] · 2H2O (4), [Ni(hexaa)](ttcH) (5) and [Ni(hexab)(ttcH)] · 2H2O (6), (baphen = 4,7-diphenyl-1,10-phenanthroline, dpa = 2,2-dipyridylamine, cyclam = 1,4,8,11-tetraazacyclotetradecane, hexaa = 1,3,6,9,11,14-hexaazatricyclo[12.2.1.16,9]-octadecane, hexab = 1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane) have been prepared and characterized by means of i.r., u.v.–vis. spectroscopies and magnetochemical measurements. The redox properties of the complexes were studied by cyclic voltammetry. The crystal and molecular structure of [Ni(pmdien)(ttcH)] was determined. The nickel atom is penta-coordinated by three N atoms of pmdien, and by S and N atoms of trithiocyanurate(2–) anion. 相似文献
7.
Trávníček Zdeněk Walla Jan Kvítek Libor Šindelář Zdeněk Biler Martin 《Transition Metal Chemistry》1999,24(6):633-637
Nickel(II) xanthate complexes of general formula, [Ni(Rxa)2(L)] [R = i-Pr, i-Am, xa = OCS–
2, L = 4,7-diphenyl-1,10-phenanthroline(baphen), 4,4-dimethyl-2,2-bipyridyl (me2bpy), 2-9-dimethyl-1,10-phenanthroline(neo) or trans-1,2-diaminocyclohexane (dch)] and [Ni(Rxa)(cyclam)](Rxa) (= 1,4,8,11-tetraazacyclotetradecane) have been synthesized and characterized by elemental analyses, i.r. and electronic spectroscopy, magnetic and conductivity measurements. The complexes with cyclam were studied by cyclic voltammetry. Values of magnetic moments at room temperature lie within the 3.25–3.51 B.M. range and thus indicate the presence of two unpaired electrons, except for the complexes with cyclam, where the anomalous values of 1.76 and 1.74 B.M. were obtained in respect to the nickel(II) complexes. Magnetic susceptibility data for [Ni(i-Prxa)(cyclam)](i-Prxa) were measured over the 79–298 K range and indicate no exchange interaction between paramagnetic nickel(II) centres. 相似文献
8.
9.
10.
The review addresses swelling of polyelectrolyte multilayers in water. Different models for the determination of the water content are compared. It is clearly shown that voids under dry conditions present cavities for water which contribute to the water content of the multilayer in the swollen state. This so-called “void water” does not lead to any changes in thickness but in scattering length density during swelling. The “swelling water” leads to both changes in scattering length density and in thickness. Depending on the preparation conditions like the type polymers, polymer charge density, ionic strength and type of salt the ratio of “void water” differs between 1 and 15 vol.% while the amount of “swelling water” is of several ten's of vol.%. 相似文献