全文获取类型
收费全文 | 16208篇 |
免费 | 10篇 |
国内免费 | 2篇 |
专业分类
化学 | 15745篇 |
晶体学 | 19篇 |
力学 | 32篇 |
数学 | 225篇 |
物理学 | 199篇 |
出版年
1987年 | 141篇 |
1985年 | 186篇 |
1984年 | 188篇 |
1982年 | 128篇 |
1980年 | 313篇 |
1979年 | 237篇 |
1978年 | 1035篇 |
1977年 | 796篇 |
1976年 | 218篇 |
1975年 | 118篇 |
1972年 | 129篇 |
1970年 | 129篇 |
1969年 | 114篇 |
1968年 | 208篇 |
1967年 | 177篇 |
1966年 | 222篇 |
1965年 | 255篇 |
1964年 | 228篇 |
1963年 | 175篇 |
1962年 | 347篇 |
1961年 | 169篇 |
1960年 | 221篇 |
1959年 | 216篇 |
1958年 | 216篇 |
1957年 | 161篇 |
1956年 | 238篇 |
1955年 | 234篇 |
1954年 | 168篇 |
1943年 | 161篇 |
1940年 | 122篇 |
1939年 | 162篇 |
1938年 | 174篇 |
1937年 | 230篇 |
1936年 | 214篇 |
1935年 | 231篇 |
1934年 | 184篇 |
1933年 | 250篇 |
1932年 | 136篇 |
1931年 | 140篇 |
1930年 | 216篇 |
1928年 | 154篇 |
1927年 | 153篇 |
1913年 | 127篇 |
1912年 | 117篇 |
1911年 | 120篇 |
1909年 | 116篇 |
1907年 | 117篇 |
1905年 | 130篇 |
1902年 | 115篇 |
1890年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
1.
Formation of porous polymer morphology by microsyneresis during divinylbenzene polymerization 下载免费PDF全文
Libuše Hanková Ladislav Holub Karel Jeřábek 《Journal of Polymer Science.Polymer Physics》2015,53(11):774-781
This article describes the investigation of the importance of various reaction conditions on microsyneretic pore formation during polymerization of divinylbenzene (DVB) under so‐called “solvothermal” conditions. To induce microsyneretic pore formation, the most important parameter is an unusually high dilution of monomers with a “good” porogen solvating the polymer chains. High dilution and solvation of the growing poly(DVB) chains promote the prolongation of the polymer chains rather than their interconnection by crosslinking. Consequently, when the polymer gel density reaches the point where syneresis starts, the polymer network is geometrically too extensive to be broken up into precipitating entities and, instead, porogen droplets are formed within the continuous polymer gel. The pore geometry created by microsyneresis offers high surface area in wide mesopores and hence, high capacity for supporting functional groups or reactions with much better accessibility than narrow pores between polymer microspheres produced by macrosyneresis in conventional styrenic polymer supports. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 774–781 相似文献
2.
3.
4.
The interaction between azathioprine (AZ) and bovine serum albumin (BSA) is mainly due to hydrophobic binding according to the dependence of the binding constant on the ionic strength obtained by equilibrium dialysis. The binding constant and partition coefficient of AZ were smaller than those of warfarin, phenylbutazone and ibuprofen. Little variation in the proton chemical shift of AZ was observed whether there was an absence or presence of BSA (7.25 x 10(-5) M). The spin-lattice relaxation time (T1) of AZ decreased in the presence of BSA to 6-22%. The spin-spin relaxation rate (1/T2) of AZ increased 16-24 times for the methyl group and the imidazole ring and 8-13 times for the purine ring in the presence of BSA. The ratio of the spin-spin relaxation rate of the free AZ to the bound AZ ((1/T2)b/(1/T2)f) of the methyl group and the imidazole ring was 2-3 times larger than that of the purine ring. The binding of AZ to BSA was concluded to be mainly at the methyl group on the imidazole ring of AZ. 相似文献
5.
Ohne Zusammenfassung 相似文献
6.
Ohne Zusammenfassung 相似文献
7.
Ohne Zusammenfassung 相似文献
8.
E. Ritsert und W. Lenz 《Fresenius' Journal of Analytical Chemistry》1889,28(1):749-750
Ohne Zusammenfassung 相似文献
9.
J. Krause und F. Umland 《Fresenius' Journal of Analytical Chemistry》1989,335(7):791-795
Summary This paper presents some applications of cyclic voltammetry at the interface of two immiscible electrolyte solutions by means of an experimental set-up described in a former publication. When using special sample preparation good results are obtained for the determination of iodide and quinine in pharmaceutical products as well as for the determination of quinine in tonic water and dodecylsulfate in a tooth-salt.
Herrn Prof. Dr. Günther Tölg zum 60. Geburtstag gewidmet 相似文献
Herrn Prof. Dr. Günther Tölg zum 60. Geburtstag gewidmet 相似文献
10.
H. Moers H. Klewe-Nebenius G. Pfennig und H. J. Ache 《Fresenius' Journal of Analytical Chemistry》1987,329(2-3):361-366
Summary The adsorption of gaseous molecular iodine on clean silver surfaces proceeds in the first stage by dissociative chemisorption. After the formation of half a monolayer of chemisorbed iodine atoms the formation of silver iodide begins, which forms a very regular overlayer on top of the substrate. Both iodine species can be distinguished due to a difference in chemical shift of the M4N4, 5N4, 5-Auger transitions. After completion of this overlayer further iodine uptake is slowed down significantly. Above an overlayer thickness of about 10 nm a further progress of the reaction cannot be followed anymore due to the limited information depth of XPS. 相似文献