全文获取类型
收费全文 | 490篇 |
免费 | 48篇 |
出版年
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 24篇 |
2012年 | 30篇 |
2011年 | 22篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 30篇 |
2007年 | 27篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 17篇 |
2003年 | 31篇 |
2002年 | 23篇 |
2001年 | 23篇 |
2000年 | 19篇 |
1999年 | 21篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 15篇 |
1991年 | 6篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 6篇 |
1963年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有538条查询结果,搜索用时 15 毫秒
531.
532.
V Baumans S J Dieleman H S Wouterse L van Tol G Dijkstra C J Wensing 《Journal of reproduction and fertility》1985,73(1):21-25
Serum testosterone concentrations ranged from 0.24 to 1.45 nmol/l between Day 53 post coitum (p.c.) until Day 40 post partum (p.p.) and did not show variations that could be correlated with the process of testicular descent. The intratesticular androgen appeared to be mainly testosterone, its concentration being about 5000-fold higher than that in serum whereas 5 alpha-dihydrotestosterone could not be demonstrated. The intratesticular testosterone concentration at the initiation of gubernacular regression (Day 0) was apparently, but not significantly, higher than at Day 49 p.c. and at Day 40 p.p. The ability of the neonatal canine testis to synthesize testosterone was indicated by increased serum testosterone concentrations after hCG stimulation. 相似文献
533.
Veniero Lenzi Piet J. Driest Dirk J. Dijkstra Marta M. D. Ramos Luis S. A. Marques 《Molecular simulation》2019,45(3):207-214
Aliphatic diisocyanates and their derivatives are key liquid components in the industrial processing of polyurethane materials. In particular, for the synthesis of crosslinked polyurethane materials, the higher functionality molecules obtained by reacting three -or more- diisocyanates are of interest. However, despite their widespread application, the relation between molecular structure and macroscopic physical properties, in particular viscosity, is poorly understood in these systems. In this work, we introduce a new force field parameter set, GAFF-IC, based on the widely-used and versatile GAFF force field, meant for accurate predictions of physical properties of isocyanate-based molecular liquids. The new parameters allow to predict the vaporization enthalpies and densities of several isocyanate-based molecules, which are found in excellent agreement with the available experimental data. The effectiveness and transferability of the improved parameters is verified by calculating the viscosities of several isocyanates, isocyanate dimers (uretdiones) and isocyanate trimers (isocyanurates), resulting in accurate viscosity predictions in excellent agreement with experimental values. 相似文献
534.
Jan Bauer Sigrid R. Ruuls Ingeborg Huitinga Christine D. Dijkstra 《The Histochemical journal》1996,28(2):83-97
Summary In this review the role of various subpopulations of macrophages in the pathogenesis of experimental autoimmune encephalomyetitis
is discussed. Immunohistochemistry with macrophage markers shows that in this disease different populations of macrophages
(i.e. perivascular cells, microglia and infiltrating blood-borne macrophages) are present in the central nervous system. These
subpopulations partially overlap in some functional activity while other activities seem to be restricted to a distinct subpopulation,
indicating that these subpopulations have different roles in the pathogenesis of encephalomyelitis. The studies discussed
in this review reveal that immunocytochemical and morphological studies, combined with new techniques such asin situ nick translation and experimental approaches like the use of bone marrow chimeras and macrophage depletion techniques, give
valuable information about the types and functions of cells involved in central nervous system inflammation. The review is
divided in three parts. In the first part the experimental autoimmune encephalomyelitis model is introduced. The second part
gives an overview of the origin, morphology and functions of the various subpopulations. In the third part the role of these
subpopulations is discussed in relation to the various stages (i.e. preclinical, clinical and recovery) of the experimental
disease. 相似文献
535.
Influence of temperature on the number of Legionella pneumophila in hot water systems 总被引:4,自引:0,他引:4
The occurrence of legionella in the hot water systems of two buildings (A and B) was investigated in relation to the water temperature. The peripheral parts of both hot water systems were found to be colonized by these organisms. A temperature of 60 degrees C in the hot water mains returning from the building eliminated legionellas from the mains as well as from the peripheral taps and showers. Legionellas could be isolated from taps, showers and the mains when the temperature in the return mains was kept at 54 degrees C. The hot water systems could not be completely decontaminated by raising the hot water temperature in the return mains to 70 degrees C combined with flushing all the taps and showers. It is suggested that failure to decontaminate the systems is due to dead ends in the pipeline network, which are not reached by the hot water and that these dead ends are the source for recolonization of the systems. 相似文献
536.
Dries B.A de Bont Gerard D.H Dijkstra Jack A.J den Hartog Rob M.J Liskamp 《Bioorganic & medicinal chemistry letters》1996,6(24):1626-3040
Using Boc or Fmoc-protected β-substituted aminoethanesulfonyl chlorides (2-substituted taurylchlorides) the solid-phase synthesis of dipeptidosulfonamides as well as peptidosulfonamide containing peptides derived from Leu-enkephalin is described. The binding activity of the peptidosulfonamide YGGFL derivatives is reported. 相似文献
537.