全文获取类型
收费全文 | 134篇 |
免费 | 2篇 |
国内免费 | 13篇 |
专业分类
化学 | 91篇 |
晶体学 | 1篇 |
力学 | 3篇 |
综合类 | 4篇 |
数学 | 5篇 |
物理学 | 45篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 1篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 4篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有149条查询结果,搜索用时 15 毫秒
31.
32.
33.
Jens Fischer Renate Ulbrich Romana Ziemann Sabinf Flatau Peter Wolna Martin Schleiff Volker Pluschke Alfred Schellenberger 《Applied biochemistry and biotechnology》1980,5(2):79-96
The thermal inactivation kinetics of chymotrypsin, trypsin, and—-amylase bound to silica, polyacrylamide, and polystyrene were studied at different temperatures. The inactivation curves were analyzed by a kinetic model, assuming a first-order reaction of differently stable enzyme fractions on the matrix. In all cases the assumption of two enzyme fractions with distinctly different inactivation constants was sufficient for describing the inactivation progress (standard deviations between experimental and calculated inactivation curves, 1-4%). Both the inactivation constants as well as the relative concentrations of the enzyme fractions were found to change in dependence on temperature. 相似文献
34.
Schicks JM Erzinger J Ziemann MA 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(10):2399-2403
It is generally accepted that Raman spectroscopic investigations of gas hydrates provide vital information regarding the structure of the hydrate, hydrate composition and cage occupancies, but most research is focused on the vibrational spectra of the guest molecules. We show that the shape and position of the Raman signals of the host molecules (H(2)O) also contain useful additional information. In this study, Raman spectra (200-4000 cm(-1)) of (mixed) gas hydrates with variable compositions and different structures are presented. The bands in the OH stretching region (3000-3800 cm(-1)), the O-H bending region (1600-1700 cm(-1)) and the O-O hydrogen bonded stretching region (100-400 cm(-1)) are compared with the corresponding bands in Raman spectra of ice Ih and liquid water. The interpretation of the differences and similarities with respect to the crystal structure and possible interactions between guest and host molecules are presented. 相似文献
35.
Al-films were prepared by quench-condensation from Al2O3-crucibles and W-boats, respectively and irradiated with 230 keV Al+-selfions at low temperatures (<15 K). Forsmall fluences (<5·1015 cm–2) the irradiation induced changes of the superconducting transition temperatureT
c
and the resistivity strongly depend on the chemical form of the oxygen incorporated into the films by the different preparation techniques. Forhigh fluences (>1016 cm–2) the behavior of the irradiated films is determined only by the integral oxygen content of the layers. The results are discussed qualitatively taking into account different physical processes during irradiation. 相似文献
36.
Capillary electrochromatography (CEC) using a neutral hydrophobic polymer-based monolithic column has been developed for classification of analytes based on their acidity and charges of group. The monolithic columns were prepared by in situ copolymerization of lauryl methacrylate and ethylene dimethacrylate without any charged monomers in the reaction mixture. The ionic analytes will only be driven by their electrophoretic mobilities and were separated on the basis of their differences in electrophoretic mobility and in hydrophobic interaction with the stationary phase. Only negatively or positively charged analyte (acid or basic) migrated toward detection window in a single run by applying negative or positive voltage. The CEC system was also applied for the analysis of basic drugs in human serum by internal standard method using acidic running buffer. The sample of human serum spiked with basic drugs was directly injected after a simple sample pretreatment. The calibration curves with regression coefficients (0.9995-0.9997) in the range of 0.318-80 microg/mL were obtained with the limits of detection being below 0.15 microg/mL. The intra- and inter-day precisions, determined as relative standard deviations, were less than 4.21%. 相似文献
37.
具有生物活性的有机硅化合物的研究(Ⅷ)——1-烷酰氧基杂氮硅三环的合成及抗癌活性的研究 总被引:1,自引:0,他引:1
报道了用1-溴代Silatrane合成1-烷酰氧基-2,8,9-三氧-5-氮-1-硅杂三环[3,3,3,0~(1.5]十一碳烷的新方法。讨论了反应条件对该类化合物合成的影响,用各种方法确证了产物的结构,对某些化合物进行了抗癌活性实验。 相似文献
38.
39.
G. Kästle H.-G. Boyen F. Weigl P. Ziemann S. Riethmüller C.H. Hartmann 《Phase Transitions》2013,86(4-5):307-313
The preparation and characterization of hexagonally ordered pure Au nanoparticles is described. Self-assembly of diblock copolymers in solution is the driving force which leads to micellar structures. Starting, for example, with Au-salt loaded inverse micelles, monomicellar arrays exhibiting a significant hexagonal order can be prepared with taylored intermicellar distances and structure heights on top of various substrates. In order to remove the polymer matrix and to finally obtain arrays of pure Au nanoparticles, the micelles are first exposed to an oxygen plasma followed by an annealing process. Special attention is given to the chemical state of the nanoparticles applying photoelectron spectroscopy to control all preparational steps. 相似文献
40.
Renan S. Ferrarini João V. Comasseto Alcindo A. Dos Santos 《Tetrahedron: Asymmetry》2009,20(17):2043-2047
The components of the pheromone blend of Mayetiola destructor, Drosophila mulleri, and Contarinia pisi were synthesized in high enantiomeric excess (99% ee) from a common enantiopure dianion prepared from an enantiopure hydroxytelluride. 相似文献