全文获取类型
收费全文 | 97篇 |
免费 | 2篇 |
专业分类
化学 | 63篇 |
力学 | 5篇 |
数学 | 13篇 |
物理学 | 18篇 |
出版年
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2013年 | 1篇 |
2012年 | 6篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1945年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 312 毫秒
1.
2.
V. Bhagavathy M. L. P. Reddy T. Prasada Rao A. D. Damodaran 《Journal of Radioanalytical and Nuclear Chemistry》1991,149(1):35-40
A method is described for the simultaneous multielement determination of yttrium and lanthanides at microgram level. This is based on the preconcentration of these lanthanides on to 1-(2-pyridylazo)-2-naphthol (PAN) modified naphthalene. The optimal conditions for quantitative preconcentration viz., pH, amount of PAN modified naphthalene, time of stirring and aqueous phase volume were systematically evaluated. The quantitation of lanthanides was carried out by energy dispersive X-ray fluorescence analyzer, employing241Am annular source, via their characteristic K X-rays. The developed procedure gave reliable results in the analysis of xenotime samples. 相似文献
3.
A synthesis of (±)-bakuchiol methyl ether, involving Claisen rearrangement of geranyl vinyl ether as the key step, is described. Further thermal reorganisation of the intermediate 3-vinyl-citronellal is discussed. 相似文献
4.
Mixed-ligand chelate extraction of Nd(III) into benzene with mixtures of thenoyltrifluoroacetone (HTTA) and bis-2-ethylhexyl sulphoxide (B2EHSO) or di-n-octyl sulphoxide (DOSO) or diphenyl sulphoxide (DPhSO) or trioctylphosphine oxide (TOPO) from thiocyanate solutions has been studied. A very high synergistic enhancement of the order 10(3) has been observed in these systems. Thus this mixed-ligand chelate system may be useful in the extraction and separation of Nd(III) from other metal ions. The mechanism of extraction can be explained by a simple chemically based model presented in this paper. 相似文献
5.
Lata Mathew Mundlapudi L. P. Reddy Tumkur R. Ramamohan Talasila Prasada Rao Chonatumatom S. P. Iyer Alathur D. Damodaran 《Mikrochimica acta》1997,127(1-2):125-128
This paper describes a sensitive spectrophotometric method for the determination of mercury, based on the flotation of a mercury iodide-brilliant green complex with cyclohexane at pH 5 and dissolution of the complex in acetone. The absorbance of the complex is measured at 625 nm. Beer's law is obeyed from 4–500 g/l of mercury. The method is highly sensitive ( = 5.96 × 105 1 mol–1 cm–1) and selective, as it is free from interferences by almost all cations and anions in the presence of EDTA. Furthermore, a two-level orthogonal array design as a chemometric method has been used for optimization of the various parameters involved. The method has been successfully applied to paper industry effluents. 相似文献
6.
A sensitive spectrophotometric method has been developed for the determination of ziram in water, vegetables and grains. The method is based on the dissociation of dithiocarbamate complex of zinc with thiocyanate and rhodamine 6G at pH 4 to form a pink coloured complex that is stabilized by gelatin. The method is simple and Beer's law is obeyed over the concentration range of 0.05-1 ppm of ziram. The method is free from interference of similar dithiocarbamate fungicides containing Mn(2+) and Fe(3+) ions. 相似文献
7.
Damodaran S 《Analytical and bioanalytical chemistry》2003,376(2):182-188
A new circular dichroism (CD) spectroscopy technique for studying conformational changes in proteins in situ at the air-water interface is described. By using this technique, conformations of four proteins, viz., beta-casein, bovine serum albumin (BSA), lysozyme, and fibrinogen in the adsorbed state at the air-water interface have been studied. beta-Casein, which is predominantly in a disordered state in solution, assumes a beta-sheet conformation at the air-water interface. On the other hand, lysozyme and fibrinogen, which are alpha+beta-type proteins in solution, become beta-type proteins by completely transforming their alpha-helix structure into beta-sheets. Bovine serum albumin, which is an alpha-type protein in solution, loses its alpha-helix and becomes a disordered protein at the air-water interface. The results indicated that during unfolding and film formation at the interface, structural changes in proteins, regardless of their initial native state, follow the course of increasing beta-sheet and disordered structure and decreasing alpha-helix content. Although this seems to be the general trend, the exceptional case of BSA suggests, however, that this is not universal. 相似文献
8.
Priyadarsini Sreenivasan Jijo Wilson Prabha Damodaran Nair Lynda Velutheril Thomas 《先进技术聚合物》2020,31(5):1139-1149
This work reports a novel fabrication technique for development of channels on paper‐based microfluidic devices using the syringe module of a 3D printing syringe–based system. In this study, printing using polycaprolactone (PCL)‐based ink (Mw 70 000‐90 000) was employed for the generation of functional hydrophobic barriers on Whatman qualitative filter paper grade 1 (approximate thickness of 180 μm and pore diameter of 11 μm), which would effectively channelize fluid flow to multiple assay zones dedicated for different analyte detection on a microfluidic paper‐based analytical device (μPAD). The standardization studies reveal that a functional hydrophilic channel for sample conduction fabricated using the reported technique can be as narrow as 460.7 ± 20 μm and a functional hydrophobic barrier can be of any width with a lower limit of about 982.2 ± 142.75 μm when a minimum number of two layers of the ink is extruded onto paper. A comparison with the hydrodynamic model established for writing with ink is used to explain the width of the line printed by this system. A fluid flow analysis through a single channel system was also carried out to establish its conformity with the Washburn model, which governs the fluid flow in two‐dimensional μPAD. The presented fabrication technique proves to be a robust strategy that effectively taps the advantages of this 3D printing technique in the production of μPADs with enhanced speed and reproducibility. 相似文献
9.
Experimental parameters governing π-electrons participation during photolysis of citronellyl iodide have been investigated. Photoproducts resulting from irradiation of 2,3-dihydro-6(Z)- and 2,3-dihydro-6(E)-farnesyl iodides have been characterised. 相似文献
10.
Gareth AD Hardy Nesrina Imami Mark R Nelson Ann K Sullivan Ron Moss Marlén MI Aasa-Chapman Brian Gazzard Frances M Gotch 《Journal of immune based therapies and vaccines》2007,5(1):6-12