全文获取类型
收费全文 | 92篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
化学 | 51篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 25篇 |
物理学 | 18篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2019年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有97条查询结果,搜索用时 15 毫秒
91.
Sotirios E. Notaris 《BIT Numerical Mathematics》2002,42(2):440-446
We consider interpolatory quadrature formulae, relative to the Legendre weight function w(t) = 1 on [–1, 1], having as nodes the zeros of the nth degree Jacobi polynomial P
n
(, ) plus the points 1 and –1. We show that in specific domains of and gb the weights of these formulae are almost all positive, exceptions occurring only with the weights corresponding to 1 and –1. 相似文献
92.
93.
Carbotrap was added to a glass beads cryotrap in order to increase the retention of the very volatile two-carbon hydrocarbons, ethylene, ethane and acetylene. Indeed the obtained recoveries increased from 2 to 3% for ethylene, the poorest retained compound, from 7 to 20% for ethane and from 23 to 31% for acetylene between the glass beads only and the Carbotrap/glass beads cryotrap. The addition of the Carbotrap, however, decreased the obtained recovery of o-xylene by 22–46%, depending on the employed conditions. The smaller decrease was observed when the longer desorption time was employed. The variation of the temperature of desorption by 40°C had very little effect on the resulting recoveries. 相似文献
94.
Sotirios I. Marras Ioannis Zuburtikudis Costas Panayiotou 《European Polymer Journal》2007,43(6):2191-2206
Nano- and micro-composites of poly(l-lactic acid) (PLLA) with various loadings of natural and hexadecylamine-modified montmorillonite were prepared by the solvent casting method to study the effect of nanostructure on the thermomechanical properties of the hybrid materials. The changes on structure and surface of montmorillonite, induced by the ion-exchange modification process, were characterized by X-ray diffraction (XRD) analysis and zeta-potential determination, while the morphology of the hybrids and the dispersion of the clay into the polymer matrix were examined by XRD, transmission electron microscopy and atomic force microscopy. The results showed that, although at low clay content exfoliation dominates, for filler loadings greater than 5 wt% both exfoliation and intercalation of the clay filler are observed. Thermal degradation studies of the materials produced using thermogravimetry revealed the introduction of a small amount of organo-modified silicate significantly improves their thermal stability. Differential scanning calorimetry showed the thermal behavior of the polymer matrix strongly depends on the nature and content of the silicate filler. Scanning electron microscopy of the deformed surfaces affirmed a different deformation process mechanism between the two types of composites. 相似文献
95.
Vlachopoulou ME Tserepi A Petrou PS Gogolides E Kakabakos SE 《Colloids and surfaces. B, Biointerfaces》2011,83(2):1321-276
Treatment of poly(dimethylsiloxane) (PDMS) surfaces with SF(6) plasma results in the creation of high-surface-area nanotextured surfaces that considerably favour protein adsorption with respect to untreated ones. In order to employ such nanotextured surfaces as substrates for microarrays to be created and analysed using standard instrumentation, we fabricated thin PDMS films on top of standard low-cost microscope glass slides. The properties of both untreated and plasma-treated PDMS-coated slides towards spotting of protein solutions were evaluated in terms of spot signal intensity and homogeneity as well as of spot shape and size. It was found that the plasma-treated PDMS-coated glass slides provided highly homogeneous spots (mean intra-spot variation 7.6%) with spot signal intensity 6-times higher than that obtained using the untreated ones. In addition, comparison with commercially available polystyrene and aminosilanized-glass microarray slides showed that the proposed slides provided 3-times higher spot signal intensity and 2-times lower intra-spot signal variation. In addition, the implementation of long-aged-after-plasma-treatment nanotextured PDMS-coated glass slides provided spots whose shape and size matched those of the spotting tip. As a consequence, denser arrays of variable spot shape can be created using SF(6) plasma-treated PDMS-coated slides instead of standard microarray slides opening new potentials for bioanalytical applications. 相似文献
96.
S. Baskoutas C. Garoufalis A. F. Terzis 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,84(2):241-247
In the present theoretical study, the linear and third-order nonlinear optical absorption coefficients have been calculated
in GaAs/Ga1−x
Al
x
As inverse parabolic quantum wells (single and double) subjected to an external electric field. Our calculations are based
on the potential morphing method in the effective mass approximation. The systematic theoretical investigation contains results
with all possible combinations of the involved parameters, as quantum well width, quantum barrier width, Al concentration
at each well center and magnitude of the external electric field. Our results indicate that in most cases investigated, the
increase of the electric field blue-shifts the peak positions of the total absorption coefficient. In all cases studied it
became apparent that the incident optical intensity considerably affects the total absorption coefficient. 相似文献
97.
Dimitra Kourti Anastasia Kanioura Theodore Manouras Maria Vamvakaki Panagiotis Argitis Margarita Chatzichristidi Sotirios Kakabakos Panagiota Petrou 《Macromolecular bioscience》2023,23(1):2200301
Surfaces for guided cell adhesion and growth are indispensable in several diagnostic and therapeutic applications. Towards this direction, four diblock copolymers comprising polyethylene glycol (PEG) and poly(2-tetrahydropyranyl methacrylate) (PTHPMA) are synthesized employing PEG macroinitiators of different chain lengths. The copolymer with a 5000 Da PEG block and a PEG-PTHPMA comonomers weight ratio of 43–57 provides a film with the highest stability in the culture medium and the strongest cell repellent properties. This copolymer is used to develop a positive photolithographic material and create stripe patterns onto silicon substrates. The highest selectivity regarding smooth muscle cell adhesion and growth and the highest fidelity of adhered cells for up to 3 days in culture is achieved for stripe patterns with widths between 25 and 27.5 µm. Smooth muscle cells cultured on such patterned substrates exhibit a decrease in their proliferation rate and nucleus area and an increase in their major axis length, compared to the cells cultured onto non-patterned substrates. These alterations are indicative of the adoption of a contractile rather than a synthetic phenotype of the smooth muscle cells grown onto the patterned substrates and demonstrate the potential of the novel photolithographic material and patterning method for guided cell adhesion and growth. 相似文献