全文获取类型
收费全文 | 102篇 |
免费 | 9篇 |
专业分类
化学 | 74篇 |
晶体学 | 1篇 |
力学 | 9篇 |
数学 | 12篇 |
物理学 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有111条查询结果,搜索用时 15 毫秒
71.
72.
73.
Asker E Uzkara E Zeybek O 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1731-1738
Series of 1,n-dicarbazolylalkanes and 1,n-di(3-methylcarbazolyl)alkanes (where n=1-5) were synthesized and the molar extinction coefficients, equilibrium constants, enthalpies, and entropies of their charge-transfer (CT) complexes with the π-acceptors p-chloranil, tetracyanoethylene, and tetracyanoquinodimethane were investigated. 1,n-Di(3-methylcarbazolyl)alkanes formed CT complexes with higher equilibrium constants, more negative enthalpies and entropies than 1,n-dicarbazolylalkanes. Vibrational spectra of CT complexes of one of the donor molecules (1,4-dicarbazolylbutane) with all three acceptors were compared. 相似文献
74.
In the present study a chitosan/ionic liquid modified pencil graphite electrode (CHIT‐IL‐PGEs) was developed for the first time for enhanced electrochemical monitoring of nucleic acid, and the interaction of the anticancer drug Mitomycin C (MC) and calf thymus double stranded DNA (dsDNA) by measuring the oxidation signals of MC and guanine in the same voltammetric scale. Differential pulse voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to evaluate the performance of the CHIT‐IL based biosensor on electrochemical monitoring of DNA, and drug‐DNA interaction. The experimental parameters, IL, dsDNA and MC concentration and the interaction time were then optimized. 相似文献
75.
M. C. Ece 《Heat and Mass Transfer》2005,41(4):291-297
A similarity analysis was performed to investigate the laminar free-convection boundary-layer flow in the presence of a transverse magnetic field over a wedge with mixed thermal boundary conditions. Boundary-layer velocity and temperature profiles were determined numerically for various values of the Prandtl number and the magnetic parameter. The results show that the magnetic field retards the velocity profiles and increases the skin friction. The temperature profiles were expanded with increasing values of the magnetic parameter resulting in higher surface temperatures. A transformation relating the similarity solutions of the boundary-layer velocity and temperature profiles associated with different values of the mixed thermal boundary condition parameter was obtained. 相似文献
76.
Buckling and vibration of a rectangular isotropic plate which has non-ideal simply supported boundary conditions along one of its edges are investigated. It is assumed that one of the edges of the plate allows a small non-zero deflection and a small non-zero moment. Externally applied in-plane loads are considered to be parallel and perpendicular to the edge where non-ideal boundary conditions are present in the buckling problem. Analytical solutions of the buckling and vibration problems are obtained by using the Linshtead–Poincare perturbation technique. Improved buckling loads and natural frequencies are determined for various values of the aspect ratio of the plate. 相似文献
77.
Servet Tural Bilsen Tural Mehmet Şakir Ece Evren Yetkin Necati Özkan 《Journal of separation science》2014,37(22):3370-3376
The isolation of β‐nicotinamide adenine dinucleotide is of great importance since it is widely used in different scientific and technologic fields such as biofuel cells, sensor technology, and hydrogen production. In order to isolate β‐nicotinamide adenine dinucleotide, first 3‐aminophenyboronic acid functionalized magnetic nanoparticles were prepared to serve as a magnetic solid support and subsequently they were used for reversible adsorption/desorption of β‐nicotinamide adenine dinucleotide in a batch fashion. The loading capacity of the 3‐aminophenyboronic acid functionalized nanoparticles for β‐nicotinamide adenine dinucleotide adsorption was 13.0 μmol/g. Adsorption kinetic and isotherm studies showed that the adsorption process followed a pseudo‐second‐order kinetic model and the experimental data can be represented using Langmuir isotherm model. The 3‐aminophenyboronic acid functionalized magnetic nanoparticles were proposed as an alternative support for the β‐nicotinamide adenine dinucleotide purification. The results elucidated the significance of magnetic separation as a fast, relatively simple, and low‐cost technique. Furthermore, the magnetic supports can be reused at least five times for purification processes. 相似文献
78.
The purpose of this study is to describe the interfacial interactions in terms of stress distributions on short fibers in
fiber-matrix unit-cell models. The fiber and matrix are subjected to tensile loading. The study consists of three main parts.
First, fiber-matrix cell segments are modeled using a 3D finite-element analysis (FEA) with ANSYS. Three different finite-element
geometrical unit-cell models are generated in order to simulate the Cox analytical model: a fiber-matrix combination, a single
fiber, and a single matrix element. The second part contains the results of 3D FE analyses, which are applied to the Cox formulations
by using a computer program developed. In the last part, the analytical solutions for distributions of normal and shear stresses
are investigated. Cox 2D linear elasticity solutions, together with finite-element ones, are presented in detail in graphs.
The interfacial interactions between the fibers and matrix are also discussed considering the relative changes in the distributions
of normal and shear stresses.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 4, pp. 505–520, July–August, 2008. 相似文献
79.
80.
Tuncer Hkelek Elif Ece Kaya Zeynel Kl 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o278-o280
The title compound, C22H30N2O2·H2O, is an 18‐membered diaza‐crown ether ligand containing two ether O and two aza N atoms. In the macrocyclic ring, the mean N⋯O distance is 4.526 (4) Å. The macrocyclic inner‐hole size, estimated as twice the mean distance of the donor atoms from their centroid, is ∼2.29 Å. 相似文献