全文获取类型
收费全文 | 88篇 |
免费 | 3篇 |
国内免费 | 17篇 |
专业分类
化学 | 59篇 |
晶体学 | 5篇 |
力学 | 5篇 |
综合类 | 2篇 |
数学 | 10篇 |
物理学 | 27篇 |
出版年
2024年 | 1篇 |
2022年 | 4篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 12篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 7篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有108条查询结果,搜索用时 0 毫秒
41.
Dezhong Liu Kang Chen Aifeng Yin Kai Ge Lihua Nie Shouzhuo Yao 《Analytica chimica acta》1996,320(2-3):245-254
Theory and characteristics of the surface acoustic wave (SAW)/impedance sensor system in electrolyte solution are reported. This kind of sensor was constructed by a 62-MHz SAW resonator and a pair of conductive electrodes in series. By using the circuit network analysis theory, two oscillation equations were derived and used to explain the frequency-shift response to solution conductance. Results showed that the sensor possesses high sensitivity to the solution conductivity and can be applied to conductivity measurements in solution. Its sensitivity and accuracy could be improved in the presence of a large amount of unreacting foreign electrolytes. The sensor was successfully applied to four types of titration (acid-base, precipitation, oxidation-reduction and compleximetric titration) by monitoring the frequency-shift response. Factors influencing the frequencimetric titration curve were also investigated. Analytes at levels down to 1 × 10−5 M could be determined by the proposed titration technique. The total acidity in several food samples was determined and the results were consistent with those obtained by conventional methods. 相似文献
42.
Pingxuan Jiao Shouxin Wang Shuobin Liang Man Li Qianqian Gao Dezhong Ji Yingying Chen Haiwei Li Fuxiang Ran Yongmin Zhang Lihe Zhang Demin Zhou Sulong Xiao 《中国化学快报》2019,30(3):690-693
Four water-soluble β-CD-pentacyclic triterpene conjugates were synthesized via ester and amide linkages. All the conjugates showed lower hydrophobicity (AlogP) than their parent. 相似文献
43.
Blood oxygenation level-dependent (BOLD) contrast-based functional magnetic resonance imaging (fMRI) has been widely utilized to detect brain neural activities and great efforts are now stressed on the hemodynamic processes of different brain regions activated by a stimulus. The focus of this paper is the comparison of Gamma and Gaussian dynamic convolution models of the fMRI BOLD response. The convolutions are between the perfusion function of the neural response to a stimulus and a Gaussian or Gamma function. The parameters of the two models are estimated by a nonlinear least-squares optimal algorithm for the fMRI data of eight subjects collected in a visual stimulus experiment. The results show that the Gaussian model is better than the Gamma model in fitting the data. The model parameters are different in the left and right occipital regions, which indicate that the dynamic processes seem different in various cerebral functional regions. 相似文献
44.
J Yu C Geng L Zheng Z Ma T Tan X Wang Q Yan D Shen 《Langmuir : the ACS journal of surfaces and colloids》2012,28(34):12681-12689
Nanosphere lithography (NSL) has been regarded as an inexpensive, inherently parallel, high-throughput, materials-general approach to the fabrication of nanoparticle arrays. However, the order of the resulting nanoparticle array is essentially dependent on the quality of the colloidal monolayer mask. Furthermore, the lateral feature size of the nanoparticles created using NSL is coupled with the diameter of the colloidal spheres, which makes it inconvenient for studying the size-dependent properties of nanoparticles. In this work, we demonstrate a facile approach to the fabrication of a large-area, transferrable, high-quality latex colloidal mask for nanosphere lithography. The approach is based on a combination of the air/water interface self-assembly method and the solvent-vapor-annealing technique. It enables the fabrication of colloidal masks with a higher crystalline integrity compared to those produced by other strategies. By manipulating the diameter of the colloidal spheres and precisely tuning the solvent-vapor-annealing process, flexible control of the size, shape, and spacing of the interstice in a colloidal mask can be realized, which may facilitate the broad use of NSL in studying the size-, shape-, and period-dependent optical, magnetic, electronic, and catalytic properties of nanomaterials. 相似文献
45.
46.
确立了一类分块矩阵M11 M12 XM21 M22 M23Y M32 M33的最大秩公式,其中,X和Y是两个受限于四元数线性矩阵方程A_1X=C_1,XB_1=C_2,A_3XB_3=C_3,A_2Y=D_1,YB_2=D_2.的变量矩阵。作为该公式的一项应用,我们推导出上述矩阵方程解集等同于另一四元数二次矩阵方程组解集的条件。 相似文献
47.
Wenlin Zhang Xiaoqing Wang Guangqiu Shen Dezhong Shen 《Crystal Research and Technology》2012,47(2):163-168
A single crystal of Te2V2O9 with dimensions of 15×15×5 mm3 has been grown by the top‐seeded growth method. Infrared and transmission spectra indicate the transmission cutoff wavelength of Te2V2O9 crystal is about 620 nm in visible region and 6.2 μm in infrared region. In addition, band structure and density of states calculations of Te2V2O9 were carried out using the total‐energy code CASTEP based on density functional theory. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
48.
Journal of Fluorescence - Upconversion nanoparticles (UCNPs) have achieved considerable success in protein sensing in vitro. And aptamer is one of the most frequently used biomolecules to modify... 相似文献
49.
Li Ao Xu Dezhong Zhang Mengnan Wu Shengzhong Li Yu Sun Weisheng Zhou Yonghui Madyan Omar Abo Fan Mizi Rao Jiuping 《Cellulose (London, England)》2022,29(3):2017-2032
Cellulose - This paper develops a novel paper additive for effectively recycling old corrugated container (OCC) by functionalizing nanocellulose (NC) with diethylenetriaminepentaacetic acid (DTPA)... 相似文献
50.
Recently, B. Chow and R.S. Hamilton [3] introduced the cross curvature flow on 3-manifolds. In this paper, we analyze two
interesting examples for this new flow. One is on a square torus bundle over a circle, and the other is on a S2 bundle over a circle. We show that the global flow exists in both cases. However, on the former the flow diverges at time
infinity, and on the latter the flow converges at time infinity.
Mathematics Subject Classification (1991) 53C44 相似文献