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81.
Liposomes play an important role in medical and pharmaceutical science as, nanoscale drug carriers. One of the most important features is their size and size distribution, influencing both their bio-distribution and their targeting efficiency to tumors and also therapeutic activity of liposomal antitumor drugs. In this study, the effect of preparation method and molecular interaction on size and shape of liposome was studied. The size and shape characterization of liposomes was performed by asymmetrical flow field-flow fractionation coupled online with multi-angle light scattering (AF4-MALS). The size distributions obtained by AF4-MALS were compared to mean particle sizes and size distribution measured with other standard method such as Photon Correlation Spectroscopy (PCS). Furthermore, the effect of molecular interaction (hydrophilic and hydrophobic model drugs) on liposomal structure was assessed.  相似文献   
82.
可见区分光光度法测量水体色度   总被引:1,自引:0,他引:1  
余潘  沈为民  黄杰  徐贲 《光学技术》2011,37(5):551-555
针对目前水质色度测量方法的局限性,采用分光光度法测量相关色度学参数,通过色度学参数与国家标准方法的色度值建立数值关系,从而测定水体的色度值.该方法不仅保证测量结果与现行国家标准测量结果一致,而且客观性强,稳定可靠,灵敏度更高,也更准确.克服了目视比色法需要水体与标准溶液色调一致的局限性,可以推广到其他色调的废水色度测量...  相似文献   
83.
We consider Bayesian estimation of the stress–strength reliability based on record values. The estimators are derived under the squared error loss function in the one parameter as well as two-parameter exponential distributions. The Bayes estimators are derived, in some cases in closed form, and their performance is investigated in terms of their bias and mean squared errors and compared with the maximum likelihood estimators. An illustrative example is given.  相似文献   
84.
主要研究差分方程a_1(z)f(x+1)+a_0(z)f(z)=F(z)的一个有穷级超越亚纯解f(z)与亚纯函数g(z)分担0,1,∞CM时的唯一性问题(其中a_(z),a0(z),F(z)为非零多项式,且满足a_1(z)+a_0(z)■0),得到f(x)≡g(z),或f(z)+g(z)≡f(z)g(z),或存在一个多项式β(z)=az+b_0和一个常数a_0满足e~(a_0)≠e~(b_0),使得f(z)=(1-e~(β(x)))/(e~(β(x))(e~(a_o-b_0)-1))与g(z)=(1-e~(β(x)))/(1-e~(b_o-a_0)),其中a(≠0),b_0为常数.  相似文献   
85.
We pose some problems on the Hadamard product and singular values of matrices.  相似文献   
86.
We give safety neighbourhoods for the necessary conditions in the change of the Jordan canonical form of a matrix under small perturbations. We also obtain the minimum distance from an n × n complex matrix which has less than k nonconstant invariant factors (2≤ kn) to the set of matrices which have more or equal to k. When k= 2, we get in particular the distance from a nonderogatory matrix to the set of derogatory matrices.  相似文献   
87.
This work establishes a strong uniqueness property for a class of planar locally integrable vector fields. A result on pointwise convergence to the boundary value is also proved for bounded solutions.Dedicated to Constantine Dafermos on his 60th birthdayWork supported in part by CNPq, FINEP, FAPESP and a Research Incentive Fund grant of Temple University.  相似文献   
88.
We consider some parametrized classes of multiple sums first studied by Euler. Identities between meromorphic functions of one or more variables in many cases account for reduction formulae for these sums.  相似文献   
89.
Limit theorems for numbers of near-records   总被引:1,自引:0,他引:1  
Observations occurring between successive record times and within a distance a > 0 of the current record value are called near-records. Limit theorems for the number ξ n (a) of near records are found for cases in which the parent distribution lies in a maximal domain of attraction and a is a function of n. Corollaries are indicated for numbers of near-k-records and sums of near-records. If the parent law is thin-tailed and a is constant, then a centered and normed version of logξ n (a) has a limit law under appropriate conditions.   相似文献   
90.
We improve upon the method of Zhu and Zhu [A method for directly finding the denominator values of rational interpolants, J. Comput. Appl. Math. 148 (2002) 341–348] for finding the denominator values of rational interpolants, reducing considerably the number of arithmetical operations required for their computation. In a second stage, we determine the points (if existent) which can be discarded from the rational interpolation problem. Furthermore, when the interpolant has a linear denominator, we obtain a formula for the barycentric weights which is simpler than the one found by Berrut and Mittelmann [Matrices for the direct determination of the barycentric weights of rational interpolation, J. Comput. Appl. Math. 78 (1997) 355–370]. Subsequently, we give a necessary and sufficient condition for the rational interpolant to have a pole.  相似文献   
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