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11.
12.
Lee MS Jang YL Huynh DP Huynh CT Lee Y Chae SY Kim SH Park TG Lee DS Jeong JH 《Macromolecular bioscience》2011,11(6):789-796
A biodegradable amphiphilic pentablock copolymer PAE‐PCL‐PEG‐PCL‐PAE with a pH‐sensitive unit was synthesized for use as a nontoxic, biodegradable carrier for gene delivery by forming nanocapsules entrapping nucleic acid drugs. The PAE block can interact with plasmid DNA to form polyelectrolyte complexes in an acidic environment. At physiological pH, the PAE blocks are deprotonated and form an insoluble skin, resulting in the formation of nanocapsules that encapsulate plasmid DNA. The surface charges of the nanocapsules became almost neutral at pH = 7.4, and their size ranged from 210 to 280 nm. The nanocapsule maintained most of its transfection efficiency even in the presence of serum. These nanocapsules are therefore potential carriers for systemic gene therapy.
13.
A.D. Kudriavtseva A.I. Sokolovskaia J. Gazengel N.Phu Xuan G. Rivoire 《Optics Communications》1978,26(3):446-448
The reconstruction of the exciting laser wave-front by the backward Stimulated Raman Scattering (S.R.S.) and Rayleigh Wing Scattering (S.W.R.S.) is observed in benzene and cyclohexane in the case of pico-second pulses. The characteristic properties of this reconstruction are different of those obtained in the nano-second range. 相似文献
14.
The problem of minimizing [(f)\tilde]=f+p{\tilde f=f+p} over some convex subset of a Euclidean space is investigated, where f(x) = x
T
Ax + b
T
x is strictly convex and |p| is only assumed to be bounded by some positive number s. It is shown that the function [(f)\tilde]{\tilde f} is strictly outer γ-convex for any γ > γ*, where γ* is determined by s and the smallest eigenvalue of A. As consequence, a γ*-local minimal solution of [(f)\tilde]{\tilde f} is its global minimal solution and the diameter of the set of global minimal solutions of [(f)\tilde]{\tilde f} is less than or equal to γ*. Especially, the distance between the global minimal solution of f and any global minimal solution of [(f)\tilde]{\tilde f} is less than or equal to γ*/2. This property is used to prove a roughly generalized support property of [(f)\tilde]{\tilde f} and some generalized optimality conditions. 相似文献
15.
H. X. Phu 《Numerical Functional Analysis & Optimization》2013,34(7-8):915-920
H. Minkowski proved C= convext C whenever C is a compact convex subset of a finite-dimensional linear space. If C is bounded but not closed, this representation does not hold anymore. In this case, we introduce the set of so-called γ-extreme points extγC of C and show C = convext γ C = raco extγ C, where raco M denotes the rational convex hull of M. 相似文献
16.
Hoang Xuan Phu 《Mathematical Methods of Operations Research》2008,67(2):207-222
A real-valued function f defined on a convex subset D of some normed linear space is said to be inner γ-convex w.r.t. some fixed roughness degree γ > 0 if there is a such that holds for all satisfying ||x
0 − x
1|| = νγ and . This kind of roughly generalized convex functions is introduced in order to get some properties similar to those of convex
functions relative to their supremum. In this paper, numerous properties of their supremizers are given, i.e., of such satisfying lim . For instance, if an upper bounded and inner γ-convex function, which is defined on a convex and bounded subset D of some inner product space, has supremizers, then there exists a supremizer lying on the boundary of D relative to aff D or at a γ-extreme point of D, and if D is open relative to aff D or if dim D ≤ 2 then there is certainly a supremizer at a γ-extreme point of D. Another example is: if D is an affine set and is inner γ-convex and bounded above, then for all , and if 2 ≤ dim D < ∞ then each is a supremizer of f.
相似文献
17.
We consider the parametric programming problem (Q
p
) of minimizing the quadratic function f(x,p):=x
T
Ax+b
T
x subject to the constraint Cx≤d, where x∈ℝ
n
, A∈ℝ
n×n
, b∈ℝ
n
, C∈ℝ
m×n
, d∈ℝ
m
, and p:=(A,b,C,d) is the parameter. Here, the matrix A is not assumed to be positive semidefinite. The set of the global minimizers and the set of the local minimizers to (Q
p
) are denoted by M(p) and M
loc
(p), respectively. It is proved that if the point-to-set mapping M
loc
(·) is lower semicontinuous at p then M
loc
(p) is a nonempty set which consists of at most ?
m,n
points, where ?
m,n
= is the maximal cardinality of the antichains of distinct subsets of {1,2,...,m} which have at most n elements. It is proved also that the lower semicontinuity of M(·) at p implies that M(p) is a singleton. Under some regularity assumption, these necessary conditions become the sufficient ones.
Received: November 5, 1997 / Accepted: September 12, 2000?Published online November 17, 2000 相似文献
18.
H. X. Phu 《Journal of Optimization Theory and Applications》1992,72(2):319-332
A macroeconomic model on the relation between economic growth and the environment is investigated with the aim of illustrating how the method of region analysis can be used in solving practical problems formulated as regular optimal control problems with state constraints.This paper was written when the author was invited by Professor R. Bulirsch to work at the Munich University of Technology with the assistance of the Alexander Von Humboldt Foundation. The author would like to express his sincere gratitude to the Alexander Von Humboldt Foundation and to Professor Bulirsch. 相似文献
19.
An analytical model for cross-Kerr nonlinearity in a four-level N-type atomic system with Doppler broadening 下载免费PDF全文
Dinh Xuan Khoa Nguyen Huy Bang Nguyen Le Thuy An Nguyen Van Phu Le Van Doai 《中国物理 B》2022,31(2):24201-024201
We present an analytical model for cross-Kerr nonlinear coefficient in a four-level N-type atomic medium under Doppler broadening.The model is applied to87 Rb atoms to analyze the dependence of the cross-Kerr nonlinear coefficient on the external light field and the temperature of atomic vapor.The analysis shows that in the absence of electromagnetically induced transparency(EIT)the cross-Kerr nonlinear coefficient is zero,but it is significantly enhanced when the EIT is established.It means that the cross-Kerr effect can be turned on/off when the external light field is on or off.Simultaneously,the amplitude and the sign of the cross-Kerr nonlinear coefficient are easily changed according to the intensity and frequency of the external light field.The amplitude of the cross-Kerr nonlinear coefficient remarkably decreases when the temperature of atomic medium increases.The analytical model can be convenient to fit experimental observations and applied to photonic devices. 相似文献
20.
Nguyen Nguyen Phuoc Nguyen Phu Thuy Nguyen Anh Tuan Le Thanh Hung Nguyen Trung Thanh Nguyen Thanh Nam 《Journal of magnetism and magnetic materials》2006
Exchange-biased CrMn/Co bilayers with various thicknesses of Co sputtered onto Si(1 0 0) substrates by the RF sputtering system have been studied. Double-shifted loops have been observed with the thickness of Co layer in a narrow range and become single-shifted loops after some cycles of measurement. Those results are interpreted as the association of positive and negative exchange bias. 相似文献