排序方式: 共有34条查询结果,搜索用时 15 毫秒
11.
The present study investigates the green synthesis of stable silver nanoparticles using Juniperus communis leaf aqueous extract at room temperature. Synthesized silver nanoparticles (AgNPs) were characterized with different techniques such as UV–vis spectroscopy, Fourier transforms infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM-EDAX) and electrochemical method. Photocatalytic and anti-bacterial activities of synthesized AgNPs are evaluated based on the obtained result showed an efficient inhibition growth for gram negative P. Aeruginosa, E. Coli, and gram positive bacteria S.aureus. The AgNPs exhibited an excellent photocatalytic activity toward the degradation of methylene blue both indoor and outdoor, under sunlight, an efficiency of 95% was achieved. As an easy and environmentally friendly process, AgNPs based on Juniperus communis leaf extract could be applied for the degradation of pollutants and wastewater treatment. 相似文献
12.
This paper is devoted to the study of large deviation behavior in the setting of the estimation of the regression function on functional data. A large deviation principle is stated for a process Z n , defined below, allowing to derive a pointwise large deviation principle for the Nadaraya- Watson-type l-indexed regression function estimator as a by-product. Moreover, a uniform over VC-classes Chernoff type large deviation result is stated for the deviation of the l-indexed regression estimator. 相似文献
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14.
Djamal Bouzida Paul A. Rejto Sandra Arthurs Anthony B. Colson Stephan T. Freer Daniel K. Gehlhaar Veda Larson Brock A. Luty Peter W. Rose Gennady M. Verkhivker 《International journal of quantum chemistry》1999,72(1):73-84
We present the results of molecular docking simulations with HIV‐1 protease for the sb203386 and skf107457 inhibitors by Monte Carlo simulated annealing. A simplified piecewise linear energy function, the standard AMBER force field, and the AMBER force field with solvation and a soft‐core smoothing component are employed in simulations with a single‐protein conformation to determine the relationship between docking simulations with a simple energy function and more realistic force fields. The temperature‐dependent binding free energy profiles of the inhibitors interacting with a single protein conformation provide a detailed picture of relative thermodynamic stability and a distribution of ligand binding modes in agreement with experimental crystallographic data. Using the simplified piecewise linear energy function, we also performed Monte Carlo docking simulations with an ensemble of protein conformations employing preferential biased sampling of low‐energy protein conformations, and the results are analyzed in connection with the free energy profiles. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 72: 73–84, 1999 相似文献
15.
This paper addresses the problem of open shop scheduling on two machines with resources constraints. In the context of our study, in order to be executed, a job requires first, for its preparation for a given period of time, a number of resources which cannot exceed a given resource capacity. Then, it goes onto its execution while the resources allocated to it become available again. We seek a schedule that minimizes the makespan. We first prove the $\mathcal{N}\mathcal{P}$ -hardness of several versions of this problem. Then, we present a well solvable case, lower bounds, and heuristic algorithms along with an experimental study. 相似文献
16.
Zerrouki D Rotenberg B Abramson S Baudry J Goubault C Leal-Calderon F Pine DJ Bibette J 《Langmuir : the ACS journal of surfaces and colloids》2006,22(1):57-62
We describe a six-step method for making colloidal clusters of 2, 3, or 4 silica particles with a radius of 1.2 microm. This method, originally described by Manoharan et al. (Manoharan, V. N.; Elsesser, M. T.; Pine, D. J. Science 2003, 301, 483), is based on the encapsulation of silica spheres in emulsion droplets. The originality of our work lies in the preparation of monodisperse emulsions, which allows us to obtain some high yields of small aggregates over a wide range of conditions. Using optical microscopy and disk centrifugation, we show that the relative fractions of 2, 3, and 4 particle aggregates are controlled by the emulsification conditions, particularly the concentration of silica in the dispersed phase. Our best yields are obtained using low to moderate shear rates, a highly viscous continuous phase, and intermediate amounts of silica. The sedimentation of the colloidal solution into a gradient of concentration leads to aqueous suspensions of identical clusters. Since the overall process can easily be scaled up, large quantities of identical clusters may be prepared, which should allow the thermodynamic properties of these new colloidal objects to be measured for the first time. These nonspherical particles could serve as building blocks for more complex assemblies, such as colloidal crystals which could find applications as photonic materials. 相似文献
17.
Bounding the optimum for the problem of scheduling the photographs of an Agile Earth Observing Satellite 总被引:1,自引:0,他引:1
Djamal Habet Michel Vasquez Yannick Vimont 《Computational Optimization and Applications》2010,47(2):307-333
The problem of managing an Agile Earth Observing Satellite consists of selecting and scheduling a subset of photographs among a set of candidate ones that
satisfy imperative constraints and maximize a gain function. We propose a tabu search algorithm to solve this NP-hard problem.
This one is formulated as a constrained optimization problem and involves stereoscopic and time window visibility constraints;
and a convex evaluation function that increases its hardness. To obtain a wide-ranging and an efficient exploration of the
search space, we sample it by consistent and saturated configurations. Our algorithm is also hybridized with a systematic
search that uses partial enumerations. To increase the solution quality, we introduce and solve a secondary problem; the minimization
of the sum of the transition durations between the acquisitions. Upper bounds are also calculated by a dynamic programming
algorithm on a relaxed problem. The obtained results show the efficiency of our approach. 相似文献
18.
Aissa Gacemi Djamal Benbertal Muriel Bagieu‐Beucher Amlie Lecchi Alain Mosset 《无机化学与普通化学杂志》2003,629(14):2516-2520
Single crystals of NH4[HgCl2(SCN)] ( 1 ) and NH4[HgCl(SCN)2] ( 2 ) are obtained by slow evaporation of ethanol solutions of HgCl2 and NH4SCN or Hg(SCN)2 and NH4Cl. 1 crystallizes in the monoclinic space group P21 (a = 9.297(1), b = 4.171(1), c = 9.198(1)Å, β = 92.827(5)°). The structure consists in HgCl2(SCN) linear chains, extending along the twofold axis, connected through the ammonium ions. 2 crystallizes in the monoclinic space group C2/c (a = 7.088(1), b = 19.986(2), c = 5.958(1)Å, β = 100.718(5)°). The structure consists of HgCl(SCN)2 molecules connected through the ammonium ions. The second order non linear optical properties of 1 are discussed. 相似文献
19.
Single crystals of Cd(IO3)2·H2O are obtained by slow evaporation of aqueous solutions of CdCl2 and KIO3. This compound crystallizes in the triclinic space group P1¯ [a = 7.119(2), b = 7.952(2), c = 6.646(2)Å, α = 102.17(2)°, β = 114.13(2)°, γ = 66.78(4)°]. The structure consists in Cd — (μ2‐O)2 — Cd dimers with a metal — metal distance of 3.74Å. These dimers are connected through two iodate bridges resulting in layers parallel to the (010) plane. The 3D linkage is ensured by I1 — O1 long bonds (2.775Å). 相似文献
20.
In this paper, we investigate functional large deviation behaviors of some nonparametric function estimates. As a first step,
we define a a vector process W
n
and study its large deviation behavior in the space L
1×L
1×L
1 with respect to the weak convergence topology. As by-products, we derive large deviation principles in the L
1-space equipped with the weak convergence topology simultaneously for several density and regression estimators built up using
the delta-sequence estimation method. 相似文献