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151.
We presented a new logarithmic-quadratic proximal alternating direction scheme for the separable constrained convex programming problem. The predictor is obtained by solving series of related systems of non-linear equations in a parallel wise. The new iterate is obtained by searching the optimal step size along a new descent direction. The new direction is obtained by the linear combination of two descent directions. Global convergence of the proposed method is proved under certain assumptions. We show the O(1 / t) convergence rate for the parallel LQP alternating direction method.  相似文献   
152.
Blends of two linear polypropylenes (PP, having different molecular weights) were prepared to develop microporous membranes through melt extrusion followed by stretching. The role of high molecular weight chains on the row-nucleated lamellar crystallization was investigated. The orientation of crystalline and amorphous phases was measured by wide angle X-ray diffraction (WAXD) and Fourier transform infrared (FTIR). Long period spacing was obtained using small angle X-ray scattering (SAXS). The effects of annealing temperature and applied elongation during annealing on the crystallinity of the films were studied using differential scanning calorimetry (DSC). It was found that annealing at 140 °C contributed significantly to the perfection of the crystalline phase. Scanning electron microscopy (SEM) images of the membrane surface showed more pore density and uniform pore size as the amount of high molecular weight component increased. The addition of the high Mw PP improved the water vapor transmission rate (WVTR) of the membranes, indicating increased interconnectivity of the pores, which was also confirmed from cross-section SEM micrographs of the membranes. The surface area and pore dimensions of the microporous membranes were measured using the BET nitrogen absorption technique and mercury porosimetry, respectively. The influences of temperature and amount of stretching during cold and hot stretching on WVTR were also explored. Tensile properties in the machine and transverse directions (MD and TD, respectively) as well as puncture resistance in the normal direction (ND) were evaluated. As the high Mw PP was added, a slight reduction in the mechanical properties along MD and TD and no changes in ND were observed.  相似文献   
153.
Integrability in the Painlevé sense of the trapped ionic system in the quadrupole field with superpositions of rotationally symmetric hexapole and octopole fields is studied. Five integrable cases of the system are reported. First Integrals of the planar motion are founded. Confirming three-dimensional integrability of the equations of motion, the third explicit integrals of motion are constructed directly for each case. We carried out a numerical study to observe the regularity and chaotic regions via the Poincaré surface of sections, and corroborate the analytical results.  相似文献   
154.
In this paper, biaxial orientation characterization techniques are briefly reviewed. Results obtained using birefringence and Fourier Transform Infrared Spectroscopy (FTIR) techniques are presented for different applications: On-line monitoring of birefringence for an amorphous polymer (polystyrene); On-line and off-line determination of orientation (birefringence) of polyethylene terephthalate (PET) and finally off-line measurement of orientation on polyethylene (LDPE) films using FTIR. Some typical morphologies of blown LDPE films are reported and discussed. Finally, correlations between orientation on one hand and shrinkage and tear strength on the other are attempted.  相似文献   
155.
To ensure the better production and sustainable management of natural resources, a chemometric investigation was conducted to examine the effect of cooperative and harvesting periods on the crop yields and chemical compositions of Salvia rosmarinus Spenn essential oils in the Oriental region of Morocco. The samples were collected from three cooperatives over nine time periods from January 2018 to April 2019. The chemical composition of Salvia rosmarinus Spenn essential oils was analyzed by gas chromatography coupled with mass spectrometry. The data from this study were processed by multivariate analyses, including principal component analysis (PCA) and hierarchical cluster analysis (HCA). The disc diffusion technique and a determination of the minimal inhibitory concentration were performed to study the antibacterial properties of the oils. Statistical analysis showed that the cooperative and harvest period have a significant effect on yields. The highest yield of essential oil was recorded in April 2019 at cooperative C1. The PCA and the HCA results were divided into two groups: Group A for the summer season and group B for the winter season. The samples collected during summer were characterized by a high amount of 1,8-cineole component and a high yield of essential oil, whereas the samples collected during winter were qualified by a high amount of α-pinene component and a low yield of essential oil. The antibacterial activity of Salvia rosmarinus Spenn essential oils showed that Mycobacterium smegmatis ATCC23857 and Bacillus subtilis ATCC 23857 are the most susceptible strains, stopping growth at 1/500 (v/v). The least susceptible strain is Escherichia coli ATCC25922, with an MIC value corresponding to 1/250 (v/v). The findings of this study could have a positive economic impact on the exploitation of rosemary in the Oriental region, especially during the best harvest periods, as they indicate how to obtain the best yields of oils richest in 1,8-cineole and α-pinene chemotypes.  相似文献   
156.
A laboratory study was undertaken on the transport and the deposition of suspended particles (silt of modal diametre 6 μm) in three columns of different length, filled with glass beads or gravel. Tracer tests were carried out at various flow velocities by short pulses of a mixture of suspended particles/dissolved tracer. The breakthrough curves were competently described with the analytical solution of a convection dispersion equation with a first-order deposition rate and the hydro-dispersive parameters were deduced. For the same experimental conditions, the results showed a difference in the behaviour of the suspended particles transport and deposition rates within the two porous media tested. The internal structure of both media governs the particle-grain collision frequency as well as the particles trapping. The scale effect was highlighted and affects the dispersivity, the size exclusion effect, the recovery rates and the deposition rates. Longitudinal dispersion increases with mean pore velocity and is described with a nonlinear relationship. The dispersivity increases with the column length. The size exclusion effect is more important in the short column. The recovery rate increases with flow velocity and decreases while increasing column length. The deposition rates increases until a critical flow velocity then decreases. This critical velocity is also sensitive to the scale effect, and increases with the column length.  相似文献   
157.
By changing the surfactant/water ratio , nanoparticles of the iron(II) spin crossover material, [Fe(NH2‐trz)3]Br2 ? 3 H2O (with NH2‐trz=4‐amino‐1,2,4‐triazole), have been synthesised from 1 μm down to 30 nm (see figure). Magnetic and reflectivity experiments indicate that the critical size for observing a thermal hysteresis in this 1D polymer family is around 50 nm, and powder X‐ray diffraction shows that particles of about 30 nm are constituted by about one coherent domain.

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158.
159.
In this study, a solvothermal method was used to synthesize anatase titanium dioxide (TiO2) nanoparticles in the presence of oleic acid (OA) and oleylamine (OM) as morphology‐directing agents. Functional nanocomposite fibers of poly(ethylene terephtalate) (PET) containing surfactants‐capped TiO2 nanoparticles were developed by electrospinning technique. The morphology, thermal stability and mechanical properties of PET/TiO2 nanocomposite mats were investigated as a function of TiO2 concentration. Morphology investigation showed interesting results in terms of the level of TiO2 dispersion inside the fibers and the improvement of the quality (smoothness) of the fibers' surface when the synthesized nanorhombic TiO2 nanoparticles were used compared to a commercial P25 TiO2 (AEROXIDE P25). The presence of OA and OM on the surface of the nanorhombic synthesized TiO2 led to a significant improvement of TiO2 dispersion inside the PET matrix. Furthermore, the physical interaction between the PET matrix and TiO2 nanoparticles resulted in an enhanced thermal stability, and an increase of the Young's modulus and tensile strength for TiO2 concentration up to 10 wt%.  相似文献   
160.
Cell division cycle 7 (CDC7) is a serine/threonine kinase, which plays a vital role in the replication initiation of DNA synthesis. Overexpression of the CDC7 in various tumor growths and in cell proliferation makes it a promising target for treatment of cancers. To investigate the binding between the CDC7 and furanone inhibitors, and in order to design highly potent inhibitors, a three-dimensional quantitative structure activity relationship (3D-QSAR) with molecular docking was performed. The optimum CoMSIA model showed significant statistical quality on all validation methods with a determination coefficient (R2?=?0.945), bootstrapping R2 mean (BS-R2?=?0.960), and leave-one-out cross-validation (Q2) coefficient of 0.545. The predictability of this model was evaluated by external validation using a test set of nine compounds with a predicted determination coefficient R2test of 0.96, besides the mean absolute error (MAE) of the test set was 0.258 log units. The extracted contour maps were used to identify the important regions, where the modification was necessary to design a new molecule with improved activity. Furthermore, a good consistency between the molecular docking and contour maps strongly demonstrates that the molecular modeling is reliable. Based on those obtained results, we designed several new potent CDC7 inhibitors, and their inhibitory activities were validated by the molecular models. Additionally, those newly designed inhibitors showed promising results in the preliminary in silico ADMET evaluations.  相似文献   
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