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排序方式: 共有95条查询结果,搜索用时 15 毫秒
1.
Seham A. Elkheshen Sabry S. Badawi Alia A. Badawi 《Drug development and industrial pharmacy》1996,22(7):623-630
In this study 24 factorial design associated with surface response methodology was used to develop and optimize a reconstitutable suspension of rifampicin. The study illustrated the effect of the percentage of each of sucrose, avicel RC-591, hydrophilic aerosil, and aerosol-OT on the flowability and the bulk density of the dry mixture as well as the viscosity, the sedimentation volume, and the redispersibility of the suspension. An empirical equation developed for each of the above responses was used with the aid of computer software to plot a contour map of the most significant effects and interactions. Five replicates at the center of the design were used to independently calculate the experimental error and to detect any curvature in the response surface. Three formulas which are not included in the design were prepared to check the validity of the model equation. 相似文献
2.
Lopez Frederick G.; Fons-Scheyd Alia; Morúa Wendy; Chaliman Rebecca 《Canadian Metallurgical Quarterly》2006,53(4):543
This study examined the nature and impact of dyadic perfectionism over a 3-month interval within a sample of 116 college students who were currently involved in an intimate heterosexual relationship. Dyadic perfectionism scores were stable and correlated as expected with scores on concurrent measures of adult attachment orientations and relationship satisfaction. Logistic regression analyses revealed that, controlling for initial commitment status and adult attachment orientations, Time 1 dyadic perfectionism scores significantly and uniquely predicted relationship continuity 3 months later. Lastly, controlling for social desirability, relationship commitment status, and Time 1 adult attachment orientation scores, Time 1 dyadic perfectionism scores also uniquely predicted Time 2 relationship distress. Findings provide additional evidence that dyadic perfectionism is a risk factor for relationship dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
High-computing speed and modularity have made RNS-based arithmetic processors attractive for a long time, especially in signal processing, where additions and multiplications are very frequent. The VLSI technology renewed this interest because RNS-based circuits are becoming more feasible; however, intermodular operations degradate their performance and a great effort results on this topic. In this paper, we deal with the problem of performing the basic operationX(modm), that is the remainder of the integer divisionX/m, for large values of the integerX, following an approximating and correcting approach, which guarantees the correctness of the result. We also define a structure to computeX(modm) by means of few fast VLSI binary multipliers, which is exemplified for 32-bit long numbers, obtaining a total response time lower than 200 nsec. Furthermore, such a structure is evaluated in terms of VLSI complexity and area and time figuresA=?(n 2 T m 2 ) andT=?(T M ) for the parameterT M in \([\log n,\sqrt n ]\) are derived. A simple positional-to-residue converter is finally presented, based on this structure; it improves some complexity results previously obtained by authors. 相似文献
4.
Miloud Boutaleb Bendouma Doumi Allel Mokaddem Adlane Sayede Abdelkader Tadjer 《Journal of Superconductivity and Novel Magnetism》2017,30(10):2855-2864
In this study, we use the first-principle calculations of density functional theory with gradient generalized approximation of Wu–Cohen to investigate the doping effect of vanadium impurity on structural, electronic and magnetic properties of In1?x V x P and B1?x V x P alloys at various concentrations x = 0.0625, 0.125 and 0.25. Owing to the metallic nature of majority spin and semiconducting minority spin, the In1?x V x P compounds exhibit a half-metallic character with total magnetic moments of 2 μ B, while the B1?x V x P has metallic nature for all concentrations. The results of exchange parameters revealed that exchange coupling between vanadium atoms and the conduction band is ferromagnetic, confirming the magnetic feature of In1?x V x P and B1?x V x P. From our findings, we have predicted that the In1?x V x P alloys seem to be potential materials for spintronics. 相似文献
5.
F. Dahmane A. Tadjer B. Doumi H. Aourag 《Journal of Superconductivity and Novel Magnetism》2014,27(12):2647-2654
We investigate the structural, electronic, and magnetic properties of zinc-blende diluted magnetic semiconductors (DMS) Al 1?x TM x N for transition metals (TM) = V, Cr, Mn, and Fe at x = 0.125 and 0.25, using first-principle calculations with the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory and local spin-density approximation, in an aim to predict properties of Al 1?x TM x N compounds. We have analysed the reliance of structural parameter values on the composition x in the range of x= 0.125?0.25. Results of calculated electronic structures reveal that Al 1?x TM x N have stable ferromagnetic ground state and they are ideal half-metallic (HM) ferromagnetic at their equilibrium lattice constants. We have also studied the magnetic moment of Al 1?x TM x N by increasing the concentration of TM atom; this is the most important source of the total magnetic moment in these alloys, while the contributions from Al, N, and interstitial moments are minor. 相似文献
6.
Marko J. Tadjer Michael A. Mastro José M. Rojo Alberto Boscá Mojena Fernando Calle Francis J. Kub Charles R. Eddy Jr. 《Journal of Electronic Materials》2014,43(4):1188-1193
Manganese dioxide films were grown on large area flexible carbon aerogel substrates. Characterization by x-ray diffraction confirmed α-MnO2 growth. Three types of films were compared as a function of hexamethylenetetramine (HMTA) concentration during growth. The highest concentration of HM TA produced MnO2 flower-like films, as observed by scanning electron microscopy, whose thickness and surface coverage lead to both a higher specific capacitance and higher series resistance. Specific capacitance was measured to be 64 F/g using a galvanostatic setup, compared to the 47 F/g-specific capacitance of the carbon aerogel substrate. Such supercapacitor devices can be fabricated on large area sheets of carbon aerogel to achieve high total capacitance. 相似文献
7.
Ahlem Alia Hassane SadokMhamed Souli 《Engineering Analysis with Boundary Elements》2012,36(3):346-350
Disceretization of boundary integral equations leads to complex and fully populated linear systems. One inherent drawback of the boundary element method (BEM) is that, the dense linear system has to be constructed and solved for each frequency. For large-scale problems, BEM can be more efficient by improving the construction and solution phases of the linear system. For these problems, the application of common direct solver is inefficient. In this paper, the corresponding linear systems are solved more efficiently than common direct solvers by using the iterative technique called CMRH (Changing Minimal Residual method based on Hessenberg process). In this method, the generation of the basis vectors of the Krylov subspace is based on the Hessenberg process instead of Arnoldi's one that the most known GMRES (Generalized Minimal RESidual) solver uses. Compared to GMRES, the storage requirements are considerably reduced in CMRH. 相似文献
8.
In this paper, we model high temperature superconducting coupled microstrip lines printed on bi-anisotropic substrates by the spectral domain Galerkin method. Hence, we have determined the behavior of the effective permittivity for the odd and even modes and the coupling coefficient as a function of several parameters characterizing superconductivity and bi-anisotropy and the geometry of this structure, such as the superconductor material temperature, the distance between the two lines and the optical deviation angles of the dielectric substrates. The validation of the numerical results has been carried out by comparisons with the bibliographic results. 相似文献
9.
Joshua D. Caldwell Kendrick X. Liu Marko J. Tadjer Orest J. Glembocki Robert E. Stahlbush Karl D. Hobart Fritz Kub 《Journal of Electronic Materials》2007,36(4):318-323
Stacking faults within 4H-SiC PiN diodes are known to be detrimental to device operation. Here, we present electroluminescence
(EL) images of 4H-SiC PiN diodes providing evidence that electrically and optically stimulated Shockley stacking fault (SSF)
propagation is a reversible process at temperatures as low as 210°C. Optical beam induced current (OBIC) images taken following
complete optical stressing of a PiN diode and that lead to a small number of completely propagated SSFs provide evidence that
such defects propagate across the n–/p+ interface and continue to grow throughout the p+ layer. These observations bring about
questions regarding the validity of the currently accepted driving force mechanism for SSF propagation. 相似文献
10.
Mohamed F. Elshal Alia M. Aldahlawi Omar I. Saadah J. Philip McCoy 《International journal of molecular sciences》2015,16(12):28998-29010
Loss of tolerance of the adaptive immune system towards indigenous flora contributes to the development of inflammatory bowel diseases (IBD). Defects in dendritic cell (DC)-mediated innate and adoptive immune responses are conceivable. The aim of this study was to investigate the expression of the inhibitory molecules CD200R1 and their ligand CD200 on DCs, to clarify the role of the DCs in the pathogenesis of IBD. Thirty-seven pediatric IBD patients (23 with Crohn’s disease (CD) and 14 with ulcerative colitis (UC)) with mean age 13.25 ± 2.9 years were included. Fourteen age-matched healthy pediatric volunteers (five males and nine females) served as a control group (HC). The percentage of CD11c+ myeloid dendritic cells (mDCs) and CD123+ plasmacytoid DCs (pDCs) expressing CD200R1 and CD200 were evaluated in peripheral blood using flow cytometry and were correlated with routine biochemical, serological markers, serum levels of cytokines and with the percentages of circulating regulatory T cells (Treg) and CD4+ producing IL-17 (Th17). IBD patients showed a significant decrease in the percentage of pDCs and mDCs expressing CD200R1 compared to that of HC. Patients with UC showed increased expressions of the CD200 molecule on pDCs as compared to HC. DCs expressing CD200R1 were found to be correlated positively with Treg and negatively with TH17 and erythrocyte sedimentation rate (ESR). Our findings suggest that IBD is associated with dysregulation in the CD200R1/CD200 axis and that the decrease in DCs expressing CD200R1 may contribute to the imbalance of Th17 and Treg cells and in the pathogenesis of IBD. 相似文献