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Temperature and frequency dependence of dielectric constant of gum arabic biopolymer—CdS nanocomposites mixed at various proportions have been studied. Powder XRD, transmission electron microscopic (TEM), and differential calorimetric (DSC) studies were made to find out structural and morphological dependence, if any. It is observed that the dielectric constant of GA is enhanced significantly with doping of CdS nanoparticles, and this enhancement shows anomalous dependence on the extent of doping of the nanoparticles and with temperature. POLYM. COMPOS., 108–114, 2016. © 2014 Society of Plastics Engineers 相似文献
105.
Durbadal Mandal Sakti Prasad Ghoshal Anup Kumar Bhattacharjee 《Journal of Infrared, Millimeter and Terahertz Waves》2010,31(6):667-680
In this paper the maximum sidelobe level (SLL) reductions without and with central element feeding in various designs of three-ring
concentric circular antenna arrays (CCAA) are examined using a real-coded Evolutionary Programming (EP) to finally determine
the global optimal three-ring CCAA design. Standard real-coded Particle Swarm Optimization (PSO) and real-coded Particle Swarm
Optimization with Constriction Factor and Inertia Weight Approach (PSOCFIWA) are also employed for comparative optimization
but both prove to be suboptimal. This paper assumes non-uniform excitation weights and uniform spacing of excitation elements
in each three-ring CCAA design. Among the various CCAA designs, the design containing central element and 4, 6 and 8 elements
in three successive concentric rings proves to be such global optimal design set with global minimum SLL (−39.66 dB) as determined
by Evolutionary Programming. 相似文献
106.
The case of a 36-year-old man who sought treatment of right facial myokymia and spastic paretic facial contracture is reported. Computed tomography and magnetic resonance imaging revealed a tumor located in the right cerebellar peduncle and the right dorsal pons bulging into the fourth ventricle. After microsurgical partial resection of the mass, which was verified histologically as an anaplastic glioma, facial myokymia initially ceased. The vermicular rippling movements were less intense upon recurrence and could be controlled by low-dose dexamethasone in the further course, when magnetic resonance imaging showed an interstitial pontine edema after percutaneous radiation therapy. It is assumed that facial myokymia and spastic paretic facial contracture were generated by ectopic activity due to alterations in the microenvironment at the intrapontine portion of the axons of the seventh nerve caused by the compressive effect of the tumor and later by edema. 相似文献
107.
The authors report a series of studies designed to determine whether effects similar to those observed in the innate categorical perception of color and phonemes are induced during the learning of simple unidimensional categories and more complex multidimensional ones. In Experiment 1 no evidence was found for such effects when stimuli varied on 1 dimension. Experiments 2 and 3 demonstrated a within-category compression effect but no between category expansion effect for stimuli varying in 2 dimensions. Compression only was also shown in Experiment 4, which used pictures of actual objects. Multidimensional scaling analyses illustrate how within-category compression without expansion was sufficient to produce categorical clustering of items in the similarity space. These analyses also show that learning changed the dimensional structure of similarity space. Results are compared with those from other studies exploring similar phenomena and with neural network simulations. 相似文献
108.
Hilar cholangiocarcinoma, a highly lethal tumor, is difficult to diagnose with conventional computed tomography (CT) because of its small size. Spiral CT allows more effective evaluation of these small lesions and better demonstrates the status of the hepatic arterial or portal venous circulation. Among 27 patients with hilar cholangiocarcinoma (infiltrative in 21, exophytic in two, polypoid in one, diffuse in three), thin-section spiral CT allowed identification of each tumor as an area of focal wall thickening that obliterated the lumen. Seventeen of the infiltrative tumors (81%) showed high attenuation. Identification of the level of biliary obstruction was possible in 63% of the patients (17 of 27). The level of obstruction was underestimated in six patients and overestimated in four. Spiral CT is a valuable method for diagnosis of hilar cholangiocarcinoma; however, spiral CT is less accurate in evaluation of intraductal tumor extent because of the limited z-axis resolution. 相似文献
109.
SA Petrill K Saudino SS Cherny RN Emde DW Fulker JK Hewitt R Plomin 《Canadian Metallurgical Quarterly》1998,69(1):68-74
Two definitions of normality ("isolated" or "correlated") are considered. The boundaries of "isolated" normality were determined by a statistical procedure, whereas the "correlated" approach was related to a clinical or predictive definition. In the latter case, the biological variations were considered abnormal if they implied a hazard with some significant future ailment as a risk factor. In this pragmatic approach, the upper limit of normal/abnormal variations is the point beyond which medical strategy is related to the most expected benefit when applied to a definite population or to an individual patient. The capacity of a diagnostic test to discriminate between patients with a defined risk and those without risk depends strictly on the value of the parameter chosen. In medical care for the prevention of vascular complications in diabetic patients or with foetal risks in pregnant women, the limits of the so-called normal range of glycaemia and other parameters should be determined according to the objective of the preventive and/or therapeutic measures to be prescribed. 相似文献
110.
D Barry J Bea D Bernd T DeFauw C Marr T McCormick JK Mitchell M O'Neil M Pittman D Strum 《Canadian Metallurgical Quarterly》1994,68(11):42, 44-46, 48
In cooperation with McManis Associates, Hospitals & Health Networks recently convened a CEO summit on physician/hospital integration activities. In the third report of a three-part series on the summit, leading health care executives discuss investor capital needs, strategic information management needs, and the management competencies required for capitated managed care success. 相似文献