Organic Materials and Thin‐Film Structures for Cross‐Point Memory Cells Based on Trapping in Metallic Nanoparticles

Non‐volatile solid‐state memory cells based on composites of metal nanoparticles and polymers are embedded in organic semiconducting host materials. This paper presents data from a wide range of materials and device structures and shows that the switching phenomenon is commonly observed.     

Intrinsic Volume Changes of Self-propagating Synthesis

The final product(s) of self-propagating synthesis are shown to be intrinsically denser than the starting reactants. This behavior results in intrinsic decreases in the sample volume that increase with both the heat of reaction and the adiabatic combustion temperature. Forming of liquid product(s) during reaction simply adds another intrinsic source of porosity, i.e. changes in volume on product solidification. Thus, obtaining fully dense bodies from self-propagating synthesis requires a mechanism for reducing porosity, e.g. hot-pressing.     

IPv6过渡机制讨论

本文在简要地介绍Ngtrans工作组提出的大多数过渡机制的基础上，尝试对它们进行区分、分类，并对每一种过渡机制的优缺点进行分析。另外．还对这些机制的布置以及一部分支持这些机制的产品平台进行讨论。     

WCDMA的软切换算法和TD-SCDMA的接力切换算法的分析与比较

本文概述了WCDMA的软切换算法和TD-SCDMA中的接力切换算法,分析和比较了这两种算法的各自得特点.     

Formation of composites fabricated by exothermic dispersion reaction in A1-TiO2-B2O3 system

The formation of aluminum matrix composites fabricated by exothermic dispersion reaction in A1-TiO2-B2O3 system was investigated. The thermal analysis results show that the reactions are spontaneous and exothermic. The Gibbs free energy of α-Al2O3 is the lowest among all the combustion products, followed by TiB2 and Al3Ti. It is noted that when the B2O3/TiO2 mole ratio is below 1, the reaction products are composed of particle-like α-Al2O3, TiB2 and rod-like Al3Ti. The α-Al2O3 crystallites, resulting from the reaction between A1 and TiO2 or B2O3, are segregated at the grain boundaries due to a lower wettability with the matrix. SEM micrographs show that rod-like Al3Ti phase distributes uniformly in the matrix. When the BEO3/TiO2 mole ratio is around 1, the Al3Ti phase almost disappears in the composites, and the distribution of α-Al2O3 particulates is improved evidently.     

Dynamic external fixation for distal radius fractures

Thirty adult patients with closed comminuted and mostly intraarticular fractures of the distal radius were treated by closed reduction and immobilization with a dynamic external wrist fixator during a 2-year period. In 13 patients with severely comminuted and unstable fractures, additional Kirschner wires were used. After 10 to 14 days of rigid fixation in neutral position, the motion element was unlocked to allow up to 30 degrees flexion. Six weeks later, the fixator was removed. The patients then were observed for an average of 24 weeks. An excellent functional outcome was seen in 6 patients (20%), a good outcome in 20 patients (67%), and a fair outcome in 4 patients (13%). Anatomically, 15 patients (50%) had an excellent result, 14 (47%) a good outcome, and 1 (3%) a fair outcome. Only minimal loss of reduction averaging 1 degree palmar tilt was seen during mobilization. There were 2 major complications: 1 deep Kirschner wire tract infection and 1 index metacarpal fracture. Minor complications such as sensory disturbances and pin tenderness were present but recovered completely after removal of the fixator. This study provides promising data and offers an alternative method in the treatment of distal radius fractures with severe comminution. In cases with postreductive unstable fragments, additional Kirschner wires should be used to allow early mobilization of the wrist.     

The Nicolas Andry Award-1995. Fracture healing. Radiation induced alterations

This study investigated the effects of radiation on fractures in a rat femur model. Two different radiation dosage fractionation schemes (1100 rads given in one dose and 2500 rads given in 10 divided doses over 12 days) and three different times of initiation of radiation (1 day before fracture, 3 or 10 days after fracture) were studied. Fractures exposed to these levels of radiation all appeared to heal during the course of this experiment, although with varying degrees of delay, with the exception of those exposed to a single dose of 1100 rads 3 days after fracture. These animals remained at a more immature level of repair histologically compared with the control group, throughout the entire time evaluated. The strength of the final repair remained less than the control for all the groups receiving treatment. These results may offer some explanation for the clinical observations of an increased incidence of delayed union and nonunion of fractures, an increased incidence of fracture and refracture in irradiated bone, and an increased incidence of fracture and nonunion in constructs using radiation in conjunction with allogeneic bone. Furthermore, the observed effects were generally no different in the animals treated with the two clinically relevant dose fractionation schemes chosen for this study.     

LP-BM5 virus causes changes in lactic dehydrogenase and oxygen radical production in splenocytes of C57BL/6J mice

The LP-BM5 murine leukemia virus causes acquired immunodeficiency syndrome in C57BL/6J mice (MAIDS), similar to that of AIDS in humans. The objective of this study was to determine the effect of LP-BM5 viral infection on cellular activation and membrane integrity of splenocytes. Oxidative burst in splenocytes in response to exposure to PMA (20 microg/ml) was significantly higher (p<.02) in infected than in control mice at two weeks post-infection using luminol-enhanced chemiluminescence. By 13 weeks post-infection superoxide anion production in infected mice was significantly lower when compared to controls coinciding with decreased proliferative response to mitogens. The extent of cell membrane damage as indicated by lactic dehydrogenase (LDH) activity in serum was significantly higher in infected than in control mice (p<.001). The results from this study suggests that LP-BM5 virus causes an initial stimulation of cellular activity followed by a decreased cell activation characterized by decreased proliferation of splenocytes and decreased oxygen radical production. Decreased cell membrane integrity indicated by increased LDH activity may partly be responsible for these changes.