A new type of ordering in Ba(Zn1/3 Ta2/3)O3 ceramics

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Investigation on Resistive Memory Switching Mechanism of NiO

ABSTRACT

Experimental investigations on the resistive memory switching in sub-micron sized NiO memory cell are presented to elucidate the resistive memory switching mechanism. The voltage or current-biased I-V measurements show that the resistive switching transitions can be regarded as the combination of a voltage-controlled negative differential resistance phenomenon and a current-controlled negative differential resistance phenomenon. Along with experimental observations of multiple resistance states, these indicate that the memory switching in NiO would come from the percolative formation and rupture of filamentary conducting paths. Pulse experiments further suggest that the memory switching would come from local domains inside filaments.     

Fracture mechanics of surface fatigue crack growth by ductile striation space measurement in notched Waspaloy

Ductile striation space (DSS), a parameter to predict actual cracks in both direction of length and depth, is proposed for the surface fatigue crack behaviors on notched Waspaloy. Three different lengths (1, 2 and 4 mm) of artificial notches are formed as the initial surface crack for an applied maximum stress of 1,103 MPa at the stress ratio R of 0.05. These notches are similar with the appearance of the surface cracks found from the survey of compressor disk. The results show that, all initial crack sites in the depth direction started from the multiple origination sites. The DSS parameter was clearly confirmed, and it also proves the high effectiveness of the measurement in the range of the stress intensity factors for acquiring the crack growth rate on the fractured surface. The surface cracks on Waspaloy at room temperature in an atmosphere perfectly follow the relation of ΔK versus da/dN and db/dN, even though there are, respectively, earlier and later timing differences on the initiation of cracks for the notch sizes of 1 and 4 mm. The results of ΔK versus da/dN and db/dN relations show a similar slope for three different kinds of notches.     

新型水基涂料及其膜的性能

1　前言近年来 ,紫外固化水基涂料由于可减少空气污染 ,降低火灾危险 ,改善现场健康条件 ,提高安全性 ,尤其是以水作为紫外固化体系稀释剂 ,降低了有毒气体对环境的污染 ,解决了粘度控制和活性稀释剂影响固化膜性能之间的矛盾 ,而且易于清洗 ,因而得到广泛的工业应用。有 2种水基体系 :含外加表面活性剂的乳液或胶体分散液和水溶性或水分散型含亲水性基团的树脂体系。前者制备时通常加入表面活性剂 ,有助于形成稳定的乳液。但外加的表面活性剂影响最终产品的性能 ,即留在紫外固化膜中的表面活性剂使涂层具有水敏性。后一种体系不用加入表面…     

GPS信号C/A码生成算法设计及仿真实现

全球定位系统(Global Positioning System,GPS)是一种基于卫星的定位系统,向全球范围内的用户全天候提供高精度的导航、定位和授时服务.GPS系统的测距码可以分为粗码(C/A码)和精码(P码),其中C/A码用于民用导航.本文在深入研究C/A码信号生成原理的基础上,利用Matlab对C/A码信号的实现方式进行了仿真实现和分析.仿真结果进一步证实了该方法的正确性和可行性.这对在仿真平台上进一步研究真实环境下的GPS信号,使其能捕获跟踪复杂环境下的卫星信号,改进卫星接收部分的性能有着十分重要的实际意义.     

EFFECTS OF EXTRUSION CONDITIONS ON PHYSICOCHEMICAL PROPERTIES OF A MUTANT RICE CULTIVAR,GOAMI2 – HIGH IN NONDIGESTIBLE CARBOHYDRATES

ABSTRACT

A mutant rice Goami2, a cultivar high in nondigestible carbohydrates (NDCs), was extrusion‐cooked at feed moisture (20, 25%), screw speed (200, 300 rpm) and barrel temperature (110, 120 and 130C). Effects of extrusion conditions on the physical and functional properties were investigated. NDCs were determined by total dietary fiber (TDF) and resistant starch (RS) contents. Increasing moisture resulted in an increment of density, water absorption index (WAI) and hardness, and a decrement in expansion and water solubility index (WSI). A higher barrel temperature decreased the hardness and increased the WSI probably due to a higher proportion of gelatinized starch. Extrusion caused a reduction in TDF in the extrudates, as well as a significant decrease in RS contents. However, extrudates processed at moisture (%), screw speed (rpm) and barrel temperature (C) combinations of 25/200/110 and 25/200/120 showed no significant difference in TDF contents compared with its raw rice. Multiple regression models showed that feed moisture had the most pronounced effect on extrudate qualities, followed by barrel temperature and screw speed.

PRACTICAL APPLICATIONS

Rice, being one of the primary dietary sources of carbohydrates worldwide, is the major energy and nutritional sources. In recent years, demands have been increasing for rice with a wide range of value‐added properties, such as enhanced nutrient, aroma, color and rice kernel shape, including functional properties. Goami2 is a mutant rice of Ilpumbyeo, a high japonica rice cultivar, and has been revealed to have higher nondigestible fractions. However, Goami2 rice has unsuitable properties for traditional cooking because of the difficulty of gelatinization, which might result in a hard texture of cooked rice compared with that of ordinary rice. On the basis of its nutritional and functional benefits, exploiting the possible utilization of Goami2 for processed food products would increase the potential consumption of Goami2 for various food products.     

唐昭陵壁画女装的3D虚拟试衣结构复原北大核心CSCD

唐昭陵保存了初唐时期大量壁画资料,但服装出土实物少,给服装结构的研究带来一定的难度。本文通过对唐昭陵壁画中的女装款式、比例的统计分析,以出现率最高的半臂套装和襦裙套装为研究对象,利用比例换算、CLO3D虚拟试衣实验法测量推算出服装尺寸,并进行试穿实验,复原出服饰结构。通过服装比例比较、可穿性、变形率及压力等评价分析,进一步验证了虚拟复原的可行性。研究得出,壁画中主流款式的服装结构构成形式、服装与身高的比例关系、穿着方法对形态的影响等相关结论,为初唐女装结构与形象研究提供思路与参考。