Watchdog在Philips 8XC552单片机系统中的应用研究

介绍了8XC552单片机Watchdog的内部结构和工作原理,提出了在以80C552为CPU的嵌入式pH值智能测控系统中的实现方法,分析了调试中容易出现的问题及解决办法,最后给出了软件设计原理及代码实现.     

关于规范高校教材建设的几点思考

针对我国高校在教材建设中存在的一些弊端,对加强高校教材建设提出几点建议,以期提高教材建设水平,提高教学质量。     

Temperature-related behavior of some migrant birds in the desert

Behavior of migrant birds in relation to temperature was studied and compared to that of resident species in the northern Mojave Desert. Migrants reduced foraging intensity above 30 C, but resident species showed no striking decrease in intensity of foraging at temperatures up to 35 C. Migrant species shifted activities to shaded microhabitats at temperatures between 20 and 30 C; the resident Verdin showed a similar shift at 35 C. Most migrants decreased the amount of time spent foraging at temperatures above 30; Verdins showed a similar but stronger response to temperatures about 30 C. Significant reductions in the use of hovering and hawking maneuvers were found among migrants at temperatures above 30 C. Migrants showed similar types of behavioral adjustments to temperatures as did resident desert species, but they responded earlier in the daily temperature cycle. Desert birds appear to correlate their daily activity strongly with temperature, but nondesert species may respond either to temperature or time of day.     

Book Reviews: Behavior Change in the Human Services: An Introduction to Principles and Applications by Martin Sundel and Sandra S. Sundel. Exploring Personality: An Intellectual Odyssey by Russell L. Ackoff. The Ecologist: The Cosmic Covenant.

Systemic Practice and Action Research -     

Direct evidence that reverse cholesterol transport is mediated by high-density lipoprotein in rabbit

Mammalian cells obtain cholesterol for membrane synthesis mostly via the receptor-mediated endocytosis of low-density lipoprotein (LDL). Macrophages and vascular endothelium additionally have receptors that recognize certain modified forms of LDL (for example, acetyl-LDL). The process by which cholesterol returns from peripheral cells to hepatocytes (reverse cholesterol transport) has not been established; although tissue culture studies have favoured high-density lipoprotein (HDL) as the principal vehicle, the in vivo evidence for this is meagre. When cholesterol-loaded macrophages are incubated in medium containing plasma, cholesterol moves from the cells to HDL and is then esterified by lecithin/cholesterol acyltransferase. The accumulation of cholesteryl esters in the particles increases their size and decreases their density; enrichment with apoprotein E (apo E) also occurs, producing a decrease in electrophoretic mobility. We now report that similar changes occur in the circulating HDL of rabbits, when their peripheral tissues are loaded with cholesterol by intravenous (i.v.) injection of acetylated or native human LDL. This result suggests that HDL is involved in reverse cholesterol transport in vivo.     

美国学校数学课程演化的历史观(1900-2006)

通过对100多年来美国学校数学课程演化的分析与思考,旨在提供一种认识美国数学课程的历史观,并从中窥探美国数学课程演化的艰巨性、曲折性和发展性,以启示如何更有效地进行数学课程改革.     

加筋土工程在油田浅海筑路中的应用研究

对浅海加筋土工程中加筋板受力进行了全面分析,给出了土压力、风力、冰压力、水流力、波浪力以及地震力的计算方法,并对某海域浅海筑路的加筋土工程板桩进行了计算.     

Interpreting animal wall-following behavior

Summary Using computer simulations and behavioral experiments with the American cockroach, we found that active vs passive (barrier-directed) wall-following can be readily distinguished and quantified by incorporating a range of convex curves into test arenas. Although previously considered strongly thigmotactic, more than 50% of running American cockroaches depart convex curves with diameters, less than 1 m. A new framework for evaluating wall-following behaviors is presented.     

宝钢RH—MFB深脱碳模型

在研究钢液脱碳机理的基础上建立了RH—MFB脱碳数学模型在深入研究影响RH—MFB脱碳因素的基础上确定了模型中的具体参数、依据数学模型编制了计算机应用软件并对模拟结果与实际生产进行了对比实验,两者数据吻合程度较高,验证了模型的正确性。     

汉英的姓氏差异及其文化根源

众所周知,中英文化的区别不仅体现在表面上,更表现为深层的人文心理差异。与发轫于两希文明的英国文化相比,中国文化自成体系,在本区属于优势文化,其传承的过程较为系统、单纯。此种文化的差异大到政治思想,经济体制和人文传统,小到姓氏文化的民族取向都有着具体细微的表现。文章试图从英国的姓氏文化和中国姓氏文化的主要特征入手寻找差异,研究其差异的深层文化因素,并从现实操作的角度来把握两种文化的人文心理差异,以期更好地实现中英之间的互解和交流。