IPv6技术分析及其应用前景

IPv4由于其自身的缺陷,造成IP地址耗尽等严重问题,为了解决这些难题,对IPv6技术的探索是必不可少的。要想真正了解IPv6的应用前景,就必须对其产生原因及技术特点加以分析,掌握其技术与应用领域的契合点。     

四甲基对苯二甲酸锌配合物的合成和晶体结构

采用扩散法,通过硝酸锌和四甲基对苯二甲酸反应,合成配合物{[Zn(C12 H12 O4)(DMSO)2]·2(DMSO)}n,并经元素分析和X射线单晶衍射法证实.配合物属单斜晶系,空间群为C2/c,晶体学参数:a=1.219 80(9)nm,b=1.294 63(10)nm,c=1.784 71(13)nm,V=2.749 4(4)nm3,Z=4.甲基取代基导致标题化合物为一维疏水链状结构.     

一类带弱奇异核的偏积分微分方程的全离散格式

给出了数值求解一类偏积分微分方程的一种全离散格式.在空间x方向一种采用六点隐格式,时间t方向都用拉普拉斯的数值逆求解.得出数值解的精度较高,计算也比较简便.     

便携式超高频射频识别读写器设计

超高频读写器的便携式设计是射频识别（RFID）系统广泛应用的关键.为实现超高频RFID读写器的便携式设计,提出一种超高频RFID读写器的设计方案.硬件系统主要包括读写器的射频前端、功率放大器、功率检测、天线阻抗调谐电路等,在设计过程中考虑信道指标并对其进行评估;在对ISO/IEC18000-6的三种协议标准进行比较的基础上选用ISO/IEC 18000-6C协议,设计相应软件系统主要包括基带模块及防冲突碰撞模块.对硬件进行评估计算并结合硬件对软件进行验证及测试,结论如下：该读写器具有功率消耗低、体积小、接口丰富等便携式优点;硬件系统性能稳定;软件功能运行良好.上述设计有效实现了射频识别系统的便携式设计.     

Protective role of 17-β-estradiol towards IL-6 leukocyte expression induced by intense training in young female athletes

Abstract

Exercise performed at a competitive level could deeply modify the immune system and the cytokine response of athletes. In this report, we demonstrated that young elite female artistic gymnasts (n = 16; age: 9–15 years) showed an increase of interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) mRNA expression in blood mononuclear cells (PBMCs), in comparison to girls performing the same sport at a recreational level (n = 16; age: 10–15 years). The increase of IL-6 and TNF-α mRNAs appeared to be directly linked to the intensity and duration of the training. Moreover, in elite athletes engaged in artistic gymnastics or in synchronised swimming (n =34; age: 9–15 years), IL-6 gene expression appeared to be modulated by the levels of circulating oestrogens: pre-pubertal athletes (n = 20; age: 11 ± 1 years) revealed a higher increase in IL-6 than pubertal athletes (n = 14; age: 14 ± 1.6 years). In pre-pubertal athletes, body mass index (BMI) percentile was inversely correlated with the increase of both IL-6 and TNF-α. The consequence of these events was the shift of the cytokine profile towards a pro-inflammatory status. These modifications, induced by training performed at an elite level, might negatively affect the growth of female children athletes.     

2010年黄冈市3～6岁幼儿体质监测结果分析

对2010年黄冈市925名3~6岁幼儿进行体质测试,并将测试结果分别与2010年湖北省3~6岁幼儿体质测试结果和2005年黄冈市3~6岁幼儿体质测试结果进行比较,旨在探讨2010年黄冈市3~6岁幼儿体质总体水平情况及其发展变化规律,为幼儿教育和管理工作提供参考。结果表明:2010年黄冈市3~6岁幼儿体质水平总体情况不容乐观,低于湖北省平均水平,但高于2005年黄冈市幼儿体质水平;男童体质水平总体上好于女童;幼儿身体形态情况总体上明显好于2005年;幼儿柔韧素质水平总体上差于2005年,速度、灵敏素质和协调性总体上好于2005年。     

The happy-fish-little-pond effect on enjoyment: Generalizability across multiple domains and countries

Academic enjoyment is an important educational construct given that it benefits students' engagement, persistence, wellbeing, and mental health. In this study, we examine two factors that determine this crucial emotion, namely student- and class-level achievement. Past research has been restricted to single-country or single-domain examinations of secondary school students, limiting generalizability of findings. To bridge this gap, we utilize the Trends in International Mathematics and Science Study and the Progress in International Reading Literacy Study (TIMSS-PIRLS) combined 2011 data (N = 180,084 4th-grade students, 37 countries). Our results provide robust evidence that student-level achievement positively predicts enjoyment in math, science, and reading, while the effects of class-level achievement are negative—the Happy-Fish-Little-Pond Effect. These results showed relative universality across the domains and countries examined.     

Teachers’ perceptions of assessments of their mathematical knowledge in a professional development course

The purpose of the project reported in this article was to evaluate how assessing teachers’ mathematical knowledge within a professional development course impacted from the teachers’ perspective their learning and their experience with the course. The professional development course consisted of a 2-week summer institute and the content focus was geometry. We had decided to assess the mathematical learning of the teachers during this professional development course for various accountability reasons, but were concerned about possible negative by-products of this decision on the teachers and their participation. Thus, we worked to design assessment in ways that we hoped would minimize negative impacts and maintain a supportive learning environment. In addition, we undertook this evaluation to examine the impacts of the assessment, which included homework, quizzes, various projects, and an examination for program evaluation. Seventeen grade 5–9 teachers enrolled in the course participated in the study by completing written reflections and by describing their experiences in interviews. We learned that while our original intent was “to do no harm,” the teachers reported that their learning was enhanced by the assessment. The article concludes by describing the various properties of the assessments that the teachers identified as contributing to their learning of the geometry content, many of which align with current recommendations for assessing and evaluating grade K-16 mathematics students.

Cloning and characterization of a glucose 6-phosphate/phosphate translocator from Oryza sativa

INTRODUCTIONNongreenplastidsofheterotrophictissuesarecarbohydrate importingorganellesand ,inthecaseofamyloplastsofstoragetissues,thesiteofstarchsynthesis.Investigationofwholetissuesfromavarietyofstarchsynthesizingcropplantsindicatedthathexoseunitswereimpo…     

移动IP的切换技术

从移动性支持的角度。介绍了当前的移动IPv4技术和新一代的移动IPv6的异同。在此基础上。讨论了移动主机切换过程现有的几类技术及其工作原理。如IPv4的低延迟切换技术和IPv6的无缝切换技术。以及MIPv6的层次切换技术。文章将提高移动切换性能途径归纳为分组缓存、组播和由第2层移动触发切换的技术。并提出路径绑定，注册和地址簿通知两项方案，最后讨论了移动IP今后发展的方向。