《解决问题的策略》一课的教学反思

全课借助王大叔围花圃买花苗的情境,把遇到的一系 列问题与书中例题及练习题结合起来’使本来比较散乱的教学 内容相对紧凑,自然连贯。课中多处采用小组合作的学习形 式’既调动了全班学生的参与热情’又兼顾了学困生,因为这-- 教学内容对于学困生难度是很大的。     

关于钠和水反应的实验

本文针对现行高中化学教科书中关于钠与水反应的实验，提出一较简便的钠和水反应的实验方法并说明该实验方法成功的关键。     

Research on new software compensation method of static and quasi-static errors for precision motion controller

To reduce mechanical vibrations induced by big errors compensation, a new software compensation method based on an improved digital differential analyzer （DDA） interpolator for static and quasi-static errors of machine tools is proposed. Based on principle of traditional DDA interpolator, a DDA interpolator is divided into command generator and command analyzer. There are three types of errors, considering the difference of positions between compensation points and interpolation segments. According to the classification, errors are distributed evenly in data processing and compensated to certain interpolation segments in machining. On-line implementation results show that the proposed approach greatly improves positioning accuracy of computer numerical control （CNC） machine tools.     

写好今年的高考作文不容易

首先要写好这20分的小作文,就不是一件易事。根据漫画写说明文,这是一种老题型,1983年高考的小作文就是如此。各地各学校在考前应该有所练习,考生不应该生疏。那么,难度在哪里呢?一是说明的漫画不是一幅,而是两幅,而第二幅漫画的信息容量又很大;二是说明的字数有限制,仅200字左右,控制的上限最多也不能超过220字。如何在这220字内,既概括全面又能突出说明重点,就是一个大难题。因     

Optimization design and residual thermal stress analysis of PDC functionally graded materials

INTRODUCTION Polycrystalline diamond compacts (PDC), con-sisting of a polycrystalline diamond (PCD) layer on a WC-Co substrate, and having high hardness and abrasive resistance, are used in a variety of drilling and machining applications (Farhad, 2001; Sadi and Muzaffer, 2001). However, due to differences of thermal and mechanical properties in diamond and WC-Co substrate, residual thermal stresses develop in regions near the interfaces during fabrication. The diamond coating exhib…     

Identification of quantitative trait loci and epistasis for root characteristics and root exudations in maize （Zea mays L.） under deficient phosphorus

The phosphorus uptake （PU） in above-ground parts of plant, root characteristics and root exudations as well as the quantitative trait loci （QTLs） associated with these characteristics were determined for a F2：3 population derived from the cross of two contrasting maize （Zea mays L.） genotypes, 082 and Yel07. A total of 241 F2：3 families were evaluated in replicated trials under deficient phosphorus conditions in 2007 at two sites （Kaixian County and Southwest University, Chongqing, P. R. China）. The results show pleiotropy and close linkage among QTLs. Four common regions in different environments were in bnlg100- bnlg1268b （bins 1.02） for QTL of H＋, bnlg1268a-umc1290a （bins 1.09） for QTL of AP （acid phospbatase activity）, dupssrl5- P 1MT/a （bins 6.06） for QTLs of PU （phosphorus uptake） and RW （root weight）, and P IM3/d-P1M3/g （bins9.04） for QTLs of PU and AP. These QTLs are non-environment or minor QTLs x environment. By epistatic analysis, three main QTLs and eighteen QTLs x QTLs interactions were detected for the seven measured characteristics. These QTLs may affect trait expression by epistatic interaction with the other loci, and make a substantial contribution to phosphorus utilization efficiency, which should be considered when breeding maize varieties with high P efficiency. Two regions were detected in dupssrl 5- P1MT/a （bins 6.06） for QTL of RW and P1M3/d- P 1M3/g （bins 9.04） for QTL of PU and AP. They were detected in two different environments and by two methods of QTL analysis, which were useful for marker-assisted selection.     

远程教育资源应用于物理教学的原则

物理教学中借助于电教媒体、运用远程教育资源,能够使抽象知识具体化、形象化,简明生动,有助于化难为易,突破重点和难点,从而提高学生的观察能力和分析能力,优化课堂教学结构.在选择远程教育资源的同时应该制定以下原则:     

1996年全国高考作文审题正误辨析

写好今年的高考作文不容易今年的高考落下帷幕,家长、考生和老师们对今年高考的作文题却谈兴正浓。其中,普遍议论的是今年的作文题到底怎么作,心里没准儿。难怪有这样的议论,事实上,要写好今年高考作文的确不容易。今年的作文题目是“一大一小”,原题是这样的: 仔细观察下面《给六指做整形手术》和《截错了》两幅漫画,完成32--33题。     

“众数的认识”教学实录与评析

教学内容：苏教版《义务教育课程标准实验教科书·数学》六年级下册第79页例2和“练一练”相关练习。 教学目标： 1．使学生通过具体的实例初步理解众数的意义，会找一组简单数据的众数，能解释众数的实际意义，并能根据具体的问题选择适当的统计量（平均数、众数）表示一组数据的特征，通过比较体会不同统计量的特点。     

地质工程一体化应用助推普光高效勘探

普光气田地表条件复杂,陆相地层倾角大,砂泥岩互层,软硬交互层多,有效控制井斜和陆相钻井提速困难;储层埋深大,高温高压,非均质性强,储层改造风险大。通过地质工程一体化理念,进行精细地质研究,优化井位设计,指导工程设计,对施工设计反复研究,规避施工难点,降低工程施工风险,有效控制陆相井斜,提高钻速,减少井下复杂情况的发生,缩短钻井周期,达到优快钻井目的。树立地质工程一体化理念,通过精细地质研究提高工程施工的针对性,有效性,同时通过有效的工程技术保障钻探目的的实现,达到降低钻探成本、提高井身质量的目的,为普光探区高效勘探打下基础。