简述给排水管线施工的具体实施程序

给排水管线的施工对于给排水的施工的整个过程是最为重要的一部分，给排水管线是城市重要的基础设施，在整个给排水的系统中占有举足轻重的地位。     

多元复合稀土钨电极使金属焊接切割绿色环保

我国“多元复合稀土钨电极及其制备技术”成果日前通过专家鉴定。这项由北京工业大学与北京矿冶研究总院北京钨钼材料厂合作研发的多元复合稀土钨电极系列新产品、制备工艺和装备，以及检测设备等全套产业化技术，产品综合性能优于放射性钍钨电极，解决了我国相关材料产业的一大技术难题。[第一段]     

巧联想妙构造速解竞赛题

在数学竞赛中,学生若能根据所提供的材料进行巧妙的联想与构造,往往可使一些赛题迅速获解,其过程能充分展示学生的创造能力与智慧.这里以近年竞赛题为例归纳几种联想、构造的方法与技巧,供大家参考.     

婚姻：切割个人的屠床

就像生猪肉渴望拥有一个蓝印，被社会所包裹、在制度中行走的大多数人，总在自愿或被迫或半推半就中，忙不迭地给自己缝上一个个标签，以证实自己是正常的乖顺的有责任感的良好公民。戏耍、上学、找份工作、结婚、生子、变老，最后躺在洁白的床单上等待自己的凋谢——这便是许多人的人生轨迹。     

用Fireworks切割图形

做过网面的朋友一定都知道：网站好，网页就得小。在不减少内容的情况下，网页能够做得越小越好。而给网页瘦     

Analyzing the Interdependence Between Some Certain Gene Loci by Epistasis Measures in Fitness Landscapes of Schemata

GA-hardness and interdependence between genes in the chromosome are important questions in the study of genetic algorithms (GA) ,Traditional methods,which are used to measure the interaction between genes,can only reflect the extent of epistasis between all genes in the chromosome, Therefore,the definition of the fitness landscape of schemata is proosed in this paper,and epistasis measures on this landscape of schemata are used to analyze the degree of interdependence between some certain gene loci in study ,Some information between these sites can be reflected by some characters of the fitness landscape of schemata which are composed of these fixed sites,The stronger the interaction between these sites,the larger the variation of the fitness of schemata whose fixed sites correspond to those sites in study ,and the more rugged the fitness landscape of these schemata,According to the degree of interaction between given gene loci ,building blocks of GA can be analyzed and determined,and further genetic operators and the structure of GA can be designed and adjusted to improve the perfomance of GA ,At last,a lot of experiments including NK-models are done,and results of empirical analysis show that this method is effective.     

基因剪刀--核酶

阐述了核酶的主要功能及结构特点，介绍了核酶作为基因剪刀在分子生物学领域的应用及其发展前景。     

高压水射流切割的CFD仿真研究

利用计算流体动力学(CFD)的方法对高压水射流流场进行了多相流的数值模拟分析。结果表明：射流在淹没流下的能量耗散远大于非淹没流；圆锥型射流喷嘴的射流效果好于圆柱型和锥直型；射流过程中不同直径的磨料对水速影响不大；靶距选择距离射流出口5～8D处，磨料颗粒和水柱速度达到最佳。