MAC算法计算二维方腔顶盖流动

二维方腔流动是不可压缩黏性的典型流动,可以用来检验各种数值算法计算精度和可靠性,目前尚不能求得它的解析解.基于Matlab编程,采用交错网格MAC算法求解二维方腔流动,计算采用控制容积积分法离散控制方程,对流项和扩散项采用中心差分格式,得到流动达到稳定状态时各物理量的分布.     

球磨机磁性衬板在铁矿选矿厂中的应用

文章介绍了磁性衬板在承德某铁矿选矿厂和滦县某铁矿（一期）选矿厂的实际应用情况,通过对其技术性能的分析和其使用寿命的调查,实践证明了这种磁性衬板优点和可靠性,两个选厂的球磨机通过采用磁性衬板从而降低了衬板及钢球消耗、降低了磨矿电耗、增加了筒体有效容积、降低了噪音,为矿山节能减排,建设绿色矿山创造条件。     

小高斯巧算物体的容积

明明是新村小学六年级的学生,平常就爱动脑筋,特别爱钻研数学题,是班里的数学兴趣小组的组长,同学们都称他是"小高斯"。周末的一天,张爷爷和李爷爷在院子里的大树下喝酒乘凉,明明在一旁看书写字,望着勤奋好学的孙子,两位老人就想考考他的数学知识和能力。张爷爷说:"明明,我这个桌子上有半瓶酒,你能算出这个酒瓶的容     

CNG无缝钢瓶弯曲原因的分析

本文对4130X钢制作的大容积无缝钢瓶调质热处理时产生弯曲的原因进行了分析,对钢瓶的校直方法进行了阐述.     

包星震:挑战传统计量理论

"计量结果是量值传递的结果"这是计量学的基本理论和人们的常识。但是,在石油零售行业中出现了"一种卧式油罐的容积检定方法"——高量拟技术,创造了计量学科中新的思想——量值溯源可实际应用。其基本理念为:"当量值传递的结果不理想时,实施逆向的量值溯源条件成立,则应用量值溯源方式可以得到超出想     

Treatment and hydraulic performances of the NiiMi process for landscape water

This paper describes the NiiMi process designed to treat landscape water. The main aim of the research was to investigate the feasibility of NiiMi for removing organic and nutriment materials from landscape water. During the batch-scale NiiMi operation, the removal rates of color ranged from 66.7%o-80% , of turbidity from 31.7%-89.3%o, of chemical oxygen demand （COD） from 7%-36.5%, of total phosphor （TP） from 43%-84.2%, of soluble phosphate from 42.9%-100%, of total nitrogen （TN） from 4.2%-46.7%, and of NH4^＋-N from 39.3%-100% at the hydraulic loading of 0.2 m^3/（m^2·d）. Results showed that the removal efficiencies of COD, TP, soluble phosphate and TN decreased with the decline in the temperature. The NiiMi process had a strong shock loading ability for the removal of the organics, turbidity, TP, soluble phosphate, TN and NH4^＋-N. Three sodium chloride tracer studies were conducted, labeled as TS 1, TS2, and TS3, respectively. The mean hydraulic retention times （mean HRTs） were 31 h and 28 h for TSI and TS2, respectively, indicating the occurrence of a dead zone volume of 12% and 20% for TS 1 and TS2, respectively. TS 1 and TS2 displayed the occurrence of short-circuiting in the NiiMi system. The comparison results between TS1 and TS2 were further confirmed in the values obtained for some indicators, such as volumetric efficiency （e）, short-circuiting （S）, hydraulic efficiency （2） and number of continuously stirred tank reactors （N）.     

可以放几个小纸盒

[病例]一个长方体纸箱从里面量长17 dm,宽12 dm,高11 dm,要在纸箱里放棱长是4 dm的小正方体纸盒,可以放几个?[病症]先求大纸箱的容积:17×12×11=2244(dm~3);再求小纸盒的体积:4×4×4=64(dm~3);最后求出可放的小纸盒个数:     

“思维训练”教学设计与评析

1.出示药瓶：在一个标有容积刻度的瓶子里，装有大半瓶的液体，求这个瓶子中窗余部分的容积是多少怎么办？小组合作交流，看着哪个小组想法更巧妙？     

把割去的再焊上

星期天,冯小明和张小虎做完作业后,一起出去玩儿。他们走到张大爷家门口时,张大爷向他们招了招手,说:"来,来,来,都说你们聪明,我正好有道难题想请你们帮忙解决。"