秋之韵

秋姑娘穿一身五彩袍,摇一手五彩铃,踏一辆五彩车,飘一袭草绿纱,放一路欢声笑语,来了!秋姑娘先抛出彩铃,化出粉、绿、红、橙、黄,分别点缀了月季、柏树、枫树、水杉和银杏树.它们看着自己的彩装,满意地点点头……     

A generalization of Kempe’s linkages

A new, general type of planar linkages is presented, which extends the classical linkages developed by Kempe consisting of two single-looped kinematic chains of linkages, interconnected by revolute hinges. Together with a locking device, these new linkages have only one degree of freedom (DOF), which makes them ideal for serving as deployable structures for different purposes. Here, we start with a fresh matrix method of analysis for double-loop planar linkages, using 2D transformation matrices and a new symbolic notation. Further inspection for one case of Kempe’s linkages is provided. Basing on the inspection, by means of some novel algebraic and geometric techniques, one particularly fascinating solution was found. Physical models were built to show that the derivation in this paper is valid and the new mechanisms are correct.     

在城雕研学中培养学生的美术学科素养

2014年,国务院印发《关于促进旅游业改革发展的若干意见》,将研学旅行纳入中小学德育、美育、体育等范畴。城雕研学通过文化考察模式、生活体验模式等进行展开。本文综述了在城雕研学过程中通过不同模式的研学逐渐培养学生图像识读、美术表现、审美态度、创新能力、文化理解的能力。     

自己装坦克

坦克——男生们的最爱!国庆阅兵仪式上,一辆辆全副武装的坦克徐徐开过,彰显国之强盛。看到这里,很多小朋友是不是都想成为名驾驶坦克的小战士呢?想要成为驾驶坦克的小战士,就得对坦克有一个全面的认识。那今天,就让小峰老师带着大家一起,走进创客课堂,揭秘坦克的“小秘密”,一起来制作坦克吧!不过,我们今天要做的只是坦克的下半部分,包括电机、轮子和履带。     

黄帝的传说

黄帝时代发生过多次战争,其中与蚩尤的涿鹿之战尤为著名,是结束各部落纷争的重要篇章。相传,战争十分激烈,那么加入蚩尤战队的都是谁呢?蚩尤的兄弟们:各个勇猛无比、铜头铁额;苗民:被发动外加逼迫就范;山精水怪:诸如魑魅魍魉之类,因怨恨黄帝手下的神荼、郁垒管制太严,前来投奔。     

主体性视野下的马尔库塞“人的异化”理论

马尔库塞结合马克思的“劳动异化说”和弗洛伊德的“爱欲说”．提出了“人的异化”理论．并从主体性哲学层面细致分析了人的异化的主要表现形态，深入剖析了人走向异化的深层原因。面对现代文明社会中人类普遍异化的现状．马尔库塞进一步探讨了克服异化、拯救主体性的有效途径，即通过艺术实现爱欲的解放。     

给2015年同学的一封信

２０１５年的各位同学： 当你们打开你们的新概念电子信箱时，我──一个２００１年的初一学生写给你们的这封信，也许能幸运地成为你们的“不速之客”。 首先恭贺你们可以坐在电脑前完成我们在学校才能完成的一切课程，用不着担心近视担心成绩担心开小差挨骂担心上课疲倦担心教室外心烦的噪音担心嘴的活动越轨……我们现在吵着闹着买电脑而你们却笑着忙着换电脑。可以这样说，你们所拥有的一切都是我们当今的梦想，社会的发展就是如此神奇，一次次把梦想变为现实，从而又产生新的 梦想…… 在你们接读此信 时，也许正是第一缕阳 光射进你们…     

X探长破案记

前言:X探长是Y小镇上声名远扬的破案高手。他每天奔波在小镇的大街小巷,各种奇案都难不倒他。瞧,X探长又要出发去破案了!01失窃的钻石“丁零零……”急促的电话声响起,X探长拿起电话:“喂!什么事?”“你是X探长吗?我是商业大街88号珠宝店经理,我这里发生了抢劫案!”“好的,保护好现场,我马上就到!”X探长放下电话,立刻驾车赶往商业大街。     

Experimental Study of Structure Shock Vibration in Soil Caused by Explosion of Conventional Weapons

When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments. The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.     

Modeling Strain Rate Effect for Heterogeneous Brittle Materials

Rocks are heterogeneous from the point of microstructure which is of significance to their dynamic failure behavior. Both the compressive and tensile strength of rock-like materials is regarded different from the static strength. The present study adopts smoothed particle hydrodynamics (SPH) which is a virtual particle based meshfree method to investigate strain rate effect for heterogeneous brittle materials. The SPH method is capable of simulating rock fracture, free of the mesh constraint of the traditional FEM and FDM models. A pressure dependent J-H constitutive model involving heterogeneity is employed in the numerical modeling. The results show the compressive strength increases with the increase of strain rate as well as the tensile strength, which is important to the engineering design.