本书是一本在20世纪末探讨“民族主义”的经典著作。作者以“哥白尼精神”独辟蹊径，从民族情感与文化根源来探讨不同民族属性的、全球各地的“想象的共同体”，认为这些“想象的共同体”的崛起主要取决于以下因素：宗教信仰的领土化、古典王朝家族的衰微、时间观念的改变、资本主义与印刷术之间的交互作用、国家方言的发展等。本书影响所及几乎横贯所有人文与社会学科，是在理解人类社会诸多现象时不可或缺的指引

• 一、二元体制：建政与盛世 • 二、盛世背后：美洲作物 • 三、被迫开放：白银与鸦片

In lecture D9, we saw the principle of impulse and momentum applied to particle motion. This principle was of particular importance when the applied forces were functions of time and when interactions between particles occurred over very short times, such as with impact forces. In this lecture, we extend these principles to two dimensional rigid body dynamics. Impulse and Momentum Equations Linear Momentum In lecture D18, we introduced the equations of motion for a two dimensional rigid body. The linear momen- tum for a system of particles is defined

In this lecture, we will particularize the conservation principles presented in the previous lecture to the case in which the system of particles considered is a 2D rigid body. Mass Moment of Inertia In the previous lecture, we established that the angular momentum of a system of particles relative to the center of mass, G, was

A pendulum is a rigid body suspended from a fixed point (hinge) which is offset with respect to the body's center of mass. If all the mass is assumed to be concentrated at a point, we obtain the idealized simple pendulum. Pendulums have played an important role in the history of dynamics. Galileo identified the pendulum as the first example of synchronous motion, which led to the first successful clock developed

In this lecture, we will derive expressions for the angular momentum and kinetic energy of a 3D rigid body. We shall see that this introduces the concept of the Inertia Tensor. Angular Momentum We start form the expression of the angular momentum of a system of particles about the center of mass

D244BD RIGID BODY DYNAMICS KINETIC EWEGY In echure we derwed am kinenc a susem u dm T= Fere ts the velouty relanve to G. for a nald body we ca wate Uing the vechor nidontklyAxB=Ax

月界旅行 [法国]儒勒·凡尔纳著 地底旅行 [法国]儒勒·凡尔纳著 域外小说集 《域外小说集》为书，词致朴讷，不足方近世名人译本。 《现代小说译丛（第一集）》，短篇小说集，鲁迅、周作人、周建人合译，收俄国、波兰、保加利亚、爱尔兰、西班牙、希腊、芬兰、亚美尼亚等国18位作家的30篇作品。 一个青年的梦 [日本]武者小路实笃著 爱罗先珂童话集 [苏联]V.爱罗先珂著

老龄化趋势与养老方式的转变 养老保险制度概述 养老保险模式 养老保险收付 典型国家养老保险体系 中国养老保险制度的改革和完善思路 Ø掌握老龄化概念及其我国老龄化特点 Ø掌握我国养老保险的制度框架 Ø了解我国养老保险制度改革中的几个关键特点； Ø了解美国私人养老金401K计划； Ø掌握养老保险的制度类型； Ø能够运用所学的知识对不同的养老保险制度做出评价 Ø对中国养老保险制度改革中出现的热点问题

In this lecture, we consider the problem of a body in which the mass of the body changes during the motion, that is, m is a function of t, i.e. m(t). Although there are many cases for which this particular model is applicable, one of obvious importance to us are rockets. We shall see that a significant fraction of the mass of a rocket is the fuel, which is expelled during flight at a high velocity and thus, provides the propulsive force for the rocket