2017-08-06 231阅读
H
Half-life
The amount of time it takes for one-half of a radioactive sample to decay.
Harmonic series
The series of standing waves supported by a string with both ends tied down. The first member of the series, called the fundamental, has two nodes at the ends and one anti-node in the middle. The higher harmonics are generated by placing an integral number of nodes at even intervals over the length of the string. The harmonic series is very important in music.
Heat
A transfer of thermal energy. We don’t speak about systems “having” heat, but about their “transferring” heat, much in the way that dynamical systems don’t “have” work, but rather “do” work.
Heat engine
A machine that operates by taking heat from a hot place, doing some work with that heat, and then exhausting the rest of the heat into a cool place. The internal combustion engine of a car is an example of a heat engine.
Heat transfer
A transfer of thermal energy from one system to another.
Hertz (Hz)
The units of frequency, dined as inverse-seconds (1 Hz = 1 s–1). “Hertz” can be used interchangeably with “cycles per second.”
Hooke’s Law
For an oscillating spring, the restoring force exerted by the spring is directly proportional to the displacement. That is, the more the spring is displaced, the stronger the force that will pull toward the equilibrium position. This law is expressed mathematically as F = –kx, where F is the restoring force and x is the displacement. The constant of proportionality, –k, is the spring constant.
Hypotenuse
The longest side of a right triangle, opposite to the right angle.
Copyright 2000 - 2020 北京澳际教育咨询有限公司
www.aoji.cn All Rights Reserved | 京ICP证050284号
总部地址:北京市东城区 灯市口大街33号 国中商业大厦2-3层
孙丹 向我咨询
行业年龄 16年
成功案例 4314人
2006年毕业于北京科技学院,英语教育专业,2008年进入澳际预科学校,负责学生管理及外教教学管理工作,后转入澳际咨询部和文案部,负责澳大利亚和新西兰学生的留学方案制定,申请及签证,擅长疑难杂症,专业,热情,有很好的亲和力,已经帮助上千名莘莘学子实现留学梦想,凭借深厚留学工作经验和不懈努力,创造了优秀业绩。
高国强 向我咨询
行业年龄 11年
成功案例 2937人
留学关乎到一个家庭的期望以及一个学生的未来,作为一名留学规划导师,我一直坚信最基本且最重要的品质是认真负责的态度。基于对学生和家长认真负责的原则,结合丰富的申请经验,更有效地帮助学生清晰未来发展方向,顺利进入理想院校。
Tara 向我咨询
行业年龄 6年
成功案例 1602人
薛占秋 向我咨询
行业年龄 10年
成功案例 1869人
从业3年来成功协助数百同学拿到英、美、加、澳等各国学习签证,递签成功率90%以上,大大超过同业平均水平。