After 100 , 000 to one million years , depending on the original mass of the star , it ceases altogether , and the remnant star settles down as an extremely dense and hot white dwarf ? a stellar ember crushed by gravity into a nearly crystalline orb about the size of earth 经过10 ~ 100万年（取决于恒星的原始质量） ，恒星风将骤然终止，而恒星的残留物会演变成极致密高热的白矮星：一种被重力挤压成地球般大小，近乎晶质球体的恒星遗骸。
Traditionally , it was thought that nutrient flow in such systems moved in one direction only , driven by gravity : nutrients , in the form of leaves , invertebrates and other material , fell from the forest into rivers and creeks , flowed downstream and moved out to the ocean 传统的观念认为，这类生态系的养份流动由重力牵引，仅遵循单一方向移动，也就是养份以树叶、无脊椎动物和其他物质的形式，从森林掉落到河流或小溪中，然后顺流而下流入大海。
An iron - containing material with an iron grade of over 20 % can be recovered from magnetic separation tailings of liuling iron mine by gravity method . this material can be used instead of partial clayey material to produce portland cement so as to reduce the mine tailings discharge amount to 43 . 52 % , to raise the iron recovery from 70 . 89 % to 84 . 62 % and to reduce the iron ore powder consumption in raw cement mixture and the energy consumption of raw material grinding 用重选法从刘岭铁矿磁选尾矿中回收铁矿物，可获得铁品位大于20 %的含铁物料，用此物料代替部分粘土质原料生产硅酸盐水泥，使矿山尾矿排放量减少至43 . 52 % ，铁的回收率由70 . 89 %提高到84 . 62 % ，并且减少了水泥生料配料中铁矿粉的用量，降低了生料粉磨能耗。
2 ) a simplified sprinkler system which is composed of water source , pipeline pump , pipes , current of water display , nozzle , contral valve , is suitable for our country . and its water is supplied by gravity tank or gravity tank or hydrant system or city 3 ) spray intensity of simplified sprinkler system is 3 l / min . m2 , protection area of them is 50m2 3 )简易自动喷水灭火系统的喷水强度为3 / min . m2 、保护面积为50m2 、喷头的安装间距为3 . 7m等参数。 4 )简易自动喷水灭火系统最大设计动作喷头数为四只,供水时间宜为30min等。
( 3 ) when evaporation was stopped during the process of soil water redistribution , soil water would move downslope by gravity . when evaporation was in process , due to low initial water content , most infiltrated water from small intensity and amount of rainfall would be consumed by intensive evapotranspiration during rainy season , and lateral downslope unsaturated flow seldom took place . however , soil water would move downslope by gravitational and matric potential gradients after continuous rainfall ( 3 )在防止蒸发条件下，再分布过程中，土壤水分在重力的作用下有沿坡向下运移的趋势；在蒸发条件下，由于初始含水量一般较低，雨季量小且分散的降雨极易为强烈的蒸发蒸腾所消耗，侧向沿坡向下流难以发生，但在持续的降雨条件下，土壤水分在重力势和基质势梯度的作用下易沿坡向下运移。
Generally , the gravity introduced deformation of an optical lens with smaller aperture ( < ( 100mm ) within visible band is about ( / 20 even less than this value . for general optical lens , this error level can be entirely neglected . but for the high - accuracy optical system within extreme ultraviolet band , the error caused by gravity deformation will lead to imaging quality degradation 本文较为系统地介绍了光学镜头的装配与调校方法，一般地讲，在可见波段内，光学镜片口径较小（ < 100mm ）时，重力引起的变形一般/ 20左右甚至更小，对于一般的光学镜头这样量级的误差完全可以忽略，但在极紫外短波长的高精度光学系统中重力变形带来的误差会使光学系统成像质量下降。
They found two events showing the shortening of pulsating cycle and decaying of radiations intensity . the signatures matched theories of what scientists would predict to see . when matter is falling so close to the event horizon , it will be circling the black hole with increasing speed and its light will rapidly dim as it is stretched by gravity to ever - longer wavelengths 研究人员分析了极大量来自致密天体天鹅座xr - 1的紫外线辐射，发现其中两组数据显示，辐射脉冲的周期随时间缩短，而其强度则随时间衰减至消失，这现象与一些物质在接近黑洞视界时绕著黑洞急促旋转，放出的辐射因为重力红移而衰减的情况相符。
In section one , by using fice scheme and time - gcm , a model of trace gases and oh airglow affected by gravity wave is set up , then the propagation of nonlinear gravity wave and the effect on trace gases and oh airglow are analyzed . the result shows gravity wave excited by tropospause forcing can propagate stably to the mesosphere through the stratosphere so that energy and momentum can be transferred from one region to another . in this process , gravity wave undergoes growth , overturning , convection and breaking 在第一部分的工作中，利用全隐欧拉格式和全球热层-电离层-中间层-电动力学环流耦合模式（ time - gcm ） ，对重力波的非线性传播及其在传播过程中对中高层大气中氧族和氢族成分和与之密切相关的oh气辉辐射的影响进行了数值模拟，结果表明，从对流层向上传播的重力波经历了产生、发展、饱和、对流产生直至破碎的非线性演化，大气的非等温结构加速了重力波在中层顶区的破碎，重力波的非线性传播是小尺度对流和湍流产生的一个重要的源。
The sedimentary water is the carrier and main driving force of petroleum migration and accumulation , which controls the fluid movement and appears centrifugal flow from the center to edge of basin , while penetrated water formed by infiltration of atmospheric precipitation and surface water appears centripetal flow from the edge to center of basin by gravity process 沉积水是油气运聚的载体和主要动力，对盆地流体的运动起控制作用，由盆地中心向盆地边缘呈离心流；渗入水由大气降水和地表水的渗入产生，受重力作用由盆地边缘向盆地中心呈向心流。
The thickening may be synthetically aroused by many factors , because of the lower maturation of source rock at forepart , the rock tar is thicker , and then many other factors impel it , which include the hydrocarbon dissipation at the process of oil and gas migration , biodegradation and bathing oxidation induced by gravity induced centripetal flow recharged by meteoric water at the basin uplift period and etc 稠油成藏则由多因素综合作用造成，由于早期源岩成熟度较低，原油本身较稠，而油气运移过程中轻质组分散失、生物降解和盆地抬升剥蚀阶段大气水下渗所导致的水洗氧化等作用则使其进一步稠化。
