雨花石的象征意义和其价值

再加上一块,则剩下的又可以包一包了
所以此时是4,5,6,7,8,9,10的公倍数
4,5,6,7,8,9,10的最小公倍数=2³*3²*5*7=2520
所以原来有2520n-1
不到5000
所以2520n-1

1,设玲玲带了X元则华华带了38-X元,列方程X-6=38-X-2得X=21,则玲玲带了21元,华华带了38-21=17元
2,设菠萝派价格为X,则饮料价格为2X,汉堡价格为6X,列方程6X+2X+2X=25,得X=2.5元,则汉堡的价格为6X=15元,菠萝派的价格为2,.5元
3,设园形等于X,则三角形等于4X,列方程4X+X=65,得X=13,则三角形为4X=52,圆形为X=13
答案给你了,但是希望你还是能靠自己做出来,自己独立的完成才能学好

滤料sieve stuff
雨花石 rain flower rock
五彩石 five color rock
网片石 net flake rock
石英沙 quartz sand
喷砂机
peening machine

孔尚任的
千岁江,万年风,滴就乾坤难老松.石玲珑,夺巧工,帷幔重重,觅个相思梦.
宋洪成的

解题思路：要想测量雨花石的密度，必须想法测出质量和体积，此题中的体积是利用等效替代法测出，即利用雨花石体积和溢出水的体积相等作为桥梁求出雨花石的体积，根据ρ=[m/V]求出雨花石的密度．

（1）实验中应用天平称出水和小玻璃杯的共同质量m₂，从而求出玻璃杯中水的质量，求出水的体积，即为雨花石的体积；
（2）玻璃杯中水的质量：m_水=m₂-m₁，雨花石的体积V=V_水=
m水
ρ水=
m2−m1
ρ水，
雨花石的密度：ρ_石=
m石
V=
m石

m2−m1
ρ水=
m石
m2−m1×ρ_水．
故答案为：（1）⑤用天平称出水和小玻璃杯的共同质量m₂；
（2）ρ_石=
m石
m2−m1×ρ_水．

点评：
本题考点： 固体的密度测量实验．

考点点评： 本题是一道测量密度的实验题，根据实验原理想法测出物体的体积是解决此题的关键，注意等效替代法的运用．

1t

千里送鹅毛，礼轻情意重

下降,石头的密度比水的大,

2.8-2.5=0.3dm 5×3×0.3=4.5m³

利用曹冲秤象的原理：
先将一只烧杯置于水巢中,烧杯中放入雨花石,在烧杯壁上与水面相平的位置用彩笔画一条线；
拿掉雨花石,向烧杯中注入水使烧杯壁画线处与水面再次相平.将烧杯中的水倒入量筒中,测得水的体积.根据水的密度可算得这些水的质量,也就是雨花石的质量.
取量筒,加入少量水,小心地将雨花石沿量筒壁置于量筒内,测得量筒内水面高度上升的量,即得雨花石体积.
质量除以体积,即得雨花石密度

有人说雨花石是泣血的，因为它上面的红色是烈士的血凝成的。在我家的书桌上就有几块，望着那美丽迷人的雨花石，我心里真有说不出的喜欢。雨花石是花形的石，是石质的花，是观赏石中的一朵奇葩。传说有位云光法师在现...

然后呢

雨花石的成分是以二氧化硅为主,其中红色成分为铁离子和亚铁离子.雨花石是石质为玛瑙、蛋白石、玉髓、石英等的卵石,见于河床、河流阶地的沉积物之中,其中最著名的是南京六合横林镇（雨花石之乡）产出的雨花石.雨花石又分为细石和粗石两类,细石以玛瑙为主,石质细腻,颜色艳丽,磨圆度高,晶莹可爱；粗石质地较粗,以石英或变质岩为主,价值较低.美丽的雨花石中常可呈现各种山水、人物、鸟兽、树木等景象,使人遐想联翩,思绪入石,非常漂亮. 由于雨花石种类繁多,它的成因和化学成分极为复杂.以玛瑙砾石为例,它来源于雨花石原生玛瑙.一般认为,原生玛瑙是由岩浆的残余热液形成的.这种热液充填在火山岩如玄武岩、流纹岩的空隙中,因空隙的形状不同,或成玛瑙球,或成玛瑙脉.经过自然力的作用,原生玛瑙脱落而出,再经过山洪冲击,流水搬运,磨成卵石.这就是我们所见到的在砾石层中的雨花玛瑙石. 雨花石以其纹奇、色艳的自然美著称于世.它的圈状花纹是二氧化硅胶液围绕火山岩空隙、空腔,由内壁开始,从外向内多层次逐层沉淀而成.在其生长过程中,常常发生带色离子和化合物的周期扩散.原生玛瑙的主要化学成分是二氧化硅,其次是少量的氧化铁和微量的锰、铜、铝、镁等元素及化合物.它们本身具有不同的色素,如赤红者为铁,蓝者为铜,紫者为锰,黄色半透明为二氧化硅胶体石髓,翡翠色含绿色矿物等等；由于这些色素离子溶入二氧化硅热液中的种类和含量不同,因而呈现出浓淡、深浅变化万千的色彩,使雨花石及其艳丽秀美
转自百度

ain flower pebbles(雨花石) 或Yuhua pebbles
变压器专用卵石

Stone
Introduction
Generally referred to stone people usually associate it with: Nanjing Yuhuatai, all thought that the stone is produced in Yuhuatai area, in fact, this is only the people's misunderstanding.
Ornamental Stones stone is one of the world in a wonderful, beautiful colors and patterns available for viewing. She mainly from the Yangtze River, Nanjing has beautiful scenery and Liuhe. Stone in order to "spend" the name of flower and crown rain, beautiful.
history and legend
Gestation to stone formation, after the formation of primary, secondary layer of gravel and sediment removal of these three stages of the complex and lengthy, but also can be experienced significant romantic side of the vicissitudes of life. Stone, is a natural flower agate, mainly produced in Luhe District, Nanjing City, Jiangsu Province, for the nation's largest stone origin. Produced by the quality of stone, shape, pattern, color, was like, six mood in both the United States, known as "heaven-sent David, the Chinese a must." Beautiful stone was appreciated, collectors have thousands of years of history, in recent years, weathering complex, the stone much at home and abroad who favor and become a gift from relatives and friends and enjoy a collection of precious gifts.
Stone unique to the United States for China's stone, in百千kinds of stones, the stone can be called the best in Queens. Referred to stone, is a head start on the stone myth: the ancient legend of the platform is a Yuhuatai Yuhuatai concept, Yuhuatai Yuhuatai concept in a real person. Yuhuatai live a dignified and wise, deep Ruoxu, he staged a sit-in rather than by the Christian and Missionary Alliance, as if their is a MacGraw玄秘by the book. One day, Yuhuatai real open altar preaching. Implication, hanging river water into the root of the matter, cough spit into beads, the charm of the character and wisdom shocked many people moved heaven and even the gods, gods command joy of colorful rainy weather to rain. Colorful rainy weather杂沓shoulder to shoulder and the next one after another, like a treasure in the National Palace Museum in the landscape scroll Mi Fu. Yuhuatai泠泠rainwater percussion on stage in a粒粒turned into a stone like agate.
Chemical composition
Silica stone composition is mainly composed of red iron ions and ferrous ions. Stone is a stone for the agate, opal, chalcedony, quartz pebbles, etc., found in the riverbed, river terrace sediments, of which the most famous Nanjing Yuhuatai stone output. Stone is divided into small two types of stone and rough stone, small stones to agate mainly stone delicate, bright colors, rounding high Jingying lovely; coarse to coarse stone, quartz or metamorphic rock mainly low value . Beautiful stone often can present a variety of landscape, figures, birds, animals, trees, such as a scene of people lost in conjunction Pina, thoughts into the stone, very beautiful.
As a result of a wide range of stone, its causes and chemical composition is extremely complex. To agate gravel for example, from the original agate. Is generally believed that agate is a native of residual magmatic hydrothermal formation. Such hydrothermal filling in the volcanic rocks such as basalt, rhyolite gap as a result of the gap of different shapes, or into agate ball, or into a vein agate. After the role of the forces of nature, native agate falling out after the impact of flash floods, water handling, ground into gravel. This is what we have seen in the gravel layer Yuhuatai agate stone.
Stria stone its surprising色艳known to the world of natural beauty. It is the ring-shaped pattern around the volcanic silica glue gap cavity, the wall began, from the outside-in multi-layered sediment layers formed. In its growth process, often with color ions and compounds the cycle of proliferation. Agate raw main chemical composition is silicon dioxide, followed by a small amount of iron oxide and traces of manganese, copper, aluminum, magnesium and other elements and compounds. They themselves have different colors, such as red for iron, copper for blue, purple for manganese, yellow translucent stone for myeloid colloidal silicon dioxide, emerald green color with minerals and so on; as a result of these ions into dioxide pigment hydrothermal silicon content in different types and, thus showing a bias, changing color depth, so colorful and beautiful scenery.Chinese knot
Historical presentation
Code 70000 to the hundreds of thousands of years ago before the end of the Paleolithic Age, when the Shanding cave people already know that the use of bone needles and line mending skills, will be wearing animal skins stitched together to cover their bodies in the body to keep out the cold, that is to say, the Peak-dong people already know how to tie the rope together, then all sorts of knots on the gradual development of out. Early Chinese literature on the knot of the records, such as the I Ching: "The Elder结绳记事, saints also future generations of mutual covenant by the book." Han Zheng Xuan Zhouyi Note: The "big event of its rope knot, small nodules of its rope."
Chinese knots from Paleolithic sewing knot, extended to the rites of the Han Dynasty Notepad,再演into today's decorative craft. Chou people wear jade portable often decorative Chinese knot, and the Warring States Period Bronze There is also a Chinese knot pattern continues until the Qing dynasty Chinese knot is really popular in the folk art of the time, when many used to interior decoration, gifts among friends and relatives and personal ornaments of the Walkman. In 69 years (1980), a group from Taiwan art-loving friends rope knot widely collected and research, because of its delicate appearance of symmetry, can represent a long history of the Chinese nation, in line with the practices of traditional Chinese decoration and aesthetic concepts, it is named for the Chinese knot.
Chinese knot establishment, the community must be prepared, pump, repair process. The provision of various node is fixed, but may decide to pump knot elastic body, ears wing length, smooth and neat lines, you can fully demonstrate the art editor of the skills and self-cultivation. Repair, compared with the final knot modification, such as sewing beads, sizing and so on. Node changes as a result of numerous and elegant decoration, made of wire used in addition to cotton, hemp, silk, nylon and皮线, there are gold and silver and other metal wire can be used with, but also enhance the function of decorative Chinese knot, and the scope of application. Whether it is a variety of jewelry, clothing accessories and gift packaging landscaping, as well as a variety of indoor furnishings decorative items can be added with Chinese knot to beauty.
Chinese knot is not only sleek, color variety, at the same time naming works, such as the "double life", "Double Happiness", "Ching Cheung Fung-lin," "跃龙门carp," "Fushou have both", "good luck", "more than Jiqing "," FANG Sheng Ping'an "... and so on, are unique to the Chinese auspicious symbol of good will of those of special significance to the relatives and friends played guitar, not only filled with joy and a thousand Italian intelligence million blessing.
At present, China's basic knot knot more than 10 kinds of law, its name is based on the shape of knots, use, or the origin and meaning of the original names.
For example,
1. Two-money knot: the shape of ancient Chinese coins like two semi-stacked format, named.
2. Button knot: used to fastens clothing, named after its function.
3. Oxalis knot: its three external ear like Oxalis leaves, hence the name.
4. Mission Kam knot: appearance similar Hanagata, named. Kam-knot knot-shaped Mission successful, dynamic, similar Hanagata guitar body is small but beautiful and not easy to loose, often inlaid stone beads, very beautiful.
5. Cross knot: Colorectal the two sides, one for a word, one for the Crusaders, known as Cross knot.
6. Auspicious knot: auspicious became an extension of Cross knot is also one of the oldest decorative knot, there are auspicious meaning auspicious. Law made simple, guitar-shaped appearance, but also very dynamic and very broad applications, when used alone, if the hoisting of heavy, guitar-shaped easy to deformation, may be fixed amorphous plastic.
7. Million characters knot: the knot body lines to as a symbol of Buddhism, named.
8. Disk long knot: basic shape as one of the Buddhist Babao disk long, long plate is a symbol of carrying out the circle is the origin of all things, is the most important one of the basic knot, many changes are often the main knot knot, but also because China has a close knot symmetrical features, so the visual sensory easily by ordinary people like.
9. Caisson knot: compact structure, beautiful, like the ancient courtyard derived from the name. Well homonym and Kam, also known as caisson.
10. Ping knot: Ping node is based on first-line or a dual axis, another line formed at both ends of the shuttle around the axis, flat-node uses a wide range of thickness can be used to connect the same string, but also the preparation of bracelets,挂链and other accessories.
Chinese knot like Chinese calligraphy and painting, sculpture, ceramics, dishes, as it is easy to identify the foreigners out, we can see Chinese knots representative of the Chinese nation.
Chinese knot Arts is unique to China handmade folk art knitting, it its unique oriental charm, rich and colorful changes, fully embodies the Chinese people's wisdom and profound culture. Bid to host the Olympic Games in Beijing, the Chinese knot as a symbol of traditional Chinese culture by a friend's favorite countries.
Chinese people will be quite a long time ago learned how to tie a knot. And 『』 knot has been people's lives in China accounted for a decisive position, balance the importance of having this reason, the main one of the reasons is because it is a very practical technology. This can be from a number of historical and traditional customs see a clue: The earliest record
As early as the late Paleolithic, that is, the culture of the Zhoukoudian Ruins Shanding cave people, they found bone needles 』『 existence. Since there are needles, then it also must have rope lines, it concluded that, when a simple guitar string and sewing technology should have been taking shape.
1, the predecessor of text
Copulative easy set: 『结绳记事Elder, generations of saints easy to book』 Lease, and and Zheng Xuan also note that the Book of Changes; 『big big knot of its rope, the rope』 small nodule in the Warring States Period Bronze seen Digital symbols are still rope knot shape, from these historical information, the knot was used as auxiliary memory is indeed a tool, it can be said to be the predecessor of the text.
2, dressed in the habit of
1) Clothing
The earliest clothes do not today's buttons, zippers and other accessories, so if their clothes fastened, it can only use this method to tie a knot衣带.
2) Yu-allocation
Chinese people have always had the habit of Peiyu, ancient jade shapes Huang Yuh-pei, Yulong, jade and other □. Both in its drilling a small hole in order to cross the rope, Yuh-pei grades in these clothes. In addition, there are a set of Yuh-pei is a good combination of several different types of Yuh-pei Cheng Lin-lin sound of loud reading the long list, and its link to the method of course, by wearing non-knotted rope not.
3) Application
Print button and the mirror button
An old Chinese saying to the Department of Indian section supervisor wear in his habits, the Chinese have been handed down more than India, Fang Fang and India have a button. Ancient bronze mirrors and the back of the central authorities have cast there mirror button, you can tether in order to facilitate the hand-held.
Decorative knot meaning: First, from the knot decorated shape; Second, select the homonym
1. FANG Sheng knot - a safe journey home
2. Double Butterfly knot - BizArt Shuangfei
3. Ruyi knot -吉祥如意
4. Mission Kam knot - best for the future
5. XIANGYUN knot - XIANGYUN continuous
6. Double Happiness knot - double
7. Guihua knot - boundless wealth
8. Reunion knot - a happy reunion
9. Have this knot - sons and daughters have both
10. Two-knot - sources Hengtong
11. Beas knot - more than Jiqing
12. Disk long knot - longevity centenarians
13. Ping'an knot - wishful Ping'an
14. Tongxin knot - never tie the knot
15. Dual-link - both pairs
16. Lei knot - more than Jiqing
17 Fan Yi Pan knot - rock-solid as a mountain

雨花石从材质来说主流的是玛瑙材质的,密度是2.65克/立方厘米左右,硬度为6.5—7立方厘米,雨花石中的水晶材质的密度为2.65克/立方厘米,硬度为7.雨花石中的高端材质蛋白石的密度为 2.15－2.23g立方厘米.硬度为5.5—6.5..

盛夏的微风轻轻地吹拂着河边长如发带的柳丝.圆圆的月亮不知什么时候已从渐渐暗去的天边升起来.路边的雨花石在柔和的月光下像极了清澈的翡翠.远处八达岭上,前来旅游的游客踏着皎洁的月光登上了这座千年历史的长城,感受着历史带来的文明.北京城四合院的一间老旧屋子里,慢慢地走出一位花白胡须,佝偻身躯的老人,一切都是那么平和安静,而时间,也在这平静中悄无声息地溜走了,留下泛黄的记忆.
仅作参考,你可以再修改修改

解题思路：实验中应按天平的使用规则进行调节和读数；在称量过程中，如果试加了最小砝码后，天平仍不能平衡，则应移动游码来使其平衡；最后的密度应通过公式计算得出．

在调节天平时，应将天平放在水平桌面上．调节时指针偏左，说明左侧质量大，应向右移动平衡螺母；
称量中，试加了最小砝码后，天平仍不能平衡，则应移动游码直至天平平衡；图中天平的示数为50g+3.4g=53.4g
雨花石的密度ρ=[m/V]=
53.4g
20cm3=2.67g/cm³．
故答案是：向右盘添加砝码或将游码向右移动；53.4；2.67．

点评：
本题考点： 固体的密度测量实验．

考点点评： 在测密度的实验中，天平的调节与使用，密度公式的计算，都是我们应该掌握的基本内容，应重点加以练习．

石灰石、苦榄岩 – 玄武岩 – 安山岩 – 花岗岩 –粗面岩 –响岩 –脉岩 – 火山碎屑岩

就是那个样子的.既然是在水中冲刷出来,那么就不会与水发生剧烈的反应.

（强壮 ）的体育健儿取得了（骄傲 ）的成绩.
（温柔 ）的微风吹拂着（细细 ）的柳丝.
（ 纯洁）的雨花石像（ 透明）的翡翠

关于雨花石的形成,据说是南朝梁代高僧云光法师在雨花台讲经,说到微妙之处,感动神灵,花落如雨,化作五彩石子,这就是雨花石.

解题思路：根据光从空气斜射入水中，折射角小于入射角，可知人看到的是雨花石的虚像，根据雨花石的位置确定折射光线的方向，再根据折射时光路是可逆的来解答此题．

连接AB，过折射点做法线，根据光从空气斜射入水中，折射角小于入射角画出折射光线的位置，虽然人看到的B点是雨花石的虚像，雨花石的实际位置在B点的正下方的C点，因为激光在进入水的时候也会发生折射，所以照着B点，激光也就刚好落在雨花石上了．如图所示：

点评：
本题考点： 作光的折射光路图．

考点点评： 本题主要考查光的折射定律：折射光线、入射光线和法线在同一平面内，折射光线、入射光线分居法线两侧，光由空气斜射进入水中或其它透明介质中时，折射光线向法线偏折，折射角小于入射角．

您好：
有“石中皇后”之称,被誉为天赐国宝,中华一绝.按照“ 六美”程度可分为绝品石、珍品石、精品石、佳品石等品级,观之令人心旷神怡,赏之可意安体泰.有高贵、艳美、华丽之意.
希望可以帮助您~

雨花石的形成可追溯到离今300万年新生代第三纪的末期,长江江源不断伸长,出现浪涛奔腾的景象,秦准河与滁河也发育成具有一定规模的水系.就在长江,秦淮河,滁河沿岸,特别在江河交汇的地方,由水流带来的卵石与砂子就在那里沉积,其中夹杂着许多彩色斑斓的天然纹石.这些纹石的前身,很多是在前期玄武岩裂缝中形成的,有些则是在更早的侏罗纪的火山岩裂隙或空洞中形成的.它们在熔岩凝结过程中,石英脉穿插其间,在低温条件下{一般低于2000度},超饱和二氧化硅呈胶体溶液状态,其带电荷的溶质体在压力影响下,电荷发生交替变化,致使二氧化硅溶质体不断与载体介质分离析出,并在以一个或多个晶核为中心凝聚,形成同心圆状的美丽花纹.由于不同的化学元素或各类元素含量的多少有别,以至形成变化多端的颜色,有白,黄,红,黑,红白相间等,成为名扬中外的观赏石,既雨花石.

因为升上来的水的体积也就是雨花石的体积,所以雨花石体积：0、312-0、3=0、012（升）=12（毫升）

雨花石的成分是以二氧化硅为主,其中红色成分为铁离子和亚铁离子.雨花石是石质为玛瑙、蛋白石、玉髓、石英等的卵石,见于河床、河流阶地的沉积物之中,其中最著名的是南京六合横林镇（雨花石之乡）产出的雨花石.雨花石又分为细石和粗石两类,细石以玛瑙为主,石质细腻,颜色艳丽,磨圆度高,晶莹可爱；粗石质地较粗,以石英或变质岩为主,价值较低.美丽的雨花石中常可呈现各种山水、人物、鸟兽、树木等景象,使人遐想联翩,思绪入石,非常漂亮.由于雨花石种类繁多,它的成因和化学成分极为复杂.以玛瑙砾石为例,它来源于雨花石原生玛瑙.一般认为,原生玛瑙是由岩浆的残余热液形成的.这种热液充填在火山岩如玄武岩、流纹岩的空隙中,因空隙的形状不同,或成玛瑙球,或成玛瑙脉.经过自然力的作用,原生玛瑙脱落而出,再经过山洪冲击,流水搬运,磨成卵石.这就是我们所见到的在砾石层中的雨花玛瑙石.雨花石以其纹奇、色艳的自然美著称于世.它的圈状花纹是二氧化硅胶液围绕火山岩空隙、空腔,由内壁开始,从外向内多层次逐层沉淀而成.在其生长过程中,常常发生带色离子和化合物的周期扩散.原生玛瑙的主要化学成分是二氧化硅,其次是少量的氧化铁和微量的锰、铜、铝、镁等元素及化合物.它们本身具有不同的色素,如赤红者为铁,蓝者为铜,紫者为锰,黄色半透明为二氧化硅胶体石髓,翡翠色含绿色矿物等等；由于这些色素离子溶入二氧化硅热液中的种类和含量不同,因而呈现出浓淡、深浅变化万千的色彩,使雨花石及其艳丽秀美.

对雨花石的养护问题一直是雨花石爱好者们,研究和探讨的话题! 那怎样进行一般的日常养护呢? 一般的做法是用水养在干净的盛具内,最好是一日一换,保持水清石秀.(如图) 雨花石不因雕啄,不能磕碰,不干不湿! 可浸于软水,(又一说,不能久浸于软水);不可浸于硬水(一般是指北方的一些地区);不可浸入沸水! (备:不可长期爆晒!不可长年累月的不换水,否则后果不堪设想!在后面我会举例!) 雨花石也可沙养,用一定大小的器具(最好是陶土质地的罐子),用筛选过的细沙子(大盖筛选一下即可), 和雨花石一起埋入罐内,(要注意几点一.要保持雨花石表面有湿度, 二.雨花石之间要保持一定的距离) 最后用塑料皮扎紧封口. (备:此法一般是用来养护家藏的精品石和绝品石,普通藏品用不到,是各路石痴们非常喜欢的一种方法!) 家中的精品石和绝品石要和普通的凡品石分开,分别养护以免发生丢失,碰撞和磨损! 雨花石要防跌!特别是一些薄片石!后果可想而知! 洗石! 洗石一般是指把石子放人干净的水中用手或软毛刷来洗. 也可用水磨细沙纸或乌丝磨擦(此法一般多用于除去雨花石上的铁锈,水垢等....不易清洗的污物!) 也可沙洗用筛选过的细沙和石头用水浸湿后,拿细沙在石头上撮洗.(此法洗石很干净而且不伤石头!) 对雨花石的保养,我国著名的收藏大家先贤王腥囚有论术: .......玩赏之道,不求有益于石,但求无害于石,斯亦足以. .......雨花石浸水观之,光艳百倍于干时,故观玩者多浸于水.惟水有清浊.......宜用雨水,需预用清洁之器, 承于天空,储以待用;其次乳泉,其次川流,其次井水,最恶者热汤. 浸水看石,不过一时,毕则捞出拭干,而后收藏, 故虽雨水也不可逾一昼夜,若经旬累月,石则消毁. 太古高山,浸水消磨,渐成沙土,以为陆地,况兹小石. 雨花石保养不利的后果! 举例:一网友,于数年前在南京买了一些雨花石子, 近日在版里与我取得联系后说他家的石子放在鱼缸里已养了一年多了, 前几天拿出来一看发线原来的一些好石头变了颜色,有好多生了青苔,怎么洗都洗不掉青苔.问我有何好办法? 我说你肯定是放在室外的对吧! 网友又说:"是的,想图个省事就往室外的鱼缸一丢!谁想到一年后会这样!" 我后来推荐他用了沙洗法给他,效果听说是不错的!

解题思路：把一块雨花石放进杯中后，水的高度由11厘米上升到15厘米，也就是增高了15-11=4厘米，也就是说雨花石的体积相当于底面半径是10厘米，高是4厘米的一个圆柱体，依据体积=πr²h，求出雨花石的体积即可解答．

3.14×10²×（15-11）
=3.14×100×4
=3.14×400
=1256（立方厘米）
答：雨花石的体积是1256立方厘米．

点评：
本题考点： 探索某些实物体积的测量方法；圆柱的侧面积、表面积和体积．

考点点评： 解答本题的关键是明确：雨花石的体积相当于底面半径是10厘米，高是15-11=4厘米的一个圆柱体，进而依据圆柱体体积计算方法，代入数据即可解答．

解题思路：要想测量雨花石的密度，必须想法测出质量和体积，此题中的体积是利用等效替代法测出，即利用雨花石体积和溢出水的体积相等作为桥梁求出雨花石的体积，根据ρ=[m/V]求出雨花石的密度．

（1）实验中应用天平称出水和小玻璃杯的共同质量m₂，从而求出玻璃杯中水的质量，求出水的体积，即为雨花石的体积；
（2）玻璃杯中水的质量：m_水=m₂-m₁，雨花石的体积V=V_水=
m水
ρ水=
m2-m1
ρ水，
雨花石的密度：ρ_石=
m石
V=
m石

m2-m1
ρ水=
m石
m2-m1×ρ_水．
故答案为：（1）⑤用天平称出水和小玻璃杯的共同质量m₂；
（2）ρ_石=
m石
m2-m1×ρ_水．

点评：
本题考点： 固体的密度测量实验．

考点点评： 本题是一道测量密度的实验题，根据实验原理想法测出物体的体积是解决此题的关键，注意等效替代法的运用．

了了

相传南朝梁武帝时,高僧云光法师在石子岗讲经,感动得上天落雨如花.花雨入地即变成无数大如鸡卵,小似蚕豆,绚丽多姿的砾石,雨花石由此得名,石子岗也改名雨花台
.
雨花台所产雨花石,是经过流水搬迁作用而磨圆的各种砾石,主要成分是石英砂岩、石英岩、硅质岩、火成岩等坚硬的岩石和石英、玉髓、蛋白石一类的矿物.前者无鲜艳的颜色与光泽；后者即石英、玉髓等化学成分是二氧化硅.常见颜色有白、乳白、微黄色.也有红、紫、绿、蔷薇、黑色.还有一种由不同颜色条纹组成同心状、环状、斑点状的玛瑙.
一些珍奇雨花石瑰丽无比,朦胧的透明中似有山川云霞、花鸟鱼虫,鬼怪神仙,还有内中图案形同猪八戒、孙悟空的,更为世人赞誉.
人们常将雨花石“养”在水盂中,陈列案头,作为观赏之物.南京的民间艺人还将雨花石琢制成各种艺术品,天然人工合为一体.
雨花石的故事
雨花石得名,源于一则神话传说：公元5世纪,梁天监年间,云光法师在金陵城南石子岗高台讲经,感动上苍,天雨赐花,天花化作五色晶莹的石子.这一则神话故事经历代传播,于是台名为雨花台,石名为雨花石.
现在说南京雨花台红红的雨花石是烈士的鲜血染成的.

沉积岩
是一种天然玛瑙石

1、即……也……（并列关系）
2、刚……就……（先后关系）

①.难道这支队伍不能经受住这样严峻的考验吗?
这支队伍能经受住这样严峻的考验.
②.我在盛产雨花石的一个采砂矿的乱石堆中,发现了一块黝黑的雨花石.
在盛产雨花石的一个采砂矿的乱石堆中,我发现了一块黝黑的雨花石.

2.4---2.8g/cm3

雨花石的成分是以二氧化硅为主,其中红色成分为铁离子和亚铁离子.雨花石是石质为玛瑙、蛋白石、玉髓、石英等的卵石,见于河床、河流阶地的沉积物之中,其中最著名的是南京六合横林镇（雨花石之乡）产出的雨花石.雨花石又分为细石和粗石两类,细石以玛瑙为主,石质细腻,颜色艳丽,磨圆度高,晶莹可爱；粗石质地较粗,以石英或变质岩为主,价值较低.美丽的雨花石中常可呈现各种山水、人物、鸟兽、树木等景象,使人遐想联翩,思绪入石,非常漂亮.由于雨花石种类繁多,它的成因和化学成分极为复杂.以玛瑙砾石为例,它来源于雨花石原生玛瑙.一般认为,原生玛瑙是由岩浆的残余热液形成的.这种热液充填在火山岩如玄武岩、流纹岩的空隙中,因空隙的形状不同,或成玛瑙球,或成玛瑙脉.经过自然力的作用,原生玛瑙脱落而出,再经过山洪冲击,流水搬运,磨成卵石.这就是我们所见到的在砾石层中的雨花玛瑙石.雨花石以其纹奇、色艳的自然美著称于世.它的圈状花纹是二氧化硅胶液围绕火山岩空隙、空腔,由内壁开始,从外向内多层次逐层沉淀而成.在其生长过程中,常常发生带色离子和化合物的周期扩散.原生玛瑙的主要化学成分是二氧化硅,其次是少量的氧化铁和微量的锰、铜、铝、镁等元素及化合物.

上面的都不专业.
还是看我的吧：
This Yuhua stone is form a good friend in my elementary school.I remembered that he had only five stones then ,but he gave me one of the five.
Maybe these letters are not that valuable but it is the most precious.They were from my best friend Bob.They contained the encouragement that Bob gave me.Therefore I preserve them until now .They are the unique gifts.

6乘3乘2点5等于45
6乘3乘1点2等于21点6
45减21点6等于23点4
好啦!

6X3X0.2=3.6DM平方

你补充的问题就是因为雨花石的成分以二氧化硅为主,而玻璃的主要成分就是二氧化硅.明白了吧?所以雨花石表面好像有层玻璃,一般的鹅卵石没有.

石块质量M石
烧杯装满水.测量总质量为m1

把石头放入后,擦干外部,称量质量为m2

宁宁=x
东东=y
x-15=y+15
(y-15)*2=x+15
得
x-15=y+15
2y-30=x+15
得
30=y-45
y=75
x=105
宁宁有105块
东东有75
好久没有动脑子了,算算也蛮好的!

我发现了雨花石.