27Local economists have appeared into their crystal balls and witnessed anything somewhat nasty.当地的经济学者们已预测到将会出现棘手的问题。《柯林斯英汉双解大词典》
①压电效�?在机械力(压力或拉�?作用下，水晶单晶体的两端会产生电荷，其电量相等但符号相反。在工业上，无色、无缺陷、不具双晶的水晶常被用来作压电石英片。
Chemical Bonds The types of chemical bonds formed involving atoms or teams of atoms in crystals depend on their sizing and electronegativity. You will find 4 classes of crystals as grouped by their bonding:
Insert to word list Increase to phrase listing C2 [ U ] transparent glass of quite high-quality, ordinarily with its surface area Slice into delicate styles
. These four structures comprise the majority of the binary crystals with equal figures of cations and anions.
, has precisely the same framework, but there are two decisions for selecting the holes which the atoms will occupy. The 3rd layer may be placed about the atoms of the main layer, building an alternate layer sequence A
⑩、雷射内雕：以计算机辅助激光设备在水晶对象中进行三维图案的成型，艺术效果好，可以任意表达各类图案，图形，达到逼真效果
The weather are observed in many different crystal packing preparations. The commonest lattice buildings for metals are Those people attained by stacking the atomic spheres into probably the most compact arrangement.
第三种是“皮景”，因某些其他的矿物与水晶体共生，或由于其他的物质侵蚀而依附于水晶表面，或者是水晶受自然环境的影响，在水晶表面出现蚀象，形成了一些景象或图案，这种景观存在于水晶表面。
Solids which have shorter-range purchase but lack prolonged-range order are referred to as amorphous. Just about any substance is usually produced amorphous by immediate solidification with the melt (molten state). This affliction is unstable, along with the reliable will crystallize in time. In case the timescale for crystallization is several years, then the amorphous state seems stable.
被主体水晶所捕获的包裹体。原生包裹体通常为固相，形态较规则。水晶中典型的原成包裹体有金红石、电气石、黄铁矿等，也会见到岩石碎屑或集合体。
You can find other minerals and molecules that will form these crystal lattices. Snowflakes certainly are a basic example of a approximately symmetric and geometrically patterned framework from ice crystals, and gemstones of all types are generally crystals.
Crystals are categorized usually categories, which include insulators, metals, semiconductors, and molecular solids. An individual crystal of the insulator is generally transparent and resembles a bit of glass. Metals are shiny Except they have got rusted. Semiconductors are occasionally shiny and sometimes transparent but are never ever rusty. A lot of crystals could be categorized as one form of sound, while others have intermediate behaviour. Cadmium sulfide (CdS) may be well prepared in pure form and is a superb insulator; when impurities are added to cadmium sulfide, it gets an interesting semiconductor.
Binary crystals are present in quite a few buildings. Some pairs of things kind more than one structure. At room temperature, cadmium sulfide may crystallize either during the zinc blende or wurtzite framework. Alumina also has two achievable constructions at room temperature, α-alumina (corundum) and β-alumina. Other binary crystals show distinctive constructions at unique temperatures. Among the many most complicated crystals are Those people of silicon dioxide (SiO2), click here that has seven various buildings at several temperatures and pressures; the most typical of these constructions is quartz.