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Materials & Crystals同质异形体同质异形体（polymorph），又称同质异晶物，是指由化学组成相同的物质，在不同的物理化学条件下（例如温度、压力、介质）形成的不同结构的晶体。同质异形体由于结构不同会表现出不同的物理化学性质。例如，氮化硼有六方氮化硼、立方氮化硼等同质异形体。相应地，称这种物质具有同质异晶现象或同质异像（polymorphism）。 同质多象的每一种变体都有其一定的热力学范围，具备独特的形态和物理性质，且其形态和物理性质差异较大，因此同质多象变体在矿物学中基本是独立的矿物种。同种物质的同质多象变体，通常依据它们的形成温度由低至高，在其名称或成分前冠以α-、β-、γ-等希腊字母以示区别，如α-石英、β-石英等，且通常以α-表示低温变体、β-与γ-表示高温变体。
In crystallography, polymorphism is a phenomenon where a compound or element can crystallize into more than one crystal structure. The definition of polymorphism has evolved over the years and as of 2023 is still under discussion. The discussion involves distinguishing among types of transitions and structural changes occurring in polymorphism versus those occurring in other phenomena.
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View content license ↗ 晶体化学（Crystal Chemistry）是物理化学中的结晶学的一个分支科学。晶体化学研究晶体矿物的化学组成、内部结构、物理性质之间的关系，并且按化学成分，对于各种矿物作出分类。
Crystal chemistry is the study of the principles of chemistry behind crystals and their use in describing structure-property relations in solids, as well as the chemical properties of periodic structures. The principles that govern the assembly of crystal and glass structures are described, models of many of the technologically important crystal structures (alumina, quartz, perovskite) are studied, and the effect of crystal structure on the various fundamental mechanisms responsible for many physical properties are discussed. The objectives of the field include: identifying important raw materials and minerals as well as their names and chemical formulae. describing the crystal structure of important materials and determining their atomic details learning the systematics of crystal and glass chemistry. understanding how physical and chemical properties are related to crystal structure and microstructure. studying the engineering significance of these ideas and how they relate to foreign products: past, present, and future.
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View content license ↗ 耦合置换（英语：Coupled substitution）又称耦合替换，是两种元素同时进入矿物晶体以保持整体电中性和电荷恒定的地质过程。在金属离子进入晶体中形成系列固溶体过程中，离子半径远比离子电荷重要，因为电荷可以从晶体结构的其他地方得到补偿。
Coupled substitution is the geological process by which two elements simultaneously substitute into a crystal in order to maintain overall electrical neutrality and keep the charge constant. In forming a solid solution series, ionic size is more important than ionic charge, as this can be compensated for elsewhere in the structure.
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View content license ↗ 冶金学（英语：metallurgy）属于材料科学，是研究从矿石中提取金属，并用各种加工方法制成具有一定性能的金属材料的学科。冶金学也研究金属、金属互化物或其混合物（称为合金）的物理及化学特性。冶金学也是一门金属的技术，有关金属制造的科学，也和金属零件的工程特性有关。金属的制造包括从矿石中提炼金属，以及金属混合物（或金属和其他元素的混合物）以制造合金。冶金学和金属加工的工艺不同，不过金属加工和冶金学有关，正如随着技术的发展，医学和医学科学有关一样。 冶金学可以分为钢铁冶金学（有时也称为黑色冶金学）及非铁金属冶金学（有时也称为有色金属冶金学）。钢铁冶金学是有关铁的合金及其制造，而非铁金属冶金学是以不含铁的合金及其制造为主，世界上的金属生产中，铁、钴、镍及其有关合金的黑色金属占了95%
Metallurgy is a domain of material science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the science and the technology of metals, including their production and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking by providing it with a scientific foundation, much as medical science supports the practice of medicine. A specialist practitioner of metallurgy is known as a metallurgist. The science of metallurgy is further subdivided into two broad categories: chemical metallurgy and physical metallurgy. Chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. Subjects of study in chemical metallurgy include mineral processing, the extraction of metals, thermodynamics, electrochemistry, and chemical degradation (corrosion).
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View content license ↗ 结晶水是以中性水分子形式参加到晶体结构中去的一定量的水，在晶格中占有一定的位置，所含水分子数量与矿物的其他成分之间常呈简单比例。 不同的含水化合物有特定的脱水温度，绝大部分伴有显著的吸热效应；土壤中土粒所含的结晶水，不能直接参加土壤中进行的物理作用，也不能被植物直接吸收。 某些晶体在从溶液当中结晶出来时，会结合并连带一定的数目的水分子。这样的水是和其他化合物以分子的型态结合在一起的水，因此不具有水的特性，这类的晶体有水合氧化铁、氯化亚钴、硫酸铜等。
In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation. Upon crystallization from water, or water-containing solvents, many compounds incorporate water molecules in their crystalline frameworks. Water of crystallization can generally be removed by heating a sample but the crystalline properties are often lost. Compared to inorganic salts, proteins crystallize with large amounts of water in the crystal lattice. A water content of 50% is not uncommon for proteins.
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View content license ↗ 维格纳-赛兹原胞（英语：Wigner–Seitz cell，以尤金·维格纳和弗雷德里克·赛兹命名）是一种几何构造，可帮助研究固体物理学中的晶体材料。晶体的独特性质是它的原子排列成一个规则的、三维的阵列，称为晶格。所有归因于晶体材料的性质都来源于这个高度有序的结构。这样的结构展示出离散平移对称。为了研究这样的周期系统，我们需要一个数学“把柄”来描述对称性，从而得出关于这个对称的结果的结论。维格纳-赛兹原胞就是实现这个目的的一种方法。
The Wigner–Seitz cell, named after Eugene Wigner and Frederick Seitz, is a primitive cell which has been constructed by applying Voronoi decomposition to a crystal lattice. It is used in the study of crystalline materials in crystallography. The unique property of a crystal is that its atoms are arranged in a regular three-dimensional array called a lattice. All the properties attributed to crystalline materials stem from this highly ordered structure. Such a structure exhibits discrete translational symmetry. In order to model and study such a periodic system, one needs a mathematical "handle" to describe the symmetry and hence draw conclusions about the material properties consequent to this symmetry. The Wigner–Seitz cell is a means to achieve this. A Wigner–Seitz cell is an example of a primitive cell, which is a unit cell containing exactly one lattice point. For any given lattice, there are an infinite number of possible primitive cells. However there is only one Wigner–Seitz cell for any given lattice.
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View content license ↗ 在几何学中，截半六边形镶嵌是一种平面密铺，是一种由两种正多边形组成的半正镶嵌图，该半正镶嵌图是由正三角形和正六边形组成，每一个顶点周围都各有2个正三角形和正六边形，在施莱夫利符号中用t1{6,3}来表示；此外其边缘形成一个无限排列的直线。 康威称截半六边形镶嵌为hexadeltille，因为它可以从正六边形镶嵌（hextille）和正三角形镶嵌（deltille）的元素替代、互相结合来构造，另外截半六边形镶嵌也可以用六边形镶嵌经过截半变换来构造。
In geometry, the trihexagonal tiling is one of 11 uniform tilings of the Euclidean plane by regular polygons. It consists of equilateral triangles and regular hexagons, arranged so that each hexagon is surrounded by triangles and vice versa. The name derives from the fact that it combines a regular hexagonal tiling and a regular triangular tiling. Two hexagons and two triangles alternate around each vertex, and its edges form an infinite arrangement of lines. Its dual is the rhombille tiling. This pattern, and its place in the classification of uniform tilings, was already known to Johannes Kepler in his 1619 book Harmonices Mundi. The pattern has long been used in Japanese basketry, where it is called kagome. The Japanese term for this pattern has been taken up in physics, where it is called a kagome lattice. It occurs also in the crystal structures of certain minerals. Conway calls it a hexadeltille, combining alternate elements from a hexagonal tiling (hextille) and triangular tiling (deltille).
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View content license ↗ 针状铁素体 (英语:Acicular Ferrite) 是钢的一种显微组织，最早在1986年被命名，针状铁素体有着极为混乱的结构，这种结构能够大大增强钢材的韧性且能够有效地阻止裂缝扩展。
Acicular ferrite is a microstructure of ferrite in steel that is characterised by needle-shaped crystallites or grains when viewed in two dimensions. The grains, actually three-dimensional in shape, have a thin lenticular shape. This microstructure is advantageous over other microstructures for steel because of its chaotic ordering, which increases toughness. Acicular ferrite is formed in the interior of the original austenitic grains by direct nucleation on the inclusions, resulting in randomly oriented short ferrite needles with a 'basket weave' appearance. Acicular ferrite is also characterised by high angle boundaries between the ferrite grains. This further reduces the chance of cleavage, because these boundaries impede crack propagation. In C-Mn steel weld metals, it is reported that nucleation of various ferrite morphologies is aided by non-metallic inclusion; in particular oxygen-rich inclusions of a certain type and size are associated with the intragranular nucleation of acicular ferrite.
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View content license ↗ 在常压下，单质铁有三种同素异形体：α铁、γ铁和δ铁。高压下存在第四种异形体称ε铁。一些实验数据表明铁可能存在第五种高压形式，但只有在极高温与高压的程况下稳定。 铁在常压下的稳定相十分重要，基于各相碳溶解度差异还可以形成不同性能的钢。铁的高压相还在行星芯固体部分的建模中有重要应用。通常假定地球的内核基本由具有ε结构的结晶铁-镍合金组成。 据信包围固态内芯的外芯由混合有镍的液态铁和痕量的较轻元素组成。
At atmospheric pressure, three allotropic forms of iron exist, depending on temperature: alpha iron (α-Fe, ferrite), gamma iron (γ-Fe, austenite), and delta iron (δ-Fe, similar to alpha iron). At very high pressure, a fourth form exists, epsilon iron (ε-Fe, hexaferrum). Some controversial experimental evidence suggests the existence of a fifth form that is stable at very high pressures and temperatures. The phases of iron at atmospheric pressure are important because of the differences in solubility of carbon, forming different types of steel. The high-pressure phases of iron are important as models for the solid parts of planetary cores. The inner core of the Earth is generally assumed to consist essentially of a crystalline iron-nickel alloy with ε structure. The outer core surrounding the solid inner core is believed to be composed of liquid iron mixed with nickel and trace amounts of lighter elements.
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View content license ↗ 貝氏体（英语：Bainite），也译作變韌鐵，是合金钢在热处理时形成的一种显微组织组成物，是由奥氏体在珠光体温度范围以下和马氏体点（马氏体转变开始的温度）以上的温度范围内分解而成的铁素体和碳化三铁的混合体。最早由埃德加·贝恩等人描述，故名。 贝氏体分为两种，在较高温度（350～550℃）形成的称“上贝氏体”，其组织在光学显微镜下呈羽毛状；在较低温度形成的称“下贝氏体”，其组织在光学显微镜下呈针状或竹叶状。贝氏体由于碳化物颗粒周围受腐蚀而变得比较粗糙，故在显微镜下呈黑色。 目前贝氏体的转变机制尚存争议，目前主要有“切变学说”和“扩散学说”两个学派。
Bainite is a plate-like microstructure that forms in steels at temperatures of 125–550 °C (depending on alloy content). First described by E. S. Davenport and Edgar Bain, it is one of the products that may form when austenite (the face-centered cubic crystal structure of iron) is cooled past a temperature where it is no longer thermodynamically stable with respect to ferrite, cementite, or ferrite and cementite. Davenport and Bain originally described the microstructure as similar in appearance to tempered martensite. A fine non-lamellar structure, bainite commonly consists of cementite and dislocation-rich ferrite. The large density of dislocations in the ferrite present in bainite, and the fine size of the bainite platelets, makes this ferrite harder than it normally would be. The temperature range for transformation of austenite to bainite (125–550 °C) is between those for pearlite and martensite. In fact, there is no fundamental lower limit to the bainite-start temperature.
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View content license ↗ 非晶态金属（英语：Amorphous metal），是指在原子尺度上结构无序的一种金属材料。大部分金属材料具有很高的有序结构，原子呈现周期性排列（晶体），表现为平移对称性，或者是旋转对称，镜面对称，角对称（准晶体）等。而与此相反，非晶态金属不具有任何的长程有序结构，但具有短程有序和中程有序（中程有序正在研究中）。一般地，具有这种无序结构的非晶态金属可以从其液体状态直接冷却得到，故又称为“玻璃态”。所以，非晶态金属又称为“金属玻璃”（Glassy metal、Metallic Glass）、“玻璃态金属”、“液态金属”（Liquid metal）或大块金属玻璃（Bulk Metallic Glass，BMG）是一种具有较低冷却速度极限的非晶态金属，所以该种金属合金可以制备出尺度超过1毫米的金属片或金属圆柱。制备非晶态金属的方法包括：物理气相沉积、固相烧结法、离子辐射法、甩带法（连续铸造法其中一种）和机械法。
An amorphous metal (also known as metallic glass, glassy metal, or shiny metal) is a solid metallic material, usually an alloy, with disordered atomic-scale structure. Most metals are crystalline in their solid state, which means they have a highly ordered arrangement of atoms. Amorphous metals are non-crystalline, and have a glass-like structure. But unlike common glasses, such as window glass, which are typically electrical insulators, amorphous metals have good electrical conductivity and can show metallic luster. Amorphous metals can be produced in several ways, including extremely rapid cooling, physical vapor deposition, solid-state reaction, ion irradiation, and mechanical alloying. Small batches of amorphous metals have been produced through a variety of quick-cooling methods, such as amorphous metal ribbons produced by sputtering molten metal onto a spinning metal disk (melt spinning). The rapid cooling (millions of degrees Celsius per second) comes too fast for crystals to form and the material is "locked" in a glassy state.
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View content license ↗ 双金属是由两种金属组成的复合材质。有许多的用途，包括量测温度的双金属片在内。 常见的双金属物件还有像是锡罐或是钱币。锡罐是在铁罐外层多增加一层锡，以用来保护罐子免于被锈蚀。钱币通常是由便宜的金属当作内核，并在外面加上一层较贵重的金属。以此避免有心人士将钱币溶化后，取得有价值的贵重金属。以一美分为例，原来是原95%铜构成，改由 95% 由锌构成，并在外表加上一个铜组成的薄层以维持原有的外貌。常见的三金属物件是具有易开口的锡罐。易开的盖子由铝做成，可以让使用者徒手进行开启，减少使用开罐器的麻烦，但因为罐子牵涉到复杂的金属构成，会增加其回收的困难度。 带钜或是电锯的刀片通常也是由双金属材质所构成。锯齿部分是由高速钢与较软的高碳钢为基底结合而成。此结构可以让刀片相聚于单一金属单片有更好的切割速度以及耐久度，因为两种金属在所处的地方发挥自己所常。锯齿的部分使用较硬的金属以得到较高的切割速度，但也因此较脆弱；而刀身使用较柔软的金属可以承受更大的冲击和破坏力。
Bimetal refers to an object that is composed of two separate metals joined together. Instead of being a mixture of two or more metals, like alloys, bimetallic objects consist of layers of different metals. Trimetal and tetrametal refer to objects composed of three and four separate metals respectively. A bimetal bar is usually made of brass and iron. Bimetallic strips and disks, which convert a temperature change into mechanical displacement, are the most recognized bimetallic objects due to their name. However, there are other common bimetallic objects. For example, tin cans consist of steel covered with tin. The tin prevents the can from rusting. To cut costs and prevent people from melting them down for their metal, coins are often composed of a cheap metal covered with a more expensive metal. For example, the United States penny was changed from 95% copper to 95% zinc, with a thin copper plating to retain its appearance. A common type of trimetallic object (before the all-aluminium can) was a tin-plated steel can with an aluminum lid with a pull tab.
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View content license ↗ 铝热反应（英语：Aluminothermic reaction）是使用铝作为还原剂在高温下进行的放热化学反应。这一过程在工业上用于生产铁的合金。氧化铁与铝最主要放热反应制铁方式如下： Fe2O3 + 2 Al → 2 Fe + Al2O3 这一特定反应本身与最重要的铝热反应的应用方式——铁合金的铸造并无关联。对于铁的生产，则使用更便宜的焦炭进行碳热反应。
Aluminothermic reactions are exothermic chemical reactions using aluminium as the reducing agent at high temperature. The process is industrially useful for production of alloys of iron. The most prominent example is the thermite reaction between iron oxides and aluminium to produce iron itself: Fe2O3 + 2 Al → 2 Fe + Al2O3 This specific reaction is however not relevant to the most important application of aluminothermic reactions, the production of ferroalloys. For the production of iron, a cheaper reducing agent, coke, is used instead via the carbothermic reaction.
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View content license ↗ 钙热还原反应（Calciothermic reactions）是一类金属热还原反应（更广义地说，也算是热化学反应），利用钙金属在高温下扮演还原剂的角色进行反应。 钙是一种强效且工业上能取得的还原剂，且在埃林汉姆图里，钙通常被视为很强的氧化物还原剂，尽管从这个角度来说镧氧化物又比钙更强。然而，前述趋势不延续于非氧化物的化合物，例如镧的氯化物可经由钙热还原反应得到镧，固可言钙是比镧的氯化物更强的还原剂。 钙热还原反应可用于从氧化矿石获得多种金属，如铀、锆、钍等。 钙热还原反应有一种有趣的运用方式，就是以在进行还原反应的同时即时生成金属钙，所有反应物皆浸泡于氯化钙熔汤中，如FFC剑桥法所采取的反应方式。
Calciothermic reactions are metallothermic reduction reactions (more generally, thermic chemical reactions) which use calcium metal as the reducing agent at high temperature. Calcium is one of the most potent reducing agents available, usually drawn as the strongest oxidic reductant in Ellingham diagrams, though the lanthanides best it in this respect in oxide processes. On the other hand, this trend does not continue to other compounds that are non-oxides, and for instance lanthanum is produced by the calciothermic reduction of the chloride, calcium being a more potent reducing agent than lanthanum involving chlorides. Calciothermic processes are used in the extraction of metals such as uranium, zirconium, and thorium from oxide ores. An interesting way of performing calciothermic reductions is by in-situ generated metallic calcium, dissolved in molten calcium chloride, as shown in the FFC Cambridge Process.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 铸造缺陷是指金属铸造过程中不希望出现的不规则特性，其中有些缺陷可以容忍，而有些无法接受的缺陷就需要再加工改善。铸造缺陷可以分为五种：气体孔隙（gas porosity）、收缩缺陷（shrinkage defects）、模具材料缺陷（mold material defects）、浇注金属缺陷（pouring metal defects）及冶金缺陷（metallurgical defects）。 冷凝现象:部分接合处，明显流动末梢提早冷却，造成未充满模穴现象 原因分析:金属铸液温度过低，或者浇流距离过远，或者浇冒道设计不良，排气不足，成形太薄流动差，铸件过于复杂流动性不易控制 缩凹现象：平面处明显凹陷，产品冷却中仍持续缩收凹陷 原因分析：平面处反面厚度差异过大，材料缩收比及厚材冷却速度不同产生缩收凹陷，常见T字肋骨结构。或者铸造冒口设计不良造成 卷气现象：铸件内部有些许小气泡产生 原因分析：浇冒口设计不当，浇铸时太快流动过急，或者浇口滤网安置不良，部分空气被卷入铝汤内流动，高温热处理时，铸件表面会涨起大小不一的小水泡变形而报废 毛边过大：成品毛边异常增厚 原因分析：合模不良，模具设计不良，安装模面调整不良，铝汤温度过高模仁增温过多，进料柱塞压力调整过大，模具磨损间隙增加 顶出位置变形： 原因分析：顶出杆长短不一，顶出杆管理安装不当，大型模具模仁厚度不足形成鼓面变形 脱模剂或柱塞剂污损成品表面： 硬点：回收料过杂或不明回收材料，使产品产生硬点，致使加工时车刀损坏率明显提高
A casting defect is an undesired irregularity in a metal casting process. Some defects can be tolerated while others can be repaired, otherwise they must be eliminated. They are broken down into five main categories: gas porosity, shrinkage defects, mould material defects, pouring metal defects, and metallurgical defects.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 难熔金属（英语：Refractory metals），又称耐火金属、耐高温金属、高熔点金属，是指特别耐热不易熔化，并且具有耐磨性的金属。此术语主要是用在材料科学、和冶金工程。这些元素在不同领域中的的定义方式有些不同。最常见的定义方式包括五个元素：两个第五周期元素（铌、钼）和三个第六周期元素（钽、钨、铼）。这些元素有一些共同性质，包括熔点超过2000 °C以上，在室温下具很高的硬度。由于其化学惰性，不易与其他元素反应，而其密度也相对较高。难熔金属因为高熔点，是粉末冶金方法制造的首选。难熔金属的一些应用包括金属工具，高温工作、丝纤维、铸造模具，或在腐蚀性环境中的化学反应器。部分是由于熔点高，难熔金属在很高温下，也不会有蠕变变形的情形。
Refractory metals are a class of metals that are extraordinarily resistant to heat and wear. The expression is mostly used in the context of materials science, metallurgy and engineering. The definitions of which elements belong to this group differ. The most common definition includes five elements: two of the fifth period (niobium and molybdenum) and three of the sixth period (tantalum, tungsten, and rhenium). They all share some properties, including a melting point above 2000 °C and high hardness at room temperature. They are chemically inert and have a relatively high density. Their high melting points make powder metallurgy the method of choice for fabricating components from these metals. Some of their applications include tools to work metals at high temperatures, wire filaments, casting molds, and chemical reaction vessels in corrosive environments. Partly due to their high melting points, refractory metals are stable against creep deformation to very high temperatures.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 形状记忆合金（英语：Shape Memory Alloys，SMA），简称记形合金，是一种在加热升温后能完全消除其在较低的温度下发生的变形，恢复其变形前原始形状的合金材料。除上述形状记忆效应外，这种合金的另一个独特性质是在高温（奥氏体状态）下发生的“伪弹性”（又称“超弹性”，英语：pseudoelasticity）行为，表现为这种合金能承载比一般金属大几倍甚至几十倍的可恢复应变。形状记忆合金的这些独特性质源于其内部发生的一种独特的固态相变——热弹性马氏体相变。
In metallurgy, a shape-memory alloy (SMA) is an alloy that can be deformed when cold but returns to its pre-deformed ("remembered") shape when heated. It is also known in other names such as memory metal, memory alloy, smart metal, smart alloy, and muscle wire. The "memorized geometry" can be modified by fixating the desired geometry and subjecting it to a thermal treatment, for example a wire can be taught to memorize the shape of a coil spring. Parts made of shape-memory alloys can be lightweight, solid-state alternatives to conventional actuators such as hydraulic, pneumatic, and motor-based systems. They can also be used to make hermetic joints in metal tubing, and it can also replace a sensor-actuator closed loop to control water temperature by governing hot and cold water flow ratio.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 在连续介质力学中，如果一种材料的应力矢量在某一特定平面上为零，则这种材料视为处于平面应力（Plane Stress）状态。当这种情况发生在整个结构上时，例如薄板的情况，因为应力状态可以用维数为2的张量来表示（可以用2×2矩阵而不是3×3来表示），应力分析因此被简化。另有与之相关的一个概念：平面应变，通常适用于较厚的结构部件。 平面应力的情况通常发生在薄的平板上，这些平板只受平行于它们的荷载力的作用。在某些情况下，为了应力分析的目的，也可以假定一个弯曲幅度较小的薄板具有平面应力。例如，在受到流体压力下的的薄壁圆柱体就是这种情况。在这种情况下，垂直于侧壁的应力成分与平行于侧壁的应力成分相比可以忽略不计。 在其他情况下，薄板的弯曲应力不能被忽略。人们仍然可以通过使用二维平面来简化分析，但每一点的平面应力的张量必须用弯曲项来补充。
In continuum mechanics, a material is said to be under plane stress if the stress vector is zero across a particular plane. When that situation occurs over an entire element of a structure, as is often the case for thin plates, the stress analysis is considerably simplified, as the stress state can be represented by a tensor of dimension 2 (representable as a 2×2 matrix rather than 3×3). A related notion, plane strain, is often applicable to very thick members. Plane stress typically occurs in thin flat plates that are acted upon only by load forces that are parallel to them. In certain situations, a gently curved thin plate may also be assumed to have plane stress for the purpose of stress analysis. This is the case, for example, of a thin-walled cylinder filled with a fluid under pressure. In such cases, stress components perpendicular to the plate are negligible compared to those parallel to it. In other situations, however, the bending stress of a thin plate cannot be neglected.
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View content license ↗ 固体物理学是凝聚态物理学中最大的分支。它研究的对象是固体，特别是原子排列具有周期性结构的晶体。固体物理学的基本任务是从微观上解释固体材料的宏观物理性质，主要理论基础是非相对论性的量子力学，还会使用到电动力学、统计物理中的理论。主要方法是应用薛定谔方程来描述固体物质的电子态，并使用布洛赫波函数表达晶体周期性势场中的电子态。在此基础上，发展了固体的能带论，预言了半导体的存在，并且为晶体管的制造提供理论基础。
Solid-state physics is the study of rigid matter, or solids, through methods such as solid-state chemistry, quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms a theoretical basis of materials science. Along with solid-state chemistry, it also has direct applications in the technology of transistors and semiconductors.
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View content license ↗ 高温合金，又称热强合金、超级合金（superalloy），是指能在高温环境及一定应力作用下长期工作的一类金属材料，具有良好的抗高温氧化和抗热腐蚀性能，以及优异的高温强度、疲劳强度、蠕变断裂韧性等综合性能。这类合金主要应用于航空航天领域、能源领域和船舶的涡轮发动机等。 高温合金按基体组织材料可分为三类：铁基、镍基和钴基。按生产方式可分为铸造高温合金、变形高温合金和粉末高温合金。按强化机理可分为碳化物强化、固溶强化、时效强化和弥散强化。在高温合金中添加其他各种金属、类金属甚至非金属元素可以优化其特定性能，包括：铬、钼、钨、铌、钽、铼、钌、铱、铝、钛、锆、铪、钇、钒、碳、硼等。 这种材料一般用于航空发动机耐高温材料的制造，特别是喷气发动机最后两级压气机和最初两级涡轮叶片、燃烧室、加力燃烧室、涡轮盘、涡轮叶片及紧固件的制造。目前市场需求主要都是军用产品，由于其军工价值所以也被视为战略物资，买卖这种材料被视为与武器贸易相同等级来加以管制，而配方与制造方法、加工使用都是重要机密，各航空大国都在极其保密的条件下研制。 中国高温合金自成系列： 变形高温合金，用GH后面跟4位阿拉伯数字表示。第一位是1，表示铁基固溶强化高温合金。第一位是2，表示铁基时效强化高温合金。第一位是3，表示镍基固溶强化高温合金。第一位是4，表示镍基时效强化高温合金。变形高温合金如果用作焊丝，在GH前添加H表示。 铸造高温合金，用K后面跟3位阿拉伯数字表示。第一位是2，表示铁基时效强化高温合金。第一位是4，表示镍基时效强化高温合金。 钴基高温合金中国尚未形成体系。
A superalloy, sometimes called a heat-resistant superalloy (HRSA) or a high-performance alloy, is an alloy with the ability to operate at a high fraction of its melting point. Key characteristics of a superalloy include mechanical strength, thermal creep deformation resistance, surface stability, and corrosion and oxidation resistance. The crystal structure is typically face-centered cubic (FCC) austenitic. Examples of such alloys are Hastelloy, Inconel, Waspaloy, Rene alloys, Incoloy, MP98T, TMS alloys, and CMSX single crystal alloys. They are broadly grouped into three families: nickel-based, cobalt-based, and iron-based. Superalloy development relies on chemical and process innovations. Superalloys develop high temperature strength through solid solution strengthening and precipitation strengthening from secondary phase precipitates such as gamma prime and carbides. Oxidation or corrosion resistance is provided by elements such as aluminium and chromium.
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View content license ↗ 马口铁（英语：Tinplate；日语：ブリキ），又名镀锡铁，是两面镀有锡的铁皮，即冷轧低碳薄钢板，可防锈、耐腐蚀、无毒。主要用于制作金属包装，包括罐头食品、饮料、化工、医药、卫生、涂料、油漆、喷雾剂、化妆品瓶盖等。台湾受日本影响，使马口铁常被认为与称为白铁的板金、钣金有着连带关系，闽南语中的白铁仔又常指不锈钢。 早在14世纪波希米亚就开始生产马口铁，主要用来制造餐具和水杯。1800年，英国人制造了长期保存食物的马口铁罐，1847年，美国人发明了制罐机器，从此马口铁的需求不断扩展，目前全世界每年生产的锡有约1/3以上用来制造马口铁。
Tinplate consists of sheets of steel coated with a thin layer of tin to impede rusting. Before the advent of cheap mild steel, the backing metal (known as "backplate") was wrought iron. While once more widely used, the primary use of tinplate now is the manufacture of tin cans. In the tinning process, tinplate is made by rolling the steel (or formerly iron) in a rolling mill, removing any mill scale by pickling it in acid and then coating it with a thin layer of tin. Plates were once produced individually (or in small groups) in what became known as a pack mill. In the late 1920s pack mills began to be replaced by strip mills which produced larger quantities more economically. Formerly, tinplate was used for tin ceiling, and holloware (cheap pots and pans), also known as tinware. The people who made tinware (metal spinning) were tinplate workers. For many purposes, tinplate has been replaced by galvanised metal, the base being treated with a zinc coating.
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View content license ↗ 煤渣山 是由采矿过程中的废料堆积而成的山堆。 煤渣山可能呈圆锥形，也可能较为平坦且风化严重，尤其是在植被已经生长的情况下。煤渣山有时会堆积数百万吨废渣，并形成危险且不稳定的斜坡。
A spoil tip (also called a boney pile, culm bank, gob pile, waste tip or bing) is a pile built of accumulated spoil – waste material removed during mining. Spoil tips are not formed of slag, but in some areas, such as England and Wales, they are referred to as slag heaps and sometimes as pit heaps. In Scotland the word bing is used. In North American English the term is mine dump or mine waste dump. The term "spoil" is also used to refer to material removed when digging a foundation, tunnel, or other large excavation. Such material may be ordinary soil and rocks (after separation of coal from waste), or may be heavily contaminated with chemical waste, determining how it may be disposed of. Clean spoil may be used for land reclamation. Spoil is distinct from tailings, which is the processed material that remains after the valuable components have been extracted from ore.
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View content license ↗ 固溶强化（英语：Solid solution strengthening）是一种利用加入溶质原子形成固溶体，并且提高整体强度的方法。加入溶质原子会降低位错周围的内应力，阻挡位错移动而使得变形更不易发生，以达到强化的效果。
In metallurgy, solid solution strengthening is a type of alloying that can be used to improve the strength of a pure metal. The technique works by adding atoms of one element (the alloying element) to the crystalline lattice of another element (the base metal), forming a solid solution. The local nonuniformity in the lattice due to the alloying element makes plastic deformation more difficult by impeding dislocation motion through stress fields. In contrast, alloying beyond the solubility limit can form a second phase, leading to strengthening via other mechanisms (e.g. the precipitation of intermetallic compounds).
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View content license ↗ 丙烯酸颜料（英语：Acrylic paint）又称为塑胶彩或亚克力颜料，为颜料粉调和丙烯酸树脂聚化乳胶制成。 丙烯酸颜料可以用水或稀释剂稀释，但在干后可溶性会迅速降低，不再溶于水，且不易褪色。由于持久性较好，丙烯酸颜料常用于制作自画像。 另外，丙烯酸颜料也是大多数人学习油画前的替代品，因为两者的成品及技法有不少类似之处。 丙烯酸颜料绘画技法又可分为类似水彩画的透明技法以及类似油画的不透明技法两种运用。在亚克力颜料中加入清水，则可让颜料呈现透明似水彩的状态。若只调和微量的水分或者不加入水分，颜料则不透明，可厚实堆叠出类似油画的效果。在颜料的变化上，也有加入增厚剂或增光剂，提升颜料的光泽度及透明度。
Acrylic paint is a fast-drying paint made of pigment suspended in acrylic polymer emulsion and plasticizers, silicone oils, defoamers, stabilizers, or metal soaps. Most acrylic paints are water-based, but become water-resistant when dry. Depending on how much the paint is diluted with water, or modified with acrylic gels, mediums, or pastes, the finished acrylic painting can resemble a watercolor, a gouache, or an oil painting, or it may have its own unique characteristics not attainable with other media. Water-based acrylic paints are used as latex house paints, as latex is the technical term for a suspension of polymer microparticles in water. Interior latex house paints tend to be a combination of binder (sometimes acrylic, vinyl, PVA, and others), filler, pigment, and water. Exterior latex house paints may also be a co-polymer blend, but the best exterior water-based paints are 100% acrylic, because of its elasticity and other factors.
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View content license ↗ 生物聚合物（英语：Biopolymer）又称为生物多聚体、生物聚合体或生物高分子，是由活的生物体产生的聚合物。因为他们是聚合物，生物聚合物包含有单体单元，相互之间以共价键相连以形成更大的结构。根据所使用的单体以及形成的生物聚合物的不同，主要有三大类主要的生物聚合物：多核苷酸是由13个或更多核苷酸单体所组成的长聚合物，多肽是氨基酸的短聚合物，而多糖通常是糖类线性链接而成的结构 。生物聚合物的其它实例包括橡胶，木栓质，黑色素和木质素。 纤维素是地球上最常见的有机化合物和生物聚合物。大约33％的所有植物物质是纤维素。棉花的纤维素含量为90％，而木材的是50％。
Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, classified according to the monomers used and the structure of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. The polynucleotides, RNA and DNA, are long polymers of nucleotides. Polypeptides include proteins and shorter polymers of amino acids; some major examples include collagen, actin, and fibrin. Polysaccharides are linear or branched chains of sugar carbohydrates; examples include starch, cellulose, and alginate. Other examples of biopolymers include natural rubbers (polymers of isoprene), suberin and lignin (complex polyphenolic polymers), cutin and cutan (complex polymers of long-chain fatty acids), melanin, and polyhydroxyalkanoates (PHAs).
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View content license ↗ 腈纶（Acrylic fiber）是一种合成纤维，主要成分是分子量约为100,000的聚丙烯腈。腈纶的单体至少含有85%的丙烯腈，并且添加有其他单体共聚，常选用的共聚分子有乙酸乙烯酯和丙烯酸甲酯。腈纶由杜邦公司首次于1941年合成，其商标命名为Orlon。但是量产是在1950年代以后。腈纶的特性是结实并且保暖，因此用于用作毛衣、运动服、靴子和手套衬里的布料，以及家具面料和地毯。首先制成腈纶长丝，然后切割成类似于羊毛的的短纤维，再纺成纱线。 改性腈纶（Modacrylic）是一种的改性丙烯腈纤维，其丙烯腈单体比例在35％至85％之间，可根据特殊用途选择共聚单体。例如，若需制造阻燃的纤维，可选的共聚单体有氯乙烯，二氯乙烯或溴乙烯等。 改性聚丙烯腈的用途包括人造毛皮，假发和防护服等。
Acrylic fibers are synthetic fibers made from a polymer (polyacrylonitrile) with an average molecular weight of ~100,000, about 1900 monomer units. For a fiber to be called "acrylic" in the US, the polymer must contain at least 85% acrylonitrile monomer. Typical comonomers are vinyl acetate or methyl acrylate. DuPont created the first acrylic fibers in 1941 and trademarked them under the name Orlon. It was first developed in the mid-1940s but was not produced in large quantities until the 1950s. Strong and warm, acrylic fiber is often used for sweaters and tracksuits and as linings for boots and gloves, as well as in furnishing fabrics and carpets. It is manufactured as a filament, then cut into short staple lengths similar to wool hairs, and spun into yarn. Modacrylic is a modified acrylic fiber that contains at least 35% and at most 85% acrylonitrile. Vinylidene chloride or vinyl bromide used in modacrylic give the fiber flame retardant properties. End-uses of modacrylic include faux fur, wigs, hair extensions, and protective clothing.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 参考电压（英语：Voltage reference）是指电路中一个与负载、功率供给、温度漂移、时间等无关，能保持始终恒定的一个电压。参考电压可以被用于电源供应系统的稳压器，模拟数字转换器和数字模拟转换器，以及许多其他测量、控制系统。参考电压的大小在不同的应用中有所不同，例如在一般的计算机电源供应系统里，参考电压误差不大于其标称值附近百分之一至百分之几间，而实验室的参考电压标准则拥有更高的、以百万分率度量的稳定性和精确度。
A voltage reference is an electronic device that ideally produces a fixed (constant) voltage irrespective of the loading on the device, power supply variations, temperature changes, and the passage of time. Voltage references are used in power supplies, analog-to-digital converters, digital-to-analog converters, and other measurement and control systems. Voltage references vary widely in performance; a regulator for a computer power supply may only hold its value to within a few percent of the nominal value, whereas laboratory voltage standards have precisions and stability measured in parts per million.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 生物降解聚合物（也称生物降解高分子）是指在使用之后，可降解的聚合物。在降解过程中，它的主要产物是气体（如二氧化碳CO₂、氮气N₂），水，生物质和无机盐。 生物降解聚合物可由天然形成或人工合成。它们主要由酯、酰胺和醚官能团组成。生物降解聚合物的特定结构决定了其特性和机理。这些聚合物一般通过缩合反应、开环聚合和金属催化剂等方式合成。生物降解聚合物的例子很多和应用极为广泛。
Biodegradable polymers are polymers that can be decomposed by the action of living organisms. Whereas most polymers are designed for longevity, biodegradable polymers are not. Biodegradable polymers can be derived from renewable raw materials, petrochemicals, or combinations thereof. Polymers are the majority component of most plastics, so the topics of biodegradable plastics and biodegradable polymers are intimately related. While the words "bioplastic" and "biodegradable polymer" are similar, they are not synonymous. Bioplastics are composed of biologically synthesized polymers, i.e., derived partly or entirely from biomass. Some are biodegradable. Definitions are debated. Biodegradable plastics are composed of polymers that can be petroleum-based, biologically derived, or a mixture thereof.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 塑质钞票中文通常称为塑料钞或塑胶钞，指由聚合物制成的纸币，如聚丙烯。该类钞票可以结合许多在纸质钞票无法实现的防伪措施，例如同色异谱油墨，提高防伪印刷水平。 塑质钞票的制造成本虽然是纸币的两倍，但拥有比纸质钞票更加优越的使用寿命，可达4倍，并且徒手难以撕开。塑质钞票适合于那些气候潮湿的国家，不会因为沾水而受损。其塑胶材质也可以使钞票的流通时间增长而不至于撕裂或者破损，从而降低对环境的影响，减少生产及更换费用。 塑质钞票最早由澳洲储备银行、澳大利亚联邦科学与工业研究组织以及墨尔本大学开发，最先于1988年被澳大利亚所使用，位于摩尔达维亚的德涅斯特河沿岸共和国则是首个使用塑料硬币的国家。在1996年澳大利亚全部更换为塑质钞票。现在有许多国家或地区正在使用塑质钞票，截止2021年，已有9个国家的流通货币已经全部由纸币更换为塑质钞票，佛得角和冈比亚是最新引进塑质钞票进入流通领域的国家。 目前，全球仅有少数国家具备生产塑质钞票基材的能力。国际市场上，提供塑质钞票基材产品的企业主要包括澳大利亚 CCL Secure 公司的 Guardian®、英国 De La Rue 公司的 Safeguard®，以及越南 Q&T Hi-Tech Polymer 公司的 PolySecure®。其中，Guardian® 和 Safeguard® 在全球塑质钞票基材市场中占有绝大多数份额。俄罗斯和中国亦曾发行采用本国生产基材的塑质钞票，分别为2018年国际足联世界杯纪念钞（面额100卢布）及2022年北京冬季奥林匹克运动会纪念钞（面额20元人民币），显示两国亦具备自行生产塑质钞票基材的能力。
Polymer banknotes are banknotes made from a synthetic polymer such as biaxially oriented polypropylene (BOPP). Such notes incorporate many security features not available in paper banknotes, including the use of metameric inks. Polymer banknotes last significantly longer than paper notes, causing a decrease in environmental impact and a reduced cost of production and replacement. DuPont Tyvek polymer notes were experimentally issued by Haiti, Costa Rica, and The Isle of Man, from 1982. Modern polymer banknotes were developed by the Reserve Bank of Australia (RBA), Commonwealth Scientific and Industrial Research Organisation (CSIRO) and The University of Melbourne. They were first issued as currency in Australia during 1988 (coinciding with Australia's bicentennial year); by 1996, the Australian dollar was switched completely to polymer banknotes. Romania was the first country in Europe to issue a plastic note in 1999 and became the third country, after Australia and New Zealand, to fully convert to polymer by 2003.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 共混物（英语：Polymerblend或者Polyblend）是由两种或更多聚合物混合所形成的混合物。共混物的性质与其含有的聚合物相异。各聚合物在共混物中没有形成化学键。
In materials science, a polymer blend, or polymer mixture, is a member of a class of materials analogous to metal alloys, in which at least two polymers are blended together to create a new material with different physical properties.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
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