首页 › 答案 › 题库 › 慕课

未分类

64005（）involves passing visible light transmitted through or reflected from the sample, through a single or multiple lenses to allow a magnified view of a sample.

64006Mass Spectrometry（MS）is the science of displaying the spectra of the masses of the（）comprising a sample of　material.

64007（）is a quantitative spectroscopic technique that measures the elemental composition, empirical formula, chemical state　and electronic state of the elements that exist within a material.

64008Before carrying out the characterization, one vital procedure is（）

64009（）is a method of thermal analysis which measures the difference in heat flow rate between a sample and inert reference as a function of time and temperature.

64010（）is a rapid analytical technique primarily used for phase identification of a crystalline material and can provide information on unit cell dimension

64011（）is the study of interaction of infrared light with matter, which can be used to identify unknown materials, examine the quality of a sample or determine the amount of components in a mixture.

64012光伏效应（）

64013A lithium-ion battery is a family of（）可充电的 battery

64014An applied temperature difference causes charged carriers in the material, whether they are（）or（）, to diffuse from the hot side to the cold side.

64015The（）of a material is a measure of the magnitude of an induced thermoelectric voltage in response to a temperature difference across that material.

64016Hydrogen fuel is a（）fuel which uses electrochemical cells, or combustion in internal engines

64017Fuel cells are different from batteries in that they can produce alternating current　continually.

64018Typically metals have larger thermapowers than semiconductors.

64019Metal hydrides, with varying degrees of efficiency,　can be used as a storage medium for hydrogen, often reversibly.

64020A solar cell is an electrical device that converts the energy of light directly into direct current.

64021Li-ion batteries use an metallic lithium compound as the electrode material。

64022A photoelectronic materials can（）optoelectronic signals.

64023Nanoscience is the study of phenomena and manipulation of materials at（）scales, where properties differ significantly from at large scale.

64024According the type of electrolyte they use, the fuel cells are devided into（）

64025The fuel cells consist of（）

64026Which of the following are the advantages of lithium ion batteries（）

64027Nanorods and nanowires are（）nanomaterials.

64028In the fuel cell，the（）is a substance specifically designed so ions can pass through it, but electrons cannot.

64029In a lithium-ion battery, lithium ions move from the（）to（）electrode during discharge, and back when charging.

64030For many materials, much higher strength can be achieved in（）form than in（）form.

64031The physical properties of composite materials are generally not（）（independent of direction of applied force）in nature, but rather are typically（）（different depending on the direction of the applied force or load）.

64032Composite in which the reinforcements are continuous fibers or whiskers can be produced so that the reinforcements have either random or biased orientation.

64033It is of great important to be able to predict the properties of a composite, given the component properties and their geometric arrangement.

64034The primary function of fibers or reinforcements is to carry load along the length of the fiber to provide strength and stiffness in one direction.

64035Fibers must often be chemically treated to ensure proper adhesion to the matrix.

64036The matrix typically has a higher density, stiffness, and strength than the fibers.

64037According to source, composite materials divided into:（）

64038The majority of composite use two consistuents:（）

64039In order to improve（）at the interface, the surface of the（）must be treated.

64040（）are offered by metal matrices than those offered by their plastic counterparts.

64041The matrix is the binder material that（）the fibers.

64042The precipitation hardening processes include（）heat treatment and（）heat treatment.

64043Metal corrosion can be calssified according to the two major processes by which it occurs.One is（）直接氧化corrosion，the second process is（）电化学 corrosion

64044The third type of point defect is impurity atom. Impurities can be classified as（）间隙 impurity atom or（）置换impurity atom.

64045The（）steels are highly resistant to corrosion（rusting）in a variety of environments, especially the ambient atmosphere.

64046（）alloys, in which, iron is the principal constituent, include steels and cast irons.

64047（）metals, by definition, have melting points are above 2000℃, some of them reaching as high as 3426℃.

64048Metal processing techniques are normally preceded by refining, alloying and often heat-treating process.

64049Ferrous metal has a relatively low density and a comparatively high electrical conductivity.

64050A ductile metal becomes harder and stronger as it is elastically deformed.

64051Steel is an interstitial solid solution with impurity carbon atoms in iron crystal lattice.

64052When stacked together, the unit cells form the whole crystal.

64053The advantages of Hot-work operation are（）

64054Protection methods against the metal corrosion include（）

64055Possible alternations in the HAZ include the following（）

64056Typical lattices of most metals are（）

64057Based on their dimensionality, defects are classified into（）,（）and（）.

64058From this diagram, a lot of information can　be got such as（）

64059Phase diagram is the graphical representation of a material system under varying conditions of（）

64060The most common cast iron types are（）

64061（）is an alloy of Cu-Zn.

64062The predominant alloying element of the stainless steel is（）

64063Forming operations are those in which the shape of a metal piece is changed by（）deformation.

64064A wax or plastic die is appropriate for（）

64065A vacancy, caused by an atom missing from a lattice site, is a type of（）defects

64066（）is also called tensile strength, which is obtained at the plastic　deformation region from the stress-strain diagram.

64067For most cast irons the carbon exists as（）

64068The（）steels are hardest, strongest, and yet least ductile of the carbon steels， and wear resistant and capable of holding a sharp cutting edge.

64069The noble or precious metals are a group of（）elements that have some physical characteristics in common.

64070（）is a homogeneous part or aggregation of material that differs from another part due to difference in structure.

64071The cause of cracks in concrete are: stress due to applied（）and stress due to temperature or（）change when concrete is restrained。

64072Concrete used in water-retaining structures or exposed to weather or other severe exposure condition must be virtually（）or（）.

64073Workability of（）concrete has a direct effect on the（）and constructibility.

64074Concrete is basically a mixture of two components:（）and a（）.

64075The clinker product of Portland cement need to add gypsum to（）the（）process.

64076Unlike crystals, glasses do not have well defined melting points, but exhibit a（）Tg.

64077Glasses are（）, not（）at all.

64078The hot step of ceramic processing, in which the green compact is first subjected to heat to（）up any liquid phase formed during the processing and then subjected to higher heating, known as firing, sintering, or（）.

64079Two common shaping techniques are utilized for forming clay-based compositions:（）and（）

64080Ceramics are, by nature, generally porous materials with varying degrees of（）.

64081White cement is achieved by decreasing the ratio of Al2O3 to Fe2O3 in the raw materials.

64082Many glasses are electrolytic conductors at elevated temperatures.

64083The surface tension　implies the energy needed to create a unit area of the surface, and the surface energy means the force acting on a unit distance in the surface.

64084For advanced ceramic, what is new are the many processes developed in recent years to produce them.

64085The silicate structures can link by sharing the atoms in three corners of the SiO4 tetrahedrons, forming chain or ring structures.

64086The product methods of the rapid-hardening Portland cements include（）

64087The raw materials of the clinker of Portland cement include（）

64088glass has many unique characteristics. Considering the structure and properties of glass, the four most significant characteristics are:（）,（）,（）, and the continuity and irreversibility of property change

64089The multistage fabrication process for advanced ceramics includes（）

64090What sets ceramics apart is their set of properties common to nearly all forms.Those properties are（）

64091Which of the following does not belong to concrete durability.（）

64092The strength of concrete is generally expressed in megapascals（MPa）at an age of（）-days.

64093（）strength may be defined as the measured maximum resistance of a concrete or mortar specimen to axial loading.

64094The main chemical composition of gypsum is（）

64095This may seem strange, but theoretically glass should be very strong because of the nature of its（）bonds.

64096One of the most important properties of molten glass is（）, which changes dramatically as the temperature changes.

64097In amorphous solids, it is believed that the atomic structure of a glass lacks any（）which is evidenced by X-ray diffraction analysis

64098Ceramics do not have a（）because they do not plastically deform.

64099For both uniaxial pressing and isostatic pressing procedures, a（）operation is required after the pressing operation.

64100Traditional ceramics are made of different types of（）

‹1…640641642…2612 ›