已选分类
工学材料科学与工程
单选题离子晶体通常借助表面离子的极化变形和重排来降低其表面能，对于下列离子晶体的表面能，最小的是______。
单选题退火孪晶出现的几率与晶体的层错能的关系为______。
单选题Which advantage do smart polymeric materials offer designers? A．Eliminate selection problem, B．Reduce raw materials costs C．Adapt to environmental change D．Reduce processing
单选题金属Mg的滑移系为______。
单选题冷变形金属的回复温度______再结晶温度。
单选题Which of the following describes is correct as for carbon and graphite fibers? A．Carbon fiber has a higher modulus than graphite fiber B．Graphite fiber has a lower content than carbon fiber C．Carbon fiber has a higher pyrolyzinig temperature than graphite fiber D．None of above.
单选题非均匀形核所需的过冷度是合金结晶温度Tm的______倍。
单选题在置换型固溶体(substitional solid solution)中，原子扩散的方式一般为______。
单选题The following statement ofinert gases is right except______ A) Inert gases are also called noble gases B) Inert gases are mostlyinactive C) Inert gases do not get involved in making compounds with other elements D) Inert gases have their outer energy levels incompletely full ofvalence electrons
单选题Inert gases can also be called ______. A) Noble gases B) Active C) Group 5 elements D) Stable
单选题Which statement of elastic modulus is NOT correct? A) Elastic modulus is also known as Youngs modulus B) The higher the magnitude ofelastic modulus the weaker the interatomic bonding forces C) Elastic modulus is the constant ofproportionality in Hookes law D) Elastic modulus can be measured graphically in the elastic region ofthe stress-strain diagram
单选题高分子的主链结构对单键内旋转有重要影响。下列最易单键内旋转的主链结构是______。
单选题______ is not a true composite? A) Bamboo B) Human bone C) Safety glass D) Steel
单选题______ is not the common phenomena of thermoplastics deterioration. A．Weight loss B．Discoloration C．Swelling D．Cracking
单选题铸件薄壁处出现白口组织，造成切削加工困难。解决的办法是( )。 A．正火 B．等温淬火 C．石墨化退火
单选题fcc、bcc、hcp三种晶体结构的材料中，塑性形变时最容易生成孪晶的是______。
单选题Which is NOT the name ofthe recently discovered carbon structure that resembles a soccer ball? A) Buckyball B) C-60 C) Fullerene D) Graphite
单选题The force ofintermolecular attraction within the adhesive or adherend is defined as ______. A．Surface tension B．Adhesive bond C．Cohesive force D．Contact bonding
单选题Interface features are regarded as a type of adhesion phenomenon and are often interpreted in terms of the surface structure of the bonded material. Which are the major factors to be considered in explaining the adhesion phenomenon? A．The color, surface electric resistance, free radical groups, and roughness of the material to be bonded B．The weight, surface free energy, smell, and roughness of the material to be bonded C．The wettability, surface free energy, polar groups, and roughness of the material to be bonded D．The thickness, surface free energy, polar groups, and flatness of the material to be bonded
单选题置换型固溶合金中溶质原子的扩散是通过______实现。