更多"若金属中的空位形成能EV,与温度无关,试证明空位的组态熵(S)随温度的"的相关试题:
[简答题]已知铝的空位形成能为0.76eV/空位,25℃时铝的点阵常数为0.405nm。铝在什么温度下空位浓度是25℃时的1000倍?
[简答题]已知铝的空位形成能为0.76eV/空位,25℃时铝的点阵常数为0.405nm。计算25℃时铝的空位浓度(空位/cm3)。
[简答题]计算某金属的空位浓度比室温(300K)空位浓度大1000倍时的温度。已知Cu的空位形成能为1.7×1019J/mol。
[简答题]证明题:证明:如果预算线给定,一条无差异曲线U(Qx,Qy)与其相切,试证明切点E的坐标为最优商品组合,切点E为消费者均衡点。
[简答题]金属中空位平衡浓度随温度的变化规律遵循NV=Nexp(-QV/RT)。某金属在被加热到1130K的时候,其空位的平衡浓度是其在1000K时的5倍。假设在1000~1130K之间金属的密度不变,气体常数为8.31J/(mol·K),试计算其空位形成能QV。
[简答题]试证明:劳动和资本的产出弹性为常数当且仅当生产函数具有Cobb-Dauglas的形式时即F(L,K)=AKαLβ。
[简答题]已知对于n阶方阵A,存在自然数k.使得Ak=0,试证明:矩阵E-A为可逆矩阵并求它的表达式(E为n阶单位矩阵)。
[简答题]用四指数表示的密排六方结构的原子最密排面和最密排方向是什么试证明理想密排六方晶胞的晶格常数比(轴比)c/a为1.633。
[简答题]已知某有效三段论的大前提为O判断,试证明:(1)其小前提必为A判断;(2)该三段论为第三格OAO式。
[简答题]设A为n阶矩阵,λ1和λ2是A的两个不同的特征值,x1.x2是分别属于λ1和λ2的特征向量.试证明:x1+x2不是A的特征向量.
[简答题]设f(x)在(-∞,+∞)上有界,且存在二阶导数.试证明:至少存在一点ξ∈(-∞,+∞)使f"(ξ)=0.
[简答题]已知某晶体在500℃时,每1010个原子中可以形成有1个空位,请问该晶体的空位形成能是多少?(已知该晶体的常数A=0.0539,波耳兹曼常数k=1.381×10-23J/K)
[简答题]由600℃降温到300℃时,锗晶体中的空位平衡浓度降低了六个数量级。试计算锗晶体中的空位形成能(玻尔兹曼常数k=1.38×10-23J/K)。
[单项选择]作为80386总线周期,如果外部不要求插入等待周期,则构成一个总线周期的总线状态数为( )
A. 1
B. 2
C. 3
D. 4
[单项选择] Americans smoke six thousand million cigarettes every year (1970 figures). This is roughly the equivalent of 4,195 cigarettes a year for every person in the country of 18 years of age or more. It is estimated that 51% of American men smoke compared with 340,6 of American women.
Since 1939, numerous scientific studies have been conducted to determine whether smoking is a health hazard. The trend of the evidence has been consisted and indicates that there is a serious health risk. Research teams have conducted studies that show beyond all reasonable doubt that tobacco smoking particularly cigarette smoking is associated with a shortened life expectancy.
Cigarette smoking is believed by most research workers in this field to be an important factor in the development of cancer of the lungs and cancer of the throat and is believed to be related to cancer of the bladder and the oral cavity. Male cigarette smokers have a higher death rate from heart disease than non- smoking males.
A. cutting off legs or arms
B. disease of legs or arms
C. curing of legs or arms
D. discomfort of legs or arms