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问题 单项选择题 A1/A2型题

某药按零级动力学消除，其消除半衰期等于（）

A.0.693/k

B.k/0.5C

C.0.5C/k

D.k/0.5

E.0.5/k

答案

参考答案：C

解析：零级消除动力学是药物在体内以恒定的速率消除，即不论血浆药物浓度高低，单位时间内消除的药物量不变。药物消除半衰期是血浆药物浓度下降一半所需要的时间。

问答题

绝热工程计算中，要考虑到绝热层的超厚系数，采用以下公式计算绝热层体积V和绝热层表面积S。
V=Lπ(D+1.033δ)×1.033δ
S=πL(D+2.1δ+0.0082)
式中V——绝热层体积(m3)；
S——绝热层表面积(m2)；
D——管道外径(m)；
L——管道长度(m)；
δ——管壁厚度(m)。
现有管D219×8管20m，保温厚度80mm，求：

保护层工程量。
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单项选择题 共用题干题

Teams are required for most engineering projects. Although some small hardware or software products can be developed by individuals, the scale and complexity of modern systems is such, and the demand for short schedules so great, that it is no longer (1) for one person to do most engineering jobs. Systems development is a team (2) ,and the effectiveness of the team largely determines the (3) of the engineering. Development teams often behave much like baseball or basketball teams. Even though they may have multiple specialties, all the members work toward (4)．However, on systems maintenance and enhancement teams, the engineers often work relatively independently, much like wrestling and track teams. A team is (5) just a group of people who happen to work together. Teamwork takes practice and it involves special skills. Teams require common processes; they need agreed-upon goals; and they need effective guidance and leadership. The methods for guiding and leading such teams are well known, but they are not obvious.

空白（4）处应选择（）

A.multipleobjectives

B.differentobjectives

C.asingleobjective

D.independentobjectives
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