主页
学科
搜索
账户
常见问题
当前学科：传热学
题目：
单选
下述哪种手段对提高管内强制对流换热表面传热系数无效？（）
A . A．提高流速
B . 增大管径
C . 采用入口段效应
D . 采用导热系数大的流体
答案：
<查看本题扣1积分>
查看答案
答案不对？请尝试站内搜索
推荐知识点:
抗甲状腺药物的主要作用是（）
善温中散寒者是（）
可摘局部义齿RPI卡环采用近中支托的主要目的是（）
土地定级的原则是()。
女性，32岁，不慎跌倒后诉左侧胸痛，咳嗽时加剧。体格检查：无反常呼吸，左肺呼吸音减弱，无啰音，左侧胸廓前后挤压试验阳性。关于此患者，下列说法哪项是正确的（）
性成熟
揉脐，摩腹，推上七节，揉龟尾配合善治小儿（）
As a senior professor she should have known better ＿＿＿＿＿＿＿ to get involved in such a scandal.
离心式空压机的主要组成及工作原理是什么？
Dear Jone, I am writing to apologize(1)my immediate going home after the exam(2)saying goodbye to you．It was very rude(3)me to do so especially as we have been such good friends. You know, shortly after the exam, I received a telephone call(4)my father, saying that my elder sister had borne a baby the day before．I was so pleased(5)this news that I couldn't wait to get home to see my elder sister and my niece．I left in such a hurry that I didn't have time to tell you．I feel terribly sorry(6)that. To make(7)for my thoughtless behavior toward you, I want to invite you to come and stay(8)my family during the vacation．My hometown is located(9)a city(10)the seashore and this is the most beautiful season of my hometown. I believe you can understand me and accept my sincere apologies．How I wish I could see you soon in my hometown! Please write and let me know your decision.Yours,