化学位移
参考答案:
由于屏蔽效应的存在不同化学环境中的H核其共振吸收峰的位置不同,这种现象称为化学位移。
患者男性,12岁。急起畏寒、高热,头痛、肌肉酸痛,并有鼻塞、流涕、咳嗽、咽干、咽痛。查体:T40℃,急性病容,鼻、咽部及结膜轻度充血。肺部可闻及干啰音。血常规显示白细胞计数减少,淋巴细胞相对增加。
有关该患者的治疗,错误的是()
A.尽早使用抗病毒药物
B.加强支持治疗
C.使用阿司匹林对症治疗
D.明确细菌感染时应用抗生素
E.使用金刚烷胺治疗甲型流感病毒感染
A transport layer protocol usually has several responsibilities. One is to create a process-to-processcommunication UDP uses(1)numbers to accomplish this. Another responsibility is to provide controlmechanisms at the transport level, UDP does this task at a very minimal level. There is no flow control mechanismand there is no(2)for received packet. UDP, however, does provide error control to some extent. If UDPdetects an error in the received packet, it will silently drop it.
The transport layer also provides a connection mechanism for the processes. The (3)must be able to sendstreams of data to the transport layer. It is the responsibility of the transport layer at (4) station to make theconnection with the receiver chop the stream into transportable units, number them, and send them one by one. Itis the responsibility of the transport layer at the receiving end to wait until all the different units belonging to thesame process have arrived, check and pass those that are (5)free, and deliver them to the receiving process asa stream.
(3)是()
A.jobs
B.processes
C.programs
D.users