通过测试低噪声高频放大器LNA()的功率值,进行比较,可以判断LNA是否正常,一般LNA有15dB增益。
参考答案:输入和输出
内分泌腺的叙述,错误的是()
A.内分泌腺有排泄管道
B.其分泌的物质是激素
C.分泌物直接透入血液或淋巴
D.内分泌腺和内分泌组织有甲状腺
E.其功能是对机体的新陈代谢等进行调节
It should go without saying that the focus of UML is modeling. However, what that means, exactly, can be an open-ended question. (1) is a means to capture ideas, relationships,decisions, and requirements in a well-defined notation that can be applied to many different domains. Modeling not only means different things to different people, but also it can use different pieces of UML depending on what you are trying to convey. In general, a UML model is made up of one or more (2) . A diagram graphically represents things, and the relationships between these things. These (3) can be representations of realworld objects,pure software constructs, or a description of the behavior of some other objects. It is common for an individual thing to show up on multiple diagrams; each diagram represents a particular interest, or view, of the thing being modeled. UML 2.0 divides diagrams into two categories: structural diagrams and behavioral diagrams. (4) are used to capture the physical organization of the things in your system, i.e., how one object relates to another. (5) focus on the behavior of elements in a system. For example, you can use behavioral diagrams to capture requirements, operations, and internal state changes for elements.
A.views
B.diagrams
C.userviews
D.structurepictures