在投影数据重建CT图像的方法中,应用最广泛的是( ) A.直接反投影法 B.迭代法

题型:单项选择题

问题:

在投影数据重建CT图像的方法中,应用最广泛的是( )

A.直接反投影法

B.迭代法

C.二维傅立叶变换重建法

D.空间滤波反投影法

E.褶积反投影法

考点:大型设备上岗证考试血管造影DSA医学成像技术CT成像技术
题型:单项选择题

小红对爸爸给患病的奶奶购买的“便携式制氧器”产生了兴趣,她阅读说明书,了解了它的工作原理(如图1)和所用药品.药品中甲剂是一种白色颗粒状固体,作制氧剂;乙剂是黑色固体,作催化剂.甲剂、乙剂和水盛放在图1的反应仓中.

[提出问题】甲剂的化学成分是什么?

[查阅资料]过碳酸钠是一种白色颗粒状固体,溶于水时,生成碳酸钠和过氧化氢. 可用于制取氧气.

[设计与实验]小红把甲剂和乙剂带到实验室与姜老师共同探究.在老师的指导下,验证出甲剂是一种钠盐后,小红接着进行如下实验:

[实验一]用甲剂、乙剂和水制取并验证氧气.

(1)根据图1和图2回答问题:

①写出图2中标有a、b的仪器名称:a______;b______.

②请指出小红在实验中制取氧气时,应选用的发生装置为______(填字母).

③收集氧气时,由于它具有______的性质,则可选用的气体收集装置是______ (填字母).

(2)将带火星的木条伸入到集气瓶内,若带火星的木条______,则说明收集到的气体是氧气.

(3)小红认为氧气是由过氧化氢,在乙剂催化作用下产生的,其化学方程式为:______.

[实验二]检验[实验一]反应后的溶液中是否含有某种离子.

实验步骤实验操作实验现象化学反应方程
步骤一取少量反应后的溶液,加入稀盐酸有气泡产生 
步骤二将步骤一产生的气体通入澄清的石灰水中澄清石灰水变浑浊______ 
[实验结论]

(1)[实验一]反应后的溶液中一定含有较多钠离子和______离子.

(2)甲剂可能是过碳酸钠.

题型:单项选择题

合同的从给付义务产生的原因不包括( )

A.法律的明确规定

B.当事人双方的约定

C.基于决定合同类型的需要

D.诚实信用原则及补充合同解释

题型:单项选择题

阅读理解

     A few years ago my sister moved from her home in Alabama to Buffalo, New York. Since moving to

Buffalo she's become a big hockey fan and has encouraged me to start watching it. Unfortunately it's very difficult to find hockey on television here in Alabama. Since hockey games don't air very much on television  I've had to look for different ways to watch hockey games.

     I often see websites that claim if you go to their website you can watch television on your computer. I

try out many of these websites hoping that one of the television stations is a northern station that airs

hockey games. Unfortunately, most of them don't work. Either the site doesn't really give you what they

advertise or their video player doesn't work properly. But finally I've found one websites that actually

works.

     Free Tube is a site that you can go to and watch Television online for free. You don't have to

download any kind special software or pay money or even sign up for anything. All you have to do is go

to Free Tube, choose your channel and start watching.

      The different channels to choose from are separated into different categories like news, business,

entertainment, music and sports. You're not going to find channels like NBC or ABC so you can watch

the latest episode of Heroes or Grey's Anatomy but it does include some popular channels like Cartoon Network and ESPN.

      There is also a movie section. Each move channel airs different sorts of films like adventure, classics,

comedy or horror and that channel will always air that kind of movies. The movie section also includes

my favorite station called Maxx Trailers (预告片). Maxx Trailers airs nothing but movies trailers 24

hours a day. Some of the trailers are for movies coming out and some are for movies that have already

been released but already released movies don't go back farther than a couple of months.

     So far I haven't had any problems with Free Tube's video player either. Whenever I choose a channel

the video almost always works and usually loads every quickly. The only problem I have with Free Tube

is that there is currently a glitch if you're using Firefox. Once you choose a channel you can't select

another channel to change to, your web browser will freeze up. So if you're using Firefox the only way to

switch channels is to leave the site and re-enter the site, when choose what channel you want to go to.

However, Free Tube is aware of this glitch and is working with Mozilla to get it fixed right away.

     If you're missing some show everyone is talking about like Grey's Anatomy or Heroes this isn't really

a solution for that. But Free Tube is a good way to find channels that you weren't aware of; there are

several good stations to be found.

1. The author mainly ________ in this passage.

A. tells us his experience in using the Web.

B. introduces Free Tube to the readers

C. shows us the disadvantages of Free Tube

D. shows us how to enjoy films online

2. The author got interested in watching hockey games ________

A. because he is a sports fan

B. due to his sister's influence

C. since everyone enjoys the games

D. because he has nothing to do all day long

3. Which of the following is TRUE about Free Tube?

A. You'll have to pay if you watch films on Free Tube.

B. You'll have to fix special software on your computer to visit Free Tube.

C. Users have to sign up their user's name first.

D. Channels are divided into different categories on Free Tube.

4. Form the passage we can learn that _________

A. the author is also very fond of movies

B. Maxx Trailers airs to-be-released movies

C. ABC is a very famous TV station in America

D. Firefox is the only software used to watch films online

5. The underlined word "glitch" probably means _________

A. cover

B. change

C. note

D. fault

题型:单项选择题

开始雷达进近前,雷达管制员应当通知航空器()情报。

A.将使用的跑道

B.适用的超障高度

C.下滑道航径的角度和无线电失效时应当遵守的程序

D.A、B和C

题型:单项选择题

我国是禁止再次委托授权立法权的。

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