网友您好， 请在下方输入框内输入要搜索的题目：
回声信号存储放大并变成视频信号，是由超声仪器的哪部分完成的()。
A、脉冲信号发生器
B、换能器
C、数字扫描转换器
D、显示器
E、电源部分
常用的仪器是（），它用（）和（）等级；另外一种是矢量示波器，它实时测量（）。
正确答案:波形监视器；图形方式测量；显示视频的亮度（亮度分量）；视频的色度（颜色）信息
回声信号存储放大并变成视频信号，是由超声仪器的哪部分完成的（）
- A、脉冲信号发生器
- B、换能器
- C、数字扫描转换器
- D、显示器
- E、电源部分
正确答案:C
有关测量仪器使用中，不符合安全要求的是（）
- A、使用具有良好接地的三线插头接通示波器电源
- B、对于通电后电风扇不转的仪器，进行停机检查
- C、对功率较大的仪器，停机后立即再次通电使用
- D、使用高频信号发生器作为电路的信号源
正确答案:C
频率特性的测量一般采用的仪器是（）。
- A、通用示波器
- B、扫频仪
- C、频率计
- D、信号发生器
正确答案:B
范文 范例 指导 参考 第一部分 常用电子测量仪器的使用本部分主要涉及实验要用到的三种仪器：数字示波器、信号发生器和稳压电源。学生在自学了电子技术应用实验教程 综合篇（后称教材）第一章内容后，填空完成这部分的内容。一、学习示波器的应用，填空完成下面的内容示波器能够将电信号转换为可以观察的视觉图形，便于人们观测。示波器可分为 模拟示波器 和 数字示波器 两大类。其中， 模拟示波器 以连续方式将被测信号显示出来；而 数字示波器 首先将被测信号抽样和量化，变为二进制信号存储起来，再从存储器中取出信号的离散值，通过算法将离散的被测信号以连续的形式在屏幕上显示出来。我们使用的是 数字示波器 。使用双踪示波器，能够同时观测两个时间相关的信号。信号通过探头从面板上的 通道1 和 通道2 端送入，分别称为CH1和CH2。 在使用示波器时，需要注意以下几点：（1）正确选择触发源和触发方式触发源的选择：如果观测的是单通道信号，就应选择 该信号 作为触发源；如果同时观测两个时间相关的信号，则应选择信号周期 大 （大/小）的通道作为触发源。（2）正确选择输入耦合方式应根据被观测信号的性质来选择正确的输入耦合方式。如图1.1所示，输入耦合方式若设为交流（AC），将阻挡输入信号的直流成分，示波器只显示输入的交流成分；耦合方式设为直流（DC），输入信号的交流和直流成分都通过，示波器显示输入的实际波形；耦合方式设为接地（GND），将断开输入信号。已知被测信号波形如图1.2所示，则在图1.3中， C 为输入耦合方式为交流（AC）时的波形， A 为输入耦合方式为直流（DC）时的波形， B 为输入耦合方式为接地（GND）时的波形。（3）合理调整扫描速度调节扫描速度旋钮，可以改变荧光屏上显示波形的个数。提高扫描速度，显示的波形少；降低扫描速度，显示的波形多。在实际测试时，显示的波形不应过多，以保证时间测量的精度。（4）波形位置和几何尺寸的调整观测信号时，波形应尽可能处于荧光屏的中心位置，以获得较好的测量线性。正确调整垂直衰减旋钮，尽可能使波形幅度占一半以上，以提高电压测量的精度。为便于读数，一般我们调节Y轴位移使0V位置位于示波器显示窗口中的暗格上。数字示波器中被测信号0V标志位于 示波器屏幕显示区的左侧 。在使用示波器前，需要检查示波器探头的好坏。简述检查的方法。将示波器输出的校准信号显示在示波器上，调节示波器的旋钮，使波形显示如图1.4所示。若波形如图1.5所示，0V标志位于波形的中间位置，则原因为 输入耦合方式选为交流 。 图 1.4 图 1.5 图 1.6若所测得的校准信号波形如图1.6所示，图中信号的幅度为30V，则原因为 探头开关设置和示波器上探头衰减系数设置值未匹配，比如探头开关设置为1´，而示波器上探头衰减系数选为10´ 。在实验原始记录纸上画出示波器上显示的波形，目的是方便课后对数据的分析和整理。如图1.7所示，同一个被测信号处于示波器的不同位置，若需要在记录纸上画出这两个波形中，哪一个更容易画呢？ 图（A） 。 （A） （B）图 1.7所以，在画示波器上的波形前，最好先调节旋钮使波形的关键点位于示波器的暗格上，这样在画图时容易定位。二、学习信号发生器的应用，填空完成下面的内容实验中，信号发生器（又称信号源）的作用是为被测电路提供输入信号。你所使用的信号发生器型号为 。在使用信号源之前，需要检查开路电缆线，检查方法为：用信号源产生一个1kHz的三角波，并在示波器上显示出来。信号源的开路电缆线应接在 50W输出 端口。调节 直流偏置（OFFSET） 旋钮，使输出的直流偏置为0V，调节 旋钮，使在示波器观测到的三角波的峰峰值为10V。用信号源产生一个1kHz的TTL信号，并在示波器上显示出来。信号源的开路电缆线应接在 TTL/CMOS 端口。在示波器上调整TTL信号的位置如图1.8所示，则在记录纸上画出波形并记录参数，如图1.9所示。在记录时不仅要画出波形的形状，还要记录0V的位置，垂直和水平方向的挡位选择，这样才能在数据整理时从图中得到波形参数。 图 1.8 图 1.9测试可知，该TTL信号的低电平为 0V ，高电平为 3V ，周期为 1ms ，频率为 1000Hz 。三、学习直流稳压电源的应用，填空完成下面的内容实验中，直流稳压电源的作用是为被测电路提供 稳定的直流电压或电流 。你所使用的稳压电源型号为_。该稳压电源能输出 连续可调的输出电压和稳流电流 ，可同时显示 双 路输出电压和电流，且具有 三（两） 路输出。使用稳压电源输出10V的稳定电压，具体调节方法为：四、实验数据的整理在完成实验后，需要将实验的原始数据进行整理，并将数据以表格或图形的方式表示出来。整理后的数据应完备，输入、输出各项参数应准确；图形应清晰，输入、输出波形应一列排出，坐标轴纵轴对齐，横轴单位长度的选取应便于时序的观察；周期信号应在波形中至少表达出一个完整的周期并在波形图上标出周期和幅度。在坐标纸上画出实验所测得的波形时，应在图上标出相关的参数。不仅要正确描述波形的形状，而且要将相关参数标在图上。例如，原始数据记录如图1.9所示，则整理后的波形图，如图1.10。图 1.10已知原始数据记录波形如图1.11所示，在图1.12的坐标纸上画出整理后的波形图。 图 1.11 图 1.12已知原始数据记录波形如图1.13所示，在图1.14的坐标纸上画出整理后的波形图。 图 1.13 图 1.14在画时序电路的波形时，不仅要记录单个波形的参数和形状，还要记录相关波形之间的时序关系。比如要测一个计数器的输入CP，输出Q1、Q2的波形，已测了CP和Q1，CP和Q2的波形如图1.15所示，则在图1.16中CP、Q1、Q2的波形时序对应关系中，正确的说法是 D 。A.图（a）对 B. 图（b）对 C. （a）、（b）都对 D. 无法确定哪个对图1.15 双踪示波器所测的CP和Q1，CP和Q2的波形图1.16 CP、Q1和Q2的波形若所测波形为CP和Q1，Q1和Q2的波形，如图1.17所示。则在图1.16中CP、Q1、Q2的波形时序对应关系中，正确的说法是 A 。A. 图（a）对 B. 图（b）对 C. （a）、（b）都对 D. 无法确定哪个对图1.17 双踪示波器所测的CP和Q1，Q1和Q2的波形 学习 资料 整理 分享 范文 范例 指导 参考 第二部分 实 验 报 告请按照要求完成实验报告的撰写，本部分中的图表序号均为教材中的图表序号。电子技术、应用实验实验报告（一）学生姓名： 学 号： 报告评分：实验地点： 实验时间： 指导老师： 一、实验项目名称 触发器实现波形整形及脉冲延时的研究1 二、实验学时 三、实验目的 四、实验器材 五、实验原理（可另加附页）1施密特触发器2CMOS门电路组成的施密特触发器利用CMOS反相器组成的施密特触发器电路图如图2.1.4所示。图2.1.4 CMOS反相器组成的施密特触发器该电路的工作原理为：可得到正向阈值电压VT+：负向阈值电压VT-：回差电压DVT=VT+-VT-2(RW1/R4)VTH。而得到上面的表达式，对反相器的要求是 VTH=1/2VDD 。若电路中RW1为5k的可调电阻，R1为5.6k、的固定电阻，则VT+的理论值为： 2.54.775V VT-的理论值为： 0.2672.5V 上式表明，该电路中回差电压的大小 可以 （可以/不可以）通过改变RW1、R4的比值来调节。3集成施密特触发器CD40106图2.1.8为CD40106的测试电路图。图2.1.8 CD40106 测试电路说明图中电阻R1、R2、R3和电容C1的作用。根据该电路，输入Vin的电压峰峰值和处的电压峰峰值相等吗？ 不相等 输入Vin的直流偏置电压变化会影响处的直流偏置电压吗？ 不会 处的直流偏置电压理论上应为 3 V。根据实验原理，回答下列问题：（1）门电路的阈值电压是指 B 。A. 门电路的输入变化引起其输
常用电子仪器包括两大类：（）
- A、电子测量仪器、电子应用仪器
- B、示波器、万用表
- C、光信号测试仪和电信号测试仪
- D、频率计、频普分析仪
正确答案:B
示波器是一种测量信号频率特性的仪器。
正确答案:错误
示波器是一种测量信号频率特性的仪器。
正确答案:错误
电子示波器是一种常用的电子仪器，它可以观察电信号的波形，通过屏幕显示直接测量信号的（）、（）和相位参数，还可以测量脉冲信号的前后沿、脉宽、上冲、下冲等参数。
正确答案:幅度参数；频率参数
电子示波器是一种常用的电子仪器，它可以观察电信号的波形，通过屏幕显示直接测量信号的（）、（）和相位参数，还可以测量脉冲信号的前后沿、脉宽、上冲、下冲等参数。
正确答案:幅度参数；频率参数
更多 “电子技术应用实验教程实验报告综合篇(附含答案解析)UESTC大三上” 相关考题
- 共用题干 Single-parent Kids Do BestSingle mums are better at raising their kids than two parents-at least in the bird world.Mother zebra finches have to work harder and raise fewer chicks on their own,but they also produce more attractive sons who are more likely to get a mate.The finding shows that family conflict is as important an evolutionary driving force as ecological factors such as hunting and food supply.______(46)In evolutionary terms,the best strategy for any parent in the animal world is to find someone else to care for their offspring,so they can concentrate on breeding again.Soit's normal for parents to try to pass the buck to each other.But Ian Hartley from the University of Lancaster and his team wondered how families solve this conflict,and how the conflict itself affects the offspring.______(47)They compared single females with pairs,by monitoring the amount of food each parent collected,and removing or adding chicks so that each pair of birds was raising four chicks,and each single mum had two-supposedly the same amount of work.But single mums,they found,put in about 25 per cent more effort than females rearing with their mate. ______(48)"The offspring suffer some of the cost of this conflict,"says Hartley.The cost does not show in any obvious decrease in size or weight,but in how attractive they are to the opposite sex.When the chicks were mature,the researchers tested the"fitness"of the male offspring by offering females their choice of partner.______( 49)Sexual conflict has long been thought to affect the quality of care given to offspring,says zoologist Rebecca Kilner at Cambridge University,who works on conflict of parents in birds."But the experimental evidence is not great.The breakthrough here is showing it empirically."More surprising,says Kilner,is Hartley',S statement that conflict may be a strong influence on the evolution of behaviour,clutch size and even appearance."People have not really made that link,"says Hartley.A female's reproductive strategy is usually thought to be affected by hunting and food supply.______(50)______(49)A:To avoid being exploited,mothers with a partner hold back from working too hard if the father is being lazy,and it's the chicks that pay the price.B:To find out,they measured how much effort zebra finch parents put into raising their babies.C:Those males reared by single mums were chosen more often than those from two一parent families.D:With two parents around,there's always a conflict of interests,which can have a detrimental effect on the quality of the offspring.E:Kilner says conflict of parents should now be taken into account as well.F:It turned out that single mums had greater influence on their offspring.
- 试述唐菖蒲切花的促成和抑制栽培。
- 单选题静脉血的血浆（清）二氧化碳结合力正常值为（）A 15～2mmol／LB 20～25mmol／LC 30～40mmol／LD 23～27mmol／LE 40～45mmol／L
- 我国花卉种质资源的特点是什么？如何合理的开发我国的种质资源？
- 细粒棘球绦虫对人的致病阶段是（）A、成虫B、虫卵C、原头蚴D、棘球蚴E、六钩蚴
- 共用题干 Optimists Really Do Live Longer,Say Scientists1 For the philosopher Arthur Schopenhauer optimism was fundamentally wrong,banal and corrupting while the father of psychoanalysis Sigmund Freud simply declared it to be neurotic.2 Experience shows that looking on the bright side of life does have advantages and recent scientific evidence points to the positive mindset as being beneficial to health.In other words,optimists live longer.3 That was the conclusion reached by experts at the Mayo Clinic in the US State of Minnesota who evaluated answers given by people to a set of questions in the 1960s.Of the 729 candidates,200 had died and according to scientists,there were a disproportionate number of pessimists among them.4 Ten points more on the pessimism scale-that was the difference between"slightly pessimistic"and "averagely pessimistic”-were enough to boost a person's chances of dying by 19 percent,according to the study by prominent psychologist Martin Seligman of the University of Pennsylvania.5 The study does not say why pessimists die.But an older survey taken among children in San Francisco and Los Angeles makes it clear that personal attitude towards the world is a key factor in the ion- gevity equation.6 The latest evidence to support the theory that optimists tend to cope better with illness of all kinds has been provided by Professor Raif Schwarzer of Berlin's Free University who questioned 600 heart and lung patients.His conclusion:Optimists recover more swiftly from operations than their pessimistic counter- parts,tend to be happier after treatment and return to work more swiftly.7 There have been suggestions that optimists do not stay healthier but rather turn into optimists later because they enjoy good health.Numerous surveys have taken into account a person's state of health at the outset and the effect remains the same.8 Studies have shown that optimists do not blind themselves to reality either.They thus interpret it in a positive way."Sublimating and denying things tend to alter reality but illusions are a way of seeing reality in the best light,"said Californian psychology professor Shelley Taylor.9 German science journal Buld der Wissenschaft，which carries a major article on the topic in its current March issue,commented on"the right attitude"to having a tumor.10 It seems psychotherapy can go some way towards extending the life span and life quality of a sick person although a complete recovery using psychological technique alone is unlikely.1 1 Doctors like,however,to point to the example of US cycling professional Lance Armstrong,who was seriously ill with cancer,but whose unshakeable optimism helped him to take the top trophy twice at cycling's premier Tour de France.1 2 The magazine also quoted a study by Sheldon Cohens of the Carnegie-Mellon-University in Pittsburgh: 420 volunteers were deliberately infected with strains of various common cold viruses.A day later checks were carried out to see who had caught a cold.13 The results showed that in the case of people who had.satisfactory,long-term relations with friends, neighbors or colleagues, the virus was less likely to trigger a cold.Of people with three or fewer firm relation- ships 62 percent became ill compared with only 35 percent of those who had six or more close human links.Some scholars did not believe______.A:to avoid unpleasant things in lifeB:in looking on the bright side of lifeC:less likely to catch coldD:how one looks on lifeE:to be unhappy all the time F:more likely to get cancer
- 共用题干 What Should I Say to the Person Who Has Cancer?It is normal to feel that you don't know what to say to someone who has cancer.You might only know the person casually,or you may have worked______(1)or lived near each other for many years and have a closer relationship.The most important ___________(2)you can do is to acknowledge the situation in some way一whatever is most comfortable for you．You can show interest and concern,you can expressencouragement,or you_________(3)offer support. Sometimes the simplestexpressions of concern are the______(4)meaningful,While it is good to be encouraging,it is also important_________(5)to show false optimism or to tell the person with cancer to always have a positive attitude.Doing _________(6)things may discount their fears,concerns,or sad feelings.It is alsotempting to say that you know __________(7)the person feels.While you may know thisis a difficult time,no one can know exactly how the person with_______(8)feels.Humor can be an important way________(9)coping.It is also another source ofsupport and encouragement.Let the person with cancer________(10)the lead; it ishealthy if they find something funny about a side effect,like hair loss or increased appetite, and you can certainly join_________(11)in a good laugh.This can be a great way to relieve stress and to take a break from the_________(12)serious nature of the situation.When the person with cancer looks good, let them know! Refrain（忍住） _____(13)comments when their appearance isn't as good,such as"You're looking pale"or"You've lost weight".Cancer and its treatment can be very unpredictable. Be prepared for good days and bad________(14).Refrain from telling the person with cancer stories about family members or friends who have had cancer. Everyone is different,and these stories may not be helpful.Instead,it is better simply to tell them you know________(15)about cancer because you've been through it with someone else._________(5) A:not B:just C:how D:still
- 共用题干 Organ Donation and Transplantation1 Organ donation（捐献）and transplantation（移植）refers to the process by which organs or tissuesfrom one person are put into another person's body.2 The number of people needing a transplant continues to rise faster than the number of donors.About 3,700 transplant candidates are added to the national waiting list each month.Each day,about 77 people receive organ transplants.However,18 people die each day waiting for transplants that can't take place because of the shortage of donated organs.3 There are rio age limits on who can donate.Newborns as well as senior citizens have been organ donors. If you are under age 18 , you must have a parent's or guardian's consent（同意）.If you are 18 years or older,you can show you want to be an organ and tissue donor by signing a donor card.4 Many people think that if they agree to donate their organs,the doctor or the emergency room staff won't work as hard to save their life.This is not true.The transplant team is completely separate from the medical staff working to save your life.The transplant team does not become involved with you until doctors have determined that all possible efforts to save your life have failed.5 If you need an organ transplant,your doctor will help you get on the national waiting list.Your name will be added to a pool of names.When an organ donor becomes available,all the patients in the pool are compared to that donor. Factors such as blood and tissue type, size of the organ, medical urgency（紧急）of the patient's illness , time already spent on the waiting list, and distance between donor and recipient（接受 者）are considered.Paragraph 3_________A: Quality of Donated OrgansB: Benefits of Organ DonationC:Distribution of Donated OrgansD:Quality of Donor Medical CareE:Age Limits for Organ DonationF:Status of Organ Donation and Transplantation
- 简述切花失鲜的原因以及保鲜措施。
- 问答题何谓强制性使用运动疗法？试述其具体实施方法及病例选择标准。