Loran-C uses the multiple pulse system because ______．A.Less signal energy is necessary for receiver operationB.More signal energy is available at the receiverC.It significantly increases the peak powerD.It increases the signal capacity

题目

Loran-C uses the multiple pulse system because ______．

A.Less signal energy is necessary for receiver operation

B.More signal energy is available at the receiver

C.It significantly increases the peak power

D.It increases the signal capacity

相似考题

1.We can use energy from the sun because ______.

2.You want to provide 802.1X access for Windows clients using Junos Pulse as the agent. Which two considerations must you take into account()A.Junos Pulse out erauth entication uses EAP-PEAP.B.Junos Pulse ou terauth entication uses EAP-TTLS.C.Junos Pulse innerauth entication uses EAP-MSCHAP-V2.D.Theend point must use thenative Microsoft 802.1X supplicant.

3.Loran-C is which type of system ________．A.Reflected electronB.Electrical radiationC.Quarterpoint electrical navigationD.Hyperbolic radio navigation

4.As used in this passage, "structures" means ______.A. enduranceB. organizationC. necessary partsD. energy

更多“Loran－C uses the multiple pulse system because ______.A.Less signal energy is necessary fo ”相关问题

  • 第1题：

    Most modern Loran-C receivers，when not tracking properly，have a（n）______．

    A.Bell alarm to warn the user

    B.Lighted alarm signal to warn the user

    C.Alternate signal keying system

    D.View finder for each station


    正确答案：B

  • 第2题：

    CDMA for cellular systems can be described as follows.As with FDMA，each cell is allocated a frequency（ ），which is split into two parts,half for reverse（mobile unit to base station）and half for（ ）（base station to mobile unit）.For full-duplex（ ）.a mobile unit uses both reverse and forwardchannels.Transmission is in the form of direct-sequence spread（本题）,which uses a chipping code to increase the data rate of the transmission,resulting inan increased signal bandwidth.Multiple access is provided by assigning（ ）chipping codes to multiple users,so that the receiver can recover the transmission of an individual unit from multiple transmissions.

    A.structure
    B.spectrum
    C.stream
    D.strategy

    答案：B
    解析：
    见下题

  • 第3题：

    Which two statements are true about analog to digital conversion of voice signals for use in digital telephony networks？（）

    • A、The three required steps in the analog to digital conversion are sampling，encoding，and compression.
    • B、The three required steps in the analog to digital conversion are sampling，quantization，and compression.
    • C、The three required steps in the analog to digital conversion are sampling，quantization，and encoding.
    • D、The output of the sampling process is a pulse code modulation （PCM） signal.
    • E、The output of the sampling process is a pulse amplitude modulation （PAM） signal.

    正确答案:C,E

  • 第4题：

    pany uses MSTP within their switched LAN.  What is the main purpose of Multiple Instance  Spanning Tree Protocol （MSTP）？（）

    • A、 To enhance Spanning Tree troubleshooting on multilayer switches
    • B、 To reduce the total number of spanning tree instances necessary for a particular topology 
    • C、 To provide faster convergence when topology changes occur in a switched network
    • D、 To provide protection for STP when a link is unidirectional and BPDUs are being sent but not  received
    • E、 None of the other alternatives apply

    正确答案:B

  • 第5题：

    To optimize performance on an IBM System Storage DS8000， the input/output activity should be spread across （）

    • A、multiple LUNs in a single array
    • B、multiple switches
    • C、multiple host bus adapters
    • D、multiple internal servers

    正确答案:C

  • 第6题：

    单选题
    Loran-C is which type of system（）.
    A

    Reflected electron

    B

    Electrical radiation

    C

    Quarterpoint electrical navigation

    D

    Hyperbolic radio navigation


    正确答案： C
    解析： 暂无解析

  • 第7题：

    多选题
    Which two statements are true about analog to digital conversion of voice signals for use in digital telephony networks？（）
    A

    The three required steps in the analog to digital conversion are sampling，encoding，and compression.

    B

    The three required steps in the analog to digital conversion are sampling，quantization，and compression.

    C

    The three required steps in the analog to digital conversion are sampling，quantization，and encoding.

    D

    The output of the sampling process is a pulse code modulation （PCM） signal.

    E

    The output of the sampling process is a pulse amplitude modulation （PAM） signal.


    正确答案： B,E
    解析： 暂无解析

  • 第8题：

    单选题
    A system must be upgraded from AIX 5.1 to 5.2.  Which of the following scheduling processes should be performed? （）
    A

     Schedule enough down time to backup, upgrade and reboot. 

    B

     Backup, upgrade, then schedule enough down time to reboot the system. 

    C

     Backup, then schedule enough down time to upgrade and reboot the system. 

    D

     No scheduling processes are necessary because no down time is required.


    正确答案： B
    解析： 暂无解析

  • 第9题：

    单选题
    According to the way the energy of the exhaust gases is utilized, pressure-charging can be divided into two main systems, namely, the constant-pressure system and （）.
    A

    the pulse-phase system

    B

    the pulse Doppler system

    C

    the pulse system

    D

    the pulse interval


    正确答案： B
    解析： 暂无解析

  • 第10题：

    多选题
    You want to provide 802.1X access for Windows clients using Junos Pulse as the agent. Which two considerations must you take into account（）
    A

    Junos Pulse out erauth entication uses EAP-PEAP.

    B

    Junos Pulse ou terauth entication uses EAP-TTLS.

    C

    Junos Pulse innerauth entication uses EAP-MSCHAP-V2.

    D

    Theend point must use thenative Microsoft 802.1X supplicant.


    正确答案： B,D
    解析： 暂无解析

  • 第11题：

    单选题
    A “full service” Loran-C receiver will provide（）.
    A

    matching pulse rates of at least 20 stations

    B

    an automatic on-and-off switch

    C

    a horizontal matching of all delayed hyperbolic signals

    D

    automatic signal acquisition and cycle matching


    正确答案： C
    解析： 暂无解析

  • 第12题：

    单选题
    In the （） pressure charging system the pulse of energy that occur as the exhaust is released from the cylinder to improve the output of the turbocharger.
    A

    constant

    B

    pulse

    C

    high

    D

    none of the above


    正确答案： A
    解析： 暂无解析

  • 第13题：

    The use of pulse groups and extremely precise timing at each Loran-C station makes possible the use of ______．

    A.High frequency pulses

    B.Combinations of high and low frequency pulses

    C.The same frequency for all stations in a chain

    D.Varied long and short pulses


    正确答案：C

  • 第14题：

    共用题干
    Green Energy

    1.Green energy is energy that is produced in a manner that has, less of a negative impact to the environment than energy sources like fossil fuels,which are often produced with harmful side effects."Greener" types of energy that often come to mind are solar,wind,geothermal and hydro energy.There are several more,even including nuclear energy,that is sometimes considered a green energy source because of its lower waste output relative to energy sources such as coal or oil.
    2.The goal of green energy is generally to create power with as little pollution as possible produced as a by-product. Every form of energy collection will result in some pollution,but those that are green are known to cause less than those that are not. Most people who advocate greener sources of energy claim that the result of worldwide use of green energy will result in the ability to preserve the planet for a longer time.Greenhouse gases,a by-product of traditional sources of energy such as fossil fuels are thought to be causing global warming,or the process of the Earth heating up at an accelerated pace.
    3.It is not completely necessary for green energy sources to come from places like solar or wind fields,which are examples of green"power plants".A green energy source can be a building that is designed in a way that it keeps itself cool in the daytime and heated in the night through its architectural design rather than having an air-conditioning or a heating system. The conservation of energy through architectural（建筑学的）design becomes, itself, a green energy source. Similarly, many sources of green energy can come directly from the area in which the energy is needed rather than from an outside source.
    4.One of the goals of green energy technology is to take existing fossil fuel energy technology and clean it up so it is produced more cleanly. One such case is that of clean coal technology,where scientists are trying to find ways to extract energy from coal and other fossil fuels without all of the harmful side effects.The success of such these types of green energy depend upon the ability to extract harmful by-products from fossil fuels while not only being energy efficient,but by being cost efficient as well.

    Nuclear energy is sometimes considered a green energy source because of its______.
    A:global warming
    B:carbon emission
    C:lower waste output
    D:a green energy source
    E:fossil fuels
    F: clean fuels

    答案：C
    解析：
    文中第一段第一句中Green energy is energy that is…这种表述方法符合科学说明文的记叙方式，首先对一个名词进行科学定义，所以本题答案为D。
    文中第二段第二句：Every form of energy collection will result in some pollution, but those that are green are known to cause less than those that are not．任何形式的能源收集都会产生一定程度的污染，但是绿色能源比其他能源造成的污染要少。可以推测出这一段是在讲绿色能源的优点，也就是说为什么要发展绿色能源，所以选择A。
    文中第三段第一句：It is not completely necessary for green energy sources to come from places like solar or wind fields．可以得出，本段主要讲述了我们传统认为的新能源，还有其他种类的新能源，所以选择F。
    文中第四段第一句：One of the goals of green energy technology is to take existing fossil fuel energy technology and clean it up so it is produced more cleanly．可以得出，该段主要是在讲新能源的目标和意义。
    第一段最后一句：There are several more, even including nuclear energy, that is sometimes considered a green energy source because of its lower waste output relative to energy sources such as coal or oil．可知，核能经常被视作绿色能源，因为相比煤和石油，它的能源输出效率更高。由此可以得出选项C正确。
    文中第二段最后一句：Greenhouse gases, a by-product of traditional sources of energy such as fossil fuels are thought to be causing global warming,or the process of the Earth heating up at an accelerated pace.温室气体，一种诸如化石能源的传统能源产生的副产品被认为会导致全球变暖，甚至使地球自转速度加快。因此可以得出A选项正确。
    第三段最后两句：The conservation of energy through architectural design becomes,itself,a green energy source .Similarly,many sources of green energy can come directly from the area in which the energy is needed rather than from an outside source．通过自身的建筑设计来保存能源本身就是一种绿色能源的来源。同样道理，许多绿色能源可以直接来源于有能源需求的地区内部而不是外部。由此可以得出D选项正确。
    最后一段最后两句：The success of such these types of green energy depend upon the ability to extract harmful by-products from fossil fuels while not only being energy efficient, but by being cost efficient as well．这些清洁能源技术的成功取决于人们从化石燃料中排除有害副产品、高效利用能源、同时降低成本的能力。由此可以得出E选项正确。

  • 第15题：

    分布式能源系统（distributed Energy System）


    正确答案: 是一种分布安置在需求侧的能 量梯级利用、 资源综合利用以及可再生能源设施。 它通过在需求现场根据用户对能源 的不同需求， 实现温度对口供应能源， 将输送环节的损耗降至最低， 从而实现能源利 用效能的最大化。

  • 第16题：

    A system must be upgraded from AIX 5.1 to 5.2.  Which of the following scheduling processes should be performed? （）

    • A、 Schedule enough down time to backup, upgrade and reboot. 
    • B、 Backup, upgrade, then schedule enough down time to reboot the system. 
    • C、 Backup, then schedule enough down time to upgrade and reboot the system. 
    • D、 No scheduling processes are necessary because no down time is required.

    正确答案:A

  • 第17题：

    单选题
    The use of pulse groups and extremely precise timing at each Loran-C station makes possible the use of（）.
    A

    High frequency pulses

    B

    Combinations of high and low frequency pulses

    C

    The same frequency for all stations in a chain

    D

    Varied long and short pulses


    正确答案： B
    解析： 暂无解析

  • 第18题：

    单选题
    When the author uses the automobile industry as an example, she argues that ______.
    A

    Japan’s auto industry is exceeding America’s auto industry

    B

    the public schooling has stagnated because of competition

    C

    the current American education system is better than the Japanese one

    D

    competition must be introduced into the public education system


    正确答案： D
    解析：
    文章倒数第二段将美国汽车和日本汽车在价格上的巨大差异进行了对比，然后把话题转到对美国的public education system的讨论上，指出美国的教育制度就是缺少这种competition而遭受损害。因此选项D的分析符合文章内容。

  • 第19题：

    单选题
    Because it is not a serious problem, we are not necessary to take strict measures against the student.
    A

    we not need

    B

    not necessary for us

    C

    it being unnecessary

    D

    it is not necessary for us


    正确答案： D
    解析：
    该题考查的是动词不定式作主语的用法。当不定式作主语时，经常把it放在句首来代替不定式，而将不定式到到谓语之后。同时可以用“介词for+代词”来引出不定式的逻辑主语。由此可知选项D为正确答案。

  • 第20题：

    单选题
    The ash content of a fuel oil is significant to the operating engineer because it （）
    A

    is an indication of the amount of noncombustible material present in the oil

    B

    indicates the quantity of energy released by burning a unit amount of the fuel

    C

    is useful for determining proper atomization temperatures

    D

    reflects the overall thermal efficiency of the fuel oil service system


    正确答案： D
    解析： 暂无解析

  • 第21题：

    单选题
    The transmission time duration of a single pulse of radio-frequency energy is a function of the（）.
    A

    persistence

    B

    pulse repetition rate

    C

    pulse length

    D

    resolution


    正确答案： D
    解析： 暂无解析

  • 第22题：

    单选题
    Loran-C uses the multiple pulse system because（）.
    A

    Less signal energy is necessary for receiver operation

    B

    More signal energy is available at the receiver

    C

    It significantly increases the peak power

    D

    It increases the signal capacity


    正确答案： B
    解析： 暂无解析

  • 第23题：

    单选题
    Most modern Loran-C receivers，when not tracking properly，have a（n）（）.
    A

    Bell alarm to warn the user

    B

    Lighted alarm signal to warn the user

    C

    Alternate signal keying system

    D

    View finder for each station


    正确答案： A
    解析： 暂无解析

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