（）is an auxiliary light source of EDFA. It causes the erbium icons of an erbium doped fiber to come from E1 to E3 quantum level.
（）is an auxiliary light source of EDFA. It causes the erbium icons of an erbium doped fiber to come from E1 to E3 quantum level.
相关考题：
What is a FALSE statement concerning the line throwing appliance on a vessel ().A.A drill on its use must be held once every three monthsB.The actual firing is at the discretion of the MasterC.The auxiliary line must be of a light colorD.The auxiliary line must be at least 500m long
The light from the sun moves away from its source in all directions, so its strength is very () . A.broken outB.spread outC.looked outD.figured out
Have you ever served the auxiliary engine to combustion heavy oil? What should be borne in mind when transferring oil; from heavy oil to light oil?
A light used to signal passing intentions must be an ______.A.all-round yellow light onlyB.all-round white light onlyC.all-round blue light onlyD.alternating red and yellow light
A vessel trawling will display a ______.A.red light over a white lightB.green light over a white lightC.yellow light over a red lightD.white light over a green light
Each life jacket light that has a non-replaceable power source must be replaced ______．A.every 6 months after initial installationB.every 12 months after initial installationC.every 24 months after initial installationD.on or before the expiration date of the power source
共用题干Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles（束）of electromagnetic（电磁）energy called photons（光子）.Today,scientists agree that light has a dual（二重）nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference（干扰）, etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel（旋转齿轮）between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum（真空）,however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane.Objects are visible to the human eye as light is______.A: sources of lightB: the speed of lightC: the path of lightD: a straight lineE: a beam of lightF: a form of energy
共用题干Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles（束）of electromagnetic（电磁）energy called photons（光子）.Today,scientists agree that light has a dual（二重）nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference（干扰）, etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel（旋转齿轮）between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum（真空）,however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane.Stars,flames,flashlights are some examples of______.A: sources of lightB: the speed of lightC: the path of lightD: a straight lineE: a beam of lightF: a form of energy
共用题干Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles（束）of electromagnetic（电磁）energy called photons（光子）.Today,scientists agree that light has a dual（二重）nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference（干扰）, etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel（旋转齿轮）between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum（真空）,however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane.Paragraph 5______A: How Is the Nature of Light Explained Today?B: What Are Sources of Light?C: How Did Physicists Measure the Speed of Light?D: How Does Light Travel?E: How Did People Think of Light Years Ago?F: What Causes a Shadow?
共用题干Learn About Light1 Ancient civilizations were amazed by the existence of light for thousands of years?The Greek philoso- phrrs believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision.However,Empedocles and a Dutch scientist named Christian Huygens believed that light wag like a wave.According to them,light spread out and travelled like a straight line.This theory was acceptedduring the 19th century.2 In 1905,Albert Einstein published a research paper in which he explained what is referred to as the photoelectric effect.This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles（束）of electromagnetic（电磁）energy called photons（光子）.Today,scientists agree that light has a dual（二重）nature一it is part particle and part wave. It is a form of energy that allows us tosee things around us.3 Things that give off light are known as sources of light.During the day,the primary source of light is the sun.Other sources of light include stars,flames,flashllights,street lamps and glowing gases in glass tube.4 When we draw the way light travels we always use straight lines.This is because normally light rays travel in a straight line.However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference（干扰）,etc.5 Physicists have attempted to measure the speed of light since the early times.In 1849,Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel（旋转齿轮）between the beam and the mirror. From the rate of rotation of the wheel, number of wheel'S teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second.In a vacuum（真空）,however,the speed of light is 299,792,458 meters per second.This is about a million times faster than the speed of an airplane.Objects are visible to the human eye as light is_______. A:sources of lightB:the speed of light C:the path of lightD:a straight lineE:a beam of lightF:a form of energy
A hollow-cathode lamp is（）A、A broad-band light sourceB、A narrow-band light sourceC、A light detectorD、Not a light source
产生彩色投影必须调整下面哪个参数（）A、light的light transmission设为100%B、light的light transmission设为0%C、投影层的阴影层的light transmission设为80%D、接受阴影层的light transmission设为100%
Which options must you configure while performing an automated Tablespace Point-in-Time Recovery (TSPITR) by using Recovery Manager (RMAN)?（）A、New channels for restore and recovery tasksB、New name for the data files of the tablespaceC、Auxiliary name for the data files of the tablespaceD、Auxiliary destinations for an auxiliary set of data files
陆地撤离当旅客在充满烟雾的客舱内时的指挥口令：（）A、低下头、用衣领、袖口捂住口鼻heads down，cover your nose and mouthB、不要吸烟No smokingC、坐下，不要动Sit down，Stay downD、朝光线方向走Toward the light source
单选题The towing light is a(n)（）.Aflashing amber lightByellow light with the same characteristics as the sternlightCall-round yellow lightDyellow light with the same characteristics as the masthead light
单选题The author mentions the activities of fisheries in order to provide an example of ______.Ahow ubiquitous the phenomenon of bioluminescence is coastallyBhow predators do make use of bioluminescence in locating their preyChow human intervention imperils bioluminescent microorganismsDhow nocturnal fishing expeditions are becoming more and more widespreadEhow limited bioluminescence is as a source of light for human use
单选题Which command would correctly start a TSPITR of the USERS tablespace？（）A recover tablespace users until time ，，10/06/2008：22：42：00 auxiliary ，，c/oracle/auxiliaryB recover tablespace users time ，，10/06/2008：22：42：00 auxiliary destination ，，c：/oracle/auxiliary； time ，， 10/06/2008：22：42：00 auxiliary destination ，，c/oracle/auxiliaryC recover tablespace users to point-in.D recover tablespace users except time ，，10/06/2008：22：42：00 auxiliary destination ，，c：/oracle/auxiliaryE recover tablespace users until time ，，10/06/2008：22：42：00 auxiliary destination ，，c：/oracle/auxiliary
单选题An anchored vessel on pilotage duty must show which light(s) at night? （）AA sternlight onlyBAnchor lights onlyCA white light over a red light onlyDA white light over a red light and anchor lights
单选题A vessel trawling will display a（）.Ared light over a white lightBgreen light over a white lightCyellow light over a red lightDwhite light over a green light
单选题After a fire has been extinguished in a closed space, personnel may safely enter the space when （）.Asmoke density has been decreased sufficiently to see the bulkhead opposite the compartments entranceBa lifeline and explosion proof flash light are usedCall smoke and toxic fumes are removed and an adequate oxygen supply is presentDoverhaul has been completed to remove any possible source of re-ignition
单选题A hollow-cathode lamp is（）AA broad-band light sourceBA narrow-band light sourceCA light detectorDNot a light source
单选题打开锚灯！ （）ASwitch on the deck light!BSwitch on the anchor light!CSwitch on the cargo light!DSwitch on the hold light!
单选题The light on a life jacket must be replaced（）.Awhen the power source is replacedBeach year after installationCevery six monthsDwhen it is no longer serviceable
单选题Which statement concerning Montauk Point Light is TRUE（）.AThe light comes on at sunsetBThere is an emergency light if the main light is extinguishedCThe height of the light is 24 feetDThe tower is painted with black and white stripes
单选题Each life jacket light that has a non-replaceable power source must be replaced（）.Aevery 6 months after initial installationBevery 12 months after initial installationCevery 24 months after initial installationDon or before the expiration date of the power source
单选题An auxiliary reservoir for starting auxiliary engines should be kept at （）.Alow pressure at all timesBfull pressure at all timesClow pressure at intermittenceDfull pressure at intermittence
单选题In which source could you find the number of a chart for a certain geographic area?（）AChart No.1BCatalog of ChartsCIMO Practical NavigatorDIMO Light List