Optical spectroscopy of galaxies in the direction of the Virgo cluster

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天体英语知识点总结高中

天体英语知识点总结高中一、IntroductionThe study of celestial bodies, or heavenly bodies, is known as astronomy. Astronomy is a natural science that involves the observation and analysis of celestial phenomena. It has been a subject of human fascination for millennia, with civilizations around the world creating myths, legends, and astronomical calendars associated with the movements of the sun, moon, and stars.In recent centuries, astronomy has developed into a field of scientific inquiry, using advanced tools and techniques to study the universe and its contents. This has led to many groundbreaking discoveries and a better understanding of the cosmos.In this article, we will explore some key concepts and terms related to astronomy and celestial bodies, providing a comprehensive overview of this fascinating field of study.二、The Solar SystemThe solar system is the collection of celestial bodies that orbit the sun, including planets, moons, asteroids, comets, and other objects. The sun is the central star of the solar system, providing light and heat to the planets and other bodies that orbit it.1. Planets: There are eight recognized planets in the solar system, including Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. These planets vary in size, composition, and distance from the sun, and each has its own unique characteristics.2. Moons: Moons are natural satellites that orbit planets. The most well-known example is Earth's moon, but many other planets in the solar system also have moons of their own. Some planets, such as Jupiter and Saturn, have a large number of moons, while others have only a few.3. Asteroids: Asteroids are small, rocky bodies that orbit the sun. They are found primarily in the asteroid belt, which lies between the orbits of Mars and Jupiter. Some asteroids have elliptical or irregular orbits that bring them close to the inner solar system, posing a potential threat to Earth and other planets.4. Comets: Comets are icy bodies that orbit the sun in highly elliptical orbits. When a comet approaches the sun, its ice begins to vaporize, creating a bright glowing tail that can be seen from Earth. Comets are thought to be remnants from the early solar system and provide valuable insights into its formation and evolution.5. Dwarf Planets: In addition to the eight recognized planets, there are also a number of dwarf planets in the solar system. These are celestial bodies that are similar to planets in some ways but do not meet all the criteria for being classified as planets. The best-known example is Pluto, which was reclassified as a dwarf planet in 2006.三、Stars and GalaxiesStars are massive, luminous spheres of plasma that emit light and heat through nuclear fusion. They are the building blocks of galaxies, which are vast collections of stars, gas, and dust held together by gravity.1. Star Formation: Stars form from the gravitational collapse of dense regions within interstellar clouds of gas and dust. As the cloud contracts, it heats up and eventually reaches a temperature and density at which nuclear fusion reactions can occur, turning hydrogen into helium and releasing large amounts of energy in the process.2. Stellar Evolution: Stars go through a life cycle that depends on their initial mass. Low-mass stars, such as our sun, spend most of their lives in a stable state, fusing hydrogen into helium in their cores. Eventually, they exhaust their nuclear fuel and expand into red giants before shedding their outer layers and becoming white dwarfs. High-mass stars, on the other hand, undergo more dramatic evolutionary stages, including supernova explosions and the formation of neutron stars or black holes.3. Galaxies: Galaxies come in a variety of shapes and sizes, from small irregular galaxies to giant elliptical and spiral galaxies. The Milky Way, the galaxy in which our solar system resides, is a spiral galaxy with several arms of stars and gas. Galaxies are thought to have formed from the gravitational collapse of large clouds of gas and dust in the early universe.4. The Universe: The universe is the vast expanse of space and time that contains all known matter and energy. It is believed to have originated from a single point in an event known as the Big Bang, which occurred approximately 13.8 billion years ago. The study of the universe, its origin, and its evolution is a fundamental aspect of astronomy, leading to many important discoveries and insights into the nature of the cosmos.四、Observational AstronomyObservational astronomy is the study of celestial objects and phenomena through direct observation using telescopes, cameras, and other instruments. This branch of astronomy plays a crucial role in advancing our understanding of the universe.1. Telescopes: Telescopes are the primary tools used by astronomers to observe celestial objects. They collect and magnify light from distant objects, allowing astronomers to study stars, planets, galaxies, and other phenomena in great detail. There are several types of telescopes, including optical telescopes that work by collecting visible light, as well as radio telescopes, X-ray telescopes, and other specialized instruments that capture non-visible forms of radiation.2. Astronomical Imaging: Astronomical imaging refers to the process of capturing and analyzing images of celestial objects. Modern digital cameras and imaging sensors have revolutionized this field, allowing astronomers to produce high-resolution images of distantgalaxies, planetary surfaces, and other astronomical features. Imaging data is often used to study the composition, structure, and evolution of celestial bodies.3. Spectroscopy: Spectroscopy is the study of the interaction between light and matter. By analyzing the spectrum of light emitted or absorbed by an object, astronomers can learn about its composition, temperature, and other important properties. Spectroscopy has been instrumental in advancing our knowledge of stars, galaxies, and the interstellar medium.4. Astronomical Surveys: Astronomical surveys are large-scale projects that aim to systematically observe and catalog objects in the sky. These surveys cover a wide range of wavelengths and are used to study the distribution of galaxies, the structure of the universe, and the properties of individual celestial objects. The data collected from these surveys is crucial for advancing our understanding of the cosmos.五、Astrophysics and CosmologyAstrophysics is the branch of astronomy that seeks to understand the physical properties and behavior of celestial objects and phenomena. It involves the application of principles from physics and other sciences to study the universe and its contents.1. Stellar Physics: Stellar physics focuses on the study of stars, including their structure, evolution, and energy production. It seeks to explain the processes that govern the behavior of stars, such as nuclear fusion in their cores, the generation of magnetic fields, and the formation of stellar remnants.2. Galactic and Extragalactic Astrophysics: This subfield of astrophysics deals with the study of galaxies and the large-scale structures of the universe. It explores the distribution of matter and energy, the formation of galaxies, and the dynamics of galactic clusters. It also addresses the properties of objects outside our galaxy, such as quasars, pulsars, and active galactic nuclei.3. Cosmology: Cosmology is the study of the origin, evolution, and ultimate fate of the universe. It seeks to understand the large-scale structure of the cosmos, the nature of dark matter and dark energy, and the cosmic microwave background radiation left over from the Big Bang. Cosmologists use principles from general relativity and particle physics to develop theoretical models of the universe and test them against observational data.4. Black Holes and Neutron Stars: Black holes and neutron stars are extreme objects that result from the gravitational collapse of massive stars. They have unique properties, such as intense gravitational fields and the emission of powerful radiation. The study of these objects is an important area of research in astrophysics, as they provide insights into the behavior of matter under extreme conditions.六、ConclusionAstronomy is a fascinating and dynamic field of study that encompasses a wide range of topics, from the study of stars and planets to the exploration of the universe on the largest scales. It offers a unique perspective on the nature of our existence and our place in the cosmos.The knowledge and insights gained from astronomy have practical applications in many areas, including space exploration, the development of new technologies, and the search for extraterrestrial life. As our understanding of the universe continues to expand, so too will the impact of astronomy on our lives and our understanding of the world around us.In conclusion, astronomy is a cornerstone of human curiosity and scientific endeavor, revealing the wonders of the universe and the beauty of the celestial realm. The study of celestial bodies continues to capture the imagination of people around the world and drive us to explore and understand the cosmos in ever-greater detail.。

科学中观察星空的方法的作文

科学中观察星空的方法的作文Observing the stars in the sky has been a fascination for humans since ancient times. 从古代开始，观察天空中的星星就一直是人类的迷恋。

Before the invention of telescopes, people relied on their naked eyes to observe and study the stars. 在望远镜发明之前，人们依靠赤裸的双眼来观察和研究星星。

The method of naked-eye observation still holds a special place in modern astronomy. 裸眼观测的方法在现代天文学中仍然占据着特殊的位置。

Apart from simply looking up at the sky without any aid, there are numerous tools and techniques that scientists use to observe the stars. 除了简单地凭空仰望，科学家使用了许多工具和技术来观察星星。

One of the most basic tools for observing stars is a pair of binoculars or a small telescope. 观察星星的最基本工具之一是一副双筒望远镜或小型望远镜。

These devices provide a closer and clearer view of the stars and celestial bodies. 这些设备可以更近距离、更清晰地观察星星和天体。

Astronomers can use binoculars or small telescopes to observe the moon, planets, and even some deep-sky objects such as star clustersand nebulae. 天文学家可以使用双筒望远镜或小型望远镜来观察月球、行星，甚至一些深空天体，如星团和星云。

我想发明高科技望远镜英语作文400字英语作文

我想发明高科技望远镜英语作文400字英语作文全文共3篇示例，供读者参考篇1I Want to Invent a High-Tech TelescopeEver since I was a little kid, I've been fascinated by the night sky. I can still vividly remember lying on the grass in my backyard, staring up at the twinkling stars and planets in awe. There was something so magical and mysterious about the cosmos that captured my imagination from a very young age.As I got older and learned more about astronomy in school, my curiosity only deepened. I was enthralled by the stories of brilliant scientists like Galileo Galilei, who revolutionized our understanding of the universe with his groundbreaking telescopic observations. I found myself dreaming of one day making a similar mark on the field of astronomy.Of course, like many kids, I also had big dreams of becoming an astronaut and traveling to space myself. However, as I progressed through my studies, I realized that my true passion lay not in space exploration itself, but in the technology that makes it possible. I was utterly captivated by the elegantengineering and innovative designs behind the telescopes and instruments used to study the cosmos.This realization set me on a path towards pursuing a degree in physics and astronomy, with a particular focus on instrumentation and telescope design. Throughout my academic career, I've immersed myself in the intricacies of optics, detectors, and imaging systems, constantly seeking ways to push the boundaries of what's possible.Now, as I approach the culmination of my studies, I find myself with an ambitious goal: to design and build acutting-edge telescope that will revolutionize our ability to peer into the depths of the universe. I envision a telescope that combines the latest advancements in adaptive optics,multi-object spectroscopy, and advanced detectors, capable of capturing unprecedented details and unlocking new realms of astronomical discovery.One of the key challenges I aim to tackle is the issue of atmospheric turbulence, which can distort and blur the images captured by ground-based telescopes. By incorporatingstate-of-the-art adaptive optics systems, my telescope would actively compensate for these distortions in real-time, deliveringcrystal-clear images and allowing for more precise measurements.Furthermore, I plan to integrate advanced multi-object spectroscopy capabilities, enabling simultaneous observations and spectral analysis of multiple celestial objects at once. This would not only vastly increase the efficiency of astronomical surveys but also open up new avenues for studying the chemical compositions, motions, and evolution of galaxies, stars, and other cosmic phenomena.Of course, at the heart of any telescope lies its detector system, responsible for converting the faint light from distant celestial objects into usable data. I intend to leverage the latest developments in ultra-low-noise detectors, coupled with sophisticated signal processing algorithms, to push the limits of sensitivity and resolution. This would allow my telescope to capture the faintest and most elusive signals from the farthest reaches of the observable universe.Beyond the technical aspects, I also envision my telescope as a powerful tool for inspiring the next generation of scientists and astronomers. By incorporating innovative educational features and outreach programs, I hope to ignite the same sense of wonder and curiosity in young minds that I experienced as achild. Perhaps my telescope will be the spark that ignites a lifelong passion for exploring the cosmos in countless others.I understand that the road ahead is long and arduous, filled with numerous challenges and obstacles. Designing and building a telescope of this caliber is no small feat, and it will require years of dedicated research, development, and problem-solving. However, I am undeterred, driven by an unwavering determination to push the boundaries of what is possible and unlock new secrets of the universe.In the end, my ambition is not merely to construct a telescope, but to create a lasting legacy – a tool that will usher in a new era of astronomical discovery and inspire generations of stargazers to come. With each observation, each groundbreaking discovery, I hope to contribute to theever-expanding tapestry of human knowledge and our understanding of our place in the vast cosmos.So, as I stand on the cusp of embarking on this ambitious endeavor, I can't help but feel a sense of excitement and anticipation. The challenges ahead are daunting, but the rewards – the potential to unravel the mysteries of the universe and ignite the curiosity of countless minds – make it all worth it. And who knows? Perhaps one day, a child will gaze through the eyepieceof my telescope, and be inspired to embark on their own journey of cosmic exploration, continuing the cycle of discovery that has defined humanity's quest to understand the heavens above.篇2I Want to Invent a High-Tech TelescopeEver since I was a little kid, I've been fascinated by the night sky. I remember lying on the grass in our backyard, staring up at the twinkling stars and the bright moon, filled with wonder about the vast universe beyond our tiny planet. My parents bought me a basic telescope for my 8th birthday, and from that moment on, I was hooked on astronomy.As I got older and learned more about the science of telescopes and optics, my childhood dream evolved from just wanting to look at celestial objects to designing and building the most advanced telescope the world has ever seen. I've always been the curious, tinkering type - taking apart old electronics and putting them back together, doing science experiments in my basement. So the idea of creating cutting-edge astronomical technology isn't just a dream, it's my calling.My telescope would use revolutionary mirror and lens technology to capture incredibly high-resolution images anddata from the farthest reaches of the observable universe. Larger than any optical telescope in existence, it would be equipped with cooling systems and atmospheric filters to eliminate interference and distortion. But most importantly, it would incorporate next-generation sensors and spectrometers capable of detecting phenomena we can barely even theorize about today.With a telescope like this, we could potentially observe the births and deaths of galaxies in real-time across billions of light years. We could analyze the atmospheric compositions of exoplanets orbiting other stars, perhaps even finding unmistakable biosignatures of alien life. We could verify or disprove theories about dark matter, dark energy, black holes, and the origin of the universe itself. The telescope I envision would unlock secrets of the cosmos that we can scarcely imagine.Of course, such an ambitious and complex instrument would require large-scale international collaboration, vast resources, and cutting-edge engineering across many disciplines. But I'm convinced that if I dedicate my life's work to this goal, bring together the brightest minds, and persist despite the inevitable setbacks, my dream telescope can and will be realized. With thisamazing new eye on the universe, humanity's understanding of our place in the cosmos would be forever transformed. And for me, that would be the ultimate achievement.篇3My Dream to Invent a Revolutionary High-Tech TelescopeEver since I was a young child, I have always been fascinated by the vast mysteries of outer space. Gazing up at the twinkling stars in the night sky filled me with a sense of wonder and an insatiable curiosity to learn more about the cosmos. As I grew older, this childhood fascination blossomed into a full-fledged passion for astronomy and space exploration.I vividly remember the first time I peered through a telescope as a kid. It was a magical experience that opened my eyes to the incredible marvels hiding amongst the celestial bodies. I could make out the craters on the moon's surface, and even glimpse a few of Jupiter's moons orbiting around the gas giant. From that moment on, I became obsessed with learning everything I could about the universe we inhabit.In school, I devoured books on astronomy, cosmology, and astrophysics. I soaked up knowledge about the formation of stars, the life cycle of galaxies, and the baffling concepts of blackholes and dark matter. The more I learned, the more my thirst for understanding grew. However, I couldn't shake the feeling that our current telescopes and observational tools, though impressive, were still quite limited in their capabilities.It was then that a bold dream began taking shape in my mind – to one day invent a revolutionary high-tech telescope that would push the boundaries of what we can observe and study in deep space. I envisioned a telescope that would not only have unparalleled magnification and resolution capabilities but would also incorporate cutting-edge technologies to analyze the data it collects in unprecedented ways.My ideal telescope would be equipped with state-of-the-art spectroscopic instruments that could detect the faintest traces of elements and compounds in the atmospheres of exoplanets light-years away. This would allow us to potentially identify biosignatures and increase our chances of discovering planets capable of supporting life as we know it.Furthermore, this telescope would harness the power of advanced computer algorithms and artificial intelligence to process and interpret the vast amounts of data it would collect. These algorithms could identify patterns and anomalies that thehuman eye might miss, leading to groundbreaking discoveries and a deeper understanding of the cosmos.Imagine being able to observe the formation of new stars and planetary systems in real-time, witnessing the birth of cosmic structures that have eluded our sight until now. Or perhaps we could even catch a glimpse of the elusive dark matter that makes up a significant portion of the universe, but whose true nature remains shrouded in mystery.Of course, such an ambitious project would require collaboration among the brightest minds in various fields, including astronomy, engineering, computer science, and materials science. It would be a monumental undertaking, but one that could propel our understanding of the universe to unprecedented heights.I am well aware of the challenges that lie ahead, but I am driven by an unwavering passion and a belief that with determination and ingenuity, we can overcome any obstacle. After all, throughout human history, our greatest achievements have often been born from dreams that once seemed impossible.As I embark on my academic journey, I am committed to dedicating my efforts towards making this dream a reality. I willimmerse myself in the study of physics, mathematics, and computer programming – the foundational pillars upon which such a groundbreaking telescope would be built.It is an audacious goal, but one that could unlock secrets of the universe that we have yet to even fathom. And who knows? Perhaps my contributions, combined with the efforts of countless other brilliant minds, could one day lead to a telescope that would redefine our understanding of the cosmos and our place within it.The universe is a vast, awe-inspiring expanse filled with wonders waiting to be uncovered. With determination, perseverance, and a relentless pursuit of knowledge, I believe we can continue to push the boundaries of what is possible in space exploration and astronomy. And that is a dream worth striving for.。

解密太阳系的奥秘：探索宇宙中行星和恒星的新发现

解密太阳系的奥秘：探索宇宙中行星和恒星的新发现1. 引言1.1 概述太阳系作为人类研究和探索的焦点之一，一直充满着令人着迷的奥秘。

随着科技的进步和观测技术的革新，我们对行星和恒星有了更深入的认识和理解。

本文将带领读者一起解密太阳系中行星和恒星的奥秘，并介绍最新的发现和研究成果。

1.2 文章结构本文主要分为五个部分。

首先，在第二部分中，我们将讨论太阳系的形成与演化过程，探索行星形成的奥秘以及冥王星地位变迁等问题。

接下来，在第三部分中，我们将介绍最新外太空行星观测技术进展，以及火星水资源探测结果和木星及其卫星探索的新突破。

然后，在第四部分中，我们将深入了解各种恒星类型和特征，并解析恒星寿命和演化过程。

此外，我们还将关注恒星间相互影响和对恒星团进行研究的进展。

最后，在第五部分中，我们将介绍一些前沿研究方向，包括超新星爆发暴涨模拟预测研究最新成果和黑洞世界边缘实验监测进展。

同时，我们还将思考观测数据背后的宇宙奥秘，并展望未来的挑战。

1.3 目的本文的目的是通过解密太阳系的奥秘，帮助读者了解行星和恒星的形成、演化和特征。

通过介绍最新的科学研究成果，我们希望激发读者对宇宙未知之谜的好奇心，并让他们对前沿研究方向有所了解。

希望读者能在本文中收获全新的知识，对宇宙充满更多的敬畏和探索欲望。

2. 太阳系的形成与演化2.1 形成过程太阳系的形成是一个约46亿年前发生的复杂过程。

最早的证据可以追溯到恒星诞生的星云，大约在宇宙诞生之后的几百万年内。

根据现代天文学家的理论和模型，太阳系的形成经历了以下几个关键步骤：首先，巨大而稳定的分子云被引力作用开始崩塌。

这种云由气体和尘埃组成，并且可能是由超新星爆炸释放出来的物质。

随着云坍缩，材料开始绕着中心点旋转。

这个旋转过程形成了一个扁平的圆盘结构，称为原行星盘或原始太阳盘。

在这个盘中，物质逐渐聚集并且形成更加紧密和密集的区域。

在原行星盘中，尘埃和气体汇聚成更大而更重的类地行星、巨型气态行星以及其他天体。

应用波谱学英文

应用波谱学英文Applications of spectroscopySpectroscopy has a wide range of applications across various scientific disciplines. Some of the common applications of spectroscopy include:1. Chemistry: Spectroscopy is extensively used in chemistry for the identification and analysis of chemical compounds. It helps in determining the chemical composition, molecular structure, and functional groups present in a sample.2. Pharmaceuticals: Spectroscopic techniques are crucial in the drug discovery and development process. They are used for quality control, impurity analysis, and determining the stability of pharmaceutical products.3. Environmental science: Spectroscopy plays a vital role in environmental monitoring and assessment. It is used to evaluate air quality, analyze water pollutants, and identify harmful substances in soil samples.4. Biochemistry and molecular biology: Spectroscopy is employed in studying the structure, function, and dynamics of biological molecules like proteins, nucleic acids, and carbohydrates. Techniques such as UV-Visible spectroscopy, fluorescence spectroscopy, and circular dichroism spectroscopy are commonly used in this field.5. Material science: Spectroscopy helps in characterizing andstudying various materials and their properties. It is used to analyze the composition, crystal structure, and surface properties of materials such as metals, ceramics, polymers, and semiconductors.6. Astronomy: Spectroscopy is fundamental in studying the properties and composition of celestial objects. Astronomers use spectroscopic techniques to analyze the light emitted or absorbed by stars, galaxies, and other astronomical phenomena to determine their chemical composition, temperature, and motion.7. Forensics: Spectroscopic methods are employed in forensic science for the detection and analysis of trace evidence, such as drugs, explosives, and chemical residues. They are also used in analyzing questioned documents and for the identification of counterfeit or forged materials.8. Food science and agriculture: Spectroscopic techniques are used for analyzing food products, determining their quality, and detecting adulteration. They are also employed in agricultural research for monitoring plant health and analyzing soil fertility. These are just a few examples of the diverse applications of spectroscopy in various fields. Overall, spectroscopy is a powerful analytical tool that enables scientists to study and understand the properties and behavior of substances in a wide range of scientific domains.。

天文学专用词汇

Galactic aggregate 银河星集Galactic astronomy 银河系天文Galactic bar 银河系棒galactic bar 星系棒galactic cannibalism 星系吞食galactic content 星系成分galactic merge 星系并合galactic pericentre 近银心点Galactocentric distance 银心距galaxy cluster 星系团Galle ring 伽勒环Galilean transformation 伽利略变换Galileo 〈伽利略〉木星探测器gas-dust complex 气尘复合体Genesis rock 创世岩Gemini Telescope 大型双子望远镜Geoalert, Geophysical Alert Broadcast 地球物理警报广播giant granulation 巨米粒组织giant granule 巨米粒giant radio pulse 巨射电脉冲Ginga 〈星系〉X 射线天文卫星Giotto 〈乔托〉空间探测器glassceramic 微晶玻璃glitch activity 自转突变活动global change 全球变化global sensitivity 全局灵敏度GMC, giant molecular cloud 巨分子云g-mode g 模、重力模gold spot 金斑病GONG, Global Oscillation Network 太阳全球振荡监测网GroupGPS, global positioning system 全球定位系统Granat 〈石榴〉号天文卫星grand design spiral 宏象旋涡星系gravitational astronomy 引力天文gravitational lensing 引力透镜效应gravitational micro-lensing 微引力透镜效应great attractor 巨引源Great Dark Spot 大暗斑Great White Spot 大白斑grism 棱栅GRO, Gamma-Ray Observatory γ射线天文台guidscope 导星镜GW Virginis star 室女GW 型星habitable planet 可居住行星Hakucho 〈天鹅〉X 射线天文卫星Hale Telescope 海尔望远镜halo dwarf 晕族矮星halo globular cluster 晕族球状星团Hanle effect 汉勒效应hard X-ray source 硬X 射线源Hay spot 哈伊斑HEAO, High-Energy Astronomical 〈HEAO〉高能天文台Observatoryheavy-element star 重元素星heiligenschein 灵光Helene 土卫十二helicity 螺度heliocentric radial velocity 日心视向速度heliomagnetosphere 日球磁层helioseismology 日震学helium abundance 氦丰度helium main-sequence 氦主序helium-strong star 强氦线星helium white dwarf 氦白矮星Helix galaxy （NGC 2685 ）螺旋星系Herbig Ae star 赫比格Ae 型星Herbig Be star 赫比格Be 型星Herbig-Haro flow 赫比格-阿罗流Herbig-Haro shock wave 赫比格-阿罗激波hidden magnetic flux 隐磁流high-field pulsar 强磁场脉冲星highly polarized quasar （HPQ ）高偏振类星体high-mass X-ray binary 大质量X 射线双星high-metallicity cluster 高金属度星团;高金属度星系团high-resolution spectrograph 高分辨摄谱仪high-resolution spectroscopy 高分辨分光high - z 大红移Hinotori 〈火鸟〉太阳探测器Hipparcos, High Precision Parallax 〈依巴谷〉卫星Collecting SatelliteHipparcos and Tycho Catalogues 〈依巴谷〉和〈第谷〉星表holographic grating 全息光栅Hooker Telescope 胡克望远镜host galaxy 寄主星系hot R Coronae Borealis star 高温北冕R 型星HST, Hubble Space Telescope 哈勃空间望远镜Hubble age 哈勃年龄Hubble distance 哈勃距离Hubble parameter 哈勃参数Hubble velocity 哈勃速度hump cepheid 驼峰造父变星Hyad 毕团星hybrid-chromosphere star 混合色球星hybrid star 混合大气星hydrogen-deficient star 缺氢星hydrogenous atmosphere 氢型大气hypergiant 特超巨星Ida 艾达（小行星243号）IEH, International Extreme Ultraviolet 〈IEH〉国际极紫外飞行器HitchhikerIERS, International Earth Rotation 国际地球自转服务Serviceimage deconvolution 图象消旋image degradation 星象劣化image dissector 析象管image distoration 星象复原image photon counting system 成象光子计数系统image sharpening 星象增锐image spread 星象扩散度imaging polarimetry 成象偏振测量imaging spectrophotometry 成象分光光度测量immersed echelle 浸渍阶梯光栅impulsive solar flare 脉冲太阳耀斑infralateral arc 外侧晕弧infrared CCD 红外CCDinfrared corona 红外冕infrared helioseismology 红外日震学infrared index 红外infrared observatory 红外天文台infrared spectroscopy 红外分光initial earth 初始地球initial mass distribution 初始质量分布initial planet 初始行星initial star 初始恒星initial sun 初始太阳inner coma 内彗发inner halo cluster 内晕族星团integrability 可积性Integral Sign galaxy （UGC 3697 ）积分号星系integrated diode array （IDA ）集成二极管阵intensified CCD 增强CCDIntercosmos 〈国际宇宙〉天文卫星interline transfer 行间转移intermediate parent body 中间母体intermediate polar 中介偏振星international atomic time 国际原子时International Celestial Reference 国际天球参考系Frame （ICRF ）intraday variation 快速变化intranetwork element 网内元intrinsic dispersion 内廪弥散度ion spot 离子斑IPCS, Image Photon Counting System 图象光子计数器IRIS, Infrared Imager / Spectrograph 红外成象器/摄谱仪IRPS, Infrared Photometer / Spectro- 红外光度计/分光计meterirregular cluster 不规则星团; 不规则星系团IRTF, NASA Infrared Telescope 〈IRTF〉美国宇航局红外Facility 望远镜IRTS, Infrared Telescope in Space 〈IRTS〉空间红外望远镜ISO, Infrared Space Observatory 〈ISO〉红外空间天文台isochrone method 等龄线法IUE, International Ultraviolet 〈IUE〉国际紫外探测器ExplorerJewel Box （NGC 4755 ）宝盒星团Jovian magnetosphere 木星磁层Jovian ring 木星环Jovian ringlet 木星细环Jovian seismology 木震学jovicentric orbit 木心轨道J-type star J 型星Juliet 天卫十一Jupiter-crossing asteroid 越木小行星Kalman filter 卡尔曼滤波器KAO, Kuiper Air-borne Observatory 〈柯伊伯〉机载望远镜Keck ⅠTelescope 凯克Ⅰ望远镜Keck ⅡTelescope 凯克Ⅱ望远镜Kuiper belt 柯伊伯带Kuiper-belt object 柯伊伯带天体Kuiper disk 柯伊伯盘LAMOST, Large Multi-Object Fibre 大型多天体分光望远镜Spectroscopic TelescopeLaplacian plane 拉普拉斯平面late cluster 晚型星系团LBT, Large Binocular Telescope 〈LBT〉大型双筒望远镜lead oxide vidicon 氧化铅光导摄象管Leo Triplet 狮子三重星系LEST, Large Earth-based Solar 〈LEST〉大型地基太阳望远镜Telescopelevel-Ⅰcivilization Ⅰ级文明level-Ⅱcivilization Ⅱ级文明level-Ⅲcivilization Ⅲ级文明Leverrier ring 勒威耶环Liapunov characteristic number 李雅普诺夫特征数（LCN ）light crown 轻冕玻璃light echo 回光light-gathering aperture 聚光孔径light pollution 光污染light sensation 光感line image sensor 线成象敏感器line locking 线锁line-ratio method 谱线比法Liner, low ionization nuclear 低电离核区emission-line regionline spread function 线扩散函数LMT, Large Millimeter Telescope 〈LMT〉大型毫米波望远镜local galaxy 局域星系local inertial frame 局域惯性架local inertial system 局域惯性系local object 局域天体local star 局域恒星look-up table （LUT ）对照表low-mass X-ray binary 小质量X 射线双星low-metallicity cluster 低金属度星团;低金属度星系团low-resolution spectrograph 低分辨摄谱仪low-resolution spectroscopy 低分辨分光low - z 小红移luminosity mass 光度质量luminosity segregation 光度层化luminous blue variable 高光度蓝变星lunar atmosphere 月球大气lunar chiaroscuro 月相图Lunar Prospector 〈月球勘探者〉Ly-α forest 莱曼-α 森林MACHO （massive compact halo 晕族大质量致密天体object ）Magellan 〈麦哲伦〉金星探测器Magellan Telescope 〈麦哲伦〉望远镜magnetic canopy 磁蓬magnetic cataclysmic variable 磁激变变星magnetic curve 磁变曲线magnetic obliquity 磁夹角magnetic period 磁变周期magnetic phase 磁变相位magnitude range 星等范围main asteroid belt 主小行星带main-belt asteroid 主带小行星main resonance 主共振main-sequence band 主序带Mars-crossing asteroid 越火小行星Mars Pathfinder 火星探路者mass loss rate 质量损失率mass segregation 质量层化Mayall Telescope 梅奥尔望远镜Mclntosh classification 麦金托什分类McMullan camera 麦克马伦电子照相机mean motion resonance 平均运动共振membership of cluster of galaxies 星系团成员membership of star cluster 星团成员merge 并合merger 并合星系; 并合恒星merging galaxy 并合星系merging star 并合恒星mesogranulation 中米粒组织mesogranule 中米粒metallicity 金属度metallicity gradient 金属度梯度metal-poor cluster 贫金属星团metal-rich cluster 富金属星团MGS, Mars Global Surveyor 火星环球勘测者micro-arcsec astrometry 微角秒天体测量microchannel electron multiplier 微通道电子倍增管microflare 微耀斑microgravitational lens 微引力透镜microgravitational lensing 微引力透镜效应microturbulent velocity 微湍速度millimeter-wave astronomy 毫米波天文millisecond pulsar 毫秒脉冲星minimum mass 质量下限minimum variance 最小方差mixed-polarity magnetic field 极性混合磁场MMT, Multiple-Mirror Telescope 多镜面望远镜moderate-resolution spectrograph 中分辨摄谱仪moderate-resolution spectroscopy 中分辨分光modified isochrone method 改进等龄线法molecular outflow 外向分子流molecular shock 分子激波monolithic-mirror telescope 单镜面望远镜moom 行星环卫星moon-crossing asteroid 越月小行星morphological astronomy 形态天文morphology segregation 形态层化MSSSO, Mount Stromlo and Siding 斯特朗洛山和赛丁泉天文台Spring Observatorymultichannel astrometric photometer 多通道天测光度计（MAP ）multi-object spectroscopy 多天体分光multiple-arc method 复弧法multiple redshift 多重红移multiple system 多重星系multi-wavelength astronomy 多波段天文multi-wavelength astrophysics 多波段天体物。

关于天文的英文名字

关于天文的英文名字Here is an English essay about astronomy, with the content exceeding 1000 words as requested. The title is not included in the word count.The celestial realm has captivated the human imagination for millennia, inspiring awe, wonder, and a relentless pursuit of understanding. Astronomy, the scientific study of the universe and its celestial bodies, has been a cornerstone of human knowledge, shaping our understanding of our place in the cosmos. From the ancient stargazers of Mesopotamia to the modern-day astrophysicists, the field of astronomy has evolved, revealing the intricate workings of the universe and unraveling the mysteries of the heavens.At the heart of astronomy lies the study of the various celestial objects that populate the universe. Planets, the wandering worlds that orbit our sun, have been a subject of intense fascination. From the majestic gas giants like Jupiter and Saturn, with their swirling storms and captivating ring systems, to the rocky terrestrial planets like Earth and Mars, each world offers a unique glimpse into the diversity of planetary formation and evolution. The discovery ofexoplanets, planets orbiting distant stars, has further expanded our understanding of planetary systems, revealing the remarkable diversity of worlds beyond our own.Alongside planets, the study of stars has been a fundamental aspect of astronomy. These luminous celestial bodies, fueled by the power of nuclear fusion, are the building blocks of galaxies and the primary sources of light in the universe. From the brilliant and short-lived O-type stars to the slowly dimming red dwarfs, each star represents a unique chapter in the life cycle of these cosmic furnaces. The studyof stellar evolution, the processes that govern the birth, life, and death of stars, has shed light on the dynamic nature of the universe, where stars are born, live, and ultimately die, often in spectacular displays of supernovae.Galaxies, the vast collections of stars, gas, and dust that populate the universe, have been another focal point of astronomical research. From the majestic spiral galaxies like the Milky Way, our home galaxy, to the elliptical and irregular galaxies, each galactic structure offers insights into the formation and evolution of these cosmic structures. The study of galaxy clusters, the vast assemblages of individual galaxies bound together by gravity, has revealed the underlying dark matter that shapes the large-scale structure of the universe.Complementing the study of celestial objects, the field of cosmologyhas sought to unravel the mysteries of the universe as a whole. From the Big Bang, the cataclysmic event that gave birth to the universe, to the ongoing expansion and evolution of the cosmos, cosmologists have developed sophisticated models and theories to explain the origins and the fate of the universe. The discovery of dark energy, the mysterious force driving the accelerated expansion of the universe, has challenged our understanding of the fundamental forces that govern the cosmos.Alongside these grand cosmic phenomena, the study of our own planet, Earth, has been an integral part of astronomy. The Earth's place within the solar system, its unique characteristics that support life, and its dynamic interactions with the sun and other celestial bodies have been the subject of intense study. The study of the Earth's atmosphere, its magnetic field, and its geological history have provided valuable insights into the planet's evolution and its role in the larger cosmic context.The tools and technologies employed in astronomical research have also evolved significantly over time. From the humble naked-eye observations of ancient stargazers to the sophisticated instruments of modern observatories, the ability to collect and analyze data has transformed our understanding of the universe. The development of telescopes, both on the ground and in space, has allowed astronomers to peer deeper into the cosmos, revealing the faint anddistant objects that were once beyond our reach. The advent of spectroscopy, the study of the light emitted by celestial objects, has enabled the identification of the chemical composition of stars, galaxies, and even the intergalactic medium.The field of astronomy has also been enriched by the contributions of diverse cultures and civilizations throughout history. From the ancient Mesopotamian astronomers who charted the movements of the planets to the Islamic scholars who made significant advancements in observational astronomy, the pursuit of understanding the cosmos has been a global endeavor. The influence of these diverse perspectives has shaped the development of astronomical knowledge, leading to a more comprehensive and inclusive understanding of the universe.As we continue to explore the cosmos, the field of astronomy remains at the forefront of scientific discovery. The ongoing search for habitable exoplanets, the quest to unravel the mysteries of dark matter and dark energy, and the exploration of the earliest moments of the universe are just a few of the many challenges that astronomers are currently tackling. With the aid of cutting-edge technologies and the collective efforts of the scientific community, the future of astronomy holds the promise of even greater revelations about the nature of the universe and our place within it.In conclusion, the field of astronomy, with its rich history and endless frontiers, continues to captivate and inspire humanity. From the study of celestial objects to the exploration of the cosmos as a whole, the pursuit of astronomical knowledge has been a driving force in our understanding of the universe. As we continue to push the boundaries of our understanding, the field of astronomy will undoubtedly continue to shape our worldview and our place in the grand tapestry of the cosmos.。

窄带滤光片光谱分光

窄带滤光片光谱分光English Answer.Narrowband Filter Photometric Spectroscopy.Narrowband filter photometric spectroscopy is a technique that uses narrowband filters to isolate specific wavelengths of light from an astronomical object. This technique is used to study the physical properties of astronomical objects, such as their temperature, density, and chemical composition.Narrowband filters are typically made of glass or plastic, and they have a very narrow transmission band.This means that they only allow light of a specific wavelength to pass through. The width of the transmission band is typically determined by the thickness of the filter.Narrowband filter photometric spectroscopy is a simple and inexpensive technique, and it can be used to study awide range of astronomical objects. This technique is often used to study the interstellar medium, the atmospheres of stars, and the intergalactic medium.Procedure.The procedure for narrowband filter photometric spectroscopy is as follows:1. Choose a narrowband filter that isolates the desired wavelength of light.2. Place the filter in front of the telescope's aperture.3. Take a series of images of the astronomical object using the filter.4. Measure the flux of the astronomical object at the wavelength of interest.5. Use the flux measurements to determine the physicalproperties of the astronomical object.Applications.Narrowband filter photometric spectroscopy has a wide range of applications in astronomy. Some of the most common applications include:Studying the interstellar medium.Studying the atmospheres of stars.Studying the intergalactic medium.Measuring the redshift of galaxies.Searching for exoplanets.Advantages.Narrowband filter photometric spectroscopy has several advantages over other spectroscopic techniques. Some of theadvantages include:Simplicity: Narrowband filter photometric spectroscopy is a simple and inexpensive technique.Sensitivity: Narrowband filter photometric spectroscopy is a very sensitive technique, and it can be used to study faint astronomical objects.Versatility: Narrowband filter photometric spectroscopy can be used to study a wide range of astronomical objects.Disadvantages.Narrowband filter photometric spectroscopy also has some disadvantages. Some of the disadvantages include:Low resolution: Narrowband filter photometric spectroscopy has a low resolution, and it cannot be used to study the fine details of astronomical objects.Limited wavelength range: Narrowband filterphotometric spectroscopy is limited to a specific wavelength range, and it cannot be used to study the entire spectrum of an astronomical object.中文回答：窄带滤光片光谱分光。

热爱光明英语

In the grand tapestry of human experience, light has emerged as an elemental force that transcends its physical properties, assuming a symbolic and spiritual significance that resonates deeply within our collective consciousness. This ode to light is a celebration of our unwavering love affair with illumination, delving into its multifaceted roles in our lives, from the practical and scientific to the artistic and philosophical.I. The Practical Necessity: Light as a Facilitator of LifeAt its most fundamental level, light is an indispensable component of life on Earth. It serves as the primary source of energy for photosynthesis, the process by which plants convert sunlight into chemical energy, forming the basis of the food chain and sustaining all terrestrial ecosystems. Without light, life as we know it would cease to exist. Moreover, light enables us to navigate our surroundings, distinguishing objects, perceiving colors, and gauging distances. It is the cornerstone of visual perception, allowing us to interact safely and effectively with our environment. From the flicker of a candle during a power outage to the high-intensity beams of searchlights guiding ships through stormy seas, light stands as a steadfast ally, illuminating our path and safeguarding our journey through the darkness.II. The Scientific Marvel: Light as a Gateway to KnowledgeLight is not merely a passive medium; it is an active participant in our quest for understanding the universe. The study of light, or optics, has been instrumental in shaping our knowledge of physics, revealing the principles governing the behavior of electromagnetic waves and the nature of matter. Isaac Newton's experiments with prisms demonstrated the spectrum of colors hidden within white light, while James Clerk Maxwell's equations predicted the existence of electromagnetic waves, later confirmed by Heinrich Hertz. Albert Einstein's theory of relativity was sparked by his contemplation of the constancy of the speed of light, fundamentally altering our understanding of space and time.Moreover, light serves as a messenger from distant realms, carryinginformation about celestial bodies and cosmic phenomena. Telescopes equipped with spectroscopy allow us to decipher the chemical composition, temperature, and velocity of stars and galaxies, while radio telescopes capture low-frequency light waves that reveal the birth and death of stars, the formation of black holes, and the cosmic microwave background radiation left over from the Big Bang. In essence, light is the key that unlocks the mysteries of the cosmos, fueling our insatiable thirst for knowledge and propelling scientific advancements.III. The Artistic Muse: Light as a Master of Emotions and Aesthetics In the realm of art, light assumes a transformative role, casting its spell upon visual compositions, imbuing them with mood, depth, and meaning. Artists across centuries and mediums have recognized light's unparalleled ability to evoke emotions and convey narratives. From Caravaggio's chiaroscuro technique, which juxtaposes dramatic light and shadow to accentuate the tension and drama in his paintings, to Monet's impressionist landscapes bathed in ethereal, ever-changing light, artists harness the power of light to create visual poetry.In photography, the interplay between light and subject is the very essence of the craft. The angle, intensity, and color of light can dramatically alter the mood and atmosphere of an image, turning the mundane into the sublime. Cinematographers, too, wield light as a narrative tool, using it to establish tone, guide the viewer's gaze, and reveal character nuances. Light, in these contexts, transcends its physical nature, becoming a vehicle for artistic expression and a catalyst for emotional resonance.IV. The Philosophical Anchor: Light as a Symbol of Enlightenment and Hope Beyond its tangible functions, light has long held profound symbolic significance in various cultures and belief systems. Across civilizations, it is often associated with knowledge, wisdom, and enlightenment. The ancient Greek allegory of the cave, penned by Plato, depicts individuals trapped in darkness, their understanding of reality limited to the shadows cast upon the wall until they are led out into the light, symbolizing the journey from ignorance to wisdom. Similarly, in Hinduism, the goddess Saraswati, embodiment of knowledge andlearning, is often depicted holding a lit lamp, symbolizing the dispelling of ignorance and the pursuit of enlightenment.Moreover, light represents hope, renewal, and divine presence in many religious traditions. The Star of Bethlehem guided the Magi to the newborn Jesus, symbolizing divine revelation and the advent of salvation. In Judaism, the menorah, with its seven branches, symbolizes the eternal flame of God's presence and the promise of redemption. The annual Hindu festival of Diwali, known as the "Festival of Lights," celebrates the victory of light over darkness, knowledge over ignorance, and good over evil.V. The Technological Revolution: Light as a Pioneering Force in Innovation In recent times, light has continued to reshape our world through groundbreaking technological innovations. Lasers, first proposed by Einstein in 1917 and realized in 1960, have found applications ranging from precision surgery and telecommunications to barcode scanners and laser shows. Optical fibers, which transmit data via pulses of light, form the backbone of the internet, enabling lightning-fast global communication.Furthermore, the advent of LED lighting has revolutionized energy efficiency, significantly reducing electricity consumption and carbon emissions. Meanwhile, researchers are exploring the potential of quantum entangled photons for unhackable communication and ultra-precise measurements, while optogenetics, which uses light to control the activity of neurons, is reshaping our understanding of the brain and opening new avenues for treating neurological disorders.In conclusion, our love affair with light transcends mere physical necessity. It is a profound, multidimensional relationship rooted in its pivotal role in our survival, its capacity to unlock the secrets of the universe, its transformative power in art, its profound symbolism in philosophy and spirituality, and its pioneering role in technological innovation. As we continue to explore the vast expanse of light's influence, we are reminded that our enduring fascination with this elemental force is a testament to itsboundless potential and the profound impact it has on every facet of human existence. In the end, it is not merely that we love light; it is that light, in all its radiant glory, loves us back, illuminating our paths, enlightening our minds, and warming our souls.。

稳定的高功率激光系统在高级引力波探测器中的应用

Stabilized high-power laser system forthe gravitational wave detector advancedLIGOP.Kwee,1,∗C.Bogan,2K.Danzmann,1,2M.Frede,4H.Kim,1P.King,5J.P¨o ld,1O.Puncken,3R.L.Savage,5F.Seifert,5P.Wessels,3L.Winkelmann,3and B.Willke21Max-Planck-Institut f¨u r Gravitationsphysik(Albert-Einstein-Institut),Hannover,Germany2Leibniz Universit¨a t Hannover,Hannover,Germany3Laser Zentrum Hannover e.V.,Hannover,Germany4neoLASE GmbH,Hannover,Germany5LIGO Laboratory,California Institute of Technology,Pasadena,California,USA*patrick.kwee@aei.mpg.deAbstract:An ultra-stable,high-power cw Nd:Y AG laser system,devel-oped for the ground-based gravitational wave detector Advanced LIGO(Laser Interferometer Gravitational-Wave Observatory),was comprehen-sively ser power,frequency,beam pointing and beamquality were simultaneously stabilized using different active and passiveschemes.The output beam,the performance of the stabilization,and thecross-coupling between different stabilization feedback control loops werecharacterized and found to fulﬁll most design requirements.The employedstabilization schemes and the achieved performance are of relevance tomany high-precision optical experiments.©2012Optical Society of AmericaOCIS codes:(140.3425)Laser stabilization;(120.3180)Interferometry.References and links1.S.Rowan and J.Hough,“Gravitational wave detection by interferometry(ground and space),”Living Rev.Rel-ativity3,1–3(2000).2.P.R.Saulson,Fundamentals of Interferometric Gravitational Wave Detectors(World Scientiﬁc,1994).3.G.M.Harry,“Advanced LIGO:the next generation of gravitational wave detectors,”Class.Quantum Grav.27,084006(2010).4. B.Willke,“Stabilized lasers for advanced gravitational wave detectors,”Laser Photon.Rev.4,780–794(2010).5.P.Kwee,“Laser characterization and stabilization for precision interferometry,”Ph.D.thesis,Universit¨a t Han-nover(2010).6.K.Somiya,Y.Chen,S.Kawamura,and N.Mio,“Frequency noise and intensity noise of next-generationgravitational-wave detectors with RF/DC readout schemes,”Phys.Rev.D73,122005(2006).7. 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A.Bullington,ntz,M.Fejer,and R.Byer,“Modal frequency degeneracy in thermally loaded optical res-onators,”Appl.Opt.47,2840–2851(2008).23.G.Mueller,“Beam jitter coupling in Advanced LIGO,”Opt.Express13,7118–7132(2005).24.V.Delaubert,N.Treps,ssen,C.C.Harb,C.Fabre,m,and H.-A.Bachor,“TEM10homodynedetection as an optimal small-displacement and tilt-measurement scheme,”Phys.Rev.A74,053823(2006). 25.P.Kwee,B.Willke,and K.Danzmann,“Laser power noise detection at the quantum-noise limit of32A pho-tocurrent,”Opt.Lett.36,3563–3565(2011).26. A.Araya,N.Mio,K.Tsubono,K.Suehiro,S.Telada,M.Ohashi,and M.Fujimoto,“Optical mode cleaner withsuspended mirrors,”Appl.Opt.36,1446–1453(1997).27.P.Kwee,B.Willke,and K.Danzmann,“Shot-noise-limited laser power stabilization with a high-power photodi-ode array,”Opt.Lett.34,2912–2914(2009).28. ntz,P.Fritschel,H.Rong,E.Daw,and G.Gonz´a lez,“Quantum-limited optical phase detection at the10−10rad level,”J.Opt.Soc.Am.A19,91–100(2002).1.IntroductionInterferometric gravitational wave detectors[1,2]perform one of the most precise differential length measurements ever.Their goal is to directly detect the faint signals of gravitational waves emitted by astrophysical sources.The Advanced LIGO(Laser Interferometer Gravitational-Wave Observatory)[3]project is currently installing three second-generation,ground-based detectors at two observatory sites in the USA.The4kilometer-long baseline Michelson inter-ferometers have an anticipated tenfold better sensitivity than theirﬁrst-generation counterparts (Inital LIGO)and will presumably reach a strain sensitivity between10−24and10−23Hz−1/2.One key technology necessary to reach this extreme sensitivity are ultra-stable high-power laser systems[4,5].A high laser output power is required to reach a high signal-to-quantum-noise ratio,since the effect of quantum noise at high frequencies in the gravitational wave readout is reduced with increasing circulating laser power in the interferometer.In addition to quantum noise,technical laser noise coupling to the gravitational wave channel is a major noise source[6].Thus it is important to reduce the coupling of laser noise,e.g.by optical design or by exploiting symmetries,and to reduce laser noise itself by various active and passive stabilization schemes.In this article,we report on the pre-stabilized laser(PSL)of the Advanced LIGO detector. The PSL is based on a high-power solid-state laser that is comprehensively stabilized.One laser system was set up at the Albert-Einstein-Institute(AEI)in Hannover,Germany,the so called PSL reference system.Another identical PSL has already been installed at one Advanced LIGO site,the one near Livingston,LA,USA,and two more PSLs will be installed at the second #161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10618site at Hanford,WA,USA.We have characterized the reference PSL and theﬁrst observatory PSL.For this we measured various beam parameters and noise levels of the output beam in the gravitational wave detection frequency band from about10Hz to10kHz,measured the performance of the active and passive stabilization schemes,and determined upper bounds for the cross coupling between different control loops.At the time of writing the PSL reference system has been operated continuously for more than18months,and continues to operate reliably.The reference system delivered a continuous-wave,single-frequency laser beam at1064nm wavelength with a maximum power of150W with99.5%in the TEM00mode.The active and passive stabilization schemes efﬁciently re-duced the technical laser noise by several orders of magnitude such that most design require-ments[5,7]were fulﬁlled.In the gravitational wave detection frequency band the relative power noise was as low as2×10−8Hz−1/2,relative beam pointingﬂuctuations were as low as1×10−7Hz−1/2,and an in-loop measurement of the frequency noise was consistent with the maximum acceptable frequency noise of about0.1HzHz−1/2.The cross couplings between the control loops were,in general,rather small or at the expected levels.Thus we were able to optimize each loop individually and observed no instabilities due to cross couplings.This stabilized laser system is an indispensable part of Advanced LIGO and fulﬁlled nearly all design goals concerning the maximum acceptable noise levels of the different beam pa-rameters right after installation.Furthermore all or a subset of the implemented stabilization schemes might be of interest for many other high-precision optical experiments that are limited by laser noise.Besides gravitational wave detectors,stabilized laser systems are used e.g.in the ﬁeld of optical frequency standards,macroscopic quantum objects,precision spectroscopy and optical traps.In the following section the laser system,the stabilization scheme and the characterization methods are described(Section2).Then,the results of the characterization(Section3)and the conclusions(Section4)are presented.ser system and stabilizationThe PSL consists of the laser,developed and fabricated by Laser Zentrum Hannover e.V.(LZH) and neoLASE,and the stabilization,developed and integrated by AEI.The optical components of the PSL are on a commercial optical table,occupying a space of about1.5×3.5m2,in a clean,dust-free environment.At the observatory sites the optical table is located in an acoustically isolated cleanroom.Most of the required electronics,the laser diodes for pumping the laser,and water chillers for cooling components on the optical table are placed outside of this cleanroom.The laser itself consists of three stages(Fig.1).An almostﬁnal version of the laser,the so-called engineering prototype,is described in detail in[8].The primary focus of this article is the stabilization and characterization of the PSL.Thus only a rough overview of the laser and the minor modiﬁcations implemented between engineering prototype and reference system are given in the following.Theﬁrst stage,the master laser,is a commercial non-planar ring-oscillator[9,10](NPRO) manufactured by InnoLight GmbH in Hannover,Germany.This solid-state laser uses a Nd:Y AG crystal as the laser medium and resonator at the same time.The NPRO is pumped by laser diodes at808nm and delivers an output power of2W.An internal power stabilization,called the noise eater,suppresses the relaxation oscillation at around1MHz.Due to its monolithic res-onator,the laser has exceptional intrinsic frequency stability.The two subsequent laser stages, used for power scaling,inherit the frequency stability of the master laser.The second stage(medium-power ampliﬁer)is a single-pass ampliﬁer[11]with an output power of35W.The seed laser beam from the NPRO stage passes through four Nd:YVO4crys-#161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10619power stabilizationFig.1.Pre-stabilized laser system of Advanced LIGO.The three-staged laser(NPRO,medium power ampliﬁer,high power oscillator)and the stabilization scheme(pre-mode-cleaner,power and frequency stabilization)are shown.The input-mode-cleaner is not partof the PSL but closely related.NPRO,non-planar ring oscillator;EOM,electro-optic mod-ulator;FI,Faraday isolator;AOM,acousto-optic modulator.tals which are longitudinally pumped byﬁber-coupled laser diodes at808nm.The third stage is an injection-locked ring oscillator[8]with an output power of about220W, called the high-power oscillator(HPO).Four Nd:Y AG crystals are used as the active media. Each is longitudinally pumped by sevenﬁber-coupled laser diodes at808nm.The oscillator is injection-locked[12]to the previous laser stage using a feedback control loop.A broadband EOM(electro-optic modulator)placed between the NPRO and the medium-power ampliﬁer is used to generate the required phase modulation sidebands at35.5MHz.Thus the high output power and good beam quality of this last stage is combined with the good frequency stability of the previous stages.The reference system features some minor modiﬁcations compared to the engineering proto-type[8]concerning the optics:The external halo aperture was integrated into the laser system permanently improving the beam quality.Additionally,a few minor designﬂaws related to the mechanical structure and the optical layout were engineered out.This did not degrade the output performance,nor the characteristics of the locked laser.In general the PSL is designed to be operated in two different power modes.In high-power mode all three laser stages are engaged with a power of about160W at the PSL output.In low-power mode the high-power oscillator is turned off and a shutter inside the laser resonator is closed.The beam of the medium-power stage is reﬂected at the output coupler of the high power stage leaving a residual power of about13W at the PSL output.This low-power mode will be used in the early commissioning phase and in the low-frequency-optimized operation mode of Advanced LIGO and is not discussed further in this article.The stabilization has three sections(Fig.1:PMC,PD2,reference cavity):A passive resonator, the so called pre-mode-cleaner(PMC),is used toﬁlter the laser beam spatially and temporally (see subsection2.1).Two pick-off beams at the PMC are used for the active power stabilization (see subsection2.2)and the active frequency pre-stabilization,respectively(see subsection2.3).In general most stabilization feedback control loops of the PSL are implemented using analog electronics.A real-time computer system(Control and Data Acquisition Systems,CDS,[13]) which is common to many other subsystems of Advanced LIGO,is utilized to control and mon-itor important parameters of the analog electronics.The lock acquisition of various loops,a few #161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10620slow digital control loops,and the data acquisition are implemented using this computer sys-tem.Many signals are recorded at different sampling rates ranging from16Hz to33kHz for diagnostics,monitoring and vetoing of gravitational wave signals.In total four real-time pro-cesses are used to control different aspects of the laser system.The Experimental Physics and Industrial Control System(EPICS)[14]and its associated user tools are used to communicate with the real-time software modules.The PSL contains a permanent,dedicated diagnostic instrument,the so called diagnostic breadboard(DBB,not shown in Fig.1)[15].This instrument is used to analyze two different beams,pick-off beams of the medium power stage and of the HPO.Two shutters are used to multiplex these to the DBB.We are able to measureﬂuctuations in power,frequency and beam pointing in an automated way with this instrument.In addition the beam quality quantiﬁed by the higher order mode content of the beam was measured using a modescan technique[16].The DBB is controlled by one real-time process of the CDS.In contrast to most of the other control loops in the PSL,all DBB control loops were implemented digitally.We used this instrument during the characterization of the laser system to measure the mentioned laser beam parameters of the HPO.In addition we temporarily placed an identical copy of the DBB downstream of the PMC to characterize the output beam of the PSL reference system.2.1.Pre-mode-cleanerA key component of the stabilization scheme is the passive ring resonator,called the pre-mode-cleaner(PMC)[17,18].It functions to suppress higher-order transverse modes,to improve the beam quality and the pointing stability of the laser beam,and toﬁlter powerﬂuctuations at radio frequencies.The beam transmitted through this resonator is the output beam of the PSL, and it is delivered to the subsequent subsystems of the gravitational wave detector.We developed and used a computer program[19]to model theﬁlter effects of the PMC as a function of various resonator parameters in order to aid its design.This led to a resonator with a bow-tie conﬁguration consisting of four low-loss mirrors glued to an aluminum spacer. The optical round-trip length is2m with a free spectral range(FSR)of150MHz.The inci-dence angle of the horizontally polarized laser beam is6◦.Theﬂat input and output coupling mirrors have a power transmission of2.4%and the two concave high reﬂectivity mirrors(3m radius of curvature)have a transmission of68ppm.The measured bandwidth was,as expected, 560kHz which corresponds to aﬁnesse of133and a power build-up factor of42.The Gaussian input/output beam had a waist radius of about568µm and the measured acquired round-trip Gouy phase was about1.7rad which is equivalent to0.27FSR.One TEM00resonance frequency of the PMC is stabilized to the laser frequency.The Pound-Drever-Hall(PDH)[20,21]sensing scheme is used to generate error signals,reusing the phase modulation sidebands at35.5MHz created between NPRO and medium power ampliﬁer for the injection locking.The signal of the photodetector PD1,placed in reﬂection of the PMC, is demodulated at35.5MHz.This photodetector consists of a1mm InGaAs photodiode and a transimpedance ampliﬁer.A piezo-electric element(PZT)between one of the curved mirrors and the spacer is used as a fast actuator to control the round-trip length and thereby the reso-nance frequencies of the PMC.With a maximum voltage of382V we were able to change the round-trip length by about2.4µm.An analog feedback control loop with a bandwidth of about 7kHz is used to stabilize the PMC resonance frequency to the laser frequency.In addition,the electronics is able to automatically bring the PMC into resonance with the laser(lock acquisition).For this process a125ms period ramp signal with an amplitude cor-responding to about one FSR is applied to the PZT of the PMC.The average power on pho-todetector PD1is monitored and as soon as the power drops below a given threshold the logic considers the PMC as resonant and closes the analog control loop.This lock acquisition proce-#161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10621dure took an average of about65ms and is automatically repeated as soon as the PMC goes off resonance.One real-time process of CDS is dedicated to control the PMC electronics.This includes parameters such as the proportional gain of the loop or lock acquisition parameters.In addition to the PZT actuator,two heating foils,delivering a maximum total heating power of14W,are attached to the aluminum spacer to control its temperature and thereby the roundtrip length on timescales longer than3s.We measured a heating and cooling1/e time constant of about2h with a range of4.5K which corresponds to about197FSR.During maintenance periods we heat the spacer with7W to reach a spacer temperature of about2.3K above room temperature in order to optimize the dynamic range of this actuator.A digital control loop uses this heater as an actuator to off-load the PZT actuator allowing compensation for slow room temperature and laser frequency drifts.The PMC is placed inside a pressure-tight tank at atmospheric pressure for acoustic shield-ing,to avoid contamination of the resonator mirrors and to minimize optical path length changes induced by atmospheric pressure variations.We used only low-outgassing materials and fabri-cated the PMC in a cleanroom in order to keep the initial mirror contamination to a minimum and to sustain a high long-term throughput.The PMCﬁlters the laser beam and improves the beam quality of the laser by suppress-ing higher order transverse modes[17].The acquired round-trip Gouy phase of the PMC was chosen in such a way that the resonance frequencies of higher order TEM modes are clearly separated from the TEM00resonance frequency.Thus these modes are not resonant and are mainly reﬂected by the PMC,whereas the TEM00mode is transmitted.However,during the design phase we underestimated the thermal effects in the PMC such that at nominal circu-lating power the round-trip Gouy-phase is close to0.25FSR and the resonance of the TEM40 mode is close to that of the TEM00mode.To characterize the mode-cleaning performance we measured the beam quality upstream and downstream of the PMC with the two independent DBBs.At150W in the transmitted beam,the circulating power in the PMC is about6.4kW and the intensity at the mirror surface can be as high as1.8×1010W m−2.At these power levels even small absorptions in the mirror coatings cause thermal effects which slightly change the mirror curvature[22].To estimate these thermal effects we analyzed the transmitted beam as a function of the circulating power using the DBB.In particular we measured the mode content of the LG10and TEM40mode.Changes of the PMC eigenmode waist size showed up as variations of the LG10mode content.A power dependence of the round-trip Gouy phase caused a variation of the power within the TEM40mode since its resonance frequency is close to a TEM00mode resonance and thus the suppression of this mode depends strongly on the Gouy phase.We adjusted the input power to the PMC such that the transmitted power ranged from100W to 150W corresponding to a circulating power between4.2kW and6.4kW.We used our PMC computer simulation to deduce the power dependence of the eigenmode waist size and the round-trip Gouy phase.The results are given in section3.1.At all circulating power levels,however,the TEM10and TEM01modes are strongly sup-pressed by the PMC and thus beam pointingﬂuctuations are reduced.Pointingﬂuctuations can be expressed toﬁrst order as powerﬂuctuations of the TEM10and TEM01modes[23,24].The PMC reduces theﬁeld amplitude of these modes and thus the pointingﬂuctuations by a factor of about61according to the measuredﬁnesse and round-trip Gouy phase.To keep beam point-ingﬂuctuations small is important since they couple to the gravitational wave channel by small differential misalignments of the interferometer optics.Thus stringent design requirements,at the10−6Hz−1/2level for relative pointing,were set.To verify the pointing suppression effect of the PMC we used DBBs to measure the beam pointingﬂuctuations upstream and downstream #161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10622Fig.2.Detailed schematic of the power noise sensor setup for theﬁrst power stabilizationloop.This setup corresponds to PD2in the overview in Fig.1.λ/2,waveplate;PBS,polar-izing beam splitter;BD,glassﬁlters used as beam dump;PD,single element photodetector;QPD,quadrant photodetector.of the PMC.The resonator design has an even number of nearly normal-incidence reﬂections.Thus the resonance frequencies of horizontal and vertical polarized light are almost identical and the PMC does not act as polarizer.Therefore we use a thin-ﬁlm polarizer upstream of the PMC to reach the required purity of larger than100:1in horizontal polarization.Finally the PMC reduces technical powerﬂuctuations at radio frequencies(RF).A good power stability between9MHz and100MHz is necessary as the phase modulated light in-jected into the interferometer is used to sense several degrees of freedom of the interferometer that need to be controlled.Power noise around these phase modulation sidebands would be a noise source for the respective stabilization loop.The PMC has a bandwidth(HWHM)of about 560kHz and acts toﬁrst order as a low-passﬁlter for powerﬂuctuations with a-3dB corner frequency at this frequency.To verify that the suppression of RF powerﬂuctuations is sufﬁ-cient to fulﬁll the design requirements,we measured the relative power noise up to100MHz downstream of the PMC with a dedicated experiment involving the optical ac coupling tech-nique[25].In addition the PMC serves the very important purpose of deﬁning the spatial laser mode for the downstream subsystem,namely the input optics(IO)subsystem.The IO subsystem is responsible,among other things,to further stabilize the laser beam with the suspended input mode cleaner[26]before the beam will be injected into the interferometer.Modiﬁcations of beam alignment or beam size of the laser system,which were and might be unavoidable,e.g., due to maintenance,do not propagate downstream of the PMC toﬁrst order due to its mode-cleaning effect.Furthermore we beneﬁt from a similar isolating effect for the active power and frequency stabilization by using the beams transmitted through the curved high-reﬂectivity mirrors of the PMC.2.2.Power stabilizationThe passiveﬁltering effect of the PMC reduces powerﬂuctuations signiﬁcantly only above the PMC bandwidth.In the detection band from about10Hz to10kHz good power stability is required sinceﬂuctuations couple via the radiation pressure imbalance and the dark-fringe offset to the gravitational wave channel.Thus two cascaded active control loops,theﬁrst and second power stabilization loop,are used to reduce powerﬂuctuations which are mainly caused by the HPO stage.Theﬁrst loop uses a low-noise photodetector(PD2,see Figs.1and2)at one pick-off port #161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10623of the PMC to measure the powerﬂuctuations downstream of the PMC.An analog electronics feedback control loop and an AOM(acousto-optic modulator)as actuator,located upstream of the PMC,are used to stabilize the power.Scattered light turned out to be a critical noise source for thisﬁrst loop.Thus we placed all required optical and opto-electronic components into a box to shield from scattered light(see Fig.2).The beam transmitted by the curved PMC mirror has a power of about360mW.This beam isﬁrst attenuated in the box using aλ/2waveplate and a thin-ﬁlm polarizer,such that we are able to adjust the power on the photodetectors to the optimal operation point.Afterwards the beam is split by a50:50beam splitter.The beams are directed to two identical photode-tectors,one for the control loop(PD2a,in-loop detector)and one for independent out-of-loop measurements to verify the achieved power stability(PD2b,out-of-loop detector).These pho-todetectors consist of a2mm InGaAs photodiode(PerkinElmer C30642GH),a transimpedance ampliﬁer and an integrated signal-conditioningﬁlter.At the chosen operation point a power of about4mW illuminates each photodetector generating a photocurrent of about3mA.Thus the shot noise is at a relative power noise of10−8Hz−1/2.The signal conditioningﬁlter has a gain of0.2at very low frequencies(<70mHz)and ampliﬁes the photodetector signal in the im-portant frequency range between3.3Hz and120Hz by about52dB.This signal conditioning ﬁlter reduces the electronics noise requirements on all subsequent stages,but has the drawback that the range between3.3Hz and120Hz is limited to maximum peak-to-peak relative power ﬂuctuations of5×10−3.Thus the signal-conditioned channel is in its designed operation range only when the power stabilization loop is closed and therefore it is not possible to measure the free running power noise using this channel due to saturation.The uncoated glass windows of the photodiodes were removed and the laser beam hits the photodiodes at an incidence angle of45◦.The residual reﬂection from the photodiode surface is dumped into a glassﬁlter(Schott BG39)at the Brewster angle.Beam positionﬂuctuations in combination with spatial inhomogeneities in the photodiode responsivity is another noise source for the power stabilization.We placed a silicon quadrant photodetector(QPD)in the box to measure the beam positionﬂuctuations of a low-power beam picked off the main beam in the box.The beam parameters,in particular the Gouy phase,at the QPD are the same as on the power sensing detectors.Thus the beam positionﬂuctuations measured with the QPD are the same as the ones on the power sensing photodetectors,assuming that the positionﬂuctuations are caused upstream of the QPD pick-off point.We used the QPD to measure beam positionﬂuctuations only for diagnostic and noise projection purposes.In a slightly modiﬁed experiment,we replaced one turning mirror in the path to the power sta-bilization box by a mirror attached to a tip/tilt PZT element.We measured the typical coupling between beam positionﬂuctuations generated by the PZT and the residual relative photocurrent ﬂuctuations measured with the out-of-the-loop photodetector.This coupling was between1m−1 and10m−1which is a typical value observed in different power stabilization experiments as well.We measured this coupling factor to be able to calculate the noise contribution in the out-of-the-loop photodetector signal due to beam positionﬂuctuations(see Subsection3.3).Since this tip/tilt actuator was only temporarily in the setup,we are not able to measure the coupling on a regular basis.Both power sensing photodetectors are connected to analog feedback control electronics.A low-pass(100mHz corner frequency)ﬁltered reference value is subtracted from one signal which is subsequently passed through several control loopﬁlter stages.With power stabilization activated,we are able to control the power on the photodetectors and thereby the PSL output power via the reference level on time scales longer than10s.The reference level and other important parameters of these electronics are controlled by one dedicated real-time process of the CDS.The actuation or control signal of the electronics is passed to an AOM driver #161737 - $15.00 USD Received 18 Jan 2012; revised 27 Feb 2012; accepted 4 Mar 2012; published 24 Apr 2012 (C) 2012 OSA7 May 2012 / Vol. 20, No. 10 / OPTICS EXPRESS 10624。

宇宙星辰对应的词

宇宙星辰对应的词1. 太阳 Sun2. 月亮 Moon3. 行星 Planet4. 彗星 Comet5. 伴星 Satellite6. 星系 Galaxy7. 星云 Nebula8. 硬束星 Pulsar9. 中子星 Neutron star10. 黑洞 Black hole11. 银河系 Milky Way12. 外星人 Extraterrestrial13. 陨石 Meteorite14. 陨星 Meteor15. 大爆炸 Big Bang16. 星际尘埃 Interstellar dust17. 行星轨道 Planetary orbit18. 星际空间 Interstellar space19. 红巨星 Red giant20. 白矮星 White dwarf21. 超新星 Supernova22. 恒星 Star23. 恒星演化 Stellar evolution24. 暗物质 Dark matter25. 星际物质 Interstellar matter26. 太阳系 Solar system27. 拉格朗日点 Lagrange point28. 氦闪 Helium flash29. 赤巨星 Red supergiant30. 核融合 Nuclear fusion31. 恒星分类 Stellar classification32. 青年恒星 Young star33. 星际射线 Cosmic ray34. 星际气体 Interstellar gas35. 磁重联 Magnetic reconnection36. 超大质量黑洞 Supermassive black hole37. 恒星表面活动 Stellar surface activity38. 核合成 Nucleosynthesis39. 耀斑 Flare40. 星系群 Galaxy cluster41. 巨星 Giant star42. 行星磁场 Planetary magnetic field43. 行星形成 Planetary formation44. 星际介质 Interstellar medium45. 天文学 Astronomy46. 天体物理学 Astrophysics47. 望远镜 Telescope48. 天文台 Observatory49. 天文学家 Astronomer50. 宇宙学 Cosmology51. 碳星 Carbon star52. 冥王星 Pluto53. 基本粒子 Elementary particle54. 牛顿引力定律 Newton's law of gravitation55. 相对论 Relativity56. 宇宙年龄 Age of the universe57. 宇宙微波背景辐射 Cosmic microwave background radiation58. 珂兹曼定律 Boltzmann's law59. 暗能量 Dark energy60. 探测器 Detector61. 夸克 Quark62. 恒星恒温 Stellar equilibrium temperature63. 双星 Binary star64. 毫秒脉冲星 Millisecond pulsar65. 引力波 Gravitational wave66. 黑洞演化 Black hole evolution67. 星际尘埃云 Interstellar dust cloud68. 行星测量 Planetary measurement69. 宇宙加速膨胀 Cosmic accelerated expansion70. 宇宙红移 Cosmic redshift71. 射电天文学 Radio astronomy72. 中微子 Neutrino73. 超新星遗迹 Supernova remnant74. 星际结构 Interstellar structure75. 行星大气 Planetary atmosphere76. 星际磁场 Interstellar magnetic field77. 恒星形成 Stellar formation78. 能量守恒 Energy conservation79. 暗流 Dark flow80. 毫秒脉冲星双星 Millisecond pulsar binary81. 白矮星新星 White dwarf nova82. 巨星演化 Giant star evolution83. 高能天体物理学 High energy astrophysics84. 统计物理学 Statistical physics85. 背景星 Background star86. 宇宙学中的引力力学 Gravity in cosmology87. 引力透镜 Gravitational lensing88. 行星大气逃逸 Planetary atmospheric escape89. 星际大气 Interstellar atmosphere90. 李普希茨定律 Lippmann's law91. 光谱学 Spectroscopy92. 筛选理论 Selection theory93. 星团 Star cluster94. 星际物质的星际物理学 Interstellar matter in interstellar physics95. 再结晶 Renewal theory96. 镜面反射 Mirror reflection97. 引力微弱 Gravity is weak98. 热核反应 Thermonuclear reaction99. 影响天文学的地球环境 Earth environment affecting astronomy100. 星系和在它们之间移动的物质 Galaxies and matter moving between them。

频率英语作文

频率英语作文Frequency is a fundamental concept in various fields, from physics and engineering to music and communication. It refers to the number of occurrences of a repeating event within a given time interval. In our daily lives, we encounter frequency in various forms, and understanding its significance can provide valuable insights.One of the most prominent applications of frequency is in the field of electronics and telecommunications. The electromagnetic spectrum, which includes radio waves, microwaves, infrared, visible light, and X-rays, is organized by frequency. Each type of electromagnetic radiation has a specific frequency range, and these frequencies are utilized for various purposes, such as radio and television broadcasting, satellite communication, and wireless internet. The accurate control and management of these frequencies are crucial for efficient and reliable communication systems.In the world of music, frequency plays a crucial role in the production and perception of sound. Musical notes are defined by their specific frequencies, and the combination of different frequencies creates theharmony and melody that we enjoy. The human ear is capable of detecting a range of frequencies, typically from 20 Hz to 20,000 Hz, and our perception of pitch is directly related to the frequency of the sound waves. Composers and musicians utilize this understanding of frequency to create complex and captivating musical compositions.Frequency also has significant implications in the field of physics. In the study of wave phenomena, frequency is a fundamental property that describes the number of oscillations or vibrations per unit of time. This concept is essential in understanding the behavior of various types of waves, such as sound waves, light waves, and even the oscillations of subatomic particles. The frequency of a wave determines its wavelength and energy, which are crucial in understanding phenomena like interference, diffraction, and the Doppler effect.In the natural world, frequency is observed in various natural cycles and processes. The rotation of the Earth on its axis and the revolution around the Sun are examples of cyclical events that occur at specific frequencies, which give rise to the concept of time and the measurement of days, months, and years. Similarly, the oscillations of atoms and molecules, which are the building blocks of matter, exhibit characteristic frequencies that are essential in understanding the behavior of materials and the structure of the universe.Frequency also plays a crucial role in the field of biology and medicine. The human body is a complex system that operates based on various frequency-dependent processes. For instance, the electrical activity of the brain, which is responsible for our cognitive functions, can be analyzed and understood through the study of its frequency patterns. Abnormalities in these brain wave frequencies can be indicators of neurological disorders, and medical professionals use this information to diagnose and treat various conditions.Furthermore, the concept of frequency is integral to our understanding of the universe. In astronomy, the study of the frequency of electromagnetic radiation emitted by celestial objects provides valuable insights into their composition, temperature, and even the dynamics of the universe itself. Astronomers use spectroscopy, a technique that analyzes the frequencies of light, to determine the chemical composition of stars, galaxies, and other cosmic phenomena.In the field of quantum physics, the behavior of subatomic particles is governed by the principles of frequency and wavelength. The wave-particle duality, a fundamental concept in quantum mechanics, suggests that particles exhibit both particle-like and wave-like properties, with their frequencies and wavelengths playing a crucial role in understanding their behavior.The importance of frequency extends beyond the scientific realm and into our daily lives. The rhythmic patterns we observe in music, the ticking of a clock, and the blinking of a light all involve the concept of frequency. Our perception of time and our ability to synchronize our activities are directly related to our understanding and awareness of frequency.In conclusion, frequency is a ubiquitous and essential concept that permeates various aspects of our lives, from the technological devices we use to the natural phenomena we observe. By understanding the significance of frequency, we can gain a deeper appreciation for the complex and interconnected world around us, and leverage this knowledge to advance our scientific understanding, technological capabilities, and overall well-being.。

太赫兹硅超表面

太赫兹硅超表面英文回答：Terahertz metasurfaces have emerged as promising platforms for manipulating and controlling electromagnetic waves due to their subwavelength feature sizes and unique optical properties. Silicon, with its high refractive index and low optical loss, is a widely used material for fabricating terahertz metasurfaces. By carefully designing the shape, size, and arrangement of silicon structures, it is possible to achieve tailored optical responses, such as focusing, beam steering, and polarization conversion, at terahertz frequencies.One of the key advantages of silicon terahertz metasurfaces is their compatibility with standard silicon fabrication processes, which enables large-scale and cost-effective manufacturing. Additionally, the high refractive index of silicon allows for the realization of subwavelength structures with strong electromagneticresonances, leading to enhanced optical performance.Various types of silicon terahertz metasurfaces have been demonstrated, including periodic, aperiodic, andchiral structures. Periodic metasurfaces are composed of regularly arranged silicon elements, while aperiodic metasurfaces feature irregular or random arrangements. Chiral metasurfaces exhibit handedness-dependent optical responses, which can be utilized for polarization control and circular dichroism.The applications of silicon terahertz metasurfaces are diverse, ranging from imaging and sensing to communication and spectroscopy. For instance, metasurface lenses can be designed to focus terahertz waves, enabling high-resolution imaging and non-destructive testing. Metasurface absorbers can be employed for selective absorption and detection of terahertz radiation, with potential applications in chemical sensing and environmental monitoring. Moreover, metasurface antennas can be used for beam steering and polarization control, which are crucial for terahertz wireless communication systems.中文回答：太赫兹硅超表面由于其亚波长特征尺寸和独特的光学特性，已成为操纵和控制电磁波的有前途的平台。

p区金属氧化物Ga_(2)O_(3)和Sb_(2)O_(3)光催化降解盐酸四环素性能差异

收稿日期：2020⁃09⁃29。

收修改稿日期：2020⁃12⁃28。

国家自然科学基金(No.21875037，51502036)和国家重点研发计划(No.2016YFB0302303，2019YFC1908203)资助。

＊通信联系人。

E⁃mail ：***************.cn ，***************第37卷第3期2021年3月Vol.37No.3509⁃515无机化学学报CHINESE JOURNAL OF INORGANIC CHEMISTRYp 区金属氧化物Ga 2O 3和Sb 2O 3光催化降解盐酸四环素性能差异毛婧芸1黄毅玮2黄祝泉1刘欣萍1薛珲＊,1肖荔人＊,3(1福建师范大学环境科学与工程学院，福州350007)(2福建师范大学生命科学学院，福州350007)(3福建师范大学化学与材料学院，福州350007)摘要：对沉淀法合成的p 区金属氧化物Ga 2O 3和Sb 2O 3紫外光光催化降解盐酸四环素的性能进行了研究，讨论了制备条件对光催化性能的影响。

最佳制备条件下得到的Ga 2O 3⁃900和Sb 2O 3⁃500样品光催化性能存在巨大差异，通过X 射线粉末衍射、傅里叶红外光谱、N 2吸附-脱附测试、荧光光谱、拉曼光谱、电化学分析及活性物种捕获实验等对样品进行分析，研究二者光催化降解盐酸四环素的机理，揭示影响光催化性能差异的本质因素。

结果表明，Ga 2O 3和Sb 2O 3光催化性能差异主要归结于二者不同的电子和晶体结构、表面所含羟基数量及光催化降解机理。

关键词：p 区金属；氧化镓；氧化锑；光催化；盐酸四环素中图分类号：O643.36；O614.37+1；O614.53+1文献标识码：A文章编号：1001⁃4861(2021)03⁃0509⁃07DOI ：10.11862/CJIC.2021.063Different Photocatalytic Performances for Tetracycline Hydrochloride Degradation of p ‑Block Metal Oxides Ga 2O 3and Sb 2O 3MAO Jing⁃Yun 1HUANG Yi⁃Wei 2HUANG Zhu⁃Quan 1LIU Xin⁃Ping 1XUE Hun ＊,1XIAO Li⁃Ren ＊,3(1College of Environmental Science and Engineering,Fujian Normal University,Fuzhou 350007,China )(2College of Life and Science,Fujian Normal University,Fuzhou 350007,China )(3College of Chemistry and Materials Science,Fujian Normal University,Fuzhou 350007,China )Abstract:The UV light photocatalytic performances of p ⁃block metal oxides Ga 2O 3and Sb 2O 3synthesized by a pre⁃cipitation method for the degradation of tetracycline hydrochloride were explored.The effects of synthesis conditions on the photocatalytic activity were discussed.The Ga 2O 3⁃900and Sb 2O 3⁃500samples prepared under optimal condi⁃tions exhibited a remarkable photocatalytic activity difference,which were characterized by X⁃ray diffraction,Fouri⁃er transform infrared spectroscopy,N 2adsorption⁃desorption tests,fluorescence spectrum,Raman spectrum,electro⁃chemical analysis and trapping experiment of active species.The photocatalytic degradation mechanisms of tetracy⁃cline hydrochloride over the photocatalysts were proposed and the essential factors influencing the difference of pho⁃tocatalytic performance were revealed.The results show that the different photocatalytic activities observed for Ga 2O 3and Sb 2O 3can be attributed to their different electronic and crystal structures,the amount of hydroxyl groupin the surface and the photocatalytic degradation mechanisms.Keywords:p ⁃block metal;Ga 2O 3;Sb 2O 3;photocatalysis;tetracycline hydrochloride无机化学学报第37卷0引言盐酸四环素(TC)作为一种四环素类广谱抗生素，被广泛应用于治疗人体疾病及预防畜禽、水产品的细菌性病害，其在世界范围的大量使用致使其在环境中积累[1]。

天文术语N-O范本一份

天文术语N-O范本一份天文术语N-O 1天文术语N-Onaked T Tauri star 显露金牛T 型星narrow-line radio galaxy ( NLRG ) 窄线射电星系Nasmyth spectrograph 内氏焦点摄谱仪natural reference frame 自然参考架natural refenence system 自然参考系natural seeing 自然视宁度near-contact binary 接近相接双星near-earth asteroid 近地小行星near-earth asteroid belt 近地小行星带near-earth et 近地彗星NEO, near-earth object 近地天体neon nova 氖新星Nepturian ring 海王星环neutrino astrophysics 中微子天文NNTT, National New Technology Telescope国立新技术望远镜NOAO, National Optical Astronomical 国立光学天文台Observatoriesnocturnal 夜间定时仪nodal precession 交点进动nodal regression 交点退行non-destroy readout ( NDRO ) 无破坏读出nonlinear infall mode 非线性下落模型nonlinear stability 非线性稳定性nonnucleated dwarf elliptical 无核矮椭圆星系nonnucleated dwarf galaxy 无核矮星系nonpotentiality 非势场性nonredundant masking 非过剩遮幅成象nonthermal radio halo 非热射电晕normal tail 正常彗尾North Galactic Cap 北银冠NOT, Nordic Optical Telescope 北欧光学望远镜nova rate 新星频数、新星出现率NTT, New Technology Telescope 新技术望远镜nucleated dwarf elliptical 有核矮椭圆星系nucleated dwarf galaxy 有核矮星系number density profile 数密度轮廓numbered asteroid 编号小行星oblique pulsator 斜脉动星observational cosmology 观测宇宙学observational dispersion 观测弥散度observational material 观测资料observing season 观测季occultation band 掩带O-Ne-Mg white dwarf 氧氖镁白矮星one-parameter method 单参数法on-line data handling 联机数据处理on-line filtering 联机滤波open cluster of galaxies 疏散星系团Ophelia 天卫七optical aperture-synthesis imaging 光波综合孔径成象optical arm 光学臂optical disk 光学盘optical light 可见光optical luminosity function 光学光度函数optically visible object 光学可见天体optical picture 光学图optical spectroscopy 光波分光orbital circularization 轨道圆化orbital eccentricity 轨道偏心率orbital evolution 轨道演化orbital frequency 轨道频率orbital inclination 轨道倾角orbit plane 轨道面order region 有序区organon parallacticon 星位尺Orion association 猎户星协orrery 太阳系仪orthogonal transformation 正交变换oscillation phase 振动相位outer asteroid belt 外小行星带outer-belt asteroid 外带小行星outer halo cluster 外晕族星团outside-eclipse variation 食外变光overshoot 超射OVV quasar, optically violently OVV 类星体variable quasar、。

非全同粒子第一激发态

非全同粒子第一激发态非全同粒子第一激发态是物理量子力学中的一个重要概念。

它指的是当原子的某个电子的角动量数比其他电子的角动量都不同，且不等于原子的绝对值时，这样的核心状态就称为非全同粒子第一激发态。

自引力企图让每一个原子中电子数目尽量相同，具有最低能量状态。

如果原子中两个电子数量不同，能量就会升高，原子会被激发去达到一个新的状态，这也就构成了非全同粒子第一激发态的基础。

Transitions from these states typically occurs through electronic interactions and processes such as photoionization and plasma production. The energy released and the pathways to these states can be modeledusing various theoretical tools such as density functional and Hartree-Fock theory. In addition, using spectroscopic techniques such as ultraviolet, visible and infrared spectroscopy, observers can measurethe energy released and other characteristics of the states in question.当非全同粒子第一激发态发生变化时，通常是通过电子相互作用和光电离、等离子体凝聚等过程发生的。

通过密度泛函和哈特里-福克理论等理论工具，可以对该状态释放出来的能量和达到此状态的途径进行建模，而通过紫外线、可见光和红外线等光谱技术，也可以测量出变化的能量以及有关该状态的其他特性。

In terms of applications, knowledge of the non-identical particle excited state is crucial in biology, chemistry and physics. For instance, understanding the excited states of proteins can allow researchers to design better drugs, while in astronomy, observations of these statescan help scientists understand the physical and chemical properties of stars and galaxies.从应用的角度来看，了解非全同粒子第一激发态是生物学、化学和物理学研究的重要基础。

星学科英语作文

When writing an essay in English for a subject like Stars,its important to structure your thoughts in a logical and engaging manner.Here are some key points to consider when crafting your essay:1.Introduction:Begin with a captivating opening sentence that introduces the topic of stars.You might want to mention why stars are fascinating or their significance in astronomy and human culture.Example:Stars have been the silent sentinels of the night sky,guiding travelers and inspiring poets for millennia.2.Types of Stars:Discuss the different types of stars,such as mainsequence stars,red giants,white dwarfs,and neutron stars.Explain the life cycle of a star,from its birth in a nebula to its eventual death.Example:Our Sun,a mainsequence star,is in the prime of its life,fusing hydrogen into helium in a process that provides the energy that sustains life on Earth.3.Properties of Stars:Describe the properties that define stars,such as their mass,size, temperature,and luminosity.Explain how these properties affect their color and the type of light they emit.Example:The color of a star is directly related to its temperature,with blue stars being the hottest and red stars the coolest.4.Constellations and Their Stories:Mention how stars are grouped into constellations and how these patterns have been used for navigation and storytelling across different cultures.Example:The constellation Orion,visible in the winter sky,is a prominent figure in both Greek mythology and ancient Egyptian astronomy.5.Stars and Life:Discuss the role of stars in supporting life,such as how the Sun provides energy for Earths ecosystems,and the ongoing search for exoplanets that might harbor life.Example:The search for exoplanets,or planets outside our solar system,is driven by the hope of finding another star system that could support life as we know it.6.Astronomy and Technology:Talk about the advancements in technology that haveallowed us to study stars more closely,such as telescopes,space probes,and the use of spectroscopy.Example:The Hubble Space Telescope has provided us with stunning images of distant galaxies,revealing the birth and death of stars across the universe.7.Conclusion:Summarize the main points of your essay and leave the reader with a thoughtprovoking statement or question about the future of our understanding of stars.Example:As we continue to explore the cosmos,the mysteries of stars will undoubtedly reveal more about the origins of the universe and our place within it.Remember to use clear and concise language,and to support your statements with evidence from scientific research or wellknown astronomical observations.Make sure to proofread your essay for grammar and spelling errors to ensure it is polished and professional.。

詹姆斯韦伯天文望远镜(JWST)调研报告精选全文

詹姆斯韦伯天文望远镜（JWST）调研报告——下一代哈勃天文望远镜1.JWST概述JWST/NGST计划是美国NASA、欧洲ESA和加拿大CSA正在合作进行的空间天文望远镜计划。

JWST/NGST预计于2014年发射，将成为HST的继承者。

JWST将发展和验证多项大口径空间望远镜技术的重大创新。

NGST（Next Generation Space Telescope）“下一代空间望远镜”在1989年提出，NASA在1995年开始组织先期论证和预研究。

2002年9月10日，NASA 宣布将NGST命名为JWST，以James Webb 这位阿波罗登月计划领导人也曾任NASA首席执行官的名字为“下一代空间望远镜”的冠名。

JWST的研究理念是：在哈勃的基础上应用更先进的技术，口径应该是哈勃的3~4倍，造价要降到哈勃的1/4~1/5。

在经过A项研究后，JWST现已转入B 项研究，研制工作已经全面开展。

JWST等效口径6.5m，集光面积25m2，探测谱段覆盖从0.6~28μm，工作温度低于35K。

JWST工作在L2轨道，距地球150万km，可以排除地球对JWST 的温度影响。

一个有网球场面积大小的遮阳板在空间拦截太阳对JWST的直接照射。

2.JWST主要参数（1）轨道：1.5*106km，L2轨道（2）预期寿命：5~10年（3）有效载荷总质量：约6200kg（4）主镜：等效6.5m，有效集光面积25m2，18块六角形镜面拼接，折叠发射，在轨展开成形（5）光学分辨率：0.1″，在λ=2000nm达到衍射极限成像（6）探测谱段：600~28000nm（7）探测仪器：近红外和可见段相机（NIRCam）、近红外多目标色散光谱仪(NIRSpec)、中红外相机和光谱仪(MIRI)以及精密指导传感器（Fine Guidance Sensor , FGS）（8）遮光板：22m*10m在轨展开（9）望远镜工作温度：<50K（10）预算：8.25亿美元3.JWST各子系统组成JWST主要由主光学望远镜系统（Optical Telescope Element, OTE）、科学仪器（Science Instrument Module, ISIM）和太空船（Spacecraft Element, SE）三部分组成。

光谱仪器原理

Spectrographys are optical instruments that form images S2(λ) of the entrance slit S1;the images are laterally separated for different wavelengths λof the incident radiation.Ω=F/f12受棱镜的有效面积F=h.a的限制，它代表光的限制孔径．的方式成像到入射狭缝上是有利的，虽然会聚透镜可以缩小光源在入射狭经上所成的像，使更多的来自扩展光源的辐射功率通过入射狭缝：但是发散度增大了．在接收角外的辐射不能被探测到，反而增大了由透镜支架和分光计任何色散型仪器的光谱分辨本领的定义为和λ2间的最小间隔．-λ2)在二个最大间显示出明显的凹陷，则可以认为强度分布是由具有强度轮廓为I1(λ-λ1)和I21(λ-λ2)的二条)依赖于比率I1/I2和二个分量的轮廓，因此最小对于不同的轮廓将是不相同．2的第一最小重合，则认为两条谱线如果强度相等的两条线的两个最大间的凹陷降到I的(8／π2)≈0.8，(a)Diffraction in a spectrometer by the limiting aperture with diameter af1f2:angular dispersion[rad/nm]成像在平面B上)间的距离△x2为=(dx/dλ)△λ:linear dispersion of the instrument,[mm/nm]为了分辨λ和λ+△λ的二条线，上式中的间距△x2至少应为二个狭缝象的宽度(λ)+δx2(λ+△λ),由于宽度x2由下式与入射狭缝宽度相联系：δx2=(f2/f1) δx1所以减小δx1便能增大分辨本领λ/△λ，可惜存在着由衍射造成的理论极限．由于分辨极限十分重要．我们将对这点作更详细的讨论．(b)Limitation of spectral resolution by diffraction=±λ/b间(见图)；仅当2 δΦ小于分光计的接收角a/f1时，它才能完全通过限制孔径a．这给出入射狭缝有效宽度bmin的下限为在一切实际情形中，入射光都是发散的．这就要求发散角和衍射角之和必须小于，而最小狭缝相应地更大。

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a r X i v :a s t r o -p h /0007127v 1 11 J u l 2000A&A manuscript no.(will be inserted by hand later)Key words:galaxies:redshift;galaxies:large-scale struc-ture;galaxies:clusters:individual:Virgo 1.IntroductionThe Virgo cluster,the nearest rich cluster of galaxies in the northern hemisphere,was surveyed with unprecedented resolution and completeness in the extensive photographic survey carryed out with the DuPont telescope at Las Cam-panas.Based on this material Binggeli et al.(1985)com-piled the Virgo Cluster Catalogue (VCC),which lists 2096galaxies brighter than B T ≤20.0(1323of which consti-tute a complete subsample to B T ≤18.0).This work has served to many important developements,in particular for mapping for the ﬁrst time the luminosity function of2Gavazzi et al.Table1.The spectrograph characteristicsLoiano Jan−F eb1999BF OSC1984060−79001024×1024T H19 Loiano Jan−F eb2000BF OSC1983600−89001340×1300EEV20 Cananea Apr2000LF OSC2284000−7100576×384T H23 OHP Mar1999CARELEC1333200−71002048×1024EEV13.5Gavazzi et al.3 Fig.1.The distribution in celestial coordinates of639Virgo galaxies with V≤3000km s−1(right)and a wedge diagram(left).Theﬁlled symbols represent measurements obtained in the present work.km s−1due to the uncertainty in the absolute wavelengthcalibration.Several absorption line spectra have statisti-cal errors up to900km s−1,reﬂecting a lack of strongfeatures.These redshifts,however,are suﬃcient to derivea membership.Column8:type of lines(A=absorption;E=emission).Column9:observing run(L99=Loiano1999,L00=Loiano2000,Can=Cananea2000,OHP=OHP1999).Column10:old membership as given in the VCC(bk=background,m=member,-=possible member)(onlyfor Table2).Column10a:new membership.Column11,12:previously available redshift,with refer-ence.Fig.1gives a representation in celestial coordinatesof639galaxies in the VCC region with redshift V≤3000km s−1(panel a)and a wedge diagram(in the samevelocity window)is given in panel b.Small symbols markgalaxies taken from the literature,ﬁlled circles mark themeasurements obtained in this work.Fig.2gives a rep-resentation in celestial coordinates of913galaxies in theVCC region with redshift≤24000km s−1(panel a)anda wedge diagram is given in panel b.Fig.3gives a rep-resentation in celestial coordinates of1109galaxies in theComa region with measured redshift(top)and a wedgediagram is given(bottom).(Same use of symbols as inFigs.1and2).3.1.redshift completenessThe VCC catalogue contains2096galaxies brighter thanB T=20.0.Of these only913have a redshift measurementso far.Even at brighter levels the redshift information isfar from complete(see Tab.4for details).For exampleamong the849galaxies with B T<16.0there are still69with no spectra available.It is not surprising,though,that4Gavazzi et al.Table2.Parameters of the observed Virgo galaxiesVCC0007120645.60114230.0Sc15.0418675425A Can bk bkVCC0014120717.80113205.0BCD?16.501789135E L00−bkVCC0019120740.80132800.0BCD?16.50680399E L00−bkVCC0045120934.70152315.0BCD?16.001523636E L00−bkVCC0064121008.50114955.0Sab15.0418142336A Can bk bkVCC0074121031.80161024.0BCD?16.3086178E Can−mVCC0099121128.9070004.0Sa?14.812476214E L99−m2444GGH98 VCC0196121400.0094624.0BCD?16.501302457E L00−bkVCC022*******.0083612.0BCD?17.0021345126E L00−bkVCC024*******.00133930.0Sa14.61749161E Can bk bkVCC0323121633.2060012.0Sa14.912402358A L99−m2756GGH98 VCC0362121709.0054856.0Sa14.511300304A L99−m1536GGH98 VCC0397121739.0065402.0dE?15.002411809A L99−m2495GGH98 VCC0482121900.8050324.0S0a14.771802709A L99−m2170GGH98 VCC0486121903.8060235.0S0a14.502386252A L99−m2498GGH98 VCC0510121922.80155518.0dE15.13804151A Can m mVCC0541121945.0043348.0BCD16.002351150E L00−bkVCC0573122009.6055454.0Sc15.2023083189E Can bk bk23083NED VCC0583122014.40154636.0Im15.76−72475A L99m mVCC0723122149.80131824.0dS0?15.0412550A L00−mVCC0762122230.0074660.0dE15.301341211A Ohp m mVCC0794122250.40164224.0dS015.50918817A Ohp m mVCC0817122306.00160642.0dE15.001168153A Can m mVCC0991122445.90142525.0dE14.70−406239A L99m mVCC1028122506.60144360.0dS0?15.7021158A Ohp−mVCC1174122645.80101246.0BCD?15.501184052E L99−bkVCC1270122743.8084800.0Sa15.0011687440A Can bk bkVCC1304122809.00152412.0dS015.50−108294A L99m mVCC1389122919.80124530.0dE15.91936193A Can m mVCC1395122923.4085248.0dE?16.2022900100E L00−bkVCC1423122942.6031630.0BCD?16.001307998A Can−bkVCC1608123247.6062325.0E14.202285193A L99−m2464GGH98 VCC1643123321.0060212.0S015.2012509258A Ohp−bk12563GGH98 VCC1671123359.6062641.0dS014.8011608809A L99−bk11846GGH98 VCC1687123416.2042242.0dE15.10616122A Can−mVCC1836123749.80145930.0dS014.541927148A Can m mVCC1849123803.6094942.0BCD?16.201590550E L00−bkVCC1906123932.20155438.0S015.70314138A Can−mVCC1927124005.40105024.0Sc14.9120085180A Can bk bkVCC1936124014.4094654.0dS015.68985276A Ohp m mVCC1947124023.3035701.0dE14.561083405A L99−m944GGH98 VCC1956124036.0035118.0S..15.101469151E L99−bk14659GGH98 VCC1982124119.20114412.0dE15.30938464A Ohp m mVCC1997124151.60102742.0Sb15.10921046E Can bk bkVCC2015124240.20103554.0BCD?16.202545115E L00−mVCC2042124407.2093448.0dE14.841765154A Can m mVCC2077124604.50110851.0Sab15.2011860225A Can bk bkVCC2082124727.60113206.0S..15.30742126E Can bk bkGavazzi et al.5 Table3.Parameters of the observed Coma galaxies127-028113851.25250457.3S015.603518330A L99fg127-029N113859.62260956.6E16.30740714E Can m127-029S113900.06260926.5E16.306927113A Can m97-153W114513.24184955.0S..16.301115620E Can bk97-153E114515.08184936.7S..16.3020261112E Can bk127-057S114550.62260223.9S..16.501366675E Can bk127-057N114551.69260251.3S..16.501371815E Can bk127-102115130.07232813.1E15.707799139A Ohp m128-028W120405.12260142.4E16.407353198A Can m128-028E120406.94260150.2E16.4013788143A Can bk98-088120903.25201024.8S015.706564215A Ohp m128-055121122.87220200.8S015.707227330A L99m98-120121341.37194405.9E15.7013208202A Ohp bk98-127121409.85183918.2E15.708954203A Ohp bk99-013121638.07193306.1Sc15.70729716E Ohp m128-083121936.55240846.0E15.7010182129E Ohp bk128-083E121939.64240847.5E17.0010292164A Ohp bk128-085122150.98212612.2Sc15.6091421E Ohp fg99-066122620.69194525.9Sb15.701358286E Ohp bk129-003122631.44245429.9Sc15.70145729E Ohp bk99-067122635.25191652.4E15.7014393250A Ohp bk159-087E124810.87274149.8Sbc15.701228616E Ohp bk160-036S125435.00305820.9S016.0015302177A Can bk160-036E125438.62305831.5E16.5014880185A Can bk160-163S131035.69272401.1E16.5017929178A Can bk160-163131036.56272421.7S0a15.701801572E Can bk161-029131912.70263359.0Sb15.70493011E Ohp m161-061S132554.00285542.1S..15.601128132E Can bk11247G99161-061N132554.69285657.4E16.5010564165A Can bk6Gavazzi et al.Fig.2.The distribution in celestial coordinates of913Virgo galaxies with V≤24000km s−1(right)and a wedge diagram (left)(same symbols as in Fig.1).Table4.redshift completeness in the Virgo cluster≤15.054954699≤16.084978092≤17.010*******≤18.0132390368≤19.0170491353≤20.020*******Gavazzi et al.7 Fig.3.The distribution in celestial coordinates of1109galaxies in the direction of the Coma supercluster with measured redshift(top)and a wedge diagram(bottom)(same symbols as in Fig.1).cluster.With these new data,the redshift completeness in the VCC region remains92%for B T≤16.0and68% for B T≤18.0.All membership estimates,as given in the VCC,are conﬁrmed.We remark that a large fraction of the possible members classiﬁed as BCDs?,are found to be giant emission-line galaxies well beyond the Virgo cluster.The redshift completeness of CGCG galaxies in the direction of the Coma–A1367supercluster is now98%. 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