Three-year Variations of Water, Energy and CO2 Fluxes of Cropland and Degraded Grassland Surfac
2023-2024学年广东省深圳市福田区红岭中学高一下学期英语期中考试
2023-2024学年广东省深圳市福田区红岭中学高一下学期英语期中考试一、单项选择1．A cut-off of the power ______ will last two hours due to routine maintenance (日常维护).A．supply B．electricity C．permission D．chain2．______ in the queue for half an hour, the old man suddenly realized he had left the check in the car.A．Waiting B．To waitC．Having waited D．To have waited3．There has been too much rain recently, ______ serious floods in the local area.A．resulting in B．putting down C．wrapping up D．suffering from 4．To the parents’ ______, the missing child was found safe and sound in a nearby village.A．relief B．anger C．grief D．extent5．He was cautioned against discussing the legal case outside of the office because ______.A．loose lips sink ships B．speech is silverC．Rome is not built in a day D．every coin has two sides.6．Although his ______ attempts had been unsuccessful, he stuck to his goals and realized his dream eventually.A．fancy B．ideal C．adjustable D．previous 7．Canada is a country _______ many different nationalities as well as one with foreign immigrants (移民) _______ the majority of its population.A．making up of; occupied with B．consisting of; making upC．made up of; consisting of D．consisted of; taking up8．The bird flu ________through Asia has jumped from birds to humans at least 20 times so far, ________16 persons.A．sweeps; killed B．swept; killing C．sweeping; to kill D．sweeping; killing 9．He ______ and began to walk to the door, without saying a word.A．passed away B．looked across C．rose to his feet D．moved on10．Your learning ________ needs to be adjusted a little so that you will have some time for your own hobbies.A．embarrassment B．complexity C．concern D．strategy11．______ about wild plants that they decided to make a trip to Madagascar for further research A．So curious the couple was B．So curious were the coupleC．How curious the couple were D．The couple was such curious12．I remember my daughter used to ask questions that girls ______ would ask.A．twice her age B．twice as older as sheC．as twice her age D．twice older as her age13．Cynthia is not ashamed of what she does, ______ she ends up doing something wrong.A．as long as B．as if C．even if D．now that 14．With the living standard improved, the ______ life span of the Chinese people is expected to rise greatly.A．false B．reusable C．normal D．average 15．There was a terrible noise the sudden burst of light.A．following B．to be followedC．followed D．being followed16．The woman ______ there under the tree, ______ in a blue shirt, is our headmaster.A．sitting; wearing B．sitting; dressed C．seating; dressed D．seated; dressing 17．The Sanxingdui ancient ruins were discovered ______ rather than by historical studies.A．in reality B．by accident C．on the spot D．with hesitation 18．The traffic rules say that no one is permitted to cross the street when the ______ is red.A．accident B．sign C．signal D．web19．A cook will be immediately fired if he is found ______ in the kitchen.A．smoke B．to smoke C．smoked D．smoking 20．Pressed from his parents, and ____ that he has wasted too much time, the boy is determined to stop playing video games.A．realizing B．realizedC．to realize D．being realized二、阅读理解a21．Where is Dr.Elwin Ransom originally from?A．Earth.B．Venus.C．Mars.D．Arrakis.22．Which book explores the potential for technology to make humans less free?A．War of the Worlds.B．The Dune Saga.C．The Space Trilogy.D．Fahrenheit 451.23．What do the four books have in common?A．They show an imaginary world.B．They each have two main characters.C．They explore the nature of humanity.D．They were published in the 20th century.Both of my parents worked fulltime when I was a little girl，so my grandmother would stay at our house during the day. We would watch game shows in the living room. Our favorite was The Price Is Right. We would call out our answers along with the contestants.When I got older and started going to school，we couldn’t watch our game shows regularly. That was okay with me，though，because the one thing I liked better than watching game shows with my grandmother was helping her bake cakes. Watching her in the kitchen was amazing：she never seemed to need the recipes（食谱）but everything she made tasted delicious.At first I would just sit in the kitchen and watch，even though I didn’t understand what she was doing. As I got older，she let me help with the easy parts，such as measuring the sugar. The day she let me separate the eggs，I felt like I had found complete pleasure.At last，my parents decided that I could take care of myself，and my grandmother stopped coming over every day. The love of baking，however，stayed with me. I started baking by myself，and even if the cookies ended up burnt sometimes，more often they turned out pretty well. I tried out new recipes，and whenever I got to a thorny part，I would call my grandmother for advice. Sometimes I would call her just to talk too. I felt like I could talk to her about anything.My grandmother passed away ten years ago，but I still think of her every day. Last week，I found a recipe book she made for me. It included her recipes for brownies，cookies，and my favorite，lemon pie. As I looked through the pages，I thought I could hear her voice. She was the one who taught me not just about baking，but about life.24．The passage is mainly developed by .A．analyzing causes B．making comparisonsC．following the time order D．examining differences25．While helping her grandmother bake，the author .A．found it interesting B．turned out to be a troublemakerC．hoped to make a living by baking D．regretted missing the game shows 26．What does the underlined word “thorny” in Paragraph 4 most probably mean?A．Basic.B．Common.C．Special.D．Difficult.27．What’s the author’s purpose in writing this passage?A．To describe her childhood memories.B．To show her good baking skills.C．To remember her grandmother.D．To talk about her happy family life.Like many people over the past few years, I have found myself turning to audiobooks as my main means of reading literature. I find it far more comfortable to “read with my ears” while my eyes are resting. My consumption of new books has doubled as a result--but a recent paper makes me wonder if this will come at the price of my comprehension.The study comes from Boaz Keysar and Janet Geipel, both at the University of Chicago, and it draws from the “dual process model” of mental processing. According to this-view, we have two ways of assessing information. System 1 is intuitive (直觉的),relying on natural ability and feeling. It is quick, but likely exposed to misinformation. System 2 is analytical involving the use of logic reasoning. It is mentally demanding. When it is engaged, we think our way through the material step by step. For decades, psychologists have designed various tests to determine which of these two systems a person is using. As one example, consider the/ following question: How many animals of each kind did Moses take on the Ark (方舟)? If you answered two, you were probably only considering the core of the question, which is System 1 thinking. To get to the right answer-zero, you need to think more carefully about the wording, which would allow you to remember it was Noah who built the Ark, not Moses. That is the kind of analytical process.Keysar and Geipel’s brilliant idea was to investigate whether the sensory form-seeing vs. hearing-of the information would make a difference. They found that it did: when answering thesekinds of simple questions, participants were more likely to make errors when the sentences were spoken out loud, rather than written.A greater reliance on our feelings could be a problem if we are consuming information that needs logical study. For this reason. I will return to reading non-fiction with my eyes rather than my ears. But I won’t stop listening to novels. I am quite happy to go with the flow of my emotions while my critical mind takes a break.28．What does the author think of listening to audiobooks?A．It is economical.B．It is demanding.C．It is time-consuming.D．It is relaxing.29．Which of the following best describes System 2 model?A．Fairly reliable.B．Fully automatic.C．Question-centered.D．Emotion-involved.30．Why is the Ark mentioned in Paragraph 3?A．To present a fact.B．To illustrate a view.C．To introduce a topic.D．To draw a conclusion.31．What does the author intend to tell us?A．Listening to books comes at a price.B．Reading non-fiction books benefits.C．Critical thinking is a must in reading.D．Ways of processing information differ.About 12% of the total global energy demand comes from heating and cooling homes and businesses. A new study suggests that using underground water to maintain comfortable temperatures could reduce consumption of natural gas and electricity in this section by 40% in the US. The approach is called A TES, short for aquifer thermal energy storage (含水层热能储存).“We need storage to absorb energy from the sun and wind. It’s crucial to creating affordable, reliable, and deeply environmental-friendly electricity systems. Most people are interested in batteries and other kinds of electrical storage. But we were wondering whether there was any opportunity to use geothermal (地热的) energy storage,” said first author A．T.D Perera. “With ATES, energy can be stored for a long period of time, without adding an additional burden to thegrid (输电网).”ATES is a pleasantly simple concept that takes advantage of the heat-absorbing property of water and the natural geological features of the planet. You simply pull existing underground water up and heat it at the surface in the summer with environmental heat or energy. Then you send it back down. It stays fairly hot because the Earth is a good insulator (绝热体).“Unlike above-ground tank-based water or ice storage systems, ATES will not need space. It’s also more efficient and can support larger communities in cooling or heating than traditional geothermal heat pump systems that rely on heat moving with the underground soil,” added co-author Hong Tianzhen.A major beneft of ATES is that it will become more efficient as weather becomes more extreme in the coming years due to climate change. The hotter summers and severer winters could increase the amount of free thermal energy that can be stored with ATES. “It’s very much a realistic thing to do and this work is really about showing its value,” said Perera. “This technology is ready to go, so to speak. We just need to do it.”32．What do we know about ATES?A．It is technologically demanding.B．It is aimed at replacing natural energy.C．It mainly relies on batteries to function.D．It helps achieve an environmentally friendly society33．How does Hong Tianzhen explain ATES’s advantages?A．By giving examples.B．By discussing results.C．By making comparisons.D．By analyzing principles.34．Which will affect ATES’s efficiency most?A．Temperature variations.B．Insulated materials.C．The duration of storage.D．The category of energy.35．What can be the best title for the text?A．A Turning Point in Energy UsageB．A Solution to Green Cooling and HeatingC．A Transformation in the US Electricity SystemD．A Discovery About Geothermal Energy StorageIt’s no surprise that there’s a link between exercise and mental health. But scientists have now made it official: research has found a direct connection between movement and mood. Why does exercise hold so many benefits for our mental health? 36 .When our muscles tighten, chains of amino acids (氨基酸) called myokines (肌细胞因子) are released into the bloodstream. 37 . This communication increases adaptation to stress, reduces symptoms of anxiety and has a direct effect on depression.A recent study published in the British Journal of Sports Medicine showed that treatment for depression can be much more effective when physical activity is added to the usual care.38 . “While exercise is not a substitute for professional mental health treatment, physical activity can complement and enhance the effects of the treatment,” says lead researcher Ben Singh, a research fellow at the University of South Australia. He says regular exercise in a group setting can boost self-esteem and decrease feelings of isolation and loneliness.Exercise helps build key connections between the networks within the brain, too.39 . Studies have shown that physical activity stimulates creativity, sharpens judgement skills and improves mental energy. It can also help to slow age-related cognitive decline, possibly even slowing the pace of developing Alzheimer’s disease.40 . In this way you’ll keep going back to them. Experts suggest that you aim for a minimum of 10 to 30 minutes, three to five days each week. Getting sweaty is good for your body and mind.A．It can improve overall cognitive performanceB．They help your muscles and organs communicateC．The answer, studies say, lies in our brain chemistryD．Here are the suggestions that you are supposed to pay attention toE．It is amazing to consider how moving our bodies can affect our mindsF．To get the biggest health boost, the key is to be engaged in sports you enjoy G．Participants found benefits after 12 weeks of exercising for 30 to 60 minutes a day三、完形填空Isabella Springmuhl Tejada is one of the first professional fashion designers with Down Syndrome (唐氏综合征).Her path to success wasn’t 41 .Although she showed her 42 .for design in childhood, when she would spend hours designing paper dresses for her dolls, she was 43 from several fashion schools due to her disease. She had no 44 but to seek other ways. She 45 for a sewing course, where she was 46 to sew clothing for finger-sized traditional Guatemalan (危地马拉的) dolls, which she 47 happily. Meanwhile, she also made a(n) 48 in designing dolls, creating some life-sized dolls and dressing them in the colorful traditional embroidered jackets she’s now famous for.This design experience helped Tejada develop her own design style, 49 traditional Guatemalan patterns, colors, and materials in her culture. She also created her own brand Down To Xjabelle, 50 for people with Down Syndrome, knowing how difficult it was for people like her to find 51 ! clothes. The new brand 52 right away, making it all the way to London Fashion Week, proving fashion can 53 all barriers and borders.And the 54 designer talks about her plans for the future as well, “I want to export my brand all over the world and 55 that people with Down Syndrome can do what they set out to do.”41．A．comfortable B．awful C．awkward D．smooth 42．A．arrangement B．talent C．determination D．responsibility 43．A．rejected B．dismissed C．ignored D．excused 44．A．guidance B．aim C．option D．right 45．A．waited B．competed C．prepared D．registered 46．A．assigned B．forced C．inspired D．persuaded 47．A．purchased B．accepted C．imagined D．contacted 48．A．discovery B．opportunity C．innovation D．schedule 49．A．indicating B．abandoning C．transforming D．highlighting 50．A．specially B．naturally C．usually D．obviously 51．A．pricey B．suitable C．fancy D．famous 52．A．paid off B．got across C．took off D．caught up53．A．combine B．fuel C．beautify D．overcome 54．A．ambitious B．enthusiastic C．humble D．proud 55．A．guarantee B．assess C．show D．conclude四、语法填空阅读下面材料，在空白处填入1个适当的单词或括号内单词的正确形式。
天然气水合物降压热激法模拟开采方案优化研究
天然气水合物降压热激法模拟开采方案优化研究金光荣;许天福;刘肖;辛欣;刘昌岭【摘要】基于南海神狐SH2钻孔水合物储层地质特点和压力温度条件,运用数值模拟方法开展天然气水合物的单一垂直井降压热激法联合试开采的优化研究.为减少气体经上覆透水岩层泄露和过量的产水,生产井过滤器放置于生产井中部,热量被平均分配到过滤器并以恒定功率注入而不是注入热水.研究结果表明:顶底板附近水合物有隔水储气作用,大部分的甲烷气被束缚在水合物储层中,但后期可成为甲烷泄露通道.对底孔压力、热激发强度、初始水合物饱和度、储层渗透率4个参数的敏感性分析表明:底孔压力降低,产气速率相差不大,产水量增加;热激发增强或高初始水合物饱和度下,产气速率增大;本征渗透率影响流体运移和热传导,本征渗透率减小时,产气速率先增大后减小.本文所采用数值模拟及参数敏感性分析方法,有助于设计和优化天然气水合物开采方案.【期刊名称】《中南大学学报（自然科学版）》【年(卷),期】2015(046)004【总页数】10页(P1534-1543)【关键词】天然气水合物;降压开采;热激法;数值模拟;神狐海域【作者】金光荣;许天福;刘肖;辛欣;刘昌岭【作者单位】吉林大学地下水资源与环境教育部重点实验室,吉林长春,130021;吉林大学地下水资源与环境教育部重点实验室,吉林长春,130021;吉林大学地下水资源与环境教育部重点实验室,吉林长春,130021;吉林大学地下水资源与环境教育部重点实验室,吉林长春,130021;国土资源部天然气水合物重点实验室,山东青岛,266071;青岛海洋地质研究所,山东青岛,266071【正文语种】中文【中图分类】P744天然气水合物，是由水和气体形成的固体结晶化合物[1]，深海和永久冻土带等高压低温环境的地质体是适合水合物形成和赋存的场所，其赋存的水合物多为甲烷水合物[2]。
天然气水合物储量超过所有常规的化石燃料的总和，被认为是未来的战略能源[3−4]，美国、日本、韩国、中国等均已开展有关天然气水合物开采潜力的研究[5−6]。
#光纤通信复习题英文
一 Make a choice 1) In graded-index optical fiber, the numerical aperture NA can be expressed as C.A. 21n n -B. ∆2aC. ∆2n 1D. 21n n a -2) In practical SMFs, the core diameter is just below the cutoff of the first higher-order mode; that is, for V slightly A.A. <2.4B. > 2.4C. =3D. =3.53) When the phase difference is an integral multiple of _2π_, the two modes will beat and the input polarization state will be reproduced.A. 2πB. πC. 1800D. π/24) It is well known that the total dispersion in the single-mode regime is composed of two components: C.A. mode-partition noise, inter- symbol InterferenceB. frequency chirp , modal dispersionC. material dispersion , waveguide dispersionD. modal dispersion , waveguide dispersion5) Which of the following codes cannot be transmitted in fibers B. A. CMI B. HDB3 C. 5B6B D. 8B1H6) Dispersion-shifted fiber (DSF) is a type of single-mode fiber designed to have zero dispersion near A nm. A. 1550 B. 850 C. 1310 D. 15107) To make sure that the APD photo detector works properly, a sufficiently D is applied across the p-n junction.A. high forward-bias voltageB. low forward-bias voltageC. low reverse-bias voltageD. high reverse-bias voltage8) A single mode fiber usually has a core diameter of A.A. 10mB. 62.5nmC. 125nmD. 50mm二Blank filling1) Each SDH frame comprising three areas: a section overhead area （SOH ）, a pointer area, a payload area including the data to be transmitted.2) List three applications of FBG(fiber Bragg grating): filter 、Optical Add Drop Multiplexer(OADM) and dispersion compensator. 3) According to whether there is electric or magnetic field in the direction of propagation or not, transverse modes of light waves are classified into different types: TEM modes, TE modes, TM modes and hybrid modes.4) Transmission of information in an optical format is carried out not by frequency modulation of the carrier, but by varying the intensity of the optical power.5) Largely due to attenuation and dispersion, the optical signals undergo waveform distortion and decreased amplitude.6) Material dispersion occurs because the index of refraction varies as a function of the optical wavelength.7) ZDSF is a dispersion shifted single mode fiber that has the zero dispersion wavelength near the 1550 nm window, but outside the window actually used to transmit signals.8)A laser is constructed from three principal parts: a pump source, a gain medium, and an optical resonator.9)An optical fiber comprises at least two layers, a core and a cladding.10)Optical transmitter consists of optical source, a modulator and a channel coupler.11)Fiber refractive index profiles classify fibers as step-index fibers and graded-index fibers.12)BER (The bit error rate) performance and jitter are two important indicators in a opticaldigital communication system.13)LASER is a mechanism for emitting light within the electromagnetic radiation region of thespectrum, via the process of stimulated emission.14)There are two kinds of SOA：Fabry-Perot Amplifier (FPA) and Traveling-Wave Amplifier(TWA) .15)The principal noises associated with photo detectors that have no internal gain are quantumnoise, dark-current noise generated in the bulk material of the photodiode, and surface leakage current noise.16)In a step-index fiber, the refractive index of the core is uniform and undergoes an abruptchange at the core-cladding boundary. In graded-index fibers, the refractive index of the core varies gradually as a function of radial distance from the fiber center.17)If the input pulse excites both polarization components, it becomes broader as the twocomponents disperse along the fiber because of their different group velocities. This phenomenon is called the PMD.18)The most common semiconductor photo detector is the pin photodiode.19)The main cause of intrinsic absorption in the infrared region is the characteristic vibrationfrequency of atomic bonds.20)In SDH transmission structures, a TU (Tributary Unit) includes a low level VC and a TUPTR.21)Extrinsic absorption is caused by impurities introduced into the fiber material.22)Intramodal dispersion is a result of the group velocity being a function of the wavelength.23)The optical amplifiers is divided into 3 groups: semiconductor optical amplifier (SOA),optical fiber amplifier (OPA) and Raman amplifier (FRA).24)There are two kinds of directional couplers: a prism-fibre and a fibre-fibre lapped coupler.25)EDFA has three pumping structures: ①the forward pumping structure; ②the backwardpumping structure; ③ the double pumping structure.26) A laser consists of a gain medium inside a highly reflective optical cavity, as well as a meansto supply energy to the gain medium.27)Attenuation in an optical fiber is caused by absorption losses, scattering losses, and bendinglosses.28)STM-1 frames provide a transmission bit rate of 155 Mbit/s.29)From the point of view of the wave theory, light wave could be described as anelectromagnetic wave.30)Intermodal dispersion is a result of each mode having a different value of the group velocityat a single frequency.31) A typical optical digital communication system usually comprises three parts: transmitter,optical fiber channel, and receiver.32)The pin Photo detector structure consists of p and n regions separated by a very lightlyn-doped intrinsic (i) region.33)Please list three steps of SDH Multiplexing: mapping，aligning ，multiplexing.34)There are three variations of WDM that are commonly used: Broad WDM, Coarse WDM, and Dense WDM. 35)The STM-1 frame is the basic transmission format for SDH. The frame lasts for 125 microseconds; therefore there are 8000 frames per second. 36)In SDH frame structure, the SOH is made up of a regenerator section overhead (RSOH) and a multiplexing section overhead (MSOH). 37)The sensitivity of a photo detector in an optical fiber communication system is describable in terms of the minimum detectable optical power. 38)Please list three applications of EDFA in optical fiber communication system: as preamplifier of receiver 、as power amplifier of transmitter and as the optical repeater. 39) An optical isolator (optical diode), is an optical component which allows the transmission oflight in only one direction.三Interpretation of terms and phrases1) AON (all-optical network) 2) DBR (distributed Bragg reflector)3）FDDI (fiber distributed data interface) 4）HFC (hybrid fiber-coaxial)5）ISDN (integrated services digital network) 6）RA (raman amplifier)7）OC (optical carrier) 8）OTDM (optical time-division multiplexing)9）PON (passive optical network) 10）SCM (subcarrier multiplexing)11）SDH (synchronous digital hierarchy) 12）SPM (self-phase modulation)13）STS (synchronous transpor signal) 14）TW (traveling wave)15）WGA (waveguide-grating router) 16）IMD (intermodulation disortion)17）AWG (arrayed-waveguide grating) 18）AOTF (acousto-optic tunable filter)四 画图题1) Draw the element block of a Distributed forward Raman amplifier2) Draw an element diagram of a Double pump EDFA3) Draw a block diagram of a typical optical digital communication system and briefly describe the functions of each part.OutputInput EDF WDM IsolatorPump Laser Isolator Pump Laser WDMPump Laser outputfiber inputAn optical communication system consists of a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the message from the received optical signal. The optical repeater is to extend the transmission distance of optical signal.4) Draw the element diagram of the application of optical amplifier.四 简答题1) Dispersion: Any phenomenon in which the velocity of propagation of any electromagnetic wave is wavelength dependent.2) Stimulated EmissionsIf a photon of energy hv 12 impinges on the system while the electron is still in its excited state, the electron is immediately stimulated to drop to the ground state and give off a photon of energy hv 12.3) There are 3 dispersion types in the optical fibers in general:1- Material Dispersion2- Waveguide Dispersion3- Polarization-Mode Dispersion4) Polarization mode dispersion (PMD) is due to slightly different velocity for each polarization mode because of the lack of perfectly symmetric & anisotropic of the fiber5) Laser is an optical oscillator. It comprises a resonant optical amplifier whose output is fed back into its input with matching phase. Any oscillator contains:1. An amplifier with a gain-saturated mechanism2. A feedback system3. A frequency selection mechanism4. An output coupling scheme Optical transmitter Repeater Opticalreceiverfiber fiber6) In thermal equilibrium the stimulated emission is essentially negligible, since the density of electrons in the excited state is very small, and optical emission is mainly because of the spontaneous emission. Stimulated emission will exceed absorption only if the population of the excited states is greater than that of the ground state. This condition is known as Population Inversion. Population inversion is achieved by various pumping techniques.7) Turn on DelayWhen the driving current suddenly jumps from low (I1 < Ith) to high (I2 > Ith) , (step input), there is a finite time before the laser will turn on8) The Quantum LimitFor an ideal photo-detector having unity quantum efficiency and producing no dark current, it is possible to find the minimum received optical power required for a specific BER performance in a digital system. This minimum received power level is known as the quantum limit.9) Gain flatness: The difference between the biggest gain and the smallest gain of the different frequency signal.10) The advantage of Raman amplifier: Simple fabricationLow noise, because amplifying action take place inside the ordinarily fiber.The wavelength can be selected in the low loss waveband.Very wide gain bandwidth.11) Micro bending Loss: microscopic bends of the fiber axis that can arise when the fibers are incorporated into cables. The power is dissipated through the micro bended fiber, because of the repetitive coupling of energy between guided modes & the leaky or radiation modes in the fiber.12) Gain saturation: when near saturation, the gain is nonlinear; saturation, the signal cannot be amplified.13) The disadvantage of Raman amplifier:Need large output power pump laser. As Raman Scattering, the energy is transferred from high frequency to low frequency. Cross talk will affect signal.14) The principal noises associated with photo detectors are:1- Quantum (Shot) noise: arises from statistical nature of the production and collection of photo-generated electrons upon optical illumination. It has been shown that the statistics follow a Poisson process.2- Dark current noise: is the current that continues to flow through the bias circuit in the absence of the light. This is the combination of bulk dark current, which is due to thermally generated e and h in the pn junction, and the surface dark current, due to surface defects, bias voltage and surface area.15) List the advantages of fiber-optic communications over other types of communication technologies.The advantage of optical fiber communication:1. Weight and Size2. Material cost (SiO2 is plentiful)3. Information Capacity4. No electromagnetic interference5. No electrical connection6. Distance between repeaters7. Better security8. Low crosstalk16) The fabrication of amplifierOptical isolator ，Optical multiplexer, EDF, Pump laser17) What are the advantages and disadvantages of SDH system as compared to PDH system? The main limitations of PDH are:Inability to identify individual channels in a higher-order bit stream;Insufficient capacity for network management;Most PDH network management is proprietary;There is no standardized definition of PDH bit rates greater than 140 Mbit/s; and,There are different hierarchies in use around the world. Specialized interface equipment is required to interwork the two hierarchies.18) List the types of fiber attenuation and dispersion.Absorbing\scattering and bending lossMaterial/ mode/ waveguide dispersion.19) The avalanche effect.The created carriers are accelerated by the high electric field, gaining enough energy to cause further impact ionization.20) Dynamic range:System dynamic range is the maximum optical power range to which any detector must be able to respond.21) Differentiate between step index and graded index optical fiber.Step index fiber has a core of one index of refraction; graded index fiber has a core in which the outside edge starts with a low index of refraction that gradually increases towards the center. 五 计算题1) Suppose two graded index fibers are misaligned with an axial offset of d=0.3a. Try to calculate the fraction of optical power coupled from the first fiber into the second fiber. （Parameter a is the core radius ）The fraction of optical power coupled in the fiber ：122222arccos()152262T P d d d d P a a a a π⎧⎫⎡⎤⎛⎫⎪⎪⎛⎫=---⎢⎥⎨⎬ ⎪ ⎪⎝⎭⎢⎥⎝⎭⎪⎪⎣⎦⎩⎭()()21220.320.15arccos(0.15)10.15532π⎧⎫⎛⎫⎪⎪⎡⎤=--- ⎪⎨⎬⎣⎦ ⎪⎪⎪⎝⎭⎩⎭0.748=Turn it into dB , obtain 10log 1.27T P dB P=- 1) A double-heterojunction InGaAsP LED emitting at a peak wavelength of 1310 nm has radiative and nonradiative recombination times of 30 and 100 ns, respectively. The drive current is 40 mA. Compute internal quantum efficiency and internal optical power. Then the internalquantum efficiency isthe internal power level is ：2) A GaAs laser operating at800nm has a 500-µm length and a refractive index n=3.7.What are the frequency and wavelength spacing? From 2c Ln ν∆=，22Lnλλ∆= obtain: 86310812250010 3.7c GHz Ln ν-⨯∆===⨯⨯⨯，3) In a 100-ns pulse, 6×106 photons at a wavelength of 1300nm fall on an In GaAs photo detector. On the average, 5.4×106 electron-hole (e-h) pairs are generated.Please calculate the quantum efficiency.The quantum efficiencyNumber of e-h pairs generated= -----------------------------------------Number of incident photons=665.410610⨯⨯0.90= 4) Consider a graded-index optical fiber, core index n1=1.50 and the core cladding index difference Δ=0.01.Try to calculate:1. The cladding index n22. The numerical aperture NA解：已知：n 1 =1.50，∆=0.01，根据(1)77.0100/130/130/1111int =+=+=---nr r r τττηmW 92.21031.110602.1/103106256.604.077.0619834int int =⨯⨯⨯⨯⨯⋅⨯⨯⨯==---s m s J q Ihc P λη(2)由（1）式，可知2 n 12∆= n 12- n 22n 22= n 12（1-2∆）n 2= n 1∆-21将n 1、∆代入上式，可得n 2==1.5002.01-=1.5098.0⨯=1.50⨯0.98995=1.48491将n 1、∆代入（2）式，可得NA = n 1∆2=1.5002.0=1.50⨯0.14142=0.21213The numerical aperture NA isNA=∆21n =22.001.02560.1=⨯⨯The normalized frequency V=∆221λπn a =01.0231.15056.11416.3⨯⨯⨯=26.454>V C =2.4057) Consider a 30-km long optical fiber that has an attenuation of 0.8dB/km at 1300 nm. If 200µW of optical power is launched into the fiber, try to calculate the optical output power P out .First we turn the input signal power unit from mW into dBm63()20010()10log 10log 7.01110in in P W W P dBm dBm mW W --⎡⎤⨯⎡⎤===-⎢⎥⎢⎥⨯⎣⎦⎣⎦From ()10(0)l g ()P dB o km z P z α=, as z=30k, the output power is ： ()()()10log 10log 11out in P W P W P dBm z out mW mW α⎡⎤⎡⎤==-⎢⎥⎢⎥⎣⎦⎣⎦7.0(0.8/)(30)31.0dBm dB km km dBm =--=- Also31.0/103(30)10(1)0.79100.79P km mW mW W μ--==⨯=8) A photodiode is constructed of GaAs, which has a band-gap energy of 1.43eV at 300K.What is the cutoff wavelength? The cutoff wavelength is ()()()()348196.62510310/8691.43 1.610/c g J s m s hc nm E eV J eV λ--⨯⋅⨯===⨯2) 一个折射率为3.6的GaAs 光源耦合进折射率为1.48的石英光纤中，如果光纤端面和光源在物理上紧密相接，于是分界面上发生菲涅尔反射：A GaAs optical source with a refractive index of 3.6 is coupled to a silica fiber that has a refractive index of 1.48 . If the fiber end and the source are in close physical contact , then , the Fresnel reflection at the interface is这相当于17.4%的发射功率反射回光源，与这一R 值相对应的耦合功率由下式给定：This value of R corresponds to a reflection of 17.4 percent of the emitted optical power back into the source . Given that由反射造成的功率损耗为：The power loss L in decibels is found from3) 有一个InGaAs 光电二极管，在100ns 内共入射了波长为1300 nm 的光子6×106 个，产生了 5.4×106 个电子空隙对，则其量子效率可以等于：In a 100-ns pulse, 6×106 photons at a wavelength of 1300 nm fall on an InGaAs photodetector. On the average, 5.4x106 electron-hole pairs are generated, quantum efficiency is .4) 能量为1.53 × 10-19 J 的光子入射到光电二极管上，此二极管的响应度为0.65 A/W ，如果入射光功率为10 mW ，则产生的光电流为：Photons of energy 1.53 × 10-19 J are incident on a photodiode which has a responsivity of 0.65 A/W. If the optical power level is 10 μW, the photocurrent is174.048.160.348.160.32211=⎪⎭⎫ ⎝⎛+-=⎪⎪⎭⎫ ⎝⎛+-=n n n n R ()em ittedcoupled P R P -=110log 10log(1)0.83dB coupled emitted P L R P ⎛⎫=-=--= ⎪⎝⎭%90106104.566=⨯⨯=ημA 5.6)μW 10()A/W 65.0(=⨯=ℜ=in p P I5) 如上图所示，波长范围为1300 nm - 1600 nm 的InGaAs pin ，量子效率约为90%，因此响应度为：As shown in above figure, for the wavelength range 1300 nm < λ < 1600 nm, the quantum efficiency for InGaAs is around 90%. So responsivity is当波长为1300 nm 时：Responsivity at 1300 nm is ：6) 一种硅APD 在波长900 nm 时的量子效率为65%，假定0.5 mW 的光功率产生的倍增电流为10 mA ，试求倍增因子M 。
4级模拟试题
4级模拟试题一、听力理解Section A1. 根据对话，男士为什么迟到了？A) 交通堵塞B) 闹钟没响C) 忘记时间D) 找不到地点2. 女士在对话中提到了什么活动？A) 看电影B) 去图书馆C) 参加派对D) 健身Section B3. 根据短文，哪个部门最近很忙？A) 市场部B) 财务部C) 人力资源部D) 研发部4. 短文中提到的项目预计何时完成？A) 一个月内B) 两个月内C) 三个月内D) 四个月内Section C5. 演讲者在演讲中主要讨论了什么主题？A) 环境保护B) 教育改革C) 科技发展D) 社会公平6. 演讲者提到了哪个国家作为例子？A) 美国B) 中国C) 英国D) 澳大利亚二、阅读理解Passage 1In recent years, the popularity of online education has surged. According to a recent survey, more than half of the students prefer online courses over traditional classroom settings. This trend has been attributed to the flexibility and convenience that online education offers. However, there are also concerns about the quality of education and the lack of interaction between students and teachers.Questions:7. What is the main reason for the surge in online education?A) Cost-effectivenessB) Flexibility and convenienceC) Better quality of educationD) Greater availability of courses8. What is the concern regarding online education?A) Technical difficultiesB) High costC) Quality of educationD) Lack of student participationPassage 2The use of renewable energy sources has been on the rise globally. Governments and private sectors are investing heavily in solar, wind, and hydroelectric power. Despite the initial costs, the long-term benefits of using renewable energy are significant. It not only reduces reliance on fossil fuels but also helps in reducing greenhouse gas emissions.Questions:9. What is the main advantage of renewable energy?A) Low initial costB) Long-term cost savingsC) High energy outputD) Wide availability10. What is the environmental benefit of using renewable energy?A) Increased biodiversityB) Reduced greenhouse gas emissionsC) Improved air qualityD) All of the above三、完形填空The internet has revolutionized the way we communicate and access information. It has made our lives more convenient and has opened up new opportunities for learning and business. However, with the growth of the internet, there are also concerns about privacy and security. It is important to be aware of the potential risks and take necessary precautions to protect our personal information.11. The internet has changed our lives in many ways, making them ______.A) more difficultB) more convenientC) less interestingD) more challenging12. As the internet grows, we need to be ______ about our privacy.A) concernedB) indifferentC) ignorantD) confused四、翻译将下列句子从中文翻译成英文：13. 随着科技的发展，我们的生活变得越来越便利。
《大气科学概论》-Atmospheric Science-10气候动力学-a英语教学课件
What is climate variability and climate change?
The distinction between climate variability and climate change is largely semantic: if the variations of interest take place within some specified interval (e.g., the 20th century), they are referred to as climate variability within that interval, whereas if they involve the differences between two successive epochs (e.g., the first and second halves of the 20th century), they are referred to as the change in climate from one epoch to the next.
5
Outline
The Present-Day Climate Climate Variability Climate Equilibria, Sensitivity, and
Feedback Greenhouse Warming Climate Monitoring and Prediction
2
What is climate variability?
The term climate variability refers to long term variations or changes in the mean state such as might be caused by orbital variations or human activities. The same term is also used in reference to short term climate variations such as those that occur in association with El Niño.
张敏版 科技英语阅读教程 英译汉 中文翻译
Unlocking the Climate Puzzle解开气候之谜(1)Life has prospered on this planet for nearly four billion years. In that time, climate had fluctuated drastically, from ice ages lasting tens of thousands of years to epochsof steamy heat. With each change, sundry species have benefited and flourished. Others adapted, faltered, or died. Now, many experts believe, humans are imperiling their own ecological niche with the threat of global warming. The vaporousby-products of civilization, in the form of greenhouse gases such as carbon dioxide (C0₂), have trapped enough heat in the atmosphere to raise Earth's average surface air temperature a half degree Celsius (one degree Fahrenheit) during this century. If the trend continues, it could alter climate patterns worldwide-thawing glaciers, boosting sea level, scorching plains into deserts, and shifting vegetation zones.（1）生命在这个星球上已经发展了近四十亿年。
中国气候介绍英文
**Climatic Zones**China can be broadly divided into five major climatic zones: tropical, subtropical, warm-temperate, temperate, and cold-temperate, each with distinct temperature and precipitation patterns.1. **Tropical Zone**: Encompassing Hainan Island and parts of Yunnan, Guangdong, and Taiwan provinces, this zone experiences year-round high temperatures, with an average annual temperature exceeding 22°C. The region receives ample rainfall, primarily from the summer monsoon, with a distinct dry season during winter.2. **Subtropical Zone**: Spanning much of southeastern China, including provinces like Fujian, Jiangsu, Zhejiang, and parts of Guangdong, Hunan, and Jiangxi, this zone has a mild winter and hot, humid summers. Annual precipitation is abundant and relatively evenly distributed throughout the year, although the summer months typically receive higher rainfall due to the East Asian monsoon.3. **Warm-Temperate Zone**: Found in central and eastern China, including regions in Shandong, Shanxi, Hebei, Henan, Anhui, and Shaanxi provinces, this zone exhibits four distinct seasons. Winters are cool to cold, while summers are warm and often rainy. Annual precipitation is generally moderate, with a peak during the summer monsoon season.4. **Temperate Zone**: Extending across northeastern China (Liaoning, Jilin, and Heilongjiang provinces) and Inner Mongolia, this zone experiences cold winters with frequent snowfall and short, warm summers. Precipitation is relatively low and concentrated mainly in summer.5. **Cold-Temperate Zone**: Occupying the northernmost regions of China, such as Xinjiang, Tibet, Qinghai, and parts of Gansu and Inner Mongolia, this zone is characterized by long, harsh winters and short, cool summers. Annual precipitation is generally low, and most of it falls as snow during the winter months.**Monsoonal Influence**The East Asian Monsoon plays a pivotal role in shaping China's climate,particularly in determining the distribution and timing of precipitation. During the summer months (June to September), moist, warm air from the Pacific Ocean flows inland, bringing heavy rains to much of eastern and southern China. In contrast, the winter monsoon (December to February) brings cold, dry winds from Siberia, leading to colder temperatures and reduced precipitation across the country.**Topographical Influence**China's diverse landscape, ranging from low-lying coastal plains to towering mountain ranges and vast deserts, significantly influences local climates. Coastal regions benefit from the moderating influence of the sea, with milder temperatures and higher humidity. Inland areas, particularly those at higher elevations, tend to have more pronounced temperature extremes and lower humidity levels. Mountainous regions often experience substantial variations in temperature and precipitation with elevation, giving rise to multiple microclimates within a relatively small area.**Desertification and Drought**China's arid and semi-arid regions, primarily in the north and west, are susceptible to desertification and drought. The Taklamakan and Gobi Deserts are expanding due to a combination of natural factors (such as climate variability) and human activities (overgrazing, deforestation, and unsustainable water usage). These phenomena pose significant challenges for agriculture, water resources, and ecological stability in affected areas.**Climate Change Impacts**China, like many other countries, is experiencing the effects of global climate change. Key trends include:1. **Temperature Increase**: China has witnessed a significant warming trend over the past few decades, with average temperatures rising faster than the global average. This has led to longer and more intense heatwaves, particularly in urban areas, posing health risks and increasing energy demand for cooling.2. **Precipitation Shifts**: While there is regional variability, overall,China has seen increased precipitation in some areas and decreased precipitation in others. Extreme precipitation events, causing flooding and landslides, have become more frequent in parts of southern and eastern China, while prolonged droughts have become more common in northern and western regions.3. **Glacier Retreat**: The Tibetan Plateau, known as the "Third Pole," is home to numerous glaciers that serve as vital freshwater sources for millions. Climate change-induced glacier retreat threatens water security in downstream regions and exacerbates the risk of glacial lake outburst floods.4. **Sea Level Rise**: Coastal regions, particularly in the economically vital eastern seaboard, face increased risks from sea level rise, storm surges, and saltwater intrusion, which can damage infrastructure, disrupt ecosystems, and displace populations.5. **Agricultural Impacts**: Climate change poses both challenges and opportunities for China's agricultural sector. Warmer temperatures may extend growing seasons in some regions, but increased frequency of extreme weather events, pests, and diseases can lead to crop yield losses. Additionally, shifting precipitation patterns and increased water stress could affect irrigation-dependent agriculture.**Mitigation and Adaptation Efforts**China has taken significant steps to address climate change, both through mitigation measures to reduce greenhouse gas emissions and adaptation strategies to cope with its impacts. Key initiatives include:1. **Renewable Energy Expansion**: China is the world's largest investor in renewable energy, particularly in solar and wind power. It aims to achieve carbon neutrality by 2060, with a peak in carbon emissions before 2030.2. **Forestry and Land Management**: China has implemented large-scale reforestation programs and strengthened land management practices to combat desertification, enhance carbon sequestration, and preserve biodiversity.3. **Water Resource Management**: Efforts to improve water efficiency, develop water-saving technologies, and implement integrated water resourcemanagement strategies help mitigate the impacts of drought and ensure water supply for agriculture, industry, and domestic use.4. **Climate-Smart Agriculture**: Research and adoption of climate-resilient crop varieties, improved irrigation techniques, and precision agriculture practices help farmers adapt to changing climate conditions.5. **Coastal Protection and Urban Planning**: Investment in coastal defense infrastructure, wetland restoration, and the implementation of resilient urban planning strategies help protect coastal communities and assets from sea level rise and extreme weather events.In conclusion, China's climate is a complex tapestry of diverse climatic zones, shaped by the interplay of latitude, monsoons, topography, and human activities. The country is experiencing significant climate change impacts, which necessitate robust mitigation and adaptation efforts to safeguard its economic development, environmental sustainability, and social well-being. As China continues to navigate the challenges posed by climate change, its actions will have profound implications not only domestically but also globally, given its status as the world's most populous nation and second-largest economy.。
电力系统专业英语词汇
Be in versely （directly）proporti onal to 与. 合成反（正）比The computer system 计算机系统collect solar energy 搜集太阳能collect stamps 集邮Conventional sign 通用标志Conventional units of measurement 常用的计量单位Crank han dle（case ）手摇曲柄（去冰箱）chemical power 化学能Diesel power plant 柴油发电厂Diesel engine generator 柴油发电机Direct（alternating） current （DC）直流电（交流电）a electrical power system 电力系统Electrical（mechanical）energy 电能（机械能）Electromagnetic principle 电磁原理a hydraulic turbine 水轮机Mechanical power 机械能A magnetic field 磁场a steam turbine 汽轮机synthetic gas （fiber）合成气体（纤维）petroleum products 石油产品petroleum equipment 石油设备pote ntial en ergy （resources）潜在的能量（资源）Prime mover（energy）原动机（原始能）light （heavy）nuclear particles 轻（重）荷粒子nu clear reaction s（weap ons）核反应（核武器）A thermal power station 火力发电站The thermal unit 热量单元Torque requirement 转矩要求The rotor shaft 转轴Rotor core 转子铁芯nuclear fission 核裂变nuclear safety 核安全chain letter 连锁反应chain reaction 连锁信号steam cycle 蒸汽循环steam power 蒸汽动力fluid medium 流质体fluid mechanics 流体力学nuclear fuel 核燃料solid fuel 固体燃料fissionable isotope 可裂变同位素fissionable materials 可裂变物质critical mass 临界质critical load 临界负载nu clear energy 核（原子）能thermal energy 热能commercial reactor 商用（核）反应堆atomic reactor 核反应堆heat source 热源redioactive source 放射源availability of machinery 机械的可用性availability of the equipment 设备的可用性high pressure zone 高压地带low pressure zone 低压地区commission of a nuclear power station 核电站的运行after commission 投产后precentage of outages 停机率percentage of maintenance 维修率instant loading 瞬间负载take full load 完全负载shutdowns for check 停机检查shutdowns for repairs and maintenance 停机保养13.self-replenishing energy 自行补充的能源self-replenishing water capacity 自行补充的水容量construction of a reservoir 修建水库construction of a dam 大坝的建筑a system of farm irrigation 农田灌溉系统a system of automatic drains 自动排水系统the multi-purpose harness of the Yellow Valley 黄河流域的综合治理the development of Yangtse Valley 长江流域的开发time invariant steady-state 时间恒定不变的稳定状态sinusoidal steady-state 正弦稳定状态conducting materials 导体原料conducting wires 导线maximum current density 最大电流密度weight density 重度a transmissionqd line 输电线路a transmission system 传输系统plane surface 平面quipotential surface 等势面额power system 电力系统power apparatus 电力仪表instantaneous value 瞬时值average value 平均值fluid insulation 液体绝缘solid insulation 固体绝缘resistance network 电阻网络network structure 网状组织allowable current 允许电流allowable load 许可负载the protective relay 继电保护器induction-type relays 感应型继电器voltage signal 电压信号current signal 电流信号measuring operation 测量动作instantaneous operation 瞬时动作alternating current circuits 交流电路direct-current circuits 直流电路static devices 静态设备rotating equipment 转动设备magnetic-induction typesv 磁感应型types of various blood 各种血型the pole face 极面the pole star 北极星a permanent magnet 永久磁铁a permanent committee 常设委员会a cooling system 冷却系统a railway system 铁路系统abnormal operation 非正常运行normal operation 正常运行Long-distance communication 远距离通信Long-distance transmission 远距离传递Voice band communications channel 音频通信信道Selecting the voice channel 选择信道Frequently modulation 频率调制Velocity modulation 速度调节Digital pulse 数字脉冲Error pulse 误差信号脉冲Give priority to the one computer 给一个计算机以优先权Give priority to women and children 给妇女儿童以优先权Have access to the central computer 有进入主计算机的通道Have access to the library 有权利使用图书馆Go out of commission 脱离了权限命令Go out of date 过时了Be identified as the primary 被标识为主机Be identified as transmission 被标识为信息传递Relay the information to its intended destination 将信息转发给预期的目的Relay TV programmes to foreign countries 将电视节目传播到国外Control system 控制系统eating system 加热系统H Physical quantity 物理量Known quantity 已知量Analog technique 模拟技术Digital technique 数字技术Data-handling capability 数据处理器能力Heat transfer capability 传热能力Desired value 理想值Given value 给定值Modify the system 调整系统Modify the design 修改设计Have no effect on 对。
Four Laws of Ecology中英对照
Four Laws of Ecology1 In broad outline,there are environmental cycles which govern the behavior of the three great global systems:the air,the water,and the soil.Within each of them live many thousands of different species of living things.Each species is suited to its particular environmental niche,and each,through its life processes,affects the physical and chemical properties of its immediate environment.1概括来讲,地球的三大系统—空气、水和土壤的行为由环境循环所决定。
每个系统中都生活着成千上万个不同物种的生物,每个物种都有与之相适宜的独特的环境生位,并且每一物种,在其整个生命历程中,都影响着它的周边环境的物理和化学特性。
2 Each living species is also linked to many others.These links are bewildering in their variety and marvelous in their intricate detail.An animal,such as a deer,may depend on plants for food;the plants depend on the action of soil bacteria for their nutrients;the bacteria in turn live on the organic wastes dropped by the animal on the soil.At the same time.the deer is food for the mountain lion. Insects may live on the juices of plants or gather pollen from their flowers.Other insects suck blood from animals.Bacteria may live on the internal tissues of animals and plants.Fungi degrade the bodies of dead plants and animals.All this,many times multiplied and organized species by species in intricate,precise relationships,makes up the vast network of life on the earth.2每个生物物种也与许多其他的物种相联系。
水能,潮汐能,波浪能基础知识PPT(英文版)
• Head (H) – m • Gravity (g) – 9.8 m s-2
• Density of water – approx 1000 kg m-3
• Efficiency (η) – between 0 & 1 (Greek letter “eta”)
More recently
• Hydro power was part of nation-building strategies and a quest for energy autonomy and independence in postcolonial states
• The growing social impacts of large dams, often funded by the World Bank and other ‘development agencies’ led to the World Commission on Dams, and its recommendations for better planning, especially involving greater public participation in decisions, mitigation and compensation
• Hugely important in industrial revolution
• First hydro-electric power plant generated 12.5 kW and was built in Appleton, Wisconsin in 1882
Hydroelectricity – various technologies
博世家用洗衣机维修保养手册说明书
PROFESSIONAL LAUNDRYWasher extractorWH6-6Images shown are a representation of the product only and variations may occur.Certified with CB certificate for Low Voltage Directive and S-mark according to the Machinery Directive. Protection class IP X4D.Washer featuring exceptional savings and effortless use Priority on peopleCertified ergonomic design with a human-centered approach for an outstanding user expe-rience• Compass Pro® microprocessor offers large display and one control knob for easy pro-gram and language selection, as well as quick selection and option buttons for the most frequently used wash programs and options• Wash program packages optimized on Economy, Perfomance and Time. (Available on general programs)• Four compartment detergent box for flexibility of manual dosing of powder or liquid detergent• Professional door with gasket and strong hinges built for heavy duty operation and hy-giene Long-term savingsInnovative features designed for lowest possible water, energy and detergent consumption, to save money and time, and embrace a sustainable lifestyle • Programs optimized for lowest water, energy and detergent consumption • High extraction force for efficient dewatering• Automatic Savings weighs the linen and adjusts the water level to the amount of linen, saving water and energy at less than full load• Power Balance measures, corrects the unbalance and adjusts the G force in real time, maximizing the dewatering, saving money and time in the drying processPure controlMonitoring of the status of the equipment and performance from anywhere, allowing to take action to improve the business•Connectable to OnE Laundry, the personal assistant for hygiene validation, process management and revenue managementGlobal Advanced HygieneGlobal Advanced Hygiene program package* with proven log 6 reduction** disinfection of textiles through the laundry process, fulfilling the criteria of all local approved standards Main options and accessories• Automatic liquid detergent supply (optional I/O board)• Efficient Dosing interface and pumps, ensures that the precise amount of chemicals will be added automatically according to the weight of the load, saving chemicals • Connection to booking- /payment- system or coin meter • Drain pump•Stacking kit to install tumble dryer TD6-6 and TD6-7 on top to save space* Programs available in the standard library of all products, excluding products for specific segments where water temperature is not controllable.** Log 6 reduction equals to 99,9999% viral infectivity reduction. The efficacy of reduction of SARS-CoV-2 and other pathogens in the process is confirmed byExperience the ExcellenceRearA r t. N o . 438913951E N /2022.03W e r e s e r v e t h e r i g h t t o a l t e r s。
地域气候差异的英语作文
地域气候差异的英语作文Title: Regional Climate Variations。
Climate is one of the most significant factors shaping the environment and influencing human activities across different regions of the world. The Earth's surface features a diverse array of climates, ranging from hot and arid deserts to frigid polar regions. These regional climate variations play a crucial role in determining the flora, fauna, and even the lifestyles of the inhabitants. In this essay, we will explore the diverse manifestations of regional climate differences and their impacts.Firstly, let us delve into the factors contributing to regional climate variations. The primary determinants include latitude, altitude, proximity to large bodies of water, ocean currents, and prevailing wind patterns. For instance, regions near the equator generally experience warmer temperatures due to direct sunlight, while polar regions remain cold throughout the year owing to theirdistance from the sun. Moreover, areas situated close to oceans or seas tend to have milder climates due to the moderating effect of water bodies, whereas inland regions often exhibit more extreme temperature fluctuations.Now, let's examine some notable examples of regional climate variations across the globe. The Sahara Desert in Africa represents an extreme arid climate, characterized by scorching temperatures and minimal precipitation. Contrastingly, the Amazon Rainforest in South America boasts a tropical climate with abundant rainfall and lush vegetation. Moving towards the polar regions, the Arctic experiences bitterly cold temperatures and long winters, whereas Antarctica is known for its ice-covered landscape and subzero conditions year-round.These climate differences profoundly influence the ecosystems and human societies inhabiting these regions. In arid climates like the Sahara, vegetation is sparse, consisting mainly of drought-resistant plants such as cacti and succulents, while desert-adapted animals like camels thrive in these harsh conditions. Conversely, the AmazonRainforest supports unparalleled biodiversity, with dense vegetation providing habitat for countless species of plants and animals. Polar regions are home to unique fauna such as polar bears and penguins, specially adapted to survive in freezing temperatures and icy environments.Furthermore, regional climate variations have significant implications for human activities and livelihoods. Agricultural practices, for instance, are heavily influenced by climate conditions. In temperate regions with fertile soil and adequate rainfall, farmers can cultivate a variety of crops throughout the year, supporting food security and economic development. However, in arid or semi-arid regions, water scarcity and desertification pose formidable challenges to agriculture, necessitating innovative irrigation methods and drought-resistant crop varieties.Moreover, regional climate variations impact various sectors such as tourism, energy production, and infrastructure development. Coastal regions vulnerable to hurricanes and tropical storms must invest in robustdisaster preparedness measures, while countries reliant on hydropower face fluctuations in energy output due to changing precipitation patterns. Additionally, urban planning initiatives must consider climate resilience and adaptation strategies to mitigate the impacts of extreme weather events and rising temperatures.In conclusion, regional climate variations are a defining characteristic of our planet, shaping landscapes, ecosystems, and human societies in diverse ways. From the blistering deserts of Africa to the frozen expanses of Antarctica, each region's climate tells a unique story of adaptation and resilience. Understanding these climate differences is essential for addressing environmental challenges, promoting sustainable development, and fostering global cooperation in combating climate change. By appreciating the rich tapestry of regional climates, we can work towards a more resilient and harmonious relationship with our natural world.。
小学上册第2次英语第6单元全练全测
小学上册英语第6单元全练全测英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.I feel ______ when I achieve my goals.2.What do we call a person who studies marine life?A. Marine BiologistB. EcologistC. ZoologistD. BiologistA3.What is the name of the famous artist known for his paintings of water lilies?A. Claude MonetB. Vincent van GoghC. Pablo PicassoD. Henri MatisseA4.I have a _____ (feather) from a bird.5.What do we call the force that pulls objects toward the Earth?A. MagnetismB. GravityC. FrictionD. Pressure6.What do we call a young seal?A. PupB. CalfC. KitD. ChickA Pup7.The chemical symbol for europium is ______.8.My aunt loves __________ (参加社会活动).9.We are going to the ___. (concert) tonight.10.The _______ (The Great Wall of China) was built over centuries.11.What do we call the first manned mission to land on the moon?A. Apollo 11B. Gemini 4C. Mercury 7D. Voyager 1A12.What do we call the process of buying and selling goods?A. TradeB. CommerceC. BusinessD. EconomyB13. A ladybug is a ______ (小虫) that brings good luck.14.The _______ (小金丝雀) chirps happily in its cage.15.I enjoy _______ (做手工) projects.16.The bison roams in the _____.17.The _______ of an object can change based on its position.18.I enjoy playing with my ________ (拼图游戏) on weekends.19.What is the primary color of a peacock's feathers?A. BlueB. GreenC. RedD. Yellow20. A ______ (海豚) can leap high out of the water.21. A squirrel's front paws are used for ______ (抓取).22.What do we call a story with magical elements?A. FictionB. FantasyC. RealityD. Non-fiction23.The dolphin loves to _______ (跳跃) out of the water.24.My uncle is a __________ (飞行员).25.My sister enjoys __________ (文学创作).26.________ (兰花) are known for their beauty.27. A hedgehog can curl into a _______ (球) when scared.28.The flowers are ______ in bright colors. (blooming)29.What is the capital of Finland?A. HelsinkiB. OsloC. StockholmD. ReykjavikA30.What do you call a young cheetah?A. CubB. KitC. PupD. FawnA31.The antelope can run very ____.32.In which direction does the sun rise?A. NorthB. SouthC. EastD. WestC33.What do we call the event when the moon passes in front of the sun?A. Lunar EclipseB. Solar EclipseC. Full MoonD. New MoonB34.What is the opposite of "day"?A. NightB. MorningC. EveningD. DawnA35.The ________ is an animal that jumps high.36.My brother has a ______ (小马). He takes care of it every ______ (天).37. A reaction that produces a change in color indicates a ______ reaction.38.What do we call the process of separating mixtures based on size?A. FiltrationB. DistillationC. ChromatographyD. SiftingA39.I see a ___ (cloud/rainbow) above.40.Which food is made from milk?A. BreadB. CheeseC. RiceD. Vegetables41.What do you wear to keep your head warm?A. GlovesB. HatC. ScarfD. BeltB42.The mantis shrimp has powerful ________________ (爪).43.We have a ______ (精彩的) plan for the upcoming festival.44.What color do you get when you mix red and white?A. PinkB. PurpleC. BrownD. Orange答案:A45.I enjoy __________ with my friends. (聊天)46.What do we call the shape of a triangle?A. RoundB. FlatC. AngularD. CurvedC47.My sister's favorite color is ______ (粉红色). She has many ______ (玩具).48.中国的________ (mythology) 描述了许多神话和传说。
初二英语形容词比较级最高级特殊用法练习题30题
初二英语形容词比较级最高级特殊用法练习题30题1<背景文章>There are three different cities with very distinct weather conditions. City A is known for its mild climate. The summers are not too hot and the winters are not too cold. In fact, it is often said that City A has the ___1___ winters among the three cities. City B, on the other hand, has extremely hot summers and relatively mild winters. People often compare the temperatures of City B to those of City A and City C. It is clear that City B has the ___2___ summers. City C has a more diverse climate. It can be very cold in the winter and quite warm in the summer. When comparing all three cities, it can be concluded that City C has the ___3___ temperature variations.In general, the weather in these three cities is always a topic of conversation. People who live in City A enjoy the moderate climate and often say it is the most pleasant place to live. Those in City B love the heat and the energy that comes with it. And people in City C appreciate the different seasons and the variety of weather they experience.The three cities also have different levels of precipitation. City A gets a moderate amount of rain throughout the year. City B has less rain, especially during the summer months. City C has the ___4___ rainfallduring the spring.Overall, each city has its own unique weather characteristics, and people can choose the city that suits their preferences best.1. A. warmest B. colder C. mildest D. coolest2. A. hottest B. coldest C. milder D. wettest3. A. smallest B. least C. greatest D. fewest4. A. most B. least C. fewer D. smaller1. C。
关于太阳正能量英语作文
关于太阳正能量英语作文The Positive Energy of the Sun: A Vital Force for Life.The sun, an incandescent celestial body, is the central figure of our solar system, providing the Earth with warmth, light, and sustenance. Its immense energy has been harnessed by humans for centuries, both directly and indirectly, shaping our civilizations and driving technological advancements. Beyond its physical contributions, the sun also holds symbolic andpsychological significance, inspiring art, literature, and spiritual beliefs.A Source of Energy.Foremost, the sun is an inexhaustible source of energy. Its nuclear fusion reactions, where hydrogen atoms combineto form helium, release vast amounts of radiant energy that travels through space as electromagnetic waves, including visible light and ultraviolet radiation. This energy makeslife on Earth possible, providing the primary source of heat and illumination.Plants utilize sunlight through photosynthesis, converting carbon dioxide and water into glucose, the fundamental building block of life. This process releases oxygen, which is essential for respiration and sustains the entire food chain. Animals, including humans, indirectly depend on the sun's energy by consuming plants or other animals that have consumed plants.Moreover, solar energy can be harnessed directly for practical applications. Solar panels, for instance, convert sunlight into electricity, providing a clean and renewable source of power. This technology has become increasingly prevalent as concerns about climate change and fossil fuel depletion grow.A Regulator of the Earth's Climate.The sun's energy also plays a pivotal role inregulating the Earth's climate. The amount of solarradiation reaching the Earth's surface varies throughout the day, year, and over longer periods, such as ice ages and warmer periods. These variations drive the Earth's weather patterns and influence long-term climate trends.The sun's energy warms the oceans, driving currentsthat distribute heat around the globe. It also evaporates water from the oceans, creating clouds and precipitation, which in turn water plants and replenishes freshwater resources.A Psychological and Spiritual Force.Beyond its physical manifestations, the sun has a profound psychological and spiritual impact on humans. Its golden rays have been associated with warmth, joy, and hope throughout history. The sun's daily cycle has inspired religious beliefs and rituals, representing renewal, rebirth, and the cycle of life.Exposure to sunlight has been found to have positive effects on mood, sleep, and overall well-being. Sunlightstimulates the production of serotonin, a neurotransmitter associated with happiness and tranquility. It also helps regulate the body's circadian rhythms, which influencesleep-wake cycles.In many cultures, the sun is seen as a symbol of divine power, wisdom, and enlightenment. Its radiance has been likened to the illumination of knowledge and understanding. The sun's presence in art, literature, and philosophy represents a connection to the divine, the search for truth, and the aspirations of humanity.Conclusion.The sun, a celestial force of immense power, providesthe Earth with the energy that sustains life. It regulates the climate, nourishes plants, and inspires humans. Beyond its physical and practical contributions, the sun holds symbolic and psychological significance, representing warmth, hope, and enlightenment. As we continue to explore and understand the sun's influence on our planet and ourlives, we come to appreciate the profound and multifaceted power of this celestial energy source.。
Wind Energy
Wind Energy -- Energy from Moving AirWind is simple air in motion. It is caused by the uneven heating of the earth surface by the sun. Since the earth surface is made of very different types of land and water, it absorbs the sun heat at different rates.During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air rushes in to take its place, creating winds. At night, the winds are reversed because the air cools more rapidly over land than over water.In the same way, the large atmospheric winds that circle the earth are created because the land near the earth's equator is heated more by the sun than the land near the North and South Poles.Today, wind energy is mainly used to generate electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines.The History of WindSince ancient times, people have harnessed the winds energy. Over 5,000 years ago, the ancient Egyptians used wind to sail ships on the Nile River. Later, people built windmills to grind wheat and other grains. The earliest known windmills were in Persia (Iran). These early windmills looked like large paddle wheels. Centuries later, the people of Holland improved the basic design of the windmill. They gave it propeller-type blades, still made with sails. Holland is famous for its windmills. American colonists used windmills to grind wheat and corn, to pump water, and to cut wood at sawmills. As late as the 1920s, Americans used small windmills to generate electricity in rural areas without electric service. When power lines began to transport electricity to rural areas in the 1930s, local windmills were used less and less, though they can still be seen on some Western ranches.The oil shortages of the 1970s changed the energy picture for the country and the world. It created an interest in alternative energy sources, paving the way for the re-entry of the windmill to generate electricity. In the early 1980s wind energy really took off in California, partly because of state policies that encouraged renewable energy sources. Support for wind development has since spread to other states, but California still produces more than twice as much wind energy as any other state.The first offshore wind park in the United States is planned for an area off the coast of Cape Cod, Massachusetts (read an article about the Cape Cod Wind Project).How Wind Machines WorkLike old fashioned windmills, today wind machines use blades to collect the wind kinetic energy. Windmills work because they slow down the speed of the wind. The wind flows over the airfoil shaped blades causing lift, like the effect on airplane wings, causing them to turn. The blades are connected to a drive shaft that turns an electric generator to produce electricity.With the new wind machines, there is still the problem of what to do when the wind is blowing. At those times, other types of power plants must be used to make electricity.Wind Power PlanWind power plants, or wind farms as they are sometimes called, are clusters of wind machines used to produce electricity. A wind farm usually has dozens of wind machines scattered over a large area. The Big Spring Wind Power Project in Texas has 46 wind turbines that generate enough electricity to power 7,300 homes.Unlike power plants, many wind plants are not owned by public utility companies. Instead they are owned and operated by business people who sell the electricity produced on the wind farm to electric utilities. These private companies are known as Independent Power Producers.Operating a wind power plant is not as simple as just building a windmill in a windy place. Wind plant owners must carefully plan where to locate their machines. One important thing to consider is how fast and how much the wind blows.As a rule, wind speed increases with altitude and over open areas with no windbreaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.Wind speed varies throughout the country. It also varies from season to season. In Tehachapi, California, the wind blows more from April through October than it does in the winter. This is because of the extreme heating of the Mojave Desert during the summer months. The hot air over the desert rises, and the cooler, denser air above the Pacific Ocean rushes through the Tehachapi mountain pass to take its place. In a state like Montana, on the other hand, the wind blows more during the winter. Fortunately, these seasonal variations are a good match for the electricity demands of the regions. In California, people use more electricity during the summer for air conditioners. In Montana, people use more electricity during the winter months for heating.Wind ProductionAll together, wind machines in the United States generate 17 billion kWh per year of electricity, enough to serve 1.6 million households. This is enough electricity to power a city the size of Chicago, but it is only a small fraction of the nation's total electricity production, about 0.4 percent. The amount of electricity generated from wind has been growing fast in recent years, tripling since 1998.New technologies have decreased the cost of producing electricity from wind, and growth in wind power has been encouraged by tax breaks for renewable energy and green pricing programs. Many utilities around the country offer green pricing options that allow customers the choice to pay more for electricity that comes from renewable sources.Wind machines generate electricity in 30 different states. The states with the most wind production are California, Texas, Minnesota, Iowa, and Wyoming.The United States ranks third in the world in wind power capacity, behind Germany and Spain. Most of the wind power plants in the world are located in Europe and in the United States where government programs have helped support wind power development.Wind and the EnvironmentIn the 1970s, oil shortages pushed the development of alternative energy sources. In the 1990s, the push came from a renewed concern for the environment in response to scientific studies indicating potential changes to the global climate if the use of fossil fuels continues to increase. Wind energy offers a viable, economical alternative to conventional power plants in many areas of the country. Wind is a clean fuel; wind farms produce no air or water pollution because no fuel is burned.The most serious environmental drawbacks to wind machines may be their negative effect on wild bird populations and the visual impact on the landscape. To some, the glistening blades of windmills on the horizon are an eyesore; to others, they are a beautiful alternative to conventional power plants.。
水的三态变化 英文版
Changes in three states of water【Teaching objectives】Scientific concept：1、There are various forms of water in nature——Clouds, fog, rain, dew, frost, snow, ice, water vapor……That means water in nature in both liquid, solid and gaseous presence。
2、Water in the natural world constantly undergoing changes in the cycle of three states，The three-state changes to promote water because of temperature changes.Process and Methods：1、Recall or observe the various forms of water in nature - clouds, fog, rain, dew, frost, snow, ice, water vapor ... ... discussions between them, changing causes and conditions.2, seeking the water varies between gaseous and solid evidence, try to design their own water, gas and solid-state changes observed between the experiments.3, analysis of water between the various states of change in the process of finishing generalthree-state variation of the water.4, think about the nature of water-related issues, and try to use "the water tri-cycle" to explain this phenomenon.Emotions, attitudes, values：1, recognizing the observational data (evidence) on the meaning and value of scientific research. 2, preliminary identification of material is constantly changing.3, the initial establishment of the material eternal point of view.【Teaching points】aware of water in various states of nature can be changed with each other.【Education】difficult on the water between the three-state transformation of an explanation.【Teaching Preparation】Group: Water morphological changes of the process and changes have occurred in the discussion record form;Class: a plastic cup, a cup of ice, salt; clouds, fog, rain, dew, frost, snow, ice and other natural phenomena of the picture or image data.【Teaching process】First, the introduction of the subject1, the conversation into: play video small water people (design intent: shock of fun, and lead to student motivation for learning)2, after reading the students think: There are several small water change of state people? (Gaseous, liquid and solid)3, located the suspect: water among these three states can change into each other do? Today, teachers and students together to explore the water on a three-state changes (courseware to expose problems, and writing on the blackboard)Second, new lesson Teaching(A) recalled the existence of water in the form of nature and discuss the morphological changes of the water course and changed the conditions of1, courseware were various forms of water to produce pictures of the students according to morphological changes of the water of life experience, he said the name, status, and produced what season or time of day to see such issues as the initial knowledge and understanding of various forms of water . (Design intent: It is to break the focus of this lesson for students to solve a variety of morphological changes of water occurred in terms of the process and pave the way)2, courseware production of a "morphological changes of the water course and changed conditions" for the students individually think 2 minutes.(Design intent: to provide students with room for thinking, know what problems can be themselves and what can not. To enable the Panel cooperation is not a mere formality, to reduce the blindness of the discussion.)3, distribution of forms, learn warm Tip: four-member team note that division of labor, we can discuss together to accomplish the task form (2 - 3 form of water), by the head of a representative of the record, heard the music sound to stop the discussion . A comparison and which team best able to first to complete this challenge.(Design intent: Each panel discussion on the completion of 2 - 3 on the water conditions, analysis of morphological changes and changes in the purpose is to reduce the degree of difficulty, both within the group reflects the cooperation and reflects the group and group co-operation.)4, students discuss their process of change and the outbreak of the conditions and to fill out the form issued by the teacher.5, the exchange of teachers and students together. The completion of courseware in the table (the default may be frost and snow are not necessarily to answer the students draw and produce well in advance of the cream cup presented to us, if the students that came out on the strong praise) (B), the tri-state cycle of water1, we performed very well, here we are, under a sound easy to see animated segment, "Why would rain"2, After reading the answer the following questions (courseware to produce). Side of the answer, while the three-state summary of the water change maps. Small water droplets and the earth will be a friend to meet? (Would be so, on the form of rain or snow, hail, etc., a hyperlink to the table slides into the slide.) Together with the completion of the tri-state water cycle diagram. (Design intent: water, three-state variation is the difficulty of this lesson, students independently completed a certain degree of difficulty, so a summary of teachers and students a common understanding of their three-state cycle of water preliminary knowledge and understanding.)2 students to think: What caused the water of the tri-state change? (Heat or the temperature of the water caused by the change of tri-state changes)3 students to think and to be able to explain why the total does not overflow the oceans, rivers,streams of water have been do not finish? (Water cycle) Student Exchange courseware after the flash presentation.Third, summary and extra-curricular classes to expand1, Summary of questions: Learning this chapter, what do you pick up? And then produce a summary of the content of courseware2, extra-curricular exploration (courseware demonstrate the problem): nature, whether, as other substances, like water, there are three-state change? The three states with a substance such as water-like at the same time be able to exist?4, Blackboard Design Changes in three states of waterGaseousLiquid Solid5, teaching reflection"Water's three-state changes" are "changes in temperature and water" is a summary and synthesis of the learning module. Student in front of learning, have already accumulated some experience. So I teaching this lesson focus on:1, recall or observation of water in various forms in nature: clouds, fog, rain, dew, frost, snow, ice, water vapor ... ...2, analyze the processes of change among the various states, organize general three-state variation of the water. Let the students know the three states of water, under certain conditions, could be another change. This lesson is the difficulty of teaching the three states of water between the transformation of an explanation.。
The Impact of Climate Change on Water Resources
The Impact of Climate Change on Water ResourcesClimate change is a phenomenon that has been affecting the world for many years. One of the significant impacts of climate change is the disruption of water resources. Water is a vital resource for human life, and its scarcity can cause serious problems for human survival. This essay will discuss the impact of climate change on water resources from multiple perspectives.From a scientific perspective, climate change has caused a significant change in the water cycle. The increase in temperature has led to more evaporation, which causes more water to be in the atmosphere. This has resulted in more frequent and intense rainfall, leading to more flooding in some areas. On the other hand, some regions are experiencing more extended periods of drought due to decreased rainfall. This change in the water cycle has caused a significant impact on water resources, making it difficult for communities to plan and manage their water supply.From an economic perspective, the impact of climate change on water resources has been significant. The disruption of water supply has led to increased costs of water supply and treatment. The cost of water treatment has increased due to the need for more advanced treatment processes to remove pollutants and contaminants from water sources. Additionally, the cost of water supply has increased due to the need for more extensive infrastructure to transport water from areas with abundant water resources to areas with water scarcity.From a social perspective, the impact of climate change on water resources has been devastating. The disruption of water supply has led to increased health problems, particularly in developing countries. The lack of clean water has led to the spread of waterborne diseases such as cholera and typhoid fever, leading to increased mortality rates. Additionally, the scarcity of water has led to conflicts between communities and even countries, particularly in regions with shared water resources.From a political perspective, the impact of climate change on water resources has been significant. The need to manage water resources has become a political issue, with countriesand communities competing for access to water resources. Climate change has also led to the need for more extensive international cooperation to manage shared water resources. The need for cooperation has led to the development of international agreements, such as the United Nations Convention on the Law of the Non-Navigational Uses of International Watercourses.From a personal perspective, the impact of climate change on water resources has been significant. The disruption of water supply has affected the daily lives of people, particularly those living in water-scarce areas. The lack of access to clean water has led to increased health problems, making it difficult for people to work and go about their daily lives. Additionally, the impact of climate change on water resources has led to increased anxiety and stress among people, particularly those living in areas prone to flooding and drought.In conclusion, the impact of climate change on water resources has been significant from multiple perspectives. The disruption of water supply has affected the environment, economy, society, politics, and personal lives of people. It is, therefore, essential to take action to mitigate the impact of climate change on water resources. This can be achieved through the development of sustainable water management practices, the reduction of greenhouse gas emissions, and the promotion of international cooperation to manage shared water resources.。
利用测井资料计算储层压力
利用测井资料计算储层压力曾科（大庆石油学院）摘要油田进行注水开发后，地层的压力会出现三大矛盾。
这些问题是调整井套损的主要原因。
为了解决这一问题，就必须清楚地了解地层的压力。
为此，本文研究了地层压力和测井资料的关系，通过9口RFT测试井93个小层孔隙压力测试结果与水淹层测井系列测井信息之间关系的研究，利用统计回归，形成了一套萨北开发区利用水淹层测井资料定量计算地层压力的理论模型。
提高了利用测井资料计算地层压力的准确程度。
AbstractAfter water flooding oil reservoir, the formation of pressure there will be three major contradictions. The problems are of predominant reason for well casing damage of matching well. Therefore the paper research relation between strata pressure and log reading. By studying the relation between test data of ninety-three small stratum and well-logging data with logging unit of water-out interval logging series of nine RFT test well, with statistical regression we come into being three theory models making use of log reading of SaBei developing district water-out interval.To improve the calculation accuracy of the formation pressure using logging data.前言利用测井资料对已注水开发的砂岩油田调整井的地层孔隙压力进行预测，这是油田地质、工程技术人员普遍关心的问题。
Series e420 HydroGuard 自动水温混合器说明书
IS-P-e420Advanced Thermal ActivationFAILURE TO COMPLY WITH PROPER INSTALLATION AND MAINTENANCE INSTRUCTIONS COULD CONTRIBUTE TO THE VALVE FAILURE, RESULTING IN INJURY AND/OR DEATH.TO ENSURE THE ACCURATE AND RELIABLE OPERA- TION OF THIS PRODUCT, IT IS ESSENTIAL TO:• P roperly design the system to minimize pressure and temperature variations.• C onduct an annual maintenance program to ensure proper operation of all critical components.WARNING!Installation n2Figure 3:NOTE: Installation should be in accordance with accepted plumbing practices. Flush all piping thoroughly before installation. Failure to do so can result in a valve malfunction.TO INSTALL 1 . P osition mixing valve 2 3/4" ±3/8" (69mm ± 10mm) from inlet center to finished wall surface. For reference a rough-in guide is provided, ensure it is pushed on fully and the valve is closed when positioning valve. The tub outlet port is marked TUB” and should face down. Facing the front of the mixing valve, connect hot water to left side and connect cold water to right side. The mixing valve has “C” and “H” cast into the body near the appropriate ports. Inlets and outlet connections must be piped correctly for proper operation of valve. If hot and cold water connections are reversed, valve will not func-tion properly. 2. F or tub and shower installations , see Figure 1. Pipe bottom outlet port “TUB” directly to the diverter tub spout. The mixing valve is designed to operate without the use of a twin ell. Pipe top outlet port “S” to the showerhead. 3. F or shower only installation , see Figure 2. Pipe top outlet port “S” directly to the showerhead and plug bottom port.CAUTION: When soldering during the installation process, do not heat the valve any higher than the temperature required to flow solder. Excessive overheating of the valve may cause damage to the valve internals. By following this recommendation, you will be able to solder the valve without removing either the cartridge or the checkstops inter-nals. If either brazing or resistance (electric) solder is used, all check- 4. T urn hot and cold water supplies on and verify there are no leaks. 5.R ough-in guide installation a. B efore strapping the pipes and before completing the finishedwall, slide rough-in guide onto the mixing valve stem and press fit into place, see Figure 3. (valve stem must be rotated fully clockwise).b. T he rough-in guide will insure the proper size opening andlocation of the finish wall.6. A fter finished wall is completed, remove rough-in guide to allow installation of the trim. 7 . P eel off backing of dial gasket and attached it to the inside top edge of dial plate. Make sure gasket is approximately 1/16" beyond the plate edge.8.H old plate firmly against the wall. Thread sleeve on the bonnet mak-ing sure that the cut away on the sleeve is towards you and is in the bottom position when tightened. Do not use any tool to tighten which will scratch the sleeve surface. 9. I nstall handle with the screw provided.10.M aximum temperature setting adjustment (Figure 4) must be set on the job. The high temperature limit stop is threaded into the bonnet and is turned counter clockwise for an increased setting and clock-wise for a decreased setting. Powers recommends a maximum setting of 110°F (43°C). To adjust temperature, rotate handle to the maximum desired outlet temperature, screw temperature limit stop until it touches stem’s shoulder. Close valve and open it to verify setting.Operation cont. nto the outlet. If the hot or cold supply water temperature or pressurechanges, the thermal actuator will contract or expand. This movement repositions the shuttle to maintain the desired temperature. With the adjustment handle in full clockwise (OFF) position, the shutoff disc closes the mixing chamber from the outlet.A temperature limit stop limits the movement of the control handle. The standard HydroGuard ® e420 valve is factory set to deliver tempered water up to 110°F [43°C] with equal supply pressures, with hot water temperature 140°F [60°C], cold water temperature 60°F [15.6°C]Preventative Maintenance n3Servicing nT o Disassemble:1.T urn off hot & cold water supply-stops 2. Remove the handle and trim plate3. Remove 4 bonnet screws and bonnet assembly4. Remove all internal components from valve body5. At this point you should have an empty valve body.WARNING: After completing any maintenance/repairs, reset the high temperature limit stop.T o Reassemble:1. E nsure the inside of the valve body is free of deposits and debris. Clean as necessary.2. P ush the cartridge into the body without the “O” rings installed. The cartridge should slide in easily, and bottom out with its large fins just inside the front surface of the casting. If the cartridge is difficult to install, or does not go in all the way, remove the cartridge and clean the body or remove any obstructions. Repeat this step until the car-tridge installs easily.3. R emove the cartridge and install the 2 “O” rings. Lubricate the “O” rings with silicon lubricant.4. I nstall the cartridge back into the body. The cartridge should go in until the large fins are just inside the front surface of the casting (same position as in step 2).If you cannot push it in all the way due to O-rings, use bonnet and two (2) screws to force in.5. P lace the wax element into the stem assembly, stem side first, and place this bonnet-stem-motor assemblyinto/onto the valve body. Rotate the bonnet assembly to line up the bonnet screw holes and reinstall and tighten the four bonnet screws.6.W ith handle, rotate the stem assembly clockwise, until it bottoms out on the cartridge. At this point your valve is in the off position.7. T urn the hot and cold water supplies back on and verify there is no leakage.8.V erify proper operation by rotating the stem from the off position, counterclockwise, to the high temperature position. Verify the temperature does not exceed your desired maximum tem-perature. Rotate stem back to the off position.9.L eave the adjusting stem in the full hot position to determine the high temperature limit stop is setproperly. If not, rotate clockwise or counterclockwise, decrease or increase the high temperature limit stop respectively. Powers rec-ommends a maximum setting of 110°F (43°C).10.I nstall handle with the screw provided onto the stem and tighten in place. Ensure that the set screw lines up with the groove on the adjustment stem.NOTE: Before servicing checkstops or piping, always turn off the upstream water supply.EVERY 12 MONTHS:Open up the checkstops and check for free movement of the poppet. To access the checkstops, remove the valve handle assembly and dial plate.Before servicing, turn off the water supply upstream.To close the checkstops, turn the adjustment screw fully clockwise on each checkstop.Remove the valve bonnet and rinse all grit and impurities from the internal components.Winterize valves that are used outdoors. Remove and store the internal components and drain all water from the valve.EVERY 3 MONTHS:Every three months, check the maximum temperaturesetting (handle rotation setting).Safety Guidelines - All Models nAdherence to these guidelines and recommendations promotes safe product use and ensures proper valve performance.1. T hermostatic water mixing valves are control devices which must be cleaned and maintained on a regular basis. Powers specifies period-ic maintenance at least once a year or immediately after any chang-es are made to the plumbing system. Annual cleaning and inspection is recommended, however, frequency of cleaning depends on quality of local water conditions. Refer to the Preventive Maintenance sec-tion for recommended cleaning procedure.2. W ARNING: To prevent injury to the user, it is important to periodi-cally check the maximum temperature adjustment on the valve.3. Q uick closing valves may cause damage to the mixing valve by cre-ating shock waves. When the HydroGuard ® supplies tempered waterto self-closing and/or solenoid valves, Powers recommends install-ing a shock absorber (Powers Part #460-353) on the discharge line, which will protect the HydroGuard ® from damage.4. P osition the e420 valve as close as possible to outlet fixture to avoid waste of energy and water (except in applications where the valve is used as a primary mixing valve).IS-P-e420 1045 EDP# 6511214© 2010 PowersA Watts Water Technologies CompanyT roubleshooting nnThe Seller warrants that the equipment manufactured by it and covered by this order or contract is free from defects in material and workmanship and, without charge, equipment found to be defective in material or workmanship will be repaired, or at Seller’s option replaced F .O.B. original point of shipment, if written notice of failure is received by Seller within one (1) year after date of shipment (unless specifically noted elsewhere), provided said equipment has been properly installed, operated in accordance with the Seller’s instructions, and provided such defects are not due to abuse or decomposition by chemical or galvanic action. ThiS expreSS warranTy iS in lieu OF and excludeS all OTher warranTieS, guaranTeeS, Or repreSenTaTiOnS, expreSS OF implied. T here are nO implied warranTieS OF merchanTaBiliTy Or OF FiTneSS FOr a parTicular purpOSe. T he Seller assumes no responsibility for repairs made on the Seller’s equipment unless done by the Seller’s authorized personnel, or by written authority from the Seller. T he Seller makes no guarantee with respect to material not manufactured by it.What to look for if:The maximum temperature cannot be obtained...a.L ime deposits may have accumulated in the hot water pipes, restrict-ing the hot water supply.b. The hot water supply temperature may be too low.c. T he temperature limit stop setting may be too low. Remove valve handle, and readjust the temperature limit stop.Flow of water is less than desired…a. The upstream supply valves may not be fully open.b. The inlet supply pressure(s) may be low.c. L ime deposits may have accumulated in cartridge, restricting water flow.d. The showerhead may be clogged. Remove and clean.e. T he checkstops may be clogged. Clean check stops.The valve opens with hot water flow rather than cold water flow...a. T he inlet water supplies are connected to the wrong ports. Remove the valve and reinstall.Flow of water is completely shut off...a.T he upstream supply valves may be completely closed.b.T he hot or cold water supply pressure may have failed. The HydroGuard ® 420 valve is designed to reduce the flow of water upon either supply failure.c. T he checkstops may be closed. Access the checkstops and open by turning the adjustment screw fully counterclockwise.。