A photoswitchable methylene-spaced fluorinated aryl azobenzene

小学上册英语第6单元期中试卷英语试题一、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.What do we call a large landmass surrounded by water?A. IslandB. PeninsulaC. ContinentD. Archipelago答案:C2.My cousin is a ______. She loves to create digital art.3.My dog loves to _______ (与我一起玩) fetch.4.What is the name of the famous character created by J.K. Rowling?A. Frodo BagginsB. Harry PotterC. Katniss EverdeenD. Percy Jackson答案:B Harry Potter5.What do we call the time before noon?A. AfternoonB. EveningC. MorningD. Midnight答案:C6.The _______ (猫) chases after the laser dot.7.I like to invite friends over to play with my __________ (玩具名).8. A base tastes _____ and can turn red litmus paper blue.9.What do we call the act of giving up something for someone else?A. SacrificeB. GenerosityC. KindnessD. Charity答案:A10.My brother is a ______. He enjoys playing basketball.11.I enjoy riding my ______.12. have sharp ______ (牙齿) for cracking nuts. Storms c13.The capital of Turkey is __________.14.The symbol for bismuth is _____.15.My friend is a talented __________ (画家).16.I like to _______ (study) science.17.The teddy bear is my _______ (favorite).18.We had a picnic by the ______ (river).19.I enjoy _______ (watching) nature documentaries.20. A ____ is a small reptile that basks in the sun.21.I want to be a ______ (vet) to help animals.22.What do we call the season when flowers bloom?A. WinterB. SpringC. SummerD. Fall答案:B23.The _______ of sound can create echoes in certain locations.24.Which animal is known for its ability to change color?A. ChameleonB. DogC. CatD. Fish答案:A25.What do we call a large body of freshwater surrounded by land?A. OceanB. LakeC. RiverD. Stream答案:B26.The state of matter that has a definite volume but no definite shape is ______.27.What do we call the process of water changing from liquid to gas?A. EvaporationB. CondensationC. FreezingD. Melting答案:A28.What do we call a person who plays a musical instrument?A. MusicianB. ComposerC. ConductorD. Singer答案:A Musician29.In ancient Greece, the people held __________ to honor their gods. (奥林匹克运动会)30.In _____ (摩洛哥), you can visit the Atlas Mountains.31.The bear is a powerful _____ animal.32.The chemical formula for hydrochloric acid is _______.33.What is the name of the event where people come together to celebrate a festival?A. GatheringB. PartyC. CeremonyD. Festival答案:D34.Which sport is played with a ball and a net?A. SoccerB. BasketballC. TennisD. All of the above答案:D35.The capital of Norway is __________.36.My _____ (堂兄) plays soccer every weekend.37.What do we call the stars and planets in the universe?A. GalaxyB. Solar SystemC. CosmosD. Constellation答案:C38. A lever can increase the ______ applied to an object.39.What do you call a collection of maps?A. AtlasB. DictionaryC. EncyclopediaD. Gazetteer答案:A40.He has a red _______ (玩具车).41.What is the name of the famous artist known for his "Starry Night" painting?A. Claude MonetB. Vincent van GoghC. Pablo PicassoD. Henri Matisse答案:B42.The ancient Egyptians built ________ (金字塔) as tombs.43.The _____ (butterfly/bird) is colorful.44.What do we call the movement of the Earth around the sun?A. RotationB. RevolutionC. OrbitsD. Cycle答案:B45.The stars are _____ in the night sky. (twinkling)46.The __________ (Columbus) sailed across the Atlantic in 1492.47.The _______ can illustrate the beauty of nature.48.The ancient Greeks held games every four years in ________.49. A ____(community initiative) promotes collective action.50.I saw a ________ flying high above.51.The reaction between vinegar and baking soda produces ______ gas.52.The ______ is known for its elaborate courtship dance.53.Which fruit is orange?A. BananaB. AppleC. OrangeD. Grape答案:C54.The measure of how much space an object occupies is called ______.55.What is the name of the bear that loves honey?A. PandaB. Polar BearC. Winnie-the-PoohD. Grizzly Bear答案:C56.The fish has bright _______ (颜色) that attract attention.57.The raccoon is known for its ______ (面具).58.The chemical symbol for radon is ______.59.She has a ________ for her birthday.60.The ________ was a significant event in the global historical context.61.ts release ______ (香氣) that can repel pests. Some pla62. A __________ (分子工程) focuses on designing new molecules for specific purposes.63.What do we call the study of weather?A. BiologyB. MeteorologyC. GeographyD. Astronomy64.environmental policy) guides government actions. The ____65.The _____ (电话) rings loudly.66.Chemical safety is important to prevent _____.67.What do we call a large, round object that orbits a planet?A. StarB. SatelliteC. CometD. Asteroid答案:B Satellite68.She is a good ___. (listener)69.The chemical formula for copper(II) sulfate is ______.70.The _____ (花瓶) holds flowers.71.I like to use my toy ________ (玩具名称) for learning.72.The Earth's atmosphere helps regulate ______.73.The rabbit's fur is very ________________ (柔软).74.They _____ (play/plays) soccer in the park.75. A bumblebee is important for _______ (授粉).76.The ocean is ________ (宽广).77.I enjoy reading books with my ____.78.We make _______ for lunch.79.My mom loves to plant ______ in the garden.80.The _____ (sky/ground) is blue.81.I can ___ (ride) a horse.82.The leaves change _______ in the fall, creating a lovely sight.83.What is the main language spoken in the UK?A. SpanishB. FrenchC. EnglishD. German答案:C84.The _______ of a pendulum can be demonstrated with a stopwatch.85.What is the term for a group of wolves?A. PackB. PrideC. FlockD. Herd答案:A86.I see _____ (birds/fishes) in the sky.87.My friend is very __________ (善解人意) and compassionate.88.They enjoy ________ together.89.The flamingo's color comes from its diet of ______ (甲壳类).90.What do you call a person who plays chess?A. Chess playerB. GambitC. StrategistD. Player答案:A91.My friend enjoys playing the ____ (drums).92.The apples are ________ (成熟的).93.Wildflowers bloom in _____ (开放的) fields.94.The ________ (bicycle) has two wheels.95.The capital of Angola is __________.96.I can ______ (理解) the importance of empathy.97.The country of Italy is shaped like a __________. (靴子)98.The _______ of a wave can be influenced by the properties of the medium.99. A ________ (地形) refers to the physical features of an area.100.What is the term for the distance around a circle?A. DiameterB. RadiusC. CircumferenceD. Area答案:C。

小学上册英语第一单元综合卷英语试题一、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 like to watch ________ in the summer.2.My favorite holiday is ________ (圣诞节). I like to decorate the ________ (圣诞树).3.My favorite book is ________.4.What do we call the place where you can buy groceries?A. StoreB. MarketC. MallD. Supermarket5.The _______ of a balloon can be affected by altitude.6.The _______ (兔子) hops around quickly when it is excited.7.What is the name of the game where you shoot hoops?A. SoccerB. BasketballC. BaseballD. TennisB8. A thermochemical reaction involves heat and chemical ______.9. (85) is a famous park in New York City. The ____10.The _______ (Apollo 11) mission successfully landed humans on the Moon.11.What is 100 - 25?A. 65B. 70C. 75D. 8012.What is the main ingredient in sushi?A. RiceB. NoodlesC. BreadD. PotatoesA13.The bear roams in the _____ woods.14.__________ are important for environmental sustainability.15.The chemical formula for table salt is ______.16.What is the capital of Honduras?A. TegucigalpaB. San Pedro SulaC. La CeibaD. CholutecaA17. A ______ (狗) has a keen sense of smell.18.The ancient Greeks created _______ to explain natural phenomena. (神话)19.The teacher, ______ (老师), guides us in our studies.20.The cake is _______ (刚出炉).21.The _____ (first) man-made satellite was Sputnik, launched by the USSR.22.The capital of Faroe Islands is __________.23.The __________ can provide critical insights into environmental health and stability.24.What do you call the place where we see many books?A. SchoolB. LibraryC. StoreD. Park25.What do you call the study of the Earth's atmosphere?A. MeteorologyB. GeologyC. AstronomyD. Ecology26.What is the term for the distance around a circle?A. AreaB. DiameterC. CircumferenceD. RadiusC27. A ___ (小蝴蝶) flutters gently in the air.28.My ________ (玩具) is made of plush material.29.What do we call the act of cleaning a room?A. TidyingB. OrganizingC. DeclutteringD. CleaningA30.What do we call the tool we use to write on paper?A. MarkerB. PenC. PencilD. All of the above31.The teacher gives _____ (作业) every week.32.The _______ of matter refers to whether it is a solid, liquid, or gas.33.What is the opposite of short?A. TallB. WideC. NarrowD. ThickA34.I like to play ___ (video games).35.I like to play ________ with my friends after school.36.My _____ (表妹) is visiting this weekend.37.The ________ was a famous treaty that settled disputes in Europe.38.What do you call the action of planting flowers in a garden?A. GardeningB. LandscapingC. CultivatingD. SowingA39.ts can live for ______ (数十年). Some pla40.My family lives near a __________ (水库).41.What is the opposite of right?A. WrongB. CorrectC. TrueD. AccurateA42.The _____ (羊) eats grass in the field.43.What is the term for a person who collects stamps?A. PhilatelistB. NumismatistC. CollectorD. HobbyistA44.Every year, we celebrate ______ (感恩节) with a big feast and share what we are thankful for.45.The ancient Egyptians created vast ________ (陵墓) for their pharaohs.46.I have a _____ (遥控车) that can go super fast. 我有一辆可以跑得非常快的遥控车。

泸州2024年11版小学英语第六单元真题考试时间：90分钟（总分:100）A卷考试人：_________题号一二三四五总分得分一、综合题(共计100题)1、填空题：Plants can be a source of ______ (灵感).2、选择题：What is the name of the famous geological feature in Arizona?A. Grand CanyonB. Yellowstone ParkC. Yosemite ValleyD. Zion National Park3、What is the main ingredient in guacamole?A. TomatoB. AvocadoC. PepperD. Onion4、听力题：The chemical symbol for chromium is ______.5、听力题：The cake is ________ and tasty.6、What is the hardest natural substance on Earth?A. GoldB. DiamondC. IronD. Silver7、ts have medicinal ______ that can help treat illnesses.(一些植物具有药用特性，可以帮助治疗疾病。

) 填空题：Some plaMy ___ (小兔子) loves to eat carrots.9、填空题：My favorite type of music is _______ (流行音乐).10、填空题：In ancient Rome, people watched __________ (角斗士) fight in the Colosseum.11、What do we call a young female seal?A. PupB. CalfC. KitD. Kid答案：A12、填空题：The _____ (植物生态策略) can guide land management practices.13、选择题：What is the main source of energy for plants?A. SoilB. WaterC. SunlightD. Air14、填空题：A ____(public space) encourages community interaction.15、填空题：The __________ (世界) is full of wonders.16、What is the opposite of empty?A. FullB. HalfC. LightD. Heavy答案:A17、What is the name of the famous festival celebrated in India?A. ChristmasB. DiwaliC. ThanksgivingD. Halloween答案: BAn alloy is a mixture of two or more __________.19、What is the name of the famous ocean current that affects weather patterns?A. Gulf StreamB. Antarctic CurrentC. Kuroshio CurrentD. California Current答案: A20、填空题：I like to go ______ (钓鱼) with my grandfather by the lake.21、听力题：My sister wants to be a ____ (vet) when she grows up.22、What is the visible surface of the sun called?A. CoreB. AtmosphereC. PhotosphereD. Chromosphere23、填空题：A _____ (小猫) is playing with a ball of yarn.24、填空题：I enjoy ______ (参与) in team sports.25、Which animal is known for its wisdom?A. DogB. OwlC. CatD. Elephant26、填空题：The __________ (文化遗产) is valuable to us.27、What is a group of three called?a. Pairb. Trioc. Quartetd. Quintet答案:b28、What is the capital of Italy?A. VeniceB. RomeC. FlorenceD. Milan29、听力题：His favorite sport is ________.30、What is the name of the famous bridge in San Francisco?A. Brooklyn BridgeB. Golden Gate BridgeC. Tower BridgeD. Sydney Harbour Bridge答案:B31、What is the term for a baby rabbit?A. KitB. CubC. FoalD. Pup答案:A. Kit32、What type of animal is a frog?A. MammalB. ReptileC. AmphibianD. Fish答案:C33、听力题：The ______ helps us learn about social entrepreneurship.34、听力题：The _______ can provide food and shelter for wildlife.35、听力题：A _______ can help visualize the concept of pressure in liquids.36、听力题：A __________ is a natural barrier that separates two areas.37、听力题：A solvent is a substance that dissolves a ______.38、听力题：The ________ (analysis) reveals important details.I enjoy learning about different ______ (文化习俗). It helps me understand the diversity of our world.40、What is the name of the famous river that runs through Egypt?A. AmazonB. NileC. MississippiD. Yangtze答案：B41、填空题：A ___ (小狐) has a bushy tail.42、选择题：What is the name of the famous clock tower in London?A. Big BenB. Eiffel TowerC. Tower of PisaD. Willis Tower43、听力题：I like to _____ on weekends. (relax)44、What season comes after winter?A. FallB. SummerC. SpringD. Autumn答案:C45、What is the name of the famous scientist known for his work on electricity?A. Nikola TeslaB. Thomas EdisonC. Alexander Graham BellD. Albert Einstein答案: A. Nikola Tesla46、What do we call the study of the universe beyond Earth?A. AstrologyB. AstronomyC. CosmologyD. Astrophysics答案: B. AstronomyThe ________ likes to sit on my shoulder.48、Listen and draw.(听录音，对的画笑脸，错的画哭脸。

CHEMICAL REMOVAL OF BIOMASS FROM WASTE AIR BIOTRICKLING FILTERS:SCREENING OF CHEMICALSOF POTENTIAL INTERESTH.H.J.COX and M.A.DESHUSSES*Department of Chemical and Environmental Engineering,University of California,Riverside,CA 92521,U.S.A.(First received July 1998;accepted in revised form October 1998)Abstract ÐA protocol was developed to rapidly assess the e ciency of chemical washing for the removal of excess biomass from biotrickling ®lters for waste air treatment.Although the experiment was performed on a small scale,conditions were chosen to simulate application in full-scale biotrickling ®lters.From 18treatments with di erent combinations and concentrations of chemicals,only washing with 0.4%(w/v)NaOH,0.26and 1.31%(w/v)NaClO and 11.3%(w/v)H 2O 2resulted in a biomass removal signi®cantly higher than treatment with pure water with wet biomass removal e ciencies of 50.2,49.2,77.0and 69.0%,respectively.Biomass removal by H 2O 2and NaClO was accompanied by complete loss of activity of unremoved biomass,whereas after treatment with NaOH low residual bio-logical activity was observed.However,treatment with NaOH resulted in generation of relatively large amounts of suspended solids (22.3%of dry biomass removed)and dissolved carbon (65.3%of C-bio-mass removed).NaClO was found to be the most promising reagent for biomass control in biotrickling ®lters because of its ability to remove large amounts of biomass and its low cost.#1999Elsevier Science Ltd.All rights reservedKey words Ðbiotrickling ®lters,waste air treatment,biomass control,chemical removalINTRODUCTIONBiological waste gas treatment in biotrickling ®lters relies on the transfer of pollutants from the gas phase into a bio®lm immobilized on a packed bed and subsequent biodegradation.High pollutant degradation rates are obtained by continuous recir-culation of a liquid phase over the immobilized mixed culture,which allows for pH control,ad-dition of nutrients and removal of inhibitory com-pounds.Clogging of high-performance biotrickling ®lters caused by excessive biomass growth is one of the main obstacles to the industrial deployment of waste air biotrickling ®lters (Sorial et al.,1995;Weber and Hartmans,1996;Cox and Deshusses,1997).To extend the life-time of biotrickling ®lters,several strategies have been proposed to either pre-vent clogging or to remove excess biomass.Reduction of the microbial growth rate in biotrick-ling ®lters may be obtained either by nutrient limi-tation (Holubar et al.,1995;Scho nduve et al.,1996;Weber and Hartmans,1996)or by maintaining high concentrations of sodium chloride in the recycle water (Diks et al.,1994;Scho nduve et al.,1996).However,reducing the process culture growth rateusually results in a decrease of the pollutant degra-dation rate;larger reactor volumes are required,which increases the investment costs.Farmer et al.(1995)proposed to increase the life-time of biotrick-ling ®lters by periods of starvation,i.e.intermittent treatment of waste gases.Although starvation may result in a decrease of biomass concentration in the starved reactor,for practical applications this may not be economically feasible since at least two reac-tors would be required to ensure continuous treat-ment (Cox and Deshusses,1999).We investigated the use of protozoa that prey upon bacteria for controlling biomass accumulation in toluene-degrading biotrickling ®lters.Inoculation with pro-tozoa resulted in a lower biomass accumulation rate and an increased carbon mineralization (Cox and Deshusses,1997).However,further optimization of protozoan predation is required to obtain a zero-balance of biomass growth in these biotrickling ®l-ters.Techniques of mechanical removal of excess bio-mass in biotrickling ®lters include backwashing of the reactor and periodic stirring of the packed bed.A stable toluene-degrading biotrickling ®lter was obtained by frequent backwashing of the reactor with water (Sorial et al.,1995;Smith et al.,1996).Although this technique proved e ective,biomass removal required high liquid ¯ow rates to obtain full medium ¯uidization.Backwashing appears toWat.Res.Vol.33,No.10,pp.2383±2391,1999#1999Elsevier Science Ltd.All rights reservedPrinted in Great Britain0043-1354/99/$-see front matterPII:S0043-1354(98)00452-7*Author to whom all correspondence should be addressed.[Fax:+1-909-7873188;e-mail:mdeshuss@].2383be limited to those biotrickling®lters containing support materials that are easily¯uidized and a 40%larger reactor volume is required to allow for bed expansion during¯uidization(Sorial et al., 1997).A proposed alternative to backwashing is to periodically stir the packed bed to shear o excess biomass(Wu bker et al.,1997).It is unclear how the latter proposal can be implemented at an industrial scale.Chemical removal of biomass is an attractive alternative for biomass control in biotrickling®lters but it remains a relatively unexplored area.So far, biomass removal from biotrickling®lters by chemi-cal washing has only been reported by Weber and Hartmans(1996),who used a sodium hydroxide solution.In the present contribution,we discuss results on the screening of various chemicals(oxi-dants,surfactants,bactericidal and hydrolyzing agents)to remove biomass from samples taken from a toluene-degrading biotrickling®lter. Experimental conditions were chosen in order to simulate future industrial treatment in biotrickling ®lters.As an inhibitory action on bacteria by the selected chemicals was expected,the biological ac-tivity of unremoved biomass was also measured.MATERIALS AND METHODSBiomass samplesBiomass was grown on the surface of2.5cm polypropy-lene Pall rings(Flexirings1,Koch Engineering,Wichita, KS)in a source biotrickling®lter(1.3m in height,0.152m in diameter)degrading toluene.The inoculum was a bac-terial species isolated from sludge using toluene as the sole carbon and energy pressed air with a metered amount of toluene resulting in an average inlet concen-tration of1.03g mÀ3was passed through the reactor from top to bottom at a volumetric load of64m3mÀ3hÀ1, resulting in a toluene load of65.9g mÀ3hÀ1.Liquid was recirculated concurrently with the air¯ow at a super®cial velocity of7.9m hÀ1and a mineral medium(Cox and Deshusses,1997)was continuously fed at a¯ow rate of 0.24l hÀ1.Pall rings with biomass were randomly taken from the upper part of the source biotrickling®lter after 79to147days of operation for the experiments described below.Experimental set-upRemoval of biomass was investigated in a small test bio-trickling®lter(0.3m in height,diameter0.152m)stacked with clean Pall rings.A schematic of the experimental set-up is shown in Fig.1and a picture of biomass attached on the Pall rings is shown in Fig.2.For each treatment,®ve rings with biomass were taken from the source bio-trickling®lter,weighed after10min of drying in air(wet biomass weight plus ring before treatment)and placed at regular intervals along the longitudinal axis of the test bio-trickling®lter.In most experiments,0.75l of liquid con-taining the tested chemical was recirculated for3h over the packed bed at a super®cial liquid velocity of7.9m hÀ1 using a centrifugal pump(model1P677A from Dayton Electric Mfg.Co.,Chicago,IL)and a needle valve and ¯owmeter combination.At the top of the test biotrickling ®lter,a liquid distribution system made of a container with equally spaced holes ensured homogenous distri-bution of the recycle liquid over the packed bed.All treat-ments lasted for3h(except for a treatment with hot water which lasted30min)and was ended by stopping the liquid recirculation.The liquid was then allowed to drain from the test biotrickling®lter for10min and collected for analysis of suspended solids and total dissolved carbon. The rings with unremoved biomass were carefully removed from the test biotrickling®lter,air-dried for10min and weighed(wet biomass weight plus ring after treatment). Unremoved biomass was separated from the Pall rings and immediately analyzed for biological activity in oxygen uptake rate(OUR)experiments.The Pall rings were cleaned,dried and weighed in order to calculate the amount of wet biomass before and after treatment.The e ciency of biomass removal was calculated as the percen-tage removal of wet biomass.In total,18di erent treatments were investigated.The principal action mechanism of each chemical is listed in Table1.The general procedure as outlined above was fol-lowed for the treatment with demineralized water(control experiment,H2O),0.04and0.4%(w/v)sodium hydroxide (NaOH),0.1and0.5%(w/v)sodium dodecylsulfate (SDS),0.01%(w/v)NaOH with0.1%(w/v)SDS,0.05Fig.1.Schematic of the experimental set-up.H.H.J.Cox and M.A.Deshusses2384and 0.2%(w/v)sodium azide (NaN 3),0.011,0.26and 1.31%(w/v)sodium hypochlorite (NaClO),1.1and 11.3%(w/v)hydrogen peroxide (H 2O 2),saturated iodine in 4%(v/v)ethanol [0.02%(w/v)I 2as determined by titration with Na 2S 2O 3],0.9%(w/v)ammonia (NH 3)and 0.9%(w/v)NH 3in combination with 0.22%(w/v)formaldehyde (HCO).For the treatment with demineralized water at el-evated temperature (H 2O,T =638C),a heating plate was used to maintain 1.2l of recycle liquid at 658C.This treat-ment lasted for only 30min and the average temperature inside the column was 638C.For the treatment with ozone,demineralized water was circulated over the column for 3h while ozone-containing air was passed counter-cur-rently at a ¯ow rate of 1.9l min À1.Ozone was prepared with an ozone generator model 100-O2from California Acrylic Industries (Pomona,CA).The ozone concen-tration in the gas phase was 0.5g m À3as determined by ti-tration with Na 2S 2O 3after trapping of ozone in 2%KI (APHA et al.,1985).Analytical proceduresThe dry matter content of the biomass was determined in quadruplicate by drying,at 958C overnight,known amounts of wet biomass,taken from the source biotrick-ling ®lter after 162days of operation.Analyses of the dried biomass for C,H and N content were done by Desert Analytics Laboratory (Tucson,AZ).Suspended solids in the liquid after treatment were determined bycentrifugation at 17,000g for 10min and by drying the pel-let at 958C overnight.Total dissolved carbon in the liquid after treatment was determined in triplicate by analyzing the supernatant using a model TOC-5050total carbon analyzer (Shimadzu,Kyoto,Japan).The activity of the biomass remaining on the rings after the treatment was determined in OUR experiments.Each of the 5rings was placed into 100ml of mineral medium and shaken vigor-ously to separate the biomass from the ring.OURs with and without 0.19mM toluene were determined in single experiments at room temperature in a custom made 57ml glass vial and by using an oxygen electrode and meter (Orion model 860,Boston,MA).OURs were related to the amount of unremoved,wet biomass and toluene-induced OURs were corrected for endogenous respiration.RESULTSCharacterization of biomass samplesBiomass sampling from the source biotrickling ®l-ter started after 79days of toluene supply,at which time the reactor contained 14.065kg wet biomass (approximately 60%of the reactor volume).The average amount of wet biomass on the Pall rings was 11.2g (average of 90rings,a range of 7.1to 16.5g with a standard deviation of 1.9g).Since the biomass content of the bioreactor was high,bio-mass was present both inside and on the outer sur-face of the rings.Assuming a bio®lm density of 1kg l À1and that Pall rings can be represented by empty cylinders,the maximum amount of wet bio-mass needed to ®ll the ring would be 12.3g.The average amount of biomass on the rings (11.2g)in-dicates that the amount of biomass on the outer surface was small compared to the amount ofbio-Fig.2.Picture of a clean Pall ring (left)and one covered with biomass (right)before cleaning.Since the biomass content was very high,a large portion of the inner volume of the ring was ®lled with biomass.Table 1.Principal action mechanisms of the chemicals tested toremove excess biomass in biotrickling ®lters CompoundMechanism H 2O none,control NaOHhydrolysis NaClO,H 2O 2,O 3,I 2oxidation SDS surfactant NaN 3toxic/reductionWater (638C),NH 3,NH 3+HCOotherRemoval of biomass from biotrickling ®lters 2385mass inside the ring.This was con®rmed by visual observation (Fig.2).The average dry matter con-tent of the biomass was 4.86%.Elemental analysis of the dried biomass showed a C:H:N ratio of 43.4:6.2:7.8%on a dry weight basis.Chemical removal of biomassThe control experiment with recirculation of demineralized water resulted in an average loss of wet biomass of 12.9%.Visual observation indicated that mainly biomass from the outer surface of the rings was removed,whereas biomass inside the rings was still present.Since no chemical reaction between water and biomass is expected,selective removal of biomass from the outer surface of the rings in this case was due to shear stresses caused by trickling of liquid on the rings in the column and/or to losses during handling of the rings.Table 2summarizes the wet biomass removal e -ciencies of the treatments investigated as well as pH measurements of the liquid before and after treat-ment.Most treatments had about the same removal e ciency as the control treatment with water.Only treatments with 0.4%(w/v)NaOH,0.26and 1.31%(w/v)NaClO and 11.3%(w/v)H 2O 2resulted in statistically signi®cant higher removal e ciencies (Student t -test,p >0.95).Biomass in the treatments using 0.26and 1.31%(w/v)NaClO and 11.3%(w/v)H 2O 2turned from an initial brown color to yel-lowish-white at the end of the treatment.This was not observed in treatments with 0.011%(w/v)NaClO nor with 1.1%(w/v)H 2O 2.In treatments using NaOH,only the 0.4%(w/v)NaOH appli-cation resulted in the remaining biomass becoming a highly viscous liquid.All treatments with SDS resulted in signi®cant parison of the pH during treatment and removal e ciencies at0.04and 0.4%NaOH (w/v)(Table 2)indicates that biomass removal induced by an alkaline environ-ment may be expected at a pH of about 12.4and higher.Analysis of the liquid after treatmentBiomass reduction may either be due to bio®lm detachment (cells and ¯ocs),to solubilization of biomass by chemical reaction or to oxidation of biomass to volatile compounds.In order to quan-tify these processes,the amounts of suspended solids and total dissolved carbon in the liquid after treatment were determined.It should be noted that larger ¯ocs tended to be captured on clean Pall rings below the test rings in the test biotrickling ®l-ter and thus determination of suspended solids in the liquid is an underestimation of bio®lm detach-ment.The liquid after treatment contained small amounts of suspended solids and dissolved carbon in cases of treatments with low biomass removal e ciencies,whereas the highest amounts were found in treatments with high biomass removal e -ciencies (Table 3).Since the total amounts of wet biomass on ®ve rings before and after treatment were known and biomass dry matter and carbon content were deter-mined,mass balances were calculated for the treat-ments with high removal e ciencies.As reported in Table 4,treatment with 0.4%(w/v)NaOH resulted in a slightly higher recovery of removed biomass as suspended solids,which may indicate that detach-ment of cells and bio®lm ¯ocs was a more import-ant process in this treatment as compared to the treatments with NaClO and H 2O 2.Marked di er-ences were found in the recovery of removed C-bio-mass as dissolved carbon,with values ranging from 18.5%for the treatment with 11.3%(w/v)H 2O 2toTable 2.Wet biomass removal e ciency from Pall rings during 3h treatment in a test biotrickling ®lterTreatment No.TreatmentWet biomass removal e ciency (%)a pH liquidstart end 1H 2O12.9(11.0)ND c 7.62H 2O,T =638C b 14.6(11.5)ND 8.030.4%(w/v)NaOH 50.2(22.4)12.812.440.04%(w/v)NaOH 10.3(9.8)12.09.550.5%(w/v)SDS 10.9(7.0) 6.78.060.1%(w/v)SDS10.4(12.0) 6.27.470.04%(w/v)NaOH +0.1%(w/v)SDS9.6(5.1)11.89.280.2%(w/v)NaN 320.4(8.0)7.87.990.05%(w/v)NaN 3 2.8(6.7)7.48.310 1.31%(w/v)NaClO 77.0(16.1)12.19.1110.26%(w/v)NaClO 49.2(13.2)11.49.0120.011%(w/v)NaClO 14.3(5.6)ND 8.01311.3%(w/v)H 2O 269.0(19.4) 4.3 6.514 1.1%(w/v)H 2O 228.2(16.0) 5.17.3150.02%(w/v)I 210.8(3.7) 5.47.4160.5g O 3m À3air 5.9(3.2)ND ND 170.9%(w/v)NH 36.5(6.4)11.59.3180.9%(w/w)NH 3+0.22%(w/v)HCO9.9(11.8)11.210.2aAverage of ®ve determinations,standard deviation (s n À1)in parentheses.b 30min treatment.c Not determined.H.H.J.Cox and M.A.Deshusses238665.3%for the treatment with0.4%(w/v)NaOH. No attempts were made to close dry matter and carbon balances,which would have required analy-sis of the liquid for dissolved solids and analysis of the gas phase for production of CO2and volatile organic compounds.However,assuming that the carbon content in suspended solids was the same as that in the biomass before treatment,the ratio of C-liquid produced to C-biomass removed in the treatments with0.4%(w/v)NaOH,0.26and1.31% (w/v)NaClO and11.3%(w/v)H2O2was88,60,63 and33%,respectively(Table4).These results may indicate that oxidation of biomass to gaseous or volatile compounds was signi®cant in the treatments using oxidants,such as NaClO and especially H2O2. Biological activity of unremoved biomass Endogenous and toluene-induced OURs of fresh biomass analyzed before chemical treatment were on average1.31and1.46m g O2gÀ1wet biomass-minÀ1,respectively.In the control experiment with water,unremoved biomass had approximately the same activity(Table5).This indicates that3h of trickling of a liquid on the test rings in the test bio-trickling®lter is in itself not a cause for loss of bio-logical activity.The data reported in Table5showsTable3.Removal of biomass from Pall rings as suspended solids and total dissolved carbon Treatment Suspended solids(SS)Dissolved carbon(C)total (mg)biomass recovered as SS(%)atotal(mg)biomass recovered as dissolved C(%)bH2O45 2.310 1.2H2O,T=638C128 6.240 4.50.4%(w/v)NaOH19411.224732.80.04%(w/v)NaOH81 3.311010.50.5%(w/v)SDS54 2.5132d14.30.1%(w/v)SDS70 3.30d00.04%(w/v)NaOH+0.1%(w/v)SDS31 1.5110d12.00.2%(w/v)NaN351 1.915 1.30.05%(w/v)NaN328 1.611 1.41.31%(w/v)NaClO24511.235337.30.26%(w/v)NaClO155 6.822422.60.011%(w/v)NaClO82 3.937 4.111.3%(w/v)H2O21879.910512.81.1%(w/v)H2O21727.739 4.00.02%(w/v)I277 4.1ND ND0.5g O3mÀ3air ND c ND ND ND0.9%(w/v)NH339 1.512511.10.9%(w/w)NH3+0.22%(w/v)HCO54 2.121d 1.9a Dry suspended solids in the liquid after treatment,as percentage of the total amount of dry biomass present on®ve Pall rings before treatment(dry biomass=0.0486Âwet biomass).b Total dissolved carbon in the liquid after treatment,as percentage of the total amount of C-biomass present on®ve Pall rings before treatment(C-biomass=0.4339Âdry biomass).c Not determined.d Values corrected for the presence of carbon containing reagents,assuming that the reagent concentration at the end of the treatment was the same as initially pre-sent.Table4.Mass balances for four treatments with the highest biomass removal e ciencyParameter Treatment0.4%(w/v) NaOH 0.26%(w/v)NaClO1.31%(w/v)NaClO11.3%(w/v)H2O2Dry biomassBiomass before treatment(g) 1.733 2.282 2.182 1.892 Biomass removed a(g)0.870 1.123 1.680 1.306 Recovered as suspended solids(g)0.1940.1550.2450.187 Recovery of removed biomass as suspended solids(%)22.313.814.614.3CarbonC-biomass before treatment(g)0.7520.9900.9470.821 C-biomass removed b(g)0.3780.4870.7290.567 Recovered as dissolved C(g)0.2470.2240.3530.105 Recovery of removed C-biomass as dissolved C(%)65.346.048.418.5 Total carbon recovery c(%)88606333a Assuming that the dry matter content in biomass before and after treatment is the same(0.0486g dry biomass gÀ1wet biomass).b Assuming that the carbon content of dry biomass before and after treatment is the same(0.4339g C gÀ1dry biomass).c(Suspended solidsÂ0.4339+dissolved carbon)/C-biomass removed.Removal of biomass from biotrickling®lters2387that chemical treatments caused various levels of inhibition of biological activity of the remaining biomass,depending on the chemical used.Interestingly,toluene oxidation generally appeared to be more inhibited than endogenous respiration,but this was not further investigated.From the four treatments with high biomass removal e ciencies,only unremoved biomass in the treatment with 0.4%(w/v)NaOH showed some level of biologicalactivity.In fact,toluene oxidation activity was found in only one sample out of the ®ve examined.Treatments with 0.26and 1.31%(w/v)NaClO and 11.3%(w/v)H 2O 2resulted in a complete loss of respiration activity of the unremoved biomass.In these cases it was found that residual H 2O 2and NaClO concentrations in suspensions for OUR ex-periments (i.e.after ten-fold dilution of unremoved biomass in mineral medium and assuming that the biomass was saturated with the reagent in a concen-tration as initially present at the start of the treat-ment)were su ciently high to cause complete inhibition of respiration activity of fresh and untreated biomass.DISCUSSIONThe e ciency of biomass removal of biomass from Pall rings was investigated in a laboratory test biotrickling ®lter at a super®cial liquid velocity commonly used in biotrickling ®lter operation.Experimental conditions were chosen to simulate chemical removal of biomass in full-scale biotrick-ling ®lters,with the exception being that the Pall rings with biomass in the test biotrickling ®lter were surrounded by clean Pall rings.The high ratio of re-agent to biomass may have facilitated reaction in the test biotrickling ®lter and,consequently,removal e ciencies as reported in Table 2may be higher than with actual treatment in biotrickling ®l-ters under otherwise identical conditions.Asindi-Fig.3.Correlation between toluene-induced oxygen uptake rate in the biomass remaining after treat-ment and wet biomass removal e ciency of the various treatments (see Table 2for identi®cation ofeach treatment).The inset shows target characteristics for various treatments.Table 5.Biological activity of unremoved biomass measured as the oxygen uptake rate (m g O 2g À1wet biomass min À1;average of ®ve determinations with standard deviation (s n À1)in parentheses)TreatmentEndogenous Toluene-induced H 2O1.21(0.27)1.92(0.54)H 2O,T =638C 00.4%(w/v)NaOH 0.76(0.52)0.12(0.26)0.04%(w/v)NaOH 1.27(0.22)0.06(0.11)0.5%(w/v)SDS 1.54(0.51)0.59(0.37)0.1%(w/v)SDS2.54(0.59)0.59(0.70)0.04%(w/v)NaOH +0.1%(w/v)SDS1.69(0.78)0.15(0.18)0.2%(w/v)NaN 30.55(0.11)0.27(0.21)0.05%(w/v)NaN 3 1.45(0.39)1.13(0.70)1.31%(w/v)NaClO 000.26%(w/v)NaClO 00.011%(w/v)NaClO 0.93(0.15)0.78(0.43)11.3%(w/v)H 2O 201.1%(w/v)H 2O 20.24(0.21)0.09(0.15)0.02%(w/v)I 2 1.63(0.41)0.64(0.32)0.5g O 3m À3air 1.21(0.58)0.82(0.38)0.9%(w/v)NH 30.67(0.33)0.05(0.09)0.9%(w/w)NH 3+0.22%(w/v)HCOH.H.J.Cox and M.A.Deshusses2388cated by the high standard deviation,removal e -ciencies per treatment sometimes varied consider-ably(Table2).Since the distribution of biomass on the ring was di erent for each sample,access of liquid to the biomass may have di ered as well. This may also have resulted in di erent ratios of inactive to active biomass in samples within each treatment,causing large¯uctuations in the biologi-cal activity of unremoved biomass as observed in OUR experiments(Table5).Chemical treatment of clogged biotrickling®lters should result in a high e ciency of biomass removal to reduce the frequency of cleaning. Ideally,chemical treatment should also have mini-mum adverse e ects on the activity of biomass remaining on the rings in order to reduce the time of recovery of the biotrickling®lter after treatment (Fig.3,Inset).In Fig.3,the toluene oxidation ac-tivity of the unremoved biomass after the treatment is plotted vs biomass removal e ciencies.Many treatments resulted in partial or complete inacti-vation of the biomass without signi®cant removal of biomass.These include the treatments with SDS (a surfactant commonly used with NaOH in an alkali lysis procedure to disrupt cell membranes; Sambrook et al.,1989),I2(an alternative for NaClO/Cl2in wastewater disinfection;White, 1972),NaN3(an inhibitor of the respiratory chain at concentrations of0.0065±0.065%;Heinen,1971) or water at638C.Biomass removal e ciencies could have been better for these treatments if higher reagent concentrations were tested.OUR exper-iments however show that these treatments should probably not be considered because of their toxicity at low concentration.The low biomass removal e -ciency in these and other treatments is most prob-ably due to the fact that cells in a bio®lm are embedded in a polymer matrix.This may have served as a means to increase cell detention but did not o er much protection against the di usion of aggressive chemicals.It further suggests that suc-cessful development of biomass washing strategies should consider chemicals that have a proven e ect on the components of the polymer matrix. Treatment with ozone did not result in biomass removal,although ozone is a stronger oxidant than NaClO(E0=1.24and0.90mV,respectively;Lide, 1996).Apparently the ozone concentration in the gas phase(0.5g mÀ3)and the corresponding con-centration in the liquid phase(0.1mg lÀ1,dimen-sionless Henry coe cient of0.2;White,1972)were too low to e ectively oxidize or remove biomass. This is further supported by Siddiqui et al.(1997) who observed that removal of biodegradable dis-solved organic carbon(BDOC)from drinking water sources was optimal at an applied ozone to DOC ratio of2:1(g gÀ1).Although ozone treatment of BDOC and immobilized biomass may not be directly comparable,the results of Siddiqui et al. (1997)indicate that the ozone to carbon ratio applied in our experiment was too low(0.25g gÀ1). The economical and ecological impacts of using a 2:1ratio to remove excess biomass in biotrickling ®lters is not yet known.No treatment was found that can combine a high biomass removal e ciency and high toluene oxi-dation activity of the biomass remaining after treat-ment(Fig.3).OUR experiments did not allow for distinction between loss of activity due to cell death during chemical treatment and permanent or tem-porary inhibition of still viable cells.Also,since unremoved biomass was not washed after treatment (to simulate industrial operation),residual reagents may have a ected OUR experiments.In control ex-periments with H2O2and NaClO,calculated re-sidual reagent concentrations were su ciently high to completely inhibit respiration of fresh biomass, even after a ten-fold dilution to suspend the bio-mass for OUR experiments.H2O2and NaClO are well-known disinfectants and concentrations used in this study were several orders of magnitude higher than that required for disinfection(White,1972). The present results indicate that rapid recovery of biotrickling®lters after treatment with NaClO or H2O2may be hindered by both cell death during treatment as well as the presence of residual reagent in unremoved biomass after treatment.This suggests that post treatments using a reducing agent in the case of a chemical wash with an oxidant or using an acid or pH bu er after an alkali treatment might be bene®cial.Such a post treatment would neutralize the active chemical and eliminate the e ect of any residual chemicals.This could poten-tially speed up the recovery of the process culture ®lter after chemical treatment.From the four treat-ments with signi®cantly higher biomass removal e ciencies,only biomass after treatment with0.4% (w/v)NaOH showed some biological activity in OUR experiments.This speaks in favor of the use of NaOH to control biomass accumulation in bio-trickling®lters.Weber and Hartmans(1996)indeed observed that the toluene elimination capacity of a biotrickling®lter was fully restored within one day after treatment with0.4%(w/v)NaOH.They also found that the NaOH washes resulted in an average removal of230g dry biomass from a71l reactor, i.e.3.2kg dry biomass mÀ3.The percentage biomass removal in the case of Weber and Hartmans(1996) could not be calculated and compared to the results of the present research,because the amount of bio-mass in their reactor was not determined.However, a removal of3.2kg dry biomass mÀ3reactor volume is insu cient for controlling biomass in high per-formance biotrickling®lters that are subject to rapid clogging.Our source-biotrickling®lter gained approximately0.37kg dry biomass mÀ3reactor-dayÀ1,which would require treatment with0.4% (w/v)NaOH once every8.7days to maintain a con-stant biomass concentration in the reactor.A more e ective reagent may be desired to obtain a higherRemoval of biomass from biotrickling®lters2389。

小学上册英语第三单元测验试卷考试时间：80分钟（总分:100）A卷一、综合题(共计100题共100分)1. 填空题：The ancient Romans were known for their ________ and engineering.2. 填空题:We usually have ________ for lunch at school.3. 选择题：Which gas do we breathe in?A. Carbon DioxideB. OxygenC. NitrogenD. Helium答案：B4. 填空题：The ________ (小溪) flows through the forest and is very peaceful.5. 填空题：I feel excited when I ______.6. 填空题：The ________ (树叶) change colors in autumn and fall to the ground.7. 选择题：What do you call a type of dance that is fast and upbeat?A. JazzB. Hip-hopC. SalsaD. All of the above答案:D8. 填空题：We visit ______ (文化中心) to learn about traditions.My friend is very ___. (funny)10. 填空题：I call my grandfather __________. (爷爷)11. 填空题：I have a special ______ (盒子) where I keep all my treasures. It is very ______ (珍贵).12. 填空题：A ____(green marketing) emphasizes sustainability in advertising.13. 听力题：The capital of Norway is __________.14. 填空题：The ancient Greeks are known for their ________ and philosophy.15. 填空题：I enjoy doing magic tricks with my ________ (玩具名称).16. 听力题：My pet is a _____ cat. (fluffy/fast/tall)17. 填空题：The __________ (颜色) of a solution can indicate its chemical properties.18. 填空题：I have a ________ that I take everywhere.19. 填空题：The _____ (枫树) turns red in autumn.20. 填空题：My brother's favorite animal is the ______ (狮子). It is strong and known as the ______ (森林之王).21. 听力题：The Earth rotates on its ______.22. 填空题：My favorite memory is ______.23. 填空题：My ________ (玩具名称) is a favorite among my family.What is the capital of Australia?A. SydneyB. MelbourneC. CanberraD. Brisbane25. 填空题：The _____ (章鱼) can squirt ink to escape danger.26. 选择题：Which of these is a popular fruit?A. SpinachB. CarrotC. StrawberryD. Broccoli答案:C27. 听力题：A __________ is a mixture of different substances.28. 填空题：The ________ was a significant treaty that fostered diplomatic relations.29. 听力题：The chemical formula for calcium hydroxide is _____.30. 填空题：My favorite dish is _______ (披萨).31. 听力题：The chemical formula for lithium carbonate is _______.32. 选择题：What is the capital of Luxembourg?A. Luxembourg CityB. Esch-sur-AlzetteC. DifferdangeD. Dudelange答案:A33. 听力题：The boiling point of water is ________ degrees Celsius.34. 填空题：My favorite _____ (游戏) is hide and seek.The rabbit is ______ (eating) a carrot.36. 填空题：The car is ________ (红色).37. 选择题：What do you call a large, thick jungle?A. ForestB. SavannaC. RainforestD. Woodland答案:C38. 听力题：The car is _______ (red).39. 填空题：I like to share my toys with ______.40. 填空题：The owl is a ______ (夜间) bird. It sleeps during the ______ (白天).41. 填空题：The _______ (The Iron Age) followed the Bronze Age in human history.42. 听力题：The capital of Nigeria is ________.43. 填空题：A horse makes a ______ sound.44. 填空题：The _____ (狮子) roars loudly to show its strength.45. 填空题：Understanding ______ (植被) can aid conservation efforts.46. 听力题：The chemical formula for ethanol is ______.47. 选择题：What is the capital of Nepal?A. KathmanduB. PokharaC. LalitpurD. Bhaktapur答案:A48. 听力题：The chemical symbol for terbium is ______.49. 填空题：My dad is a __________ (专业顾问).50. 听力题：The Great Barrier Reef is off the coast of _______.51. 听力题：The ____ has a long snout and loves to sniff around.52. 听力题：The gas released when vinegar reacts with baking soda is ______.53. 听力题：The cake is on the ________.54. 选择题：What is the main source of light during the day?A. MoonB. StarsC. SunD. Lamp55. 听力题：We recognize ________ (hard work) in our team.56. 填空题：A mouse can fit through very ______ (小) holes.57. 听力题：The capital of Taiwan is _______.58. 听力题：She is _______ (coloring) in her book.59. 填空题：Did you hear the _____ (小狗) barking joyfully?60. 听力题：She is ________ (kind) to her friends.Which insect makes a web?A. AntB. ButterflyC. SpiderD. Bee62. 选择题：Which animal is known for its ability to change colors?A. ZebraB. ChameleonC. ElephantD. Kangaroo答案:B63. 填空题：The ______ (生态环境) is changing worldwide.64. 选择题：What is the chemical symbol for gold?A. AuB. AgC. PbD. Fe答案:A65. 听力题：My brother is _____ his homework. (doing)66. 填空题：The __________ Mountains are found in North America. (落基山)67. 听力题：My sister is a ______. She loves to read poetry.68. 填空题：Certain plants produce ______ that are used in perfumes. (某些植物产生用于香水的香料。

烟台2024年小学4年级下册英语第六单元综合卷[有答案]考试时间：80分钟（总分:120）A卷考试人：_________题号一二三四五总分得分一、综合题(共计100题)1、听力题：The car is _____ fast. (going)2、听力题：The chemical symbol for nitrogen is _______.3、填空题：The _______ (马) pulls a cart.4、Which planet is known for its great red spot?A. EarthB. JupiterC. MarsD. Saturn答案:B5、What is the name of the famous ancient city located in Peru?A. Machu PicchuB. TikalC. PetraD. Angkor Wat答案: A6、听力题：The chemical formula for sodium sulfite is ______.7、听力题：A __________ is created when two or more substances react.8、听力题：The atmosphere contains layers, including the troposphere and ______.9、听力题：Space is a vacuum, meaning it has no ______.10、What is the capital city of Tunisia?A. TunisB. SfaxC. KairouanD. Bizerte11、填空题：The ________ (气候适应) is necessary for survival.12、听力题：Earth has one moon, while Mars has ______.13、听力题：The tree is ___ (full) of leaves.14、听力题：In a chemical reaction, substances change into new __________.15、听力题：The superhero is very ___ (brave).16、填空题：The bear searches for _________ in the forest. (食物)17、填空题：I want to learn how to ______.18、听力题：I want to _____ (travel/go) to the beach.19、填空题：He is a _____ (医生) who helps sick people.20、What is the capital of the United Kingdom?a. Londonb. Edinburghc. Dublind. Cardiff答案:a21、What is the capital of Tajikistan?a. Dushanbeb. Khujandd. Qurghonteppa答案:a22、What is the primary color of the sun?A. YellowB. BlueC. RedD. Green23、选择题：What do we call the area of land that is covered in rocks?A. MountainB. HillC. PlateauD. Desert24、听力题：The _______ can attract butterflies.25、What is the hardest natural substance?A. GoldB. IronC. DiamondD. Silver答案: C26、填空题：The doctor, ______ (医生), gives advice on staying healthy.27、听力题：My grandma loves to bake ____ (bread).28、听力题：The Earth's rotation creates patterns in ocean ______.29、听力题：The snow is ______ on the ground. (falling)30、听力题：The main method of separating mixtures in a laboratory is _____.31、What do you call a place where animals are kept for public display?A. ParkB. ZooC. Farm答案: B32、What do bees make?A. MilkB. HoneyC. ButterD. Sugar答案:B33、填空题：The __________ (历史的交织) illustrates interconnectedness.34、填空题：I like to ______ (完成) my chores on time.35、听力题：We will _______ (go) to the theater tonight.36、What is the capital of Egypt?A. CairoB. GizaC. AlexandriaD. Luxor答案: A. Cairo37、What do you call the person who teaches you in school?A. DoctorB. TeacherC. ChefD. Engineer答案：B38、填空题：The _____ (露水) on the grass is refreshing in the morning.39、填空题：We have a ______ (丰富的) library collection.40、填空题：She is a _____ (记者) who reports on local news.41、听力题：The periodic table organizes elements by their ______.42、听力题：The capital of South Korea is __________.43、听力题：Many _______ are known for their vibrant colors.44、What do you call the place where you buy books?A. LibraryB. BookstoreC. SupermarketD. School45、听力题：My favorite season is ______ (winter).46、听力题：A light-year is a measure of ______.47、填空题：There are many ______ (花) in the garden. They are very ______ (美丽).48、填空题：During lunch, I like to eat _______ (食物) with my friends. We talk about our _______ (事情).49、填空题：My dad is my hero _______ because he protects me.50、听力题：The chemical symbol for yttrium is _______.51、What is the capital of Monaco?A. Monte CarloB. Monaco CityC. La CondamineD. Moneghetti答案:B. Monaco City52、填空题：A ferret is a playful ________________ (小动物).53、填空题：Certain plants can regenerate after ______ (火灾).54、听一听，选一选。

Received date :2002-09-02Foundation item :T he financial suppo rt o f this w ork by the China -Spain Joint P roject Biograph :Liu Xin -yong (1963-),M ale Han nationality ,w as born in Ping du City ,Professor ,research interests include :an -tivrial and cardiov ascular drug ,Tel :(0531)8382005,E -mail :xinyongl @jn -public .sd .cninfo .ne t 。

Article ID :1005-0108(2003)01-0021-04Synthesis of methyl 4-mercapto -3-thiophenecarboxylateLIU Xin -yong 1,XU Wen -fang 1,M olina M aria Teresa 2,Vega Salvador2(1.Institute of Medicinal Chemistry ,School of Pharmac y ,Shandong U niversity ,Ji ′nan250012,China ;2.Instituto de Quim ica Medica (CS IC ),C /Jun de la Cierva 3,28006Madrid ,Spain )A bstract :Aim To design specially and synthesize me thyl 4-mercapto -3-thiophenecarboxy late ,a very im -po rtant new intermediate fo r sy nthesis of drugs and herbicides .Method I t was prepared in 6steps startingfrom the piperidine catalyzed addition of methy l thiogly colate to methyl acrylate ,followed by the Dick -mann condensa tio n ,tosy lation ,disulfide substitutio n ,dehydrogenation and reduction .Results T he struc -tures of all the sy nthesized compounds were confirmed by elementary analysis ,and spectroscopic analysis of I R ,1H -N M R and 13C -NM R .T he total y ield of the preparatio n amounted to 16%.Conclusion The procedure described can prove to be a more effective and applicable complement to the sy nthesis of methyl 4-mercapto -3-thiophenecarboxylate .Key words :medicinal chemistry ;preparation ;chemical sy nthesis ;thio phene derivatives ;methyl 4-mercap -to -3-thiophenecarbo xylate C LC number :R914 Document code :A Substituted thiophene derivatives are very im -po rtant intermediates for drugs and herbicides syn -thesis [1,2].Recently w e found that 1,1,3-trioxo -2H ,4H -thieno [3,4-e ][1,2,4]thiadiazine deriva -tives (figure 1)as non -nucleoside reverse transcrip -tase inhibitors selectively blocked human immunod -eficiency virus type 1(HIV -1)replication[3].Fig .1　The structure of 2,4-disubstitutedthieno [3,4-e ][1,2,4]thiadiazine -1,1,3-trioxidesIn order to study the structure activity rela -tionships of this kind of compounds ,much wo rk had been focused on the structural modification at the thiophene substituted functional g roups w hich w ould bind to thiadiazines moiety .In this paper ,wereported the feasible synthetic method for a new approach to the com pound of methyl 4-mercapto -3-thiophenecarboxylate ,w hich has no t been reported in literature so far .The general synthetic approach involved 6steps starting from the piperidine catalyzed additionof methyl thiogly colate to methyl acry late ,follow ed by Dickmann condensation for a diester of α,β′-di -carbometho xymethy lethyl sulfide (1)in the base of sodium methoxide methanol solution to obtain the β-keto ester (2),w hich was treated w ith tosyl chlo -ride to achieve the methy l 2,5-dihy dro -4-(p -tolue -nesulfonato )thiophene -3-carboxylate (3).The sub -stitutio n reaction of compound 3w ith sodium disul -fide afforded the diethyl 4,4′-dithiobis (2,5-dihy -dro thiophene -3-carboxy late )(4).Subsequently ,a mild ,operationally simple dehydrogenation method by means of sulfo nyl chlo ride in methylene chloride was used and resulted in an ex cellent yield of di -ethyl 4,4′-dithiobis (thiophene -3-carboxy late )(5).第13卷　第1期2003年2月　总51期中国药物化学杂志Chinese Journal o f M edicinal ChemistryVol .13　No .1　p .21Feb .2003Sum 51DOI :10.14142/j .cn ki .cn21-1313/r .2003.01.005Compound 5w as reduced with zinc powder and hy -drochloric acid in methanol solution to fo rm the fi -nal product of methy l 4-mercapto -3-thiophenecar -bo xylate (6).The reaction sequence w as outlined in figure 2.Fig .2　The synthetic route1　CHEMICAL EXPERIMENTSAll melting points were measured on a Re -ichert -Jung Kofler melting point apparatus and w ere uncorrected .Elementary analysis data w ere determined w ith a Hearus CHN -RAPID instrument and analy tical results w ere in the 0.5%of the the -oretical value .1H -NM R spectra were recorded onthe spectrometers ,including Varian XL -300(300M Hz )and Varian Gemini -200(200MHz ).Theused solvents were indicated (DM SO -d 6or CDCl 3).Chemical shifts w ere reported in ppm units related to the internal standard tetramethy lsilane (TMS ).The coupling constants w ere given in Hz ,and dif -ferent signals were expressed as the abbreviation (s ,singlet ;d ,doublet ;t ,triplet ;m ,mutiplet ,etc ).13C -NM R spectra were performed on the spectrometers of Varian Gimini 200(50MHz )and Varian XL -300(75M Hz ).Infrared spectra (IR )(KBr or Nujol mulls )w ere reco rded on a Shimadzu IR -435Spec -trometer .The assig nment data were only the maxi -mum value of the absorption perk .All the com -pounds were routinely checked by TLC and 1H -NM R .Merck silica gel 60w as used for the flash column chromatographic purification .Solvents w ere up to the reagent g rade and w hen necessary ,w ere purified and dried by the standard methods .Con -centrations of the reaction solutions involved the use of a rotary evaporator at a reduced pressure .1.1　α,β′-Dicar bomethoxym ethylethyl sulfide (1)It w as prepared acco rding to the reference pro -cedure [4],but w ith some improvement in theworkup .Methyl acrylate (45g ,0.52mol )was added dropw ise to a well stirred solution of methyl thioglycolate (53g ,0.5mol )and 1.5m L of piperi -dine during a period of 1h ,w hile maintaining the reaction mixture at 40℃by ex ternal cooling .After methyl acrylate had been added ,the reaction mix -ture w as w armed to 50℃for 10min ,filtered to re -move a small amount of solid ,washed w ith water and dried w ith sodium sulfate (Na 2SO 4),The dried oil w as distilled under vacuum to obtain a viscous oil of α,β′-dicarbomethoxymethylethyl sulfide (1)77.1g ,yield 80%,bp 148～150℃/1999.5Pa .1.2　Methyl tetrahydro -4-oxothiophen -3-carboxy -late (2)This Dieckmann condensation w as performedacco rding to the reference method [5]　w ith the fol -lowing modification .Sodium methoxide w as pre -pared by slow addition of a small piece of sodium metal (10.5g ,0.456mol ),w hich w as previously pealed off and rinsed w ith hexane ,into a 250mL Erlenmeyer flask containing 100mL of anhy drous methanol w ith vig orous stirring .When the sodiummetal w as completely reacted (disappeared ),α,β′-dicarbomethoxymethylethyl sulfide (1)(29.2g ,0.15mol )was added dropwise into the solution (about 1h ).The final part of diester (1)w as rinsed with a little amount of methanol .At the end of the addition ,heating was turned on ,the reaction solu -22中国药物化学杂志13卷tion w as under refluxing for1h with its color being changed from yellow to dark brow n.When cooled dow n to the room temperature,it w as poured into the ice-w ater(about100m L),and neutralized by hydrochlo ric acid to adjust the pH to2in an ice-sodium chloride cold bath(-10℃).The precipitate w as collected by filtration,washed with cold w ater, dried under vacuum,obtained the w hite solid 10.5g,y ield43.5%,and recry stallized from car-bon tetrachlo ride,mp36～37℃.1H-NM R(CDCl3)δ:10.95(s,OH,enol form),3.8(m,5H),3.4(m, 3H).I R(KBr)νcm-1:1750,1725(C O),1660, 1620(C C,enol fo rm).1.3　Methyl2,5-dihydro-4-(p-toluenesulfonato) thiophene-3-carboxylate(3)The solution of p-toluene sulfony l chloride (20.9g,0.11mol)in30m L of methy lene dichlo-ride w as added dropw ise to the cooled solution (10℃)of methy l tetrahydro-4-ox othiophen-3-car-box ylate(2)(16g,0.1mol)and N-methylmor-pholine(14.2g,0.14mol)in30mL of methy lene dichloride over a period of30min.The mix ture so-lution w as stirred further fo r1h,and then w ashed w ith w ater.The org anic layer w as separated,dried over sodium sulfate,and evaporated to dryness un-der vacuum.The crude product was purified by re-cry stallization from methanol,obtained the white prism crystals,28g,yield89.2%,mp91～92℃. 1H-NM R(CDCl3)δ:7.88(d,2H,J=7.35Hz, Ph),7.38(d,2H,J=8.06Hz,Ph),3.97(m,2H, hydrothiophene),3.83(m,2H,hydrothiophene), 3.629(s,3H,OCH3),2.47(s,3H,CH3-Ar).13C-NM R(CDCl3)δ:162.76(C=O),153.05(C-3), 146.61(C-4′),133.24(C-1′),130.51(C-2′), 128.95(C-3′),120.88(C-4),52.44(OCH3), 36.81(C-5),33.37(C-2),22.36(CH3).IR(KBr)νcm-1:1695(C O),1360,1190(SO2).1.4　Diethyl4,4′-dithiobis(2,5-dihydrothio-phene-3-carboxylate)(4)A sodium disulfide solution(Na2S2)w as previ-ously prepared by the process of heating a mix ture solution of sodium sulfide(Na2S·9H2O)43.2g (0.18mol)in165mL of methanol under reflux-ing.While the solid was dissolved,sulfur in the form of powder(5.76g,0.18mol)was added and heated to reflux again till the sulfur w as dissolved in it.The solution w as added dropw ise into the ice-cooled(under10℃)solution of methy l2,5-dihydro-4-(p-toluenesulfonato)thiophene-3-carboxy late(3) 94.2g(0.3mol)in450m L of acetone over a peri-od of2h.The mixture solution was continued to stir fo r additio nal8h at10℃,and was poured into 450m L of cold w ater when the reaction was com-pleted.The w hite solid w as collected by filtration, washed w ith cold w ater(100m L×2),follow ed with cold methanol(100m L×2),then w ith cold acetone(100mL×2),obtained the crude product, 49.3g,yield94%.The product w as recrystallized from toluene to give pure w hite prism crystals,mp 169～170℃.1H-NM R(CDCl3)δ:4.20(m,4H,hy-dro thiophene),4.06(m,4H,hydrothiophene),3.79(s,6H,OCH3).13C-NMR(CDCl3)δ:164.27(C O),153.95(C-3),125.16(C-4),52.12 (OCH3),42.56(C-5),39.13(C-2).IR(KBr)νcm-1:1690(C O).1.5　Diethyl-4,4′-dithiobis(thiophene-3-carboxy-late)(5)Diethyl4,4′-dithiobis(2,5-dihy drothiophene-3-carbox ylate)(4)11.6g(33mmol)was suspended in80m L of methylene dichloride.To this solution was added sulfonyl chloride9.4g(5.6mL, 70mmol)in80mL of methy lene dichloride over a period of1h.After an additional reaction time of 1h,the mix ture w as w ashed w ith water and10% aqueous sodium bicarbonate,and the org anic layer was separated,dried over sodium sulfite,then evap-orated to dryness,got a crude product11.2g,yield 98%.It w as purified by recrystallization from methanol,obtained the pure prism cry stals.m p93～95℃(methanol).1H-NM R(CDCl3)δ:8.19(d, 2H,J=3.5Hz,thiophene),7.26(d,2H,J=3.5 Hz,thiophene),3.92(s,6H,OCH3).13C-NM R (CDCl3)δ:163.33(C O),136.03(C-2),134.90 (C-3),130.77(C-4),120.92(C-5),52.71 (OCH3).IR(KBr)νcm-1:3110(thiophene-H), 1710(C O).1.6　Methyl4-mer capto-3-thiophenecar boxylate(6)10m L of concentration hydrochloric acid was231期LI U Xin-yo ng et al:Sy nthesis of methyl4-mercapto-3-thiophenecarboxy lateadded dropw ise to a suspended solution of dithio-phene(5)3.46g(10mmol)and pure zinc pow der 2.62g(40mmol)in100mL of methanol under re-fluxing fo r1h.The mix ture solution w as filtered to remove the excess zinc dust and some unsoluble im-purity.The filtrate w as concentrated under reduced pressure,w hite cry stals were precipitated out and recrystallized by ethanol,obtained the desired mecapto thiophene(6)2.85g,yield82%,m p138～140℃.1H-NM R(DM SO-d6)δ:8.13(d,1H,J= 3.5Hz,thiophene),7.04(d,1H,J=3.5Hz,thio-phene),3.74(s,3H,OCH3).13C-NM R(DMSO-d6)δ:164.25(C O),138.66,133.72,132.41, 120.82,51.72(OCH3).IR(KBr)νcm-1:3083.3, 3073.6(thiophene-H),1632(C O),1480.9, 1446.7(C C),1289.9(C—O).Elemental analy-sis(C6H6O2S2),Calcd(%):C41.36,H3.47,S 36.85;Found(%):C41.46,H3.58,S36.67.2　DISCUS SIONThe mercapto substituent introducing at the aromatic system is usually prepared by diazonium salt of aromatic amine in the reaction w ith disulfide reagents,such as sodium disulfide(Na2S2)and potassium ethoxymethanedithioide(C2H5OCSSK) o r by hydrolysis of the intermediate derived from halogenated compound reacted with thiourea[6]. But the preparation of aminothiophene or halo-genated thiophene also needed multisteps in syn-thetic routes.These procedures described here could prove to be a more effective and applicable comple-ment to the mercaptothiophene synthesis w hich is also commercially available fo r the starting materi-als.In the process of preparing compound(4),the reaction mixture w as in trouble with semi-solidifi-cation during the initiation reaction of sodium disul-fide solution w ith tosylate(3)solution.Vigorous mechanical stirring is necessary to keep the comple-tion of the reaction as the solid w as re-dissolved. This phenomenon should be attributed to the sub-stitution reaction mechanism which w ould be divid-ed into two steps:Dithio salt R-S-S-Na+,as the transition state,w as firstly fo rmed by equal moles of ROTs reacting with Na2S2,w hich is unsoluble in acetone.When it w as nucleophilically reacted w ith ano ther molecule of tosylate,the dithio-compound (R-S-S-R)w as generated and soluble in the sol-vent.RO TsNa2S2R-S-S NaROTsR-S-S-R Sulfonyl chlo ride has been verified to be a highly efficient reagent for dehydrogenation of the substituted dihydrothiophene under mild condi-tions[7]which have the advantages of being inex-pensive,and easy to isolate a product,any excess can be readily removed off.The conditio ns of the reaction are in1.1mol equivalent of sulfonyl chlo-ride under the ambient temperature. References:[1]　Stephens CE,Felder TM,Sowell JW,et al.Synthesisand antiviral/antitumor evaluation of2-amino-and2-carboxamido-3-arylsulfonylthiophenes and related com-pounds as a new class of diary lsulfo nes[J].Bioo rg MedChem,2001,9(5):1123-1132.[2]　M ori F,Tanji K,Wakabayashi K.T hiophene,a sulfur-containing heterocy clic hydrocarbon,causes widespreadneuro nal degeneratio n in rats[J].Neuropathology.2000,20(4):283-288.[3]　Arranz E,Dia JA,Ingate ST,et al.N ovel1,1,3-trio x-o-2H,4H-thieno[3,4-e][1,2,4]thiadiazine deriva-tives as N N RT Is tha t inhibit human immunodeficiencyvirus type1replicatio n[J].J M ed Chem,1998,41:4109-4115.[4]　Woodward RB,Eastmann RH.Tetrahydrothiophene(“Thiophane”)derivatives[J].J Am Chem Soc,1946,68:2229-2235.[5]　Hromatka O,Binder D,Eichinger K.Uber den mechanis-mus der Dieckmann-Reaktion von[J].3-(methoxycar-bonylthio)-propionsauremethylester.M onatshefte furChemie,1973,104:1520-1525.[6]　M arston T,Boger t,A rthur S,et al.Di-o-nitrophenyldisulfide[J].O rg Sy nth,1941,Coll.V ol.1:220-221.[7]　Rossy Phillp A,Werner Hffmann,Norbert Muller.Aro-matiization of dihydrothiophenes.T hiophene saccharin:asweet surpris e[J].J Org Chem,1980,45:617-620.(下转至第43页)24中国药物化学杂志13卷时,停止通氯气。

photosynthesis PhotosynthesisIntroductionPhotosynthesis is a vital process that occurs in plants, algae, and some bacteria. It is the process by which these organisms convert light energy into chemical energy, which is stored in the form of glucose. This energy is essential for the survival and growth of these organisms, and it also plays a significant role in maintaining the oxygen levels in the atmosphere.Process of PhotosynthesisPhotosynthesis consists of several interconnected reactions that take place in the chloroplasts of plant cells. The overall process can be summarized as follows:1. Absorption of LightThe first step in photosynthesis is the absorption of light energy by specialized pigments called chlorophyll. Plants have chlorophyll molecules located in the chloroplasts, which allow them to capture light energy from the sun.2. Conversion of Light EnergyOnce the chlorophyll captures light energy, it undergoes a series of chemical reactions called the light-dependent reactions. In these reactions, the energy from the absorbed light is used to convert water molecules into oxygen and protons. These protons are then used to generate ATP (adenosine triphosphate), which is the energy currency of all living cells.3. Conversion of Carbon DioxideThe second set of reactions in photosynthesis is called the light-independent reactions, or the Calvin cycle. In these reactions, the ATP and protons generated in the light-dependent reactions are used to convert carbon dioxide into glucose. This process is also known as carbon fixation.4. Storage of GlucoseThe glucose produced through photosynthesis serves as a source of energy for the plants. It is either used immediately for various cellular processes or converted into other compounds for storage. Some glucose is also transported to other parts of the plant for growth and development.Importance of PhotosynthesisPhotosynthesis is crucial for the existence of life on Earth. Here are some reasons why photosynthesis is so important:1. Production of OxygenDuring photosynthesis, plants release oxygen as a byproduct. This oxygen is essential for the survival of all living organisms, providing the necessary oxygen for respiration.2. Source of EnergyThe glucose produced during photosynthesis serves as the primary energy source for plants. This energy is utilized for various cellular functions such as growth, reproduction, and repair.3. Carbon Dioxide SinkPhotosynthesis helps in regulating the levels of carbon dioxide in the atmosphere. Plants absorb carbon dioxide during photosynthesis, reducing the greenhouse effect and mitigating climate change.4. Food ProductionPhotosynthesis is the process that allows plants to convert sunlight into food. This food, in the form of fruits, vegetables,grains, and other plant-based products, is the foundation of the entire food chain. Humans and animals depend on photosynthesis indirectly for their sustenance.ConclusionPhotosynthesis is a critical process that sustains life on Earth. It plays a vital role in producing oxygen, regulating the atmospheric carbon dioxide levels, and providing energy for all living organisms. Understanding the intricacies of photosynthesis is important for scientists and researchers as they explore ways to improve agricultural practices, develop renewable energy sources, and combat climate change. By studying and appreciating the process of photosynthesis, we can enhance our appreciation for the interconnectedness and beauty of the natural world.。

湛江“PEP”2024年11版小学三年级英语第二单元期中试卷考试时间：90分钟（总分:120）B卷考试人：_________题号一二三四五总分得分一、综合题(共计100题)1、听力题：We play _____ (soccer) on Sundays.2、填空题：The __________ (历史的叙述模式) shape our perceptions.3、填空题：In addition, this animal is a great ______. It helps keep the ecosystem balanced by______ smaller animals. I learned that some of them can even ______ very long distances to find food.4、填空题：The _______ (小鲨鱼) swims near the coral reef.5、填空题：I can ______ (保持) positive relationships with others.6、What is the name of the famous clock tower in London?A. Big BenB. Tower BridgeC. London EyeD. Buckingham Palace7、听力填空题：I love discovering new hobbies. Recently, I started __________, and it has been an exciting adventure. Trying new things helps me learn more about myself.8、听力题：We are going to the ___ (zoo).9、What do you call a person who takes care of animals?A. VeterinarianB. ZookeeperC. Animal caretakerD. All of the above答案:D10、填空题：A frog's eyes bulge out for better ______ (观察).11、填空题：This is my . (这是我的。

小学下册英语第三单元全练全测(含答案)英语试题一、综合题(本题有50小题，每小题1分，共100分.每小题不选、错误，均不给分)1 The teacher is _______ (kind/mean).2 We will _______ a big celebration.3 What is the name of the famous artist known for his abstract paintings?A. PicassoB. Van GoghC. Da VinciD. Monet答案:A4 What do you call the imaginary line that divides the Earth into the Northern and Southern Hemispheres?A. EquatorB. Prime MeridianC. Tropic of CancerD. International Date Line答案:A5 The ancient Egyptians used ________ to measure time.6 The girl loves to ________.7 The __________ (人类进化) from primates took millions of years.8 The __________ (花香) fills the air in spring.9 What is the most common pet?A. FishB. CatC. BirdD. Hamster答案:B10 What do you use to cut paper?A. GlueB. PencilC. ScissorsD. Ruler答案:C11 We are friends with the ______ (neighbors).12 How do you say "fruit" in Spanish?A. FrutaB. FruitsC. FruitaD. Frut13 What is the capital of China?A. BeijingB. ShanghaiC. Hong KongD. Guangzhou14 The _____ (glacier) is melting.15 What do you call a young wolf?A. PupB. CubC. KitD. Fawn答案:A16 I am inspired by __________ because he/she achieved so much. His/Her story motivates me to work hard and follow my dreams. I hope to be like him/her one day.17 A concentrated solution contains a high amount of ______.18 The ________ has a long neck.19 The chemical structure of DNA contains ______.20 What is 3 + 5?A. 7B. 8C. 9D. 10答案:B21 What do you call the time when day changes to night?A. MorningB. AfternoonC. EveningD. Midnight22 erranean Sea is located between ________ (地中海位于________之间). The Medi23 What is the capital of the Netherlands?A. AmsterdamB. RotterdamC. The HagueD. Utrecht24 The chemical formula for lithium carbonate is _______.25 The __________ is a region known for its rich soil.26 Plants help to keep our _______ clean.27 The __________ is a famous city in the Netherlands known for its tulips. (阿姆斯特丹)28 What do you call a young rabbit?A. KittenB. BunnyC. PupD. Calf29 A delta is formed at the mouth of a river where it meets the ______.30 My grandma has a lovely _____ at her house.31 The capital of Taiwan is _______.32 What do we call the time it takes for the Earth to rotate on its axis?A. DayB. YearC. MonthD. Hour答案:A33 A flamingo's diet consists mainly of ________________ (浮游生物).34 What do we wear on our feet?A. HatsB. ShoesC. GlovesD. Scarves35 My family has a tradition of having dinner together every ______ (星期日). It’s a time for us to catch up and enjoy each othe r’s company.36 I enjoy imagining adventures with my ________ (玩具名称).37 What do you use to write?A. SpoonB. ForkC. PencilD. Plate答案: C38 Which of these is a winter sport?A. SwimmingB. SkiingC. SurfingD. Running答案:B39 Did you find a _______ (小蝴蝶) in your garden?40 A ____ is a swift animal that can leap great distances.41 The _____ (章鱼) can fit through tiny spaces.42 I want to ________ (encourage) others.43 Butterflies go through _______ (变形) stages.44 The teacher is ___ the lesson. (teaching)45 We enjoy camping in the ________ (森林).46 The _____ (金鲨) glides through the ocean with grace. 金鲨优雅地穿梭于海洋中。