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一个氘核(H)和一个氚核(H)聚变时产生一个中子(n)和一个α粒子(He).已知氘核的质量mD,氚核的质量为mT,中子的质量mn,α粒子的质量ma,光速为c,元电荷电量为e. (1)写出核反应方程...
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高三下学期物理《》真题及答案
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一个原来静止的锂核俘获一个速度为7.7×104m/s的中子后生成一个氚核和一个氦核已知氚核的速度大小
一个氘核和一个氚核经过反应后生成一个氦核和一个中子同时放出一个γ光子.已知氘核氚核中子氦核的质量分别
这个反应的核反应方程是
H
H
He
n+γ
这个反应既不是聚变反应也不是裂变反应
辐射出的γ光子的能量E.=(m
3
+m
4
-m
1
-m
2
)c
2
辐射出的γ光子的波长λ=
下列说法正确的是
氡的半衰期为3.8天,若取8个氡原子核,经3.8天后可能还剩5个氡原子核
β衰变的实质是原子核内的一个中子转化成一个质子和一个电子,这种转化产生的电子发射到核外,就是β粒子
物质波的波长由动能所决定
氘核和氚核可发生热核聚变,核反应方程是
H+
H→
He+
n E. 按照玻尔理论,氢原子核外电子从半径较小的轨道跃迁到半径较大的轨道时,电子的动能减小,电势能增大,原子的总能量不变
2个氘核可聚变成一个氚核放出4MeV的能量写出核反应方程_____________当1kg氘完全聚变
一个质子和一个中子经过聚变结合成一个氘核同时辐射一个γ光子已知质子中子氘核的质量分别为m1m2m3普
一个质子和一个中子聚变结合成一个氘核同时辐射一个γ光子.已知质子中子氘核的质量分别为m1m2m3普朗
核反应方程是
H+
n→
H+γ
聚变反应中的质量亏损Δm=m1+m2-m3
辐射出的γ光子的能量E.=(m3-m1-m2)c
γ光子的波长λ=
关于近代物理学的结论中下面叙述中正确的是
比结合能越大表示原子核中的核子结合的越牢固
β衰变所释放的电子是原子核内的中子转化成质子和电子所产生的
一个氘核(
H)与一个氚核(
H)聚变生成一个氦核(
He)的同时,放出一个中子
Bi的半衰期是5天,1000个
Bi经过10天后还剩下250个
一个氘核与一个氘核发生聚变产生一个中子和一个新核并出现质量亏损若用m1m2m3m4分别表示氘核氘核中
一个氘核与一个氚核发生聚变产生一个中子和一个新核并出现质量亏损则聚变过程中
吸收能量,生成的新核为
吸收能量,生成的新核为
放出能量,生成的新核为
放出能量,生成的新核为
一个质子和两个中子聚变成一个氚核已知质子质量为1.0073u中子质量为1.0087u氚核质量为3.0
一个氘核和一个氚核聚变成一个氦核其核反应方程是以下说法正确的是
X.是质子,反应过程中有质量亏损
X.是中子,反应过程中有质量亏损
X.是质子,反应过程中没有质量亏损
X.是中子,反应过程中没有质量亏损
中新网2006年2月2日报道中国科学家率先建成了世界上第一个全超导核聚变人造太阳实验装置这个装置进入
一个氚原子比一个氕(
1
H.)原子多两个中子
人造太阳可为人类提供清洁的核聚变能源
氘和氚在人造太阳装置中可发生核聚变反应
上述“人造太阳”实验的成功说明人类可以控制太阳中的核聚变反应
太阳内部不断进行着各种核聚变反应一个氘核和一个氚核结合成一个氦核是其中一种请写出其核反应方程____
一个原来静止的锂核36Li俘获一个速度为7.7×104m/s的中子后生成一个氚核和一个氦核已知氚核
中子和质子结合成氘核时质量亏损为Δm相应的能量ΔE.=Δmc2=2.2MeV是氘核的结合能.下列说法
用能量小于2.2 MeV的光子照射静止氘核时,氘核能分解为一个质子和一个中子
用能量等于2.2 MeV的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和为零
用能量大于2.2 MeV的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和为零
用能量大于2.2 MeV的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和不为零
中子和质子结合成氘核时质量亏损△m相应的能量△E.=△mc2=2.2MeV.是氘核的结合能下列说法正
用能量小于2.2MeV.的光子照射静止氘核时,氘核不能分解为一个质子和一个中子
用能量等于2.2MeV.的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和为零
用能量大于2.2MeV.的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和为零
用能量大于2.2MeV.的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和不为零
一个氘核与一个氚核发生聚变产生一个中子和一个新核并出现质量亏损若用mlm2m3m4分别表示氘核氚核中
中子和质子结合成氘核时质量亏损为△m相应的能量△E.=△mc2=2.2MeV是氘核的结合能已知波长为
用能量小于2.2MeV的光子照射静止氘核时,氘核可能分解为一个质子和一个中子
用能量等于2.2 Mev的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和为零
用能量大于2.2MeV的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和为零
用能量大于2.2MeV的光子照射静止氘核时,氘核可能分解为一个质子和一个中子,它们的动能之和不为零
一个氘核和一个氚核聚变成一个氦核其核反应方程是以下说法正确的是
X.是质子,反应过程中有质量亏损
X.是中子,反应过程中有质量亏损
X.是质子,反应过程中没有质量亏损
X.是中子,反应过程中没有质量亏损
一个氘核和一个氚核聚变成一个氦核其核反应方程是以下说法正确的是
X.是质子,反应过程中有质量亏损
X.是中子,反应过程中有质量亏损
X.是质子,反应过程中没有质量亏损
X.是中子,反应过程中没有质量亏损
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如图为速度选择器示意图P1P2为其两个极板.某带电粒子以速度v0从S1射入恰能沿虚线从S2射出.不计粒子重力下列说法正确的是
某物理兴趣小组利用如图所示的电路给一个原来不带电的电容器充电在充电过程中电路中的电流为i电容器所带的电荷量为q两极板问的电势差为u电容器储存的能量为E电.下面的四幅示意图分别表示iqu和E电随时间t的变化关系其中可能正确的是
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一个铀核U发生裂变核反应方程是U+n→Ba+K+3X并出现质量亏损.则
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回答下列与生态系统相关的问题. 1在森林生态系统中生产者的能量来自于生产者的能量可以直接流向答出2点即可. 2通常对于一个水生生态系统来说可根据水体中含氧量的变化计算出生态系统中浮游植物的总初级生产量生产者所制造的有机物总量.若要测定某一水生生态系统中浮游植物的总初级生产量可在该水生生态系统中的某一水深处取水样将水样分成三等份一份直接测定O2含量A另两份分别装入不透光甲和透光乙的两个玻璃瓶中密闭后放回取样处若干小时后测定甲瓶中的O2含量B和乙瓶中的O2含量C.据此回答下列问题. 在甲乙瓶中生产者呼吸作用相同且瓶中只有生产者的条件下本实验中C与A的差值表示这段时间内C与B的差值表示这段时间内A与B的差值表示这段时间内.
下列根据实验操作和现象所得出的结论正确的是
某研究小组切取某种植物胚芽鞘的顶端分成甲乙两组按如图所示的方法用琼脂块收集生长素再将含有生长素的琼脂块置于去顶胚芽鞘切段的一侧一段时间后测量胚芽鞘切段的弯曲程度α角测得数据如下表据此回答问题. 1生长素在胚芽鞘中的运输属于极性运输这种运输的方向是. 2如图中α角形成的原因是. 3据表可知乙组中左右两侧的琼脂块所引起的α角基本相同但小于甲琼脂块所引起的α角原因是.
在真核细胞的内质网和细胞核中能够合成的物质分别是
传统果园常进行单一化种植经常爆发病虫害.某生态果园采用“果一草一禽牧”立体种养模式如图.请回答相关问题. 1传统果园容易爆发病虫害的原因是. 2图中果树饲草可以为鸡鹅兔等动物提供. 3与传统果园相比该生态果园具有哪三个方面的优势
如图所示用半径相同的AB两球的碰撞可以验证“动量守恒定律”.实验时先让质量为m1的A球从斜槽轨道上某一固定位置S由静止开始滚下从轨道末端抛出落到位于水平地面的复写纸上在下面的白纸上留下痕迹.重复上述操作10次得到10个落点痕迹.再把质量为m2的B球放在斜槽轨道末端让A球仍从位置S由静止滚下与B球碰撞后分别在白纸上留下各自的落点痕迹重复操作10次.MPN为三个落点的平均位置. ①实验中直接测定小球碰撞前后的速度是不容易的.但是可以通过测量间接地解决这个问题. A.小球开始释放高度hB.小球抛出点距地面的高度HC.小球做平抛运动的射程 ②以下提供的测量工具中本实验必须使用的是多选. A.刻度尺B.天平C.游标卡尺D.秒表 ③关于本实验下列说法正确的是. A.斜槽轨道必须光滑B.斜槽轨道末端必须水平C.实验过程中复写纸和白纸都可以移动 ④在实验误差允许范围内若满足关系式则可以认为两球碰撞前后总动量守恒. A.m1.OP=m1.OM+m2•ONB.mc.OP=m1.ON+m2.OM C.m1.OM=m1.OP+m2.OND.m1.ON=ml.OP+m2.OM ⑤在实验中为了让A球碰后沿原方向运动应满足A球的质量m1大于B球的质量m2请推理说明.
如图所示一理想变压器的原线圈接正弦交流电源副线圈接有电阻R和小灯泡.电流表和电压表均可视为理想电表.闭合开关S下列说法正确的是
光子除了有能量还有动量.若光子能量为E动量为J则光子动量p=式中c为真空中的光速.当光照射到物体表面上时不论光被物体吸收还是被物体表面反射光子的动量都会发生改变因而对物体表面产生一种压力. 如图是1901年俄同物理学家列别捷夫测量光压的实验装置.T型架通过悬丝竖直悬挂横臂水平悬丝一端同定在横臂中点.在横臂的两侧有圆片P和Q两圆片与T型架在同一竖直平面内.圆片P是涂黑的当光线照射到P上时可以认为光子全部被吸收圆片Q是光亮的当光线照射到Q上时可以认为光子全部被反射.分别将光线照射在P或Q上都可以引起悬丝的旋转.在悬丝上固定一__面M用一细光束照射时就可以获知悬丝扭转的角度.已知光速为c两个圆片PQ的半径都为r.悬丝转过的角度与光对网片的压力成正比. a.用光强单位时间内通过与传播方向垂直的单位面积的光能为I0的激光束垂直照射整个圆片P求激光束对圆片P的压力F2的大小 b.实验中第一次用光强厶为的激光束单独照射整个圆片P平衡时光束与圆片垂直且悬丝有一扭转角第二次仍用该光束单独照射整个圆片Q平衡时光束与圆片不垂直悬丝的扭转角与第一次相同.求激光束与圆片Q所在平面的夹角φ.
Mycolortelevisionhasgivenmenothingbutaheadache.IwasabletobuyitalittleoverayearagobecauseIhadmyrelativesgivememoneyformybirthdayinsteadofalotofclothesthatwouldn'tfit.IletasalesclerkfoolmeintobuyingadiscontinuedmodelIrealizedthisadaylatewhenIsawnewspaperadvertisementsforthesetatseventy﹣fivedollarslessthanIhadpaidThesetworkedsobeautifullywhenIfirstgotithomethatIwouldkeepitonuntilstationssignedoffforthenightFortunatelyIdidn'tgotanychannelsshowingall﹣nightmoviesorIwouldneverhavegottentobed. ThenIstarteddevelopingaproblemwiththesetthatinvolvedstatic静电noise.Forsomereasonwhencertainshowsswitchedintoacommercialaloudnoisewouldsoundforafewseconds.GraduallythisnoisebegantoappearduringashowandtogetridofitIhadtochangetoanotherchannelandthenchangeitback.SometimesthistechniquewouldnotworkandIhadtopickupthesetandshakeittoremovethesound.Iactuallybegantobuildupmyarmmuscles肌肉shakingmyset. WhenneitherofthesemethodsremovedthestaticnoiseIwouldsithelplesslyandwaitforthenoisetogoaway.AtlastIendeduphittingthesetwithmyfistanditstoppedworkingaltogether.Mytriptotherepairshopcostme$62andthesetisworkingwellnowbutIkeepexpectingmoretrouble. 21.WhydidtheauthorsayhewasfooledintobuyingtheTVset? A.Hegotanoldermodelthanhehadexpected. B.Hecouldn'treturnitwhenitwasbroken. C.Hecouldhaveboughtitatalowerprice. D.Hefailedtofindanymovieshowsonit. 22.WhichofthefollowingcanbestreplacethephrasesignedoffinParagraph1? A.endedalltheirprograms B.providedfewerchannels C.changedtocommercials D.showedall﹣nightmovies 23.HowdidtheauthorfinallygethisTVsetworkingagain? A.Byshakingandhittingit. B.Byturningitonandoff. C.Byswitchingchannels. D.Byhavingitrepaired. 24.Howdoestheauthorsoundwhentellingthestory? A.Curious B.Anxious C.Cautious D.Humorous.
如图为香芹酮分子的结构下列有关叙述正确的是
直流电动机的基本结构由永磁铁和矩形线圈构成如图1所示.现将标有“3V3W”的直流电动机串联一个滑动变阻器接在电动势为E=4.0V内阻为r=0.40Ω的电源的两端如图2所示.已知电动机线圈的电阻R0=0.10Ω不计其它电阻. 1若滑动变阻器接入电路的阻值R1=3.5Ω且电动机卡住不转求此时电路中的电流I1. 2调节滑动变阻器接入电路的阻值或电动机工作时的负载发生变化回路中的电流I及电源的输出功率P随之改变. a.请从理论上推导P与I的关系式并在图3中定性画出P﹣I图象 b.求该电源对外电路能够输出的最大功率Pm. 3调节滑动变阻器接入电路的阻值使电动机正常工作.现保持滑动变阻器接入电路的阻值不变增加电动机的负载电动机将通过转速调节达到新的稳定状态.请分析说明在这个过程中电路中的电流如何变化.
常温下向20.00mL0.1000mol•L﹣1NH42SO4溶液中逐滴加入0.2000mol•L﹣1NaOH溶液时溶液的pH与所加NaOH溶液体积的关系如图所示不考虑NH3•H2O的分解.下列说法不正确的是
物质W是一种含氮有机物会污染土壤.W在培养基中达到一定量时培养基表现为不透明.某研究小组欲从土壤中筛选出能降解W的细菌目标菌.回答下列问题. 1要从土壤中分离目标菌所用选择培养基中的氮源应该是. 2在从土壤中分离目标菌的过程中发现培养基上甲乙两种细菌都能生长并形成菌落如图所示.如果要得到目标菌应该选择菌落进一步纯化.选择的依据是. 3土壤中的某些微生物可以利用空气中的氮气作为氮源若要设计实验进一步确定甲乙菌能否利用空气中的氮气作为氮源请简要写出实验思路预期结果和结论即. 4该小组将人工合成的一段DNA转入大肠杆菌使大肠杆菌产生能降解W的酶酶E.为了比较酶E与天然酶降解W能力的差异该小组拟进行如下实验请完善相关内容. ①在含有一定浓度W的固体培养基上A处滴加含有酶E的缓冲液B处滴加含有相同浓度天然酶的缓冲液C处滴加三处滴加量相同. ②一段时间后测量透明圈的直径.若C处没有出现透明圈说明若AB处形成的透明圈直径大小相近说明.
Theadobedwellings土坯房61buildbythePuebloIndiansoftheAmericanSouthwestareadmiredbyeven62mostmodernofarchitectsandengineers.Inadditiontotheirsimplebeautywhatmakestheadobedwellingsadmirableistheir63abletoairconditionahousewithout64useelectricequipment.Wallsmadeofadobetakeintheheatfromthesunonhotdaysandgiveoutthatheat65slowduringcoolnightsthuswarningthehouse.Whenanewdaybreaksthewallshavegivenuptheirheatandarenowcoldenough66coolthehouseduringthehotday67thesametimetheywarmupagainforthenightThiscycle68godayafterdayThewallswarmupduringthedayandcooloffduringthenightandthusalwaysatimelyoffset抵消fortheoutsidetemperatures.As69naturearchitectsthePuebloIndiansfiguredoutexactly70thicktheadobewallsneededtobetomakethecycleworkonmostdays. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70.
AsakidIlovedeverythingaboutschool.Ilovedbooks1testsandhomework.MostofallIlongedtosomedaymarchdowntheaisle通道toreceivemy2.Thatseemedmoreappealingeventhangettingmarried.Butat15Ihadto3becausemyparents4affordtuition学费.Myhopeofgettingadiplomawasdead. PrettysoonImarried.IhadthreeChildrenandIthoughtThere5mydiploma.EvensoIwantedmychildrentobeeducated.ButLindaouryoungestchildhadjuvenilearthritis幼年型关节炎inher6andkneeswhichmadeit7forhertofunctioninanormalclassroom. OnedayIsawanadinthenewspaperforeveningcourses. That'stheanswerIsaidtomyself.Lindaalwaysfeels8intheeveningsoI'lljustsignherupfornightschool. Lindawasbusy9outenrollment入学formswhenthesecretarysaidMrsSchantzwhydon'tyoucomebackto10? I11There'snoway!I'm! 12heinsistedandbeforeIknewwhatIhaddoneIwasenrolledforclassesinEnglishandcrafts.ThisisonlyanexperimentI13himbuthejustsmiled.TomysurprisebothLindaandIthrived茁壮成长ineveningschool.Iwentbackagainthenextsemesterandmygrades14improved. Itwas15togotoschoolagainbutitwasnogame.Sittinginaclassfullofkidswasawkward16mostofthemwererespectfulandencouraging.DuringthedayIstillhadloadsofhouseworktodo.ButwhenIwasdownLindaencouragedme.Mumyoucan't17now!AndwhenshewasdownI18her.Togetherwesawitthrough.AtlastIgotmydiploma.19myclassmatesvotedunanimously一致地formetobeclassspeakerandIgota$3000collegescholarship. YesMumIwaslateforschoolbutIgotthere20. 1.A.parents B.teachers C.trees D.flowers 2.A.job B.present C.certification D.diploma 3.A.dropout B.watchout C.keepout D.findout 4.A.wouldn't B.couldn't C.shouldn't D.needn't 5.A.goes B.comes C.exists D.breaks 6.A.hands B.head C.eyes D.stomach 7.A.1ikely B.frequent C.easy D.impossible 8.A.Worse B.excited C.better D.annoyed 9.A.giving B.taking C.filling D.sending 10.A.work B.school C.home D.office 11.A.laughed B.told C.argued D.shouted 12.A.And B.But C.Although D.So 13.A.informed B.asked C.warned D.convinced 14.A.regularly B.happily C.steadily D.naturally 【考点】记叙文人生感悟类阅读 【分析】文章讲述了作者小时候很喜欢上学因为父母负担不起学费而辍学.她55岁时和女儿一起上夜校并获得了大学奖学金最终实现了自己小时候的梦想. 【解答】C副词辨析.regularly有规律地happily开心地steadily稳定地natumlly自然地.我的成绩稳步提高.故选C. 【点评】完型填空题的命题趋势 【备注】1#1#1#C ~15.A.interesting B.disappointing C.concerned D.exciting 16.A.asif B.evenif C.incase D.ifonly 17.A.continue B.rest C.quit D.hesitate 18.A.raised B.discouraged C.cheered D.defeated 19.A.Tomysurprise B.Tomysatisfaction C.Tomyrelief D.Tomycredit 20.A.naturally B.frequently C.constantly D.eventually
某课题组就固氮菌和纤维素分解菌混合培养对纤维素降解的效果进行研究实验步骤大致如下取250mL三角瓶装入50mL基础培养基接种不同比例的混合菌种放入滤纸条150r/min摇床振荡培养.根据滤纸条的分解情况测定纤维素酶的活性实验结果如表. 1上述实验中培养基中填需要”或“不需要”加入琼脂滤纸条的作用是. 2完成上述实验时还必须进行. 3由上表可得出如下实验结论. 4有同学推测混合培养也能促进固氮菌的生长理由是.若想比较IIIIIIV组的固氮菌数目实验思路如下最后统计各组固氮菌的菌落数.
Trainingforamarathonrequirescarefulpreparationandsteadygradualincreasesinthelengthoftheruns.36buythebest﹣fittingbest﹣builtrunningshoesyoucanfind.Noonecansaywhichbrandwillworkbestforyouorfeelbestonyourfeetsoyouhavetorelyonyourexperienceandonthefeelofeachpairasyoushop.Whenyouhavefoundshoesthatseemrightwalkinthemforafewdaystodouble﹣checkthefit.37.Asalwaysyoushouldstretch伸展atleasttenminutesbeforeeachruntopreventinjuries. Duringthefirstweekdonotthinkaboutdistancebutrunfiveminuteslongereachday.38itiswisetotakeadayofftorest.Butduringthenextweeksetagoalofatleastamileandahalfperrun.39.Aftertwoweeksstarttimingyourself.40.Dependingonthekindofraceyouplantoenteryoucansetupatimetablefortheremainingweeksbeforetherace. A.Aftersixdays B.Foragoodmarathonrunner C.Beforeyoubeginyourtraining D.Witheachdayincreasethedistancebyahalfmile E.Iftheystillfeelgoodyoucanbeginrunninginthem F.Timespentforpreparationraisesthequalityoftraining G.Nowyouarereadytofigureoutagoalofimprovingdistanceandtime. 36. 37. 38. 39. 40.
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