• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    A K-CELL injection system for SH-PermEBIT?

    2014-03-07 12:24:22HANChuan韓川ZHAORuiFeng趙瑞峰SHIZhan施展RogerHuttonandLUDi路迪
    Nuclear Science and Techniques 2014年4期
    關(guān)鍵詞:施展

    HAN Chuan(韓川),ZHAO Rui-Feng(趙瑞峰),SHI Zhan(施展),Roger Hutton,,and LU Di(路迪),

    1The Key Lab of Applied Ion Beam Physics,Ministry of Education,Shanghai 200433,China

    2Shanghai EBIT Laboratory,Modern Physics Institute,Fudan University,Shanghai 200433,China

    A K-CELL injection system for SH-PermEBIT?

    HAN Chuan(韓川),1,2ZHAO Rui-Feng(趙瑞峰),1,2SHI Zhan(施展),1,2Roger Hutton,1,2,?and LU Di(路迪)1,2,?

    1The Key Lab of Applied Ion Beam Physics,Ministry of Education,Shanghai 200433,China

    2Shanghai EBIT Laboratory,Modern Physics Institute,Fudan University,Shanghai 200433,China

    In this paper,we report a newly developed Knudsen Cell injection system for SH-PermEBIT.This technique canovercomedisadvantagesofintroducingorganometallicgasesandwiredprobesintoEBITandprovidesteady continuous injection.A specially designed vacuum line is used to ensure that the Knudsen Cell satisfies the vacuum level of SH-permEBIT.Using this system we successfully injected ytterbium into the SH-permEBIT and recorded a spectrum in the visible wavelength region.

    Knudsen Cell,EBIT,Metallic atom injection

    I.INTRODUCTION

    Electron beam ion traps(EBITs)[1]are devices designed for studying the spectra of highly charged ions or their interactions with electrons.Unlike traditional EBITs which occupy large areas due to requirements on high electron beam energy and cryogenic operation,the Shanghai permanent magnet EBIT,SH-permEBIT[2,3],has its specific advantages.It can be operated at relatively low electron beam energies(down to~60eV)and at room temperature.A major problem with an EBIT is how to inject the element of interest into the vacuum chamber,for spectroscopic or electron collision studies.For SH-permEBIT,it is difficult to use the methods of injecting elements into a traditional EBIT,such as metal-vapor vacuum arc and laser ion source, which can hardly be installed on it.Wire probes[4]and organometallic gases[3]have been successfully used to introducemetalelementsintoEBITs,buttheyaredisadvantageous in that wire probes may destroy the electron beam shape and organometallic compounds may cause C/O contamination in the trap.For SH-permEBIT,organometallic compound condensation may even occur in the vacuum chamber when it is operated at the same temperature as the injection system,i.e. room temperature.Steady and continuous injection of simple substance is crucial for some experiments,and for wider applications of the SH-permEBIT,hence the development of a Knudsen Cell(K-CELL)injection system is required.

    II.DEVICE SETUP

    K-CELL is a high-temperature effusion cell working under fairly high vacuum conditions[5].It has been widely used in molecular-beam-epitaxy(MBE)[6]experiments and in electron cyclotron-resonance ion source[7].The Tokyo EBIT(traditional EBIT)has employed a K-CELL for metal vapor injection[8].

    Fig.1.Schematics of the K-CELL injection system.The valve keeps the vacuum of the main-chamber when the crucible needs to be charged or changed,and prevents it from contaminant gases of initial heating.The fl exible fl ange is used for collimation.

    Traditionally EBITs are operated at liquid helium temperatures with high vacuum in their drift tube region,while SH-permEBIT is operated at room temperature,hence a very different vacuum level in its drift tube region.So,modifications were made to accommodate for the operation conditions.As shown in Fig.1,the K-CELL was fixed via a 4-way cross to the main body and central drift tube of the EBIT.A plate sloped at 45?containing a 1-mm aperture is installed in the centre of the cross.The K-CELL injection system is isolated from the EBIT by a vacuum valve,and a short vacuum pipe leads its way into the EBIT and ends at the central drift tube.

    Aperture 1 in the 45?plate is used to confine diffused metallic vapor effusing out from the crucible. The vacuum between the two apertures is better than 10-6Torr (1.3×10-4Pa),and the mean free path of gas is over 50m, being longer than the distance between the two apertures.So, after passing Aperture 1,the vacuum is high enough for metal atoms to go through the tube,or hit the wall of the vacuum line without collisions with other atoms.The valve keeps vacuum of the main-chamber when the K-CELL crucible needs to be charged or changed,and to prevent it from contaminant gasesofinitialheatingoftheK-CELL.Thestraightpipe,with a fl exible fl ange connecting the EBIT,has a small aperture (Aperture 2)into the main-chamber and near the center drift tube(DT2),allowing the atomic beam to enter the drift tube region and cross with the electron beam.The drift tube has a 1mm×20mm slit.Aperture 2 and the crucible of the KCELL can be shifted by one or two millimeters by changing their support frames.

    The K-CELL,four-way cross,valve and straight pipe line were assembled,making sure the crucible center and the two apertures were aligned(the K-CELL axis),and the whole injection system was installed on the EBIT,making use of the fl exible fl ange to finally align the K-CELL axis and the slit on the same axis.

    Fig.2.Schematics of a traditional K-CELL injection system,from Tokyo EBIT[9].A copy was made in our laboratory,but it did not work well.Our design,with a four-way cross with 45?sloped plate to replace the two three-way pipes(1 and 2),decreases transport loss in Sec.I.Our design has no third pipe and structure 3,so thefinal orifice can be placed near to the EBIT drift tubes,with reduced divergence of the atomic beam.

    Compared to traditional schemes[9](Fig.2),our design halved the transport distance of the effusing vapor from the crucible to Aperture 1.This drastically reduces the loss of effusing metallic atoms,according to the transport-residual formula[5]:

    where nxis number of residual atoms after a transport length of x,n0is total number of atoms effusing from the crucible, and s is mean-free-path of the vapor.Besides,Aperture 2 is placed near the slit of center drift tube,which reduces divergence of the atom beam and raises the injection efficiency, according to the injection rate formula[12]:

    where J is the injection rate,P is pressure,m is atom’s weight,k is Boltzmann constant,T is temperature in Kelvins, l is the length from crucible to the slit of DT2 and S is the aperture area.

    The temperature was controlled by a Eurotherm 2408 Temperature Controller[14]with an accuracy of±2?C.The upper temperature limit of the K-CELL is 1400?C according to the manufacture[15]and the vacuum is better than 10-3Torr (0.13Pa).It is often difficult,and unnecessary in some ways, to know the exact injection rate for a given element.Besides, the absolute strength of spectrum from EBITs depends on a number of factors,including vacuum of the EBIT chamber or residual gases from previous experiment.The injection pressure is usually set when a good spectrum of the injected elementisobtained.Relativeintensityofthespectrum,ofanelementinjectedintoEBITbytraditionalandimprovedK-CELL injection systems under the same operating condition,would indicate our improvement.Efficiencies of magnesium injection into SH-PermEBIT by the two K-CELL injection system are shown in Fig.3.The pressures in crucible were about 10-4Torr(0.013Pa)and electron beam energy was 730eV. Only weak Mg I(285.21nm)[16]signal was recorded with the traditional injection system,while strong Mg I and clear Mg II double line(279.55nm,280.27nm)[16]were recorded with the improved K-CELL system.

    Fig.3.Magnesium injection efficiencies of different schemes at 350?C and 10-4Torr of the crucible,with 730eV electron beams of about 8.0mA.The trap depth was 50eV.The spectra were recorded for 1 hour by Andor(SR-303i)with 30μm slit and 1200l/mm grating blazed at 300nm.With the traditional K-CELL,only a week Mg I line(285.21nm)was recorded,while with the improved design, the Mg I line was much stronger and two Mg II lines(279.55nm, 280.27nm)were recorded clearly.

    TABLE 1.The relationship between vapor pressure and temperature for ytterbium

    Fig.4.Ag-like Yb M1 line at(5157.7±1.0)?A in air,measured with 1100eV E-beam at about 8.5mA,and the trap depth of 200eV. The K-CELL was operated at 400?C.

    III.EXPERIMENTAL

    We contrived an experiment with the K-CELL injection system,trying to observe the2F7/2→2F5/2M1 transition line[11]in Ag-like Yb(Yb23+).The temperature/vaporpressure relationship for ytterbium is listed in Table 1[13].

    In this experiment,the crucible was heated to 400?C,with the vapor pressure of nearly 10-4Torr(0.013Pa).The excited ions were produced and confined in the drift tube region, some of which decayed through emitting photons.The light was analyzed by a Czerny-Turner spectrometer from Andor (SR-303i),which covers wavelength range of 200–800nm. To obtain a larger collection solid angle,we used a quartz lens of f=185mm between the EBIT window and the 30-μmentranceslitofspectrometer.Lightfromthecenterofdrift tube was dispersed by a 1200l/mm grating blazed at 300nm and detected by a charge coupled device(Andor DU940PBU2).The spectrum was recorded on the CCD-controlling computer.A typical spectrum is shown in Fig.4.For the first time,we observed this M1 line.Analysis is on the way for future publications.

    IV.CONCLUSION

    In conclusion,the K-CELL injection system works well with the SH-permEBIT.This system can be used for injecting many metal or rare earth elements into SH-permEBIT, instead of using wire probes or organometallic gases.More experiments with the EBIT and K-CELL combination can be expected in the future.

    [1]Zou Y and Hutton R.J Phys Conf Ser,2007,72,012003.

    [2]Xiao J,Fei Z,Yang Y,et al.Rev Sci Instrum,2012,83,013303.

    [3]Fei Z,Zhao R,Shi Z,et al.Phys Rev A,2012,86,062501.

    [4]Elliot S R and Marrs R E.Nucl Instrum Methods Phys Res B, 1986,57,1069–1084.

    [5]Molecular Beam Epitaxy:Fundamentals and Current Status, Maria A.Herman,Springer-Verlag,1996.

    [6]Pardo R C and Billquist P J.Rev Sci Instrum,1990,61,239–241.

    [7]Yamada C,Negata K,Nakamura N,et al.Rev Sci Instrum, 2006,77,066110.

    [8]Winterbottom W L and Hirth J P.J Chem Phys,1962,37,784–793.

    [9]Nakamura N,Kinugawa T,Shimizu H,et al.Rev Sci Instrum, 2000,71,684–686.

    [10]Pardo R C and Billquist P J.Rev Sci Instrum,1990,61,239–241.

    [11]Grumer J,Zhao R,Brage T,et al.arXiv:1405.2672.

    [12]Winterbottom W L and Hirth J P.J Chem Phys,1962,37,784–793.

    [13]Margrave J L.The Characterization of High-Temperature Vapors.New York(USA):John Wileyamp;Sons,Inc.,1967.

    [14]http://www.eurotherm.co.uk/en-gb/ products/controllers/single-loop/2400/ 2408/

    [15]http://www.hx-vac.cn/product_6.html

    [16]Kramida A,Ralchenko Yu,Reader J,et al.NIST Atomic Spectra Database(ver.5.1).http://physics.nist.gov/ asd

    (Received April 1,2014;accepted in revised form July 2,2014;published online August 15,2014)

    10.13538/j.1001-8042/nst.25.040203

    ?Supported by the National Natural Science Foundation of China(No. 11374061)

    ?rhutton@fudan.edu.cn

    ?ludi@fudan.edu.cn

    猜你喜歡
    施展
    會魔法的書
    一歲一禮
    再見吧,貓毛
    張弛有度 開創(chuàng)班級管理新局面
    合法“施展”法術(shù)
    看天下(2017年17期)2017-06-29 19:50:56
    變“廢”為“寶”施展錯題“魅力”
    改善訓(xùn)練條件 為官兵施展拳腳提供保障
    搏擊
    校園足球(2010年6期)2010-01-24 08:12:38
    明暗兩重天
    国产老妇伦熟女老妇高清| 精品人妻熟女av久视频| 国产精品伦人一区二区| 一个人免费看片子| 精品人妻熟女av久视频| 中文天堂在线官网| 免费看不卡的av| 国产在线男女| 美女高潮的动态| 99久久精品国产国产毛片| 精品国产露脸久久av麻豆| 久久人人爽人人片av| 一二三四中文在线观看免费高清| 最新中文字幕久久久久| 久久影院123| 美女福利国产在线 | 成人特级av手机在线观看| 麻豆乱淫一区二区| 亚洲美女搞黄在线观看| 国产精品无大码| 网址你懂的国产日韩在线| tube8黄色片| 99国产精品免费福利视频| 在线观看av片永久免费下载| 男女国产视频网站| 建设人人有责人人尽责人人享有的 | 久久久久久人妻| 91狼人影院| 久久久久久久久久人人人人人人| 国产伦理片在线播放av一区| 日本av手机在线免费观看| 美女脱内裤让男人舔精品视频| 亚洲精品一二三| tube8黄色片| 联通29元200g的流量卡| 成人毛片60女人毛片免费| 精品国产三级普通话版| 久久精品久久精品一区二区三区| 99热这里只有精品一区| 夫妻性生交免费视频一级片| 成人国产av品久久久| 国产亚洲精品久久久com| 国产精品欧美亚洲77777| 亚洲怡红院男人天堂| 少妇丰满av| 色视频在线一区二区三区| 麻豆乱淫一区二区| 午夜视频国产福利| 亚洲中文av在线| 国产伦精品一区二区三区四那| 色网站视频免费| 亚洲自偷自拍三级| 亚洲成人av在线免费| 午夜免费男女啪啪视频观看| 91精品一卡2卡3卡4卡| 国产精品久久久久久久电影| 97超视频在线观看视频| 欧美成人a在线观看| 亚洲va在线va天堂va国产| a 毛片基地| 欧美极品一区二区三区四区| 黄色配什么色好看| av线在线观看网站| 中文乱码字字幕精品一区二区三区| 丝袜脚勾引网站| 国产色婷婷99| 亚洲av国产av综合av卡| 日日撸夜夜添| 久久久成人免费电影| 我的老师免费观看完整版| 狂野欧美激情性bbbbbb| 丰满人妻一区二区三区视频av| 午夜日本视频在线| 久久人妻熟女aⅴ| 日韩制服骚丝袜av| 国产精品久久久久久精品电影小说 | 中国美白少妇内射xxxbb| 99精国产麻豆久久婷婷| 亚洲久久久国产精品| 亚洲av不卡在线观看| 欧美zozozo另类| 搡女人真爽免费视频火全软件| 最黄视频免费看| 国产午夜精品久久久久久一区二区三区| 日韩制服骚丝袜av| 黄色视频在线播放观看不卡| 亚洲久久久国产精品| 中文欧美无线码| 欧美精品国产亚洲| 啦啦啦中文免费视频观看日本| 国产国拍精品亚洲av在线观看| 久久婷婷青草| 亚洲欧美一区二区三区国产| 大香蕉97超碰在线| 大香蕉97超碰在线| 99久久精品国产国产毛片| 青春草国产在线视频| 丝袜喷水一区| 午夜日本视频在线| 六月丁香七月| 夜夜爽夜夜爽视频| 男的添女的下面高潮视频| 免费久久久久久久精品成人欧美视频 | 婷婷色综合大香蕉| 观看av在线不卡| 久久精品国产自在天天线| 亚洲欧美一区二区三区黑人 | 成人国产av品久久久| 美女主播在线视频| av免费在线看不卡| 少妇被粗大猛烈的视频| 国产成人精品福利久久| 免费看不卡的av| 免费看不卡的av| 欧美日本视频| 99re6热这里在线精品视频| 永久网站在线| av一本久久久久| 日本黄色片子视频| 免费看光身美女| 婷婷色麻豆天堂久久| 黄片wwwwww| 日本免费在线观看一区| 免费看不卡的av| 成人综合一区亚洲| 国产日韩欧美在线精品| 中文字幕免费在线视频6| 欧美97在线视频| 亚洲人成网站高清观看| 在线精品无人区一区二区三 | 老司机影院成人| 欧美高清性xxxxhd video| 久久久久久久国产电影| 香蕉精品网在线| 国产成人a区在线观看| 国产精品不卡视频一区二区| 亚洲经典国产精华液单| 亚洲精华国产精华液的使用体验| 天堂俺去俺来也www色官网| av在线播放精品| 美女xxoo啪啪120秒动态图| 激情 狠狠 欧美| 亚洲国产最新在线播放| 久久久欧美国产精品| 国产精品偷伦视频观看了| 欧美zozozo另类| 国产久久久一区二区三区| 久久毛片免费看一区二区三区| 免费av不卡在线播放| 国产午夜精品一二区理论片| 丰满少妇做爰视频| www.色视频.com| 亚洲av福利一区| 色哟哟·www| 18禁在线无遮挡免费观看视频| 中文在线观看免费www的网站| 寂寞人妻少妇视频99o| 男女国产视频网站| 麻豆乱淫一区二区| 久久久欧美国产精品| 美女脱内裤让男人舔精品视频| 国产精品99久久久久久久久| 日本黄色片子视频| 人妻少妇偷人精品九色| 日韩一区二区三区影片| 熟妇人妻不卡中文字幕| 亚洲欧美成人精品一区二区| 日日撸夜夜添| 亚洲精品456在线播放app| 国产男女超爽视频在线观看| 最新中文字幕久久久久| 久久6这里有精品| 久久久久精品性色| 少妇丰满av| av视频免费观看在线观看| 伦理电影大哥的女人| av网站免费在线观看视频| 十分钟在线观看高清视频www | 一级毛片久久久久久久久女| 老女人水多毛片| 老司机影院毛片| 亚洲国产精品专区欧美| 国产男女内射视频| 亚洲欧美成人精品一区二区| 国产乱人视频| 色网站视频免费| 夫妻午夜视频| 国产 一区 欧美 日韩| 免费观看av网站的网址| 各种免费的搞黄视频| 久久久久网色| 亚洲第一av免费看| 国精品久久久久久国模美| 国产免费一级a男人的天堂| 人妻一区二区av| 人妻制服诱惑在线中文字幕| 亚洲av中文av极速乱| 一二三四中文在线观看免费高清| 国产伦精品一区二区三区四那| 国产黄色免费在线视频| 成人影院久久| 大香蕉97超碰在线| 麻豆精品久久久久久蜜桃| 久久6这里有精品| 男女边吃奶边做爰视频| 久久人人爽av亚洲精品天堂 | 国产v大片淫在线免费观看| 老女人水多毛片| 成年美女黄网站色视频大全免费 | 国产精品免费大片| 简卡轻食公司| 日韩一区二区视频免费看| 女性生殖器流出的白浆| av在线app专区| 99热这里只有精品一区| 亚洲美女搞黄在线观看| 不卡视频在线观看欧美| 久久久久久九九精品二区国产| 一本色道久久久久久精品综合| 国产成人免费无遮挡视频| 亚洲第一av免费看| 亚洲国产精品专区欧美| 女性被躁到高潮视频| 亚洲三级黄色毛片| 街头女战士在线观看网站| 国产综合精华液| 少妇熟女欧美另类| 性色avwww在线观看| 亚洲第一区二区三区不卡| 新久久久久国产一级毛片| 久久精品熟女亚洲av麻豆精品| 久久久欧美国产精品| 在线看a的网站| 爱豆传媒免费全集在线观看| 国产精品久久久久久精品古装| 亚洲欧美一区二区三区黑人 | 国产国拍精品亚洲av在线观看| 国产成人免费无遮挡视频| 大片免费播放器 马上看| 嫩草影院新地址| 夜夜骑夜夜射夜夜干| 欧美丝袜亚洲另类| 欧美精品亚洲一区二区| 国产欧美日韩一区二区三区在线 | 大又大粗又爽又黄少妇毛片口| av免费观看日本| 欧美xxxx黑人xx丫x性爽| 97在线人人人人妻| 九草在线视频观看| 亚洲电影在线观看av| 五月开心婷婷网| 亚洲性久久影院| 肉色欧美久久久久久久蜜桃| 丰满人妻一区二区三区视频av| 99久久中文字幕三级久久日本| 校园人妻丝袜中文字幕| 久久毛片免费看一区二区三区| 日日撸夜夜添| 欧美成人午夜免费资源| 黄片无遮挡物在线观看| 一级黄片播放器| 网址你懂的国产日韩在线| 爱豆传媒免费全集在线观看| 人妻少妇偷人精品九色| 夜夜爽夜夜爽视频| av在线老鸭窝| 你懂的网址亚洲精品在线观看| 中国三级夫妇交换| 亚洲精品久久午夜乱码| 美女视频免费永久观看网站| 国产成人freesex在线| 精品人妻视频免费看| 精品一区在线观看国产| 国产精品久久久久久精品古装| 国产精品.久久久| 精品国产乱码久久久久久小说| 亚洲精品色激情综合| 日日撸夜夜添| 女人十人毛片免费观看3o分钟| 插逼视频在线观看| 亚洲美女黄色视频免费看| 久久久久网色| 男女免费视频国产| 毛片一级片免费看久久久久| 伦精品一区二区三区| 丰满人妻一区二区三区视频av| 久久久久久久大尺度免费视频| 亚洲精品视频女| 精品少妇久久久久久888优播| 久久精品国产亚洲av天美| 亚洲电影在线观看av| 亚洲精品aⅴ在线观看| 国产综合精华液| 蜜臀久久99精品久久宅男| 伦精品一区二区三区| 日韩一本色道免费dvd| 久久 成人 亚洲| 熟女av电影| 啦啦啦在线观看免费高清www| 国产久久久一区二区三区| 亚洲欧美日韩无卡精品| 国产乱来视频区| 久久久久久久久久久免费av| 国产精品人妻久久久影院| 99久久精品国产国产毛片| 日韩电影二区| 日产精品乱码卡一卡2卡三| 国产精品秋霞免费鲁丝片| 久久久欧美国产精品| 99热这里只有精品一区| 99久久精品一区二区三区| 黑丝袜美女国产一区| 黄片无遮挡物在线观看| 免费大片18禁| 亚洲不卡免费看| 在线观看免费日韩欧美大片 | 久久久久久久久久久丰满| 最近的中文字幕免费完整| 99热这里只有是精品在线观看| 精品亚洲乱码少妇综合久久| 永久网站在线| 欧美精品国产亚洲| 51国产日韩欧美| 人人妻人人看人人澡| 国产av码专区亚洲av| 各种免费的搞黄视频| 王馨瑶露胸无遮挡在线观看| 国产欧美日韩一区二区三区在线 | 在线亚洲精品国产二区图片欧美 | 少妇人妻久久综合中文| 99热网站在线观看| 国产成人精品婷婷| 亚洲电影在线观看av| 男女下面进入的视频免费午夜| 久久久成人免费电影| 深爱激情五月婷婷| 成年免费大片在线观看| 亚洲真实伦在线观看| 男人爽女人下面视频在线观看| 国产男女超爽视频在线观看| 男男h啪啪无遮挡| 看免费成人av毛片| 日本av手机在线免费观看| 在线播放无遮挡| 精品久久久久久久久av| av视频免费观看在线观看| 亚洲内射少妇av| 男人添女人高潮全过程视频| 亚洲天堂av无毛| 日本一二三区视频观看| av视频免费观看在线观看| 婷婷色麻豆天堂久久| 日韩中字成人| 免费久久久久久久精品成人欧美视频 | 又爽又黄a免费视频| 内射极品少妇av片p| 欧美性感艳星| 伊人久久精品亚洲午夜| 啦啦啦视频在线资源免费观看| 最近最新中文字幕大全电影3| 亚洲精品亚洲一区二区| 久久 成人 亚洲| 18禁裸乳无遮挡免费网站照片| 天堂8中文在线网| 久久 成人 亚洲| 蜜桃亚洲精品一区二区三区| 午夜免费观看性视频| 天天躁夜夜躁狠狠久久av| 一级毛片久久久久久久久女| 97超碰精品成人国产| 亚洲国产欧美人成| 午夜视频国产福利| 多毛熟女@视频| 晚上一个人看的免费电影| 亚洲精品aⅴ在线观看| 久久久久久久久大av| 亚洲国产欧美人成| 午夜福利视频精品| 高清欧美精品videossex| 亚洲人成网站高清观看| 成人毛片a级毛片在线播放| 免费久久久久久久精品成人欧美视频 | 91精品国产九色| 免费人妻精品一区二区三区视频| 性色avwww在线观看| 99re6热这里在线精品视频| 亚洲怡红院男人天堂| 中文字幕精品免费在线观看视频 | 在线免费观看不下载黄p国产| 丝袜喷水一区| 男女啪啪激烈高潮av片| 国模一区二区三区四区视频| 高清午夜精品一区二区三区| 热99国产精品久久久久久7| 大话2 男鬼变身卡| 国内精品宾馆在线| 亚洲成色77777| 国产精品爽爽va在线观看网站| 国产乱人偷精品视频| 日韩一本色道免费dvd| 多毛熟女@视频| 久久久国产一区二区| 免费久久久久久久精品成人欧美视频 | 亚洲精品久久久久久婷婷小说| 亚洲精品日本国产第一区| 欧美三级亚洲精品| av卡一久久| 亚洲精华国产精华液的使用体验| 少妇人妻久久综合中文| 国产免费福利视频在线观看| 日韩av免费高清视频| 亚洲人成网站在线播| 男女啪啪激烈高潮av片| 最近手机中文字幕大全| 国产白丝娇喘喷水9色精品| 色视频在线一区二区三区| tube8黄色片| 亚洲综合色惰| 国产爽快片一区二区三区| 国产黄频视频在线观看| 国产成人aa在线观看| 在线看a的网站| 春色校园在线视频观看| 亚洲色图av天堂| 久久精品久久精品一区二区三区| 97超碰精品成人国产| 国产精品三级大全| 丝袜喷水一区| 一区二区av电影网| 亚洲精品456在线播放app| 成年美女黄网站色视频大全免费 | 国产乱人偷精品视频| 亚洲真实伦在线观看| 日韩 亚洲 欧美在线| 人人妻人人澡人人爽人人夜夜| 久久人人爽人人爽人人片va| 国产亚洲一区二区精品| 国产精品久久久久久精品古装| 久久人人爽人人片av| 亚洲精华国产精华液的使用体验| 日本午夜av视频| 视频中文字幕在线观看| 一级爰片在线观看| 亚洲欧美精品专区久久| 啦啦啦视频在线资源免费观看| 夜夜爽夜夜爽视频| 亚洲经典国产精华液单| 亚洲电影在线观看av| 色婷婷av一区二区三区视频| 免费观看性生交大片5| 一级av片app| 久久久欧美国产精品| 久久99精品国语久久久| 97在线视频观看| 亚洲精品中文字幕在线视频 | 大码成人一级视频| 欧美 日韩 精品 国产| 亚洲一区二区三区欧美精品| 麻豆成人午夜福利视频| 三级经典国产精品| 91久久精品国产一区二区三区| 性色av一级| 麻豆成人av视频| 亚洲内射少妇av| av网站免费在线观看视频| 久久精品久久精品一区二区三区| 99re6热这里在线精品视频| 偷拍熟女少妇极品色| 国产乱人偷精品视频| 汤姆久久久久久久影院中文字幕| 亚洲,一卡二卡三卡| 久久久久久久久久久丰满| 插逼视频在线观看| 午夜福利网站1000一区二区三区| 国产精品无大码| 午夜福利视频精品| 80岁老熟妇乱子伦牲交| 国产精品蜜桃在线观看| a级一级毛片免费在线观看| 观看av在线不卡| 青春草亚洲视频在线观看| 国产伦精品一区二区三区视频9| 亚洲av男天堂| 亚洲av免费高清在线观看| 国产成人免费无遮挡视频| 亚洲真实伦在线观看| 久久99热这里只频精品6学生| 国产在线男女| 又粗又硬又长又爽又黄的视频| 欧美 日韩 精品 国产| 一区二区三区精品91| 亚洲精品国产av成人精品| 免费看不卡的av| 欧美亚洲 丝袜 人妻 在线| 亚洲aⅴ乱码一区二区在线播放| 亚洲av成人精品一区久久| 国产精品三级大全| 亚洲av电影在线观看一区二区三区| 久久久久性生活片| 国产免费福利视频在线观看| 国产亚洲91精品色在线| 18禁动态无遮挡网站| 午夜福利网站1000一区二区三区| 97热精品久久久久久| 亚洲国产精品999| 国产亚洲午夜精品一区二区久久| 97在线人人人人妻| av播播在线观看一区| 成人无遮挡网站| 亚洲精华国产精华液的使用体验| 亚洲欧洲国产日韩| 国产 精品1| 全区人妻精品视频| 校园人妻丝袜中文字幕| 国产精品不卡视频一区二区| 又大又黄又爽视频免费| 春色校园在线视频观看| 亚洲国产日韩一区二区| 欧美国产精品一级二级三级 | 噜噜噜噜噜久久久久久91| 天堂中文最新版在线下载| 日韩精品有码人妻一区| 国产一级毛片在线| 天堂中文最新版在线下载| 丰满少妇做爰视频| 国产成人freesex在线| 免费久久久久久久精品成人欧美视频 | 日韩一区二区三区影片| 99久久人妻综合| 久久久久久久久久人人人人人人| 欧美另类一区| 联通29元200g的流量卡| 久久国产乱子免费精品| 91精品国产九色| 身体一侧抽搐| 黄色怎么调成土黄色| 久久精品熟女亚洲av麻豆精品| 中国三级夫妇交换| 亚洲欧美清纯卡通| 国产淫语在线视频| 黑丝袜美女国产一区| 日本av手机在线免费观看| 亚洲国产精品国产精品| 成人亚洲欧美一区二区av| 久久精品夜色国产| 51国产日韩欧美| 九九在线视频观看精品| 日日摸夜夜添夜夜爱| 赤兔流量卡办理| 亚洲怡红院男人天堂| 丝瓜视频免费看黄片| 搡女人真爽免费视频火全软件| 男女无遮挡免费网站观看| 免费大片18禁| 国产免费福利视频在线观看| 一级av片app| 国产亚洲91精品色在线| 日韩,欧美,国产一区二区三区| 亚洲精品国产av成人精品| 欧美精品一区二区免费开放| 国产高清三级在线| 在线观看美女被高潮喷水网站| 亚洲av二区三区四区| 少妇熟女欧美另类| 七月丁香在线播放| 久久久久久久久久成人| 在线 av 中文字幕| 深夜a级毛片| 99热这里只有是精品50| av国产精品久久久久影院| 大话2 男鬼变身卡| 亚洲精品国产av蜜桃| 97在线视频观看| 亚洲成色77777| 久久久久性生活片| 国产精品一及| 人人妻人人爽人人添夜夜欢视频 | 国产成人a∨麻豆精品| 国产乱人视频| av在线app专区| 少妇裸体淫交视频免费看高清| 欧美三级亚洲精品| 亚洲av不卡在线观看| 免费av中文字幕在线| 亚洲成色77777| 久久99热6这里只有精品| 大码成人一级视频| 欧美人与善性xxx| 热99国产精品久久久久久7| 观看av在线不卡| 国产欧美日韩精品一区二区| 王馨瑶露胸无遮挡在线观看| 免费人妻精品一区二区三区视频| 亚洲av成人精品一区久久| 最近中文字幕高清免费大全6| 国产爱豆传媒在线观看| 丝瓜视频免费看黄片| 精品一区在线观看国产| 肉色欧美久久久久久久蜜桃| 特大巨黑吊av在线直播| 亚洲欧洲日产国产| 欧美+日韩+精品| 99久久综合免费| 高清黄色对白视频在线免费看 | 我要看黄色一级片免费的| 国产精品久久久久久久电影| 亚洲精品国产av成人精品| av天堂中文字幕网| 国产在视频线精品| 免费观看在线日韩| 日韩亚洲欧美综合| 你懂的网址亚洲精品在线观看| 国产淫片久久久久久久久| 尾随美女入室| 久久97久久精品|