• <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 ?

    Analysis of the characteristics of the plasma of an RF driven ion source for a neutral beam injector

    2020-03-09 13:22:26YongjianXU許永建LiZHANG張黎ChundongHU胡純棟YahongXIE謝亞紅CaichaoJIANG蔣才超JianglongWEI韋江龍LizhenLIANG梁立振andYuanlaiXIE謝遠(yuǎn)來
    Plasma Science and Technology 2020年2期
    關(guān)鍵詞:張黎江龍

    Yongjian XU (許永建), Li ZHANG (張黎), Chundong HU (胡純棟),Yahong XIE (謝亞紅), Caichao JIANG (蔣才超), Jianglong WEI (韋江龍),Lizhen LIANG (梁立振)and Yuanlai XIE (謝遠(yuǎn)來)

    1 Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, People’s Republic of China

    2 Nuclear Power Institute of China, Chengdu 10213, People’s Republic of China

    Abstract A radio frequency (RF) driven ion source is a very important component of a neutral beam injector for large magnetic confinement fusion devices.In order to study the key technology and physics of an RF driven ion source for a neutral beam injector in China, an RF ion source test facility was developed at the Institute of Plasma Physics,Chinese Academy of Sciences. In this paper,a two-dimensional fluid model is used to simulate the fundamental physical characteristics of RF plasma discharge.Simulation results show the relationship of the characteristics of plasma(such as electron density and electron temperature) and RF power and gas pressure. In order to verify the effectiveness of the model, the characteristics of the plasma are investigated using a Langmuir probe. In this paper, experimental and simulation results are presented, and the possible reasons for the discrepancies between them are given.This paper can help us understand the characteristics of RF plasma discharge, and give a basis for further R&D for an RF ion source.

    Keywords: RF ion source, numerical simulation, neutral beam injection, inductive coupled plasma

    1. Introduction

    In order to bridge the gap between ITER and the fusion demonstration reactor(DEMO)and to realize fusion power in China, a new fusion facility (China Fusion Engineering Test Reactor,CFETR)has been developed and some key technical hurdles are being addressed [1-4]. Neutral beam injection is one of the most efficient means of four auxiliary plasma heating and has been applied to drive current in nuclear fusion physics studies [5-9]. For a simpler mechanical structure,convenient maintenance, and longer lifetime, RF driven ion sources have been selected as the preferred ion source for the CFETR heating neutral beam injector (NBI) [10-13].According to the latest physics design of CFETR, two NBIs,which deliver a total of 40 MW not less than 3600 s with 1 MeV D0, are needed to support the current drive and the plasma rotation. To minimize the risks and time to provide CFETR with reliable NBIs, a negative RF driven ion source test facility was developed in 2017 at the Institute of Plasma Physics, Chinese Academy of Science (ASIPP) [14-16]. Its mission is to understand the characteristics of the RF driven ion source,the generation and extraction of negative ions,and to improve the RF efficiency and beam quality. The main parameters of the negative RF driven ion source test facility are listed in table 1.Generally,the structure of an NBI RF ion source can be roughly divided into three parts:the cylindrical driver, the rectangular expansion chamber, and the extraction area. The RF plasma is generated by inductively coupled discharge which is produced by six-turn RF coils in the driver.The main function of expansion chamber is to reduce the electron temperature and the extraction area aims to extract plasma and form a high energy ion beam (see figure 1).

    Figure 1.Three-dimensional diagram of the RF driven ion source.

    Figure 2.Simulation geometry of the RF ion source.

    2. Simulation and analysis

    Computer simulations are widely used to optimize the parameters of the designed ion sources, as well as to better understand ion production, extraction, and transport phenomena[17-20],so some simulations of the characteristics of the plasma of the RF ion source have been carried out.In the simulation,a two-dimensional(2D)fluid model is chosen and the variation trend of the electron density and temperature is given with increasing the gas pressure and RF power.

    2.1. Simulation conditions of the model

    A 2D schematic diagram of the inductive coupled plasma source is given in figure 2.The driver is a cylinder of diameter D1= 200 mm and height D2= 120 mm, and the dimension of the expansion chamber is 650 mm (L) × 260 mm(W) × 190 mm(H).Due to the the limitation of a 2D model,in order to keep the consistency between the simulation results and the actual structure, the shape of the expansion chamber is changed from a regular hexahedron to a cylinderaccording to the volume/surface ratio [21]. So, we chose D3= 190 mm and D4= 360 mm. Under these conditions,the volume/surface ratio of the experimental reactor (regular hexahedron) and the cylindrical model source are similar within less than 2%.The initial parameters are as follows:the working gas is hydrogen, the electron density is 1.0 × 1015m?3, the environmental temperature is 300 K, the average temperature is 5 eV, and the electron mobility is 4.0 × 1024m2· V?1· s?1. The particle species of the discharge gas mainly include H2molecules, H2+ions, and electrons. In the process of hydrogen gas discharge, the possibility of a reaction process mainly includes elastic collision,ionization,dissociation,excitation,and recombination.Table 2 gives the details of the reaction process [17, 21].

    Table 1.The main parameters of the negative RF driven ion source test facility.

    2.2. Simulation results and analysis

    The aim of the simulation is to explore the distribution of the space of the plasma in the driver and expansion chamber and explain the operation of the RF ion source. So, the electron density, electron temperature, and plasma potential are simulated under the boundary and initial conditions mentioned above (see figure 3).

    Figure 3 shows that (1) the peak of the electron density appears slightly above the center of the expansion chamber,(2) the peak of the electron temperature appears in the area close to the coil in the driver,(3)the spatial distribution of the plasma potential is similar to that of the electron density.

    The discharge gas pressure and RF power are the key parameters which influence the plasma properties of an ion source.The electron density and temperature are investigated with different plasma discharge gas pressures and RF powers.Two key positions are selected for research in the simulation;the locations are at 150 mm(position 1)and 20 mm(position 2) above the center of the bottom of the extension chamber,respectively(see figure 2).According to figure 3,position 1 is in the area with the highest plasma density and position 2 is located in the extraction area and the electron density andtemperature in this area have a strong influence on the extracted current density of the negative ions.

    Table 2.The main reaction processes and values of the characteristics of various types of particles produced by hydrogen discharge (only part of the reactions are shown in this table).

    RF power is one of the factors that determines the plasma parameters in the ion source. The magnitude of the induced magnetic field is affected by the RF power and the magnitude of the induced electric field is determined by the induced magnetic field, so the electron energy obtained from the electric field and ionization rate is closely related to RF power[22]. Figure 4 shows the variation trend of electron density and temperature with increasing RF power.

    As can be seen from figure 4, the electron density increases approximately in line with increasing RF power.The reason is that with increasing RF power, the electrons obtain more energy from the induced electric field and a higher effective collision frequency resulting in a higher ionization rate. But the electron temperature remains approximately constant with the increase of RF power. A possible reason is that in the process of plasma diffusion the high energy electrons transfer their energy to the background particles through collisions, as the route is long enough to exhaust the energy of high energy electrons after multiple collisions, so figure 4(b) shows that the electron temperature is unrelated to the RF power.

    Gas pressure is another key parameter for ion source operation, which has some influence on the plasma properties and stripping-loss during beam extraction. Therefore, a set of simulations is carried out to explore the relationship between electron density, electron temperature, and gas pressure. Figure 5 gives the variation trend of electron density and temperature with increasing gas pressure. It is shown that the electron density increases clearly as gas pressure increases(see figure 5(a)) and electron temperature decreases with the increase of gas pressure,especially below 1 Pa (see figure 5(b)). A possible reason is that the electron average free path decreases with increasing gas pressure and the collision frequency between electrons and nearby particle rises, so the ionization rate increases and more electrons are generated. A possible reason for the decline of electron temperature is that the particle density in the extension chamber rises with increasing gas pressure and the electron average free path decreases, resulting in the collision cross section between electrons and particles rises and a greater amount of electrons are used in ionization and excitation,so a drop in the electron energy leads to the decrease of the electron temperature [22]. These simulation results are consistent with the experimental results in other ion source test beds [23, 24].

    Figure 4.(a) Electron density, (b) electron temperature as a function of RF power (gas pressure 2 Pa).

    Figure 5.(a) Electron density, (b) electron temperature as a function of gas pressure (RF power 35 kW).

    Figure 6.Schematic diagram of the installation position of the probe.

    Figure 7.Electron density and temperature as a function of RF power (gas pressure 0.5 Pa).

    Figure 8.Electron density and temperature as a function of gas pressure (RF power 30 kW).

    Figure 9.The spatial distribution of (a) electron density, (b) electron temperature at different RF powers (gas pressure 0.5 Pa).

    3. Primary experimental results and discussion

    In order to understand the spatial distribution of plasma and verify the validity of the model, the electron temperature and electron density are measured using a Langmuir probe(ESPion,British Hiden Analytical Ltd). The probe is installed in the diagnostic flange along the central line of the short side of the extension chamber and the distance between the probe tip and the bottom of the extension chamber is about 20 mm. (see figure 6).In order to assess the relationship between the plasma parameters and RF power,a fixed measuring point of a probe is set as 20 cm (scale of probe, see figure 6). In addition, the spatial distribution of electron temperature and electron density is also measured.Due to the limitation of the retractable scope of the probe, the measuring range is set from 18-28 cm.Figures 7 and 8 show the variation trend of the electron density/electron temperature with increasing RF power and gas pressure, respectively. The electron density increases and the electron temperature remains approximately constant with increasing RF power (see figure 7). Figure 8 shows that the electron density increases and the electron temperature decreases with increasing gas pressure. The variation trends are consistent with the simulation results except for the value of electron temperature. According to the simulation result, the value of the electron temperature is about 8 eV. A possible reason is that the magnetic field generated by the magnet filter(see figure 1)cools the electrons when the hot electrons diffuse from the extension area to the extraction area, so that the yield of negative hydrogen ion can be improved further [17].

    The spatial distribution of electron density and temperature is also measured by the probe(see figure 9).Figure 9 shows that(1)the electron density increases when the probe is moved from 18 to 28 cm and the electron temperature almost remains constant; (2) the electron density at 30 kW is larger than that at 20 kW and the electron temperature is nearly the same at 20 and 30 kW. The variation trend is consistent with the simulation results presented in section 2. In order to overcome the shortcomings of the current Langmuir probe, a set of plane probes will be installed in the plasma grid and bias plate for measuring the plasma parameters in the extraction area.

    4. Conclusion

    Up to now,the negative RF driven ion source test facility has achieved a 50 kW stable long pulse plasma discharge at the 0.5 Pa gas pressure. In order to understand the plasma behavior, a set of simulations and experiments were carried out.The simulation results give the spatial distribution of the plasma and the relationship between electron density/temperature and RF power/gas pressure. Compared with the simulation results, a similar variation trend can seen in the experimental results. The results show that the electron density increases with increasing gas pressure/RF power and the electron temperature decreases with gas pressure, but almost remains constant when the RF power increases. These simulation and experimental results provide a foundation for cesium injection and beam extraction operation of an ion source in the future.

    Some shortcomings in this work should be noted,such as the influence of the magnetic filter on the electron temperature,the scope of the Langmuir probe measurements,and so on. In future work, the drawbacks above will be eliminated one by one and the extraction of a H?beam will be carried out with Cs seed.

    Acknowledgments

    This work was supported by National Natural Science Foundation of China (Nos. 11675216, 11905248, 11975261,11975262, 11975263, and 11975264), the Key Program of Research and Development of Hefei Science Center,CAS (Contract No. 2016HSC-KPRD002) and the National Key R&D Program of China (Nos. 2017YFE0300101,2017YFE0300103, and 2017YFE0300503).

    ORCID iDs

    Lizhen LIANG (梁立振)https://orcid.org/0000-0002-5744-5727

    猜你喜歡
    張黎江龍
    Spin torque oscillator based on magnetic tunnel junction with MgO cap layer for radio-frequency-oriented neuromorphic computing
    Raman lasing and other nonlinear effects based on ultrahigh-Q CaF2 optical resonator
    創(chuàng)新企業(yè)民主管理途徑的探索
    美食鑒定師
    《西安交通大學(xué)學(xué)報(bào)(社會(huì)科學(xué)版)》90后編委李江龍被評(píng)為西安交大第四屆“十大學(xué)術(shù)新人”
    變臉
    帶愛回家
    絕情刀
    變臉
    變臉
    国产免费视频播放在线视频| 丝袜美足系列| 国产人伦9x9x在线观看| 久久人人爽av亚洲精品天堂| 国产成人av激情在线播放| 综合色丁香网| 国产成人av激情在线播放| 亚洲成人手机| 国产免费一区二区三区四区乱码| 久久久久国产精品人妻一区二区| 亚洲美女搞黄在线观看| 嫩草影视91久久| 伊人久久大香线蕉亚洲五| 中文字幕亚洲精品专区| 黑人巨大精品欧美一区二区蜜桃| 丝袜喷水一区| 精品人妻在线不人妻| 19禁男女啪啪无遮挡网站| 国产成人精品无人区| 亚洲国产最新在线播放| 国产在视频线精品| 男男h啪啪无遮挡| 美国免费a级毛片| 韩国av在线不卡| 亚洲精品国产av蜜桃| 国产精品香港三级国产av潘金莲 | 男女高潮啪啪啪动态图| 成人国产av品久久久| 熟女少妇亚洲综合色aaa.| 日韩一卡2卡3卡4卡2021年| 最新的欧美精品一区二区| 国产熟女午夜一区二区三区| 亚洲美女视频黄频| 熟女少妇亚洲综合色aaa.| 夫妻午夜视频| 丰满迷人的少妇在线观看| 午夜免费鲁丝| 免费日韩欧美在线观看| 亚洲图色成人| 捣出白浆h1v1| 久久性视频一级片| 2018国产大陆天天弄谢| 国产精品欧美亚洲77777| 欧美日韩亚洲国产一区二区在线观看 | 日韩一本色道免费dvd| 国产精品一国产av| 亚洲精品乱久久久久久| 精品午夜福利在线看| 欧美日韩亚洲国产一区二区在线观看 | 婷婷成人精品国产| 亚洲,欧美精品.| 日韩大码丰满熟妇| 国产一区二区 视频在线| 精品少妇一区二区三区视频日本电影 | 免费女性裸体啪啪无遮挡网站| 一级毛片 在线播放| 少妇猛男粗大的猛烈进出视频| 欧美 日韩 精品 国产| 亚洲精品美女久久久久99蜜臀 | 校园人妻丝袜中文字幕| 亚洲国产成人一精品久久久| videosex国产| 国产成人欧美在线观看 | 晚上一个人看的免费电影| 久久精品国产亚洲av涩爱| 黄片无遮挡物在线观看| 啦啦啦视频在线资源免费观看| 免费黄色在线免费观看| 国产成人午夜福利电影在线观看| 亚洲一码二码三码区别大吗| 伦理电影免费视频| 老司机靠b影院| 精品人妻熟女毛片av久久网站| 在线观看免费日韩欧美大片| 国产免费视频播放在线视频| 少妇精品久久久久久久| 日韩人妻精品一区2区三区| 久久久久精品国产欧美久久久 | 国产高清国产精品国产三级| 女人被躁到高潮嗷嗷叫费观| 中文字幕人妻丝袜制服| 亚洲精品国产色婷婷电影| 国产精品免费视频内射| 久久亚洲国产成人精品v| 街头女战士在线观看网站| 久久99热这里只频精品6学生| 国产成人欧美| 美女高潮到喷水免费观看| 日韩精品有码人妻一区| 热99国产精品久久久久久7| 男人添女人高潮全过程视频| 免费人妻精品一区二区三区视频| 日日摸夜夜添夜夜爱| 国产在线一区二区三区精| 大陆偷拍与自拍| 国产97色在线日韩免费| 曰老女人黄片| 久久亚洲国产成人精品v| 一区二区三区精品91| xxxhd国产人妻xxx| 嫩草影视91久久| 香蕉丝袜av| 亚洲国产欧美在线一区| 国产无遮挡羞羞视频在线观看| 十八禁网站网址无遮挡| 久久这里只有精品19| 国产精品久久久久成人av| 国产日韩欧美在线精品| 成人手机av| 国产99久久九九免费精品| 天天躁夜夜躁狠狠躁躁| 天堂中文最新版在线下载| 国产激情久久老熟女| 国产精品免费视频内射| 午夜福利免费观看在线| 亚洲精品国产一区二区精华液| 国产精品免费视频内射| 色94色欧美一区二区| 七月丁香在线播放| 丝袜脚勾引网站| 国产午夜精品一二区理论片| 久久久精品国产亚洲av高清涩受| 97人妻天天添夜夜摸| 1024香蕉在线观看| 99久久精品国产亚洲精品| 亚洲自偷自拍图片 自拍| 成年动漫av网址| 丝袜人妻中文字幕| 午夜日韩欧美国产| 一本—道久久a久久精品蜜桃钙片| 国产免费视频播放在线视频| 成人午夜精彩视频在线观看| 欧美日韩一级在线毛片| 男人爽女人下面视频在线观看| 亚洲精华国产精华液的使用体验| 婷婷色综合大香蕉| 在现免费观看毛片| 亚洲国产日韩一区二区| 中文精品一卡2卡3卡4更新| 一二三四在线观看免费中文在| 国产成人一区二区在线| 桃花免费在线播放| 最近的中文字幕免费完整| 国产精品二区激情视频| 日韩中文字幕视频在线看片| 999精品在线视频| 国产成人精品在线电影| 一级毛片电影观看| 亚洲av成人不卡在线观看播放网 | 人人妻人人爽人人添夜夜欢视频| 性少妇av在线| 一级黄片播放器| 精品酒店卫生间| 色吧在线观看| 亚洲欧美日韩另类电影网站| 不卡视频在线观看欧美| 在线观看三级黄色| 国产精品蜜桃在线观看| 天堂中文最新版在线下载| 国产视频首页在线观看| 亚洲成人免费av在线播放| 国产精品久久久久久人妻精品电影 | 亚洲成人免费av在线播放| 久久免费观看电影| 在线观看免费高清a一片| 国产精品久久久av美女十八| 麻豆av在线久日| 亚洲,一卡二卡三卡| 一个人免费看片子| 美女主播在线视频| 久热爱精品视频在线9| 亚洲精品美女久久av网站| 一本—道久久a久久精品蜜桃钙片| 国产精品一区二区精品视频观看| 老汉色av国产亚洲站长工具| 中国三级夫妇交换| 韩国av在线不卡| 性高湖久久久久久久久免费观看| 大片电影免费在线观看免费| 精品国产超薄肉色丝袜足j| 久久久国产精品麻豆| 日韩中文字幕视频在线看片| 三上悠亚av全集在线观看| 亚洲av日韩在线播放| 欧美久久黑人一区二区| 精品亚洲乱码少妇综合久久| 国产黄频视频在线观看| www日本在线高清视频| 国产伦理片在线播放av一区| av又黄又爽大尺度在线免费看| 久久精品久久久久久久性| 国产av精品麻豆| 亚洲精品国产色婷婷电影| 亚洲图色成人| 亚洲色图 男人天堂 中文字幕| 高清欧美精品videossex| 宅男免费午夜| 欧美日韩亚洲国产一区二区在线观看 | 97人妻天天添夜夜摸| 欧美激情极品国产一区二区三区| av一本久久久久| 999久久久国产精品视频| 国产精品久久久久久人妻精品电影 | 国产午夜精品一二区理论片| 亚洲成国产人片在线观看| 国产日韩欧美视频二区| 精品免费久久久久久久清纯 | 天天躁夜夜躁狠狠躁躁| 交换朋友夫妻互换小说| 精品卡一卡二卡四卡免费| 考比视频在线观看| 亚洲精品乱久久久久久| 亚洲美女搞黄在线观看| 国产精品成人在线| 美女国产高潮福利片在线看| 精品酒店卫生间| 国产亚洲午夜精品一区二区久久| 伊人久久国产一区二区| 观看av在线不卡| 国产精品熟女久久久久浪| 久久久久精品人妻al黑| 国产精品三级大全| 久久久国产欧美日韩av| 亚洲欧洲国产日韩| 超碰97精品在线观看| 欧美日韩一区二区视频在线观看视频在线| 国产1区2区3区精品| 午夜福利一区二区在线看| 精品国产一区二区久久| 妹子高潮喷水视频| 麻豆av在线久日| 亚洲欧美一区二区三区久久| 亚洲久久久国产精品| 午夜激情久久久久久久| 午夜福利视频在线观看免费| 久久久精品国产亚洲av高清涩受| 悠悠久久av| 欧美在线一区亚洲| 老司机深夜福利视频在线观看 | 国产精品国产av在线观看| 国产成人91sexporn| 秋霞在线观看毛片| 人成视频在线观看免费观看| 超碰成人久久| 亚洲av电影在线进入| 国产一区二区 视频在线| 日本欧美视频一区| 少妇人妻久久综合中文| 亚洲国产成人一精品久久久| 两性夫妻黄色片| av女优亚洲男人天堂| 人人妻人人澡人人爽人人夜夜| 久久影院123| 午夜福利视频在线观看免费| 色精品久久人妻99蜜桃| 男男h啪啪无遮挡| 午夜免费男女啪啪视频观看| 亚洲天堂av无毛| 久久精品国产综合久久久| 亚洲,欧美,日韩| 2018国产大陆天天弄谢| 99久久人妻综合| 久久精品亚洲av国产电影网| 少妇人妻精品综合一区二区| 纵有疾风起免费观看全集完整版| 高清欧美精品videossex| 欧美激情极品国产一区二区三区| 午夜免费鲁丝| 深夜精品福利| av天堂久久9| 日韩视频在线欧美| 极品人妻少妇av视频| 激情视频va一区二区三区| 亚洲欧美精品自产自拍| 99久久99久久久精品蜜桃| 亚洲精品美女久久久久99蜜臀 | 青春草国产在线视频| 成年美女黄网站色视频大全免费| 免费在线观看视频国产中文字幕亚洲 | 青春草国产在线视频| 最近最新中文字幕大全免费视频 | videos熟女内射| 中文字幕人妻熟女乱码| 欧美亚洲日本最大视频资源| 欧美日韩成人在线一区二区| 亚洲精品成人av观看孕妇| 在线看a的网站| 丝袜美足系列| 亚洲av日韩精品久久久久久密 | netflix在线观看网站| 十八禁网站网址无遮挡| 观看美女的网站| 午夜福利一区二区在线看| av又黄又爽大尺度在线免费看| 99久久人妻综合| 观看av在线不卡| 韩国av在线不卡| 永久免费av网站大全| av电影中文网址| 不卡视频在线观看欧美| 日本av手机在线免费观看| 久久天堂一区二区三区四区| 男女边吃奶边做爰视频| 一区二区日韩欧美中文字幕| 国产亚洲午夜精品一区二区久久| 午夜福利乱码中文字幕| 男女边吃奶边做爰视频| 午夜福利乱码中文字幕| www.精华液| 国产xxxxx性猛交| 七月丁香在线播放| 国产亚洲av片在线观看秒播厂| 国产国语露脸激情在线看| 妹子高潮喷水视频| 制服诱惑二区| 悠悠久久av| 街头女战士在线观看网站| 亚洲欧美日韩另类电影网站| 婷婷色麻豆天堂久久| 9热在线视频观看99| av.在线天堂| 午夜91福利影院| 久久鲁丝午夜福利片| 精品一区二区三区av网在线观看 | 亚洲综合色网址| 高清在线视频一区二区三区| 免费不卡黄色视频| 老熟女久久久| 国产一区二区在线观看av| 久久久久久久国产电影| 操出白浆在线播放| 日韩制服丝袜自拍偷拍| 亚洲av成人精品一二三区| 黄色 视频免费看| 亚洲精品,欧美精品| 一级a爱视频在线免费观看| 成人毛片60女人毛片免费| 超碰成人久久| 午夜福利网站1000一区二区三区| a级毛片黄视频| 黄频高清免费视频| 国产老妇伦熟女老妇高清| 你懂的网址亚洲精品在线观看| 美女福利国产在线| 性高湖久久久久久久久免费观看| 国产成人a∨麻豆精品| 国产成人精品福利久久| av卡一久久| videosex国产| 欧美乱码精品一区二区三区| 免费女性裸体啪啪无遮挡网站| 欧美乱码精品一区二区三区| 久久人妻熟女aⅴ| 最近手机中文字幕大全| 男女免费视频国产| 成年人午夜在线观看视频| 51午夜福利影视在线观看| 最近手机中文字幕大全| 亚洲国产精品一区二区三区在线| 五月天丁香电影| 亚洲成av片中文字幕在线观看| 亚洲欧美精品综合一区二区三区| 两个人免费观看高清视频| 亚洲,欧美,日韩| 99热网站在线观看| 一级黄片播放器| 色94色欧美一区二区| 国产黄频视频在线观看| 最近2019中文字幕mv第一页| 一级片免费观看大全| 天天躁日日躁夜夜躁夜夜| 欧美精品高潮呻吟av久久| 亚洲欧美色中文字幕在线| 午夜福利一区二区在线看| 深夜精品福利| 国产熟女午夜一区二区三区| 国产精品一国产av| 大香蕉久久成人网| 青草久久国产| 在线观看免费午夜福利视频| 国产一区亚洲一区在线观看| 一本—道久久a久久精品蜜桃钙片| 18禁裸乳无遮挡动漫免费视频| 亚洲国产av新网站| 日本猛色少妇xxxxx猛交久久| 国语对白做爰xxxⅹ性视频网站| 黄网站色视频无遮挡免费观看| 91成人精品电影| 大香蕉久久网| 久久精品亚洲av国产电影网| 青春草亚洲视频在线观看| 日韩 亚洲 欧美在线| 国产精品久久久av美女十八| 大香蕉久久网| 欧美日韩视频精品一区| a级毛片黄视频| 纵有疾风起免费观看全集完整版| 下体分泌物呈黄色| 永久免费av网站大全| 热99国产精品久久久久久7| 欧美激情高清一区二区三区 | 久久99精品国语久久久| 久久久精品区二区三区| 汤姆久久久久久久影院中文字幕| 亚洲欧美激情在线| 久久99精品国语久久久| 欧美成人精品欧美一级黄| 亚洲熟女精品中文字幕| 伊人久久大香线蕉亚洲五| 又大又黄又爽视频免费| 亚洲国产精品国产精品| 狂野欧美激情性xxxx| 欧美av亚洲av综合av国产av | 免费看不卡的av| 国产亚洲最大av| 久久天堂一区二区三区四区| 两个人看的免费小视频| 捣出白浆h1v1| 亚洲精品av麻豆狂野| 国产一区二区激情短视频 | 制服人妻中文乱码| 欧美人与善性xxx| 综合色丁香网| 国产一区二区激情短视频 | 久久97久久精品| 女人久久www免费人成看片| 久久 成人 亚洲| 色94色欧美一区二区| 最近手机中文字幕大全| 母亲3免费完整高清在线观看| 五月天丁香电影| 亚洲欧美一区二区三区黑人| a 毛片基地| 久久免费观看电影| 天堂俺去俺来也www色官网| 亚洲美女黄色视频免费看| 精品人妻一区二区三区麻豆| 精品一区二区免费观看| 亚洲国产毛片av蜜桃av| www.精华液| 亚洲欧美成人精品一区二区| 日韩成人av中文字幕在线观看| 成人午夜精彩视频在线观看| www.熟女人妻精品国产| 人妻一区二区av| 天美传媒精品一区二区| 女人久久www免费人成看片| 午夜91福利影院| 中文字幕另类日韩欧美亚洲嫩草| 在线 av 中文字幕| 男女边摸边吃奶| 国产精品一二三区在线看| 午夜av观看不卡| 伊人久久大香线蕉亚洲五| 亚洲一级一片aⅴ在线观看| 亚洲第一av免费看| 在线观看国产h片| 91精品三级在线观看| 亚洲精品av麻豆狂野| 最近中文字幕2019免费版| 国产精品久久久久成人av| 成人毛片60女人毛片免费| 九色亚洲精品在线播放| 91国产中文字幕| 欧美 日韩 精品 国产| 亚洲欧洲国产日韩| 久久国产精品男人的天堂亚洲| 午夜久久久在线观看| 亚洲精品一二三| 精品少妇久久久久久888优播| 国产一区二区激情短视频 | 久久韩国三级中文字幕| 国产免费福利视频在线观看| 少妇人妻精品综合一区二区| 91国产中文字幕| 九九爱精品视频在线观看| 十分钟在线观看高清视频www| 国产日韩欧美在线精品| 国产人伦9x9x在线观看| 在线天堂中文资源库| 国产免费一区二区三区四区乱码| 永久免费av网站大全| 一区二区三区激情视频| 极品人妻少妇av视频| 美女午夜性视频免费| 精品一区在线观看国产| 国产精品.久久久| 最近手机中文字幕大全| 最新的欧美精品一区二区| 悠悠久久av| 99久久精品国产亚洲精品| 日韩视频在线欧美| 国产日韩一区二区三区精品不卡| 五月开心婷婷网| 我要看黄色一级片免费的| a级毛片在线看网站| 亚洲av综合色区一区| 久久久精品国产亚洲av高清涩受| 日本欧美视频一区| 欧美日韩视频高清一区二区三区二| 久久久久久久久久久免费av| 免费日韩欧美在线观看| 国产精品成人在线| 精品亚洲成a人片在线观看| 日韩av免费高清视频| 免费在线观看完整版高清| 国产免费视频播放在线视频| 欧美xxⅹ黑人| 麻豆乱淫一区二区| 少妇人妻 视频| 欧美在线黄色| 青青草视频在线视频观看| 成人亚洲精品一区在线观看| 在线 av 中文字幕| 国产熟女午夜一区二区三区| 天天影视国产精品| 午夜免费鲁丝| 欧美激情高清一区二区三区 | 亚洲国产av新网站| 久久久精品免费免费高清| 丁香六月欧美| 久久99一区二区三区| 国产乱来视频区| 一区二区av电影网| 久久精品熟女亚洲av麻豆精品| 久久综合国产亚洲精品| 成人亚洲欧美一区二区av| 9热在线视频观看99| 欧美日韩视频精品一区| 天天影视国产精品| xxxhd国产人妻xxx| 免费女性裸体啪啪无遮挡网站| 黄网站色视频无遮挡免费观看| 极品人妻少妇av视频| 少妇被粗大的猛进出69影院| 久久国产亚洲av麻豆专区| 久久精品国产亚洲av高清一级| 建设人人有责人人尽责人人享有的| 一区二区av电影网| 午夜免费男女啪啪视频观看| 91精品伊人久久大香线蕉| 高清黄色对白视频在线免费看| 久久久久久免费高清国产稀缺| 免费不卡黄色视频| 久久久欧美国产精品| 男男h啪啪无遮挡| 日韩av不卡免费在线播放| 三上悠亚av全集在线观看| 中文精品一卡2卡3卡4更新| 老汉色av国产亚洲站长工具| 欧美 亚洲 国产 日韩一| 欧美日韩成人在线一区二区| 97在线人人人人妻| 成人影院久久| 午夜福利,免费看| 一边亲一边摸免费视频| 中文字幕制服av| 夫妻性生交免费视频一级片| 久久午夜综合久久蜜桃| 亚洲第一av免费看| 久久久亚洲精品成人影院| 卡戴珊不雅视频在线播放| 欧美黑人精品巨大| 日本午夜av视频| 亚洲欧美一区二区三区久久| 免费黄频网站在线观看国产| 欧美精品一区二区大全| 国产成人av激情在线播放| 女人被躁到高潮嗷嗷叫费观| 亚洲欧美精品自产自拍| 久久97久久精品| 人妻 亚洲 视频| 99热国产这里只有精品6| 最近2019中文字幕mv第一页| 国产伦人伦偷精品视频| 综合色丁香网| 久久毛片免费看一区二区三区| 久久久久视频综合| 18禁观看日本| 国产精品无大码| 少妇 在线观看| 午夜福利网站1000一区二区三区| 一级毛片我不卡| 亚洲中文av在线| 欧美国产精品一级二级三级| 精品少妇黑人巨大在线播放| 国产精品久久久久久精品电影小说| 日本av免费视频播放| 美女中出高潮动态图| 亚洲 欧美一区二区三区| 成人毛片60女人毛片免费| 嫩草影视91久久| 国产人伦9x9x在线观看| 免费女性裸体啪啪无遮挡网站| 欧美日韩亚洲高清精品| av一本久久久久| 国产av精品麻豆| 国产一级毛片在线| 夫妻午夜视频| 免费高清在线观看日韩| 亚洲三区欧美一区| 爱豆传媒免费全集在线观看| 不卡视频在线观看欧美| 国产精品久久久久久精品电影小说| 国产麻豆69| 欧美老熟妇乱子伦牲交| www日本在线高清视频| 少妇人妻 视频| 国产成人一区二区在线| 色婷婷久久久亚洲欧美| 亚洲av成人精品一二三区| 久久天堂一区二区三区四区| 超碰成人久久| 欧美日韩一级在线毛片| 欧美变态另类bdsm刘玥|