• <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 ?

    Studies of world carbon fiber industry from a perspective of patent analysis①

    2016-12-05 06:39:02ZhengJiaYuanXueminZhangZeyu
    High Technology Letters 2016年3期

    Zheng Jia (鄭 佳),Yuan Xuemin,Zhang Zeyu

    (*Institute of Scientific and Technical Information of China:Beijing 100038:P.R.China)(**Institute of Scientific and Technical Information of Gansu:Lanzhou 730000:P.R.China)

    ?

    Studies of world carbon fiber industry from a perspective of patent analysis①

    Zheng Jia (鄭 佳)*,Yuan Xuemin**,Zhang Zeyu*To whom correspondence should be addressed.E-mail:zhangzy@istic.ac.cnReceived on Mar.1,2016*

    (*Institute of Scientific and Technical Information of China:Beijing 100038:P.R.China)(**Institute of Scientific and Technical Information of Gansu:Lanzhou 730000:P.R.China)

    Patents are the manifestation of the industry R&D endeavor; therefore:World carbon fiber industry from the perspective of patent analysis is studied.Findings from the analysis show a continual increase of carbon fibers patents since 1969:and the growth rate began even faster after the year of 2005.Five countries (Japan:China:US:Germany and Korea) took dominant positions in global carbon fibers R&D:and the sum of patents applied in these five countries accounted for 80% of the total patents in the world.Corporations do play an active role in global carbon fibers R&D:and over 60% of patents were applied by corporations.Among them:the top 3 corporations were all from Japan:which had much more patents than the other patent assignees.Furthermore:most corporations were not active in cooperation with others:except Toyota Motor Corp.Global carbon fibers R&D focused on sheet manufacture cloth:core wire layer:heat connect provide and filter activated draw.And there is big difference between Japan and China in the R&D focus.China’s corporations have exhibited rapid growth in the number of patent applications in recent years:but there is still a large gap between China and foreign countries in view of global patent layout and influence.By providing the insight into the evolution of global carbon fibers industrial and technological development through the perspective of patent analysis:this study hopes to provide an objective statistic reference for future policy directions and academic researches.

    carbon fiber:world:patent analysis:Japan:China:corporation

    0 Introduction

    Carbon fibers are made of a fibrous polymer material with the carbon content of more than 90%:which have high strength and high modulus.During the preparation process:other elements other than carbon are almost completely removed due to the high temperature.Only the flake graphite crystallites are left along the axial direction of the fiber.Thus:carbon fiber has a strong tensile strength of carbon materials:and also has the flexibility of fiber materials.The Characteristics of “l(fā)ight and hard” and “l(fā)ight and strong” make carbon fibers widely used in aerospace:automotive:energy storage:and sports goods:etc[1,2].According to the relevant statics:the global demand for carbon fibers composites is about 10×1012$ in 2009:and it is expected to increase to 18×1012$ in 2015.Such huge market potential and key role in the military filed has made carbon fibers the world’s hottest key new materials.

    Carbon fiber was first made from viscose fiber as the raw material by Union Carbide Corporation of US in 1959:then Polyacrylonitrile based carbon fiber was developed by Japan Osaka Industrial Technology Experiment Institute and Toray Company in 1961.After that:Pitch based carbon fiber was successfully developed by Japan’s Gunma University and Union Carbide Corporation of US.For decades:key technologies in the field of global carbon fiber have been monopolized by Japanese and American companies.Among them:the production capacity of three Japanese companies:Toray:Toho Rayon and Mitsubishi Rayon:account for more than 70% of the whole world’s production capacity.Accordingly:Japanese corporations obviously held the leading positions in the global carbon fiber market[3-5].

    China’s carbon fiber research can be traced back to the 60s’s of last century:almost synchronized with the world.However:after decades of development:there is still a huge gap between China and western countries in the production and application of carbon fibers.China’s carbon fibers production accounts for less than 1% of the global production:and more than 90% of the domestic carbon fibers is dependent on imports.After 2005:western countries have implemented strict embargo on China:which is a serious constraint to the development of carbon fiber industry in China.In order to change the situation:and meet the needs of domestic military and civilian products for high performance carbon fibers:the Chinese government:research institutes and enterprises have been trying hard to realize the localization of high performance carbon fibers.However:when China’s enterprises have finally realized the localization of T300 carbon fibers:what they face is malicious price dumping led by foreign carbon fiber corporations:with the price ratio up to 50%.In addition:foreign leading enterprises have decided to phase out T300 carbon fiber:and turn to the development of T600:T700 and etc.All these above mentioned are really a big challenge for China’s carbon fiber enterprises[6,7].

    Foreign leading corporations are strictly confidential on key technologies and equipments.Through a market oriented intellectual property protection strategy and global patent application layout:these leading corporations continue to strengthen their monopoly position in the world’s carbon fiber market.China’s corporations should not only purse in technology R&D:but also pay special attention to the potential intellectual property disputes and the consequent huge losses[8,9].Thus:this study aims at revealing the competition situation of global carbon fiber industry from a perspective of patent layout.On one hand:this study is to find key technological direction and business trends.On the other hand:it also recovers the potential competition of intellectual property right.In a word:this study will provide objective basis and valuable reference for China’s relevant institutions and enterprises on the direction of development planning and avoid the risk of intellectual property rights.

    1 Methodology

    Patents are the achievements of science and technology:and they can reflect the latest technological inventions as well as represent innovative capability of a nation.Accordingly:patents provide a reliable indicator of measuring technology development.Consequently:patents have become an important indicator of evaluating national technology competitiveness.More and more scholars are devoting more efforts to patent analysis of carbon fibers and applying the corresponding results for policy references[10-13].

    The patent data were retrieved from Derwent Innovation Index (DII) database.It is widely used by patent consulting companies:patent documenting and authoring departments in many countries.The data were retrieved and downloaded on July 2nd:2015:which contained 52912 application patents related to carbon fibers in the world from 1963 to 2015.This study:search strategies are as used as follows:TS=(“carbon fiber” OR “carbon fibers” OR “carbon fibre” OR “carbon fibres”) or IP= C04B-035/83.The research first reviewed the history of carbon fiber patent applied in the world and exhibited distribution among different countries.Then:the research moved into deep analysis of patent assignees:technology focus and key patents.TDA:TI and excel are main analysis tools in this study.

    2 Results and discussion

    2.1 Development trends of the number of patents

    From the first carbon fiber patent appeared in 1969:there have been 52912 patents in DII patent database till now.As shown in Fig.1:there was a slow increase in the number of carbon fiber patents before the 1990s:with annual application of less than 1000 patents.Additionally:the applications every year once declined after the year of 1991.The situation did not get improved until the year of 2005.The relatively low increase and even decline in the early stage may be due to two reasons:one is that there are lots of difficulties in early technology R&D:the other is that key technologies were held by a few corporations:others are hard to get in.However:since the importance and application potential have arisen widespread concern all over the world:lots of countries began to devote to this area.The R&D in carbon fibers developed again.After that:the number of carbon fiber patent applications began to grow up quickly:with the highest number of more than 6000 patents in 2014.There is a time delay between patent applications and disclosure:so patent applications exhibited a certain degree of decline in 2015.According to the current trends:the increase of patent application is believed to continue in 2015.

    Fig.1 The carbon fiber patents in the world by year

    2.2 Patent distribution among countries

    Carbon fiber patents applications involve 47 countries/regions:Fig.2 shows the distribution of carbon fiber applications across the world.It can be seen that both Japan and China are located in the first echelon:followed by the US:Korea and Germany.In general:the carbon fiber patent applications in the world are not balanced.

    Fig.2 Distribution of carbon fiber patents across the world

    Further analysis revealed by Table 1 tells that:the sum of patents in Japan:China:US:Germany and Korea have accounted for roughly 80% of the total patents in the global carbon fiber market.Among them:the number of patents applied in Japan and China far exceeded the other countries/regions.Japan has always held the core technologies in carbon fibers since decades:and its three major carbon fiber corporations have always occupied the leading position in this market.Thus:it is not surprise to see that Japan hold the leading positions in the carbon fiber patent applications.

    Table 1 Top 5 countries according to application patents

    As for China:the huge applications in carbon fiber patents were due to special attention to the R&D carbon fiber in the whole society of China.In the “12th Five-Year-Plan of National strategic emerging industry” of China:high performance fibers including carbon fibers have become the focus of deployment.Additionally:“technology innovation strategic alliance of carbon fiber and relevant composites materials industry” was established in 2010.After that:industrial bases were set up by Jilin and Shanxi province:respectively.As a result:the number of carbon fiber patents in China grew drastically after the year of 2008:as seen in Fig.3.The Blowout development has made China become the top 2 countries in the patent applications of global carbon fibers.

    Fig.3 The carbon fibers patents applied in different countries by year

    2.3 Patent layout of world top enterprises

    Fig.4 exhibits the patent distribution among different types of patent assignees.The patent assignees can be assigned to four types:that are corporate:academic:government and individual.According to Fig.4:it can be seen that corporate obviously held the leading positions in different type of patent assignees:with the number of 32633 patents:which account for 67% of the total patents.Generally speaking:in a technology area:when the corporate occupies the leading positions:the technology is close to industrialization or has been industrialized.From this view:industry values of carbon fibers have been fully confirmed by enterprises.The number of patent applications by individual was 11332:which accounts for 23% of the total patents.The sum of academic and government accounts for 10% of the total patents.Obviously:academic and government showed little interest in patent application of carbon fibers.There is a large gap between academic and corporate:which reflects that:core technologies of carbon fiber were mostly held by leading corporations.There must be fierce competition among corporations.Fig.5 shows the relative proportion of the patent assignees with different number of patent applications.From a global perspective:the number of patent assignees with more than 100 patents accounts for 12%:and the number of patent assignees with less than 20 patents accounts for 74%.This field is still in the stage of free competition:there is no monopoly in the corporate level.So:although Japan has obvious advantages:there are still a lot of opportunities.

    Fig.4 The patent distribution among different type of patent assignees

    Fig.5 Comparison between patent assignees with different number of patents

    Over the past 50 years:the top 15 corporations in the number of carbon fiber patent applications in the world were Mitsubishi Rayon Co Ltd:Toray Ind Inc:Toho Tenax Co Ltd:Osaka Gas Co Ltd:Henan Kosen Cable Co.Ltd:Asahi Chem Ind Co Ltd:Showa Denko KK:Nippon Steel Corp:Teijin Ltd:Kawasakisteel Corp:Matsushita Electric Ind Co Ltd:Tonen Corp:Hitachi Ltd:Donghua University:Toyota Motor Corp.:as described in Fig.6.Among the top 15 enterprises:more than 10 were from Japan:and furthermore:the top 3 corporations were all from Japan:which had much more patents than the other patent assignees.That is to say:Japan held the prominent leading positions in carbon fiber market.It is worth mentioning that two patent assignees from China have entered this top l5 list:one is Henan Kosen Cable Bo.Ltd.and Donghua University.It reflects that China’s R&D capacity in carbon fiber has been improved drastically in recent years.As far as we know:Henan Kosen Cable Bo.Ltd.’s research focused on cable:and Donghua university’s research interests were relatively balanced.But both of them applied patents mostly in China:they seldom applied abroad.From the perspective of global patent layout:there is still a long way for China to catch up with Japan’s corporations.

    Fig.6 Top 15 corporations in the number of patent applications in carbon fiber market

    Fig.7 exhibits cooperation network among leading corporations.It reflects that most corporations were not active in cooperating with others.For example:Asahi Chem Ind Co Ltd and Nippon Steel Corp both applied patents only by themselves.As for Teijin Ltd:Showa Denko KK:Toho Rayon KK.Kaeasaklsteel Corp:Mitsubishi Rayon Co Ltd:there were only a few patents applied by collaborating with other corporations.And additionally:their collaboration partners were no more than 2.There is a special case among these corporations:which is Toyota Motor Corp.The number of its patents was relatively smaller than other corporations:but there is a lot of cooperation between Toyota Motor Corp.and other corporations in patent applications.And also it has lots of partners:such as Osaka Gas Co Ltd:Toray Ind Inc:Showa Denko KK:and Mitsubishi Rayon Co Ltd.Probably because Toyota Motor Corp.is automobile company:different parts of the car need different raw materials providers.

    Fig.7 Collaboration among corporations in global carbon fiber market

    2.4 Technology focus and key patent

    Fig.8 reveals the technology focus of carbon fibers all over the world.This thematic map was made by the theme scape function of Thomson innovation software:through text clustering analysis according to the frequency of related words.The distribution of peaks and the distance between them reflect the technical topics and the correlation degree between these topics.From this map:it can be seen that global carbon fibers R&D focused on sheet manufacture cloth:core wire layer:heat conncet provide and filter activated draw.Besides:polyacrylonitrile precursor solution:fuel cell:battery secondary lithium:composite layer:resin epoxy:reinforce plastic:and mix preparation method also have drawn great attention in global carbon fibers R&D.Further analysis on the comparison between Japan and China was conducted as shown in Fig.9.Japan undoubtedly held the leading positions in global carbon fibers market:while China has exhibited dramatically increase in the number of carbon fibers patents.So:a deep comparison on R&D focus between the two countries would be interesting.Japan’s technology R&D was focused on gas metal hydrocarbon:heat:fuel cell:micron length:and reinforce plastic draw.China paid more attention to the R&D in mix preparation method:heat connect provide:surface polyimide spray and core wire layer.Although there are some common areas that both of the two countries have devoted to:the R&D interest and key points of these two countries were obviously different.Whether the difference is because of different interests:or it is due to huge gap in R&D capability:it is needed to be studied further.

    Fig.8 Technology focus in global carbon fiber field

    Fig.9 Comparison of technology focus between China and Japan.(White:China.Black:Japan)

    Table 2 gives the list of top 10 highly cited patents of carbon fibers in the world.Generally speaking:the more a patent is cited:the greater the influence it exerts.In another word:its technical value is more recognized by the others.Among the highly cited patents:most of them are from US.Although US is not the country with the most patents:its technology innovation has been widely recognized.China now is vigorously promoting the number of patents:while:the innovation model of US is more worth learning for China.

    Table 2 Top 10 highly cited patents

    3 Conclusions

    Through analysis of patent application in carbon fibers field in the world:the research herein has studied the development of world carbon fiber industry and drawn the following conclusions.

    The number of carbon fibers patents has exhibited continual growth ever since the first carbon fiber patent appeared in 1969:and the growth rate began even faster after the year of 2005.Additionally:the increase trend is believed to continue in the future due to the global emphasis on carbon fiber technologies.Although carbon fiber patents applications involve 47 countries/regions:most of them come from five countries.That is Japan:China:US:Germany and Korea.The sum of patents applied in these five countries accounted for 80% of the total patents in the world.Among them:Japan took the leading positions:while China exhibited the fastest growth in recent years.

    Corporation played an active role in global carbon fibers R&D:over 60% of patents were applied by corporations.Among the top 15 enterprises:more than 10 were from Japan:and the top 3 corporations were all from Japan:which had much more patents then the other patent assignees.Thus:Japan’s corporations held the prominent leading positions in global carbon fiber market.It is worth mentioning that two patent assignees from China have entered this top l5 list:one is Henan Kosen Cable Bo.Ltd.and Donghua University.But both of them applied patents mostly in China:and there is still a long way for China to catch up with Japan’s corporations in global patent layout.Furthermore:most corporations were not active in cooperating with others:except Toyota Motor Corp.

    Global carbon fibers R&D focused on sheet manufacture cloth:core wire layer:heat connect provide and filter activated draw.And there is large difference between Japan and China in the R&D focus.Japan’s technology R&D was focused on gas metal hydrocarbon:heat:fuel cell:micron length:and reinforce plastic draw.While:China paid more attention to the R&D in mix preparation method:heat connect provide:surface polyimide spray and core wire layer.Furthermore:it is worth mentioning that although US is not the country with the most patents:which technology innovation has been widely recognized.When China is vigorously promoting the number of patents:the innovation model of US is more worth learning.

    Analysis of patent data together with other information:such as R&D input of different application fields in carbon fibers:would be an effective compliment for revealing and analyzing the development of global carbon fibers market.Those above-mentioned points will be added in future studies.

    [1] Zhao J X.Present status and progress of carbon fiber in the world.FiberReinforcedPlastics/Composites.2003:(2):41-44 (in Chinese)

    [2] Wang X C:Li F:Tang Y S.Summary of domestic carbon fiber industry.ShandongTextileScienceTechnology.2011:(4):46-48 (in Chinese)

    [3] Lu C C.Latest developments of global carbon fiber market and technology.ChinaTextileLeader.2014,(9):44-48 (in Chinese)

    [4] Ma X L:Ren T:Duan X S:et al.Current development and trend of PAN-based carbon fiber.ChinaTextileLeader.2014,(12):44-46 (in Chinese)

    [5] Lu C C.The demand and supply status of carbon fibers and its production cost.SyntheticFiberinChina.2013:42(2):1-5 (in Chinese)

    [6] Wang H Y.Development foreground and market analyse of carbon fiber.Hi-TechFiber&Application.2007:32(4):23-26 (in Chinese)

    [7] Luo Y F.The prosperous development situation in global carbon fiber industries will appears.Hi-TechFiber&Application.2011:36(4):1-6 (in Chinese)

    [8] Feng L:Wen Y P.Present situation and suggestions of carbon fibers in China.ProgressinTextileScience&Technology.2012,(1):5-8:31 (in Chinese)

    [9] Chen X M.Property:development and application research of carbon fiber.TextileAuxiliaries.2015:32(5):1-4 (in Chinese)

    [10] Li X:Wang J:Ji Z S.Analysis on Chinese patents in carbon fibers industry.JournalofIntelligence.2012:31(12):7-11 (in Chinese)

    [11] Gao X:Dai L:Sun L:et al.Patent information study on carbon industry of Jilin Province based on patent map.ScienceTechnologyandIndustry.2013:(1):124-129 (in Chinese)

    [12] Li J:Tang H:Gui Y.Patent competitive intelligence analysis on domestic and foreign.JournalofIntelligence:2011:30(9):14- 19 (in Chinese)

    [13] Zheng J:Yuan X M.Study of the development of carbon fiber applications in several fields.Chinese High Technology Letters.2016:26(1):37- 44 (in Chinese)

    Zheng Jia:born in 1982:obtained her Ph.D in Peking University in 2009.Her research interests include S&T innovation:advanced material and patent analysis.She is now working as associate professor in Institute of Scientific and Technical Information of China.

    10.3772/j.issn.1006-6748.2016.03.011

    ①Supported by the Scientific Monitoring and Key Areas in-Depth Investigation and Research (No.ZD2015-20).

    热re99久久精品国产66热6| 美女午夜性视频免费| 宅男免费午夜| 伊人亚洲综合成人网| 亚洲国产av新网站| 色播在线永久视频| 亚洲国产成人一精品久久久| 国产免费又黄又爽又色| 在线天堂最新版资源| 国产极品粉嫩免费观看在线| 久久99热这里只频精品6学生| 免费日韩欧美在线观看| 无遮挡黄片免费观看| 午夜福利免费观看在线| 男的添女的下面高潮视频| 最近最新中文字幕大全免费视频 | 黑人猛操日本美女一级片| 日本一区二区免费在线视频| 精品免费久久久久久久清纯 | 高清av免费在线| 午夜福利视频精品| 嫩草影视91久久| 午夜福利,免费看| 亚洲激情五月婷婷啪啪| 男女边吃奶边做爰视频| 亚洲欧美中文字幕日韩二区| 天天影视国产精品| 天天操日日干夜夜撸| 日韩精品有码人妻一区| 免费观看性生交大片5| 国产黄色视频一区二区在线观看| 国产淫语在线视频| 免费女性裸体啪啪无遮挡网站| 69精品国产乱码久久久| 日日爽夜夜爽网站| 国产在线一区二区三区精| 国产在线视频一区二区| 视频区图区小说| 久久99热这里只频精品6学生| 亚洲欧美日韩另类电影网站| 亚洲第一青青草原| 日韩av在线免费看完整版不卡| 亚洲精品乱久久久久久| 我要看黄色一级片免费的| 女的被弄到高潮叫床怎么办| 久久鲁丝午夜福利片| 亚洲av国产av综合av卡| 免费观看性生交大片5| 建设人人有责人人尽责人人享有的| 美女午夜性视频免费| 男女免费视频国产| 777米奇影视久久| 一本大道久久a久久精品| 十八禁高潮呻吟视频| 90打野战视频偷拍视频| 各种免费的搞黄视频| 午夜福利影视在线免费观看| 欧美97在线视频| 成人亚洲欧美一区二区av| 日本av免费视频播放| 国产日韩一区二区三区精品不卡| 97精品久久久久久久久久精品| 天天影视国产精品| 汤姆久久久久久久影院中文字幕| 在线观看国产h片| 国产日韩欧美视频二区| 亚洲国产日韩一区二区| 亚洲欧洲国产日韩| netflix在线观看网站| 嫩草影视91久久| 夫妻性生交免费视频一级片| 色吧在线观看| 丝袜脚勾引网站| 国产淫语在线视频| 最新的欧美精品一区二区| www.熟女人妻精品国产| 老汉色∧v一级毛片| 91精品三级在线观看| 香蕉国产在线看| 观看美女的网站| 亚洲av综合色区一区| 亚洲久久久国产精品| 如日韩欧美国产精品一区二区三区| 一级毛片电影观看| 国产无遮挡羞羞视频在线观看| 另类亚洲欧美激情| 欧美人与性动交α欧美精品济南到| 大片电影免费在线观看免费| 免费日韩欧美在线观看| 欧美黄色片欧美黄色片| 制服诱惑二区| 精品久久久精品久久久| 午夜福利乱码中文字幕| 亚洲一卡2卡3卡4卡5卡精品中文| 国产av国产精品国产| 自线自在国产av| 波野结衣二区三区在线| 午夜激情久久久久久久| 久久人人爽人人片av| 精品一品国产午夜福利视频| 日韩一本色道免费dvd| 夫妻午夜视频| 婷婷成人精品国产| 大陆偷拍与自拍| 最新在线观看一区二区三区 | av不卡在线播放| 日本欧美视频一区| 久久精品亚洲av国产电影网| 毛片一级片免费看久久久久| 国产野战对白在线观看| 久久免费观看电影| av国产精品久久久久影院| 美女视频免费永久观看网站| 精品国产露脸久久av麻豆| 狂野欧美激情性xxxx| 免费日韩欧美在线观看| 一本一本久久a久久精品综合妖精| 日韩大码丰满熟妇| 男男h啪啪无遮挡| 亚洲精品一区蜜桃| 亚洲国产精品一区二区三区在线| svipshipincom国产片| 亚洲欧美日韩另类电影网站| 90打野战视频偷拍视频| √禁漫天堂资源中文www| 97精品久久久久久久久久精品| 久久天堂一区二区三区四区| 视频区图区小说| 中文字幕精品免费在线观看视频| 少妇被粗大的猛进出69影院| 一区在线观看完整版| 精品少妇内射三级| 国产亚洲av片在线观看秒播厂| 美女脱内裤让男人舔精品视频| 99热网站在线观看| 女性被躁到高潮视频| 人妻 亚洲 视频| 亚洲精品,欧美精品| 两个人看的免费小视频| 高清在线视频一区二区三区| 日韩大码丰满熟妇| 丰满少妇做爰视频| 赤兔流量卡办理| 黄片无遮挡物在线观看| 天美传媒精品一区二区| 波多野结衣av一区二区av| 色精品久久人妻99蜜桃| 久久韩国三级中文字幕| 精品视频人人做人人爽| 又大又黄又爽视频免费| 亚洲欧美中文字幕日韩二区| 精品少妇黑人巨大在线播放| 午夜福利在线免费观看网站| 国产激情久久老熟女| 青春草国产在线视频| 欧美人与善性xxx| 69精品国产乱码久久久| 久久久久精品性色| 欧美老熟妇乱子伦牲交| 看非洲黑人一级黄片| 91精品伊人久久大香线蕉| videos熟女内射| 亚洲欧美精品自产自拍| 亚洲av电影在线观看一区二区三区| 侵犯人妻中文字幕一二三四区| 国产日韩欧美亚洲二区| 国产老妇伦熟女老妇高清| 人妻一区二区av| 大香蕉久久成人网| 两个人看的免费小视频| 老司机在亚洲福利影院| 午夜福利视频在线观看免费| 黄片小视频在线播放| 又大又爽又粗| 国产精品 欧美亚洲| av卡一久久| 国产欧美日韩一区二区三区在线| 日韩,欧美,国产一区二区三区| 国产精品偷伦视频观看了| 黄片播放在线免费| 韩国av在线不卡| 久热这里只有精品99| 人体艺术视频欧美日本| 又大又黄又爽视频免费| 天天躁日日躁夜夜躁夜夜| 亚洲av成人不卡在线观看播放网 | 在线天堂中文资源库| 国产欧美日韩综合在线一区二区| 久久人人爽av亚洲精品天堂| 欧美精品亚洲一区二区| 巨乳人妻的诱惑在线观看| 亚洲国产欧美一区二区综合| 久久久久久久久免费视频了| 中文字幕亚洲精品专区| 国产高清不卡午夜福利| 国产精品秋霞免费鲁丝片| 日本爱情动作片www.在线观看| 亚洲欧美激情在线| 免费在线观看完整版高清| 国产精品偷伦视频观看了| 亚洲欧洲精品一区二区精品久久久 | svipshipincom国产片| 在线 av 中文字幕| 人妻 亚洲 视频| 欧美精品一区二区免费开放| 国产av国产精品国产| 久久精品国产a三级三级三级| 亚洲第一av免费看| 天天添夜夜摸| 国产国语露脸激情在线看| 校园人妻丝袜中文字幕| 亚洲欧美激情在线| a级片在线免费高清观看视频| 天天添夜夜摸| 日韩av免费高清视频| 亚洲五月色婷婷综合| 国产伦理片在线播放av一区| 国产黄频视频在线观看| 国精品久久久久久国模美| 日韩制服丝袜自拍偷拍| 一级毛片黄色毛片免费观看视频| 亚洲av成人精品一二三区| 亚洲国产最新在线播放| 在线亚洲精品国产二区图片欧美| 99re6热这里在线精品视频| 久久精品亚洲av国产电影网| 国产成人av激情在线播放| 亚洲美女搞黄在线观看| 天天添夜夜摸| av又黄又爽大尺度在线免费看| 久久青草综合色| 女人高潮潮喷娇喘18禁视频| 免费观看人在逋| 男女边吃奶边做爰视频| 一边摸一边做爽爽视频免费| 看免费成人av毛片| 高清黄色对白视频在线免费看| 如日韩欧美国产精品一区二区三区| 大片电影免费在线观看免费| 亚洲四区av| 午夜福利乱码中文字幕| 大陆偷拍与自拍| 国产麻豆69| 王馨瑶露胸无遮挡在线观看| 在线观看人妻少妇| 国产女主播在线喷水免费视频网站| 中文字幕色久视频| 国产黄色视频一区二区在线观看| 久热这里只有精品99| 制服诱惑二区| 少妇猛男粗大的猛烈进出视频| 亚洲专区中文字幕在线 | 少妇人妻久久综合中文| 热re99久久国产66热| 涩涩av久久男人的天堂| 叶爱在线成人免费视频播放| 少妇的丰满在线观看| 在线 av 中文字幕| 考比视频在线观看| 久久精品亚洲av国产电影网| 日本爱情动作片www.在线观看| 老汉色∧v一级毛片| 看十八女毛片水多多多| 一级毛片 在线播放| 五月天丁香电影| 两个人免费观看高清视频| 在线观看免费日韩欧美大片| 久久久久精品国产欧美久久久 | 伊人久久大香线蕉亚洲五| 人妻一区二区av| 精品一区二区三区四区五区乱码 | 欧美日韩亚洲国产一区二区在线观看 | 啦啦啦啦在线视频资源| 国产激情久久老熟女| 国产精品久久久久成人av| 在线观看人妻少妇| 人体艺术视频欧美日本| 精品一区二区免费观看| 国产精品久久久久成人av| 秋霞伦理黄片| 在线看a的网站| 精品第一国产精品| 热re99久久精品国产66热6| av.在线天堂| 日韩中文字幕视频在线看片| 我要看黄色一级片免费的| 午夜福利一区二区在线看| 亚洲人成电影观看| 18禁裸乳无遮挡动漫免费视频| 最近手机中文字幕大全| 日韩 欧美 亚洲 中文字幕| 如日韩欧美国产精品一区二区三区| 亚洲,一卡二卡三卡| 国产精品蜜桃在线观看| 伦理电影大哥的女人| 美女扒开内裤让男人捅视频| 欧美日韩精品网址| 一本一本久久a久久精品综合妖精| 美女主播在线视频| 天美传媒精品一区二区| 国产精品久久久久久精品电影小说| 在线观看人妻少妇| 午夜福利一区二区在线看| 18在线观看网站| 精品少妇久久久久久888优播| 国产黄色视频一区二区在线观看| 国产乱人偷精品视频| 黄片小视频在线播放| 人成视频在线观看免费观看| 一级片'在线观看视频| 久久精品亚洲熟妇少妇任你| 午夜免费观看性视频| 日韩av不卡免费在线播放| 精品久久久久久电影网| 日本av手机在线免费观看| 中文乱码字字幕精品一区二区三区| 青春草视频在线免费观看| 精品免费久久久久久久清纯 | 大片免费播放器 马上看| 亚洲成人免费av在线播放| 永久免费av网站大全| 又大又黄又爽视频免费| 亚洲婷婷狠狠爱综合网| 国产亚洲av高清不卡| 男女无遮挡免费网站观看| 亚洲精品久久久久久婷婷小说| 国产精品欧美亚洲77777| 亚洲av综合色区一区| 成人亚洲欧美一区二区av| 街头女战士在线观看网站| 日本爱情动作片www.在线观看| 2021少妇久久久久久久久久久| 波多野结衣av一区二区av| a级毛片在线看网站| 天美传媒精品一区二区| 日韩制服丝袜自拍偷拍| 国产成人精品久久久久久| 精品福利永久在线观看| 国产精品一区二区在线不卡| 欧美日韩亚洲高清精品| 欧美激情 高清一区二区三区| 波野结衣二区三区在线| 一本色道久久久久久精品综合| 91精品伊人久久大香线蕉| 超碰97精品在线观看| 久久天堂一区二区三区四区| 国产成人91sexporn| 一本久久精品| 日本欧美视频一区| 国产福利在线免费观看视频| 黄色怎么调成土黄色| a 毛片基地| 国产亚洲精品第一综合不卡| 中文字幕人妻丝袜一区二区 | 国产亚洲午夜精品一区二区久久| 午夜日韩欧美国产| 男人舔女人的私密视频| 国产探花极品一区二区| 国产97色在线日韩免费| 欧美日韩精品网址| 国产精品久久久久久人妻精品电影 | 夜夜骑夜夜射夜夜干| 欧美av亚洲av综合av国产av | 国产熟女午夜一区二区三区| 亚洲欧洲国产日韩| 国产男女内射视频| 我要看黄色一级片免费的| 日韩精品免费视频一区二区三区| 成年美女黄网站色视频大全免费| 国产男女内射视频| 久久久久久人人人人人| 国产欧美日韩综合在线一区二区| 久久久久久人人人人人| 亚洲欧美成人综合另类久久久| 亚洲精品在线美女| 亚洲熟女精品中文字幕| 欧美成人精品欧美一级黄| 亚洲精品久久久久久婷婷小说| 老司机在亚洲福利影院| 日韩大码丰满熟妇| 性色av一级| 两性夫妻黄色片| 久久久久久免费高清国产稀缺| 丝袜人妻中文字幕| 少妇人妻精品综合一区二区| 母亲3免费完整高清在线观看| 老司机亚洲免费影院| 免费女性裸体啪啪无遮挡网站| 欧美日韩国产mv在线观看视频| 亚洲av日韩精品久久久久久密 | 热re99久久国产66热| 午夜福利免费观看在线| 婷婷色综合www| 99国产综合亚洲精品| 人妻人人澡人人爽人人| 狠狠婷婷综合久久久久久88av| 嫩草影院入口| 美女脱内裤让男人舔精品视频| 国产免费一区二区三区四区乱码| 国产成人精品在线电影| 天天躁日日躁夜夜躁夜夜| 一级毛片黄色毛片免费观看视频| 超碰成人久久| 日韩av不卡免费在线播放| 黄色视频在线播放观看不卡| 欧美亚洲 丝袜 人妻 在线| 在线观看www视频免费| 成人黄色视频免费在线看| 亚洲国产成人一精品久久久| 日本一区二区免费在线视频| 少妇被粗大的猛进出69影院| 久久影院123| 亚洲成av片中文字幕在线观看| 欧美久久黑人一区二区| 大香蕉久久网| 精品卡一卡二卡四卡免费| 夫妻性生交免费视频一级片| 女人爽到高潮嗷嗷叫在线视频| 黑丝袜美女国产一区| 欧美乱码精品一区二区三区| 国产成人精品无人区| 最近2019中文字幕mv第一页| 亚洲激情五月婷婷啪啪| 建设人人有责人人尽责人人享有的| 日韩大码丰满熟妇| 女的被弄到高潮叫床怎么办| 一区二区av电影网| 精品亚洲成国产av| 国产成人啪精品午夜网站| 80岁老熟妇乱子伦牲交| 我的亚洲天堂| 亚洲av日韩精品久久久久久密 | 9热在线视频观看99| 日韩人妻精品一区2区三区| 亚洲三区欧美一区| 婷婷色综合大香蕉| 又黄又粗又硬又大视频| 永久免费av网站大全| a级毛片黄视频| 18在线观看网站| 韩国av在线不卡| 国产成人精品久久久久久| 啦啦啦视频在线资源免费观看| 日韩欧美一区视频在线观看| 亚洲国产av新网站| 日韩一区二区三区影片| 国产av码专区亚洲av| av国产精品久久久久影院| 午夜福利免费观看在线| 亚洲自偷自拍图片 自拍| 久久久久久久久久久久大奶| 婷婷色av中文字幕| 美女主播在线视频| 高清在线视频一区二区三区| 国产男女内射视频| 91精品三级在线观看| 嫩草影院入口| 亚洲精品aⅴ在线观看| 亚洲一区中文字幕在线| 久久性视频一级片| 亚洲精品一区蜜桃| 亚洲国产欧美在线一区| 80岁老熟妇乱子伦牲交| av国产精品久久久久影院| 国产av精品麻豆| 老司机影院成人| 一级片免费观看大全| 妹子高潮喷水视频| 日本wwww免费看| 一个人免费看片子| 成人影院久久| 亚洲成色77777| 国产在视频线精品| 中文天堂在线官网| 亚洲欧美日韩另类电影网站| 久久久久精品久久久久真实原创| 久久精品国产a三级三级三级| 色吧在线观看| 免费看不卡的av| 亚洲精品av麻豆狂野| 99精国产麻豆久久婷婷| 一级a爱视频在线免费观看| 国产精品无大码| 女人被躁到高潮嗷嗷叫费观| 狂野欧美激情性xxxx| 国产一卡二卡三卡精品 | 午夜福利影视在线免费观看| 亚洲一区二区三区欧美精品| 欧美亚洲日本最大视频资源| 波多野结衣一区麻豆| 啦啦啦啦在线视频资源| 日本一区二区免费在线视频| 亚洲国产看品久久| 亚洲情色 制服丝袜| 久久精品人人爽人人爽视色| 女性被躁到高潮视频| 街头女战士在线观看网站| 伊人久久国产一区二区| 午夜久久久在线观看| 欧美黑人欧美精品刺激| 国语对白做爰xxxⅹ性视频网站| 亚洲一码二码三码区别大吗| 激情视频va一区二区三区| 菩萨蛮人人尽说江南好唐韦庄| 丝袜喷水一区| 国产成人啪精品午夜网站| 捣出白浆h1v1| 在现免费观看毛片| 国产 一区精品| 嫩草影视91久久| 成人三级做爰电影| 欧美日本中文国产一区发布| 免费日韩欧美在线观看| 日本av免费视频播放| 日本91视频免费播放| 成人影院久久| 黑丝袜美女国产一区| 97精品久久久久久久久久精品| 亚洲熟女精品中文字幕| 国产成人系列免费观看| 综合色丁香网| 精品国产露脸久久av麻豆| 国产黄色视频一区二区在线观看| 一区在线观看完整版| 一级爰片在线观看| 久久影院123| 最近中文字幕2019免费版| 成年人午夜在线观看视频| 欧美精品一区二区免费开放| 国产成人系列免费观看| 午夜免费鲁丝| 肉色欧美久久久久久久蜜桃| 亚洲欧美激情在线| 色吧在线观看| 人人妻人人爽人人添夜夜欢视频| 亚洲欧美一区二区三区久久| 免费高清在线观看视频在线观看| 日韩制服丝袜自拍偷拍| 男女国产视频网站| 19禁男女啪啪无遮挡网站| 亚洲一区中文字幕在线| 久久精品久久久久久噜噜老黄| 无遮挡黄片免费观看| 国产精品女同一区二区软件| 成人亚洲精品一区在线观看| 水蜜桃什么品种好| 欧美日韩福利视频一区二区| h视频一区二区三区| 久久国产亚洲av麻豆专区| 美女大奶头黄色视频| 自线自在国产av| 丰满乱子伦码专区| 成人亚洲欧美一区二区av| 亚洲欧美一区二区三区国产| 在线观看免费午夜福利视频| 日韩欧美一区视频在线观看| 亚洲国产欧美网| 日韩av在线免费看完整版不卡| 18禁观看日本| 国产亚洲午夜精品一区二区久久| www.av在线官网国产| 老司机深夜福利视频在线观看 | 中文字幕人妻丝袜制服| 亚洲精品国产区一区二| 国产精品人妻久久久影院| 1024香蕉在线观看| 高清欧美精品videossex| 亚洲天堂av无毛| 一区福利在线观看| 99久久综合免费| 视频在线观看一区二区三区| 91成人精品电影| 国产精品女同一区二区软件| 精品国产乱码久久久久久男人| 青春草国产在线视频| 亚洲av男天堂| 欧美老熟妇乱子伦牲交| 超碰成人久久| 99热国产这里只有精品6| 赤兔流量卡办理| 一区二区三区乱码不卡18| 亚洲一区二区三区欧美精品| 国产亚洲av片在线观看秒播厂| 青春草亚洲视频在线观看| 国产av精品麻豆| 亚洲精品国产区一区二| 日本猛色少妇xxxxx猛交久久| 岛国毛片在线播放| 9热在线视频观看99| 国产一区二区在线观看av| 国产毛片在线视频| 不卡av一区二区三区| 婷婷色综合大香蕉| 亚洲人成网站在线观看播放| 久久精品久久精品一区二区三区| 欧美xxⅹ黑人| 男人舔女人的私密视频| 在线观看国产h片| 亚洲七黄色美女视频| 九九爱精品视频在线观看| 久久久精品94久久精品| 亚洲av日韩精品久久久久久密 | 久久久久久久国产电影| 中文精品一卡2卡3卡4更新| 久久鲁丝午夜福利片| 免费日韩欧美在线观看| 亚洲欧美成人综合另类久久久| 少妇被粗大的猛进出69影院| 婷婷色综合www| 日韩伦理黄色片| 国产精品国产av在线观看| av电影中文网址| 精品国产乱码久久久久久小说| 久热这里只有精品99| 国产在视频线精品|