• <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 ?

    Reply to the note by Li Piani et al.

    2024-03-30 02:06:40LiPianiWeerheijmSluys
    Defence Technology 2024年1期

    T.Li Piani , J.Weerheijm , L.J.Sluys

    a TU Delft, Stevinweg 1, 2628 CN, Delft, the Netherlands

    b TNO, PO Box 45, 2280 AA, Rijswijk, the Netherlands

    c NLDA, Faculty of Military Sciences,1781 CA, Den Helder, the Netherlands

    Keywords: Adobe ballistic model

    In 2017, a ballistic phenomenological model was proposed by the authors of Ref.[1] to numerically simulate the experimental depths of small caliber projectiles impacting walls made of adobe.The opportunity for a new model in the field revealed from the observation that two older models recently used by the authors of Ref.[2]shared a linear relationship between the penetration depthPand the impacting velocityvo, which was experimentally confirmed by the ballistic tests performed by the authors of Ref.[1]as presented in Ref.[3].However, these two models substantially differ in the physical hypotheses used to interpret the penetration process in adobe targets.Thus,it was concluded that the process of penetration in Adobe was still unclear and it was plausible to propose a new approach.The new approach in Ref.[1] was consistent with the results of experimental trends observed in previous experimental campaigns in Refs.[4,5], which pioneered adobe as a quasi-brittle material similar to concrete.This hypothesis was lately used by several other authors in the field of adobe(e.g.Ref.[6]).

    However, the authors of Ref.[2] now claim that the work of Ref.[1] implicitly criticized their approach and instead claim that the ballistic model in Ref.[1] is not suitable for interpreting the process of penetration into targets of adobe.In particular, the criticism of the authors of Ref.[2] on the approach of authors in Ref.[1] is based on two claims:

    a) ‘Theresistingforceiszeroatthebeginning(v=v0),andattheend ofthepenetrationprocess(…)thevalueoftheforce is-√μρTgAPmPv0(…)Itisconcludedthatthefactthattheforce increasesduringthedecelerationoftheprojectileissuitablefor describingthebehaviorofadensifyingfoamuponlow-velocity impactbutnotadobe’.

    In order to counter this claim, a comprehensive background and reasoning of the proposed model is given in this rebuttal.The ballistic phenomenological model in Ref.[1] starts its premises from the well-known so called‘Forrestal model’(Ref.[7]).This was developed in the early '90ties at the Sandia National Laboratories following the investigations at the US Naval weapons laboratory on the penetration process on concrete and soil targets based on ogive-nose projectiles.From these experiments,it was observed that the penetration process of concrete could be distinguished in a crater region (<2D, with D the diameter of the impactor) and in a tunnel region (>2D),respectively.The corresponding mathematical framework was translated in Ref.[7] in the following equation of motion:

    Wheremis the mass-of the projectile,tis time,xis the horizontal coordinate at timetof the impactor,cis a constant,aτ0depends on the shear strength,Nis a nose shape factor,ρ is the density of the target,vis the velocity of the impactor at time t andBa compressibility factor.In the Forrestal model, the force at impact location (x= 0,v=vo) is, of course, 0.In fact, this model belongs to the so called ‘cavity expansion theory’.This family of models shapes the force required to open a crater starting from a 0 mm initial opening,by modelling the resisting forces ahead of the impactor nose.This is indeed the conceptual framework which has been adopted by the authors in Ref.[1],which motivates the use of Eq.(1) in the crater region.In the tunneling region, only a shear Coulomb force has been implemented.For continuity reasons,this corresponds to Eq.(3).

    WhereAis the cross-sectional area of the impactor and μ is a friction coefficient.Eqs.(2) and (3) correspond to a setting where the inertial contribution of resistance is neglected and only shear is considered.This heavy simplification in the model developed for adobe was supported by some recent empirical evidence and experimental results.On the one hand,it was observed that a weak correlation was obtained by the authors of Ref.[2,8]in Refs.[9,10],by fitting experimental laboratory tests on adobe with inertial force based phenomenological ballistic models(proportional toV2).This observation was strengthened by the data of the ballistic test campaign performed by the authors of Ref.[1].These empirical findings were further supported by some recent experimental evidence emerging from partially confidential projects run in US laboratories, which revealed that in case of ballistic impacts into thick soil-based targets, shear resistance is dominant with respect to compression forces, and assumes the form of a frictional resistance.At this point, it is worthy to stress out that a Coulomb approach does not solely correspond to a‘static’approach,but to a material constitutive law, potentially valid also in a dynamic and impact regime provided strain rate dependencies are taken into account.Ref.[11]is recommended providing thorough background of the resisting mechanisms involved in high velocity penetration in soil based targets.On this basis,the model developed in Ref.[1]corresponds to the Forrestal framework where the inertial term is neglected and a Coulomb shear force is used.This formulation allowed to heavily simplify the math of the model.The used Coulomb friction law has been already extensively used in other phenomenological ballistic models developed for soil-based materials [12].For frictional drag in soil, the combination of hydrostatic pressure and Coulomb friction givesR=μgρtAx as in Eq.(4).Of course,more complex shear laws can be used.For instance,other authors argued that the form of resisting forceF(z) should vary from quadratic to constant,owing to the shape of the projectile and of growing crater excavated by its motion.Overall,starting from Eq.(4), the math of the model can be unveiled in the following steps:

    Givenxo= 0, and whenxequals the penetration depthPthe corresponding final velocity is 0, these equations evolve into Eqs.(8)-(10).Generalizingkin Eq.(10b):

    In the setting of Eq.(10),a linear relationship betweenvoandPemerges with constantk.Alternatively, the kinetic energy of the projectile at a given time during penetration is the total initial kinetic energy subtracted by the dissipated energy via Coulomb friction dislocated between grains and projectile ahead of projectile nose as from Eqs.(11)-(13).

    To conclude, the mathematical formulation of the model in Ref.[1] and the physical meaning of resistance R have been explained and confirmed.

    Overall,as pointed out by the independent reviewer invited to review the submitted note of Ref.[2], the model of Ref.[1] is correct and consistent with a Poncelet approach.

    b) ‘ThemodelisnotP/Dscale-independent.’

    The authors in Ref.[2] claim that the model of Ref.[1] is not scale independent and that this contradicts the scale independent relationships of the models used by the authors in Ref.[2],to interpret their experimental data.The authors of Ref.[1]confirm that the model is not linearly scale independent.However, this evidence does not necessarily contradict the physical hypotheses of the model, nor its consistency with the physics of the problem.Claims of scale independence by definition for any ballistic phenomenological model are not definitely supported by physical principles or theories at the current stage.Let us briefly review the elementary models developed over time.The model used since 2011 by the authors starting in Ref.[9] is based on a class of phenomenological models called analytical models (or semi-empirical).Using II Newton's laws,these parametrize the sources of energy dissipation governing penetration into an inertial term (proportional to the square of projectile velocity), a viscous term (proportional to projectile velocity) and a bearing strength term.These terms are presented in Eq.(15) (Ref.[13]).The earliest analytical model is from Robins-Euler in the middle of XVIII century,who assumed a constant resistance over penetration.Integration in order to determine the penetration length of the projectile in the target results in Eq.(16).One of the most widely used models nowadays,especially for sandy and concrete materials,was presented by Poncelet in 1839, who defined the resistance of penetration as the sum of an inertial and bearing strength component as in Eq.(17).Ignoring the bearing strength leads instead to the penetration length in Eq.(18), developed first by Resal.The approach developed by Resal in 1895 was adopted in 2011 by the authors of Ref.[2] as the initial framework to interpret experimental data of spherical impact tests on semi-infinite adobe targets.In the case of spherical impactors,Eqs.(16)-(18)show a cubic dependence between penetration depth and impactor diameter.

    However, by fitting the model in Eq.(18) with the values of penetration depthsPfrom experiments, the authors of Ref.[2]revealed a weak correlation with the inertial term (~A0), with respect to the viscous one(B).Thus,the general Eq.(15)could be reformulated by considering onlyBand excludingAandC.This leaded to a simplified equation forPshown in Eq.(19).The resulting model yields that given a same velocity and mass of the projectile,Pis linearly dependent of the diameter of the impacting sphere, namely the model is geometrically independent.The authors of Ref.[2] claim that this linear relationship fits well with their experimental data and these reviewers do not have reasons to doubt on this statement.Further experimental reference is indeed needed to clarify all the unknowns which characterized so called ‘not-engineered materials’ as adobe, especially against high velocity impacts with respect to simplified models and inherent uncertainties caused by basics physical hypotheses.This wish for new tests was also reported in the publication of the authors of Ref.[1].For this reason,real shooting tests using wide ranges of impactors shapes and impacting velocities are still needed.Utilizing the public data of an in-field small caliber shooting tests as in Ref.[3], a large scatter when using the hypothesis of linear scale independence was observed.This happens because,not only the diameter,but the shape of the projectile exerts a dominant influence on the overall impact response.Also the Forrestal model based on ogive impactors,is not solely scale independent,but is equipped with a nose shape factor.Also factorkin Ref.[1]depends on a series of variables including the friction coefficient and the nose shape factor.If being scale independent is not a definite requirement yet (at the current state of the art), most of literature agree ballistic phenomenological model parameters shall not being dimensional dependent.This was the claim of the model in Ref.[1], whose model is consistently implemented.In fact, the origin of the model in Ref.[1]does not refer to the independence of scale, but to the independence of dimension (which are different concepts).Dimensional dependent variables expose to controversy and debate on the physical interpretation of the parameters used to calibrate any model with respect to experimental data.For instance, from Eq.(15), onlyChas a unit of measure directly referred to the physical resistance the term incorporates.Ais proportional to[kg/m]and B is proportional to[kg/s].Physically interpreting these parameters and possibly curing the dimensional dependence of many other empirical models is a task scientific works are currently focusing on(Ref.[14]).Instead,the parameterkof the model of the authors in Ref.[1]is consistent with a cavity expansion theory and may assume also a physical interpretation of amplification of dynamic effects (DIF), as well as Eq.(10) is dimensionally independent.The overall framework of the authors in Ref.[1]lies on interpreting adobe as a quasi-brittle material, following the results of previous experimental evidence followed by further experimental and numerical validations in the static as well as in the dynamic regime.Overall,the model in Ref.[1]represents an alternative vision on a series of previous models and approaches whose physical consistency has not been fully assessed yet.For instance, the material parameters A and B in Eqs.(16)-(19) may be related to dimensionless drag coefficients in aero and fluid dynamics by employing momentum transfer and Newton's third law.In this sense,A can be related to the Newton quadratic drag force model,while B is linked to the Stokes'drag law for cylindrical bodies as in Eq.(19).Translated to solids,the first term represents the“dynamic pressure”determined by the inertia of the material in front of the projectile.The second term used by the authors of Ref.[2]to interpolate experimental data on adobe, may correspond to the shear-resistance of the target material activated along the projectile.On the one hand, treating adobe targets as Stoke's fluids and thus considering only the contribution to resistance of the shear layers activated along the penetrating projectile, implies neglecting the effect of adobe ahead of the impactors.On the other hand,the same authors of Ref.[2]also used a different model directly coming from satellite impacts which is based on a shock wave approach.Both are plausible, neither are definitely correct nor consistent in their physical interpretations of ballistic impact on adobe.In fact,the models as shown in this submission have been already previously published.In the current stages, all of these models including in Ref.[1]are simplistic interpretations of the physical reality.The set of hypotheses at the basis of all the analytical models following Eq.(15) is in itself far from being physically consistent with real tests and actual reality.Hypothesizing a rectilinear trajectory with no deviations,intact projectile at the end of the test as well as constant density of the target are hypotheses which can not be (hardly) met in any ballistic tests.Thus, any of the ballistic phenomenological models should not be considered to assess the physics of adobe, nor published in scientific journals?

    Overall, these reviewers feel sorry if Ref.[1] might have appeared to implicitly criticized previous papers.This was not in the intention of the authors.On the other hand, as pointed out by the independent reviewer, also in the view of these reviewers the model of Ref.[1] is plausible and instead it is self-evident that the elucubrations and interpretations as emerging from the submitted note unfortunately appear to be out of context, inconsistent, and ultimately, wrong.However, these reviewers hope that the provided comments will be of any help to authors of the note to refine and update the message of the submitted paper in the revision process.In fact, these reviewers are in favour of the publication of the note, because the option of a double publication will enhance and consolidate the reasoning on the premises, content and interpretation of the model in Ref.[1].Scientific debate is always welcome to promote knowledge and progress.

    Declaration of competing interest

    No conflict of interest.

    热99re8久久精品国产| 亚洲一卡2卡3卡4卡5卡精品中文| 亚洲av电影在线进入| 国产三级黄色录像| 90打野战视频偷拍视频| 五月开心婷婷网| 成人亚洲精品一区在线观看| 又大又爽又粗| 两性夫妻黄色片| 免费不卡黄色视频| 亚洲国产av新网站| 视频区图区小说| 国产97色在线日韩免费| 精品一区二区三区四区五区乱码| 日韩一卡2卡3卡4卡2021年| 99热国产这里只有精品6| 精品国产一区二区久久| 在线av久久热| 夫妻午夜视频| 正在播放国产对白刺激| 亚洲色图综合在线观看| 夜夜骑夜夜射夜夜干| 不卡av一区二区三区| 国产精品99久久99久久久不卡| 国产精品久久久久久精品古装| 亚洲少妇的诱惑av| 深夜精品福利| 久久人妻熟女aⅴ| 国产色视频综合| 高清在线国产一区| 欧美激情久久久久久爽电影 | 日韩视频一区二区在线观看| 极品人妻少妇av视频| 啦啦啦在线免费观看视频4| 妹子高潮喷水视频| 亚洲,欧美精品.| 亚洲一区二区三区欧美精品| 91大片在线观看| 亚洲五月色婷婷综合| 久久精品aⅴ一区二区三区四区| 18禁美女被吸乳视频| 99热网站在线观看| 99九九在线精品视频| 午夜免费成人在线视频| 天天添夜夜摸| 18禁裸乳无遮挡动漫免费视频| 99九九在线精品视频| 99国产极品粉嫩在线观看| 国产免费现黄频在线看| 亚洲中文日韩欧美视频| 一区二区三区激情视频| 国产一卡二卡三卡精品| 一边摸一边抽搐一进一小说 | 国产精品一区二区精品视频观看| 精品视频人人做人人爽| 女性生殖器流出的白浆| 久热这里只有精品99| 水蜜桃什么品种好| 国产男靠女视频免费网站| 国产成人系列免费观看| 亚洲中文av在线| 亚洲av欧美aⅴ国产| av福利片在线| 亚洲精品国产一区二区精华液| 看免费av毛片| 搡老熟女国产l中国老女人| 水蜜桃什么品种好| 女人被躁到高潮嗷嗷叫费观| 搡老岳熟女国产| 亚洲欧美色中文字幕在线| 日韩 欧美 亚洲 中文字幕| 人人妻人人爽人人添夜夜欢视频| 精品久久久久久久毛片微露脸| cao死你这个sao货| 嫁个100分男人电影在线观看| 人人妻人人澡人人看| 久久久久久亚洲精品国产蜜桃av| 亚洲免费av在线视频| 男女高潮啪啪啪动态图| 国产av国产精品国产| 久久精品亚洲熟妇少妇任你| 亚洲欧美激情在线| 在线亚洲精品国产二区图片欧美| 丁香欧美五月| 国产在线视频一区二区| 亚洲av电影在线进入| 这个男人来自地球电影免费观看| 国产欧美日韩一区二区精品| av片东京热男人的天堂| 一区在线观看完整版| 免费在线观看黄色视频的| 午夜激情久久久久久久| 精品国产乱子伦一区二区三区| 王馨瑶露胸无遮挡在线观看| 免费在线观看视频国产中文字幕亚洲| 黄色视频在线播放观看不卡| 国产在线观看jvid| 欧美黑人欧美精品刺激| 男女边摸边吃奶| 国产黄色免费在线视频| 久久性视频一级片| 亚洲国产av新网站| 一本—道久久a久久精品蜜桃钙片| 老司机午夜十八禁免费视频| 巨乳人妻的诱惑在线观看| 波多野结衣av一区二区av| 午夜福利,免费看| 肉色欧美久久久久久久蜜桃| 精品国产一区二区久久| 精品欧美一区二区三区在线| 久久ye,这里只有精品| 亚洲成人手机| 久久久久久免费高清国产稀缺| tube8黄色片| 十八禁高潮呻吟视频| 99久久人妻综合| 亚洲国产看品久久| 一二三四社区在线视频社区8| 免费高清在线观看日韩| 久久精品国产亚洲av高清一级| 亚洲国产精品一区二区三区在线| 欧美亚洲 丝袜 人妻 在线| 菩萨蛮人人尽说江南好唐韦庄| 色综合欧美亚洲国产小说| 日日摸夜夜添夜夜添小说| 大片免费播放器 马上看| 岛国在线观看网站| 亚洲专区国产一区二区| 国产一区二区三区视频了| 人妻 亚洲 视频| 久久免费观看电影| 在线播放国产精品三级| 黑人巨大精品欧美一区二区mp4| 日韩视频在线欧美| 69av精品久久久久久 | 热99国产精品久久久久久7| 久久久国产欧美日韩av| 久久人妻福利社区极品人妻图片| 成人国产av品久久久| 极品少妇高潮喷水抽搐| 露出奶头的视频| 久久香蕉激情| 国产国语露脸激情在线看| 国产亚洲午夜精品一区二区久久| 欧美 亚洲 国产 日韩一| 欧美+亚洲+日韩+国产| 捣出白浆h1v1| 久久性视频一级片| 国产人伦9x9x在线观看| 欧美日韩av久久| 精品国产一区二区三区四区第35| 大陆偷拍与自拍| 欧美日韩一级在线毛片| 久久久久久久久免费视频了| 热99国产精品久久久久久7| 亚洲精品在线观看二区| 日本黄色日本黄色录像| 亚洲精品自拍成人| 久久久久国产一级毛片高清牌| 黄片播放在线免费| 不卡av一区二区三区| 精品亚洲成国产av| 国产精品一区二区在线观看99| 欧美日韩成人在线一区二区| 成人18禁高潮啪啪吃奶动态图| 亚洲精品成人av观看孕妇| 丝袜喷水一区| 国产欧美亚洲国产| 一区二区三区精品91| 亚洲人成伊人成综合网2020| 成人18禁高潮啪啪吃奶动态图| 老司机亚洲免费影院| av天堂在线播放| 国产三级黄色录像| 国产熟女午夜一区二区三区| 久久久久久久久免费视频了| 精品少妇一区二区三区视频日本电影| 久久亚洲精品不卡| 18禁美女被吸乳视频| 两人在一起打扑克的视频| 精品卡一卡二卡四卡免费| 在线亚洲精品国产二区图片欧美| 欧美黑人欧美精品刺激| 桃红色精品国产亚洲av| 伦理电影免费视频| 日韩中文字幕欧美一区二区| 午夜福利一区二区在线看| 高清黄色对白视频在线免费看| 久久影院123| 国产深夜福利视频在线观看| 高清毛片免费观看视频网站 | 在线观看免费午夜福利视频| 欧美 亚洲 国产 日韩一| 欧美黄色片欧美黄色片| 免费不卡黄色视频| 国产日韩欧美视频二区| 成在线人永久免费视频| av一本久久久久| www.自偷自拍.com| 一级片免费观看大全| 一级毛片女人18水好多| 欧美精品高潮呻吟av久久| 日韩大码丰满熟妇| 在线观看舔阴道视频| 在线永久观看黄色视频| 老司机午夜十八禁免费视频| 妹子高潮喷水视频| 51午夜福利影视在线观看| 精品第一国产精品| 丁香六月天网| 亚洲人成电影免费在线| a级毛片黄视频| 亚洲精品美女久久av网站| 国产单亲对白刺激| 美女视频免费永久观看网站| 电影成人av| 男男h啪啪无遮挡| 日韩欧美一区视频在线观看| 夜夜夜夜夜久久久久| 建设人人有责人人尽责人人享有的| 大陆偷拍与自拍| 久久人妻av系列| tube8黄色片| 欧美日韩视频精品一区| 老司机深夜福利视频在线观看| 深夜精品福利| www.熟女人妻精品国产| 免费看a级黄色片| 高清毛片免费观看视频网站 | 成年女人毛片免费观看观看9 | 久久国产精品男人的天堂亚洲| 波多野结衣一区麻豆| 在线十欧美十亚洲十日本专区| 国产精品二区激情视频| 精品欧美一区二区三区在线| 精品亚洲乱码少妇综合久久| av福利片在线| 亚洲精品在线美女| 天天操日日干夜夜撸| 一区二区三区国产精品乱码| 一本一本久久a久久精品综合妖精| 两人在一起打扑克的视频| 在线观看www视频免费| 男女免费视频国产| 99国产精品99久久久久| a级片在线免费高清观看视频| 亚洲成a人片在线一区二区| 建设人人有责人人尽责人人享有的| 免费女性裸体啪啪无遮挡网站| 精品少妇久久久久久888优播| 美女午夜性视频免费| 欧美日韩福利视频一区二区| 建设人人有责人人尽责人人享有的| 国产伦人伦偷精品视频| 脱女人内裤的视频| 午夜福利乱码中文字幕| 日韩一卡2卡3卡4卡2021年| 日本黄色视频三级网站网址 | 久久久国产一区二区| 成人av一区二区三区在线看| 汤姆久久久久久久影院中文字幕| 丁香六月欧美| 丝袜喷水一区| 日本vs欧美在线观看视频| 美国免费a级毛片| 丁香欧美五月| 夜夜夜夜夜久久久久| 丝袜在线中文字幕| 久久精品国产亚洲av高清一级| 91精品国产国语对白视频| 18禁国产床啪视频网站| 欧美一级毛片孕妇| 亚洲精品在线观看二区| 国产欧美日韩一区二区精品| 丰满饥渴人妻一区二区三| 满18在线观看网站| 99久久99久久久精品蜜桃| 深夜精品福利| 国产日韩一区二区三区精品不卡| 午夜福利乱码中文字幕| 一本色道久久久久久精品综合| 国产精品久久久久久精品古装| a级毛片在线看网站| 国产成人精品久久二区二区免费| 欧美黑人欧美精品刺激| av一本久久久久| 巨乳人妻的诱惑在线观看| 久久久精品国产亚洲av高清涩受| 国产欧美日韩一区二区三区在线| 国产欧美日韩一区二区精品| 不卡一级毛片| 视频在线观看一区二区三区| 曰老女人黄片| 69av精品久久久久久 | 这个男人来自地球电影免费观看| 国产精品一区二区精品视频观看| 国产精品久久久久久人妻精品电影 | 蜜桃国产av成人99| 一边摸一边抽搐一进一小说 | 久久狼人影院| 精品欧美一区二区三区在线| 国产在线观看jvid| 操美女的视频在线观看| 久久人人97超碰香蕉20202| 欧美乱妇无乱码| 一级黄色大片毛片| 交换朋友夫妻互换小说| 99国产精品一区二区三区| 欧美日韩中文字幕国产精品一区二区三区 | 国产精品99久久99久久久不卡| 免费观看av网站的网址| 在线观看舔阴道视频| 美女高潮到喷水免费观看| 国产aⅴ精品一区二区三区波| 精品视频人人做人人爽| 久久久久视频综合| 亚洲伊人色综图| 久久香蕉激情| 在线亚洲精品国产二区图片欧美| 99精品久久久久人妻精品| 一区二区三区激情视频| 亚洲av国产av综合av卡| 水蜜桃什么品种好| 久久久久久久精品吃奶| 国产精品熟女久久久久浪| 一个人免费在线观看的高清视频| 中文字幕av电影在线播放| 亚洲,欧美精品.| 男女高潮啪啪啪动态图| 日韩欧美一区视频在线观看| 成人18禁在线播放| av欧美777| 老司机福利观看| 日韩成人在线观看一区二区三区| 一区二区av电影网| 欧美日韩亚洲高清精品| 久久午夜亚洲精品久久| 一区二区三区激情视频| 丝袜人妻中文字幕| 亚洲欧美精品综合一区二区三区| 1024视频免费在线观看| 97人妻天天添夜夜摸| 99精国产麻豆久久婷婷| 亚洲欧美一区二区三区久久| 丝袜美腿诱惑在线| 亚洲欧美一区二区三区久久| 香蕉丝袜av| 精品久久久精品久久久| 免费高清在线观看日韩| 99九九在线精品视频| 午夜福利免费观看在线| 一区二区三区国产精品乱码| 一个人免费在线观看的高清视频| 91九色精品人成在线观看| 91成年电影在线观看| 真人做人爱边吃奶动态| 国产欧美日韩一区二区三| 99久久精品国产亚洲精品| 成人国产av品久久久| 一本—道久久a久久精品蜜桃钙片| av网站在线播放免费| 精品少妇一区二区三区视频日本电影| 一二三四社区在线视频社区8| 免费在线观看黄色视频的| 欧美久久黑人一区二区| 久久人人97超碰香蕉20202| 国产有黄有色有爽视频| 午夜久久久在线观看| 在线亚洲精品国产二区图片欧美| 99国产精品一区二区蜜桃av | 久久精品国产综合久久久| 久久中文看片网| 最新在线观看一区二区三区| 亚洲欧美激情在线| 免费观看av网站的网址| 高潮久久久久久久久久久不卡| 国产精品麻豆人妻色哟哟久久| 国产av又大| www日本在线高清视频| 欧美激情极品国产一区二区三区| 国产男女内射视频| 亚洲全国av大片| 这个男人来自地球电影免费观看| 亚洲国产欧美网| 欧美黄色片欧美黄色片| 国产国语露脸激情在线看| 老熟妇乱子伦视频在线观看| 国产视频一区二区在线看| 中文字幕人妻丝袜一区二区| 人人妻人人澡人人看| a级毛片黄视频| 美女高潮喷水抽搐中文字幕| 久久精品亚洲av国产电影网| 一区二区三区乱码不卡18| 他把我摸到了高潮在线观看 | 国产欧美日韩一区二区三区在线| 亚洲国产欧美一区二区综合| 午夜日韩欧美国产| 久久久欧美国产精品| 女人精品久久久久毛片| 老汉色∧v一级毛片| 亚洲av第一区精品v没综合| 国产成人免费无遮挡视频| 一进一出好大好爽视频| 久久久久视频综合| 中文字幕制服av| 一边摸一边抽搐一进一小说 | 在线亚洲精品国产二区图片欧美| 精品久久久久久电影网| 色在线成人网| 午夜成年电影在线免费观看| 午夜福利,免费看| av国产精品久久久久影院| 日韩熟女老妇一区二区性免费视频| 精品卡一卡二卡四卡免费| 国产有黄有色有爽视频| 下体分泌物呈黄色| 99riav亚洲国产免费| 国产无遮挡羞羞视频在线观看| 波多野结衣一区麻豆| 国产欧美日韩一区二区三区在线| e午夜精品久久久久久久| 天天影视国产精品| 免费av中文字幕在线| 亚洲,欧美精品.| av国产精品久久久久影院| 人人妻人人澡人人爽人人夜夜| 一本综合久久免费| 欧美精品人与动牲交sv欧美| 999久久久精品免费观看国产| 在线观看免费午夜福利视频| 亚洲美女黄片视频| 国产亚洲午夜精品一区二区久久| 男女床上黄色一级片免费看| 91精品国产国语对白视频| 伊人久久大香线蕉亚洲五| 日本av手机在线免费观看| 国产一区有黄有色的免费视频| 国产av又大| 丝瓜视频免费看黄片| 亚洲成国产人片在线观看| 成年动漫av网址| 搡老乐熟女国产| 亚洲成av片中文字幕在线观看| 窝窝影院91人妻| 国产男女超爽视频在线观看| 热99国产精品久久久久久7| 男女边摸边吃奶| 亚洲精品国产区一区二| 老司机午夜十八禁免费视频| avwww免费| 精品第一国产精品| 一个人免费在线观看的高清视频| 色老头精品视频在线观看| 视频在线观看一区二区三区| 久久久久久人人人人人| 中文字幕色久视频| kizo精华| 精品高清国产在线一区| 亚洲七黄色美女视频| 黄色成人免费大全| 亚洲人成电影免费在线| 免费少妇av软件| 久久ye,这里只有精品| 国产欧美亚洲国产| 不卡av一区二区三区| 免费看十八禁软件| 好男人电影高清在线观看| 成年女人毛片免费观看观看9 | 丁香欧美五月| 中文字幕最新亚洲高清| 国产三级黄色录像| 五月天丁香电影| 亚洲五月婷婷丁香| 亚洲av成人不卡在线观看播放网| 婷婷丁香在线五月| 欧美黑人欧美精品刺激| 国产亚洲精品一区二区www | 成人18禁高潮啪啪吃奶动态图| 国产精品九九99| 老司机深夜福利视频在线观看| 亚洲一区二区三区欧美精品| 91字幕亚洲| 777米奇影视久久| 1024香蕉在线观看| 国产成人精品久久二区二区免费| 天天操日日干夜夜撸| 999久久久精品免费观看国产| 老司机午夜十八禁免费视频| 久久精品国产亚洲av香蕉五月 | 大型黄色视频在线免费观看| 高清av免费在线| 欧美黄色片欧美黄色片| 精品久久久精品久久久| 日韩大码丰满熟妇| 午夜免费成人在线视频| 亚洲精品国产色婷婷电影| 五月开心婷婷网| 国产老妇伦熟女老妇高清| 香蕉国产在线看| 乱人伦中国视频| 法律面前人人平等表现在哪些方面| 精品少妇黑人巨大在线播放| 久久精品亚洲精品国产色婷小说| 丝袜人妻中文字幕| 人人妻,人人澡人人爽秒播| √禁漫天堂资源中文www| 黄色视频不卡| 一边摸一边抽搐一进一出视频| 欧美日韩视频精品一区| 亚洲欧美色中文字幕在线| 欧美久久黑人一区二区| 精品国产乱码久久久久久男人| 国产视频一区二区在线看| 国产精品秋霞免费鲁丝片| 一区福利在线观看| 亚洲 欧美一区二区三区| 亚洲av第一区精品v没综合| 激情视频va一区二区三区| e午夜精品久久久久久久| 亚洲视频免费观看视频| 欧美日韩国产mv在线观看视频| 中国美女看黄片| 99久久人妻综合| 老司机福利观看| 国产av一区二区精品久久| 国产aⅴ精品一区二区三区波| 王馨瑶露胸无遮挡在线观看| 欧美黄色片欧美黄色片| 50天的宝宝边吃奶边哭怎么回事| 中文字幕人妻丝袜一区二区| av国产精品久久久久影院| 五月开心婷婷网| 9191精品国产免费久久| 男女之事视频高清在线观看| 水蜜桃什么品种好| 国产精品久久久久久人妻精品电影 | 精品久久久精品久久久| 午夜福利在线免费观看网站| 亚洲午夜理论影院| 国产欧美日韩精品亚洲av| 黑人欧美特级aaaaaa片| 欧美日本中文国产一区发布| 我的亚洲天堂| 成年人免费黄色播放视频| 免费高清在线观看日韩| 丰满少妇做爰视频| 51午夜福利影视在线观看| 国产精品国产高清国产av | 国产色视频综合| 久久久久久久大尺度免费视频| 三级毛片av免费| 精品亚洲成国产av| 亚洲综合色网址| 欧美变态另类bdsm刘玥| 搡老乐熟女国产| 精品人妻熟女毛片av久久网站| 国精品久久久久久国模美| 久久国产精品大桥未久av| 女人爽到高潮嗷嗷叫在线视频| 国产精品久久久久久人妻精品电影 | 日韩人妻精品一区2区三区| 天天躁夜夜躁狠狠躁躁| 国产高清videossex| 丝袜美腿诱惑在线| 亚洲精品中文字幕一二三四区 | 国产麻豆69| 国产不卡av网站在线观看| 国产亚洲精品一区二区www | 日日夜夜操网爽| 电影成人av| 亚洲少妇的诱惑av| 色视频在线一区二区三区| 日本a在线网址| 日韩免费av在线播放| 高清在线国产一区| 欧美日韩亚洲综合一区二区三区_| 不卡一级毛片| 法律面前人人平等表现在哪些方面| 露出奶头的视频| 国产亚洲一区二区精品| 自拍欧美九色日韩亚洲蝌蚪91| 五月开心婷婷网| 亚洲五月色婷婷综合| 一本—道久久a久久精品蜜桃钙片| 久久天堂一区二区三区四区| 我要看黄色一级片免费的| 亚洲熟女精品中文字幕| av欧美777| 欧美日韩国产mv在线观看视频| 欧美精品一区二区免费开放| 精品视频人人做人人爽| 久久精品国产综合久久久| 欧美乱妇无乱码| 亚洲精品久久成人aⅴ小说| 黑人操中国人逼视频| 欧美精品一区二区免费开放| 精品一品国产午夜福利视频| 亚洲欧美一区二区三区久久| 国产欧美日韩一区二区精品| 80岁老熟妇乱子伦牲交| 亚洲专区字幕在线| 国产熟女午夜一区二区三区| 国产免费av片在线观看野外av| 又黄又粗又硬又大视频| 99热国产这里只有精品6| 欧美老熟妇乱子伦牲交| 岛国在线观看网站| 日本vs欧美在线观看视频| www.999成人在线观看| 九色亚洲精品在线播放| 首页视频小说图片口味搜索| 国产三级黄色录像| 建设人人有责人人尽责人人享有的| 久久久国产一区二区|