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基于锐捷仿真实验平台的NAT技术实现

科技创新与应用 2024年第21期14卷 74-77页

作者：滕君华陈文耿梁丽芳李婵娟金莹王莹林彬大连海事大学国家级电子信息技术实验教学示范中心辽宁大连116026

为更加深入认识与了解网络组态,要加强对NAT技术的研究学习。该文通过对NAT技术的背景、原理、实现等方面较为全面地阐述,分析介绍静态NAT、动态NAT、NAPT技术及相关联的acl技术;同时通过锐捷网络公司的真实验平台,模拟实现公司内网服... 详细信息

为更加深入认识与了解网络组态,要加强对NAT技术的研究学习。该文通过对NAT技术的背景、原理、实现等方面较为全面地阐述,分析介绍静态NAT、动态NAT、NAPT技术及相关联的acl技术;同时通过锐捷网络公司的真实验平台,模拟实现公司内网服务器地址的公网映射,分别对不同类别的NAT技术进行实验验证,并进行分析讨论。实验证明,NAT技术在当前仍有很好的应用前景,在企业组网中发挥一定作用。

关键词：网络地址转换动态地址转换仿真 acl 网络安全

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交换机传输网络在卫星地球站的应用

广播与电视技术 2024年第1期51卷 103-106页

作者：戴庆荣广东省广播电视卫星地球站广东511400

广东卫星地球站交换机传输网络通过使用2层VLAN划分不同虚拟网络,缩小广播域,提高带宽资源的使用效率。在远距离传输的链路上,使用链路聚合技术LACP的方式实现链路冗余备份,提高传输链路的可靠性。在交换机之间互联的端口使用acl(Access... 详细信息

广东卫星地球站交换机传输网络通过使用2层VLAN划分不同虚拟网络,缩小广播域,提高带宽资源的使用效率。在远距离传输的链路上,使用链路聚合技术LACP的方式实现链路冗余备份,提高传输链路的可靠性。在交换机之间互联的端口使用acl(Access Control List,访问控制列表),实现了对网络中IP报文的精准过滤和通过,提高了网络环境的安全性和可靠性。

关键词：交换机 VLAN 链路聚合 acl

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铁路数据网高危端口屏蔽控制研究

通信与信息技术 2024年第2期 68-70页

作者：李铭煜常根刘勇雷欣雅符静雯中国铁路广州局集团有限公司广东广州510080

通过研究铁路数据网存在的常见高危端口,提出了基于acl、Traffic-filter和防火墙的屏蔽控制方案,在接入设备相应端口部署基于acl和Traffic-filter的安全策略或设置防火墙部署安全访问控制策略,屏蔽高危端口,对铁路数据网业务终端及业务... 详细信息

通过研究铁路数据网存在的常见高危端口,提出了基于acl、Traffic-filter和防火墙的屏蔽控制方案,在接入设备相应端口部署基于acl和Traffic-filter的安全策略或设置防火墙部署安全访问控制策略,屏蔽高危端口,对铁路数据网业务终端及业务服务器进行有效的防护。

关键词：数据网 acl Traffic-filter 防火墙

股骨隧道偏移扩大及高度轴移的前交叉韧带二次断裂1例报道

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实用骨科杂志 2024年第1期30卷 87-89页

作者：杨登军王福科施青吕余洋张奇爱昆明医科大学第一附属医院运动医学科云南昆明650032

近年来前交叉韧带(anterior cruciate ligament, acl)重建后再断裂患者逐年增加,相比初次acl重建,acl翻修更复杂更具挑战性[1]。为保证临床疗效,对重建失败原因、有无合并损伤、个体化手术方案制定、患者期望值等均应仔细考量[2]。2022... 详细信息

近年来前交叉韧带(anterior cruciate ligament, acl)重建后再断裂患者逐年增加,相比初次acl重建,acl翻修更复杂更具挑战性[1]。为保证临床疗效,对重建失败原因、有无合并损伤、个体化手术方案制定、患者期望值等均应仔细考量[2]。2022年11月昆明医科大学第一附属医院收治1例伴股骨隧道偏移扩大及高度轴移的acl二次断裂患者,行越顶技术联合前外侧韧带(anterolateral ligament, ALL)建一期翻修手术,现报告如下。

关键词：前交叉韧带合并损伤股骨隧道临床疗效前外侧韧带失败原因再断裂 acl

Is hamstrings-to-quadriceps torque ratio useful for predicting anterior cruciate ligament and hamstring injuries?A systematic and critical review

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Journal of Sport and Health Science 2023年第3期12卷 343-358页

作者： Eleftherios Kellis Chrysostomos Sahinis Vasilios Baltzopoulos Laboratory of Neuromechanics Department of Physical Education and Sport Sciences at SerresAristotle University of ThessalonikiSerres 62100Greece Research Institute for Sport and Exercise Sciences(RISES) Faculty of ScienceLiverpool John Moores UniversityLiverpool L35UXUK

Background:For the past 30 years,the hamstring(H)-to-quadriceps(Q)(H:Q)torque ratio has been considered an important index of muscle strength imbalance around the knee joint.The purpose of this systematic review was to examine the value of H:Q torque ratio as an independent risk factor for hamstring and anterior cruciate ligament(acl)injuries.Methods:Database searches were performed to identify all relevant articles in PubMed,MEDLINE,Cochrane Library,and Scopus.Prospective studies evaluating the conventional(concentric H:Q),functional(eccentric H:concentric Q),and mixed(eccentric H at 300/s:concentric Q at2400/s)H:Q ratios as risk factors for occurrence of hamstring muscle strain or acl injury were considered.Risk of bias was assessed using the Quality In Prognosis Studies tool.Results:Eighteen included studies reported 585 hamstrings injuries in 2945 participants,and 5 studies documented 128 acl injuries in 2772participants.Best evidence synthesis analysis indicated that there is very limited evidence that H:Q strength ratio is an independent risk factor for hamstring and acl injury,and this was not different between various ratio types.Methodological limitations and limited evidence for acl injuries and some ratio types might have influenced these results.Conclusion:The H:Q ratio has limited value for the prediction of acl and hamstring injuries.Monitoring strength imbalances along with other modifiable factors during the entire competitive season may provide a better understanding of the association between H:Q ratio and injury.

关键词： acl Isokinetic Prospective Strains Strength imbalance

A re-evaluation of the average chain length of lacustrine sedimentary n-alkanes as a paleoproxy on the Qinghai-Tibet Plateau

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Frontiers of Earth Science 2023年第4期17卷 905-919页

作者： Mingda WANG Qin LI Jaime TONEY David HENDERSON Juzhi HOU School of Geography Liaoning Normal UniversityDalian 116029China Alpine Paleoecology and Human Adaptation(ALPHA)Group State Key Laboratory of Tibetan Plateau Earth SystemResources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China School of Geographical and Earth Sciences University of GlasgowGlasgow G128QQScotlandUK CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China

Long-chain n-alkanes are one of the most common organic compounds in terrestrial plants and they are well-preserved in various geological archives.n-alkanes are relatively resistant to degradation and thus they can provide high-fidelity records of past vegetation and climate changes.Nevertheless,previous studies have shown that the interpretation of n-alkane proxies,such as the average chain length(acl),is often ambiguous since this proxy depends on more than one variable.Both vegetation and climate could exert controls on the n-alkane acl,and hence its interpretation requires careful consideration,especially in regions like the Qinghai-Tibet Plateau(QTP)where topography,biome type and moisture source are highly variable.To further evaluate the influences of vegetation and climate on the acl in high-elevation lakes,we examined the n-alkane distributions of the surface sediments of 55 lakes across the QTP.Our results show that the acl across a climatic gradient is significantly affected by precipitation,rather than by temperature.The positive correlation between acl and precipitation may be because of the effect of microbial degradation during deposition.Finally,we suggest that more caution is needed in the interpretation of acl data in different regions.

关键词： acl average chain length n-alkanes leaf wax lake sediments Qinghai-Tibet Plateau

Effects of a soccer-specific vertical jump on lower extremity landing kinematics

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Sports Medicine and Health Science 2022年第3期4卷 209-214页

作者： Sophia Mancini DClark Dickin Dorice Hankemeier Caroline Ashton Jordan Welch Henry Wang Biomechanics Laboratory Ball State University47306USA School of Kinesiology Ball State University2000 W University AvenueMuncieIN47306USA

Anterior cruciate ligament(acl)injury frequently occurs in female soccer athletes during deceleration movements such as landings.In soccer,landings mostly occur following jumping headers.Little research has been done to determine the mechanics that follow and how they compare to standard drop vertical jumps(DVJ).The purpose of this study was to analyze differences in kinematics between the DVJ and the soccer-specific vertical jump(SSVJ)in female soccer athletes to better assess the sport-specific risk for acl injury.A secondary aim was to compare second landings(L2)to first landings(L1).Eight female recreational soccer athletes performed DVJs and SSVJs initiated from a 31 cm height.Motion capture was performed during landings and data were analyzed using repeated-measures ANOVA.SSVJs produced less peak hip flexion(p=0.03)and less peak knee flexion(p=0.002)than DVJs.SSVJs also demonstrated increased ankle plantarflexion at initial contact(IC)than DVJs(p=0.005).L2s produced less peak hip(p=0.007)and knee flexion(p=0.002)than L1s.SSVJs and L2s displayed a more erect landing posture than the DVJs and L1s at the hip and knee,a known acl risk factor.The significant results between jump styles show that the SSVJ displays mechanics that are different from the DVJ.The SSVJ may be a better sport-specific screening tool for acl injury mechanisms than the DVJ in soccer athletes as it has a more direct translation to the sport.

关键词： acl Female soccer athletes Jump landing Kinematics Injury mechanisms

A comparison of lower limb stiffness and mechanical muscle function in acl-reconstructed,elite,and adolescent alpine ski racers/ski cross athletes

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Journal of Sport and Health Science 2018年第4期7卷 416-424页

作者： matthew j.jordan per aagaard walter herzog canadian sport institute calgary Calgary AB T2N 1N4 Canada department of sports science and clinical biomechanics sdu muscle research clusteruniversity of southern denmarkOdense DK-5230Denmark human performance laboratory university of calgaryCalgary AB T2N 1N4Canada

Purpose: The aim of this study was to compare mechanical muscle function in the eccentric/concentric phases of vertical bilateral jumping in anterior cruciate ligament-reconstructed(aclR), elite(ELITE), and adolescent(ADOL) alpine ski racers and ski cross athletes.Methods: Alpine ski racers/ski crossers(aclR: n = 12, age = 26.7 § 3.8 years; ELITE: n = 12, age = 23.9 § 3.0 years; ADOL: n = 12, age = 17.8§ 0.7 years; females: n = 6 per group, males: n = 6 per group) performed 5 maximal countermovement jumps(CMJs) and 5 squat jumps. The ground reaction forces for each limb were analyzed using dual force plate recording to obtain body center of mass(BCM) velocity, displacement,and power. The eccentric deceleration(ECC) and concentric phases were determined from BCM velocity. CMJ net concentric and ECC impulses were calculated(body mass normalized) along with the peak and mean BCM power and maximal vertical jump height. CMJ lower limb stiffness(LLS) was determined by the slope of the ground reaction forces vs. the BCM displacement curve over the ECC phase. Concentric and ECC asymmetry indices were calculated for each leg, and the left vs. right LLS was compared. Outcome measures(reported as mean § SD) calculated as a 5-jump mean were normalized to body mass and compared using an analysis of variance.Results: No between-group differences were found for peak and mean power or jump heights. There were no group differences for LLS or net concentric phase impulse, but the net ECC impulse was lower in the ADOL group compared with ELITE skiers(ADOL: 1.33 § 0.32 Ns/kg;ELITE: 1.59 § 0.16 Ns/kg; p aclR and ELITE skiers. The implication of these f

关键词：运动员滑雪高山肌肉机械僵硬 acl 青春期

The effect of performance demands on lower extremity biomechanics during landing and cutting tasks

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Journal of Sport and Health Science 2019年第3期8卷 228-234页

作者： Boyi Dai William E.Garrett Michael T.Gross Darin A.Padua Robin M.Queen Bing Yu Division of Kinesiology and Health University of Wyoming Department of Orthopaedic Surgery Duke University Division of Physical Therapy University of North Carolina at Chapel Hill Department of Exercise and Sport Science University of North Carolina at Chapel Hill Kevin Granata Biomechanics Lab Department of Biomedical Engineering and MechanicsVirginia Tech

Background: Anterior cruciate ligament(acl) injuries commonly occur during the early phase of landing and cutting tasks that involve sudden decelerations. The purpose of this study was to investigate the effects of jump height and jump speed on lower extremity biomechanics during a stop-jump task and the effect of cutting speed on lower extremity biomechanics during a side-cutting task.Methods: Thirty-six recreational athletes performed a stop-jump task under 3 conditions: jumping fast, jumping for maximum height, and jumping for 60% of maximum height. Participants also performed a side-cutting task under 2 conditions: cutting at maximum speed and cutting at 60% of maximum speed. Three-dimensional kinematic and kinetic data were collected.Results:The jumping fast condition resulted in increased peak posterior ground reaction force(PPGRF), knee extension moment at PPGRF,and knee joint stiffness and decreased knee flexion angle compared with the jumping for maximum height condition. The jumping for 60% of maximum height condition resulted in decreased knee flexion angle compared with the jumping for maxrimum height condition. Participants demonstrated greater PPGRF, knee extension moment at PPGRF, knee valgus angle and varus moment at PPGRF, knee joint stiffness, and knee flexion angle during the cutting at maximum speed condition compared with the cutting at 60% maximum speed condition.Conclusion: Performing jump landing at an increased jump speed resulted in lower extremity movement patterns that have been previously associated with an increase in acl loading. Cutting speed also affected lower extremity biomechanics. Jump speed and cutting speed need to be considered when designing AC.L injury risk screening and injury prevention programs.

关键词： acl injury Injury prevention Kinematics Kinetics Loading mechanism Risk factor