Present-day movement characteristics of the Qinghai Nanshan fault and its surrounding area from GPS observation

The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang Plateau.In previous studies,its movement characteristics are mainly investigated with geological and seismic observations,and the tectonic transformation role of the fault on its east is not yet clear.This study uses data fusion to obtain denser GPS observations near the Qinghai Nanshan fault.Based on tectonic characteristics,we establish a block model to investigate the fault slip rate,locking degree,and slip deficit.The results show that the Qinghai Nanshan fault slip rate is characterized by sinistral and convergent movement.Both the sinistral and convergent rates display a decreasing trend from west to east.The locking degree and slip deficit are higher in the western segment(with an average of about 0.74 and 1.1 mm/a)and lower in the eastern segment.Then,we construct a strain rate field using GPS observations to analyze the regional strain characteristics.The results indicate that along the fault,the western segment shows a larger shear strain rate and negative dilation rate.Regional earthquake records show that the frequency of earthquakes is lower near the fault.The joint results suggest that the western segment may have a higher earthquake risk.In addition,the insignificant fault slip rate in the eastern segment may indicate that it does not participate in the tectonic transformation among the Riyueshan,Lajishan,and West Qinling faults.

Research on the influences of motion characteristics of jetting projectile charge under water

Shaped charge warhead is important for enhancing the damage performance of underwater weapons.This paper used finite element analysis software and based on JPC water penetration experiments to examine the influence of liner parameters(wall thickness,material),charge aspect ratio,and stand-off distance on the movement characteristics of JPC in water.The findings reveal that the head diameter of the JPC increases and experiences significant erosion after entering the water,the effective length of the JPC in water undergoes two distinct phases:a growth phase and a decrease phase,with the velocity of the JPC decaying exponentially.Increasing the liner thickness,stand-off distance and the charge aspect ratio can improve the erosion resistance and the velocity retention capacity of the JPC.The optimal ranges for liner thickness and stand-off distance are 0.0363D_(k) to 0.0545D_(k)(D_(k) is the charge diameter),the stand-off distance should be within 1.0D_(k).After the charge aspect ratio higher than 1.25,the charge structure exerts minimal influence the movement characteristics of the JPC in water.Material density plays a crucial role in the velocity decay pattern of the JPC during penetration.JPC with higher densities exhibit superior velocity retention capabilities in water,with the velocity decay pattern converging if the densities are similar.Consequently,copper,tantalum and tungsten liners are deemed appropriate for underwater shaped charge warhead.Finally,the results will provide an important reference for the design of underwater shaped charge warhead.

Experimental study on age and gender differences in microscopic movement characteristics of students

Campus security has aroused many concerns from the whole society.Stampede is one of the most frequent and influential accidents in campus.Studies on pedestrian dynamics especially focusing on students are essential for campus security,which are helpful to improve facility design and emergency evacuation strategy.In this paper,primary and middle school students were recruited to participate in the single-file experiments.The microscopic movement characteristics,including walking speed,headway,gait characteristics(step length,step frequency and swaying amplitude)and their relations were investigated.Age and gender differences in the headway-speed diagram and space requirements were analyzed by statistical tests.The results indicated that the impacts of age and gender were significant.There were three stages for the influence of gender on the headway-speed diagram for both age groups.The impacts on students'space requirements were consistent for different age and gender groups.But the impacts of age and gender on free-flow speed were affected by each other.Due to the connection of walking speed and gait characteristics,the comparisons of gait characteristics between different ages and genders were performed to understand the corresponding differences in speed more deeply.The results showed that differences in step length and swaying amplitude between males and females were significant for both age groups.The effect of gender on step frequency was significant for primary students.But for middle school students,whether gender had significant impact on step frequency was not clear here because of the large P-value.Besides,the influence of age on gait characteristics changed with gender.

Characteristics of Horizontal Crustal Movement in the North China Region in the Last Decade

Based on high-precision data obtained in the past decade from GPS re-measurement in the North China Network, the Crustal Movement Observation Network of China (CMONOC) and GPS measurement along the Shanxi graben zone, the status and evolution of horizontal crustal movement in the North China region are analyzed. The results show that(1) the Yanshan tectonic zone (Zhangjiakou-Bohai Sea zone)is an active one with the largest horizontal strain in the North China region; The largest tendency differential movement of adjacent blocks is seen between the Yanshan block and the North China plain block; about 2mm/a (left lateral); (2) The significant horizontal differential movement along the boundaries of the North China region is characterized by right-lateral strike-slip movement at the middle-north segment on its west boundary (composed of Yinchuan and other active tectonic zones) and compressive movement at the south segment; while the Yinshan rift zone located along the west segment on its north boundary is dominated by tensile movement. Other boundaries and zones have no obvious differential movement; (3) On the whole, measurements of each period differ from one another, which might result from the nonlinear movement component as well as from the error effect. In the paper, results of the relative movement and strain in different periods are given for different blocks and boundary zones.

Construction of GPS MonitoringNetwork,Characteristics of RecentCrustal Movement,and Relationbetween Stress Field andEarthquake Activity in the NingxiaRegion

GPS observation network is deployed in the central part of Ningxia, which is the juncture of the Alxa block, Ordos block and Qinghai-Xizang (Tibet) block. Using the data of five phases of repeated survey sine 1996, the current state of crustal movement in the central part of Ningxia is analyzed. From the result, we can know the following. (1) In the period from Dec. 1996 to May 1999, the central part of Ningxia had the phenomenon of left-lateral movement about the west margin of Ordos (measuring station P2) and the Lingwu fault on the east of the Yinchuan basin displayed the mode of left-lateral reverse strike slip movement. In that region, the direction of the principal stress field was NNE-SSW (with an azimuth of 29.8?; the central part to the south of the measuring station P2 displaced eastward; the vertical deformation was obviously greater than the horizontal deformation in order of magnitude; the Yinchuan basin and Qinghai-Xizang (Tibet) block were in a state of rising; the measuring station P1 in the hinterland of Ordos showed a trend of subsiding year by year; and there may be a hidden fault to exist between the measuring points P3 and P4. (2) About one year before the occurrence of moderately strong earthquakes in the vicinity of the measuring region, deformation anomalies and abnormal changes of principal stress direction can be observed by the GPS measuring stations in that region; before moderately strong earthquakes near the measuring region and before strong earthquakes in adjacent regions, the simulated GPS deformation vector field ofthat region can betoken the approximate position of the coming earthquake. These results can be regarded as the eigenvalues of earthquake prediction for consideration.

XI JINPING THOUGHT ON SOCIALISM WITH CHINESE CHARACTERISTICS FOR A NEW ERA OPENS NEW HORIZON FOR INTERNATIONAL COMMUNIST MOVEMENT

The 19th National Congress of the Communist Party of China （CPC） established Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era as the guiding ideol- ogy of the CPC, marking a new leap forward in synthesizing basic principles of Marxism with China＇s concrete conditions. This Thought enriches and develops scientific socialism, the guiding ideology of the International Communist Movement. With brave new intellectual horizon, it deepens the understanding of the laws governing government by communist parties, construction of socialism and development of human society, occupying an important place of historical significance in the history of development of Marxism and the International Communist Movement. Guided by Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era, socialism with Chinese characteristics has made great historical achievements, creating new splendor and helping open new vista for the International Communist Movement.

Crustal Motion Characteristics in the Eastern Margin of the Tibetan Plateau and Adjacent Regions after the Wenchuan Earthquake

The Wenchuan earthquake has altered the crustal motion characteristics in the eastern margin of the Tibetan Plateau and adjacent regions.Using discontinuous GPS survey data for 2008–2012, the velocity field for the Eurasia reference framework has been obtained, and the general trend of contemporary crustal motion after the occurrence of the Wenchuan earthquake has been studied.In addition, using the velocity field, the block movement velocity has been estimated by least-squares fitting.Furthermore, the properties and displacement rates of main faults have been obtained from the differences in velocity vectors of the blocks on both sides of the faults.The results reveal that there are no obvious changes in the general characteristics of crustal motion in this area after the Wenchuan earthquake.The earthquake mainly changed the rate of the movement of the Chuan-Qing block and caused variation in the movement direction of the South China block.The effect of the earthquake on faults is mainly reflected in variations in fault displacement velocity; there is no fundamental change in the properties of fault activity.The displacement rates of the Xianshuihe fault decreased by 3–4 mm/a, the Longmenshan fault increased by 9–10 mm/a, and the northern segment of the Anninghe fault increased by approximately 9 mm/a.Furthermore, the displacement rates of the Minjiang, Xueshan, Huya, Longquanshan, and Xinjin faults increased by 2–3 mm/a.This implies that the effects of the Wenchuan earthquake on crustal movement can mainly be observed in the Chuan-Qing, South China, and N-Chuan-Dian blocks and their internal faults, as well as the Xianshuihe and Longmenshan faults and the northern section of the Anninghe fault.The reason for this is that the Wenchuan earthquake disturbed the kinematic and dynamic balance in the region.

Characteristics of Gas Emission at Super-Length Fully-Mechanized Top Coal Caving Face

Characteristics of gas emission at the K8206 working face in the Third mine of the Yangquan Coal Group were investigated. The effects of strata movement,advancing velocity of working face,production capacity of working face and gas extraction capability of strike high-level entry on gas emission at K8206 working face were analyzed. A regression equation,reflecting the relationship between relative gas emission rate and the production capacity of work-ing faces,was established. Another regression equation showing the relationship between the gas emission rate from adjacent layers when the working face was advancing for one metre and advancing velocity was derived. It can be con-cluded that,1) the amount of gas emitted at the K8206 working face is far greater than that of ordinary top coal caving faces with a dip length of 180-190 m; 2) the dynamic process of gas emission from adjacent layers during the initial mining stage is controlled by the movement of key strata; 3) the amount of gas emitted that needs to be forced out by air is greatly affected by the capability of gas extraction; 4) when the advancing velocity is between 3.5-5.5 m/d or when the output is up to 8-12 kt/d,the gas emission from adjacent layers is almost constant.

Research on dynamic characteristics of arc under electrode relative motion

The relative motion of the electrodes is a typical feature of sliding electrical contact systems.The system fault caused by the arc is the key problem that restricts the service life of the sliding electrical contact system.In this paper,an arcing experimental platform that can accurately control the relative speed and distance of electrodes is built,and the influence of different electrode speeds and electrode distances on arc motion characteristics is explored.It is found that there are three different modes of arc root motion:single arc root motion mode,single and double arc roots alternating motion mode,and multiple arc roots motion mode.The physical process and influence mechanism of different arc root motion modes are further studied,and the corresponding relationship between arc root motion modes and electrode speed is revealed.In addition,to further explore the distribution characteristics of arc temperature and its influencing factors,an arc magnetohydrodynamic model under the relative motion of electrodes is established,and the variation law of arc temperature under the effect of different electrode speeds and electrode distances is summarized.Finally,the influence mechanism of electrode speed and electrode distance on arc temperature,arc root distance,and arc root speed is clarified.The research results enrich the research system of arc dynamic characteristics in the field of sliding electrical contact,and provide theoretical support for restraining arc erosion and improving the service life of the sliding electrical contact system.

Effect of Precipitation Characteristics on Spatial and Temporal Variations of Landslide in Kermanshah Province in Iran

Landslide can be defined as the mass movement of sloping slopes under the influence of mass gravity and its stimuli such as earthquakes,floods and flood plains.This phenomenon is one of the natural hazards that every year causes a lot of financial and financial losses in mountainous,rain-fed and seismic areas.Detection of time and the magnitude of landslides are necessary to understand the causes of landslide and to warn potential hazards.In this research,the amount of landslide displacement in Kermanshah province was evaluated by the characteristics of rainfall.To this end,a network of fixed points in and out of the slipping mass of 20 points was created to monitor the amount of displacement on different slip load users and the amount of displacement of each point in 5 time intervals using the Global Positioning System for two-dimensional GPS measurement.The results of the 511-day follow-up showed that the total horizontal displacement of the moving points in the 5 intervals measured at 1658 mm has a monthly displacement rate of 112 mm.Also,the total vertical displacement of moving points at the same time is 899 mm,with a monthly movement rate of 71 mm.Then,precipitation variances such as rainfall,rainfall,precipitation duration,maximum rainfall intensity in the intervals of 10,20,30 and 60 minutes and the average rainfall intensity were calculated and extracted for each of the 5 time periods.The drawing of the vectors of points on the topographic map of the area indicated that the direction of mass movement is in the direction of elevation gradient of the region.The results showed that only the precipitation severity with the landslide had a good correlation.The landslide movement had the highest correlation with average rainfall intensity(R=0.85)and with maximum 30 minutes rainfall(R=0.67),respectively,and other rainfall characteristics like amount,duration,and type of rainfall had not significantly correlated with movement of landslides.

Current tectonic deformation and seismogenic characteristics along the northeast margin of Qinghai -Xizang block

Based on the data from repeated precise leveling and across-fault deformation measurements carried out in recent 30 years and the analyzed results from GPS observations made in recent years along the northeastern margin of Qinghai-Xizang block, and combined with the geological structures and seismic activities, some characteristics in regional tectonic deformation and strong earthquake development are studied and approached preliminarily. The results show that: a) The space-time distribution of current tectonic deformation in this area is inhomogeneous with relatively intensive tectonic deformation in the vicinity of main boundary faults and weak deformation in the farther areas. The intensity of vertical differential movement and the deformation status vary with time, and the horizontal movement and deformation are characterized by apparent compression and strike-slip. b) The tectonic stress field generated by the NE-trending continuous compressive movement of Qinghai-Xizang block due to the northward press and collision of India plate is the principal stress for the tectonic deformation and earthquake development in this area. The evolution of space-time distribution of tectonic deformation and seismicity is closely related to the block activity and dynamic evolution of regional tectonic stress field. c) The vertical deformation uplift and high-gradient deformation zones and the obvious fault deformation anomaly appeared along the boundaries of tectonic blocks can be considered as the indicators of hindered block motion and intensified tectonic stress field for strong earthquake development. Usually, the above-mentioned phenomena would be followed by the seismicity of M6.0, but the earthquake might not occur in the place with the maximum movement. The zones with the fault deformation anomaly characterized by tendencious accumulation acceleration turning and the surrounding areas might be the positions for accumulation of strain energy and development and occurrence of strong earthquakes.

Dynamic response characteristics of a circular lined tunnel under anisotropy frost heave of overlying soil at the tunnel portal section in cold regions

The rapid development of traffic engineering in cold regions and its consequent problems need to be considered.In this paper,the dynamic response characteristics of the tunnel portal section in cold regions with harmonic load acting on the lining were studied in the frequency domain.The lining is in close contact with the frozen soil,and there is relative movement between the frozen and unfrozen soil due to the phase change.The analytical solution of the vibration of tunnel portal section caused by the harmonic load acting on the lining was derived under the consideration of the anisotropy frost heave of overlying soil.Based on the continuity conditions and boundary conditions,the undetermined coefficients were obtained,and the analytical solutions for different medium displacements and stresses of the cold-region tunnel system were acquired.The vertical pressure coefficient was equivalently simplified as a variable that could be used to replace the thickness of the overlying soil above the tunnel.The analysis of the parameter model shows that the change of the medium parameters(lining,frozen,and unfrozen soil)affects the circumferential stresses,the radial displacements and their peak frequencies of the soil.For example,the increase of density ratio of tunnel lining to frozen soil decreases the radial stresses of the frozen and unfrozen soil;the increase of volumetric frost heaving strain of the frozen soil increases the radial displacements of the frozen surface and decreases the stability of the frozen surface;the increasing of thickness of the frozen soil significantly reduces the radial displacement of unfrozen soil at dimensionless radius η=4.5 compared with that of frozen soil at η=1.5.

舌功能运动与骨性Ⅲ类错牙合畸形骨性和牙性形态特征关系的研究

目的:探讨成人骨性Ⅲ类错牙合畸形患者的舌肌功能运动状况,观察舌功能运动对骨性Ⅲ类错牙合畸形骨性和牙性特征产生的影响。方法:选取2020年1月-2022年6月笔者医院口腔科的骨性Ⅲ类错牙合畸形患者89例,测量最适张口(Comfortable mouth opening,CMO)的切牙间距离、舌尖上抬至切牙乳头(Tongue tip extended to the incisive papilla,TIP)的切牙间距离、舌体吸附至腭部(Lingual-palatal suction,LPS)的切牙间距离,计算舌前部的活动度(Mobility of the anterior one-third of the tongue,TRMR-TIP=TIP/CMO),舌后部的活动度(Mobility of the posterior two-thirds of the tongue,TRMR-LPS=LPS/CMO),将舌活动度分为四级。通过头颅侧位片和模型分析测量骨性和牙性指标。比较各分级间舌功能活动度与骨性Ⅲ类错牙合畸形骨性和牙性特征的关系。结果:舌前后部活动度三级(低于平均水平)、四级(显著低于平均水平)的SNB、L1-MP比一级(显著高于平均水平)、二级(平均水平)大;舌前后部活动度一级、二级的Go-Gn-SN°比三级、四级大;舌后部活动度一级、二级的上颌尖牙间宽度、上颌磨牙间宽度、下颌尖牙间宽度比三级、四级大;舌后部活动度三级、四级的下颌磨牙间宽度比一级、二级大,差异均有统计学意义(P<0.05)。结论:舌活动度越小,下颌前突越严重,下颌骨向后下旋转趋势越小,下前牙越唇倾。随着舌后部活动度减小,下颌磨牙间宽度增大,上颌尖牙和上颌磨牙间宽度、下颌尖牙间宽度减小。

矸石胶结充填体力学特性及充填效应研究

传统的垮落法采空区处理方式造成岩层大范围移动破坏、地表沉陷变形等生态环境问题不断发生。地下煤炭采出后顶板发生破碎、垮冒现象,在覆岩压力作用下各岩层移动不断活化、破断,进而向地表方向发展形成地面沉陷和破坏,由此引发了水土流失、地下水断流、地表建筑物破坏、居民搬迁等一系列问题。结合煤矿矸石胶结充填开采技术的特点,在研究胶结充填材料力学特性的基础上,深入研究矸石胶结充填采煤采场顶板岩层受力、移动、变形规律以及采空区充填率对采空区上覆岩层活动的影响等方面。研究成果矸石胶结充填技术既能够充分利用固废,减少煤矸石及粉煤灰给环境带来的污染问题,而且保护地面建筑物稳定不破坏,对于解决“三下”压煤问题具有极高的应用价值,为充填开采采场矿压规律、上覆岩层移动控制、矸石胶结充填材料选择设计、地表沉陷预计等方面提供理论依据和技术支持,进一步丰富和完善充填开采基础理论,有利于促进充填开采技术的推广应用。

Correlation between Tectonic Environment and Chracteristics of Mass Movement （Landslides）： A Case Study from Java, Indonesia

In Central Java and Yogyakarta Special Region, there are several zones, which potential of landslide disaster. The zones are in general located at uplitted and or folded mountains, such as North Serayu Mountains, South Serayu Mountains, Menoreh Mountains, Southern Mountains and slopes of young volcanic area, including Ungaran-Merbabu-Merapi area, and Slamet-Sundoro-Sumbing area. Besides morphology, another main factor influencing vulnerability of the terrain is physical properties of the composing lithology. The geologic formations in the study area are predominantly composed of clayey and volcanic rocks. The cohesion force of clayey rock ranges 0.4-0.7 kg/cm^2, the internal friction angle ranges 20°-35°, while the cohesion force of volcanic rock （weathered） ranges 0.25-0.27 kg/cm^2, and the friction angle ranges 20°-35°. In general, rocks occupying the area are collectively dissected by joints and active faults, with soil of more than 5 m thick. Local rainfall belongs to high category （〉 2,500 mm/y）. However, landslides that occur in each physiographic zone mentioned above show different characterizations.

我国男子跳马单项决赛动作特征分析--以2022年全国体操锦标赛为例

文章运用文献资料、录像观察、数理统计等方法,以2022年全国体操锦标赛男子跳马单项决赛动作选择为切入点。按照上板、第一腾空、第二腾空、落地的顺序进行对比分析,研究国内优秀跳马运动员动作选择倾向以及动作特征,找出特长与优势,为运动员日常训练提供理论指导从而将运动训练过程置于科学控制状态之下,提高训练的科学性。研究得出:通过预赛的层层选拔,进入跳马单项决赛的8名选手在一定程度上代表了国内跳马的最高水平,随着国内跳马项目迅速发展,运动员动作难度价值整体上升了一个水平,但完成质量有待提高;跳马单项决赛中5.4是基本难度水平;动作选择依旧集中在手翻类动作,踺子上板类动作较少;单一轴转体的动作是运动员动作选择的主流;动作完成质量以及落地稳定性是世界大赛中夺金的有力保障。以上结论有利于了解当前国内跳马现状;为运动员提出了未来训练的发展方向和要求;为备战巴黎奥运会,在世界大赛上冲击奖牌具有重要意义。

库区浮泥层纵向流速垂线分布特性研究

水库浮泥是存在于水库底部的一层高含沙水体,流动性较强,直接影响水库淤积形态和水库排沙,研究其运动规律对水库减淤优化调度具有重要意义。根据三峡库区实测泥沙矿物组成和级配资料,配置沙样进行流变试验,以幂律流变模型描述浮泥的本构关系。构建了浮泥运动的速度分布理论模型,通过水槽试验对模型进行了验证,计算结果与试验结果吻合较好。结果表明,浮泥运动速度随浮泥厚度、上层水流流速、床面坡度增大而增大,随浮泥密度增大而减少。沿水深方向浮泥纵向流速分布始终呈抛物线型,表层的浮泥流速要远大于底层浮泥,浮泥纵向流速沿垂向方向不断减少,最底部的浮泥几乎处于静止状态。

不同风格驾驶员眼动特性分析——夜间快速路分流区

为提高驾驶员在夜间快速路分流区换道的安全性,以不同风格的驾驶员为研究对象,分析不同风格驾驶员换道时眼动参数的变化规律。首先在前人研究基础上自编夜间快速路驾驶风格量表,对量表进行信度和Pearson相关系数法的效度检验;然后通过主成分分析法对问卷调查法得出的结果进行分析,得出驾驶风格综合得分量化模型,并使用K均值聚类分析法划分驾驶风格;最后基于眼动仪进行实车试验,获取三种风格驾驶员换道的眼动数据。试验结果表明:谨慎型、一般型、激进型驾驶员对于后视镜平均注视次数占比为48%、27%、25%;对左右两侧的平均累计注视时间占比是31%、25%、19%;平均瞳孔面积占比为56.3%、27.6%、16.1%。试验结果可以为提高驾驶员换道的行车安全性研究提供一定的数据支持。

扬尘寿命试验中某小口径步枪的特性参数变化

扬尘环境对枪械的性能与可靠性有着重要影响,依照扬尘试验标准开展全枪寿命试验,得到枪械特性参数的变化规律并分析原因。利用高速摄影与光幕靶记录枪械初速、射频、特征点速度的变化情况,分析解释参数变化对步枪性能退化的影响。将试验用枪设置为对照组,分析枪支的保养对枪械性能的维持效果。试验结果表明:在扬尘环境下弹簧的预压力、自由长度随射弹量增加呈下降趋势,但刚度并没有明显变化,同时弹簧性能退化幅度活塞簧>复进簧>击锤簧;步枪随着射弹量增加会出现明显的挂铜现象,导致导气室的结构参数发生变化;对摩擦副的磨损会导致构件之间的运动间隙增大,但涂油保养会减缓这一退化。基于全枪寿命试验,为阐明扬尘环境下自动机运动特性和故障的影响机理提供了试验验证,对研究小口径步枪性能变化规律提供了数据支撑。

秀山花灯的舞蹈动作形态研究

秀山花灯系第一批国家级非物质文化遗产名录,是融合了歌、舞、戏等多种艺术形式为一体的综合表演艺术。秀山花灯具有高台花灯、单花灯、双花灯、群花灯等多种表演形式,舞蹈作为其重要组成部分,主要以扇法、身法、步法三种舞蹈动作技法为主,舞蹈形态特征则主要表现在扇法中的“绕转”、身法中的“颤膝”以及步法中的“弧线”等。这些舞蹈形态特征所展现出的艺术魅力,可推动秀山花灯的现代性传承与发展。