The wave and vibratory power transmission in a finite L-shaped Mindlin plate with two simply supported opposite edges

In this paper,wave and vibratory power transmission in a finite L-shaped Mindlin plate with two simply supported opposite edges are investigated using the wave approach.The dynamic responses,active and reactive power flow in the finite plate are calculated by the Mindlin plate theory （MPT） and classic plate theory （CPT）.To satisfy the boundary conditions and continuous conditions at the coupled junction of the finite L-shaped plate,the near-field and far-field waves are entirely contained in the wave approach.The in-plane longitudinal and shear waves are also considered.The results indicate that the vibratory power flow based on the MPT is different from that based on the CPT not only at high frequencies but also at low and medium frequencies.The influence of the plate thickness on the vibrational power flow is investigated.From the results it is seen that the shear and rotary inertia correction of the MPT can influence the active and reactive power at the junction of the L-shaped plate not only at high frequencies but also at low and medium frequencies.Furthermore,the effects of structural damping on the active and reactive power flow at the junction are also analyzed.

Axial Compression Behavior and Analytical Method of L-Shaped Column Composed of Concrete-Filled Square Steel Tubes

Based on the characteristics of an L-shaped column composed of concrete-filled square steel tubes, the axial compression experiment and nonlinear finite element analysis were carried out to study the mechanical property of the L-shaped column. The load-displacement curve for the L-shaped column, the deflection and load-strain curves for the mono columns were obtained by the axial compression experiment. The results show that the L-shaped column exhibits a flexural-torsional buckling failure mode. The numerical simulation by the finite element analysis shows that the bearing capacity and failure mode are in accordance with those of the axial compression experiment and the feasi- bility of the finite element analysis is proved. For the calculation of the bearing capacity of the L-shaped column com- posed of concrete-filled square steel tubes, an analytical method is proposed based on the theory of the elastic stability and spatial truss model. The results of the analytical method are in good agreement with those of the axial compression experiment and the finite element analysis.

Joint 2D DOA and Doppler frequency estimation for L-shaped array using compressive sensing

A joint two-dimensional(2D)direction-of-arrival(DOA)and radial Doppler frequency estimation method for the L-shaped array is proposed in this paper based on the compressive sensing(CS)framework.Revised from the conventional CS-based methods where the joint spatial-temporal parameters are characterized in one large scale matrix,three smaller scale matrices with independent azimuth,elevation and Doppler frequency are introduced adopting a separable observation model.Afterwards,the estimation is achieved by L1-norm minimization and the Bayesian CS algorithm.In addition,under the L-shaped array topology,the azimuth and elevation are separated yet coupled to the same radial Doppler frequency.Hence,the pair matching problem is solved with the aid of the radial Doppler frequency.Finally,numerical simulations corroborate the feasibility and validity of the proposed algorithm.

Research on vibration characteristics of L-shaped plate using a mobility power flow approach

L-shaped plates have become an important focuses in structural vibration research. To determine their vibration characteristics, this paper applied a mobility power flow method. Firstly, the L-shaped plate was divided into two substructures to simplify analysis. The coupled bending moment was then deduced by applying a continuous vibration property on the common edge. Next, the response on any point of the plate and the input and transmitted power flow formulas were calculated. Numerical simulations showed the distribution of the coupled bending moment and the response of the whole structure. The validity of this method was verified by the SEA approach.

Laboratory test on the combined cooling effect of L-shaped thermosyphons and thermal insulation on high-grade roadway construction in permafrost regions

With the completion of the Qinghai-Tibetan Railway,economic development of related areas has been greatly accelerated.This,in return,calls for building or upgrading more roadways,especially high-grade roadways.In cold regions,the thawing of permafrost can induce settlement damage of and even failure to railway (or roadway) embankments.Thermosyphons (self-powered refrigera-tion devices that are used to help keep the permafrost cool) have proved effective in mitigating thaw settlement by maintaining the thermal stability of the embankments.However,for high-grade roadway embankments of great width,stabilizing or cooling ef-fects of traditional geotechnological measures may be limited.To enhance the cooling effect of thermosyphons,an L-shaped thermosyphon was designed.A laboratory test was carried out to study the combined cooling effect of the L-shaped thermosyphon and thermal insulation applying to roadbed construction.The angle between the evaporator and condenser sections of the L-shaped thermosyphon is 134 degrees,and the L-shaped thermosyphon was inserted into the soil at an angle of 5 degrees with the road surface.The tested results show that the L-shaped thermosyphon is effective in removing heat from a roadway in winter.When the ambient air temperature is lower than the soil temperature,the thermosyphon is active and extracts the heat in the soil around it.When the ambient air temperature is higher than the soil temperature,the thermosyphon is inactive,and no heat is in-jected into the soil through the L-shaped thermosyphon.Compared to embankments with straight thermosyphons,the inner parts of the embankments with L-shaped thermosyphons were significantly cooled.It is hoped that the present study would be useful to the application of L-shaped thermosyphons in the construction of high-grade roadways in cold regions.

Test on mechanical behavior of SRC L-shaped columns under combined torsion and bending moment

Investigations of the seismic behavior of steel reinforced concrete L-shaped columns under constant axial compression and cycled bending-shear-torsion load were performed.Six specimens,which considered two parameters,i.e.,the moment ratio of torsion to bending(γ)and the aspect ratio(column length-to-depth ratio,φ),were prepared for the experiment.In this study,the failure process,torsion-displacement hysteresis curves,and flexure-displacement hysteresis curves were obtained.The failure characteristics,mechanical behavior of specimens such as the failure patterns,hysteresis curves,rigidity degradation,ductility and energy dissipation,are analyzed.The experimental research indicated that the major failures of the specimens were bending failure,bending-shear failure and bending-torsion failure as the moment ratio of torsion to bending(γ)increased.The torsion-displacement hysteresis curves were pinched in the middle,formed a slip platform,and the phenomenon of“load drop”occurred after the peak load.The bending-displacement hysteresis curves were plump,which showed that bending capacity of the specimen was better than its torsion capacity.Additionally,the energy dissipation of the specimen was dominated by torsion in the early stage and ultimately governed by the bending moment in the later phase.Test results also indicated that the displacement ductility coefficient and interstory rotation angle of the failure point were less than 3.0 and 1/50,respectively,which means the test specimen performance does not meet the requirement of the Chinese Code for Seismic Design of Buildings(GB 50011-2014)in this respect.

Bandwidth Numerical Analysis of Triangular Patch Antenna Fed by L-Shaped Probe

A single layer triangular patch antenna fed by an L-shaped probe was investigated numerically by using FDTD (Finite Difference Time Domain) method. It achieves >40% impedance bandwidth (VSWR<2) and stable radiation pattern across the passband. The triangular patch antenna with two orientations of L-shaped probe has almost the same characteristics, such as impedance bandwidth and radiation pattern. The bandwidth vs feeding position was also investigated, the broadband characteristic can be observed when the feeding position is only in a small segment along the centerline.

The Effects of Cross Sectional Dimensions on the Behavior of L-Shaped RC Structural Members

The behavior of L-Shaped RC （reinforced concrete） shear walls was investigated in the Erciyes University Earthquake Investigation Laboratory under the influence of constant axial load together with reversed cyclic lateral load. The objective of this study was to evaluate the effects of cross sectional dimensions on the behavior of L-shaped structural members and to assess their earthquake performance. In order to investigate L-shaped RC structural members, the special experiment setup and four type of 1/2 scaled specimens which have different aspect ratio were constructed. The specimens were loaded in line with the major principal axes direction laterally. Axial load ratio was 0.1 and cross section height to thickness ratios were＇ 3：1, 5：1, 8：1, 10：1. Cross section thickness was 120 mm which corresponds to （360：120）, （600：120）, （960：120）, （1,200：120） wall legs cross sectional dimensions in mm. The specimens height was 1,500 mm, together with upper and lower slabs overall height was 2,000 mm. Concrete compression strength was 30 N/mm2, steel yield stress 420 N/mm2 and vertical reinforcement ratio was 1% for all specimens. According to the test results, the specimen of which the aspect ratio is 3 （360：120） has shown column behavior, the specimen of which the aspect ratio is 5 （600：120） has shown slender wall behavior and last two specimens of which the aspect ratios are 8 （960：120） and 10 （1,200：120） have shown squat wall behavior. When considering the cracking patterns and hysteretic behavior, since the aspect ratio 8, the specimens show flexure-shear interaction behavior and prone to brittle failure.

Multicut L-Shaped Algorithm for Stochastic Convex Programming with Fuzzy Probability Distribution

Two-stage problem of stochastic convex programming with fuzzy probability distribution is studied in this paper. Multicut L-shaped algorithm is proposed to solve the problem based on the fuzzy cutting and the minimax rule. Theorem of the convergence for the algorithm is proved. Finally, a numerical example about two-stage convex recourse problem shows the essential character and the efficiency.

青海都兰热水墓群血渭一号墓2021~2022年清理简报

为了厘清血渭一号大墓的形制与营建,帮助推进文化遗产保护与旅游开发,2021~2022年,热水联合考古队对血渭一号大墓进行了重新清理,清理范围主要包括血渭一号大墓的墓室、附属建筑及大墓南侧的第4、5号殉马沟。通过清理发现,血渭一号墓营建于自然山体平台上,有覆斗式封土,墓室为木石结构的多室墓,附属建筑位于平台东北部,由3座建筑基址组成。血渭一号墓南侧4号殉马沟内发现马骨17具,5号殉马沟内发现马骨21具,结合早年刊布的1~3号殉马沟的马匹数量,可知殉马沟内殉马总数为90具。

牛马不同槽——嘉峪关魏晋墓两幅壁画的现实表达与文化意涵

嘉峪关魏晋墓葬壁画描绘了“牛马不同槽”的现象。结合礼仪艺术与世俗绘卷中的同类图像,揭示了此类现象的现实原因,并指出其进入文化层面后的意涵。先秦哲学从牛马习性出发,抽象出了其间的对立统一关系,很多情境中牛马间的对立还可转化为对应,例如祭祀中的牛马,图像中的牛马合犋犁耕、牧马牧牛、牛车鞍马,宗教语境下的牛头马面等。“牛马不同槽”从民间俗语到文献与图像的表达,反映了古代艺术与生活的密切关系。

湖北云梦县郑家湖墓地M274葬具木材研究

云梦郑家湖C区墓葬均为战国晚期至西汉初的秦文化中小型饱水墓葬。其中M274一棺一椁制且规模较小,从形制规模和随葬品来看,墓主人应当为一名下层吏士。本文作者从M274的棺、椁上分别取样9份,除去一份腐烂严重无法鉴定,其余8份鉴定结果均为紫葳科梓属(Catalpa sp.)。综合文献记载和考古发现,我们认为春秋战国时期,人们已经开始应用梓木,且梓木是楚地乡土树种,就地取材作为棺椁很合理,但当时梓木葬具还不是高等贵族的专属。西汉及以后,梓木葬具与社会等级之间的关系得到强调。

世界遗产地保护传承导向的镇域国土空间规划探索

自北京总规批复以来,国土空间规划按照三级三类四体系的整体框架层层推进,镇域国土空间规划作为“中腰”部分,重在对控制要求的上传下达,做好各类指标和空间管控要素的刚性传导.北京历史悠久,文化资源丰富,是全国文化中心,如何保护好北京历史文化“金名片”,将历史文化保护的要求更好地传导到镇域国土空间规划中,又能向下贯彻落实,指引城乡发展建设,让历史文化遗产能够保得住、用得好是一个值得研究的课题.在分析世界遗产地面临的核心挑战的基础上,提出镇域国土空间规划应转变认知,协调好“遗产与区域、文物与本底、文化与空间、保护与发展”四组关系,并以世界文化遗产保护与乡镇发展共荣的十三陵实践为例,搭建起“整体认知-格局引领-分层保护-传承发展”的国土空间规划编制技术框架,以期能给相关工作提供有益借鉴.

西安曲江翠竹园西汉壁画墓妇女身份考——以服饰器物与图像程式为中心

西安曲江翠竹园壁画墓出土的壁画,保存完好、内容完整、风格独特,是研究西汉丧葬习俗以及物质文化的重要资料。遗憾的是,现有研究针对壁画中东壁与南壁五位妇女的身份认定仍众说纷纭。本文尝试从服饰器物、图像程式的角度出发,通过与汉代相关文献与出土文物进行互证、比对,系统考证这些妇女的身份。研究认为,曲江翠竹园壁画墓侧壁人物绘画构成的母题来源,应为早期临沂金雀山九号汉墓帛画与民安四号汉墓帛画;其人物身份组合也延续着母题中“贵人—侍者”的图像程式,其中东壁屏风图像是图像中“贵人”身份的符号象征。结合人物服饰器物,笔者推测包括东壁人物三、人物四以及南壁人物三、人物四、人物五在内的十位妇女,其真实身份应均为侍婢。

拉萨北部江多墓群墓主考释

江多墓群位于今西藏拉萨市林周县唐古乡江多村,海拔4200米左右,墓群均坐北朝南,依山临水,坐落于热振藏布北岸。墓群共有101座封土墓,其中14座分布在江多沟西岸台地,87座分布在玛钦山腰坡地上。根据地表上封土形状,可分为梯形和圆形两种。在墓群中,大型墓葬都坐落于视野开阔处,其封土平面呈梯形,最大者为编号M1的梯形墓,封土底边长50米、腰长32米、高7米,为众墓之首。而中小型墓葬封土平面以圆形为主,居于大型墓葬的两侧。文章通过考古类型学的研究方法,从封土外观、构筑方式、布局特征、选址环境等方面将江多墓地与青藏高原其他高等级吐蕃墓地的比较分析,认为江多墓地属于吐蕃时期营建的高等级墓地群。并结合《弟吴宗教源流》等藏文史籍的相关记载,发现江多一带在吐蕃时期为迥巴东岱,其地正是属庐氏领地。另外,根据《格西仲敦巴传记(写本)》中关于热振周围墓地相关的史料记载,推测江多墓地为庐氏家族之墓。

汉晋南朝买地券镇墓功能探析——以砖质买地券为中心

汉晋南朝买地券书写模式的转变,经历了东汉初、汉末吴晋、南朝三个演变阶段,其镇墓功能也随着书写模式的转变而发生改变。东汉初年初兴之际的买地券,书写模式更接近实用买卖契约,但其随葬明器的性质和买卖契约的书写格式,决定了它本身所具备的镇墓属性。这种镇墓属性是买地券作为“冥契”的固有属性,其存在与否与券文中宗教神仙色彩的有无强弱无关。汉末吴晋时期,买地券诸要项日渐完备,宗教神仙色彩日益浓厚,并出现了程式化演变趋势,但买地券的镇墓方式并未发生改变,其镇墓功能亦并未实现根本性的增强。汉末出现的糅杂了解注文内容的特殊买地券,不代表这一时期买地券演变的主流趋势。南朝时期由于道教的深入影响,一系列厌镇神仙鬼吏、慰抚亡魂、护佑生人的宗教语言出现在买地券文之中,至南梁时期,这种新式的券文书写模式已成为南朝各地买地券文的主流。南朝买地券书写模式的转变拓展了买地券的镇墓方式,增强了买地券的镇墓功能。

城固饶家营“张骞墓”札记二则

城固饶家营“张骞墓”是重要的世界文化遗产,1938年经西北联合大学“修理”后得到更好保护。在收集、整理新发现档案资料、原始资料后,认为现在将当时对该墓所做的工作通称“发掘”,不符合当时的目的、经过,以及当事人、当时人记述。对墓中出土“封泥”的性质,应以陈直先生“决不可目为泥封”为正,当回归何士骥先生“字纹陶片”的命名。

河南禹州阎寨遗址新莽时期墓葬发掘简报

2018年,河南大学历史文化学院在禹州市阎寨遗址发掘汉代墓葬6座。其中,M5和M7两座新莽时期墓葬形制较为特殊,所见随葬品组合及葬俗特征鲜明,双墓室四人合葬、海蓝宝石珠等在河南地区尚不多见,为了解新莽时期豫中地区的葬俗与社会增加了新的实物资料。

河南新密打虎亭汉墓景区文旅产品的包装设计研究

河南新密打虎亭汉墓是我国东汉时期重要的墓葬遗迹,保留了大量技艺精湛的石刻画像与壁画,为研究东汉时期中上层阶级的社会生活状况、思想意识形态,以及东汉石刻画像与绘画艺术等,提供了极为重要的实物资料。同时也为河南新密提供了旅游文化资源,对打造特色文化旅游、树立特色文旅品牌具有重要的价值和意义。基于此,以“汉乐神游”为主题,提取打虎亭汉墓壁画中的汉代生活场景及奇珍异兽等图形元素,探索与开发具有国潮风格的包装与广告设计,以期顺应人们对文化旅游产品个性化、审美化、体验化的需求,提升打虎亭汉墓景区的传播力和影响力。

宋元时期墓室壁画“六鹤图”考论

宋元时期几处墓葬中所遗存的屏风鹤画,是以唐薛稷“屏风六扇鹤样”为祖源,主要传写五代黄筌“六鹤图”而成的。墓葬中鹤画的丰富反映了宋元时期“六鹤图”的流变脉络。宋元时期墓葬中鹤画的流行以及各种“六鹤图”的绘制,是重道修道时代风气和丧葬观念影响的产物。在墓室壁画中,“六鹤图”被视为一种祥瑞及胎仙,通过屏风鹤画及相关空间营构,寄寓了宋元社会世人升仙重生的思想观念。