Stable Isotope Sourcing of Wool from Textiles at Pacatnamú

Stable carbon and nitrogen isotopic compositions were determined for wool textiles from the Lambayeque (c. ad 1100–1320) occupation at Pacatnamú in the Jequetepeque Valley, northern Peru. The isotopic data demonstrate that the wool was not obtained via long‐distance exchange with the highlands and was most probably derived from locally raised camelids. In light of other lines of evidence (diversity of dyes used to produce the same colours in textiles and the low quality of the weaving), textiles at Pacatnamú appear not to have been as effective a marker of political power and prestige for local elites as they were elsewhere in the Andean region.     

西周金文“佃人”身份考

西周铜器铭刻资料中习见的"佃人"一词,是指隶属于王朝或依附于贵族家族的农业人口,属于庶民阶层,而非传世文献中所记载的"甸师"、"甸人"与"田畯"之类的官师。这些"佃人",有他们自己的包括土地、生产工具和家畜在内的私产。他们在农官或私臣的带领和监督下,以耕作"公田"的劳役为形式,服务于大大小小的贵族阶层,受各级统治者的剥削。通过各方面的比较,他们的身份地位与当时的"仆庸"颇为相近,故"佃人"一词很可能就是"仆庸"的异称。     

Landscapes of death: GIS-based analyses of chullpas in the western Lake Titicaca basin

The western Lake Titicaca basin is marked by above-ground funerary towers, known as chullpas, located in a variety of geographical contexts and dating to the Late Intermediate Period, or LIP (AD 1100–1450), and Late Horizon (AD 1450–1532). Over the years, interpretations of these tombs have concentrated upon their roles as loci for ancestral veneration and their abilities to perpetuate memory, delineate social ties and territories, and demarcate access to resources. These views share the implicit or explicit assumption that these mortuary structures were intended to be highly visible. Yet this assumption has never been formally tested. By using GIS-based geospatial tools and statistical analysis, this paper investigates the extent to which chullpas surveyed in the western Lake Titicaca basin visually dominated the landscape. These tombs were not positioned in random locations; they exhibit a high degree of clustering and were built in highly visible areas that could be seen from sites of occupation and regions of economic importance such as Lake Umayo. This paper suggests that this landscape of death was deliberately constructed to have an enduring social impact.     

论十六国时期胡人政权速亡原因及其历史启示

十六国胡人政权速亡的根本原因有三个方面,一是胡人统治者在统治民族本身不够成熟和强大的情况下,普遍实行民族本位、民族压迫和民族防范政策,既埋下了统治力量先天不足的隐患,又加重了民族隔阂,激化了民族矛盾;二是各政权普遍存在内乱不断的现象,导致自相残杀、自取灭亡和外敌乘虚而入的惨重恶果;三是统治者普遍在政治、生活上极度腐败,重用奸臣,沉迷享乐,不恤民力,穷奢极欲,导致民不聊生,民怨沸腾,激化了社会矛盾,动摇了统治基础。民族矛盾和社会矛盾,大大削弱了十六国胡人政权自身实力,制约了政权发展壮大,导致了政权的迅速崩溃和灭亡。十六国胡人政权速亡现象具有深刻的历史启示意义。     

岭南战国秦汉墓的“架棺”葬俗

在部分岭南战国秦汉墓葬中,随葬器物的空间分布和保存状态显示出"架棺"的迹象。结合广州汉墓中"架棺"和"架举棺室"的实例,以及部分岭南战国秦汉墓葬中墓底柱洞和凹槽的发现情况,推测"架棺"葬俗在战国秦汉时期岭南地区的越人墓葬中使用较为普遍。"架棺"的方式较为复杂,此葬俗的文化含义也值得深入研究。     

Seismic Site Response Modeling for Three Missouri River Highway Bridges

Three highway bridges spanning the Missouri River flood plain were selected for evaluation of seismic site response for moderate size earthquakes emanating from the New Madrid Seismic Zone (NMSZ) in the Midwestern United States. The NMSZ is known to be capable spawning earthquakes larger than magnitude (M) 7.0, four of which occurred in a three-month period between 1811 and 1812, and the M_w 6.0 earthquake of October 1895 centered near Charleston, Missouri. This study evaluated the likely impacts of long period motion of these historic earthquakes on three long-span highway bridges using geotechnical data obtained from recent investigations. Our results suggest site amplification between 6× and 9×, depending on the magnitude and epicentral distance. We believe that threshold magnitude for serious foundation failure and damage to these bridges is between M_w 6.5 and 6.6. Above these magnitudes widespread liquefaction is predicted, which would effect the peak horizontal acceleration and spectral accelerations, causing the ground motions to be different than predicted. Increase in amplification of the response spectra also should be expected where the periods are higher than 1.0 sec. Therefore, M_w 6.5+ earthquakes at ranges 210–260 km could be expected to engender resonant frequency problems for multiple span bridges and tall buildings (10 to 25 stories) in channel corridors containing 20 to 46 m of unconsolidated sediment.     

Estimating the Higher-Mode Response of Ductile Structures

While the importance of higher-mode actions is appreciated within the engineering community, the affect that ductile nonlinear response has on higher-mode characteristics and the subsequent implications this has for design has received little attention. In this article, the manner in which the higher-mode response of frame-wall structures is affected by inelastic behavior is closely examined and a means of accounting for this in design is proposed. The work focuses firstly on the characteristics of the higher modes present at the development of peak response and then considers how these characteristics would affect the total forces in the building. The study utilizes a series of nonlinear time-history analyses of two different groups of RC frame-wall structures subject to a suite of real records. It is shown that a new modal analysis approach that incorporates transitory inelastic modal characteristics gives significantly improved predictions of peak base shear in frame-wall structures than more traditional modal analysis methods which use elastic higher-mode characteristics. The issues associated with the use of transitory inelastic modal characteristics are discussed and various challenges that would need addressing for the prediction of other response parameters and structural types are identified.     

Evaluation of Approaches to Characterize Seismic Isolation Systems for Design

Current design codes generally use an equivalent linear approach for preliminary design of a seismic isolation system. The equivalent linear approach is based on effective parameters, rather than physical parameters of the system, and may not accurately account for the nonlinearity of the isolation system. This article evaluates an alternative normalized strength characterization against the equivalent linear characterization. Considerations for evaluation include: (1) ability to effectively account for variations in ground motion intensity; (2) ability to effectively describe the energy dissipation capacity of the isolation system; and (3) conducive to developing design equations that can be implemented within a code framework.     

An Investigation of Characteristic Periods of Seismic Ground Motions

The design seismic base shear was obtained from the spectral elastic acceleration S_a divided by a system behavior factor R, accounting for ductility and overstrength. The behavior factor is currently taken as a constant for a given type of structures in various codes regardless of structural periods. In fact, the behavior factor is also a spectrum varying with the natural periods of structures. In order to understand the relationship between the spectral values and the corresponding characteristic periods in these two spectra, S_a and R_μ, this article carries out an investigation into the characteristic periods of 370 seismic ground motions from 4 site types. It is found that the periods T_ga at which the peak values appear in the S_a spectra are much less than the periods T _gR at which the R_μ spectra take a maximum value. Two characteristic periods are necessary to determine the seismic action if a more elaborate procedure is required in practice. Statistical study on these two periods is carried out for the 370 records, and results are presented. For site types A–D, the ratio of these two periods has a statistically averaged value of 5.5–6.7.

The maximum input energy S _EI , relative velocity S _v , power density P _SD , and the Fourier amplitude F _S spectra were constructed to determine their characteristic periods, respectively. These four spectra predict similar characteristic periods to T _gR . T _gR is very close to the characteristic period T _gd of the elastic displacement spectra.

Analysis of SDOF systems under combined harmonic excitations shows that the S_a spectrum is more sensitive to high-frequency excitations, while the displacement spectrum is more sensitive to long period excitations. For the elastic-plastic S_a spectra, peak values tend to appear at shorter periods even the amplitudes of the longer periods are greater than that of the shorter period. This provides an explanation on different characteristic periods in the S_a and R_μ spectra.     

秦高陵君史迹探微

高陵君弩机及高陵君鼎为秦昭王时期器物。高陵君名悝,又号叶阳君,因封于高陵而得名,还曾封于彭、邓等地。高陵即今陕西省高陵县,彭在今甘肃省东部镇原县一带,邓在今河南省郾城县一带。高陵君约生于公元前320年前后,卒于公元前262年,享年59岁。高陵君为秦昭王前期秦国实权派人物之一,掌控秦国大权、左右秦国局势,其统治十分张扬跋扈、奢华腐朽。在其母宣太后死后,被秦昭王所杀害。