《味水轩日记》所反映长江下游地区1609—1616年间气候冷暖分析

虽然明清时期我国气候总体呈现出寒冷的特征,但其间气候并不是一成不变的,而是呈现出多次冷暖波动的格局。通过对高分辨率资料《味水轩日记》中降雪率、初终雪日期、河流初冰日期、红梅始花日期、初雷日期以及一些感应记录等证据进行分析,表明1609-1616年间长江下游地区的冬半年气温较为温暖,略微高于现代(1951-1980年)气温。这对于分析10年尺度上气候变化,了解明代气候及变化的特征具有重要意义。     

Seismic constraints on the effects of gas hydrate on sediment physical properties and fluid flow: a review

The formation of gas hydrates in marine sediments changes their physical properties and hence influences fluid flow. Here, we review seismic indicators of gas hydrates and relate these indicators to gas hydrate formation and fluid migration. Analyses of seismic data from sediments containing gas and gas hydrates in a variety of locations have shown that the characteristic bottom‐simulating reflector (BSR), which commonly marks the hydrate phase boundary is caused mainly by the presence of gas beneath the gas hydrate stability zone (GHSZ). The amplitude of the BSR is also dependent on the hydrate concentration and on the porosity of the sediment. The presence of gas hydrate alters the elastic properties of sediments, particularly if it cements sediment grains. However, multifrequency studies in various geological provinces show that any loss of reflectivity or blanking observed within the GHSZ is dependent on both the nature of the sediments and concentration of hydrate present. Gas beneath the BSR may cause amplitude anomalies and may result in bright spots and enhanced reflections. The presence of gas beneath the BSR is the primary cause of observed amplitude versus offset (AVO) anomalies, but the amplitude of these anomalies is also dependent on the amount of cementation brought by the gas hydrates within the GHSZ. Fluid migration appears to play an important role in the formation and dissociation of gas hydrates in both active and passive margin settings. Fluid migration in accretionary prisms influences hydrate accumulation and may therefore control the spatial distribution of BSRs. Fluid migration may influence also the type of hydrate formed by bringing thermogenic gas containing higher order hydrocarbons to the GHSZ from below. Fluid advection may cause local dissociation of gas hydrates by bringing heat from below, thus shifting the gas hydrate phase boundary. Fluid flow within the GHSZ is limited by the formation of hydrate in the pore space, which reduces the permeability of the sediment. Features such as pockmarks, acoustic masking and acoustic turbidity are indirect indicators of fluid flow and identification of these features in seismic sections within and beneath the GHSZ may also suggest the formation of gas hydrate.     

INVESTIGATING SEASONALITY AND SEASON OF BIRTH IN PAST HERDS: A REFERENCE SET OF SHEEP ENAMEL STABLE OXYGEN ISOTOPE RATIOS

Intra‐tooth sequential analysis of enamel δ¹⁸O is currently used to investigate birth seasonality in past animal populations, offering new insights into seasonal availability of animal resources, herd management and seasonality of site occupation. Reference data sets are still required to address two major difficulties: (1) that inter‐individual variability in the record of the seasonal cycle is affected by tooth size; and (2) that the season of birth cannot be directly estimated from the timing of tooth growth, because of a delay in enamel mineralization. We present a data set acquired on the lower second molar of 10 modern sheep from Rousay (Orkney) born within a few weeks of each other in April/May and submitted to the same environmental conditions until death. All sheep have recorded a sinusoidal pattern of δ¹⁸O variation spanning approximately a year. From the difference between the expected and the measured time sequence, the delay of enamel mineralization is estimated to be 5–6 months. The data set is then described using a model mainly based on a cosine function. The period, corresponding to the length of the M2 crown formed over a year, averaged 35.8 mm. A very slight variation of tooth growth rate with time and no attenuation of the isotopic signal towards the cervical margin of the crown could be detected in this data set. The lowest δ¹⁸O values, corresponding to the sheep's first winter, were tracked at a distance from the enamel/root junction that varied between 23.0 and 30.3 mm (x_min mean = 27.6 mm); the highest δ¹⁸O values, corresponding to the sheep's second summer, were between 6.3 and 11.6 mm (x_max mean = 9.9 mm). Most of the variability can be attributed to tooth size. When normalized on the period, x_min and x_max are 0.28 (± 0.05) and 0.78 (± 0.05) on average, meaning that the Rousay sheep have recorded the minimum and maximum δ¹⁸O values on average at 78% and 28%, respectively, of the end of the periodic cycle recorded in the second molar.     

SELECTION AND HEATING OF COLOURING MATERIALS IN THE MOUSTERIAN LEVEL OF ES‐SKHUL (c. 100 000 YEARS BP,MOUNT CARMEL,ISRAEL)

The transformation of yellow goethite into red hematite by heating has long been assumed for Palaeolithic red artefacts excavated close to fireplaces. However, this transformation is extremely rare. Using SEM–FEG–EDX, PIXE–PIGE, TEM and μXRD, we characterized the mineralogical and chemical compositions of four microsamples of colouring materials from the Mousterian layer B in the es‐Skhul rock‐shelter, from about 100 kya ago. For some colouring materials, the Mousterian people of es‐Skhul chose to gather remote yellow lumps for heating. Their significant transport distance provides evidence of the possible high cultural value of these colouring materials for transformation into red pigments.     

The Dynamic Behavior of the Basilica of San Francesco in Assisi Using Simplified Analytical Models

The Basilica of San Francesco in Assisi endured stronger earthquakes for centuries before 1997 earthquake, which generated the collapse of the two vaults. Experts blame as possible reasons of collapse the damage cumulated from previous earthquakes and/or the retrofitting made to the structure over its lifetime. This article presents the history of the retrofit interventions of the Basilica through the centuries, focusing mainly on the roof, which has been subjected to three major restorations through its life. It is shown using simple analytical models that the cumulative effects of the changes made to the roof of the Basilica affected the structure’s dynamic behavior in a negative manner, increasing the seismic loads on the existing structural members. In particular, the numerical results show that the 1958 roof intervention has stiffened the structure, redistributing the seismic loads on the façade and the transept. This overload might explain the collapse of the two Gothic vaults during 1997 earthquake.     

南京市区就业空间布局研究

本文采取就业密度分析方法,对南京市区就业空间布局进行实证研究。在南京市区现有11个区的基础上将南京市区划分为159个研究单元。依据2005年南京市1%人口抽样调查资料中\"区县层面\"分行业就业数据,以及2006年南京市用地现状图,修正匹配得到各个研究单元制造业、服务业、商业金融业及总的就业密度值。并运用Arcgis软件对就业密度值进行核密度分析以及3D模拟,分析南京市区制造业、服务业以及总就业的空间布局特征及原因机制。     

岩画病害的红外热成像检测技术初探

为探索红外热成像检测技术在岩画病害检测中的可行性,利用红外热像仪对广西花山岩画的病害进行了检测。检测结果表明,利用红外热成像技术可以有效检测岩画中的钟乳石覆盖、片状剥离及渗水病;不同病害其检测的最佳时段不同,钟乳石在夜间或早晨进行检测效果好,而片状剥离岩石使用午后的热像检测效果好;与可见光检测相比,红外热成像检测具有独特优势。     

GIS技术在萨拉乌苏考古遗址公园规划设计中的应用

传统规划设计工作的技术平台多以计算机辅助设计(CAD)为主,本工作以内蒙古自治区鄂尔多斯萨拉乌苏考古遗址公园规划为例,将Arc GIS Desktop作为技术平台应用到公园的规划设计工作中。首先,通过对规划区的实地踏勘,采集相关数据和资料,进行规划区数据库建设;其次,在数据库建设的基础上,通过GIS技术构建与现实环境对应的虚拟地理信息空间,实现规划区景观的三维可视化;最后,利用三维景观模型对现实地理环境进行模拟、分析及虚拟场景飞行。不同于传统CAD的二维工作平台,本工作借助GIS对空间数据和属性数据的强大处理功能及其三维景观可视化模块,为实现内蒙古鄂尔多斯萨拉乌苏考古遗址公园的科学规划提供辅助。     

30年来国际“贸易-交通-旅游”(3T)互动的统计分析

经济全球化背景下,国际\"贸易-交通-旅游\"(3T)互动日益增强。采用1982-2011年时间序列数据,分析国际贸易、交通和旅游总量的发展历程,从进、出口分量视角考察三者相关关系,运用最小二乘法构建回归方程。结果发现:①30年来国际贸易、交通和旅游的发展呈持续增长态势。国际贸易和旅游日益重要。②国际贸易、交通和旅游增长过程具有同步性,表现为波动周期同涨同落。③所构建的回归方程决断系数R²均在0.99以上,国际贸易、交通和旅游存在显著相关性。国际货运与国际贸易,国际客运与国际旅游之间具有确定、直接的因果关系;国际贸易与国际旅游的因果性尚待探究。