Refined chronology of prehistoric cultures and its implication for re-evaluating human-environment relations in the Hexi Corridor,northwest China

The reconstruction of high-resolution chronologies for prehistoric cultures is a prerequisite for understanding the history of human evolution and its relationship with environmental change, and is valuable for exploring the trajectory of transcontinental cultural exchanges in prehistoric time. The Hexi Corridor of northwest China was one of the earliest centers for long-distance culture exchange in the prehistoric world. The timing and sequence of cultural changes in this area remains poorly understood resulting from the lack of radiometric age control. This paper presents a refined radiocarbon(14 C) chronology to resolve the timing of human occupation and cultural evolution in the Hexi Corridor. Radiocarbon dating of crop remains, which have an annual life cycle, has the advantage of eliminating problems such as the carbon stored in ‘old wood'. As a result,~(14)C dates from crop remains are used to test the validity of the~(14)C dates derived from charcoal, bone and plant remains. The resultant database of ages is modelled using the Bayesian approach. The updated chronology presented in this paper shows generally good agreement with the original dates used to constrain cultural evolution in the Hexi Corridor. However, the occupation of the corridor by the Shajing and Shanma Late Bronze Age-Early Iron Age cultures appears to have taken place ～300 years later than previously thought. On the basis of comparing this updated chronology of cultural evolution with palaeoclimatic and historical records, it is proposed that the collapse of the Shajing and Shanma cultures occurred as a result of geopolitical impact rather than climate change.     

黑龙江省公众防震减灾科普知识调查分析

目前,在地震预报不准确的情况下,全面加强防震减灾宣传教育工作,不断增强社会公众的危机意识和防震减灾能力,是减少灾害损失、保障群众生命财产安全和社会安全稳定的基础工作。近年来,黑龙江省地震局持续开展防震减灾宣传教育,取得了一定的成绩,但通过调研数据可以看出,宣教工作仍然存在着一些问题和不足。希望通过对黑龙江省防震减灾宣教工作的现状进行分析,提出相应对策,有的放矢的做好防震减灾宣传教育工作,引导社会公众共同参与防震减灾活动。     

气枪信号触发台站的自动快速识别

气枪震源是高度可重复的人工震源,在深部探测工作中应用广泛。以福建省地震局组织开展的水库气枪实验为研究对象,面向未来技术的发展,提出基于气枪激发波形的相关性计算,自动获取气枪信号触发台站情况,并绘制触发台站的分布图。对处理结果分析认为:该方法能快速准确识别触发台站,可迅速作出分布图,直观地反应气枪激发效果,较好地为实验现场实验条件的调整提供依据。     

Influence of impulse waves generated by rocky landslides on the pressure exerted on bank slopes

Rocky landslides on river banks can result in the generation of ultra-high waves, which may destroy structures on the opposite bank. Existing methods to calculate the pressure on bank slopes under the effect of impulse waves generated by landslides are, however, few and of low precision. Therefore, in this study, a three-dimensional physical model test was conducted by taking into account factors such as landslide geometry parameters and the bank slope angle. The model test section was generalized on the basis of a certain section of the Three Gorges reservoir area as a prototype, after which the wave parameters and wave pressure acting on the bank slope were measured. Subsequently, the magnitude, acting point, and distribution of the pressure of the impulse waves generated by the rocky landslide upon the bank slope were determined. The distribution curve of the impact pressure was similar to that calculated using the СНиПⅡ57-75 formula, and the experimental pulsating pressure value was close to the value calculated using the Subgrade formula. Based on the test results, a power function of the relative pulsating pressure steepness with respect to the reciprocal of the wave steepness, relative water depth, and slope ratio was proposed. The acting point of the maximum pulsating pressure was found to be located near the still water level. Finally, an empirical formula for calculating the envelope of the maximum pulsating pressure distribution curve was proposed. These formulas can serve as a theoretical basis for the prediction of impulse wave pressure generated owing to landslides on bank slopes.     

中国福建省亚热带山地4 000年来植被变化的孢粉记录

根据采自福建省中部戴云山脉亚高山水系源头地带(大致25°40'N,118°11'E)泥炭沉积洼地的孢粉纪录,对该地区亚热带山地植被近4 000年来的变化进行了研究.孢粉记录和其他沉积资料显示,3个取样点的泥炭沉积开始于4 000年前,很可能是全新世后期气候转冷的结果.在距今4 000～1 200年前期间,戴云山脉上部(海拔1 300～1 600 m)的植被为亚热带针阔叶混交类型,优势种属包括Cryptomeria(柳杉)、Castanopsis(栲)、Quercus(栎)和Tsuga(铁杉)等.距今1 200年前左右,该区域的植被发生了一次大的变化,表现在上述优势属种的孢粉在样品总孢粉数的比例突然下降,而Pinus(松),Gramineae(禾本科)以及Dicranopteris(芒萁)等属种的比例则提高了.这次剧烈的植被变化在其中的一个泥炭钻孔中留下了一层粘土记录,它代表了当时流域内植被受破坏后出现的严重土壤侵蚀.从泥炭沉积提取的孢粉记录还可以看出,研究区内广泛分布的松林是一种次生植被,它是人类不断干扰的结果.     

煤矿瓦斯监测系统防雷探析

通过对小型煤矿瓦斯监测系统组成介绍及其遭受雷击原因分析。结合工程实践,对完善煤矿监测系统的雷电防护措施进行探讨。     

宁波地震台ZK03井水温异常与8级及以上地震的关系

通过近5年时间的观测,发现宁波台ZK03井水温测值变化具有一定的规律性。即在没有明显地震活动和干扰背景下,测值呈缓慢平稳趋势性上升,日波动值仅为仪器的短期稳定性值。虽然没有对应本学科认为的预报效能范围内的地震发生,但地球上发生的共6次8级及以上地震前,该井水温测值都有较明显的异常现象出现。除印尼8.7、8.5级地震前可能有中、短、临异常出现外,其它4次都表现为临震异常。异常主要表现形式为脉冲式向上突跳或阶跃式变化,最大异常量可达日均正常上升速率的数倍至数千倍。水温异常出现的可能原因是由于地震前的长周期波通过上地幔或软流层传播,间接地导致了地下流体温度发生了微小的变化,被高精度的测温仪记录下来。     

浅谈适应气候条件的建筑设计策略

以广西一些城市地域特点的气候条件为背景,浅析建筑设计适应气候条件的一些思路和若干手法和策略。     

开源技术在高校WebGIS课程教学中的应用探讨

WebGIS课程是GIS专业课程建设的重要分支,其教学实践对GIS本科人才培养与就业具有重要作用.首先分析了WebGIS课程的特点,指出开源GIS技术能有效促进高校学生科研能力和创新思维的培养;然后对现有的开源GIS软件与技术进行了总结,并以山东建筑大学地理信息科学专业的《网络GIS设计与实现》教学课程与课程设计为例,...     

Distribution Features of the Nanhua‐Sinian Rifts and their Significance to Hydrocarbon Accumulation in the Tarim Basin

On the basis of reprocessing 34 new two-dimensional spliced long sections(20,191 km) in the Tarim Basin, the deep structure features of the Tarim Basin were analyzed through interpreting 30,451 km of two-dimensional seismic data and compiling basic maps. Seismic interpretation and geological analysis conclude that the Nanhua-Sinian strata are a set of rift-depression depositional systems according to their tectonic and depositional features. The rift valley formed in the Nanhua Period, and the transformation became weaker during the late Sinian Period, which eventually turned into depression. From bottom to top, the deposited strata include mafic igneous, tillite, mudstone, and dolomite. Three major depocenters developed inside this basin during the rift stage and are distributed in the eastern Tarim Basin, the Awati area, and the southwestern Tarim Basin. Among them, the rift in the eastern Tarim Basin strikes in the near east-west direction on the plane and coincides with the aeromagnetic anomaly belt. This represents a strong magnetic zone formed by upwelling basic volcanic rock along high, steep normal faults of the Nanhua Period. Controlled by the tectonic background, two types of sedimentary systems were developed in the rift stage and depression stage, showing two types of sequence features in the Sinian depositional stage. The Nanhua System appears as a wedge-shaped formation, with its bottom in unconformable contact with the base. The rifting event has a strong influence on the current tectonic units in the Tarim Basin, and affects the distribution of source rock in the Yuertus Formation and reservoir beds in the Xiaoerbulake Formation in Lower Cambrian, as well as the gypseous cap rock in Middle Cambrian. The distribution features of the rifts have important and realistic significance for determining the direction of oil and gas exploration in the deep strata of the Tarim Basin. Comprehensive analysis suggests that the Tazhong region is the most favorable zone, and the Kalpin-Bachu region is the optimal potential zone for exploring sub-salt oil and gas in deep Cambrian strata.