关键路径法在地震监测设施建设定额编制中的应用

从项目管理角度出发,介绍关键路径法在项目管理中应用的基本原则和方法,并在《地震监测设施建设标准定额体系研究》项目管理中实际应用,不仅在计划制定期间求得工期、资源、成本的优化,而且在计划的执行过程中,通过信息反馈,进行有效的监督、控制和调整,保证项目在预定期望中的目标实现,通过识别并严格执行关键路径,提高项目管理的效率,压缩项目实施进度.     

A~200 ka pollen record from Okinawa Trough:Paleoenvironment reconstruction of glacial-interglacial cycles

Pollen analysis was carried out on the Core MD982194 of 29.78 m retrieved from the Middle Okinawa Trough which was dated as old as~200 ka BP.The results revealed that pollen assemblages mainly presented an alternation of coniferous and herb pollen.The coniferous saccate pollen,principally Pinus and Tsuga,predominated in most parts of the core,especially highlighted in the interstadial stages including MIS 1,3,5 and MIS7,whereas the herb pollen significantly increased in the glacial periods.Thus the pollen flora and their percentages showed the sensitive changes under the influence of ice volume during the glacial and interglacial periods.Our record from this core has first documented that the percentage of Cyperaceae was extremely high in the glacial stages with a notable increase in Artemisia,Gramineae,Asteraceae,Chenopodiaceae,and freshwater algae,which can be used as a proxy for sea-level change at the study site because of their close negative correlation of the orbital-scale changes in sea level.The distance between the continental coastline and the Okinawa Trough has deeply shortened due to the sea-level drop in the LGM.As a result,the sediment materials from Yangtze River were extensively deposited on the flat,exposed continental shelf owing to the rapid decline of river flow speed,leading to that pollen grains from Okinawa Trough are derived mainly from the flat coastal vegetation of exposed continental shelf at glacial stages.Changes of pollen assemblage were consistent with the variation of temperature and humidity,which showed that the percentage of arboreal pollen was highly augmented at MIS 7,5 and MIS 1,corresponding to the strengthening of the East Asian summer monsoon and increasing of rainfall.Moreover,the peak of Pinus percentage in MIS 5.3,5.1 and MIS 3.3 may be closely linked by orbital and sub-orbital cycles of solar radiation and monsoonal variability.The present study of core MD981294 implied lower temperature and precipitation during the lowest sea-level stage(LGM),and more visibly testified that the vegetation of the flat plain on the exposed continental shelf was dominated by intrazonal communities such as halophyte grasslands and freshwater wetlands instead of zonal steppe or semi-arid desert.All above evidence demonstrated that the fundamental changes of pollen assemblage and their origins in Okinawa Trough since~200 ka BP were affected by combine factors including the coastline position and climate fluctuation.Moreover,the substantial shortening of distance between shoreline and the Okinawa Trough driven by orbital insolation cycles was clearly indicated by the pollen spectra,whereas the source-area climate signal of the pollen record was largely weakened.     

Factors Affecting UV/H2O2 Oxidation of 17α‐Ethynyestradiol in Water

In this study, bench‐scale experiments were conducted to examine the UV/H₂O₂ oxidation of 17α‐ethynyestradiol (EE2) in water in a batch operation mode. The EE2 degradation exhibited pseudo‐first‐order kinetics, and the removal was ascribed to the production of hydroxyl radicals (^?OH) by the UV/H₂O₂ system. Typically, the EE2 oxidation rate increased with increasing UV intensity and H₂O₂ dose, and with deceasing initial EE2 levels and solution pH. At EE2₀ = 650 µg/L, UV intensity = 154 µW/cm², H₂O₂ = 5 mg/L, and neutral pH, the UV/H₂O₂ treatment was able to remove 90% of the EE2 content within 30 min. Four anions commonly present in water were found to inhibit EE2 degradation to varying degrees: > > Cl^? > . Our results demonstrate that the described UV/H₂O₂ process is an effective method to control EE2 pollution in water.     

滇中城市群产业演进研究

滇中城市群作为云南省优先开发区,其产业结构近年来一直处于"二、三、一"的演进状态。在剖析滇中城市群经济发展及产业结构时空演进特征的基础上,运用以结构多元化系数和区位熵为主要指标体系的关联分析方法,对滇中城市群现代化进程中城市产业结构演进状态进行评价,并提出滇中城市群产业结构优化调整的对策建议,以期为滇中城市群经济的稳定发展和功能区划的演进提供有益借鉴。     

基于“污染天堂”假说检验的湖南经济增长与环境综合质量关系研究

选取湖南省1990-2010年经济增长、对外贸易以及环境综合质量的时间序列数据,建立经济增长与环境污染水平的计量模型,检验湖南省环境综合质量的变动轨迹.结果表明:研究期内,湖南省环境污染的变动轨迹大致呈底部平滑的正“U”型曲线,由于湖南经济增长对环境始终存在负的规模效应与正的技术效应,环境曲线的变动轨迹主要取决于经济增长的结构效应,因此,实现产业结构的升级,合理配制轻重工业的比重,在经济增长与环境效益中寻求平衡,是湖南改善环境质量与经济发展关系的关键;此外,无论从FDI还是出口贸易的角度来看,“污染天堂”假说在湖南均不成立.     

DEM resolution dependencies of terrain attributes across a landscape

This paper documents resolution dependencies in terrain analysis and describes how they vary across landform location. Six terrain attributes were evaluated as a function of DEM resolution—slope, plan curvature, profile curvature, north–south slope orientation, east–west slope orientation, and topographic wetness index. The research highlights the effect of varying spatial resolution through a spatial sampling/resampling scheme while maintaining sets of indexed sample points at various resolutions. Tested sample points therefore coincide exactly between two directly compared resolutions in terms of their location and elevation value. An unsupervised landform classification procedure based on statistical clustering algorithms was employed to define landform classes in a reproducible manner. Correlation and regression analyses identified sensitive and consistent responses for each attribute as resolution was changed, although the tested terrain attributes responded in characteristically different ways. These responses displayed distinguishable patterns among various landform classes, a conclusion that was further verified by a series of two‐sample, two‐tailed t‐tests.     

A spatial cognition-based urban building clustering approach and its applications

This article presents a spatial cognition analysis technique for automated urban building clustering based on urban morphology and Gestalt theory. The proximity graph is selected to present the urban mrphology. The proximity graph considers the local adjacency among buildings, providing a large degree of freedom in object displacement and aggregation. Then, three principles of Gestalt theories, proximity, similarity, and common directions, are considered to extract potential Gestalt building clusters. Next, the Gestalt features are further characterized with seven indicators, that is, area difference, height difference, similarity difference, orientation difference, linear arrangement difference, interval difference, and oblique degree of arrangement. A support vector machine (SVM)-based approach is employed to extract the Gestalt building clusters. This approach transforms the Gestalt cluster extraction into a supervised discrimination process. The method presents a generalized approach for clustering buildings of a given street block into groups, while maintaining the spatial pattern and adjacency of buildings during the displacement operation. In applications of urban building generalization and three-dimensional (3D) urban panoramic-like view, the method presented in this article adequately preserves the spatial patterns, distributions, and arrangements of urban buildings. Moreover, the final 3D panoramic-like views ensure the accurate appearance of important features and landscapes.     

The morphological characteristics of glacial deposits during the Last Glaciation, taking the Parlung Zangbo River Basin as an example

Moraine morphology is a valuable indicator of climate change. The glacial deposits of ten valleys were selected in the Parlung Zangbo River Basin, southeastern Tibetan Plateau, to study the glacial characteristics of the Last Glaciation and the climate change processes as revealed by these moraines. Investigation revealed that a huge moraine ridge was formed by ancient glacier in the Marine Isotope Stage 2 （MIS2）, and this main moraine ridge indicates the longest sustained and stable climate. There are at least two smaller moraine ridges that are external extensions of or located at the bottom of the main moraine ridge, indicating that the climate of the glacial stage before MIS2 was severer but the duration was relatively shorter. This distribution may reflect the climate of MIS4 or MIS3b. The glacial valleys show multi-channel, small-scale moraine ridges between the contemporary glacial tongue and the main moraine ridge. Some of these multi-channel mo- raine ridges might be recessional moraine, indicating the significant glacial advance during the Younger Dryas or the Heinrich event. The moraine ridges of the Neoglaciation and the Little Ice Age are near the ends of the contemporary glaciers. Using high-precision system dating, we can fairly well reconstruct the pattern of climate change by studying the shape, extent, and scale characteristics of glacial deposits in southeastern Tibet. This is valuable research to understand the relationship between regional and global climate change.     

轮古西奥陶系潜山洞穴型岩溶储层发育特征与充填规律

洞穴型岩溶储层是塔里木盆地轮古油田缝洞型碳酸盐岩油藏的主要储集空间类型,多数高效井均钻遇大型洞穴型岩溶储层。依据轮古西奥陶系潜山大量单井资料分析,洞穴型岩溶储层可分为充填洞穴、半充填洞穴和未充填洞穴三种类型。结合古地貌精细刻画与岩溶垂向分带成果,认为古地貌位置由岩溶台地向岩溶缓坡和岩溶盆地逐渐降低,而洞穴发育和充填程度在逐渐增高。未充填与半充填洞穴主要发育在岩溶台地和岩溶缓坡的溶峰边坡、溶丘边坡及沟槽谷洼地边坡等地貌单元。表层岩溶带、径流溶蚀带洞穴型岩溶储层发育频率最高,其次为垂直渗滤带和潜流溶蚀带。未充填与半充填洞穴型岩溶储层主要发育在表层岩溶带。     

Relations between density of earthquake-damaged trace and environmental factors in seismic intensity: a case study in Wenchuan County, China

Many studies have been designed to assess seismic hazard and to improve post-earthquake damage evaluation models. Compared with previous studies, the research attempted to solve the problems of the effectiveness differences of seismic intensity on density of Earthquake-damaged trace (D _e) and established the appropriate models for D _e in different scale of seismic intensity. D _e as a relative value reduced the influence of area on earthquake-damaged trace. The research will provide the necessary scientific support to fast post-earthquake damage assessment and modeling. By utilizing GIS, RS and field investigation data, the spatial distribution characteristic of earthquake-damaged traces was analyzed. Effective factors including seismic intensity, distance to rivers and slope were identified through PCA. Specifically, seismic intensity was identified as the key factor. The inherent relations between D _e and seismic intensity, D _e and distance to rivers in seismic intensity, and D _e and slope in seismic intensity were modeled by regression analysis. The results demonstrated that both earthquake energy and D _e have attenuation characteristics. There is a significant positive correlation between D _e and seismic intensity (the pearson correlation is 0.917). That is, the higher the seismic intensity, the greater the D _e was. The erosion of river leads to steep slope, which is in favor of the formation of mountain hazards. D _e showed the decreasing tendency with the increasing distance to river. With the increase of slope, the D _e gradually became stronger. For distance to river, the largest changing rate of D _e appeared on seismic intensity XI, but for slope, the largest changing rate of D _e appeared on seismic intensity X.