点物源扇三角洲的岩相与构型特征:以希里沟湖现代扇三角洲为例

扇三角洲沉积体具有良好的储集性能,是重要的油气储层。为了阐明扇三角洲储层的岩相与构型特征,定量表征构型单元的几何属性,明确构型分布规律,应用探地雷达技术和野外剖面观察技术,采用露头实测、精细构型解释等方法,对青海省乌兰县希里沟湖现代点物源扇三角洲进行了系统研究,共识别出16种岩相类型、8种垂向序列和8种构型单元。点物源扇三角洲主要发育主水道(MCH)、分支辫状水道(DCH)、片状洪流沉积(SF)、辫流坝(CB)、洪漫沉积(OF)、水下分流河道(UCH)、河口坝(RMB)以及间湾/席状砂(SS)共计8种典型构型单元,以分支辫状水道和辫流坝构型单元为主。分支辫状水道构型单元厚度1.5~2.0m,宽厚比30~70。辫流坝厚度2.0~3.0m,宽厚比50~70。同一沉积时期,点物源扇三角洲发育5种基本构型单元组合,分别为SF-MCH-SF、OF-DCH-CB-DCH-OF、SS-UCH-RMB-UCH-SS、SS-RMB-SS和SS-UCH-SS。不同沉积时期的构型单元分布表现为4种基本组合类型在横向上的重复和垂向上的叠加。

Physical-layer security enhancement method for wireless HetNets via transmission pair scheduling

In order to enhance the physical-layer security of wireless transmission in a wireless heterogeneous network (HetNet), a two-stage-based cooperative framework is advocated. To be specific, a source-destination (SD) pair is opportunistically chosen at the beginning of the transmission slot, which can be used to assist the transmissions of other SD pairs. Under this framework, a transmit antenna selection assisted opportunistic SD pair scheduling (TAS-OSDS) scheme is proposed, and the intercept probability (IP) of the proposed TAS-OSDS, the conventional round-robin source-destination pair scheduling (RSDS) and the conventional non-cooperation (non-coop) schemes is also analyzed, where the RSDS and non-coop schemes are used for comparison with the proposed TAS-OSDS. Numerical results show that increasing the number of the SD pairs can effectively reduce the IP of the TAS-OSDS scheme, whereas the IP of the RSDS and the non-coop remain unchanged with an increasing number of the SD pairs. Furthermore, the TAS-OSDS scheme achieves a lower IP than that of the RSDS and the non-coop schemes, showing the superiority of the proposed TAS-OSDS.

Distribution characteristics of China's key cultural relic tourism resources and suggestions to its development and protection

SPSS13.0 was used to process the data of the 1-6 batch of key cultural relic conservation units promulgated by the State Administration of Cultural Heritage of China;and multi-element evaluation method was used to calculate the composite distribution index.The spatial distribution of cultural relics of provinces in China can be divided into four grades,namely:very rich areas,rich areas,poor areas and very poor areas;the article analyzes the characteristics of cultural resources in spatial and temporal distribution.The paper holds that(1)the distribution of China's cultural relic tourism resources is relatively concentrated,different sharply from region to region,with more Han nation's heritage,less relics of the ethnic minorities;(2) Henan,Hebei,Shaanxi,Shanxi Province are the main regions with heavy distribution of cultural resources;(3) relics appeared in specific time periods in China's history.Ming and Qing Dynasties,Sui,Tang and Five Dynasties,Song,Liao and Jin,the Western Han,Shang and Zhou dynasties,the New Stone Age are the major periods producing more cultural relics.This paper also analyzes relationships of the emergence of cultural relics with production technology,specific historical process,specific geographical location,political system,religion,national culture,customs,architectural styles and techniques of the traditional cultural educational system.Finally,the paper discusses the development and protection of heritage.

气候变化与粗砾冲积扇的改造过程的响应与其影响因素分析——以岱海湖园子沟-半滩子冲积扇为例

粗砾冲积扇作为我国砾岩油气藏的优势相带,深入分析其沉积特征、建立沉积模式及序列对油气勘探具有重要的指导作用。半干旱气候中,洪水容易对早期形成的粗砾冲积扇产生差异性改造。本次研究通过对卫星和无人机照片分析确定了内蒙古省乌兰察布市凉城县岱海湖西侧园子沟冲积扇为点物源型冲积扇,半滩子冲积扇为线物源冲积扇;针对岱海湖园子沟-半滩子地区出露全长约276 m的粗砾冲积扇剖面进行现场粒度筛析、剖面描述和沉积特征研究,刻画了受改造的粗砾冲积扇不同层位沉积物的颗粒大小和排列方式,并建立对应的沉积序列。园子沟点物源沉积据物源区较近,地形变化明显,形成厚层的粗砾-巨砾沉积;而半滩子线物源据物源区较远地形变化平缓,形成连续的粗砂-细砾沉积。通次本次针对季节性洪水对两种类型的扇体改造过程的研究,指出由于岱海湖在1500年以来气候发生3次明显的变化,因此存在不同类型的洪水改造冲积扇的过程,即早期的粗粒碎屑流改造过程和后期的细粒洪流(牵引流)改造过程。参考演化过程,本次研究从沉积物供给和可容纳空间角度对影响因素进行探讨,指出气候因素的为降水量变化导致可容纳空间的变化,与湿润气候造成的大量沉积物剥蚀与粗粒碎屑的供给。