基于瓦斯防治工程的隐伏构造勘查与瓦斯异常区域预测

隐伏构造勘查与瓦斯异常区域预测研究是瓦斯灾害防治工程的基础。根据中国煤矿生产法律规章,开采具有瓦斯灾害危险的煤层前,必须实施瓦斯抽放工程。通常,地质异常区域即是瓦斯灾害危险区,构造应力场和采动应力场的叠加会扰动煤体并加压瓦斯。为精准定位地质异常区,评价其瓦斯致灾潜能,提出了一种基于瓦斯抽采工程进行瓦斯异常区域勘测的研究方法。该方法利用抽采钻孔参数和施工记录,采集钻孔数据并计算煤层顶底板控制点坐标,进而利用二维投影图件及三维应力场模型对隐伏地质构造（如小的断层、褶曲、局部煤厚异常变化等）进行勘查和预测;通过分析小型地质构造周围的附加应力场,并对瓦斯致灾潜能进行动态预测。应用该方法,可以对地质异常区进行精细调查,揭示采煤工作面瓦斯地质演化的一般规律。其研究结果为高瓦斯或突出煤层瓦斯灾害防治措施优化设计及有效实施提供科学依据。     

Relationship between trawl selectivity and fish body size in a simulated population

Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.     

八角形FPSO与穿梭油轮串靠外输中碰撞风险分析

针对300 m作业水深下的八角形FPSO,提出采用穿梭油轮串靠的外输作业方案,研究外输过程中穿梭油轮与FPSO之间由于过分纵荡运动而引起的碰撞风险发生概率。建立由八角形FPSO及其系泊系统、穿梭油轮、系泊大缆等组成的浮式多体系统分析模型,在外输海况条件下,得到穿梭油轮与FPSO间距的时历曲线,结合极值理论,对过分纵荡运动进行预报,进而对外输系统的碰撞风险进行分析;揭示海流的方向变化对于外输系统碰撞风险的影响规律。     

地理国情与基础地理信息数据同步更新外业调绘系统的构建

利用全新的外业数据调绘理念,在地图数据缓存切片技术、GPS定位技术及手持移动终端等技术设备基础上构建了地理国情与基础地理信息数据同步更新外业调绘系统,实现野外作业时,同一地物要素只需补测一次即可完成地理国情与基础地理信息数据的外业调绘工作,避免了重复外业采集生产,有利于降低地理国情与基础地理信息数据的更新成本。     

THE SPATIOTEMPORAL CHARACTERISTICS OF LIGHT RAIN DAYS AND LOW CLOUD COVER UNDER HEAVY POLLUTION OVER SOUTH CHINA

By using the data set of light rain days and low cloud cover at 51 stations in South China (SC), and the method of linear regression and correlative analysis, we analyze the spatiotemporal characteristics of the light rain days and low cloud cover including annual variation and long-term seasonal change. The results are as follows: (1) The trends of light rain days and low cloud cover over SC are opposite (light rain days tended to decrease and low cloud cover tended to increase in the past 46 years). The value distributed in east is higher than that in west, and coastal area higher than inland area. (2) The regression coefficients of light rain days and low cloud cover during 1960–2005 are 4.88 d/10 years and 1.14%/10 years respectively, which had all passed the 0.001 significance level. (3) Variations of light rain days are relatively small in spring and summer, but their contributions are larger for annual value than that of autumn and winter. (4) There are two regions with large values of aerosol optical depth (AOD), which distribute in central and southern Guangxi and Pearl River Delta (PRD) of Guangdong, and the value of AOD in PRD is up to 0.7. The aerosol index distributed in coastal area is higher than in the inland area, which is similar to the light rain days and low cloud cover over SC. Aerosol indexes in SC kept increasing with fluctuation during the past 27 years. The GDP of the three provinces in SC increased obviously during the past 28 years, especially in Guangdong, which exhibited that there is simultaneous correlation between light rain days with the variables of low cloud cover and release of aerosols over SC during 1960 to 2005.