基于改进灰狼算法的岩石声发射定位研究

针对岩石力学试验中传统的声发射定位算法存在局限性,将灰狼算法(GWO)引入声发射定位研究中,该算法模仿了狼群的领导阶层与狩猎机制,用α、β、δ和ω 4种灰狼来模拟头狼领导,通过搜寻猎物、包围猎物和攻击猎物3个步骤实现目标的发现到捕获的全过程。在原始灰狼算法的基础上,针对其局部搜索能力欠佳的缺陷,修改收敛因子递减方式和淘汰最劣个体,提出基于种群记忆淘汰制的改进灰狼算法(BGWO)。基于预制裂隙岩石试件单轴压缩声发射试验结果,对比分析BGWO、GWO、引力搜索法(GSA)、Geiger算法、最小二乘法(LS)算法等5种定位算法的性能,发现改进后的BGWO算法在声发射定位搜索效率、搜索精度、稳定性和试验结果模拟方面效果优于其他算法。     

神农架大九湖湿地摇蚊群落组成及其环境指示意义

泥炭地是一种水-陆过渡型的湿地生态系统。水体沼泽化过程中,植被等生物群落也随之改变,进而影响泥炭地碳埋藏和发育过程。作为泥炭地生态系统重要的次级生产者,摇蚊群落结构变迁可以为追溯泥炭地环境演变和发育历史提供关键线索。泥炭地在发育过程中将经历各种不同阶段,然而,现有的泥炭地摇蚊群落调查仅限于泥炭生境或泥炭地中开阔水域,较短的生境梯度不足以提供更为全面的摇蚊群落变化信息。神农架大九湖湿地包含泥炭地、湖泊、临时性水体等多种生境,本研究选择该湿地公园作为研究区域,通过采集不同生境的表层沉积物及水体样品,提取底泥亚化石摇蚊头壳,分析大九湖湿地中不同生境下的摇蚊群落结构差异,并对其与环境因子间的关系进行探讨。结果表明:1)大九湖湿地不同生境中摇蚊优势种迥异,泥炭藓藓丘生境中Limnophyes、Psilometriocnemus、Pseudosmittia等半陆生种类为主要优势种,湖泊生境中则以典型静水种Polypedilum nubeculosum-type为主要优势种,而过渡性水域(泥炭地洼地、沟渠及水洼生境)中,静水种与半陆生种共存;2)烧失量、水位埋深和pH是塑造不同生境类型下摇蚊群落结构的显著环境因子,水文条件主要通过改变碳积累过程等其他环境条件间接影响生物群落组成;3)沿水生-半陆生生境梯度,有机质含量和类型均发生显著变化,而摇蚊群落也由静水种、静水/半陆生共存转变为以半陆生种为主,摇蚊群落对生境变化表现出良好的响应过程。本研究揭示了不同生境条件下摇蚊群落的结构差异及影响摇蚊群落结构的潜在因子,为未来基于摇蚊的长时间尺度上泥炭地发育过程分析提供参考依据。     

华北地区断层运动与三维构造应力场的演化

利用华北地区断层形变测量资料，通过三维有限元模型，数值模拟了华北地区三维构造应力场的演化过程，得到了1986～1997年以一年为时间尺度的演化图象，并分析了应力场的演化特征；结合华北地区该时间段内的地震活动性，初步探讨了应力场的演化过程与地震活动性的关系．      

Wave height statistical characteristic analysis

When exploring the temporal and spatial change law of ocean environment, the most common method used is using smaller-scale observed data to derive the change law for a larger-scale system. For instance, using 30-year observation data to derive 100-year return period design wave height. Therefore,the study of inherent self-similarity in ocean hydrological elements becomes increasingly important to the study of multi-year return period design wave height derivation. In this paper, we introduced multifractal to analyze the statistical characteristics of wave height series data observed from oceanic hydrological station.An improvement is made to address the existing problems of the multifractal detrended fluctuation analysis(MF-DFA) method, where trend function showed a discontinuity between intervals. The improved MFDFA method is based on signal mode decomposition, replacing piecewise polynomial fitting used in the original method. We applied the proposed method to the wave height data collected at Chaolian Island,Shandong, China, from 1963 to 1989 and was able to conclude the wave height sequence presented weak multi-fractality. This result provided strong support to the past research on the derivation of multi-year return period design wave height with observed data. Moreover, the new method proposed in this paper also provides a new perspective to explore the intrinsic characteristic of data.     

Determination of water level design for an estuarine city

Based on the extreme value theory,self-affinity,and scale invariance,we studied the temporal and spatial relationship and the variation of water level and established a model of Gumbel-Pareto distribution for designed flood calculation.The model includes the previous extreme value models,the over-threshold data,and the fractal features shared by previous extreme value models.The model was simplified into a logarithmic normal distribution and a Pareto distribution for specific parameter values,and was used to calculate the designed flood values for the Shanghai Wusong Station in 100-and 1 000-year return periods.The calculated results show that the value of the designed flood height calculated in the Gumbel-Pareto distribution is between those in the Gumbel and Pearson-III distributions.The designed flood values in the100-and 1 000-year return periods of the model were 0.0 3%and 0.11%lower,respectively,than the Gumbel distribution and 0.06%and 1.54%higher,respectively,than the Pearson-III distribution.Compared to the traditional model based solely on extreme probability,the Gumbel-Pareto distribution model could better describe the probabilistic characteristics of extreme marine elements and better use the data.     

Study on evaluation standard of uncertainty of design wave height calculation model

The accurate calculation of marine environmental design parameters depends on the probability distribution model, and the calculation results of different distr...     

塔里木盆地轮南地区下奥陶统碳酸盐岩储层的控制因素分析

轮南地区下奥陶统潜山是一个具有良好勘探前景的油气富集区 ,但该区碳酸盐岩储层的不均一性及其预测的难度制约了该区勘探的进展 ,这也是碳酸盐岩地区油气勘探的难题之一。从影响碳酸盐岩储层发育的基本地质条件入手 ,对该区的构造特征、沉积环境及成岩作用分别进行了探讨 ,同时结合近年来的钻探成果进行了分析。结果表明 ,该区储层的储集性主要与次生孔隙有关 ,即主要受构造作用和成岩作用控制 ,而与沉积环境没有直接的关系 ,这一分析为该区碳酸盐岩储层的预测和评价提供了依据     

Research and Application of New Methods to Oil-Gas Geochemical Exploration

Based on the results of researches and applications for many years, it has been discovered that new methods and techniques for geochemical exploration of oil and gas such as AC, altered carbonate, Hg in absorption phase, Ks, Fe2+ ,δ13C, fluorescence in two and three dimensions, and N2 and O2 in heat release can give full play in the following five fields: (1) optimization of the favourable target or hollow zones and structural zones in a region; (2) evaluation of oil traps and delineation of prospective oil and gas areas; (3) prediction of deep-seated oil-bearing horizons; (4) evaluation of the genesis of oil and gas geochemical anomalies and determination of the types of oil and gas accumulations; (5) forecast of the burial depths of oil and gas pools.     

近400年来湖北大九湖泥炭地摇蚊对湿度变化的响应

神农架大九湖泥炭地是华中地区少有的亚高山泥炭藓湿地,是研究长江中游气候变化及其生态效应的理想区域.本文通过大九湖一根泥炭岩芯的年代学、元素及摇蚊亚化石记录,结合区域古气候资料,探讨大九湖泥炭地地表干湿变化历史及生物响应过程.结果表明,近400年来大九湖泥炭地古水文和摇蚊种群变化经历了3个主要阶段：1820s之前研究区内气候偏冷湿,尤其是1720s-1820s年间,冷湿的环境有利于泥炭中碳的大量积累,较高的地表有效湿度使得摇蚊大量生长,同时湖泊相摇蚊属种丰富度及含量均较高;1820s-1940s年间,区域内夏季降水量显著降低,同时伴随明显的区域增温过程,泥炭地地表有效湿度过低不利于水生生物生长,摇蚊种群生物量极低;1940s （尤其1970s）后,摇蚊种群丰度逐渐回升,但湖泊相摇蚊丰度较1820s以前明显降低,半陆生摇蚊属种丰度有所增加,说明尽管该时期泥炭地表湿度有所增加,但较1820s前仍较低,暖湿气候下泥炭分解也较为明显.本研究探索性地分析了气候变化背景下泥炭地摇蚊种群对泥炭地湿度变化的响应过程,这不仅为摇蚊亚化石在气候变化研究中的应用开拓了新的领域,同时也为全面、精准地理解泥炭地演化及区域环境变化过程提供了新线索.     

深海上浮平台线型设计及水动力特性预报

深海上浮平台是水下装备技术朝信息化、智能化方向发展的未来趋势,对根本扭转我海上战略安全形势、在深远海有效拒止强敌具有重大意义。针对深海上浮平台长期服役、水下快速上浮、大深度耐压密封等特点,提出了一种基于回转体外形的大型航行器外形设计及水动力特性预报,着重解决平台在无动力上浮时的低阻性要求,经过理论估算和CFD软件仿真验证,仿真结果满足设计要求,对深入研究无动力深海上浮平台提供重要技术支撑。