Frequency analysis of nonstationary annual maximum flood series using the time‐varying two‐component mixture distributions

The most popular practice for analysing nonstationarity of flood series is to use a fixed single‐type probability distribution incorporated with the time‐varying moments. However, the type of probability distribution could be both complex because of distinct flood populations and time‐varying under changing environments. To allow the investigation of this complex nature, the time‐varying two‐component mixture distributions (TTMD) method is proposed in this study by considering the time variations of not only the moments of its component distributions but also the weighting coefficients. Having identified the existence of mixed flood populations based on circular statistics, the proposed TTMD was applied to model the annual maximum flood series of two stations in the Weihe River basin, with the model parameters calibrated by the meta‐heuristic maximum likelihood method. The performance of TTMD was evaluated by different diagnostic plots and indexes and compared with stationary single‐type distributions, stationary mixture distributions and time‐varying single‐type distributions. The results highlighted the advantages of TTMD with physically‐based covariates for both stations. Besides, the optimal TTMD models were considered to be capable of settling the issue of nonstationarity and capturing the mixed flood populations satisfactorily. Copyright © 2016 John Wiley & Sons, Ltd.     

一株产碳酸酐酶附生菌对铜绿微囊藻(Microcystis aeruginosa)生长的影响

为研究生长环境中微生物对铜绿微囊藻碳代谢的影响,本文分析太湖典型微囊藻水华样品附生菌中产碳酸酐酶(CA)细菌的比例,结果显示CA菌占11.6%;从微囊藻群体中分离获得了一株高胞外CA附生菌P201,通过ITS基因鉴定,该菌为一株荧光假单胞菌(Pseudomonas fluorescence).并研究了该菌在不同浓度HCO3-条件下对铜绿微囊藻生长的影响,结果表明无论是高HCO3-浓度还是低HCO3-浓度环境中,加入该菌对铜绿微囊藻的生长均有促进作用,说明产CA酶附生菌对铜绿微囊藻的生长有一定的促进作用.     

基于最优极化相干系数的倾斜建筑物解译研究

基于Freeman_Durden分解的全极化SAR影像分类方法能够较好地保持地物极化散射特性,但在分类的过程中,不能改变初始散射机制,导致分解结果对分类精度影响很大。在Freeman_Durden分解中,排列方向相对雷达飞行方向不平行的建筑物（简称为倾斜建筑物）常被分为体散射类型,使得该类建筑物往往被误分为植被。通过分析建筑物在SAR影像中的后向散射特性,利用建筑物具有较高相干性的特点,引入最优极化相干系数,在目标分解的基础上通过阈值分割将两者区分开来,进而提高反射非对称性人工目标的分类效果。通过使用E—SAR系统在德国DLR附近Oberp—faffenhofen地区获取的L波段PollnSA     

滇黔桂晚海西—中印支伸展裂谷海盆地的演化

在详细研究各类喾体积的相序构成和沉积演化过程的基础上，采用动态成因及地层分析的方法，恢复了已曹受严重构造破坏的滇黔桂伸展裂谷海盆地的地层格架，根据各类等时地层界面的性质和地层序列划分出了５个沉积幕，详细解剖了各沉积幕的三维空间构成。同时以沉积体系或为单位，恢复了各沉积幕中相应阶段的构造古地理环境，将伸展裂谷盆地的演化历史划分为陆壳初始裂陷和洋壳化阶段，盆地伸展扩张阶段、洋壳俯冲和盆地分化段以及盆地     

2005年度天文学科科学基金项目申请和资助情况分析

介绍了2005年度天文学科科学基金申请、资助的基本情况,并对其结果进行了分析。     

Design and development of safety evaluation system of buildings on a seismic field based on the network platform

This paper describes a set of on-site earthquake safety evaluation systems for buildings, which were developed based on a network platform. The system embedded into the quantitative research results which were completed in accordance with the provisions from Post-earthquake Field Works, Part 2: Safety Assessment of Buildings, GB18208.2-2001, and was further developed into an easy-to-use software platform. The system is aimed at allowing engineering professionals, civil engineeing technicists or earthquake-affected victims on site to assess damaged buildings through a network after earthquakes. The authors studied the function structure, process design of the safety evaluation module, and hierarchical analysis algorithm module of the system in depth, and developed the general architecture design, development technology and database design of the system. Technologies such as hierarchical architecture design and Java EE were used in the system development, and My SQL5 was adopted in the database development. The result is a complete evaluation process of information collection, safety evaluation, and output of damage and safety degrees, as well as query and statistical analysis of identified buildings. The system can play a positive role in sharing expert post-earthquake experience and promoting safety evaluation of buildings on a seismic field.     

新疆于田MS7.3地震同震与震后形变机制研究

利用InSAR技术获取2008-03-21新疆于田MS7.3地震的同震和震后形变场。同震分布式滑动反演结果表明,同震断层最大滑动量达5.4 m,主要分布在南部断层的0~5 km深度附近,地震以正断错动为主,兼有左旋走滑分量。震后形变结果表明,发震断层北段两侧存在差异性运动,最大累积差异形变在震后782 d达15 cm。进一步分析表明,震后断层余滑可能是震后形变的主要机制。余滑反演结果表明,震后2 a断层余滑量相对较小,滑移区范围明显减小且均位于浅部区域,北部断层能量释放较彻底,南部仍存有少量能量,整体能量基本释放完。     

川东及邻区上二叠统生物礁的白云岩化

白云岩化是川东及邻区上二叠统礁体的重要成岩事件。根据矿物岩石学、X光衍射、流体包裹体、碳氧稳定同位素、微量元素及阴极发光等项目的研究,笔者认为,礁体白云岩主要是埋藏交代成因,礁顶有少量微-粉晶白云岩为潮坪成因。本文着重讨论礁体围岩为生屑灰岩的埋藏压实流体白云岩化模式,简述礁控白云岩储集特征及其成因。在此研究基础上,提出了一个白云石结构成因分类方案。     

土城住宅楼工程锚杆拉力监测及数值模拟分析

支护结构中锚杆的受力在一定程度上反映了作用在支护结构上的土压力大小.对锚杆受力进行原位监测,通过对数据进行研究、分析,可以了解土压力的大小和分布规律,这对于优化深基坑支护结构设计具有重要的实际意义.以某基坑工程为依托,对锚杆在张拉锁定及工作过程中的实际受力情况进行了全程监测,通过FLAC数值模拟分析,研讨了作用于支护结构上的土压力计算问题.     

基于Web的流动地震监测数据库查询系统的设计与实现

介绍了基于Web的流动地震监测数据库查询系统的开发背景和目的,描述了数据库查询系统的设计和实现过程。该系统借助Internet/Intranet网络,以B/S(浏览器/服务器)体系结构作为基础架构,采用WAMP集成化软件开发,具有系统加密、数据查询、数据维护、数据导出和资料下载等功能。