ShakeMap在2014年于田7.3级地震快速损失评估中的应用

本文介绍了2014年2月12日新疆于田Ms7.3级地震的震害特征,将改进的ShakeMap烈度图成功地运用到了于田7.3级地震的快速损失评估中.结果表明,考虑了场地效应的ShakeMap烈度图明显优于当前“十五”应急指挥系统的衰减关系模型的烈度图,能更好地为地震灾害损失评估服务,其快速评估的结果更接近官方公布的数据.因此,应用ShakeMap技术在震害损失快速评估中,能显著地提高评估结果的准确性.     

Geochemical evolution during the cracking of crude oil into gas under different pressure systems

Two comparative simulation experiments(a normal atmospheric-pressure opening system and a 20 MPa closed system)were conducted to study the geochemical evolution of n-alkane,sterane,and terpane biomarkers in the process of oil cracking into gas under different pressures.With an initial experimental temperature set at 300°C,the temperature was increased to 650°C at a heating rate of 30°C/h.The products were tested every 50°C starting at 300°C,and a pressure of 20 MPa was achieved using a water column.The low-maturity crude oil sample was from the Paleogene system in the Dongying sag in eastern China.The threshold temperature obtained for the primary oil cracking process in both pressure systems was 450°C.Before the oil was cracked into gas,some components,including macromolecular n-alkanes,were cracked into medium-or small-sized n-alkanes.The secondary oil cracking of heavy hydrocarbon gases of C2–5to methane mainly occurred between 550°C to 650°C,and the parameters Ln(C1/C2)and Ln(C1/C3),as well as the dry coefficients,increased.Overpressure inhibited the oil cracking process.In the 20 MPa system,the oil conversion rate decreased,the temperature threshold for gas generation rose,and oil cracking was inhibited.Compared with the normal pressure system,high-carbon n-alkanes and other compounds in the 20 MPa pressure system were reserved.Furthermore,the parameters∑C21-/∑22+,Ln(C1/C2),and Ln(C1/C3),as well as the dry coefficients,decreased within the main temperature range.During secondary oil cracking(550°C to 600°C),the Ph/nC18and Pr/nC17decreased.High pressure influenced the evolution of the biomarkers Ts and Tm,C31homohopane,C29sterane,and their related maturity parameters to different extents during oil cracking under different temperature ranges.     

Upper mantle seismic anisotropy beneath a convergent boundary: SKS waveform modeling in central Tibet

This study used SKS waveforms from the International Deep Profiling of Tibet and the Himalayas (INDEPTH) III dataset and a new 2D method for modeling seismic waves in anisotropic media to construct an image of anisotropic structures beneath central Tibet. A preferred model revealed three-segment anisotropic structures in the upper mantle beneath the study region. Waveform modeling demonstrated that the anisotropy was mainly generated by the lithosphere but not the asthenosphere, and that an anisotropic model with a flatter axis of symmetry provides a more consistent interpretation of the observations than models having steeply dipping symmetry axes. A relatively low velocity zone may underlie or intermingle with the anisotropic structures in the northern portion of the region. Synthetic tests also indicate that variations in the elastic constants and depth extent of the anisotropy assumed by the calculations do not affect the general conclusions, although trade-offs exist among certain model parameters. The modeling results suggest that the complex seismic structures in central Tibet were associated with underthrusting of the Indian lithosphere beneath the Asian lithosphere; the inferred flat symmetry axis of the anisotropy was likely generated during this collision process. If this were not the case, the inherited anisotropy would exhibit a steeply dipping axis of symmetry, parallel to the direction of underthrusting.     

台站运行率自动检测系统的应用和技术要点

地震监测台站的实时运行率是测震台网运行评比中一个重要的指标。本文就如何运用java定时器来实现台站运行率自动检测进行探讨,介绍了黑龙江省地震台网台站实时运行率自动检测系统的实现。     

四种南极数字高程模型的精度比较与分析

南极数字高程模型（DEM）是南极冰盖研究的基础数据,目前国际通用的全南极DEM数据主要有JLB97 DEM、RAMPv2 DEM、ICESat DEM以及Bamber 1km DEM. 利用DEM对DEM验证的方式对四种DEM的精度进行比较分析. 结果表明：Bamber 1km DEM和ICESat DEM之间的高程差异最小,平均高程差小于1.8 m,二者均有较高的可靠性. RAMPv2 DEM与Bamber 1km DEM的高程差大于1.9 m,在81.5° S以南和坡度较大的区域,高程差异更为明显,高程可靠性较低. JLB97 DEM与上述三种DEM的偏差超过10 m,高程可靠性最低.     

入射频率对煤系薄互层地震响应特征影响的物理模拟

建立薄互层地震物理模型,分别从低频和高频入射时地震记录的振幅谱形态、振幅、频率特征、AVO特征等方面入手,分析了入射频率对煤系薄互层模型地震响应特征的影响。结果表明:入射频率对薄互层层数变化反映敏感,高频入射时振幅谱形态可分辨的厚度比较小,分辨率较高;振幅谱幅值以及主频值的变化与薄互层的总厚度和波长之比有关,并且随着厚度的增加其变化规律符合薄层的振幅调谐规律与频率调谐规律;入射频率不同时,AVO曲线特征也不相同,在进行薄互层资料的对比解释及AVO分析时,要充分考虑入射频率所引起的差异。      

社会—生态系统综合风险防范的凝聚力模式

在综合风险防范“凝聚力”概念的基础上,从社会—生态系统综合风险防范的“凝聚力”基本原理、凝聚力形成中的协同效能、凝聚力实现手段、凝聚力优化对提高系统抗打击能力的作用等方面系统研究了“凝聚力”的科学内涵,并初步建立了“凝聚力”的模式,以期完善现有综合风险防范理论体系。结果表明：协同宽容、协同约束、协同放大和协同分散四个基本原理阐述了社会—生态系统综合风险凝聚力在协同运作上的四种表现,同时也是凝聚力在“凝心”和“聚力”具体问题上的4 种优化目标的阐释;凝聚力模式将四个协同原理及其优化目标转化为社会认知普及化、成本分摊合理化、组合优化智能化、费用效益最大化等一系列手段,实现了社会—生态系统综合风险防范产生的共识最高化、成本最低化、福利最大化以及风险最小化;运用复杂系统建模和仿真的方法,通过设计社会—生态系统结构和功能的表达,验证了随着系统凝聚力的提高,系统抵抗局部和全局打击的能力均得以增强,而且,可通过优化社会—生态系统中节点的结构和功能,以达到提升系统凝聚力的目的;凝聚力模式补充了灾害系统中脆弱性、恢复性、适应性等概念在阐释社会—生态系统综合风险防范问题上存在的缺陷。     

1736-2010年华南前汛期始日变化

根据清代华南雨雪分寸记载的内容、特点,参照华南地区前汛期降水特征,提出了利用雨雪分寸记载重建华南前汛期开始时间的方法,重建了1736-1911 年福州与广州前汛期开始日期变化序列;并利用福州与广州（分别始于1953 和1952 年）逐日降水观测记录辨识了器测时期两地前汛期的逐年开始时间;据此分析了过去300 年华南前汛期开始日期的年-年代际变化特征。结果表明：1736-2010 年间,福州、广州两地前汛期开始时间平均为5 月第1 候;但存在显著的年际和年代际波动,其中重建时段（1736-1911 年）的主周期为2~3 年、准10 年和准40年,器测时段的主周期为2~3 年、准10 年和准22 年。在年际尺度,重建时段福州和广州前汛期开始时间最早的年份均为4 月第4 候,最晚的年份则分别为5 月第6 候和6 月第1 候;而器测时段两地前汛期开始时间的最早年、最晚年均为4 月第4 候和6 月第1 候。在年代际尺度,重建时段福州和广州相邻年代最大变幅分别为2.2 候和1.6 候;器测时段福州和广州相邻年代最大变幅则分别为2.5 候和2.4 候。