Characterization of low-temperature pyroclastic surges that occurred in the northeastern Japan arc during the late 19th century

Three eruption events occurring in the central part of the northeastern Japan arc were investigated and compared: Adatara AD1900, Zao AD1895, and Bandai AD1888. Producing low-temperature (LT) pyroclastic surges, these events are characterized by steam eruptions ejecting no juvenile material. These eruptions' well-preserved eruptive deposits and facies facilitated granulometric analyses of the beds, which revealed the transport and deposition mechanisms of LT surges. Combining these results with those of investigations of documents reporting the events, we correlated each eruption to the relevant individual bed and reconstructed the LT surge development sequence. Important findings related to the transport and deposition modes are the following. (1) Bed sets consisting of thin, laminated ash and its overlying thick massive tuff were recognized in the Adatara 1900 proximal deposits. The bed set was probably produced by a strong wind that discharged and propagated quickly from the vent (leading wind) and a gravitationally segregated, highly concentrated flow originated from the eruption column, within a discrete eruption episode. A similar combination might have occurred during the first surge of the Bandai 1888 event. (2) Comparison of the proximal and distal facies for the largest eruption of Adatara 1900 event indicates that the initial turbulence of the eruption cloud decreased rapidly, transforming into a density-stratified surge with a highly concentrated part near the base. Similar surges occurred in the climatic stage of Zao 1895. (3) Bandai 1888 ejecta indicate massive beds deposited preferentially at topographic lows. Co-occurring planar beds showed no topographic affection, as indicated by the topographic blocking of a stratified surge. The observed facies–massive tuffs, crudely stratified tuffs, and thin bedded tuffs–are compatible with those for high-temperature surges. At Bandai, absence of dune bedded tuffs and commonly poorer sorting in the LT surge deposits might be attributable to poor thermally induced turbulence of eruption columns. Condensation of vapor in the surges might have contributed to the poor sorting. The estimated explosion energies were 6 × 10¹³ J for Adatara AD1900, 6.5 × 10¹⁰ J for Zao AD1895, and 6.5 × 10¹⁵ J for Bandai AD1888, implying that the three events were hydrothermal eruptions with distinctive eruptive mechanisms. Regarding eruption sources, the Adatara 1900 event was caused solely by thermal energy of the hydrothermal fluid, although magma intrusion likely triggered evolution of hydrothermal systems at Zao in 1895. Steam eruptions in the Bandai 1888 event occurred simultaneously with sudden exposure of the hydrothermal system, whose triggers require no internal energy.     

从顺义地表破裂带分析顺义-良乡断裂北段的活动性

沿北京顺义 -良乡断裂北段存在地表破裂带。对这条破裂带进行了成因分析、野外调查、化探和槽探研究 ,认为该破裂带反映了顺义 -良乡断裂北段的现今活动性。今后应注意沿该段断裂的地震活动并在建设规划中充分考虑它对工程可能造成的灾害     

Industrial arrangement of large-scale, non-grid-connected wind power industrial zones in coastal areas of China

Constructing an industrial system for a large-scale,non-grid-connected wind power industry is a key step towards the diverse utilization of wind power.However,wind power exploitation is not only a technical challenge but an industrial problem as well.The objective of this study is to introduce a concept of large-scale,non-grid-connected wind power(LSNGCWP) industrial zones and establish an evaluation model to assess their industrial arrangement.The data of wind energy,industry,nature resources and socio-economy were collected in this study.Using spatial overlay analysis of geographic information system,this study proposes a spatial arrangement of the LSNGCWP indus-trial zones in the coastal areas of China,which could be summarized as the ’one line and three circles’ structure,which will contribute to the optimization of the industrial structure,advance the wind power technology,coordinate the multi-industrial cooperation,and upgrade the industrial transformation of China’s coastal areas.     

地震应急指挥协同技术平台设计研究

地震应急指挥协同服务能力是国家地震社会服务能力建设的核心内容,我国的地震应急指挥协同服务能力在研究和建设方面尚处于起步阶段,在未来一段时间将开展地震应急指挥协同技术平台的建设。因此,地震应急指挥协同技术平台的关键构成、设计和实现方式还有许多方面有待进一步研究和探讨。本文根据国家地震社会服务工程的初步设计,对地震应急指挥协同技术平台几个方面的内容进行了初步探讨,在此基础上讨论了其未来进一步发展应进行的工作。     

浙江及邻区地震烈度衰减关系研究

浙江省及其周边的历史震例资料稀少,其地震烈度衰减关系一直沿用中国东部地区的地震烈度衰减关系模型。本文采用椭圆模型,利用浙江及邻区历史地震的震害资料,建立了浙江及邻区天然地震烈度衰减公式。根据东南沿海地区水库地震多发的特点,收集整理了水库地震相关震例数据,建立了浙江及邻区水库地震烈度衰减公式。最后,将本文拟合结果与其他学者拟合出的衰减模型通过实际震例进行了对比,并进行了相关讨论。     

国家地震安全公共服务平台研究

本文主要立足于我国地震多发、震灾严重的国情,着眼于经济社会快速发展和社会公众对地震安全信息服务提出的新要求,探讨把防震减灾工作成果转化为公共服务产品,实现从被动救灾到主动救灾的创新和转变。以地震安全公共服务为目标,以地理信息技术为手段,为国家防震减灾信息化建设提供先进的关键技术支撑,不断提高地震行业应对地震灾害的基础信息保障能力,更好地发挥地震行业中各个业务技术系统的功能,使防震减灾成果更好、持续地为社会提供服务,最大限度减轻地震灾害损失。     

VAX计算机及图象系统硬磁盘扩充

本文介绍了为VAX计算机系统扩充硬磁盘以及为ARIES-Ⅱ图象处理系统建立图象伪磁盘的方法及步骤。     

基于虚点影响域重构的CD-TIN约束线删除算法

根据CDTIN中约束线的多态性,提出了利用虚点描述约束线交叉的情况,并用虚点影响域重构算法(influence domain retriangulating for virtual point,IDRVP)来解决CDTIN约束线删除操作中的约束线交叉问题,确保了CDTIN的拓扑完备性,并对算法进行了验证。     

Earthquake interaction forces between two structures of different rigidities

A combined structure is assumed to be composed of a rigid part and a flexible part. Each component structure would have a different period of natural vibration if it were built independently. When they are combined in one structure and subjected to an earthquake, there must be generated some interaction forces so that the component structures will have a common vibration. In this paper is an analytical method described to evaluate such interaction forces The general principle is as follows. For each of the component structures, equations of motion taking account of the unknown interaction forces are derived first. Then by eliminating the interaction forces, equations of motion of the combined structure are obtained. After solving these equations and substituting the solution into the equations of motion of the component structures, the unknown interaction forces are obtained directly In the present paper, two structures corresponding to two-degree elastic systems are considered; numerical examples also are included.     

富硒、高镉地质背景下水稻种植实验研究

富硒(Se)的土地常常富镉(Cd)，如何从该类土地中过滤掉Cd而安全地利用Se是农业生产的关键。本文以水稻种植为切入点，选取了7种水稻品种，以硅肥调节和农家常规种植方式作为对照进行了实验田与对照田实验。实验结果发现：(1)硅肥具有通过调节土壤理化性质、促进Se和Cd有效态的释放以及通过与Cd²⁺反应降低Cd有效态的双重效果，使水稻更有利于富集Se而不富集Cd；(2)“深两优5814”和“C两优华占”水稻品种，在富集Se和抑制Cd方面的效果上较好。