δ~(18)O, δD and d-excess signatures of ground ice in permafrost in the Beiluhe Basin on the Qinghai-Tibet Plateau,China

In this paper, stable isotope(δ~(18)O, δD) investigations were completed in ground ice from a deep borehole in the Beiluhe Basin on northern Qinghai-Tibet Plateau to unravel the isotopic variations of ground ice and their possible source water. The δ~(18)O and δD of ground ice show distinctive characteristics compared with precipitation and surface water. The near-surface ground ice is highly enriched in heavier isotopes(δ~(18)O and δD), which were gradually depleted from top to bottom along the profile. It is suggestive of different origin and ice formation process. According to isotopic variations, the ice profile was divided into three sections: the near-surface ground ice at 2.5 m is frozen by the active-layer water which suffered evaporation. It is possible that ground ice between 3 and 4.2 m is recharged by the infiltration of snowmelt. From 5 to 6 m, the ground ice show complex origin and formation processes. Isotopic variations from 6 to 11.1 m and 20.55 m indicate different replenishment water. The calculated slope of freezing line(S=6.4) is larger than the experimental value(5.76), and is suggestive of complex origin and formation process of ground ice.     

复杂条件陆-气相互作用研究领域有关科学问题探讨

实际大气都是在复杂条件之下,所以复杂条件带来的问题已成为陆-气相互作用研究领域面临的最大科学挑战,严重制约了该领域研究成果在解决实际天气气候问题中的应用。在概要总结近年来中国复杂条件陆-气作用研究领域进展的基础上,对复杂条件下陆-气相互作用有关的科学问题进行了探讨。从陆面过程和大气边界层这两个陆-气相互作用的关键环节分析了影响陆-气相互作用复杂条件的机制,归纳了复杂条件下陆-气相互作用研究领域面临的关键科学问题。同时,以复杂下垫面陆面过程和非均匀大气边界层问题为重点讨论了突破复杂条件陆-气相互作用关键科学问题的基本思路,并对进一步开展复杂条件陆-气相互作用研究提出了初步的科学建议。      

河南义马煤矿矿区生态系统服务价值动态演化过程分析

基于联合国千年生态系统评估的基本理念和评价框架,从供给服务、调节服务、支持服务和文化服务4个方面对河南省义马矿区单位面积的生态功能价值进行测算,并分析了义马矿区生态系统服务价值在2005—2012年间的演化过程及敏感因素。结果表明:(1)义马矿区单项生态服务价值在2005—2008年间,废弃物处理、水源涵养、娱乐活动和控制侵蚀呈正向变化,食物生产、生物多样性、空气净化、土壤保持、气候调节呈负向变化,在2008—2012年间,仅有土壤保持功能价值为负向变化,其他均为正向变化;(2)矿区生态系统服务总价值呈现出降低—上升—缓慢下降的趋势;(3)农田和水域为义马矿区生态系统服务价值最敏感的因素,即矿区实现可持续发展的关键举措是进行土地与生态修复和水资源保护。     

贵州绥阳阴河洞洞穴壶穴的演化过程

通过对贵州绥阳寒武系中上统娄山关组中发育洞穴之阴河洞地下河河床基岩面上49个壶穴进行详细测量和统计学定量分析,对其形态特征及空间分布进行描述,并探讨其形成演化过程和影响因素。主要结论为：阴河洞壶穴的整体形态以极浅的倒“Ω”型和“锅”型壶穴为主,并且壶穴发育相对较年轻;壶穴长短轴具有一定的相关性,但平均口径与深度的相关性较差,说明壶穴在发育的过程在洪水期以口径增大为主,枯水期以溶蚀深度加深为主,且表现为地下河河床下切的形式之一;从发育阶段看,阴河洞壶穴的形成演化主要分为3个阶段：“碟型”壶穴形成阶段;倒“Ω”型壶穴发育阶段;“锅”型壶穴发育阶段,其形成主要受水动力条件、构造条件、推移质、基岩性质和溶蚀作用等因素耦合的作用;洞穴壶穴主要是流水的侵—溶蚀作用形成的,并非冰川作用的结果,与“冰臼”的发育存在本质上的区别。     

大气气溶胶中的铁及其溶解度研究综述

生物活性铁(Fe) 进入生物地球化学循环中能够调节碳循环,影响海洋初级生产力,间接影响全球气候变化。决定 Fe生物可利用度的关键因子是可溶Fe含量,其中大气气溶胶的长距离传输是上层海洋获取生物可利用Fe的重要来源。近年来,对气溶胶中的Fe及溶解度的研究取得了重要进展,包括对不同区域Fe质量浓度和溶解度的观测以及对Fe溶解度影响因素的讨论。基于以上研究成果,汇总了近二十年全球部分陆地和海洋站点观测所得的不同粒径气溶胶颗粒物中的Fe质量浓度及其溶解度数据;重点介绍了气溶胶沉降入海洋前影响Fe溶解度的主要因素,包括Fe的来源、大气物理过程以及大气化学和传输混合过程等,并就各影响因素间的关联及相对重要性展开讨论;对未来气溶胶 Fe的研究方向和方法提出建议。     

GIS互操作的实现途径评述

文中主要探讨了开放式GIS的规程和关键技术,促进数据、系统和机构的互操作,总结了世界上著名公司最近GIS产品实现互操作的技术途径,给出了国际上有关GIS互操作、开放式GIS研究的最新进展以及近期发展方向。     

用钾-氩法求地质事件真实年龄的方法探讨

钾-氩法所测出的地质事件的表面年龄一般小于地质事件发生的真实年龄,其中很多没有地质意义。本文利用随机过程理论,在对地质体内⁴⁰Ar的逸散作用进行分析的基础上,推导出如下年龄计算公式: 在一定条件下,利用这些公式,可以据钾-氩法测试资料求出地质体形成时代t+t⁰、热扰动结束时代t⁰及热事件所持续的时期t’。据所导出的公式,对冀东迁西群地层的年龄进行讨论,求得2500Ma左右结束的那期热事件所持续的时期t’为4.76亿年,迁西群形成时代为3000—3300Ma。检验表明,公式有效。     

On the identification of ship coupled heave–pitch motions using neural networks

This paper outlines a procedure for the derivation of the differential equations describing the free response of a heaving and pitching ship from its stationary response to random waves. The coupled heave–pitch motion of a ship in random seas is modelled as a multi-dimensional Markov process. The partial differential equation describing the transition probability density function, known as the Fokker-Planck equation, for this process is derived. The Fokker-Planck equation is used to derive the random decrement equations for the coupled heave–pitch motion. The parameters in these equations are then identified using a neural network approach. The method is validated using numerical simulations and experimental results. The experimental data was obtained using an icebreaker ship model heaving and pitching in random waves. It is shown that the method produces good results when the system is lightly damped. An extension for using this method to identify couple heave–pitch motion in realistic seas is suggested.     

沉积盆地中恢复地层剥蚀量的新方法

主要介绍了磷灰石裂变径迹分析法,沉积波动过程分析法和宇宙成因核素分析法等３种恢复和计算地层剥蚀量的新方法。它们的优点是不但给出一个剥蚀面造成的地层总的剥蚀量,还能详细刻画整个剥蚀过程,从而能计算出每一期构造抬升引起的地层剥蚀量。     

Magma ascent beneath Unzen Volcano, SW Japan, deduced from the electrical resistivity structure

The resistivity structure of Unzen Volcano has been revealed by extensive magnetotelluric surveys since the first eruption on November 17, 1990. This structure comprises a highly resistive surface layer, a low-resistive second layer at several hundred meters depth, interpreted as a water-saturated layer, a resistive third layer, and a low-resistive fourth layer at 10 km depth, possibly related to the deep magmatic activity. The structure has influenced the volcanic activity of Unzen. This activity was characterized by a series of dramatic changes in eruption type: a minor phreatic eruption on November 17, 1990; phreatic eruptions after February 12, 1991, preceded by several weeks of volcanic tremor; phreatomagmatic eruptions after April 9, and dome effusion beginning May 19, 1991. This paper presents a hypothesis in which the top of the magma column rose about 20 m/day, reached the base of the water-saturated layer at the end of January, 1991, and approached the upper boundary of this layer on April 9. Thus, the temporal change of eruption type and associated phenomena are systematically explained by an interaction between magma and groundwater contained in the saturated layer.