我国港口城市的功能模式研究

基于港口城市功能的评价指标体系,采用主成分分析法,提取反映港口城市功能特征的4个主成分因子;运用分层聚类法对我国21个港口城市的主成分得分进行聚类分析;结合港口功能、城市功能、港口与城市关系等指标对我国港口城市功能模式进行总结,并分析不同功能模式港口城市的发展特征和存在问题;基于港口城市功能模式差异性分析,提出我国港口城市发展的几点建议。     

开源GIS支持下的气象灾害风险区划分析

近年来气象灾害频繁发生,给我国人民生活、经济发展带来严重威胁。灾害风险区划分析作为防灾减灾的基础工作,在我国逐渐展开。为探索一种基于开源GIS的县级区域气象灾害风险区划分析技术方案,首先分析开源GIS的发展状况,探讨了开源GIS的质量、性能及应用中需注意的法律因素等,而后以东营市河口区为例,选择QGIS、ILWIS等开源软件,基于区域灾害系统论构建不同气象灾害的分析模型及综合气象灾害分析模型,进行县级区域气象灾害风险区划分析,最终编制实验区气象灾害风险区划分级图。     

得尔布干成矿带西南段矿床类型、成矿分带及找矿方向

得尔布干成矿带的西南段位于内蒙古自治区的新巴尔虎右旗至满洲里一带,是大兴安岭成矿省内极具找矿潜力的地区.铜、钼、铅、锌、银是该区的主要矿种,区内已发现大型矿床4处,小型矿床和矿点多处,分别形成于燕山早期和燕山晚期这2个主要成矿期,并可划分为3个矿床类型、6个矿床式.燕山早期的成矿元素主要是Cu、Mo、Au,以斑岩型和矽卡岩型矿床为主;燕山晚期的成矿元素主要为Pb、Zn、Ag,以次火山热液型和浅成热液型矿床为主.燕山期隆坳相间的构造格局和超浅成-浅成的中-酸性小岩体,控制着矿床的产出和分布.矿产地集中于燕山期隆坳交接带及其两侧,并形成以隆坳交接带为中心的、与成矿流体温度和盐度降低相伴的不对称分带.文章提出,得尔布干成矿带西南段的找矿潜力主要在隆坳交接带及其两侧,具体为已知矿区的深部及边部、乌奴格吐山-哈拉胜隆坳交接带和甲乌拉-山登脑隆坳交接带的两侧.此外,位于该区西南部的另一个隆坳交接带是潜在的矿化集中区.     

多重水力断裂的分形扩张

应用复杂性理论对于赣南脉钨矿床的著名“五层楼”式形态垂直分带进行研究 ,获得如下结果。 (1 )赣南脉钨矿床的“五层楼”式形态垂直分带是“多重水力断裂分形扩张”的结果。脉钨矿床的控矿多重断裂是一种以水力断裂为主导的热致与流体驱动断裂构造。脉钨矿床的自组织临界性是多重分形扩张之源 ,而中观破裂尖端周围流体静力学应力场梯度最大区则是分形扩张的驱动力。多重水力断裂的发生和发展是一种分形扩张过程 ,其演化服从串级“崩塌间断平衡”的时空分形生长动力学 ,与地震的Omori余震律相类似。 (2 )脉钨矿床“三环一帽”式的成矿地球化学分带是一种多组分成矿溶液的渗滤、溶解沉淀波结构 ,是成矿反应扩散系统中化学波的时空同步化传播而形成的目标斑图 ,是近平衡地质介质内 ,通过外界的“短暂局部激发”、继之以构造、岩浆和成矿脉动作用等“局部中断”而形成的径向对称、嵌套球状、远离平衡的局域化耗散结构 ,即脉动型自孤子。 (3)赣南脉钨矿床是近平衡区域地质背景中远离平衡的局域化耗散结构。赣南钨矿集区是复合自孤子的群集体。它们是在构造、岩浆多期次脉动条件下 ,来自①矿源层部分熔融的“区域提纯”、②岩浆期后成矿热液输运反应和③含钨地层、岩石淋滤交代的成矿物质 ,通过岩浆和热液孤     

矿物白度的影响因素与增白机理研究

白度是矿物的重要光学性质之一。为了深化矿物的光学性质及白色矿物功能材料的研究与应用,根据测试分析结果和叶大年的结构光性矿物学理论,系统研究了影响矿物白度的主要因素,以及矿物增白效果的差异性及其产生机理。研究结果表明:(1)晶体化学是决定不同种类透明矿物白度的最主要因素,但对于某种透明矿物来说,影响其白度的主要因素是矿物中的碳质有机质、含铁钛矿物杂质、杂质元素的价态与晶体化学环境、介质环境、矿物中的水和粒度大小等。(2)证明了透明矿物白度大小与折射率呈正相关。白度相同的不同矿物的增白效果存在很大差异性,其根本原因是由矿物折射率所决定的反射率存在很大差别。(3)提出了真白度和假白度的概念,即主要由自色产生的白度称为真白度,主要由假色产生的白度称为假白度;真白度高的矿物具有增白作用,而真白度低的矿物,即使粉末白度高,也没有增白作用。(4)在影响矿物白度的主要因素中,矿物中的碳质有机质、含铁钛矿物杂质、杂质元素的价态等杂质成分对矿物白度和增白效果起负面作用。(5)矿物中与晶体结构相关的水所产生的颜色属于自色,脱去结晶水、层间水和结构水都有利于提高矿物的真白度或增白效果,但脱去沸石水的效果正好相反;由矿物粒度大小变化产生的颜色属于假色;通过降低粉体粒度大小所提高的白度属于假白度,由此增加的白度没有增白作用。另外,矿物粉体与使用介质之间的折射率大小差别越大,增白效果越明显。     

重庆甑子岩崩塌落石动力学特征及危险性分区

针对重庆市南川区甑子岩危岩体面临的崩塌地质灾害问题,分析不同高度、不同规模的危岩体对东侧居民区的落石风险及危害性。以甑子岩处岩质边坡为研究对象,根据其结构面发育情况及崩塌落石特征确定模型尺寸,运用RocFall软件对崩塌落石的能量、速度、运动轨迹、落点位置及冲击力等进行模拟计算。以此对崩塌落石区进行落石风险评估,根据崩塌落石的动量和动能,按最危险原则法将崩塌落石的危险性分区,分为Ⅰ危险性极大、Ⅱ危险性大、Ⅲ危险性一般、Ⅳ危险性较小、Ⅴ无危险五个分区,并将此分区应用于甑子岩危岩体,评价崩子岩危岩体居民区的落石风险及危险性,确保居民安全。通过对崩塌落石区的危险性分区,可以用来指导居民区的安置和防护措施。     

The duration of near‐peak metamorphism from diffusion modelling of garnet zoning

Garnet in a staurolite–kyanite zone sample from central Vermont displays a bell‐shaped Mn growth zoning with diffusional modification over the outer 100 μm. The diffusion is driven by the prograde net transfer reaction garnet + chlorite = kyanite + biotite as is evidenced by a well‐defined resorption zone on the rim. Analysis of the reaction history and resorbed garnet composition suggests that the peak temperature attained was 620–660 °C. Diffusional modelling of the rim diffusion provides an estimate of the duration of the metamorphic episode over which significant garnet diffusion occurs. The duration is a function of the assumed peak temperature and garnet diffusivities and range from a few hundred thousand years to a few million years. Such short durations require rapid tectonic burial and exhumation of relatively thin tectonic slices.     

A method for evaluating the longitudinal functional connectivity of a river–lake–marsh system and its application in China

The longitudinal functional connectivity of a river–lake–marsh system (RLMS) refers to the actual water-mediated transport of material from upstream to downstream areas along a spatial gradient and is fundamental to understand hydrological and biogeochemical cycles. However, due to a lack of consensus on appropriate data and methods, the quantification of connectivity is still a challenge, especially at the catchment scale. We developed a new method to evaluate longitudinal functional connectivity based on fluxes of materials (water, sediment, and chemicals) along a RLMS. The calculation of fluxes is based on the longitudinal pattern of terrain gradient, which influences transport efficiency, and on contributions from hillslopes, which set the initial spatial template of material loading to the RLMS. We evaluate the contributions from hillslopes to RLMS based on a new modified version of the index of sediment connectivity (IC) proposed by Borselli et al. (2008) and revised by Chartin et al. (2017).We applied this method to the Baiyangdian Basin covering an area of 3.4 × 10⁴ km² in China and quantified longitudinal functional connectivity during normal, wet, and dry periods(April, July and December) in year 2016. We found that areas with good structural connectivity exhibited poor functional connectivity during the normal and dry periods. Modelling testing with discharge data from hydrological stations and measured chemicals from Baiyangdian Lake was satisfactory in test periods. We conclude that public data and Digital Elevation Model-derived information can be used to reliably map the longitudinal functional connectivity of RLMSs. The proposed method provides a useful tool for monitoring and restoring the longitudinal functional connectivity of RLMSs and our results indicate that efforts aimed at restoring functional connectivity in RLMSs should take into account landscape patterns that can greatly influence fluxes in the watershed.     

Grain‐scale pressure variations and chemical equilibrium in high‐grade metamorphic rocks

In the classical view of metamorphic microstructures, fast viscous relaxation (and so constant pressure) is assumed, with diffusion being the limiting factor in equilibration. This contribution is focused on the only other possible scenario – fast diffusion and slow viscous relaxation – and brings an alternative interpretation of microstructures typical of high‐grade metamorphic rocks. In contrast to the pressure vessel mechanical model applied to pressure variation associated with coesite inclusions in various host minerals, a multi‐anvil mechanical model is proposed in which strong single crystals and weak grain boundaries can maintain pressure variation at geological time‐scales in a polycrystalline material. In such a mechanical context, exsolution lamellae in feldspar are used to show that feldspar can sustain large differential stresses (>10 kbar) at geological time‐scales. Furthermore, it is argued that the existence of grain‐scale pressure gradients combined with diffusional equilibrium may explain chemical zoning preserved in reaction rims. Assuming zero net flux across the microstructure, an equilibrium thermodynamic method is introduced for inferring pressure variation corresponding to the chemical zoning. This new barometric method is applied to plagioclase rims around kyanite in felsic granulite (Bohemian Massif, Czech Republic), yielding a grain‐scale pressure variation of 8 kbar. In this approach, kinetic factors are not invoked to account for mineral composition zoning preserved in rocks metamorphosed at high grade.     

城市职能特征及其形成机理研究进展与展望

城市职能是城市定位、制定发展战略的重要依据,城市职能具有阶段性、等级性、地域性等特征,论文通过对不同学者的相关研究成果进行归纳总结,以期把握城市职能特征及其形成机理的普遍性规律。结果表明：① 不同城市发展阶段的职能特征表现为城市主导职能不断更替,农业社会阶段主要是政治和商业职能,工业社会阶段主要是制造业、商贸和物流职能,后工业化阶段是服务业职能且以生产性服务业职能为主。② 不同城市规模等级的职能特征表现为城市等级越高,城市职能综合性越强,服务业职能越强。③ 不同空间层面城市职能特征表现为,全球层面,发达国家本土通过城市职能升级,全球产业转移,形成以服务业为主导职能,发展中国家通过承接制造业转移,加速工业化,形成工业职能为主导职能,服务业职能地位不断提升;全国层面,城市职能地带性差异较大,东部工业职能依然突出,西部矿业职能、科技职能、行政职能较明显;城市群层面,世界发育成熟的城市群,在区域中心城市与外围城市之间,以及外围城市之间已经形成紧密的联系和职能分工。中国的许多城市群在中心和外围城市之间也具有明确的职能分工,中心城市以服务业职能为主,但外围城市之间职能分工还不明确。④ 城市职能演变影响因素方面,自然条件、人口、交通、政府引导、区位等传统因素起基础作用,科技、全球化、信息化等新因素作用越来越大。城市职能演变还受区域分工、产业升级、产业转移、趋同发展等机制共同作用。⑤ 未来研究方面,研究时间上应补充完善长时间尺度和近期研究的城市职能研究,研究内容上应加深城市职能效应、城市职能演变机制和职能优化方面的研究,与国家战略进行融合;研究方法上除了统计分析,还可采用调研、问卷、访谈等方法进行补充。