1949年以来兰州城市资本密度空间变化及其机制

构建了计划经济体制和中国转型期城市资本密度空间分布理论模型,并以兰州市为例进行了实证.利用高精度卫星影象和大规模实地调查方法获取数据,采用GIS手段和数理统计方法,利用建筑高度指标,分区、分行业对兰州城市资本密度空间变化进行了深入研究.同时,采用资本存量增量(或增长率)/建成区面积增量(或增长率)的指标衡量资本角度的城市紧凑化程度,研究了城市紧凑化变动过程.结果表明:①中国计划经济体制下的城市资本空间密度为缓慢波动下降或均衡分布规律,甚至出现上升趋势.转轨期(中国)城市资本空间密度由中心到外围的相应规律则居于两者之间,存在向市场经济空间模型靠近的趋势;②中国城市计划经济体制下的用地空间由中心到外围呈现商务→住宅→工业→农业的模式,而转轨期依然基本保留了此特征;③转轨期的建筑高度提高速度存在加速趋势,住宅、商业、办公等类建筑高度明显高于计划时期,其空间分布模型也更接近市场经济体制模型;④从资本视角审视,中国城市将更加紧凑化,且随时间的推移,城市资本密度空间变化曲线大致存在较为明显的"雁行波动上升式"规律.     

Measurement of the Dielectric Properties of Volcanic Scoria and Basalt at 9370 MHz

Dielectric data for volcanic scoria and basalt on the earth at microwave frequency are extremely sparse, and also crucial for volcanic terrains imaging, and development. In consideration of their similarity to lunar regolith (soils and rocks) in chemical and mineral composition, the dielectric data is significative for passive and active microwave remote sensing on the Moon. This study provides the data about the dielectric properties of three kinds of scoria and two kinds of basalt in China. The method put forward in this paper is also applicable for measuring the dielectric properties of dry rocks and other granular ground materials with low complex dielectric constants. Firstly, the authors measured the ε‘ and tanδ values of strip specimens prepared from the mixture of scoria or basalt powder and polythene with the resonant cavity perturbation method at 9370 MHz. Secondly, from the ε‘ and tang values of the mixture, the ε‘s and tanδs values of sofid scoria and basalt were calculated using Lichtenecker‘s mixture formulae. Finally, the effective complex dielectric constants, ε‘e and tanδs, of scoria at different bulk densities were calculated. The results have shown that the ε‘s and tang svalues of all solid basaltic materials measured (both solid basaltic scoria or basalt) are approximately 7 and 0.05,respectively. With increasing bulk density of scoria, the ε‘s and tanδs values of scoria increase significantly.     

SAVER救援技术在地震救援中的应用

国际紧急技术中心(International Centerfor Emergency Techniques,简称ICET)在1994年研究开发出SAVER救援方案,SAVER的全称为Systematic Approachto Victim Entrapment Rescue,其实质就是接近被困于有限空间的人并将其救援出来的系统方法。ICET总部设在荷兰,于1993年成立,当时属于荷兰荷玛特公司;1996年从荷玛特公司分离出来;1997年改名为“国际紧急技术中心”。ICET是世界上许多最知名的备受称赞与尊敬的与救援相关的组织成员之一。SAVER救援技术在各类灾害救援中得到广泛应用,本文主要介绍SAVER救援技术和地震救援。     

琼东南盆地崖 13-1气田气源区圈定与成藏运聚模式

琼东南盆地崖 13 -1气田成藏运聚模式一直存在不同的认识.应用生烃动力学、碳同位素动力学及流体包裹体方法对该气田有效气源区、气藏充注时间和运聚效率等进行了研究.结果表明, 崖 13 -1气藏成藏时间较晚,天然气主成藏期出现在 2 Ma以后;有效气源区是崖南凹陷斜坡带崖城组,现埋深范围 4 000～ 5 500 m; 天然气为累积聚集气,目前天然气仍在有效的充注阶段.在此基础上,提出了崖 13 1气田天然气成藏运聚模式.此研究方法及建立起的成藏模式对于莺-琼盆地天然气勘探具有重要指导意义.     

中国西部河谷型城市发展及其环境问题

分析了1949年以来中国西部河谷型城市的数目变化与空间分布、规模与职能变化。在此基础上，以西部部分河谷型城市为例，讨论了影响该类城市的环境污染和热岛效应等城市环境问题，并研究了环境问题的成因，认为工业化过程与城市化过程、地形条件、工业的空间布局、建设用地结构不合理和城市建设的间接效应等是造成目前西部河谷型城市环境问题突出的主要原因。     

The role of labile sulfur compounds in thermochemical sulfate reduction

The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A series of gold-tube hydrous pyrolysis experiments were conducted with n-octane and CaSO₄ in the presence of reduced sulfur (e.g. H₂S, S°, organic S) at temperatures of 330 and 356 °C under a constant confining pressure. The in-situ pH was buffered to 3.5 (∼6.3 at room temperature) with talc and silica. For comparison, three types of oil with different total S and labile S contents were reacted under similar conditions. The results show that the initial presence of organic or inorganic sulfur compounds increases the rate of TSR. However, organic sulfur compounds, such as 1-pentanethiol or diethyldisulfide, were significantly more effective in increasing the rate of TSR than H₂S or elemental sulfur (on a mole S basis). The increase in rate is achieved at relatively low concentrations of 1-pentanethiol, less than 1 wt% of the total n-octane, which is comparable to the concentration of organic S that is common in many oils (∼0.3 wt%). We examined several potential reaction mechanisms to explain the observed reactivity of organic LSC. First, the release of H₂S from the thermal degradation of thiols was discounted as an important mechanism due to the significantly greater reactivity of thiol compared to an equivalent amount of H₂S. Second, we considered the generation of olefines in association with the elimination of H₂S during thermal degradation of thiols because olefines are much more reactive than n-alkanes during TSR. In our experiments, olefines increased the rate of TSR, but were less effective than 1-pentanethiol and other organic LSC. Third, the thermal decomposition of organic LSC creates free-radicals that in turn might initiate a radical chain-reaction that creates more reactive species. Experiments involving radical initiators, such as diethyldisulfide and benzyldisulfide, did not show an increase in reactivity compared to 1-pentanethiol. Therefore, we conclude that none of these can sufficiently explain our observations of the initial stages of TSR; they may, however, be important in the later stages. In order to gain greater insight into the potential mechanism for the observed reactivity of these organic sulfur compounds during TSR, we applied density functional theory-based molecular modeling techniques to our system. The results of these calculations indicate that 1-pentanethiol or its thermal degradation products may directly react with sulfate and reduce the activation energy required to rupture the first S-O bond through the formation of a sulfate ester. This study demonstrates the importance of labile sulfur compounds in reducing the onset timing and temperature of TSR. It is therefore essential that labile sulfur concentrations are taken into consideration when trying to make accurate predictions of TSR kinetics and the potential for H₂S accumulation in petroleum reservoirs.     

时间成本是否成为电子商务区位的核心机制————基于成都市O2O电子商务的实证分析

空间距离是影响传统商业区位的关键因子.但随着信息通信技术(ICT)的迅速普及,空间距离对经济活动尤其是电子商务发展的限制越来越小,时间成本的影响地位日益凸显.然而,时间成本是否成为电子商务区位发展的核心机制,仍有待商榷.以成都市为例,通过建立O2O电子商务市场规模与时/空距离可达性和区位优势度的空间关系,尝试回答这一问题.结果表明:① 整体上,时间成本对成都市O2O电子商务空间发展的影响地位已经高于空间距离,成为了其区位核心机制的首要因素.② 基于空间距离的成都市O2O电子商务区位发展更自由,但对时间距离更敏感,市场规模更严格地按照时间距离区位优势度进行分布,这导致其与时间距离区位优势度的空间匹配性更好,依赖性更高.③ 随着城市"中心--边缘"的空间过渡,时间成本对O2O电子商务区位的影响基本不变,空间距离的影响逐渐减弱,时间成本的影响地位得到相对提升;空间距离和时间成本分别成为影响城市中心区和边缘区O2O电子商务区位发展的核心因子.④ 当前,受信息化,城市化,商业决策者和消费者等的影响,空间距离对O2O电子商务区位的影响仍不能忽视,其区位核心机制由时间和空间共同决定.⑤ 消费者和供应商的利益诉求,以及ICT的便捷性,是时间成本对O2O电子商务区位发展影响地位整体上高于空间距离的主要原因.     

Eopriapulites Sphinx—The Oldest Priapulid-Like Scalidophoran Animal

正Objective Priapulid belong to scalidophoran and is located in the Cycloneuralia branch of the Ecdysozoa.It has survived for more than 50 million years,is a real"living fossil".Priapulid was extremely prosperous in the Cambrian period.It is a small phylum in the modern ocean;only 18current types have been described.In the Cambrian life,priapulid is one of the most important living organisms in     

成都市博物馆发展的过程、特征及空间效应研究

自改革开放以来,中国博物馆发展的制度环境呈现根本变化,探究博物馆发展状况及其与制度环境的关系对于指导博物馆发展、丰富博物馆研究的理论内涵具有重要意义。以成都市为例,采用参与式观察、半结构访谈和文本分析等质性方法,对成都市博物馆发展的过程、特征及空间效应进行系统研究,研究发现：① 成都市博物馆主要经历了国有化发展、非国有化发展和产业化发展三个阶段,在数量与类型、规模与等级、功能与产业、迁移与集聚等方面呈现出显著变化。② 制度变迁通过改变参与主体及其认知、行为进而作用于博物馆发展,当前参与博物馆发展的主体日渐增多,且其目的、行为与计划经济时期相比转变较大。③ 成都市国有博物馆发展的空间效应与民办博物馆发展的空间效应差异较大,前者主要是单个国有博物馆对其周边区域的产业类型、用地性质的影响,后者主要为多个民办博物馆通过集聚对整个集聚区的产业与功能结构的影响。