Effect of salinity on mass and energy transport by hydrothermal fluids based on the physical and thermodynamic properties of H2O‐NaCl

Various thermodynamic properties of H₂O that are defined as pressure or temperature derivatives of some other variable, such as isothermal compressibility (β, pressure derivative of density), isobaric thermal expansion (α, temperature derivative of density), and specific isobaric heat capacity (c_f, temperature derivative of enthalpy), all show large magnitudes near the critical point, reflecting large variations in fluid density and specific enthalpy with small changes in temperature and pressure. As a result, mass (related to fluid density) and energy (related to fluid enthalpy) transport in this PT region are sensitive to changing PT conditions. Addition of NaCl to H₂O causes the region of anomalous behavior, here defined as the critical region, to migrate to higher temperatures and pressures. The critical region is defined as that region of PT space in which the dimensionless reduced susceptibility  ≥ 0.5. When NaCl is added to H₂O, the critical region migrates to higher temperature and pressure. However, the absolute magnitudes of thermodynamic properties that are defined as temperature and/or pressure derivatives (α, β, and c_f) all decrease with increasing salinity. Thus, the mass and energy transporting capacities of hydrothermal fluids in the critical region become less sensitive to changing PT conditions as the salinity increases. For example, quartz solubility can be described as a function of fluid density, and because density becomes less sensitive to changing PT conditions as salinity increases, quartz solubility also becomes less sensitive to changing PT conditions as fluid salinity increases. Similarly, fluxibility describes the ability of a fluid to transport heat by buoyancy‐driven convection, and fluxibility decreases with increasing salinity. Results of this study show that the mass and energy transport capacity of fluids in the Earth's crust are maximized in the critical region and that the sensitivity to changing PT conditions decreases with increasing salinity.     

Capillary seal capacity of faults under hydrodynamic conditions

Many fault bound traps are underfilled despite the top seal capacity being secure. The hydrocarbon sealing performance of faults themselves can be compromised either by mechanical or capillary process. Capillary process can be important either due to juxtaposition or to fine‐grained clay or cataclastic material within the fault zone itself. There is debate about how important each of these mechanisms is over geological timescales of hydrocarbon trapping. Recent work has provided insights into fine‐tuning capillary‐related fault seal calibration methodologies. Over the last 15 years, vigorous scientific debate with multiple published laboratory experiments and modelling studies has led some researchers and industry technologists to theorise that for water‐wet conventional hydrocarbon reservoirs, the relative water permeability in the reservoir (towards the top of the hydrocarbon column) may become very small, but in practice never reach zero. While not advocating for either side in this debate, the importance of accounting for hydrodynamic conditions regardless of the capillary sealing mechanism is demonstrated. Additionally, it is noted that nonzero relative water permeability has implications on how a seal's capillary threshold pressure for the nonwetting hydrocarbon phase is estimated from field data. In the particular case where there are pressure differences between unproduced hydrocarbon reservoirs on either side of a fault, then the hydrocarbon saturation must be discontinuous across the fault. For hydrocarbon leakage to occur across the entire thickness of the fault zone, the hydrocarbon pressure must exceed the threshold pressure on the side of the fault zone with the highest formation water hydraulic head. This approach to estimating across‐fault pressure difference will result in an improved calibration data set used for predrill estimation of capillary fault seal capacity.     

NRM Regions in Australia: the ‘Haves’ and the ‘Have Nots’

This paper identifies external factors affecting the capacity of Australia's now‐formalised 56 regional natural resource management (NRM) bodies and their community‐based Boards to meet planning and management responsibilities. It demonstrates that little is known about the basic capacity‐related characteristics of NRM regions, despite the lengthy and elaborate process of regionalism that Australia has embarked upon, with its associated and substantial devolution of responsibilities and resources. A suite of indicators is used to develop an ‘exploratory’ capacity typology of NRM regions. The ten regional ‘types’ identified are found to attract varying budget allocations under the Natural Heritage Trust Extension and National Action Plan for Salinity and Water Quality. There are indications that State and regional interests within and outside NRM can significantly influence the distribution of resources. An examination of resources allocated to capacity‐building activities shows significant differences between regions in the scale of resources allocated (0–96% of total budget). The paper argues the case for intervention to reduce the gap between ‘have’ and ‘have not’ regions, and for further exploration of disparities in the allocation of resources to capacity‐building activities. Clarification is needed of the extent to which capacity‐building activities adequately target regional NRM bodies and their Boards.     

民国钢筋混凝土结构中的梁构件计算方法研究

为研究民国时期混凝土梁构件的设计计算方法,从材料层面到构件层面,对民国时期混凝土设计与结构计算的相关历史文献进行研究,总结出民国时期混凝土梁构件的设计与计算方法,并结合案例分析,与现代混凝土梁构件的设计计算方法进行比较研究,包括钢筋混凝土梁的受弯承载力计算方法及受剪承载力计算方法。通过对比计算分析,不考虑地震荷载作用时,在1.0%~2.0%纵筋配筋率的范围内,采用现行规范计算的受弯承载力是采用民国规范计算的受弯承载力的3.6~4.0倍;在配箍率0.1%~1.0%范围内,采用现行规范计算的受剪承载力是采用民国规范计算的受剪承载力的1.6~2.4倍;在弯起钢筋配筋率0.5%~1.5%范围内,采用现行规范计算的受剪承载力是采用民国规范计算的受剪承载力的2.0~2.4倍。研究结果可为民国钢筋混凝土梁的结构安全评估提供科学依据。     

Big data analytics for mitigating carbon emissions in smart cities: opportunities and challenges

The paper addresses the growing scepticism around big data use in the context of smart cities. Big data is said to transform city governments into being more efficient, effective and evidence-based. However, critics point towards the limited capacity of government to overcome the siloed structure of data storage and manage the diverse stakeholders involved in setting up a data ecosystem. On the basis of this, the paper investigates the challenges city governments face when dealing with big data in the context of carbon emission reduction. Through the lens of the evidence-based policy and policy capacity literature, the cities of Copenhagen (Denmark), London (UK), Malmö (Sweden), Oxford (UK) and Vienna (Austria) are analysed. The cases reveal that the institutional complexity underlying big data integration limits local government capacity to set up data management structures that would allow further utilization of big data and that current solutions focus on local pilot sites and outsourcing of data analytics.     

Complexity,Capacity, and Budget Punctuations

The budgeting literature has long focused on “institutional friction” as a cause of ubiquitous punctuated equilibrium (PE) findings. A recent wave of scholarship looks to identify specific institutional mechanisms that affect the number of punctuations in policy outputs. We contribute to this growing body of research by focusing on the complexity of the institutional environment surrounding a policy area as well as that of the government as a whole. These factors have opposite effects: the more complex a policy area, the greater the likelihood of extreme spending changes. But, higher institutional capacity in general leads to greater stability. To test these ideas, we develop a novel index of budgetary change that balances the conceptual importance of extreme changes while analyzing the entire distribution of budget changes, not only the tails. In addition, we also demonstrate that findings are robust to a number of important distinctions, such as between series associated with slowly moving demographic trends or quickly moving stochastic events. We, therefore, demonstrate the robustness of important findings from the established literature, add a new measure of the dependent variable, and push the literature forward with a new focus on issue complexity and institutional capacity.     

旅游环境可持续承载的路径分析

旅游业的迅猛发展、旅游环境管理的粗放型及短期化倾向,导致旅游环境问题日益突出,同时也使旅游环境承载力研究成为旅游研究的焦点之一。作为描述自然环境、经济环境和社会环境系统能够承受旅游活动强度的量值,旅游环境承载力既是旅游规划、开发与管理的重要工具,又是判断旅游业可持续发展与否的重要指标。在深入分析旅游环境承载力内涵的基础上,从可持续发展的角度提出实现旅游环境可持续承载的基本路径:建立自然环境系统的维护机制、发展经济环境系统的保障机制、建设社会环境系统的和谐机制以及完善旅游环境可持续承载的配套机制,这为控制旅游活动对旅游环境的负面影响和拓展旅游环境承载力提供了明确的思路。     

主题公园游客心理容量及其影响因素研究——来自深圳欢乐谷的实证

旅游容量是旅游地理学研究的核心问题之一,游客心理容量是旅游容量的重要议题。学界一般认为游客心理容量曲线呈现单调递减性,然而在实践中,主题公园游客心理容量曲线可能呈现非单调递减性。基于这一争论,本文以深圳欢乐谷为案例,采用满意度法论证主题公园游客心理容量曲线的性质,并检验其影响因素。研究发现,主题公园游客心理容量曲线呈现非单调递减性;旺季游客心理容量比平季的大,淡季游客心理容量比平季的小;青少年与成年人的游客心理容量差异不大,老年人游客心理容量比其他人群的小;女性游客心理容量比男性的小,女性的满意度比男性的更容易受到游客量增加的影响;游客心理容量与文化程度呈现逆相关关系。     

Governance, institutional capacity and partnerships in local economic development: theoretical issues and empirical evidence from the Humber Sub-region

Recent research on local and regional economic development has focused upon transformations in local governance and institutional capacity. It has been argued that local authorities have ceded power to other actors and institutions involved in economic development and regeneration, and that the success of local and regional economic development is closely related to the strength of 'institutional capacity' within an area. In this paper, we examine these claims with reference to the operation of EU Structural Funds in the Humber Sub-region of the UK. Previous research on local governance and institutional capacity has had a limited empirical focus, drawing conclusions from studies of either economically 'successful' regions or regions undergoing regulatory and institutional transformation and precluding analysis of the nature and conditions of local governance and institutional capacity in less developed regions. Our case study evidence not only suggests that arguments about the declining influence of the local state are overdrawn, but also indicates a need for more nuanced accounts of the role of institutional capacity in regional development.     

新时期的新疆人口问题及其调控对策

西部大开发战略给新疆发展带来了难得的历史机遇,人口作为PRED的重要组成部分,对新疆的开发和实施可持续发展具有十分重要的作用。本文详细分析了新疆人口的空间分布特点及其时间变化态势,并运用系统动力学模型对未来人口的变化趋势和绿洲人口合理容量进行了模拟仿真,提出了人口增长的高中低三个方案,在分析了人口增长过快所带来问题的基础上,提出了相应的对策建议。