Analytical solution to axisymmetric consolidation of unsaturated soil stratum under equal strain condition incorporating smear effects

This paper proposes closed‐form analytical solutions to the axisymmetric consolidation of an unsaturated soil stratum using the equal strain hypothesis. Following the 1‐dimensional (1D) consolidation theory for unsaturated soil mechanics, polar governing equations describing the air and water flows are first presented on the basis of Fick's law and Darcy's law, respectively. The current study takes into account the peripheral smear caused by an installation of vertical drain. Separation of variables and Laplace transformation are mainly adopted in the analytical derivation to obtain final solutions. Then, the hydraulic conductivity ratio, the radius of influence zone and smear parameters influencing time‐dependent excess pore pressures, and the average degree of consolidation are graphically interpreted. In this study, a comparison made between the proposed equal strain results and the existing free strain results suggests that both hypotheses would deliver similar predictions. Moreover, it is found that the smear zone resulting from vertical drain installations would hinder the consolidation rate considerably.     

技术扩散还是效率优先——基于“美团网”的中国O2O电子商务空间渗透探讨

关于电子商务的空间发展问题,学界提出了技术扩散假说和效率假说。技术扩散假说认为发达城市地区的电子商务发展更好,效率假说则认为欠发达城市地区的电子商务发展更好,两者内涵存在明显争议。以中国286个地级市的O2O电子商务为例,采用空间计量模型、多元线性回归等方法,尝试探讨了其空间发展更倾向于技术扩散还是效率优先。结果表明：① 中国O2O电子商务的规模指数在空间上呈现出由东部沿海向西北内陆逐渐递减的等级式特征,但其发展水平指数的空间格局表现出均质化特征,其渗透指数呈现出由东部沿海向西北内陆逐渐递增的“逆等级”式空间格局。② 实体商业对O2O电子商务的发展具有显著约束力,但交通条件对其具有明显的促进作用,因此,中国O2O电子商务的空间发展更倾向遵循效率假说内涵,但也并非完全契合于该假说。③ 中国O2O电子商务“逆等级”式的空间格局对欠发达城市地区实体商业有更强的促进作用,这会引导中国宏观商业格局趋于均质化。     

生长速率假说及其在浮游动物营养动力学中的研究进展

生物体由元素组成,其生长、繁殖以及代谢过程均涉及营养元素的吸收、利用与储存。有机体的P含量决定了RNA的形成,并作用于核糖体,进而对蛋白质和生长速率产生影响。浮游动物体内P含量增加,以及C∶P和N∶P的降低,主要反映了不同生长速率下,富P的核糖体RNA含量的改变。关于生长速率假说（Growth Rate Hypothesis,GRH）的研究表明,在低C∶P、高P含量的饵料条件下,浮游动物C∶P和N∶P的稳态性特征发生改变,将获取的P分配至RNA中,增加蛋白质合成,提高生长速率;反之,浮游动物的次级生产力将会降低,C的同化效率和传递效率下降,进而对生态系统的C收支产生影响。加强浮游动物GRH的研究,有助于增强对生态系统C收支以及未来变化过程的认识。     

矿山对生态环境的“黑洞与白洞”效应假说

矿山就是矿产资源开发建设与施工在自然生态面上挖除了一块,使完整的自然生态面出现一个“空洞”,它就像宇宙中“黑洞”与“白洞”干扰和影响宇宙场一样,对自然生态及其环境有很大的破坏作用。矿山对生态环境是否存在“黑洞与白洞”效应？单个矿山生态环境有怎样的“黑洞与白洞”效应？矿山集群对生态环境有怎样的“黑洞与白洞”效应？矿山生态环境可以人为优化吗？对这些问题的探索与研究对矿山生态环境的总治理与保护具有重要意义。     

Irrigation impact on annual water balance of the oases in Tarim Basin,Northwest China

By taking the sum of annual precipitation and lateral water input (in which irrigation water withdrawal is the main component) for water availability, the Budyko hypothesis and Fu's formula derived from it was extended to the study of oases in the Tarim Basin, Northwest China. For both long‐term (multi‐year) and annual values on water balances in the 26 oases subregions, the extended Fu's formula was confirmed. Regional patterns on water balance on the 26 oases subregions were related to change in land‐use types due to increased area for irrigation. Moreover, an empirical formula for the parameter was established to reflect the influences of change in land use on water balance. The extended Budyko framework was employed to evaluate the impact of irrigation variability on annual water balance. According to the multi‐year mean timescale, variabilities in actual evapotranspiration in the oases were mainly controlled by variability in irrigation water withdrawal rather than potential evapotranspiration. The influences of variability on potential evapotranspiration became increasingly apparent together with increases in irrigation water withdrawal. Copyright © 2010 John Wiley & Sons, Ltd.     

Investing in low-carbon transitions: energy finance as an adaptive market

The amount of capital required to transition energy systems to low-carbon futures is very large, yet analysis of energy systems change has been curiously quiet on the role of capital markets in financing energy transitions. This is surprising given the huge role finance and investment must play in facilitating transformative change. We argue this has been due to a lack of suitable theory to supplant neoclassical notions of capital markets and innovation finance. This research draws on the notion from Planetary economics: Energy, climate change and the three domains of sustainable development, by Grubb and colleagues, that planetary economics is defined by three ‘domains’, which describe behavioural, neoclassical, and evolutionary aspects of energy and climate policy analysis. We identify first- and second-domain theories of finance that are well established, but argue that third-domain approaches, relating to evolutionary systems change, have lacked a compatible theory of capital markets. Based on an analysis of electricity market reform and renewable energy finance in the UK, the ‘adaptive market hypothesis' is presented as a suitable framework with which to analyse energy systems finance. Armed with an understanding of financial markets as adaptive, scholars and policy makers can ask new questions about the role of capital markets in energy systems transitions.

Policy relevance

This article explores the role of financial markets in capitalising low-carbon energy systems and long-term change. The authors demonstrate that much energy and climate policy assumes financial markets are efficient, meaning they will reliably capitalise low-carbon transitions if a rational return is created by subsidy regimes or other market mechanisms. The authors show that the market for renewable energy finance does not conform to the efficient markets hypothesis, and is more in line with an ‘adaptive’ markets understanding. Climate and energy policy makers that design policy, strategy, and regulation on the assumption of efficient financial markets will not pay attention to structural and behavioural constraints on investment; they risk falling short of the investment levels needed for long-term systems change. In short, by thinking of financial markets as adaptive, the range of policy responses to enable low-carbon investment can be much broader.     

“两类错误”谈论有益

本文是作者９３年发表一文［２］的补充，也是对本刊９８年第二期一文［１］的商榷。文中重述了两种决策的不同可靠性，即在否定虚假设Ｈ０时可以控制出错率到指定要求，使结论可靠；而接受Ｈ０则不易做到这点。对被检验假设的否定或接受均通过否定Ｈ０来获得是最好的。叙述了设置Ｈ０和备择假设Ｈ１的考虑。指出当前应用中的主要问题是对Ｈ０的不适当接受，即对第二类错误的忽视。重温一些基本概念等。     

大地构造和海陆起源的内波假说（Ⅲ）———内波动力机制及能源分析

莫霍面的起伏波动可看成壳—幔分层介质中的内波现象。引入推动地壳底部物质迁移的驱动力，用有限元数值方法模拟了莫霍面内波的运动，并探究了内波运动的动力来源及潮汐在内波生长中的作用     

地震可预测性研究的CSEP计划及其启示

地震可预测性是当前地震预测预报研究关注的前沿问题,对此问题的关注也代表了地震预测预报研究的现状,即采用更务实的态度、“循序渐进”地研究地震的可预测属性。本文介绍了国际上目前在地震可预测性研究中影响较大的“地震可预测性合作研究”（Collaboratory for the Study of Earthquake Predictability,CSEP）计划,通过对CSEP计划的历史背景、研究现状和技术特点的介绍,讨论了其对中国地震预测预报研究的可能的启发意义。     

Observational uncertainties in hypothesis testing: investigating the hydrological functioning of a tropical catchment

Hypothesis testing about catchment functioning with conceptual hydrological models is affected by uncertainties in the model representation of reality as well as in the observed data used to drive and evaluate the model. We formulated a learning framework to investigate the role of observational uncertainties in hypothesis testing using conceptual models and applied it to the relatively data‐scarce tropical Sarapiqui catchment in Costa Rica. Observational uncertainties were accounted for throughout the framework that incorporated different choices of model structures to test process hypotheses, analyses of parametric uncertainties and effects of likelihood choice, a posterior performance analysis and (iteratively) formulation of new hypotheses. Estimated uncertainties in precipitation and discharge were linked to likely non‐linear near‐surface runoff generation and the potentially important role of soils in mediating the hydrological response. Some model‐structural inadequacies could be identified in the posterior analyses (supporting the need for an explicit soil‐moisture routine to match streamflow dynamics), but the available information about the observational uncertainties prevented conclusions about other process representations. The importance of epistemic data errors, the difficulty in quantifying them and their effect on model simulations was illustrated by an inconsistent event with long‐term effects. Finally we discuss the need for new data, new process hypotheses related to deep groundwater losses, and conclude that observational uncertainties need to be accounted for in hypothesis testing to reduce the risk of drawing incorrect conclusions. Copyright © 2015 John Wiley & Sons, Ltd.