基于能量守恒原理滑石板岩质边坡滑坡速度分析

针对云南省金沙江两家人水电站滑石板边坡拉裂区岩体,考虑滑坡体下滑过程中与坡下已有堆积体发生冲击碰撞的作用,基于能量守恒的原理,依据滑坡体锁固段储能方式的不同,计算了滑坡遽发时的速度,并且依次分析了滑坡下滑各阶段速度和加速度的变化,得出了滑坡体下滑的最终速度;考虑到初始启滑速度及其与坡下堆积体的冲击碰撞作用在预测滑坡的速度及堆积规模方面不可忽略,可为其他滑坡速度的预测和滑坡后减灾防灾综合分析提供参考.     

The cross-country impact of ECB policies: Asymmetries in – Asymmetries out?

Since its inception, the adequacy of the Eurozone to be an Optimal Currency Area has been questioned, and, along with it, the homogeneous transmission and impact of the monetary impulses across the member countries. We provide a comprehensive assessment of the transmission mechanism’s functioning, its symmetry, impact on target variables, and evolution, addressing all the questions which have remained unanswered in the previous literature, while adding evidence on the impact of non-standard policy measures. We do so by adopting a Bayesian Time-Varying Parameters FAVAR model that fixes the flaws present in past research. The empirical analysis shows that the occurrence of the two crises significantly altered policy transmission, with both the interest rate and credit channel being consistently affected. It also shows that while they provided effective stimuli to the economies, the unconventional measures implemented were not able to fix those asymmetries. Policy-wise, our findings suggest that authorities must push towards consistent innovation on the fiscal side, while gaining more confidence with regards to the new monetary toolkit.     

Macroeconomic Effects of Government Spending: The Great Recession was (Really) Different

We estimate the effect of government spending shocks on the U.S. economy with a time‐varying parameter vector autoregression. The recent Great Recession period appears to be characterized by uniquely large impulse responses of output to fiscal shocks. Moreover, the particularity of this period is underlined by highly unusual responses of several other variables. The pattern of fiscal shock responses neither completely fits the predictions of the New Keynesian model of an economy subject to the zero lower bound on nominal interest rates, nor does it suggest regular variation of fiscal policy effects depending on the state of the business cycle. Rather, the Great Recession period seems special in that government spending shocks had a strongly negative effect on the spread between corporate and government bond yields and a strongly positive effect on consumer confidence and private consumption spending.     

Living in an imaginary world that looks real

In the paper we show – using standard approaches, general equilibrium modeling and the assumption of complete rationality – that the macroeconomic environment is endogenous and is indeterminate. Specifically, it is argued – without resorting to sunspot type arguments – that microeconomic fundamentals do not suffice to characterize the economy at the macro level. In particular, we show how perceptions of rational agents of the workings of the economy (a) shape the environment, (b) affect the environment sufficiently to ensure that rational economic agents find the observed environment consistent with their beliefs even though it is not. As a by-product, we illustrate that endogenous macro uncertainty can arise as an outcome if rational economic agents whose expectations are anchored on endogenous variables expect them to arise. Finally, we show that systematic errors can persist indefinitely under rationality.     

预应力钢结构拉索参数的研究进展

拉索参数的确定是预应力钢结构的关键问题之一。本文总结了预应力钢结构中拉索关键参数的研究状况,着重分析了存在问题和研究趋势,并结合竖向预应力钢结构体系简要介绍了一种新的拉索参数确定方法。     

弹性材料3J21微槽的微细电解加工研究

为解决高硬度、高强度弹性材料3J21微结构的成形加工难题,在分析进给速度、微细电极、加工电压、电解液浓度等工艺参数对弹性材料3J21加工精度的影响规律基础上,进行了微槽的微细电解铣削加工工艺实验,加工出了宽度约为40μm的微槽,具有较好的加工质量。     

浅析高压气流引射防尘雨幕在煤矿安全生产中的应用

矿尘始终是困扰井下安全生产的最大因素之一。长期从事采掘和粉尘作业环境的职工,易引起尘肺病,在高度粉尘作业场所工作的职工,视线易受阻挡,操作中易造成人身事故。其最大危害在于煤尘具有爆炸危险的矿井,煤尘在一定的条件下易发生煤尘爆炸事故,给矿井安全生产带来很大威胁。     

车削细长丝杆的技术应用

车细长轴是车削的难点,而加工细长丝杆就更困难,车削细长丝杆中根据工艺要点,抓住跟刀架与中心架的使用。解决工件的热度形伸长及合理选择几何参数,问题就可解决。     

Bayesian robustness modelling using the O‐regularly varying distributions

The theory of robustness modelling is essentially based on heavy‐tailed distributions, because longer tails are more prepared to deal with diverse information (such as outliers) because of the higher probabilities on the tails. There are many classes of distributions that can be regarded as heavy tails; some of them have interesting properties and are not explored in statistics. In the present work, we propose a robustness modelling approach based on the O‐regularly varying class (ORV), which is a generalization of the regular variation family; however, the ORV class allows more flexible tails behaviour, which can improve the way in which the outlying information is discarded by the model. We establish sufficient conditions in the location and in the scale parameter structures, which allow to resolve automatically the conflicts of information. We also provide a procedure for generating new distributions within the ORV class.     

Capabilities as shift parameters for the outsourcing decision

In this paper, we argue that capabilities serve as shift parameters that result in a change in the critical value of asset specificity at which firms switch from in‐sourcing to outsourcing. Capabilities have two effects: they result in a change in firm production costs and in firm governance costs relative to the market. As a result, the frontier at which market governance gives way to firm governance shifts. Three factors that produce such shifts are the value, rarity, and inimitability of capabilities employed in firm processes. Considered as shift parameters, the effect of capabilities integrates seamlessly into transaction costs reasoning and is not a competing view of firm governance. We demonstrate these arguments empirically using a sample of 180 information systems sourcing decisions. Copyright © 2013 John Wiley & Sons, Ltd.