水源涵养内涵及估算方法综述

水源涵养和生态系统过程与人类生产生活紧密相关,深入研究水源涵养对维持生态系统健康和人类社会可持续发展至关重要,对促进人与水和谐共生具有指导意义。随着对水源涵养研究与应用的深入,水源涵养内涵逐渐丰富,评估方法愈加多样,但以往的研究中水源涵养定义模糊,缺乏对各种评估方法的综合性对比分析,因此急需明确界定水源涵养内涵,分析各种估算方法的适用性。采用文献分析法系统梳理水源涵养研究历程,将其划分为认识与萌芽期、理论发展期、定量计算和模型综合评估等4个阶段;从定义、水量与功能等3个方面明确界定水源涵养内涵,从原理、时空尺度、适用范围及优缺点方面对已有水源涵养量估算方法进行对比和分析,并展望水源涵养研究的未来发展方向。     

围岩一支护动态系统稳定性判据——变形速率比值判别法

本文以围岩稳定性判据现有研究成果为基础,总结若干新奥法软弱围岩隧道工程监控量测的经验教训,针对现行判据在现场往往难以掌握应用的问题,提出“围岩与支护动态系统稳定性判据(变形速率比值判别法)”,给出工程实例,并以开放的复杂巨系统方法论为指导,试图从原理和方法上加以阐明。     

Heterogeneity in Economics

This paper argues that heterogeneity of agents’ characteristics plays a fundamental role in the economy and should do so in economic models. Three aspects are considered. Firstly the notion that assuming heterogeneity was a solution to the problem posed by the results of Sonnenschein Mantel and Debreu is considered and it is suggested that the more pragmatic approach adopted by Hildenbrand is likely to be more productive. Next the role of adaptation and evolution which necessarily involve variety or heterogeneity is examined. It is suggested that heterogeneity will persist since agents will only slowly learn to adapt and that in the meantime the environment will change. Lastly the role of heterogeneity in financial markets is examined. It is suggested that heterogeneous and varying expectations may account for many of the stylised facts which do not seem to be consistent with the standard financial markets model.“Variety is the spice of life”     

倒排计划和安全库存计划相结合的物料需求计划与控制方法--用于非定型产品制造业

介绍生产非定型产品企业的物料需求计划与控制的原则，根据制造业企业的物料整体逻辑流程图，找出影响物料需求计划与控制的各个因素，提出合理实效的需求计划与控制方法并以实例加以说明。     

坡向与斜坡稳定性的关系研究

文章简要介绍了滑坡分布特征,并在此基础上系统分析了坡向(阳坡与阴坡)与斜坡稳定性之间的关系,表明坡向也是诱发滑坡的因素之一,一般而言,阳坡易发生滑坡灾害。     

两端铰支二跨梁的临界压力分析

推导出了两端铰支二跨梁的临界压力表达式，具体导出了两跨长度相等情况下的临界压力计算公式，此公式与等长度的单跨梁的欧拉临界压力公式的形式完全相同。     

砼偏心受压构件折减系数计算公式的几个注解

根据弹性稳定理论,对当量弯矩折减系数Cm的计算公式的应用范围作了进一步说明,并确定了其应用范围.同时,考虑砼偏心受压构件的弹塑性性能,推导了新的公式,与原有的公式比较,具有同样的精确度,由于考虑了砼材料的变形模量,因此其结果更接近实际.     

我国铜市场形势分析与发展前景预测

90年代,与世界铜矿资源总量相比,我国铜资源是比较贫乏和短缺的,这种状况将延续到下一个世纪。本文对我国近五年的铜金属市场进行了跟踪分析,对进出口进行了统计和形势分析,并对铜产品的市场价格和产量进行预测,提出了研究对策和建议。     

未来中国经济仍有较强稳定性

未来中国经济的稳定性是全社会关注的一个焦点。从国际、国内形势看，中国经济至少在未来5年内具有较强的稳定性。     

Sovereign and bank dependence in the eurozone: A multi-scale approach using wavelet-network analysis

This study establishes time–frequency networks of sovereign and bank contagion in the eurozone over the period 2009–2021. By applying discrete wavelet transformation, daily CDS premia of sovereigns and systemically important banks are decomposed into multi-horizon components to specify directed and dependence-weighted networks. Dynamic analysis shows that the network connectivity and the strength of the dependencies are significantly lower after the introduction of the European Banking Union in 2014. While the strength effect is pronounced across all time horizons, the network connectivity only reduces in the short and medium run. This provides evidence that the new regulatory framework promotes financial stability but is more effective in the short and medium horizons. The consideration of the COVID-19 pandemic as a real-life stress test confirms these findings as the strength of the dependencies keeps at significantly lower levels.