WAVE INTERACTION WITH PERFORATED CAISSON BREAKWATERS

The reflection coefficient of perforated caissons and the total horizontal forces acting on them were experimentally and numerically analyzed and discussed when wave propagates normally. To consider the viscosity effect of fluid and nonlinear action of waves on structures, the VOF (Volume Of Fluid) method combined with the k-ε turbulence model was used to simulate the interaction between waves and structures. Governing equations were solved with the finite difference method. Through 2D experimental study in the wave flume, the empirical relationship between the reflection coefficient of perforated caissons and the main affecting factors were obtained from the experimental data using the least square method. Also the correlation between the ratio of the total horizontal force acting on perforated caisson and the force acting on solid caisson and the main affecting factors were regressed from the experimental data.     

Efficient Liability Rules: Complete Characterization

Received May, 18, 2000; revised version received March, 19, 2001     

建设项目全寿命期综合计划体系

建立了建设项目综合计划的工作过程和工作内容。与传统的狭义的项目计划不同，建设项目全寿命期综合计划必须以全寿命期项目目标为主导，以项目的功能建设和运行为核心．包括设计、组织策划、实施方案和实施过程计划、运行策划等，它们之间有复杂的内在联系，具有高度的系统性。     

Multilateral Comparison of Cost Structures in the Input–Output Tables of Japan,the US and West Germany

This paper presents a multilateral comparison of relative levels and structures of costs of production in Japan, the US and West Germany. The analysis is carried out by using harmonized input–output tables, which are converted at US prices by using adjusted sectoral purchasing power parities. A new accounting methodology is derived from recent developments of index number theory, whereas the chosen multilateral comparison procedure gives results that are invariant with respect to the order of the pairs of countries examined.     

关于饱和软土地基堤坝边坡稳定分析总应力法的讨论

在饱和的软土地基上修筑堤坝,由于孔隙水压力不易准确测定,需采用“φ=0”的总应力法进行稳定分析。这一做法在国外已明确纳入设计规范,在国内工程界较少受到重视,导致过高地估计了安全系数。本文首先系统地回顾了临界状态土力学中的伏斯列夫强度理论,在理论上阐述了饱和软土地基快速填筑时采用总应力法的原因,同时引用了Bishop和Bjerrum、美国联邦公路局、美国陆军工程师团与我国水电水利工程边坡设计规范的相关条文,确认在饱和软土地基采用总应力法进行稳定分析的合理性。以花敖泡土石坝和拉哇水电站围堰为工程实例,分别采用对土的固结不排水剪的两种做法开展稳定性分析,结果表明,直接将土的固结不排水剪强度指标ccu与φcu作为填筑后的强度参数,将严重高估其安全系数。因此建议正在修订的碾压式土石坝与边坡设计规范增加相应条文,并期望引起工程界对这一问题的重视。     

信息技术在工程建设领域中应用的发展趋势--信息孤岛与信息集成

详细分析了国际上信息技术在工程建设领域中应用的发展趋势，主要包括三个方面的内容：首先是介绍信息技术在工程建设领域中应用的信息孤岛现象，然后引进并阐述总体项目系统的概念，最后则描述了基于信息模型的集成和基于Internet的集成等两种解决思路。     

Polyhedral Combinatorics in Combinatorial Optimization

Polyhedral combinatorics is a subarea of combinatorial optimization of increasing practical importance. It deals with the application of the theory of linear systems and linear algebra to combinatorial problems. The paper is not intended as a survey on polyhedral combinatorics but it reviews some of the main concepts and proof techniques.     

加入WTO后对我国产品质量管理的新思考

我国加入 WTO后对产品质量管理应有一个新的认识新的思考 ,本文研究了质量管理环境的变化 ,分析了世界质量管理的发展趋势 ,提出了质量管理内涵的扩展。鉴于质量管理已成为新世纪产品战略的制高点 ,针对质量管理的新认识提出质量管理保证体系的思考。     

数字经济对我国碳排放的影响研究

基于2013-2020年的30个省份数据构建面板数据模型,从碳排放总量和碳排放强度两个视角研究数字经济发展对区域碳排放的影响。研究发现：数字经济的发展有效地降低了人均碳排放量、碳排放增量与碳排放增速,数字经济与碳排放强度之间存在倒“U”形关系,数字经济与碳排放强度、边际碳排放强度的关系呈现区域性特征,在省域层面数字经济对边际碳排放强度的影响不存在明显的空间效应,数字经济对碳排放增长率的影响存在基于产业结构优化、人口集聚、城镇化的遮掩效应。     

城市径流总量控制指标分解及实现路径探索与实践

针对海绵城市径流总量控制目标,提出一种在城市规划体系中控制性详细规划和修建性详细规划阶段分解落实年径流总量控制率的方法。在控制性详细规划阶段分解径流总量控制指标时,分步骤先后确定各项低影响开发措施的面积率和下沉深度;在修建性详细规划阶段,配合径流总量控制指标分解结果,给出适宜的各项低影响开发措施的技术实施导则,以保证各单项指标的正确实施,并以某项目为例介绍了技术实施导则的构建方法。