DYNAMIC RESPONSE IN ESTUARIES-AN ANALYTICAL MODEL

A simple analytical model is developed to interview the general features of theestuarine responses induced both by ocean tides and by low-frequency coastal fluctuations andwind forcings.Model estuary is assumed ideally with constant depth and linearly varyingbreadth.The results indicate that the effects of bottom friction coefficient,the water depth andthe breadth variation parameter on the estuarine response field virtually reflect the difference ofthe energy accumulation,transformation and dissipation in estuaries,It is found by comparisonthat there are obvious differences between tidally-induced and low-frequency forcing inducedestuarine variations.For tidal response,bottom friction is a very important factor to affect theresponse magnitude,while for low-frequency response this effect becomes negligible.Thus amore simplified model for low-frequency estuarine response is produced,which gives morestraightforward view to the response characteristics.Moreover,from the model solutions wededuce a general qualification for the estuarine resonance and discuss the relation between theresonance frequency and the estuarine geometry.     

PROBABILITY DISTRIBUTION OF IN-LINE WAVE FORCES ON A PILE IN IRREGULAR WAVES

The probability distribution of in-line wave forces on a pile can bemathematically summed up to that of a theory and the assumption of wave period being constantare used and the above probability distribution is simplified to that of a single dimentsionfunction.The probability density functions of the peak values of total wave forces on a wholevertical pile in irregular waves are derived from that of wave height which is the Rayleighdistribution(deep water wave)or the Kerohovski distribution(shallow water waves)on the baseof the Morison Equation.The identification with experimental data shows that suchsimplification is successful.These distributions are compared with Weibull distribution andRayleigh distribution and the result shows that the shallow water distribution of wave forcesobtained here is the best one and can be used in practice.     

改革的努力为何会失败

一些企业的改革是非常成功的,一些是极为失败的,大部分公司介于两者之间。但它们总是本能地向不太成功的那个方向倾斜。     

成功的理财规划不分国界

请选择临时遗忘--忘记你的出生地、母校、居住地,工作单位和国籍,一起来看下面所说的这些情况以及这个人你是否熟悉.相信最后的结论将让你大吃一惊.     

Getting real about virtual commerce

In its first generation, electronic commerce has been a landgrab. Space on the Internet was claimed by whoever got there first with enough resources to create a credible business. It took speed, a willingness to experiment, and a lot of cybersavvy. Companies that had performed brilliantly in traditional settings seemed hopelessly flat-footed on the Web. And despite their astronomical valuations, the new e-commerce stars have appeared to be just as confused. Many have yet to make a profit, and no one has any idea when they will. Now, the authors contend, we are entering the second generation of e-commerce, and it will be shaped more by strategy than by experimentation. The key players--branded-goods suppliers, physical retailers, electronic retailers, and pure navigators--will shift their attention from claiming territory to defending or capturing it. They will be forced to focus on strategies to achieve competitive advantage. Success will go to the businesses that get closest to consumers, the ones that help customers navigate their way through the Web. Indeed, the authors argue, navigation is the battlefield on which competitive advantage will be won or lost. There are three dimensions of navigation: Reach is about access and connection. Affiliation is about whose interests the business represents. And richness is the depth of the information that a business gives to or collects about its customers. Navigators and e-retailers have the natural advantage in reach and affiliation, while traditional product suppliers and retailers have the edge in richness. The authors offer practical advice to each player on competing in the second generation of e-commerce.     

如何在庞氏骗局中挽回损失

臭名昭著的金融诈骗案--伯纳德·麦道夫案和艾伦·斯坦福案等庞氏骗局在全球金融界引发地震效应,并余波不断.对受骗入局的投资者来说,如何尽可能减少损失并通过退税索取等方式进行弥补,在美国是近来受到关注的话题之一.