激光生物热作用的一维瞬态温度分布规律研究

采用数学物理方程的定解求法解一维热传导偏微分方程 ;讨论结果的物理意义 ,与相关实验作对比分析。结果表明 ,激光热源在一维生物组织空间引起的温升一般随时间呈指数形式增大 ;随激光照射处的距离呈指数形式减少。     

Calculation Model of Mass Action Concentration for Mg-Al, Sr-Al and Ba-Al Melts and Determination of Their Thermodynamic Parameters

Basedonthermodynamicpropertiesofdifferentkindsofmetallicmelts[1 5] ,ageneralunderstandingofcoexistencetheoryforstructureofmetallicmeltscanbeachieved .ThispaperaimsatdeterminationofthermodynamicparametersofMg Al,Sr AlandBa Almetallicmeltsbycalculationwithmassactionconcentrationsmodel.Therearesomeresearchworksaboutthephasediagramofthesebinarysys tems[6 ,7] ,dataofactivityinthesemelts[8 13 ] aswellasthethermodynamicparametersofSr AlandBa Almelts[12 ,13 ] .Thesedataareusedtobuildcalculationmod…     

在役结构抗震评估地震作用取值研究

本文阐述了研究在役结构评估用地震作用取值的必要性。并提出了评估基准期和评估烈度的概念；根据现有的烈度分布函数。建立了考虑不同评估基准期和不同地区地震危险性差异的地震烈度概率模型；按照等超越概率原则，提出了确定在役结构抗震评估用地震烈度的取值标准和方法，并给出了强度验算和变形验算地震作用参数的具体取值；对服役期间已遭遇过地震的结构。提出了烈度调整建议，为在役结构的抗震安全性评估提供了合理可行的荷载标准。     

Remedial measures to control seepage problems in the Kafrein dam, Jordan

The Kafrein dam, 480 m long and 30 m high, is located on the Wadi Kafrein, a few kilometres from the active Jordan Valley fault. The Jordan Valley Authority proposed raising the crest of the existing dam by approximately 7 m and extending the length of the embankment to 554 m, in order to increase its storage capacity by 6 million m³ to a total of 8.5 million m³. The paper discusses the likelihood that existing seepage problems will be exacerbated when the dam is raised and proposes some remedial actions to increase the safety of the dam and minimise both the amount of seepage and any adverse effects. Electronic Publication     

砖混结构房屋顶层端部墙体开裂成因再认识

雨水侵入基础下的地基,改变了土体结构,从而产生房屋端部地基土与中部地基土的不均匀性,这种不均匀性等同于在端部基础上作用了附加应力,使房屋端部的整体弯曲下沉,砖混结构房屋顶层端部窗洞削弱了此处的整体性,在抵抗下沉的过程中产生附加应力应变,从而导致窗洞周围形成裂缝,这一结论揭示了此类裂缝是由温度变形原因之外的另外成因。     

Coping With Deficits and Losses in Later Life: From Compensatory Action to Accommodation.

Processes of coping with performance deficits in different domains of functioning were investigated in a 4-year longitudinal study involving a core sample of 762 participants (initial age range: 58-81 years). Compensatory efforts to counteract functional impairments were found to increase up to the age of 70 years. Above that age, a decrease in compensatory efforts was observed that was linked to a decrease in the availability and efficiency of action resources. Contentment with actual performance levels remained stable across the entire age range of the study. Stability of self-evaluations was found to depend on adjustment of personal standards: Scarce action resources were accompanied by a lowering of personal comparison standards and by a downgrading of the importance of the respective domains. Accepting more lenient standards of comparison was found to buffer negative effects of performance deficits on contentment with performance among the older participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

商品住宅设计中应处理好的几个关系问题

商品住宅的设计要达到好的效果,必须在设计的建设过程中处理好几方面的关系。建筑师既要与开发商做好前期沟通工作,获得共同的价值取向,又要与各种的工程师通力合作,在技术价值观上获得统一,这样才能在住宅设计过程中求精创新,设计出好的作品。     

动态效应在电渣离心铸造中的应用

研究了电渣离心铸造过程中采用动态效应时合金的凝固现象，结果表明，周期性改变铸模旋转速度，使结晶前沿得到适当的切向加速度，可以细化铸管组织、显著提高其高温性能和使用寿命，当切向加速度为０．１５６ｍ／ｓ＾２，电渣离心铸造耐热合金炉管的高温性能最好，使用寿命最长。     

龙羊峡和刘家峡水库联合调度问题探讨

龙羊峡水库投运以来，遭遇到了罕见的连续枯水年，电网在获得“水火互浊”便得的同时，更经受了水电站“靠天吃饭”所造成的困难，通过分析天然径流及水库特性，对近年来的水库调度作了初步总结和分析，论述了水库调度方法必须要适应水库性能，对龙羊峡，刘家峡两水库进行联合调度必须以水库调度图为基本依据，电网及其他部位的用水要服从水库设计规定，以保持水库的正常运行状态。