Analysis of Existing Problems with Management of Construction Projects Bidding and Solutions to the Problems

Bidding is a key link during the implementation of a construction project.For the same construction project,there are usually multiple construction companies bidding together to obtain the right to contract for the project.However,there are still various irregularities in the bidding stage.This article analyzed the above problems and proposed a management strategy for the optimization of bidding,looking forward to improving the quality of bidding management of construction projects,solving various illegal bidding problems,and purifying the environment of bidding management.

Research on the Complication of Documents for Largescale Infrastructure Projects in Colleges and Universities

With the practical experience of constru-ction bidding documentation,for example,in view of the large infrastructure project construction in colleges and universities bidding documents for the main body,the construction technology,qualification,performance requirements,bill of quantities,the terms of the contract set aspects were discussed,and put forward practical measures and methods,for similar project construction bidding document preparation to provide certain reference.

基于复炸油的微藻采收方法及其作用机理研究

随着现代能源发展,使用清洁、可再生的新能源逐渐成为解决环境和能源问题的主要思路。在众多新能源中,生物质能不仅可以降低温室气体排放,还具有良好的可再生特性,小球藻作为一种理想的制备生物质能,不仅生长速度快,且油脂含量高。但因其密度与水接近而导致采收困难,这也成为制约微藻产业发展的主要原因之一。以浮珠浮选法为基础,提出一种以复炸油乳化液为浮珠的浮选法用于采收小球藻,即将复炸油与纯水按照一定比例在乳化剂作用下充分乳化,并结合响应面法,筛选出影响采收率的显著因素为p H、搅拌速率和原藻体积占比;影响富集比的显著因素为pH、浮选时间和原藻体积占比;同时结合多目标优化结果得出最佳采收率和富集比分别为92.79%和2.07%。以小球藻为研究对象,获得复炸油采收微藻机理:微藻与浮珠在铝盐的作用下,通过吸附电中和及桥接作用形成聚合体;微藻与浮珠首先在搅拌提供的动能作用下相互靠近,之后在范德华力作用下发生黏附,在14.73 nm时引力作用达到临界值。在最佳采收条件下,处理成本仅为4.38元/吨,降低采收成本和能耗的同时也为复炸油再利用提供了一种新方法。