Competitiveness of Inexperienced and Experienced Contractors in Bidding

This paper tests the assertion that experienced contractors are more competitive than inexperienced contractors by measuring the effect of experience on bidding competitiveness for building contracts procured by a regular client. Contractors are grouped into experienced and inexperienced contractors, and two levels of contractors’ experience are identified: (1) bidding experience only and (2) bidding plus construction experience. Results of two-sample t tests show that experienced contractors are more competitive than inexperienced contractors. Contractors’ competitiveness in respect of school contracts and other contracts are further compared in evaluating the relationship between the project type and experience effect. Experienced contractors are, on average, more competitive in competing for school contracts. It emerges that the factor of project type familiarity amplifies the experience effect. A comparison of experienced contractors’ competitiveness in bidding for (1) new building works and (2) alteration and extension works shows that the effect of experience would be more significant when contract works packages are highly standardized.     

Carbon mineralization from composts and food industry wastes added to soil

We have studied the short term C mineralization of six wastes from important food industries, one sludge from a biogas plant and three composts. All the wastes were characterized chemically and fractionated according to the Van Soest method. The fresh wastes were incubated under controlled environment conditions to determine the C mineralization rate. Based on first order mineralization kinetics, we calculated the hypothetical amount of stable C in the wastes as the amount of C that would not be mineralized within one year under field conditions. The percentage of stable organic C in the organic matter was in general much larger in the composts than in the other wastes, but when expressed on dry matter, the non-composted wastes had comparable or larger amounts of stable organic C than the composts and have a considerable potential for supplying organic matter to soils, and hence for C sequestration. The amount of stable organic C could best be predicted by the total N content of the wastes (R _a ² = 0.855), whereas the results of the fractionation had very little predictive power, probably due to problems related to the high ash content of some of the wastes. An index that combined stable organic C and N and P content in the wastes was calculated to assess possible limitations for applying these wastes in agriculture. Under current nutrient legislation in Western Europe, a number of these wastes will only be usable in small amounts, but these and other food industry wastes could still prove to be valuable soil amendments in nutrient poor situations, for increasing soil organic C content and supplying nutrients.     

Renewable energy in competitive electricity markets

A restructured electricity system may undervalue renewable energy. We remain wary of unregulated markets, but urge the renewable energy community to begin considering how they could adapt to increasing customer choice.     

努力攀登科技高峰 为把石化工业建成支柱产业多做贡献

概述中国石化总公司成立以来所取得的重大科技成果。     

试论入世对中国氧化铝工业的影响

随着中国加入WTO，给企业带来了发展的机会，也带来了挑战。本文通过对中国氧化铝工业的现状及其与世界水平的差距的分析，阐明了入世后随着关税等贸易壁垒的消除，国内、国际市场的竞争更加激烈。明确指出了我国氧化铝工业面临的多重挑战，以及给中国氧化铝工业带来的机遇。强调充分利用WTO给企业创设的权利，借入世东风，促进我国氧化铝工业快速发展，只有发展，中国氧化铝工业才有出路。     

化工企业环境因素的评价

化工企业环境因素评价是建立环境管理体系的核心任务，化工企业生产过程的特点决定了其环境因素数量多、环境影响大、识别评价难、控制难度大。本文介绍了化工企业环境因素评价的技术方法和过程，可以为提高环境因素评价的科学性、客观性和充分性提供参考。     

我国秸杆人造板工业若干问题之我见

阐述我国发展秸秆人造板工业的必要性和可行性，介绍了秸秆人造板的种类、我国秸秆人造板工业发展现状和发展过程中应注意的问题，并对今后的发展提出了建议。     

催化裂化烟气转硫脱氮和助燃三功能催化剂FP-DSN的工业应用

烟气转硫、脱氮和助燃三功能新型催化剂FP DSN在中国石油天然气股份有限公司锦西石化分公司 1.4Mt/a重油催化裂化装置的工业应用表明 ,此种以La ,Ce ,Sr和Co等元素的氧化物或复合物为活性组分的催化剂 ,在其用量为催化裂化催化剂总藏量的 1%～ 2 %的情况下 ,有较强的脱除烟气中SOx 和NOx 的能力 ,大大减轻了烟气对反应器壁的腐蚀 ,减少了污染气体的排放 ,同时有CO助燃效果 ,装置可不使用其他专门的助燃剂。应用试验时 ,再生器烟气中SOx 的平均脱除率达 72 .85 %,NOx 的平均脱除率达 85 .90 %。该催化剂的使用对催化裂化产品的分布和质量无明显影响。该剂的应用为装置带来了可观的经济效益。     

全球化的挑战——再论面对WTO的中国暖通空调业

2001年11月，中国在历时15年之后终于加入了世贸组织。针对中国暖通空调业从体制、观念和人才培养上如何适应经济全球化的形势，首次提出个人观点，并对暖通空调业如何发挥自身优势、参与国际竞争提出了建议。     

氮肥工业与21世纪的生物能源

介绍近年来美国生物能源的开发进展情况及其先进的支撑系统，提出如何使我国氮肥工业在发展我国生物能源中起促进作用。