大朝山水电站地下洞室安全监测资料分析

大朝山水电站引水发电系统为地下工程，根据各项安全监测物理量的主要观测成果，对最大观测值分析其对工程的安全影响，为保证其安全运行具有重要意义。为此，分别对大朝山水电站的主要地下建筑物，包括压力引水隧洞、地下厂房、尾水调压室的最大观测值进行了分析研究，并提出了一些建议，有较大的参考价值。     

Flocculation morphology: effect of particulate shape and coagulant species on flocculation.

Flocculation morphology is a new concept that investigates the morphological characteristics of colloidal particles and coagulants in water during the flocculation process, and the influence that these characteristics have on flocculation process efficiency. This paper is a summary of advances in research on this topic over several years. Morphological characteristics of colloids in natural waters and different kinds of hydrolysed coagulants are investigated, and their effect on colloid stability, flocculation kinetics and efficiency is analysed. It is confirmed that the traditional theory has some deviations in coagulation of nonspherical particles, and these deviations are revised by the flocculation morphology model. Flocculation morphology can not only promote research about flocculation theory, but also instruct the production, application and flocculation control. It can be foreseen that more progress will be made in research and application of flocculation morphology in the near future.     

论生态经济系统稳态

本文论述了生态经济系统非平衡稳定态的概念、特性及其实现的途径。指出生态经济系统稳态,是非平衡的,对外全面开放、激烈竞争、充分利用涨落作用,对内协同、有序、自组织、自适应、自催化、且有非线性作用和支配性、良性运转、进展演替的耗散结构状态。生态经济系统平衡的提法应被生态经济系统稳态的概念所取代。     

浅谈集邮业务的个性化服务

文章回顾了我国集邮业务的历史演变和发展状况,分析了集邮业务的业务结构变化及其所带来的经营方式和经营策略的变化,提出个性化服务是集邮业务的发展方向,论述了个性化服务的社会需求、市场前景和发展空间,探讨了个性化服务的发展措施及经营思路。     

Pricing options using implied trees: Evidence from FTSE‐100 options

Previously, few, if any, comparative tests of performance of Jackwerth's ( 1997 ) generalized binomial tree (GBT) and Derman and Kani ( 1994 ) implied volatility tree (IVT) models were done. In this paper, we propose five different weight functions in GBT and test them empirically compared to both the Black‐Scholes model and IVT. We use the daily settlement prices of FTSE‐100 index options from January to November 1999. With both American and European options traded on the FTSE‐100 index, we construct both GBT and IVT from European options and examine their performance in both the hedging of European option and the pricing of its American counterpart. IVT is found to produce least hedging errors and best results for American call options with earlier maturity than the maturity span of the implied trees. GBT appears to produce better results for American ATM put pricing for any maturity, and better in‐sample fit for options with maturity equal to the maturity span of the implied trees. Deltas calculated from IVT are consistently lower (higher) than Black‐Scholes deltas for both European and American calls (puts) in absolute term. The reverse holds true for GBT deltas. These empirical findings about the relative performance of GBT, IVT, and Standard Black‐Scholes models are important to practitioners as they indicate that different methods should be used for different applications, and some cautions should be exercised. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:601–626, 2002     

“以大代小”火力发电企业的价值评估

在火力发电行业进行“以大代小”技改工程后,为了解决“一厂多制”的问题,需要对完成“以大代小”技改项目后所产生的新发电企业进行价值评估。在评估过程中,应明确价值类型,充分考虑租赁的资产、委托运行维护管理等要素对企业价值的影响。本文对大型火电发电机组的生命周期进行了分析,并在此基础上提出了对“以大代小”新火力发电企业进行收益测算的“三阶段测算模型”。     

造林整地排水产生水土流失及其防止措施

造林整地排水产生水土流失及其防止措施［英］Ｐ．Ａ．ＣａｒｔｉｎｇＭ．Ｓ．ＧｌａｉｓｔｅｒＴ．Ｐ．Ｆｌｉｎｔｈｅｍ１引言英国高地造林整地的常规方法是采用顺坡和横坡开沟相结合的办法进行翻耕排水。现已制订有森林排水网路的设计准则及河道管理准则，遵循这些准则...     

The transformation of aluminium species in the processes of coagulation, sedimentation and filtration.

The aluminium toxicity is closely related to aluminium species. In this work aluminium was fractionated into seven forms: Al(T), Al(Sus), Al(C + S), Al(S), Al(C), Al(O) and Al(I). Four Al-based coagulants and simulated raw water were used in the laboratory to investigate the aluminium transformation in coagulation, sedimentation and filtration processes. It is the use of Al-based coagulants that contributes more to the increase of the residual aluminium for the low-turbidity raw water, while the Al-based coagulants, especially the polymeric aluminium coagulants, work to remove the aluminium from the high-turbidity raw water. In the case of traditional coagulants, the increase of the turbidity or the dissolved organic carbon (DOC) concentration in the raw water results in a high concentration of Al(C + S). The removal rate of aluminium species in the filtration process is not only related to its size: RAl(Sus) > RAl(C+S), RAl(C) > RAl(S), but also to the physicochemical properties of aluminium species and filter. For the kaolin-polyaluminium chloride system, a lower removal rate of aluminium species results is due to the complexation of humic acid and aluminium species.