低热硅酸盐水泥在特高拱坝中的应用

针对中热硅酸盐水泥在水化过程中释放的热量相对较多,难以满足特高拱坝温控防裂要求的问题,本文从研究低热硅酸盐水泥性能的角度出发,结合其在等特高拱坝中的应用情况,得出:相比于中热硅酸盐水泥,低热硅酸盐水泥在水化过程中释放的热量相对较小,有利于控制混凝土最高温度和温升速率,低热硅酸盐水泥的综合抗裂性能更好.目前,在溪洛渡、白鹤滩等特高拱坝应用低热硅酸盐水泥后并未发现任何裂缝,为在其他300级特高拱坝建设中使用低热硅酸盐水泥提供依据.     

Impulse response function analysis of the impacts of land value-added tax policy on government performance

In this study, an epsilon-based network data envelopment analysis is employed to construct assessment mechanisms for government performance. Moreover, performance indicators of two dimensions of tax collection efficiency and financial effectiveness are measured. We propose a vector autoregression model in which all economic variables are regarded as dependent variables to address the disadvantages of traditional regression model. The conclusions are as follows: (a) measures of tax collection efficiency deteriorated, whereas those of financial effectiveness improved. (b) In an impulse response analysis of the model, an increase in government-published land values produced significantly increased tax collection efficiency.     

Volatility forecasting: long memory,regime switching and heteroscedasticity

In this article, we account for the first time for long memory, regime switching and the conditional time-varying volatility of volatility (heteroscedasticity) to model and forecast market volatility using the heterogeneous autoregressive model of realized volatility (HAR-RV) and its extensions. We present several interesting and notable findings. First, existing models exhibit significant nonlinearity and clustering, which provide empirical evidence on the benefit of introducing regime switching and heteroscedasticity. Second, out-of-sample results indicate that combining regime switching and heteroscedasticity can substantially improve predictive power from a statistical viewpoint. More specifically, our proposed models generally exhibit higher forecasting accuracy. Third, these results are widely consistent across a variety of robustness tests such as different forecasting windows, forecasting models, realized measures, and stock markets. Consequently, this study sheds new light on forecasting future volatility.     

跨入新世纪的石油、能源和经济发展记"2001·北京--世纪石油论坛"

“2001·北京——世纪石油论坛”于10月23～24日在北京举行。论坛由国家经贸委主办,中国石油天然气集团公司、中国石油化工集团公司、中国海洋石油总公司和中国化工进出口总公司协办,国家经贸委经济研究中心和3E信息咨询公司承办。这是在“9·11”恐     

征占用林地生态公益林价值评估的探讨

国家重点工程建设常常需要征占用生态公益林的林地.在进行补偿时,如何评估此生态公益林林木的价值呢?不同评估方法,其评估价值有很大的差异.本文将征占用林地的天然生态公益林的评估价值定为以培育中径材为目标的同类林分用材林评估价值的三倍至五倍.作者认为这样的评估价值最接近现行市场交易价,能够为征占用单位和林木所有者所接受.     

“济南就是我的家”——济南外商服务月侧记

5月下甸,又是一个烈日炎炎的夏日,杰克·史密斯先生按照惯例早早就起了床。但与平日不同的是,作为公司行政总监的他并没有直接去自己的办公室开始一天的工作,而是手拿一份查体表来到了济南市中医院,成为济南市第二届外商服务月活动中的首项内容“为济南市外企员工查体活动”的第一批受益者。在经过非常细致的心、脑、血液等项目的     

加大关键性领域改革力度奠定经济发展体制基础

2005年,是我国改革与发展继往开来的重要年份。我国将要完成“十五”规划提出的各项主要任务,并向全面建设小康社会的第二个五年迈进;同时,加入世贸组织的三年过渡期基本结束,开始跨进范围更广、层次更深的开放型经济。2005年能否保持经济平稳较快增长,不仅关乎年度宏观经济稳定,而且涉及能否为“十一五”期间奠定坚实的、可持续的基础,甚至将影响到整个“十一五”时期的经济走势。因此,今年经济工作不仅应实现年度宏观调控的四大目标(经济增长、物价稳定、就业增加和国际收支基本平衡),而且还要为延长经济上升期创造有利条件。一、目前我国…     

诚实守信是构建和谐社会的前提--中国社会信任危机成因分析

诚实守信是构建和谐社会的前提.信任危机是当代中国构建和谐社会的最大障碍,其产生于社会的转型变革,形成于社会制度性体制的缺失,加深于人的存在危机.而消除的唯一途径只能是积极地构建一种新型的社会信任保障制度体制,以强化人们对制度性承诺的信任理念意识,为构建和谐社会创造条件.