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内部回收率查算图的制作与应用
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作者 张炳勋 郭胜 刘世平 《技术经济》 1987年第Z1期41-45,共5页
一、前言内部回收率法简称回收率法或收益率法,是动态经济学中的主要经济效果分析方法之一。本法的基本概念是:工程在分析期内的净收益用于还本付息及提供经济效益。当净收益只能还本付息,即经济效益等于零时的资金折算率即回收率。因... 一、前言内部回收率法简称回收率法或收益率法,是动态经济学中的主要经济效果分析方法之一。本法的基本概念是:工程在分析期内的净收益用于还本付息及提供经济效益。当净收益只能还本付息,即经济效益等于零时的资金折算率即回收率。因而在其它条件相同,分析期内的净收益愈大,则回收率愈高。用现值法或年金法都可推求回收率。由于在作工程方案的分析比较时,本法可不必预定资金折算率,故在工程基建资金来源未定时,有其优越方便的特点,因而本法得到广泛的应用。 展开更多
关键词 内部回收率 回收率法 分析期 动态经济学 折算率 现值 年金 分析方 工程基建 工程方案
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用什么方法合理分配建设资金较好? 被引量:1
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作者 周之豪 《水利经济》 1988年第3期58-59,共2页
问题:我们用你刊介绍的内部经济回收率法和净现值比法在竞争项目间分配建设资金时,两种方法得出的结果不一致,这是为什么?遇到这种情况时,如何选定分配方案为好?
关键词 回收率法 净现值 内部经济 待分配 周之豪 施国庆 组合方案 多郎 水利经济 小排列
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高青县南部地区地热资源评价 被引量:4
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作者 周亚红 郝凌霄 陈康 《南水北调与水利科技》 CAS CSCD 北大核心 2014年第3期24-28,共5页
高青县南部地区的热储层主要为新近系馆陶组和古近系东营组。通过野外勘察和室内分析结果,选取合理的计算参数,建立了热储概念模型。在此基础上,分别利用热储法、回收率法对研究区内的地热资源量和可利用地热资源量进行计算评价,同时利... 高青县南部地区的热储层主要为新近系馆陶组和古近系东营组。通过野外勘察和室内分析结果,选取合理的计算参数,建立了热储概念模型。在此基础上,分别利用热储法、回收率法对研究区内的地热资源量和可利用地热资源量进行计算评价,同时利用体积法、最大降深法对地下热水的储存量和允许开采量进行了计算评价。结果显示,研究区地热资源量总量为2.516 1×1018J,折合标准煤8.587×107t;回收率采用25%,计算得可利用地热资源量为6.290×1017J,折合标准煤2.147×107t;地下热水储存量为6.542×109 m3,其中允许开采量为3.833×106m3/a(开采年限为100a)。 展开更多
关键词 热储层 地热资源 热储 回收率法 最大降深 体积
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Germanium separation and purification by leaching and precipitation 被引量:4
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作者 Saeid Bayat Sajjad Aghazadeh +2 位作者 Mohammad Noaparast Mahdi Gharabaghi Behrooz Taheri 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2214-2222,共9页
In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, ... In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively. 展开更多
关键词 experimental design di-ammonium oxalate monohydrate GERMANIUM leaching tannic acid
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Optimal control of cobalt crust seabedmining parameters based on simulated annealing genetic algorithm 被引量:2
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作者 夏毅敏 张刚强 +2 位作者 聂四军 卜英勇 张振华 《Journal of Central South University》 SCIE EI CAS 2011年第3期650-657,共8页
Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head (the feed speed, the axes height of collecting hea... Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head (the feed speed, the axes height of collecting head, and the rotate speed) are chosen as the optimized parameters. According to the force on the cutting pick, the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head, the optimized design model of collecting head is built. Taking two hundred groups seabed microtopography for grand in the range of depth displacement from 4.5 to 5.5 era, then making use of the improved simulated annealing genetic algorithm (SAGA), the corresponding optimized result can be obtained. At the same time, in order to speed up the controlling of collecting head, the optimization results are analyzed using the regression analysis method, and the conclusion of the second parameter of the seabed microtopography is drawn. 展开更多
关键词 cobalt crust mining parameter specific energy consumption simulated annealing genetic algorithm
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