Phase equilibrium modeling using internally consistent thermodynamic dataset and associated activity-composition(a-x)models are very helpful for quantifying P-T evolution for eclogite,which is the basis for decipherin...Phase equilibrium modeling using internally consistent thermodynamic dataset and associated activity-composition(a-x)models are very helpful for quantifying P-T evolution for eclogite,which is the basis for deciphering the geodynamic processes in subduction zones.In this study,we apply different versions of datasets(ds55 and ds62)and associated a-x relations to a wellestablished LT-HP eclogite at Huwan in the classic western Dabie orogen to constrain its P-T evolution.The eclogite comprises garnet+omphacite+amphibole+white mica+epidote+quartz+chlorite+rutile/ilmenite/sphene.Garnet porphyroblasts show mono-variation in the end members(spessartine from 17 mol%to 0,pyrope from 2 mol%to 18 mol%,almandine from 47 mol%to 64mol%and grossular from 35 mol%to 18 mol%)from core to rim.Phase diagrams combined with compositional isopleth thermobarometry show that dataset ds62 and associated a-x relations yield P_(max)of~33 kbar at~560℃,conflicting with our petrological observations and previous studies.On the other hand,phase equilibrium modeling using dataset ds62 and a revised symmetric garnet a-x model irrespective of Fe^(3+)(O)gives P_(max)of~27 kbar at~560℃,consistent with the results using dataset ds55 and associated a-x relations.Therefore,we recommend a symmetric model for garnet involving py,alm,gr and spss,without Fe~(3+)components,instead of the asymmetric garnet a-x relations involving py,alm,gr,spss and kho by White et al.(2014),for calculating phase diagrams for LT-(U)HP eclogite when using dataset ds62.In this study,the defined P-T path is characterized by a segment of the prograde evolution showing a first moderate slope,followed by gentle then steep slopes,representing the thermal structure evolution recorded by slab surface during continental subduction.Our work combined with previous studies conclude that in western Dabie,the Huwan HP eclogite belt to the north and the Hong'an HP eclogite belt to the south belong to the same HP slice overlying the Xinxian UHP slice.展开更多
Using a modified subgradient extragradient algorithm, this paper proposed a novel approach to solving a supply chain network equilibrium model. The method extends the scope of optimisation and improves the accuracy at...Using a modified subgradient extragradient algorithm, this paper proposed a novel approach to solving a supply chain network equilibrium model. The method extends the scope of optimisation and improves the accuracy at each iteration by incorporating adaptive parameter selection and a more general subgradient projection operator. The advantages of the proposed method are highlighted by the proof of strong convergence presented in the paper. Several concrete examples are given to demonstrate the effectiveness of the algorithm, with comparisons illustrating its superior CPU running time compared to alternative techniques. The practical applicability of the algorithm is also demonstrated by applying it to a realistic supply chain network model.展开更多
The role of the construction industry in economic growth has been widely discussed in the extant literature,but existing studies have not investigated the disaggregated impact of construction investments on the produc...The role of the construction industry in economic growth has been widely discussed in the extant literature,but existing studies have not investigated the disaggregated impact of construction investments on the production and social sectors.This study examines the disaggregated effect of construction investments on the Saudi economy.The study uses a social accounting matrix of Saudi Arabia and constructs a dynamic computable general equilibrium model.The findings reveal that construction investments significantly boosted GDP and aggregate investments in the first two periods;however,the growth declined in the following three periods.This finding underlines the importance of long-term investments in the construction sector and calls for continuous monitoring and updating of the investment policy for sustainable development.This study also presents the disaggregated impact of investments on the value-added by each sector of the economy.The ranking of sectors exhibits that mining and quarry activities underwent a high increase in value-added,second to construction activities.Other economic activities also experienced growth in value-added and some of them changed their ranks within the five years.展开更多
A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiersbased on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification teml^erature. Th...A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiersbased on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification teml^erature. The model is divided into three stages including pyrolysis and combustion stage, char gas reaction stage, and gas p.hase reaction stage. Part of the water produced in thepyrolysis and combust!on stag.e is assumed to be involved inthe second stage to react with the unburned carbon. Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature. And the gas product compositions are calculated from gas phase reactions in the third stage. The simulation results are consistent with published experimental data.展开更多
A computational thermodynamics model for the oxygen bottom-blown copper smelting process(Shuikoushan,SKS process)was established,based on the SKS smelting characteristics and theory of Gibbs free energy minimization.T...A computational thermodynamics model for the oxygen bottom-blown copper smelting process(Shuikoushan,SKS process)was established,based on the SKS smelting characteristics and theory of Gibbs free energy minimization.The calculated results of the model show that,under the given stable production condition,the contents of Cu,Fe and S in matte are71.08%,7.15%and17.51%,and the contents of Fe,SiO2and Cu in slag are42.17%,25.05%and3.16%.The calculated fractional distributions of minor elements among gas,slag and matte phases are As82.69%,11.22%,6.09%,Sb16.57%,70.63%,12.80%,Bi68.93%,11.30%,19.77%,Pb19.70%,24.75%,55.55%and Zn17.94%,64.28%,17.79%,respectively.The calculated results of the multiphase equilibrium model agree well with the actual industrial production data,indicating that the credibility of the model is validated.Therefore,the model could be used to monitor and optimize the industrial operations of SKS process.展开更多
Advanced traveler information systems （ATIS） can not only improve drivers＇ accessibility to the more accurate route travel time information, but also can improve drivers＇ adaptability to the stochastic network cap...Advanced traveler information systems （ATIS） can not only improve drivers＇ accessibility to the more accurate route travel time information, but also can improve drivers＇ adaptability to the stochastic network capacity degradations. In this paper, a mixed stochastic user equilibrium model was proposed to describe the interactive route choice behaviors between ATIS equipped and unequipped drivers on a degradable transport network. In the proposed model the information accessibility of equipped drivers was reflected by lower degree of uncertainty in their stochastic equilibrium flow distributions, and their behavioral adaptability was captured by multiple equilibrium behaviors over the stochastic network state set. The mixed equilibrium model was formulated as a fixed point problem defined in the mixed route flows, and its solution was achieved by executing an iterative algorithm. Numerical experiments were provided to verify the properties of the mixed network equilibrium model and the efficiency of the iterative algorithm.展开更多
The intensity allocation criteria of carbon emissions permits and its influence on China's regional development are analyzed through the 30-province/autonomous region computable general equilibrium(CGE)model.Simul...The intensity allocation criteria of carbon emissions permits and its influence on China's regional development are analyzed through the 30-province/autonomous region computable general equilibrium(CGE)model.Simulation results show that:industrial intensity criteria without taking regional economic development into account deepen the unbalance of regional economic development;regional intensity criteria without taking industrial properties into account exert little negative impact on regional harmonious development,but relatively high negative influence on high-carbon emission industries.The two-step allocation scheme that the central government allocates emissions permits to provincial governments based on regional economic development and then provincial governments allocate emissions permits to emission resources or entities based on industrial properties is a feasible and operable choice.展开更多
The extraction equilibrium mathematic models for gadolinium,terbium and dysprosium in HCl-1.5 mol/L HEH(EHP)system covering a relatively wide range of lanthanide concentration and acidity,have been developed.There are...The extraction equilibrium mathematic models for gadolinium,terbium and dysprosium in HCl-1.5 mol/L HEH(EHP)system covering a relatively wide range of lanthanide concentration and acidity,have been developed.There are four independent variables and nine parameters.The average relative error is 4.56%.A computer program for the simulation of the counter current solvent extraetion process has also been written.Thus,the Gd,Tb and Dy concentrations in both aqueous and organic phase in eaeh stage as well as the aqueous acidity may be calculated.Product purities,distribution ratio and extraction factors may also be obtained thereby.The simulation results so obtained may serve as the referenee data for designing solvent ex- traction processes including those processes providing apart from the conventional outgoing organic stream, outgoing raffinate and an extra outgoing third exit stream either organic or aqueous.展开更多
The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,...The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,the pressure-temperature(P-T)conditions of metamorphism and partial melting remain poorly studied in the region.To elucidate metamorphic P-T conditions,phase equilibrium modelling was applied to two sillimanite-garnet paragneisses,one amphibole-orthogneiss,and one amphibolite.Sillimanite-garnet paragneisses exhibit a lepidoblastic texture with a biotite+sillimanite+kyanite+garnet+quartz+plagioclase+K-feldspar mineral assemblage.Amphibole-orthogneiss and amphibolite display a nematoblastic texture with an amphibole+(1)plagioclase+quartz+(1)titanite assemblage and an amphibole+(2)plagioclase+(2)titanite+ilmenite retrograde mineral assemblage.Pseudosections calculated for the two sillimanite-garnet paragneiss samples show P-T peak conditions at~6-7.5 kbar and~725-740℃.The results for amphibole-orthogneiss and the amphibolite yield P-T peak conditions at~8.5-10 kbar and~690-710℃.The mode models imply that metasedimentary and metaigneous units can produce up to~20 vol%and~10 vol%of melt,respectively.Modelling within a closed system during isobaric heating suggests that melt compositions of metasedimentary and metaigneous units are likely to have direct implications for the petrogenesis of the Puerto Vallarta Batholith.Our new data indicate that the Yelapa-Chimo Metamorphic Complex evolved through a metamorphic gradient between~23-33℃km^-1and the metamorphic rocks formed at depths between~22 km and~30 km with a burial rate of~2.0 km Ma^-1.Finally,the P-T data for both metasedimentary and metaigneous rocks provide new constraints on an accretionary framework,which is responsible for generating metamorphism and partial melting in the YelapaChimo Metamorphic Complex during the Early Cretaceous.展开更多
The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change o...The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change on the agriculture sector of Ethiopia using a dynamic computable general equilibrium (CGE) model. The study simulated the scenarios of agricultural productivity change induced by climate change up to the year 2050. At national level, the simulation results suggest that crop production will be adversely affected during the coming four decades and the severity will increase over the time period. Production of teff, maize and sorghum will decline by 25.4, 21.8 and 25.2 percent, respectively by 2050 compared to the base period. Climate change will also cause losses of 31.1 percent agricultural GDP at factor cost by 2050. Climate change affects more the income and consumption of poor rural households than urban rural non-farming households. The reduction in agricultural production will not be evenly distributed across agro ecological zones, and will not all be negative. Among rural residents, climate change impacts tend to hurt the income of the poor more in drought prone regions. Income from labor, land and livestock in moisture sufficient highland cereal-based will decline by 5.1, 8.8 and 15.2 percent in 2050. This study indicated that since climate change is an inevitable phenomenon, the country should start mainstreaming adaptation measures to sustain the overall performance of the economy.展开更多
In the past several years, there has been growing concern on the scarcity of energy resources, the volatility of energy prices, and the impact of energy sector on climate change. In this context, energy-environment mo...In the past several years, there has been growing concern on the scarcity of energy resources, the volatility of energy prices, and the impact of energy sector on climate change. In this context, energy-environment models designed for analysis of energy systems have become more important. In this paper, a Computable General Equilibrium Model （CGE） using an energy-environmental version of Global Trade Analysis Project （GTAP） model （known as GTAP-E） for Vietnam is presented based on the GTAP Data Base version 7. The model is developed following the original structure and the revised version of the GTAP-E model. This model is used to simulate the adoption of carbon tax for Vietnam for the base year of 2004. The economy-level and detailed sector-specific effects are also examined considering energy intensive and non-intensive sectors. Simulation results show the negative influences of different carbon tax scenarios to Vietnam＇s economy. The results would also indicate the potential of carbon taxation as a driving force for the mitigation of carbon dioxide and for new and renewable energy promotion in Vietnam. In fact, this study is the first simulation exercise of energy-environmental policy for the Vietnamese case.展开更多
The granulitized eclogites from the Luliangshan terrane of the North Qaidam UHP metamorphic belt occur as lenses within pelitic gneisses and orthogneisses. Combined petrologic data and phase equilibrium modeling indic...The granulitized eclogites from the Luliangshan terrane of the North Qaidam UHP metamorphic belt occur as lenses within pelitic gneisses and orthogneisses. Combined petrologic data and phase equilibrium modeling indicate a multi-stage metamorphic history of the granulitized eclogites:(1) an earlier eclogite facies metamorphism(P>18.5 kbar, T> 830℃) is deduced from omphacite relics in the matrix and rare omphacite inclusions within garnet. The possible assemblage is garnet+omphacite+rutile+ quartz;(2) the early stage of high pressure granulite facies assemblages(garnet+clinopyroxene+ plagioclase+rutile+quartz+liquid) developed in the early decompression process has a P-T regime of 17.5 kbar and 852–858 ℃, constrained by plagioclase and clinopyroxene inclusions in garnet. The late stage of high pressure granulite assemblages(garnet+clinopyroxene+amphibole+plagioclase+rutile+quartz+liquid) records an isothermal decompression process with the pressure successively declining from 17.5 to 14.7 kbar and to 11.3 kbar at 858 ℃;(3) the later medium pressure granulite facies assemblage(garnet+ orthopyroxene+clinopyroxene+amphibole+plagioclase+ilmenite+liquid+quartz) indicates a drop in pressure and rise in temperature at P-T conditions of 7.6–7.7 kbar and 878–883 ℃;(4) retrogressive amphibolite facies stage, which is represented by amphibole+plagioclase kelyphitic rims around garnet, formed under conditions of <5 kbar and <650 ℃. The preservation of medium pressure granulite facies assemblage and the garnet composition feature constrain a following isobaric cooling path during late exhumation. This process suggests a clockwise P-T path and indicates that the granulitized eclogites record a high grade "Barrovian" metamorphic overprint at the middle-lower crust during exhumation. The present data show that the Luliangshan terrane is a "hot" HP-UHP terrane.展开更多
This paper deals with an extension of the one-period model in non-life insurance markets (cf. [1]) by using a transition probability matrix depending on some economic factors. We introduce a multi-period model and in ...This paper deals with an extension of the one-period model in non-life insurance markets (cf. [1]) by using a transition probability matrix depending on some economic factors. We introduce a multi-period model and in each period the solvency constraints will be updated. Moreover, the model has the inactive state including some uninsured population. Similar results on the existence of premium equilibrium and sensitivity analysis for this model are presented and illustrated by numerical results.展开更多
Since the recent economic crisis, the undervaluation of China＇s exchange rate has been a focus in the debate on the global policy mix. Using a non-competitive input-output table, we establish a comparative-static gen...Since the recent economic crisis, the undervaluation of China＇s exchange rate has been a focus in the debate on the global policy mix. Using a non-competitive input-output table, we establish a comparative-static general equilibrium model to simulate the impact of real exchange rate changes on Sino-US trade and labor markets. The simulation shows that the impacts of a lO-percent RMB revaluation on the trade surplus of China and the labor market of the USA are more modest than is generally perceived, and the negative impact on the output of the non-processing industry in China is more significant than that on the processing industry. The Sino--US trade imbalance will continue to deteriorate, China ＇s non-processing trade surplus will decline and the processing trade will increase, with the combined effect being small. For the USA, labor-intensive goods imported from China will shift to different Asian countries instead of transferring back to the US market. The simulation results indicate that the impacts of an RMB revaluation on both Chinese and US labor markets would be limited.展开更多
With growing regional economic integration,transportation systems have become critical to regional development and economic vitality but vulnerable to disasters.However,the regional economic ripple effect of a disaste...With growing regional economic integration,transportation systems have become critical to regional development and economic vitality but vulnerable to disasters.However,the regional economic ripple effect of a disaster is difficult to quantify accurately,especially considering the cumulated influence of traffic disruptions.This study explored integrating transportation system analysis with economic modeling to capture the regional economic ripple effect.A state-of-the-art spatial computable general equilibrium model is leveraged to simulate the operation of the economic system,and the marginal rate of transport cost is introduced to reflect traffic network damage post-disaster.The model is applied to the 50-year return period flood in2020 in Hubei Province,China.The results show the following.First,when traffic disruption costs are considered,the total output loss of non-affected areas is 1.81 times than before,and non-negligible losses reach relatively remote zones of the country,such as the Northwest Comprehensive Economic Zone(36%of total ripple effects).Second,traffic disruptions have a significant hindering effect on regional trade activities,especially in the regional intermediate input—about three times more than before.The industries most sensitive to traffic disruptions were transportation,storage,and postal service(5 times),and processing and assembly manufacturing(4.4 times).Third,the longer the distance,the stronger traffic disruptions'impact on interregional intermediate inputs.Thus,increasing investment in transportation infrastructure significantly contributes to mitigating disaster ripple effects and accelerating the process of industrial recovery in affected areas.展开更多
Purpose The tensions and threats in historic urban landscapes brought about by heritage tourism are still regional,global,general,and dynamic issues.For Kulangsu,there is an obvious problem in the connection between t...Purpose The tensions and threats in historic urban landscapes brought about by heritage tourism are still regional,global,general,and dynamic issues.For Kulangsu,there is an obvious problem in the connection between the current conservation plan and public policy.To a large extent,public policy cannot effectively,specifically,and flexibly respond to the dynamic problems in the implementation of the conservation plan,which seems insufficient concerning the effect of these conservation plans and public policies on promoting the adaptive reuse and sustainable tourism of the historic urban in Kulangsu heritage sites.Thus,giving more consideration to the combination of public policies and conservation plans of historic urban landscapes under the heritage tourism milieu,ensuring a balanced,sustainable,and integrated development pattern still calls for new discussions in achieving good performance of sustainable heritage tourism.This study conceptually discusses the equilibrium model of historic urban landscapes with a range of strategies under a sustainable heritage tourism background and responds to the synthetic contradiction of the imbalances among public policy,conservation plans,and development practices.Design/methodology/approach The study is based on a range of prepared desktop studies(public policy studies,conservation plans),field surveys,participant observations,and randomised interviews to respond to the insufficiency of the current heritagepractices.Findings This study discusses the equilibrium model of sustainable heritage tourism at heritage sites.It takes Kulangsu Island,a UNESCO World Heritage site in Southeast China,as an example to discuss the equilibrium model,which encompasses a convergent parallel framework and three dimensions concerning heritage management and policymaking.The equilibrium model of historic urban landscapes is a dynamic framework that integrates social,economic,environmental,and cultural concerns into a holistic collaborative framework under a sustainable heritage tourism background.Originality/value In line with the requirements of the Historic Urban Landscape(HUL)approach and general principles in support of sustainable urban heritage management promoted by UNESCO and ICOMOS,the study points out the peculiarities and potential of the equilibrium mode in solving the current challenges of historic urban landscapes for sustainable heritage tourism.Finding ways of linking policymaking,conservation,development,heritage tourism,and different interest groups to a holistic framework can stimulate effective means and management mechanisms for the complicated and changeable issues of sustainable heritage tourism.展开更多
Two types of equilibrium and non-equilibrium stage models are generally used to simulate the mass transfer of packed distillation column. Using non-equilibrium model requires the calculation of mass transfer coefficie...Two types of equilibrium and non-equilibrium stage models are generally used to simulate the mass transfer of packed distillation column. Using non-equilibrium model requires the calculation of mass transfer coefficients, thus, usually equilibrium-based methods are preferred to be used for simulations of distillation columns. In this paper, packed column distillation of production of Mono Ethylene Glycol in FARSA SHIMI Company （Assaluyeh-Iran）＇s Ethylene Glycol portion has been simulated through using the equilibrium model and solving the related equations. The simulation has been carried out in the MATLAB environment. The column also has been simulated in the Aspen Hysys and Aspen Plus ver. 2006.5 environments. Then, the output has been compared with software results, designing and operating data of the underlying columns which demonstrate good consistency with the model. Having the model validated, the effect of some operating parameters has been analyzed through the model.展开更多
Zircon is a common accessory mineral in various rocks,especially in the crustal ones.It is the best mineral for U-Pb dating.Meanwhile,trace elements and isotopes of the mineral can also provide much information concer...Zircon is a common accessory mineral in various rocks,especially in the crustal ones.It is the best mineral for U-Pb dating.Meanwhile,trace elements and isotopes of the mineral can also provide much information concerning the formation and evolution of rocks.There are a growing number of reports of zircon existing in mantle peridotite.However,it is generally considered that zircon is unlikely crystallized in ultrabasic rocks due to SiO_(2)-unsaturation.In this paper,the SiO_(2) activity and zircon/baddeleyite transition curve at different conditions were calculated through thermodynamic phase equilibrium modeling,to reveal the main factors affecting the SiO_(2) activity and the stability of zircon/baddeleyite in ultrabasic and basic rocks,especially in mantle peridotite.These results provide a thermodynamic basis for interpreting the genesis and significance of zircon in mantle rocks.That is,the SiO_(2) activity is mainly controlled by stable mineral assemblages and temperature-pressure conditions.The orthopyroxene+olivine assemblage in peridotite as an effective buffer restricts the SiO_(2) activity in a relatively high range with a small variation.The upper temperature limit of zircon can reach more than 1500℃ with this mineral assemblage.During the low-temperature serpentinization of peridotite,the replacement of olivine and pyroxene by serpentine can result in a significant decrease of SiO_(2) activity,and baddeleyite can be stabilized at<530℃ and<2.7 GPa.When peridotite is strongly metasomatized by the SiO_(2)-bearing fluid,the addition of SiO_(2) can increase its activity and make zircon stable at low temperatures.The SiO_(2) activity in ultrabasic-basic rocks is not only positively correlated with the SiO_(2) content but also negatively correlated with the Ca and Na contents of rocks.This is because Ca and Na preferentially combine with Si and Al to form Si-rich minerals,such as clinopyroxene and feldspar.This process will consume excessive SiO_(2),decreasing the SiO_(2) activity.This may be the reason why zircon can be found in ultrabasic rocks,while baddeleyite can exist in some basic and alkaline rocks.The thermodynamic modeling can also reasonably explain the mutual transformation between zircon and baddeleyite in ultrabasic-basic rocks.Our results indicate that zircon can exist stably in mantle peridotite in a wide range of temperature-pressure conditions and its formation is related to melt/fluid metasomatism.That is,the presence of zircon in mantle peridotite is an important information carrier of crust-mantle interaction for deep material cycling.展开更多
This paper explores possible synergies between techniques used to minimise seismicity in deep South African gold mines and their applicability to control coal bumps. The paper gives a summary of the techniques used in...This paper explores possible synergies between techniques used to minimise seismicity in deep South African gold mines and their applicability to control coal bumps. The paper gives a summary of the techniques used in the deep gold mines and a critical appraisal if these are useful in coal mines. The techniques typically include control of mining rate, preconditioning, optimisation of extraction sequences and centralised blasting. Of particular interest to the coal bump problem is an experimental limit equilibrium fracture zone model implemented in a displacement discontinuity code. This was recently developed for the gold mines to enable the interactive analysis of complex tabular mine layout extraction sequences. The model specifically accommodates energy dissipation computations in the developing fracture zone near the edges of these excavations. This allows the released energy to be used as a surrogate measure of ongoing seismic activity and addresses a number of the weaknesses in the traditional usage of this quantity as a criterion for the design of seismically active layouts. This paper investigates the application of the model to a hypothetical coal longwall layout and the specific problem of coal bumps.展开更多
基金financially supported by the National Natural Science Foundation of China(No.41930215)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)。
文摘Phase equilibrium modeling using internally consistent thermodynamic dataset and associated activity-composition(a-x)models are very helpful for quantifying P-T evolution for eclogite,which is the basis for deciphering the geodynamic processes in subduction zones.In this study,we apply different versions of datasets(ds55 and ds62)and associated a-x relations to a wellestablished LT-HP eclogite at Huwan in the classic western Dabie orogen to constrain its P-T evolution.The eclogite comprises garnet+omphacite+amphibole+white mica+epidote+quartz+chlorite+rutile/ilmenite/sphene.Garnet porphyroblasts show mono-variation in the end members(spessartine from 17 mol%to 0,pyrope from 2 mol%to 18 mol%,almandine from 47 mol%to 64mol%and grossular from 35 mol%to 18 mol%)from core to rim.Phase diagrams combined with compositional isopleth thermobarometry show that dataset ds62 and associated a-x relations yield P_(max)of~33 kbar at~560℃,conflicting with our petrological observations and previous studies.On the other hand,phase equilibrium modeling using dataset ds62 and a revised symmetric garnet a-x model irrespective of Fe^(3+)(O)gives P_(max)of~27 kbar at~560℃,consistent with the results using dataset ds55 and associated a-x relations.Therefore,we recommend a symmetric model for garnet involving py,alm,gr and spss,without Fe~(3+)components,instead of the asymmetric garnet a-x relations involving py,alm,gr,spss and kho by White et al.(2014),for calculating phase diagrams for LT-(U)HP eclogite when using dataset ds62.In this study,the defined P-T path is characterized by a segment of the prograde evolution showing a first moderate slope,followed by gentle then steep slopes,representing the thermal structure evolution recorded by slab surface during continental subduction.Our work combined with previous studies conclude that in western Dabie,the Huwan HP eclogite belt to the north and the Hong'an HP eclogite belt to the south belong to the same HP slice overlying the Xinxian UHP slice.
文摘Using a modified subgradient extragradient algorithm, this paper proposed a novel approach to solving a supply chain network equilibrium model. The method extends the scope of optimisation and improves the accuracy at each iteration by incorporating adaptive parameter selection and a more general subgradient projection operator. The advantages of the proposed method are highlighted by the proof of strong convergence presented in the paper. Several concrete examples are given to demonstrate the effectiveness of the algorithm, with comparisons illustrating its superior CPU running time compared to alternative techniques. The practical applicability of the algorithm is also demonstrated by applying it to a realistic supply chain network model.
文摘The role of the construction industry in economic growth has been widely discussed in the extant literature,but existing studies have not investigated the disaggregated impact of construction investments on the production and social sectors.This study examines the disaggregated effect of construction investments on the Saudi economy.The study uses a social accounting matrix of Saudi Arabia and constructs a dynamic computable general equilibrium model.The findings reveal that construction investments significantly boosted GDP and aggregate investments in the first two periods;however,the growth declined in the following three periods.This finding underlines the importance of long-term investments in the construction sector and calls for continuous monitoring and updating of the investment policy for sustainable development.This study also presents the disaggregated impact of investments on the value-added by each sector of the economy.The ranking of sectors exhibits that mining and quarry activities underwent a high increase in value-added,second to construction activities.Other economic activities also experienced growth in value-added and some of them changed their ranks within the five years.
基金Supported by the Major State Basic Research Development Program of China(2012CB720500)the National Natural Science Foundation of China(U1162202,61174118)+1 种基金the National Science Fund for Outstanding Young Scholars(61222303)Shanghai Leading Academic Discipline Project(B504)
文摘A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiersbased on Aspen Plus to calculate the composition of product gas, carbon conversion, and gasification teml^erature. The model is divided into three stages including pyrolysis and combustion stage, char gas reaction stage, and gas p.hase reaction stage. Part of the water produced in thepyrolysis and combust!on stag.e is assumed to be involved inthe second stage to react with the unburned carbon. Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature. And the gas product compositions are calculated from gas phase reactions in the third stage. The simulation results are consistent with published experimental data.
基金Project(51620105013)supported by the National Natural Science Foundation of China
文摘A computational thermodynamics model for the oxygen bottom-blown copper smelting process(Shuikoushan,SKS process)was established,based on the SKS smelting characteristics and theory of Gibbs free energy minimization.The calculated results of the model show that,under the given stable production condition,the contents of Cu,Fe and S in matte are71.08%,7.15%and17.51%,and the contents of Fe,SiO2and Cu in slag are42.17%,25.05%and3.16%.The calculated fractional distributions of minor elements among gas,slag and matte phases are As82.69%,11.22%,6.09%,Sb16.57%,70.63%,12.80%,Bi68.93%,11.30%,19.77%,Pb19.70%,24.75%,55.55%and Zn17.94%,64.28%,17.79%,respectively.The calculated results of the multiphase equilibrium model agree well with the actual industrial production data,indicating that the credibility of the model is validated.Therefore,the model could be used to monitor and optimize the industrial operations of SKS process.
基金Projects(51378119,51578150)supported by the National Natural Science Foundation of China
文摘Advanced traveler information systems （ATIS） can not only improve drivers＇ accessibility to the more accurate route travel time information, but also can improve drivers＇ adaptability to the stochastic network capacity degradations. In this paper, a mixed stochastic user equilibrium model was proposed to describe the interactive route choice behaviors between ATIS equipped and unequipped drivers on a degradable transport network. In the proposed model the information accessibility of equipped drivers was reflected by lower degree of uncertainty in their stochastic equilibrium flow distributions, and their behavioral adaptability was captured by multiple equilibrium behaviors over the stochastic network state set. The mixed equilibrium model was formulated as a fixed point problem defined in the mixed route flows, and its solution was achieved by executing an iterative algorithm. Numerical experiments were provided to verify the properties of the mixed network equilibrium model and the efficiency of the iterative algorithm.
基金supported by National Natural Sci- ence Foundation of China(No.71173212,41101556 and 71203215)the President Fund of GUCAS(No Y1510RY00)
文摘The intensity allocation criteria of carbon emissions permits and its influence on China's regional development are analyzed through the 30-province/autonomous region computable general equilibrium(CGE)model.Simulation results show that:industrial intensity criteria without taking regional economic development into account deepen the unbalance of regional economic development;regional intensity criteria without taking industrial properties into account exert little negative impact on regional harmonious development,but relatively high negative influence on high-carbon emission industries.The two-step allocation scheme that the central government allocates emissions permits to provincial governments based on regional economic development and then provincial governments allocate emissions permits to emission resources or entities based on industrial properties is a feasible and operable choice.
文摘The extraction equilibrium mathematic models for gadolinium,terbium and dysprosium in HCl-1.5 mol/L HEH(EHP)system covering a relatively wide range of lanthanide concentration and acidity,have been developed.There are four independent variables and nine parameters.The average relative error is 4.56%.A computer program for the simulation of the counter current solvent extraetion process has also been written.Thus,the Gd,Tb and Dy concentrations in both aqueous and organic phase in eaeh stage as well as the aqueous acidity may be calculated.Product purities,distribution ratio and extraction factors may also be obtained thereby.The simulation results so obtained may serve as the referenee data for designing solvent ex- traction processes including those processes providing apart from the conventional outgoing organic stream, outgoing raffinate and an extra outgoing third exit stream either organic or aqueous.
基金funded by Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica(PAPIIT)grant IN112314。
文摘The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,the pressure-temperature(P-T)conditions of metamorphism and partial melting remain poorly studied in the region.To elucidate metamorphic P-T conditions,phase equilibrium modelling was applied to two sillimanite-garnet paragneisses,one amphibole-orthogneiss,and one amphibolite.Sillimanite-garnet paragneisses exhibit a lepidoblastic texture with a biotite+sillimanite+kyanite+garnet+quartz+plagioclase+K-feldspar mineral assemblage.Amphibole-orthogneiss and amphibolite display a nematoblastic texture with an amphibole+(1)plagioclase+quartz+(1)titanite assemblage and an amphibole+(2)plagioclase+(2)titanite+ilmenite retrograde mineral assemblage.Pseudosections calculated for the two sillimanite-garnet paragneiss samples show P-T peak conditions at~6-7.5 kbar and~725-740℃.The results for amphibole-orthogneiss and the amphibolite yield P-T peak conditions at~8.5-10 kbar and~690-710℃.The mode models imply that metasedimentary and metaigneous units can produce up to~20 vol%and~10 vol%of melt,respectively.Modelling within a closed system during isobaric heating suggests that melt compositions of metasedimentary and metaigneous units are likely to have direct implications for the petrogenesis of the Puerto Vallarta Batholith.Our new data indicate that the Yelapa-Chimo Metamorphic Complex evolved through a metamorphic gradient between~23-33℃km^-1and the metamorphic rocks formed at depths between~22 km and~30 km with a burial rate of~2.0 km Ma^-1.Finally,the P-T data for both metasedimentary and metaigneous rocks provide new constraints on an accretionary framework,which is responsible for generating metamorphism and partial melting in the YelapaChimo Metamorphic Complex during the Early Cretaceous.
文摘The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change on the agriculture sector of Ethiopia using a dynamic computable general equilibrium (CGE) model. The study simulated the scenarios of agricultural productivity change induced by climate change up to the year 2050. At national level, the simulation results suggest that crop production will be adversely affected during the coming four decades and the severity will increase over the time period. Production of teff, maize and sorghum will decline by 25.4, 21.8 and 25.2 percent, respectively by 2050 compared to the base period. Climate change will also cause losses of 31.1 percent agricultural GDP at factor cost by 2050. Climate change affects more the income and consumption of poor rural households than urban rural non-farming households. The reduction in agricultural production will not be evenly distributed across agro ecological zones, and will not all be negative. Among rural residents, climate change impacts tend to hurt the income of the poor more in drought prone regions. Income from labor, land and livestock in moisture sufficient highland cereal-based will decline by 5.1, 8.8 and 15.2 percent in 2050. This study indicated that since climate change is an inevitable phenomenon, the country should start mainstreaming adaptation measures to sustain the overall performance of the economy.
文摘In the past several years, there has been growing concern on the scarcity of energy resources, the volatility of energy prices, and the impact of energy sector on climate change. In this context, energy-environment models designed for analysis of energy systems have become more important. In this paper, a Computable General Equilibrium Model （CGE） using an energy-environmental version of Global Trade Analysis Project （GTAP） model （known as GTAP-E） for Vietnam is presented based on the GTAP Data Base version 7. The model is developed following the original structure and the revised version of the GTAP-E model. This model is used to simulate the adoption of carbon tax for Vietnam for the base year of 2004. The economy-level and detailed sector-specific effects are also examined considering energy intensive and non-intensive sectors. Simulation results show the negative influences of different carbon tax scenarios to Vietnam＇s economy. The results would also indicate the potential of carbon taxation as a driving force for the mitigation of carbon dioxide and for new and renewable energy promotion in Vietnam. In fact, this study is the first simulation exercise of energy-environmental policy for the Vietnamese case.
基金financially supported by the National Natural Science Foundation of China (Nos. 41630207, 41572180)the China Geological Survey (No. DD20160022)
文摘The granulitized eclogites from the Luliangshan terrane of the North Qaidam UHP metamorphic belt occur as lenses within pelitic gneisses and orthogneisses. Combined petrologic data and phase equilibrium modeling indicate a multi-stage metamorphic history of the granulitized eclogites:(1) an earlier eclogite facies metamorphism(P>18.5 kbar, T> 830℃) is deduced from omphacite relics in the matrix and rare omphacite inclusions within garnet. The possible assemblage is garnet+omphacite+rutile+ quartz;(2) the early stage of high pressure granulite facies assemblages(garnet+clinopyroxene+ plagioclase+rutile+quartz+liquid) developed in the early decompression process has a P-T regime of 17.5 kbar and 852–858 ℃, constrained by plagioclase and clinopyroxene inclusions in garnet. The late stage of high pressure granulite assemblages(garnet+clinopyroxene+amphibole+plagioclase+rutile+quartz+liquid) records an isothermal decompression process with the pressure successively declining from 17.5 to 14.7 kbar and to 11.3 kbar at 858 ℃;(3) the later medium pressure granulite facies assemblage(garnet+ orthopyroxene+clinopyroxene+amphibole+plagioclase+ilmenite+liquid+quartz) indicates a drop in pressure and rise in temperature at P-T conditions of 7.6–7.7 kbar and 878–883 ℃;(4) retrogressive amphibolite facies stage, which is represented by amphibole+plagioclase kelyphitic rims around garnet, formed under conditions of <5 kbar and <650 ℃. The preservation of medium pressure granulite facies assemblage and the garnet composition feature constrain a following isobaric cooling path during late exhumation. This process suggests a clockwise P-T path and indicates that the granulitized eclogites record a high grade "Barrovian" metamorphic overprint at the middle-lower crust during exhumation. The present data show that the Luliangshan terrane is a "hot" HP-UHP terrane.
文摘This paper deals with an extension of the one-period model in non-life insurance markets (cf. [1]) by using a transition probability matrix depending on some economic factors. We introduce a multi-period model and in each period the solvency constraints will be updated. Moreover, the model has the inactive state including some uninsured population. Similar results on the existence of premium equilibrium and sensitivity analysis for this model are presented and illustrated by numerical results.
基金supported by the National Natural Science Foundation of China(Grant No.70810107020)the Science Foundation of Ministfy of Education of China(Grant No.2009JJD790002)the China Postdoctoral Science Foundation (No.20100470125)
文摘Since the recent economic crisis, the undervaluation of China＇s exchange rate has been a focus in the debate on the global policy mix. Using a non-competitive input-output table, we establish a comparative-static general equilibrium model to simulate the impact of real exchange rate changes on Sino-US trade and labor markets. The simulation shows that the impacts of a lO-percent RMB revaluation on the trade surplus of China and the labor market of the USA are more modest than is generally perceived, and the negative impact on the output of the non-processing industry in China is more significant than that on the processing industry. The Sino--US trade imbalance will continue to deteriorate, China ＇s non-processing trade surplus will decline and the processing trade will increase, with the combined effect being small. For the USA, labor-intensive goods imported from China will shift to different Asian countries instead of transferring back to the US market. The simulation results indicate that the impacts of an RMB revaluation on both Chinese and US labor markets would be limited.
基金supported by the National Natural Science Foundation of China(Grant Nos.42177448 and 41907393)。
文摘With growing regional economic integration,transportation systems have become critical to regional development and economic vitality but vulnerable to disasters.However,the regional economic ripple effect of a disaster is difficult to quantify accurately,especially considering the cumulated influence of traffic disruptions.This study explored integrating transportation system analysis with economic modeling to capture the regional economic ripple effect.A state-of-the-art spatial computable general equilibrium model is leveraged to simulate the operation of the economic system,and the marginal rate of transport cost is introduced to reflect traffic network damage post-disaster.The model is applied to the 50-year return period flood in2020 in Hubei Province,China.The results show the following.First,when traffic disruption costs are considered,the total output loss of non-affected areas is 1.81 times than before,and non-negligible losses reach relatively remote zones of the country,such as the Northwest Comprehensive Economic Zone(36%of total ripple effects).Second,traffic disruptions have a significant hindering effect on regional trade activities,especially in the regional intermediate input—about three times more than before.The industries most sensitive to traffic disruptions were transportation,storage,and postal service(5 times),and processing and assembly manufacturing(4.4 times).Third,the longer the distance,the stronger traffic disruptions'impact on interregional intermediate inputs.Thus,increasing investment in transportation infrastructure significantly contributes to mitigating disaster ripple effects and accelerating the process of industrial recovery in affected areas.
基金This study is supported by The National Natural Science Foundation of China(Project No.42171219)The Provincal Science Fundation of Fujian(Project No.2020J01011)The research project of Xiamen Academy of Social Sciences:Research on the Activation and Utilization of Gulangyu Cultural Heritage(Project No.General Project of XASS[2023]C27).
文摘Purpose The tensions and threats in historic urban landscapes brought about by heritage tourism are still regional,global,general,and dynamic issues.For Kulangsu,there is an obvious problem in the connection between the current conservation plan and public policy.To a large extent,public policy cannot effectively,specifically,and flexibly respond to the dynamic problems in the implementation of the conservation plan,which seems insufficient concerning the effect of these conservation plans and public policies on promoting the adaptive reuse and sustainable tourism of the historic urban in Kulangsu heritage sites.Thus,giving more consideration to the combination of public policies and conservation plans of historic urban landscapes under the heritage tourism milieu,ensuring a balanced,sustainable,and integrated development pattern still calls for new discussions in achieving good performance of sustainable heritage tourism.This study conceptually discusses the equilibrium model of historic urban landscapes with a range of strategies under a sustainable heritage tourism background and responds to the synthetic contradiction of the imbalances among public policy,conservation plans,and development practices.Design/methodology/approach The study is based on a range of prepared desktop studies(public policy studies,conservation plans),field surveys,participant observations,and randomised interviews to respond to the insufficiency of the current heritagepractices.Findings This study discusses the equilibrium model of sustainable heritage tourism at heritage sites.It takes Kulangsu Island,a UNESCO World Heritage site in Southeast China,as an example to discuss the equilibrium model,which encompasses a convergent parallel framework and three dimensions concerning heritage management and policymaking.The equilibrium model of historic urban landscapes is a dynamic framework that integrates social,economic,environmental,and cultural concerns into a holistic collaborative framework under a sustainable heritage tourism background.Originality/value In line with the requirements of the Historic Urban Landscape(HUL)approach and general principles in support of sustainable urban heritage management promoted by UNESCO and ICOMOS,the study points out the peculiarities and potential of the equilibrium mode in solving the current challenges of historic urban landscapes for sustainable heritage tourism.Finding ways of linking policymaking,conservation,development,heritage tourism,and different interest groups to a holistic framework can stimulate effective means and management mechanisms for the complicated and changeable issues of sustainable heritage tourism.
文摘Two types of equilibrium and non-equilibrium stage models are generally used to simulate the mass transfer of packed distillation column. Using non-equilibrium model requires the calculation of mass transfer coefficients, thus, usually equilibrium-based methods are preferred to be used for simulations of distillation columns. In this paper, packed column distillation of production of Mono Ethylene Glycol in FARSA SHIMI Company （Assaluyeh-Iran）＇s Ethylene Glycol portion has been simulated through using the equilibrium model and solving the related equations. The simulation has been carried out in the MATLAB environment. The column also has been simulated in the Aspen Hysys and Aspen Plus ver. 2006.5 environments. Then, the output has been compared with software results, designing and operating data of the underlying columns which demonstrate good consistency with the model. Having the model validated, the effect of some operating parameters has been analyzed through the model.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.41972067&41930215)the Fund from the Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources(Grant No.J1901-11).
文摘Zircon is a common accessory mineral in various rocks,especially in the crustal ones.It is the best mineral for U-Pb dating.Meanwhile,trace elements and isotopes of the mineral can also provide much information concerning the formation and evolution of rocks.There are a growing number of reports of zircon existing in mantle peridotite.However,it is generally considered that zircon is unlikely crystallized in ultrabasic rocks due to SiO_(2)-unsaturation.In this paper,the SiO_(2) activity and zircon/baddeleyite transition curve at different conditions were calculated through thermodynamic phase equilibrium modeling,to reveal the main factors affecting the SiO_(2) activity and the stability of zircon/baddeleyite in ultrabasic and basic rocks,especially in mantle peridotite.These results provide a thermodynamic basis for interpreting the genesis and significance of zircon in mantle rocks.That is,the SiO_(2) activity is mainly controlled by stable mineral assemblages and temperature-pressure conditions.The orthopyroxene+olivine assemblage in peridotite as an effective buffer restricts the SiO_(2) activity in a relatively high range with a small variation.The upper temperature limit of zircon can reach more than 1500℃ with this mineral assemblage.During the low-temperature serpentinization of peridotite,the replacement of olivine and pyroxene by serpentine can result in a significant decrease of SiO_(2) activity,and baddeleyite can be stabilized at<530℃ and<2.7 GPa.When peridotite is strongly metasomatized by the SiO_(2)-bearing fluid,the addition of SiO_(2) can increase its activity and make zircon stable at low temperatures.The SiO_(2) activity in ultrabasic-basic rocks is not only positively correlated with the SiO_(2) content but also negatively correlated with the Ca and Na contents of rocks.This is because Ca and Na preferentially combine with Si and Al to form Si-rich minerals,such as clinopyroxene and feldspar.This process will consume excessive SiO_(2),decreasing the SiO_(2) activity.This may be the reason why zircon can be found in ultrabasic rocks,while baddeleyite can exist in some basic and alkaline rocks.The thermodynamic modeling can also reasonably explain the mutual transformation between zircon and baddeleyite in ultrabasic-basic rocks.Our results indicate that zircon can exist stably in mantle peridotite in a wide range of temperature-pressure conditions and its formation is related to melt/fluid metasomatism.That is,the presence of zircon in mantle peridotite is an important information carrier of crust-mantle interaction for deep material cycling.
文摘This paper explores possible synergies between techniques used to minimise seismicity in deep South African gold mines and their applicability to control coal bumps. The paper gives a summary of the techniques used in the deep gold mines and a critical appraisal if these are useful in coal mines. The techniques typically include control of mining rate, preconditioning, optimisation of extraction sequences and centralised blasting. Of particular interest to the coal bump problem is an experimental limit equilibrium fracture zone model implemented in a displacement discontinuity code. This was recently developed for the gold mines to enable the interactive analysis of complex tabular mine layout extraction sequences. The model specifically accommodates energy dissipation computations in the developing fracture zone near the edges of these excavations. This allows the released energy to be used as a surrogate measure of ongoing seismic activity and addresses a number of the weaknesses in the traditional usage of this quantity as a criterion for the design of seismically active layouts. This paper investigates the application of the model to a hypothetical coal longwall layout and the specific problem of coal bumps.
