Farmland ecosystems are the primary ecosystem type in inland river basins,providing the biological and material basis for human development and survival.The foundation for monetizing the value of agricultural ecologic...Farmland ecosystems are the primary ecosystem type in inland river basins,providing the biological and material basis for human development and survival.The foundation for monetizing the value of agricultural ecological products and transforming green mountains into gold mountains is the precise assessment of ecosystem products in specific geographic units(VEP)within farmland ecosystems,which elucidates regional agricultural resource endowments and spatial distribution.However,agricultural ecological products face challenges in valuation,trading,and monetization,and research on pathways for their value transformation remains limited.This study uses Zhangye City in inland river basins as an example to construct a catalog of farmland ecosystem ecological products and explores VEP accounting methods based on multi-source data,including statistical,remote sensing,and monitoring data,at the city and county scales,and analyzes differentiated value transformation pathways according to the attributes of various agricultural ecological products.The results show that material supply value ranks highest among the VEP of farmland ecosystems in inland river basins,followed by regulatory services,while recreational agriculture value ranks lowest.The ranking of VEP varies from the ranking of farmland ecosystem area,with available agricultural water being a major constraint on the VEP of farmland ecosystems in inland river basins.Regional climate,geographic position,and transportation are linked to the value of agricultural ecosystem products within material supply products.Precipitation,soil structure,and cropping patterns are linked to the value of agricultural ecosystem products within regulatory services.The local cultural resources and tourism infrastructure are linked to the value of agricultural ecosystem products within cultural services.Regarding the pathways for achieving the value of agricultural ecological products,market-oriented strategies dominate the mainstay of material supply products,government-led mechanisms are pivotal for regulatory service products,and a combination of government and market strategies is essential for cultural service products.展开更多
The objective of this paper is the valuation of radiological health effects of Yatagan Power Plant. To this aim the radiation dose calculations are carried out for the population living within 80 km radius of the plan...The objective of this paper is the valuation of radiological health effects of Yatagan Power Plant. To this aim the radiation dose calculations are carried out for the population living within 80 km radius of the plant. The average of the maximum measured specific isotopes 238U, 232Th and 226Ra in the flying ash samples are considered as radioactive sources. Based on the dose calculations, first the stochastic health effects and then monetary health effects are estimated. The estimated total collective dose and economic value of the pre-dicted health effects are 0.3098 man Sv/y and 14791 US$/y respectively. The results obtained from the dose calculations are lower than the limits of International Commission of Radiation Protection (ICRP) and it does not pose any risk for public health. Monetary value of health risks is also negligible in comparison to the av-erage yearly sales revenue of the plant which is 250 million US$.展开更多
Cultural tourism helps preserve historical architecture and develop traditional arts in Xinjiangas the sun rises over Kazanqi in northwest China,the early morning silence is broken only by the tinkling sound of a hors...Cultural tourism helps preserve historical architecture and develop traditional arts in Xinjiangas the sun rises over Kazanqi in northwest China,the early morning silence is broken only by the tinkling sound of a horse’s sleigh bells.The old horsedrawn carriage bringing the day’s first visitors make its way slowly through the Kazanqi Folk Tourism District,a triple-A scenic spot in the Xinjiang Uygur Autonomous Region.No tourist buses or cars are allowed here.Visitors travel around the area using traditional means of展开更多
In this study,we develop and empirically test a valuation model for a commonly encountered option in office leases:a tenant’s option to renew at future market rent(a fair market value)with lease termination as the ma...In this study,we develop and empirically test a valuation model for a commonly encountered option in office leases:a tenant’s option to renew at future market rent(a fair market value)with lease termination as the maturity date.The model integrates decision analysis with real options analysis and market risk with private risks.“Option value”is defined as the private value of the option to either party pre-contract,while“option price”assumes a fair agreement between transacting parties and can be positive(rental premium paid)or negative(rental discount offered).Without manifest expectations,an analysis of a sample of office leases supports the model’s logic with price estimates in a practical range.The tenants’option price/value is shown to have a negative relationship with the original/renewal lease term;conversely,the landlords’option value is positively related to the original/renewal term.Comparative analyses show that transaction costs have a positive effect on tenants’option value and on prices,while vacancy costs and the vacancy period are both positively related to the landlords’option value and negatively related to price.Market rent is found to have a negative relationship with option price.Overall,this study provides a theoretical analysis and empirical tests of the value of a real option that allows option holders to renew/extend their contracts at a fair market value.展开更多
This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodo...This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodologies examine the value of ecological resources, but are often criticized for their monetary focus. These methods generally produce quasi-market values for non-market resources. The natural and cultural resources associated with a national park are analyzed in terms of the expressed values of active stakeholders to quantitatively produce multiple dimensions of value for each resource relative to all others. The resulting abstract and graphical value-space quantitatively reflects stakeholder participation, reflects non-market intrinsic value, and proactively contributes to environmental management and decision making.展开更多
The existing building (EB) as a system and part of the whole system is causing expansion knowledge, which we need if valuate heritage building (HB) or building in the city center (CCB). In many reasons, HB should not ...The existing building (EB) as a system and part of the whole system is causing expansion knowledge, which we need if valuate heritage building (HB) or building in the city center (CCB). In many reasons, HB should not be the subject of capital, and therefore not dependent on supply and demand. Valuation of HB or CCB needs attention to the understanding of the difference between buildings even if they stand in the same street or part of the city. This involves so many things, for example, intangible heritage, position on the street, sun expose, traffic, metro, bus station, school, park, etc. We need enough knowledge and mechanism for support to get it. How to get enough knowledge for valuation HB or CCB? Background of real estate value of cultural HB or CCB arises from the system, which needs many elements. Firstly, understanding the building as a system with materials, installations, details, and intangible cultural heritage has an impact on details in buildings. Secondly, HB or CCB is important to understand our history, and they are like books that content history knowledge of engineering and arts. Thirdly, property value does not always arise from buildings. Value involves traffic, sun-exposed, the distance from social buildings (hospital, bus station, railway station) or parks, noise, air pollution, etc. HB or CCB is part of the higher/bigger system. This type of real estate presents many reasons for introducing interdisciplinarity and is part of a complete global system. Interdisciplinarity requires knowledge and new approaches to help in the acquisition of knowledge. The goal of these approaches is how in a simpler and faster way to gain knowledge about the object, HB and CCB, and the wider system. Information technology allows collecting a wider range of information faster and better than in the past. At the same time, the same information changes into the necessary knowledge, but the question is if we have enough mass of data and what kind of data we need. The paper shows the theoretical background for the valuation of HB and CCB system.展开更多
Recreation and beach use constitute core aspects of coastal tourism development since they incorporate various stakeholders at different levels and diverse activities. This research investigates the economical recreat...Recreation and beach use constitute core aspects of coastal tourism development since they incorporate various stakeholders at different levels and diverse activities. This research investigates the economical recreational value of the coastal zone between Molos and Arkitsa, in prefecture of Fthiotida, in Sterea Ellada region, in Greece. The study area provides substantial benefits to host community and remains an advantageous natural setting for tourism sustainable development. An economic valuation of the benefits largely assists the efforts of the local authorities to establish viable tourism products and preferred destination attributes. The travel cost method was used to estimate recreation demand. Based on personal and on site interviews 1,433 questionnaires were collected. The consumer surplus per day enjoyed by the visitors is 22,352.28 （Euros）. The analysis assigned a considerable value to the coastal zone. Results shed light on core issues such as environmental management and proper resource allocation in view of finding areas for further improvement so as to increase consumer surplus by satisfying the needs and wants of coastal visitors.展开更多
Wisdom and Belief of the East-Understanding the Chinese Values Author:Han Zhen Price:RMB 95 Paperback,207 pages Published by Foreign Languages Press China is increasingly taking center stage in the international arena...Wisdom and Belief of the East-Understanding the Chinese Values Author:Han Zhen Price:RMB 95 Paperback,207 pages Published by Foreign Languages Press China is increasingly taking center stage in the international arena,and people from around the world are particularly interested in the path the country has taken and the direction it is heading in.More importantly,they want to know what China can contribute to the world.All this curiosity may be boiled down to a seemingly simple question:How to understand China?However,it is not a question that is easily answered in just a few words.展开更多
Water resource management is critical to Turkey’s economy and environment. The country has about 112 billion m<sup>3</sup> per year of economically exploitable water. However, population growth, climate c...Water resource management is critical to Turkey’s economy and environment. The country has about 112 billion m<sup>3</sup> per year of economically exploitable water. However, population growth, climate change and pollution of water bodies are putting increasing pressure on these resources. In this context, understanding the contribution of water to the economy and environment is crucial for its conservation. To meet this need, the World Bank launched a program aiming at improving valuation and accounting systems of natural resources in Turkey. As part of this program, this article estimates in monetary terms the economic value of water in Bey?ehir Lake, the largest freshwater lake in Turkey. Valuation is based on the Total Economic Value concept, which includes use and non-use values. The results show that the economic value of water is about seven times higher than its financial value. In addition, the economic value of water allocated for municipal use (TL5/m<sup>3</sup>) is substantially greater than that supplied for irrigation (TL0.5/m<sup>3</sup>). The analysis suggests that allocation of water from Bey?ehir Lake among different uses is inefficient. To validate this conclusion and improve allocation, a more comprehensive assessment of the economic benefits of water resources is needed, particularly of water supply for irrigation, municipal use, recreation and biodiversity. The analysis also indicates that economic valuation can be a powerful tool to improve water management at the river basin level.展开更多
The present research developed a bioeconomic model for control of Californian thistle （Cirsium arvense L. Scop.） in intensive, lowland sheep pastures in New Zealand. Production costs included two control methods： h...The present research developed a bioeconomic model for control of Californian thistle （Cirsium arvense L. Scop.） in intensive, lowland sheep pastures in New Zealand. Production costs included two control methods： herbicides and defoliation, with defoliation encompassing both physical means and biocontrol measures. The model was used to examine the economic value of a research programme into biological control of the weed, given several different future scenarios. These scenarios were high herbicide prices, a price premium for lamb raised without chemical herbicides, and development of herbicide resistance. The model results were used to estimate national impacts. If the only change in the agricultural sector was the cost of the biocontrol to the nation＇s farmers, the research programme to find an effective biocontrol agent had little economic impact. If other factors changed, such as the price of petroleum or levels of herbicide resistance in the weed. the model＇s results suggested that intensive sheep farming could grow or shrink by as much as NZ$219 million dollars over five years. In the latter case, having an alternative control method reduced potential losses and increased potential gains, resulting in a net benefit of between NZ$81 million and NZ$153 million. This work extended prior research in several ways. First. Californian thistle reproduces via root buds, which affected the modelling of weed behaviour. Secondly, the model allowed optimistation over continuous levels of weed control for two different methods. Thirdly, the model accounted for both weed control and damage to nitrogen-fixing clover from herbicide use. Finally, the research investigated optimal weed control in several different alternative future states.展开更多
Highlights:Values and valuing are seen as enhancing pedagogical actions.•Throughout the papers,the review of the literature is complemented and each research includes specific theoretical constructs.•Regarding researc...Highlights:Values and valuing are seen as enhancing pedagogical actions.•Throughout the papers,the review of the literature is complemented and each research includes specific theoretical constructs.•Regarding research methods,quantitative comparative research projects,which explore students'values related to mathematics,have been influencing other research about values.•A broad and shared theme by the group is the observation of the educational phenomena from a perspective that acknowledges culture and the humanness of the mathematical knowledge.In their research,the collective of authors truly incorporates humaneness in the production and in the teaching and learning of mathematics.展开更多
This paper is concerned with a class of nonlinear fractional differential equations with a disturbance parameter in the integral boundary conditions on the infinite interval.By using Guo-Krasnoselskii fixed point theo...This paper is concerned with a class of nonlinear fractional differential equations with a disturbance parameter in the integral boundary conditions on the infinite interval.By using Guo-Krasnoselskii fixed point theorem,fixed point index theory and the analytic technique,we give the bifurcation point of the parameter which divides the range of parameter for the existence of at least two,one and no positive solutions for the problem.And,by using a fixed point theorem of generalized concave operator and cone theory,we establish the maximum parameter interval for the existence of the unique positive solution for the problem and show that such a positive solution continuously depends on the parameter.In the end,some examples are given to illustrate our main results.展开更多
This paper studies high order compact finite volume methods on non-uniform meshes for one-dimensional elliptic and parabolic differential equations with the Robin boundary conditions.An explicit scheme and an implicit...This paper studies high order compact finite volume methods on non-uniform meshes for one-dimensional elliptic and parabolic differential equations with the Robin boundary conditions.An explicit scheme and an implicit scheme are obtained by discretizing the equivalent integral form of the equation.For the explicit scheme with nodal values,the algebraic system can be solved by the Thomas method.For the implicit scheme with both nodal values and their derivatives,the system can be implemented by a prediction-correction procedure,where in the correction stage,an implicit formula for recovering the nodal derivatives is introduced.Taking two point boundary value problem as an example,we prove that both the explicit and implicit schemes are convergent with fourth order accuracy with respect to some standard discrete norms using the energy method.Two numerical examples demonstrate the correctness and effectiveness of the schemes,as well as the indispensability of using non-uniform meshes.展开更多
Foreign Trade Posts Strong Growth China’s foreign trade has posted a robust start to the year,with the total value of trade in goods surging 18.3 percent year on year in the January–February period,latest official d...Foreign Trade Posts Strong Growth China’s foreign trade has posted a robust start to the year,with the total value of trade in goods surging 18.3 percent year on year in the January–February period,latest official data showed.Data released on 10 March by the General Administration of Customs revealed that total goods trade value had reached 7.73 trillion yuan(about$1.12 trillion)during this period.展开更多
Extreme traffic loads significantly challenge the safety and cost-effectiveness of highway bridges,especially under site-specific traffic conditions.Conventional assessments often rely on overly conservative load mode...Extreme traffic loads significantly challenge the safety and cost-effectiveness of highway bridges,especially under site-specific traffic conditions.Conventional assessments often rely on overly conservative load models,leading to excessive structural design.In this study,a framework for the prediction of maximum bending moments in simply supported bridges is developed by integrating weigh-in-motion(WIM)data,traffic microsimulation,and generalized extreme value(GEV)regression modeling to establish relationships between the GEV parameters(μ,σ,ξ)and traffic factors—heavy vehicle proportion,bridge span length,vehicle speed,headway,and traffic volume.Using one-year WIM data from 7.4 million vehicles,the developed models for μ and σ exhibit high predictive accuracy(R^(2)>0.95)and are validated through leave-one-out cross-validation.The prediction of ξ is less accurate(R^(2)≈0.6),requiring further improvement.Applying these models to a 1000-year return level yields a reliable,data-driven extrapolation,supporting optimized bridge design and safety assessment under varying traffic conditions.展开更多
BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) a...BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.展开更多
Weak measurement offers a powerful framework for probing nonclassical features of quantum mechanics,with anomalous weak values serving as operational signatures of contextuality.While the anomalous weak value verifica...Weak measurement offers a powerful framework for probing nonclassical features of quantum mechanics,with anomalous weak values serving as operational signatures of contextuality.While the anomalous weak value verification of quantum contextuality has been predominantly investigated in the single-photon regime and analyzed under approximation condition of infinitesimally small perturbation strength.This study releases the approximation condition and takes into account the impact of perturbation strength on the rigor of the verification.And the investigation on the verification of contextuality is extended to the multi-photon scenarios for observing the influence of the correlation between photons on the verification.Without the limitation of infinitesimally small probability of disturbance,anomalous weak values are identified as necessary for contextuality to emerge,thereby refining the criterion proposed by Pusey[Phys.Rev.Lett.113200401(2014)].In the multi-photon scenarios,the emergence of contextuality also depends strongly on both the photon number and the photon-number distribution state.In particular,contextuality is found to be maximized when the single-photon component dominates and the second-order correlation is lower.These results highlight the critical role of photon statistics in experimental tests of contextuality via anomalous weak values.展开更多
An optimization model has been established and solved to determine the optimal threshold value for the event-triggered self-adaptive optimization strategy,which aims to strike a balance between optimization performanc...An optimization model has been established and solved to determine the optimal threshold value for the event-triggered self-adaptive optimization strategy,which aims to strike a balance between optimization performance and control load while ensuring continuous optimization.First,evaluation indicators are introduced to comprehensively analyze the impact of power fluctuations on the objective function and system voltage at both the system-wide and local levels.Based on these indicators,a multi-stage centralized optimization(MCO)is selectively applied,addressing system state deviations to achieve optimal operating states while maintaining a voltage security margin to ensure system safety.Then,distributed optimization(DO)is carried out at each bus with a renewable energy source or random load integration to accommodate short-term uncertainties using a self-adaptive reactive power algorithm.The optimal threshold value for event-triggered DO is calculated to balance control burden and optimization effectiveness.Utilizing the local state deviation evaluation indicator,unnecessary DOs are skipped when minor power fluctuations occur at the local level.Finally,following the linear superposition principle,event-triggered DOs executed at all distributed controllers collectively constitute the self-adaptive optimization strategy for the entire system.A case study on the IEEE New England 39-bus power system illustrates the effectiveness of the proposed strategy.展开更多
Solar-driven H_(2) production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals,yet its feasibility relies critically on effecti...Solar-driven H_(2) production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals,yet its feasibility relies critically on effective bifunctional photocatalysts.Herein,we report the synthesis of ultrafine Cd_(x)Zn_(1-x)S nanocrystals derived from a zeolitic imidazolate framework(ZIF),featuring high surface area,shortened charge diffusion path,and enhanced H_(2) evolution activity.Anchoring amorphous Pt sub-nanoclusters onto these nanocrystals created a bifunctional catalyst(Pt-Cd_(x)Zn_(1-x)S)for efficient lactic acid photoreforming,enabling coproduction of H_(2) with switchable selectivity toward pyruvic acid(PA)or 2,3-dihydroxy-2,3-dimethylsuccinic acid(DTA).The optimized 0.5Pt-Cd_(0.3)Zn_(0.7)S catalyst achieved an exceptional H_(2) production rate of 270.6 mmol h^(-1) g^(-1),73.1%PA selectivity,and 62.8% apparent quantum efficiency at 400 nm.Mechanistic studies revealed that lactic acid undergoes C-H cleavage to form carbon-centered radicals.Pt sub-nanoclusters served as electron sinks to facilitate O-H dissociation and PA formation,whereas pristine Cd_(0.3)Zn_(0.6)7S promoted direct C-C coupling of radicals to predominantly yield DTA.This work offers critical insights for designing advanced bifunctional photocatalysts to integrate solar hydrogen and value-added chemical synthesis.展开更多
Lhasa,one of the world's highest cities,confronts the challenge of harmonizing cultural heritage preservation with ecological protection.Assessing the spatiotemporal dynamics of ecosystem service value(ESV)in its ...Lhasa,one of the world's highest cities,confronts the challenge of harmonizing cultural heritage preservation with ecological protection.Assessing the spatiotemporal dynamics of ecosystem service value(ESV)in its central urban area is therefore critical for informing future urban planning and land management.This study systematically analyzed land use evolution,the spatiotemporal characteristics of ecosystem services,and ecological network construction within Lhasa's central urban area.It integrated multi-source data,including Landsat remote sensing imagery from 2000,2010,and 2023,with multiple modeling methods such as the InVEST model,MaxEnt for cultural service assessment,the Minimum Cumulative Resistance(MCR)model,and circuit theory.Based on these analyses,optimization strategies were proposed.The results indicate that from 2000 to 2023,areas of cultivated land,grassland,and water bodies decreased by 7.47%,6.85%,and 0.68%,respectively,while wetland and forest areas expanded by 1.44%and 0.64%.Construction land exhibited significant expansion(12.94%),leading to an overall ESV reduction of 462.8×10^(5)yuan.Vegetation coverage was identified as the pivotal factor influencing ESV distribution,with higher values concentrated in the Lhasa River Basin and near the Lhalu Wetland,diminishing towards the urban core.Furthermore,spatial autocorrelation analysis revealed significant positive spatial clustering,with low-low aggregation in the eastern and central regions and high-high aggregation in the Lhasa River Basin and its surrounding water bodies.Moreover,based on a comprehensive ecosystem service assessment,11 ecological source sites were identified,primarily in the southwestern mountains and northeastern foothills.A comprehensive resistance surface,incorporating factors such as elevation,Normalized Difference Vegetation Index(NDVI),and land use,facilitated the extraction of 23 potential ecological corridors totaling 124.96 km in length.Topological network analysis indicated high redundancy and connectivity;however,marginal source sites relying on single connections exhibited significant vulnerability to rupture.Additionally,the application of circuit theory identified 30 ecological pinch points(current density≥1.5 A/km^(2))and 23 obstacle points,revealing significant blockages to ecological flow along the Qinghai-Xizang Highway,within the old city,and in other areas of high-intensity human activity.To address the identified network deficiencies—‘scattered cores,fragmented corridors,and insufficient resilience’—this study proposes an optimization strategy conceptualized as‘one vein,three corridors,and multiple cores’.Recommendations for enhancing network resilience include the delineation of ecological protection red lines,the integration of plateau-adapted technologies,and the fostering of community governance mechanisms.This approach aims to provide a scientific basis for constructing an ecological security pattern and promoting sustainable development in plateau cities.Ultimately,this research contributes to the enhancement of ecological well-being in the Himalayan region.展开更多
基金supported by Humanities and Social Sciences research project of Ministry of Education(Grant No.24YJCZH342)the Inventory of ecological products and calculation of Gross ecosystem product(GEP)in Zhangye City(Grant No.E4390901)。
文摘Farmland ecosystems are the primary ecosystem type in inland river basins,providing the biological and material basis for human development and survival.The foundation for monetizing the value of agricultural ecological products and transforming green mountains into gold mountains is the precise assessment of ecosystem products in specific geographic units(VEP)within farmland ecosystems,which elucidates regional agricultural resource endowments and spatial distribution.However,agricultural ecological products face challenges in valuation,trading,and monetization,and research on pathways for their value transformation remains limited.This study uses Zhangye City in inland river basins as an example to construct a catalog of farmland ecosystem ecological products and explores VEP accounting methods based on multi-source data,including statistical,remote sensing,and monitoring data,at the city and county scales,and analyzes differentiated value transformation pathways according to the attributes of various agricultural ecological products.The results show that material supply value ranks highest among the VEP of farmland ecosystems in inland river basins,followed by regulatory services,while recreational agriculture value ranks lowest.The ranking of VEP varies from the ranking of farmland ecosystem area,with available agricultural water being a major constraint on the VEP of farmland ecosystems in inland river basins.Regional climate,geographic position,and transportation are linked to the value of agricultural ecosystem products within material supply products.Precipitation,soil structure,and cropping patterns are linked to the value of agricultural ecosystem products within regulatory services.The local cultural resources and tourism infrastructure are linked to the value of agricultural ecosystem products within cultural services.Regarding the pathways for achieving the value of agricultural ecological products,market-oriented strategies dominate the mainstay of material supply products,government-led mechanisms are pivotal for regulatory service products,and a combination of government and market strategies is essential for cultural service products.
文摘The objective of this paper is the valuation of radiological health effects of Yatagan Power Plant. To this aim the radiation dose calculations are carried out for the population living within 80 km radius of the plant. The average of the maximum measured specific isotopes 238U, 232Th and 226Ra in the flying ash samples are considered as radioactive sources. Based on the dose calculations, first the stochastic health effects and then monetary health effects are estimated. The estimated total collective dose and economic value of the pre-dicted health effects are 0.3098 man Sv/y and 14791 US$/y respectively. The results obtained from the dose calculations are lower than the limits of International Commission of Radiation Protection (ICRP) and it does not pose any risk for public health. Monetary value of health risks is also negligible in comparison to the av-erage yearly sales revenue of the plant which is 250 million US$.
文摘Cultural tourism helps preserve historical architecture and develop traditional arts in Xinjiangas the sun rises over Kazanqi in northwest China,the early morning silence is broken only by the tinkling sound of a horse’s sleigh bells.The old horsedrawn carriage bringing the day’s first visitors make its way slowly through the Kazanqi Folk Tourism District,a triple-A scenic spot in the Xinjiang Uygur Autonomous Region.No tourist buses or cars are allowed here.Visitors travel around the area using traditional means of
基金research grants(P0030199 and P0038209)from the Hong Kong Polytechnic University。
文摘In this study,we develop and empirically test a valuation model for a commonly encountered option in office leases:a tenant’s option to renew at future market rent(a fair market value)with lease termination as the maturity date.The model integrates decision analysis with real options analysis and market risk with private risks.“Option value”is defined as the private value of the option to either party pre-contract,while“option price”assumes a fair agreement between transacting parties and can be positive(rental premium paid)or negative(rental discount offered).Without manifest expectations,an analysis of a sample of office leases supports the model’s logic with price estimates in a practical range.The tenants’option price/value is shown to have a negative relationship with the original/renewal lease term;conversely,the landlords’option value is positively related to the original/renewal term.Comparative analyses show that transaction costs have a positive effect on tenants’option value and on prices,while vacancy costs and the vacancy period are both positively related to the landlords’option value and negatively related to price.Market rent is found to have a negative relationship with option price.Overall,this study provides a theoretical analysis and empirical tests of the value of a real option that allows option holders to renew/extend their contracts at a fair market value.
文摘This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodologies examine the value of ecological resources, but are often criticized for their monetary focus. These methods generally produce quasi-market values for non-market resources. The natural and cultural resources associated with a national park are analyzed in terms of the expressed values of active stakeholders to quantitatively produce multiple dimensions of value for each resource relative to all others. The resulting abstract and graphical value-space quantitatively reflects stakeholder participation, reflects non-market intrinsic value, and proactively contributes to environmental management and decision making.
文摘The existing building (EB) as a system and part of the whole system is causing expansion knowledge, which we need if valuate heritage building (HB) or building in the city center (CCB). In many reasons, HB should not be the subject of capital, and therefore not dependent on supply and demand. Valuation of HB or CCB needs attention to the understanding of the difference between buildings even if they stand in the same street or part of the city. This involves so many things, for example, intangible heritage, position on the street, sun expose, traffic, metro, bus station, school, park, etc. We need enough knowledge and mechanism for support to get it. How to get enough knowledge for valuation HB or CCB? Background of real estate value of cultural HB or CCB arises from the system, which needs many elements. Firstly, understanding the building as a system with materials, installations, details, and intangible cultural heritage has an impact on details in buildings. Secondly, HB or CCB is important to understand our history, and they are like books that content history knowledge of engineering and arts. Thirdly, property value does not always arise from buildings. Value involves traffic, sun-exposed, the distance from social buildings (hospital, bus station, railway station) or parks, noise, air pollution, etc. HB or CCB is part of the higher/bigger system. This type of real estate presents many reasons for introducing interdisciplinarity and is part of a complete global system. Interdisciplinarity requires knowledge and new approaches to help in the acquisition of knowledge. The goal of these approaches is how in a simpler and faster way to gain knowledge about the object, HB and CCB, and the wider system. Information technology allows collecting a wider range of information faster and better than in the past. At the same time, the same information changes into the necessary knowledge, but the question is if we have enough mass of data and what kind of data we need. The paper shows the theoretical background for the valuation of HB and CCB system.
文摘Recreation and beach use constitute core aspects of coastal tourism development since they incorporate various stakeholders at different levels and diverse activities. This research investigates the economical recreational value of the coastal zone between Molos and Arkitsa, in prefecture of Fthiotida, in Sterea Ellada region, in Greece. The study area provides substantial benefits to host community and remains an advantageous natural setting for tourism sustainable development. An economic valuation of the benefits largely assists the efforts of the local authorities to establish viable tourism products and preferred destination attributes. The travel cost method was used to estimate recreation demand. Based on personal and on site interviews 1,433 questionnaires were collected. The consumer surplus per day enjoyed by the visitors is 22,352.28 （Euros）. The analysis assigned a considerable value to the coastal zone. Results shed light on core issues such as environmental management and proper resource allocation in view of finding areas for further improvement so as to increase consumer surplus by satisfying the needs and wants of coastal visitors.
文摘Wisdom and Belief of the East-Understanding the Chinese Values Author:Han Zhen Price:RMB 95 Paperback,207 pages Published by Foreign Languages Press China is increasingly taking center stage in the international arena,and people from around the world are particularly interested in the path the country has taken and the direction it is heading in.More importantly,they want to know what China can contribute to the world.All this curiosity may be boiled down to a seemingly simple question:How to understand China?However,it is not a question that is easily answered in just a few words.
文摘Water resource management is critical to Turkey’s economy and environment. The country has about 112 billion m<sup>3</sup> per year of economically exploitable water. However, population growth, climate change and pollution of water bodies are putting increasing pressure on these resources. In this context, understanding the contribution of water to the economy and environment is crucial for its conservation. To meet this need, the World Bank launched a program aiming at improving valuation and accounting systems of natural resources in Turkey. As part of this program, this article estimates in monetary terms the economic value of water in Bey?ehir Lake, the largest freshwater lake in Turkey. Valuation is based on the Total Economic Value concept, which includes use and non-use values. The results show that the economic value of water is about seven times higher than its financial value. In addition, the economic value of water allocated for municipal use (TL5/m<sup>3</sup>) is substantially greater than that supplied for irrigation (TL0.5/m<sup>3</sup>). The analysis suggests that allocation of water from Bey?ehir Lake among different uses is inefficient. To validate this conclusion and improve allocation, a more comprehensive assessment of the economic benefits of water resources is needed, particularly of water supply for irrigation, municipal use, recreation and biodiversity. The analysis also indicates that economic valuation can be a powerful tool to improve water management at the river basin level.
文摘The present research developed a bioeconomic model for control of Californian thistle （Cirsium arvense L. Scop.） in intensive, lowland sheep pastures in New Zealand. Production costs included two control methods： herbicides and defoliation, with defoliation encompassing both physical means and biocontrol measures. The model was used to examine the economic value of a research programme into biological control of the weed, given several different future scenarios. These scenarios were high herbicide prices, a price premium for lamb raised without chemical herbicides, and development of herbicide resistance. The model results were used to estimate national impacts. If the only change in the agricultural sector was the cost of the biocontrol to the nation＇s farmers, the research programme to find an effective biocontrol agent had little economic impact. If other factors changed, such as the price of petroleum or levels of herbicide resistance in the weed. the model＇s results suggested that intensive sheep farming could grow or shrink by as much as NZ$219 million dollars over five years. In the latter case, having an alternative control method reduced potential losses and increased potential gains, resulting in a net benefit of between NZ$81 million and NZ$153 million. This work extended prior research in several ways. First. Californian thistle reproduces via root buds, which affected the modelling of weed behaviour. Secondly, the model allowed optimistation over continuous levels of weed control for two different methods. Thirdly, the model accounted for both weed control and damage to nitrogen-fixing clover from herbicide use. Finally, the research investigated optimal weed control in several different alternative future states.
文摘Highlights:Values and valuing are seen as enhancing pedagogical actions.•Throughout the papers,the review of the literature is complemented and each research includes specific theoretical constructs.•Regarding research methods,quantitative comparative research projects,which explore students'values related to mathematics,have been influencing other research about values.•A broad and shared theme by the group is the observation of the educational phenomena from a perspective that acknowledges culture and the humanness of the mathematical knowledge.In their research,the collective of authors truly incorporates humaneness in the production and in the teaching and learning of mathematics.
基金Supported by the National Natural Science Foundation of China(11361047)Fundamental Research Program of Shanxi Province(20210302124529)。
文摘This paper is concerned with a class of nonlinear fractional differential equations with a disturbance parameter in the integral boundary conditions on the infinite interval.By using Guo-Krasnoselskii fixed point theorem,fixed point index theory and the analytic technique,we give the bifurcation point of the parameter which divides the range of parameter for the existence of at least two,one and no positive solutions for the problem.And,by using a fixed point theorem of generalized concave operator and cone theory,we establish the maximum parameter interval for the existence of the unique positive solution for the problem and show that such a positive solution continuously depends on the parameter.In the end,some examples are given to illustrate our main results.
文摘This paper studies high order compact finite volume methods on non-uniform meshes for one-dimensional elliptic and parabolic differential equations with the Robin boundary conditions.An explicit scheme and an implicit scheme are obtained by discretizing the equivalent integral form of the equation.For the explicit scheme with nodal values,the algebraic system can be solved by the Thomas method.For the implicit scheme with both nodal values and their derivatives,the system can be implemented by a prediction-correction procedure,where in the correction stage,an implicit formula for recovering the nodal derivatives is introduced.Taking two point boundary value problem as an example,we prove that both the explicit and implicit schemes are convergent with fourth order accuracy with respect to some standard discrete norms using the energy method.Two numerical examples demonstrate the correctness and effectiveness of the schemes,as well as the indispensability of using non-uniform meshes.
文摘Foreign Trade Posts Strong Growth China’s foreign trade has posted a robust start to the year,with the total value of trade in goods surging 18.3 percent year on year in the January–February period,latest official data showed.Data released on 10 March by the General Administration of Customs revealed that total goods trade value had reached 7.73 trillion yuan(about$1.12 trillion)during this period.
基金The National Natural Science Foundation of China(No.52278149)the Natural Science Foundation of Jiangsu Province(No.BZ2024015)+1 种基金the Opening Project of State Key Laboratory for Track Technology of High-Speed Railway(No.2023YJ375)the Opening Project of Zhejiang Engineering Centre of Road and Bridge Intelligent Operation and Maintenance Technology(No.202402G).
文摘Extreme traffic loads significantly challenge the safety and cost-effectiveness of highway bridges,especially under site-specific traffic conditions.Conventional assessments often rely on overly conservative load models,leading to excessive structural design.In this study,a framework for the prediction of maximum bending moments in simply supported bridges is developed by integrating weigh-in-motion(WIM)data,traffic microsimulation,and generalized extreme value(GEV)regression modeling to establish relationships between the GEV parameters(μ,σ,ξ)and traffic factors—heavy vehicle proportion,bridge span length,vehicle speed,headway,and traffic volume.Using one-year WIM data from 7.4 million vehicles,the developed models for μ and σ exhibit high predictive accuracy(R^(2)>0.95)and are validated through leave-one-out cross-validation.The prediction of ξ is less accurate(R^(2)≈0.6),requiring further improvement.Applying these models to a 1000-year return level yields a reliable,data-driven extrapolation,supporting optimized bridge design and safety assessment under varying traffic conditions.
基金supported by the CAMS Innovation Fund for Medical Sciences (CIFMS)(No.2021-1-I2M-020)National High Level Hospital Clinical Research Funding (No.2022-PUMCH-B-109)National Natural Science Foundation of China (82402543)。
文摘BACKGROUND:Although the Confusion Assessment Methods for the Intensive Care Unit(CAMICU) is a recommended tool for diagnosing sepsis-associated encephalopathy(SAE),it has several limitations.Mismatch-negativity(MMN) and P3a are components of event-related potentials(ERPs) used with electroencephalography(EEG) and are associated with cerebral function changes in critically ill patients.This study aimed to provide a quantitative,non-invasive method to guide SAE diagnosis in nonsedated patients.METHODS:From January 2022 to March 2023,sepsis patients without sedation were enrolled and assessed via the CAM-ICU,Glasgow Coma Scale(GCS),and ERP under standard procedures.Both MMN and P3a data were collected.The diagnostic value of MMN and P3a was assessed with processed ERP data.RESULTS:Thirty-six patients were included in this study,comprising 19 patients with SAE and 17 patients without SAE(NSAE).MMN and P3a amplitudes decreased,and only FzMMN amplitude significantly decreased in SAE patients(2.03 [1.08,2.93] mV vs.3.21 [1.92,4.34] mV,P=0.040).After median dichotomization,low F3P3a and FzP3a amplitudes were associated with higher CAM-ICU positivity rates and APACHE II scores.Both amplitude in F3P3a(AUC=0.710,95%CI:0.527–0.893,P=0.034) and FzP3a(AUC=0.700,95%CI:0.519–0.881,P=0.041) exhibited moderate diagnostic efficacy for SAE,while FzMMN amplitude lacks effective diagnostic value.CONCLUSION:In this pilot study,ERP components F3P3a and FzP3a amplitudes demonstrated moderate diagnostic value for SAE.These exploratory findings require confirmation in larger and powered cohorts.
基金Project supported by the National Natural Science Foun-dation of China(Grant Nos.62371199 and 62071186)the Natural Science Foundation of Guangdong Province,China(Grant No.2024A1515012427)+1 种基金the Quantum Science Strate-gic Initiative Project of Guangdong Province,China(Grant No.GDZX2305001)the Key Laboratory Project of Guangdong Province,China(Grant No.2020B1212060066).
文摘Weak measurement offers a powerful framework for probing nonclassical features of quantum mechanics,with anomalous weak values serving as operational signatures of contextuality.While the anomalous weak value verification of quantum contextuality has been predominantly investigated in the single-photon regime and analyzed under approximation condition of infinitesimally small perturbation strength.This study releases the approximation condition and takes into account the impact of perturbation strength on the rigor of the verification.And the investigation on the verification of contextuality is extended to the multi-photon scenarios for observing the influence of the correlation between photons on the verification.Without the limitation of infinitesimally small probability of disturbance,anomalous weak values are identified as necessary for contextuality to emerge,thereby refining the criterion proposed by Pusey[Phys.Rev.Lett.113200401(2014)].In the multi-photon scenarios,the emergence of contextuality also depends strongly on both the photon number and the photon-number distribution state.In particular,contextuality is found to be maximized when the single-photon component dominates and the second-order correlation is lower.These results highlight the critical role of photon statistics in experimental tests of contextuality via anomalous weak values.
基金supported in part by National Key R&D Program of China(2022YFF0610600).
文摘An optimization model has been established and solved to determine the optimal threshold value for the event-triggered self-adaptive optimization strategy,which aims to strike a balance between optimization performance and control load while ensuring continuous optimization.First,evaluation indicators are introduced to comprehensively analyze the impact of power fluctuations on the objective function and system voltage at both the system-wide and local levels.Based on these indicators,a multi-stage centralized optimization(MCO)is selectively applied,addressing system state deviations to achieve optimal operating states while maintaining a voltage security margin to ensure system safety.Then,distributed optimization(DO)is carried out at each bus with a renewable energy source or random load integration to accommodate short-term uncertainties using a self-adaptive reactive power algorithm.The optimal threshold value for event-triggered DO is calculated to balance control burden and optimization effectiveness.Utilizing the local state deviation evaluation indicator,unnecessary DOs are skipped when minor power fluctuations occur at the local level.Finally,following the linear superposition principle,event-triggered DOs executed at all distributed controllers collectively constitute the self-adaptive optimization strategy for the entire system.A case study on the IEEE New England 39-bus power system illustrates the effectiveness of the proposed strategy.
基金supported by the National Natural Science Foundation of China(Grant 52276212)the National Key Research and Development Program of China(Grant 2022YFB3803600)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant BK20231211)the China Fundamental Research Funds for the Central Universities.
文摘Solar-driven H_(2) production coupled with selective organic transformation represents a promising strategy for co-generation of green hydrogen and high-value chemicals,yet its feasibility relies critically on effective bifunctional photocatalysts.Herein,we report the synthesis of ultrafine Cd_(x)Zn_(1-x)S nanocrystals derived from a zeolitic imidazolate framework(ZIF),featuring high surface area,shortened charge diffusion path,and enhanced H_(2) evolution activity.Anchoring amorphous Pt sub-nanoclusters onto these nanocrystals created a bifunctional catalyst(Pt-Cd_(x)Zn_(1-x)S)for efficient lactic acid photoreforming,enabling coproduction of H_(2) with switchable selectivity toward pyruvic acid(PA)or 2,3-dihydroxy-2,3-dimethylsuccinic acid(DTA).The optimized 0.5Pt-Cd_(0.3)Zn_(0.7)S catalyst achieved an exceptional H_(2) production rate of 270.6 mmol h^(-1) g^(-1),73.1%PA selectivity,and 62.8% apparent quantum efficiency at 400 nm.Mechanistic studies revealed that lactic acid undergoes C-H cleavage to form carbon-centered radicals.Pt sub-nanoclusters served as electron sinks to facilitate O-H dissociation and PA formation,whereas pristine Cd_(0.3)Zn_(0.6)7S promoted direct C-C coupling of radicals to predominantly yield DTA.This work offers critical insights for designing advanced bifunctional photocatalysts to integrate solar hydrogen and value-added chemical synthesis.
基金National Natural Science Foundation of China Youth Fund Project:Research on the Construction of Ecological Security Pattern in the Transition Zone of Nature Reserves along the Sichuan-Xizang Railway(Western Sichuan Section)(51908470).
文摘Lhasa,one of the world's highest cities,confronts the challenge of harmonizing cultural heritage preservation with ecological protection.Assessing the spatiotemporal dynamics of ecosystem service value(ESV)in its central urban area is therefore critical for informing future urban planning and land management.This study systematically analyzed land use evolution,the spatiotemporal characteristics of ecosystem services,and ecological network construction within Lhasa's central urban area.It integrated multi-source data,including Landsat remote sensing imagery from 2000,2010,and 2023,with multiple modeling methods such as the InVEST model,MaxEnt for cultural service assessment,the Minimum Cumulative Resistance(MCR)model,and circuit theory.Based on these analyses,optimization strategies were proposed.The results indicate that from 2000 to 2023,areas of cultivated land,grassland,and water bodies decreased by 7.47%,6.85%,and 0.68%,respectively,while wetland and forest areas expanded by 1.44%and 0.64%.Construction land exhibited significant expansion(12.94%),leading to an overall ESV reduction of 462.8×10^(5)yuan.Vegetation coverage was identified as the pivotal factor influencing ESV distribution,with higher values concentrated in the Lhasa River Basin and near the Lhalu Wetland,diminishing towards the urban core.Furthermore,spatial autocorrelation analysis revealed significant positive spatial clustering,with low-low aggregation in the eastern and central regions and high-high aggregation in the Lhasa River Basin and its surrounding water bodies.Moreover,based on a comprehensive ecosystem service assessment,11 ecological source sites were identified,primarily in the southwestern mountains and northeastern foothills.A comprehensive resistance surface,incorporating factors such as elevation,Normalized Difference Vegetation Index(NDVI),and land use,facilitated the extraction of 23 potential ecological corridors totaling 124.96 km in length.Topological network analysis indicated high redundancy and connectivity;however,marginal source sites relying on single connections exhibited significant vulnerability to rupture.Additionally,the application of circuit theory identified 30 ecological pinch points(current density≥1.5 A/km^(2))and 23 obstacle points,revealing significant blockages to ecological flow along the Qinghai-Xizang Highway,within the old city,and in other areas of high-intensity human activity.To address the identified network deficiencies—‘scattered cores,fragmented corridors,and insufficient resilience’—this study proposes an optimization strategy conceptualized as‘one vein,three corridors,and multiple cores’.Recommendations for enhancing network resilience include the delineation of ecological protection red lines,the integration of plateau-adapted technologies,and the fostering of community governance mechanisms.This approach aims to provide a scientific basis for constructing an ecological security pattern and promoting sustainable development in plateau cities.Ultimately,this research contributes to the enhancement of ecological well-being in the Himalayan region.
