Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph (DLG) and up-to-date remote sensitive images which have high precision and have been orthographically rectifi...Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph (DLG) and up-to-date remote sensitive images which have high precision and have been orthographically rectified precisely. Quick Bird panchromatic remote sensing image is used and an urban area with even terrain and dense buildings is selected as experimental area. Ground control points (GCPs) are selected on a new 1∶500 topographical map and multinomial model is applied for rectification. After rectification the absolute positional error of a single point of the image is less than 1m, therefore this method is suitable for renewing topographical maps of up to (1∶2 000) scale.展开更多
Renewing warranty can provide customers with better service,and thus help manufacturers to gain market opportunities.In engineering practice,the cost for replacement is usually higher than the cost for maintenance,hen...Renewing warranty can provide customers with better service,and thus help manufacturers to gain market opportunities.In engineering practice,the cost for replacement is usually higher than the cost for maintenance,hence manufacturers often face huge challenge to reduce the warranty service cost.With consideration of the warranty deadline,we propose a two-stage optimization model for renewing warranty.In the first stage,a renewing warranty with deadline(RWD)policy is implemented,where the deadline represents the cumulative uptime threshold.When the cumulative uptime exceeds the deadline,the product will be minimally repaired and kept to the residual warranty period.When RWD is expired,the replacement warranty with limited repairs(RWLR)policy is applied.Under the free replacement and pro-rata warranty policy,the corresponding two-stage cost optimization model is established from the manufacturer’s perspective,the aim is to minimize the cost rate and obtain the optimal warranty period.A numerical example is provided to illustrate the validity of the proposed model,and the sensitivity analysis is also carried out.展开更多
To create a scientific way to renew the grades of cultivated land at county level, monitoring points were set up according to the monitoring control regions and grade types of cultivated land in Daxing District, Beiji...To create a scientific way to renew the grades of cultivated land at county level, monitoring points were set up according to the monitoring control regions and grade types of cultivated land in Daxing District, Beijing, and soil samples were collected to carry out chemical analysis. Afterwards, the input and output data of cultivated land in each village were surveyed to renew the grades of cultivated land. The results indicate that the average natural grade of cultivated land was 8.4, which was equal to that of 2004; the average utilization grade was 8.1, which was slightly higher than that of 2004; the average economic grade was 9.9, which was lower than that of 2004. It is concluded that it is scientific to renew cultivated land grades through scientifically setting monitoring points according to the monitoring control regions and grade types of cultivated land.展开更多
Distinguished Vice-Minister Li Jinjun,Ladies and gentlemen,friends,It is a delightful event for all of us to renew the MOU between FES and CAFIU for the nineth time.Years of cooperation and fruitful results are worth ...Distinguished Vice-Minister Li Jinjun,Ladies and gentlemen,friends,It is a delightful event for all of us to renew the MOU between FES and CAFIU for the nineth time.Years of cooperation and fruitful results are worth celebrating.For a long period of time,the two organizations have been making efforts to put the thoughts of Deng Xiaopeng and Willy Brandt into practice,namely,the thoughts of having dialogue and enhancing mutual understanding while展开更多
Respected President Beck,Respected guests,Ladies,gentlemen,friends,I am delighted to sign the Memorandum of Understanding on Cooperation between CAFIU and FES with President Beck here today.This is an important moment...Respected President Beck,Respected guests,Ladies,gentlemen,friends,I am delighted to sign the Memorandum of Understanding on Cooperation between CAFIU and FES with President Beck here today.This is an important moment in the history of the relations between CAFIU and FES,which signifies that the sound cooperation between both sides will展开更多
美国作曲家玛丽莲·丝露德(Marilyn Shrude)是著名的钢琴家和作曲家,她所作的《重新开始的神话》(Renewing the Myth)是当代萨克斯管经典音乐作品之一,也是萨克斯管最著名的比赛——第三届阿道夫萨克斯管比赛的必奏曲目.我们通过对...美国作曲家玛丽莲·丝露德(Marilyn Shrude)是著名的钢琴家和作曲家,她所作的《重新开始的神话》(Renewing the Myth)是当代萨克斯管经典音乐作品之一,也是萨克斯管最著名的比赛——第三届阿道夫萨克斯管比赛的必奏曲目.我们通过对这首作品的分析可以了解萨克斯管当代音乐的曲式和技巧.展开更多
The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3...The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells. The stem cells give rise to three main progenitors: prepit, preneck and preparietal cells. Parietal cells develop either directly from the noncycling preparietal cells or less commonly via differentiation of the cycling prepit and preneck cell progenitors. The formation of a parietal cell is a sequential process which involves diminishment of glycocalyx, production of cytoplasmic tubulovesicles, an increase in number and length of microvilli, an increase in number and size of mitochondria, and fi nally, expansion and invagination of the apical membrane with the formation of an intracellular canalicular system. Little is known about the genetic counterparts of these morphological events. However, the time dimension of parietal cell production and the consequences of its alteration on the biological features of the gastric gland are well documented. The production of a new parietal cell takes about 2 d. However, mature parietal cells have a long lifespan during which they migrate bidirectionally while their functional activity for acid secretion gradually diminishes. Following an average lifespan of about 54 d, in mice, old parietal cells undergo degeneration and elimination. Various approaches for genetic alteration of the development of parietal cells have provided evidence in support of their role as governors of the stem/progenitor cell proliferation and differentiation programs. Revealing the dynamic features and the various roles of parietal cells would help in a better understanding of the biological features of the gastric glands and would hopefully help in providing a basis for the development of new strategies for prevention, early detection and/or therapy of various gastric disorders in which parietal cells are involved, such as atrophic gastritis, peptic ulcer disease and gastric cancer.展开更多
Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest chang...Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.展开更多
Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified ...Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy.展开更多
Biogas is a renewable and clean energy source that plays an important role in the current environment of lowcarbon transition.If high-content CO_(2) in biogas can be separated,transformed,and utilized,it not only real...Biogas is a renewable and clean energy source that plays an important role in the current environment of lowcarbon transition.If high-content CO_(2) in biogas can be separated,transformed,and utilized,it not only realizes high-value utilization of biogas but also promotes carbon reduction in the biogas field.To improve the combustion stability of biogas,an inhomogeneous,partially premixed stratified(IPPS)combustion model was adopted in this study.The thermal flame structure and stability were investigated for a wide range of mixture inhomogeneities,turbulence levels,CO_(2) concentrations,air-to-fuel velocity ratios,and combustion energies in a concentric flow slot burner(CFSB).A fine-wire thermocouple is used to resolve the thermal flame structure.The flame size was reduced by increasing the CO_(2) concentration and the flames became lighter blue.The flame temperature also decreased with increase in CO_(2) concentration.Flame stability was reduced by increasing the CO_(2) concentration.However,at a certain level of mixture inhomogeneity,the concentration of CO_(2) in the IPPS mode did not affect the stability.Accordingly,the IPPS mode of combustion should be suitable for the combustion and stabilization of biogas.This should support the design of highly stabilized biogas turbulent flames independent of CO_(2) concentration.The data show that the lower stability conditions are partially due to the change in fuel combustion energy,which is characterized by the Wobbe index(WI).In addition,at a certain level of mixture inhomogeneity,the effect of the WI on flame stability becomes dominant.展开更多
Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,...Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its production.In this study,an engineered strain Escherichia coli(E.coli)showcasing harmonized coexpression of a lipase(from Thermomyces lanuginosus lipase,TLL)and a fatty acid photodecarboxylase(from Chlorella variabilis,CvFAP)was first constructed to transform triglycerides into alkanes.The potential of E.coli BL21(DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process conditions.Following a comprehensive examination of the reaction parameters,the scope of the biotransformation was expanded to‘real’substrates(vegetable oils).The results showed that bioderived oils can be transformed into alkanes with high yields(0.80-10.20 mmol·L^(-1))under mild conditions(35℃,pH 8.0,and 36 h)and blue light illumination.The selected processes were performed on an increased lab scale(up to 100 ml)with up to 24.77 mmol·L^(-1) tripalmitin,leading to a yield of 18.89 mmol·L^(-1) pentadecane.With the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system,the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based biodiesel.Thus,this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production.展开更多
Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source.Among several hydrogen production methods,it has become the most promising technology.However,there is no large-...Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source.Among several hydrogen production methods,it has become the most promising technology.However,there is no large-scale renewable hydrogen production system currently that can compete with conventional fossil fuel hydrogen production.Renewable energy electrocatalytic water splitting is an ideal production technology with environmental cleanliness protection and good hydrogen purity,which meet the requirements of future development.This review summarizes and introduces the current status of hydrogen production by water splitting from three aspects:electricity,catalyst and electrolyte.In particular,the present situation and the latest progress of the key sources of power,catalytic materials and electrolyzers for electrocatalytic water splitting are introduced.Finally,the problems of hydrogen generation from electrolytic water splitting and directions of next-generation green hydrogen in the future are discussed and outlooked.It is expected that this review will have an important impact on the field of hydrogen production from water.展开更多
In the contemporary era,the global expansion of electrical grids is propelled by various renewable energy sources(RESs).Efficient integration of stochastic RESs and optimal power flow(OPF)management are critical for n...In the contemporary era,the global expansion of electrical grids is propelled by various renewable energy sources(RESs).Efficient integration of stochastic RESs and optimal power flow(OPF)management are critical for network optimization.This study introduces an innovative solution,the Gaussian Bare-Bones Levy Cheetah Optimizer(GBBLCO),addressing OPF challenges in power generation systems with stochastic RESs.The primary objective is to minimize the total operating costs of RESs,considering four functions:overall operating costs,voltage deviation management,emissions reduction,voltage stability index(VSI)and power loss mitigation.Additionally,a carbon tax is included in the objective function to reduce carbon emissions.Thorough scrutiny,using modified IEEE 30-bus and IEEE 118-bus systems,validates GBBLCO’s superior performance in achieving optimal solutions.Simulation results demonstrate GBBLCO’s efficacy in six optimization scenarios:total cost with valve point effects,total cost with emission and carbon tax,total cost with prohibited operating zones,active power loss optimization,voltage deviation optimization and enhancing voltage stability index(VSI).GBBLCO outperforms conventional techniques in each scenario,showcasing rapid convergence and superior solution quality.Notably,GBBLCO navigates complexities introduced by valve point effects,adapts to environmental constraints,optimizes costs while considering prohibited operating zones,minimizes active power losses,and optimizes voltage deviation by enhancing the voltage stability index(VSI)effectively.This research significantly contributes to advancing OPF,emphasizing GBBLCO’s improved global search capabilities and ability to address challenges related to local minima.GBBLCO emerges as a versatile and robust optimization tool for diverse challenges in power systems,offering a promising solution for the evolving needs of renewable energy-integrated power grids.展开更多
Metal-organic frameworks(MOFs)possess a distinct advantage over conventional heterogeneous photocatalysts because of their carefully defined architecture and particular pores,which facilitate the targeted incorporatio...Metal-organic frameworks(MOFs)possess a distinct advantage over conventional heterogeneous photocatalysts because of their carefully defined architecture and particular pores,which facilitate the targeted incorporation of other efficient cocatalysts or semiconductor materials.The integration of MOFs with other materials has resulted in significant breakthroughs,as the coupled materials improve the performance due to the combined effect.The unique MOF structures allow them to host foreign materials,which results in harvesting the visible region of the solar spectrum and effectively mitigating charge recombination by promoting charge separation.The review presents an evaluation of the latest developments in the utilization of surface and/or pore chemistry of MOF-supported heterojunctions for photocatalytic green-hydrogen generation with a basic understanding of the mechanism involved.The review begins with the basic principles of photocatalysis,the significance of MOFs,their optical properties,the methods used for synthesizing MOFs,and their coordination with other inorganic and polymeric materials.Furthermore,methods to increase photocatalytic H2 evolution using MOF-supported heterojunction have been proposed as standard practice.Lastly,to address environmental challenges,we highlight the future potential of MOF-supported heterojunctions for use in green-energy production.We hope that this review provides guidance to researchers in the development of effective heterojunctions based on MOFs to address challenges in energy applications and catalytic processes.展开更多
The world is undergoing profound changes in energy and technology.Countries are vigorously developing new sustainable energy sources and technologies.Renewable energy sources encompass various technologies such as win...The world is undergoing profound changes in energy and technology.Countries are vigorously developing new sustainable energy sources and technologies.Renewable energy sources encompass various technologies such as wind turbines,solar energy,nuclear energy,and bioenergy.Additionally,emerging technology fields include new energy vehicles,robots,and artificial intelligence devices,among others.The renewable energy industries and implementation of new technologies necessitate the development and adoption of new equipment and components.Austempered ductile iron(ADI)is renowned for its unique microstructure and superior properties.By utilizing ADI,lightweight and innovative castings can be designed to not only reduce weight but also save energy and decrease emissions.More importantly,these castings enhance the efficiency and reliability of new energy equipment and emerging technology installations.This paper describes the development,applications,and future prospects of lightweight and innovative ADI castings within sectors such as solar photovoltaic(PV),wind power generation,industry robots,and trucks in China.展开更多
Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix an...Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen.Based on the incremental cost principle,we quantified the provincial and national clean hydrogen production cost performance levels in 2030.The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces,with a national average value of less than 2 USD·kg^(-1) at the 40-megaton hydrogen supply scale.Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg^(-1).However,performance is affected by the potential distribution of hydrogen demand.From the supply side,competitiveness of the mechanism is limited to clean hydrogen production,while from the demand side,it could help electrolytic hydrogen fulfil a more significant role.This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.展开更多
The global shift toward next-generation energy systems is propelled by the urgent need to combat climate change and the dwindling supply of fossil fuels.This review explores the intricate challenges and opportunities ...The global shift toward next-generation energy systems is propelled by the urgent need to combat climate change and the dwindling supply of fossil fuels.This review explores the intricate challenges and opportunities for transitioning to sustainable renewable energy sources such as solar,wind,and hydrogen.This transition economically challenges traditional energy sectors while fostering new industries,promoting job growth,and sustainable economic development.The transition to renewable energy demands social equity,ensuring universal access to affordable energy,and considering community impact.The environmental benefits include a significant reduction in greenhouse gas emissions and a lesser ecological footprint.This study highlights the rapid growth of the global wind power market,which is projected to increase from$112.23 billion in 2022 to$278.43 billion by 2030,with a compound annual growth rate of 13.67%.In addition,the demand for hydrogen is expected to increase,significantly impacting the market with potential cost reductions and making it a critical renewable energy source owing to its affordability and zero emissions.By 2028,renewables are predicted to account for 42%of global electricity generation,with significant contributions from wind and solar photovoltaic(PV)technology,particularly in China,the European Union,the United States,and India.These developments signify a global commitment to diversifying energy sources,reducing emissions,and moving toward cleaner and more sustainable energy solutions.This review offers stakeholders the insights required to smoothly transition to sustainable energy,setting the stage for a resilient future.展开更多
Several actions from both the environmental and human viewpoints have already been made to meet the sustainability goals targeted at food systems.Still,new place-based ideas to improve sustainability are needed.Agroec...Several actions from both the environmental and human viewpoints have already been made to meet the sustainability goals targeted at food systems.Still,new place-based ideas to improve sustainability are needed.Agroecological symbiosis(AES),a novel food system model,is an example of a suggested system-level change to attain sustainability targets;it is a symbiosis of food production and processing using renewable energy that uses its own feedstock.AES has already been found advantageous from the ecological and biophysical viewpoints,but a regional economic evaluation of the model is still lacking.Thus,the aim of our paper is to assess the regional economic impact of a possible systemic change in the food system using the network of agroecological symbiosis(NAES)as an example.We applied scenarios representing different ways of moving towards envisioned NAES models in Mäntsälä,Finland,and a computable general equilibrium model to evaluate the regional economic impact.According to our results,both regional economy and employment would increase,and the regional production base would diversify with NAES implementation applied to the region,but the extent of the benefits varies between scenarios.The scenario that includes change in both public and private food demand,production of bioenergy and utilization of by-products would cause the largest impacts.However,realizing NAES requires investments that may influence the actual implementation of such models.Nonetheless,a change towards NAES can promote an economically and spatially just transition to sustainability,as NAES seems to be economically most beneficial for rural areas.展开更多
Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production.However,relevant out-lab research is still in its infancy.Herein,a novel S...Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production.However,relevant out-lab research is still in its infancy.Herein,a novel Sn-based MXene/MAX hybrid with abundant Sn vacancies,Sn@Ti_(2)CTX/Ti_(2)SnC–V,was synthesized by controlled etching Sn@Ti_(2)SnC MAX phase and demonstrated as an efficient electrocatalyst for electrocatalytic N2 reduction.Due to the synergistic effect of MXene/MAX heterostructure,the existence of Sn vacancies and the highly dispersed Sn active sites,the obtained Sn@Ti2CTX/Ti_(2)SnC–V exhibits an optimal NH_(3) yield of 28.4μg h^(−1) mg_(cat)^(−1) with an excellent FE of 15.57% at−0.4 V versus reversible hydrogen electrode in 0.1 M Na_(2)SO_(4),as well as an ultra-long durability.Noticeably,this catalyst represents a satisfactory NH3 yield rate of 10.53μg h^(−1) mg^(−1) in the home-made simulation device,where commercial electrochemical photovoltaic cell was employed as power source,air and ultrapure water as feed stock.The as-proposed strategy represents great potential toward ammonia production in terms of financial cost according to the systematic technical economic analysis.This work is of significance for large-scale green ammonia production.展开更多
Considerable research efforts have been dedicated to investigating the side reactions and the growth of Zn dendritic in aqueous zinc-ion batteries(AZIBs).The incorporation of organic solvents as additives in electroly...Considerable research efforts have been dedicated to investigating the side reactions and the growth of Zn dendritic in aqueous zinc-ion batteries(AZIBs).The incorporation of organic solvents as additives in electrolytes has yielded highly promising results.Nevertheless,their pervasive use has been hindered by concerns regarding their toxicity,flammability,and economic viability.Herein,we propose the utilization of γ-valerolactone(γ-V),a novel eco-friendly solvent,as an alternative for conventional organic additives to improve the performance of Zn anode.Experimental investigations and theoretical analyses have verified that γ-V additives can diminish the Zn^(2+)-desolvation energy and enhance Zn^(2+) transport kinetics.The adsorbed γ-V molecules modulate the nucleation and diffusion of Zn^(2+),facilitating Zn growth along the(002) crystal plane,thus inhibiting dendrite formation and side reactions.Consequently,the modified electrolyte with 3% γ-V exhibit highly reversible cycling for 2800 h at1 mA cm^(-2) and 1 mA h cm^(-2) in Zn//Zn symmetric cell.The Zn//KVOH coin cells deliver a capacity retention of 74.7% after 1000 cycles at 5 A g^(-1).The Zn//KVOH pouch cells maintain a capacity retention of78.7% over 90 cycles at 3 A g^(-1).Notably,the γ-V additives also effectively alleviate the self-discharge phenomenon.This work provides valuable insights on the development of aqueous zinc-ion batteries with superior safety through the modulation of electrolytes using eco-friendly additives.展开更多
文摘Urban large-scale topographical maps can be renewed by means of overlapping the original digital line graph (DLG) and up-to-date remote sensitive images which have high precision and have been orthographically rectified precisely. Quick Bird panchromatic remote sensing image is used and an urban area with even terrain and dense buildings is selected as experimental area. Ground control points (GCPs) are selected on a new 1∶500 topographical map and multinomial model is applied for rectification. After rectification the absolute positional error of a single point of the image is less than 1m, therefore this method is suitable for renewing topographical maps of up to (1∶2 000) scale.
基金Project(71671035) supported by the National Natural Science Foundation of China
文摘Renewing warranty can provide customers with better service,and thus help manufacturers to gain market opportunities.In engineering practice,the cost for replacement is usually higher than the cost for maintenance,hence manufacturers often face huge challenge to reduce the warranty service cost.With consideration of the warranty deadline,we propose a two-stage optimization model for renewing warranty.In the first stage,a renewing warranty with deadline(RWD)policy is implemented,where the deadline represents the cumulative uptime threshold.When the cumulative uptime exceeds the deadline,the product will be minimally repaired and kept to the residual warranty period.When RWD is expired,the replacement warranty with limited repairs(RWLR)policy is applied.Under the free replacement and pro-rata warranty policy,the corresponding two-stage cost optimization model is established from the manufacturer’s perspective,the aim is to minimize the cost rate and obtain the optimal warranty period.A numerical example is provided to illustrate the validity of the proposed model,and the sensitivity analysis is also carried out.
基金Supported by the Scientific Research Project of Ministry of Land and Resources of the People's Public of China in Public Welfare Industries(201011006)
文摘To create a scientific way to renew the grades of cultivated land at county level, monitoring points were set up according to the monitoring control regions and grade types of cultivated land in Daxing District, Beijing, and soil samples were collected to carry out chemical analysis. Afterwards, the input and output data of cultivated land in each village were surveyed to renew the grades of cultivated land. The results indicate that the average natural grade of cultivated land was 8.4, which was equal to that of 2004; the average utilization grade was 8.1, which was slightly higher than that of 2004; the average economic grade was 9.9, which was lower than that of 2004. It is concluded that it is scientific to renew cultivated land grades through scientifically setting monitoring points according to the monitoring control regions and grade types of cultivated land.
文摘Distinguished Vice-Minister Li Jinjun,Ladies and gentlemen,friends,It is a delightful event for all of us to renew the MOU between FES and CAFIU for the nineth time.Years of cooperation and fruitful results are worth celebrating.For a long period of time,the two organizations have been making efforts to put the thoughts of Deng Xiaopeng and Willy Brandt into practice,namely,the thoughts of having dialogue and enhancing mutual understanding while
文摘Respected President Beck,Respected guests,Ladies,gentlemen,friends,I am delighted to sign the Memorandum of Understanding on Cooperation between CAFIU and FES with President Beck here today.This is an important moment in the history of the relations between CAFIU and FES,which signifies that the sound cooperation between both sides will
文摘美国作曲家玛丽莲·丝露德(Marilyn Shrude)是著名的钢琴家和作曲家,她所作的《重新开始的神话》(Renewing the Myth)是当代萨克斯管经典音乐作品之一,也是萨克斯管最著名的比赛——第三届阿道夫萨克斯管比赛的必奏曲目.我们通过对这首作品的分析可以了解萨克斯管当代音乐的曲式和技巧.
基金Supported by Terry Fox Fund for Cancer Research and UAE University
文摘The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells. The stem cells give rise to three main progenitors: prepit, preneck and preparietal cells. Parietal cells develop either directly from the noncycling preparietal cells or less commonly via differentiation of the cycling prepit and preneck cell progenitors. The formation of a parietal cell is a sequential process which involves diminishment of glycocalyx, production of cytoplasmic tubulovesicles, an increase in number and length of microvilli, an increase in number and size of mitochondria, and fi nally, expansion and invagination of the apical membrane with the formation of an intracellular canalicular system. Little is known about the genetic counterparts of these morphological events. However, the time dimension of parietal cell production and the consequences of its alteration on the biological features of the gastric gland are well documented. The production of a new parietal cell takes about 2 d. However, mature parietal cells have a long lifespan during which they migrate bidirectionally while their functional activity for acid secretion gradually diminishes. Following an average lifespan of about 54 d, in mice, old parietal cells undergo degeneration and elimination. Various approaches for genetic alteration of the development of parietal cells have provided evidence in support of their role as governors of the stem/progenitor cell proliferation and differentiation programs. Revealing the dynamic features and the various roles of parietal cells would help in a better understanding of the biological features of the gastric glands and would hopefully help in providing a basis for the development of new strategies for prevention, early detection and/or therapy of various gastric disorders in which parietal cells are involved, such as atrophic gastritis, peptic ulcer disease and gastric cancer.
基金funded by the Guangxi Natural Science Foundation Program (2022GXNSFAA035583 and 2020GXNSFAA159108)National Natural Science Foundation of China (32060305)+2 种基金Foundation of Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University)Ministry of Education, China (ERESEP 2021Z06)Chinese Forest Biodiversity Monitoring Network
文摘Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.
基金supported in part by the Scientific Foundation for Outstanding Young Scientists of Sichuan under Grant No.2021JDJQ0032in part by the National Natural Science Foundation of China under Grant No.52107128in part by the Natural Science Foundation of Sichuan Province under Grant No.2022NSFSC0436.
文摘Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy.
基金funded by the American University in Cairo research grants(Project number SSE-MENG-M.M.-FY18-FY19-FY20-RG(1-18)–2017-Nov-11-17-52-02).
文摘Biogas is a renewable and clean energy source that plays an important role in the current environment of lowcarbon transition.If high-content CO_(2) in biogas can be separated,transformed,and utilized,it not only realizes high-value utilization of biogas but also promotes carbon reduction in the biogas field.To improve the combustion stability of biogas,an inhomogeneous,partially premixed stratified(IPPS)combustion model was adopted in this study.The thermal flame structure and stability were investigated for a wide range of mixture inhomogeneities,turbulence levels,CO_(2) concentrations,air-to-fuel velocity ratios,and combustion energies in a concentric flow slot burner(CFSB).A fine-wire thermocouple is used to resolve the thermal flame structure.The flame size was reduced by increasing the CO_(2) concentration and the flames became lighter blue.The flame temperature also decreased with increase in CO_(2) concentration.Flame stability was reduced by increasing the CO_(2) concentration.However,at a certain level of mixture inhomogeneity,the concentration of CO_(2) in the IPPS mode did not affect the stability.Accordingly,the IPPS mode of combustion should be suitable for the combustion and stabilization of biogas.This should support the design of highly stabilized biogas turbulent flames independent of CO_(2) concentration.The data show that the lower stability conditions are partially due to the change in fuel combustion energy,which is characterized by the Wobbe index(WI).In addition,at a certain level of mixture inhomogeneity,the effect of the WI on flame stability becomes dominant.
基金financially supported by the National Natural Science Foundation of China(42376097)Guangdong Basic and Applied Basic Research Foundation(2023A1515030226,2021A1515010829).
文摘Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its production.In this study,an engineered strain Escherichia coli(E.coli)showcasing harmonized coexpression of a lipase(from Thermomyces lanuginosus lipase,TLL)and a fatty acid photodecarboxylase(from Chlorella variabilis,CvFAP)was first constructed to transform triglycerides into alkanes.The potential of E.coli BL21(DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process conditions.Following a comprehensive examination of the reaction parameters,the scope of the biotransformation was expanded to‘real’substrates(vegetable oils).The results showed that bioderived oils can be transformed into alkanes with high yields(0.80-10.20 mmol·L^(-1))under mild conditions(35℃,pH 8.0,and 36 h)and blue light illumination.The selected processes were performed on an increased lab scale(up to 100 ml)with up to 24.77 mmol·L^(-1) tripalmitin,leading to a yield of 18.89 mmol·L^(-1) pentadecane.With the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system,the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based biodiesel.Thus,this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production.
基金supported by the National Natural Science Foundation of China(U23A20573,U23A20140,22109038)the Starting Research Funds of Hebei University of Science and Technology,Hebei Natural Science Foundation(D2022208001)+1 种基金the S&T Program of Hebei(23314401D)Hebei Pharmaceutical and Chemical Technology Innovation Center(225676121H).
文摘Green hydrogen from electrolysis of water has attracted widespread attention as a renewable power source.Among several hydrogen production methods,it has become the most promising technology.However,there is no large-scale renewable hydrogen production system currently that can compete with conventional fossil fuel hydrogen production.Renewable energy electrocatalytic water splitting is an ideal production technology with environmental cleanliness protection and good hydrogen purity,which meet the requirements of future development.This review summarizes and introduces the current status of hydrogen production by water splitting from three aspects:electricity,catalyst and electrolyte.In particular,the present situation and the latest progress of the key sources of power,catalytic materials and electrolyzers for electrocatalytic water splitting are introduced.Finally,the problems of hydrogen generation from electrolytic water splitting and directions of next-generation green hydrogen in the future are discussed and outlooked.It is expected that this review will have an important impact on the field of hydrogen production from water.
基金supported by the Deanship of Postgraduate Studies and Scientific Research at Majmaah University in Saudi Arabia under Project Number(ICR-2024-1002).
文摘In the contemporary era,the global expansion of electrical grids is propelled by various renewable energy sources(RESs).Efficient integration of stochastic RESs and optimal power flow(OPF)management are critical for network optimization.This study introduces an innovative solution,the Gaussian Bare-Bones Levy Cheetah Optimizer(GBBLCO),addressing OPF challenges in power generation systems with stochastic RESs.The primary objective is to minimize the total operating costs of RESs,considering four functions:overall operating costs,voltage deviation management,emissions reduction,voltage stability index(VSI)and power loss mitigation.Additionally,a carbon tax is included in the objective function to reduce carbon emissions.Thorough scrutiny,using modified IEEE 30-bus and IEEE 118-bus systems,validates GBBLCO’s superior performance in achieving optimal solutions.Simulation results demonstrate GBBLCO’s efficacy in six optimization scenarios:total cost with valve point effects,total cost with emission and carbon tax,total cost with prohibited operating zones,active power loss optimization,voltage deviation optimization and enhancing voltage stability index(VSI).GBBLCO outperforms conventional techniques in each scenario,showcasing rapid convergence and superior solution quality.Notably,GBBLCO navigates complexities introduced by valve point effects,adapts to environmental constraints,optimizes costs while considering prohibited operating zones,minimizes active power losses,and optimizes voltage deviation by enhancing the voltage stability index(VSI)effectively.This research significantly contributes to advancing OPF,emphasizing GBBLCO’s improved global search capabilities and ability to address challenges related to local minima.GBBLCO emerges as a versatile and robust optimization tool for diverse challenges in power systems,offering a promising solution for the evolving needs of renewable energy-integrated power grids.
基金the financial support they received from the National Research Foundation of Korea(NRF)grants funded by the Korean government(MSIT)(NRF-2018R1A5A1025137 and 2023R1A2C1002599)。
文摘Metal-organic frameworks(MOFs)possess a distinct advantage over conventional heterogeneous photocatalysts because of their carefully defined architecture and particular pores,which facilitate the targeted incorporation of other efficient cocatalysts or semiconductor materials.The integration of MOFs with other materials has resulted in significant breakthroughs,as the coupled materials improve the performance due to the combined effect.The unique MOF structures allow them to host foreign materials,which results in harvesting the visible region of the solar spectrum and effectively mitigating charge recombination by promoting charge separation.The review presents an evaluation of the latest developments in the utilization of surface and/or pore chemistry of MOF-supported heterojunctions for photocatalytic green-hydrogen generation with a basic understanding of the mechanism involved.The review begins with the basic principles of photocatalysis,the significance of MOFs,their optical properties,the methods used for synthesizing MOFs,and their coordination with other inorganic and polymeric materials.Furthermore,methods to increase photocatalytic H2 evolution using MOF-supported heterojunction have been proposed as standard practice.Lastly,to address environmental challenges,we highlight the future potential of MOF-supported heterojunctions for use in green-energy production.We hope that this review provides guidance to researchers in the development of effective heterojunctions based on MOFs to address challenges in energy applications and catalytic processes.
文摘The world is undergoing profound changes in energy and technology.Countries are vigorously developing new sustainable energy sources and technologies.Renewable energy sources encompass various technologies such as wind turbines,solar energy,nuclear energy,and bioenergy.Additionally,emerging technology fields include new energy vehicles,robots,and artificial intelligence devices,among others.The renewable energy industries and implementation of new technologies necessitate the development and adoption of new equipment and components.Austempered ductile iron(ADI)is renowned for its unique microstructure and superior properties.By utilizing ADI,lightweight and innovative castings can be designed to not only reduce weight but also save energy and decrease emissions.More importantly,these castings enhance the efficiency and reliability of new energy equipment and emerging technology installations.This paper describes the development,applications,and future prospects of lightweight and innovative ADI castings within sectors such as solar photovoltaic(PV),wind power generation,industry robots,and trucks in China.
基金support provided by the National Science Fund for Distinguished Young Scholars(52325703)Postdoctoral Innovation Talents Support Program(BX20220066)+1 种基金China Postdoctoral Science Foundation(2022M720709)State Key Laboratory of Power System Operation and Control(SKLD23KM06).
文摘Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen.Based on the incremental cost principle,we quantified the provincial and national clean hydrogen production cost performance levels in 2030.The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces,with a national average value of less than 2 USD·kg^(-1) at the 40-megaton hydrogen supply scale.Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg^(-1).However,performance is affected by the potential distribution of hydrogen demand.From the supply side,competitiveness of the mechanism is limited to clean hydrogen production,while from the demand side,it could help electrolytic hydrogen fulfil a more significant role.This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.
文摘The global shift toward next-generation energy systems is propelled by the urgent need to combat climate change and the dwindling supply of fossil fuels.This review explores the intricate challenges and opportunities for transitioning to sustainable renewable energy sources such as solar,wind,and hydrogen.This transition economically challenges traditional energy sectors while fostering new industries,promoting job growth,and sustainable economic development.The transition to renewable energy demands social equity,ensuring universal access to affordable energy,and considering community impact.The environmental benefits include a significant reduction in greenhouse gas emissions and a lesser ecological footprint.This study highlights the rapid growth of the global wind power market,which is projected to increase from$112.23 billion in 2022 to$278.43 billion by 2030,with a compound annual growth rate of 13.67%.In addition,the demand for hydrogen is expected to increase,significantly impacting the market with potential cost reductions and making it a critical renewable energy source owing to its affordability and zero emissions.By 2028,renewables are predicted to account for 42%of global electricity generation,with significant contributions from wind and solar photovoltaic(PV)technology,particularly in China,the European Union,the United States,and India.These developments signify a global commitment to diversifying energy sources,reducing emissions,and moving toward cleaner and more sustainable energy solutions.This review offers stakeholders the insights required to smoothly transition to sustainable energy,setting the stage for a resilient future.
文摘Several actions from both the environmental and human viewpoints have already been made to meet the sustainability goals targeted at food systems.Still,new place-based ideas to improve sustainability are needed.Agroecological symbiosis(AES),a novel food system model,is an example of a suggested system-level change to attain sustainability targets;it is a symbiosis of food production and processing using renewable energy that uses its own feedstock.AES has already been found advantageous from the ecological and biophysical viewpoints,but a regional economic evaluation of the model is still lacking.Thus,the aim of our paper is to assess the regional economic impact of a possible systemic change in the food system using the network of agroecological symbiosis(NAES)as an example.We applied scenarios representing different ways of moving towards envisioned NAES models in Mäntsälä,Finland,and a computable general equilibrium model to evaluate the regional economic impact.According to our results,both regional economy and employment would increase,and the regional production base would diversify with NAES implementation applied to the region,but the extent of the benefits varies between scenarios.The scenario that includes change in both public and private food demand,production of bioenergy and utilization of by-products would cause the largest impacts.However,realizing NAES requires investments that may influence the actual implementation of such models.Nonetheless,a change towards NAES can promote an economically and spatially just transition to sustainability,as NAES seems to be economically most beneficial for rural areas.
基金This work was supported by the National Natural Science Foundation of China(Nos.22308139,52071171,52202248)Natural Science Foundation of Liaoning Province(2023-MS-140)+11 种基金Liaoning BaiQianWan Talents Program(LNBQW2018B0048)Shenyang Science and Technology Project(21-108-9-04)Young Scientific and Technological Talents Project of the Department of Education of Liaoning Province(LQN202008)Key Research Project of Department of Education of Liaoning Province(LJKZZ20220015)Foundation of State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology(MJNYSKL202301)Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(KF2023006)Anhui Province Key Laboratory of Coal Clean Conversion and High Valued Utilization,Anhui University of Technology(CHV22-05)Australian Research Council(ARC)through Future Fellowship(FT210100298,FT210100806)Discovery Project(DP220100603)Linkage Project(LP210100467,LP210200504,LP210200345,LP220100088)Industrial Transformation Training Centre(IC180100005)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077).
文摘Renewable energy driven N_(2) electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production.However,relevant out-lab research is still in its infancy.Herein,a novel Sn-based MXene/MAX hybrid with abundant Sn vacancies,Sn@Ti_(2)CTX/Ti_(2)SnC–V,was synthesized by controlled etching Sn@Ti_(2)SnC MAX phase and demonstrated as an efficient electrocatalyst for electrocatalytic N2 reduction.Due to the synergistic effect of MXene/MAX heterostructure,the existence of Sn vacancies and the highly dispersed Sn active sites,the obtained Sn@Ti2CTX/Ti_(2)SnC–V exhibits an optimal NH_(3) yield of 28.4μg h^(−1) mg_(cat)^(−1) with an excellent FE of 15.57% at−0.4 V versus reversible hydrogen electrode in 0.1 M Na_(2)SO_(4),as well as an ultra-long durability.Noticeably,this catalyst represents a satisfactory NH3 yield rate of 10.53μg h^(−1) mg^(−1) in the home-made simulation device,where commercial electrochemical photovoltaic cell was employed as power source,air and ultrapure water as feed stock.The as-proposed strategy represents great potential toward ammonia production in terms of financial cost according to the systematic technical economic analysis.This work is of significance for large-scale green ammonia production.
基金National Natural Science Foundation of China (Grant No. 52103302, and No. 52070124)Shandong Provincial Natural Science Foundation (ZR2021QB182)+1 种基金Start-up Foundation for Senior Talents of Jiangsu University (21JDG041)China Postdoctoral Science Foundation (2023M731357)。
文摘Considerable research efforts have been dedicated to investigating the side reactions and the growth of Zn dendritic in aqueous zinc-ion batteries(AZIBs).The incorporation of organic solvents as additives in electrolytes has yielded highly promising results.Nevertheless,their pervasive use has been hindered by concerns regarding their toxicity,flammability,and economic viability.Herein,we propose the utilization of γ-valerolactone(γ-V),a novel eco-friendly solvent,as an alternative for conventional organic additives to improve the performance of Zn anode.Experimental investigations and theoretical analyses have verified that γ-V additives can diminish the Zn^(2+)-desolvation energy and enhance Zn^(2+) transport kinetics.The adsorbed γ-V molecules modulate the nucleation and diffusion of Zn^(2+),facilitating Zn growth along the(002) crystal plane,thus inhibiting dendrite formation and side reactions.Consequently,the modified electrolyte with 3% γ-V exhibit highly reversible cycling for 2800 h at1 mA cm^(-2) and 1 mA h cm^(-2) in Zn//Zn symmetric cell.The Zn//KVOH coin cells deliver a capacity retention of 74.7% after 1000 cycles at 5 A g^(-1).The Zn//KVOH pouch cells maintain a capacity retention of78.7% over 90 cycles at 3 A g^(-1).Notably,the γ-V additives also effectively alleviate the self-discharge phenomenon.This work provides valuable insights on the development of aqueous zinc-ion batteries with superior safety through the modulation of electrolytes using eco-friendly additives.