The available heat content (stored heat energy) of hot dry rock (HDR) at a depth of 1–10 km in the global land crust is estimated to be 5.06×10~8 EJ,attracting considerable global attention.This paper presents a...The available heat content (stored heat energy) of hot dry rock (HDR) at a depth of 1–10 km in the global land crust is estimated to be 5.06×10~8 EJ,attracting considerable global attention.This paper presents a comprehensive analysis of the geological framework,HDR resource potential,exploration advancements,and the development of enhanced geothermal systems (EGSs) in China.HDR resources are extensively distributed across China.Within the depth range of 3–10 km,China’s estimated potential approximates2.29×10~7 EJ,with a theoretical power generation capacity of approximately 1.67×10^(16) k Wh.Replacing coal power with HDR can help to achieve a net emission reduction of 1.34×10^(16) kg CO_(2) (approximately1.34×10^(13) t),representing an emission reduction efficiency of 94.4%.Based on a development cycle of100 years,the average annual emission reduction reaches 1.34×10^(10) t CO_(2),equivalent to 117%of China’s annual carbon emissions in 2022.Furthermore,in the context of global warming,the development and utilization of HDR,which is feasible in virtually any region worldwide,offers significant potential to support global carbon reduction efforts.China has made substantial progress in HDR exploration in recent years.This paper systematically classifies China’s HDR resources into four genetic types—highly radioactive heat-producing,sedimentary basin,active volcanic,and intensely tectonic zones—and offers detailed exploration insights for each category.Each classification exhibits distinct geological and tectonic characteristics that influence heat source mechanisms and resource distribution.Furthermore,this paper documents significant advances in EGS construction,particularly in the Gonghe Basin on the northeastern margin of the Qianghai-Xizang Plateau and the Matouying uplift in the North China Basin,where successful reservoir stimulation,microseismic monitoring,and experimental power generation have been achieved.Despite these developments,challenges persist,including technical adaptability under complex geological conditions and the economic viability of large-scale HDR development.This paper suggests that future initiatives should emphasize resource exploration,technological research,and policy support to foster sustainable HDR resource development in China,thereby contributing to the global energy transition and environmental sustainability.展开更多
Effects of meta-substituent of 3,4＇/4,3＇/3,3＇-substituted benzylideneanilines （XBAYs） on the electrochemical reduction potentials （E（Red）） were investigated, in which 49 samples of target compounds were synth...Effects of meta-substituent of 3,4＇/4,3＇/3,3＇-substituted benzylideneanilines （XBAYs） on the electrochemical reduction potentials （E（Red）） were investigated, in which 49 samples of target compounds were synthesized, and their reduction potentials were measured by cyclic voltammetry. The substituent effects on the E（Red） of target compounds were analyzed and an optimality equation with four parameters （Hammett constant a of X, Hammett constant a of Y, excited-state substituent constant σexCC of X, and the substituent specific cross-interaction effect △σexCC2 between X and Y） was obtained. The results show that the factors affecting the E（Red） of 3,4＇/4,31/3,3P-substituted XBAYs are different from those of 4,4＇-substituted XBAYs. For 3,4＇/4,3＇/3,3＇-substituted XBAYs, σ（X） and σ（Y） must be employed, and the contribution of △σexCC2 is important and not negligible. Compared with 4,4＇-substituted XBAYs, X group contributes less to 3,4＇/4,3＇/3,3＇-substituted XBAYs, while Y group contributes more to them. Additionally, it was observed that either para-substituted XBAYs or meta-substituted XBAYs, the substituent effects of X are larger than those of Y on the E（Red） of substituted XBAYs.展开更多
The influences of the time, temperature and atmosphere on the reduction swelling of oxidized pellets were investigated by single factor experiments. The mechanisms of reduction swelling of oxidized pellets were analyz...The influences of the time, temperature and atmosphere on the reduction swelling of oxidized pellets were investigated by single factor experiments. The mechanisms of reduction swelling of oxidized pellets were analyzed and investigated by SEM （scanning electron microscopy） and XRD （X-ray diffractometer） analysis. The results show that the change rules of reduction swelling index of oxidized pellets in different reduction atmospheres are very similar. With the increase of reduction time, the reduction swelling index moves up firstly and then down. When the reduction temperature is above 900 ℃, α-quartz turns into α-tridymite, and the transition generates additional volume expansion effect. The reduction swelling index changes faster in H2 atmosphere than in CO atmosphere. Increasing Ha content in the reduction atmosphere is useful to decrease the reduction swelling index, but it is also easy to cause oxidized pellets cracking.展开更多
The treatment of domestic and industrial wastewater is one of the major sources of CH_4 in the Chinese waste sector. On the basis of statistical data and country-specific emission factors, using IPCC methodology, the ...The treatment of domestic and industrial wastewater is one of the major sources of CH_4 in the Chinese waste sector. On the basis of statistical data and country-specific emission factors, using IPCC methodology, the characteristics of CH_4 emissions from wastewater treatment in China were analyzed. The driving factors of CH_4 emissions were studied, and the emission trend and reduction potential were predicted and analyzed according to the current situation. Results show that in 2010, CH_4 emissions from the treatment of domestic and industrial wastewater were0.6110 Mt and 1.6237 Mt, respectively. Eight major industries account for more than 92% of emissions, and CH_4 emissions gradually increased from 2005 to 2010. From the controlling management scenario, we predict that in 2020, CH_4 emissions from the treatment of domestic and industrial wastewater will be 1.0136 Mt and 2.3393 Mt, respectively, and the reduction potential will be 0.0763 Mt and 0.2599 Mt, respectively.From 2010 to 2020, CH_4 emissions from the treatment of domestic and industrial wastewater will increase by 66% and 44%, respectively.展开更多
Coal-based olefin(CTO)industry as a complement of traditional petrochemical industry plays vital role in China’s national economic development.However,high CO2 emission in CTO industry is one of the fatal problems to...Coal-based olefin(CTO)industry as a complement of traditional petrochemical industry plays vital role in China’s national economic development.However,high CO2 emission in CTO industry is one of the fatal problems to hinder its development.In this work,the carbon emission and mitigation potentials by different reduction pathways are evaluated.The economic cost is analyzed and compared as well.According to the industry development plan,the carbon emissions from China’s CTO industry will attain 189.43 million ton C02(MtC02)and 314.11 MtC02 in 2020 and 2030,respectively.With the advanced technology level,the maximal carbon mitigation potential could be attained to 15.3%and 21.9%in 2020 and 2030.If the other optional mitigation ways are combined together,the carbon emission could further reduce to some extent.In general,the order of mitigation potential is followed as:feedstock alteration by natural gas>C02 hydrogenation with renewable electricity applied>CCS technology.The mitigation cost analysis indicates that on the basis of 2015 situation,the economic penalty for feedstock alteration is the lowest,ranged between 186 and 451 CNY/tCO2,and the cost from CCS technology is ranged between 404 and 562 CNY/tC02,which is acceptable if the C02 enhanced oil recovery and carbon tax are considered.However,for the C02 hydrogenation technology,the cost is extremely high and there is almost no application possibility at present.展开更多
Based on the total-factor energy efficiency framework,this paper calculates China's industrial energy efficiency and CO2 emissions reduction potential from 2000 to 2009 by utilizing the directional distance functi...Based on the total-factor energy efficiency framework,this paper calculates China's industrial energy efficiency and CO2 emissions reduction potential from 2000 to 2009 by utilizing the directional distance function and data envelopment analysis.The empirical results show that:China's industrial overall energy efficiency is relatively lower while the emis-sions reduction potential is relatively greater,given the optimum production frontier.Significant indus-trial disparities of energy efficiency and emissions reduction potential exist.Energy efficiency and emis-sions reduction potential significantly show different tendencies of industrial dynamic variation.This paper suggests the Chinese government impose differential carbon taxes,flexibly utilize carbon market mecha-nism,strengthen energy-saving technological R&D,promote the utilization of renewable energy,and strengthen environmental supervision and regulation,so as to improve China's industrial energy efficiency and reduce CO2 emissions.展开更多
This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework,focusing on their carbon footprints from inception to disposal.Specifically,the entire life...This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework,focusing on their carbon footprints from inception to disposal.Specifically,the entire life cycle carbon emissions of High-Speed Rail(HSR),battery electric vehicles,conventional internal combustion engine vehicles,battery electric buses,and conventional internal combustion engine buses are analyzed.The life cycle is segmented into vehicle manufacturing,fuel or electricity production,operational,and dismantlingrecycling stages.This analysis is applied to the Beijing-Tianjin intercity transportation system to explore emission reduction strategies.Results indicate that HSR demonstrates significant carbon emission reduction,with an intensity of only 24%-32% compared to private vehicles and 47%-89% compared to buses.Notably,HSR travel for Beijing-Tianjin intercity emits only 24% of private vehicle emissions,demonstrating the emission reduction benefits of transportation structure optimization.Additionally,predictive modeling reveals the potential for carbon emission reduction through energy structure optimization,providing a guideline for the development of effective transportation management systems.展开更多
An interactive web tool,PredPotS,has been developed for predicting one-electron standard reduction potentials of organic molecules in aqueous solutions.The predictions are generated using deep learning models trained ...An interactive web tool,PredPotS,has been developed for predicting one-electron standard reduction potentials of organic molecules in aqueous solutions.The predictions are generated using deep learning models trained and validated on a chemically diverse database comprising reduction potentials of approximately 8000 organic compounds.The reduction potentials of this database were computed using a composite computational protocol that combines the semiempirical quantum chemical method(GFN2-xTB)and awell-established DFT approach(M06-2X functional along with the SMD solvent model).While this computational approach is cost-effective,it is subject to certain limitations,which are nonetheless duly accounted for in the development of the database.The applied graph-based deep learning methods perform remarkably well in terms of the standard performance metrics.By entering or uploading the SMILES codes of the molecules,PredPotS provides fast and sensible predictions for one-electron standard reduction potentials for a diverse set of organic molecules also in the range compatible with the electrochemical stability of aqueous electrolytes.The PredPotS web tool is particularly well-suited for screening redox-active candidates for aqueous organic redox flow batteries,but it may also prove useful in a variety of other electrochemical applications.展开更多
Accurate prediction of practical reduction electrode potentials(Ered)of electrolyte solvents of electrochemical energy storage devices relies on calculating the Gibbs free energy in their reduction reaction.However,th...Accurate prediction of practical reduction electrode potentials(Ered)of electrolyte solvents of electrochemical energy storage devices relies on calculating the Gibbs free energy in their reduction reaction.However,the emergence of new electrolyte solvents and additives leaves most of the reaction mechanisms unveiled.Here,we provide a machine-learning-assisted workflow of thermodynamically quantified Ered prediction for electrolyte solvents.A computational hydrogen electrode model based on density functional theory calculation is generalized for calculating the reaction free energy of electrochemical elementary steps.Machine-learning models are trained based on the organic and inorganic electrolyte solvents that possess experimentally identified reduction mechanisms.Validation of the best-scoring model is conducted by experimental validation of 6 additional solvents.Multiple thermodynamics features are found impactful on Ered through different chemical bonding with reaction intermediates.This workflow enables accurate Ered prediction for electrolyte solvents without identified reduction mechanisms,and is widely applicable in the electrochemical energy storage area.展开更多
This study compared effects of three different valent iron(Fe^(0),Fe(II)and Fe(III))on enhanced anaerobic sludge digestion,focusing on the changes of oxidation reduction potential(ORP),dissolved organic nitrogen(DON),...This study compared effects of three different valent iron(Fe^(0),Fe(II)and Fe(III))on enhanced anaerobic sludge digestion,focusing on the changes of oxidation reduction potential(ORP),dissolved organic nitrogen(DON),and microbial community.Under the same iron dose in range of 0−160 mg/L after an incubation period of 30 days(d),the maximum methane production rate of sludge samples dosed with respective Fe^(0),Fe(II)and Fe(III)at the same concentration showed indiscernible differences at each iron dose,regardless of the different iron valence.Moreover,their behavior in changes of ORP,DON and microbial community was different:(1)the addition of Fe^(0) made the ORP of sludge more negative,and the addition of Fe(II)and Fe(III)made the ORP of sludge less negative.However,whether being more or less negative,the changes of ORP may show unobservable effects on methane yield when it ranged from−278.71 to−379.80 mV;(2)the degradation of dissolved organic nitrogen,particularly proteins,was less efficient in sludge samples dosed with Fe^(0) compared with those dosed with Fe(II)and Fe(III)after an incubation period of 30 d.At the same dose of 160 mg/L iron,more cysteine was noted in sludge samples dosed with Fe(II)(30.74 mg/L)and Fe(III)(27.92 mg/L)compared with that dosed with Fe^(0)(21.75 mg/L);(3)Fe^(0) particularly promoted the enrichment of Geobacter,and it was 6 times higher than those in sludge samples dosed with Fe(II)and Fe(III)at the same dose of 160 mg/L iron.展开更多
Carbon capture, utilization, and storage (CCUS) have garnered extensive attention as a target of carbon neutrality in China. The development trend of international CCUS projects indicates that the cluster construction...Carbon capture, utilization, and storage (CCUS) have garnered extensive attention as a target of carbon neutrality in China. The development trend of international CCUS projects indicates that the cluster construction of CCUS projects is the main direction of future development. The cost reduction potential of CCUS cluster projects has become a significant issue for CCUS stakeholders. To assess the cost reduction potential of CCUS cluster projects, we selected three coal-fired power plants in the coastal area of Guangdong as research targets. We initially assessed the costs of building individual CCUS projects for each plant and subsequently designed a CCUS cluster project for these plants. By comparing individual costs and CCUS cluster project costs, we assessed the cost reduction potential of CCUS cluster projects. The results show that the unit emission reduction cost for each plant with a capacity of 300 million tonnes per year is 392.34, 336.09, and 334.92 CNY/tCO_(2). By building CCUS cluster project, it could save 56.43 CNY/tCO_(2) over the average cost of individual projects (354.45 CNY/tCO_(2)) when the total capture capacity is 9 million tonnes per year (by 15.92%). Furthermore, we conducted a simulation for the scenario of a smaller designed capture capacity for each plant. We found that as the capture scale increases, the cost reduction potential is higher in the future.展开更多
Accurate estimation of the postmortem interval(PMI)is an important task in forensic practice.In the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time...Accurate estimation of the postmortem interval(PMI)is an important task in forensic practice.In the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time of death.The present study was carried out to determine the correlation between blood oxidation-reduction potential(ORP)values and PMIs,and to develop a three-dimensional surface equation to estimate the PMI under various temperature conditions.A total of 48 rabbits were placed into six groups and sacrificed by air embolism.Blood was obtained from the right ventricle of each rabbit,and specimens were stored at 10℃,15℃,20℃,25℃,30℃,and 35℃.At different PMIs(once every 4 h),the blood ORP values were measured using a PB-21 electrochemical analyzer.Statistical analysis and curve fitting of the data yielded cubic polynomial regression equations and a surface equation at different temperatures.Result:The results showed that there was a strong positive correlation between the blood ORP values at different temperatures and the PMI.This study provides another example of using a three-dimensional surface equation as a tool to estimate the PMI at various temperature conditions.展开更多
The effects of cathode potentials and initial nitrate concentrations on nitrate reduction in bio- electrochemical systems （BESs） were reported. These factors could partition nitrate reduction between denitrification...The effects of cathode potentials and initial nitrate concentrations on nitrate reduction in bio- electrochemical systems （BESs） were reported. These factors could partition nitrate reduction between denitrification and dissimilatory nitrate reduction to ammonium （DNRA）. Pseudomonas alcaliphilastrain MBR utilized an electrode as the sole electron donor and nitrate as the sole electron acceptor. When the cathode potential was set from -0.3 to -I.1 V （vs. Ag/AgC1） at an initial nitrate concentration of 100 mg NO^-N/L, the DNRA electron recovery increased from （10.76 ± 1.6）% to （35.06 ± 0.99）%; the denitrification electron recovery decreased from （63.42 ± 1,32）% to （44.33 ± 1.92）%. When the initial nitrate concentration increased from （29.09 ± 0.24） to （490.97 ± 3.49） mg NO3-N/L at the same potential （-0.9 V）, denitrification electron recovery increased from （5.88 ± 1.08）% to （50.19 ±2.59）%; the DNRA electron recovery declined from （48.79 ±1.32）% to （16.02 ± 1.41）%. The prevalence of DNRA occurred at high ratios of electron donors to acceptors in the BESs and denitrification prevailed against DNRA under a lower ratio of electron donors to acceptors. These results had a potential application value of regulating the transformation of nitrate to N2 or ammonium in BESs for nitrate removal.展开更多
A potential reduction algorithm is proposed for optimization of a convex function subject to linear constraints.At each step of the algorithm,a system of linear equations is solved to get a search direction and the Ar...A potential reduction algorithm is proposed for optimization of a convex function subject to linear constraints.At each step of the algorithm,a system of linear equations is solved to get a search direction and the Armijo's rule is used to determine a stepsize.It is proved that the algorithm is globally convergent.Computational results are reported.展开更多
China is one of the major producers of chlorodifluoromethane(HCFC-22)in the world.A large amount of fluoroform(HFC-23)is emitted during the production of HCFC-22.Emission factors of HFC-23 were calculated in accordanc...China is one of the major producers of chlorodifluoromethane(HCFC-22)in the world.A large amount of fluoroform(HFC-23)is emitted during the production of HCFC-22.Emission factors of HFC-23 were calculated in accordance with the monitoring reports of eleven HFC-23 clean development mechanism(CDM)projects in China and the HFC-23emissions in 2000–2010 as well as that in 2011–2020 were estimated and projected,respectively.It is expected that,by the end of 2020,emissions of HFC-23 in China will be as much as 230 Mt CO2-eq.If HCFC-22 producers voluntarily reduced HFC-23 emissions,it would contribute 3.2%–3.6%to the national CO2emission reduction target for 2020.展开更多
The quantitative structure-property relationship(QSPR) of anabolic androgenic steroids was studied on the half-wave reduction potential(E1/2) using quantum and physico-chemical molecular descriptors. The descriptors w...The quantitative structure-property relationship(QSPR) of anabolic androgenic steroids was studied on the half-wave reduction potential(E1/2) using quantum and physico-chemical molecular descriptors. The descriptors were calculated by semi-empirical calculations. Models were established using partial least square(PLS) regression and back-propagation artificial neural network(BP-ANN). The QSPR results indicate that the descriptors of these derivatives have significant relationship with half-wave reduction potential. The stability and prediction ability of these models were validated using leave-one-out cross-validation and external test set.展开更多
Crop residues in agriculture pose disposal challenges and contribute to air pollution when burned.This study aims to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures.Biochar can se...Crop residues in agriculture pose disposal challenges and contribute to air pollution when burned.This study aims to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures.Biochar can serve in carbon sequestration,as a soil amendment,and as an alternative fuel source.Pyrolysis was conducted at 400,500,and 600°C to examine the effects on physicochemical properties,fuel,and energy related properties.Increase in temperatures resulted in decrease of biochar yield,volatile matter,and O/C and H/C atomic ratios,while ash content and essential nutrients increased.Yield was observed to be higher in pigeonpea stalks derived biochar compared to maize stalks derived biochar at same pyrolysis temperatures.The yields of pigeonpea stalks derived biochar at 400°C,500°C,and 600°C are 34,33 and 29%,respectively,and the yields of maize biomass-derived biochar at 400°C,500°C,and 600°C are 29,28,and 26%,respectively.The organic carbon content is found to be higher in the biochar samples prepared at 600°C,i.e.,10.44%,and 10.39%for pigeonpea and maize-derived biochar,respectively.The essential elements of biochar were increased with an increase in pyrolysis temperature except nitrogen which is conversely related to temperature.The biochar obtained through pyrolysis at 400°C demonstrated superior characteristics compared to biochar produced at other temperatures.It exhibited a higher biochar yield,with approximately 84.60%for pigeonpea and 64.85%for maize fixed carbon content.Additionally,the energy retention efficiency was higher,reaching 67.33%for pigeonpea and 42.70%for maize-derived biochar at a pyrolysis temperature of 400°C.The fixed carbon recovery efficiency was also notable at around 200.44%for PPS and 142.37%for maize biochar which is higher compared to biochar produced at other temperatures.Furthermore,the higher heating value(HHV)was approximately 30.75 MJ kg^(−1) for both the biochars,indicating their suitability as alternative solid fuels.A significant CO_(2) reduction potential of 84 CO_(2) eq kg^(−1) and 55 CO_(2) eq kg^(−1) was observed for pigeonpea and maize biochar,respectively.Hence,biochar is a promising and effective option for carbon sequestration,offering environmental benefits.展开更多
Potential field due to line sources residing on slender heterogeneities is involved in various areas,such as heat conduction,potential flow,and electrostatics.Often dipolar line sources are either prescribed or induce...Potential field due to line sources residing on slender heterogeneities is involved in various areas,such as heat conduction,potential flow,and electrostatics.Often dipolar line sources are either prescribed or induced due to close interaction with other objects.Its calculation requires a higher-order scheme to take into account the dipolar effect as well as net source effect.In the present work,we apply such a higher-order line element method to analyze the potential field with cylindrical slender heterogeneities.In a benchmark example of two parallel rods,we compare the line element solution with the boundary element solution to show the accuracy as a function in terms of rods distance.Furthermore,we use more complicated examples to demonstrate the capability of the line element technique.展开更多
The demand for Ni and Co has surged due to the rapid expansion of the electric vehicle industry.Thus,developing efficient and eco-friendly metallurgical routes for extracting these metals has become imperative.This st...The demand for Ni and Co has surged due to the rapid expansion of the electric vehicle industry.Thus,developing efficient and eco-friendly metallurgical routes for extracting these metals has become imperative.This study introduces a sustainable and effective method for extracting Ni and Co from Ni–Co–Fe alloy powder obtained from limonitic laterite ores through selective reduction and magnetic separation.The leaching efficiency for Ni,Co,and Fe was 89.4%,94.8%,and 96.5%,respectively,under the following conditions for leaching:3 mol/L H_(2)SO_(4),85℃,10 m L/g liquid–solid ratio,and 90 min leaching time.The incorporation of H_(2)O_(2)enhanced the leaching efficiency for Ni,Co,and Fe.The redox potential of the solution plays a crucial role in acid dissolution,and H_(2)O_(2)enhances Ni and Co dissolution.Phosphate precipitation facilitated the removal of Fe from the leachate,affording a 96.1%Fe removal ratio and 2.29%Ni loss.展开更多
[Objective] The study aimed to research the nutrients release of ponds sediment.[Method] The sediments which from a new pond(A) and an old one (B) these analyses used to carry out indoor experiment under the anaerobic...[Objective] The study aimed to research the nutrients release of ponds sediment.[Method] The sediments which from a new pond(A) and an old one (B) these analyses used to carry out indoor experiment under the anaerobic dark condition for researching on nutrient release. The N(nitrogenous) and P(phosphorous) release were analyzed every two days.[Result] At the prophase, the N release in B was bigger than that in A, while the decline sediment release in A was gentle.[Conclusion] There was no accumulation of organic compound during the breeding time. The NH4-N was the main form of N release; and the P release was correlated with N release, while PO4-P was the main form of P release.展开更多
基金supported by the National Key Research and Development Program of China (2021YFB1507401)Qinghai Province Clean Energy Minerals Special Project(2022013004qj004)Geological Survey Project of China Geological Survey (DD20221676, DD20230019)。
文摘The available heat content (stored heat energy) of hot dry rock (HDR) at a depth of 1–10 km in the global land crust is estimated to be 5.06×10~8 EJ,attracting considerable global attention.This paper presents a comprehensive analysis of the geological framework,HDR resource potential,exploration advancements,and the development of enhanced geothermal systems (EGSs) in China.HDR resources are extensively distributed across China.Within the depth range of 3–10 km,China’s estimated potential approximates2.29×10~7 EJ,with a theoretical power generation capacity of approximately 1.67×10^(16) k Wh.Replacing coal power with HDR can help to achieve a net emission reduction of 1.34×10^(16) kg CO_(2) (approximately1.34×10^(13) t),representing an emission reduction efficiency of 94.4%.Based on a development cycle of100 years,the average annual emission reduction reaches 1.34×10^(10) t CO_(2),equivalent to 117%of China’s annual carbon emissions in 2022.Furthermore,in the context of global warming,the development and utilization of HDR,which is feasible in virtually any region worldwide,offers significant potential to support global carbon reduction efforts.China has made substantial progress in HDR exploration in recent years.This paper systematically classifies China’s HDR resources into four genetic types—highly radioactive heat-producing,sedimentary basin,active volcanic,and intensely tectonic zones—and offers detailed exploration insights for each category.Each classification exhibits distinct geological and tectonic characteristics that influence heat source mechanisms and resource distribution.Furthermore,this paper documents significant advances in EGS construction,particularly in the Gonghe Basin on the northeastern margin of the Qianghai-Xizang Plateau and the Matouying uplift in the North China Basin,where successful reservoir stimulation,microseismic monitoring,and experimental power generation have been achieved.Despite these developments,challenges persist,including technical adaptability under complex geological conditions and the economic viability of large-scale HDR development.This paper suggests that future initiatives should emphasize resource exploration,technological research,and policy support to foster sustainable HDR resource development in China,thereby contributing to the global energy transition and environmental sustainability.
文摘Effects of meta-substituent of 3,4＇/4,3＇/3,3＇-substituted benzylideneanilines （XBAYs） on the electrochemical reduction potentials （E（Red）） were investigated, in which 49 samples of target compounds were synthesized, and their reduction potentials were measured by cyclic voltammetry. The substituent effects on the E（Red） of target compounds were analyzed and an optimality equation with four parameters （Hammett constant a of X, Hammett constant a of Y, excited-state substituent constant σexCC of X, and the substituent specific cross-interaction effect △σexCC2 between X and Y） was obtained. The results show that the factors affecting the E（Red） of 3,4＇/4,31/3,3P-substituted XBAYs are different from those of 4,4＇-substituted XBAYs. For 3,4＇/4,3＇/3,3＇-substituted XBAYs, σ（X） and σ（Y） must be employed, and the contribution of △σexCC2 is important and not negligible. Compared with 4,4＇-substituted XBAYs, X group contributes less to 3,4＇/4,3＇/3,3＇-substituted XBAYs, while Y group contributes more to them. Additionally, it was observed that either para-substituted XBAYs or meta-substituted XBAYs, the substituent effects of X are larger than those of Y on the E（Red） of substituted XBAYs.
基金Sponsored by National Natural Science Foundation of China(51104014)National Natural Science Foundation of China and Baosteel(51134008)National Basic Research Program(973Program)of China(2012CB720401)
文摘The influences of the time, temperature and atmosphere on the reduction swelling of oxidized pellets were investigated by single factor experiments. The mechanisms of reduction swelling of oxidized pellets were analyzed and investigated by SEM （scanning electron microscopy） and XRD （X-ray diffractometer） analysis. The results show that the change rules of reduction swelling index of oxidized pellets in different reduction atmospheres are very similar. With the increase of reduction time, the reduction swelling index moves up firstly and then down. When the reduction temperature is above 900 ℃, α-quartz turns into α-tridymite, and the transition generates additional volume expansion effect. The reduction swelling index changes faster in H2 atmosphere than in CO atmosphere. Increasing Ha content in the reduction atmosphere is useful to decrease the reduction swelling index, but it is also easy to cause oxidized pellets cracking.
基金supported by the National Natural Science Foundation of China (41175137)the Climate Change Working Program of MEP in 2015 (CC(2015)-9-3)the Climate Change Project of Beijing in 2014 (ZHCKT4)
文摘The treatment of domestic and industrial wastewater is one of the major sources of CH_4 in the Chinese waste sector. On the basis of statistical data and country-specific emission factors, using IPCC methodology, the characteristics of CH_4 emissions from wastewater treatment in China were analyzed. The driving factors of CH_4 emissions were studied, and the emission trend and reduction potential were predicted and analyzed according to the current situation. Results show that in 2010, CH_4 emissions from the treatment of domestic and industrial wastewater were0.6110 Mt and 1.6237 Mt, respectively. Eight major industries account for more than 92% of emissions, and CH_4 emissions gradually increased from 2005 to 2010. From the controlling management scenario, we predict that in 2020, CH_4 emissions from the treatment of domestic and industrial wastewater will be 1.0136 Mt and 2.3393 Mt, respectively, and the reduction potential will be 0.0763 Mt and 0.2599 Mt, respectively.From 2010 to 2020, CH_4 emissions from the treatment of domestic and industrial wastewater will increase by 66% and 44%, respectively.
基金sponsored by the National Key Research and Development Program(No.2016YFA0602603,No.2016YFA0602602)Chinese Academy of Sciences Youth Innovation Promotion Association FundingShanghai Natural Science Foundation(No.18ZR1444200)
文摘Coal-based olefin(CTO)industry as a complement of traditional petrochemical industry plays vital role in China’s national economic development.However,high CO2 emission in CTO industry is one of the fatal problems to hinder its development.In this work,the carbon emission and mitigation potentials by different reduction pathways are evaluated.The economic cost is analyzed and compared as well.According to the industry development plan,the carbon emissions from China’s CTO industry will attain 189.43 million ton C02(MtC02)and 314.11 MtC02 in 2020 and 2030,respectively.With the advanced technology level,the maximal carbon mitigation potential could be attained to 15.3%and 21.9%in 2020 and 2030.If the other optional mitigation ways are combined together,the carbon emission could further reduce to some extent.In general,the order of mitigation potential is followed as:feedstock alteration by natural gas>C02 hydrogenation with renewable electricity applied>CCS technology.The mitigation cost analysis indicates that on the basis of 2015 situation,the economic penalty for feedstock alteration is the lowest,ranged between 186 and 451 CNY/tCO2,and the cost from CCS technology is ranged between 404 and 562 CNY/tC02,which is acceptable if the C02 enhanced oil recovery and carbon tax are considered.However,for the C02 hydrogenation technology,the cost is extremely high and there is almost no application possibility at present.
文摘Based on the total-factor energy efficiency framework,this paper calculates China's industrial energy efficiency and CO2 emissions reduction potential from 2000 to 2009 by utilizing the directional distance function and data envelopment analysis.The empirical results show that:China's industrial overall energy efficiency is relatively lower while the emis-sions reduction potential is relatively greater,given the optimum production frontier.Significant indus-trial disparities of energy efficiency and emissions reduction potential exist.Energy efficiency and emis-sions reduction potential significantly show different tendencies of industrial dynamic variation.This paper suggests the Chinese government impose differential carbon taxes,flexibly utilize carbon market mecha-nism,strengthen energy-saving technological R&D,promote the utilization of renewable energy,and strengthen environmental supervision and regulation,so as to improve China's industrial energy efficiency and reduce CO2 emissions.
基金the financial support of the National Natural Science Foundation of China(U2268208)Science and Technology Program of China National Railway Group Co.,Ltd.(N2022×037).
文摘This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework,focusing on their carbon footprints from inception to disposal.Specifically,the entire life cycle carbon emissions of High-Speed Rail(HSR),battery electric vehicles,conventional internal combustion engine vehicles,battery electric buses,and conventional internal combustion engine buses are analyzed.The life cycle is segmented into vehicle manufacturing,fuel or electricity production,operational,and dismantlingrecycling stages.This analysis is applied to the Beijing-Tianjin intercity transportation system to explore emission reduction strategies.Results indicate that HSR demonstrates significant carbon emission reduction,with an intensity of only 24%-32% compared to private vehicles and 47%-89% compared to buses.Notably,HSR travel for Beijing-Tianjin intercity emits only 24% of private vehicle emissions,demonstrating the emission reduction benefits of transportation structure optimization.Additionally,predictive modeling reveals the potential for carbon emission reduction through energy structure optimization,providing a guideline for the development of effective transportation management systems.
基金funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 875565 (CompBat project).
文摘An interactive web tool,PredPotS,has been developed for predicting one-electron standard reduction potentials of organic molecules in aqueous solutions.The predictions are generated using deep learning models trained and validated on a chemically diverse database comprising reduction potentials of approximately 8000 organic compounds.The reduction potentials of this database were computed using a composite computational protocol that combines the semiempirical quantum chemical method(GFN2-xTB)and awell-established DFT approach(M06-2X functional along with the SMD solvent model).While this computational approach is cost-effective,it is subject to certain limitations,which are nonetheless duly accounted for in the development of the database.The applied graph-based deep learning methods perform remarkably well in terms of the standard performance metrics.By entering or uploading the SMILES codes of the molecules,PredPotS provides fast and sensible predictions for one-electron standard reduction potentials for a diverse set of organic molecules also in the range compatible with the electrochemical stability of aqueous electrolytes.The PredPotS web tool is particularly well-suited for screening redox-active candidates for aqueous organic redox flow batteries,but it may also prove useful in a variety of other electrochemical applications.
基金supported by National Key Research and Development(R&D)Program of China(2022YFB4101600)National Natural Science Foundation of China(22179139,22379157)+1 种基金Key Research and Development(R&D)Projects of Shanxi Province(202102040201003)Fundamental Research Program of Shanxi Province(202203021211203),The authors appreciate Beijing Paratera Technology Co.,Ltd,and the Supercomputer Center in Lvliang,China,for providing computational resources.
文摘Accurate prediction of practical reduction electrode potentials(Ered)of electrolyte solvents of electrochemical energy storage devices relies on calculating the Gibbs free energy in their reduction reaction.However,the emergence of new electrolyte solvents and additives leaves most of the reaction mechanisms unveiled.Here,we provide a machine-learning-assisted workflow of thermodynamically quantified Ered prediction for electrolyte solvents.A computational hydrogen electrode model based on density functional theory calculation is generalized for calculating the reaction free energy of electrochemical elementary steps.Machine-learning models are trained based on the organic and inorganic electrolyte solvents that possess experimentally identified reduction mechanisms.Validation of the best-scoring model is conducted by experimental validation of 6 additional solvents.Multiple thermodynamics features are found impactful on Ered through different chemical bonding with reaction intermediates.This workflow enables accurate Ered prediction for electrolyte solvents without identified reduction mechanisms,and is widely applicable in the electrochemical energy storage area.
基金funded by the National Natural Science Foundation of China(Grant Nos.52170133,U1901216,51708239)the Natural Science Foundation of Hubei Province(No.2020CFA042)Applied Basic Research Program of Wuhan(No.2020020601012277),and Program for HUST Academic Frontier Youth Team.
文摘This study compared effects of three different valent iron(Fe^(0),Fe(II)and Fe(III))on enhanced anaerobic sludge digestion,focusing on the changes of oxidation reduction potential(ORP),dissolved organic nitrogen(DON),and microbial community.Under the same iron dose in range of 0−160 mg/L after an incubation period of 30 days(d),the maximum methane production rate of sludge samples dosed with respective Fe^(0),Fe(II)and Fe(III)at the same concentration showed indiscernible differences at each iron dose,regardless of the different iron valence.Moreover,their behavior in changes of ORP,DON and microbial community was different:(1)the addition of Fe^(0) made the ORP of sludge more negative,and the addition of Fe(II)and Fe(III)made the ORP of sludge less negative.However,whether being more or less negative,the changes of ORP may show unobservable effects on methane yield when it ranged from−278.71 to−379.80 mV;(2)the degradation of dissolved organic nitrogen,particularly proteins,was less efficient in sludge samples dosed with Fe^(0) compared with those dosed with Fe(II)and Fe(III)after an incubation period of 30 d.At the same dose of 160 mg/L iron,more cysteine was noted in sludge samples dosed with Fe(II)(30.74 mg/L)and Fe(III)(27.92 mg/L)compared with that dosed with Fe^(0)(21.75 mg/L);(3)Fe^(0) particularly promoted the enrichment of Geobacter,and it was 6 times higher than those in sludge samples dosed with Fe(II)and Fe(III)at the same dose of 160 mg/L iron.
基金the Department of Education of Guangdong Province(No.2021KQNCX143)the National Social Science Foundation of China(Grant No.21AGJ009)the Research Base of Carbon Neutral Finance for Guangdong-Hong Kong-Macao(No.22ATJR03).
文摘Carbon capture, utilization, and storage (CCUS) have garnered extensive attention as a target of carbon neutrality in China. The development trend of international CCUS projects indicates that the cluster construction of CCUS projects is the main direction of future development. The cost reduction potential of CCUS cluster projects has become a significant issue for CCUS stakeholders. To assess the cost reduction potential of CCUS cluster projects, we selected three coal-fired power plants in the coastal area of Guangdong as research targets. We initially assessed the costs of building individual CCUS projects for each plant and subsequently designed a CCUS cluster project for these plants. By comparing individual costs and CCUS cluster project costs, we assessed the cost reduction potential of CCUS cluster projects. The results show that the unit emission reduction cost for each plant with a capacity of 300 million tonnes per year is 392.34, 336.09, and 334.92 CNY/tCO_(2). By building CCUS cluster project, it could save 56.43 CNY/tCO_(2) over the average cost of individual projects (354.45 CNY/tCO_(2)) when the total capture capacity is 9 million tonnes per year (by 15.92%). Furthermore, we conducted a simulation for the scenario of a smaller designed capture capacity for each plant. We found that as the capture scale increases, the cost reduction potential is higher in the future.
基金This study was supported by the Key Projects in the National Science and Technology Pillar Program during the Eleventh Five‑year Plan Period(2012BAK16B02)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the State Education Ministry[(2013)1792]+2 种基金the Training Programmers Foundation for the Beijing Talents(2013D002023000002)the Beijing Planning Project of Philosophy and Social Science(13FXC032)the Project of Young Teachers’Academic Innovation Team by China University of Political Science and Law(2014CXTD04).
文摘Accurate estimation of the postmortem interval(PMI)is an important task in forensic practice.In the last half-century,the use of postmortem biochemistry has become an important ancillary method in determining the time of death.The present study was carried out to determine the correlation between blood oxidation-reduction potential(ORP)values and PMIs,and to develop a three-dimensional surface equation to estimate the PMI under various temperature conditions.A total of 48 rabbits were placed into six groups and sacrificed by air embolism.Blood was obtained from the right ventricle of each rabbit,and specimens were stored at 10℃,15℃,20℃,25℃,30℃,and 35℃.At different PMIs(once every 4 h),the blood ORP values were measured using a PB-21 electrochemical analyzer.Statistical analysis and curve fitting of the data yielded cubic polynomial regression equations and a surface equation at different temperatures.Result:The results showed that there was a strong positive correlation between the blood ORP values at different temperatures and the PMI.This study provides another example of using a three-dimensional surface equation as a tool to estimate the PMI at various temperature conditions.
基金supported by the National Natural Science Foundation of China(No.51074149,31270166,31270531 and 31000070)the West Light Foundation of the Chinese Academy of Sciences
文摘The effects of cathode potentials and initial nitrate concentrations on nitrate reduction in bio- electrochemical systems （BESs） were reported. These factors could partition nitrate reduction between denitrification and dissimilatory nitrate reduction to ammonium （DNRA）. Pseudomonas alcaliphilastrain MBR utilized an electrode as the sole electron donor and nitrate as the sole electron acceptor. When the cathode potential was set from -0.3 to -I.1 V （vs. Ag/AgC1） at an initial nitrate concentration of 100 mg NO^-N/L, the DNRA electron recovery increased from （10.76 ± 1.6）% to （35.06 ± 0.99）%; the denitrification electron recovery decreased from （63.42 ± 1,32）% to （44.33 ± 1.92）%. When the initial nitrate concentration increased from （29.09 ± 0.24） to （490.97 ± 3.49） mg NO3-N/L at the same potential （-0.9 V）, denitrification electron recovery increased from （5.88 ± 1.08）% to （50.19 ±2.59）%; the DNRA electron recovery declined from （48.79 ±1.32）% to （16.02 ± 1.41）%. The prevalence of DNRA occurred at high ratios of electron donors to acceptors in the BESs and denitrification prevailed against DNRA under a lower ratio of electron donors to acceptors. These results had a potential application value of regulating the transformation of nitrate to N2 or ammonium in BESs for nitrate removal.
文摘A potential reduction algorithm is proposed for optimization of a convex function subject to linear constraints.At each step of the algorithm,a system of linear equations is solved to get a search direction and the Armijo's rule is used to determine a stepsize.It is proved that the algorithm is globally convergent.Computational results are reported.
基金supported by Special Fund for Public Environmental Research"Study of the Characterization of Non-CO_2 Green House Gases Emissions and the Framework for Policy Control"(No.201009052)
文摘China is one of the major producers of chlorodifluoromethane(HCFC-22)in the world.A large amount of fluoroform(HFC-23)is emitted during the production of HCFC-22.Emission factors of HFC-23 were calculated in accordance with the monitoring reports of eleven HFC-23 clean development mechanism(CDM)projects in China and the HFC-23emissions in 2000–2010 as well as that in 2011–2020 were estimated and projected,respectively.It is expected that,by the end of 2020,emissions of HFC-23 in China will be as much as 230 Mt CO2-eq.If HCFC-22 producers voluntarily reduced HFC-23 emissions,it would contribute 3.2%–3.6%to the national CO2emission reduction target for 2020.
基金Project supported by the Postdoctoral Science Foundation of Central South University,ChinaProject(2015SK20823)supported by Science and Technology Project of Hunan Province,China+2 种基金Project(15A001)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(CX2015B372)supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject supported by Innovation Experiment Program for University Students of Changsha University of Science and Technology,China
文摘The quantitative structure-property relationship(QSPR) of anabolic androgenic steroids was studied on the half-wave reduction potential(E1/2) using quantum and physico-chemical molecular descriptors. The descriptors were calculated by semi-empirical calculations. Models were established using partial least square(PLS) regression and back-propagation artificial neural network(BP-ANN). The QSPR results indicate that the descriptors of these derivatives have significant relationship with half-wave reduction potential. The stability and prediction ability of these models were validated using leave-one-out cross-validation and external test set.
文摘Crop residues in agriculture pose disposal challenges and contribute to air pollution when burned.This study aims to use pigeonpea and maize stalks to produce biochar at different pyrolysis temperatures.Biochar can serve in carbon sequestration,as a soil amendment,and as an alternative fuel source.Pyrolysis was conducted at 400,500,and 600°C to examine the effects on physicochemical properties,fuel,and energy related properties.Increase in temperatures resulted in decrease of biochar yield,volatile matter,and O/C and H/C atomic ratios,while ash content and essential nutrients increased.Yield was observed to be higher in pigeonpea stalks derived biochar compared to maize stalks derived biochar at same pyrolysis temperatures.The yields of pigeonpea stalks derived biochar at 400°C,500°C,and 600°C are 34,33 and 29%,respectively,and the yields of maize biomass-derived biochar at 400°C,500°C,and 600°C are 29,28,and 26%,respectively.The organic carbon content is found to be higher in the biochar samples prepared at 600°C,i.e.,10.44%,and 10.39%for pigeonpea and maize-derived biochar,respectively.The essential elements of biochar were increased with an increase in pyrolysis temperature except nitrogen which is conversely related to temperature.The biochar obtained through pyrolysis at 400°C demonstrated superior characteristics compared to biochar produced at other temperatures.It exhibited a higher biochar yield,with approximately 84.60%for pigeonpea and 64.85%for maize fixed carbon content.Additionally,the energy retention efficiency was higher,reaching 67.33%for pigeonpea and 42.70%for maize-derived biochar at a pyrolysis temperature of 400°C.The fixed carbon recovery efficiency was also notable at around 200.44%for PPS and 142.37%for maize biochar which is higher compared to biochar produced at other temperatures.Furthermore,the higher heating value(HHV)was approximately 30.75 MJ kg^(−1) for both the biochars,indicating their suitability as alternative solid fuels.A significant CO_(2) reduction potential of 84 CO_(2) eq kg^(−1) and 55 CO_(2) eq kg^(−1) was observed for pigeonpea and maize biochar,respectively.Hence,biochar is a promising and effective option for carbon sequestration,offering environmental benefits.
文摘Potential field due to line sources residing on slender heterogeneities is involved in various areas,such as heat conduction,potential flow,and electrostatics.Often dipolar line sources are either prescribed or induced due to close interaction with other objects.Its calculation requires a higher-order scheme to take into account the dipolar effect as well as net source effect.In the present work,we apply such a higher-order line element method to analyze the potential field with cylindrical slender heterogeneities.In a benchmark example of two parallel rods,we compare the line element solution with the boundary element solution to show the accuracy as a function in terms of rods distance.Furthermore,we use more complicated examples to demonstrate the capability of the line element technique.
基金financially supported by the National Natural Science Foundation of China(Nos.52174288 and 51804346)。
文摘The demand for Ni and Co has surged due to the rapid expansion of the electric vehicle industry.Thus,developing efficient and eco-friendly metallurgical routes for extracting these metals has become imperative.This study introduces a sustainable and effective method for extracting Ni and Co from Ni–Co–Fe alloy powder obtained from limonitic laterite ores through selective reduction and magnetic separation.The leaching efficiency for Ni,Co,and Fe was 89.4%,94.8%,and 96.5%,respectively,under the following conditions for leaching:3 mol/L H_(2)SO_(4),85℃,10 m L/g liquid–solid ratio,and 90 min leaching time.The incorporation of H_(2)O_(2)enhanced the leaching efficiency for Ni,Co,and Fe.The redox potential of the solution plays a crucial role in acid dissolution,and H_(2)O_(2)enhances Ni and Co dissolution.Phosphate precipitation facilitated the removal of Fe from the leachate,affording a 96.1%Fe removal ratio and 2.29%Ni loss.
基金Supported by the National High Technology Research and Development Program of China (863 Program)(2007AA10Z239)the National Key Technology R&D Program(2006BAD03B0102)+2 种基金the Natural Science Foundation of Guangdong Province(5004159)Scienceand Technology Planning Project of Guangdong Province(2005N33201012)the Open Fund of Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes,Ministry of Agriculture(BM2007-03)~~
文摘[Objective] The study aimed to research the nutrients release of ponds sediment.[Method] The sediments which from a new pond(A) and an old one (B) these analyses used to carry out indoor experiment under the anaerobic dark condition for researching on nutrient release. The N(nitrogenous) and P(phosphorous) release were analyzed every two days.[Result] At the prophase, the N release in B was bigger than that in A, while the decline sediment release in A was gentle.[Conclusion] There was no accumulation of organic compound during the breeding time. The NH4-N was the main form of N release; and the P release was correlated with N release, while PO4-P was the main form of P release.
