This study aims to reveal the spatial structural characteristics of 1,652 Ethnic-Minority Villages(EMV)in China and to analyze the mechanisms driving their spatial heterogeneity.EMV are a special type of settlement sp...This study aims to reveal the spatial structural characteristics of 1,652 Ethnic-Minority Villages(EMV)in China and to analyze the mechanisms driving their spatial heterogeneity.EMV are a special type of settlement space that preserve a large number of historical traces of the ethnic culture of ancient China.They are important carriers of China’s excellent traditional culture and are key to the implementation of rural revitalization strategies.In this study,1652 EMV in China were selected as the research subjects.The Nearest Neighbor Index,kernel density,and spatial autocorrelation index were employed to reveal the spatial structural characteristics of minority villages.Neural network models,spatial lag models,and geographical detectors were used to analyze the formation mechanism of spatial heterogeneity in EMV.The results indicate that:(1)EMV exhibit significant spatial differentiation characterized by“single-core with multiple surrounding sub-centers,”“polarization between east and west,”“decreasing quantity from southwest to east coast to northeast to northwest,”and“large dispersion with small agglomeration.”(2)EMV are mainly distributed in areas rich in intangible cultural heritage,with high vegetation coverage and low altitude,far from central cities,and having limited arable land and an underdeveloped economy and transportation,particularly in shaded or riverbank areas.(3)Distance from the nearest river(X3),distance from central cities(X8),national intangible cultural heritage(X9),and NDVI(X10)were the main driving factors affecting the spatial distribution of EMV,whereas elevation(X1)and GDP(X5)had the weakest influence.As EMV are a relatively unique territorial spatial unit,the identification of their spatial heterogeneity characteristics not only deepens the research content of settlement geography,but also involves the assessment,protection,and development of Minority Villages,which is of great significance for the inheritance and utilization of excellent ethnic cultures in the era.展开更多
Ni-Ru bimetallic porous carbon sphere(Ni-Ru@PCS) catalysts were synthesized via formaldehyde-assisted, metal-coordinated crosslinking sol-gel chemistry, in which biomass-derived tannic acid and F127 surfactant were us...Ni-Ru bimetallic porous carbon sphere(Ni-Ru@PCS) catalysts were synthesized via formaldehyde-assisted, metal-coordinated crosslinking sol-gel chemistry, in which biomass-derived tannic acid and F127 surfactant were used as carbon precursor and soft template, respectively, and Ni2+and Ru3+were used as cross-linkers. In the developed method, Ni-Ru particles became uniformly dispersed in the carbon skeleton due to strong coordination bonds between metal ions(Ni2+and Ru^(3+)) and tannic acid molecules and bimetal interactions. The as-synthesized Ni-Ru10:1@PCS catalyst with a loading Ni:Ru mole ratio of 10:1 was applied for the selective hydrogenation of glucose to sorbitol, and provided 99% glucose conversion with a sorbitol selectivity of 100% at 140℃ in 150 min reaction time and exhibited good stability and recyclability in which sorbitol yield remained at 98% after 4 cycles with little or no metal agglomeration. The catalyst was applied to glucose solutions as high as 20 wt% with 97% sorbitol yields being obtained at 140℃ in 20 h. The developed bimetallic porous carbon sphere catalysts take advantage of sustainably-derived materials in their structure and are applicable to related biomass conversion reactions.展开更多
Co_(3)O_(4) was synthesized on carbon paper(CP)using a facile method to improve electrochemical nitrate-toammonia conversion efficiency.The resulting Co_(3)O_(4)-CP electrode demonstrated an exceptional Faradaic effic...Co_(3)O_(4) was synthesized on carbon paper(CP)using a facile method to improve electrochemical nitrate-toammonia conversion efficiency.The resulting Co_(3)O_(4)-CP electrode demonstrated an exceptional Faradaic efficiency of almost 100% across a broad range of application conditions,with a peak NH3 yield of 3.43 mmol h^(-1) cm^(-2)(2.25 mol gCo^(-1) h^(-1)).展开更多
Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by im...Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by immobilization for 6 and 9 weeks by Videman method.Nine groups of rabbits(control,6 weeks and 9 weeks model,6 weeks and 9 weeks acupotomy,6 weeks and 9 weeks electroacupuncture,and 6 weeks and 9 weeks drug groups)received acupotomy,electroacupuncture and risedronate sodium intervention,respectively,for 3 weeks.Results:Acupotomy can inhibit the activity of osteoclasts and osteoblasts in subchondral bone by reducing the proteins expression of cathepsin K(CK)and tartrate-resistant acid phosphatase(TRAP)and decreasing the proteins expression of osteocalcin(OCN)and alkaline phosphatase(ALP),to intercept the abnormal bone resorption and bone formation of subchondral bone in 6-week and 9-week immobilization-induced KOA rabbits.Conclusion:These findings indicated that acupotomy may be more advantageous than risedronate sodium intervention in modulating subchondral bone remodeling in KOA rabbits,especially in 9-week immobilization-induced KOA rabbits.展开更多
Artificial intelligence(AI)models have significantly impacted various areas of the atmospheric sciences,reshaping our approach to climate-related challenges.Amid this AI-driven transformation,the foundational role of ...Artificial intelligence(AI)models have significantly impacted various areas of the atmospheric sciences,reshaping our approach to climate-related challenges.Amid this AI-driven transformation,the foundational role of physics in climate science has occasionally been overlooked.Our perspective suggests that the future of climate modeling involves a synergistic partnership between AI and physics,rather than an“either/or”scenario.Scrutinizing controversies around current physical inconsistencies in large AI models,we stress the critical need for detailed dynamic diagnostics and physical constraints.Furthermore,we provide illustrative examples to guide future assessments and constraints for AI models.Regarding AI integration with numerical models,we argue that offline AI parameterization schemes may fall short of achieving global optimality,emphasizing the importance of constructing online schemes.Additionally,we highlight the significance of fostering a community culture and propose the OCR(Open,Comparable,Reproducible)principles.Through a better community culture and a deep integration of physics and AI,we contend that developing a learnable climate model,balancing AI and physics,is an achievable goal.展开更多
Vapor pressure of lead and lead chlorides from FeOT?CaO?SiO2?Al2O3 slag system was measured by using Knudsen effusion method. The results suggest that the vapor pressures of lead and lead chlorides increase with in...Vapor pressure of lead and lead chlorides from FeOT?CaO?SiO2?Al2O3 slag system was measured by using Knudsen effusion method. The results suggest that the vapor pressures of lead and lead chlorides increase with increasing temperature. For the slag systems without chlorine, the logarithm of vapor pressure (lnp) shows highly linear dependency on the reciprocal of temperature (1/T), and higher vapor pressure is observed in the condition where more metallic lead vapor is formed. In this case, the vapor pressure of lead increases with increasing slag basicity (w(CaO)/w(SiO2)), increasing FeO content andw(Fe2+)/w(Fe3+) ratio. For the case of slag system with chlorine addition, the total pressures of PbCl2 and PbCl increase with decreasing basicity and FeO content of slag.展开更多
The program described herein (LEADAT) serves to calculate sediment date and sedimentation rate using the ^210pb method for the studies of environmental processes and pollution history on a time scale of 100 - 150 a....The program described herein (LEADAT) serves to calculate sediment date and sedimentation rate using the ^210pb method for the studies of environmental processes and pollution history on a time scale of 100 - 150 a. The program written in MATLAB ( Version7.0) permits the user to select the principal models of ^210pb method, i. e. , the constant fluxes of sediment and lead-210 ( CF- SL) model, the constant flux of lead-210 (CFL) model, the constant initial concentration of lead-210 (CICL) model and the twolayer mixing (TLM) model. Although appropriate model selection is essentially based on understanding of the sedimentary processes, the pattern of the excess ^210pb profile is also helpful for model selection. The excess ^210pb profiles for two sediment cores collected from a brackish lake and an embayment respectively are used to demonstrate the application of the program. With a graphical user interface, the program can be easily executed. Not only ASCII but also graphical output can be generated by means of the program. Meanwhile, the code can be modified easily for extension.展开更多
Macro-texture of an Mg-Al-Ca alloy prepared by friction stir welding (FSW) was investigated through pole figure measurement and X-ray diffraction (XRD) pattern analysis. It was found that at the top and bottom sur...Macro-texture of an Mg-Al-Ca alloy prepared by friction stir welding (FSW) was investigated through pole figure measurement and X-ray diffraction (XRD) pattern analysis. It was found that at the top and bottom surfaces of friction stir zone (FSZ), (0002) basal planes of magnesium tend to be arranged parallel to the plate surface. In the cross section of FSZ, no obvious texture had evolved and (0002) basal planes showed a random distribution.展开更多
Biodegradable polymers are highly attractive as potential alternatives to petroleum-based polymers in an attempt to achieve carbon neutrality whilst maintaining the mechanical properties of the structures.Among these ...Biodegradable polymers are highly attractive as potential alternatives to petroleum-based polymers in an attempt to achieve carbon neutrality whilst maintaining the mechanical properties of the structures.Among these polymers,polylactic acid(PLA)is particularly promising due to its good mechanical properties,biocompatibility and thermoplasticity.In this work,we aim to enhance the mechanical properties of PLA using mechanically-defibrated cellulose nanofibers(CNFs)that exhibit remarkable mechanical properties and biodegradability.We also employ fused deposition modeling(FDM),one of the three-dimensional printing methods for thermoplastic polymers,for the low-cost fabrication of the products.Mechanically-defibrated CNF-reinforced PLA matrix composites are fabricated by FDM.Their tensile properties are investigated in two printing directions(0°/90°and+45°/-45°).The discussion about the relationship between printing direction and tensile behavoir of mechanically-defibrated CNF-reinforced PLA matrix composite is the unique point of this study.We further discuss the microstructure and fracture surface of mechanically-defibrated CNF-reinforced PLA matrix composite by scanning electron microscope.展开更多
This study analyzes the management of wastewater pollutants in a number of Chinese industrial sectors from 1998 to 2010. We use decomposition analysis to calculate changes in wastewater pollutant emissions that result...This study analyzes the management of wastewater pollutants in a number of Chinese industrial sectors from 1998 to 2010. We use decomposition analysis to calculate changes in wastewater pollutant emissions that result from cleaner production processes, end-of-pipe treatment, structural changes in industry, and changes in the scale of production. We focus on one indicator of water quality and three pollutants: chemical oxygen demand (COD), petroleum, cyanide, and volatile phenols. We find that until 2002, COD emissions were mainly reduced through end-of-pipe treatments. Cleaner production processes didn’t begin contributing to COD emissions reductions until the introduction of a 2003 law that enforced their implementation. Petroleum emissions were primarily lowered through cleaner production mechanisms, which have the added benefit of reducing the input cost of intermediate petroleum. Diverse and effective pollution abatement strategies for cyanide and volatile phenols are emerging among industries in China. It will be important for the government to consider differences between industries should they choose to regulate the emissions of specific chemical substances.展开更多
Four sediment cores were collected from Mikawa Bay, Japan, and excess ^210pb and ^137Cs were measured by gamma spectrometry. Sedimentation rates for the four cores were determined by ^210Pb method. The sedimentation r...Four sediment cores were collected from Mikawa Bay, Japan, and excess ^210pb and ^137Cs were measured by gamma spectrometry. Sedimentation rates for the four cores were determined by ^210Pb method. The sedimentation rate range is 0.10-0.70 g/(cm^2.year). The bio-mixing depth for each core is less than 7.0 cm, and was determined by the excess 210^pb profiles as well. Therefore, the bioturbation is slight. The 210^pb-derived dates coincided with the results from ^137Cs geochronology. Acceleration in sedimentation rate due to environmental alteration has been found in cores A2.5 and 05AS8, representing two depocenters due to their topography. Evidence of the Tokal Flood in 2000 was found in core 05AS8 according to the profiles of both radioisotopes and trace metals.展开更多
Mg-Al layered double hydroxide intercalated with CO_(3)^(2-)(CO_(3)·Mg-Al LDH) is effective for treating HCl exhaust gas.HCl reacts with CO_(3)^(2-) in CO_(3)·Mg-Al LDH, resulting in the formation of Cl·...Mg-Al layered double hydroxide intercalated with CO_(3)^(2-)(CO_(3)·Mg-Al LDH) is effective for treating HCl exhaust gas.HCl reacts with CO_(3)^(2-) in CO_(3)·Mg-Al LDH, resulting in the formation of Cl·Mg-Al LDH.We propose that CO_(2) can be used for the desorption of Cl^(-)from Cl·Mg-Al LDH to regenerate CO_(3)·Mg-Al LDH.Herein,we studied the desorption of a from CI-Mg-Al LDH by adding water to Cl·Mg-Al LDH and blowing CO_(2) into it.We also analyzed the effects of temperature and water addition speed on the desorption of CI^(-)from Cl·Mg-Al LDH.Our results show that the added water adhered to CI·Mg-Al LDH and that CO_(2) in the gaseous phase was dissolved in this adhered water,thus generating CO_(3)^(2-).Therefore,anion exchange occurred between CO_(3)^(2-) and Cl^(-)in the Cl·Mg-Al LDH,thus desorbing Cl^(-).展开更多
To investigate the effect of hafnium addition on the solidification structure, Ti-46AI alloys with nominal compositions of Ti-46AI-xHf (x = 0, 3, 5, 7) (at.%) were arc-melted into small ingots in an argon atmosphe...To investigate the effect of hafnium addition on the solidification structure, Ti-46AI alloys with nominal compositions of Ti-46AI-xHf (x = 0, 3, 5, 7) (at.%) were arc-melted into small ingots in an argon atmosphere. The characteristics of the macrostructures and microstructures were studied using a linear intercept method, OM, SEM (BSE), XRD and TEM. The results showed that the ingots with Hf have near lamellar microstructure in columnar and dendrite morphology. The hafnium concentration has a strong effect on the columnar spacing refinement. Increasing Hf from 0 to 7 (at.%), the columnar spacing can be reduced from - 1000 to-400 μm. Constitute phases of the ingots are a2, a small amount of B2 and 7. Most of the B2 phases, richer in Hf and leaner in AI and Ti, exist on the node of the dendrite core in block shape and a little across the lamellar colonies in stick shape. The 7 phases exist on the boundaries of lamellar colonies in small cellular shape. There also exists a segregation of Hf on the columnar and dendrite core. Particularly, both the a-and ,β-phase form from the melt as prior phases. The possible phase sequencing during solidification and solid-state transformations with Hf is given in this paper.展开更多
Climate change and sea level rise necessitate adaptation strategies for coastal areas. This paper showcases five strategies for sea level rise adaptation: hard protection, soft protection, accommodation, retreat, and ...Climate change and sea level rise necessitate adaptation strategies for coastal areas. This paper showcases five strategies for sea level rise adaptation: hard protection, soft protection, accommodation, retreat, and attack. This study proposes adaptation measures and a phased development strategy for coastal areas of Mokpo, an old port city on the southwestern tip of the Korean Peninsula that has been expanded by land reclamation. Mokpo presently experiences frequent flooding during high-water and storm events;due to their low elevation and land subsidence, most of the reclaimed areas are susceptible to future inundation via sea level rise. The fundamental adaptation strategies for the impact areas are: hard protection of important infrastructures via multi-tiered terraces;the retreat of coastal developments accompanied by green buffer zones such as wetlands and parks to accommodate temporary inundation;and up-leveling the ground for new development and phased relocation of existing development. Through the case study of Mokpo, the paper emphasizes the importance of resilient planning strategies for urban development, and highlights both the challenges and opportunities for sea level rise adaptation.展开更多
A three-dimensional fixed offshore platform in deep water modeled by the finite element method is studied in this paper. Analysis of the dynamic response of the MDOF structure is realized taking the non-linearity of t...A three-dimensional fixed offshore platform in deep water modeled by the finite element method is studied in this paper. Analysis of the dynamic response of the MDOF structure is realized taking the non-linearity of the wave drag force and the wave-structure interaction into account. The structural response statistics, which have Gaussian distributions, are used to evaluate the vibration effect of the structure without TMD and with TMD. And an optimal method to design TMD controlling the first mode of the multi-mode structure is proposed. Moreover, the probabilities of occurrence of sea states at the platform site are considered for prediction of the long-term effect of a TMD. Simulation results demonstrate that the long-term effect of a well-designed TMD is good and the practical use is possible due to the good stability of its optimal parameters under different sea states.展开更多
We have previously developed a new process of highly efficient conversion of COand water into formic acid with metallic Zn without the addition of catalyst, however, its mechanism is not clear, particularly in the cat...We have previously developed a new process of highly efficient conversion of COand water into formic acid with metallic Zn without the addition of catalyst, however, its mechanism is not clear, particularly in the catalytic role of Zn/ZnO interface. Herein, the autocatalytic role of Zn/ZnO interface formed in situ during the reduction of COinto formic acid with Zn in water was studied by combining high resolution transmission electron microscopy(HRTEM), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) techniques and experimental data. The electron microscope results show that possible defects or dislocations formed on Zn/ZnO interface, in which plays a key role for Zn H-formation. Further XPS analyses indicate that oxygen vacancies on Zn/ZnO interface increased at short reaction times(less than 10 min). These analyses and experimental results suggest that a highly efficient and rapid conversion of COand water into formic acid should involve an autocatalytic role of the Zn/ZnO interface formed in situ, particularly at the beginning of the reaction.展开更多
The Earth’s sustainable development is threatened by the increasing atmospheric COlevel which can be attributed to the imbalance of COdue to the rapid consumption of fossil fuels caused by human activities and the sl...The Earth’s sustainable development is threatened by the increasing atmospheric COlevel which can be attributed to the imbalance of COdue to the rapid consumption of fossil fuels caused by human activities and the slow absorption and conversion of COby nature. One of the efficient methods for reconstructing the balance of COshould involve the rapid conversion of COinto fuels and chemicals.The hydrogenation of COwith gaseous hydrogen is currently considered to be the most commercially feasible synthetic route, however, the supply of safe and economical hydrogen sources poses a significant challenge to up-scaling application. Direct utilization of hydrogen from dissociation of water, the most abundant, cheap and clean hydrogen resource, for the reduction of COwould be one of the most promising approaches for COutilization. This paper provides an overview of the current advances in research on highly efficient reduction of COor NaHCO, a representative compound of CO, into formic acid/formate by in situ hydrogen from water dissociation with a metal/metal oxide redox cycle under mild hydrothermal conditions.展开更多
Recent observations of Asian dust storms show an eastern expansion of the source area to degraded lands, where dust emissions have been little studied. The dust concentrations over the saline land of the western Songn...Recent observations of Asian dust storms show an eastern expansion of the source area to degraded lands, where dust emissions have been little studied. The dust concentrations over the saline land of the western Songnen Plain (SSL), Northeastern China, are circumstantially higher than those from the northwestern Chinese deserts. These concentrations are sensitive to the surface soil conditions and wind velocity on the ground. The dust samples collected during dust storm events on the SSL contain abundant Na, Mg, A1, K, Ca, Fe and Ti, as well as toxic elements such as Cu, V, Zn and Ba. Individual particle analysis reveals that fine saline particles (〈 10 μm in diameter) on the saline land, consisting largely of carbonate, halite and sulfate together with lithogenic minerals such as SiO2 and aluminosilicate, are eventually uplifted during the interval from spring to autuum. The predominantly fine saline particles uplifted from the SSL are likely transported eastward by the winter monsoon circulation and westerlies. Recent degradation of saline lands in Northeastern China would not only increase the frequency of dust storm events in the downwind area, but also might change the chemical composition of the Asian dust emissions.展开更多
In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activa...In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis.We studied the adsorption of artificial waste dialysate,which is a mixed solution of urea,creatinine,and uric acid,and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical.The amount of adsorption was approximately 1.4 mg·g^−1 for urea,18 mg·g^−1 for creatinine,and 20 mg·g^−1 for uric acid.The urea,creatinine,and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃,and the adsorption capacity of the spherical activated carbon was regenerated.Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process.展开更多
Shrub species are used in restoration projects on dryland for their facilitation effects,which include environmental improvements and protection from herbivore feeding.Facilitation effects on forage grasses are potent...Shrub species are used in restoration projects on dryland for their facilitation effects,which include environmental improvements and protection from herbivore feeding.Facilitation effects on forage grasses are potentially important in improving grazing capacity on rangelands.However,the morphology-dependent performance of benefactor plants in facilitating forage species growth and supplementation under moderate grazing intensity remains unclear.Here,our main purpose was to measure facilitation performance in terms of the survival of a native forage grass,Agropyron cristatum(L.)Gaertn.(Gramineae).,in accordance with the growth conditions of a sand-fixing benefactor shrub,Caragana microphylla Lam.,in the Hulun Buir Grassland,northern China.Six study sites with patches of A.cristatum and C.microphylla were established at the foot of fixed sand dunes.At each site,five quadrats were set in places where C.microphylla coverage was 100%and A.cristatum grew among the shrubs(shrub quadrats),and another five were set where A.cristatum grew alone without C.microphylla(grass quadrats).We measured the morphological traits of C.microphylla and A.cristatum in all 60 quadrats,along with the soil water content and soil temperature.The data were compared between the shrub and grass quadrats by generalized linear mixed-effect models to assess the shrub's facilitation effects.We also used such models to elucidate the relationship between the average height of C.microphylla and the morphological traits of A.cristatum in the shrub quadrats.The maximum height,average grazed height,and the number of seed heads of A.cristatum were greater in the shrub quadrats than in the grass quadrats.The soil surface temperature was lower in the shrub quadrats.The maximum height and seed head number of A.cristatum were positively associated with the average height of C.microphylla.These results suggest that the grazing impact and heat stress were smaller in shrub quadrats than in grass quadrats,and that the degree of this protective effect depended on the shrub height.The shrub canopy seemed to reduce the increase in soil temperature and keep the grass vigorous.Livestock likely avoided grazing grasses in the C.microphylla patches because of the shrub's spiny leaves;only the upper parts of the grass stems(including the seed heads)protruding from the shrub canopy were grazed.The sand-fixing shrub thus moderates the grazing impact and soil temperature,and contributes to vegetation restoration and grazing system sustainability.展开更多
文摘This study aims to reveal the spatial structural characteristics of 1,652 Ethnic-Minority Villages(EMV)in China and to analyze the mechanisms driving their spatial heterogeneity.EMV are a special type of settlement space that preserve a large number of historical traces of the ethnic culture of ancient China.They are important carriers of China’s excellent traditional culture and are key to the implementation of rural revitalization strategies.In this study,1652 EMV in China were selected as the research subjects.The Nearest Neighbor Index,kernel density,and spatial autocorrelation index were employed to reveal the spatial structural characteristics of minority villages.Neural network models,spatial lag models,and geographical detectors were used to analyze the formation mechanism of spatial heterogeneity in EMV.The results indicate that:(1)EMV exhibit significant spatial differentiation characterized by“single-core with multiple surrounding sub-centers,”“polarization between east and west,”“decreasing quantity from southwest to east coast to northeast to northwest,”and“large dispersion with small agglomeration.”(2)EMV are mainly distributed in areas rich in intangible cultural heritage,with high vegetation coverage and low altitude,far from central cities,and having limited arable land and an underdeveloped economy and transportation,particularly in shaded or riverbank areas.(3)Distance from the nearest river(X3),distance from central cities(X8),national intangible cultural heritage(X9),and NDVI(X10)were the main driving factors affecting the spatial distribution of EMV,whereas elevation(X1)and GDP(X5)had the weakest influence.As EMV are a relatively unique territorial spatial unit,the identification of their spatial heterogeneity characteristics not only deepens the research content of settlement geography,but also involves the assessment,protection,and development of Minority Villages,which is of great significance for the inheritance and utilization of excellent ethnic cultures in the era.
基金the financial support from the National Natural Science Foundation of China (Nos. 22178181 and 21876091)the Natural Science Foundation of Tianjin (No. 21JCZDJC00180)+1 种基金the Fundamental Research Funds for the Central Universities (Nankai University (No. 63213075))Young Elite Scientists Sponsorship Program by Tianjin (TJSQNTJ-2018-06)。
文摘Ni-Ru bimetallic porous carbon sphere(Ni-Ru@PCS) catalysts were synthesized via formaldehyde-assisted, metal-coordinated crosslinking sol-gel chemistry, in which biomass-derived tannic acid and F127 surfactant were used as carbon precursor and soft template, respectively, and Ni2+and Ru3+were used as cross-linkers. In the developed method, Ni-Ru particles became uniformly dispersed in the carbon skeleton due to strong coordination bonds between metal ions(Ni2+and Ru^(3+)) and tannic acid molecules and bimetal interactions. The as-synthesized Ni-Ru10:1@PCS catalyst with a loading Ni:Ru mole ratio of 10:1 was applied for the selective hydrogenation of glucose to sorbitol, and provided 99% glucose conversion with a sorbitol selectivity of 100% at 140℃ in 150 min reaction time and exhibited good stability and recyclability in which sorbitol yield remained at 98% after 4 cycles with little or no metal agglomeration. The catalyst was applied to glucose solutions as high as 20 wt% with 97% sorbitol yields being obtained at 140℃ in 20 h. The developed bimetallic porous carbon sphere catalysts take advantage of sustainably-derived materials in their structure and are applicable to related biomass conversion reactions.
基金the financial support from China Scholarship Council for financial support(201906890004)during his Ph.D.studying abroad.
文摘Co_(3)O_(4) was synthesized on carbon paper(CP)using a facile method to improve electrochemical nitrate-toammonia conversion efficiency.The resulting Co_(3)O_(4)-CP electrode demonstrated an exceptional Faradaic efficiency of almost 100% across a broad range of application conditions,with a peak NH3 yield of 3.43 mmol h^(-1) cm^(-2)(2.25 mol gCo^(-1) h^(-1)).
基金supported by the Beijing Municipal Natural Science Foundation(7192110)。
文摘Objective:To investigate whether acupotomy could inhibit subchondral bone remodeling in knee osteoarthritis(KOA)rabbits by regulating the activity of osteoblasts and osteoclasts.Methods:KOA rabbits were prepared by immobilization for 6 and 9 weeks by Videman method.Nine groups of rabbits(control,6 weeks and 9 weeks model,6 weeks and 9 weeks acupotomy,6 weeks and 9 weeks electroacupuncture,and 6 weeks and 9 weeks drug groups)received acupotomy,electroacupuncture and risedronate sodium intervention,respectively,for 3 weeks.Results:Acupotomy can inhibit the activity of osteoclasts and osteoblasts in subchondral bone by reducing the proteins expression of cathepsin K(CK)and tartrate-resistant acid phosphatase(TRAP)and decreasing the proteins expression of osteocalcin(OCN)and alkaline phosphatase(ALP),to intercept the abnormal bone resorption and bone formation of subchondral bone in 6-week and 9-week immobilization-induced KOA rabbits.Conclusion:These findings indicated that acupotomy may be more advantageous than risedronate sodium intervention in modulating subchondral bone remodeling in KOA rabbits,especially in 9-week immobilization-induced KOA rabbits.
基金supported by the National Natural Science Foundation of China(Grant Nos.42141019 and 42261144687)and STEP(Grant No.2019QZKK0102)supported by the Korea Environmental Industry&Technology Institute(KEITI)through the“Project for developing an observation-based GHG emissions geospatial information map”,funded by the Korea Ministry of Environment(MOE)(Grant No.RS-2023-00232066).
文摘Artificial intelligence(AI)models have significantly impacted various areas of the atmospheric sciences,reshaping our approach to climate-related challenges.Amid this AI-driven transformation,the foundational role of physics in climate science has occasionally been overlooked.Our perspective suggests that the future of climate modeling involves a synergistic partnership between AI and physics,rather than an“either/or”scenario.Scrutinizing controversies around current physical inconsistencies in large AI models,we stress the critical need for detailed dynamic diagnostics and physical constraints.Furthermore,we provide illustrative examples to guide future assessments and constraints for AI models.Regarding AI integration with numerical models,we argue that offline AI parameterization schemes may fall short of achieving global optimality,emphasizing the importance of constructing online schemes.Additionally,we highlight the significance of fostering a community culture and propose the OCR(Open,Comparable,Reproducible)principles.Through a better community culture and a deep integration of physics and AI,we contend that developing a learnable climate model,balancing AI and physics,is an achievable goal.
基金Project supported by the Japan Oil,Gas and Metals National Corporation(JOGMEC)Project(51474021)supported by the National Natural Science Foundation of China
文摘Vapor pressure of lead and lead chlorides from FeOT?CaO?SiO2?Al2O3 slag system was measured by using Knudsen effusion method. The results suggest that the vapor pressures of lead and lead chlorides increase with increasing temperature. For the slag systems without chlorine, the logarithm of vapor pressure (lnp) shows highly linear dependency on the reciprocal of temperature (1/T), and higher vapor pressure is observed in the condition where more metallic lead vapor is formed. In this case, the vapor pressure of lead increases with increasing slag basicity (w(CaO)/w(SiO2)), increasing FeO content andw(Fe2+)/w(Fe3+) ratio. For the case of slag system with chlorine addition, the total pressures of PbCl2 and PbCl increase with decreasing basicity and FeO content of slag.
文摘The program described herein (LEADAT) serves to calculate sediment date and sedimentation rate using the ^210pb method for the studies of environmental processes and pollution history on a time scale of 100 - 150 a. The program written in MATLAB ( Version7.0) permits the user to select the principal models of ^210pb method, i. e. , the constant fluxes of sediment and lead-210 ( CF- SL) model, the constant flux of lead-210 (CFL) model, the constant initial concentration of lead-210 (CICL) model and the twolayer mixing (TLM) model. Although appropriate model selection is essentially based on understanding of the sedimentary processes, the pattern of the excess ^210pb profile is also helpful for model selection. The excess ^210pb profiles for two sediment cores collected from a brackish lake and an embayment respectively are used to demonstrate the application of the program. With a graphical user interface, the program can be easily executed. Not only ASCII but also graphical output can be generated by means of the program. Meanwhile, the code can be modified easily for extension.
文摘Macro-texture of an Mg-Al-Ca alloy prepared by friction stir welding (FSW) was investigated through pole figure measurement and X-ray diffraction (XRD) pattern analysis. It was found that at the top and bottom surfaces of friction stir zone (FSZ), (0002) basal planes of magnesium tend to be arranged parallel to the plate surface. In the cross section of FSZ, no obvious texture had evolved and (0002) basal planes showed a random distribution.
基金supported by the Program for Creation of Interdisciplinary Research and Ensemble Program of Frontier Research Institute for Interdisciplinary Sciences,Tohoku University。
文摘Biodegradable polymers are highly attractive as potential alternatives to petroleum-based polymers in an attempt to achieve carbon neutrality whilst maintaining the mechanical properties of the structures.Among these polymers,polylactic acid(PLA)is particularly promising due to its good mechanical properties,biocompatibility and thermoplasticity.In this work,we aim to enhance the mechanical properties of PLA using mechanically-defibrated cellulose nanofibers(CNFs)that exhibit remarkable mechanical properties and biodegradability.We also employ fused deposition modeling(FDM),one of the three-dimensional printing methods for thermoplastic polymers,for the low-cost fabrication of the products.Mechanically-defibrated CNF-reinforced PLA matrix composites are fabricated by FDM.Their tensile properties are investigated in two printing directions(0°/90°and+45°/-45°).The discussion about the relationship between printing direction and tensile behavoir of mechanically-defibrated CNF-reinforced PLA matrix composite is the unique point of this study.We further discuss the microstructure and fracture surface of mechanically-defibrated CNF-reinforced PLA matrix composite by scanning electron microscope.
文摘This study analyzes the management of wastewater pollutants in a number of Chinese industrial sectors from 1998 to 2010. We use decomposition analysis to calculate changes in wastewater pollutant emissions that result from cleaner production processes, end-of-pipe treatment, structural changes in industry, and changes in the scale of production. We focus on one indicator of water quality and three pollutants: chemical oxygen demand (COD), petroleum, cyanide, and volatile phenols. We find that until 2002, COD emissions were mainly reduced through end-of-pipe treatments. Cleaner production processes didn’t begin contributing to COD emissions reductions until the introduction of a 2003 law that enforced their implementation. Petroleum emissions were primarily lowered through cleaner production mechanisms, which have the added benefit of reducing the input cost of intermediate petroleum. Diverse and effective pollution abatement strategies for cyanide and volatile phenols are emerging among industries in China. It will be important for the government to consider differences between industries should they choose to regulate the emissions of specific chemical substances.
基金partially benefited from a scholarship from the Ministry of Education, Culture, Sports, Science and Technology, Japana fellowship from the 21st century COE program, Dynamicsof the Sun-Earth-Life Interactive System , Japan (No. G-4).
文摘Four sediment cores were collected from Mikawa Bay, Japan, and excess ^210pb and ^137Cs were measured by gamma spectrometry. Sedimentation rates for the four cores were determined by ^210Pb method. The sedimentation rate range is 0.10-0.70 g/(cm^2.year). The bio-mixing depth for each core is less than 7.0 cm, and was determined by the excess 210^pb profiles as well. Therefore, the bioturbation is slight. The 210^pb-derived dates coincided with the results from ^137Cs geochronology. Acceleration in sedimentation rate due to environmental alteration has been found in cores A2.5 and 05AS8, representing two depocenters due to their topography. Evidence of the Tokal Flood in 2000 was found in core 05AS8 according to the profiles of both radioisotopes and trace metals.
文摘Mg-Al layered double hydroxide intercalated with CO_(3)^(2-)(CO_(3)·Mg-Al LDH) is effective for treating HCl exhaust gas.HCl reacts with CO_(3)^(2-) in CO_(3)·Mg-Al LDH, resulting in the formation of Cl·Mg-Al LDH.We propose that CO_(2) can be used for the desorption of Cl^(-)from Cl·Mg-Al LDH to regenerate CO_(3)·Mg-Al LDH.Herein,we studied the desorption of a from CI-Mg-Al LDH by adding water to Cl·Mg-Al LDH and blowing CO_(2) into it.We also analyzed the effects of temperature and water addition speed on the desorption of CI^(-)from Cl·Mg-Al LDH.Our results show that the added water adhered to CI·Mg-Al LDH and that CO_(2) in the gaseous phase was dissolved in this adhered water,thus generating CO_(3)^(2-).Therefore,anion exchange occurred between CO_(3)^(2-) and Cl^(-)in the Cl·Mg-Al LDH,thus desorbing Cl^(-).
基金supported by the National Natural Science Foundation of China(50771041)NCET 05-0350.
文摘To investigate the effect of hafnium addition on the solidification structure, Ti-46AI alloys with nominal compositions of Ti-46AI-xHf (x = 0, 3, 5, 7) (at.%) were arc-melted into small ingots in an argon atmosphere. The characteristics of the macrostructures and microstructures were studied using a linear intercept method, OM, SEM (BSE), XRD and TEM. The results showed that the ingots with Hf have near lamellar microstructure in columnar and dendrite morphology. The hafnium concentration has a strong effect on the columnar spacing refinement. Increasing Hf from 0 to 7 (at.%), the columnar spacing can be reduced from - 1000 to-400 μm. Constitute phases of the ingots are a2, a small amount of B2 and 7. Most of the B2 phases, richer in Hf and leaner in AI and Ti, exist on the node of the dendrite core in block shape and a little across the lamellar colonies in stick shape. The 7 phases exist on the boundaries of lamellar colonies in small cellular shape. There also exists a segregation of Hf on the columnar and dendrite core. Particularly, both the a-and ,β-phase form from the melt as prior phases. The possible phase sequencing during solidification and solid-state transformations with Hf is given in this paper.
文摘Climate change and sea level rise necessitate adaptation strategies for coastal areas. This paper showcases five strategies for sea level rise adaptation: hard protection, soft protection, accommodation, retreat, and attack. This study proposes adaptation measures and a phased development strategy for coastal areas of Mokpo, an old port city on the southwestern tip of the Korean Peninsula that has been expanded by land reclamation. Mokpo presently experiences frequent flooding during high-water and storm events;due to their low elevation and land subsidence, most of the reclaimed areas are susceptible to future inundation via sea level rise. The fundamental adaptation strategies for the impact areas are: hard protection of important infrastructures via multi-tiered terraces;the retreat of coastal developments accompanied by green buffer zones such as wetlands and parks to accommodate temporary inundation;and up-leveling the ground for new development and phased relocation of existing development. Through the case study of Mokpo, the paper emphasizes the importance of resilient planning strategies for urban development, and highlights both the challenges and opportunities for sea level rise adaptation.
文摘A three-dimensional fixed offshore platform in deep water modeled by the finite element method is studied in this paper. Analysis of the dynamic response of the MDOF structure is realized taking the non-linearity of the wave drag force and the wave-structure interaction into account. The structural response statistics, which have Gaussian distributions, are used to evaluate the vibration effect of the structure without TMD and with TMD. And an optimal method to design TMD controlling the first mode of the multi-mode structure is proposed. Moreover, the probabilities of occurrence of sea states at the platform site are considered for prediction of the long-term effect of a TMD. Simulation results demonstrate that the long-term effect of a well-designed TMD is good and the practical use is possible due to the good stability of its optimal parameters under different sea states.
基金the financial support of the National Natural Science Foundation of China (No. 21277091 & 51472159)the State Key Program of National Natural Science Foundation of China (No. 21436007)+1 种基金the Key Basic Research Projects of Science and Technology Commission of Shanghai (No. 14JC1403100)the Chenxing-SMG Young Scholar Project of Shanghai Jiao Tong University
文摘We have previously developed a new process of highly efficient conversion of COand water into formic acid with metallic Zn without the addition of catalyst, however, its mechanism is not clear, particularly in the catalytic role of Zn/ZnO interface. Herein, the autocatalytic role of Zn/ZnO interface formed in situ during the reduction of COinto formic acid with Zn in water was studied by combining high resolution transmission electron microscopy(HRTEM), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) techniques and experimental data. The electron microscope results show that possible defects or dislocations formed on Zn/ZnO interface, in which plays a key role for Zn H-formation. Further XPS analyses indicate that oxygen vacancies on Zn/ZnO interface increased at short reaction times(less than 10 min). These analyses and experimental results suggest that a highly efficient and rapid conversion of COand water into formic acid should involve an autocatalytic role of the Zn/ZnO interface formed in situ, particularly at the beginning of the reaction.
基金the financial support of the National Natural Science Foundation of China (Nos. 21277091 and 51472159)the State Key Program of National Natural Science Foundation of China (No. 21436007)+1 种基金the Key Basic Research Projects of Science and Technology Commission of Shanghai (No. 14JC1403100)the Chenxing-SMG Young Scholar Project of Shanghai Jiao Tong University
文摘The Earth’s sustainable development is threatened by the increasing atmospheric COlevel which can be attributed to the imbalance of COdue to the rapid consumption of fossil fuels caused by human activities and the slow absorption and conversion of COby nature. One of the efficient methods for reconstructing the balance of COshould involve the rapid conversion of COinto fuels and chemicals.The hydrogenation of COwith gaseous hydrogen is currently considered to be the most commercially feasible synthetic route, however, the supply of safe and economical hydrogen sources poses a significant challenge to up-scaling application. Direct utilization of hydrogen from dissociation of water, the most abundant, cheap and clean hydrogen resource, for the reduction of COwould be one of the most promising approaches for COutilization. This paper provides an overview of the current advances in research on highly efficient reduction of COor NaHCO, a representative compound of CO, into formic acid/formate by in situ hydrogen from water dissociation with a metal/metal oxide redox cycle under mild hydrothermal conditions.
基金supported in a part by Chinese National Key Project of Basic Research (No G2000048703)the Grant-in-Aid for Scientific Research (No 16310008,18403002) from the Ministry of Education, Culture,Sports, Science and Technology, Japan
文摘Recent observations of Asian dust storms show an eastern expansion of the source area to degraded lands, where dust emissions have been little studied. The dust concentrations over the saline land of the western Songnen Plain (SSL), Northeastern China, are circumstantially higher than those from the northwestern Chinese deserts. These concentrations are sensitive to the surface soil conditions and wind velocity on the ground. The dust samples collected during dust storm events on the SSL contain abundant Na, Mg, A1, K, Ca, Fe and Ti, as well as toxic elements such as Cu, V, Zn and Ba. Individual particle analysis reveals that fine saline particles (〈 10 μm in diameter) on the saline land, consisting largely of carbonate, halite and sulfate together with lithogenic minerals such as SiO2 and aluminosilicate, are eventually uplifted during the interval from spring to autuum. The predominantly fine saline particles uplifted from the SSL are likely transported eastward by the winter monsoon circulation and westerlies. Recent degradation of saline lands in Northeastern China would not only increase the frequency of dust storm events in the downwind area, but also might change the chemical composition of the Asian dust emissions.
文摘In this paper,we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis.We studied the adsorption of artificial waste dialysate,which is a mixed solution of urea,creatinine,and uric acid,and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical.The amount of adsorption was approximately 1.4 mg·g^−1 for urea,18 mg·g^−1 for creatinine,and 20 mg·g^−1 for uric acid.The urea,creatinine,and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃,and the adsorption capacity of the spherical activated carbon was regenerated.Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process.
基金supported by the Tripartite Environment Ministers Meeting(TEMM)JSPS KAKENHI(JP19H04316).We thank the staff of the Chinese Research Academy of Environmental Sciences(CRAES)the Overseas Environmental Cooperation Center(OECC),Japan for their support during the field survey.
文摘Shrub species are used in restoration projects on dryland for their facilitation effects,which include environmental improvements and protection from herbivore feeding.Facilitation effects on forage grasses are potentially important in improving grazing capacity on rangelands.However,the morphology-dependent performance of benefactor plants in facilitating forage species growth and supplementation under moderate grazing intensity remains unclear.Here,our main purpose was to measure facilitation performance in terms of the survival of a native forage grass,Agropyron cristatum(L.)Gaertn.(Gramineae).,in accordance with the growth conditions of a sand-fixing benefactor shrub,Caragana microphylla Lam.,in the Hulun Buir Grassland,northern China.Six study sites with patches of A.cristatum and C.microphylla were established at the foot of fixed sand dunes.At each site,five quadrats were set in places where C.microphylla coverage was 100%and A.cristatum grew among the shrubs(shrub quadrats),and another five were set where A.cristatum grew alone without C.microphylla(grass quadrats).We measured the morphological traits of C.microphylla and A.cristatum in all 60 quadrats,along with the soil water content and soil temperature.The data were compared between the shrub and grass quadrats by generalized linear mixed-effect models to assess the shrub's facilitation effects.We also used such models to elucidate the relationship between the average height of C.microphylla and the morphological traits of A.cristatum in the shrub quadrats.The maximum height,average grazed height,and the number of seed heads of A.cristatum were greater in the shrub quadrats than in the grass quadrats.The soil surface temperature was lower in the shrub quadrats.The maximum height and seed head number of A.cristatum were positively associated with the average height of C.microphylla.These results suggest that the grazing impact and heat stress were smaller in shrub quadrats than in grass quadrats,and that the degree of this protective effect depended on the shrub height.The shrub canopy seemed to reduce the increase in soil temperature and keep the grass vigorous.Livestock likely avoided grazing grasses in the C.microphylla patches because of the shrub's spiny leaves;only the upper parts of the grass stems(including the seed heads)protruding from the shrub canopy were grazed.The sand-fixing shrub thus moderates the grazing impact and soil temperature,and contributes to vegetation restoration and grazing system sustainability.