We present a formalism of charge self-consistent dynamical mean field theory(DMFT)in combination with densityfunctional theory(DFT)within the linear combination of numerical atomic orbitals(LCNAO)framework.We implemen...We present a formalism of charge self-consistent dynamical mean field theory(DMFT)in combination with densityfunctional theory(DFT)within the linear combination of numerical atomic orbitals(LCNAO)framework.We implementedthe charge self-consistent DFT+DMFT formalism by interfacing a full-potential all-electron DFT code with threehybridization expansion-based continuous-time quantum Monte Carlo impurity solvers.The benchmarks on several 3d,4fand 5f strongly correlated electron systems validated our formalism and implementation.Furthermore,within the LCANOframework,our formalism is general and the code architecture is extensible,so it can work as a bridge merging differentLCNAO DFT packages and impurity solvers to do charge self-consistent DFT+DMFT calculations.展开更多
Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant charact...Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.展开更多
Cohesive failure is one of the primary reasons for low-temperature cracking in asphalt pavements.Understanding the micro-level mechanism is crucial for comprehending cohesive failure behavior.However,previous literatu...Cohesive failure is one of the primary reasons for low-temperature cracking in asphalt pavements.Understanding the micro-level mechanism is crucial for comprehending cohesive failure behavior.However,previous literature has not fully reported on this aspect.Moreover,there has been insufficient attention given to the correlation between macroscopic and microscopic failures.To address these issues,this study employed molecular dynamics simulation to investigate the low-temperature tensile behavior of asphalt binder.By applying virtual strain,the separation work during asphalt binder tensile failure was calculated.Additionally,a correlation between macroscopic and microscopic tensile behaviors was established.Specifically,a quadrilateral asphalt binder model was generated based on SARA fractions.By applying various combinations of virtual strain loading,the separation work at tensile failure was determined.Furthermore,the impact of strain loading combinations on separation work was analyzed.Normalization was employed to establish the correlation between macroscopic and microscopic tensile behaviors.The results indicated that thermodynamic and classical mechanical indicators validated the reliability of the tetragonal asphalt binder model.The strain loading combination consists of strain rate and loading number.All strain loading combinations exhibited the similar tensile failure characteristic.The critical separation strain was hardly influenced by strain loading combination.However,increasing strain rate significantly enhanced both the maximum traction stress and separation work of the asphalt binder.An increment in the loading number led to a decrease in separation work.The virtual strain combination of 0.5%-80 provided a more accurate representation of the actual asphalt's tensile behavior trend.展开更多
In terms of the reaction of COreduction to CO with hydrogen, COconversion is very low at low temperature due to the limitation of thermodynamic equilibrium(TE). To overcome this limitation, plasma catalytic reductio...In terms of the reaction of COreduction to CO with hydrogen, COconversion is very low at low temperature due to the limitation of thermodynamic equilibrium(TE). To overcome this limitation, plasma catalytic reduction of COto CO in a catalyst-filled dielectric barrier discharge(DBD) reactor is studied. An enhanced effect of plasma on the reaction over Au/CeOcatalysts is observed. For both the conventionally catalytic(CC) and plasma catalytic(PC, Pin= 15 W) reactions under conditions of 400 °C, H/CO= 1,200 SCCM, GHSV = 12,000 mL·gcat·h, COconversions over Au/CeOreach 15.4% and 25.5% due to the presence of Au, respectively, however, those over CeOare extremely low and negligible. Moreover,COconversion over Au/CeOin the PC reaction exceeds 22.4% of the TE conversion. Surface intermediate species formed on the catalyst samples during the reactions are determined by in-situ temperatureprogrammed decomposition(TPD) technique. Interestingly, it disclosed that in the PC reaction, the formation of formate intermediate is enhanced by plasma, and the acceleration by plasma in the decomposition of formate species is much greater than that in the formation of formate species on Au/CeO. Enhancement factor is introduced to quantify the enhanced effect of plasma. Lower reactor temperature, higher gas hourly space velocity(GHSV), and lower molar ratio of H/COwould be associated with larger enhancement factor.展开更多
To reveal the potential aging mechanism for self-irradiation in Pu-Ga alloy,we choose Au-Ag alloy as its substitutional material in terms of its mass density and lattice structure.As a first step for understanding the...To reveal the potential aging mechanism for self-irradiation in Pu-Ga alloy,we choose Au-Ag alloy as its substitutional material in terms of its mass density and lattice structure.As a first step for understanding the microscopic behavior of point defects in Au-Ag alloy,we perform a molecular dynamics(MD)simulation on energetics and diffusion of point defects in Au and Ag metal.Our results indicate that the octahedral self-interstitial atom(SIA)is more stable than the tetrahedral SIA.The stability sequence of point defects for He atom in Au/Ag is:substitutional site>octahedral interstitial site>tetrahedral interstitial site.The He-V cluster(Hen Vm,V denotes vacancy)is the most stable at n=m.For the mono-vacancy diffusion,the MD calculation shows that the first nearest neighbour(1 NN)site is the most favorable site on the basis of the nudged elastic band(NEB)calculation,which is in agreement with previous experimental data.There are two peaks for the second nearest neighbour(2 NN)and the third nearest neighbour(3 NN)diffusion curve in octahedral interstitial site for He atom,indicating that the 2 NN and 3 NN diffusion for octahedral SIA would undergo an intermediate defect structure similar to the 1 NN site.The 3 NN diffusion for the tetrahedral SIA and He atom would undergo an intermediate site in analogy to its initial structure.For diffusion of point defects,the vacancy,SIA,He atom and He-V cluster may have an analogous effect on the diffusion velocity in Ag.展开更多
First-principles calculations based on density functional theory corrected by Hubbard parameter U (DFT+U) are applied to the study on the co-adsorption of O2 and H2O molecules to a-U(110) surface. The calculation...First-principles calculations based on density functional theory corrected by Hubbard parameter U (DFT+U) are applied to the study on the co-adsorption of O2 and H2O molecules to a-U(110) surface. The calculation results show that DFT+U method with Ueff = 1.5 eV can yield the experimental results of lattice constant and elastic modulus of a-uranium bulk well. Of all 7 low index surfaces of a-uranium, the (001) surface is the most stable with lowest surface energy while the (110) surface possesses the strongest activity with the highest surface energy. The adsorptions of O2 and H2O molecules are investigated separated. The O2 dissociates spontaneously in all initial configurations. For the adsorption of H2O molecule, both molecular and dissociative adsorptionsoccur. Through calculations of co-adsorption, it can be confirmed that the inhibition effect of O2 on the corrosion of uranium by water vapor originates from the preferential adsorption mechanism, while the consumption of H atoms by O atoms exerted little influence on the corrosion of uranium.展开更多
To investigate the impact of dynamic assessment(DA)on the development of speaking skills,a case study was conducted,recruiting a non-English major undergraduate.DA was constructed following the design combining sandwi...To investigate the impact of dynamic assessment(DA)on the development of speaking skills,a case study was conducted,recruiting a non-English major undergraduate.DA was constructed following the design combining sandwich and cake format with an interactionist approach.To collect data,a profile was designed in accordance with the China’s Standards of English Language Ability(CSE)to record the learner’s changes.A semi-structured interview was conducted to reveal his perspectives on DA.The generated profile with specific mediator-learner’s moves revealed the learner’s microgenetic development in both organizational knowledge and oral expression strategy ability.The thematic analysis of the interview demonstrated the learner’s positive experience with DA,while also unveiling the weak points of DA.Finally,the operational framework for applying interactionist DA in the oral classroom was discussed,and the complementary relationship between DA and traditional teaching and testing practices was highlighted.展开更多
Formaldehyde donor preservatives are under debate because formaldehyde at high concentration is known to the public as a toxic substance to humans and the environment, inducing mutation in living organisms. Chemical m...Formaldehyde donor preservatives are under debate because formaldehyde at high concentration is known to the public as a toxic substance to humans and the environment, inducing mutation in living organisms. Chemical methods, such as using acetylacetone (Nash reagent), are commonly used to determine total formaldehyde concentration in cosmetics. However, these methods will perturb the equilibrium between formaldehyde and formaldehyde donor. A new method, based on C-13 NMR, not perturbing the equilibrium and more suitable for formaldehyde measurement, is reviewed. This review describes the background, distinction, and applications of formaldehyde and formaldehyde donor in cosmetics.展开更多
Recent articles reviewed the molecular damaging pathway of various pollutants especially PM2.5 particles and polycylic aromatic hydrocarbon. AhR (aryl hydrocarbon receptor) pathway, tobacco-similar pathway, oxidatio...Recent articles reviewed the molecular damaging pathway of various pollutants especially PM2.5 particles and polycylic aromatic hydrocarbon. AhR (aryl hydrocarbon receptor) pathway, tobacco-similar pathway, oxidation, as well as epigenetics pathway were reviewed. Based on the working mechanism, the reported study method and methodology used in Ashland lab were reviewed, including cell level experiment, through reconstructed human skin to in vivo study.展开更多
Integrating electrochemical reduction of CO_(2)and electrochemical oxidation to recycle degraded superalloys is a promising solution to ease resource scarcity and safeguard environmental sustainability.Herein,we propo...Integrating electrochemical reduction of CO_(2)and electrochemical oxidation to recycle degraded superalloys is a promising solution to ease resource scarcity and safeguard environmental sustainability.Herein,we propose an electrochemical technique for the conversion of bulk superalloy scraps and CO_(2)into oxide powder at the anode and solid carbon at the cathode,respectively.In particular,a borax-modifi ed CaCl_(2)-based molten salt electrolyte is used for enhancing the electrochemical oxidation of superalloy scraps.At a temperature of 700℃and a voltage of 2.8 V,90.55 wt.%of alloy scraps were oxidized in a molten CaCl_(2)–NaCl–CaCO_(3)–Na_(2)B_(4)O_(7)with an acid–base ratio(K_(a/b))of 1.The synergy of Cl−and B_(4)O_(7)2−of electrolyte prevents the passivation of the alloy anode and enables continuous oxidation.Furthermore,the Ni and Co in the anode products are recovered by sulfation roasting with recovery efficiencies of 85.58%and 95.27%for Ni and Co,respectively.Overall,modulating the alkalinity of the electrolyte for enhancing oxidation/pulverization of alloy scrap anode provides new insight into electrochemically recovering superalloy scraps.展开更多
Background Glibenclamide has garnered attention due to its multifaceted neuroprotective effects in cases of acute central nervous system injury.We initiated a trial to explore the effectiveness and safety of a high do...Background Glibenclamide has garnered attention due to its multifaceted neuroprotective effects in cases of acute central nervous system injury.We initiated a trial to explore the effectiveness and safety of a high dose of glibenclamide in the management of cerebral oedema following aneurysmal subarachnoid haemorrhage(aSAH).Methods This trial constituted a single-centre,randomised clinical study.Half of the 56 patients assigned to the glibenclamide group received 15mg of glibenclamide tablets daily for 10 days(5mg,three times/day).The primary outcome was the proportion of patients achieving the subarachnoid haemorrhage early brain oedema score dichotomy(defined as Subarachnoid Haemorrhage Early Brain Oedema Score 0–2)at the 10-day postmedication.The secondary outcome of cerebral oedema was the concentration of sulfonylurea receptor 1-transient receptor potential melastatin 4(SUR1-TRPM4)in the plasma and cerebrospinal fluid.Results We enrolled 56 patients diagnosed with aSAH,who were admitted to the neurosurgery intensive care unit between 22 August 2021 and 25 April 2023.The primary outcome revealed that the glibenclamide group exhibited a notably higher proportion of mild cerebral oedema in comparison to the placebo group(60.7%vs 42.9%,adjusted OR:4.66,95%CI 1.14 to 19.10,p=0.032).Furthermore,the concentration of SUR1-TRPM4 in the cerebrospinal fluid of the glibenclamide group was significantly higher than the placebo group(p=0.0002;p=0.026),while the plasma TRPM4 concentration in the glibenclamide group was significantly lower than the placebo group(p=0.001).Conclusion Oral administration of high-dose glibenclamide notably reduced radiological assessment of cerebral oedema after 10 days of medication.Significant alterations were also observed in the concentration of SUR1-TRPM4 in plasma and cerebrospinal fluid.However,it is worth noting that glibenclamide was associated with a higher incidence of hypoglycaemia.Larger trials are warranted to evaluate the potential benefits of glibenclamide in mitigating swelling and then improving neurological function.Trial registration number ChiCTR2100049908.展开更多
Background: Over the years, the mechanical ventilation (MV) strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation (LPV), ...Background: Over the years, the mechanical ventilation (MV) strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation (LPV), among brain-injured patients in China. Methods: This study was a multicenter, 1-day, cross-sectional study in 47 Intensive Care Units (ICUs) across China. Mechanically ventilated patients (18 years and older) with brain injury in a participating ICU during the time of the study, including traumatic brain injury, stroke, postoperation with intracranial tumor, hypoxic-ischemic encephalopathy, intracranial infection, and idiopathic epilepsy, were enrolled. Demographic data, primary diagnoses, indications for MV, MV modes and settings, and prognoses on the 60th day were collected. Multivariable logistic analysis was used to assess factors that might affect the use of LPV. Results: A total of 104 patients were enrolled in the present study, 87 (83.7%) of whom were identified with severe brain injury based on a Glasgow Coma Scale 〈8 points. Synchronized intermittent mandatory ventilation (SIMV) was the most frequent ventilator mode, accounting for 46.2% of the entire cohort. The median tidal volume was set to 8.0 ml/kg (interquartile range [IQR], 7.0-8.9 ml/kg) of the predicted body weight; 50 (48.1%) patients received LPV. The median positive end-expiratory pressure (PEEP) was set to 5 cmH20 (IQR, 5-5 cmH20). No PEEP values were higher than 10 cmH20. Compared with partially mandatory ventilation, supportive and spontaneous ventilation practices were associated with LPV. There were no significant differences in mortality and MV duration between patients subjected to LPV and those were not. Conclusions: Among brain-injured patients in China, SIMV was the most frequent ventilation mode. Nearly one-half of the brain-injured patients received LPV. Patients under supportive and spontaneous ventilation were more likely to receive LPV.展开更多
Over the course of storm or rainfall event,water thickness builds up on road surface resulting in a loss of contact between vehicle tires and road surface and puts drivers into immediate danger especially at high spee...Over the course of storm or rainfall event,water thickness builds up on road surface resulting in a loss of contact between vehicle tires and road surface and puts drivers into immediate danger especially at high speeds.Therefore this is a considerably dangerous condition of the road and the realistic measurements and prediction model of water film thickness(WFT)on pavement surface is crucial for determining the road friction coefficient and evaluating the impact of rainfall on traffic safety.A review of the principle as well as critical evaluation of current detection methods of pavement WFT were compared for consistency and accuracy in this paper.The method selection guidelines are given for different road surface water film thickness detection requirements.This paper also introduces the latest development of WFT detection and prediction models for asphalt pavement,and gives the calculation elements and conditions of different WFT prediction models from different modeling ideas,which provides a basis for the selection and optimization of WFT models for future researchers.This article also suggests a few insights as further research directions on this topic.(1)The research can consider the influencing factors of WFT to conduct research on the delineation standard of pavement WFT.(2)In order to meet the future traffic safety dynamic early warning needs,road factors of different material types,disease conditions and linear conditions should be studied,as well as a comprehensive and accurate real-time water film thickness detection and evaluation method considering meteorological factors of rainfall timing,scale and intensity.(3)The prediction model of WFT should be further studied by the analytical method to clarify the influence of the pavement WFT on the driving safety.展开更多
Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges.In the past 10 years,the pavement infrastructure strongly supports the rapid development of the global so...Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges.In the past 10 years,the pavement infrastructure strongly supports the rapid development of the global social economy.New theories,new methods,new technologies and new materials related to pavement engineering are emerging.Deterioration of pavement infrastructure is a typical multi-physics problem.Because of actual coupled behaviors of traffic and environmental conditions,predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis.In order to summarize the current and determine the future research of pavement engineering,Journal of Traffic and Transportation Engineering(English Edition)has launched a review paper on the topic of"New innovations in pavement materials and engineering:A review on pavement engineering research 2021".Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering,this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world.The content includes asphalt binder performance and modeling,mixture performance and modeling of pavement materials,multi-scale mechanics,green and sustainable pavement,and intelligent pavement.Overall,this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering.展开更多
Objective:Our aim was to investigate the correlation between free fatty acid(FFA) spectrum, blood stasis(BS) score, and macroangiopathy in type 2 diabetic patients with or without BS, as well as the possible relations...Objective:Our aim was to investigate the correlation between free fatty acid(FFA) spectrum, blood stasis(BS) score, and macroangiopathy in type 2 diabetic patients with or without BS, as well as the possible relationship between BS and lipotoxicity. Methods: A total of 50 type 2 diabetes(T2D) patients with or without BS were enrolled from June to December 2014 in Shenzhen Traditional Chinese Medicine(TCM) Hospital, with 25 patients allocated to each of two groups. Basic information, BS score, blood glucose, blood lipids, etc., were measured for each patient. In addition, we tested the levels of interleukin(IL)?6, tumor necrosis factor α(TNF?α), and IL?18 with enzyme?linked immunosorbent assay. The macroangiopathy status of patients in the two groups was examined by color ultrasound and all factors related to BS scores were analyzed. Gas chromatography?mass spectrometry was used to explore the difference in the serum FFA spectra between the two different groups. In addition, the relationship between FFA spectra, BS scores, and macroangiopathy was analyzed. Results: BS scores, total cholesterol(TC), total triglyceride(TG), low?density lipoprotein cholesterol, IL?6, TNF?α, IL?18, carotid and femoral artery plaque, carotid intima?media thickness, carotid plaque area, and femoral artery plaque area were all significantly increased in T2D patients with BS syndrome(P < 0.05). A positive correlation was observed between age, duration of diabetes, carotid intima?media thickness, carotid plaque area, femoral artery plaque area, and BS score(P < 0.05). A total of 21 fatty acids were found in the serum, and total FFA(TFFA), saturated fatty acid(SFA), lauric acid(C12:0), palmitic acid(16:0), stearic acid(C18:0), arachidonic acid(C20:4n6), behenic acid(C22:0), and lignoceric acid(C24:0) scores were all found to contribute to the difference between FFA spectrums of the two groups; of the fatty acids, C12:0, C16:0, C18:0, C22:0, TFFA, and SFA positively correlated with BS scores as evaluated by Pearson's or Spearman's correlation analysis(P < 0.05). Only SFA entered the regression equation in the multiple linear regression analysis. C12:0, C16:0, C18:0, C20:4n6, TFFA, and SFA were positively correlated with carotid plaque area, whereas linoleic acid(C18:3n3), Cis?5, 8, 11, 14, and 17?eicosapentaenoic acids(C20:5n3) were negatively correlated(P < 0.05). C16:0 was positively correlated with the femoral artery plaque area and C18:3n3, cis?4, 7, 10, 13, 16, and 19?docosahexaenoic acids(C22:6) and nervonic acid were negatively correlated(P < 0.05). Conclusion: Serum FFA spectra were significantly different between T2D patients with BS and those without, and long?chain SFA made the greatest contribution. Serum FFA spectra were correlated with BS scores and diabetic macroangiopathy, which means that lipotoxicity and BS are correlated in T2D.展开更多
The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical synthesi...The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical synthesis.However,only a few inorganic electrides have been successfully synthesized thus far,limiting the variety of electride examples.Here,we show the stabilization of inorganic electrides in the Ti-rich Ti–O system through first-principles calculations in conjunction with swarm-intelligence-based CALYPSO method for structure prediction.Besides the known Ti-rich stoichiometries of Ti_(2)O,Ti_(3)O,and Ti_(6)O,two hitherto unknown Ti_(4)O and Ti_(5)O stoichiometries are predicted to be thermodynamically stable at certain pressure conditions.We found that these Tirich Ti–O compounds are primarily zero-dimensional electrides with excess electrons confined in the atom-sized lattice voids or between the cationic layers playing the role as anions.The underlying mechanism behind the stabilization of electrides has been rationalized in terms of the excess electrons provided by Ti atoms and their accommodation of excess electrons by multiple cavities and layered atomic packings.The present results provide a viable direction for searching for practical electrides in the technically important Ti–O system.展开更多
文摘We present a formalism of charge self-consistent dynamical mean field theory(DMFT)in combination with densityfunctional theory(DFT)within the linear combination of numerical atomic orbitals(LCNAO)framework.We implementedthe charge self-consistent DFT+DMFT formalism by interfacing a full-potential all-electron DFT code with threehybridization expansion-based continuous-time quantum Monte Carlo impurity solvers.The benchmarks on several 3d,4fand 5f strongly correlated electron systems validated our formalism and implementation.Furthermore,within the LCANOframework,our formalism is general and the code architecture is extensible,so it can work as a bridge merging differentLCNAO DFT packages and impurity solvers to do charge self-consistent DFT+DMFT calculations.
基金the General Project of National Natural Science Foundation of China(51778078)General Project of Natural Science Foundation of Chongqing City(cstc2021jcyj-msxmX1055).
文摘Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.
基金The work described in this article is supported by the National Key Research and Development Program of China(No.2021YFB2601000)the National Natural Science Foundation of China(No.51878063,No.52078048,and No.52008029)the Fundamental Research Funds for the Central Universities,CHD(300102213504).
文摘Cohesive failure is one of the primary reasons for low-temperature cracking in asphalt pavements.Understanding the micro-level mechanism is crucial for comprehending cohesive failure behavior.However,previous literature has not fully reported on this aspect.Moreover,there has been insufficient attention given to the correlation between macroscopic and microscopic failures.To address these issues,this study employed molecular dynamics simulation to investigate the low-temperature tensile behavior of asphalt binder.By applying virtual strain,the separation work during asphalt binder tensile failure was calculated.Additionally,a correlation between macroscopic and microscopic tensile behaviors was established.Specifically,a quadrilateral asphalt binder model was generated based on SARA fractions.By applying various combinations of virtual strain loading,the separation work at tensile failure was determined.Furthermore,the impact of strain loading combinations on separation work was analyzed.Normalization was employed to establish the correlation between macroscopic and microscopic tensile behaviors.The results indicated that thermodynamic and classical mechanical indicators validated the reliability of the tetragonal asphalt binder model.The strain loading combination consists of strain rate and loading number.All strain loading combinations exhibited the similar tensile failure characteristic.The critical separation strain was hardly influenced by strain loading combination.However,increasing strain rate significantly enhanced both the maximum traction stress and separation work of the asphalt binder.An increment in the loading number led to a decrease in separation work.The virtual strain combination of 0.5%-80 provided a more accurate representation of the actual asphalt's tensile behavior trend.
基金supported by the National Natural Science Foundation of China(21673030)the Fundamental Research Funds for the Central Universities(DUT16QY49)
文摘In terms of the reaction of COreduction to CO with hydrogen, COconversion is very low at low temperature due to the limitation of thermodynamic equilibrium(TE). To overcome this limitation, plasma catalytic reduction of COto CO in a catalyst-filled dielectric barrier discharge(DBD) reactor is studied. An enhanced effect of plasma on the reaction over Au/CeOcatalysts is observed. For both the conventionally catalytic(CC) and plasma catalytic(PC, Pin= 15 W) reactions under conditions of 400 °C, H/CO= 1,200 SCCM, GHSV = 12,000 mL·gcat·h, COconversions over Au/CeOreach 15.4% and 25.5% due to the presence of Au, respectively, however, those over CeOare extremely low and negligible. Moreover,COconversion over Au/CeOin the PC reaction exceeds 22.4% of the TE conversion. Surface intermediate species formed on the catalyst samples during the reactions are determined by in-situ temperatureprogrammed decomposition(TPD) technique. Interestingly, it disclosed that in the PC reaction, the formation of formate intermediate is enhanced by plasma, and the acceleration by plasma in the decomposition of formate species is much greater than that in the formation of formate species on Au/CeO. Enhancement factor is introduced to quantify the enhanced effect of plasma. Lower reactor temperature, higher gas hourly space velocity(GHSV), and lower molar ratio of H/COwould be associated with larger enhancement factor.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51401237,11474358,and 51271198)the Fund from Shaanxi Provincial Education Department,China(Grant No.18JK1207)the Defence Technology Foundation of China(Grant No.2301003)
文摘To reveal the potential aging mechanism for self-irradiation in Pu-Ga alloy,we choose Au-Ag alloy as its substitutional material in terms of its mass density and lattice structure.As a first step for understanding the microscopic behavior of point defects in Au-Ag alloy,we perform a molecular dynamics(MD)simulation on energetics and diffusion of point defects in Au and Ag metal.Our results indicate that the octahedral self-interstitial atom(SIA)is more stable than the tetrahedral SIA.The stability sequence of point defects for He atom in Au/Ag is:substitutional site>octahedral interstitial site>tetrahedral interstitial site.The He-V cluster(Hen Vm,V denotes vacancy)is the most stable at n=m.For the mono-vacancy diffusion,the MD calculation shows that the first nearest neighbour(1 NN)site is the most favorable site on the basis of the nudged elastic band(NEB)calculation,which is in agreement with previous experimental data.There are two peaks for the second nearest neighbour(2 NN)and the third nearest neighbour(3 NN)diffusion curve in octahedral interstitial site for He atom,indicating that the 2 NN and 3 NN diffusion for octahedral SIA would undergo an intermediate defect structure similar to the 1 NN site.The 3 NN diffusion for the tetrahedral SIA and He atom would undergo an intermediate site in analogy to its initial structure.For diffusion of point defects,the vacancy,SIA,He atom and He-V cluster may have an analogous effect on the diffusion velocity in Ag.
基金Project supported by the National Nature Science Foundation of China(Grant Nos.51401237,11474358,and 51271198)
文摘First-principles calculations based on density functional theory corrected by Hubbard parameter U (DFT+U) are applied to the study on the co-adsorption of O2 and H2O molecules to a-U(110) surface. The calculation results show that DFT+U method with Ueff = 1.5 eV can yield the experimental results of lattice constant and elastic modulus of a-uranium bulk well. Of all 7 low index surfaces of a-uranium, the (001) surface is the most stable with lowest surface energy while the (110) surface possesses the strongest activity with the highest surface energy. The adsorptions of O2 and H2O molecules are investigated separated. The O2 dissociates spontaneously in all initial configurations. For the adsorption of H2O molecule, both molecular and dissociative adsorptionsoccur. Through calculations of co-adsorption, it can be confirmed that the inhibition effect of O2 on the corrosion of uranium by water vapor originates from the preferential adsorption mechanism, while the consumption of H atoms by O atoms exerted little influence on the corrosion of uranium.
基金supported by the Project of Research on the Evaluation of the Cultivation of Language Talents for International Cultural Communication in Beijing(No.19JDYYB003),which is funded by Beijing Planning Office of Philosophy and Social Science。
文摘To investigate the impact of dynamic assessment(DA)on the development of speaking skills,a case study was conducted,recruiting a non-English major undergraduate.DA was constructed following the design combining sandwich and cake format with an interactionist approach.To collect data,a profile was designed in accordance with the China’s Standards of English Language Ability(CSE)to record the learner’s changes.A semi-structured interview was conducted to reveal his perspectives on DA.The generated profile with specific mediator-learner’s moves revealed the learner’s microgenetic development in both organizational knowledge and oral expression strategy ability.The thematic analysis of the interview demonstrated the learner’s positive experience with DA,while also unveiling the weak points of DA.Finally,the operational framework for applying interactionist DA in the oral classroom was discussed,and the complementary relationship between DA and traditional teaching and testing practices was highlighted.
文摘Formaldehyde donor preservatives are under debate because formaldehyde at high concentration is known to the public as a toxic substance to humans and the environment, inducing mutation in living organisms. Chemical methods, such as using acetylacetone (Nash reagent), are commonly used to determine total formaldehyde concentration in cosmetics. However, these methods will perturb the equilibrium between formaldehyde and formaldehyde donor. A new method, based on C-13 NMR, not perturbing the equilibrium and more suitable for formaldehyde measurement, is reviewed. This review describes the background, distinction, and applications of formaldehyde and formaldehyde donor in cosmetics.
文摘Recent articles reviewed the molecular damaging pathway of various pollutants especially PM2.5 particles and polycylic aromatic hydrocarbon. AhR (aryl hydrocarbon receptor) pathway, tobacco-similar pathway, oxidation, as well as epigenetics pathway were reviewed. Based on the working mechanism, the reported study method and methodology used in Ashland lab were reviewed, including cell level experiment, through reconstructed human skin to in vivo study.
基金support from Fundamental Research Funds for the Central Universities(N2025034)Xingliao Project(XLYC1807042)the 111 Project(B16009).
文摘Integrating electrochemical reduction of CO_(2)and electrochemical oxidation to recycle degraded superalloys is a promising solution to ease resource scarcity and safeguard environmental sustainability.Herein,we propose an electrochemical technique for the conversion of bulk superalloy scraps and CO_(2)into oxide powder at the anode and solid carbon at the cathode,respectively.In particular,a borax-modifi ed CaCl_(2)-based molten salt electrolyte is used for enhancing the electrochemical oxidation of superalloy scraps.At a temperature of 700℃and a voltage of 2.8 V,90.55 wt.%of alloy scraps were oxidized in a molten CaCl_(2)–NaCl–CaCO_(3)–Na_(2)B_(4)O_(7)with an acid–base ratio(K_(a/b))of 1.The synergy of Cl−and B_(4)O_(7)2−of electrolyte prevents the passivation of the alloy anode and enables continuous oxidation.Furthermore,the Ni and Co in the anode products are recovered by sulfation roasting with recovery efficiencies of 85.58%and 95.27%for Ni and Co,respectively.Overall,modulating the alkalinity of the electrolyte for enhancing oxidation/pulverization of alloy scrap anode provides new insight into electrochemically recovering superalloy scraps.
基金National Natural Youth Science Foundation Project(82001324).
文摘Background Glibenclamide has garnered attention due to its multifaceted neuroprotective effects in cases of acute central nervous system injury.We initiated a trial to explore the effectiveness and safety of a high dose of glibenclamide in the management of cerebral oedema following aneurysmal subarachnoid haemorrhage(aSAH).Methods This trial constituted a single-centre,randomised clinical study.Half of the 56 patients assigned to the glibenclamide group received 15mg of glibenclamide tablets daily for 10 days(5mg,three times/day).The primary outcome was the proportion of patients achieving the subarachnoid haemorrhage early brain oedema score dichotomy(defined as Subarachnoid Haemorrhage Early Brain Oedema Score 0–2)at the 10-day postmedication.The secondary outcome of cerebral oedema was the concentration of sulfonylurea receptor 1-transient receptor potential melastatin 4(SUR1-TRPM4)in the plasma and cerebrospinal fluid.Results We enrolled 56 patients diagnosed with aSAH,who were admitted to the neurosurgery intensive care unit between 22 August 2021 and 25 April 2023.The primary outcome revealed that the glibenclamide group exhibited a notably higher proportion of mild cerebral oedema in comparison to the placebo group(60.7%vs 42.9%,adjusted OR:4.66,95%CI 1.14 to 19.10,p=0.032).Furthermore,the concentration of SUR1-TRPM4 in the cerebrospinal fluid of the glibenclamide group was significantly higher than the placebo group(p=0.0002;p=0.026),while the plasma TRPM4 concentration in the glibenclamide group was significantly lower than the placebo group(p=0.001).Conclusion Oral administration of high-dose glibenclamide notably reduced radiological assessment of cerebral oedema after 10 days of medication.Significant alterations were also observed in the concentration of SUR1-TRPM4 in plasma and cerebrospinal fluid.However,it is worth noting that glibenclamide was associated with a higher incidence of hypoglycaemia.Larger trials are warranted to evaluate the potential benefits of glibenclamide in mitigating swelling and then improving neurological function.Trial registration number ChiCTR2100049908.
文摘Background: Over the years, the mechanical ventilation (MV) strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation (LPV), among brain-injured patients in China. Methods: This study was a multicenter, 1-day, cross-sectional study in 47 Intensive Care Units (ICUs) across China. Mechanically ventilated patients (18 years and older) with brain injury in a participating ICU during the time of the study, including traumatic brain injury, stroke, postoperation with intracranial tumor, hypoxic-ischemic encephalopathy, intracranial infection, and idiopathic epilepsy, were enrolled. Demographic data, primary diagnoses, indications for MV, MV modes and settings, and prognoses on the 60th day were collected. Multivariable logistic analysis was used to assess factors that might affect the use of LPV. Results: A total of 104 patients were enrolled in the present study, 87 (83.7%) of whom were identified with severe brain injury based on a Glasgow Coma Scale 〈8 points. Synchronized intermittent mandatory ventilation (SIMV) was the most frequent ventilator mode, accounting for 46.2% of the entire cohort. The median tidal volume was set to 8.0 ml/kg (interquartile range [IQR], 7.0-8.9 ml/kg) of the predicted body weight; 50 (48.1%) patients received LPV. The median positive end-expiratory pressure (PEEP) was set to 5 cmH20 (IQR, 5-5 cmH20). No PEEP values were higher than 10 cmH20. Compared with partially mandatory ventilation, supportive and spontaneous ventilation practices were associated with LPV. There were no significant differences in mortality and MV duration between patients subjected to LPV and those were not. Conclusions: Among brain-injured patients in China, SIMV was the most frequent ventilation mode. Nearly one-half of the brain-injured patients received LPV. Patients under supportive and spontaneous ventilation were more likely to receive LPV.
基金This research is supported by the National Key Research and Development Program of China(No.2021YFB2601000)the National Natural Science Foundation of China(NSFC)(No.51878063 and No.52008029)the Fundamental Research Funds for the Central Universities,CHD(300102213504).
文摘Over the course of storm or rainfall event,water thickness builds up on road surface resulting in a loss of contact between vehicle tires and road surface and puts drivers into immediate danger especially at high speeds.Therefore this is a considerably dangerous condition of the road and the realistic measurements and prediction model of water film thickness(WFT)on pavement surface is crucial for determining the road friction coefficient and evaluating the impact of rainfall on traffic safety.A review of the principle as well as critical evaluation of current detection methods of pavement WFT were compared for consistency and accuracy in this paper.The method selection guidelines are given for different road surface water film thickness detection requirements.This paper also introduces the latest development of WFT detection and prediction models for asphalt pavement,and gives the calculation elements and conditions of different WFT prediction models from different modeling ideas,which provides a basis for the selection and optimization of WFT models for future researchers.This article also suggests a few insights as further research directions on this topic.(1)The research can consider the influencing factors of WFT to conduct research on the delineation standard of pavement WFT.(2)In order to meet the future traffic safety dynamic early warning needs,road factors of different material types,disease conditions and linear conditions should be studied,as well as a comprehensive and accurate real-time water film thickness detection and evaluation method considering meteorological factors of rainfall timing,scale and intensity.(3)The prediction model of WFT should be further studied by the analytical method to clarify the influence of the pavement WFT on the driving safety.
基金National Key R&D Program of China(No.2018YFB1600200,2021YFB1600200)National Natural Science Foundation of China(No.51608457,51778038,51808016,51808403,51908057,51908072,51908165,51908331,52008029,52008069,52078018,52078025,52078049,52078209,52108403,52122809,52178417)+9 种基金Marie Sk?odowska-Curie Individual Fellowships of the European Commission’s Horizon 2020 programme(No.101024139)Natural Science Foundation of Heilongjiang Province(No.JJ2020ZD0015)China Postdoctoral Science Foundation funded project(No.BX20180088)Research Capability Enhancement Program for Young Professors of Beijing University of Civil Engineering and Architecture(No.02080921021)Young Scholars of Beijing Talent Program(No.02082721009)Beijing Municipal Natural Science Foundation and Beijing Municipal Education Commission(No.KZ201910016017)German Research Foundation(No.OE 514/15-1(459436571))Fundamental Research Funds for the Central Universities(No.2020kfyXJJS127)Marie Sk?odowska-Curie Individual Fellowships of the European Commission’s Horizon 2020 Programme(No.101030767)Research Fund for High Level Talent Program(No.22120210108)。
文摘Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges.In the past 10 years,the pavement infrastructure strongly supports the rapid development of the global social economy.New theories,new methods,new technologies and new materials related to pavement engineering are emerging.Deterioration of pavement infrastructure is a typical multi-physics problem.Because of actual coupled behaviors of traffic and environmental conditions,predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis.In order to summarize the current and determine the future research of pavement engineering,Journal of Traffic and Transportation Engineering(English Edition)has launched a review paper on the topic of"New innovations in pavement materials and engineering:A review on pavement engineering research 2021".Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering,this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world.The content includes asphalt binder performance and modeling,mixture performance and modeling of pavement materials,multi-scale mechanics,green and sustainable pavement,and intelligent pavement.Overall,this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering.
基金Natural Science Foundation of China(No.81173253)Sanming Project of Medicine in Shenzhen(No.SZSM201512043)supported the study
文摘Objective:Our aim was to investigate the correlation between free fatty acid(FFA) spectrum, blood stasis(BS) score, and macroangiopathy in type 2 diabetic patients with or without BS, as well as the possible relationship between BS and lipotoxicity. Methods: A total of 50 type 2 diabetes(T2D) patients with or without BS were enrolled from June to December 2014 in Shenzhen Traditional Chinese Medicine(TCM) Hospital, with 25 patients allocated to each of two groups. Basic information, BS score, blood glucose, blood lipids, etc., were measured for each patient. In addition, we tested the levels of interleukin(IL)?6, tumor necrosis factor α(TNF?α), and IL?18 with enzyme?linked immunosorbent assay. The macroangiopathy status of patients in the two groups was examined by color ultrasound and all factors related to BS scores were analyzed. Gas chromatography?mass spectrometry was used to explore the difference in the serum FFA spectra between the two different groups. In addition, the relationship between FFA spectra, BS scores, and macroangiopathy was analyzed. Results: BS scores, total cholesterol(TC), total triglyceride(TG), low?density lipoprotein cholesterol, IL?6, TNF?α, IL?18, carotid and femoral artery plaque, carotid intima?media thickness, carotid plaque area, and femoral artery plaque area were all significantly increased in T2D patients with BS syndrome(P < 0.05). A positive correlation was observed between age, duration of diabetes, carotid intima?media thickness, carotid plaque area, femoral artery plaque area, and BS score(P < 0.05). A total of 21 fatty acids were found in the serum, and total FFA(TFFA), saturated fatty acid(SFA), lauric acid(C12:0), palmitic acid(16:0), stearic acid(C18:0), arachidonic acid(C20:4n6), behenic acid(C22:0), and lignoceric acid(C24:0) scores were all found to contribute to the difference between FFA spectrums of the two groups; of the fatty acids, C12:0, C16:0, C18:0, C22:0, TFFA, and SFA positively correlated with BS scores as evaluated by Pearson's or Spearman's correlation analysis(P < 0.05). Only SFA entered the regression equation in the multiple linear regression analysis. C12:0, C16:0, C18:0, C20:4n6, TFFA, and SFA were positively correlated with carotid plaque area, whereas linoleic acid(C18:3n3), Cis?5, 8, 11, 14, and 17?eicosapentaenoic acids(C20:5n3) were negatively correlated(P < 0.05). C16:0 was positively correlated with the femoral artery plaque area and C18:3n3, cis?4, 7, 10, 13, 16, and 19?docosahexaenoic acids(C22:6) and nervonic acid were negatively correlated(P < 0.05). Conclusion: Serum FFA spectra were significantly different between T2D patients with BS and those without, and long?chain SFA made the greatest contribution. Serum FFA spectra were correlated with BS scores and diabetic macroangiopathy, which means that lipotoxicity and BS are correlated in T2D.
基金The authors acknowledge funding from the National Natural Science Foundation of China under Grant Nos.11704151,11774127,U1530124,61475063,61505067,11504007,and 11534003the Science Challenge Project,No.TZ2016001+3 种基金Science Challenge Project,No.TZ2016001Program for JLU Science and Technology Innovative Research Team(JLUSTIRT)the program for JLU Science and Technology Innovative Research Team,No.201705The Scientific and Technological Research Project of the“13th Five-Year Plan”of Jilin Provincial Education Department under Grant Nos.JJKH20180772KJ,JJKH20180769KJ,JJKH20180761KJ,and 201648.
文摘The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical synthesis.However,only a few inorganic electrides have been successfully synthesized thus far,limiting the variety of electride examples.Here,we show the stabilization of inorganic electrides in the Ti-rich Ti–O system through first-principles calculations in conjunction with swarm-intelligence-based CALYPSO method for structure prediction.Besides the known Ti-rich stoichiometries of Ti_(2)O,Ti_(3)O,and Ti_(6)O,two hitherto unknown Ti_(4)O and Ti_(5)O stoichiometries are predicted to be thermodynamically stable at certain pressure conditions.We found that these Tirich Ti–O compounds are primarily zero-dimensional electrides with excess electrons confined in the atom-sized lattice voids or between the cationic layers playing the role as anions.The underlying mechanism behind the stabilization of electrides has been rationalized in terms of the excess electrons provided by Ti atoms and their accommodation of excess electrons by multiple cavities and layered atomic packings.The present results provide a viable direction for searching for practical electrides in the technically important Ti–O system.