Sustainable production of H2 through electrochemical water splitting is of great importance in the foreseeable future.Transition-metal metaphosphates(TMMPs)have a three-dimensional(3D)open-framework structure and a hi...Sustainable production of H2 through electrochemical water splitting is of great importance in the foreseeable future.Transition-metal metaphosphates(TMMPs)have a three-dimensional(3D)open-framework structure and a high content of P(which exists as PO3-),and therefore have been recognized as highly efficient catalysts for oxygen evolution reaction(OER)and the bottleneck of electrochemical water splitting.Furthermore,TMMPs can also contribute to hydrogen evolution reaction(HER)in alkaline and neutral media by facilitating water dissociation,and thus,overall water splitting can be achieved using this kind of material.In this timely review,we summarize the recent advances in the synthesis of TMMPs and their applications in OER and HER.We present a brief introduction of the structure and synthetic strategies of TMMPs in the first two parts.Then,we review the latest progress made in research on TMMPs as OER,HER,and overall water-splitting electrocatalysts.In this part,the intrinsic activity of TMMPs as well as the current strategy for improving the catalytic activity will be discussed systematically.Finally,we present the future opportunities and the remaining challenges for the application of TMMPs in the electrocatalysis field.展开更多
Designing readily available and highly active electrocatalysts for water splitting is essential for renewable energy technologies.Here we present the construction of FeCo-FeCoP@C hollow nanocubes encapsulated in nitro...Designing readily available and highly active electrocatalysts for water splitting is essential for renewable energy technologies.Here we present the construction of FeCo-FeCoP@C hollow nanocubes encapsulated in nitrogen-doped carbon nanocages(FeCo-FeCoP@C@NCCs) through controlled carbonization and subsequent phosphorization of a Prussian blue analogue.With stronger electronic interaction and hollow structure,the as-obtained FeCo-FeCoP@C@NCCs material requires small overpotentials of 91 mV and280 mV to deliver 10 mA cm^(-2) in 1 M KOH toward hydrogen and oxygen evolution,respectively.More importantly,applying this material for overall water splitting,it only requires 1.64 V to afford10 mA cm^(-2) and exhibits impressively durability over 40 h without obvious performance decay.The present approach inspires potentials for the controllable synthesis of multi-component catalysts for practical applications.展开更多
Electrocatalytic oxygen evolution reaction(OER)has been recognized as the bottleneck of overall water splitting,which is a promising approach for sustainable production of H_(2).Transition metal(TM)hydroxides are the ...Electrocatalytic oxygen evolution reaction(OER)has been recognized as the bottleneck of overall water splitting,which is a promising approach for sustainable production of H_(2).Transition metal(TM)hydroxides are the most conventional and classical non-noble metal-based electrocatalysts for OER,while TM basic salts[M^(2+)(OH)_(2-x)(A_(m^(-))_(x/m),A=CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)]consisting of OH−and another anion have drawn extensive research interest due to its higher catalytic activity in the past decade.In this review,we summarize the recent advances of TM basic salts and their application in OER and further overall water splitting.We categorize TM basic salt-based OER pre-catalysts into four types(CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)according to the anion,which is a key factor for their outstanding performance towards OER.We highlight experimental and theoretical methods for understanding the structure evolution during OER and the effect of anion on catalytic performance.To develop bifunctional TM basic salts as catalyst for the practical electrolysis application,we also review the present strategies for enhancing its hydrogen evolution reaction activity and thereby improving its overall water splitting performance.Finally,we conclude this review with a summary and perspective about the remaining challenges and future opportunities of TM basic salts as catalysts for water electrolysis.展开更多
Surface reconstruction of electrocatalysts has been widely witnessed during the electrochemical processes.Here,NiS_(2),NiSe_(2), and Se doped NiS_(2)(Se-NiS_(2)) are fabricated for oxygen evolution reaction(OER) throu...Surface reconstruction of electrocatalysts has been widely witnessed during the electrochemical processes.Here,NiS_(2),NiSe_(2), and Se doped NiS_(2)(Se-NiS_(2)) are fabricated for oxygen evolution reaction(OER) through a mild sulfuration and/or selenylation process of Ni(OH)_(2) supported on carbon cloth(CC).Through careful in-situ Raman spectroscopy and ex-situ X-ray photoelectron spectroscopy,surface reconstruction of NiS_(2),NiSe_(2),and Se-NiS_(2) during the OER process has been revealed.A potentialdependent study shows that Se-NiS_(2) undergoes surface evolution at lower potentials and requires the lowest potential for conversion to NiOOH as a highly OER-active species,accompanied by the leaching of SO_(4)^(2-) and SeO_(4)^(2-) that can again be adsorbed on the catalyst surface to enhance the catalytic activity.Density functional theory(DFT) calculations confirm that Se-NiS_(2) is more susceptible to surface oxidation through the OER process.Therefore,Se-NiS_(2) exhibits outstanding OER activity and stability in alkaline conditions,requiring an overpotential of 343 mV at a current density of 50 mA cm^(-2).A novel insight is provided by our work in understanding the surface reconstruction and electrocatalytic mechanism of Ni-based chalcogenides.展开更多
The iron and steel industry(ISI) involves high energy consumption and high pollution. ISI in China, a leading country in the ISI,consumed 15% of the country’s total energy and produced more than 50% of the global ISI...The iron and steel industry(ISI) involves high energy consumption and high pollution. ISI in China, a leading country in the ISI,consumed 15% of the country’s total energy and produced more than 50% of the global ISI’s carbon emissions. Therefore, in the context of global low-carbon economy and emission reduction requirements, low-carbon smelting technology in the ISI has attracted increasingly more attention in China. This review summarizes the current status of carbon emissions and energy consumption in China’s ISI and discusses the development status and prospects of low-carbon ironmaking technology. The main route to effectively reducing carbon emissions is to develop a gas-based direct reduction process and replace sintering with pelletizing, both of which focus on developing pelletizing technology. However,the challenge of pelletizing process development is to obtain high-quality iron concentrates. Consequently, the present paper also summarizes the development status of China’s mineral processing technology, including fine-grained mineral processing technology, magnetization roasting technology, and flotation collector application. This paper aims to provide a theoretical basis for the low-carbon development of China’s ISI in terms of a dressing–smelting combination.展开更多
Estrogen withdrawal in postmenopausal women increases bone loss and bone fragility in the vertebra. Bone loss with osteoporosis not only reduces bone mineral density(BMD), but actually alters bone quality, which can b...Estrogen withdrawal in postmenopausal women increases bone loss and bone fragility in the vertebra. Bone loss with osteoporosis not only reduces bone mineral density(BMD), but actually alters bone quality, which can be comprehensively represented by bone post-yield behaviors. This study aimed to provide some information as to how osteoporosis induced by estrogen depletion could influence the evolution of post-yield microdamage accumulation and plastic deformation in vertebral bodies. This study also tried to reveal the part of the mechanisms of how estrogen deficiency-induced osteoporosis would increase the bone fracture risk. A rat bilateral ovariectomy(OVX)model was used to induce osteoporosis. Progressive cyclic compression loading was developed for vertebra testing to elucidate the post-yield behaviors. BMD, bone volume fraction, stiffness degradation, and plastic deformation evolution were compared among rats raised for 5 weeks(ovx5w and sham5 w groups) and 35 weeks(ovx35w and sham35 w groups) after sham surgery and OVX. The results showedthat a higher bone loss in vertebral bodies corresponded to lower stiffness and higher plastic deformation. Thus, osteoporosis could increase the vertebral fracture risk probably through microdamage accumulation and plastic deforming degradation.展开更多
H_(2) tends to be a crucial medium in the foreseeable future as it is not only a green and renewable energy source for vehicles but also a fundamental feedstock for the chemical industry.For instance,selective hydroge...H_(2) tends to be a crucial medium in the foreseeable future as it is not only a green and renewable energy source for vehicles but also a fundamental feedstock for the chemical industry.For instance,selective hydrogenation,one of the catalytic processes used to produce fine compounds,is of vital importance because it enables the selective and efficient conversionof a variety of functional groups under mild reaction conditions.Catalytic hydrogenation of liquid organic hydrogen carriers(LOHCs;eg,methylbenzene)is a safe and economic approach for H_(2) storage.展开更多
This paper addresses the planning problem of parallel DC electric springs (DCESs). DCES, a demand-side management method, realizes automatic matching of power consumption and power generation by adjusting non-critical...This paper addresses the planning problem of parallel DC electric springs (DCESs). DCES, a demand-side management method, realizes automatic matching of power consumption and power generation by adjusting non-critical load (NCL) and internal storage. It can offer higher power quality to critical load (CL), reduce power imbalance and relieve pressure on energy storage systems (RESs). In this paper, a planning method for parallel DCESs is proposed to maximize stability gain, economic benefits, and penetration of RESs. The planning model is a master optimization with sub-optimization to highlight the priority of objectives. Master optimization is used to improve stability of the network, and sub-optimization aims to improve economic benefit and allowable penetration of RESs. This issue is a multivariable nonlinear mixed integer problem, requiring huge calculations by using common solvers. Therefore, particle Swarm optimization (PSO) and Elitist non-dominated sorting genetic algorithm (NSGA-II) were used to solve this model. Considering uncertainty of RESs, this paper verifies effectiveness of the proposed planning method on IEEE 33-bus system based on deterministic scenarios obtained by scenario analysis.展开更多
Previous studies demonstrated that the El Niño–Southern Oscillation(ENSO)could modulate regional climate thus influencing air quality in the low-middle latitude regions like southern China.However,such influence...Previous studies demonstrated that the El Niño–Southern Oscillation(ENSO)could modulate regional climate thus influencing air quality in the low-middle latitude regions like southern China.However,such influence has not been well evaluated at a long-term historical scale.To filling the gap,this study investigated two-decade(2002 to 2020)aerosol concentration and particle size in southern China during the whole dynamic development of ENSO phases.Results suggest strong positive correlations between aerosol optical depth(AOD)and ENSO phases,as low AOD occurred during El Niño while high AOD occurred during La Niña event.Such correlations are mainly attributed to the variation of atmospheric circulation and precipitation during corresponding ENSO phase.Analysis of the angstrom exponent(AE)anomalies further confirmed the circulation pattern,as negative AE anomalies is pronounced in El Niño indicating the enhanced transport of sea salt aerosols from the South China Sea,while the La Niña event exhibits positive AE anomalies which can be attributed to the enhanced import of northern fine anthropogenic aerosols.This study further quantified the AOD variation attributed to changes in ENSO phases and anthropogenic emissions.Results suggest that the long-term AOD variation from 2002 to 2020 in southern China is mostly driven(by 64.2%)by the change of anthropogenic emissions from 2002 to 2020.However,the ENSO presents dominant influence(70.5%)on year-to-year variations of AOD during 2002–2020,implying the importance of ENSO on varying aerosol concentration in a short-term period.展开更多
Base editor techniques have been developed as a means of precisely converting bases without the need for double-stranded DNA breaks(DSBs)or editing templates.Currently,these techniques can be used for cytosine(C)to th...Base editor techniques have been developed as a means of precisely converting bases without the need for double-stranded DNA breaks(DSBs)or editing templates.Currently,these techniques can be used for cytosine(C)to thymine(T)conversions(cytosine base editors,CBEs)(Komor et al.,2016;Nishida et al.,2016),adenine(A)to guanine(G)conversions(adenine base editors,ABEs)(Gaudelli et al.,2017),and cytosine(C)to guanine(G)conversions(glycosylase base editors,GBEs)(Zhao et al.,2021)in mammalian cells.GBE,in particular,is a promising base editing technique capable of correcting up to 11%of the 32,044 pathogenic single nucleotide polymorphisms(SNPs)known to date(Gaudelli et al.,2017).Despite its potential,the performance of GBE is still not optimal,and its editing outcomes exhibit a wider variation range than those of CBEs due to the dependence on cellular DNA repair systems(Jiang et al.,2021),which implies that efficient GBE performance remains a challenge.展开更多
CRISPR base editor(BE)techniques are a promising tool for precise cytosine(C)to thymine(T),adenine(A)to guanine(G),and C to G base editing(CBE,ABE,and GBE,respectively)without the use of a donor DNA template conversio...CRISPR base editor(BE)techniques are a promising tool for precise cytosine(C)to thymine(T),adenine(A)to guanine(G),and C to G base editing(CBE,ABE,and GBE,respectively)without the use of a donor DNA template conversion(Komor et al.,2016;Nishida et al.,2016;Gaudelli et al.,2017;Kurt et al.,2021;Zhao et al.,2021).展开更多
Dear Editor,The conductive nanomaterials,such as carbon nanotubes(CNTs),have attracted much attention in biomedical applications.Particularly,it has been found that CNTs can promote the electrical activity of cardiomy...Dear Editor,The conductive nanomaterials,such as carbon nanotubes(CNTs),have attracted much attention in biomedical applications.Particularly,it has been found that CNTs can promote the electrical activity of cardiomyocytes,but little is known about the mechanism.^(1,2)To better understand the CNTs’biological effects on cardiomyocytes and the underlying mechanism.展开更多
Constructing and understanding the doping effect of secondary metal in transition metal carbide(TMC)catalysts is pivotal for the design of low-cost hydrogen evolution reaction(HER) electrocatalysts. In this work, we d...Constructing and understanding the doping effect of secondary metal in transition metal carbide(TMC)catalysts is pivotal for the design of low-cost hydrogen evolution reaction(HER) electrocatalysts. In this work, we developed a wet-chemistry strategy for synthesizing Co-modified Fe_5C_2 nanoparticles((Fe_(1-x)Cox)_5C_2 NPs) as highly active HER electrocatalysts in basic solution. The structure of(Fe_(1-x)Cox)_5C_2 NPs was characterized by X-ray diffraction(XRD), extended X-ray absorption fine structure spectra(EXAFS) and scanning/transmission electron microscopy(S/TEM), indicating that the isomorphous substitution of cobalt in the lattice of Fe_5C_2.(Fe_(0.75) Co_(0.25))_5C_2 exhibited the best HER activity(174 mV for j = -10 mA/cm^2). Computational calculation results indicate that Co provides the most active site for HER. X-ray adsorption spectra(XAS) studies further suggested that the electron transfer in Fe–C bonds are enhanced by the substitution of Co, which modulates the hydrogen adsorption on the adjacent electronic-enriched carbon, and therefore promotes HER activity. Our results affirm the design of lowcost bimetallic TMCs based HER catalysts.展开更多
Fe-based catalysts have been discovered as the best elementary metal-based heterogeneous catalysts for the ammonia synthesis in industrial application during the last century.Herein,a novel and scalable strategy is de...Fe-based catalysts have been discovered as the best elementary metal-based heterogeneous catalysts for the ammonia synthesis in industrial application during the last century.Herein,a novel and scalable strategy is developed to prepare the K-promoted Fe/C catalyst with extremely high Fe loading (> 50 wt.%) through pyrolysis of the Fe-based metal-organic framework (MOF) xerogel.The obtained K-Fe/C catalysts exhibited superior activity and stability towards ammonia synthesis.The weight-specific reaction rate of Fe/C with K2O as promoter can achieve 12.4 mmol·g-1·h-1 at 350 ℃ and 30.4 mmol·g-1·h-1 at 400 ℃,approximately four and two times higher than that of the commercial fused-iron catalyst (3.4 mmol·g-1·h-1 at 350 ℃ and 16.7 mmol·g-1·h-1 at 400 ℃) under the same condition,respectively.The excellent performance of K-Fe/C can be ascribed to the inherited structure derived from the metal-organic frame precursors and the promotion of potassium,which can modify the binding energy of reactant molecules on the Fe surface,transfer electrons to iron for effective activation of nitrogen,prevent agglomeration of Fe nanoparticle (NPs) and restrain side reaction of carbon matrix to methane.展开更多
The deposition rate, phase, chemical composition and microstructure of deposits were determined from 950 to 1100℃. With increasing temperature, the deposition rate increases, and the morphology changes from smooth to...The deposition rate, phase, chemical composition and microstructure of deposits were determined from 950 to 1100℃. With increasing temperature, the deposition rate increases, and the morphology changes from smooth to coarse, meanwhile, the concentration of silicon increases while that of boron decreases. The deposition process is controlled by chemical reactions, and the activation energy is 271 kJ/mol. At relatively lower temperature (below 1000℃), the deposition process is dominated by formation of B4C. While at higher temperature (above 1000℃), it is governed by formation of SiC. B4C and SiC disperse uniformly in the Si-B-C co-deposition system and form a dense network structure.展开更多
The cell-derived extracellular matrix(ECM)-modified scaffolds have advantages of mimic tissue specificity and been thought to better mimic the native cellular microenvironment in vitro.ECM derived from cardiac fibrobl...The cell-derived extracellular matrix(ECM)-modified scaffolds have advantages of mimic tissue specificity and been thought to better mimic the native cellular microenvironment in vitro.ECM derived from cardiac fibroblasts(CFs)are considered as key elements that provide a natural cell growth microenvironment and change the fate of cardiomyocytes(CMs).Here,a new hybrid scaffold is designed based on silk fibroin(SF)scaffold and CFs-derived ECM.CFs were seeded on the SF scaffold for 10days culturing and decellularized to produce CFs-derived ECM-coated SF scaffold.The results showed that the cell-derived ECM-modified silk fibroin scaffold material contained collagen,laminin,fibronectin and other ECM components with myocardial-like properties.Further to explore its effects on brown adipose stem cells(BASCs)differentiation into CMs.We found that the CFderived ECM-coated scaffold also increased the expression of CM-specific proteins(e.g.cardiac troponin T and α-actinin)of BASCs.Notably,the b1-integrin-dependent transforming growth factor-β1 signaling pathway was also involved in the regulation of CF-derived ECM by promoting the differentiation of BASCs into CMs.Overall,these findings provide insights into the bionic manufacturing of engineered cardiac tissues(ECTs)and establish a theoretical basis for the construction of ECTs.展开更多
基金the Natural Science Foundation of China(Grant Nos.21871065,22209129,and 22071038)the Heilongjiang Touyan Team(HITTY-20190033)+3 种基金High-Level Innovation and Entrepreneurship(QCYRCXM-2022-123)the Talent Project of Qinchuangyuan and Interdisciplinary Research Foundation of HIT(IR2021205)Professor Li acknowledges the financial support from the“Young Talent Support Plan”of Xi'an Jiaotong University(HG6J024)the“Young Talent Lift Plan”of Xi'an city(095920221352).
文摘Sustainable production of H2 through electrochemical water splitting is of great importance in the foreseeable future.Transition-metal metaphosphates(TMMPs)have a three-dimensional(3D)open-framework structure and a high content of P(which exists as PO3-),and therefore have been recognized as highly efficient catalysts for oxygen evolution reaction(OER)and the bottleneck of electrochemical water splitting.Furthermore,TMMPs can also contribute to hydrogen evolution reaction(HER)in alkaline and neutral media by facilitating water dissociation,and thus,overall water splitting can be achieved using this kind of material.In this timely review,we summarize the recent advances in the synthesis of TMMPs and their applications in OER and HER.We present a brief introduction of the structure and synthetic strategies of TMMPs in the first two parts.Then,we review the latest progress made in research on TMMPs as OER,HER,and overall water-splitting electrocatalysts.In this part,the intrinsic activity of TMMPs as well as the current strategy for improving the catalytic activity will be discussed systematically.Finally,we present the future opportunities and the remaining challenges for the application of TMMPs in the electrocatalysis field.
基金financial support from the National Natural Science Foundation of China (21471039, 21571043, 21671047, 21673273, 21872163 and 21871065)the Natural Science Foundation of Heilongjiang Province (B2015001)the Guangdong Provincial Key Laboratory of Energy Materials for Electric Power (No. 2018B030322001)。
文摘Designing readily available and highly active electrocatalysts for water splitting is essential for renewable energy technologies.Here we present the construction of FeCo-FeCoP@C hollow nanocubes encapsulated in nitrogen-doped carbon nanocages(FeCo-FeCoP@C@NCCs) through controlled carbonization and subsequent phosphorization of a Prussian blue analogue.With stronger electronic interaction and hollow structure,the as-obtained FeCo-FeCoP@C@NCCs material requires small overpotentials of 91 mV and280 mV to deliver 10 mA cm^(-2) in 1 M KOH toward hydrogen and oxygen evolution,respectively.More importantly,applying this material for overall water splitting,it only requires 1.64 V to afford10 mA cm^(-2) and exhibits impressively durability over 40 h without obvious performance decay.The present approach inspires potentials for the controllable synthesis of multi-component catalysts for practical applications.
基金supported by the financial support from Natural Science Foundation of China(Nos.21871065,22209129 and 22071038)High-Level Innovation and Entrepreneurship(QCYRCXM-2022-123)+1 种基金support from the“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J024)“Young Talent Lift Plan”of Xi’an city(095920221352).
文摘Electrocatalytic oxygen evolution reaction(OER)has been recognized as the bottleneck of overall water splitting,which is a promising approach for sustainable production of H_(2).Transition metal(TM)hydroxides are the most conventional and classical non-noble metal-based electrocatalysts for OER,while TM basic salts[M^(2+)(OH)_(2-x)(A_(m^(-))_(x/m),A=CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)]consisting of OH−and another anion have drawn extensive research interest due to its higher catalytic activity in the past decade.In this review,we summarize the recent advances of TM basic salts and their application in OER and further overall water splitting.We categorize TM basic salt-based OER pre-catalysts into four types(CO_(3)^(2−),NO_(3)^(−),F^(−),Cl^(−)according to the anion,which is a key factor for their outstanding performance towards OER.We highlight experimental and theoretical methods for understanding the structure evolution during OER and the effect of anion on catalytic performance.To develop bifunctional TM basic salts as catalyst for the practical electrolysis application,we also review the present strategies for enhancing its hydrogen evolution reaction activity and thereby improving its overall water splitting performance.Finally,we conclude this review with a summary and perspective about the remaining challenges and future opportunities of TM basic salts as catalysts for water electrolysis.
基金supported by the financial support from the National Natural Science Foundation of China (21871065, 22071038, 22209129)the Heilongjiang Touyan Team (HITTY20190033)the Interdisciplinary Research Foundation of HIT (IR2021205)。
文摘Surface reconstruction of electrocatalysts has been widely witnessed during the electrochemical processes.Here,NiS_(2),NiSe_(2), and Se doped NiS_(2)(Se-NiS_(2)) are fabricated for oxygen evolution reaction(OER) through a mild sulfuration and/or selenylation process of Ni(OH)_(2) supported on carbon cloth(CC).Through careful in-situ Raman spectroscopy and ex-situ X-ray photoelectron spectroscopy,surface reconstruction of NiS_(2),NiSe_(2),and Se-NiS_(2) during the OER process has been revealed.A potentialdependent study shows that Se-NiS_(2) undergoes surface evolution at lower potentials and requires the lowest potential for conversion to NiOOH as a highly OER-active species,accompanied by the leaching of SO_(4)^(2-) and SeO_(4)^(2-) that can again be adsorbed on the catalyst surface to enhance the catalytic activity.Density functional theory(DFT) calculations confirm that Se-NiS_(2) is more susceptible to surface oxidation through the OER process.Therefore,Se-NiS_(2) exhibits outstanding OER activity and stability in alkaline conditions,requiring an overpotential of 343 mV at a current density of 50 mA cm^(-2).A novel insight is provided by our work in understanding the surface reconstruction and electrocatalytic mechanism of Ni-based chalcogenides.
基金financially supported by the Natural Science Foundation China (No.52274343)the Youth Natural Science Foundation China (No.51904347)the China Baowu Low Carbon Metallurgy Innovation Foundation (No.BWLCF202102)。
文摘The iron and steel industry(ISI) involves high energy consumption and high pollution. ISI in China, a leading country in the ISI,consumed 15% of the country’s total energy and produced more than 50% of the global ISI’s carbon emissions. Therefore, in the context of global low-carbon economy and emission reduction requirements, low-carbon smelting technology in the ISI has attracted increasingly more attention in China. This review summarizes the current status of carbon emissions and energy consumption in China’s ISI and discusses the development status and prospects of low-carbon ironmaking technology. The main route to effectively reducing carbon emissions is to develop a gas-based direct reduction process and replace sintering with pelletizing, both of which focus on developing pelletizing technology. However,the challenge of pelletizing process development is to obtain high-quality iron concentrates. Consequently, the present paper also summarizes the development status of China’s mineral processing technology, including fine-grained mineral processing technology, magnetization roasting technology, and flotation collector application. This paper aims to provide a theoretical basis for the low-carbon development of China’s ISI in terms of a dressing–smelting combination.
基金supported by the National Natural Science Foundation of China (Grants 11472017, 11002004)
文摘Estrogen withdrawal in postmenopausal women increases bone loss and bone fragility in the vertebra. Bone loss with osteoporosis not only reduces bone mineral density(BMD), but actually alters bone quality, which can be comprehensively represented by bone post-yield behaviors. This study aimed to provide some information as to how osteoporosis induced by estrogen depletion could influence the evolution of post-yield microdamage accumulation and plastic deformation in vertebral bodies. This study also tried to reveal the part of the mechanisms of how estrogen deficiency-induced osteoporosis would increase the bone fracture risk. A rat bilateral ovariectomy(OVX)model was used to induce osteoporosis. Progressive cyclic compression loading was developed for vertebra testing to elucidate the post-yield behaviors. BMD, bone volume fraction, stiffness degradation, and plastic deformation evolution were compared among rats raised for 5 weeks(ovx5w and sham5 w groups) and 35 weeks(ovx35w and sham35 w groups) after sham surgery and OVX. The results showedthat a higher bone loss in vertebral bodies corresponded to lower stiffness and higher plastic deformation. Thus, osteoporosis could increase the vertebral fracture risk probably through microdamage accumulation and plastic deforming degradation.
基金financially supported by the National Natural Science Foundation of China(21725301,21932002,21821004,22209129,and 22278367)the National Key R&D Programof China(2021YFA1501100)+2 种基金“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J024)the High-Level Innovation and Entrepreneurship Talent Project of Qinchuangyuan(QCYRCXM-2022-123)support from the Tencent Foundation through the EXPLORER PRIZE.
文摘H_(2) tends to be a crucial medium in the foreseeable future as it is not only a green and renewable energy source for vehicles but also a fundamental feedstock for the chemical industry.For instance,selective hydrogenation,one of the catalytic processes used to produce fine compounds,is of vital importance because it enables the selective and efficient conversionof a variety of functional groups under mild reaction conditions.Catalytic hydrogenation of liquid organic hydrogen carriers(LOHCs;eg,methylbenzene)is a safe and economic approach for H_(2) storage.
基金supported in part by the National Natural Science Foundation of China under Grant No.52177171 and 51877040Jiangsu Provincial Key Laboratory of Smart Grid Technology and Equipment,Southeast University,China.
文摘This paper addresses the planning problem of parallel DC electric springs (DCESs). DCES, a demand-side management method, realizes automatic matching of power consumption and power generation by adjusting non-critical load (NCL) and internal storage. It can offer higher power quality to critical load (CL), reduce power imbalance and relieve pressure on energy storage systems (RESs). In this paper, a planning method for parallel DCESs is proposed to maximize stability gain, economic benefits, and penetration of RESs. The planning model is a master optimization with sub-optimization to highlight the priority of objectives. Master optimization is used to improve stability of the network, and sub-optimization aims to improve economic benefit and allowable penetration of RESs. This issue is a multivariable nonlinear mixed integer problem, requiring huge calculations by using common solvers. Therefore, particle Swarm optimization (PSO) and Elitist non-dominated sorting genetic algorithm (NSGA-II) were used to solve this model. Considering uncertainty of RESs, this paper verifies effectiveness of the proposed planning method on IEEE 33-bus system based on deterministic scenarios obtained by scenario analysis.
基金This research was funded by the Foundation for Innovative Research Groups of the Hubei Natural Science Foundation,grant number 2020CFA003the National Natural Science Foundation of China,grant number 41975022The authors are grateful to NOAA CPC for ONI-3.4 index data,LAADS DAAC for Aqua MODIS AOD data,and ECMWF for sharing the reanalysis data publicly accessible.
文摘Previous studies demonstrated that the El Niño–Southern Oscillation(ENSO)could modulate regional climate thus influencing air quality in the low-middle latitude regions like southern China.However,such influence has not been well evaluated at a long-term historical scale.To filling the gap,this study investigated two-decade(2002 to 2020)aerosol concentration and particle size in southern China during the whole dynamic development of ENSO phases.Results suggest strong positive correlations between aerosol optical depth(AOD)and ENSO phases,as low AOD occurred during El Niño while high AOD occurred during La Niña event.Such correlations are mainly attributed to the variation of atmospheric circulation and precipitation during corresponding ENSO phase.Analysis of the angstrom exponent(AE)anomalies further confirmed the circulation pattern,as negative AE anomalies is pronounced in El Niño indicating the enhanced transport of sea salt aerosols from the South China Sea,while the La Niña event exhibits positive AE anomalies which can be attributed to the enhanced import of northern fine anthropogenic aerosols.This study further quantified the AOD variation attributed to changes in ENSO phases and anthropogenic emissions.Results suggest that the long-term AOD variation from 2002 to 2020 in southern China is mostly driven(by 64.2%)by the change of anthropogenic emissions from 2002 to 2020.However,the ENSO presents dominant influence(70.5%)on year-to-year variations of AOD during 2002–2020,implying the importance of ENSO on varying aerosol concentration in a short-term period.
基金financially supported by the National Key Research and Development Program of China(2018YFA0901300)the National Natural Science Foundation of China(32171449,81903776)+2 种基金a Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-001)Tianjin Natural Science Foundation(20JCYBJC00310)Youth Innovation Promotion Association CAS(2022177).
文摘Base editor techniques have been developed as a means of precisely converting bases without the need for double-stranded DNA breaks(DSBs)or editing templates.Currently,these techniques can be used for cytosine(C)to thymine(T)conversions(cytosine base editors,CBEs)(Komor et al.,2016;Nishida et al.,2016),adenine(A)to guanine(G)conversions(adenine base editors,ABEs)(Gaudelli et al.,2017),and cytosine(C)to guanine(G)conversions(glycosylase base editors,GBEs)(Zhao et al.,2021)in mammalian cells.GBE,in particular,is a promising base editing technique capable of correcting up to 11%of the 32,044 pathogenic single nucleotide polymorphisms(SNPs)known to date(Gaudelli et al.,2017).Despite its potential,the performance of GBE is still not optimal,and its editing outcomes exhibit a wider variation range than those of CBEs due to the dependence on cellular DNA repair systems(Jiang et al.,2021),which implies that efficient GBE performance remains a challenge.
基金This work was financially supported by the National Key Research and Development Program of China(2018YFA0904900)the National Natural Science Foundation of China(32225031,32171449,81903776)+2 种基金the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-017)the Tianjin Natural Science Foundation(20JCYBJC00310)the Youth Innovation Promotion Association CAS(2022177).
文摘CRISPR base editor(BE)techniques are a promising tool for precise cytosine(C)to thymine(T),adenine(A)to guanine(G),and C to G base editing(CBE,ABE,and GBE,respectively)without the use of a donor DNA template conversion(Komor et al.,2016;Nishida et al.,2016;Gaudelli et al.,2017;Kurt et al.,2021;Zhao et al.,2021).
基金supported by the National Natural Science Foundation of China(Grant Nos.31830030)National Key Research and Development Program of China(Grant Nos.2017YFA0106100)Joint Fund project of National Natural Science Foundation of China(Grant Nos.U21A20394).
文摘Dear Editor,The conductive nanomaterials,such as carbon nanotubes(CNTs),have attracted much attention in biomedical applications.Particularly,it has been found that CNTs can promote the electrical activity of cardiomyocytes,but little is known about the mechanism.^(1,2)To better understand the CNTs’biological effects on cardiomyocytes and the underlying mechanism.
基金supported by the National Natural Science Foundation of China(91645115,21473003,21673273,21473229,21821004,and 91545121)the National Basic Research Program of China(2013CB933100)+4 种基金the financial support of China Postdoctoral Science Foundation(2016M590216)the financial support of China Postdoctoral Science Foundation(2015M580011)National Thousand Young Talents Program of ChinaHundred-Talent Program of Chinese Academy of SciencesShanxi Hundred-Talent Program
文摘Constructing and understanding the doping effect of secondary metal in transition metal carbide(TMC)catalysts is pivotal for the design of low-cost hydrogen evolution reaction(HER) electrocatalysts. In this work, we developed a wet-chemistry strategy for synthesizing Co-modified Fe_5C_2 nanoparticles((Fe_(1-x)Cox)_5C_2 NPs) as highly active HER electrocatalysts in basic solution. The structure of(Fe_(1-x)Cox)_5C_2 NPs was characterized by X-ray diffraction(XRD), extended X-ray absorption fine structure spectra(EXAFS) and scanning/transmission electron microscopy(S/TEM), indicating that the isomorphous substitution of cobalt in the lattice of Fe_5C_2.(Fe_(0.75) Co_(0.25))_5C_2 exhibited the best HER activity(174 mV for j = -10 mA/cm^2). Computational calculation results indicate that Co provides the most active site for HER. X-ray adsorption spectra(XAS) studies further suggested that the electron transfer in Fe–C bonds are enhanced by the substitution of Co, which modulates the hydrogen adsorption on the adjacent electronic-enriched carbon, and therefore promotes HER activity. Our results affirm the design of lowcost bimetallic TMCs based HER catalysts.
基金Acknowledgements This work was financially supported by the National Natural Science Foundation of China （Nos. 21473003 and 21303119） and the National Basic Research Program of China （No. 2013CB933100）. C. Y. acknowledges the financial support of China Postdoctoral Science Foundation （No. 2015M580011）. XAS analysis was performed at the Beijing Synchrotron Radiation Fadlity.
基金This work was financially supported by the National Key Research and Development Program of China(Nos.2017YFB0602200 and 2017YFA0206701)National Program for Support of Top-notch Young Professionals,Changjiang Scholar Program and the National Natural Science Foundation of China(Nos.21725301,91645115,21673273,21473003,21872104,and 21821004)The XPS experiments were conducted at Lab of Multitechniques Electron&Ion Spectrometer for Surface Analysis of Peking University.We thank Jinglin Xie for XPS data discussion.
文摘Fe-based catalysts have been discovered as the best elementary metal-based heterogeneous catalysts for the ammonia synthesis in industrial application during the last century.Herein,a novel and scalable strategy is developed to prepare the K-promoted Fe/C catalyst with extremely high Fe loading (> 50 wt.%) through pyrolysis of the Fe-based metal-organic framework (MOF) xerogel.The obtained K-Fe/C catalysts exhibited superior activity and stability towards ammonia synthesis.The weight-specific reaction rate of Fe/C with K2O as promoter can achieve 12.4 mmol·g-1·h-1 at 350 ℃ and 30.4 mmol·g-1·h-1 at 400 ℃,approximately four and two times higher than that of the commercial fused-iron catalyst (3.4 mmol·g-1·h-1 at 350 ℃ and 16.7 mmol·g-1·h-1 at 400 ℃) under the same condition,respectively.The excellent performance of K-Fe/C can be ascribed to the inherited structure derived from the metal-organic frame precursors and the promotion of potassium,which can modify the binding energy of reactant molecules on the Fe surface,transfer electrons to iron for effective activation of nitrogen,prevent agglomeration of Fe nanoparticle (NPs) and restrain side reaction of carbon matrix to methane.
基金the support of the National Natural Sciences foundation of China (Nos. 51002120 and51032006)supported by the Research Fund of the State Key Laboratory of Solidification Processing(NWPU), China (No.45-QP-2010)
文摘The deposition rate, phase, chemical composition and microstructure of deposits were determined from 950 to 1100℃. With increasing temperature, the deposition rate increases, and the morphology changes from smooth to coarse, meanwhile, the concentration of silicon increases while that of boron decreases. The deposition process is controlled by chemical reactions, and the activation energy is 271 kJ/mol. At relatively lower temperature (below 1000℃), the deposition process is dominated by formation of B4C. While at higher temperature (above 1000℃), it is governed by formation of SiC. B4C and SiC disperse uniformly in the Si-B-C co-deposition system and form a dense network structure.
基金FOOTNOTES We are grateful to the staff at the beamline BL-17A at Photon Fac- tory （Tsukuba, Japan） and at the beamline BL17U1 of the Shanghai Synchrotron Radiation Facility for excellent technical assistance during data collection. This work was supported by the National Basic Research Program （973 Program） （Nos. 2012CB917200 and 2013CB910400 to YS grant 2014CB910201 to XY）, the National Natural Science Foundation of China （Grant No. 31370826 to YS and 31300628 to XY）, Tianjin Basic Research Program （Grant 14JCQNJ09300 to XY）. Fengzhi Li, Siwei Li, Xiaofen Liu, Xue Yang, Peng Wang and Yuequan Shen declare that they have no conflict of interest. This article does not contain any studies with human or animal subjects performed by the any of the authors.
基金supported by the Key Program of the National Key Research and Development Program of China(nos.2017YFA0106100,2016YFY1101303)the National Natural Science Funds for Outstanding Young Scholar(no.81622027)+2 种基金the Key Program of National Natural Science Foundation of China(no.31830030)the Beijing NOVA Program of China(no.2016B615)Joint funds for National Natural Science Foundation of China(no.U1601221).
文摘The cell-derived extracellular matrix(ECM)-modified scaffolds have advantages of mimic tissue specificity and been thought to better mimic the native cellular microenvironment in vitro.ECM derived from cardiac fibroblasts(CFs)are considered as key elements that provide a natural cell growth microenvironment and change the fate of cardiomyocytes(CMs).Here,a new hybrid scaffold is designed based on silk fibroin(SF)scaffold and CFs-derived ECM.CFs were seeded on the SF scaffold for 10days culturing and decellularized to produce CFs-derived ECM-coated SF scaffold.The results showed that the cell-derived ECM-modified silk fibroin scaffold material contained collagen,laminin,fibronectin and other ECM components with myocardial-like properties.Further to explore its effects on brown adipose stem cells(BASCs)differentiation into CMs.We found that the CFderived ECM-coated scaffold also increased the expression of CM-specific proteins(e.g.cardiac troponin T and α-actinin)of BASCs.Notably,the b1-integrin-dependent transforming growth factor-β1 signaling pathway was also involved in the regulation of CF-derived ECM by promoting the differentiation of BASCs into CMs.Overall,these findings provide insights into the bionic manufacturing of engineered cardiac tissues(ECTs)and establish a theoretical basis for the construction of ECTs.
