Understanding the complex interactions between human activities and ecosystem functions is a prerequisite for achieving sustainable development.Since the implementation of the“Grain for Green”Project in 1999,ecosyst...Understanding the complex interactions between human activities and ecosystem functions is a prerequisite for achieving sustainable development.Since the implementation of the“Grain for Green”Project in 1999,ecosystem functions in China’s Loess Plateau have significantly improved.However,intensified human activities have also exacerbated the pressures on the region’s fragile ecological environment.This study investigates the spatiotemporal variations in the human activity intensity index(HAI)and net ecosystem benefits(NEB)from 2000 to 2020,using expert-based assessments and an enhanced cost-benefit evaluation framework.Results indicate that HAI increased by 16.7% and 16.6% at the grid and county levels,respectively.NEB exhibited pronounced spatial heterogeneity,with a total increase of USD 36.2 trillion at the grid scale.At the county level,the average NEB rose by 75%.The degree of trade-off was higher at the grid scale than at the county scale,while the synergistic areas initially expanded and then declined at both scales.Key areas for improvement and regions of lagging development were identified as priority zones for ecological management and spatial planning at both spatial resolutions.This study offers scientific insights and practical guidance for harmonizing ecological conservation with high-quality development in ecologically vulnerable regions.展开更多
Ecological restorations(ERs)have been widely implemented in recent decades to enhance ecosystem stability.However,the extent of their impacts on ecosystem stability and the underlying mechanism remain poorly understoo...Ecological restorations(ERs)have been widely implemented in recent decades to enhance ecosystem stability.However,the extent of their impacts on ecosystem stability and the underlying mechanism remain poorly understood.This study developed a comprehensive framework for ecosystem stability assessment by integrating the temporal stability of ecosystem service(ES)provision,ecological resistance,and ecological resilience.Additionally,ER intensity was quantified using vegetation index trends,while the pathways and magnitudes of key factors driving ecosystem stability were identified by partial least squares structural equation modeling.Using the Jialing River Basin as a case study,our results revealed that forests exhibited the highest ecosystem stability due to their enhanced capacity to maintain temporal stability of ES provision and ecological resilience.However,farmlands demonstrated the strongest ecological resistance,followed by forests and grasslands.ER projects were primarily implemented in northern and southern farmland regions characterized by low ecological resilience.Pathway analysis identified that favorable climates significantly enhanced the temporal stability of ES provision,and rugged topography improved the ecological resistance.However,fragmented landscape patches disrupted stable ES provision by reducing ecological connectivity,and socioeconomic development diminished both resistance and resilience through land-use intensification.Notably,ERs improved ecological resilience,which in turn elevated overall ecosystem stability.Our results indicated that the proposed framework provides a systematic approach for comprehensive ecosystem stability evaluation and offers critical insights for developing region-specific ER strategies.展开更多
Objectives:This prospective cohort study examined the change trajectories of cognitive and physical functions of individuals with motoric cognitive risk(MCR)syndrome,as well as the longitudinal associations between MC...Objectives:This prospective cohort study examined the change trajectories of cognitive and physical functions of individuals with motoric cognitive risk(MCR)syndrome,as well as the longitudinal associations between MCR syndrome and changes in cognitive and physical functions,to provide a new perspective on preventing dementia.Methods:Participants were selected from the China Health and Retirement Longitudinal Study(CHARLS).Demographic characteristics,health status,and lifestyle variables were assessed in 2011.MCR syndrome was defined as the presence of subjective cognitive complaints and objective slow gait,with preserved activities of daily living and absence of dementia,and assessed in 2011.Cognitive function,including orientation,attention and calculation,episodic memory,and visuospatial ability,was measured from 2011 to 2018.Physical function,including grip strength,balance ability,and repeated chair stand tests,was measured from 2011 to 2015.Generalized estimating equation was employed to analyze the longitudinal associations between MCR syndrome in 2011 and changes in cognitive functions over 7 years and physical functions over 4 years.Results:Among 4,217 participants,475 had MCR syndrome in 2011.Both participants with MCR syndrome and those without exhibited a decline in both cognitive and physical function over 7 years and 4 years of follow-up,except for fluctuations in visuospatial ability.Non-MCR syndrome participants demonstrated significantly better overall cognitive function in 2018 compared to 2011(Group×Time:B=0.44,P=0.035)than those in the MCR syndrome group.However,participants with non-MCR syndrome demonstrated significantly worse visuospatial ability in 2013(Group×time:B=−0.44,P=0.002)and 2018(Group×time:B=−0.34,P=0.016)compared to those in the MCR syndrome group.Non-MCR syndrome participants demonstrated significantly better performance in repeated chair stand tests in 2013(Group×time:B=0.31,P<0.001)and 2015(Group×time:B=0.37,P<0.001)compared to those in the MCR syndrome group in 2011.Conclusions:Older adults with MCR syndrome experience worse overall cognitive and physical function performance,especially in repeated chair stand tests,than individuals without MCR syndrome over 7-year and 4-year follow-up periods.It is suggested that future interventional studies will target both physical and cognitive functions in MCR syndrome individuals,providing insights for the prevention of dementia.展开更多
Multi-components landfill leachate is one type of wastewater that is challenging to deal with.The excellent degrading ability and low secondary pollution of electrochemical oxidation make it a promising technology for...Multi-components landfill leachate is one type of wastewater that is challenging to deal with.The excellent degrading ability and low secondary pollution of electrochemical oxidation make it a promising technology for leachate treatment.However,the commercial application of this method is restricted by some technical barriers such as limited anode activity and intricate operating conditions.To improve the efficiency of electrochemical leachate treatment,many researchers commit to developing efficient electrode and optimizing operation process for eliminating these limitations.This review summarized the recently studied countermeasures for accelerating the performance of electrochemical oxidation of leachate with respect to the electron transfer,active sites and stability of electrode.The performance of electrochemical leachate treatment with different anode and the corresponding underlying mechanisms were summarized and discussed.Besides,the effects of critical parameters including temperature,pH,current density and electrolyte on reaction were discussed.With these in mind,this work offers recommendations for the improvement of electrooxidation performance as well as direction for the design of leachate treatment engineering.展开更多
Metal oxide semiconductor heterojunctions(MOSHs)can enhance the performance of ethanol gas sen-sors substantially.Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing response,good selectiv...Metal oxide semiconductor heterojunctions(MOSHs)can enhance the performance of ethanol gas sen-sors substantially.Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing response,good selectivity,fast response and recovery,long-term stability or repeatability,a low operating temperature,a facile fabrica-tion process,and versatile applications.This paper reviews the recent advances in gas sensors that are based on MOSHs and the advantages of using them to detect ethanol gas.According to the literature,compared with ethanol gas sen-sors that use single-component sensing materials,the MOSHs exhibit superior performance due to the synergy between the different components,which can amplify the reception and transduction components of the sensor signals.To the best of our knowledge,heterojunctions can be grouped into four main categories as metal oxide/metal oxide,metal oxide/metal sulfide,metal oxide/noble metal,and metal oxide/other materials,including rare-earth metals,g-C_(3)N_(4),and graphene,heterojunctions.The future trends and challenges that would be faced in the development of ethanol gas sensors based on MOSHs are discussed in detail.Finally,critical ideas and thinking regarding the future progress of MOSH-based gas sensors are presented.展开更多
Non-volatile memory(NVM)devices with non-volatility and low power consumption properties are important in the data storage field.The switching mechanism and packaging reliability issues in NVMs are of great research i...Non-volatile memory(NVM)devices with non-volatility and low power consumption properties are important in the data storage field.The switching mechanism and packaging reliability issues in NVMs are of great research interest.The switching process in NVM devices accompanied by the evolution of microstructure and composition is fast and subtle.Transmission electron microscopy(TEM)with high spatial resolution and versatile external fields is widely used in analyzing the evolution of morphology,structures and chemical compositions at atomic scale.The various external stimuli,such as thermal,electrical,mechanical,optical and magnetic fields,provide a platform to probe and engineer NVM devices inside TEM in real-time.Such advanced technologies make it possible for an in situ and interactive manipulation of NVM devices without sacrificing the resolution.This technology facilitates the exploration of the intrinsic structure-switching mechanism of NVMs and the reliability issues in the memory package.In this review,the evolution of the functional layers in NVM devices characterized by the advanced in situ TEM technology is introduced,with intermetallic compounds forming and degradation process investigated.The principles and challenges of TEM technology on NVM device study are also discussed.展开更多
AIM: To investigate the role of single nucleotide polymorphisms(SNPs) in CD24 gene in susceptibility and overall survival of gastric cancer(GC).METHODS: We genotyped 3 tagging SNPs of CD24-P-534 in the promoter region...AIM: To investigate the role of single nucleotide polymorphisms(SNPs) in CD24 gene in susceptibility and overall survival of gastric cancer(GC).METHODS: We genotyped 3 tagging SNPs of CD24-P-534 in the promoter region, P170 in the coding region of exon 2 and P1527 in the 3′ untranslated region- using polymerase chain reaction-restriction fragment length polymorphism in specimens from 679 histologically-confirmed GC cases, 111 gastric atrophy(GA) cases and 976 tumor-free controls. Serumimmunoglobulin G antibodies to Helicobacter pylori(H. pylori) of all subjects were detected by enzyme-linked immunosorbent assay. CD24 expression was evaluated by immunohistochemistry in 131 GC specimens. Correlations between SNPs and risk of GC or GA were shown by P values and odd ratios(ORs) with 95% confidence intervals(95%CI) compared with the most common genotype of each SNP using the unconditional logistic regression model after adjusting for age, sex and H. pylori infection. Survival within each SNP group was plotted by Kaplan-Meier method and compared by log-rank test(recessive model). Hazard ratios with 95%CIs were computed by Cox regression model after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy.RESULTS: All of the three loci were in Hardy-Weinberg equilibrium in the control group. Median followup time for the 600 GC patients included in the survival analysis was 36.2 mo(range, 2.1-66.7 mo; 95%CI: 34.3-36.5 mo). Patients with the P-534 A/A genotype had significantly shorter survival(HR = 1.38, 95%CI: 1.01-1.88, P = 0.042) than did the C/C or C/A genotype carriers after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy. This trend was more evident in patients who lived longer than 2.5 years(HR = 7.55, 95%CI: 2.16-26.32, P = 0.001). The P170 T/T genotype was associated with a shorter lifespan than the non-T/T genotypes, but not significantly so. None of the three genetic variants was found to be associated with risk of GC(including tumor stage, grade and distant metastasis) or with risk of gastric atrophy. Furthermore, no difference of CD24 expression was found among the genotypes.CONCLUSION: The P-534 site in CD24 gene affects the overall survival of gastric cancer and may serve as a prognostic marker for gastric cancer.展开更多
Two-dimensional(2D) transition metal dichalcogenides alloys are potential materials in the application of photodetectors over a wide spectral range due to their composition-dependent bandgaps. The study of bandgap eng...Two-dimensional(2D) transition metal dichalcogenides alloys are potential materials in the application of photodetectors over a wide spectral range due to their composition-dependent bandgaps. The study of bandgap engineering is important for the application of 2D materials in devices. Here, we grow the Mo1-xWxSe2 alloys on mica, sapphire and SiO2/Si substrates by chemical vapor deposition(CVD) method. Mo1-x Wx Se2 alloys are grown on the mica substrates by CVD method for the first time. Photoluminescence(PL) spectroscopy is used to investigate the effects of substrates and interlayer coupling force on the optical bandgaps of as-grown Mo1-xWxSe2 alloys. We find that the substrates used in this work have an ignorable effect on the optical bandgaps of as-grown Mo1-xWxSe2. The interlayer coupling effect on the optical bandgaps of as-grown Mo1-xWxSe2 is larger than the substrates effect. These findings provide a new way for the future study of the growth and physical properties of 2D alloy materials.展开更多
The deformation control of surrounding rock in gobside roadway with thick and hard roof poses a significant challenge to the safety and efficiency of coal mining.To address this issue,a novel approach combining direct...The deformation control of surrounding rock in gobside roadway with thick and hard roof poses a significant challenge to the safety and efficiency of coal mining.To address this issue,a novel approach combining directional and non-directional blasting techniques,known as combined blasting,was proposed.This study focuses on the experimental investigation of the proposed method in the 122108 working face in Caojiatan Coal Mine as the engineering background.The initial phase of the study involves physical model experiments to reveal the underlying mechanisms of combined blasting for protecting gob-side roadway with thick and hard roof.The results demonstrate that this approach effectively accelerates the collapse of thick and hard roofs,enhances the fragmentation and expansion coefficient of gangue,facilitates the filling of the goaf with gangue,and provides support to the overlying strata,thus reducing the subsidence of the overlying strata above the goaf.Additionally,the method involves cutting the main roof into shorter beams to decrease the stress and disrupt stress transmission pathways.Subsequent numerical simulations were conducted to corroborate the findings of the physical model experiments,thus validating the accuracy of the experimental results.Furthermore,field engineering experiments were performed,affirming the efficacy of the combined blasting method in mitigating the deformation of surrounding rock and achieving the desired protection of the gob-side roadway.展开更多
Tooeleite(Fe6(As03)4 SO4(OH)4·4 H2 O)is widely precipitated for direct As(III)removal from sulfate-rich industrial effluents.However,whether or not Fe(III)-As(III)-Cl(-I)precipitate is produced in chloridizing le...Tooeleite(Fe6(As03)4 SO4(OH)4·4 H2 O)is widely precipitated for direct As(III)removal from sulfate-rich industrial effluents.However,whether or not Fe(III)-As(III)-Cl(-I)precipitate is produced in chloridizing leaching media for As immobilization is almost unknown.This work founded the existence of ferric arsenite(hydroxy)chloride as a new mineral for As(III)removal.Its chemical composition and solid characterization were subsequently studied by using scanning electron microscope with an energy dispersive spectrometer(SEM-EDS),X-ray diffraction(XRD),infrared(FT-IR),Raman spectroscopy and thermogravimetric(TG)curve.The results showed the formation of a yellow precipitate after 3-days reaction of Fe(III)/As(III)with molar ratio≈1.7 in chloride solution at pH 2.3 neutralized with NaOH.Compared with tooeleite,chemical analysis and solid characterization indicated that Cl(-I)replaces S04(-II)producing ferric arsenite hydroxychloride with formula Fe5(As03)3-Cl2(OH)4·5 H2 O.This new plate shaped solid showed better crytallinity than tooeleite,although it has similar morphology and characteristic bands to tooeleite.The FT-IR bands at 628,964 cm-1 and the Raman bands at 448,610,961 cm-1 were assigned to Fe-O or As(Ⅲ)-O-Fe or As(Ⅲ)-O bending/stretching vibration,indicating that both arsenite and chloride substituted for the position of sulfate for ferric arsenite hydro xychloride produced due to the lack of the SO42-vibrations.Cl-(I)also contributed to increase As removal efficiency in aqueous sulfate media under acidic pH conditions via the probable formation of sulfatechloride ferric arsenite.展开更多
Advanced electronic materials are the fundamental building blocks of integrated circuits(ICs).The microscale properties of electronic materials(e.g.,crystal structures,defects,and chemical properties)can have a consid...Advanced electronic materials are the fundamental building blocks of integrated circuits(ICs).The microscale properties of electronic materials(e.g.,crystal structures,defects,and chemical properties)can have a considerable impact on the performance of ICs.Comprehensive characterization and analysis of the material in real time with high-spatial resolution are indispensable.In situ transmission electron microscope(TEM)with atomic resolution and external field can be applied as a physical simulation platform to study the evolution of electronic material in working conditions.The high-speed camera of the in situ TEM generates a high frame rate video,resulting in a large dataset that is beyond the data processing ability of researchers using the traditional method.To overcome this challenge,many works on automated TEM analysis by using machine-learning algorithm have been proposed.In this review,we introduce the technical evolution of TEM data acquisition,including analysis,and we summarize the application of machine learning to TEM data analysis in the aspects of morphology,defect,structure,and spectra.Some of the challenges of automated TEM analysis are given in the conclusion.展开更多
Continuous expansion of rat neural stem cell lines has not been achieved due to proliferation arrest and spontaneous differentiation in vitro. In the current study, neural precursor cells derived from the subventricul...Continuous expansion of rat neural stem cell lines has not been achieved due to proliferation arrest and spontaneous differentiation in vitro. In the current study, neural precursor cells derived from the subventricular zone of adult rats spontaneously underwent astroglial and oligodendroglial differentiation after limited propagation. This differentiation was largely induced by autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signals. The results showed that, by inhibiting bone morphogenetic protein and platelet derived growth factor signals, adult rat neural precursor cells could be extensively cultured in vitro as tripotent stem cell lines. In addition to adult rat neural stem cells, we found that bone morphogenetic protein antagonists can promote the proliferation of human neural stem cells. Therefore, the present findings illustrated the role of autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signaling in determining neural stem cell self-renewal and differentiation. By antagonizing both signals, the long-term propagation of rat neural stem cell lines can be achieved.展开更多
Two-dimensional （2D） materials have become a hot study topic in recent years due to their outstanding electronic, optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and wea...Two-dimensional （2D） materials have become a hot study topic in recent years due to their outstanding electronic, optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and weak out-of-plane van der Waals （vdW） interactions make 2D materials promising for nanodevices and various other applications. Raman spectroscopy is a powerful and non-destructive characterization tool to study the properties of 2D materials. In this work, we review the research on the characterization of 2D materials with Raman spectroscopy. In addition, we discuss the application of the Raman spectroscopy technique to semiconductors, superconductivity, photoelectricity, and thermoelectricity.展开更多
基金National Natural Science Foundation of China(Grant No.U2243225)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB40000000)+2 种基金the Natural Science Basic Research Program of Shaanxi(Grant No.Z2024-ZYFS-0065)the Funding of Top Young talents of Ten Thousand talents Plan in China(2021)the Fundamental Research Funds for the Central Universities(Grants No.2452023071 and 2023HHZX002).
文摘Understanding the complex interactions between human activities and ecosystem functions is a prerequisite for achieving sustainable development.Since the implementation of the“Grain for Green”Project in 1999,ecosystem functions in China’s Loess Plateau have significantly improved.However,intensified human activities have also exacerbated the pressures on the region’s fragile ecological environment.This study investigates the spatiotemporal variations in the human activity intensity index(HAI)and net ecosystem benefits(NEB)from 2000 to 2020,using expert-based assessments and an enhanced cost-benefit evaluation framework.Results indicate that HAI increased by 16.7% and 16.6% at the grid and county levels,respectively.NEB exhibited pronounced spatial heterogeneity,with a total increase of USD 36.2 trillion at the grid scale.At the county level,the average NEB rose by 75%.The degree of trade-off was higher at the grid scale than at the county scale,while the synergistic areas initially expanded and then declined at both scales.Key areas for improvement and regions of lagging development were identified as priority zones for ecological management and spatial planning at both spatial resolutions.This study offers scientific insights and practical guidance for harmonizing ecological conservation with high-quality development in ecologically vulnerable regions.
基金supported by the National Key Research and Development Project(Grants No.2022YFF1303204 and 2024YFF1307902)the National Natural Science Foundation of China(Grant No.42271099)。
文摘Ecological restorations(ERs)have been widely implemented in recent decades to enhance ecosystem stability.However,the extent of their impacts on ecosystem stability and the underlying mechanism remain poorly understood.This study developed a comprehensive framework for ecosystem stability assessment by integrating the temporal stability of ecosystem service(ES)provision,ecological resistance,and ecological resilience.Additionally,ER intensity was quantified using vegetation index trends,while the pathways and magnitudes of key factors driving ecosystem stability were identified by partial least squares structural equation modeling.Using the Jialing River Basin as a case study,our results revealed that forests exhibited the highest ecosystem stability due to their enhanced capacity to maintain temporal stability of ES provision and ecological resilience.However,farmlands demonstrated the strongest ecological resistance,followed by forests and grasslands.ER projects were primarily implemented in northern and southern farmland regions characterized by low ecological resilience.Pathway analysis identified that favorable climates significantly enhanced the temporal stability of ES provision,and rugged topography improved the ecological resistance.However,fragmented landscape patches disrupted stable ES provision by reducing ecological connectivity,and socioeconomic development diminished both resistance and resilience through land-use intensification.Notably,ERs improved ecological resilience,which in turn elevated overall ecosystem stability.Our results indicated that the proposed framework provides a systematic approach for comprehensive ecosystem stability evaluation and offers critical insights for developing region-specific ER strategies.
基金supported by the National Natural Science Foundation of China(grant number:72304153)the Supporting Project of National Natural Science Foundation of China from Nanjing University of Chinese Medicine,China,(grant number:XPT72304153)the University Philosophy and Social Science Research in Jiangsu Province Jiangsu Province,China(grant number:2023SJYB0318)。
文摘Objectives:This prospective cohort study examined the change trajectories of cognitive and physical functions of individuals with motoric cognitive risk(MCR)syndrome,as well as the longitudinal associations between MCR syndrome and changes in cognitive and physical functions,to provide a new perspective on preventing dementia.Methods:Participants were selected from the China Health and Retirement Longitudinal Study(CHARLS).Demographic characteristics,health status,and lifestyle variables were assessed in 2011.MCR syndrome was defined as the presence of subjective cognitive complaints and objective slow gait,with preserved activities of daily living and absence of dementia,and assessed in 2011.Cognitive function,including orientation,attention and calculation,episodic memory,and visuospatial ability,was measured from 2011 to 2018.Physical function,including grip strength,balance ability,and repeated chair stand tests,was measured from 2011 to 2015.Generalized estimating equation was employed to analyze the longitudinal associations between MCR syndrome in 2011 and changes in cognitive functions over 7 years and physical functions over 4 years.Results:Among 4,217 participants,475 had MCR syndrome in 2011.Both participants with MCR syndrome and those without exhibited a decline in both cognitive and physical function over 7 years and 4 years of follow-up,except for fluctuations in visuospatial ability.Non-MCR syndrome participants demonstrated significantly better overall cognitive function in 2018 compared to 2011(Group×Time:B=0.44,P=0.035)than those in the MCR syndrome group.However,participants with non-MCR syndrome demonstrated significantly worse visuospatial ability in 2013(Group×time:B=−0.44,P=0.002)and 2018(Group×time:B=−0.34,P=0.016)compared to those in the MCR syndrome group.Non-MCR syndrome participants demonstrated significantly better performance in repeated chair stand tests in 2013(Group×time:B=0.31,P<0.001)and 2015(Group×time:B=0.37,P<0.001)compared to those in the MCR syndrome group in 2011.Conclusions:Older adults with MCR syndrome experience worse overall cognitive and physical function performance,especially in repeated chair stand tests,than individuals without MCR syndrome over 7-year and 4-year follow-up periods.It is suggested that future interventional studies will target both physical and cognitive functions in MCR syndrome individuals,providing insights for the prevention of dementia.
基金financially supported by the Innovative Research Groups of the National Natural Science Foundation of China(No.52121004)the project of National Natural Science Foundation(No.U21A20294)+1 种基金the Scientific Foundation of Hunan Province(Nos.2024RC1012,2022JJ40622)The Technology Innovation Guidance Project of Jiangxi Province,China(Nos.20203BDH80W017,20212BDH81030)。
文摘Multi-components landfill leachate is one type of wastewater that is challenging to deal with.The excellent degrading ability and low secondary pollution of electrochemical oxidation make it a promising technology for leachate treatment.However,the commercial application of this method is restricted by some technical barriers such as limited anode activity and intricate operating conditions.To improve the efficiency of electrochemical leachate treatment,many researchers commit to developing efficient electrode and optimizing operation process for eliminating these limitations.This review summarized the recently studied countermeasures for accelerating the performance of electrochemical oxidation of leachate with respect to the electron transfer,active sites and stability of electrode.The performance of electrochemical leachate treatment with different anode and the corresponding underlying mechanisms were summarized and discussed.Besides,the effects of critical parameters including temperature,pH,current density and electrolyte on reaction were discussed.With these in mind,this work offers recommendations for the improvement of electrooxidation performance as well as direction for the design of leachate treatment engineering.
基金financially supported by Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea (No.2021H1D3A2A01100019)the National Natural Science Foundation of China (No.62074057)+2 种基金Projects of Science and Technology Commission of Shanghai Municipality (Nos.19ZR1473800 and 18DZ2270800)the Open Research Projects of Zhejiang Lab (No.2021MCOAB06)the Postdoctoral Scientific Research Foundation of Qingdao
文摘Metal oxide semiconductor heterojunctions(MOSHs)can enhance the performance of ethanol gas sen-sors substantially.Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing response,good selectivity,fast response and recovery,long-term stability or repeatability,a low operating temperature,a facile fabrica-tion process,and versatile applications.This paper reviews the recent advances in gas sensors that are based on MOSHs and the advantages of using them to detect ethanol gas.According to the literature,compared with ethanol gas sen-sors that use single-component sensing materials,the MOSHs exhibit superior performance due to the synergy between the different components,which can amplify the reception and transduction components of the sensor signals.To the best of our knowledge,heterojunctions can be grouped into four main categories as metal oxide/metal oxide,metal oxide/metal sulfide,metal oxide/noble metal,and metal oxide/other materials,including rare-earth metals,g-C_(3)N_(4),and graphene,heterojunctions.The future trends and challenges that would be faced in the development of ethanol gas sensors based on MOSHs are discussed in detail.Finally,critical ideas and thinking regarding the future progress of MOSH-based gas sensors are presented.
基金the Projects of Science and Technology Commission of Shanghai Municipality(19ZR1473800 and 14DZ2260800)the Shanghai Rising-Star Program(17QA1401400)+1 种基金Young Elite Scientists Sponsorship Program by CAST(YESS)the Fundamental Research Funds for the Central Universities.
文摘Non-volatile memory(NVM)devices with non-volatility and low power consumption properties are important in the data storage field.The switching mechanism and packaging reliability issues in NVMs are of great research interest.The switching process in NVM devices accompanied by the evolution of microstructure and composition is fast and subtle.Transmission electron microscopy(TEM)with high spatial resolution and versatile external fields is widely used in analyzing the evolution of morphology,structures and chemical compositions at atomic scale.The various external stimuli,such as thermal,electrical,mechanical,optical and magnetic fields,provide a platform to probe and engineer NVM devices inside TEM in real-time.Such advanced technologies make it possible for an in situ and interactive manipulation of NVM devices without sacrificing the resolution.This technology facilitates the exploration of the intrinsic structure-switching mechanism of NVMs and the reliability issues in the memory package.In this review,the evolution of the functional layers in NVM devices characterized by the advanced in situ TEM technology is introduced,with intermetallic compounds forming and degradation process investigated.The principles and challenges of TEM technology on NVM device study are also discussed.
基金National Natural Science Foundation of China,No.81373084 and No.81273065the Norman Bethune Program of Jilin Universit,No.2013025the Youth Fund of the First Hospital of Jilin University,No.JDYY42013014
文摘AIM: To investigate the role of single nucleotide polymorphisms(SNPs) in CD24 gene in susceptibility and overall survival of gastric cancer(GC).METHODS: We genotyped 3 tagging SNPs of CD24-P-534 in the promoter region, P170 in the coding region of exon 2 and P1527 in the 3′ untranslated region- using polymerase chain reaction-restriction fragment length polymorphism in specimens from 679 histologically-confirmed GC cases, 111 gastric atrophy(GA) cases and 976 tumor-free controls. Serumimmunoglobulin G antibodies to Helicobacter pylori(H. pylori) of all subjects were detected by enzyme-linked immunosorbent assay. CD24 expression was evaluated by immunohistochemistry in 131 GC specimens. Correlations between SNPs and risk of GC or GA were shown by P values and odd ratios(ORs) with 95% confidence intervals(95%CI) compared with the most common genotype of each SNP using the unconditional logistic regression model after adjusting for age, sex and H. pylori infection. Survival within each SNP group was plotted by Kaplan-Meier method and compared by log-rank test(recessive model). Hazard ratios with 95%CIs were computed by Cox regression model after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy.RESULTS: All of the three loci were in Hardy-Weinberg equilibrium in the control group. Median followup time for the 600 GC patients included in the survival analysis was 36.2 mo(range, 2.1-66.7 mo; 95%CI: 34.3-36.5 mo). Patients with the P-534 A/A genotype had significantly shorter survival(HR = 1.38, 95%CI: 1.01-1.88, P = 0.042) than did the C/C or C/A genotype carriers after adjusting for age, sex, histological type, tumor differentiation, clinical stage and post-operational chemotherapy. This trend was more evident in patients who lived longer than 2.5 years(HR = 7.55, 95%CI: 2.16-26.32, P = 0.001). The P170 T/T genotype was associated with a shorter lifespan than the non-T/T genotypes, but not significantly so. None of the three genetic variants was found to be associated with risk of GC(including tumor stage, grade and distant metastasis) or with risk of gastric atrophy. Furthermore, no difference of CD24 expression was found among the genotypes.CONCLUSION: The P-534 site in CD24 gene affects the overall survival of gastric cancer and may serve as a prognostic marker for gastric cancer.
基金supported by the National Natural Science Foundation of China(Nos.11504111,61574060)the Projects of Science and Technology Commission of Shanghai Municipality(Nos.15JC1401800,14DZ2260800)+3 种基金the Program for Professor of Special Appointment(Eastern Scholar)the Shanghai Rising-Star Program(No.17QA1401400)the Young Elite Scientists Sponsorship(YESS)Program by CASTthe Fundamental Research Funds for the Central Universities
文摘Two-dimensional(2D) transition metal dichalcogenides alloys are potential materials in the application of photodetectors over a wide spectral range due to their composition-dependent bandgaps. The study of bandgap engineering is important for the application of 2D materials in devices. Here, we grow the Mo1-xWxSe2 alloys on mica, sapphire and SiO2/Si substrates by chemical vapor deposition(CVD) method. Mo1-x Wx Se2 alloys are grown on the mica substrates by CVD method for the first time. Photoluminescence(PL) spectroscopy is used to investigate the effects of substrates and interlayer coupling force on the optical bandgaps of as-grown Mo1-xWxSe2 alloys. We find that the substrates used in this work have an ignorable effect on the optical bandgaps of as-grown Mo1-xWxSe2. The interlayer coupling effect on the optical bandgaps of as-grown Mo1-xWxSe2 is larger than the substrates effect. These findings provide a new way for the future study of the growth and physical properties of 2D alloy materials.
基金funding support from the National Natural Science Foundation of China(Grant Nos.52074298 and 52204164)Fundamental Research Funds for the Central Universities(Grant No.2022XJSB03).
文摘The deformation control of surrounding rock in gobside roadway with thick and hard roof poses a significant challenge to the safety and efficiency of coal mining.To address this issue,a novel approach combining directional and non-directional blasting techniques,known as combined blasting,was proposed.This study focuses on the experimental investigation of the proposed method in the 122108 working face in Caojiatan Coal Mine as the engineering background.The initial phase of the study involves physical model experiments to reveal the underlying mechanisms of combined blasting for protecting gob-side roadway with thick and hard roof.The results demonstrate that this approach effectively accelerates the collapse of thick and hard roofs,enhances the fragmentation and expansion coefficient of gangue,facilitates the filling of the goaf with gangue,and provides support to the overlying strata,thus reducing the subsidence of the overlying strata above the goaf.Additionally,the method involves cutting the main roof into shorter beams to decrease the stress and disrupt stress transmission pathways.Subsequent numerical simulations were conducted to corroborate the findings of the physical model experiments,thus validating the accuracy of the experimental results.Furthermore,field engineering experiments were performed,affirming the efficacy of the combined blasting method in mitigating the deformation of surrounding rock and achieving the desired protection of the gob-side roadway.
基金supported by the National Natural Science Foundation of China(Nos.41530643,41703133 and 41877393)the Chinese Academy of Sciences(No.QYZDJSSW-DQC038)the Liaoning Province Doctoral Scientific Research Initiation Fund Project(No.2019-BS-261)
文摘Tooeleite(Fe6(As03)4 SO4(OH)4·4 H2 O)is widely precipitated for direct As(III)removal from sulfate-rich industrial effluents.However,whether or not Fe(III)-As(III)-Cl(-I)precipitate is produced in chloridizing leaching media for As immobilization is almost unknown.This work founded the existence of ferric arsenite(hydroxy)chloride as a new mineral for As(III)removal.Its chemical composition and solid characterization were subsequently studied by using scanning electron microscope with an energy dispersive spectrometer(SEM-EDS),X-ray diffraction(XRD),infrared(FT-IR),Raman spectroscopy and thermogravimetric(TG)curve.The results showed the formation of a yellow precipitate after 3-days reaction of Fe(III)/As(III)with molar ratio≈1.7 in chloride solution at pH 2.3 neutralized with NaOH.Compared with tooeleite,chemical analysis and solid characterization indicated that Cl(-I)replaces S04(-II)producing ferric arsenite hydroxychloride with formula Fe5(As03)3-Cl2(OH)4·5 H2 O.This new plate shaped solid showed better crytallinity than tooeleite,although it has similar morphology and characteristic bands to tooeleite.The FT-IR bands at 628,964 cm-1 and the Raman bands at 448,610,961 cm-1 were assigned to Fe-O or As(Ⅲ)-O-Fe or As(Ⅲ)-O bending/stretching vibration,indicating that both arsenite and chloride substituted for the position of sulfate for ferric arsenite hydro xychloride produced due to the lack of the SO42-vibrations.Cl-(I)also contributed to increase As removal efficiency in aqueous sulfate media under acidic pH conditions via the probable formation of sulfatechloride ferric arsenite.
基金supported by NSFC under Grant Nos.62074057,62174056Projects of Science and Technology Commission of Shanghai Municipality Grant Nos.(19ZR1473800,18DZ2270800)+1 种基金‘Shuguang Program’supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities.
文摘Advanced electronic materials are the fundamental building blocks of integrated circuits(ICs).The microscale properties of electronic materials(e.g.,crystal structures,defects,and chemical properties)can have a considerable impact on the performance of ICs.Comprehensive characterization and analysis of the material in real time with high-spatial resolution are indispensable.In situ transmission electron microscope(TEM)with atomic resolution and external field can be applied as a physical simulation platform to study the evolution of electronic material in working conditions.The high-speed camera of the in situ TEM generates a high frame rate video,resulting in a large dataset that is beyond the data processing ability of researchers using the traditional method.To overcome this challenge,many works on automated TEM analysis by using machine-learning algorithm have been proposed.In this review,we introduce the technical evolution of TEM data acquisition,including analysis,and we summarize the application of machine learning to TEM data analysis in the aspects of morphology,defect,structure,and spectra.Some of the challenges of automated TEM analysis are given in the conclusion.
基金the National Natural Science Foundation of China,No.81000518China Postdoctoral Science Foundation,No.201003237+2 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of ChinaShanghai Pujiang Program by Science and Technology Commission of Shanghai Municipality,No. 09PJ1408300Key Basic Research Project by Science and Technology Commission of Shanghai Municipality,No. 10JC1402300
文摘Continuous expansion of rat neural stem cell lines has not been achieved due to proliferation arrest and spontaneous differentiation in vitro. In the current study, neural precursor cells derived from the subventricular zone of adult rats spontaneously underwent astroglial and oligodendroglial differentiation after limited propagation. This differentiation was largely induced by autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signals. The results showed that, by inhibiting bone morphogenetic protein and platelet derived growth factor signals, adult rat neural precursor cells could be extensively cultured in vitro as tripotent stem cell lines. In addition to adult rat neural stem cells, we found that bone morphogenetic protein antagonists can promote the proliferation of human neural stem cells. Therefore, the present findings illustrated the role of autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signaling in determining neural stem cell self-renewal and differentiation. By antagonizing both signals, the long-term propagation of rat neural stem cell lines can be achieved.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504111,61574060,and 61574056)the Projects of Science and Technology Commission of Shanghai Municipality of China(Grant Nos.15JC1401800 and 14DZ2260800)+2 种基金the Program for Professor of Special Appointment(Eastern Scholar)Shanghai Rising-Star Program,China(Grant No.17QA1401400)the Fundamental Research Funds for the Central Universities of China
文摘Two-dimensional （2D） materials have become a hot study topic in recent years due to their outstanding electronic, optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and weak out-of-plane van der Waals （vdW） interactions make 2D materials promising for nanodevices and various other applications. Raman spectroscopy is a powerful and non-destructive characterization tool to study the properties of 2D materials. In this work, we review the research on the characterization of 2D materials with Raman spectroscopy. In addition, we discuss the application of the Raman spectroscopy technique to semiconductors, superconductivity, photoelectricity, and thermoelectricity.
