Yunnan in southwest China is a geographically and ethnically complex region at the intersection of southern China and Southeast Asia,and a focal point for human migrations.To clarify its maternal genetic history,we ge...Yunnan in southwest China is a geographically and ethnically complex region at the intersection of southern China and Southeast Asia,and a focal point for human migrations.To clarify its maternal genetic history,we generated 152 complete mitogenomes from 17 Yunnan archaeological sites.Our results reveal distinct genetic histories segregated by geographical regions.Maternal lineages of ancient populations from northwestern and northern Yunnan exhibit closer affinities with past and present-day populations from northern East Asia and Xizang,providing important genetic evidence for the migration and interaction of populations along the Tibetan-Yi corridor since the Neolithic.Between 5500 and 1800 years ago,central Yunnan populations maintained their internal genetic relationships,including a 7000-year-old basal lineage of the rare and widely dispersed haplogroup M61.At the Xingyi site,changes in mitochondrial DNA haplogroups occurred between the Late Neolithic and Bronze Age,with haplogroups shifting from those predominant in the Yellow River region to those predominant in coastal southern China.These results highlight the high diversity of Yunnan populations during the Neolithic to Bronze Age.展开更多
Simple cubic black phosphorus(BP)has been recognized as a strategic material due to its exceptional structural stability under extreme conditions.In this investigation,simple cubic BP was successfully synthesized thro...Simple cubic black phosphorus(BP)has been recognized as a strategic material due to its exceptional structural stability under extreme conditions.In this investigation,simple cubic BP was successfully synthesized through shock-induced phase transformation,utilizing amorphous red phosphorus as the precursor material.The phase evolution process was systematically investigated using plane shock loading apparatus,with shock pressure and temperature parameters being precisely controlled to optimize transformation kinetics.Comprehensive phase characterization revealed the correlation between thermodynamic loading profiles and cubic BP formation efficiency.Precursor modification strategies were implemented through orthorhombic BP utilization,resulting in enhanced cubic phase yield and crystallinity.The synthesized cubic BP variants are considered promising candidates for advanced protective material systems,particularly where combinations of mechanical resilience and thermal stability are required under extreme operational conditions.This research provides critical insights into shock-induced phase transformation mechanics,while establishing foundational protocols for manufacturing non-equilibrium materials with potential applications in next-generation defensive technologies.展开更多
The metal triazole(MTA)-based MOFs were found to preferentially adsorb O-rich species,which had enhanced electrocatalytic oxygen reduction reactions(ORR)and stabilized the O-containing species during the discharge and...The metal triazole(MTA)-based MOFs were found to preferentially adsorb O-rich species,which had enhanced electrocatalytic oxygen reduction reactions(ORR)and stabilized the O-containing species during the discharge and charge processes in Li-O_(2)battery.However,the MOFs exhibited low electron conductivity and poor electron transfer interface in the electrocatalysis,limiting the electrocatalytic activity.To address this issue,a nanocomposite with the Co-MTA-coated carbon nano tubes(Co-MTA-C)was constructed,which formed the three-dimensional conductivity network connected with the intersecting carbon nano tube(CNT).In this composite,the electron-rich Co-MTA interacted with the highly conductive CNT,resulting in a charge redistribution.Optimized the electronic structure of the Co center through compositional modifications presented a high valence compared to the pure MOFs.In situ X-ray absorption spectroscopy revealed a direct reaction of Co sites with intermediates such as LiO_(x),leading to the formation of nanosheet array discharge products.The battery based on optimized CoMTA-C demonstrated fast kinetics and superior stability,with a low overpotential of 1.13 V,high specific capacity of 9057 mAh g^(-1),and long-term durability of 600 cycles.It provides a facile and effective strategy for enhancing the electrocatalytic performance through rational tuning of high-conductivity substances.展开更多
The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation products.To th...The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation products.To this end,this paper is based on the impedance matching method to test the ODD conditions of CL-20 type aluminium explosive particle velocity.Calculated the interfacial pressure of the shock wave in different media.Determined the characteristic parameters of the reaction zone of the detonation of CL-20 aluminized explosives.Calibrated the parameters of the JoneseWilkinseLee(JWL)+γ equation for the detonation products(DPs).Revealed the effect of different DPs equation of state(EOS)on the Hugoniot pressure of ODD.The results indicate that when the content of aluminum powder ranges from 0%to 30%,the duration of the ODD reaction zone and the width of the detonation reaction zone of the CL-20-based aluminized explosive are directly proportional to the content of aluminum powder.The width of the detonation reaction zone is increased by 1.97 times to 2.7 times compared to that of the reaction zone without the addition of aluminum powder.However,the energy release efficiency of the detonation reaction zone is inversely proportional to the content of aluminum powder.When the aluminum powder content was held constant,the incorporation of AP caused a 25%reduction in the energy release efficiency of the detonation reaction zone.Compared with existing ODD state equations,the JWL +γ equation is superior in calibrating overpressure Hugoniot data and the isentropic expansion in the C-J state.The deviation between calculated pressure results and experimental measurements is within 6%.展开更多
β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy ...β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy on the in-situ synthesis of β-Sialon within Al_(2)O_(3)-C refractory materials,as well as its oxidation behavior,was investigated.The findings indicate that the presence of Al/Si alloy promotes the formation of AlN and SiC whiskers at 1300℃,which subsequently facilitate the production of plate-like β-Sialon at 1500℃.Density functional theory analysis reveals that the(020)crystal plane of β-Sialon exhibits the lowest adsorption energy for Al2O and AlO molecules under the influence of iron atoms,suggesting a solid-liquid-vapor growth mechanism for β-Sialon formation.The introduction of these ceramic phases significantly enhances the mechanical properties of Al_(2)O_(3)-C refractories.Specifically,the addition of 6 wt.%Al/Si alloy yielded specimens with the highest cold modulus of rupture and cold crushing strength at 1500℃,achieving values of 35.2 and 127.5 MPa,respectively--representing increases of 40.1%and 37.4%.Furthermore,during high-temperature oxidation,the formation of plate-like β-Sialon leads to the development of a dense protective layer on the surface.This impedes the diffusion pathways of oxygen and consequently enhances the oxidation resistance of the refractory.展开更多
The applications of Al alloy foam require consideration of potential damage risks,which are closely related to the evolution of its internal pore structures.However,conventional ex situ experimental observation cannot...The applications of Al alloy foam require consideration of potential damage risks,which are closely related to the evolution of its internal pore structures.However,conventional ex situ experimental observation cannot provide information on the structure evolution during deformation.In order to investigate the failure mechanism of Al alloy foam under quasi-static compression,by utilizing X-ray imaging technology,in situ CT image data were obtained during the loading process.A geometric model characterizing the real structure of Al alloy foam was reconstructed from the initial CT images and used for finite element simulation.Besides,based on the digital volume correlation(DVC)method,the displacement and strain fields of Al alloy foam were calculated.The results show that the in situ experimental observation based on X-ray imaging can effectively obtain the failure information of Al alloy foam.The simulation results for deformation and failure behavior of Al alloy foam are consistent with experimental results.During the quasi-static compression,a shear band can be observed diagonally across the profile of Al alloy foam,with weak regions occurring in the cells with larger volume and higher aspect ratios.Using these weak regions as boundaries,the relative displacement of cell structures on one side compared to another side was identified as the intrinsic cause of shear band formation.The high-strain regions identified by DVC closely match the crack locations on the cell walls,validating the accuracy of DVC on localizing cracks on cell walls and predicting their propagation trends.展开更多
According to the elastic-viscoelastic correspondence principle, an elastic microme- chanical framework taking the inclusion-matrix interface effect into account is extended for predicting viscoelastic properties of as...According to the elastic-viscoelastic correspondence principle, an elastic microme- chanical framework taking the inclusion-matrix interface effect into account is extended for predicting viscoelastic properties of asphalt mixture, which is simply treated as elastic coarse aggregate inclusions periodically and isotropically embedded in a viscoelastic asphalt mastic matrix. The Burgers model is adopted for characterizing the matrix mechanical behavior, so that the homogenized relaxation modulus of asphalt mixture in compression creep is derived. After a series of uniaxial compression creep tests are performed on asphalt mastic in different temperature and stress conditions in order to determine the matrix constitutive parameters, the framework presented is validated by comparison with the experiment, and then some predictions of uniaxial compression creep behavior of asphalt mixture in different temperature and stress conditions are given.展开更多
Circulating tumor cells(CTCs) are a population of tumor cells mediating metastasis, which results in most of the cancer related deaths. The number of CTCs in the peripheral blood of patients is rare, and many platform...Circulating tumor cells(CTCs) are a population of tumor cells mediating metastasis, which results in most of the cancer related deaths. The number of CTCs in the peripheral blood of patients is rare, and many platforms have been launched for detection and enrichment of CTCs. Enumeration of CTCs has already been used as a prognosis marker predicting the survival rate of cancer patients. Yet CTCs should be more potential. Studies on CTCs at single cell level may help revealing the underlying mechanism of tumorigenesis and metastasis. Though far from developed, this area of study holds much promise in providing new clinical application and deep understanding towards metastasis and cancer development.展开更多
Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs...Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs)with a thickness of 2−4 atomic layers were fabricated via vacuum freeze-drying and nitridation.Then,the h-BNNSs/reduced graphene oxide(rGO)composite were further prepared using a hydrothermal method.Due to the combination of two two-dimensional(2D)van der Waals-bonded materials,the as-prepared h-BNNSs/rGO electrode exhibited robustness to wide-temperature-range operations from−10 to 50℃.When the electrodes worked in a neutral aqueous electrolyte(1 M Na2SO4),they showed a great stable cycling performance with almost 107%reservation of the initial capacitance at 0℃ and 111% at 50℃ for 5000 charge−discharge cycles.展开更多
Biogas residue （BR） is widely used as a new green fertilizer in agriculture in China. However, it often contains a high concentration of heavy metals so its application should cause our concern. An incubation experi...Biogas residue （BR） is widely used as a new green fertilizer in agriculture in China. However, it often contains a high concentration of heavy metals so its application should cause our concern. An incubation experiment was conducted to study the risk of pig biogas residue （PBR） and chicken biogas residue （CBR） application on Liuminying soil （LS） and Yixing soil （YS）. The soils were incubated for one, three and six months with 0, 2%, 4% and 6% addition of BRs. According to BCR extraction results, the PBR and CBR applications induced an increase in the concentration of exchangeable fraction of Zn. As for the concentration of exchangeable fraction of Cu, an increase was only observed in the treatments with PBR application. The heavy metal binding intensity also showed a similar trend. With the PBR application, for the LS and YS, the highest concentrations of exchangeable Zn increased 3.6 and 9.5 times, respectively, while the exchangeable Cu was increased by 52.6% and 187.1%. Dissolved organic carbon was the limiting factor for the exchangeable Cu while the exchangeable Zn was controlled by soil pH. PBR presented more agricultural risk than CBR when used as fertilizer. Meanwhile, BRs were more adaptable to LS than YS according to the heavy metal release results.展开更多
Objective: Previous investigations of circulating tumor cells(CTCs) have mainly focused on their genomic or transcriptomic features, leaving their epigenetic landscape relatively uncharacterized. Here, we investigated...Objective: Previous investigations of circulating tumor cells(CTCs) have mainly focused on their genomic or transcriptomic features, leaving their epigenetic landscape relatively uncharacterized. Here, we investigated the genome-wide DNA methylome of CTCs with a view to understanding the epigenetic regulatory mechanisms underlying cancer metastasis.Methods: We evaluated single-cell DNA methylome and copy number alteration(CNA) in 196 single cells,including 107 CTCs collected from 17 cancer patients covering six different cancer types. Our single-cell bisulfite sequencing(sc BS-seq) covered on average 11.78% of all Cp G dinucleotides and accurately deduced the CNA patterns at 500 kb resolution.Results: We report distinct subclonal structures and different evolutionary histories of CTCs inferred from CNA and DNA methylation profiles. Furthermore, we demonstrate potential tumor origin classification based on the tissue-specific DNA methylation profiles of CTCs.Conclusions: Our work provides a comprehensive survey of genome-wide DNA methylome in single CTCs and reveals 5-methylcytosine(5-m C) heterogeneity in CTCs, addressing the potential epigenetic regulatory mechanisms underlying cancer metastasis and facilitating the future clinical application of CTCs.展开更多
As fixed compression ratio is used in traditional deep space exploration image transmission application,the same compression code rate is allocated to each image.However,since the information of each image in a space ...As fixed compression ratio is used in traditional deep space exploration image transmission application,the same compression code rate is allocated to each image.However,since the information of each image in a space observation mission is nonuniform,the image with more information will inevitably lead to more compression distortion than the image with less information.Obviously,it’s not an efficient way to transmit information in terms of data importance or overall distortion.Therefore,we proposed a combinatorial optimal bit rate allocation algorithm to improve the efficiency of image transmission in space application.Different from traditional method,the rate-distortion model of wavelet coefficients for each image in a transmission task was built,and under the overall maximum transmission rate constraint,an bit-rate optimal allocation was applied for each image to minimize the overall distortion of a batch of images.The proposed algorithm can be widely used in image compression algorithm with embedded code stream characteristics,such as JPEG2000 and SPIHT.Experimental results shows that in the range of 2.6 to 10 compression ratio,the algorithm can reduce image distortion MSB by 40%~64%at the same overall transmission code rate,which equivalent to improvement of PSNR 3 dB to 5.4 dB.展开更多
In this work,the removal of 2,4,6-tribromophenol(TBP)by ferric ion-activated sulfite[Fe(Ⅲ)/S(Ⅳ)]process was systematically investigated with determining the intermediate products and evaluating the influences of som...In this work,the removal of 2,4,6-tribromophenol(TBP)by ferric ion-activated sulfite[Fe(Ⅲ)/S(Ⅳ)]process was systematically investigated with determining the intermediate products and evaluating the influences of some operational conditions and water matrices.Our results show that batching addition of S(Ⅳ)benefits the S(Ⅳ)utilization efficiency and TBP removal,with SO_(4)^(-)being the primary reactive radical accounting for TBA degradation.The maximum TBP removal in the Fe(Ⅲ)/S(Ⅳ)process was observed at pH 4.0 and oxygen is essential in this process.With increasing Fe(Ⅲ)and S(Ⅳ)dosages from 0.05 and 0.1 mmol/L to 0.2 and 2.0 mmol/L,respectively,TBP removal followed trends of first increase then decrease.As the acute toxicity of the TBP solution was significantly reduced,the Fe(Ⅲ)/S(Ⅳ)process was believed to be a good choice in the treatment of TBP.展开更多
基金supported by the National Natural Science Foundation of China(41925009)National Key R&D Program of China(2022YFE0203800)+2 种基金the Ministry of Finance of the People’s Republic of China(YSBR-019)Science and Technology Innovation Team of Shaanxi Province(2024RS-CXTD-74)Xiaohong Wu was supported by the Key National Social Science Foundation of China(No.16ZDA144).
文摘Yunnan in southwest China is a geographically and ethnically complex region at the intersection of southern China and Southeast Asia,and a focal point for human migrations.To clarify its maternal genetic history,we generated 152 complete mitogenomes from 17 Yunnan archaeological sites.Our results reveal distinct genetic histories segregated by geographical regions.Maternal lineages of ancient populations from northwestern and northern Yunnan exhibit closer affinities with past and present-day populations from northern East Asia and Xizang,providing important genetic evidence for the migration and interaction of populations along the Tibetan-Yi corridor since the Neolithic.Between 5500 and 1800 years ago,central Yunnan populations maintained their internal genetic relationships,including a 7000-year-old basal lineage of the rare and widely dispersed haplogroup M61.At the Xingyi site,changes in mitochondrial DNA haplogroups occurred between the Late Neolithic and Bronze Age,with haplogroups shifting from those predominant in the Yellow River region to those predominant in coastal southern China.These results highlight the high diversity of Yunnan populations during the Neolithic to Bronze Age.
基金supported by the Youth Project of the Independent Subject of the State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology(Grant Nos.QNKT25-13 and QNKT24-02)the 76th batch of Project funded by China Postdoctoral Science Foundation(Grant No.2024M764116)+3 种基金the National Natural Science Foundation of China(Grant Nos.12002048,12072037,12102050,and 12202067)the Science and Technology Commission,China(Grant No.2019-jcjc-zd-011-00)the Project supported by the Open Funds of Kui Yuan Laboratory(Grant No.KY202431)the State Key Laboratory of Explosion Science and Safety Protection(Grant No.KFJJ25-21M)。
文摘Simple cubic black phosphorus(BP)has been recognized as a strategic material due to its exceptional structural stability under extreme conditions.In this investigation,simple cubic BP was successfully synthesized through shock-induced phase transformation,utilizing amorphous red phosphorus as the precursor material.The phase evolution process was systematically investigated using plane shock loading apparatus,with shock pressure and temperature parameters being precisely controlled to optimize transformation kinetics.Comprehensive phase characterization revealed the correlation between thermodynamic loading profiles and cubic BP formation efficiency.Precursor modification strategies were implemented through orthorhombic BP utilization,resulting in enhanced cubic phase yield and crystallinity.The synthesized cubic BP variants are considered promising candidates for advanced protective material systems,particularly where combinations of mechanical resilience and thermal stability are required under extreme operational conditions.This research provides critical insights into shock-induced phase transformation mechanics,while establishing foundational protocols for manufacturing non-equilibrium materials with potential applications in next-generation defensive technologies.
基金financially supported by the National Natural Science Foundations of China(No.12304037)the Interdisciplinary Intelligence Super Computer Center of BNUZH
文摘The metal triazole(MTA)-based MOFs were found to preferentially adsorb O-rich species,which had enhanced electrocatalytic oxygen reduction reactions(ORR)and stabilized the O-containing species during the discharge and charge processes in Li-O_(2)battery.However,the MOFs exhibited low electron conductivity and poor electron transfer interface in the electrocatalysis,limiting the electrocatalytic activity.To address this issue,a nanocomposite with the Co-MTA-coated carbon nano tubes(Co-MTA-C)was constructed,which formed the three-dimensional conductivity network connected with the intersecting carbon nano tube(CNT).In this composite,the electron-rich Co-MTA interacted with the highly conductive CNT,resulting in a charge redistribution.Optimized the electronic structure of the Co center through compositional modifications presented a high valence compared to the pure MOFs.In situ X-ray absorption spectroscopy revealed a direct reaction of Co sites with intermediates such as LiO_(x),leading to the formation of nanosheet array discharge products.The battery based on optimized CoMTA-C demonstrated fast kinetics and superior stability,with a low overpotential of 1.13 V,high specific capacity of 9057 mAh g^(-1),and long-term durability of 600 cycles.It provides a facile and effective strategy for enhancing the electrocatalytic performance through rational tuning of high-conductivity substances.
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.11872120,12102050)Key Laboratory of Explosion Science and Technology(Grant No.QNKT22-01).
文摘The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation products.To this end,this paper is based on the impedance matching method to test the ODD conditions of CL-20 type aluminium explosive particle velocity.Calculated the interfacial pressure of the shock wave in different media.Determined the characteristic parameters of the reaction zone of the detonation of CL-20 aluminized explosives.Calibrated the parameters of the JoneseWilkinseLee(JWL)+γ equation for the detonation products(DPs).Revealed the effect of different DPs equation of state(EOS)on the Hugoniot pressure of ODD.The results indicate that when the content of aluminum powder ranges from 0%to 30%,the duration of the ODD reaction zone and the width of the detonation reaction zone of the CL-20-based aluminized explosive are directly proportional to the content of aluminum powder.The width of the detonation reaction zone is increased by 1.97 times to 2.7 times compared to that of the reaction zone without the addition of aluminum powder.However,the energy release efficiency of the detonation reaction zone is inversely proportional to the content of aluminum powder.When the aluminum powder content was held constant,the incorporation of AP caused a 25%reduction in the energy release efficiency of the detonation reaction zone.Compared with existing ODD state equations,the JWL +γ equation is superior in calibrating overpressure Hugoniot data and the isentropic expansion in the C-J state.The deviation between calculated pressure results and experimental measurements is within 6%.
基金supported by the Natural Science Foundation of Henan Province(No.232300420329)Key Scientific Research Project of Colleges and Universities in Henan Province(Nos.23B430012,22A430028,and 25B430022)+2 种基金Henan Provincial Science and Technology Research Project(No.242102231064)National Natural Science Foundation of China(No.52202064)Luoyang Major Science and Technology Innovation Project(No.2301009A).
文摘β-Sialon has emerged as a promising material for enhancing the service life of Al_(2)O_(3)-C refractories due to its excellent physicochemical properties.The impact of varying concentrations of nanometer Al/Si alloy on the in-situ synthesis of β-Sialon within Al_(2)O_(3)-C refractory materials,as well as its oxidation behavior,was investigated.The findings indicate that the presence of Al/Si alloy promotes the formation of AlN and SiC whiskers at 1300℃,which subsequently facilitate the production of plate-like β-Sialon at 1500℃.Density functional theory analysis reveals that the(020)crystal plane of β-Sialon exhibits the lowest adsorption energy for Al2O and AlO molecules under the influence of iron atoms,suggesting a solid-liquid-vapor growth mechanism for β-Sialon formation.The introduction of these ceramic phases significantly enhances the mechanical properties of Al_(2)O_(3)-C refractories.Specifically,the addition of 6 wt.%Al/Si alloy yielded specimens with the highest cold modulus of rupture and cold crushing strength at 1500℃,achieving values of 35.2 and 127.5 MPa,respectively--representing increases of 40.1%and 37.4%.Furthermore,during high-temperature oxidation,the formation of plate-like β-Sialon leads to the development of a dense protective layer on the surface.This impedes the diffusion pathways of oxygen and consequently enhances the oxidation resistance of the refractory.
基金supported by the National Natural Science Foundation of China(Nos.12072105,11932006,and 52474388).
文摘The applications of Al alloy foam require consideration of potential damage risks,which are closely related to the evolution of its internal pore structures.However,conventional ex situ experimental observation cannot provide information on the structure evolution during deformation.In order to investigate the failure mechanism of Al alloy foam under quasi-static compression,by utilizing X-ray imaging technology,in situ CT image data were obtained during the loading process.A geometric model characterizing the real structure of Al alloy foam was reconstructed from the initial CT images and used for finite element simulation.Besides,based on the digital volume correlation(DVC)method,the displacement and strain fields of Al alloy foam were calculated.The results show that the in situ experimental observation based on X-ray imaging can effectively obtain the failure information of Al alloy foam.The simulation results for deformation and failure behavior of Al alloy foam are consistent with experimental results.During the quasi-static compression,a shear band can be observed diagonally across the profile of Al alloy foam,with weak regions occurring in the cells with larger volume and higher aspect ratios.Using these weak regions as boundaries,the relative displacement of cell structures on one side compared to another side was identified as the intrinsic cause of shear band formation.The high-strain regions identified by DVC closely match the crack locations on the cell walls,validating the accuracy of DVC on localizing cracks on cell walls and predicting their propagation trends.
基金supported by the National Natural Science Foundation of China(No.10872073)National Basic Research Program of China(Program 973:2011CB013800)
文摘According to the elastic-viscoelastic correspondence principle, an elastic microme- chanical framework taking the inclusion-matrix interface effect into account is extended for predicting viscoelastic properties of asphalt mixture, which is simply treated as elastic coarse aggregate inclusions periodically and isotropically embedded in a viscoelastic asphalt mastic matrix. The Burgers model is adopted for characterizing the matrix mechanical behavior, so that the homogenized relaxation modulus of asphalt mixture in compression creep is derived. After a series of uniaxial compression creep tests are performed on asphalt mastic in different temperature and stress conditions in order to determine the matrix constitutive parameters, the framework presented is validated by comparison with the experiment, and then some predictions of uniaxial compression creep behavior of asphalt mixture in different temperature and stress conditions are given.
文摘Circulating tumor cells(CTCs) are a population of tumor cells mediating metastasis, which results in most of the cancer related deaths. The number of CTCs in the peripheral blood of patients is rare, and many platforms have been launched for detection and enrichment of CTCs. Enumeration of CTCs has already been used as a prognosis marker predicting the survival rate of cancer patients. Yet CTCs should be more potential. Studies on CTCs at single cell level may help revealing the underlying mechanism of tumorigenesis and metastasis. Though far from developed, this area of study holds much promise in providing new clinical application and deep understanding towards metastasis and cancer development.
基金financially supported by the National Natural Science Foundation for Excellent Young Scholars of China (No. 51522402)the National Postdoctoral Program for Innovative Talents of China (No. BX20180034)+2 种基金the National Natural Science Foundation of China (No. 51902020)the Fundamental Research Funds for the Central Universities (No. FRF-TP-18-045A1)the China Postdoctoral Science Foundation (No. 2018M641192)
文摘Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs)with a thickness of 2−4 atomic layers were fabricated via vacuum freeze-drying and nitridation.Then,the h-BNNSs/reduced graphene oxide(rGO)composite were further prepared using a hydrothermal method.Due to the combination of two two-dimensional(2D)van der Waals-bonded materials,the as-prepared h-BNNSs/rGO electrode exhibited robustness to wide-temperature-range operations from−10 to 50℃.When the electrodes worked in a neutral aqueous electrolyte(1 M Na2SO4),they showed a great stable cycling performance with almost 107%reservation of the initial capacitance at 0℃ and 111% at 50℃ for 5000 charge−discharge cycles.
基金supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(No. XMXX280724)
文摘Biogas residue （BR） is widely used as a new green fertilizer in agriculture in China. However, it often contains a high concentration of heavy metals so its application should cause our concern. An incubation experiment was conducted to study the risk of pig biogas residue （PBR） and chicken biogas residue （CBR） application on Liuminying soil （LS） and Yixing soil （YS）. The soils were incubated for one, three and six months with 0, 2%, 4% and 6% addition of BRs. According to BCR extraction results, the PBR and CBR applications induced an increase in the concentration of exchangeable fraction of Zn. As for the concentration of exchangeable fraction of Cu, an increase was only observed in the treatments with PBR application. The heavy metal binding intensity also showed a similar trend. With the PBR application, for the LS and YS, the highest concentrations of exchangeable Zn increased 3.6 and 9.5 times, respectively, while the exchangeable Cu was increased by 52.6% and 187.1%. Dissolved organic carbon was the limiting factor for the exchangeable Cu while the exchangeable Zn was controlled by soil pH. PBR presented more agricultural risk than CBR when used as fertilizer. Meanwhile, BRs were more adaptable to LS than YS according to the heavy metal release results.
基金financially supported by the Guangdong Province Key Research and Development Program (No. 2019B020226002)the National Science and Technology Major Project (No. 2019YFC1315702)。
文摘Objective: Previous investigations of circulating tumor cells(CTCs) have mainly focused on their genomic or transcriptomic features, leaving their epigenetic landscape relatively uncharacterized. Here, we investigated the genome-wide DNA methylome of CTCs with a view to understanding the epigenetic regulatory mechanisms underlying cancer metastasis.Methods: We evaluated single-cell DNA methylome and copy number alteration(CNA) in 196 single cells,including 107 CTCs collected from 17 cancer patients covering six different cancer types. Our single-cell bisulfite sequencing(sc BS-seq) covered on average 11.78% of all Cp G dinucleotides and accurately deduced the CNA patterns at 500 kb resolution.Results: We report distinct subclonal structures and different evolutionary histories of CTCs inferred from CNA and DNA methylation profiles. Furthermore, we demonstrate potential tumor origin classification based on the tissue-specific DNA methylation profiles of CTCs.Conclusions: Our work provides a comprehensive survey of genome-wide DNA methylome in single CTCs and reveals 5-methylcytosine(5-m C) heterogeneity in CTCs, addressing the potential epigenetic regulatory mechanisms underlying cancer metastasis and facilitating the future clinical application of CTCs.
文摘As fixed compression ratio is used in traditional deep space exploration image transmission application,the same compression code rate is allocated to each image.However,since the information of each image in a space observation mission is nonuniform,the image with more information will inevitably lead to more compression distortion than the image with less information.Obviously,it’s not an efficient way to transmit information in terms of data importance or overall distortion.Therefore,we proposed a combinatorial optimal bit rate allocation algorithm to improve the efficiency of image transmission in space application.Different from traditional method,the rate-distortion model of wavelet coefficients for each image in a transmission task was built,and under the overall maximum transmission rate constraint,an bit-rate optimal allocation was applied for each image to minimize the overall distortion of a batch of images.The proposed algorithm can be widely used in image compression algorithm with embedded code stream characteristics,such as JPEG2000 and SPIHT.Experimental results shows that in the range of 2.6 to 10 compression ratio,the algorithm can reduce image distortion MSB by 40%~64%at the same overall transmission code rate,which equivalent to improvement of PSNR 3 dB to 5.4 dB.
基金The support by the National Natural Science Foundation of China(No.51878308)the Young Top-notch Talent Cultivation Program of Hubei Province。
文摘In this work,the removal of 2,4,6-tribromophenol(TBP)by ferric ion-activated sulfite[Fe(Ⅲ)/S(Ⅳ)]process was systematically investigated with determining the intermediate products and evaluating the influences of some operational conditions and water matrices.Our results show that batching addition of S(Ⅳ)benefits the S(Ⅳ)utilization efficiency and TBP removal,with SO_(4)^(-)being the primary reactive radical accounting for TBA degradation.The maximum TBP removal in the Fe(Ⅲ)/S(Ⅳ)process was observed at pH 4.0 and oxygen is essential in this process.With increasing Fe(Ⅲ)and S(Ⅳ)dosages from 0.05 and 0.1 mmol/L to 0.2 and 2.0 mmol/L,respectively,TBP removal followed trends of first increase then decrease.As the acute toxicity of the TBP solution was significantly reduced,the Fe(Ⅲ)/S(Ⅳ)process was believed to be a good choice in the treatment of TBP.
