This study aimed to investigate the microstructure and mechanical properties of TixZrVNb(x=1,1.5,2)refractory high-entropy alloys at room and elevated temperatures.The TiZrVNb alloy consisted of the body-centered cubi...This study aimed to investigate the microstructure and mechanical properties of TixZrVNb(x=1,1.5,2)refractory high-entropy alloys at room and elevated temperatures.The TiZrVNb alloy consisted of the body-centered cubic(bcc)matrix with a small amount of V2Zr phase.The Ti1.5ZrVNb and Ti2ZrVNb alloys exhibited a single-phase bcc structure.At room temperature,the tensile ductility of the as-cast alloys increased from 3.5%to 12.3%with the increase in the Ti content.The TixZrVNb alloys exhibited high yield strength at 600°C,and the ultimate yield strength was more than 900 MPa.Softening occurred at 800°C,but the ultimate yield strength could still exceed 200 MPa.Moreover,the TixZrVNb alloys displayed low densities but high specific yield strengths(SYSs).The lowest density of TixZrVNb alloys was only 6.12 g/cm^3,but the SYS could reach about 180 MPa·cm^3·g^−1,which is better than those of most reported high-entropy alloys(HEAs).展开更多
AIM： To study the postoperative complications in patients with preoperative portal vein thrombosis （PVT） undergoing liver transplantation （LT） and to evaluate the complications with Doppler ultrasonography.METHOD...AIM： To study the postoperative complications in patients with preoperative portal vein thrombosis （PVT） undergoing liver transplantation （LT） and to evaluate the complications with Doppler ultrasonography.METHODS： Retrospective studies were performed on 284 patients undergoing LT （286 LT） with respect to pre- and postoperative clinical data and Doppler ultrasonography. According to the presence and grade of preoperative PVT, 286 LTs were divided into three groups： complete PVT （c-PVT）, partial PVT （p-PVT） and non-PVT, with 22, 30 and 234 LTs, respectively. Analyses were carried out to compare the incidence of early postoperative complications.RESULTS： PVT, inferior vena cava （IVC） thrombosis, hepatic artery thrombosis （HAT） and biliary complications were found postoperatively. All complications were detected by routine Doppler ultrasonography and diagnoses made by ultrasound were confirmed by clinical data or/and other imaging studies. Nine out of 286 LTs had postoperative PVT. The incidence of the c-Pv-r group was 22.7%, which was higher than that of the p-Pv-r group （3.3%, P 〈 0.05） and non- PVT group （1.3%, P 〈 0.005）. No difference was found between the p-PVT and non-PVT groups （P 〉 0.25）. Of the 9 cases with postoperative PVT, recanalizations were achieved in 7 cases after anticoagulation under the guidance of ultrasound, 1 case received portal vein thrombectomy and 1 case died of acute injection. Ten LTs had postoperative 1VC thrombosis. The c-PVT group had a higher incidence of IVC thrombosis than the non- PVT group （9.1% vs 2.6%, P 〈 0.05）; no significant difference was found between either the c-PV-T and p-PVT groups （9.1% vs 6.7%, P 〉 0.5） or between the p-PVT and non-PVT groups （P 〉 0.25）. Nine cases with IVC thrombosis were cured by anticoagulation under the guidance of ultrasound, and 1 case gained natural cure without any medical treatment after 2 mo. HAT was found in 2 non-PVT cases, giving a rate of 0.7% among 286 LTs. Bilia展开更多
A series of Ti2ZrHf0.5VNbx( x = 0, 0.25, 0.5, 0.75 and 1.0) refractory high-entropy alloys were prepared to investigate the alloying effect of Nb on the microstructures and mechanical properties.All the alloys display...A series of Ti2ZrHf0.5VNbx( x = 0, 0.25, 0.5, 0.75 and 1.0) refractory high-entropy alloys were prepared to investigate the alloying effect of Nb on the microstructures and mechanical properties.All the alloys displayed a simple BCC structure.The microstructures of the alloys changed from the initial single-phase columnar structure( x = 0) to dendrite microstructure( x > 0).At room temperature, all the alloys exhibited high ductility(with the compressive strains of more than 50%).With the increase in Nb content, the yield strength slightly decreased from 1160 to 980 MPa and the hardness dropped from 338 to 310 HV.Moreover, the alloys exhibited low density from 6.47 to 6.84 g/cm3 and high specific yield strength(SYS) from 143 to 179 kPa m3/kg.The comprehensive performance of ductility and SYS was superior to most of the reported highentropy alloys.The yield strength of the alloys increased from 405 to 859 MPa and from 85 to 195 MPa with the addition of Nb element at 873 K and 1073 K, respectively.展开更多
Alloying is one of the most effective means to confer superior properties to metal materials.For far too long,conventional W-based alloys were generally improved by the addition of minor elements.The exploitation of c...Alloying is one of the most effective means to confer superior properties to metal materials.For far too long,conventional W-based alloys were generally improved by the addition of minor elements.The exploitation of conventional W-based alloy is restricted to the corner of multielement phase diagrams with tiny compositional space.High-entropy alloys(HEAs)are a novel kind of alloys consisting of multi-principal alloying elements(usually more than 4)and have attracted increasing attention,since they were first reported in 2004.The emergence of HEAs filled the gap of the unexplored central region of multielement phase diagrams.Among them,tungsten-containing HEAs(TCHEAs)exhibit excellent mechanical properties,especially at extraordinarily elevated temperatures.Moreover,recent studies showed that TCHEAs had outstanding irradiation resistance properties.TCHEAs might serve as a promising candidate for plasma-facing materials in the fusion reactor.Many characteristics of TCHEAs are different from other HEAs due to the addition of tungsten with ultrahigh-melting temperature.Here,this paper aimed to introduce the manufacturing routes of TCHEAs;review the phase selection,mechanical properties,and irradiation resistance properties of TCHEAs;and propose the future prospects of TCHEAs.展开更多
AIM： To investigate the immunogenidty of a novel DNA vacoine, pSW3891/HBc, based on HBV core gene in Balb/c mice. METHODS： A novel DNA vaccine, pSW3891/HBc, encoding HBV core gene was constructed using a vector plas...AIM： To investigate the immunogenidty of a novel DNA vacoine, pSW3891/HBc, based on HBV core gene in Balb/c mice. METHODS： A novel DNA vaccine, pSW3891/HBc, encoding HBV core gene was constructed using a vector plasmid pSW3891. Balb/c mice were immunized with either pSW3891/HBc or empty vector DNA via gene gun. IgG anti-HBc responses in mouse sera were demonstrated by ELISA. Specific cytotoxicity of cytotoxic T lymphocytes （CTLs） of mice was quantitatively measured by lactate dehydrogenase release assay. RESULTS： HBcAg was expressed effectively in 293T cell line transiently transfected with pSW3891/HBc. Strong IgG anti-HBc responses were elicited in mice immunized with pSW3891/HBc. The end-point titers of anti-HBc reached the highest 1：97 200, 4 wk after the third immunization. The specific CTL killing with the highest specific lysis reached 73.25% at effector：target ratio of 20：1 in mice that received pSW3891/HBc DNA vaccine. CONCLUSION： pSW3891/HBc vaccination elicits specific anti-HBc response and induces HBc-specific CTL response in immunized Balb/c mice.展开更多
We designed a novel Co-free AlCrFe2Ni2Ti0.5 high-entropy alloy(HEA)that features an excellent combination of strength and ductility in this study.The as-cast AlCrFe2Ni2Ti0.5 alloy showed equiaxed grains undergoing spi...We designed a novel Co-free AlCrFe2Ni2Ti0.5 high-entropy alloy(HEA)that features an excellent combination of strength and ductility in this study.The as-cast AlCrFe2Ni2Ti0.5 alloy showed equiaxed grains undergoing spinodal decomposition,which consisted of ultrafine-grained laminated body-centered cubic(bcc)phases and an ordered body-centered cubic(b2)phase,and some precipitates embedded in the b2 matrix.The bcc and b2 phases also feature a coherent interface.This unique structure impedes mobile dislocations and hinders the formation of cracks,thereby giving the AlCrFe2Ni2Ti0.5 HEA both high strength and plasticity.At room temperature,the as-cast AlCrFe2Ni2Ti0.5 alloy exhibited a compressive yield strength of 1714 MPa,an ultimate strength of 3307 MPa,and an elongation of 43%.These mechanical properties are superior to those of most reported HEAs.展开更多
The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-b...The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.展开更多
Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring,exhaled breath diagnosis,and food freshness analys...Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring,exhaled breath diagnosis,and food freshness analysis.Among various chemiresistive sensing materials,noble metal-decorated semiconducting metal oxides(SMOs)have currently aroused extensive attention by virtue of the unique electronic and catalytic properties of noble metals.This review highlights the research progress on the designs and applications of different noble metal-decorated SMOs with diverse nanostructures(e.g.,nanoparticles,nanowires,nanorods,nanosheets,nanoflowers,and microspheres)for high-performance gas sensors with higher response,faster response/recovery speed,lower operating temperature,and ultra-low detection limits.The key topics include Pt,Pd,Au,other noble metals(e.g.,Ag,Ru,and Rh.),and bimetals-decorated SMOs containing ZnO,SnO_(2),WO_(3),other SMOs(e.g.,In_(2)O_(3),Fe_(2)O_(3),and CuO),and heterostructured SMOs.In addition to conventional devices,the innovative applications like photo-assisted room temperature gas sensors and mechanically flexible smart wearable devices are also discussed.Moreover,the relevant mechanisms for the sensing performance improvement caused by noble metal decoration,including the electronic sensitization effect and the chemical sensitization effect,have also been summarized in detail.Finally,major challenges and future perspectives towards noble metal-decorated SMOs-based chemiresistive gas sensors are proposed.展开更多
基金the National Magnetic Confinement Fusion Energy R&D Program(No.2018YFE0312400)the National Natural Science Foundation of China(Nos.51822402 and 51671044)+3 种基金the National Key Research and Development Program of China(Nos.019YFA0209901 and 2018YFA0702901)the Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University(Grant No.SKLSP201902)the Liaoning Revitalization Talents Program(No.XLYC1807047)the Fund of Science and Technology on Reactor Fuel and Materials Laboratory(No.STRFML-2020-04).
文摘This study aimed to investigate the microstructure and mechanical properties of TixZrVNb(x=1,1.5,2)refractory high-entropy alloys at room and elevated temperatures.The TiZrVNb alloy consisted of the body-centered cubic(bcc)matrix with a small amount of V2Zr phase.The Ti1.5ZrVNb and Ti2ZrVNb alloys exhibited a single-phase bcc structure.At room temperature,the tensile ductility of the as-cast alloys increased from 3.5%to 12.3%with the increase in the Ti content.The TixZrVNb alloys exhibited high yield strength at 600°C,and the ultimate yield strength was more than 900 MPa.Softening occurred at 800°C,but the ultimate yield strength could still exceed 200 MPa.Moreover,the TixZrVNb alloys displayed low densities but high specific yield strengths(SYSs).The lowest density of TixZrVNb alloys was only 6.12 g/cm^3,but the SYS could reach about 180 MPa·cm^3·g^−1,which is better than those of most reported high-entropy alloys(HEAs).
文摘AIM： To study the postoperative complications in patients with preoperative portal vein thrombosis （PVT） undergoing liver transplantation （LT） and to evaluate the complications with Doppler ultrasonography.METHODS： Retrospective studies were performed on 284 patients undergoing LT （286 LT） with respect to pre- and postoperative clinical data and Doppler ultrasonography. According to the presence and grade of preoperative PVT, 286 LTs were divided into three groups： complete PVT （c-PVT）, partial PVT （p-PVT） and non-PVT, with 22, 30 and 234 LTs, respectively. Analyses were carried out to compare the incidence of early postoperative complications.RESULTS： PVT, inferior vena cava （IVC） thrombosis, hepatic artery thrombosis （HAT） and biliary complications were found postoperatively. All complications were detected by routine Doppler ultrasonography and diagnoses made by ultrasound were confirmed by clinical data or/and other imaging studies. Nine out of 286 LTs had postoperative PVT. The incidence of the c-Pv-r group was 22.7%, which was higher than that of the p-Pv-r group （3.3%, P 〈 0.05） and non- PVT group （1.3%, P 〈 0.005）. No difference was found between the p-PVT and non-PVT groups （P 〉 0.25）. Of the 9 cases with postoperative PVT, recanalizations were achieved in 7 cases after anticoagulation under the guidance of ultrasound, 1 case received portal vein thrombectomy and 1 case died of acute injection. Ten LTs had postoperative 1VC thrombosis. The c-PVT group had a higher incidence of IVC thrombosis than the non- PVT group （9.1% vs 2.6%, P 〈 0.05）; no significant difference was found between either the c-PV-T and p-PVT groups （9.1% vs 6.7%, P 〉 0.5） or between the p-PVT and non-PVT groups （P 〉 0.25）. Nine cases with IVC thrombosis were cured by anticoagulation under the guidance of ultrasound, and 1 case gained natural cure without any medical treatment after 2 mo. HAT was found in 2 non-PVT cases, giving a rate of 0.7% among 286 LTs. Bilia
基金supported financially by the National Natural Science Foundation of China (Nos.51671044, 51822402 and 51574058)the Dalian Support Plan for Innovation of High-level Talents (Top and Leading Talents, No.2015R013)+1 种基金the Fundamental Research Funds for the Central Universities (No.DUT16ZD206)the Dalian Support Plan for Innovation of Highlevel Talents (Youth Technology Stars, No.2016RQ005)
文摘A series of Ti2ZrHf0.5VNbx( x = 0, 0.25, 0.5, 0.75 and 1.0) refractory high-entropy alloys were prepared to investigate the alloying effect of Nb on the microstructures and mechanical properties.All the alloys displayed a simple BCC structure.The microstructures of the alloys changed from the initial single-phase columnar structure( x = 0) to dendrite microstructure( x > 0).At room temperature, all the alloys exhibited high ductility(with the compressive strains of more than 50%).With the increase in Nb content, the yield strength slightly decreased from 1160 to 980 MPa and the hardness dropped from 338 to 310 HV.Moreover, the alloys exhibited low density from 6.47 to 6.84 g/cm3 and high specific yield strength(SYS) from 143 to 179 kPa m3/kg.The comprehensive performance of ductility and SYS was superior to most of the reported highentropy alloys.The yield strength of the alloys increased from 405 to 859 MPa and from 85 to 195 MPa with the addition of Nb element at 873 K and 1073 K, respectively.
基金financially supported by National MCF Energy Research and Development Program(Grant No.2018YFE0312400)National Natural Science Foundation of China(Grant Nos.51822402 and 51671044)+3 种基金National Key Research and Development Program of China(Grant Nos.2019YFA0209901 and 2018YFA0702901)Liao Ning Revitalization Talents Program(Grant No.XLYC1807047)Fund of Science and Technology on Reactor Fuel and Materials Laboratory(Grant No.6142A06190304)Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University(Grant No.SKLSP201902)
文摘Alloying is one of the most effective means to confer superior properties to metal materials.For far too long,conventional W-based alloys were generally improved by the addition of minor elements.The exploitation of conventional W-based alloy is restricted to the corner of multielement phase diagrams with tiny compositional space.High-entropy alloys(HEAs)are a novel kind of alloys consisting of multi-principal alloying elements(usually more than 4)and have attracted increasing attention,since they were first reported in 2004.The emergence of HEAs filled the gap of the unexplored central region of multielement phase diagrams.Among them,tungsten-containing HEAs(TCHEAs)exhibit excellent mechanical properties,especially at extraordinarily elevated temperatures.Moreover,recent studies showed that TCHEAs had outstanding irradiation resistance properties.TCHEAs might serve as a promising candidate for plasma-facing materials in the fusion reactor.Many characteristics of TCHEAs are different from other HEAs due to the addition of tungsten with ultrahigh-melting temperature.Here,this paper aimed to introduce the manufacturing routes of TCHEAs;review the phase selection,mechanical properties,and irradiation resistance properties of TCHEAs;and propose the future prospects of TCHEAs.
基金Supported by the 135 Project of Jiangsu Province, No. 044
文摘AIM： To investigate the immunogenidty of a novel DNA vacoine, pSW3891/HBc, based on HBV core gene in Balb/c mice. METHODS： A novel DNA vaccine, pSW3891/HBc, encoding HBV core gene was constructed using a vector plasmid pSW3891. Balb/c mice were immunized with either pSW3891/HBc or empty vector DNA via gene gun. IgG anti-HBc responses in mouse sera were demonstrated by ELISA. Specific cytotoxicity of cytotoxic T lymphocytes （CTLs） of mice was quantitatively measured by lactate dehydrogenase release assay. RESULTS： HBcAg was expressed effectively in 293T cell line transiently transfected with pSW3891/HBc. Strong IgG anti-HBc responses were elicited in mice immunized with pSW3891/HBc. The end-point titers of anti-HBc reached the highest 1：97 200, 4 wk after the third immunization. The specific CTL killing with the highest specific lysis reached 73.25% at effector：target ratio of 20：1 in mice that received pSW3891/HBc DNA vaccine. CONCLUSION： pSW3891/HBc vaccination elicits specific anti-HBc response and induces HBc-specific CTL response in immunized Balb/c mice.
基金the National Key Research and Development Program of China(No.2017YFA0403803)the National Natural Science Foundation of China(Nos.51525401,51774065,51601028,and 51690163).
文摘We designed a novel Co-free AlCrFe2Ni2Ti0.5 high-entropy alloy(HEA)that features an excellent combination of strength and ductility in this study.The as-cast AlCrFe2Ni2Ti0.5 alloy showed equiaxed grains undergoing spinodal decomposition,which consisted of ultrafine-grained laminated body-centered cubic(bcc)phases and an ordered body-centered cubic(b2)phase,and some precipitates embedded in the b2 matrix.The bcc and b2 phases also feature a coherent interface.This unique structure impedes mobile dislocations and hinders the formation of cracks,thereby giving the AlCrFe2Ni2Ti0.5 HEA both high strength and plasticity.At room temperature,the as-cast AlCrFe2Ni2Ti0.5 alloy exhibited a compressive yield strength of 1714 MPa,an ultimate strength of 3307 MPa,and an elongation of 43%.These mechanical properties are superior to those of most reported HEAs.
基金Supported by National Natural Science Foundation of China(Nos.U2067205 and 12205098)National Key Laboratory of Computational Physics(HX02021-35).
文摘The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.
基金supported by the National Key R&D Program of China(No.2020YFB2008604,2021YFB3202500)the National Natural Science Foundation of China(No.61874034)the International Science and Technology Cooperation Program of Shanghai Science and Technology Innovation Action Plan(No.21520713300)。
文摘Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring,exhaled breath diagnosis,and food freshness analysis.Among various chemiresistive sensing materials,noble metal-decorated semiconducting metal oxides(SMOs)have currently aroused extensive attention by virtue of the unique electronic and catalytic properties of noble metals.This review highlights the research progress on the designs and applications of different noble metal-decorated SMOs with diverse nanostructures(e.g.,nanoparticles,nanowires,nanorods,nanosheets,nanoflowers,and microspheres)for high-performance gas sensors with higher response,faster response/recovery speed,lower operating temperature,and ultra-low detection limits.The key topics include Pt,Pd,Au,other noble metals(e.g.,Ag,Ru,and Rh.),and bimetals-decorated SMOs containing ZnO,SnO_(2),WO_(3),other SMOs(e.g.,In_(2)O_(3),Fe_(2)O_(3),and CuO),and heterostructured SMOs.In addition to conventional devices,the innovative applications like photo-assisted room temperature gas sensors and mechanically flexible smart wearable devices are also discussed.Moreover,the relevant mechanisms for the sensing performance improvement caused by noble metal decoration,including the electronic sensitization effect and the chemical sensitization effect,have also been summarized in detail.Finally,major challenges and future perspectives towards noble metal-decorated SMOs-based chemiresistive gas sensors are proposed.
