In the Temperature-Pressure phase diagram, the quasi-one-dimensional conductor, HMTSF-TCNQ, the ground state at ambient pressure is an insulator of charge density wave (CDW) below 30 K, while it shows a good metallic ...In the Temperature-Pressure phase diagram, the quasi-one-dimensional conductor, HMTSF-TCNQ, the ground state at ambient pressure is an insulator of charge density wave (CDW) below 30 K, while it shows a good metallic nature at higher temperature. The CDW insulating state is suppressed by a pressure of 1 GPa, which is considered to be a quantum critical point. Neither at 0 - 0.5 nor 2 GPa but only around this critical point in pressure, field-induced phases appear from 0.2 T through 10 T, where Rxy is almost constant and Rxx is very low. These phenomena are achieved when the magnetic field is applied along the least conducting axis. The behaviors are consistent with a kind of Quantum Hall Effect (QHE). The field-induce phase accompanied by the QHE might be the field-induced CDW (FICDW) similar to that of FISDW, observed in (TMTSF)2X salts. This paper presents the latest result of the Hall effects reviewing the history of the authors’ work on this material from preliminary to the latest ones.展开更多
The effect of an external magnetic field on the structural and magnetic properties of bond frustrated ZnCr2 Se4 at low temperatures is investigated using magnetization, dielectric constants and thermal conductivity ex...The effect of an external magnetic field on the structural and magnetic properties of bond frustrated ZnCr2 Se4 at low temperatures is investigated using magnetization, dielectric constants and thermal conductivity experiments. With an increase in the magnetic field H, the antiferromagnetic transition temperature TN is observed to shift progressively toward lower temperatures. The corresponding high temperature cubic （Fd3m） to low temperature tetragonal （I41amd） structural transition is tuned simultaneously due to the inherent strong spin-lattice coupling. In the antiferromagnetic phase, an anomaly at Hc2 defined as a steep downward peak in the derivative of the M-H curve is dearly drawn. It is found that TN versus H and Hc2 versus T exhibit a consistent tendency, indicative of a field-induced tetragonal （I41amd） to cubic （Fd3m） structural transition. The transition is further substantiated by the field-dependent dielectric constant and thermal conductivity measurements. We modify the T-H phase diagram, highlighting the coexistence of the paramagnetic state and ferromagnetic clusters between 100K and TN.展开更多
Thermoelectric coolers utilizing the Peltier effect have dominated the field of solid-state cooling but their efficiency is hindered by material limitations.Alternative routes based on the Thomson and Nernst effects o...Thermoelectric coolers utilizing the Peltier effect have dominated the field of solid-state cooling but their efficiency is hindered by material limitations.Alternative routes based on the Thomson and Nernst effects offer new possibilities.Here,we present a comprehensive investigation of the thermoelectric properties of 1T-TiSe_(2),focusing on these effects around the charge density wave transition(≈200 K).The abrupt Fermi surface reconstruction associated with this transition leads to an exceptional peak in the Thomson coefficient of 450μVK^(-1) at 184 K,surpassing the Seebeck coefficient.Furthermore,1T-TiSe_(2) exhibits a remarkably broad temperature range(170-400 K)with a Thomson coefficient exceeding 190μV K^(-1),a characteristic highly desirable for the development of practical Thomson coolers with extended operational ranges.Additionally,the Nernst coefficient exhibits an unusual temperature dependence,increasing with temperature in the normal phase,which we attribute to bipolar conduction effects.The combination of solid-solid pure electronic phase transition to a semimetallic phase with bipolar transport is identified as responsible for the unusual Nernst trend and the unusually large Thomson coefficient over a broad temperature range.展开更多
Bio-carbonation of reactive MgO has been regarded as a promising and eco-friendly method for construction and demolition waste(CDW)cementation in various geotechnical engineering applications.However,the beneficial ef...Bio-carbonation of reactive MgO has been regarded as a promising and eco-friendly method for construction and demolition waste(CDW)cementation in various geotechnical engineering applications.However,the beneficial effect of bio-carbonation of reactive MgO cemented CDW(BCM-samples)can be altered when exposed to wetting-drying cycles induced by extreme climate changes or groundwater fluctuations.To better understand the durability of BCM-samples and their underlying deterioration mechanisms,a series of BCM-samples was prepared to investigate their physical-mechanical performance and microstructure evolution subjected to the wetting-drying cycles.The results indicated that the wetting-drying cycles can deteriorate the BCM-samples,and their physical-mechanical behaviors change quickly at the cycle beginning and then smoothly after 2 cycles.With the increase in cycling,the apparent deterioration with efflorescence and microcrack development can be observed.The mass loss and water absorption rates increased while the dry density,compressional wave velocity,and unconfined compression strength decreased.Urea pre-hydrolysis treatment can significantly improve the durability of BCM-samples,as the more hydrated magnesia carbonates(HMCs)enhance the cementing effects.After 10 cycles,the UCS of pre-hydrolyzed samples decreased 25.4%to 4.45 MPa,while that of ordinary samples decreased 50.7%to 1.20 MPa.The deterioration of BCM-samples caused by wetting-drying cycles can be attributed to two factors.One of the main factors is the structural integrity changes caused by the rapid loss of soluble material at the initial cycling stages.Another factor is the decrease in cementation induced by the loss of brucite and HMCs at the following cycle stages.展开更多
目的:探讨CDw75(cluster of differentiation antigen 75)在大肠癌组织中的表达及其和大肠癌浸润、转移和TNM分期等病理特征之间的关系。方法:采用免疫组化SP法检测CDw75抗原在61例大肠癌组织和30例相应正常大肠黏膜组织中的表达,计算...目的:探讨CDw75(cluster of differentiation antigen 75)在大肠癌组织中的表达及其和大肠癌浸润、转移和TNM分期等病理特征之间的关系。方法:采用免疫组化SP法检测CDw75抗原在61例大肠癌组织和30例相应正常大肠黏膜组织中的表达,计算阳性细胞的百分率。结果:CDw75在30例正常大肠黏膜中均阴性表达,在61例大肠癌组织中有30例阳性表达。CDw75表达阳性多见于肿瘤直径≥5cm、浸润深度较深、伴淋巴结转移和远处转移及TNMⅢ+Ⅳ期的大肠癌。结论:大肠癌组织中CDw75抗原的表达可作为大肠黏膜恶性转化的一个标志物,并可能用于判断大肠癌的恶性生物学行为。展开更多
Worldwide construction and demolition waste (CDW) is currently dumped. To close the building cycle and the building materials cycle by recycling CDW in high technical applications, the technical quality of stony mater...Worldwide construction and demolition waste (CDW) is currently dumped. To close the building cycle and the building materials cycle by recycling CDW in high technical applications, the technical quality of stony materials must be improved. For this purpose, concrete rubbles and brick rubbles, the two major stony constituents of CDW, should be separated from each other. Based on the differences in density and content of Fe-2O-3 between the two materials, a wet method of jigging and a dry method of magnetic separation are effective,tested.展开更多
The operation of reinforced concrete structures is directly associated with the adhesion between the steel bar and the concrete,which allows the internal forces to be transferred to the reinforcement during the ...The operation of reinforced concrete structures is directly associated with the adhesion between the steel bar and the concrete,which allows the internal forces to be transferred to the reinforcement during the process of loading the structural elements.The modification of the concrete composition,with the introduction of recycled aggregate from construction and demolition waste(CDW),affects the steel-concrete interface and can modify the bonding stress,which is also influenced by the type and diameter of the bar used.In this work,the influence of the recycled fine aggregate(RFA)and types of steel bar on the steel-concrete bond was experimentally evaluated using the pullout test.Conventional concrete and recycled concrete,with RFA replacement level of 25%,were produced.Two types of steel rebars(i.e.,plain and deformed)with diameters of 10.0 and 16.0 mm were considered in this paper.The results indicate a reduction in the adhesion stress with the introduction of recycled aggregate,but this trend is influenced by the diameter of the bar used.The use of ribbed bars modifies the stress bon-slip behavior,with an increase in the average bond strength,which is also observed with the reduction of the diameter of the bar.展开更多
We reference the tunneling Hamiltonian to have particle tunneling among different states represented as wave-functions. Our problem applies wave-functionals to a driven sine-Gordon system. We apply the tunneling Hamil...We reference the tunneling Hamiltonian to have particle tunneling among different states represented as wave-functions. Our problem applies wave-functionals to a driven sine-Gordon system. We apply the tunneling Hamiltonian to charge density wave (CDW) transport problems where we consider tunneling among states that are wave-functionals of a scalar quantum field, i.e. derived I-E curves that match Zenier curves used to fit data experimentally with wave-functionals congruent with the false vacuum hypothesis. The open question is whether the coefficients picked in both wave-functionals and the magnitude of the coefficients of the driven sine-Gordon physical system are picked by topological charge arguments that appear to assign values consistent with the false vacuum hypothesis. Crucial results by Fred Cooper et al. allow a mature quantum foam interpretation of false vacuum nucleation for further refinement of our wave-functional results. In doing so, we give credence to topological arguments as a first order phase transition in CDW I-E curves.展开更多
As a crucial component of the Earth’s climate system,Antarctic sea ice has demonstrated significant variability over the satellite era.Here,we identify a remarkable decadal transition in the total Antarctic Sea Ice E...As a crucial component of the Earth’s climate system,Antarctic sea ice has demonstrated significant variability over the satellite era.Here,we identify a remarkable decadal transition in the total Antarctic Sea Ice Extent(SIE).The stage from 1979 to 2006 is characterized by high-frequency(i.e.,seasonal to interannual)temporal variability in SIE and zonal asymmetry in Sea Ice Concentration(SIC),which is primarily under the control of the Amundsen Sea Low(ASL).After 2007,however,sea ice changes exhibit a more spatially homogeneous pattern in SIC and a more temporally long-lasting mode in SIE.Further analysis reveals that sea ice-ocean interaction plays a major role in the low-frequency(i.e.,multiannual)variability of Antarctic sea ice from 2007−22.The related physical process is inferred to manifest as a strong coupling between the surface and the subsurface ocean layers,involving enhanced vertical convection and the downward delivery of the surface anomalies related to ice melting and freezing processes,thus maintaining the SIE anomalies for a longer time.Furthermore,this process mainly occurs in the Amundsen-Bellingshausen Sea(ABS)sector,and the weakened subsurface ocean stratification is the key factor triggering the coupling process in this region.We find that the Circumpolar Deep Water(CDW)over the ABS sector continued to shoal before 2007 and remained stable thereafter.It is speculated that the shoaling of the CDW may be a possible driver leading to the weakening of the subsurface stratification.展开更多
Ferroelectric oxide films with a large field-induced polarization can be used in dielectric capacitors for charge or energy storage in microelectronic systems and hence have attracted intense research interest.A high ...Ferroelectric oxide films with a large field-induced polarization can be used in dielectric capacitors for charge or energy storage in microelectronic systems and hence have attracted intense research interest.A high processing temperature is usually required to produce a well-crystallized polar phase and hence a large polarization in the film,corresponding to a high charge or energy density.However,high processing temperature not only reduces the charge‒discharge efficiency by producing a sizable remnant polarization but is also incompatible with the integration process.In this study,we address this problem by creating a large field-induced polarization(~55.8μC/cm^(2))in BaTiO_(3)films sputter-deposited on Si at 200℃ via a buffer-layer technique.This large polarization led to a high energy density and efficiency(Wrec≈94.7 J/cm^(3),η≈78.2%@4 MV/cm).The thickness of LaNiO_(3)buffer layer was revealed to be the key factor determining the electric polarization(remnant and field-induced ones).A 50 nm LaNiO_(3)thickness,corresponding to the aforementioned polarization and energy storage performance,not only ensures proper crystallization in the BaTiO_(3)film,but also leads to an optimal combination of polycrystalline grains with a high dielectric constant.The latter accounts for the majority of the field-induced polarization.Our results revealed the key role of a buffer layer in tuning the microstructure of a low-temperature deposited ferroelectric oxide film.Furthermore,the excellent charge/energy storage performance of these 200℃-deposited BaTiO_(3)films has provided many opportunities for this simple dielectric in microelectronics.展开更多
文摘In the Temperature-Pressure phase diagram, the quasi-one-dimensional conductor, HMTSF-TCNQ, the ground state at ambient pressure is an insulator of charge density wave (CDW) below 30 K, while it shows a good metallic nature at higher temperature. The CDW insulating state is suppressed by a pressure of 1 GPa, which is considered to be a quantum critical point. Neither at 0 - 0.5 nor 2 GPa but only around this critical point in pressure, field-induced phases appear from 0.2 T through 10 T, where Rxy is almost constant and Rxx is very low. These phenomena are achieved when the magnetic field is applied along the least conducting axis. The behaviors are consistent with a kind of Quantum Hall Effect (QHE). The field-induce phase accompanied by the QHE might be the field-induced CDW (FICDW) similar to that of FISDW, observed in (TMTSF)2X salts. This paper presents the latest result of the Hall effects reviewing the history of the authors’ work on this material from preliminary to the latest ones.
基金Supported by the National Basic Research Program of China under Grant No 2011CBA00111the National Natural Science Foundation of China under Grant No U1332143
文摘The effect of an external magnetic field on the structural and magnetic properties of bond frustrated ZnCr2 Se4 at low temperatures is investigated using magnetization, dielectric constants and thermal conductivity experiments. With an increase in the magnetic field H, the antiferromagnetic transition temperature TN is observed to shift progressively toward lower temperatures. The corresponding high temperature cubic （Fd3m） to low temperature tetragonal （I41amd） structural transition is tuned simultaneously due to the inherent strong spin-lattice coupling. In the antiferromagnetic phase, an anomaly at Hc2 defined as a steep downward peak in the derivative of the M-H curve is dearly drawn. It is found that TN versus H and Hc2 versus T exhibit a consistent tendency, indicative of a field-induced tetragonal （I41amd） to cubic （Fd3m） structural transition. The transition is further substantiated by the field-dependent dielectric constant and thermal conductivity measurements. We modify the T-H phase diagram, highlighting the coexistence of the paramagnetic state and ferromagnetic clusters between 100K and TN.
基金S.A.and M.Z.acknowledge support by NSF,grant number 2230352S.S.D.acknowledges support from the UVA Research Innovation AwardK.S.D.and D.L.work on TMDs has been supported by National Science Foundation Grant No.221949.
文摘Thermoelectric coolers utilizing the Peltier effect have dominated the field of solid-state cooling but their efficiency is hindered by material limitations.Alternative routes based on the Thomson and Nernst effects offer new possibilities.Here,we present a comprehensive investigation of the thermoelectric properties of 1T-TiSe_(2),focusing on these effects around the charge density wave transition(≈200 K).The abrupt Fermi surface reconstruction associated with this transition leads to an exceptional peak in the Thomson coefficient of 450μVK^(-1) at 184 K,surpassing the Seebeck coefficient.Furthermore,1T-TiSe_(2) exhibits a remarkably broad temperature range(170-400 K)with a Thomson coefficient exceeding 190μV K^(-1),a characteristic highly desirable for the development of practical Thomson coolers with extended operational ranges.Additionally,the Nernst coefficient exhibits an unusual temperature dependence,increasing with temperature in the normal phase,which we attribute to bipolar conduction effects.The combination of solid-solid pure electronic phase transition to a semimetallic phase with bipolar transport is identified as responsible for the unusual Nernst trend and the unusually large Thomson coefficient over a broad temperature range.
基金supported by the National Natural Science Foundation of China(Grant Nos.42525201 and 42230710).
文摘Bio-carbonation of reactive MgO has been regarded as a promising and eco-friendly method for construction and demolition waste(CDW)cementation in various geotechnical engineering applications.However,the beneficial effect of bio-carbonation of reactive MgO cemented CDW(BCM-samples)can be altered when exposed to wetting-drying cycles induced by extreme climate changes or groundwater fluctuations.To better understand the durability of BCM-samples and their underlying deterioration mechanisms,a series of BCM-samples was prepared to investigate their physical-mechanical performance and microstructure evolution subjected to the wetting-drying cycles.The results indicated that the wetting-drying cycles can deteriorate the BCM-samples,and their physical-mechanical behaviors change quickly at the cycle beginning and then smoothly after 2 cycles.With the increase in cycling,the apparent deterioration with efflorescence and microcrack development can be observed.The mass loss and water absorption rates increased while the dry density,compressional wave velocity,and unconfined compression strength decreased.Urea pre-hydrolysis treatment can significantly improve the durability of BCM-samples,as the more hydrated magnesia carbonates(HMCs)enhance the cementing effects.After 10 cycles,the UCS of pre-hydrolyzed samples decreased 25.4%to 4.45 MPa,while that of ordinary samples decreased 50.7%to 1.20 MPa.The deterioration of BCM-samples caused by wetting-drying cycles can be attributed to two factors.One of the main factors is the structural integrity changes caused by the rapid loss of soluble material at the initial cycling stages.Another factor is the decrease in cementation induced by the loss of brucite and HMCs at the following cycle stages.
文摘目的:探讨CDw75(cluster of differentiation antigen 75)在大肠癌组织中的表达及其和大肠癌浸润、转移和TNM分期等病理特征之间的关系。方法:采用免疫组化SP法检测CDw75抗原在61例大肠癌组织和30例相应正常大肠黏膜组织中的表达,计算阳性细胞的百分率。结果:CDw75在30例正常大肠黏膜中均阴性表达,在61例大肠癌组织中有30例阳性表达。CDw75表达阳性多见于肿瘤直径≥5cm、浸润深度较深、伴淋巴结转移和远处转移及TNMⅢ+Ⅳ期的大肠癌。结论:大肠癌组织中CDw75抗原的表达可作为大肠黏膜恶性转化的一个标志物,并可能用于判断大肠癌的恶性生物学行为。
文摘Worldwide construction and demolition waste (CDW) is currently dumped. To close the building cycle and the building materials cycle by recycling CDW in high technical applications, the technical quality of stony materials must be improved. For this purpose, concrete rubbles and brick rubbles, the two major stony constituents of CDW, should be separated from each other. Based on the differences in density and content of Fe-2O-3 between the two materials, a wet method of jigging and a dry method of magnetic separation are effective,tested.
基金The authors would like to thank the CAPES which sponsored the first author.
文摘The operation of reinforced concrete structures is directly associated with the adhesion between the steel bar and the concrete,which allows the internal forces to be transferred to the reinforcement during the process of loading the structural elements.The modification of the concrete composition,with the introduction of recycled aggregate from construction and demolition waste(CDW),affects the steel-concrete interface and can modify the bonding stress,which is also influenced by the type and diameter of the bar used.In this work,the influence of the recycled fine aggregate(RFA)and types of steel bar on the steel-concrete bond was experimentally evaluated using the pullout test.Conventional concrete and recycled concrete,with RFA replacement level of 25%,were produced.Two types of steel rebars(i.e.,plain and deformed)with diameters of 10.0 and 16.0 mm were considered in this paper.The results indicate a reduction in the adhesion stress with the introduction of recycled aggregate,but this trend is influenced by the diameter of the bar used.The use of ribbed bars modifies the stress bon-slip behavior,with an increase in the average bond strength,which is also observed with the reduction of the diameter of the bar.
文摘We reference the tunneling Hamiltonian to have particle tunneling among different states represented as wave-functions. Our problem applies wave-functionals to a driven sine-Gordon system. We apply the tunneling Hamiltonian to charge density wave (CDW) transport problems where we consider tunneling among states that are wave-functionals of a scalar quantum field, i.e. derived I-E curves that match Zenier curves used to fit data experimentally with wave-functionals congruent with the false vacuum hypothesis. The open question is whether the coefficients picked in both wave-functionals and the magnitude of the coefficients of the driven sine-Gordon physical system are picked by topological charge arguments that appear to assign values consistent with the false vacuum hypothesis. Crucial results by Fred Cooper et al. allow a mature quantum foam interpretation of false vacuum nucleation for further refinement of our wave-functional results. In doing so, we give credence to topological arguments as a first order phase transition in CDW I-E curves.
基金supported by the National Natural Science Foundation China(Grant No.42176222).
文摘As a crucial component of the Earth’s climate system,Antarctic sea ice has demonstrated significant variability over the satellite era.Here,we identify a remarkable decadal transition in the total Antarctic Sea Ice Extent(SIE).The stage from 1979 to 2006 is characterized by high-frequency(i.e.,seasonal to interannual)temporal variability in SIE and zonal asymmetry in Sea Ice Concentration(SIC),which is primarily under the control of the Amundsen Sea Low(ASL).After 2007,however,sea ice changes exhibit a more spatially homogeneous pattern in SIC and a more temporally long-lasting mode in SIE.Further analysis reveals that sea ice-ocean interaction plays a major role in the low-frequency(i.e.,multiannual)variability of Antarctic sea ice from 2007−22.The related physical process is inferred to manifest as a strong coupling between the surface and the subsurface ocean layers,involving enhanced vertical convection and the downward delivery of the surface anomalies related to ice melting and freezing processes,thus maintaining the SIE anomalies for a longer time.Furthermore,this process mainly occurs in the Amundsen-Bellingshausen Sea(ABS)sector,and the weakened subsurface ocean stratification is the key factor triggering the coupling process in this region.We find that the Circumpolar Deep Water(CDW)over the ABS sector continued to shoal before 2007 and remained stable thereafter.It is speculated that the shoaling of the CDW may be a possible driver leading to the weakening of the subsurface stratification.
基金supported by the Natural Science Foundation of Shandong Province(Nos.ZR2022ZD39,ZR2022QB138,ZR2020QE042,ZR2023QE138,ZR2022QB119,and ZR2022ME031)the National Natural Science Foundation of China(Nos.92463306 and 52002192)+4 种基金the Innovation Capacity Improvement Project of Small and Medium-sized Technologybased Enterprises of Shandong Province(No.2021TSGC1087)the Jinan City Science and Technology Bureau(No.2021GXRC055)the Science,Education and Industry Integration Pilot Projects of Qilu University of Technology(Shandong Academy of Sciences)(Nos.2022GH018,2023PX062,and 2023PX041)the Seed Funding for Top Talents at Qilu University of Technology(Shandong Academy of Sciences)the Excellent Teaching Team Training Plan Project of Qilu University of Technology,the Education Department of Hunan Province/Xiangtan University(No.KZ0807969).
文摘Ferroelectric oxide films with a large field-induced polarization can be used in dielectric capacitors for charge or energy storage in microelectronic systems and hence have attracted intense research interest.A high processing temperature is usually required to produce a well-crystallized polar phase and hence a large polarization in the film,corresponding to a high charge or energy density.However,high processing temperature not only reduces the charge‒discharge efficiency by producing a sizable remnant polarization but is also incompatible with the integration process.In this study,we address this problem by creating a large field-induced polarization(~55.8μC/cm^(2))in BaTiO_(3)films sputter-deposited on Si at 200℃ via a buffer-layer technique.This large polarization led to a high energy density and efficiency(Wrec≈94.7 J/cm^(3),η≈78.2%@4 MV/cm).The thickness of LaNiO_(3)buffer layer was revealed to be the key factor determining the electric polarization(remnant and field-induced ones).A 50 nm LaNiO_(3)thickness,corresponding to the aforementioned polarization and energy storage performance,not only ensures proper crystallization in the BaTiO_(3)film,but also leads to an optimal combination of polycrystalline grains with a high dielectric constant.The latter accounts for the majority of the field-induced polarization.Our results revealed the key role of a buffer layer in tuning the microstructure of a low-temperature deposited ferroelectric oxide film.Furthermore,the excellent charge/energy storage performance of these 200℃-deposited BaTiO_(3)films has provided many opportunities for this simple dielectric in microelectronics.
