The development of aqueous Zn batteries is limited by parasitic water reactions,corrosion,and dendrite growth.To address these challenges,an inner Helmholtz plane(IHP)regulation method is proposed by employing low-cos...The development of aqueous Zn batteries is limited by parasitic water reactions,corrosion,and dendrite growth.To address these challenges,an inner Helmholtz plane(IHP)regulation method is proposed by employing low-cost,non-toxic maltitol as the electrolyte additive.The preferential adsorption behavior of maltitol can expel the water from the inner Helmholtz plane,and thus hinder the immediate contact between Zn metal and H_(2)O.Meanwhile,strong interaction between maltitol and H_(2)O molecules can restrain the activity of H_(2)O.Besides,the"IHP adsorption effect"along with the low LUMO energy level of maltitol-CF_(3)SO_(3)^(-)can promote the in-situ formation of an organic-inorganic complex solid electrolyte interface(SEI)layer.As a result,the hydrogen/oxygen evolution side reaction,corrosion,and dendrites issues are effectively suppressed,thereby leading to highly reversible and dendrite-free Zn plating/stripping.The Zn‖I_(2)battery with hybrid electrolytes also demonstrates high electrochemical performance and ultralong cycling stability,showing a capacity retention of 75%over 20000 charge-discharge cycles at a large current density of 5 A g^(-1).In addition,the capacity of the device has almost no obvious decay over20000 cycles even at-30℃.This work offers a successful electrolyte regulation strategy via the IHP adsorption effect to design electrolytes for high-performance rechargeable Zn-ion batteries.展开更多
为揭示半干旱草原露天矿区生态环境质量状况,分离矿区人类活动生态累积效应并识别其演变态势,在厘清矿区生态累积效应概念的基础上,构建适用于半干旱草原的露天矿区生态环境质量评估指数(Surface Mining Areas Eco-environmental Evalua...为揭示半干旱草原露天矿区生态环境质量状况,分离矿区人类活动生态累积效应并识别其演变态势,在厘清矿区生态累积效应概念的基础上,构建适用于半干旱草原的露天矿区生态环境质量评估指数(Surface Mining Areas Eco-environmental Evaluation Index,SMAEEI)以及矿区生态累积效应定量评估模型。选取内蒙古胜利矿区为研究区,量化分析1986—2020年区域生态环境质量和生态累积效应的时空分布规律,以及主要人类活动的生态累积效应差异。结果表明:①SMAEEI适用于半干旱草原露天矿区,能客观呈现各地类生态环境质量高低顺序。35 a间研究区生态环境质量呈极显著下降趋势,且其空间差异显著减弱。露天矿场、城镇扩张区、锡林河湿地及北侧草地生态环境质量出现极显著、显著的退化趋势。②半干旱草原露天矿区生态累积效应定量评估模型能剔除气候因素对生态系统的耦合影响,分离并量化人类活动对矿区生态系统的累积效应,揭示累积的方向、程度和空间范围。35 a间研究区生态服务价值累积量(Change of Ecosystem Service Value Cumulant,COESVC)共减少1186157.03万元,出现负向生态累积效应,生态系统服务功能下降。高度、中度负向累积区集中在湿地和草地退化区、城镇区、露天矿场。③露天开采、城镇建设造成的单位面积负向生态累积效应最明显,前者在单位时间内带来的负向累积变化最剧烈,后者负向累积效应的局部影响程度和偏离度最大;放牧活动引起的负向生态累积效应影响范围最广、总量最大,但局部影响程度最小,生态系统服务功能较其余人类活动更稳定。研究成果可将矿区人类活动引起的生态环境实物量变动转化为价值量描述,为采用货币形式测算矿区生产生活行为的环境损害成本提供可行方法。展开更多
An opened bottom cylinder is a large-diameter cylinder placed on a rubber base or embedded in a soil foundation. The settlement of such a cylinder differs greatly from that of a closed bottom cylinder and so does the ...An opened bottom cylinder is a large-diameter cylinder placed on a rubber base or embedded in a soil foundation. The settlement of such a cylinder differs greatly from that of a closed bottom cylinder and so does the distribution of inner soil pressure over the opened bottom cylindrical structure. Through investigation of the settlement and the inner soil pressure on the opened bottom cylinder by model experiments, the interactions among the filler inside the cylinder, subsoil and cylinder are analyzed. The adjusting mechanism of friction resistance between the inner filler and the wall of the cylinder during overturning of the cylinder is discussed. Based on the experimental study, a method for calculating the inner soil pressure on the cylindrical structure under axisymmetric loading or non- axisymmetric (with lateral) loading is proposed in this paper. Meanwhile, the effective anti-overturning ratio of the opened bottom cylinder is derived.展开更多
For uniform tube inner coating of non-conductive thin films, the double-ended coaxial magnetron pulsed plasma (DCMPP) method was investigated. In this study, coating of TiN and TiO2 was performed. It was clearly shown...For uniform tube inner coating of non-conductive thin films, the double-ended coaxial magnetron pulsed plasma (DCMPP) method was investigated. In this study, coating of TiN and TiO2 was performed. It was clearly shown that the extended anode effect was strongly influenced by the electric resistance of the coated thin films on the inner surface of an insulator tube. Additionally, high frequency (100 kHz) was better for relatively high plasma density. On the other hand, in the case of titanium oxide deposition, negative ion productions drastically decrease the deposition rate and the shifting velocity of plasma main position for coated TiO2 films.展开更多
Active control of the local environment of the cold atmospheric plasma(CAP) jet is of great importance in actual applications since the CAP operates in an open atmosphere with the inevitable entrainment of the surroun...Active control of the local environment of the cold atmospheric plasma(CAP) jet is of great importance in actual applications since the CAP operates in an open atmosphere with the inevitable entrainment of the surrounding cold air. In this paper, the solid shielding effects of the cylindrical quartz tubes with different inner diameters on the characteristics of the CAP jets driven by a radio-frequency(RF) power supply are studied experimentally. The experimental results show that the total length of the shielded plasma jet can be increased significantly by an appropriate combination of the quartz tube inner diameter and that of the plasma generator nozzle exit with other parameters being unchanged. This phenomenon may be qualitatively attributed to the loss of diffusion of the charged particles in the radial direction under different inner diameters of the quartz tubes. Compared with the plasma free jet, the plasma shielding jet is produced with optimized parameters including longer plasma jet length, higher concentrations of chemically reactive species, higher rotational, vibrational, and electron excitation temperatures when the inner diameters of the solid shielding tube and the generator nozzle exit are the same. A maximum plasma jet length of 52.0 cm is obtained in contrast to that of 5.0 cm of the plasma free jet in this study. The experimental results indicate that the solid shielding effect provides a new method for the active control of the local environment of the RF-CAP jet operating in an open atmosphere.展开更多
For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Be...For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Bekenstein-Smarr formula and the effective first law of thermodynamics are derived.展开更多
基金supported by the National Natural Science Foundation of China(52261160384)the Shenzhen Science and Technology Innovation Commission(RCYX20221008092934093)+1 种基金the Shenzhen Science and Technology Program(KJZD20230923114107014)the support from Testing Technology Center of Materials and Devices,Tsinghua Shenzhen International Graduate School。
文摘The development of aqueous Zn batteries is limited by parasitic water reactions,corrosion,and dendrite growth.To address these challenges,an inner Helmholtz plane(IHP)regulation method is proposed by employing low-cost,non-toxic maltitol as the electrolyte additive.The preferential adsorption behavior of maltitol can expel the water from the inner Helmholtz plane,and thus hinder the immediate contact between Zn metal and H_(2)O.Meanwhile,strong interaction between maltitol and H_(2)O molecules can restrain the activity of H_(2)O.Besides,the"IHP adsorption effect"along with the low LUMO energy level of maltitol-CF_(3)SO_(3)^(-)can promote the in-situ formation of an organic-inorganic complex solid electrolyte interface(SEI)layer.As a result,the hydrogen/oxygen evolution side reaction,corrosion,and dendrites issues are effectively suppressed,thereby leading to highly reversible and dendrite-free Zn plating/stripping.The Zn‖I_(2)battery with hybrid electrolytes also demonstrates high electrochemical performance and ultralong cycling stability,showing a capacity retention of 75%over 20000 charge-discharge cycles at a large current density of 5 A g^(-1).In addition,the capacity of the device has almost no obvious decay over20000 cycles even at-30℃.This work offers a successful electrolyte regulation strategy via the IHP adsorption effect to design electrolytes for high-performance rechargeable Zn-ion batteries.
文摘为揭示半干旱草原露天矿区生态环境质量状况,分离矿区人类活动生态累积效应并识别其演变态势,在厘清矿区生态累积效应概念的基础上,构建适用于半干旱草原的露天矿区生态环境质量评估指数(Surface Mining Areas Eco-environmental Evaluation Index,SMAEEI)以及矿区生态累积效应定量评估模型。选取内蒙古胜利矿区为研究区,量化分析1986—2020年区域生态环境质量和生态累积效应的时空分布规律,以及主要人类活动的生态累积效应差异。结果表明:①SMAEEI适用于半干旱草原露天矿区,能客观呈现各地类生态环境质量高低顺序。35 a间研究区生态环境质量呈极显著下降趋势,且其空间差异显著减弱。露天矿场、城镇扩张区、锡林河湿地及北侧草地生态环境质量出现极显著、显著的退化趋势。②半干旱草原露天矿区生态累积效应定量评估模型能剔除气候因素对生态系统的耦合影响,分离并量化人类活动对矿区生态系统的累积效应,揭示累积的方向、程度和空间范围。35 a间研究区生态服务价值累积量(Change of Ecosystem Service Value Cumulant,COESVC)共减少1186157.03万元,出现负向生态累积效应,生态系统服务功能下降。高度、中度负向累积区集中在湿地和草地退化区、城镇区、露天矿场。③露天开采、城镇建设造成的单位面积负向生态累积效应最明显,前者在单位时间内带来的负向累积变化最剧烈,后者负向累积效应的局部影响程度和偏离度最大;放牧活动引起的负向生态累积效应影响范围最广、总量最大,但局部影响程度最小,生态系统服务功能较其余人类活动更稳定。研究成果可将矿区人类活动引起的生态环境实物量变动转化为价值量描述,为采用货币形式测算矿区生产生活行为的环境损害成本提供可行方法。
文摘An opened bottom cylinder is a large-diameter cylinder placed on a rubber base or embedded in a soil foundation. The settlement of such a cylinder differs greatly from that of a closed bottom cylinder and so does the distribution of inner soil pressure over the opened bottom cylindrical structure. Through investigation of the settlement and the inner soil pressure on the opened bottom cylinder by model experiments, the interactions among the filler inside the cylinder, subsoil and cylinder are analyzed. The adjusting mechanism of friction resistance between the inner filler and the wall of the cylinder during overturning of the cylinder is discussed. Based on the experimental study, a method for calculating the inner soil pressure on the cylindrical structure under axisymmetric loading or non- axisymmetric (with lateral) loading is proposed in this paper. Meanwhile, the effective anti-overturning ratio of the opened bottom cylinder is derived.
文摘For uniform tube inner coating of non-conductive thin films, the double-ended coaxial magnetron pulsed plasma (DCMPP) method was investigated. In this study, coating of TiN and TiO2 was performed. It was clearly shown that the extended anode effect was strongly influenced by the electric resistance of the coated thin films on the inner surface of an insulator tube. Additionally, high frequency (100 kHz) was better for relatively high plasma density. On the other hand, in the case of titanium oxide deposition, negative ion productions drastically decrease the deposition rate and the shifting velocity of plasma main position for coated TiO2 films.
基金supported by National Natural Science Foundation of China (Nos. 11475103, 21627812, 51578309)the National Key Research and Development Program of China (No. 2016YFD0102106)the Tsinghua University Initiative Scientific Program (No. 20161080108)
文摘Active control of the local environment of the cold atmospheric plasma(CAP) jet is of great importance in actual applications since the CAP operates in an open atmosphere with the inevitable entrainment of the surrounding cold air. In this paper, the solid shielding effects of the cylindrical quartz tubes with different inner diameters on the characteristics of the CAP jets driven by a radio-frequency(RF) power supply are studied experimentally. The experimental results show that the total length of the shielded plasma jet can be increased significantly by an appropriate combination of the quartz tube inner diameter and that of the plasma generator nozzle exit with other parameters being unchanged. This phenomenon may be qualitatively attributed to the loss of diffusion of the charged particles in the radial direction under different inner diameters of the quartz tubes. Compared with the plasma free jet, the plasma shielding jet is produced with optimized parameters including longer plasma jet length, higher concentrations of chemically reactive species, higher rotational, vibrational, and electron excitation temperatures when the inner diameters of the solid shielding tube and the generator nozzle exit are the same. A maximum plasma jet length of 52.0 cm is obtained in contrast to that of 5.0 cm of the plasma free jet in this study. The experimental results indicate that the solid shielding effect provides a new method for the active control of the local environment of the RF-CAP jet operating in an open atmosphere.
文摘For a black hole with two horizons, the effective entropy is assumed to be a linear combination of the two entropies of the outer and inner horizons. In terms of the effective thermodynamic quantities the effective Bekenstein-Smarr formula and the effective first law of thermodynamics are derived.
