This article aims to investigate the possibility to turn the multiferroic orders and magnetocapacitance effect close to/above room temperature in nanosized GaFeO3 ceramics by a sol-gel preparation method and substitut...This article aims to investigate the possibility to turn the multiferroic orders and magnetocapacitance effect close to/above room temperature in nanosized GaFeO3 ceramics by a sol-gel preparation method and substitution with non-magnetic Zn atoms. Therefore, in this work, we have synthesized a series of nanocrystalline Ga1-xZnxFeO3(GZFO, x = 0, 0.01, 0.05 and 0.1) ceramic samples and study the effect of Zn substitution on their structural, magnetic, and electric properties. All the GZFO samples have an orthorhombic structure with Pc21n space group and the value of lattice parameters increase systematically with increasing Zn concentration. Interestingly, it shows that magnetic and electric properties are strongly dependent on the Zn substitution concentration. Based on the results of temperature-dependent magnetizations, M(T), it is observed that with increasing Zn-content up to 0.10, the ferrimagnetic transition temperature (TC) increases from 306 to 320 K. It is also found that the nanocrystalline Zn-doped GaFeO3 (GFO) samples exhibit the characteristics of ferroelectricity at room temperature. Furthermore, the?magnetization, ferroelectric polarization and magnetocapacitance of Zn-doped GFO nanosized ceramics are enhanced compared to those of the pristine sample of GFO ferrite. These results open wide perspectives for the applications of room temperature multiferroic devices.展开更多
The magnetic properties of spinel ferrites Cu_(1-x)Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_...The magnetic properties of spinel ferrites Cu_(1-x)Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_(AA), J_(BB) and J_(AB) are obtained using a probability distribution law. The critical exponent associated with the magnetic susceptibility is obtained.展开更多
The effect of Zn substitution on the structure and magnetic properties of τ-MnAl has been investigated sys-tematically. It is found that Zn substitution can stabilize the structure of τ-phase and thus a significant ...The effect of Zn substitution on the structure and magnetic properties of τ-MnAl has been investigated sys-tematically. It is found that Zn substitution can stabilize the structure of τ-phase and thus a significant amount of τ-phase can be produced. Zn increases the coercivity and saturation magnetization of the τ-MnAl but reduces the Currie temperature. However, excess Zn is detrimental to the magnetic parameters. The optimum magnetic performance was found in samples with Zn substitution to 2.9% Mn atoms and 3.5% Al atoms, respectively.展开更多
Adsorption/desorption in a new Zn(Ⅱ)-TiO2 adsorption system was investigated at different particle concentrations (Cp). TEM, SEM and XRD analyses revealed that the TiO2 particles were an aggregation of nano-sized...Adsorption/desorption in a new Zn(Ⅱ)-TiO2 adsorption system was investigated at different particle concentrations (Cp). TEM, SEM and XRD analyses revealed that the TiO2 particles were an aggregation of nano-sized (approximately 10 nm) pure anatase-type TiO2. Adsorption experiments were carried out with particle concentrations of 100, 400 and 1000 mg/L, and their adsorption isotherms were found to decline successively, showing an obvious Cp effect. Desorption experiments indicated that adsorption in this system was irreversible, and the irreversibility increased with increasing Cp. These phenomena could be explained by the MEA (metastable equilibrium adsorption) theory and the Cp effect could be modeled well with an MEA-Freundlich-type Cp effect isotherm equation. This study may heln understand environmental behavior of contaminants on ultrafine natural particles.展开更多
Experimental results of the investigation on the hardness of two Al-Zn-Mg alloys [Al-10.0 Zn-4.0 Mg and Al-8.5 Zn-3.0 Mg (wt pct)] aged in the temperature range 60~310℃ for different intervals of time from 1/4 h to ...Experimental results of the investigation on the hardness of two Al-Zn-Mg alloys [Al-10.0 Zn-4.0 Mg and Al-8.5 Zn-3.0 Mg (wt pct)] aged in the temperature range 60~310℃ for different intervals of time from 1/4 h to 168 h are presented. Both the alloys were found to show identical behaviour of hardness with ageing time. Alloy with higher Zn and Mg content had higher hardness than the alloy with lower solute content. There were three ranges of temperature in which different types of precipitates formed and affected the hardness. Some of the grain boundaries were found to migrate and precipitate free zone has been observed.展开更多
The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH g...The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.展开更多
This study deals with the toxic effects of Zn2+, Cu2+, Cd2+ and NH3 on Chinese prawn (Penaeus orientalis). The median lethal concentrations of the toxic matters on Chinese prawn were determined. Cd2+】Cu2+】Zn2+】NH3-...This study deals with the toxic effects of Zn2+, Cu2+, Cd2+ and NH3 on Chinese prawn (Penaeus orientalis). The median lethal concentrations of the toxic matters on Chinese prawn were determined. Cd2+】Cu2+】Zn2+】NH3-Nm is the toxic order of these chemicals to Chinese prawn. The toxic order of concentrated Zn2+ and Cd2+ in tissues and organs of Chinese prawn is in the order gill 】 shell + appendage】viscera 】 muscle..展开更多
The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples.This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical perfo...The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples.This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical performance of three different normalization methods, namely normalization with background, internal normalization and three point smoothing techniques at different parameter settings is studied for quantification of Ag and Zn by Laser induced breakdown spectroscopy(LIBS).The LIBS spectra of five known concentration of silver zinc binary composites have been investigated at various laser irradiances(LIs). Calibration curves for both Ag(I) line(4d^(10)5s^2S_(1/2)→4d^(10)5p^2P_(1/2) at 338.28 nm) and Zn(I) line(4s5s^3S_1→4s4p^3P_2 at 481.053 nm) have been determined at LI of 5.86?×?10^(10)W cm^(-2). Slopes of these calibration curves provide the valuation of matrix effect in the Ag–Zn composites. With careful sample preparation and normalization after smoothing at optimum parameter setting(OPS), the minimization of sample matrix effect has been successfully achieved. A good linearity has been obtained in Ag and Zn calibration curve at OPS when normalized the whole area of spectrum after smoothing and the obtained coefficients of determination values were R^2?=?0.995 and 0.998 closer to 1. The results of matrix effect have been further verified by analysis of plasma parameters. Both plasma parameters showed no change with varying concentration at OPS. However, at high concentration of Ag, the observed significant changes in both plasma parameters at common parameter setting PS-1 and PS-2 were the gesture of matrix effect. In our case, the better analytical results were obtained at smoothing function with optimized parameter setting that indicates it is more efficient than normalization with background and internal normalization method.展开更多
Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, ...Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, densification, microstructure and a.c. electrical conductivity have been studied. Under the effect of changing the firing temperature and Zn content, high sintered Li-Zn ferrite bodies are achieved. More fine structure bodies having high electrical resistance are obtained at high Zn content展开更多
Li metal is the most ideal anode material for next-generation high energy lithium-ion batteries.The uncontrollable growth of Li dendrites,however,hinders its practical application.Herein,we propose the adoption of Zn ...Li metal is the most ideal anode material for next-generation high energy lithium-ion batteries.The uncontrollable growth of Li dendrites,however,hinders its practical application.Herein,we propose the adoption of Zn nanoparticles uniformly embedded in N-doped carbon polyhedra homogeneously built on carbon cloth(Zn@NC@CC)to prevent the formation of Li dendrites.Based on theoretical calculation and experimental observation,lithiophilic Zn nanoparticles and N-doping inside of the assynthesized Zn@NC play a synergistic role in enhancing the adsorption capacity with Li,thus resulting in uniform Li deposition and complete suppression of Li dendrites.Moreover,the porous N-doped carbon polyhedras uniformly distributed on carbon cloth effectively relieves the volume change of Li upon repeated Li stripping/plating process,which contributes to preserving the structural integrity of the whole electrode and hence enhancing its long-term cycling stability.Benefiting from these synergistic effects,the Li-Zn@NC@CC electrode delivers a prolonged lifespan of over 1200 h at 1 mA cm^(-2) with an areal capacity of 1 mA h cm^(-2) in symmetric cells and high Coulombic efficiencies of 95.4%under an ultrahigh capacity of 12 mA h cm^(-2).Remarkably,Li-Zn@NC@CC//LiFePO_(4) full cells deliver a high reversible capacity of 110.2 mA h g^(-1) at 1 C over 200 cycles.展开更多
A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary...A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃.展开更多
The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of ...The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10-6 to 650×10-6 with an average of 310×10-6. In primary ores, Cd concentrations range from 14×10-6 to 2800×10-6 with an average of 767×10-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10-6 to 8200×10-6 , averaging 1661×10-6. It is shown that the oxidized ores are the main carrier and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn>Pb>Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.展开更多
Evaluation of the genetic effect on yield and fiber quality can provide useful information on cotton breeding. Sixteen CSB lines and TM-1 introduced from USDA/ARS were used as male and top-crossed with three elite cul...Evaluation of the genetic effect on yield and fiber quality can provide useful information on cotton breeding. Sixteen CSB lines and TM-1 introduced from USDA/ARS were used as male and top-crossed with three elite cultivars and the 51 F1 hybrids, 16 CSB lines, TM-1, and 3 elite cultivars were planted at the Cotton Research Institute of CAAS, Anyang, Henan Province and Xiajin, Shandong Province, China. The yield traits and fiber quality data were obtained and additive and dominance effect on each trait were measured by AD model. Boll weight takes the largest additive proration, whereas boll number takes the least additive proration. The largest and the least dominant proration for lint yield and boll weight were measured, respectively. Fiber length has the additive and dominance effect, and dominance effect was slightly more than additive effect. Larger additive and no dominance effect on uniformity, micronaire, and fiber strength were measured. Significantly, positive additive effect on boll weight of CSB06 and CSB12Sh was observed. CSB14Sh and CSB01 have significantly positive additive effect on 4 and 3 traits of fiber quality, respectively. CSB01 has the greatest dominant effect on lint yield among CSB lines. The dominant effect on fiber length of CSB lines showed positive. It is beneficial to use CSB06 and CSB12Sh as parents to improve boll size, to use CSB14Sh and CSB01 as parents to improve fiber quality. As for hybrid cotton breeding, it is reasonable using CSB01 to improve lint yield traits, and using CSB01, CSB11Sh, and CSB06 to improve fiber length.展开更多
The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, w...The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes.展开更多
Two-photon fluorescence dyes have shown promising applications in biomedical imaging.However,the substitution site effect on geometric structures and photophysical properties of fluorescence dyes is rarely illustrated...Two-photon fluorescence dyes have shown promising applications in biomedical imaging.However,the substitution site effect on geometric structures and photophysical properties of fluorescence dyes is rarely illustrated in detail.In this work,a series of new lipid droplets detection dyes are designed and studied,molecular optical properties and non-radiative transitions are analyzed.The intramolecular weak interaction and electron-hole analysis reveal its inner mechanisms.All dyes are proven to possess excellent photophysical properties with high fluorescence quantum efficiency and large stokes shift as well as remarkable two-photon absorption cross section.Our work reasonably elucidates the experimental measurements and the effects of substitution site on two-photon absorption and excited states properties of lipid droplets detection NAPBr dyes are highlighted,which could provide a theoretical perspective for designing efficient organic dyes for lipid droplets detection in biology and medicine fields.展开更多
Five experiment ecosystems (MEEE) were employed in April, 1985 to test the effects of a mixture of Cu, Cd, Hg, Pb and Zn on a subtropical planktonic ecosystem in Xiamen Bay, Xiamen, China. The results indicated that t...Five experiment ecosystems (MEEE) were employed in April, 1985 to test the effects of a mixture of Cu, Cd, Hg, Pb and Zn on a subtropical planktonic ecosystem in Xiamen Bay, Xiamen, China. The results indicated that the ppb-level of the mixture could suppress the planktonic production. Zooplankton in Xiamen were very sensitive to the metal contamination, especially the larvaceans.展开更多
[Zn(POM)_2Br_2](POM is 3-Methyl-4-Nitropyridine-1-Oxide),C_(12)H_(12)Br_2N_4O_6Zn, Mr=533.44,triclinic,P1,a=11.450(3),b=13.027(2),c=6.605(1),α=101.25(1),β=96.96(2), γ=108.06(2)°,V=901.2(4)~3,Z=2,D_c=1.97g·...[Zn(POM)_2Br_2](POM is 3-Methyl-4-Nitropyridine-1-Oxide),C_(12)H_(12)Br_2N_4O_6Zn, Mr=533.44,triclinic,P1,a=11.450(3),b=13.027(2),c=6.605(1),α=101.25(1),β=96.96(2), γ=108.06(2)°,V=901.2(4)~3,Z=2,D_c=1.97g·cm^(-3),(MoK_α)=0.71069,F(000)=520, μ=58.21cm^(-1),final R=0.040 for 2192 observed reflections,T=296K.The compound is a mononuclear complex,containing a tetrahedrally coordinated zinc atom.展开更多
Zn 2+-TiO2 nanotube arrays were prepared by anodic oxidation method.The current-time curves were used to investigate their growth mechanism.Scanning electron microscopy and X-ray diffractometry were applied to charact...Zn 2+-TiO2 nanotube arrays were prepared by anodic oxidation method.The current-time curves were used to investigate their growth mechanism.Scanning electron microscopy and X-ray diffractometry were applied to characterizing their structures and properties.The photoelectrochemical properties were studied by electrochemical impedance spectrum(EIS).The optimised working conditions for TiO2 nanotube arrays were found to be pH 1,0.5%HF(mass fraction),20 V oxidation voltage and for 2 h.The produced sample was in anatase form,with length of 70-100 nm,thickness of 10 nm,uniform diameter and structure that does not collapse under the preparation conditions.The EIS results show that TiO2 nanotube arrays prepared with 0.5%HF(mass fraction) present a low impedance and TiO2 nanotube arrays loaded by Zn 2+could have a decreased resistance.This decrease could likely accelerate the transfer of carriers and even increase photoelectric conversion.展开更多
The Cu2ZnSnS4 (CZTS)-based solar cell is numerically simulated by a one-dimensional solar cell simulation soft- ware analysis of microelectronic and photonic structures (AMPS-1D). The device structure used in the ...The Cu2ZnSnS4 (CZTS)-based solar cell is numerically simulated by a one-dimensional solar cell simulation soft- ware analysis of microelectronic and photonic structures (AMPS-1D). The device structure used in the simulation is Al/ZnO:Al/nZn(O,S)/pCZTS/Mo. The primary motivation of this simulation work is to optimize the composition in the ZnO1-xSx buffer layer, which would yield higher conversion efficiency. By varying S/(S+O) ratio x, the conduction band offset (CBO) at CZTS/Zn(O,S) interface can range from -0.23 eV to 1.06eV if the full range of the ratio is considered. The optimal CBO of 0.23eV can be achieved when the ZnO1-xSx buffer has an S/(S+O) ratio of 0.6. The solar cell efficiency first increases with increasing sulfur content and then decreases abruptly for x〉 0.6, which reaches the highest value of 17.55% by our proposed optimal sulfur content x= 0.6. Our results provide guidance in dealing with the ZnO1-xSx buffer layer deposition for high efficiency CZTS solar cells.展开更多
Chemically synthesized ZnS thin film is found to be a good x-ray radiation sensor. We report the effect of annealing on the x-ray radiation detection sensitivity of a ZnS thin film synthesized by a chemical bath depos...Chemically synthesized ZnS thin film is found to be a good x-ray radiation sensor. We report the effect of annealing on the x-ray radiation detection sensitivity of a ZnS thin film synthesized by a chemical bath deposition technique. The chemically synthesized ZnS films are annealed at 333, 363 and 393K for 1 h. Structural analyses show that the lattice defects in the films decrease with annealing. Further, the band gap is also found to decrease from 3.38 to 3.21 eV after annealing at 393K. Current-voltage characteristics of the films are studied under dark and x-ray irradiation conditions. Due to the decrease of lattice defects and band gap, the conductivity under dark conditions is found to increase from 2.06 × 10^-6 to 1.69 × 10^-5 S/em, while that under x-ray irradiation increases from 4.13 × 10^-5 to 5.28 ×10^-5 S/cm. On the other hand, the x-ray radiation detection sensitivity of the films is found to decrease with annealing. This decrease of detection sensitivity is attributed to the decrease of the band gap as well as some structural and surface morphological changes occurring after annealing.展开更多
文摘This article aims to investigate the possibility to turn the multiferroic orders and magnetocapacitance effect close to/above room temperature in nanosized GaFeO3 ceramics by a sol-gel preparation method and substitution with non-magnetic Zn atoms. Therefore, in this work, we have synthesized a series of nanocrystalline Ga1-xZnxFeO3(GZFO, x = 0, 0.01, 0.05 and 0.1) ceramic samples and study the effect of Zn substitution on their structural, magnetic, and electric properties. All the GZFO samples have an orthorhombic structure with Pc21n space group and the value of lattice parameters increase systematically with increasing Zn concentration. Interestingly, it shows that magnetic and electric properties are strongly dependent on the Zn substitution concentration. Based on the results of temperature-dependent magnetizations, M(T), it is observed that with increasing Zn-content up to 0.10, the ferrimagnetic transition temperature (TC) increases from 306 to 320 K. It is also found that the nanocrystalline Zn-doped GaFeO3 (GFO) samples exhibit the characteristics of ferroelectricity at room temperature. Furthermore, the?magnetization, ferroelectric polarization and magnetocapacitance of Zn-doped GFO nanosized ceramics are enhanced compared to those of the pristine sample of GFO ferrite. These results open wide perspectives for the applications of room temperature multiferroic devices.
文摘The magnetic properties of spinel ferrites Cu_(1-x)Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_(AA), J_(BB) and J_(AB) are obtained using a probability distribution law. The critical exponent associated with the magnetic susceptibility is obtained.
文摘The effect of Zn substitution on the structure and magnetic properties of τ-MnAl has been investigated sys-tematically. It is found that Zn substitution can stabilize the structure of τ-phase and thus a significant amount of τ-phase can be produced. Zn increases the coercivity and saturation magnetization of the τ-MnAl but reduces the Currie temperature. However, excess Zn is detrimental to the magnetic parameters. The optimum magnetic performance was found in samples with Zn substitution to 2.9% Mn atoms and 3.5% Al atoms, respectively.
基金Project supported by the National Natural Science Foundation of China(No.20537020)the "Hundred Talent Scientist Program" of the Chinese Academy of Sciences.
文摘Adsorption/desorption in a new Zn(Ⅱ)-TiO2 adsorption system was investigated at different particle concentrations (Cp). TEM, SEM and XRD analyses revealed that the TiO2 particles were an aggregation of nano-sized (approximately 10 nm) pure anatase-type TiO2. Adsorption experiments were carried out with particle concentrations of 100, 400 and 1000 mg/L, and their adsorption isotherms were found to decline successively, showing an obvious Cp effect. Desorption experiments indicated that adsorption in this system was irreversible, and the irreversibility increased with increasing Cp. These phenomena could be explained by the MEA (metastable equilibrium adsorption) theory and the Cp effect could be modeled well with an MEA-Freundlich-type Cp effect isotherm equation. This study may heln understand environmental behavior of contaminants on ultrafine natural particles.
文摘Experimental results of the investigation on the hardness of two Al-Zn-Mg alloys [Al-10.0 Zn-4.0 Mg and Al-8.5 Zn-3.0 Mg (wt pct)] aged in the temperature range 60~310℃ for different intervals of time from 1/4 h to 168 h are presented. Both the alloys were found to show identical behaviour of hardness with ageing time. Alloy with higher Zn and Mg content had higher hardness than the alloy with lower solute content. There were three ranges of temperature in which different types of precipitates formed and affected the hardness. Some of the grain boundaries were found to migrate and precipitate free zone has been observed.
基金supported by the National Natural Science Foundation of China (Grant Nos.92372101,52162036 and 21875155)the Fundamental Research Funds for the Central Universities (Grant Nos.20720220010)the National Key Research and Development Program of China (Grant Nos.2021YFA1201502)。
文摘The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.
文摘This study deals with the toxic effects of Zn2+, Cu2+, Cd2+ and NH3 on Chinese prawn (Penaeus orientalis). The median lethal concentrations of the toxic matters on Chinese prawn were determined. Cd2+】Cu2+】Zn2+】NH3-Nm is the toxic order of these chemicals to Chinese prawn. The toxic order of concentrated Zn2+ and Cd2+ in tissues and organs of Chinese prawn is in the order gill 】 shell + appendage】viscera 】 muscle..
基金supported by National Natural Science Foundation of China (Nos. 11475039, 11705020, 11605023)Liaoning Provincial Natural Science Foundation of China (No. 20170540153)
文摘The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples.This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical performance of three different normalization methods, namely normalization with background, internal normalization and three point smoothing techniques at different parameter settings is studied for quantification of Ag and Zn by Laser induced breakdown spectroscopy(LIBS).The LIBS spectra of five known concentration of silver zinc binary composites have been investigated at various laser irradiances(LIs). Calibration curves for both Ag(I) line(4d^(10)5s^2S_(1/2)→4d^(10)5p^2P_(1/2) at 338.28 nm) and Zn(I) line(4s5s^3S_1→4s4p^3P_2 at 481.053 nm) have been determined at LI of 5.86?×?10^(10)W cm^(-2). Slopes of these calibration curves provide the valuation of matrix effect in the Ag–Zn composites. With careful sample preparation and normalization after smoothing at optimum parameter setting(OPS), the minimization of sample matrix effect has been successfully achieved. A good linearity has been obtained in Ag and Zn calibration curve at OPS when normalized the whole area of spectrum after smoothing and the obtained coefficients of determination values were R^2?=?0.995 and 0.998 closer to 1. The results of matrix effect have been further verified by analysis of plasma parameters. Both plasma parameters showed no change with varying concentration at OPS. However, at high concentration of Ag, the observed significant changes in both plasma parameters at common parameter setting PS-1 and PS-2 were the gesture of matrix effect. In our case, the better analytical results were obtained at smoothing function with optimized parameter setting that indicates it is more efficient than normalization with background and internal normalization method.
文摘Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, densification, microstructure and a.c. electrical conductivity have been studied. Under the effect of changing the firing temperature and Zn content, high sintered Li-Zn ferrite bodies are achieved. More fine structure bodies having high electrical resistance are obtained at high Zn content
基金partially supported by the National Science Fund for Distinguished Young Scholars(51625102)the National Natural Science Foundation of China(51971065,51901045)+3 种基金the National Natural Science Foundation of China(NSFCàU1903217)the National Natural Science Foundation of China(No.21978073)the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-07-E00028)the Programs for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Li metal is the most ideal anode material for next-generation high energy lithium-ion batteries.The uncontrollable growth of Li dendrites,however,hinders its practical application.Herein,we propose the adoption of Zn nanoparticles uniformly embedded in N-doped carbon polyhedra homogeneously built on carbon cloth(Zn@NC@CC)to prevent the formation of Li dendrites.Based on theoretical calculation and experimental observation,lithiophilic Zn nanoparticles and N-doping inside of the assynthesized Zn@NC play a synergistic role in enhancing the adsorption capacity with Li,thus resulting in uniform Li deposition and complete suppression of Li dendrites.Moreover,the porous N-doped carbon polyhedras uniformly distributed on carbon cloth effectively relieves the volume change of Li upon repeated Li stripping/plating process,which contributes to preserving the structural integrity of the whole electrode and hence enhancing its long-term cycling stability.Benefiting from these synergistic effects,the Li-Zn@NC@CC electrode delivers a prolonged lifespan of over 1200 h at 1 mA cm^(-2) with an areal capacity of 1 mA h cm^(-2) in symmetric cells and high Coulombic efficiencies of 95.4%under an ultrahigh capacity of 12 mA h cm^(-2).Remarkably,Li-Zn@NC@CC//LiFePO_(4) full cells deliver a high reversible capacity of 110.2 mA h g^(-1) at 1 C over 200 cycles.
基金Funded by the Open Project Program of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(No.KLIFMD201606)the Open Fund of National Innovation Platform(No.2017YJ163)+1 种基金the National Natural Science Foundation of China(Nos.51502220,51521001,and 51672197)the Open Foundation of Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics(Wuhan University of Technology)(No.TAM201802)。
文摘A temperature stable Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics were fabricated using a conventional solid-state route sintered at 1100℃for 4 h.The XRD results indicate that the main phase Li2ZnTi3O8 and secondary phase including SrxCa1-xTiO3(0≤x≤1)solid solution and TiO2 co-exist in composite and form a stable composite system when the(CaxSr1-x)(0≤x≤1)substitutes for Zn of Li2ZnTi3O8 ceramic.As x is increased from 0 to 1,the relative permittivity(εr)increases from 26.65 to 27.12,and the quality factor(Q×f)increases from 63300 to 66600 GHz.With the increased of x,the temperature coefficient of resonant frequency(τf)increases from 0.27 to 8.23 ppm/℃,and then decreases to 3.51 ppm/℃.On the whole,the Li2Zn0.95(SrxCa1-x)0.05Ti3O8(0≤x≤1)ceramics show excellent comprehensive properties of middleεr=25-27,higher Q×f≥60000 GHz andτf≤±8.5 ppm/℃.
基金the National Natural Science Foundation of China(Grand No.40773072);the “Western Talent Plan” sponsored by the Chinese Academy of Sciences(2006);the Special Fund provided by the Chongqing Institute of Geology and Mineral Resources.
文摘The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10-6 to 650×10-6 with an average of 310×10-6. In primary ores, Cd concentrations range from 14×10-6 to 2800×10-6 with an average of 767×10-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10-6 to 8200×10-6 , averaging 1661×10-6. It is shown that the oxidized ores are the main carrier and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn>Pb>Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.
基金supported by the National Key Tech-nology R&D Program of China (2006BAD01A05)
文摘Evaluation of the genetic effect on yield and fiber quality can provide useful information on cotton breeding. Sixteen CSB lines and TM-1 introduced from USDA/ARS were used as male and top-crossed with three elite cultivars and the 51 F1 hybrids, 16 CSB lines, TM-1, and 3 elite cultivars were planted at the Cotton Research Institute of CAAS, Anyang, Henan Province and Xiajin, Shandong Province, China. The yield traits and fiber quality data were obtained and additive and dominance effect on each trait were measured by AD model. Boll weight takes the largest additive proration, whereas boll number takes the least additive proration. The largest and the least dominant proration for lint yield and boll weight were measured, respectively. Fiber length has the additive and dominance effect, and dominance effect was slightly more than additive effect. Larger additive and no dominance effect on uniformity, micronaire, and fiber strength were measured. Significantly, positive additive effect on boll weight of CSB06 and CSB12Sh was observed. CSB14Sh and CSB01 have significantly positive additive effect on 4 and 3 traits of fiber quality, respectively. CSB01 has the greatest dominant effect on lint yield among CSB lines. The dominant effect on fiber length of CSB lines showed positive. It is beneficial to use CSB06 and CSB12Sh as parents to improve boll size, to use CSB14Sh and CSB01 as parents to improve fiber quality. As for hybrid cotton breeding, it is reasonable using CSB01 to improve lint yield traits, and using CSB01, CSB11Sh, and CSB06 to improve fiber length.
基金Project(2013CB228600)supported by the National Basic Research Program of China
文摘The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes.
基金This work was supported by the National Natural Science Foundation of China(No.11804196 and No.11904210)the Project funded by China Postdoctoral Science Foundation(No.2018M642689)the Open Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates,(South China University of Technology)(No.2019B030301003).
文摘Two-photon fluorescence dyes have shown promising applications in biomedical imaging.However,the substitution site effect on geometric structures and photophysical properties of fluorescence dyes is rarely illustrated in detail.In this work,a series of new lipid droplets detection dyes are designed and studied,molecular optical properties and non-radiative transitions are analyzed.The intramolecular weak interaction and electron-hole analysis reveal its inner mechanisms.All dyes are proven to possess excellent photophysical properties with high fluorescence quantum efficiency and large stokes shift as well as remarkable two-photon absorption cross section.Our work reasonably elucidates the experimental measurements and the effects of substitution site on two-photon absorption and excited states properties of lipid droplets detection NAPBr dyes are highlighted,which could provide a theoretical perspective for designing efficient organic dyes for lipid droplets detection in biology and medicine fields.
文摘Five experiment ecosystems (MEEE) were employed in April, 1985 to test the effects of a mixture of Cu, Cd, Hg, Pb and Zn on a subtropical planktonic ecosystem in Xiamen Bay, Xiamen, China. The results indicated that the ppb-level of the mixture could suppress the planktonic production. Zooplankton in Xiamen were very sensitive to the metal contamination, especially the larvaceans.
文摘[Zn(POM)_2Br_2](POM is 3-Methyl-4-Nitropyridine-1-Oxide),C_(12)H_(12)Br_2N_4O_6Zn, Mr=533.44,triclinic,P1,a=11.450(3),b=13.027(2),c=6.605(1),α=101.25(1),β=96.96(2), γ=108.06(2)°,V=901.2(4)~3,Z=2,D_c=1.97g·cm^(-3),(MoK_α)=0.71069,F(000)=520, μ=58.21cm^(-1),final R=0.040 for 2192 observed reflections,T=296K.The compound is a mononuclear complex,containing a tetrahedrally coordinated zinc atom.
基金Project(20976016)supported by the National Natural Science Foundation of ChinaProject(09JJ606)supported by the Natural Science Foundation of Hunan Province,ChinaProject(08FJ1002)supported by Key Science Research Project of the Hunan Provincial Natural Science,China
文摘Zn 2+-TiO2 nanotube arrays were prepared by anodic oxidation method.The current-time curves were used to investigate their growth mechanism.Scanning electron microscopy and X-ray diffractometry were applied to characterizing their structures and properties.The photoelectrochemical properties were studied by electrochemical impedance spectrum(EIS).The optimised working conditions for TiO2 nanotube arrays were found to be pH 1,0.5%HF(mass fraction),20 V oxidation voltage and for 2 h.The produced sample was in anatase form,with length of 70-100 nm,thickness of 10 nm,uniform diameter and structure that does not collapse under the preparation conditions.The EIS results show that TiO2 nanotube arrays prepared with 0.5%HF(mass fraction) present a low impedance and TiO2 nanotube arrays loaded by Zn 2+could have a decreased resistance.This decrease could likely accelerate the transfer of carriers and even increase photoelectric conversion.
基金Supported by the Guiding Project of Strategic Emerging Industries of Fujian Provincial Department of Science and Technology under Grant No 2015H0010the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure of Shanghai Institute of Ceramics of Chinese Academy of Sciences under Grant No SKL201404SICthe Natural Science Foundation of Fujian Province under Grant No 2016J01751
文摘The Cu2ZnSnS4 (CZTS)-based solar cell is numerically simulated by a one-dimensional solar cell simulation soft- ware analysis of microelectronic and photonic structures (AMPS-1D). The device structure used in the simulation is Al/ZnO:Al/nZn(O,S)/pCZTS/Mo. The primary motivation of this simulation work is to optimize the composition in the ZnO1-xSx buffer layer, which would yield higher conversion efficiency. By varying S/(S+O) ratio x, the conduction band offset (CBO) at CZTS/Zn(O,S) interface can range from -0.23 eV to 1.06eV if the full range of the ratio is considered. The optimal CBO of 0.23eV can be achieved when the ZnO1-xSx buffer has an S/(S+O) ratio of 0.6. The solar cell efficiency first increases with increasing sulfur content and then decreases abruptly for x〉 0.6, which reaches the highest value of 17.55% by our proposed optimal sulfur content x= 0.6. Our results provide guidance in dealing with the ZnO1-xSx buffer layer deposition for high efficiency CZTS solar cells.
文摘Chemically synthesized ZnS thin film is found to be a good x-ray radiation sensor. We report the effect of annealing on the x-ray radiation detection sensitivity of a ZnS thin film synthesized by a chemical bath deposition technique. The chemically synthesized ZnS films are annealed at 333, 363 and 393K for 1 h. Structural analyses show that the lattice defects in the films decrease with annealing. Further, the band gap is also found to decrease from 3.38 to 3.21 eV after annealing at 393K. Current-voltage characteristics of the films are studied under dark and x-ray irradiation conditions. Due to the decrease of lattice defects and band gap, the conductivity under dark conditions is found to increase from 2.06 × 10^-6 to 1.69 × 10^-5 S/em, while that under x-ray irradiation increases from 4.13 × 10^-5 to 5.28 ×10^-5 S/cm. On the other hand, the x-ray radiation detection sensitivity of the films is found to decrease with annealing. This decrease of detection sensitivity is attributed to the decrease of the band gap as well as some structural and surface morphological changes occurring after annealing.