We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 （LLZO）. A direct incorporation of AI is first promoted in a Li-insufficient garne...We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 （LLZO）. A direct incorporation of AI is first promoted in a Li-insufficient garnet solid electrolyte during the calcination process of 850 ℃ and then the cubic phase of LLZO is obtained after successive annealing step of 1000 ℃. Comparing to pristine LLZO, AI incorporated LLZO shows less formation of Li_2CO_3, keeping crystallographic and physicochemical properties. This AI incorporation im- proves both the ionic conductivity and interfacial resistance to poisoning procedure.展开更多
The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image restoration.This paper proposes a novel apodized cubic phase mask to suppress the s...The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image restoration.This paper proposes a novel apodized cubic phase mask to suppress the side-lobes of the PSF.Simulated annealing algorithm is used to optimize the cubic and the truncation parameter of the phase mask.The system with the novel phase mask has better performance in the modulation transfer function(MTF)especially in low-and-medium spatial frequency region.The simulation results show that the restored images with the novel phase mask are superior to the one with the classic cubic phase mask in contrast and ringing effect.The experimental results show that the side-lobes of the PSF are suppressed by using the apodized cubic phase mask.展开更多
In the present note, through partial substituting of O<sup>2-</sup> by F<sup>-</sup>, CL<sup>-</sup> halogen ions, the HPCP （high-pressure cubic phase） of SrB<sub>2</sub&...In the present note, through partial substituting of O<sup>2-</sup> by F<sup>-</sup>, CL<sup>-</sup> halogen ions, the HPCP （high-pressure cubic phase） of SrB<sub>2</sub>O<sub>4-y</sub>X<sub>y</sub>: Eu<sup>2+</sup> （X=F, Cl） has been synthesized at 800℃ and 3.05GPa for the first time. The results show that the QE （luminescence quantum efficience） of HPCP doped by Cl is twice that of HPCP without doping, and 200展开更多
The purpose of the research is to develop a dynamical theory of phase transitions in crystalline structures, when except for temperature, the pressure is acting. So, the phase diagram temperature-pressure (dimensions)...The purpose of the research is to develop a dynamical theory of phase transitions in crystalline structures, when except for temperature, the pressure is acting. So, the phase diagram temperature-pressure (dimensions) must be constructed. In general case, it is a complicated question, which can be solved for simple models of crystal, as three atomic models, introduced in the work of Frenkel [1]. In this model, three identical atoms are placed on the straight line and interact with the forces, which can be described by the expression, given in the article of Lennard-Jones [2]. Such simple model may have success, when the crystalline structure is simple, which consists of one type of atoms, for example: carbon. The model was generalized to cubic cell model with a moving atom in the inner part of the cell. The rigorous calculation of phase diagram for transition graphite-diamond shows some similarity with results of numerous experimental investigations (which are not discussed here). So, the way of phase diagram calculation may attract attention.展开更多
ABX_(2)(A=Ag,Na,Cu;B=Sb,Bi;X=S,Se,Te)(GroupsⅠ-Ⅴ-Ⅵ_(2))compounds,which are all characterized by the ultralow lattice thermal conductivity because of their strong lattice anharmonicity caused by lone-pair electrons,h...ABX_(2)(A=Ag,Na,Cu;B=Sb,Bi;X=S,Se,Te)(GroupsⅠ-Ⅴ-Ⅵ_(2))compounds,which are all characterized by the ultralow lattice thermal conductivity because of their strong lattice anharmonicity caused by lone-pair electrons,have aroused wide attention in thermoelectric community.The practical application of thermoelectric devices usually requires both the compatible n-type and p-type materials simultaneously.However,most ofⅠ-Ⅴ-Ⅵ_(2)compounds are intrinsic p-type semiconductors,lacking their n-type counterparts for thermoelectrics.Herein,in this work,we increase the configuration entropy of AgBiTe_(2)by alloying SnTe,in order to stabilize the cubic phase at room temperature.With further optimization of thermal and electrical performance,the thermoelectric performance could be improved simultaneously in both n-and p-type(AgBiTe_(2))_(1-x)(SnTe)_(x)(x=0.3,0.4)solid solutions.Finally,p-type compound with the nominal composition of(AgBi_(0.99)Cd_(0.01)Te_(2))_(0.6)(SnTe)_(0.4)and n-type of(AgBiTe_(2))_(0.7)(SnTe)_(0.3)~Br 6%show the maximum zT of~0.33 and~0.21,at 381 and 423 K,respectively.展开更多
The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these compounds.During the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)...The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these compounds.During the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)and InOOH are formed,which are the precursors of stable cubic(c-In_(2)O_(3))and metastable rhombohedral(rh-In_(2)O_(3))phases,respectively.A transition from c-In_(2)O_(3)to rh-In_(2)O_(3)is observed with the addition of CeO_(2).The introduction of cerium into rh-In_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)O_(3).The data on the sensor activity of the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In_(2)O_(3).The reverse situation is observed in composites based on c-In_(2)O_(3).Compared to In_(2)O_(3)and CeO_(2)–In_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between In_(2)O_(3)and CeO_(2).展开更多
Glyceryl monooleate(GMO)is a polar lipid that can exist in various liquid crystalline phases in the presence of different amounts of water.It is regarded as a permeation enhancer due to its amphiphilic property.Variou...Glyceryl monooleate(GMO)is a polar lipid that can exist in various liquid crystalline phases in the presence of different amounts of water.It is regarded as a permeation enhancer due to its amphiphilic property.Various phases of GMO/solvent system containing sodium fluorescein were prepared to compare permeability using confocal laser scanning microscopy(CLSM).GMO was melted in a vial in a water bath heated to 45℃.Propylene glycol and hexanediol were homogeneously dissolved in the melted GMO.Sodium fluorescein in aqueous solution was diluted to various ratios and thoroughly mixed by an ultrasonic homogenizer.Each GMO/Solvent system with fluorescein was applied onto the epidermal side of excised pig skin and incubated overnight.CLSM was performed to observe how the GMO/solvent system in its different phases affect skin permeability.Cubic and lamellar phase formulations enhanced the fluorescein permeation through the stratum corneum.A solution system had the weakest permeability compared to the other two phases.Due to the amphiphilic nature of GMO,cubic and lamellar phases might reduce the barrier function of stratum corneum which was observed by CLSM as fluorescein accumulated in the dermis.Based on the results,the glyceryl monooleate lyotropic mixtures could be applied to enhance skin permeation in various topical and transdermal formulations.展开更多
In the present work, the elastic constants and derived properties of tetragonal Heusler compounds were calculated using the high accuracy of the full-potential linearized augmented plane wave (FPLAPW) method. To find ...In the present work, the elastic constants and derived properties of tetragonal Heusler compounds were calculated using the high accuracy of the full-potential linearized augmented plane wave (FPLAPW) method. To find the criteria required for an accurate calculation, the consequences of increasing the numbers of k-points and plane waves on the convergence of the calculated elastic constants were explored. Once accurate elastic constants were calculated, elastic anisotropies, sound velocities, Debye temperatures, malleability, and other measurable physical properties were determined for the studied systems. The elastic properties suggested metallic bonding with intermediate malleability, between brittle and ductile, for the studied Heusler compounds. To address the effect of off-stoichiometry on the mechanical properties, the virtual crystal approximation (VCA) was used to calculate the elastic constants. The results indicated that an extreme correlation exists between the anisotropy ratio and the stoichiometry of the Heusler compounds, especially in the case of Ni2MnGa. Metastable cubic Ni2MnGa exhibits a very high anisotropy (≈28) and hypothetical cubic Rh2FeSn violates the Born-Huang stability criteria in the L21 structure. The bulk moduli of the investigated tetragonal compounds do not vary much (≈130 ...190 GPa). The averaged values of the other elastic moduli are also rather similar, however, rather large differences are found for the elastic anisotropies of the compounds. These are reflected in very different spatial distributions of Young’s moduli when comparing the different compounds. The slowness surfaces of the compounds also differ considerably even though the average sound velocities are in the same order of magnitude (3.2 ... 3.6 km/s). The results demonstrate the importance of the elastic properties not only for purely tetragonal Heusler compounds but also for phase change materials that exhibit magnetic shape memory or magnetocaloric effects.展开更多
Micron-scale face-centered cubic titanium phase（named as δ phase） were noticed in the re-melted zone of laser surface re-melted commercially pure titanium plate.The morphology,sub-structure,orientation and distribu...Micron-scale face-centered cubic titanium phase（named as δ phase） were noticed in the re-melted zone of laser surface re-melted commercially pure titanium plate.The morphology,sub-structure,orientation and distribution of δ phase were investigated by scanning electron microscopy,electron back-scattered diffraction and transmission electron microscopy.Three kind formation processes of δ phase were put forward based on the investigation.The first one is α＇→δ transformation which takes place in single α＇grains and leads to the orientation relationship {001}δ//{0001}α＇〈 110 〉 δ//〈 112^-0 〉α＇.The second one is β→α＇＋ δ transformation which takes place at α＇/α＇interfaces and leads to the orientation relationship{001}δ//{11^-0}β〈110〉 δ//〈111〉β.The third one is another kind of β→α＇＋ δ transformation that takes place at α＇/α＇interfaces and leads to the orientation relationship{11^-1}δ//{11^-0}β〈 110 〉 δ//〈 111 〈 β.It is believed that the transformations of δ phase are stress assistant ones and in the present investigation,the phase transformation stress of β→α＇transformation acts as the assistant driving force for the formation of δ phase.展开更多
We will build a cubic anvil cell （CAC） apparatus for high-pressure and low-temperature physical property measurements in the synergic extreme condition user facility （SECUF）. In this article, we first introduce th...We will build a cubic anvil cell （CAC） apparatus for high-pressure and low-temperature physical property measurements in the synergic extreme condition user facility （SECUF）. In this article, we first introduce the operating principle, the development history, and the current status of the CAC apparatus, and subsequently describe the design plan and technical targets for the CAC in SECUF. We will demonstrate the unique advantages of CAC, i.e., excellent pressure homogeneity and large hydrostatic pressure capacity, by summarizing our recent research progresses using CAC. Finally, we conclude by providing some perspectives on the applications of CAC in the related research fields.展开更多
Due to advanced technology,electromagnet interference and dissipation problems in the electronic and portable devices at GHz range are increasing daily.Magnetic absorbing materials with outstanding electromagnetic pro...Due to advanced technology,electromagnet interference and dissipation problems in the electronic and portable devices at GHz range are increasing daily.Magnetic absorbing materials with outstanding electromagnetic properties,wide bandwidth,and strong absorption are highly desirable.The present investigation deals with the preparation of Ni-Mg-Cu-Zn(NMCZ)substituted nano ferrites with composition of Ni_(0.3)Mg_(0.2)Cu_(0.3)Zn_(0.2)X_(0.02)Fe_(1.98)O_(4)(X=Nd,Ho,Pr,Gd,Yb).X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),a vibratory sample magnetometer(VSM),and a Vector network analyzer(VNA)were used to investigate these rare earth-doped nanocrystalline ferrites'features.XRD reveals the single spinel phase structure in all Ni-Mg-Cu-Zn ferrites.FTIR spectroscopy shows the presence of tetrahedral and octahedral bands of spinel ferrites.FESEM images reveal the lowest agglomeration for the Ho-doped NMCZ nano-spinel ferrites sample.TEM images show the hexagon shapes of the Yb-and Nd-doped NMCZ ferrites.Pr-doped NMCZ ferrites show more coercivity than other rare earth metals substituted NMCZ nanocrystalline ferrites.VSM analysis was used to calculate the magnetic features like initial permeability,magnetic anisotropy constant,remanence,coercivity,and magnetic moment.High-frequency switching field distributions(SFD)analyses were also investigated.Magnetodielectric characteristics such as losses,permittivity,modulus,Q,ac conductivity,and impedance of the Nd^(-),Ho^(-),Pr^(-),Gd^(-),Yb-doped Ni-Mg-Cu-Zn ferrites were evaluated.The minimum reflection loss(-57.3 dB)is found at 1.4 GHz for Pr-doped Ni-Mg-Cu-Zn ferrite absorber.However,the reflection loss(RL)of-53.9 dB at 2.9 GHz is observed for Ho-doped Ni-Mg-Cu-Zn ferrite absorber.Soft magnetization,low coercivity,outstanding magnetodielectric,and absorption properties of theNd^(-),Ho^(-),Pr^(-),Gd^(-)and Yb^(-)doped Ni-Mg-Cu-Zn ferrites are suitable candidates for absorption in telecommunication,defense,and technological industries.展开更多
Given the safety concerns and low energy density induced by liquid electrolytes,the interest in solidstate lithium metal batteries is rapidly growing.Among various solid electrolytes,garnet-type lithium lanthanum zirc...Given the safety concerns and low energy density induced by liquid electrolytes,the interest in solidstate lithium metal batteries is rapidly growing.Among various solid electrolytes,garnet-type lithium lanthanum zirconate (LLZO) has attracted extensive attention due to its numerous advantages.This review systematically summarizes the intrinsic issues faced by unstable bare LLZO and the resolution strategy of metallic doping in the electrochemical application.It comprehensively discusses the doping arrangements for high ionic conductivity based on element types and gap filling using second phases/sintering aids for LLZO grains/pellets.Emphasizing diverse doping strategies for bulk LLZO,it relates to simulation and characterization findings along with novel synthesis approaches.By identifying the inherent scientific questionsof LLZO,this review bridges the long-existing gaps between the doping strategy guidelines for suitable crystalline phase and the surge of high Li^(+)conductivity for practical solid-state lithium batteries.展开更多
We investigate the Eulerian bond-cubic model on the square lattice by means of Monte Carlo simulations, using an efficient cluster algorithm and a finite-size scaling analysis. The critical points and four critical ex...We investigate the Eulerian bond-cubic model on the square lattice by means of Monte Carlo simulations, using an efficient cluster algorithm and a finite-size scaling analysis. The critical points and four critical exponents of the model are determined for several values of n. Two of the exponents are fractal dimensions, which are obtained numerically for the first time. Our results are consistent with the Coulomb gas predictions for the critical O（n） branch for n 〈 2 and the results obtained by previous transfer matrix calculations. For n = 2, we find that the thermal exponent, the magnetic exponent and the fractal dimension of the largest critical Eulerian bond component are different from those of the critical 0（2） loop model. These results confirm that the cubic anisotropy is marginal at n = 2 but irrelevant for n〈2.展开更多
A four-parameter, Ghoderao–Dalvi–Narayan 2 cubic equation of state(GDN2 CEOS), is presented which incorporates the following: 1. The experimental value of the critical compressibility factor has been used as a fixed...A four-parameter, Ghoderao–Dalvi–Narayan 2 cubic equation of state(GDN2 CEOS), is presented which incorporates the following: 1. The experimental value of the critical compressibility factor has been used as a fixed input parameter for calculations;2. All the parameters(a, b, c, d) of CEOS are temperature dependent functions in the subcritical region and are temperature independent functions in the supercritical region and;3. A new α function is introduced with two compound specific parameters which are estimated by matching saturated vapor pressure at two fixed temperature points Tr= 0.5, 0.7. Our formalism enables us to cast three of the four parameters of the CEOS as a function of the remaining parameter. The proposed CEOS is used to predict properties of 334 pure compounds, including saturated vapor pressure and liquid density, compressed liquid density, heat capacities at the constant pressure and volume, enthalpy of vaporization, sound velocity. To calculate thermodynamic properties of a pure compound, the present CEOS require the critical temperature, the critical pressure, the Pitzer’s acentric factor, the critical compressibility factor, and two parameters of the alpha function. The saturated liquid density predictions for pure fluids are very accurate when compared with GDN1(Ghoderao–Dalvi–Narayan 1),MPR(Modified Peng–Robinson), and PT(Patel–Teja) equations of state. Unlike MPR EOS, the proposed temperature dependent covolume parameter b in the present work satisfies all the constraints mentioned in the literature to avoid thermodynamic inconsistencies at the extreme temperature and pressure. Using van der Waals one-fluid mixing rule, the present CEOS is further used to predict bubble pressure and the vapor mole fraction of binary mixtures.展开更多
Deposition and structural characteristics of cadmium sulfide (CdS) thin films by chemical bath deposition (CBD) technique from a bath containing thiourea,cadmium acetate,ammonium acetate and ammonia in an aqueous solu...Deposition and structural characteristics of cadmium sulfide (CdS) thin films by chemical bath deposition (CBD) technique from a bath containing thiourea,cadmium acetate,ammonium acetate and ammonia in an aqueous solution are reported.Researches are made on the influence of the fundamental parameters including pH,temperature,and concentrations of the solution involved in the chemical bath deposition of CdS and titration or dumping of the thiourea solution on the structure characteristic of CdS thin films.The pH of the solution plays a vital role on the characteristic of the CdS thin films.The XRD patterns show that the change in the pH of the solution results in the change in crystal phase from predominant hexagonal phase to predominant cubic phase.The CdS thin films with the two different crystal phases have different influences on CIGS thin film solar cells.The crystal mismatch and the interface state density of the c-CdS(cubic phase CdS) and CIGS are about 1 419% and 8 507×10 12cm -2 respectively,and those of the h-CdS(hexagonal phase CdS) and CIGS are about 32 297% and 2 792×10 12cm -2 respectively.It is necessary for high efficiency CIGS thin film solar cells to deposit the cubic phase CdS thin films.展开更多
基金financial support from the R&D Convergence Program (CAP-14-02-KITECH)the National Research Council of Science & Technology of the Republic of Korea
文摘We observe the influence of AI occupancies in Li sites on the formation process of the garnet solid elec- trolyte of Li_7La_3Zr_2O_12 （LLZO）. A direct incorporation of AI is first promoted in a Li-insufficient garnet solid electrolyte during the calcination process of 850 ℃ and then the cubic phase of LLZO is obtained after successive annealing step of 1000 ℃. Comparing to pristine LLZO, AI incorporated LLZO shows less formation of Li_2CO_3, keeping crystallographic and physicochemical properties. This AI incorporation im- proves both the ionic conductivity and interfacial resistance to poisoning procedure.
文摘The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image restoration.This paper proposes a novel apodized cubic phase mask to suppress the side-lobes of the PSF.Simulated annealing algorithm is used to optimize the cubic and the truncation parameter of the phase mask.The system with the novel phase mask has better performance in the modulation transfer function(MTF)especially in low-and-medium spatial frequency region.The simulation results show that the restored images with the novel phase mask are superior to the one with the classic cubic phase mask in contrast and ringing effect.The experimental results show that the side-lobes of the PSF are suppressed by using the apodized cubic phase mask.
基金Project supported by the National Natural Science Foundation of China
文摘In the present note, through partial substituting of O<sup>2-</sup> by F<sup>-</sup>, CL<sup>-</sup> halogen ions, the HPCP （high-pressure cubic phase） of SrB<sub>2</sub>O<sub>4-y</sub>X<sub>y</sub>: Eu<sup>2+</sup> （X=F, Cl） has been synthesized at 800℃ and 3.05GPa for the first time. The results show that the QE （luminescence quantum efficience） of HPCP doped by Cl is twice that of HPCP without doping, and 200
文摘The purpose of the research is to develop a dynamical theory of phase transitions in crystalline structures, when except for temperature, the pressure is acting. So, the phase diagram temperature-pressure (dimensions) must be constructed. In general case, it is a complicated question, which can be solved for simple models of crystal, as three atomic models, introduced in the work of Frenkel [1]. In this model, three identical atoms are placed on the straight line and interact with the forces, which can be described by the expression, given in the article of Lennard-Jones [2]. Such simple model may have success, when the crystalline structure is simple, which consists of one type of atoms, for example: carbon. The model was generalized to cubic cell model with a moving atom in the inner part of the cell. The rigorous calculation of phase diagram for transition graphite-diamond shows some similarity with results of numerous experimental investigations (which are not discussed here). So, the way of phase diagram calculation may attract attention.
基金financially supported by the National Natural Science Foundation of China(Nos.51772035 and 11874356)the Fundamental Research Funds for the Central Universities(No.2020CDJ-LHZZ-011)Chongqing Entrepreneurship and Innovation Program for the Returned Overseas Chinese Scholars(No.cx2019002)
文摘ABX_(2)(A=Ag,Na,Cu;B=Sb,Bi;X=S,Se,Te)(GroupsⅠ-Ⅴ-Ⅵ_(2))compounds,which are all characterized by the ultralow lattice thermal conductivity because of their strong lattice anharmonicity caused by lone-pair electrons,have aroused wide attention in thermoelectric community.The practical application of thermoelectric devices usually requires both the compatible n-type and p-type materials simultaneously.However,most ofⅠ-Ⅴ-Ⅵ_(2)compounds are intrinsic p-type semiconductors,lacking their n-type counterparts for thermoelectrics.Herein,in this work,we increase the configuration entropy of AgBiTe_(2)by alloying SnTe,in order to stabilize the cubic phase at room temperature.With further optimization of thermal and electrical performance,the thermoelectric performance could be improved simultaneously in both n-and p-type(AgBiTe_(2))_(1-x)(SnTe)_(x)(x=0.3,0.4)solid solutions.Finally,p-type compound with the nominal composition of(AgBi_(0.99)Cd_(0.01)Te_(2))_(0.6)(SnTe)_(0.4)and n-type of(AgBiTe_(2))_(0.7)(SnTe)_(0.3)~Br 6%show the maximum zT of~0.33 and~0.21,at 381 and 423 K,respectively.
基金supported by the Russian Science Foundation(grant No.22-19-00037),https://rscf.ru/project/22-19-00037/.
文摘The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these compounds.During the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)and InOOH are formed,which are the precursors of stable cubic(c-In_(2)O_(3))and metastable rhombohedral(rh-In_(2)O_(3))phases,respectively.A transition from c-In_(2)O_(3)to rh-In_(2)O_(3)is observed with the addition of CeO_(2).The introduction of cerium into rh-In_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)O_(3).The data on the sensor activity of the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In_(2)O_(3).The reverse situation is observed in composites based on c-In_(2)O_(3).Compared to In_(2)O_(3)and CeO_(2)–In_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between In_(2)O_(3)and CeO_(2).
基金This study was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Korean Ministry of Education,Science and Technology(2012002399)a grant of the Korean Healthcare Technology R&D Project,Ministry of Health and Welfare,Republic of Korea.(Grant No.:A103017).
文摘Glyceryl monooleate(GMO)is a polar lipid that can exist in various liquid crystalline phases in the presence of different amounts of water.It is regarded as a permeation enhancer due to its amphiphilic property.Various phases of GMO/solvent system containing sodium fluorescein were prepared to compare permeability using confocal laser scanning microscopy(CLSM).GMO was melted in a vial in a water bath heated to 45℃.Propylene glycol and hexanediol were homogeneously dissolved in the melted GMO.Sodium fluorescein in aqueous solution was diluted to various ratios and thoroughly mixed by an ultrasonic homogenizer.Each GMO/Solvent system with fluorescein was applied onto the epidermal side of excised pig skin and incubated overnight.CLSM was performed to observe how the GMO/solvent system in its different phases affect skin permeability.Cubic and lamellar phase formulations enhanced the fluorescein permeation through the stratum corneum.A solution system had the weakest permeability compared to the other two phases.Due to the amphiphilic nature of GMO,cubic and lamellar phases might reduce the barrier function of stratum corneum which was observed by CLSM as fluorescein accumulated in the dermis.Based on the results,the glyceryl monooleate lyotropic mixtures could be applied to enhance skin permeation in various topical and transdermal formulations.
文摘In the present work, the elastic constants and derived properties of tetragonal Heusler compounds were calculated using the high accuracy of the full-potential linearized augmented plane wave (FPLAPW) method. To find the criteria required for an accurate calculation, the consequences of increasing the numbers of k-points and plane waves on the convergence of the calculated elastic constants were explored. Once accurate elastic constants were calculated, elastic anisotropies, sound velocities, Debye temperatures, malleability, and other measurable physical properties were determined for the studied systems. The elastic properties suggested metallic bonding with intermediate malleability, between brittle and ductile, for the studied Heusler compounds. To address the effect of off-stoichiometry on the mechanical properties, the virtual crystal approximation (VCA) was used to calculate the elastic constants. The results indicated that an extreme correlation exists between the anisotropy ratio and the stoichiometry of the Heusler compounds, especially in the case of Ni2MnGa. Metastable cubic Ni2MnGa exhibits a very high anisotropy (≈28) and hypothetical cubic Rh2FeSn violates the Born-Huang stability criteria in the L21 structure. The bulk moduli of the investigated tetragonal compounds do not vary much (≈130 ...190 GPa). The averaged values of the other elastic moduli are also rather similar, however, rather large differences are found for the elastic anisotropies of the compounds. These are reflected in very different spatial distributions of Young’s moduli when comparing the different compounds. The slowness surfaces of the compounds also differ considerably even though the average sound velocities are in the same order of magnitude (3.2 ... 3.6 km/s). The results demonstrate the importance of the elastic properties not only for purely tetragonal Heusler compounds but also for phase change materials that exhibit magnetic shape memory or magnetocaloric effects.
基金financially supported by the Natural Science Foundation of Beijing (Grant No.Z140002)
文摘Micron-scale face-centered cubic titanium phase（named as δ phase） were noticed in the re-melted zone of laser surface re-melted commercially pure titanium plate.The morphology,sub-structure,orientation and distribution of δ phase were investigated by scanning electron microscopy,electron back-scattered diffraction and transmission electron microscopy.Three kind formation processes of δ phase were put forward based on the investigation.The first one is α＇→δ transformation which takes place in single α＇grains and leads to the orientation relationship {001}δ//{0001}α＇〈 110 〉 δ//〈 112^-0 〉α＇.The second one is β→α＇＋ δ transformation which takes place at α＇/α＇interfaces and leads to the orientation relationship{001}δ//{11^-0}β〈110〉 δ//〈111〉β.The third one is another kind of β→α＇＋ δ transformation that takes place at α＇/α＇interfaces and leads to the orientation relationship{11^-1}δ//{11^-0}β〈 110 〉 δ//〈 111 〈 β.It is believed that the transformations of δ phase are stress assistant ones and in the present investigation,the phase transformation stress of β→α＇transformation acts as the assistant driving force for the formation of δ phase.
基金Project supported by the National Natural Science Foundation of China(Grant No.11574377)the State Key Development Program for Basic Research of China(Grant Nos.2018YFA0305700 and 2014CB921500)+1 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH013)the JSPS KAKENHI(Grant No.15H03681)
文摘We will build a cubic anvil cell （CAC） apparatus for high-pressure and low-temperature physical property measurements in the synergic extreme condition user facility （SECUF）. In this article, we first introduce the operating principle, the development history, and the current status of the CAC apparatus, and subsequently describe the design plan and technical targets for the CAC in SECUF. We will demonstrate the unique advantages of CAC, i.e., excellent pressure homogeneity and large hydrostatic pressure capacity, by summarizing our recent research progresses using CAC. Finally, we conclude by providing some perspectives on the applications of CAC in the related research fields.
基金Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2024R42),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabiathe Deanship of Scientific Research at King Khalid University for funding this work through large group Research Project(RGP2/387/44)。
文摘Due to advanced technology,electromagnet interference and dissipation problems in the electronic and portable devices at GHz range are increasing daily.Magnetic absorbing materials with outstanding electromagnetic properties,wide bandwidth,and strong absorption are highly desirable.The present investigation deals with the preparation of Ni-Mg-Cu-Zn(NMCZ)substituted nano ferrites with composition of Ni_(0.3)Mg_(0.2)Cu_(0.3)Zn_(0.2)X_(0.02)Fe_(1.98)O_(4)(X=Nd,Ho,Pr,Gd,Yb).X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),a vibratory sample magnetometer(VSM),and a Vector network analyzer(VNA)were used to investigate these rare earth-doped nanocrystalline ferrites'features.XRD reveals the single spinel phase structure in all Ni-Mg-Cu-Zn ferrites.FTIR spectroscopy shows the presence of tetrahedral and octahedral bands of spinel ferrites.FESEM images reveal the lowest agglomeration for the Ho-doped NMCZ nano-spinel ferrites sample.TEM images show the hexagon shapes of the Yb-and Nd-doped NMCZ ferrites.Pr-doped NMCZ ferrites show more coercivity than other rare earth metals substituted NMCZ nanocrystalline ferrites.VSM analysis was used to calculate the magnetic features like initial permeability,magnetic anisotropy constant,remanence,coercivity,and magnetic moment.High-frequency switching field distributions(SFD)analyses were also investigated.Magnetodielectric characteristics such as losses,permittivity,modulus,Q,ac conductivity,and impedance of the Nd^(-),Ho^(-),Pr^(-),Gd^(-),Yb-doped Ni-Mg-Cu-Zn ferrites were evaluated.The minimum reflection loss(-57.3 dB)is found at 1.4 GHz for Pr-doped Ni-Mg-Cu-Zn ferrite absorber.However,the reflection loss(RL)of-53.9 dB at 2.9 GHz is observed for Ho-doped Ni-Mg-Cu-Zn ferrite absorber.Soft magnetization,low coercivity,outstanding magnetodielectric,and absorption properties of theNd^(-),Ho^(-),Pr^(-),Gd^(-)and Yb^(-)doped Ni-Mg-Cu-Zn ferrites are suitable candidates for absorption in telecommunication,defense,and technological industries.
基金supported by the National Natural Science Foundation of China(No.52303245)the Innovative Training/Entrepreneurial Program for Undergraduate(No.202410057057)the"Huacai"training special program of Tianjin University of Science and Technology
文摘Given the safety concerns and low energy density induced by liquid electrolytes,the interest in solidstate lithium metal batteries is rapidly growing.Among various solid electrolytes,garnet-type lithium lanthanum zirconate (LLZO) has attracted extensive attention due to its numerous advantages.This review systematically summarizes the intrinsic issues faced by unstable bare LLZO and the resolution strategy of metallic doping in the electrochemical application.It comprehensively discusses the doping arrangements for high ionic conductivity based on element types and gap filling using second phases/sintering aids for LLZO grains/pellets.Emphasizing diverse doping strategies for bulk LLZO,it relates to simulation and characterization findings along with novel synthesis approaches.By identifying the inherent scientific questionsof LLZO,this review bridges the long-existing gaps between the doping strategy guidelines for suitable crystalline phase and the surge of high Li^(+)conductivity for practical solid-state lithium batteries.
基金Project supported by the National Natural Science Foundation of China (Grant No.10675021)the New Century Excellent Talents in University of China,the Natural Science Foundation of Anhui Province of China (Grant No.090416224)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20103402110053)
文摘We investigate the Eulerian bond-cubic model on the square lattice by means of Monte Carlo simulations, using an efficient cluster algorithm and a finite-size scaling analysis. The critical points and four critical exponents of the model are determined for several values of n. Two of the exponents are fractal dimensions, which are obtained numerically for the first time. Our results are consistent with the Coulomb gas predictions for the critical O（n） branch for n 〈 2 and the results obtained by previous transfer matrix calculations. For n = 2, we find that the thermal exponent, the magnetic exponent and the fractal dimension of the largest critical Eulerian bond component are different from those of the critical 0（2） loop model. These results confirm that the cubic anisotropy is marginal at n = 2 but irrelevant for n〈2.
基金supported by the University Grants Commission (UGC – BSR)
文摘A four-parameter, Ghoderao–Dalvi–Narayan 2 cubic equation of state(GDN2 CEOS), is presented which incorporates the following: 1. The experimental value of the critical compressibility factor has been used as a fixed input parameter for calculations;2. All the parameters(a, b, c, d) of CEOS are temperature dependent functions in the subcritical region and are temperature independent functions in the supercritical region and;3. A new α function is introduced with two compound specific parameters which are estimated by matching saturated vapor pressure at two fixed temperature points Tr= 0.5, 0.7. Our formalism enables us to cast three of the four parameters of the CEOS as a function of the remaining parameter. The proposed CEOS is used to predict properties of 334 pure compounds, including saturated vapor pressure and liquid density, compressed liquid density, heat capacities at the constant pressure and volume, enthalpy of vaporization, sound velocity. To calculate thermodynamic properties of a pure compound, the present CEOS require the critical temperature, the critical pressure, the Pitzer’s acentric factor, the critical compressibility factor, and two parameters of the alpha function. The saturated liquid density predictions for pure fluids are very accurate when compared with GDN1(Ghoderao–Dalvi–Narayan 1),MPR(Modified Peng–Robinson), and PT(Patel–Teja) equations of state. Unlike MPR EOS, the proposed temperature dependent covolume parameter b in the present work satisfies all the constraints mentioned in the literature to avoid thermodynamic inconsistencies at the extreme temperature and pressure. Using van der Waals one-fluid mixing rule, the present CEOS is further used to predict bubble pressure and the vapor mole fraction of binary mixtures.
文摘Deposition and structural characteristics of cadmium sulfide (CdS) thin films by chemical bath deposition (CBD) technique from a bath containing thiourea,cadmium acetate,ammonium acetate and ammonia in an aqueous solution are reported.Researches are made on the influence of the fundamental parameters including pH,temperature,and concentrations of the solution involved in the chemical bath deposition of CdS and titration or dumping of the thiourea solution on the structure characteristic of CdS thin films.The pH of the solution plays a vital role on the characteristic of the CdS thin films.The XRD patterns show that the change in the pH of the solution results in the change in crystal phase from predominant hexagonal phase to predominant cubic phase.The CdS thin films with the two different crystal phases have different influences on CIGS thin film solar cells.The crystal mismatch and the interface state density of the c-CdS(cubic phase CdS) and CIGS are about 1 419% and 8 507×10 12cm -2 respectively,and those of the h-CdS(hexagonal phase CdS) and CIGS are about 32 297% and 2 792×10 12cm -2 respectively.It is necessary for high efficiency CIGS thin film solar cells to deposit the cubic phase CdS thin films.
