We described a method for obtaining fluorine-free Ti_(3)C_(2)Cl_(2)MXene phases by melting copper in CuCl_(2)instead of aluminum in Ti_(3)AlC_(2).XRD results show that when molten salt CuCl_(2)etches Ti_(3)AlC_(2),it ...We described a method for obtaining fluorine-free Ti_(3)C_(2)Cl_(2)MXene phases by melting copper in CuCl_(2)instead of aluminum in Ti_(3)AlC_(2).XRD results show that when molten salt CuCl_(2)etches Ti_(3)AlC_(2),it forms an intermediate product Ti_(3)CuC_(2),and then reacts with Ti_(3)CuC_(2)to obtain Ti_(3)C_(2)Cl_(2).The reaction of Ti_(3)AlC_(2)and CuCl_(2)at a temperature of 800℃for 2 h to obtain Ti_(3)C_(2)Cl_(2)with an optimal lamellar structure is shown in SEM results.The pseudopotential plane-wave(PP-PW)method is used to calculate on the electronic structure.The etching mechanism is investigated by the total energies of each substance.The chemical reaction of Ti_(3)AlC_(2)and CuCl_(2)will first become Ti_(3)CuC_(2)and Cu,and then become Ti_(3)C_(2)Cl_(2)during the Lewis acid etching process,which are consistent with the experimental results.展开更多
The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibite...The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.展开更多
This study presents a novel two-step approach to assess plate-like structural laminar damages,particularly for delamination damage detection of composite structures.Firstly,a 2-D continuous wavelet transform is employ...This study presents a novel two-step approach to assess plate-like structural laminar damages,particularly for delamination damage detection of composite structures.Firstly,a 2-D continuous wavelet transform is employed to identify the damage location and sizes from vibration curvature data.An inverse method is subsequently then used to determine the bending stiffness reduction ratio along a specified direction,enabling the quantification of the delamination severity.The method employed in this study is an extension of the one-dimensional inverse method developed in a previous work of the authors.The applicability of the two-step inverse approach is demonstrated in a simulation analysis and by an experimental study on a cantilever composite plate containing a single delamination.The inverse method is shown to have the capacity to reveal the detailed damage information of delamination within a constrained searching space and can be used to determine the effective flexural stiffness of composite plate structures,even in cases of complex delamination damage.展开更多
The zinc oxide seed film was coated on conductive glass (FTO) substrate by the Czochralski method,Zinc acetate and hexamethylenetetramine were used as raw materials to prepare growth solution,and then ZnO film was pre...The zinc oxide seed film was coated on conductive glass (FTO) substrate by the Czochralski method,Zinc acetate and hexamethylenetetramine were used as raw materials to prepare growth solution,and then ZnO film was prepared by a low-temperature solution method.The effects of annealing temperature on the morphology,structure,stress and optical properties of ZnO films were studied.The thin films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),UV-visible absorption spectra (UV-vis),photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS).The results show that the films are ZnO nanorods.With the increase of annealing temperature,the diameter of the rod increases,and the nanorods tend to be oriented.The band gap of the sample obtained from the light absorption spectra first increases and then decreases with the increase of annealing temperature.When the annealing temperature is 350 ℃,the crystallinity of zinc oxide film is the highest,the band gap is close to the theoretical value of pure ZnO.展开更多
The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X...The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors.展开更多
Objective: To analyze the dynamic evaluation of chemiluminescence, colloidal gold, and immunofluorescence chromatography in detecting antibodies in COVID-19 patients within four weeks of infection, and to provide evid...Objective: To analyze the dynamic evaluation of chemiluminescence, colloidal gold, and immunofluorescence chromatography in detecting antibodies in COVID-19 patients within four weeks of infection, and to provide evidence for clinical application. Method: 74 patients with confirmed SARS-COV-2 infection in the local area were selected as the experimental group, while 231 patients with negative SARS-COV-2 results but not vaccinated with Covid19 vaccine were selected as the control group;during the first, second, third, and fourth weeks after enrollment in the experimental group, three methods were used to detect SARS-COV-2 IgG and IgM in patients’ blood: chemiluminescence method, colloidal gold antibody method, and immuno-fluorescence chromatography. In the control group, three methods were used to detect SARS-COV-2 IgG and IgM during physical examination for SARS-COV-2 nucleic acids. The ROC curve was drawn to analyze the value of each indicator in predicting SARS-COV-2 infection, and the kappa method was used to analyze the consistency of the detection results of each indicator. Results: There was no significant difference in the positive rates of SARS-COV-2 IgM and IgG antibodies detected by chemiluminescence, colloidal gold, and immunofluorescence chromatography during the four-week period (P > 0.05). The positive rates of SARS-COV-2 IgM and IgG antibodies detected by the three methods during the first week of infection were not higher than 60%;when the three methods were used to detect SARS-COV-2 IgM and IgG in vivo, the AUC diagnosed by the test results was less than 0.80 at the first week, the diagnostic efficacy of the three methods was above 0.95 from the second week to the fourth week, and the diagnostic efficacy of the three methods was higher than 0.97 at the fourth week. The diagnostic efficacy of the three methods was comparable;the three methods for detecting SARS-COV-2 IgM and IgG antibodies showed high consistency in four cycles. Conclusion: Chemiluminescence, colloidal gold, and immunofluorescence chromatography are highly consistent in the detection of SARS-COV-2 IgM and IgG antibodies, and can be used as an auxiliary diagnosis and efficacy observation of novel coronavirus infections according to the needs, but the positive rate of infected people in the first week is low.展开更多
The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibr...The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibrations. This vibrational MCDW method is employed to calculate the TDCSs of 1b3gorbital of ethylene at low(100 eV) and medium(250 eV) incident electron energies in coplanar asymmetric kinematic condition. The results show that molecular vibrations significantly influence the angular distributions of the TDCSs, especially in the binary region along momentum transfer near the Bethe ridge.展开更多
In this experiment, Cu<sup>2+</sup> doped ZnO (Cu-ZnO) nanorods materials have been fabricated by hydrothermal method. Cu<sup>2+</sup> ions were doped into ZnO with ratios of 2, 5 and 7 mol.% (...In this experiment, Cu<sup>2+</sup> doped ZnO (Cu-ZnO) nanorods materials have been fabricated by hydrothermal method. Cu<sup>2+</sup> ions were doped into ZnO with ratios of 2, 5 and 7 mol.% (compared to the mole’s number of Zn<sup>2+</sup>). The hexamethylenetetramine (HMTA) solvent used for the fabrication of Cu-ZnO nanorods with the mole ratio of Zn<sup>2+</sup>:HMTA = 1:4. The characteristics of the materials were analyzed by techniques, such as XRD, Raman shift, SEM and UV-vis diffuse reflectance spectra (DRS). The photocatalytic properties of the materials were investigated by the decomposition of the methylene blue (MB) dye solution under ultraviolet light. The results show that the size of Cu-ZnO nanorods was reduced when the Cu<sup>2+</sup> doping ratio increased from 2 mol.% to 7 mol.%. The decomposition efficiency of the MB dye solution reached 92% - 97%, corresponding to the Cu<sup>2+</sup> doping ratio changed from 2 - 7 mol.% (after 40 minutes of ultraviolet irradiation). The highest efficiency for the decomposition of the MB solution was obtained at a Cu<sup>2+</sup> doping ratio of 2 mol.%.展开更多
In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 eq...In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 equation, Joseph-Egri (TRLW) equation, and Calogro-Degasperis (CD) equation. As a result, we have obtained solutions for the equations expressed in terms of trigonometric, hyperbolic and rational functions. Moreover, some selected solutions are plotted using some specific values for the parameters.展开更多
Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, XRD, SEM and EDAX data. U...Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, XRD, SEM and EDAX data. UV-Visible spectroscopy measurements reveal that the Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has maximum absorption at 353.04 nm and this peak position reflects the band gap of particles and it is found to be 2.51 eV which was calculated using Tauc plot. X-Ray diffraction (XRD) reveals crystaline size to be 49.85 nm which was calculated using Williamson-Hall (W-H) plot method. Photocatalytic degradation of acetic acid, chloroacetic acid and trichloroacetic acid has been studied by volumetric method using NaOH solution. Photocatalytic degradation of chloroacetic acid and acetic acid follows first order kinetics. The photodegradation efficiency for Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite was found to be ≈97.8%. A Taft linear free energy relationship is noted for the catalysed reaction with ρ* = 0.233 and indicating electron withdrawing groups enhance the rate. An isokinetic relation is observed with β = 358 K indicating that enthalpy factor controls the reaction rate. The result of this paper suggests the possibility of degradation of organic compounds, industrial effluants and toxic organic compounds by photodegradation process by ecofriendly Al<sub>2</sub>S<sub>3</sub>/ MoS<sub>2</sub>. The antibacterial activity of Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite was investigated. These particles were shown to have an effective bactericide.展开更多
基金Funded by the National Natural Science Foundation for Young Scholars of China(No.51302073)the Hubei Provincial Key Laboratory of Green Materials for Light IndustryHubei University of Technology(No.202307B07)。
文摘We described a method for obtaining fluorine-free Ti_(3)C_(2)Cl_(2)MXene phases by melting copper in CuCl_(2)instead of aluminum in Ti_(3)AlC_(2).XRD results show that when molten salt CuCl_(2)etches Ti_(3)AlC_(2),it forms an intermediate product Ti_(3)CuC_(2),and then reacts with Ti_(3)CuC_(2)to obtain Ti_(3)C_(2)Cl_(2).The reaction of Ti_(3)AlC_(2)and CuCl_(2)at a temperature of 800℃for 2 h to obtain Ti_(3)C_(2)Cl_(2)with an optimal lamellar structure is shown in SEM results.The pseudopotential plane-wave(PP-PW)method is used to calculate on the electronic structure.The etching mechanism is investigated by the total energies of each substance.The chemical reaction of Ti_(3)AlC_(2)and CuCl_(2)will first become Ti_(3)CuC_(2)and Cu,and then become Ti_(3)C_(2)Cl_(2)during the Lewis acid etching process,which are consistent with the experimental results.
文摘The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.
文摘This study presents a novel two-step approach to assess plate-like structural laminar damages,particularly for delamination damage detection of composite structures.Firstly,a 2-D continuous wavelet transform is employed to identify the damage location and sizes from vibration curvature data.An inverse method is subsequently then used to determine the bending stiffness reduction ratio along a specified direction,enabling the quantification of the delamination severity.The method employed in this study is an extension of the one-dimensional inverse method developed in a previous work of the authors.The applicability of the two-step inverse approach is demonstrated in a simulation analysis and by an experimental study on a cantilever composite plate containing a single delamination.The inverse method is shown to have the capacity to reveal the detailed damage information of delamination within a constrained searching space and can be used to determine the effective flexural stiffness of composite plate structures,even in cases of complex delamination damage.
基金Funded by Henan International Science and Technology Cooperation Program (No.152102410035)Ph D Research Startup Foundation of Henan University of Science and Technology(No.13480107)。
文摘The zinc oxide seed film was coated on conductive glass (FTO) substrate by the Czochralski method,Zinc acetate and hexamethylenetetramine were used as raw materials to prepare growth solution,and then ZnO film was prepared by a low-temperature solution method.The effects of annealing temperature on the morphology,structure,stress and optical properties of ZnO films were studied.The thin films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),UV-visible absorption spectra (UV-vis),photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS).The results show that the films are ZnO nanorods.With the increase of annealing temperature,the diameter of the rod increases,and the nanorods tend to be oriented.The band gap of the sample obtained from the light absorption spectra first increases and then decreases with the increase of annealing temperature.When the annealing temperature is 350 ℃,the crystallinity of zinc oxide film is the highest,the band gap is close to the theoretical value of pure ZnO.
基金financially supported by (i) Suranaree University of Technology,(ii) Thailand Science Research and Innovation,and (iii) National Science,Research and Innovation Fund(project codes 90464 and 160363)。
文摘The effect of Na-excess content in the precursor on the structural and electrochemical performances of sodium nickel manganese oxide(NNMO)prepared by sol-gel and electrospinning methods is investigated in this paper.X-ray diffraction results of the prepared NNMO without adding Na-excess content indicate sodium loss,while the mixed phase of P2/O′3-type layered NNMO presented after adding Na-excess content.Compared with the sol-gel method,the secondary phase of NiO is more suppressed by using the electrospinning method,which is further confirmed by field emission scanning electron microscope images.N_(2) adsorption-desorption isotherms show no remarkably difference in specific surface areas between different preparation methods and Na-excess contents.The analysis of X-ray absorption near edge structure indicates that the oxidation states of Ni and Mn are+2 and+4,respectively.For the electrochemical properties,superior electrochemical performance is observed in the NNMO electrode with a low Na-excess content of 5wt%.The highest specific capacitance is 36.07 F·g^(-1)at0.1 A·g^(-1)in the NNMO electrode prepared by using the sol-gel method.By contrast,the NNMO electrode prepared using the electrospinning method with decreased Na-excess content shows excellent cycling stability of 100%after charge-discharge measurements for 300 cycles.Therefore,controlling the Na excess in the precursor together with the preparation method is important for improving the electrochemical performance of Na-based electrode materials in supercapacitors.
文摘Objective: To analyze the dynamic evaluation of chemiluminescence, colloidal gold, and immunofluorescence chromatography in detecting antibodies in COVID-19 patients within four weeks of infection, and to provide evidence for clinical application. Method: 74 patients with confirmed SARS-COV-2 infection in the local area were selected as the experimental group, while 231 patients with negative SARS-COV-2 results but not vaccinated with Covid19 vaccine were selected as the control group;during the first, second, third, and fourth weeks after enrollment in the experimental group, three methods were used to detect SARS-COV-2 IgG and IgM in patients’ blood: chemiluminescence method, colloidal gold antibody method, and immuno-fluorescence chromatography. In the control group, three methods were used to detect SARS-COV-2 IgG and IgM during physical examination for SARS-COV-2 nucleic acids. The ROC curve was drawn to analyze the value of each indicator in predicting SARS-COV-2 infection, and the kappa method was used to analyze the consistency of the detection results of each indicator. Results: There was no significant difference in the positive rates of SARS-COV-2 IgM and IgG antibodies detected by chemiluminescence, colloidal gold, and immunofluorescence chromatography during the four-week period (P > 0.05). The positive rates of SARS-COV-2 IgM and IgG antibodies detected by the three methods during the first week of infection were not higher than 60%;when the three methods were used to detect SARS-COV-2 IgM and IgG in vivo, the AUC diagnosed by the test results was less than 0.80 at the first week, the diagnostic efficacy of the three methods was above 0.95 from the second week to the fourth week, and the diagnostic efficacy of the three methods was higher than 0.97 at the fourth week. The diagnostic efficacy of the three methods was comparable;the three methods for detecting SARS-COV-2 IgM and IgG antibodies showed high consistency in four cycles. Conclusion: Chemiluminescence, colloidal gold, and immunofluorescence chromatography are highly consistent in the detection of SARS-COV-2 IgM and IgG antibodies, and can be used as an auxiliary diagnosis and efficacy observation of novel coronavirus infections according to the needs, but the positive rate of infected people in the first week is low.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12004370 and 12127804)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB34020000)。
文摘The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibrations. This vibrational MCDW method is employed to calculate the TDCSs of 1b3gorbital of ethylene at low(100 eV) and medium(250 eV) incident electron energies in coplanar asymmetric kinematic condition. The results show that molecular vibrations significantly influence the angular distributions of the TDCSs, especially in the binary region along momentum transfer near the Bethe ridge.
文摘In this experiment, Cu<sup>2+</sup> doped ZnO (Cu-ZnO) nanorods materials have been fabricated by hydrothermal method. Cu<sup>2+</sup> ions were doped into ZnO with ratios of 2, 5 and 7 mol.% (compared to the mole’s number of Zn<sup>2+</sup>). The hexamethylenetetramine (HMTA) solvent used for the fabrication of Cu-ZnO nanorods with the mole ratio of Zn<sup>2+</sup>:HMTA = 1:4. The characteristics of the materials were analyzed by techniques, such as XRD, Raman shift, SEM and UV-vis diffuse reflectance spectra (DRS). The photocatalytic properties of the materials were investigated by the decomposition of the methylene blue (MB) dye solution under ultraviolet light. The results show that the size of Cu-ZnO nanorods was reduced when the Cu<sup>2+</sup> doping ratio increased from 2 mol.% to 7 mol.%. The decomposition efficiency of the MB dye solution reached 92% - 97%, corresponding to the Cu<sup>2+</sup> doping ratio changed from 2 - 7 mol.% (after 40 minutes of ultraviolet irradiation). The highest efficiency for the decomposition of the MB solution was obtained at a Cu<sup>2+</sup> doping ratio of 2 mol.%.
文摘In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 equation, Joseph-Egri (TRLW) equation, and Calogro-Degasperis (CD) equation. As a result, we have obtained solutions for the equations expressed in terms of trigonometric, hyperbolic and rational functions. Moreover, some selected solutions are plotted using some specific values for the parameters.
文摘Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, XRD, SEM and EDAX data. UV-Visible spectroscopy measurements reveal that the Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite has maximum absorption at 353.04 nm and this peak position reflects the band gap of particles and it is found to be 2.51 eV which was calculated using Tauc plot. X-Ray diffraction (XRD) reveals crystaline size to be 49.85 nm which was calculated using Williamson-Hall (W-H) plot method. Photocatalytic degradation of acetic acid, chloroacetic acid and trichloroacetic acid has been studied by volumetric method using NaOH solution. Photocatalytic degradation of chloroacetic acid and acetic acid follows first order kinetics. The photodegradation efficiency for Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite was found to be ≈97.8%. A Taft linear free energy relationship is noted for the catalysed reaction with ρ* = 0.233 and indicating electron withdrawing groups enhance the rate. An isokinetic relation is observed with β = 358 K indicating that enthalpy factor controls the reaction rate. The result of this paper suggests the possibility of degradation of organic compounds, industrial effluants and toxic organic compounds by photodegradation process by ecofriendly Al<sub>2</sub>S<sub>3</sub>/ MoS<sub>2</sub>. The antibacterial activity of Al<sub>2</sub>S<sub>3</sub>/MoS<sub>2</sub> nanocomposite was investigated. These particles were shown to have an effective bactericide.
