The aim of this study was to investigate the role of Dendrobium officinale crude polysaccharides(DOPS)and D.officinale purified polysaccharides(DOPS100)in attenuating immune dysfunction in subfertile mice.The results ...The aim of this study was to investigate the role of Dendrobium officinale crude polysaccharides(DOPS)and D.officinale purified polysaccharides(DOPS100)in attenuating immune dysfunction in subfertile mice.The results of the study revealed several noteworthy findings.First,DOPS and DOPS100 treatments led to significant improvement in weight gain and reversal of fatigue-related behaviors compared to the normal group.Second,both DOPS and DOPS100 showed effectiveness in reducing immune organ swelling,modulating immunoglobulin A(IgA)and immunoglobulin M(IgM)levels,and restoring complement(C3c and C4)levels.In addition,they demonstrated a significant ability to enhance the integrity of the intestinal mechanical barrier by differentially upregulating the tight junction proteins Occludin and Zonula occludens 1(ZO-1).In addition,it was found that DOPS100 specifically enhanced the CD4^(+)-T helper 17 cell(Th17)/regulatory T cell(Treg)immune axis in the gut,as evidenced by increased expression of forkhead box protein 3(Foxp3)as well as decreased expression of retinoic acid receptor-related orphan receptor γt(RORγt),and further modulation of interleukin 10(IL-10),interleukin 22(IL-22),and interleukin 17A(IL-17A)expression levels of inflammatory factors.These findings collectively suggest that DOPS100 holds significant potential in improving sub-healthy status by repairing the intestinal barrier,restoring local immune homeostasis,and activating the intestinal immune regulatory network.The study’s outcomes provide valuable insights into the therapeutic implications of DOPS and DOPS100 in addressing immune dysfunction in sub-healthy conditions.展开更多
The microstructure and mechanical properties of Mg94Zn2Y4 extruded alloy containing long-period stacking ordered structures were systematically investigated by SEM and TEM analyses. The results show that the 18R-LPSO ...The microstructure and mechanical properties of Mg94Zn2Y4 extruded alloy containing long-period stacking ordered structures were systematically investigated by SEM and TEM analyses. The results show that the 18R-LPSO structure and α-Mg phase are observed in cast Mg94Zn2Y4 alloy. After extrusion, the LPSO structures are delaminated and Mg-slices with width of 50-200 nm are generated. By ageing at 498 K for 36 h, the ageing peak is attained andβ′phase is precipitated. Due to this novel precipitation, the microhardness ofα-Mg matrix increases apparently from HV108.9 to HV129.7. While the microhardness for LPSO structure is stabilized at about HV145. TEM observations and SAED patterns indicate that the β′ phase has unique orientation relationships betweenα-Mg and LPSO structures, the direction in the close-packed planes ofβ′precipitates perpendicular to that ofα-Mg and LPSO structures. The ultimate tensile strength for the peak-aged alloy achieves 410.7 MPa and the significant strength originates from the coexistence ofβ′precipitates and 18R-LPSO structures.展开更多
Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-...Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4 with the coexistence of a-NiMoO4 and fl-NiMoO4 showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoOa was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4 catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogena- tion of propane in comparison with bulk NiMoO4.展开更多
Studies the existence of solutions of nonlinear two point boundary value problems for nonlinear 4n-th-order differential equationy (4n)=f(t,y,y′,y″,...,y (4n-1))(a)with the boundary conditions g 2i(y (2i)(a),y (2i+1...Studies the existence of solutions of nonlinear two point boundary value problems for nonlinear 4n-th-order differential equationy (4n)=f(t,y,y′,y″,...,y (4n-1))(a)with the boundary conditions g 2i(y (2i)(a),y (2i+1)(a))=0,h 2i(y (2i)(c),y (2i+1)(c))=0,(i=0,1,...,2n-1)(b) where the functions f, g i and h i are continuous with certain monotone properties. For the boundary value problems of nonlinear nth order differential equationy (n)=f(t,y,y′,y″,...,y (n-1))many results have been given at the present time. But the existence of solutions of boundary value problem (a),(b) studied in this paper has not been covered by the above researches. Moreover, the corollary of the important theorem in this paper, i.e. existence of solutions of the boundary value problem.y (4n)=f(t,y,y′,y″,...,y (4n-1)) a 2iy (2i)(a)+a 2i+1y (2i+1)(a)=b 2i,c 2iy (2i)(c)+c 2i+1y (2i+1)(c)=d 2i,(i=0,1,...2n-1)has not been dealt with in previous works.展开更多
The fracture behavior of disordered and ordered Ni4Mo alloy was investigated by tensile tests in hydrogen gas or during hydrogen charging. The results show that the ductility of the disordered alloy decreased slightly...The fracture behavior of disordered and ordered Ni4Mo alloy was investigated by tensile tests in hydrogen gas or during hydrogen charging. The results show that the ductility of the disordered alloy decreased slightly with the hydrogen pressure increasing, while that of the ordered alloy decreased rapidly with the hydrogen pressure increasing. However, the ductility of both disordered and ordered alloys reduced similarly seriously with the charging current density increasing. Therefore, the mechanism of order-induced embrittlement of Ni4 Mo alloy in hydrogen gas is supposed to be that atomic order accelerates the kinetics of the catalytic reaction for the dissociation of molecular H2 into atomic H.展开更多
The nanolaminated MAB phases have attracted great research interests due to their unusual combination of metal-like and ceramic-like properties, which is similar to MAX phases. Recently, ordered quaternary MAX phases ...The nanolaminated MAB phases have attracted great research interests due to their unusual combination of metal-like and ceramic-like properties, which is similar to MAX phases. Recently, ordered quaternary MAX phases have been discovered, which enriches the family of MAX phases, and opens a new window to tailor the properties of MAX phases and to develop new MXenes. In the present work, we explored possible ordered quaternary MAB phases with Cr3AlB4 structure(space group: Pmmm) by first-principles calculations. The predictions show that M2M’AlB4 phases with M = Mn, Fe, Co and M’ = Cr, Mo, W exhibit strong tendency of ordering, where M locates at 2t site(0.5, 0.5, z2t) and M’ locates at 1 g site(0, 0.5,0.5). The main driving force of ordering may be the differences in bonding strengths between Al and M elements. Analyses on chemical bonds reveal that bonding strengths increase following the order:Al-Mn < Al-Fe < Al-Co, which is consistent with the prediction that ordering tendency increases when M changes from Mn to Co, as derived from enthalpy differences. The ordered M2M’AlB4 phases with M =Mn or Fe are predicted ferromagnetic and ordered M2M’AlB4 phases display lower shear resistance and possibly better ductility in comparison to Cr3AlB4.展开更多
This work extends to fourth-order previously published work on developing the adjoint sensitivity and uncertainty analysis of the numerical model of a <u>p</u>oly<u>e</u>thylene-<u>r</...This work extends to fourth-order previously published work on developing the adjoint sensitivity and uncertainty analysis of the numerical model of a <u>p</u>oly<u>e</u>thylene-<u>r</u>eflected <u>p</u>lutonium (acronym: PERP) OECD/NEA reactor physics benchmark. Previous works showed that the third-order sensitivities of the PERP leakage response with respect to these total microscopic cross sections are far larger than the corresponding 1<sup>st</sup>-order and 2<sup>nd</sup>-order ones, thereby having the largest impact on the uncertainties induced in the PERP benchmark’s response. This finding has motivated the development of the original 4<sup>th</sup>-order formulas presented in this work, which are valid not only for the PERP benchmark but can also be used for computing the 4<sup>th</sup>-order sensitivities of response of any nuclear system involving fissionable material and internal or external neutron sources. Subsequent works will use the adjoint-based mathematical expressions obtained in this work to compute exactly and efficiently the numerical values of the largest fourth-order sensitivities of the PERP benchmark’s response to the total microscopic cross sections, and use them for a pioneering fourth-order uncertainty analysis of the PERP benchmark’s response.展开更多
Catalytic oxidation of Hgo to Hg~O is an efficient way to remove Hg^(0) from coal-fired flue gas.The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg^(0) oxidation efficie...Catalytic oxidation of Hgo to Hg~O is an efficient way to remove Hg^(0) from coal-fired flue gas.The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg^(0) oxidation efficiency.Therefore,in the present work,wood vessels were used as sacrificial template to obtain Co_(3)O_(4) with ordered pore structure.SEM and BET results show that,when the mass concentrations of Co(NO_(3))_(2)·6H_(2)O was 20%,the obtained catalyst(Co_(3)O_(4) [20%Co(NO_(3))_(2)])possesses better pore structure and higher surface area.It will expose more available surface active sites and lower the mass transfer resistance.Furthermore,XPS results prove that Co_(3)O_(4) [20%Co(NO_(3))_(2)]has the highest ratio of chemisorbed oxygen which plays an important role in Hg^(0) oxidation process.These results lead to a better Hg^(0) oxidation efficiency of Co_(3)O_(4) [20%Co(NO_(3))_(2)],which is about 90%in the temperature range of 200 to 350℃,Furthermore,Co_(3)O_(4) [20%Co(NO_(3))_(2)]has a stable catalytic activity,and its Hg^(0) oxidation efficiency maintains above 90%at 250℃even after 90 h test,A probable reaction mechanism is deduced by the XPS results of the fresh,used and regenerated catalyst of Co_(3)O_(4) [20%Co(NO3)2].Chemisorbed oxygen can react with Hg^(0) forming HgO with the reduction of Co^(3+)to Co^(2)+.And lattice oxygen and gaseous oxygen can supplement the consumption of chemisorbed oxygen to oxidize Co^(2+)to Co^(3+).展开更多
Models of the coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations submit various critical physical phenomena with a typical equation for optical fibres with linear refrac...Models of the coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations submit various critical physical phenomena with a typical equation for optical fibres with linear refraction. In this article, we will presuppose the Compact Finite Difference method with Runge-Kutta of order 4 (explicit) method, which is sixth-order and fourth-order in space and time respectively, to solve coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations. Many methods used to solve coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations are second order in time and need to use extra-technique to rise up to fourth-order as Richardson Extrapolation technique. The scheme obtained is immediately fourth-order in one step. This approach is a conditionally stable method. The conserved quantities and the exact single soliton solution indicate the competence and accuracy of the article’s suggestion schemes. Furthermore, the article discusses the two solitons interaction dynamics.展开更多
In this paper we present and test a numerical method for computing eigenvalues of 4th order Sturm-Liouville (SL) differential operators on finite intervals with regular boundary conditions. This method is a 4th order ...In this paper we present and test a numerical method for computing eigenvalues of 4th order Sturm-Liouville (SL) differential operators on finite intervals with regular boundary conditions. This method is a 4th order shooting method based on Magnus expansions (MG4) which use MG4 shooting as the integrator. This method is similar to the SLEUTH (Sturm-Liouville Eigenvalues Using Theta Matrices) method of Greenberg and Marletta which uses the 2nd order Pruess method (also known as the MG2 shooting method) for the integrator. This method often achieves near machine precision accuracies, and some comparisons of its performance against the well-known SLEUTH software package are presented.展开更多
The Fourier Transform Infrared (FTIR) and FT-Raman spectra of 4-methyl-3-nitrobenzoic acid have been recorded in the range 4000 - 400 cm-1 and 3500 - 50 cm-1, respectively. The optimized geometry of the molecule, its ...The Fourier Transform Infrared (FTIR) and FT-Raman spectra of 4-methyl-3-nitrobenzoic acid have been recorded in the range 4000 - 400 cm-1 and 3500 - 50 cm-1, respectively. The optimized geometry of the molecule, its vibrational frequencies along with corresponding intensities have been computed using the Density Functional Theory (DFT) employing B3LYP/6-311++G basis set. The scaled values of harmonic vibrational frequencies obtained in the computations have been compared with their experimental counter parts. The scaling factors have been refined to reproduce the frequencies with an RMS error of 11.68 cm-1 between the experimental and computed frequencies. The theoretically constructed spectra agree satisfactorily with those of experimental spectra. First order hyperpolarizability constants have also been evaluated.展开更多
To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction(OER),there is an imperative need for the development of highly efficient,cost-effective,and durable electrocatalysts.This...To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction(OER),there is an imperative need for the development of highly efficient,cost-effective,and durable electrocatalysts.This study presents for the first time a strategy for in situ SO_(4)^(2−)regulation of HEMs.Unlike previous studies SO_(4)^(2−)is directly anchored to HEMs rather than formed through uncontrolled transformation or surface reconstruction.A series of novel electrocatalysts N@(ZrFeCoNiAl)O_(x)-SO_(4)[HE/NS-(0–4)]were prepared by the low-temperature NaBH4 reduction method.The content of SO_(4)^(2−)showed an inverse volcano relationship with the OER catalytic activity,all the samples exhibit excellent OER activity and remarkable stability over 50 h.The moderate introduction of SO_(4)^(2−)-oriented HE/NS-2 forms a short-range ordered and long-range disordered structure,which stably combines high catalytic activity and excellent electrical conductivity,exhibiting LOM-dominated OER mechanism with an overpotential of 257 mV at 10 mA cm^(−2)and a Tafel slope of 41.86 mV dec^(−1).The catalytic performance of the highly crystalline HE/NS-4 electrode(291 mV@10 mA cm^(−2))containing a large amount of SO_(4)^(2−)and the HE/NS-0(340 mV@10 mA cm^(−2))without SO_(4)^(2−)is both poor.SO_(4)^(2−)as the main promoting factor,controlling the growth of HEMs morphology,structural evolution,and the adjustment of the valence state of active metal sites,playing a vital role in activating lattice oxygen and promoting O–O coupling.N as an electron donor,further improves the electronic structure of HEMs.In situ Raman spectroscopy to probe the dynamic reconstruction of HE/NS-2,anion/cation leaching facilitates self-reconstruction,and the formed metal(oxy)hydroxide is considered the active center of OER.This study pioneers a novel avenue for the controlled synthesis of oxidized anion-adsorbed HEMs and enhancing OER catalytic activity.展开更多
基金supported by the National Natural Science Foundation of China(82274134)the National Key R&D Plan(2017YFC1702200,2017YFC1702202)+1 种基金Key R&D Program Projects in Zhejiang Province(2020C04020)the Key Research and Development Program of Zhejiang Province(2025C02183).
文摘The aim of this study was to investigate the role of Dendrobium officinale crude polysaccharides(DOPS)and D.officinale purified polysaccharides(DOPS100)in attenuating immune dysfunction in subfertile mice.The results of the study revealed several noteworthy findings.First,DOPS and DOPS100 treatments led to significant improvement in weight gain and reversal of fatigue-related behaviors compared to the normal group.Second,both DOPS and DOPS100 showed effectiveness in reducing immune organ swelling,modulating immunoglobulin A(IgA)and immunoglobulin M(IgM)levels,and restoring complement(C3c and C4)levels.In addition,they demonstrated a significant ability to enhance the integrity of the intestinal mechanical barrier by differentially upregulating the tight junction proteins Occludin and Zonula occludens 1(ZO-1).In addition,it was found that DOPS100 specifically enhanced the CD4^(+)-T helper 17 cell(Th17)/regulatory T cell(Treg)immune axis in the gut,as evidenced by increased expression of forkhead box protein 3(Foxp3)as well as decreased expression of retinoic acid receptor-related orphan receptor γt(RORγt),and further modulation of interleukin 10(IL-10),interleukin 22(IL-22),and interleukin 17A(IL-17A)expression levels of inflammatory factors.These findings collectively suggest that DOPS100 holds significant potential in improving sub-healthy status by repairing the intestinal barrier,restoring local immune homeostasis,and activating the intestinal immune regulatory network.The study’s outcomes provide valuable insights into the therapeutic implications of DOPS and DOPS100 in addressing immune dysfunction in sub-healthy conditions.
基金Project (BK2010392) supported by the Natural Science Foundation of Jiangsu Province of ChinaProject (3212000502) supported by the Innovation Foundation of Southeast University,China
文摘The microstructure and mechanical properties of Mg94Zn2Y4 extruded alloy containing long-period stacking ordered structures were systematically investigated by SEM and TEM analyses. The results show that the 18R-LPSO structure and α-Mg phase are observed in cast Mg94Zn2Y4 alloy. After extrusion, the LPSO structures are delaminated and Mg-slices with width of 50-200 nm are generated. By ageing at 498 K for 36 h, the ageing peak is attained andβ′phase is precipitated. Due to this novel precipitation, the microhardness ofα-Mg matrix increases apparently from HV108.9 to HV129.7. While the microhardness for LPSO structure is stabilized at about HV145. TEM observations and SAED patterns indicate that the β′ phase has unique orientation relationships betweenα-Mg and LPSO structures, the direction in the close-packed planes ofβ′precipitates perpendicular to that ofα-Mg and LPSO structures. The ultimate tensile strength for the peak-aged alloy achieves 410.7 MPa and the significant strength originates from the coexistence ofβ′precipitates and 18R-LPSO structures.
基金supported by NSFC(21073235,21173270,21177160,21376261)863 Program(2013AA065302)PetroChina Innovation Foundation(2011D-5006-0403)
文摘Highly ordered mesoporous NiMoO4 material was successfully synthesized using mesoporous silica KIT-6 as hard template via vacuum nanocasting method. The structure was characterized by means of XRD, TEM, N2 adsorption-desorption, Raman and FT-IR. The mesoporous NiMoO4 with the coexistence of a-NiMoO4 and fl-NiMoO4 showed well-ordered mesoporous structure, a bimodal pore size distribution and crystalline framework. The catalytic performance of NiMoOa was investigated for oxidative dehydrogenation of propane. It is demonstrated that the mesoporous NiMoO4 catalyst with more surface active oxygen species showed better catalytic performance in oxidative dehydrogena- tion of propane in comparison with bulk NiMoO4.
文摘Studies the existence of solutions of nonlinear two point boundary value problems for nonlinear 4n-th-order differential equationy (4n)=f(t,y,y′,y″,...,y (4n-1))(a)with the boundary conditions g 2i(y (2i)(a),y (2i+1)(a))=0,h 2i(y (2i)(c),y (2i+1)(c))=0,(i=0,1,...,2n-1)(b) where the functions f, g i and h i are continuous with certain monotone properties. For the boundary value problems of nonlinear nth order differential equationy (n)=f(t,y,y′,y″,...,y (n-1))many results have been given at the present time. But the existence of solutions of boundary value problem (a),(b) studied in this paper has not been covered by the above researches. Moreover, the corollary of the important theorem in this paper, i.e. existence of solutions of the boundary value problem.y (4n)=f(t,y,y′,y″,...,y (4n-1)) a 2iy (2i)(a)+a 2i+1y (2i+1)(a)=b 2i,c 2iy (2i)(c)+c 2i+1y (2i+1)(c)=d 2i,(i=0,1,...2n-1)has not been dealt with in previous works.
基金Project supported by National Natural Science Foundatron of China（ Grant No.59895157）, and Science Foundation of Shanghai Municipal Commission of Science and Technology （Grant No. 02ZE14033 ）
文摘The fracture behavior of disordered and ordered Ni4Mo alloy was investigated by tensile tests in hydrogen gas or during hydrogen charging. The results show that the ductility of the disordered alloy decreased slightly with the hydrogen pressure increasing, while that of the ordered alloy decreased rapidly with the hydrogen pressure increasing. However, the ductility of both disordered and ordered alloys reduced similarly seriously with the charging current density increasing. Therefore, the mechanism of order-induced embrittlement of Ni4 Mo alloy in hydrogen gas is supposed to be that atomic order accelerates the kinetics of the catalytic reaction for the dissociation of molecular H2 into atomic H.
基金supported by National Natural Science Foundation of China under Grant No. U1435206 and No. 51672064
文摘The nanolaminated MAB phases have attracted great research interests due to their unusual combination of metal-like and ceramic-like properties, which is similar to MAX phases. Recently, ordered quaternary MAX phases have been discovered, which enriches the family of MAX phases, and opens a new window to tailor the properties of MAX phases and to develop new MXenes. In the present work, we explored possible ordered quaternary MAB phases with Cr3AlB4 structure(space group: Pmmm) by first-principles calculations. The predictions show that M2M’AlB4 phases with M = Mn, Fe, Co and M’ = Cr, Mo, W exhibit strong tendency of ordering, where M locates at 2t site(0.5, 0.5, z2t) and M’ locates at 1 g site(0, 0.5,0.5). The main driving force of ordering may be the differences in bonding strengths between Al and M elements. Analyses on chemical bonds reveal that bonding strengths increase following the order:Al-Mn < Al-Fe < Al-Co, which is consistent with the prediction that ordering tendency increases when M changes from Mn to Co, as derived from enthalpy differences. The ordered M2M’AlB4 phases with M =Mn or Fe are predicted ferromagnetic and ordered M2M’AlB4 phases display lower shear resistance and possibly better ductility in comparison to Cr3AlB4.
文摘This work extends to fourth-order previously published work on developing the adjoint sensitivity and uncertainty analysis of the numerical model of a <u>p</u>oly<u>e</u>thylene-<u>r</u>eflected <u>p</u>lutonium (acronym: PERP) OECD/NEA reactor physics benchmark. Previous works showed that the third-order sensitivities of the PERP leakage response with respect to these total microscopic cross sections are far larger than the corresponding 1<sup>st</sup>-order and 2<sup>nd</sup>-order ones, thereby having the largest impact on the uncertainties induced in the PERP benchmark’s response. This finding has motivated the development of the original 4<sup>th</sup>-order formulas presented in this work, which are valid not only for the PERP benchmark but can also be used for computing the 4<sup>th</sup>-order sensitivities of response of any nuclear system involving fissionable material and internal or external neutron sources. Subsequent works will use the adjoint-based mathematical expressions obtained in this work to compute exactly and efficiently the numerical values of the largest fourth-order sensitivities of the PERP benchmark’s response to the total microscopic cross sections, and use them for a pioneering fourth-order uncertainty analysis of the PERP benchmark’s response.
基金the financial supports from the National Natural Science Foundation of China(51978124)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(22021005)the Cheung Kong Scholars Programme of China(T2012049)。
文摘Catalytic oxidation of Hgo to Hg~O is an efficient way to remove Hg^(0) from coal-fired flue gas.The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg^(0) oxidation efficiency.Therefore,in the present work,wood vessels were used as sacrificial template to obtain Co_(3)O_(4) with ordered pore structure.SEM and BET results show that,when the mass concentrations of Co(NO_(3))_(2)·6H_(2)O was 20%,the obtained catalyst(Co_(3)O_(4) [20%Co(NO_(3))_(2)])possesses better pore structure and higher surface area.It will expose more available surface active sites and lower the mass transfer resistance.Furthermore,XPS results prove that Co_(3)O_(4) [20%Co(NO_(3))_(2)]has the highest ratio of chemisorbed oxygen which plays an important role in Hg^(0) oxidation process.These results lead to a better Hg^(0) oxidation efficiency of Co_(3)O_(4) [20%Co(NO_(3))_(2)],which is about 90%in the temperature range of 200 to 350℃,Furthermore,Co_(3)O_(4) [20%Co(NO_(3))_(2)]has a stable catalytic activity,and its Hg^(0) oxidation efficiency maintains above 90%at 250℃even after 90 h test,A probable reaction mechanism is deduced by the XPS results of the fresh,used and regenerated catalyst of Co_(3)O_(4) [20%Co(NO3)2].Chemisorbed oxygen can react with Hg^(0) forming HgO with the reduction of Co^(3+)to Co^(2)+.And lattice oxygen and gaseous oxygen can supplement the consumption of chemisorbed oxygen to oxidize Co^(2+)to Co^(3+).
文摘Models of the coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations submit various critical physical phenomena with a typical equation for optical fibres with linear refraction. In this article, we will presuppose the Compact Finite Difference method with Runge-Kutta of order 4 (explicit) method, which is sixth-order and fourth-order in space and time respectively, to solve coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations. Many methods used to solve coupled nonlinear Schr<span style="white-space:nowrap;">ödinger equations are second order in time and need to use extra-technique to rise up to fourth-order as Richardson Extrapolation technique. The scheme obtained is immediately fourth-order in one step. This approach is a conditionally stable method. The conserved quantities and the exact single soliton solution indicate the competence and accuracy of the article’s suggestion schemes. Furthermore, the article discusses the two solitons interaction dynamics.
文摘In this paper we present and test a numerical method for computing eigenvalues of 4th order Sturm-Liouville (SL) differential operators on finite intervals with regular boundary conditions. This method is a 4th order shooting method based on Magnus expansions (MG4) which use MG4 shooting as the integrator. This method is similar to the SLEUTH (Sturm-Liouville Eigenvalues Using Theta Matrices) method of Greenberg and Marletta which uses the 2nd order Pruess method (also known as the MG2 shooting method) for the integrator. This method often achieves near machine precision accuracies, and some comparisons of its performance against the well-known SLEUTH software package are presented.
文摘The Fourier Transform Infrared (FTIR) and FT-Raman spectra of 4-methyl-3-nitrobenzoic acid have been recorded in the range 4000 - 400 cm-1 and 3500 - 50 cm-1, respectively. The optimized geometry of the molecule, its vibrational frequencies along with corresponding intensities have been computed using the Density Functional Theory (DFT) employing B3LYP/6-311++G basis set. The scaled values of harmonic vibrational frequencies obtained in the computations have been compared with their experimental counter parts. The scaling factors have been refined to reproduce the frequencies with an RMS error of 11.68 cm-1 between the experimental and computed frequencies. The theoretically constructed spectra agree satisfactorily with those of experimental spectra. First order hyperpolarizability constants have also been evaluated.
基金financially supported by the Natural Science Foundation of Guangxi Province(No.2022GXNSFDA035062)the Director's Fund Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(No.2023Z011).
文摘To overcome the sluggish kinetics and excessive overpotentials of the oxygen evolution reaction(OER),there is an imperative need for the development of highly efficient,cost-effective,and durable electrocatalysts.This study presents for the first time a strategy for in situ SO_(4)^(2−)regulation of HEMs.Unlike previous studies SO_(4)^(2−)is directly anchored to HEMs rather than formed through uncontrolled transformation or surface reconstruction.A series of novel electrocatalysts N@(ZrFeCoNiAl)O_(x)-SO_(4)[HE/NS-(0–4)]were prepared by the low-temperature NaBH4 reduction method.The content of SO_(4)^(2−)showed an inverse volcano relationship with the OER catalytic activity,all the samples exhibit excellent OER activity and remarkable stability over 50 h.The moderate introduction of SO_(4)^(2−)-oriented HE/NS-2 forms a short-range ordered and long-range disordered structure,which stably combines high catalytic activity and excellent electrical conductivity,exhibiting LOM-dominated OER mechanism with an overpotential of 257 mV at 10 mA cm^(−2)and a Tafel slope of 41.86 mV dec^(−1).The catalytic performance of the highly crystalline HE/NS-4 electrode(291 mV@10 mA cm^(−2))containing a large amount of SO_(4)^(2−)and the HE/NS-0(340 mV@10 mA cm^(−2))without SO_(4)^(2−)is both poor.SO_(4)^(2−)as the main promoting factor,controlling the growth of HEMs morphology,structural evolution,and the adjustment of the valence state of active metal sites,playing a vital role in activating lattice oxygen and promoting O–O coupling.N as an electron donor,further improves the electronic structure of HEMs.In situ Raman spectroscopy to probe the dynamic reconstruction of HE/NS-2,anion/cation leaching facilitates self-reconstruction,and the formed metal(oxy)hydroxide is considered the active center of OER.This study pioneers a novel avenue for the controlled synthesis of oxidized anion-adsorbed HEMs and enhancing OER catalytic activity.
