There are a number of structures and structural styles found in extensional tectonic settings of the world,and it is a big challenge to study the evolution of these structures. Evolution of structures formed in extens...There are a number of structures and structural styles found in extensional tectonic settings of the world,and it is a big challenge to study the evolution of these structures. Evolution of structures formed in extensional tectonic settings have been studied by researchers on different extensional basins of the world. Southern Sindh Monocline lies on the western corner of Indian Plate and the tectonic history of Indian plate has also experienced different extensional episodes, and its journey rifted from Gondwanaland to its final welding to Asia. The aim of this study is to figure out the evolution of structures in the subsurface of Southern Sindh Monocline, Pakistan using the seismic data interpretation and flattening of horizons approach. Structures within the subsurface of Southern Sindh Monocline have been characterized by different tectonic episodes of Indian plate while rifting from Gondwanaland, rifting from other plates at different geological times and to its collision with the Asia. Basic structures within study area are classified into nine types while the structural styles have been classified into six types as horst and grabens, dominos, crotch, synthetic and antithetic, negative and flashlight structural style. The structures within the study area revealed evidence for three major structural episodes which can be characterized as Episode 1: Structures associated with rifting of Indian plate from Gondwanaland during Late Jurassic to Early Cretaceous, Episode 2: Modification and reactivation of previous structures while Madagascar rifted from Indian Plate during the Middle Cretaceous and during Episode 3: Inversion and reactivation of structures occurred when Indian Plate collided with Asia during Early Eocene.展开更多
The anisotropic properties and applications ofβ-gallium oxide(β-Ga_(2)O_(3))are comprehensively reviewed.All the anisotropic properties are essentially resulted from the anisotropic crystal structure.The process flo...The anisotropic properties and applications ofβ-gallium oxide(β-Ga_(2)O_(3))are comprehensively reviewed.All the anisotropic properties are essentially resulted from the anisotropic crystal structure.The process flow of how to exfoliate nanoflakes from bulk material is introduced.Anisotropic optical properties,including optical bandgap,Raman and photolumines-cence characters are comprehensively reviewed.Three measurement configurations of angle-resolved polarized Raman spec-tra(ARPRS)are reviewed,with Raman intensity formulas calculated with Raman tensor elements.The method to obtain the Raman tensor elements of phonon modes through experimental fitting is also introduced.In addition,the anisotropy in elec-tron mobility and affinity are discussed.The applications,especially polarization photodetectors,based onβ-Ga_(2)O_(3)were summa-rized comprehensively.Three kinds of polarization detection mechanisms based on material dichroism,1D morphology and metal-grids are discussed in-depth.This review paper provides a framework for anisotropic optical and electric properties ofβ-Ga_(2)O_(3),as well as the applications based on these characters,and is expected to lead to a wider discussion on this topic.展开更多
The piezoelectric strain of K_(0.5)Na_(0.5)NbO_(3)-based lead-free ceramic at different temperatures was studied.The Rayleigh analysis shows that the intrinsic and extrinsic contributions are increased at temperature ...The piezoelectric strain of K_(0.5)Na_(0.5)NbO_(3)-based lead-free ceramic at different temperatures was studied.The Rayleigh analysis shows that the intrinsic and extrinsic contributions are increased at temperature from 173 to 298 K.In addition,a monoclinic phase structure was observed at 83 K.The results of phase field simulation show that the temperature dependent microstructure evolution is a function of the local structure size.This work contributes to understanding the structure and properties relationship of the multi-cations doped KNN-based piezoelectric ceramics as a function of temperature.展开更多
Monoclinicα-MoP_(2),with the OsGe2-type structure(space group C2/m,Z=4)and lattice parameters a=8.7248(11)Å,b=3.2322(4)Å,c=7.4724(9)Å,andβ=119.263°,was synthesized under a pressure of 4~GPa at a ...Monoclinicα-MoP_(2),with the OsGe2-type structure(space group C2/m,Z=4)and lattice parameters a=8.7248(11)Å,b=3.2322(4)Å,c=7.4724(9)Å,andβ=119.263°,was synthesized under a pressure of 4~GPa at a temperature between 1100℃and 1200℃.The structure ofα-MoP_(2) and its relationship to other transition metal diphosphides are discussed.Surprisingly,the ambient pressure phase orthorhombicβ-MoP_(2)(space group Cmc21)is denser in structure thanα-MoP_(2).Room-temperature high-pressure x-ray diffraction studies exclude the possibility of phase transition fromβ-MoP_(2) to α-MoP_(2),suggesting thatα-MoP_(2) is a stable phase at ambient conditions;this is also supported by the total energy and phonon calculations.展开更多
First-principles calculations of structural, electronic, optical, elastic, mechanical properties, and Born effective charges of monoclinic HfO2 are performed with the plane-wave pseudopotential technique based on the ...First-principles calculations of structural, electronic, optical, elastic, mechanical properties, and Born effective charges of monoclinic HfO2 are performed with the plane-wave pseudopotential technique based on the density-functional theory. The calculated structural properties are consistent with the previous theoretical and experimental results. The electronic structure reveals that monoclinic HfO2 has an indirect band gap. The analyses of density of states and Mulliken charges show mainly covalent nature in Hf-O bonds. Optical properties, including the dielectric function, refractive index, extinction coefficient, reflectivity, absorption coefficient, loss function, and optical conductivity each as a function of photon energy are calculated and show an optical anisotropy. Moreover, the independent elastic constants, bulk modulus, shear modulus, Young's modulus, Poisson's ratio, compressibility, Lam6 constant, sound velocity, Debye temperature, and Born effective charges of monoclinic HfO2 are obtained, which may help to understand monoclinic HfO2 for future work.展开更多
The flotation separation of chalcopyrite from monoclinic pyrrhotite using food-grade guar gum(FGG) as a depressant was studied through flotation tests, kinetic studies, dynamic potential measurements, adsorption exper...The flotation separation of chalcopyrite from monoclinic pyrrhotite using food-grade guar gum(FGG) as a depressant was studied through flotation tests, kinetic studies, dynamic potential measurements, adsorption experiments, and infrared spectral analyses. The microflotation results showed that the flotation separation of chalcopyrite from monoclinic pyrrhotite could not be realized by adding mixed aerofloat(CSU11) alone. The depressant FGG exhibited a selective depression effect on monoclinic pyrrhotite by controlling the pulp pH range from 5.0 to 6.0, with a maximum floatability variation of 79.36% in the presence of CSU11. The flotation kinetics, zeta-potential, adsorption, and infrared spectroscopy studies revealed that the FGG could absorb more strongly on the surface of monoclinic pyrrhotite than on the surface of chalcopyrite. In addition, the results revealed that the interaction of FGG with the monoclinic pyrrhotite surface was governed primarily by strong chemisorption, whereas FGG mainly bonded to chalcopyrite through hydrogen bonding. This difference was responsible for the excellent depression selectivity of FGG toward monoclinic pyrrhotite flotation and weak depression effect toward chalcopyrite flotation.展开更多
The effect of chloride ions on a monoclinic ZrO2-supported RuOx (RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate (MF) at a low tem...The effect of chloride ions on a monoclinic ZrO2-supported RuOx (RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate (MF) at a low temperature of 373 K. The m-ZrO2 support was Cl-free, and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K. The structures of these catalysts were characterized by X-ray diffraction, Raman and X-ray photoelectron spectroscopies. Their reducibility was probed by temperature-programmed reduction in H2. The RuOx domains were present as highly dispersed Rut42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl ions. Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity, whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2. The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates. This finding provides novel insights into the promoting effect of Cl- ions on oxides-based catalysts for selective oxidation reactions.展开更多
We report a comprehensive high-pressure study on the monoclinic TIFeSe2 single crystal,which is an antiferromagnetic jnsulator with quasi-one-dimensional crystal structure at ambient pressure.It is found that TIFeSe2 ...We report a comprehensive high-pressure study on the monoclinic TIFeSe2 single crystal,which is an antiferromagnetic jnsulator with quasi-one-dimensional crystal structure at ambient pressure.It is found that TIFeSe2 undergoes a pressure-induced structural transformation from the monoclinic phase to an orthorhombic structure above Pc≈13 GPa,accompanied with a large volume collapse of ΔV/V0=8.3%.In the low-pressure monoclinic phase,the insulating state is easily metallized at pressures above 2 GPa;while possible superconductivity with Tconset^2 K is found to emerge above 30 GPa in the high-pressure phase.Such a great tunability of TIFeSe2 under pressure indicates that the ternary AFeSe2 system(A=Tl,K,Cs,Rb) should be taken as an important platform for explorations of interesting phenomena such as insulator-metal transition,dimensionality crossover,and superconductivity.展开更多
Monochnic and hexagonal CePO4 nanoparticles and nanorods were successfully synthesized from Ce(NO3)36H2O and Na3PO4 121-120 solu- tions at pH 1-5 by a 180 W microwave radiation for 60 min. The products were characte...Monochnic and hexagonal CePO4 nanoparticles and nanorods were successfully synthesized from Ce(NO3)36H2O and Na3PO4 121-120 solu- tions at pH 1-5 by a 180 W microwave radiation for 60 min. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FFIR) spectroscopy, and scanning electron microscopy (SEM). XRD patterns revealed that the products are hexagonal CePO4 structures at pH 2-5, and monoclinic CePO4 structtLres at pH 1. SEM characterization shows that these products were nanoparticles, short nanorods, and long nanorods, controlled by the pH of the precursor solutions. Optical properties of the nanorods were also investigated by ultraviolet-visible (UV-vis) and photoluminescence (PL) spectroscopy.展开更多
Monoclinic SrAl_(2)Si_(2)O_(8) ceramics for Sr immobilization were prepared by a liquid-phase sintering method.The sintering temperature,mineral phase composition,microstructure,flexural strength,bulk density,and Sr i...Monoclinic SrAl_(2)Si_(2)O_(8) ceramics for Sr immobilization were prepared by a liquid-phase sintering method.The sintering temperature,mineral phase composition,microstructure,flexural strength,bulk density,and Sr ion leaching characteristics of the SrAl_(2)Si_(2)O_(8) ceramics were investigated.A crystalline monoclinic SrAl_(2)Si_(2)O_(8) phase formed through liquid-phase sintering at 1223 K.The introduction of four flux agents(B_(2)O_(3),CaO·2B_(2)O_(3),SrO·2B_(2)O_(3),and BaO·2B_(2)O_(3))to the SrAl_(2)Si_(2)O_(8) ceramics not only reduced the densification temperature and decreased the volatilization of Sr during high-temperature sintering but also impacted the mechanical properties of the ceramics.Product consistency tests showed that the leaching concentration of Sr ions in the sample with flux agent B_(2)O_(3) was the lowest,whereas that of Sr ions in the sample with flux agent BaO·2B_(2)O_(3) was the highest.These results show that the leaching concentration of Sr ions depends largely on the amorphous phase in the ceramics.Meanwhile,the formation of mineral analog ceramics containing Sr is an important factor to improve Sr immobilization.展开更多
The aim of this study was to determine if accelerated aging of porcelain veneering had an effect on the surface properties specific to a tetragonal-to-monoclinic transformation(TMT) of zirconia restorations. Thirty-...The aim of this study was to determine if accelerated aging of porcelain veneering had an effect on the surface properties specific to a tetragonal-to-monoclinic transformation(TMT) of zirconia restorations. Thirty-six zirconia samples were milled and sintered to simulate core fabrication followed by exposure to various combinations of surface treatments including as-received(control),hydrofluoric acid(HF), application of liner plus firings, application of porcelain by manual layering and pressing with firing, plus accelerated aging. The quantity of transformed tetragonal to monoclinic phases was analyzed utilized an X-ray diffractometer and one-way analysis of variance was used to analyze data. The control samples as provided from the dental laboratory after milling and sintering process had no TMT(X m5 0). There was an effect on zirconia samples of HF application with TMT(X m5 0.8%) and liner plus HF application with TMT(X m5 8.7%). There was an effect of aging on zirconia samples(no veneering) with significant TMT(X m5 70.25%). Both manual and pressing techniques of porcelain applications reduced the TMT(manual, X m5 4.41%, pressing,X m5 11.57%), although there was no statistical difference between them. It can be concluded that simulated applications of porcelain demonstrated the ability to protect zirconia from TMT after aging with no effect of a liner between different porcelain applications.The HF treatment also caused TMT.展开更多
A pyridine-contained Schiff base ligand L(L =(pyridine-2-vinyl)hydrazine) has been synthesized and fully characterized. By self-assembly of the ligand with HgI2, a binuclear complex Hg2I4L(C) was obtained. The s...A pyridine-contained Schiff base ligand L(L =(pyridine-2-vinyl)hydrazine) has been synthesized and fully characterized. By self-assembly of the ligand with HgI2, a binuclear complex Hg2I4L(C) was obtained. The structures of L and C were analyzed through single-crystal X-ray diffraction. L crystallizes in monoclinic, space group P21/n with a=11.286(5), b=3.981(5), c=23.865(5) , β=100.043(5)°, V=1056(1) 3, Z=4, Dc=1.323 g/m3, F(000)=440, Μr=210.24, μ=0.084 mm(-1), the final R=0.0928 and w R=0.2867 for 6955 observed reflections with I > 2(I). The complex is of monoclinic system, space group P21/n with a=8.706(5), b=17.468(5), c=14.675(5) , β=93.922(5)°, V=2227(2) 3, Z=4, Dc=3.338 g/m3, F(000)=1928, Μr=1119.02, μ=19.321 mm(-1), the final R=0.0366 and w R=0.1276 for 3920 observed reflections with I > 2(I). The structural analysis revealed that the molecule of L possesses a well planar structure. However, in the complex, the coordinated ligand distorts greatly. The absorption spectra of L and the complex in ethanol were experimentally and theoretically studied. The result indicates that the complex exhibits different absorption spectrum compared with the free ligand.展开更多
The room temperature stabled monoclinic KNbO3 nanowires were found to act as photocatalyst for photocatalytic methane production and dye degradation in this work. Higher activities have been observed for monoclinic ph...The room temperature stabled monoclinic KNbO3 nanowires were found to act as photocatalyst for photocatalytic methane production and dye degradation in this work. Higher activities have been observed for monoclinic phase compared to the reference(orthorhombic phase). In the photoreduction of CO2 reaction, the monoclinic KNbO3 nanowires exhibited a CH4 evolution rate of 0.025 μmol·g-1·h-1, which was higher than 0.021 μmol·g-1·h-1 of orthorhombic KNbO3 nanowires. In the photodegradation of rhodamine B(Rh B), almost all the Rh B were degraded after 90 min light illumination for monoclinic KNbO3 nanowires. But for orthorhombic KNbO3 nanowires, the concentration of Rh B only decreased to 62% of the initial value.展开更多
A new Zn(Ⅱ) complex [Zn(Phen)2(C(12)H6O4N2)(H2O)]·3H2O with 2,2-bipyridine-3,3-dicarboxylic acid and 1,10-phenanthroline(Phen) as ligands was synthesized, and the crystal data are as follows: monocl...A new Zn(Ⅱ) complex [Zn(Phen)2(C(12)H6O4N2)(H2O)]·3H2O with 2,2-bipyridine-3,3-dicarboxylic acid and 1,10-phenanthroline(Phen) as ligands was synthesized, and the crystal data are as follows: monoclinic, space group P2(1/n), a=12.5581(11), b=17.3382(17), c=15.6687(14) , β=110.579(2)o, Mr=731.02, V=3193.9(5) 3, Dc=1.520 g/cm3, Z=4, μ(Mo Kα)=0.833 mm(-1), F(000)=1508, the final R=0.0431 and w R=0.0936. In the title complex, the central Zn(Ⅱ) ion is located in a distorted octahedral coordination environment. The electrochemical and fluorescent properties were studied. The title complex possesses irreversible electron transfer in the electrode reaction, and it has a strong emission peak in the range of 470505 nm, with the excitation wavelength being 488 nm.展开更多
In order to investigate the effect of lanthanum ion implantation on theoxidation behavior of zircaloy at 500℃, Zircaloy specimens were implanted by lanthanum ions with adose range from 5xl0^(16) to 2xl0^(17) ions/cm^...In order to investigate the effect of lanthanum ion implantation on theoxidation behavior of zircaloy at 500℃, Zircaloy specimens were implanted by lanthanum ions with adose range from 5xl0^(16) to 2xl0^(17) ions/cm^2 at room temperature, and then oxidized at 500℃ for100 min. The valence of the oxides in the scale was analyzed by X-ray Photoelectron Spectroscopy(XPS). The phase structures of the oxides in the scale were examined by Glancing Angle X-rayDiffraction (GAXRD). With the increase of implanted lanthanum ions dose, the phase structures in theoxide scale are transformed from monoclinic zirconia to hexagonal one and then to monoclinic oneagain. The measurement of weight gain showed that a similar change from the decreased gain toincreased one again is achieved in the oxidation behavior of lanthanum ion implanted zircaloycompared with that of as-received zircaloy.展开更多
Two novel coordination polymers with molecular structures(2MI)+[Zn(2MI)Cl3]-(1) and(2MI)+NO3-(2) based on ligand 2-methylimidazole(2MI) were synthesized under solution method. Compound 1 crystallizes in ...Two novel coordination polymers with molecular structures(2MI)+[Zn(2MI)Cl3]-(1) and(2MI)+NO3-(2) based on ligand 2-methylimidazole(2MI) were synthesized under solution method. Compound 1 crystallizes in the monoclinic system, space group Cc with a=7.489(2), b=13.448(4), c=13.983(4) , β=98.402(2)°, Z=4 and V=102.246(2) 3. Compound 2 crystallizes in the orthorhombic system, space group pnma with a=14.296(3), b=6.3180(12), c=7.3862(13) , β=90°, Z=4 and V=667.1(2) 3. Dielectric measurements show compounds 1 and 2 have reversible dielectric anomalous behaviors with variation frequencies at different temperature.展开更多
A new energetic dipotassium 3,3-dinitro-5,5-bis-1,2,4-triazole-1,1-diolate [K2(DNOBT)] was synthesized, and structurally characterized by elemental analysis, IR spectra, 13 C NMR and single-crystal X-ray diffraction...A new energetic dipotassium 3,3-dinitro-5,5-bis-1,2,4-triazole-1,1-diolate [K2(DNOBT)] was synthesized, and structurally characterized by elemental analysis, IR spectra, 13 C NMR and single-crystal X-ray diffraction. K2(DNOBT)·2H2O crystallizes in monoclinic system, space group P21/n with a=6.0446(10), b=15.999(3), c=6.4169(11) , β=99.421(2)°, V=612.21(18) 3, Z=4, Dc=2.009 g·cm(-3), F(000)=372, μ=0.838 mm(-1), S=1.012, the final R=0.0248 and w R(I 〉 2σ(I))=0.0604. Thermal decomposition of the title compound was studied by using DSC and TG-DTG, and there is primarily one exothermic decomposition process at 371.5 ℃.展开更多
A new copper(Ⅱ) coordination polymer [Cu2(C7H5N4)2(3-C6H5NO2)2]n(1) has been hydrothermally synthesized with copper hydroxide, 3-(pyridin-2-yl)-1,2,4-triazole(Hpt) and 3-pyridinecarboxylic acid(3-PCA). ...A new copper(Ⅱ) coordination polymer [Cu2(C7H5N4)2(3-C6H5NO2)2]n(1) has been hydrothermally synthesized with copper hydroxide, 3-(pyridin-2-yl)-1,2,4-triazole(Hpt) and 3-pyridinecarboxylic acid(3-PCA). It crystallizes in the monoclinic space group C2/c, with a=16.854(2), b=7.8616(8), c=20.630(2) , β=111.126(2)o, V=2549.7(5) 3, Dc=1.723 g/cm3, Z=8, F(000)=1336, the final GOOF=1.065, R=0.0380 and w R=0.0972. The whole molecule consisting of two copper ions are bridged by two μ2-η1:η0-3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of Cu(1) ion is CuO2N4, giving a distorted octahedron geometry. 1 exhibits antiferromagnetic interaction, and the electron transfer of 1 is irreversible in electrode reactions and the TG analysis shows that 1 is stable below 235 ℃.展开更多
The potassium terbium polyphosphate crystal KTb(PO3)4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, pow...The potassium terbium polyphosphate crystal KTb(PO3)4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, powder X-ray diffraction and elemental analysis. The compound crystallizes in the monoclinic space group P21/n with a=10.3182(6), b=8.9129(5), c=10.7940(6) , β=105.993(1)o, V=954.3 3, Z=4, Mr=513.91, Dc=3.577 g/cm3, μ=8.585 mm(-1), F(000)=960, S=0.955,(Δρ)max=1.380,(Δρ)min=–3.428 e/3, the final R=0.0301 and w R=0.0400 for 2301 observed reflections with I 〉 2σ(I). In addition, pure powder of isostructural Rb Tb(PO3)4 was synthesized in order to investigate the optical property. Photoluminescence measurements show that both crystals ATb(PO3)4(A=K(1), Rb(2)) are promising candidates to become solid-state visible green light-emitting sources.展开更多
Dicyanide building block cis-Fe(phen)2(CN)2 and [MnⅢ(salen)](ClO4) have been used to design and synthesize a cyanide-bridged complex, resulting in a heterobimetallic one-dimensional(1D) zigzag chain complex...Dicyanide building block cis-Fe(phen)2(CN)2 and [MnⅢ(salen)](ClO4) have been used to design and synthesize a cyanide-bridged complex, resulting in a heterobimetallic one-dimensional(1D) zigzag chain complex 1, [cis-Fe(phen)2(CN)2Mn(salen)](PF6)(phen =1,10-phenanthroline, salen=N,N-ethylenebis-(salicylideneaminato) dianion). Single-crystal X-ray diffraction analysis shows complex 1 crystallizes in the monoclinic P2(1/c) space group and the asymmetric unit contains one [-NC-Fe(phen)2(μ-CN)-MnⅢ-(salen)-]+ cation and one PF6- anion. In the cationic structure of 1, each FeⅡ(phen)2(CN)2 connects two [MnⅢ(salen)]+ with two cyanide groups in a cis-conformation, and in turn each [MnⅢ(salen)]+ unit links two FeⅡ(phen)2(CN)2 building blocks in a trans-conformation, resulting in a 1D [-NC-FeⅡ-CN-MnⅢ-]n chain. Furthermore, the electronic absorption spectra and electrochemical and magnetic properties of complex 1 have also been studied.展开更多
文摘There are a number of structures and structural styles found in extensional tectonic settings of the world,and it is a big challenge to study the evolution of these structures. Evolution of structures formed in extensional tectonic settings have been studied by researchers on different extensional basins of the world. Southern Sindh Monocline lies on the western corner of Indian Plate and the tectonic history of Indian plate has also experienced different extensional episodes, and its journey rifted from Gondwanaland to its final welding to Asia. The aim of this study is to figure out the evolution of structures in the subsurface of Southern Sindh Monocline, Pakistan using the seismic data interpretation and flattening of horizons approach. Structures within the subsurface of Southern Sindh Monocline have been characterized by different tectonic episodes of Indian plate while rifting from Gondwanaland, rifting from other plates at different geological times and to its collision with the Asia. Basic structures within study area are classified into nine types while the structural styles have been classified into six types as horst and grabens, dominos, crotch, synthetic and antithetic, negative and flashlight structural style. The structures within the study area revealed evidence for three major structural episodes which can be characterized as Episode 1: Structures associated with rifting of Indian plate from Gondwanaland during Late Jurassic to Early Cretaceous, Episode 2: Modification and reactivation of previous structures while Madagascar rifted from Indian Plate during the Middle Cretaceous and during Episode 3: Inversion and reactivation of structures occurred when Indian Plate collided with Asia during Early Eocene.
基金supported by the National Natural Science Foundation of China(Grant No.61505109)Youth Innovative Talents Attracting and Cultivating Plan of Colleges and Universities in Shandong Province(No.21)+1 种基金Youth Innovation Team of colleges and universities in Shandong Province(Grant No.2022KJ223)Shandong Provincial Natural Science Foundation(Grant No.ZR2021QF020).
文摘The anisotropic properties and applications ofβ-gallium oxide(β-Ga_(2)O_(3))are comprehensively reviewed.All the anisotropic properties are essentially resulted from the anisotropic crystal structure.The process flow of how to exfoliate nanoflakes from bulk material is introduced.Anisotropic optical properties,including optical bandgap,Raman and photolumines-cence characters are comprehensively reviewed.Three measurement configurations of angle-resolved polarized Raman spec-tra(ARPRS)are reviewed,with Raman intensity formulas calculated with Raman tensor elements.The method to obtain the Raman tensor elements of phonon modes through experimental fitting is also introduced.In addition,the anisotropy in elec-tron mobility and affinity are discussed.The applications,especially polarization photodetectors,based onβ-Ga_(2)O_(3)were summa-rized comprehensively.Three kinds of polarization detection mechanisms based on material dichroism,1D morphology and metal-grids are discussed in-depth.This review paper provides a framework for anisotropic optical and electric properties ofβ-Ga_(2)O_(3),as well as the applications based on these characters,and is expected to lead to a wider discussion on this topic.
基金Founded by the National Natural Science Foundation of China (Nos.U1806221 and 51932006)the Instruction&Development Zone of Shandong Province (2018ZCQZB01 and 2019ZCQZB03)。
文摘The piezoelectric strain of K_(0.5)Na_(0.5)NbO_(3)-based lead-free ceramic at different temperatures was studied.The Rayleigh analysis shows that the intrinsic and extrinsic contributions are increased at temperature from 173 to 298 K.In addition,a monoclinic phase structure was observed at 83 K.The results of phase field simulation show that the temperature dependent microstructure evolution is a function of the local structure size.This work contributes to understanding the structure and properties relationship of the multi-cations doped KNN-based piezoelectric ceramics as a function of temperature.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.92065201,11874264,and 11974154)the Starting Grant of ShanghaiTech University and Analytical Instrumentation Center,SPST,ShanghaiTech University (Grant No.SPST-AIC10112914)support from the Natural Science Foundation of Shandong Province,China (Grant No.ZR2022MA004)。
文摘Monoclinicα-MoP_(2),with the OsGe2-type structure(space group C2/m,Z=4)and lattice parameters a=8.7248(11)Å,b=3.2322(4)Å,c=7.4724(9)Å,andβ=119.263°,was synthesized under a pressure of 4~GPa at a temperature between 1100℃and 1200℃.The structure ofα-MoP_(2) and its relationship to other transition metal diphosphides are discussed.Surprisingly,the ambient pressure phase orthorhombicβ-MoP_(2)(space group Cmc21)is denser in structure thanα-MoP_(2).Room-temperature high-pressure x-ray diffraction studies exclude the possibility of phase transition fromβ-MoP_(2) to α-MoP_(2),suggesting thatα-MoP_(2) is a stable phase at ambient conditions;this is also supported by the total energy and phonon calculations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11347199,11072225,10874141,and 10974160)the Specialized Research Fund for Doctoral Program of Higher Education of China(Grant No.20130184120028)+1 种基金the National Basic Research Program of China(GrantNo.2011CB808201)the Fundamental Research Funds for the Central Universities,China(Grant Nos.SWJTU112T23 and 2682013CX054)
文摘First-principles calculations of structural, electronic, optical, elastic, mechanical properties, and Born effective charges of monoclinic HfO2 are performed with the plane-wave pseudopotential technique based on the density-functional theory. The calculated structural properties are consistent with the previous theoretical and experimental results. The electronic structure reveals that monoclinic HfO2 has an indirect band gap. The analyses of density of states and Mulliken charges show mainly covalent nature in Hf-O bonds. Optical properties, including the dielectric function, refractive index, extinction coefficient, reflectivity, absorption coefficient, loss function, and optical conductivity each as a function of photon energy are calculated and show an optical anisotropy. Moreover, the independent elastic constants, bulk modulus, shear modulus, Young's modulus, Poisson's ratio, compressibility, Lam6 constant, sound velocity, Debye temperature, and Born effective charges of monoclinic HfO2 are obtained, which may help to understand monoclinic HfO2 for future work.
基金support of the National Key Technology R&D Program of China(No.2015BAB12B02)the Science and Technology Planning Project Guangdong Province,China(No.2013B090800016)
文摘The flotation separation of chalcopyrite from monoclinic pyrrhotite using food-grade guar gum(FGG) as a depressant was studied through flotation tests, kinetic studies, dynamic potential measurements, adsorption experiments, and infrared spectral analyses. The microflotation results showed that the flotation separation of chalcopyrite from monoclinic pyrrhotite could not be realized by adding mixed aerofloat(CSU11) alone. The depressant FGG exhibited a selective depression effect on monoclinic pyrrhotite by controlling the pulp pH range from 5.0 to 6.0, with a maximum floatability variation of 79.36% in the presence of CSU11. The flotation kinetics, zeta-potential, adsorption, and infrared spectroscopy studies revealed that the FGG could absorb more strongly on the surface of monoclinic pyrrhotite than on the surface of chalcopyrite. In addition, the results revealed that the interaction of FGG with the monoclinic pyrrhotite surface was governed primarily by strong chemisorption, whereas FGG mainly bonded to chalcopyrite through hydrogen bonding. This difference was responsible for the excellent depression selectivity of FGG toward monoclinic pyrrhotite flotation and weak depression effect toward chalcopyrite flotation.
基金supported by the National Natural Science Foundation of China(20825310 and 20973011)National Basic Research Project of China (2011CB201400 and 2011CB808700)
文摘The effect of chloride ions on a monoclinic ZrO2-supported RuOx (RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate (MF) at a low temperature of 373 K. The m-ZrO2 support was Cl-free, and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K. The structures of these catalysts were characterized by X-ray diffraction, Raman and X-ray photoelectron spectroscopies. Their reducibility was probed by temperature-programmed reduction in H2. The RuOx domains were present as highly dispersed Rut42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl ions. Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity, whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2. The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates. This finding provides novel insights into the promoting effect of Cl- ions on oxides-based catalysts for selective oxidation reactions.
基金Supported by the National Key R&D Program of China(2018YFA0305700)the National Natural Science Foundation of China(11904391,11834016,11874400,11888101,11921004)+3 种基金the Beijing Natural Science Foundation(Z190008)the Strategic Priority Research Program and the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(XDB25000000,QYZDB-SSW-SLH013)the CAS Interdisciplinary Innovation Team(JCTD-2019-01)JPS acknowledges the support from the China Postdoctoral Science Foundation and the Postdoctoral Innovative Talent Program.
文摘We report a comprehensive high-pressure study on the monoclinic TIFeSe2 single crystal,which is an antiferromagnetic jnsulator with quasi-one-dimensional crystal structure at ambient pressure.It is found that TIFeSe2 undergoes a pressure-induced structural transformation from the monoclinic phase to an orthorhombic structure above Pc≈13 GPa,accompanied with a large volume collapse of ΔV/V0=8.3%.In the low-pressure monoclinic phase,the insulating state is easily metallized at pressures above 2 GPa;while possible superconductivity with Tconset^2 K is found to emerge above 30 GPa in the high-pressure phase.Such a great tunability of TIFeSe2 under pressure indicates that the ternary AFeSe2 system(A=Tl,K,Cs,Rb) should be taken as an important platform for explorations of interesting phenomena such as insulator-metal transition,dimensionality crossover,and superconductivity.
基金the National Nanotechnology Center (NANOTEC)National Science and Technology Development Agency, Thailand, for providing financial support through the project code: P-10-11345+1 种基金the Thailand's Office of the Higher Education Commission through the National Research University Projectthe Thailand Research Fund (TPF) through the TPF Basic Research Grant,includ-ing the Graduate School of Chiang Mai University through the general support
文摘Monochnic and hexagonal CePO4 nanoparticles and nanorods were successfully synthesized from Ce(NO3)36H2O and Na3PO4 121-120 solu- tions at pH 1-5 by a 180 W microwave radiation for 60 min. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FFIR) spectroscopy, and scanning electron microscopy (SEM). XRD patterns revealed that the products are hexagonal CePO4 structures at pH 2-5, and monoclinic CePO4 structtLres at pH 1. SEM characterization shows that these products were nanoparticles, short nanorods, and long nanorods, controlled by the pH of the precursor solutions. Optical properties of the nanorods were also investigated by ultraviolet-visible (UV-vis) and photoluminescence (PL) spectroscopy.
基金This work was financially supported by the National Natural Science Foundation of China(No.11605116).
文摘Monoclinic SrAl_(2)Si_(2)O_(8) ceramics for Sr immobilization were prepared by a liquid-phase sintering method.The sintering temperature,mineral phase composition,microstructure,flexural strength,bulk density,and Sr ion leaching characteristics of the SrAl_(2)Si_(2)O_(8) ceramics were investigated.A crystalline monoclinic SrAl_(2)Si_(2)O_(8) phase formed through liquid-phase sintering at 1223 K.The introduction of four flux agents(B_(2)O_(3),CaO·2B_(2)O_(3),SrO·2B_(2)O_(3),and BaO·2B_(2)O_(3))to the SrAl_(2)Si_(2)O_(8) ceramics not only reduced the densification temperature and decreased the volatilization of Sr during high-temperature sintering but also impacted the mechanical properties of the ceramics.Product consistency tests showed that the leaching concentration of Sr ions in the sample with flux agent B_(2)O_(3) was the lowest,whereas that of Sr ions in the sample with flux agent BaO·2B_(2)O_(3) was the highest.These results show that the leaching concentration of Sr ions depends largely on the amorphous phase in the ceramics.Meanwhile,the formation of mineral analog ceramics containing Sr is an important factor to improve Sr immobilization.
基金supported in part by Deanship of Research, Taibah University, Kingdom of Saudi Arabia, and Matt Winstead, CDT, Vice President, Oral Arts Dental Labs, Huntsville, AL, USA
文摘The aim of this study was to determine if accelerated aging of porcelain veneering had an effect on the surface properties specific to a tetragonal-to-monoclinic transformation(TMT) of zirconia restorations. Thirty-six zirconia samples were milled and sintered to simulate core fabrication followed by exposure to various combinations of surface treatments including as-received(control),hydrofluoric acid(HF), application of liner plus firings, application of porcelain by manual layering and pressing with firing, plus accelerated aging. The quantity of transformed tetragonal to monoclinic phases was analyzed utilized an X-ray diffractometer and one-way analysis of variance was used to analyze data. The control samples as provided from the dental laboratory after milling and sintering process had no TMT(X m5 0). There was an effect on zirconia samples of HF application with TMT(X m5 0.8%) and liner plus HF application with TMT(X m5 8.7%). There was an effect of aging on zirconia samples(no veneering) with significant TMT(X m5 70.25%). Both manual and pressing techniques of porcelain applications reduced the TMT(manual, X m5 4.41%, pressing,X m5 11.57%), although there was no statistical difference between them. It can be concluded that simulated applications of porcelain demonstrated the ability to protect zirconia from TMT after aging with no effect of a liner between different porcelain applications.The HF treatment also caused TMT.
基金Supported by the National Natural Science Foundation of China(21401024)Natural Science Foundation of Anhui Province(1508085MB21)+3 种基金Key Project of Natural Science Research in Universities of Anhui Province(KJ2016A550)Major Scientific and Technological Achievements Incubation Fund Project of Fuyang Normal College(kjfh201606)National Students Research Training Program(201510371013,201610371015)Doctoral Startup Foundation of Fuyang Normal College(FSB201501010)
文摘A pyridine-contained Schiff base ligand L(L =(pyridine-2-vinyl)hydrazine) has been synthesized and fully characterized. By self-assembly of the ligand with HgI2, a binuclear complex Hg2I4L(C) was obtained. The structures of L and C were analyzed through single-crystal X-ray diffraction. L crystallizes in monoclinic, space group P21/n with a=11.286(5), b=3.981(5), c=23.865(5) , β=100.043(5)°, V=1056(1) 3, Z=4, Dc=1.323 g/m3, F(000)=440, Μr=210.24, μ=0.084 mm(-1), the final R=0.0928 and w R=0.2867 for 6955 observed reflections with I > 2(I). The complex is of monoclinic system, space group P21/n with a=8.706(5), b=17.468(5), c=14.675(5) , β=93.922(5)°, V=2227(2) 3, Z=4, Dc=3.338 g/m3, F(000)=1928, Μr=1119.02, μ=19.321 mm(-1), the final R=0.0366 and w R=0.1276 for 3920 observed reflections with I > 2(I). The structural analysis revealed that the molecule of L possesses a well planar structure. However, in the complex, the coordinated ligand distorts greatly. The absorption spectra of L and the complex in ethanol were experimentally and theoretically studied. The result indicates that the complex exhibits different absorption spectrum compared with the free ligand.
基金supported by the National Basic Research Program of China(973 Program,2013CB632400)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China(Nos.51272102 and 21103070)
文摘The room temperature stabled monoclinic KNbO3 nanowires were found to act as photocatalyst for photocatalytic methane production and dye degradation in this work. Higher activities have been observed for monoclinic phase compared to the reference(orthorhombic phase). In the photoreduction of CO2 reaction, the monoclinic KNbO3 nanowires exhibited a CH4 evolution rate of 0.025 μmol·g-1·h-1, which was higher than 0.021 μmol·g-1·h-1 of orthorhombic KNbO3 nanowires. In the photodegradation of rhodamine B(Rh B), almost all the Rh B were degraded after 90 min light illumination for monoclinic KNbO3 nanowires. But for orthorhombic KNbO3 nanowires, the concentration of Rh B only decreased to 62% of the initial value.
基金Supported by the Open Fund Project of Key Laboratory of Functional Organometallic Materials of Hengyang Normal University(GN15K02)the Science Foundation of Hengyang Normal University(16D06)
文摘A new Zn(Ⅱ) complex [Zn(Phen)2(C(12)H6O4N2)(H2O)]·3H2O with 2,2-bipyridine-3,3-dicarboxylic acid and 1,10-phenanthroline(Phen) as ligands was synthesized, and the crystal data are as follows: monoclinic, space group P2(1/n), a=12.5581(11), b=17.3382(17), c=15.6687(14) , β=110.579(2)o, Mr=731.02, V=3193.9(5) 3, Dc=1.520 g/cm3, Z=4, μ(Mo Kα)=0.833 mm(-1), F(000)=1508, the final R=0.0431 and w R=0.0936. In the title complex, the central Zn(Ⅱ) ion is located in a distorted octahedral coordination environment. The electrochemical and fluorescent properties were studied. The title complex possesses irreversible electron transfer in the electrode reaction, and it has a strong emission peak in the range of 470505 nm, with the excitation wavelength being 488 nm.
文摘In order to investigate the effect of lanthanum ion implantation on theoxidation behavior of zircaloy at 500℃, Zircaloy specimens were implanted by lanthanum ions with adose range from 5xl0^(16) to 2xl0^(17) ions/cm^2 at room temperature, and then oxidized at 500℃ for100 min. The valence of the oxides in the scale was analyzed by X-ray Photoelectron Spectroscopy(XPS). The phase structures of the oxides in the scale were examined by Glancing Angle X-rayDiffraction (GAXRD). With the increase of implanted lanthanum ions dose, the phase structures in theoxide scale are transformed from monoclinic zirconia to hexagonal one and then to monoclinic oneagain. The measurement of weight gain showed that a similar change from the decreased gain toincreased one again is achieved in the oxidation behavior of lanthanum ion implanted zircaloycompared with that of as-received zircaloy.
基金Supported by the National Natural Science Foundation of China(No.21201087 and 21671084)NSF of Jiangsu Province(BK20131244 and BK20130460)+1 种基金the Foundation of Jiangsu Educational Committee(16KJB430011)the Qing Lan Project of Jiangsu Province and Jiangsu Overseas Research&Training Program for University Prominent Young&Middle-aged Teacher and Presidents,Six talent peaks project in Jiangsu Province(2014-XCL-008)
文摘Two novel coordination polymers with molecular structures(2MI)+[Zn(2MI)Cl3]-(1) and(2MI)+NO3-(2) based on ligand 2-methylimidazole(2MI) were synthesized under solution method. Compound 1 crystallizes in the monoclinic system, space group Cc with a=7.489(2), b=13.448(4), c=13.983(4) , β=98.402(2)°, Z=4 and V=102.246(2) 3. Compound 2 crystallizes in the orthorhombic system, space group pnma with a=14.296(3), b=6.3180(12), c=7.3862(13) , β=90°, Z=4 and V=667.1(2) 3. Dielectric measurements show compounds 1 and 2 have reversible dielectric anomalous behaviors with variation frequencies at different temperature.
基金Financially supported by the National Natural Science Foundation of China(No.21373157)
文摘A new energetic dipotassium 3,3-dinitro-5,5-bis-1,2,4-triazole-1,1-diolate [K2(DNOBT)] was synthesized, and structurally characterized by elemental analysis, IR spectra, 13 C NMR and single-crystal X-ray diffraction. K2(DNOBT)·2H2O crystallizes in monoclinic system, space group P21/n with a=6.0446(10), b=15.999(3), c=6.4169(11) , β=99.421(2)°, V=612.21(18) 3, Z=4, Dc=2.009 g·cm(-3), F(000)=372, μ=0.838 mm(-1), S=1.012, the final R=0.0248 and w R(I 〉 2σ(I))=0.0604. Thermal decomposition of the title compound was studied by using DSC and TG-DTG, and there is primarily one exothermic decomposition process at 371.5 ℃.
基金Supported by the Doctoral Scientific Research Foundation of Hengyang Normal University(16D06)Technology Support of Hengyang City(2015KG23)
文摘A new copper(Ⅱ) coordination polymer [Cu2(C7H5N4)2(3-C6H5NO2)2]n(1) has been hydrothermally synthesized with copper hydroxide, 3-(pyridin-2-yl)-1,2,4-triazole(Hpt) and 3-pyridinecarboxylic acid(3-PCA). It crystallizes in the monoclinic space group C2/c, with a=16.854(2), b=7.8616(8), c=20.630(2) , β=111.126(2)o, V=2549.7(5) 3, Dc=1.723 g/cm3, Z=8, F(000)=1336, the final GOOF=1.065, R=0.0380 and w R=0.0972. The whole molecule consisting of two copper ions are bridged by two μ2-η1:η0-3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of Cu(1) ion is CuO2N4, giving a distorted octahedron geometry. 1 exhibits antiferromagnetic interaction, and the electron transfer of 1 is irreversible in electrode reactions and the TG analysis shows that 1 is stable below 235 ℃.
基金Supported by the National Natural Science Foundation of China(No.20901066)the Natural Science Foundation of Yunnan Province(No.2012FB122)+3 种基金the Education Science Foundation of Yunnan Province(No.2013Z050)the Science Foundation of State Key Laboratory of Structural Chemistry(No.20140012)Training Program for Young Academic and Technical Leader in Yunnan Provincethe Science Foundation of Key Laboratory of Micro-and Nano-materials and Technology in Yunnan Province(No.ZZ2016002)
文摘The potassium terbium polyphosphate crystal KTb(PO3)4 has been synthesized using a high temperature solution reaction method. The structure and composition were characterized by single-crystal X-ray diffraction, powder X-ray diffraction and elemental analysis. The compound crystallizes in the monoclinic space group P21/n with a=10.3182(6), b=8.9129(5), c=10.7940(6) , β=105.993(1)o, V=954.3 3, Z=4, Mr=513.91, Dc=3.577 g/cm3, μ=8.585 mm(-1), F(000)=960, S=0.955,(Δρ)max=1.380,(Δρ)min=–3.428 e/3, the final R=0.0301 and w R=0.0400 for 2301 observed reflections with I 〉 2σ(I). In addition, pure powder of isostructural Rb Tb(PO3)4 was synthesized in order to investigate the optical property. Photoluminescence measurements show that both crystals ATb(PO3)4(A=K(1), Rb(2)) are promising candidates to become solid-state visible green light-emitting sources.
基金Supported by the Project of Hubei Provincial Department of Education(No.Q20144302 and Q20164302)the Natural Science Foundation of Hubei Province(No.2013CFA015)+1 种基金the Doctoral Scientific Research Foundation of Jingchu University of Technology(No.QDB201603)the Open Project Program of Hubei Key Laboratory of Drug Synthesis and Optimization,Jingchu University of Technology(No.OPP2016ZD02)
文摘Dicyanide building block cis-Fe(phen)2(CN)2 and [MnⅢ(salen)](ClO4) have been used to design and synthesize a cyanide-bridged complex, resulting in a heterobimetallic one-dimensional(1D) zigzag chain complex 1, [cis-Fe(phen)2(CN)2Mn(salen)](PF6)(phen =1,10-phenanthroline, salen=N,N-ethylenebis-(salicylideneaminato) dianion). Single-crystal X-ray diffraction analysis shows complex 1 crystallizes in the monoclinic P2(1/c) space group and the asymmetric unit contains one [-NC-Fe(phen)2(μ-CN)-MnⅢ-(salen)-]+ cation and one PF6- anion. In the cationic structure of 1, each FeⅡ(phen)2(CN)2 connects two [MnⅢ(salen)]+ with two cyanide groups in a cis-conformation, and in turn each [MnⅢ(salen)]+ unit links two FeⅡ(phen)2(CN)2 building blocks in a trans-conformation, resulting in a 1D [-NC-FeⅡ-CN-MnⅢ-]n chain. Furthermore, the electronic absorption spectra and electrochemical and magnetic properties of complex 1 have also been studied.