The solubilities of the quinary system Na^＋ ,K^＋ ,Mg^2＋ //Cl ,NO 3 ^-H2O and its two quaternary subsystems, Na^＋ ,K^＋ ,Mg^2＋ //NO 3 -H2O and K^ ＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,were studied by isothermal method at 2...The solubilities of the quinary system Na^＋ ,K^＋ ,Mg^2＋ //Cl ,NO 3 ^-H2O and its two quaternary subsystems, Na^＋ ,K^＋ ,Mg^2＋ //NO 3 -H2O and K^ ＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,were studied by isothermal method at 25°C and their phase diagrams were plotted.In the equilibrium phase diagram of quaternary system Na^ ＋ ,K^ ＋ ,Mg ^2＋ //NO 3 ^-H2O, there are one invariant point,three univariant curves and three regions of crystallization with one salt：NaNO3, KNO3 and Mg（NO3）2·6H2O.In the equilibrium phase diagram of quaternary system K ^＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,there are three invariant points,seven univariant curves and five regions of crystallization with one salt：KNO3,KCl, Mg（NO3）2·6H2O,MgCl2·6H2O and KCl·MgCl2·6H2O.In the equilibrium phase diagram of the quinary system Na ^＋ , K^ ＋ ,Mg ^2＋ //Cl ,NO 3^ -H2O,there are four invariant points,and seven regions of crystallization with one salt：NaCl, KCl,NaNO3,KCl·MgCl2·6H2O,KNO3,MgCl2·6H2O and Mg（NO3）2·6H2O.展开更多
In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of ...In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of graphs of these functions and give a detailed proof.展开更多
Two quinary high-entropy alloys （HEAs） with equiatomic concentrations formed by doping either Cu or A1 elements into the quaternary NiFeCoCr alloy are produced by arc melting and spray casting techniques. Their entr...Two quinary high-entropy alloys （HEAs） with equiatomic concentrations formed by doping either Cu or A1 elements into the quaternary NiFeCoCr alloy are produced by arc melting and spray casting techniques. Their entropy of fusion, thermal expansion coefficient and thermal diffusivity are experimentally investigated with differential scanning cMorimetry, dilatometry and laser flash methods. The NiFeCoCrCu HEAs contain a face- centered cubic high-entropy phase plus a minor interdendritic （Cu） phase and display a lower entropy of fasion and the Vickers hardness. The NiFeCoCrAl HEAs consist of two body-centered cubie high-entropy phases with coarse dendritic structures and show higher entropy of fusion and the Vickers hardness. Both the thermal expansion coefficient and the thermal diffusivity of the former Cu-doped alloy are signitieantly larger than those of the latter At-doped M1oy. Although the temperature dependence of thermal diffusivity is similar for both HEAs, it is peculiar that the thermal expansion curve of the NiFeCoCrAl alloy exhibits an inflexion at temperatures of 860-912 K.展开更多
The synthesis of discrete polyoxometalate clusters composed of more than 3 metallic elements has always been attractive but seldom successful.For the first time,we have developed a de novo synthetic route to quinary C...The synthesis of discrete polyoxometalate clusters composed of more than 3 metallic elements has always been attractive but seldom successful.For the first time,we have developed a de novo synthetic route to quinary Cu-Ni-Co-Mn-Zn Keplerate clusters with a nuclearity of 20.Seven single-crystalline quinary Keplerates in a medium-entropy state with various compositions have been obtained.展开更多
We report the discovery of bulk superconductivity in a new quinary intermetallic compound Th_(2)Mo_(2)Ru_(2)Si_(4)C,crystallized in a collapsed 22241-type structure.This structure is characterized by the intergrowth o...We report the discovery of bulk superconductivity in a new quinary intermetallic compound Th_(2)Mo_(2)Ru_(2)Si_(4)C,crystallized in a collapsed 22241-type structure.This structure is characterized by the intergrowth of ThMo_(2)Si_(2)C and ThRu_(2)Si_(2) units interconnected by equivalent Si-Si bonds that enhance inter-sublattice coupling.The refined lattice parameters are a=4.2212(1)Å and c=20.3899(7)Å.Electrical resistivity and magnetic susceptibility measurements of both polycrystalline and single-crystal samples consistently demonstrate bulk superconductivity with a transition temperature T_(c)∼6.0 K significantly higher than those of the constituent compound ThMo_(2)Si_(2)C and its related analogs.Under magnetic fields,the superconducting state exhibits a nearly isotropic behavior,which is attributed to strong covalent interlayer coupling.First-principles calculations reveal a substantial contribution from the Mo-d orbitals near the Fermi level,which exhibit several band-crossing points.The enhancement in T_(c) can be attributed to the synergistic combination of the valence electron concentration and the inter-sublattice self-doping effect between the[Ru_(2)Si_(2)]and[Mo_(2)Si_(2)C]layers.展开更多
Nuclear magnetic resonance(NMR)serves as a powerful tool for studying both the structure and dynamics of proteins.The NOE method,alongside residual dipolar;coupling,paramagnetic effects,J-coupling,and other related te...Nuclear magnetic resonance(NMR)serves as a powerful tool for studying both the structure and dynamics of proteins.The NOE method,alongside residual dipolar;coupling,paramagnetic effects,J-coupling,and other related techniques,has reached a level of maturity that allows for the determination of protein structures.Furthermore,NMR relaxation methods prove to be highly effective in characterizing protein dynamics across various timescales.The properties of protein systems are dictated by intra-and intermo-lecular interactions among atoms,which involve covalent bonds,hydrogen bonds(H-bonds),electrostatic interactions,and van der Waals forces.Multiple NMR approaches have been developed to measure noncovalent interactions,and this paper offers a concise overview of noncovalent interaction measurements using NMR,with a specific emphasis on the advancements accomplished in our laboratory.展开更多
Birefringent crystals play a crucial role in regulating the polarization of light and are widely used in optoelectronic fields.However,the effective design of novel infrared(IR)birefringent crystals with large birefri...Birefringent crystals play a crucial role in regulating the polarization of light and are widely used in optoelectronic fields.However,the effective design of novel infrared(IR)birefringent crystals with large birefringence(Δn)still face significant challenges.In this study,we present the rational design and successful synthesis of two novel quinary oxychalcogenides with the formula Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd),employing a heteroanion-introduction strategy via high-temperature solid-state reactions.Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd)crystallized in the monoclinic space group P2_(1)/n(no.14)and the structures comprised one-dimensional(1D)[M^(II)Ge_(3)S_(8)O_(2)]^(6−)chains arranged in an antiparallel manner and separated by Ba^(2+)cations.The coexistence of multiple heteroanionic ligands([M^(II)OS_(5)]octahedra,[GeOS_(3)],and[GeO_(2)S_(2)]tetrahedra)in one material was surprisingly discovered for the first time in the realm of oxychalcogenides.It was revealed that the heteroanion-introduction strategy not only leads to a reduction in the structural dimensionality but also enhances the optical anisotropy significantly.Notably,Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd)demonstrated large Δn values of 0.11 and 0.14,which represent a remarkable improvement compared to the three-dimensional(3D)parent AE_(3)M^(II)M^(IV)_(2)Q_(8) system(Δn=0).Furthermore,theoretical calculations suggest that the significantΔn of Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd)resulted primarily from the combination of polarizabilities from the various heteroanionic groups.Overall,these results highlight the potential of the heteroanion-introduction strategy for designing novel IR birefringent materials for optoelectronic applications.展开更多
基金Supported by the National Natural Science Foundation of China（20466003 20866008）
文摘The solubilities of the quinary system Na^＋ ,K^＋ ,Mg^2＋ //Cl ,NO 3 ^-H2O and its two quaternary subsystems, Na^＋ ,K^＋ ,Mg^2＋ //NO 3 -H2O and K^ ＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,were studied by isothermal method at 25°C and their phase diagrams were plotted.In the equilibrium phase diagram of quaternary system Na^ ＋ ,K^ ＋ ,Mg ^2＋ //NO 3 ^-H2O, there are one invariant point,three univariant curves and three regions of crystallization with one salt：NaNO3, KNO3 and Mg（NO3）2·6H2O.In the equilibrium phase diagram of quaternary system K ^＋ ,Mg ^2＋ //Cl ,NO 3 ^-H2O,there are three invariant points,seven univariant curves and five regions of crystallization with one salt：KNO3,KCl, Mg（NO3）2·6H2O,MgCl2·6H2O and KCl·MgCl2·6H2O.In the equilibrium phase diagram of the quinary system Na ^＋ , K^ ＋ ,Mg ^2＋ //Cl ,NO 3^ -H2O,there are four invariant points,and seven regions of crystallization with one salt：NaCl, KCl,NaNO3,KCl·MgCl2·6H2O,KNO3,MgCl2·6H2O and Mg（NO3）2·6H2O.
文摘In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of graphs of these functions and give a detailed proof.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51571163,51371150,51271150 and 51327901
文摘Two quinary high-entropy alloys （HEAs） with equiatomic concentrations formed by doping either Cu or A1 elements into the quaternary NiFeCoCr alloy are produced by arc melting and spray casting techniques. Their entropy of fusion, thermal expansion coefficient and thermal diffusivity are experimentally investigated with differential scanning cMorimetry, dilatometry and laser flash methods. The NiFeCoCrCu HEAs contain a face- centered cubic high-entropy phase plus a minor interdendritic （Cu） phase and display a lower entropy of fasion and the Vickers hardness. The NiFeCoCrAl HEAs consist of two body-centered cubie high-entropy phases with coarse dendritic structures and show higher entropy of fusion and the Vickers hardness. Both the thermal expansion coefficient and the thermal diffusivity of the former Cu-doped alloy are signitieantly larger than those of the latter At-doped M1oy. Although the temperature dependence of thermal diffusivity is similar for both HEAs, it is peculiar that the thermal expansion curve of the NiFeCoCrAl alloy exhibits an inflexion at temperatures of 860-912 K.
基金supported by the National Natural Science Foundation of China(Grant No.21301057 and 22075073)Fundamental Research Funds for the Central Universities(531107051077).
文摘The synthesis of discrete polyoxometalate clusters composed of more than 3 metallic elements has always been attractive but seldom successful.For the first time,we have developed a de novo synthetic route to quinary Cu-Ni-Co-Mn-Zn Keplerate clusters with a nuclearity of 20.Seven single-crystalline quinary Keplerates in a medium-entropy state with various compositions have been obtained.
基金supported by the National Key Research and Development Program of China (Grant Nos.2022YFA1403202 and 2023YFA1406101)the CAS Superconducting Research Project (Grant No.SCZX-0101)。
文摘We report the discovery of bulk superconductivity in a new quinary intermetallic compound Th_(2)Mo_(2)Ru_(2)Si_(4)C,crystallized in a collapsed 22241-type structure.This structure is characterized by the intergrowth of ThMo_(2)Si_(2)C and ThRu_(2)Si_(2) units interconnected by equivalent Si-Si bonds that enhance inter-sublattice coupling.The refined lattice parameters are a=4.2212(1)Å and c=20.3899(7)Å.Electrical resistivity and magnetic susceptibility measurements of both polycrystalline and single-crystal samples consistently demonstrate bulk superconductivity with a transition temperature T_(c)∼6.0 K significantly higher than those of the constituent compound ThMo_(2)Si_(2)C and its related analogs.Under magnetic fields,the superconducting state exhibits a nearly isotropic behavior,which is attributed to strong covalent interlayer coupling.First-principles calculations reveal a substantial contribution from the Mo-d orbitals near the Fermi level,which exhibit several band-crossing points.The enhancement in T_(c) can be attributed to the synergistic combination of the valence electron concentration and the inter-sublattice self-doping effect between the[Ru_(2)Si_(2)]and[Mo_(2)Si_(2)C]layers.
文摘Nuclear magnetic resonance(NMR)serves as a powerful tool for studying both the structure and dynamics of proteins.The NOE method,alongside residual dipolar;coupling,paramagnetic effects,J-coupling,and other related techniques,has reached a level of maturity that allows for the determination of protein structures.Furthermore,NMR relaxation methods prove to be highly effective in characterizing protein dynamics across various timescales.The properties of protein systems are dictated by intra-and intermo-lecular interactions among atoms,which involve covalent bonds,hydrogen bonds(H-bonds),electrostatic interactions,and van der Waals forces.Multiple NMR approaches have been developed to measure noncovalent interactions,and this paper offers a concise overview of noncovalent interaction measurements using NMR,with a specific emphasis on the advancements accomplished in our laboratory.
基金supported by the National Natural Science Foundation of China(21771179)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR118)the Natural Science Foundation of Fujian Province(2022L3092 and 2023H0041).
文摘Birefringent crystals play a crucial role in regulating the polarization of light and are widely used in optoelectronic fields.However,the effective design of novel infrared(IR)birefringent crystals with large birefringence(Δn)still face significant challenges.In this study,we present the rational design and successful synthesis of two novel quinary oxychalcogenides with the formula Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd),employing a heteroanion-introduction strategy via high-temperature solid-state reactions.Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd)crystallized in the monoclinic space group P2_(1)/n(no.14)and the structures comprised one-dimensional(1D)[M^(II)Ge_(3)S_(8)O_(2)]^(6−)chains arranged in an antiparallel manner and separated by Ba^(2+)cations.The coexistence of multiple heteroanionic ligands([M^(II)OS_(5)]octahedra,[GeOS_(3)],and[GeO_(2)S_(2)]tetrahedra)in one material was surprisingly discovered for the first time in the realm of oxychalcogenides.It was revealed that the heteroanion-introduction strategy not only leads to a reduction in the structural dimensionality but also enhances the optical anisotropy significantly.Notably,Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd)demonstrated large Δn values of 0.11 and 0.14,which represent a remarkable improvement compared to the three-dimensional(3D)parent AE_(3)M^(II)M^(IV)_(2)Q_(8) system(Δn=0).Furthermore,theoretical calculations suggest that the significantΔn of Ba_(3)M^(II)Ge_(3)O_(2)S_(8)(M^(II)=Mn,Cd)resulted primarily from the combination of polarizabilities from the various heteroanionic groups.Overall,these results highlight the potential of the heteroanion-introduction strategy for designing novel IR birefringent materials for optoelectronic applications.
