Phase structure and electrochemical properties of laser sintered La2MgNi9 alloys were studied. The sintered alloys contained a main phase, LaNi5, and a ternary La-Mg-Ni phase, with a PuNi3 structure and a small amount...Phase structure and electrochemical properties of laser sintered La2MgNi9 alloys were studied. The sintered alloys contained a main phase, LaNi5, and a ternary La-Mg-Ni phase, with a PuNi3 structure and a small amount of LaMgNi4. The ternary La-Mg-Ni phase with a PuNi3 structure had the composition of La1.8Mg1.2Ni9 and La2MgNi9, for alloys laser sintered at 1000 and 1400 W, respectively. Owing to further reactions between LaNi5 and LaMgNi4, the amount of the PuNi3 phase increased for alloys sintered at 1400 W. Both alloys had good activation property （three charge/discharge cycles）. The discharge capacities of the sintered alloys were 321.8 and 344.8 mAh/g, respectively. Compared with the alloy laser sintered at 1000 W, the poor cyclic stability of the alloy sintered at 1400 W was mainly attributed to the lower corrosion resistance of the La2MgNi9 phase.展开更多
Two novel clusters [Mn~Ⅲ_3（μ_3-O）（phendox）3]X·13H_2O（X = Cl（1）, Br（2]） have been obtained from the solvothermal reactions of 1,10-phenanthroline-2,9-dicarbaldehyde dioxime（H_2phendox） with MnCl_2...Two novel clusters [Mn~Ⅲ_3（μ_3-O）（phendox）3]X·13H_2O（X = Cl（1）, Br（2]） have been obtained from the solvothermal reactions of 1,10-phenanthroline-2,9-dicarbaldehyde dioxime（H_2phendox） with MnCl_2·4H_2O or anhydrous MnBr_2, and their structures were characterized by elemental analysis, FT-IR, XRD, TGA, MS and single-crystal X-ray diffraction. It crystallizes in trigonal, space group P3_1/c. X-ray analysis reveals that the neighbouring [Mn_3（μ_3-O）（phendox）_3]＋ cores are linked by C–H···Cl hydrogen bonds and form an infinite supramolecular chain along the c-axis. Neighbouring chains are packed with each other by off-set p-p interactions of the aromatic rings on phenox2-. A 3D supramolecular architecture in a honeycomb topology is formed with 1D hexagonal channel in the dimensions of 13？ × 13？ along the c-axis. The gas adsorption studies show that compound 1·13H_2O is stable upon the removal of guest molecules and the desolvated compound absorbed considerable amount of CO_2.展开更多
The magnetic properties of Fe_(72.5)Cu_1Nb_2V_2Si_(13.5)B_9 alloy are investigated from an amorphous to a nanocrystalline and complete crystalline state. The sample annealed at 550℃ for 0.5 h shows a homogeneous nano...The magnetic properties of Fe_(72.5)Cu_1Nb_2V_2Si_(13.5)B_9 alloy are investigated from an amorphous to a nanocrystalline and complete crystalline state. The sample annealed at 550℃ for 0.5 h shows a homogeneous nanocrystalline structure and presents excellent soft magnetic properties. When the specimens were annealed at a temperature above 600℃, the magnetic properties are obviously deteriorated because the grain size grows up, exceeding the exchange length.展开更多
The title compound, 4β,6α,9α-trimethy-2-carboxyltricyclo[6.3.0.0^（4,5）]undec-2-ene, is a sesquiterpene which was first isolated from Ligularia caloxantha and characterized by MS and NMR. In addition, the structur...The title compound, 4β,6α,9α-trimethy-2-carboxyltricyclo[6.3.0.0^（4,5）]undec-2-ene, is a sesquiterpene which was first isolated from Ligularia caloxantha and characterized by MS and NMR. In addition, the structure was determined by X-ray single-crystal diffraction. It crystallizes in orthorhombie, space group P212121 with a = 8.197（2）, b = 14.876（3）, c = 22.281（6） A, α = β = γ = 90°, V = 2716.9（11） ]A^3, Z = 8, C15H22O2, Mr = 234.34, Dc = 1.146 g/cm^3, μ（MoKa） = 0.074 mm^-1, F（000） = 1024, the final R = 0.0384 and wR = 0.0856 for 6200 independent reflections （Rint = 0.066） and 2538 observed ones （I 〉 2σ（I））. In the molecule, there are three fused five-membered rings; while in this crystal form, the asymmetric unit contains two molecules of the same hand and they are linked together by two intermolecular O-H...O hydrogen bonds to form a dimer.展开更多
The piezoelectric,dielectric,and ferroelectric properties of the(LiCe) co-substituted calcium bismuth niobate(CaBi2Nb2O9,CBNO) are investigated.The piezoelectric properties of CBNO ceramics are significantly enhanced ...The piezoelectric,dielectric,and ferroelectric properties of the(LiCe) co-substituted calcium bismuth niobate(CaBi2Nb2O9,CBNO) are investigated.The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan δ decreased.This makes poling using(LiCe) co-substitution easier.The ceramics(where represents A-site Ca2+ vacancies,possess a pure layered structure phase and no other phases can be found.The Ca0.88(LiCe)0.04 0.04Bi2Nb2O9 ceramics possess optimal piezoelectric properties,with piezoelectric coefficient(d 33) and Curie temperature(TC) found to be 13.3 pC/N and 960 C,respectively.The dielectric and piezoelectric properties of the(LiCe) co-substituted CBNO ceramics exhibit very stable temperature behaviours.This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.展开更多
To achieve high parallel computation of discrete wavelet transform （DWT） in JPEG2000, a high-throughput two-dimensional （2D） 9/7 DWT very large scale integration （VLSI） design is proposed, in which the row proce...To achieve high parallel computation of discrete wavelet transform （DWT） in JPEG2000, a high-throughput two-dimensional （2D） 9/7 DWT very large scale integration （VLSI） design is proposed, in which the row processor is based on flipping structure. Due to the difference of the input data flow, the column processor is obtained by adding the input selector and data buffer to the row processor. Normalization steps in row and column DWT are combined to reduce the number of multipliers, and the rationality is verified. By rearranging the output of four-line row DWT with a multiplexer （MUX）, the amount of data processed by each column processor becomes half, and the four-input/four- output architecture is implemented. For an image with the size of N x N, the computing time of one-level 2D 9/7 DWT is 0.25N2 ＋ 1.5N clock cycles. The critical path delay is one multiplier delay, and only 5N internal memory is required. The results of post-route simulation on FPGA show that clock frequency reaches 136 MHz, and the throughput is 544 Msample/s, which satisfies the requirements of high-speed applications.展开更多
A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, sc...A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. The results show that a homogeneous transparent gel can be obtained with EDTA as the organic complexing reagent under the pH value of 3.0. Further thermal decomposition of the as-synthesized transparent gel by increasing the temperature up to 600℃ for 3 h results in the formation of La2Mo2O9 nanoparticles with a crystal size of about 30 nm. Moreover, the nanoparticles tend to form micrometer-sized aggregates with a three-dimensional network structure, which shows promising applications in solid oxide fuel cells （SOFC）, catalysts and so on.展开更多
Two new organic supramolecular cocrystal complexes C18H18O4·C10H8N2（I） and C18H18O4·C12H10N2（II）（C18H18O4 = 2,3,6,7-tetrahydroxyl-9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene（LH4）, C10H8N2 = 4,4＇...Two new organic supramolecular cocrystal complexes C18H18O4·C10H8N2（I） and C18H18O4·C12H10N2（II）（C18H18O4 = 2,3,6,7-tetrahydroxyl-9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene（LH4）, C10H8N2 = 4,4＇-bipyridine（bpy） and C12H10N2 = 4,4＇-bipyridinylethane（bpe）） have been obtained by mixing LH4 with corresponding bpy or bpe ligand. The two complexes have been determined by X-ray crystal structure analysis, elemental analysis and IR analysis. Compound I crystallizes in the orthorhombic Pnma with a = 9.7078（4）, b = 22.4974（10）, c = 20.6272（9） V = 4505.0（3）3, Mr = 454.51, Dc. = 1.340 g·cm^-3, μ = 0.09 mm-1, F（000） = 1920, Z = 8, R = 0.0503 and wR = 0.1360. Compound II crystallizes in monoclinic C2/c with a = 29.944（6）, b = 9.820（2）, c = 22.643（5） , V = 5048.4（18）3, Mr = 480.54, Dc. = 1.265 g cm^–3, μ = 0.084 mm^–1, F（000） = 2032, Z = 8, R = 0.0548 and wR = 0.1600. X-ray single-crystal structure analysis shows that two-dimensional（2D） layer supramolecular structures are formed through hydrogen bonds and π-π interactions in the two complexes. IR analysis also indicates that there are only associated hydroxyl groups in the two complexes.展开更多
The intrinsic poor electrical conductivity,severe dissolution of K x S y intermediates,and inferior conversion reaction reversibility extremely impede the practical application of the transition-metal chalcogenides(TM...The intrinsic poor electrical conductivity,severe dissolution of K x S y intermediates,and inferior conversion reaction reversibility extremely impede the practical application of the transition-metal chalcogenides(TMDs)anode for potassium-ion batteries(PIBs).Herein,a rationally designed Cu_(9)S_(5)/MoS_(2)/C heterostruc-ture hollow nanocage was synthesized with assistance from metal-organic frameworks(MOFs)precursor.During the K-storage process,the homogeneously distributed the sulfiphilic nature of Cu 0 reaction prod-uct could act as a dual-functional catalyst,not only facilitating the rapid charge transfer but also effec-tively anchoring(K x S y)polysulfides,thus boosting K-storage reactions reversibility during the conversion reaction process.When applied as an anode for PIBs,the as-prepared heterostructure exhibits excellent reversible capacity and long cycle lifespan(350.5 mAh g^(-1)at 0.1 A g^(-1)and 0.04%per cycle capacity de-cay at 1 A g^(-1)after 1000 cycles).Additionally,the potassium storage mechanism is distinctly revealed by in-situ characterizations.The nanoarchitecture designing strategy for the advanced electrode in this work could provide vital guidance for relevant energy storage materials.展开更多
基金the Natural Science Foundation of Anhui Province (070414159)the Science Research Foundation for the Candidates of Academic Leaders of Anhui Proince
文摘Phase structure and electrochemical properties of laser sintered La2MgNi9 alloys were studied. The sintered alloys contained a main phase, LaNi5, and a ternary La-Mg-Ni phase, with a PuNi3 structure and a small amount of LaMgNi4. The ternary La-Mg-Ni phase with a PuNi3 structure had the composition of La1.8Mg1.2Ni9 and La2MgNi9, for alloys laser sintered at 1000 and 1400 W, respectively. Owing to further reactions between LaNi5 and LaMgNi4, the amount of the PuNi3 phase increased for alloys sintered at 1400 W. Both alloys had good activation property （three charge/discharge cycles）. The discharge capacities of the sintered alloys were 321.8 and 344.8 mAh/g, respectively. Compared with the alloy laser sintered at 1000 W, the poor cyclic stability of the alloy sintered at 1400 W was mainly attributed to the lower corrosion resistance of the La2MgNi9 phase.
基金supported by Guangdong Ocean University with doctor start-up fund(1112263)the Science and Technology Plan Projects of Zhanjiang City(No.2013B01073)
文摘Two novel clusters [Mn~Ⅲ_3（μ_3-O）（phendox）3]X·13H_2O（X = Cl（1）, Br（2]） have been obtained from the solvothermal reactions of 1,10-phenanthroline-2,9-dicarbaldehyde dioxime（H_2phendox） with MnCl_2·4H_2O or anhydrous MnBr_2, and their structures were characterized by elemental analysis, FT-IR, XRD, TGA, MS and single-crystal X-ray diffraction. It crystallizes in trigonal, space group P3_1/c. X-ray analysis reveals that the neighbouring [Mn_3（μ_3-O）（phendox）_3]＋ cores are linked by C–H···Cl hydrogen bonds and form an infinite supramolecular chain along the c-axis. Neighbouring chains are packed with each other by off-set p-p interactions of the aromatic rings on phenox2-. A 3D supramolecular architecture in a honeycomb topology is formed with 1D hexagonal channel in the dimensions of 13？ × 13？ along the c-axis. The gas adsorption studies show that compound 1·13H_2O is stable upon the removal of guest molecules and the desolvated compound absorbed considerable amount of CO_2.
基金This work is supported by the National Natural Science Foundation of China(No.59671020).
文摘The magnetic properties of Fe_(72.5)Cu_1Nb_2V_2Si_(13.5)B_9 alloy are investigated from an amorphous to a nanocrystalline and complete crystalline state. The sample annealed at 550℃ for 0.5 h shows a homogeneous nanocrystalline structure and presents excellent soft magnetic properties. When the specimens were annealed at a temperature above 600℃, the magnetic properties are obviously deteriorated because the grain size grows up, exceeding the exchange length.
文摘The title compound, 4β,6α,9α-trimethy-2-carboxyltricyclo[6.3.0.0^（4,5）]undec-2-ene, is a sesquiterpene which was first isolated from Ligularia caloxantha and characterized by MS and NMR. In addition, the structure was determined by X-ray single-crystal diffraction. It crystallizes in orthorhombie, space group P212121 with a = 8.197（2）, b = 14.876（3）, c = 22.281（6） A, α = β = γ = 90°, V = 2716.9（11） ]A^3, Z = 8, C15H22O2, Mr = 234.34, Dc = 1.146 g/cm^3, μ（MoKa） = 0.074 mm^-1, F（000） = 1024, the final R = 0.0384 and wR = 0.0856 for 6200 independent reflections （Rint = 0.066） and 2538 observed ones （I 〉 2σ（I））. In the molecule, there are three fused five-membered rings; while in this crystal form, the asymmetric unit contains two molecules of the same hand and they are linked together by two intermolecular O-H...O hydrogen bonds to form a dimer.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50632030 and 10804130)the Shaanxi Provincial Natural Science Foundation,China (Grant No. 2011JM6012)
文摘The piezoelectric,dielectric,and ferroelectric properties of the(LiCe) co-substituted calcium bismuth niobate(CaBi2Nb2O9,CBNO) are investigated.The piezoelectric properties of CBNO ceramics are significantly enhanced and the dielectric loss tan δ decreased.This makes poling using(LiCe) co-substitution easier.The ceramics(where represents A-site Ca2+ vacancies,possess a pure layered structure phase and no other phases can be found.The Ca0.88(LiCe)0.04 0.04Bi2Nb2O9 ceramics possess optimal piezoelectric properties,with piezoelectric coefficient(d 33) and Curie temperature(TC) found to be 13.3 pC/N and 960 C,respectively.The dielectric and piezoelectric properties of the(LiCe) co-substituted CBNO ceramics exhibit very stable temperature behaviours.This demonstrates that the CBNO ceramics are a promising candidate for ultrahigh temperature applications.
基金The National Science and Technology M ajor Project of the M inistry of Science and Technology of China(No.2014ZX03003007-009)
文摘To achieve high parallel computation of discrete wavelet transform （DWT） in JPEG2000, a high-throughput two-dimensional （2D） 9/7 DWT very large scale integration （VLSI） design is proposed, in which the row processor is based on flipping structure. Due to the difference of the input data flow, the column processor is obtained by adding the input selector and data buffer to the row processor. Normalization steps in row and column DWT are combined to reduce the number of multipliers, and the rationality is verified. By rearranging the output of four-line row DWT with a multiplexer （MUX）, the amount of data processed by each column processor becomes half, and the four-input/four- output architecture is implemented. For an image with the size of N x N, the computing time of one-level 2D 9/7 DWT is 0.25N2 ＋ 1.5N clock cycles. The critical path delay is one multiplier delay, and only 5N internal memory is required. The results of post-route simulation on FPGA show that clock frequency reaches 136 MHz, and the throughput is 544 Msample/s, which satisfies the requirements of high-speed applications.
基金the Opening Subject of the State Key Laboratory of Powder Metallurgy of China (Nos. 200506123105A and 20070620090631B14)
文摘A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. The results show that a homogeneous transparent gel can be obtained with EDTA as the organic complexing reagent under the pH value of 3.0. Further thermal decomposition of the as-synthesized transparent gel by increasing the temperature up to 600℃ for 3 h results in the formation of La2Mo2O9 nanoparticles with a crystal size of about 30 nm. Moreover, the nanoparticles tend to form micrometer-sized aggregates with a three-dimensional network structure, which shows promising applications in solid oxide fuel cells （SOFC）, catalysts and so on.
基金supported by the National Natural Science Foundation of China(No.21176246)Jiangsu Qinglan Project
文摘Two new organic supramolecular cocrystal complexes C18H18O4·C10H8N2（I） and C18H18O4·C12H10N2（II）（C18H18O4 = 2,3,6,7-tetrahydroxyl-9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene（LH4）, C10H8N2 = 4,4＇-bipyridine（bpy） and C12H10N2 = 4,4＇-bipyridinylethane（bpe）） have been obtained by mixing LH4 with corresponding bpy or bpe ligand. The two complexes have been determined by X-ray crystal structure analysis, elemental analysis and IR analysis. Compound I crystallizes in the orthorhombic Pnma with a = 9.7078（4）, b = 22.4974（10）, c = 20.6272（9） V = 4505.0（3）3, Mr = 454.51, Dc. = 1.340 g·cm^-3, μ = 0.09 mm-1, F（000） = 1920, Z = 8, R = 0.0503 and wR = 0.1360. Compound II crystallizes in monoclinic C2/c with a = 29.944（6）, b = 9.820（2）, c = 22.643（5） , V = 5048.4（18）3, Mr = 480.54, Dc. = 1.265 g cm^–3, μ = 0.084 mm^–1, F（000） = 2032, Z = 8, R = 0.0548 and wR = 0.1600. X-ray single-crystal structure analysis shows that two-dimensional（2D） layer supramolecular structures are formed through hydrogen bonds and π-π interactions in the two complexes. IR analysis also indicates that there are only associated hydroxyl groups in the two complexes.
基金financially supported by the National Natural Science Foundation of China (Nos.52070194,52073309,51902347,and 51908555)the Natural Science Foundation of Hunan Province (Nos.2022JJ20069 and 2020JJ5741).
文摘The intrinsic poor electrical conductivity,severe dissolution of K x S y intermediates,and inferior conversion reaction reversibility extremely impede the practical application of the transition-metal chalcogenides(TMDs)anode for potassium-ion batteries(PIBs).Herein,a rationally designed Cu_(9)S_(5)/MoS_(2)/C heterostruc-ture hollow nanocage was synthesized with assistance from metal-organic frameworks(MOFs)precursor.During the K-storage process,the homogeneously distributed the sulfiphilic nature of Cu 0 reaction prod-uct could act as a dual-functional catalyst,not only facilitating the rapid charge transfer but also effec-tively anchoring(K x S y)polysulfides,thus boosting K-storage reactions reversibility during the conversion reaction process.When applied as an anode for PIBs,the as-prepared heterostructure exhibits excellent reversible capacity and long cycle lifespan(350.5 mAh g^(-1)at 0.1 A g^(-1)and 0.04%per cycle capacity de-cay at 1 A g^(-1)after 1000 cycles).Additionally,the potassium storage mechanism is distinctly revealed by in-situ characterizations.The nanoarchitecture designing strategy for the advanced electrode in this work could provide vital guidance for relevant energy storage materials.
