Ph 2NH and PCl 3 interacted at a molar ratio of 1∶1 05 and slow elevated temperature and then at 210-220 ℃ for 6 h. The brown solution obtained was treated with H 2O to produce a very hard brown solid believed to be...Ph 2NH and PCl 3 interacted at a molar ratio of 1∶1 05 and slow elevated temperature and then at 210-220 ℃ for 6 h. The brown solution obtained was treated with H 2O to produce a very hard brown solid believed to be a mixture of 5,10 dihydrophenophosphazine 10 oxide(1a) and 10,10(5H,5H) spirobipenophosphazinium chloride(1b). This brown solid was directly oxidized with peracetic acid in HOAc prior to the separation of them to give compound 10 hydroxy 5,10 dihydropheno phosphazine 10 oxide(2) with a higher yield(45%) than that of the literature(27%). When treated with excess SOCl 2, compound 2 could quantitatively be converted to the corresponding phosphinyl chloride and the latter could further be transformed into 10 methoxy 5,10 dihydrophenophosphazine 10 oxide in 70% as treated with NaOMe in methanol. Compound 2 could also be converted to a bisanion when treated with NaH in DMF. The resulted bisanion reacted with MeI to give 5 methyl 10 hydroxy 5,10 dihydrophenophosphazine 10 oxide in a 73% yield which would be converted to 5 methyl 10 methoxy 5,10 dihydrophenophosphazine 10 oxide in a 56% yield by the same way of synthesizing 10 methoxy 5,10 dihydrophenophosphazine 10 oxide. All these compounds obtained were identified by surveying their melting points, and spectra and elemental analysis.展开更多
Let f(x) be an almost spirallike mapping of type β with order α on unit ball Bof complex Banach space X. In this paper, we consider the growth and covering theoremsfor f(x), we also prove that the estimation is prec...Let f(x) be an almost spirallike mapping of type β with order α on unit ball Bof complex Banach space X. In this paper, we consider the growth and covering theoremsfor f(x), we also prove that the estimation is precise when β = 0 and still give growth upperbound and distortion upper bound for subordinate mapping. This result include some resultsknown.展开更多
Using DFT/TDDFT methods,the excited-state lifetimes of Ru(Ⅱ) polypyridyl complexes were computed accurately and the reason of Ru(Ⅱ) polypyridyl complexes with long excited-state lifetimes was explained by the el...Using DFT/TDDFT methods,the excited-state lifetimes of Ru(Ⅱ) polypyridyl complexes were computed accurately and the reason of Ru(Ⅱ) polypyridyl complexes with long excited-state lifetimes was explained by the electron-transfer distances and HOMO-LUMO gaps.Finally,the photovoltaic conversion efficiencies of complexes were predicted using DFT and docking methods.This work has provided methods of predicting the excited-state lifetimes and photovoltaic conversion efficiencies of Ru(Ⅱ) polypyridyl complexes.展开更多
To improve the cycle performance of eco-friendly and cost-effective spinel LiMn2O4 as the Li secondary batteries, the Th-doped LiThxMn1-xO4 spinel powers were synthesized by solid-state method. The starting materials,...To improve the cycle performance of eco-friendly and cost-effective spinel LiMn2O4 as the Li secondary batteries, the Th-doped LiThxMn1-xO4 spinel powers were synthesized by solid-state method. The starting materials, Li2CO3, MnO2 and Th(NO3)4·4H2O, were mixed uniformly using a traditional ball milling, which resulted in a uniform particle size distribution in the mixed powers. Tests of X-ray diffraction, SEM, impedance spectra and charge-discharge were carried out for LiThxMn1-xO4 cathode materials. Results show that the synthesized LiTh0.01Mn1.99O4 material exhibits standard spinel structure, regular particle morphology and excellent property of charge-discharge for big current. The capacity retention of the material modified by doping Th is more than 85.1% of the first discharge specific capacity of 111.5 mAh·g-1 after 20 cycles at the current rate 1C, while the pristine LiMn2O4 is only 57% of the first discharge specific capacity of 110.2 mAh·g-1 after the same cycles at the same current rate.展开更多
In the search for improved materials for rechargeable lithium batteries, LiFePO4 offers interesting possibilities because of its low raw materials cost, environmental friendliness and safety. The main drawback with us...In the search for improved materials for rechargeable lithium batteries, LiFePO4 offers interesting possibilities because of its low raw materials cost, environmental friendliness and safety. The main drawback with using the material is its poor electronic conductivity and this limitation has to be overcome. Here Al-doped LiFePO4/C composite cathode materials were prepared by a polymer-network synthesis technique. Testing of X-ray diffraction, charge-discharge, and cyclic voltammetry were carried out for its performance. Results show that Al-doped LiFePO4/C composite cathode materials have a high initial capacity, good cycle stability and excellent low temperature performance. The electrical conductivity of LiFePO4 material can be obviously improved by doping Al. The better electrochemical performances of Al-doped LiFePO4/C composite cathode materials have a connection with its conductivity.展开更多
A binuclear copper(I) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space...A binuclear copper(I) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space group C2/c with a = 14.167(3), b = 21.209(4), c =20.680(4)A°, β = 103.93(3)°, C32H28CuN3O3P2, Mr = 628.05, Z = 8, μ = 0.868 mm^-1, V = 6031 (2) ,A°^3,F(000) = 2592, De= 1.383 g/cm^3, R = 0.0593 and wR = 0.1736. A total of 5297 independent reflections were collected, of which 3503 were observed with 1 〉 2σ(/). The central copper atom is tri-coordinated by phosphorus atoms from bridging dppm and nitrogen atom from benzimidazole. In the coordination sphere, the bond lengths of Cu-P(1) and Cu-P(2) are 2.2607(17) and 2.2503(16) A°,respectively and the P-Cu-P bond angle is 127.26(6)°.展开更多
Nanometer-sized SnO_(2) particles were prepared by a sol-gel method using inorganic salt as a precursor material. Its crystallization was investigated by means of TG-DTA,IR absorption spectra, X-ray diffractometry and...Nanometer-sized SnO_(2) particles were prepared by a sol-gel method using inorganic salt as a precursor material. Its crystallization was investigated by means of TG-DTA,IR absorption spectra, X-ray diffractometry and TEM as well as its resistivity change and the gas sensitivity varied with temperature were measured in various reducing gas. The results indicate that well-crystallized nano-sized SnO_(2)with size around 15nm can be obtained at annealing temperature 600℃. The activation energy for the growth of nano-SnO_(2) was calculated to be 26.55kJ.mol^(-1) when the annealing temperature was higher than 500℃. The measurements also show that there is a peculiar resistance change varied with temperature for nano SnO_(2).It has relevance to the increase in surface adsorbed oxygen. The selective detectivities to C_(4)H_(10) and petrol can be increased when ruthenium ion was doped in nano SnO_(2)as a catalyst and so do the gas sensitivity to CO,CH_(4),H_(2) etc. when rhodium ion was doped in.The detection to the several reducing gas can be realized when the temperature ranged from 260℃ to 400℃.展开更多
Fine powders of γ-Fe_2O_3,doped with Y_2O_3,CeO_2,Eu_2O_3 or Tb_2O_3 have been prepared by the chemical co-precipitation method.The sensitivity of gas sensation has been measured with respect to the relative resist- ...Fine powders of γ-Fe_2O_3,doped with Y_2O_3,CeO_2,Eu_2O_3 or Tb_2O_3 have been prepared by the chemical co-precipitation method.The sensitivity of gas sensation has been measured with respect to the relative resist- ance change in the ceramic matrix upon introduction of inflammable gases.The structure of the materials has been studied with X-ray diffraction spectroscopy(XRD),electron diffraction spectroscopy( ED) and transmis- sion electron microscopy(TEM).The addition of rare earth oxides,which improves ceramic microstructure of γ-Fe_2O_3,improves gas sensitivity of γ-Fe_2O_3.The stability can be increased because of the increase of phase transition temperature.In addition,the selectivity of gas sensation of γ-Fe_2O_3 can be improved because of the variation of rare earth oxides.展开更多
It is widely known that the equation 2xx= has and only has two roots 0 and 1. Jiglevich A.B. and Petrov N. N. discovered that equation has two other roots, i.e. infinite place’s numbers (called super numbers): 821289...It is widely known that the equation 2xx= has and only has two roots 0 and 1. Jiglevich A.B. and Petrov N. N. discovered that equation has two other roots, i.e. infinite place’s numbers (called super numbers): 8212890625X=L and 1787109376Y=L, and obtained 4 (super number) roots of the equation2xx=. For progressing to wider conditions, with the way of exactly divisible and mutually orthogonal Latin squares, three attractive results are obtained: 1) A kind of polynomial 1()()niiPxxa==P-, ,1,2,,iain?KZ has and only has different n2 super number roots; 2) When n>2 and n 6, those n2 roots of the polynomial ()Px can be arranged in an n-order square matrix, of which n roots of every row and every column satisfy Vieta Formula of roots and coefficients; 3) In *Z ring of super number, the polynomial1()()niiPxxa==P-, ,1,2,,iain?KZ has n! different factorizations.展开更多
Distributing real-time video stream in large scale group communication over Internet poses several challenging problems due to the complex network dynamics,stringent requirement of delay and loss.This paper proposes a...Distributing real-time video stream in large scale group communication over Internet poses several challenging problems due to the complex network dynamics,stringent requirement of delay and loss.This paper proposes a novel peer-to-peer scheme,named TeamCast,to combat with these issues.Constructing multiple diverse application layer multicast (ALM) trees to transmit multiple independent complementary descriptions produced by multiple description coding (MDC) simultaneously,TeamCast improves error resilient ability in the presence of various levels of packet loss caused by unpredictable congestion of Internet and node failure,as well as enlarges system capacity.The results of extensive simulations indicate that TeamCast achieves low latency,scalability,and fault tolerance for the delivery of live media stream.展开更多
At room temperature, the chain-like polymeric copper (II) complexes bridged by bis (diphenylphosphino oxide) ethane (dppeO2), [Cu(dppeO2)X2]n[XCI(1), Br(2)] have been prepared and characterized by elemental analysis, ...At room temperature, the chain-like polymeric copper (II) complexes bridged by bis (diphenylphosphino oxide) ethane (dppeO2), [Cu(dppeO2)X2]n[XCI(1), Br(2)] have been prepared and characterized by elemental analysis, 31P NMR, TG-DTA and X-ray analysis for [ CuBr2 ( dppeO2) ]n. The chain is composed of submits containing tetrahedron coordinated copper (II) atoms. The four-coordinated copper(II) atom is ligated to another four-coordinated copper(II) atom through dppeO2. The coordination sphere of copper (II) atom is completed by two monodentate bromide and two oxygen atoms from bridging dppeO2. Crystal data are as follows: C26-H24CuP2Br2O2, 0.50 mm × 0.40 mm × 0.40 mm, monoclinic, space group: C2/c, λ = 0.07107 nm(Mo Kα), a= 1.2286(2) nm, b=2.0555(8) nm, c = 1.0652(2) nm, β=97.366(9)°, V = 2.668nm3 Z = 4, Dcalc =1.628 g·cm?3, R=0.066; Rw = 0.091.展开更多
The novel trinuelear copper(I) complex [Cu3(μ3-Br)2(dppm)3]Br has been obtained by reaction of bis(diphenyl-phosphino)methane (dppm) with cupric bromide. The title complex was characterized by single-crystal X-ray an...The novel trinuelear copper(I) complex [Cu3(μ3-Br)2(dppm)3]Br has been obtained by reaction of bis(diphenyl-phosphino)methane (dppm) with cupric bromide. The title complex was characterized by single-crystal X-ray analysis, elemental analysis, molecular weight determination, 31P NMR and its conductivity was also measured. The [Cu3(dppm)3Br2] + cation consists of a triangular array of copper atoms, with dppm ligands (Ph2PCH2PPh2) bridging each edge of the triangle and two triply bridging Br groups bound to the two faces of the Cu3 unit. Crystallographic data: monoclinic, space group P21/c, a = 1.4739(4) , b = 1.7708(5), c = 2.8395(8) nm, β= 97.16(3)°, V = 7.353nm3, Z = 4,F(000)= 3296, Dcalc = 1.472 g/cm3, μ= 26.478 cm-1, R = 0.06, Rw = 0.08, 4654 reflections observed with I > 3σ(I).展开更多
基金Supported by National Natural Science Foundation of China(No.2 9972 0 0 6 ) .
文摘Ph 2NH and PCl 3 interacted at a molar ratio of 1∶1 05 and slow elevated temperature and then at 210-220 ℃ for 6 h. The brown solution obtained was treated with H 2O to produce a very hard brown solid believed to be a mixture of 5,10 dihydrophenophosphazine 10 oxide(1a) and 10,10(5H,5H) spirobipenophosphazinium chloride(1b). This brown solid was directly oxidized with peracetic acid in HOAc prior to the separation of them to give compound 10 hydroxy 5,10 dihydropheno phosphazine 10 oxide(2) with a higher yield(45%) than that of the literature(27%). When treated with excess SOCl 2, compound 2 could quantitatively be converted to the corresponding phosphinyl chloride and the latter could further be transformed into 10 methoxy 5,10 dihydrophenophosphazine 10 oxide in 70% as treated with NaOMe in methanol. Compound 2 could also be converted to a bisanion when treated with NaH in DMF. The resulted bisanion reacted with MeI to give 5 methyl 10 hydroxy 5,10 dihydrophenophosphazine 10 oxide in a 73% yield which would be converted to 5 methyl 10 methoxy 5,10 dihydrophenophosphazine 10 oxide in a 56% yield by the same way of synthesizing 10 methoxy 5,10 dihydrophenophosphazine 10 oxide. All these compounds obtained were identified by surveying their melting points, and spectra and elemental analysis.
基金Supported by the National Natural Science Foundation of China(10271117)
文摘Let f(x) be an almost spirallike mapping of type β with order α on unit ball Bof complex Banach space X. In this paper, we consider the growth and covering theoremsfor f(x), we also prove that the estimation is precise when β = 0 and still give growth upperbound and distortion upper bound for subordinate mapping. This result include some resultsknown.
基金supported by the Research Foundation of the National Natural Science Foundation of China(No.U1204209)the Major Program of the Natural Science of Anhui University(No.KJ2016SD52)+1 种基金the Key Program of the Natural Science of Anhui University for Young and Middle-aged Key Talent to Study in the Domestic(No.gxfx ZD2016097)Undergraduates Innovating Project(No.201510373083)
文摘Using DFT/TDDFT methods,the excited-state lifetimes of Ru(Ⅱ) polypyridyl complexes were computed accurately and the reason of Ru(Ⅱ) polypyridyl complexes with long excited-state lifetimes was explained by the electron-transfer distances and HOMO-LUMO gaps.Finally,the photovoltaic conversion efficiencies of complexes were predicted using DFT and docking methods.This work has provided methods of predicting the excited-state lifetimes and photovoltaic conversion efficiencies of Ru(Ⅱ) polypyridyl complexes.
基金This work was financially supported by the Middle Age and Youth Backbone Teacher Project (2004) of Henan Province, China.
文摘To improve the cycle performance of eco-friendly and cost-effective spinel LiMn2O4 as the Li secondary batteries, the Th-doped LiThxMn1-xO4 spinel powers were synthesized by solid-state method. The starting materials, Li2CO3, MnO2 and Th(NO3)4·4H2O, were mixed uniformly using a traditional ball milling, which resulted in a uniform particle size distribution in the mixed powers. Tests of X-ray diffraction, SEM, impedance spectra and charge-discharge were carried out for LiThxMn1-xO4 cathode materials. Results show that the synthesized LiTh0.01Mn1.99O4 material exhibits standard spinel structure, regular particle morphology and excellent property of charge-discharge for big current. The capacity retention of the material modified by doping Th is more than 85.1% of the first discharge specific capacity of 111.5 mAh·g-1 after 20 cycles at the current rate 1C, while the pristine LiMn2O4 is only 57% of the first discharge specific capacity of 110.2 mAh·g-1 after the same cycles at the same current rate.
基金This work was financially supported by the Middle Age and Youth Backbone Teacher Project (2004) of Henan Province, China.
文摘In the search for improved materials for rechargeable lithium batteries, LiFePO4 offers interesting possibilities because of its low raw materials cost, environmental friendliness and safety. The main drawback with using the material is its poor electronic conductivity and this limitation has to be overcome. Here Al-doped LiFePO4/C composite cathode materials were prepared by a polymer-network synthesis technique. Testing of X-ray diffraction, charge-discharge, and cyclic voltammetry were carried out for its performance. Results show that Al-doped LiFePO4/C composite cathode materials have a high initial capacity, good cycle stability and excellent low temperature performance. The electrical conductivity of LiFePO4 material can be obviously improved by doping Al. The better electrochemical performances of Al-doped LiFePO4/C composite cathode materials have a connection with its conductivity.
基金This work was supported by the National Natural Science Foundation of China (No. 20271017) and Henan Provincial Innovation Foundation (No. 0421001300)
文摘A binuclear copper(I) complex [Cu2(dppm)2(C7H6N2)2](NO3)2 (C7H6N2 = benzimidazole, dppm = Ph2PCH2PPh2) has been synthesized and characterized by X-ray crystallography.The crystal belongs to monoclinic, space group C2/c with a = 14.167(3), b = 21.209(4), c =20.680(4)A°, β = 103.93(3)°, C32H28CuN3O3P2, Mr = 628.05, Z = 8, μ = 0.868 mm^-1, V = 6031 (2) ,A°^3,F(000) = 2592, De= 1.383 g/cm^3, R = 0.0593 and wR = 0.1736. A total of 5297 independent reflections were collected, of which 3503 were observed with 1 〉 2σ(/). The central copper atom is tri-coordinated by phosphorus atoms from bridging dppm and nitrogen atom from benzimidazole. In the coordination sphere, the bond lengths of Cu-P(1) and Cu-P(2) are 2.2607(17) and 2.2503(16) A°,respectively and the P-Cu-P bond angle is 127.26(6)°.
文摘Nanometer-sized SnO_(2) particles were prepared by a sol-gel method using inorganic salt as a precursor material. Its crystallization was investigated by means of TG-DTA,IR absorption spectra, X-ray diffractometry and TEM as well as its resistivity change and the gas sensitivity varied with temperature were measured in various reducing gas. The results indicate that well-crystallized nano-sized SnO_(2)with size around 15nm can be obtained at annealing temperature 600℃. The activation energy for the growth of nano-SnO_(2) was calculated to be 26.55kJ.mol^(-1) when the annealing temperature was higher than 500℃. The measurements also show that there is a peculiar resistance change varied with temperature for nano SnO_(2).It has relevance to the increase in surface adsorbed oxygen. The selective detectivities to C_(4)H_(10) and petrol can be increased when ruthenium ion was doped in nano SnO_(2)as a catalyst and so do the gas sensitivity to CO,CH_(4),H_(2) etc. when rhodium ion was doped in.The detection to the several reducing gas can be realized when the temperature ranged from 260℃ to 400℃.
基金The project supported by the National Natural Science Foundation of China
文摘Fine powders of γ-Fe_2O_3,doped with Y_2O_3,CeO_2,Eu_2O_3 or Tb_2O_3 have been prepared by the chemical co-precipitation method.The sensitivity of gas sensation has been measured with respect to the relative resist- ance change in the ceramic matrix upon introduction of inflammable gases.The structure of the materials has been studied with X-ray diffraction spectroscopy(XRD),electron diffraction spectroscopy( ED) and transmis- sion electron microscopy(TEM).The addition of rare earth oxides,which improves ceramic microstructure of γ-Fe_2O_3,improves gas sensitivity of γ-Fe_2O_3.The stability can be increased because of the increase of phase transition temperature.In addition,the selectivity of gas sensation of γ-Fe_2O_3 can be improved because of the variation of rare earth oxides.
文摘It is widely known that the equation 2xx= has and only has two roots 0 and 1. Jiglevich A.B. and Petrov N. N. discovered that equation has two other roots, i.e. infinite place’s numbers (called super numbers): 8212890625X=L and 1787109376Y=L, and obtained 4 (super number) roots of the equation2xx=. For progressing to wider conditions, with the way of exactly divisible and mutually orthogonal Latin squares, three attractive results are obtained: 1) A kind of polynomial 1()()niiPxxa==P-, ,1,2,,iain?KZ has and only has different n2 super number roots; 2) When n>2 and n 6, those n2 roots of the polynomial ()Px can be arranged in an n-order square matrix, of which n roots of every row and every column satisfy Vieta Formula of roots and coefficients; 3) In *Z ring of super number, the polynomial1()()niiPxxa==P-, ,1,2,,iain?KZ has n! different factorizations.
基金Major State Basic Research Development Program of China(973 Program,No.2005CB321903)
文摘Distributing real-time video stream in large scale group communication over Internet poses several challenging problems due to the complex network dynamics,stringent requirement of delay and loss.This paper proposes a novel peer-to-peer scheme,named TeamCast,to combat with these issues.Constructing multiple diverse application layer multicast (ALM) trees to transmit multiple independent complementary descriptions produced by multiple description coding (MDC) simultaneously,TeamCast improves error resilient ability in the presence of various levels of packet loss caused by unpredictable congestion of Internet and node failure,as well as enlarges system capacity.The results of extensive simulations indicate that TeamCast achieves low latency,scalability,and fault tolerance for the delivery of live media stream.
基金Project supported by the National Natural Science Foundation of China(No. 29871009), Henan Province Outstanding Youth Science Foundation and Henan Natural Science Foundation.
文摘At room temperature, the chain-like polymeric copper (II) complexes bridged by bis (diphenylphosphino oxide) ethane (dppeO2), [Cu(dppeO2)X2]n[XCI(1), Br(2)] have been prepared and characterized by elemental analysis, 31P NMR, TG-DTA and X-ray analysis for [ CuBr2 ( dppeO2) ]n. The chain is composed of submits containing tetrahedron coordinated copper (II) atoms. The four-coordinated copper(II) atom is ligated to another four-coordinated copper(II) atom through dppeO2. The coordination sphere of copper (II) atom is completed by two monodentate bromide and two oxygen atoms from bridging dppeO2. Crystal data are as follows: C26-H24CuP2Br2O2, 0.50 mm × 0.40 mm × 0.40 mm, monoclinic, space group: C2/c, λ = 0.07107 nm(Mo Kα), a= 1.2286(2) nm, b=2.0555(8) nm, c = 1.0652(2) nm, β=97.366(9)°, V = 2.668nm3 Z = 4, Dcalc =1.628 g·cm?3, R=0.066; Rw = 0.091.
基金Project supported by the National Natural Science Foundation of China (No. 29871009), Nanjing State Key Laboratory of Coordination ChemistryNatural Science Foundation of Henan Province.
文摘The novel trinuelear copper(I) complex [Cu3(μ3-Br)2(dppm)3]Br has been obtained by reaction of bis(diphenyl-phosphino)methane (dppm) with cupric bromide. The title complex was characterized by single-crystal X-ray analysis, elemental analysis, molecular weight determination, 31P NMR and its conductivity was also measured. The [Cu3(dppm)3Br2] + cation consists of a triangular array of copper atoms, with dppm ligands (Ph2PCH2PPh2) bridging each edge of the triangle and two triply bridging Br groups bound to the two faces of the Cu3 unit. Crystallographic data: monoclinic, space group P21/c, a = 1.4739(4) , b = 1.7708(5), c = 2.8395(8) nm, β= 97.16(3)°, V = 7.353nm3, Z = 4,F(000)= 3296, Dcalc = 1.472 g/cm3, μ= 26.478 cm-1, R = 0.06, Rw = 0.08, 4654 reflections observed with I > 3σ(I).