This paper gives a new generalization of Hilbert＇s inequality with a best constant factor involving the β function. An applications, we consider the equivalent form and some particular results.
A new complex of melamine（MA） with benzoic acid（HBA） was prepared, affording [（HMA＋）（BA-）]-2H2O. Each HBA molecule is deprotonated and one triazine nitrogen atom of MA is protonated. The adjacent HMA＋ cation...A new complex of melamine（MA） with benzoic acid（HBA） was prepared, affording [（HMA＋）（BA-）]-2H2O. Each HBA molecule is deprotonated and one triazine nitrogen atom of MA is protonated. The adjacent HMA＋ cations are related via an inverse center to form ribbons with a pair of N--H…N hydrogen bonds. COO- groups of BA- anions are hydrogen bonded to alternate sides of the （HMA＋）∞ ribbons to generate indention ID tapes, which are extended into a 3D structure via N--H…O- and N--H…OW hydrogen bonds and π-π stacking interactions. Predominant patterns of the hydrogen bond present in the complex are anion/water and amino/water tape structures. The hydrogen-bonding patterns consist of alternate 6, 10-membered rings sharing two edges. Infrared（IR） spectroscopy conforms that proton transfer has taken place in the complex.展开更多
A novel interpenetrating structure [（HMA^＋）（FB^- ）] ·2H2O of melamine（MA） with 4-fluoro-benzoic acid （HFB） was synthesized. It crystallized in the monoclinic system with space group P21/c. The complex ha...A novel interpenetrating structure [（HMA^＋）（FB^- ）] ·2H2O of melamine（MA） with 4-fluoro-benzoic acid （HFB） was synthesized. It crystallized in the monoclinic system with space group P21/c. The complex has a interpenetrating 2D structure with hydrogen-bonded grid networks. Carboxylic acid to melamine proton transfer occurs in the complex. The adjacent HMA^＋ cations related by an inverse center form cationic [HMA^＋]∞ ribbons via a pair of N-H…N hydrogen bonds. Adjacent FB-anions are paired by C-H…F hydrogen bonds to form dimers, which are connected to [HMA^＋]∞ ribbons through N-H…O interactions. The supramolecular features in the complex are guided by control of strong N-H…N, N-H…O and O-H…O hydrogen bonds, as well as highly directional weak C-H…F interactions and aromatic π-π stacking interactions.展开更多
N, N??, N??-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) amine (TOTIA) has been synthesized and characterized by X-ray crystallography, and its crystal is of monoclinic, space group P21/c with a = 6.0158(5), b ...N, N??, N??-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) amine (TOTIA) has been synthesized and characterized by X-ray crystallography, and its crystal is of monoclinic, space group P21/c with a = 6.0158(5), b = 16.3851(2), c = 31.6650(3) ?, β = 90.867(2)o, V = 3120.8(5) ?3, C39H36N4O3, Mr = 608.72, Dc = 1.296 g/cm3, Z = 4, F(000) = 1288, μ(MoKα) = 0.083 cm-1, R = 0.0641 and wR = 0.1615. The total reflections were 12598 and 5410 were independent, of which 3342 were observed with I > 2σ(I). There exist strong intramolecular hydrogen bonds between hy- droxy hydrogen atoms and azomethine nitrogen atoms, and obvious π-π stacking interaction between the phenyl rings of TOTIA.展开更多
A subgroup H of a group G is said to have the sub-cover-avoidance property in G ffthereis a chief series 1 = G0 ≤ G1 ≤…≤ Gn - G, such that Gi-1（H ∩ Gi） G for every i = 1,2,... ,l. In this paper, we give some...A subgroup H of a group G is said to have the sub-cover-avoidance property in G ffthereis a chief series 1 = G0 ≤ G1 ≤…≤ Gn - G, such that Gi-1（H ∩ Gi） G for every i = 1,2,... ,l. In this paper, we give some characteristic conditions for a group to be solvable under the assumptions that some subgroups of a group satisfy the sub-cover-avoidance property.展开更多
This paper aims at demonstrating what is motivational comments from teachers which can motivate students to participate in classroom activities and showing patterns of feedback occurring in real classroom teacher-stud...This paper aims at demonstrating what is motivational comments from teachers which can motivate students to participate in classroom activities and showing patterns of feedback occurring in real classroom teacher-student interaction by doing a case study of episodes of teacher＇s feedback in an English class.展开更多
With quantitative method, this paper attempts to figure out in L2 motivation perspective the factors that affect the classroom oral participation of the teacher-learners in their further education. The findings obtain...With quantitative method, this paper attempts to figure out in L2 motivation perspective the factors that affect the classroom oral participation of the teacher-learners in their further education. The findings obtained after a correlation study of the relationship between the learners＇ oral participation and the factors in the levels of language, learner and learning situation indicate that self-perceived competence and desire to communicate display greater correlation with participation. This paper also puts forwards some suggestions on how to improve learners＇ self-perceived competence and promote their desire to communicate in class.展开更多
This English teaching in language classroom essay is based on an investigation into the use of pair work and group work in middle school China by means of a corpus to throw some light on the interaction patterns of ou...This English teaching in language classroom essay is based on an investigation into the use of pair work and group work in middle school China by means of a corpus to throw some light on the interaction patterns of our English teaching展开更多
The new complex of melamine （MA） with isophthalic acid （H2IA）, [（HMA^＋）- （HIA^-）]·2H2O, has been prepared and its structure was characterized by X-ray crystallography. The crystal is of triclinic, space ...The new complex of melamine （MA） with isophthalic acid （H2IA）, [（HMA^＋）- （HIA^-）]·2H2O, has been prepared and its structure was characterized by X-ray crystallography. The crystal is of triclinic, space group P^-1 with a = 7.0228（6）, b = 9.1706（8）, c = 12.170（1） A, α = 95.337（2）, β = 105.247（2）, γ = 97.813（2）^o, V = 742.3（1） A ^3, Mr= 328.30, Z = 2, Dc = 1.469 g/cm^3, ;λ = 0.71073 A,μ（MoKa） = 0.121 mm^-1 and F（000） = 344. The structure was refined to R = 0.0389 and wR = 0.1093 for 2513 observed reflections with I 〉 2σ（I）. Melamine dimer and isophthalic acid anion are interlinked by N-H…N and N-H…O hydrogen bonds, resulting in a 1D rosette ribbon in which water molecules and amino groups are self-assembled into quasihexagonal patterns.展开更多
In this paper, the expression of the norm of a self-adjoint integral operator T ： L^2（0, ∞） → L^2 （0, ∞） is obtained. As applications, a new bilinear integral inequality with a best constant factor is establis...In this paper, the expression of the norm of a self-adjoint integral operator T ： L^2（0, ∞） → L^2 （0, ∞） is obtained. As applications, a new bilinear integral inequality with a best constant factor is established and some particular cases are considered.展开更多
A new kind of excited even q-coherent states （aq^-1）^m｜α〉q^e and excited odd q-coherent states （aq^-1）^m｜α〉q^o is constructed by acting with inverse boson operators on the even and odd q-coherent states. ...A new kind of excited even q-coherent states （aq^-1）^m｜α〉q^e and excited odd q-coherent states （aq^-1）^m｜α〉q^o is constructed by acting with inverse boson operators on the even and odd q-coherent states. The m dependence of the kth-order antibunching effect is numerically studied for k = 2, 3, 4, 5. It is shown that the kth-order antibunching effect enhances as m increases. The larger k, the quicker the antibunching effect enhances.展开更多
By using the integral averaging technique, oscillating criteria for certain even order neutral differential equation with deviating arguments are established. These results extend some known oscillation criteria due t...By using the integral averaging technique, oscillating criteria for certain even order neutral differential equation with deviating arguments are established. These results extend some known oscillation criteria due to Xu and Xia.展开更多
Using an improved lattice Hamiltonian with massive Wilson quarks a variational method is applied to study the dependence of the vector meson mass Mv on the quark mass m and the Wilson parameter r in two-dimensional SU...Using an improved lattice Hamiltonian with massive Wilson quarks a variational method is applied to study the dependence of the vector meson mass Mv on the quark mass m and the Wilson parameter r in two-dimensional SU（Nc） lattice gauge theory. The numerical results show that for Nc = 2, 3, 4, 5, 6, 7, ..., in the scaling window 1 ≤ 1/g^2 ≤ 2, Mv/g is approximately linear in m, but Mv/g obviously does not depend on r （this differs from the quark condensate）. Particularly for m → 0 our numerical results agree very well with Bhattacharya＇s analytical strong coupling result in the continuum, and the value of （δMv/δm） ｜m=0 in two-dimensional SU（Nc） lattice gauge theory is very close to that in Schwinger model.展开更多
基金Supported by the NSF of Guangdong Institutions of Higher Learning, College and University(0177).
文摘This paper gives a new generalization of Hilbert＇s inequality with a best constant factor involving the β function. An applications, we consider the equivalent form and some particular results.
基金the Guangdong Provincial Science and Technology Bureau(No.5003750)the Ph.D.Foundation of Guangdong Institute of Education,China
文摘A new complex of melamine（MA） with benzoic acid（HBA） was prepared, affording [（HMA＋）（BA-）]-2H2O. Each HBA molecule is deprotonated and one triazine nitrogen atom of MA is protonated. The adjacent HMA＋ cations are related via an inverse center to form ribbons with a pair of N--H…N hydrogen bonds. COO- groups of BA- anions are hydrogen bonded to alternate sides of the （HMA＋）∞ ribbons to generate indention ID tapes, which are extended into a 3D structure via N--H…O- and N--H…OW hydrogen bonds and π-π stacking interactions. Predominant patterns of the hydrogen bond present in the complex are anion/water and amino/water tape structures. The hydrogen-bonding patterns consist of alternate 6, 10-membered rings sharing two edges. Infrared（IR） spectroscopy conforms that proton transfer has taken place in the complex.
基金Supported by the National Natural Science Foundation of China(No.20972178)a Grant for Key Research Items in Na-tural Science of Guangdong Higher Education Institutions of China(No.06Z027)
文摘A novel interpenetrating structure [（HMA^＋）（FB^- ）] ·2H2O of melamine（MA） with 4-fluoro-benzoic acid （HFB） was synthesized. It crystallized in the monoclinic system with space group P21/c. The complex has a interpenetrating 2D structure with hydrogen-bonded grid networks. Carboxylic acid to melamine proton transfer occurs in the complex. The adjacent HMA^＋ cations related by an inverse center form cationic [HMA^＋]∞ ribbons via a pair of N-H…N hydrogen bonds. Adjacent FB-anions are paired by C-H…F hydrogen bonds to form dimers, which are connected to [HMA^＋]∞ ribbons through N-H…O interactions. The supramolecular features in the complex are guided by control of strong N-H…N, N-H…O and O-H…O hydrogen bonds, as well as highly directional weak C-H…F interactions and aromatic π-π stacking interactions.
基金This work was supported by the National Natural Science Foundation of China(20131020)
文摘N, N??, N??-Tris-(2-oxynaphthalidene)-tris-(2-iminoethyl) amine (TOTIA) has been synthesized and characterized by X-ray crystallography, and its crystal is of monoclinic, space group P21/c with a = 6.0158(5), b = 16.3851(2), c = 31.6650(3) ?, β = 90.867(2)o, V = 3120.8(5) ?3, C39H36N4O3, Mr = 608.72, Dc = 1.296 g/cm3, Z = 4, F(000) = 1288, μ(MoKα) = 0.083 cm-1, R = 0.0641 and wR = 0.1615. The total reflections were 12598 and 5410 were independent, of which 3342 were observed with I > 2σ(I). There exist strong intramolecular hydrogen bonds between hy- droxy hydrogen atoms and azomethine nitrogen atoms, and obvious π-π stacking interaction between the phenyl rings of TOTIA.
基金The NSF(10871210)of Chinathe NSF(06023728)of Guangdong Province
文摘A subgroup H of a group G is said to have the sub-cover-avoidance property in G ffthereis a chief series 1 = G0 ≤ G1 ≤…≤ Gn - G, such that Gi-1（H ∩ Gi） G for every i = 1,2,... ,l. In this paper, we give some characteristic conditions for a group to be solvable under the assumptions that some subgroups of a group satisfy the sub-cover-avoidance property.
文摘This paper aims at demonstrating what is motivational comments from teachers which can motivate students to participate in classroom activities and showing patterns of feedback occurring in real classroom teacher-student interaction by doing a case study of episodes of teacher＇s feedback in an English class.
文摘With quantitative method, this paper attempts to figure out in L2 motivation perspective the factors that affect the classroom oral participation of the teacher-learners in their further education. The findings obtained after a correlation study of the relationship between the learners＇ oral participation and the factors in the levels of language, learner and learning situation indicate that self-perceived competence and desire to communicate display greater correlation with participation. This paper also puts forwards some suggestions on how to improve learners＇ self-perceived competence and promote their desire to communicate in class.
文摘This English teaching in language classroom essay is based on an investigation into the use of pair work and group work in middle school China by means of a corpus to throw some light on the interaction patterns of our English teaching
基金This work was supported by the Guangdong Provincial Science and Technology Bureau (No. 5003750) Ph. D Foundation of Guangdong Institute of Education
文摘The new complex of melamine （MA） with isophthalic acid （H2IA）, [（HMA^＋）- （HIA^-）]·2H2O, has been prepared and its structure was characterized by X-ray crystallography. The crystal is of triclinic, space group P^-1 with a = 7.0228（6）, b = 9.1706（8）, c = 12.170（1） A, α = 95.337（2）, β = 105.247（2）, γ = 97.813（2）^o, V = 742.3（1） A ^3, Mr= 328.30, Z = 2, Dc = 1.469 g/cm^3, ;λ = 0.71073 A,μ（MoKa） = 0.121 mm^-1 and F（000） = 344. The structure was refined to R = 0.0389 and wR = 0.1093 for 2513 observed reflections with I 〉 2σ（I）. Melamine dimer and isophthalic acid anion are interlinked by N-H…N and N-H…O hydrogen bonds, resulting in a 1D rosette ribbon in which water molecules and amino groups are self-assembled into quasihexagonal patterns.
基金Supported by the Emphases Natural Science Foundation of Guangdong Institutions of Higher Learning,College and University(No.05Z026)
文摘In this paper, the expression of the norm of a self-adjoint integral operator T ： L^2（0, ∞） → L^2 （0, ∞） is obtained. As applications, a new bilinear integral inequality with a best constant factor is established and some particular cases are considered.
文摘A new kind of excited even q-coherent states （aq^-1）^m｜α〉q^e and excited odd q-coherent states （aq^-1）^m｜α〉q^o is constructed by acting with inverse boson operators on the even and odd q-coherent states. The m dependence of the kth-order antibunching effect is numerically studied for k = 2, 3, 4, 5. It is shown that the kth-order antibunching effect enhances as m increases. The larger k, the quicker the antibunching effect enhances.
文摘By using the integral averaging technique, oscillating criteria for certain even order neutral differential equation with deviating arguments are established. These results extend some known oscillation criteria due to Xu and Xia.
基金Supported by Natural Science Foundation of the Education Department of Guangdong Province of China(06Z027)Professor Foundation of Guangdong Education Institute
文摘Using an improved lattice Hamiltonian with massive Wilson quarks a variational method is applied to study the dependence of the vector meson mass Mv on the quark mass m and the Wilson parameter r in two-dimensional SU（Nc） lattice gauge theory. The numerical results show that for Nc = 2, 3, 4, 5, 6, 7, ..., in the scaling window 1 ≤ 1/g^2 ≤ 2, Mv/g is approximately linear in m, but Mv/g obviously does not depend on r （this differs from the quark condensate）. Particularly for m → 0 our numerical results agree very well with Bhattacharya＇s analytical strong coupling result in the continuum, and the value of （δMv/δm） ｜m=0 in two-dimensional SU（Nc） lattice gauge theory is very close to that in Schwinger model.
