The ultra-dense low earth orbit(LEO)integrated satellite-terrestrial networks(UDLEO-ISTN)can bring lots of benefits in terms of wide coverage,high capacity,and strong robustness.Meanwhile,the broadcasting and open nat...The ultra-dense low earth orbit(LEO)integrated satellite-terrestrial networks(UDLEO-ISTN)can bring lots of benefits in terms of wide coverage,high capacity,and strong robustness.Meanwhile,the broadcasting and open natures of satellite links also reveal many challenges for transmission security protection,especially for eavesdropping defence.How to efficiently take advantage of the LEO satellite’s density and ensure the secure communication by leveraging physical layer security with the cooperation of jammers deserves further investigation.To our knowledge,using satellites as jammers in UDLEO-ISTN is still a new problem since existing works mainly focused on this issue only from the aspect of terrestrial networks.To this end,we study in this paper the cooperative secrecy communication problem in UDLEOISTN by utilizing several satellites to send jamming signal to the eavesdroppers.An iterative scheme is proposed as our solution to maximize the system secrecy energy efficiency(SEE)via jointly optimizing transmit power allocation and user association.Extensive experiment results verify that our designed optimization scheme can significantly enhance the system SEE and achieve the optimal power allocation and user association strategies.展开更多
Highway tunnel traffic safety is an important part of traffic safety.With the aging of tunnels,increase in traffic flow,changes in the operating environment and traffic accidents,the many problems started to occur in ...Highway tunnel traffic safety is an important part of traffic safety.With the aging of tunnels,increase in traffic flow,changes in the operating environment and traffic accidents,the many problems started to occur in tunnels,affecting the operational and structural safety.In this paper,we summarize and analyze the types and causes of defects found in the process of tunnel maintenance at home and abroad,and propose corresponding suggestions for the current maintenance of the main structure of highway tunnels.展开更多
The effects of the addition of rare earth (RE) elements on the void band in the diffusion layer, and the re sistances to both oxidation and spalling of aluminized steel were investigated through high temperature oxi...The effects of the addition of rare earth (RE) elements on the void band in the diffusion layer, and the re sistances to both oxidation and spalling of aluminized steel were investigated through high temperature oxidation and spalling tests. The results showed that RE had significant effects on the void band in the diffusion layer and the properties of aluminized steel. After diffusion treatment, a considerable number of the voids between the middle layer and transitional layer of pure aluminized coating, aggregated into wavy-line-shaped void bands parallel to the outer surface. For the RE added aluminized coating, only a few voids aggregated into intermittent block shapes. During high temperature oxidation at 800 ℃ for 200 h, the wavy void band of pure aluminized coating aggregated further into a linear crack parallel to the outer surface, and the internal oxidation occurred within them; the open cracks perpendicular to the surface penetrated through the diffusion layer. For the RE added aluminized coating, only a few voids aggregated into intermittent meniscus shapes. During cyclic spalling tests, the peeling, spallation, and pulver ulent cracking occurred along the void band in the diffusion layer of pure aluminized coating, but only a little spallation occurred in the diffusion layer of the RE-added aluminized coating, in which cracks perpendicular to the surface were much smaller than those of pure aluminized coating and did not penetrate through the diffusion layer. It is evident that RE addition can restrain the formation and aggregation of voids and subsequently improve the resistances to oxidation and spalling. The mechanism of the RE effect on the void band in the diffusion layer is also discussed.展开更多
Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studie...Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that the characteristics of SOC were different not only among function districts in urban area, but also between urban area and suburbs. The order of SOC in topsoil was industrial district 〉 recreational district 〉 traffic district 〉 cultural/educational district 〉 residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed the orders of recreational district 〉 industrial district 〉 traffic district〉cultural/educational district 〉 residential/adminis-trative district, and cultural/educational district 〉 traffic district〉industrial district〉recreational district 〉 administrative/residential district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased with the depth and was mainly distributed within the scope of 0-30 cm. The variances of SOC in urban area were more complicated than that in suburbs.展开更多
X-ray emission spectra for L-shell of Li-like aluminium ions are simulated by using the flexible atomic code based on the collisional radiative model. Atomic processes including radiative recombination, dielectronic r...X-ray emission spectra for L-shell of Li-like aluminium ions are simulated by using the flexible atomic code based on the collisional radiative model. Atomic processes including radiative recombination, dielectronic recombination, collisional ionization and resonance excitation from the neighbouring ion (Al^9+ and Al^11+ ) charge states of the target ion (Al^10+) are considered in the model. In addition, the contributions of different atomic processes to the x-ray spectrum are analysed. The results show that dielectronic recombination, radiative recombination, collisional ionization and resonance excitation, other than direct collisional excitation, are very important processes.展开更多
The title compound, 2-(N-cyclohexyl)-imino-1,4-succinic acid dihydrate 4, has been prepared and structurally determined by X-ray diffraction analysis. Crystal data: monoclinic, space group Cc, a = 7.5790(15), b = 24...The title compound, 2-(N-cyclohexyl)-imino-1,4-succinic acid dihydrate 4, has been prepared and structurally determined by X-ray diffraction analysis. Crystal data: monoclinic, space group Cc, a = 7.5790(15), b = 24.860(5), c = 7.1394(14) ?, β = 104.23(3)°, V = 1303.9(4) ?3, C10H21NO6, Mr = 251.28, Z = 4, Dc = 1.280 g/cm3, μ = 0.105 mm-1, F(000) = 544, R = 0.0397 and wR = 0.0918 for 1212 observed reflections with I ≥ 2σ(I). X-ray structure analysis reveals that there exist two intramolecular and six intermolecular hydrogen-bonding interactions in the crystal lattice, which can stabilize the configuration of the α-imino acid dihydrate 4.展开更多
Secure key distribution among classical parties is impossible both between two parties and in a network. In this paper, we present a quantum key distribution (QKD) protocol to distribute secure key bits among one qu...Secure key distribution among classical parties is impossible both between two parties and in a network. In this paper, we present a quantum key distribution (QKD) protocol to distribute secure key bits among one quantum party and numerous classical parties who have no quantum capacity. We prove that our protocol is completely robust, i.e., any eavesdropping attack should be detected with nonzero probability. Our calculations show that our protocol may be secure against Eve's symmetrically individual attack.展开更多
The purpose of this paper is to establish some identities with products of qHermite polynomials, q-ultraspherical polynomials and reciprocals of q-binomial coefficients.
The estimation of the functionθ=exp{αμ+bσ2} of parameters (μ,σ2) in normal distribution N(μ,σ2) is discussed. And when the prior distributions ofμandσ2 are independent, under the loss function L(θ,δ)=(θ-1...The estimation of the functionθ=exp{αμ+bσ2} of parameters (μ,σ2) in normal distribution N(μ,σ2) is discussed. And when the prior distributions ofμandσ2 are independent, under the loss function L(θ,δ)=(θ-1×δ-1)2, the Bayesian estimation and the existence and computing method on minimax estimation are deeply discussed.展开更多
Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doub...Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doubled when compared with the prepare-and-measure QKD. An interesting question is whether the transmission distance can be extended further. In this work, we consider the contributions of the two-way local operations and classical communications to the key generation rate and transmission distance of the MDI-QKD. Our numerical results show that the secure transmission distances are increased by about 12kin and 8 km when the 1 13 and the 2 B steps are implemented, respectively.展开更多
The title compound, spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]- hxane-2,2?-(3?-diethyl-α-(S)-4??-Cl-benzyloxyphosphonyl-4?-(1R,2S,5R)-menthyloxybutyrolact- one)] has been synthesized via the tandem a...The title compound, spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]- hxane-2,2?-(3?-diethyl-α-(S)-4??-Cl-benzyloxyphosphonyl-4?-(1R,2S,5R)-menthyloxybutyrolact- one)] has been synthesized via the tandem asymmetric reaction and it crystallizes in a mono- clinic system, space group P21 with a = 11.067(3), b = 12.484(2), c = 12.356(2) ?, β = 101.95°, C29H39BrClO10P, Mr = 693.93, V = 1670.2(6) ?3, Z = 2, Dc= 1.380 g/cm3, λ(MoKα) = 0.071073 nm, μ = 1.410 mm-1, F(000) = 720, the final R = 0.0570 and wR = 0.0758 for 6190 observed reflections with I > 2σ(I). The structure is characterized by the special combination of biologic phosphonyl group and one cyclopropane as well as two butyrolactones. The intermolecular hydrogen bond between O(3)–H(3A)…O(10) in the crystal lattice has been observed.展开更多
The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ (IGF-Ⅰ) and its binding protein 3 (IGFBP3) genes on growth and development traits in beef cows, includ...The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ (IGF-Ⅰ) and its binding protein 3 (IGFBP3) genes on growth and development traits in beef cows, including 130 Chinese Simmental, 42 Nanyang, and 47 Luxi Yellow cattle. Sequence variations in the bovine IGF-Ⅰ and IGFBP3 genes were investigated by single strand conformation polymorphism (SSCP). SSCPs were detected in 6 fragments, which is the 5'-flanking region, the 2nd exon, the 5th exon, and the 5th intron of the IGF-1 gene, and the 2nd exon, the 3rd exon of the 1GFBP3 gene. Two polymorphisms, an A-to-G transition in the 2rid exon of the IGF-Ⅰ gene and a T-to-C transition in the 2rid exon of IGFBP3 gene were detected in 3 breeds. The allele frequencies of 2 polymorphisms were 0.0411 (A), 0.9589 (B), and 0.7237 (A), 0.2763 (B), respectively. These 2 loci were analyzed to associate with body weight, height at withers, body length, heart girth, rump width, and beef production index (BPI) at 0, 6, 12, 24, and 36-month old. The IGFBP3 locus was shown to be associated with rump width, heart girth at 24-month and 36-month. Animals with BB genotype had higher rump width (24.86 ± 0.47) cm at 24-month and (27.50 ± 0.63) em at 36-month. The heart girth was highest for the individuals with BB genotype (171.33 ± 1.84) cm and higher than those with AB genotype (166.68 ± 1.13) cm (P〈 0.05) at 36-month.展开更多
Previous experimental investigations have shown that when a narrow pipe is inserted into a granular bed and is vibrated vertically but the granular bed is kept still, the grains in the bed can enter the pipe and rise ...Previous experimental investigations have shown that when a narrow pipe is inserted into a granular bed and is vibrated vertically but the granular bed is kept still, the grains in the bed can enter the pipe and rise against gravity along the pipe and finally stabilized at a certain height. The growth velocity and final stable height of the grain column inside the pipe can be controlled by varying the vibration conditions. In this paper, we discuss those experimental findings. We establish a mathematic relation between the grain column height(h) and time(t), and by using the relation we discuss the change of the growth velocity( dh/ dt) and acceleration( d^2h/ dt^2) with t and h, respectively. We also analyze the mechanism of the rising motion of the grains during vibration. Furthermore, we derive a theoretical expression for describing the final stable height(h st), which shows that the main factors influencing the height are vibration strength(Γ), bulk density of grains,inner diameter of the pipe, and vibration frequency, and that h st increases nonlinearly in the presence of air and linearly in a vacuum environment with increasing Γ.展开更多
The crystal structure of the title complex having thestoichiometric formula [Ni-(phen)3]Pic2.2CH3CN (Pic=picrate anion; phen=1,10-phenanthroline) has been determined by single-crystal X-ray diffraction. The crystal (C...The crystal structure of the title complex having thestoichiometric formula [Ni-(phen)3]Pic2.2CH3CN (Pic=picrate anion; phen=1,10-phenanthroline) has been determined by single-crystal X-ray diffraction. The crystal (C52H34N14O14Ni, Mr=1137.63) belongs to the triclinic system, space group P(#2) with the following crystallographic parameters: a = 14.130(1), b=15.256(3), c=13.673(2)Å; α=109.11(1), β =90.92(4), γ=66.75(3)°; V=2537.72Å3, Dc=1.489g/cm3, μ(MoKα)=4.66cm-1, F(000)=1168, Z=2, and final R=0.062 and Rw=0.078 for 4917 observed reflections (I>2.00σ(I)). The analytical results of crystal structure and spectroscopic properties show that nickel(II) cation coordination environment is a distorted octahedral geometry, the Ni2+ ion is coordinated with six nitrogen atoms~ of three phen directly, while two picrate anions and two acetonitrile molecules do not take part in coordination~.展开更多
A hydrogen-bonded supermolecular compound [(C6H5N2O)3·Cu1.5]·6H2O was synthesized from picolinamide and Cu(NO3)2·6H2O at the presence of sodium pyrophosphate decahydrate. It crystallizes in triclini...A hydrogen-bonded supermolecular compound [(C6H5N2O)3·Cu1.5]·6H2O was synthesized from picolinamide and Cu(NO3)2·6H2O at the presence of sodium pyrophosphate decahydrate. It crystallizes in triclinic, space group P1^- with a = 1.05947(8), b = 1.09130(8), c = 1.11456(8) nm, a = 67.8460(10), β= 84.497(1), γ = 74.6210(10)°, C18H27Cu1.5N6O9, Mr = 566.77, V = 1.15077(15) nm^3, Z = 2, Dc = 1.636 g/cm^3, F(000) = 585,μ= 1.461 mm^-1, R1 = 0.0278 and wR2 = 0.0749. In the complex, the Cu(Ⅱ) ion reveals a distorted tetradentate plane-tetragonal geometry. The structure consists of neutral two-dimensional layers via hydrogen bonds O-H...O and N-H...O between the molecules, and the layers are connected by weak interactions of the Cu-Cu, Cu-N, π-π and hydrogen bonds to form a three-dimensional network structure.展开更多
The title compound, 5(R)-(1R,2S,5R)-menthoxy-4(R)-N-cyclohexylaminobutyrolactone 1, has been synthesized via the asymmetric Micheal addition reaction of 5(R)-menthoxy- 2(5H)-furanone 4 with cyclohexylamine 5...The title compound, 5(R)-(1R,2S,5R)-menthoxy-4(R)-N-cyclohexylaminobutyrolactone 1, has been synthesized via the asymmetric Micheal addition reaction of 5(R)-menthoxy- 2(5H)-furanone 4 with cyclohexylamine 5, and structurally determined by single-crystal X-ray diffraction. Crystal data: C20H36NO3, Mr = 337.49, monoclinic system, space group P21, a = 9.8677(7), b = 9.7737(7), c=11.0204(8) A, β= 103.7820(10)°, V= 1032.25(13) A^3, Z = 2, Dc= 1.086 g/cm^3, 2(MoKα) = 0.071073 nm,μ= 0.071 mm^-1 and F(000) = 372. The structure was refined to R = 0.0328 and wR = 0.0864 for 4203 observed reflections (I 〉 2σ(I)). The crystallographic results of molecule 1 show that the functionalized N-cyclohexylamino group is linked in the 4-position of butyrolactone to form the novel chiral optically active compound.展开更多
This paper has made researches on first order neutral differential equations with varia-ble coefficients and several deviations.The asymptotic behavior of nonoscillatory solutions of the equations are discussed.Necess...This paper has made researches on first order neutral differential equations with varia-ble coefficients and several deviations.The asymptotic behavior of nonoscillatory solutions of the equations are discussed.Necessary and sufficient conditions and several sufficient conditions for the oscillations of the equations are obtained.The relevent results in [1-3] are improved and genera-lized.展开更多
Er3+-doped TiO2-SiO2 powders are prepared by the sol-gel method, and they are characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) spectra, and Raman spectra of the ...Er3+-doped TiO2-SiO2 powders are prepared by the sol-gel method, and they are characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) spectra, and Raman spectra of the samples. It is shown that the TiO2 nanocrystals are surrounded by an SiO2 glass matrix. The photoluminescence (PL) spectra are recorded at room temperature. A strong green luminescence and less intense red emission are observed in the samples when they are excited at 325 nm. The intensity of the emission, which is related to the defect states, is strongest at the annealing temperature of 800℃. The PL intensity of Er3+ ions increases with increasing Ti/Si ratio due to energy transfer between nano-TiO2 particles and Er3+ ions.展开更多
The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3(M=Zn,Mg,Al) are investigated by means of the first-principles calculations.The calculated structural parame...The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3(M=Zn,Mg,Al) are investigated by means of the first-principles calculations.The calculated structural parameters and elastic properties of MNNi 3 are in good agreement with the experimental and the other theoretical results.From the elastic constants under high pressure,we predict that ZnNNi 3,MgNNi 3,and AlNNi 3 are not stable at the pressures above 61.2 GPa,113.3 GPa,and 122.4 GPa,respectively.By employing the Debye model,the thermodynamic properties,such as the heat capacity and the thermal expansion coefficient,under pressures and at finite temperatures are also obtained successfully.展开更多
基金supported by National Key R&D Program of China(2022YFB3104200)in part by National Natural Science Foundation of China(62202386)+6 种基金in part by Basic Research Programs of Taicang(TC2021JC31)in part by Fundamental Research Funds for the Central Universities(D5000210817)in part by Xi’an Unmanned System Security and Intelligent Communications ISTC Centerin part by Special Funds for Central Universities Construction of World-Class Universities(Disciplines)and Special Development Guidance(0639022GH0202237 and 0639022SH0201237)in part by the Henan Key Scientific Research Program of Higher Education(23B510003,21A510008 and 21A510009)in part by Henan Key Scientific and Technological Projects(212102210553)。
文摘The ultra-dense low earth orbit(LEO)integrated satellite-terrestrial networks(UDLEO-ISTN)can bring lots of benefits in terms of wide coverage,high capacity,and strong robustness.Meanwhile,the broadcasting and open natures of satellite links also reveal many challenges for transmission security protection,especially for eavesdropping defence.How to efficiently take advantage of the LEO satellite’s density and ensure the secure communication by leveraging physical layer security with the cooperation of jammers deserves further investigation.To our knowledge,using satellites as jammers in UDLEO-ISTN is still a new problem since existing works mainly focused on this issue only from the aspect of terrestrial networks.To this end,we study in this paper the cooperative secrecy communication problem in UDLEOISTN by utilizing several satellites to send jamming signal to the eavesdroppers.An iterative scheme is proposed as our solution to maximize the system secrecy energy efficiency(SEE)via jointly optimizing transmit power allocation and user association.Extensive experiment results verify that our designed optimization scheme can significantly enhance the system SEE and achieve the optimal power allocation and user association strategies.
文摘Highway tunnel traffic safety is an important part of traffic safety.With the aging of tunnels,increase in traffic flow,changes in the operating environment and traffic accidents,the many problems started to occur in tunnels,affecting the operational and structural safety.In this paper,we summarize and analyze the types and causes of defects found in the process of tunnel maintenance at home and abroad,and propose corresponding suggestions for the current maintenance of the main structure of highway tunnels.
基金Item Sponsored by Key Science and Technology Plan Foundation of Henan of China (0423023500) and Natural ScienceFoundation of Henan Province (0511021600)
文摘The effects of the addition of rare earth (RE) elements on the void band in the diffusion layer, and the re sistances to both oxidation and spalling of aluminized steel were investigated through high temperature oxidation and spalling tests. The results showed that RE had significant effects on the void band in the diffusion layer and the properties of aluminized steel. After diffusion treatment, a considerable number of the voids between the middle layer and transitional layer of pure aluminized coating, aggregated into wavy-line-shaped void bands parallel to the outer surface. For the RE added aluminized coating, only a few voids aggregated into intermittent block shapes. During high temperature oxidation at 800 ℃ for 200 h, the wavy void band of pure aluminized coating aggregated further into a linear crack parallel to the outer surface, and the internal oxidation occurred within them; the open cracks perpendicular to the surface penetrated through the diffusion layer. For the RE added aluminized coating, only a few voids aggregated into intermittent meniscus shapes. During cyclic spalling tests, the peeling, spallation, and pulver ulent cracking occurred along the void band in the diffusion layer of pure aluminized coating, but only a little spallation occurred in the diffusion layer of the RE-added aluminized coating, in which cracks perpendicular to the surface were much smaller than those of pure aluminized coating and did not penetrate through the diffusion layer. It is evident that RE addition can restrain the formation and aggregation of voids and subsequently improve the resistances to oxidation and spalling. The mechanism of the RE effect on the void band in the diffusion layer is also discussed.
基金Key Scientific and Technological Research Projects of Henan Province, No.72102150029
文摘Urban soil, forming along with the development of city, has unique properties of soil organic carbon. On the basis of field investigation and laboratory analysis, soil organic carbon (SOC) of Kaifeng city was studied, and the results showed that the characteristics of SOC were different not only among function districts in urban area, but also between urban area and suburbs. The order of SOC in topsoil was industrial district 〉 recreational district 〉 traffic district 〉 cultural/educational district 〉 residential/administrative district. The density of soil organic carbon (SOCD) in both topsoil and profile followed the orders of recreational district 〉 industrial district 〉 traffic district〉cultural/educational district 〉 residential/adminis-trative district, and cultural/educational district 〉 traffic district〉industrial district〉recreational district 〉 administrative/residential district, respectively. SOCD in both topsoil and profile decreased along the transection line from urban area to suburbs and urban area had 2.53-fold more SOCD in topsoil and 1.56-fold more SOCD in profile than suburbs, respectively. SOC decreased with the depth and was mainly distributed within the scope of 0-30 cm. The variances of SOC in urban area were more complicated than that in suburbs.
文摘X-ray emission spectra for L-shell of Li-like aluminium ions are simulated by using the flexible atomic code based on the collisional radiative model. Atomic processes including radiative recombination, dielectronic recombination, collisional ionization and resonance excitation from the neighbouring ion (Al^9+ and Al^11+ ) charge states of the target ion (Al^10+) are considered in the model. In addition, the contributions of different atomic processes to the x-ray spectrum are analysed. The results show that dielectronic recombination, radiative recombination, collisional ionization and resonance excitation, other than direct collisional excitation, are very important processes.
基金Supported by the National Natural Science Foundation of China (No. 29672004)
文摘The title compound, 2-(N-cyclohexyl)-imino-1,4-succinic acid dihydrate 4, has been prepared and structurally determined by X-ray diffraction analysis. Crystal data: monoclinic, space group Cc, a = 7.5790(15), b = 24.860(5), c = 7.1394(14) ?, β = 104.23(3)°, V = 1303.9(4) ?3, C10H21NO6, Mr = 251.28, Z = 4, Dc = 1.280 g/cm3, μ = 0.105 mm-1, F(000) = 544, R = 0.0397 and wR = 0.0918 for 1212 observed reflections with I ≥ 2σ(I). X-ray structure analysis reveals that there exist two intramolecular and six intermolecular hydrogen-bonding interactions in the crystal lattice, which can stabilize the configuration of the α-imino acid dihydrate 4.
基金Project supported by the National Natural Science Foundation of China (Grant No 10774039)
文摘Secure key distribution among classical parties is impossible both between two parties and in a network. In this paper, we present a quantum key distribution (QKD) protocol to distribute secure key bits among one quantum party and numerous classical parties who have no quantum capacity. We prove that our protocol is completely robust, i.e., any eavesdropping attack should be detected with nonzero probability. Our calculations show that our protocol may be secure against Eve's symmetrically individual attack.
基金Supported by the National Natural Science Foundation of China(10771093) Supported by the Youth Foundation of Luoyang Normal College(2013-QNJJ-001) Supported by the Youth Foundation of the Luoyang Institute of Science and Technology(2012QZ05)
文摘The purpose of this paper is to establish some identities with products of qHermite polynomials, q-ultraspherical polynomials and reciprocals of q-binomial coefficients.
文摘The estimation of the functionθ=exp{αμ+bσ2} of parameters (μ,σ2) in normal distribution N(μ,σ2) is discussed. And when the prior distributions ofμandσ2 are independent, under the loss function L(θ,δ)=(θ-1×δ-1)2, the Bayesian estimation and the existence and computing method on minimax estimation are deeply discussed.
基金Supported by the National Natural Science Foundation of China under Grant No 61378011the Program for Science and Technology Innovation Research Team in University of Henan Province under Grant No 13IRTSTHN020
文摘Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doubled when compared with the prepare-and-measure QKD. An interesting question is whether the transmission distance can be extended further. In this work, we consider the contributions of the two-way local operations and classical communications to the key generation rate and transmission distance of the MDI-QKD. Our numerical results show that the secure transmission distances are increased by about 12kin and 8 km when the 1 13 and the 2 B steps are implemented, respectively.
基金Supported by the National Natural Science Foundation of China (No. 29672004)
文摘The title compound, spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]- hxane-2,2?-(3?-diethyl-α-(S)-4??-Cl-benzyloxyphosphonyl-4?-(1R,2S,5R)-menthyloxybutyrolact- one)] has been synthesized via the tandem asymmetric reaction and it crystallizes in a mono- clinic system, space group P21 with a = 11.067(3), b = 12.484(2), c = 12.356(2) ?, β = 101.95°, C29H39BrClO10P, Mr = 693.93, V = 1670.2(6) ?3, Z = 2, Dc= 1.380 g/cm3, λ(MoKα) = 0.071073 nm, μ = 1.410 mm-1, F(000) = 720, the final R = 0.0570 and wR = 0.0758 for 6190 observed reflections with I > 2σ(I). The structure is characterized by the special combination of biologic phosphonyl group and one cyclopropane as well as two butyrolactones. The intermolecular hydrogen bond between O(3)–H(3A)…O(10) in the crystal lattice has been observed.
基金funded by the National Key Technology R&D Program of the China (2006BAD01A10,2006BAD14B07, 2006BAD04A16)the National High Technology Research and Development Program of China (2006AA10Z197)
文摘The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ (IGF-Ⅰ) and its binding protein 3 (IGFBP3) genes on growth and development traits in beef cows, including 130 Chinese Simmental, 42 Nanyang, and 47 Luxi Yellow cattle. Sequence variations in the bovine IGF-Ⅰ and IGFBP3 genes were investigated by single strand conformation polymorphism (SSCP). SSCPs were detected in 6 fragments, which is the 5'-flanking region, the 2nd exon, the 5th exon, and the 5th intron of the IGF-1 gene, and the 2nd exon, the 3rd exon of the 1GFBP3 gene. Two polymorphisms, an A-to-G transition in the 2rid exon of the IGF-Ⅰ gene and a T-to-C transition in the 2rid exon of IGFBP3 gene were detected in 3 breeds. The allele frequencies of 2 polymorphisms were 0.0411 (A), 0.9589 (B), and 0.7237 (A), 0.2763 (B), respectively. These 2 loci were analyzed to associate with body weight, height at withers, body length, heart girth, rump width, and beef production index (BPI) at 0, 6, 12, 24, and 36-month old. The IGFBP3 locus was shown to be associated with rump width, heart girth at 24-month and 36-month. Animals with BB genotype had higher rump width (24.86 ± 0.47) cm at 24-month and (27.50 ± 0.63) em at 36-month. The heart girth was highest for the individuals with BB genotype (171.33 ± 1.84) cm and higher than those with AB genotype (166.68 ± 1.13) cm (P〈 0.05) at 36-month.
文摘Previous experimental investigations have shown that when a narrow pipe is inserted into a granular bed and is vibrated vertically but the granular bed is kept still, the grains in the bed can enter the pipe and rise against gravity along the pipe and finally stabilized at a certain height. The growth velocity and final stable height of the grain column inside the pipe can be controlled by varying the vibration conditions. In this paper, we discuss those experimental findings. We establish a mathematic relation between the grain column height(h) and time(t), and by using the relation we discuss the change of the growth velocity( dh/ dt) and acceleration( d^2h/ dt^2) with t and h, respectively. We also analyze the mechanism of the rising motion of the grains during vibration. Furthermore, we derive a theoretical expression for describing the final stable height(h st), which shows that the main factors influencing the height are vibration strength(Γ), bulk density of grains,inner diameter of the pipe, and vibration frequency, and that h st increases nonlinearly in the presence of air and linearly in a vacuum environment with increasing Γ.
文摘The crystal structure of the title complex having thestoichiometric formula [Ni-(phen)3]Pic2.2CH3CN (Pic=picrate anion; phen=1,10-phenanthroline) has been determined by single-crystal X-ray diffraction. The crystal (C52H34N14O14Ni, Mr=1137.63) belongs to the triclinic system, space group P(#2) with the following crystallographic parameters: a = 14.130(1), b=15.256(3), c=13.673(2)Å; α=109.11(1), β =90.92(4), γ=66.75(3)°; V=2537.72Å3, Dc=1.489g/cm3, μ(MoKα)=4.66cm-1, F(000)=1168, Z=2, and final R=0.062 and Rw=0.078 for 4917 observed reflections (I>2.00σ(I)). The analytical results of crystal structure and spectroscopic properties show that nickel(II) cation coordination environment is a distorted octahedral geometry, the Ni2+ ion is coordinated with six nitrogen atoms~ of three phen directly, while two picrate anions and two acetonitrile molecules do not take part in coordination~.
文摘A hydrogen-bonded supermolecular compound [(C6H5N2O)3·Cu1.5]·6H2O was synthesized from picolinamide and Cu(NO3)2·6H2O at the presence of sodium pyrophosphate decahydrate. It crystallizes in triclinic, space group P1^- with a = 1.05947(8), b = 1.09130(8), c = 1.11456(8) nm, a = 67.8460(10), β= 84.497(1), γ = 74.6210(10)°, C18H27Cu1.5N6O9, Mr = 566.77, V = 1.15077(15) nm^3, Z = 2, Dc = 1.636 g/cm^3, F(000) = 585,μ= 1.461 mm^-1, R1 = 0.0278 and wR2 = 0.0749. In the complex, the Cu(Ⅱ) ion reveals a distorted tetradentate plane-tetragonal geometry. The structure consists of neutral two-dimensional layers via hydrogen bonds O-H...O and N-H...O between the molecules, and the layers are connected by weak interactions of the Cu-Cu, Cu-N, π-π and hydrogen bonds to form a three-dimensional network structure.
基金Supported by the National Natural Science Foundation of China (No. 29672004)
文摘The title compound, 5(R)-(1R,2S,5R)-menthoxy-4(R)-N-cyclohexylaminobutyrolactone 1, has been synthesized via the asymmetric Micheal addition reaction of 5(R)-menthoxy- 2(5H)-furanone 4 with cyclohexylamine 5, and structurally determined by single-crystal X-ray diffraction. Crystal data: C20H36NO3, Mr = 337.49, monoclinic system, space group P21, a = 9.8677(7), b = 9.7737(7), c=11.0204(8) A, β= 103.7820(10)°, V= 1032.25(13) A^3, Z = 2, Dc= 1.086 g/cm^3, 2(MoKα) = 0.071073 nm,μ= 0.071 mm^-1 and F(000) = 372. The structure was refined to R = 0.0328 and wR = 0.0864 for 4203 observed reflections (I 〉 2σ(I)). The crystallographic results of molecule 1 show that the functionalized N-cyclohexylamino group is linked in the 4-position of butyrolactone to form the novel chiral optically active compound.
文摘This paper has made researches on first order neutral differential equations with varia-ble coefficients and several deviations.The asymptotic behavior of nonoscillatory solutions of the equations are discussed.Necessary and sufficient conditions and several sufficient conditions for the oscillations of the equations are obtained.The relevent results in [1-3] are improved and genera-lized.
基金Project supported by the Key Science and Technology Program of Henan Province of China (Grant Nos. 102102210448 and 102102210452)the Scientific Research Fundation of the Education Department of Henan Province,China (Grant No. 2010A140011)
文摘Er3+-doped TiO2-SiO2 powders are prepared by the sol-gel method, and they are characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) spectra, and Raman spectra of the samples. It is shown that the TiO2 nanocrystals are surrounded by an SiO2 glass matrix. The photoluminescence (PL) spectra are recorded at room temperature. A strong green luminescence and less intense red emission are observed in the samples when they are excited at 325 nm. The intensity of the emission, which is related to the defect states, is strongest at the annealing temperature of 800℃. The PL intensity of Er3+ ions increases with increasing Ti/Si ratio due to energy transfer between nano-TiO2 particles and Er3+ ions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11147101 and 11071107)the Henan Research Program of Basic and Frontier Technology,China(Grant Nos.112300410024 and 102102210452)+1 种基金the Henan Natural Science Basic Research,China(Grant Nos.2011B140013 and 2010A140011)the Scientific Research Foundation of Luoyang Normal University, China(Grant No.2010-QNJJ-003)
文摘The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3(M=Zn,Mg,Al) are investigated by means of the first-principles calculations.The calculated structural parameters and elastic properties of MNNi 3 are in good agreement with the experimental and the other theoretical results.From the elastic constants under high pressure,we predict that ZnNNi 3,MgNNi 3,and AlNNi 3 are not stable at the pressures above 61.2 GPa,113.3 GPa,and 122.4 GPa,respectively.By employing the Debye model,the thermodynamic properties,such as the heat capacity and the thermal expansion coefficient,under pressures and at finite temperatures are also obtained successfully.