Showing papers by "Capital Normal University published in 2002"
TL;DR: In this article, the authors analyse symmetry breaking for ground states of the Henon equation in a ball and give asymptotic estimates of the transition when p is close to either 2 or 2 *.
Abstract: We analyse symmetry breaking for ground states of the Henon equation [7] in a ball. Asymptotic estimates of the transition are also given when p is close to either 2 or 2*.
226 citations
TL;DR: Polymer-stabilized tetragonal ZrO(2) nanopowders with average size of ca.
Abstract: Polymer-stabilized tetragonal ZrO2 nanopowders with average size of ca. 2.0 nm have been prepared by microwave heating in an aqueous solution containing Zr(NO3)4·5H2O, PVA, and NaOH. The photoluminescence of the synthesized ZrO2 fine particles has been investigated.
188 citations
TL;DR: In this paper, an explicit expression for the quantum channel associated with the optimal teleportation with an arbitrary mixed state resource is presented, and the optimal transmission fidelity of the corresponding quantum channel is calculated and shown to be related to the fully entangled fraction of the quantum resource.
Abstract: We study optimal teleportation based on Bell measurements. An explicit expression for the quantum channel associated with the optimal teleportation with an arbitrary mixed state resource is presented. The optimal transmission fidelity of the corresponding quantum channel is calculated and shown to be related to the fully entangled fraction of the quantum resource, rather than the singlet fraction as in the standard teleportation protocol.
125 citations
TL;DR: In this paper, general point interactions for the second derivative operator in one dimension were studied and the spectrum of such non-Hermitian operators was investigated and conditions when the spectrum is pure real were presented.
Abstract: General point interactions for the second derivative operator in one dimension are studied. In particular, PT -self-adjoint point interactions with the support at the origin and at pointsl are considered. The spectrum of such non-Hermitian operators is investigated and conditions when the spectrum is pure real are presented. The results are compared with those for standard self-adjoint point interactions.
100 citations
85 citations
TL;DR: This study confirms most previous reports about personality in patients with primary headaches and establishes elevated aggression-hostility only in MO sufferer, from the perspective of a five-factor model.
Abstract: Although abnormal personality traits have been frequently reported in patients with primary headaches, the overlaps between these domains need a clear standard definition, for example, by a five-facto
70 citations
TL;DR: Sophoranone inhibited cell growth and induced apoptosis in various lines of cells from human solid tumors, with 50% inhibition of growth of human stomach cancer MKN7 cells at 1.2 ± 0.3 μM.
Abstract: Screening of various natural products in a search for novel inducers of apoptosis in human leukemia cells led us to identify the strong apoptosis-inducing activity in a fraction extracted with methanol from the roots of Sophora subprostrata Chun et T. Chen. We purified the compound that induced apoptosis in human leukemia cells and identified it as sophoranone. Sophoranone inhibited cell growth and induced apoptosis in various lines of cells from human solid tumors, with 50% inhibition of growth of human stomach cancer MKN7 cells at 1.2 +/- 0.3 microM. The growth-inhibitory and apoptosis-inducing activities of sophoranone for leukemia U937 cells were very much stronger than those of other flavonoids, such as daidzein, genistein and quercetin. At the early stages of treatment of U937 cells with sophoranone, reactive oxygen species were formed, mitochondrial permeability pores were opened and cytochrome c was released from mitochondria. Cytochrome c was also released upon treatment of isolated mitochondria with sophoranone. Inhibitors of complexes III and IV, but not complexes I and II, of the mitochondrial respiratory chain prevented the release of cytochrome c from isolated mitochondria by sophoranone, as well as the induction of apoptosis in U937 cells in response to sophoranone. Our results indicate that sophoranone might be a unique apoptosis-inducing anticancer agent that targets mitochondria.
65 citations
TL;DR: This work has shown that for Western subjects, the self-reference condition, relative to the mother condition, was associated with a higher proportion of correct remember responses and a lowerportion of correct know responses.
Abstract: Self-reference at encoding increases the probability of recollective experience in recognition memory. Self-reference effect (SRE) in memory is observed when the degree of self-reference of to-be-remembered materials is varied. Usually items encoded in terms of self-reference are associated with significantly higher recall performance relative to items encoded in other ways, including semantic encoding. In our three experiments, four orientating tasks formed four levels in a between-subjects design. The conditions were rating personality traits with reference to self, mother, Lu Xun (a famous Chinese writer) or rating the traits on a negative-positive dimension. In a recognition test, subjects first identified old items and then indicated which of these were accompanied by recollective experience ('remember' responses) and which were recognized on some other basis ('know' responses). Our results showed that both the self-reference condition and mother condition were associated with the same highest proportion of correct remember responses and the same lowest proportion of correct know responses. In contrast, for Western subjects, the self-reference condition, relative to the mother condition, was associated with a higher proportion of correct remember responses and a lower proportion of correct know responses. We discussed the results with reference to the HERA model (hemispheric encoding/retrieval asymmetry).
64 citations
TL;DR: In this article, a variational cumulant expansion (VCE) was applied to investigate phase transitions in magnetic alloy nano-particles, in which a random site distribution of component atoms is assumed.
Abstract: The method of variational cumulant expansion (VCE) on the Ising model is applied to investigate phase transitions in magnetic alloy nano-particles, in which a random site distribution of component atoms is assumed. By introducing the effect exchange constant, it is shown numerically that nano-particles can be treated the same way as bulk materials. The Curie temperature and the Neel temperature of binary magnetic nano-particles with cubic lattices are calculated. It is found that both the Curie temperature and the Neel temperature decrease with decreasing size of the nano-particle. Phase diagrams of binary alloy nano-particles are investigated for variable doping concentration and the results are discussed. As the nano-particle size grows larger, the critical point approaches that of a bulk. On the other hand, the tri-critical point is independent of the nano-particle size and is always the same as that of the bulk.
56 citations
TL;DR: A simple and sensitive fluorometric method to detect the hydroxyl radical is described, which employs the reaction between OH and dimethyl sulfoxide to generate quantitatively formaldehyde, which then reacts with ammonia and 1,3-cyclohexanedione to produce fluorescence.
48 citations
TL;DR: In this article, the Hartmann potential and ring-shaped oscillator were shown to have supersymmetry and shape invariance in the r and θ dimensions, respectively, in spherical polar coordinates.
Abstract: This article shows that in spherical polar coordinates, some noncentral separable potentials have supersymmetry and shape invariance in the r and θ dimensions, we choose Hartmann potential and ring-shaped oscillator as two important examples, thus in principle the energy eigenvalues and energy eigenfunctions of such the potentials in the r and θ dimensions can be obtained by the method of supersymmetric quantum mechanics. Here we use an alternative method to get the required results.
TL;DR: A new family, Grammolingiidae of fossil lacewings is erected, of which 3 new genera and 6 new species are described and illustrated, demonstrating that present knowledge of the Jurassic Neuropetra fauna remains very poor.
Abstract: A new family, Grammolingiidae of fossil lacewings is erected, of which 3 new genera and 6 new species are described and illustrated: Grammolingia boi. gen. nov. et sp. nov., Litholingia rhora gen. nov. et sp. nov., Litholingia eumorpha gen. nov. et sp. nov. and Litholingia polychotoma gen. nov. et sp. nov., Leptolingia jurassica gen. nov. et sp. nov. and Leptolingia tianyiensis gen. noc. et sp. nov.. A key to genera within this new family is provided. All specimens described were collected from the Middle Jurassic Jiulongshan Formation of Eastern Inner Mongolia, China. The present discovery demonstrates that present knowledge of the Jurassic Neuropetra fauna remains very poor. The fossil specimens are deposited in Yizhou Fossil Museum and Department of Biology, Capital Normal University, respectively.
TL;DR: In this paper, the difference discrete variational principle in the framework of multi-parameter differential approach is studied. But the difference is not considered as an entire geometric object in view of non-commutative differential geometry.
Abstract: In this first paper of a series, we study the difference discrete variational principle in the framework of multi-parameter differential approach by regarding the forward difference as an entire geometric object in view of noncommutative differential geometry. Regarding the difference as an entire geometric object, the difference discrete version of Legendre transformation can be introduced. By virtue of this variational principle, we can discretely deal with the variation problems in both the Lagrangian and Hamiltonian formalisms to get difference discrete Euler-Lagrange equations and canonical ones for the difference discrete versions of the classical mechanics and classical field theory.
TL;DR: In this paper, three binuclear europium complexes containing bidentate and tridentate bridging carboxylates with diimines, namely [Eu(m-MOBA)2NO3phen]2, [eu(2,3-DMOBA), 2NO3phoen]2 and [ eu(3-dMOBA, 3bpy], have been synthesized and characterized by X-ray diffraction.
TL;DR: In this paper, the star chromatic number of planar graphs is derived from a 3-or 5-wheel by subdivisions, and the first two families are derived from 2+2/(2n + 1), 2+3/(3n+ 1), and 2+ 3(3n−1), respectively.
Abstract: The notion of the star chromatic number of a graph is a generalization of the chromatic number. In this paper, we calculate the star chromatic numbers of three infinite families of planar graphs. The first two families are derived from a 3-or 5-wheel by subdivisions, their star chromatic numbers being 2+2/(2n + 1), 2+3/(3n + 1), and 2+3(3n−1), respectively. The third family of planar graphs are derived from n odd wheels by Hajos construction with star chromatic numbers 3 + 1/n, which is a generalization of one result of Gao et al.
TL;DR: In this article, a ternany europium complex with furoic acid (α-FURA) and 1,10-phenanthroline(phen), [Eu(α-FURRA)3phen]H2O(I) and a quaternary Europium furoate complex with 1, 10-phennthroline and nitrate, Eu( α-FurRA)2NO3phen(II) were synthesized and characterized by X-ray diffraction.
TL;DR: In this article, the existence of stationary solutions for some cross-di® usion systems with small parameters was proved using a singular perturbation method, which extends the results of Fife and Ito to the cross-dictionary usion cases.
Abstract: This paper is concerned with the existence of stationary solutions for some cross-di® usion systems with small parameters. Using a singular perturbation method, we prove the existence of stationary solutions with boundary and interior layers, which extends the results of Fife and Ito to the cross-di® usion cases.
TL;DR: In this article, the structural and electronic properties of the endohedral Be@C60 were studied via density functional theory method and it was shown that Be occupies the center of the fullerene cage and approximately keeps its atomic electronic configuration.
TL;DR: A set of entropy conditions for combustion and noncombustion waves to the nonconvex CJ combustion model is proposed, which is the indispensable preparation for the study of multidimensional combustion problems.
Abstract: We study the transition from the Zeldovich--von Neumann--Doring (ZND) theory to the Chapman--Jouguet (CJ) theory as the reaction rate tends to infinity for a nonconvex scalar combustion model. The Riemann solution of the nonconvex ZND combustion model is constructed, and the limit of solutions as the reaction rate goes to infinity is investigated. We classify the reaction solutions of the ZND combustion model as detonation and deflagration waves according to the essential difference that the former contains the von Neumann spike but the latter does not. Based on the analysis of this limit, we propose a set of entropy conditions for combustion and noncombustion waves to the nonconvex CJ combustion model, which is the indispensable preparation for the study of multidimensional combustion problems.
TL;DR: In this article, sufficient and necessary conditions for separability of N-dimensional rank two multiparty quantum mixed states are presented, and a nonseparability inequality is also given, for the case where one of the eigenvectors corresponding to nonzero eigenvalues of the density matrix is maximally entangled.
TL;DR: In this article, the difference discrete variational principle and Euler-Lagrange cohomology were applied to the multisymplectic and multi-parameter differential algorithms.
Abstract: In the previous papers I and II, we have studied the difference discrete variational principle and the Euler–Lagrange cohomology in the framework of multi-parameter differential approach. We have gotten the difference discrete Euler–Lagrange equations and canonical ones for the difference discrete versions of classical mechanics and field theory as well as the difference discrete versions for the Euler–Lagrange cohomology and applied them to get the necessary and sufficient condition for the symplectic or multisymplectic geometry preserving properties in both the Lagrangian and Hamiltonian formalisms. In this paper, we apply the difference discrete variational principle and Euler–Lagrange cohomological approach directly to the symplectic and multisymplectic algorithms. We will show that either Hamiltonian schemes or Lagrangian ones in both the symplectic and multisymplectic algorithms are variational integrators and their difference discrete symplectic structure-preserving properties can always be established not only in the solution space but also in the function space if and only if the related closed Euler–Lagrange cohomological conditions are satisfied.
Posted Content•
TL;DR: In this article, general point interactions for the second derivative operator in one dimension are studied and conditions when the spectrum is pure real are presented, and the results are compared with those for standard self-adjoint point interactions.
Abstract: General point interactions for the second derivative operator in one dimension are studied. In particular, ${\mathcal P \mathcal T}$-self-adjoint point interactions with the support at the origin and at points $\pm l$ are considered. The spectrum of such non-Hermitian operators is investigated and conditions when the spectrum is pure real are presented. The results are compared with those for standard self-adjoint point interactions.
TL;DR: The present experiments suggest that the secretion of testosterone could be regulated, at least in part, by acetylcholine through the inferior spermatic nerves.
Abstract: Strong evidence indicated that spermatic nerves are involved in the regulation of testosterone secretion. Our previous work showed that the inferior spermatic nerves play a more significant role than the superior ones in the regulation of testosterone secretion. However, it is unknown whether traditional neurotransmitters are involved in this regulation. In order to evaluate this point, the present experiments were carried out in an in vitro system where an isolated testis-spermatic nerve plexus preparation was incubated in two separate containers, one for the testis and the other for the nerve plexus and both interconnected by the inferior spermatic nerves. Both tissues were maintained in the same environmental conditions except for the neurotransmitter treatment, applied only to the nerve plexus. Acetylcholine can significantly inhibit the secretion of testosterone until the end of incubation. The present experiments suggest that the secretion of testosterone could be regulated, at least in part, by acetylcholine through the inferior spermatic nerves.
TL;DR: In this paper, the separation and determination of ephedrine enantiomers by capillary electrophoresis using l-leucine as chiral selector is described, and the influence of buffer pH, buffer concentration, chiral selector concentration and organic modifier added to the background electrolyte on the resolution of enantiomer was studied.
Abstract: The separation and determination of ephedrine enantiomers by capillary electrophoresis usingl-leucine as chiral selector is described. The influence of buffer pH, buffer concentration, chiral selector concentration and organic modifier added to the background electrolyte on the resolution of enantiomers were studied. Based on these parameters the analytical method developed was found to be suitable for the analysis of ephedrine and related compounds inEphedra plant extracts.
03 Jun 2002
TL;DR: In this article, the authors prove the existence of orbits that go to infinity in the future or in the past by using the well-known Birkhoff Ergodic Theorem.
Abstract: In this paper, we study the dynamics of the mappings θ 1 = θ + 2απ + μ 1 (θ) + o(r -1 ), r 1 = r + μ 2 (θ) + o(1), r → +∞, where a is a irrational rotation number. We prove the existence of orbits that go to infinity in the future or in the past by using the well-known Birkhoff Ergodic Theorem. Applying this conclusion, we deal with the unboundedness of solutions of Lienard equations with asymmetric nonlinearities.
TL;DR: In this paper, general conditions for perfect teleportation in the case where the Hilbert spaces involved have different dimensions are given and an explicit expression for the quantum channel associated with the standard teleportation protocol To with an arbitrary mixed state resource is given.
Abstract: General conditions are given in order to perform a perfect teleportation process in the case where the Hilbert spaces involved have different dimensions. An explicit expression is obtained for the quantum channel associated with the standard teleportation protocol To with an arbitrary mixed state resource. The transmission fidelity of the corresponding quantum channel is given.
TL;DR: In this paper, the difference discrete versions for the Euler-Lagrange cohomology and their preserving properties in both the Lagrangian and Hamiltonian formalisms for discrete mechanics and field theory were explored.
Abstract: In this second paper of a series of papers, we explore the difference discrete versions for the Euler-Lagrange cohomology and apply them to the symplectic or multisymplectic geometry and their preserving properties in both the Lagrangian and Hamiltonian formalisms for discrete mechanics and field theory in the framework of multi-parameter differential approach. In terms of the difference discrete Euler-Lagrange cohomological concepts, we show that the symplectic or multisymplectic geometry and their difference discrete structure-preserving properties can always be established not only in the solution spaces of the discrete Euler-Lagrange or canonical equations derived by the difference discrete variational principle but also in the function space in each case if and only if the relevant closed Euler-Lagrange cohomological conditions are satisfied.
TL;DR: In this article, the exchange bias field of NiFe/FeMn films with Ta/Cu buffer is lower than that of the films withTa buffer, which is mainly caused by the diffusion of Cu atoms through NiFe layer, which stayed at the interface of the NiFe or even intruded into FeMn layer.
Abstract: The films of NiFe/FeMn with Ta and Ta/Cu buffer layers were prepared by magnetron sputtering. Results show that the exchange bias field of NiFe/FeMn films with Ta/Cu buffer is lower than that of the films with Ta buffer. The crystalline texture, surface roughness and element distribution of these two sets of samples were examined, and there is no apparent difference for the texture and roughness. However, the segregation of Cu atoms on the surface of NiFe in the trilayer of Ta/Cu/NiFe has been observed by using the angle-resolved X-ray photoelectron spectroscopy. The decrease of the exchange bias field for NiFe/FeMn films with Ta/Cu buffer layers is mainly caused by the diffusion of Cu atoms through NiFe layer, which stayed at the interface of NiFe/FeMn film or even intruded into FeMn layer. The present results indicate that Cu segregation through NiFe layer should be suppressed in order to improve the exchange bias field in giant magnetoresistance spin valves with Cu spacer.
TL;DR: In this paper, the watershed in Miyun County was selected as the study region with a total area of 1400 km2, and four typical monitoring catchments and two experimental units were used to monitor the precipitation, runoff, sediment yield and pollutant loading related to various land uses.
Abstract: Nitrogen and phosphorus are the major nutrients to cause eutrophication to degrade water quality of the Miyun Reservoir, a very important drinking water source of Beijing, China, and they are mainly from non-point sources. The watershed in Miyun County was selected as the study region with a total area of 1400 km2. Four typical monitoring catchments and two experimental units were used to monitor the precipitation, runoff, sediment yield and pollutant loading related to various land uses in the meantime. The results show that the total nutrient loss amounts of TN and TP are 898.07 t/a, and 40.70 t/a, respectively, in which nutrients N and P carried by runoff are 91.3% and 77.3%, respectively. There is relatively heavier soil erosion in the northern mountain area whereas the main nutrient loss occurs near the northeast edge of the reservoir. Different land uses would influence the loss amounts of non-point source pollutants. The amount of nutrient loss from the agricultural land per unit is highest, that from forestry comes next and that from grassland is lowest. However, due to the variability of land use areas, agricultural land contributes a lot to TP and forestry lands to TN.