具有一般广义阻尼力和强迫周期力的相对转动非线性动力学模型的周期解

研究了一类具有一般广义阻尼力和强迫周期力项的相对转动非线性动力学模型的周期解问题.讨论了对应自治系统的周期解问题.运用Mawhin重合度理论,得到了该模型的周期解存在惟一性结果,推广了已有的结果,并且列举了具体的例子来说明结果的新颖性.     

Non-Gaussianity and decoherence of generalized photon-added coherent state as a Hermite-excited coherent state

Generalized photon-added coherent state (GPACS) is obtained by repeatedly acting the combination of Bose creation and annihilation operations on the coherent state. It is found that GPACS can be regarded as a Hermite-excited coherent state due to its normalization factor related to a Hermite polynomial. In addition, we adopt the Hilbert-Schmidt distance to quantify the non-Gaussian character of GPACS and discuss the decoherence of GPACS in dissipative channel by studying the loss of nonclassicality in reference of the negativity of Wigner function.     

Synthesis and structural characterization of a novel two-dimensional 3d-4f heterometallic coordination framework based on pentanuclear lanthanide cluster

A novel 3d-4f heterometallic coordination polymer, {[Tm₅(μ₃-OH)₂(BDC)₆(IN)₂Cu(H₂O)₂]·(H₂O)₃}_n (1) [BDC = benzene-1,2-dicarboxylate, IN = isonicotinate], has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, FTIR, elemental analysis, powder X-ray diffraction and thermogravimetric analysis. The compound crystallizes in monoclinic system, space group P2₁/c (No. 14), a = 13.7302(5) Å, b = 23.5428(3) Å, c = 21.5789(2) Å, β = 91.491(3)°, V = 6973.0(3) ų, and Z = 4. The structure exhibits unusual two-dimensional Tm-carboxylate layer, which is constructed from the expansion of novel pentanuclear {Tm₅} clusters. More interestingly, the heterometallic Cu(I) ions were successfully planted into such Ln-carboxylate layer by the bifunctional IN bridging ligands, resulting in the formation of an unprecedented 2D heterometallic lanthanide-transition-metal framework.     

Saturation molalities and standard molar enthalpies of solution of α-d-xylose(cr) in H2O(l); standard molar enthalpies of solution of 1,4-β-d-xylobiose(am), and 1,4-β-d-xylotriose(am) in H2O(l)

The saturation molality of α-d-xylose(cr) in water was measured by using HPLC and is m(sat) = (8.43 ± 0.42) mol · kg⁻¹ at T = 298.15 K. It was also established that the anhydrous form of α-d-xylose(cr) is the crystalline form that is in equilibrium with the aqueous solution at T = 298.15 K. Solution calorimetry was used to measure the following standard molar enthalpies of solution at T = 298.15 K: ${\mathrm{\Delta }}_{\text{sol}}{H}_{\text{m}}^{\circ }$ = (12.10 ± 0.12) kJ · mol⁻¹ for α-d-xylose(cr); ${\mathrm{\Delta }}_{\text{sol}}{H}_{\text{m}}^{\circ }$ = −(8.1 ± 2.7) kJ · mol⁻¹ for 1,4-β-d-xylobiose(am); and ${\mathrm{\Delta }}_{\text{sol}}{H}_{\text{m}}^{\circ }$ = −(24.1 ± 6.4) kJ · mol⁻¹ for 1,4-β-d-xylotriose(am). It was observed that both 1,4-β-d-xylobiose(am) and 1,4-β-d-xylotriose(am) were amorphous substances and that they form thick gels in water in which no solid phase is present. Consequently, it is not possible to measure m(sat) for these two substances. All substances were carefully characterized by using both HPLC and Karl Fischer analysis. NMR was used to measure the anomeric purity of the α-d-xylose(cr). Thermodynamic network calculations were used to calculate standard molar formation properties for the aforementioned substances.     

一个解大规模无约束优化问题的全局梯度法(英文)

本文提出一种新的解大规模无约束优化问题的全局收敛的梯度法.新算法沿着负梯度方向选择步长,而初始步长根据目标函数的海赛矩阵的近似数量矩阵来确定.理论上证明了新算法产生的点列的每个聚点都是稳定的,数值试验表明新算法是可靠且有效的.     

Hermitian Operators Conjugate to Two-Mode Number-Difference Operator Studied in Entangled State Representation

In similar to the derivation of phase angle operator conjugate to the number operator by Arroyo Carrasco-Moya Cessay we deduce the Hermitian phase operators that are conjugate to the two-mode number-difference operator and the three-mode number combination operator. It is shown that these operators are on the same footing in the entangled state representation as the one of Turski in the coherent state representation.     

Transient chaos in smooth memristor oscillator

This paper presents a new smooth memristor oscillator, which is derived from Chua's oscillator by replacing Chua's diode with a flux-controlled memristor and a negative conductance. Novel parameters and initial conditions are dependent upon dynamical behaviours such as transient chaos and stable chaos with an intermittence period and are found in the smooth memristor oscillator. By using dynamical analysis approaches including time series, phase portraits and bifurcation diagrams, the dynamical behaviours of the proposed memristor oscillator are effectively investigated in this paper.     

基于磁/惯性传感器旋转弹体定姿的Kalman滤波器设计

微惯性传感器精度较低,其漂移会引起很大的姿态误差,不能提供长时间稳定姿态;磁传感器组合的姿态角误差不随时间累积但姿态角更新速度慢。针对这一问题提出了利用磁/惯性传感器构建低成本姿态探测系统的方案,设计了Kalman滤波器融合二者信息——以磁传感器解算的姿态角和等效旋转矢量法解算的姿态角之差作为观测量,以惯性传感器的漂移和姿态误差角作为状态变量,整个解算过程无需使用地磁场强度。仿真结果表明了该算法的有效性,二者组合定姿可实现高精度的姿态测量。     

Three-Mode Cyclic Squeezed States Constructed via EPR Entangled State

We construct the three-mode cyclic squeezed states and analyze its squeezing property by using the technique of integration within an ordered product of operators and the natural representation of the two-mode squeezing operator in the Einstein-Podolsky-Rosen entangled state basis.     

Energy Shift Caused by Non-isotropy of 2-Dimensional Anisotropic Quantum Dot in Presence of Uniform Magnetic Field

Based on the squeezing mechanism in quantum dots in the presence of uniform magnetic field, we derive the energy shift caused by the non-isotropy of 2-dimensional anisotropic quantum dot. We also study sudden squeezing of the size of the quantum dot. The whole discussion is proceeded smoothly by virtue of the entangled state representation.