航天器在轨角动量演化及卸载策略研究

为了减少在轨卫星的喷气卸载次数,节省推进剂,延长卫星的使用寿命,对地球静止轨道零动量卫星和V型轮偏置动量卫星的角动量管理问题进行了研究.根据卫星角动量累计演化特点,给出两类卫星的角动量管理方法,提出优化的喷气卸载策略.基于上述研究对在轨卫星非正常卸载情况进行了理论分析与仿真验证,提出解决措施.在轨试验表明,基于优化的喷气卸载策略进行卫星角动量管理,可明显减少卫星的卸载次数,验证了策略的正确性.

黑龙江国有林区林业产业生态位演化机理及动力评价研究

描述了黑龙江国有林区林业产业生态系统的空间结构和功能结构,建立了林业产业生态位的因子模型,阐释了自然选择、人工选择和生态位构建对国有林区林业产业生态位演化的推动机制,并以黑龙江12家区域代表性较强的国有森工林业局为分析对象,综合评价了黑龙江国有林区林业产业生态位演化动力。研究结果表明:第一,从整体上看,黑龙江省国有林区林业产业生态位演化惯量相对较低,但产业生态位演化动量显著较高;第二,从生态元上看,国有森工林业局的生态位演化动量基本持平,但演化惯量水平差异较大。

耗散型随机非线性薛定谔方程的共形动量

在本文中,介绍了耗散型随机非线性薛定谔方程,它是通过对经典薛定谔方程进行修正得到的,证明了它具有随机共形动量演化规律,并研究了耗散型随机非线性薛定谔方程的一种新的离散数值格式,离散梯度格式,众所周知,构造出可以保持原始系统物理性质的数值格式具有重要意义,因此接下来我们研究了随机共形动量演化规律在离散梯度格式下是否成立,通过证明它是成立的。

Dynamic Visualization Approach of the Multiphase Flow Using Electrical Capacitance Tomography

Identifying the flow patterns is vital for understanding the complicated physical mechanisms in multiphase flows.For this purpose,electrical capacitance tomography(ECT) technique is considered as a promising visualization method for the flow pattern identification,in which image reconstruction algorithms play an important role.In this paper,a generalized dynamic reconstruction model,which integrates ECT measurement information and physical evolution information of the objects of interest,was presented.A generalized objective functional that simultaneously considers the spatial constraints,temporal constraints and dynamic evolution information of the objects of interest was proposed.Numerical simulations and experiments were implemented to evaluate the feasibility and efficiency of the proposed algorithm.For the cases considered in this paper,the proposed algorithm can well reconstruct the flow patterns,and the quality of the reconstructed images is improved,which indicates that the proposed algorithm is competent to reconstruct the flow patterns in the visualization of multiphase flows.

Soliton Motion in （1＋1）-Dimensions

By using the variable separation approach, which is based on the corresponding Backlund transformation, new exact solutions of a （1＋1）-dimensional nonlinear evolution equation are obtained. Abundant new soliton motions of the potential field can be found by selecting appropriate functions.

光晶格动量依赖偶极势中原子运动

研究了原子在光晶格偶极势依赖原子动量情况下的运动,特别考虑了偶极势对原子动量的依赖特性.对动量和位置的方差研究表明,原子的动量方差呈现压缩性质,位置方差呈现放大性质.据此我们预言光晶格动量依赖偶极势中的单粒子态可能接近动量压缩线态.研究结果还表明,红失谐情况下原子的动量演化可分为三个过程:第一个过程是慢减速过程,初始动量较大的原子,动量以近似阻尼振荡的形式衰减;第二个过程是快减速过程,当动量被减速到接近到光子动量时,动量迅速减小到hˉk(Ω/γ)2,其中hˉk为光子动量,Ω为拉比频率,γ为原子波函数衰减函数;第三个过程是原子被囚禁过程,当原子动能被降低到小于势井深度时,原子被囚禁在晶格波腹附近.

Modeling Evolution of Weighted Clique Networks

We propose a weighted clique network evolution model, which expands continuously by the addition of a new clique （maximal complete sub-graph） at. each time step. And the cliques in the network overlap with each other. The structural expansion of the weighted clique network is combined with the edges＇ weight and vertices＇ strengths dynamical evolution. The model is based on a weight-driven dynamics and a weights＇ enhancement mechanism combining with the network growth. We study the network properties, which include the distribution of vertices＇ strength and the distribution o~ edges＇ weight, and find that both the distributions follow the scale-free distribution. At the same time, we also find that the relationship between strength and degree of a vertex are linear correlation during the growth of the network. On the basis of mean-field theory, we study the weighted network model and prove that both vertices＇ strength and edges＇ weight of this model follow the scale-free distribution. And we exploit an algorithm to forecast the network dynamics, which can be used to reckon the distributions and the corresponding scaling exponents. Furthermore, we observe that mean-field based theoretic results are consistent with the statistical data of the model, which denotes the theoretical result in this paper is effective.

Direct dynamical characterization of higher-order topological phases with nested band inversion surfaces

Higher-order topological phases(HOTPs) are systems with topologically protected in-gap boundary states localized at their ed à nT-dimensional boundaries, with d the system dimension and n the order of the topology. This work proposes a dynamics-based characterization of one large class of Z-type HOTPs without specifically relying on any crystalline symmetry considerations. The key element of our innovative approach is to connect quantum quench dynamics with nested configurations of the socalled band inversion surfaces(BISs) of momentum-space Hamiltonians as a sum of operators from the Clifford algebra(a condition that can be partially relaxed), thereby making it possible to dynamically detect each and every order of topology on an equal footing. Given that experiments on synthetic topological matter can directly measure the winding of certain pseudospin texture to determine topological features of BISs, the topological invariants defined through nested BISs are all within reach of ongoing experiments. Further, the necessity of having nested BISs in defining higher-order topology offers a unique perspective to investigate and engineer higher-order topological phase transitions.

Dynamic and steady control of quantum coherence in photonic crystals via the Zeeman effect

The dynamic evolution of a multi-level atom in the three-dimensional photonic crystal under an applied magnetic field is investigated.By combining the Zeeman effect with the photonic band gap effect,the dynamic quantum superposition states and steady quantum coherent trapping states of the atom can be flexibly controlled.This paves the way for coherent manipulation of quantum states in the solid-state system,which has important applications in quantum information processing.

Dynamics of Information Entropies of Atom-Field Entangled States Generated via the Jaynes-Cummings Model

In this paper we have studied the dynamical evolution of Shannon information entropies in position and momentum spaces for two classes of（nonstationary） atom-field entangled states,which are obtained via the JaynesCummings model and its generalization.We have focused on the interaction between two- and（1）-type three-level atoms with the single-mode quantized field.The three-dimensional plots of entropy densities in position and momentum spaces are presented versus corresponding coordinates and time,numerically.It is observed that for particular values of the parameters of the systems,the entropy squeezing in position space occurs.Finally,we have shown that the well-known BBM（Beckner,Bialynicki-Birola and Mycielsky） inequality,which is a stronger statement of the Heisenberg uncertainty relation,is properly satisfied.

Quantum field entropy of the system with interaction between moving Bell-state atoms and coherent light field

The field entropy of the system with two moving atoms interacting with the coherent state is investigated by means of the full quantum theory. Under the different initial states with two atoms, the influences of the light field intensity and the atomic motion on the field entropy are discussed. The results indicate that the motion of the atoms leads to strict periodicity in the field entropy evolution. When the two atoms are in the Bell state ｜β11〉 initially, the system is in a completely disentangled state. For the atoms initially at other Bell states, the field periodically entangles with the atoms.

Quantum Fisher Information of Driven Multi-particle Systems in Structured Bosonic Reservoirs

We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.

Statistical physics in QCD evolution towards high energies

The concepts and methods used for the study of disordered systems have proven useful in the analysis of the evolution equations of quantum chromodynamics in the high-energy regime: Indeed, parton branching in the semi-classical approximation relevant at high energies and at a fixed impact parameter is a peculiar branching-diffusion process, and parton branching supplemented by saturation effects(such as gluon recombination) is a reaction-diffusion process. In this review article, we first introduce the basic concepts in the context of simple toy models, we study the properties of the latter, and show how the results obtained for the simple models may be taken over to quantum chromodynamics.

Diagnosing ΛHDE model with statefinder hierarchy and fractional growth parameter

Recently, a new dark energy model called AHDE was proposed. In this model, dark energy consists of two parts： cosmological constant A and holographic dark energy （HDE）. Two key parameters of this model are the fractional density of cosmological constant Ω2A0, and the dimensionless HDE parameter c. Since these two parameters determine the dynamical properties of DE and the destiny of universe, it is important to study the impacts of different values of ΩA0 and c on the AHDE model. In this paper, we apply various DE diagnostic tools to diagnose AHDE models with different values of ΩA0 and c; these tools include statefinder hierarchy {S3^（1） ,S4（1）fractional growth parameter E, and composite null diagnostic （CND）, which is a combination of{S3（1）,S4（1）} and E. We find that： （1） adopting different values of ΩA0 only has quantitative impacts on the evolution of the AHDE model, while adopting different c has qualitative impacts; （2） compared with S（1）, S（41） can give larger differences among the cosmic evolutions of the AHDE model associated with different ΩA0 or different c; （3） compared with the case of using a single diagnostic, adopting a CND pair has much stronger ability to diagnose the AHDE model.