用时空线分析多普勒效应

采用描述波源运动，观察者运动及声波在静止空气中以声速传播的三组时空线，用几何方法导出多普勒公式，并通过时空线相交分析多普勒效应中观察者接收声波信号的时序及周期，着重讨论了一般文献中未曾涉及的不同条件下多普勒效应的结果及其物理意义。     

Optical Spectrogram Scope Using Time-to-Two-Dimensional Space Conversion and Interferometric Time-of-Flight Cross Correlation

We demonstrate a new tool called optical spectrogram scope for visualization of a spectrogram or a scalogram of optical ultrafast phenomena. The optical spectrogram scope is constructed on the basis of the time-to-two-dimensional-space conversion technique capable of converting a set of time-varying frequency distributions into two-dimensional spatial ones.     

Modeling biomembranes and red blood cells by coarse-grained particle methods

In this work, the previously developed coarse-grained (CG) particle models for biomembranes and red blood cells (RBCs) are reviewed, and the advantages of the CG particle methods over the continuum and atomistic simulations for modeling biological phenomena are discussed. CG particle models can largely increase the length scale and time scale of atomistic simulations by eliminating the fast degrees of freedom while preserving the mesoscopic structures and properties of the simulated system. Moreover, CG particle models can be used to capture the microstructural alternations in diseased RBCs and simulate the topological changes of biomembranes and RBCs, which are the major challenges to the typical continuum representations of membranes and RBCs. The power and versatility of CG particle methods are demonstrated through simulating the dynamical processes involving significant topological changes, e.g., lipid self-assembly vesicle fusion and membrane budding.     

自由质点测地线仿射参量时空坐标系

以时序t为自变量,可给出自由质点空间测地线的参数方程组{Xⁱ(t)},借助于仿射参量R(t)变换实现测地线微分方程的齐次化, 推导出仿射参量R满足的一阶微分方程、获得以有理数C_u为标志的序列解析解R.基于R定义平直四维坐标系{t,r,θ,φ}的空间距离单位,建立自由质点测地线仿射参量时空坐标系{t,ξ,θ,φ}.研究{t,ξ,θ,φ}中狭义相对论时空间隔模型度规张量g的对角化过程, 发现与对角化度规对应的特征量t₁(t,ξ), τ₁(τ,ξ),t_t(t,τ,ξ),τ_τ1(t,τ,ξ); 从而推出时空坐标系{t,ξ,θ,φ}维数小于4.     

时-空混和元与多辛

指出所谓多辛相当于时间-空间混和坐标内的分别离散的规则网格;而时-空混和元则不用对时间、空间分别离散,而是组成混和的时空混和有限元网格,更加灵活些。     

爆炸烟云扩散的时空分布模型及特性

针对爆炸烟云扩散的时空分布问题,在严格限定实验条件的前提下,设计并开展了不同当量、不同地面条件、不同炸药装置壳体厚度的3组TNT爆炸烟云扩散外场实验,获得了不同实验条件下烟云扩散时空分布数据,运用计算流体力学(computational fluid dynamics, CFD)对爆炸烟云的扩散过程进行了数值模拟。通过分析实验和数值模拟获取的烟云时空分布数据,得到了烟云扩散形态演变过程及浮力流场信息,确定了厚水泥地面条件和硬质地面条件下不同的爆炸烟云扩散高度分布模型。研究结果表明:采用实验与数值模拟相结合的方法来表征烟云时空分布模型是科学可行的,爆炸烟云高度随时间呈1/2次幂函数增长,烟云宽度短时间内几乎呈线性扩展,烟云温度随时间呈反比例函数衰减,爆轰地面条件和炸药装置壳体厚度对烟云扩散高度均有不同程度的影响。     

双掺杂LiNbO3:Fe:Mn体全息光栅的时空衍射特性

通过联立求解两中心带输运物质方程和双光束耦合波方程 ,建立了研究双掺杂LiNbO3:Fe :Mn晶体采用双色光记录光折变体全息的时空特性的动力学模型 .数值计算表明 ,该动态体全息光栅的时空衍射特性与晶体中的折射率光栅相对于干涉场的空间相移有关 ,该空间相移的取值范围为 (-π ,π) ,当空间相移的符号发生变化时 ,双光束之间的能量耦合方向也相应地发生反转 .给出了晶体内的等相位线和光强的重新分布 .     

Design of Header Recognition Filter for Binary Phase Shift Keying in Header Recognition Unit using Time-Space Conversion

Optical header recognition is one key function that enables ultrafast optical routing in photonic packet-switched networks. Especially, optical header recognition based on optical correlation processing has attracted much attention. Header signals using optical codes are decoded using optical correlation processing. We improve the decoding method for Binary Phase Shift Keying (BPSK) header signals in order to suppress crosstalk caused by matched filtering in the header recognition unit. We design a header recognition filter using the technique of a multiple-object discriminant filter (MODF). Results of preliminary experiments show that the designed header recognition filter can suppress crosstalk. The intensity ratio of correlation signals of a target header signal to non-target ones is higher than 1.95 : 1 in case of 4-bits BPSK header signals.     

A NON－INCREMENTAL TIME－SPACE ALGORITHM FOR NUMERICAL SIMULATION OF FORMING PROCESS

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思维的多时空模型初探

给出一种拓扑意义上的记忆多空间模型,探讨了思维的多时空性,提出了思维的多时空模型,阐述了建立在思维多时空上的思维压迫机制等问题,并用思维的多时空模型解释了某些思维现象和规律。