国外红外光谱连续变焦成像系统的研究进展

相比红外光谱定焦成像系统和红外光谱两档成像系统而言,红外光谱连续变焦成像系统具有连续变化的视场,可对目标进行连续成像,是未来红外光谱成像技术的发展方向。为了提高红外光谱连续变焦成像系统的探测性能、实现低成本、良好的消热差性能,近年来国外开发了一些新技术。概述了国外红外材料、红外探测器、冷光阑等方面的新技术,及这些新技术在红外光谱变焦成像系统中的具体应用,列举了使用新型红外材料实现消热差的红外目标探测连续变焦系统,中波红外、长波红外光谱双波段连续变焦系统,高变焦比红外光谱连续变焦系统,应用可变冷光阑技术的红外光谱连续变焦系统设计实例,作为国内红外光谱变焦成像系统发展的借鉴。     

Causally continuous spacetimes

Causally continuous general relativistic spacetimes are defined and analyzed. In a causally continuous spacetime, the past and future of a local observer behave continuously under small perturbations of the metric or small changes in his location. Causally simple spacetimes are causally continuous; causally continuous spacetimes are causally stable. Possible reasons for taking causal continuity as a basic postulate in macrophysics are briefly discussed.     

Inverse halftoning based on sparse representation

This Letter proposes a novel inverse halftoning algorithm that introduces a way of generating a pair of binary and continuous dictionaries optimized to a training image database composed of many pairs of halftoned patches and the corresponding continuous patches. The experiment results show that the two created binary and continuous dictionaries can be nicely used with the estimated sparse coefficients to represent an unknown continuous image with less noise and fine details from an input halftoned image.     

LED红蓝光连续光照及其光强对生菜生长及矿质元素吸收的影响

红光和蓝光是植物进行光合作用和光形态建成的主要光谱,且红蓝LED是植物工厂光源的发展趋势。因此为实现连续光照在植物工厂中的应用,植物对红蓝光谱连续光照的响应特征及其机理亟待探究。在环境可控的植物工厂内,应用ICP-AES技术,研究了红蓝光谱下连续光照及其光强对生菜生长和矿质元素吸收的影响。该研究共包含两个试验,试验一设置了常规光照（12 h/12 h）和连续光照（24 h/0 h）2个光照处理及5个生菜品种,试验二设置了5个连续光照光强处理（80,120,160,200和240 μmol·m-2·s-1）。结果表明,连续光照30 d内生菜的干重和干物质含量能够持续显著提高,且表现为随连续光照光强增加而升高的趋势。但地上部鲜重仅在连续光照的前15 d得到显著提高,并随光强增加而升高。而连续光照30天时,连续光照对生菜地上部鲜重无显著促进作用,甚至显著降低意大利生菜的地上部鲜重。相比常规光照,连续光照30 d显著降低了生菜的Ca,Mg,Fe,Mn,Cu和Zn含量,但这些元素积累量均有所增加。不同光强下,生菜Ca,Fe,Cu和Zn的含量随光强增加而降低,其中Ca和Fe积累量随光强增强而升高,Cu和Zn积累量不受光强影响。Mg元素含量和积累量均随光强增强先升高后降低。Mn元素含量受光强影响不显著,但积累量随光强增大而升高。此外,连续光照30 d生菜叶片出现褪绿萎黄的伤害症状,且伤害症状随光强增加而逐渐加重,说明矿质元素含量的降低在一定程度上加剧了连续光照伤害。综上所述,15 d连续光照能够显著提高生菜产量。全生长期（30 d）连续光照虽能促进生菜干物质累积,但对产量无显著促进作用,同时还会导致生菜矿质元素含量的降低及叶片伤害。相对而言,低光强（80和120 μmol·m-2·s-1）连续光照对生菜无明显伤害作用,且矿质元素含量相对较高,但不能提高产量。研究结果表明短期红蓝光连续光照更适宜应用于在植物工厂生菜栽培,能够获得相比能量投入更高的产量。矿质元素含量的降低可能是长期连续光照伤害的机制之一。     

Simulations of continuous/cluster-pinned recording media

Continuous/cluster-pinned recording media, consisting of cuboid clusters of various sizes exchange-coupled to a continuous hard layer, were modelled to investigate their suitability for high density data storage. The pinning field due to the clusters was determined by modelling domain-wall motion in the continuous layer. Larger clusters, a thinner continuous layer and increased saturation magnetisation of the clusters all increased the pinning field. Simulations of recording demonstrated the feasibility of using domain-wall pinning to control the written bit size in continuous media.     

Groups without nontrivial pseudocharacters

As is well known, the group SL(2, ? _p ) has no nontrivial continuous finite-dimensional representations. It is proved that this group has no nontrivial continuous finite-dimensional pseudorepresentations either. This helps to prove that the split simple algebraic groups over totally disconnected locally compact fields of characteristic zero have neither (not necessarily continuous) nontrivial pseudocharacters nor nontrivial continuous finite-dimensional pseudorepresentations.     

Path integrals for diffusion processes in Riemannian spaces

The Onsager-Machlup lagrangian for general continuous Markov processes in curved spaces will be derived invoking (i) continuous and differentiable trajectories, (ii) a Fourier series analysis of stochastic paths and (iii) the principle of general covariance. No discretization rule will be required in order to put the continuous action on a lattice.     

直接冷却高温超导电流引线的有限时间热力学分析

用有限时间热力学最小熵产率的方法对连续冷却电流引线进行优化 ,比较高温超导电流引线连续冷却和冷端冷却两种直接冷却方式。优化后的连续冷却电流引线上热流量随温度的降低而减小 ,温度在高温段变化较快 ,熵产率小。冷端冷却时在整个引线上热流量分布相同 ,温度在低温端变化较明显 ,熵产率较大。优化后的连续冷却方式比冷端冷却方式合理。     

Four-mode coherent-entangled state and its application

A new kind of four-mode continuous variable coherent-entangled state is proposed in the Fock space by using the technique of integration within an ordered product, which exhibits both the properties of a coherent state and an entangled state, and spans a complete and orthonormal representation. The conjugate state of the four-mode continuous variable coherent-entangled state is derived by using the Fourier transformation. Moreover, a simple experimental protocol of generating a four-mode continuous variable coherent-entangled state is proposed by using beam splitters. As applications of this four-mode continuous variable coherent-entangled state, a four-mode entangled state and a four-mode squeezing-Fresnel operator are constructed.     

Qualitative and numerical study of bianchi IX models

The continuous evolution of the Mixmaster universe toward the cosmological singularity contains features that differ substantially from its discrete counterpart. We examine here the determination and interpretation of the Liapunov exponent of the continuous orbit. It is briefly mentioned that this is not the only aspect of the Mixmaster dynamics to be affected when we switch from continuous to discrete mode of evolution.     

Perturbation approach to plasma oscillations

It is shown that the complete spectrum, continuous as well as discrete, and corresponding eigenfunctions of the Vlasov operator can be obtained by a single perturbation procedure from the purely continuous spectrum and corresponding eigenfunctions of the free-streaming operator. In addition we present an alternative definition of the eigenfunctions and show that the problem of normalizing the continuous eigenmodes is thus solved automatically.     

Continuous Selections of Solution Sets of Lipschitzian Quantum Stochastic Differential Inclusions

A multifunction associated with the set of solutions of Lipschitzian quantum stochastic differential inclusion (QSDI) admits a selection continuous from some subsets of complex numbers to the space of the matrix elements of adapted weakly absolutely continuous quantum stochastic processes. In particular, the solution set map as well as the reachable set of the QSDI admit some continuous representations.     

Improved discrete fractional Fourier transform

The fractional Fourier transform is a useful mathematical operation that generalizes the well-known continuous Fourier transform. Several discrete fractional Fourier transforms (DFRFT's) have been developed, but their results do not match those of the continuous case. We propose a new DFRFT. This improved DFRFT provides transforms similar to those of the continuous fractional Fourier transform and also retains the rotation properties.     

连续辐射谱法计算闪电通道电子温度

基于连续辐射理论,得到连续辐射能量与等离子体电子温度的关系式。依据青海地区一次强地闪回击过程的光谱,从中分离出连续辐射强度,对其吸收特征进行分析以减小吸收带来的计算误差。通过对连续谱强度的曲线拟合得到闪电放电通道电子温度,温度峰值为29 800 K,温度下限为16 200 K,由同一波段光谱中的O Ⅰ线和N Ⅱ线分别拟合了电子温度。比较结果发现：由连续辐射得到的闪电通道电子温度从高温向低温过渡,高温值与离子线信息获得的闪电核心电流通道处的温度符合较好,而低温则与原子线计算的结果接近,反映了外围电晕发光通道的温度。所以,依据连续谱得到的结果能更全面地反映温度沿通道径向的分布。对于闪电热等离子体通道,连续谱法提供了一种计算闪电放电通道电子温度的新途径,对地闪回击研究有一定的意义。     

Localization of intermittent sound with head movement: Basic study on optimum temporal characteristics of acoustic guide signals

Acoustic guide signals for visually impaired persons sometimes do not include the high frequency components necessary for front–back discrimination in sound localization. However, head movement makes this discrimination possible, even in such cases. This paper clarifies the necessary duration of continuous sound to be able to use head movement effectively in sound localization and whether or not, the effect of head movement appears in sound localization of intermittent sound used in place of continuous one. Head movement is effective for sound localization when the duration of continuous sound exceeds 800 ms, and persists even if the sound is intermittent rather than continuous.     

Regularity and other properties of absolutely continuous invariant measures for the quadratic family

In the current paper we study in more detail some properties of the absolutely continuous invariant measures constructed in the course of the proof of Jakobson's Theorem. In particular, we show that the density of the invariant measure is continuous at Misiurewicz points. From this we deduce that the Lyapunov exponent is also continuous at these points (our considerations apply just to the parameters constructed in the proof of Jakobson's Theorem). Other properties, like the positivity of the Lyapunov exponent, uniqueness of the absolutely continuous invariant measure and exactness of the corresponding dynamical system, are also proved.This paper was written during the author's stay at the IAS while supported by NSF grant DMS-860 1978     

Phase Transitions for Uniformly Expanding Maps

Given a uniformly expanding map of two intervals we describe a large class of potentials admitting unique equilibrium measures. This class includes all Hölder continuous potentials but goes far beyond them. We also construct a family of continuous but not Hölder continuous potentials for which we observe phase transitions. This provides a version of the example in (9) for uniformly expanding maps.     

保护有效结构的整型/连续变量分离优化策略改进RWCE算法

强制进化随机游走算法优化换热网络时,连续变量进化阶段产生年综合费用更低的结构会被整型变量进化操作所破坏,导致连续变量进化后形成的结构未能充分发挥优势,制约了连续变量进化.本文提出保护有效结构的整型/连续变量分离优化策略,将连续变量进化与整型变量进化两个阶段的结构费用分别进行判断,从而保护具有发展潜力的结构,使年综合费用...     

An analysis of maximum clique formulations and saturated linear dynamical network

Several formulations and methods used in solving an NP-hard discrete optimization problem, maximum clique, are considered in a dynamical system perspective proposing continuous methods to the problem. A compact form for a saturated linear dynamical network, recently developed for obtaining approximations to maximum clique, is given so its relation to the classical gradient projection method of constrained optimization becomes more visible. Using this form, gradient-like dynamical systems as continuous methods for finding the maximum clique are discussed. To show the one to one correspondence between the stable equilibria of the saturated linear dynamical network and the minima of objective function related to the optimization problem, La Salle's invariance principle has been extended to the systems with a discontinuous right-hand side. In order to show the efficiency of the continuous methods simulation results are given comparing saturated the linear dynamical network, the continuous Hopfield network, the cellular neural networks and relaxation labelling networks. It is concluded that the quadratic programming formulation of the maximum clique problem provides a framework suitable to be incorporated with the continuous relaxation of binary optimization variables and hence allowing the use of gradient-like continuous systems which have been observed to be quite efficient for minimizing quadratic costs.     

Continuous Spectrum of Automorphism Groups and the Infraparticle Problem

This paper presents a general framework for a refined spectral analysis of a group of isometries acting on a Banach space, which extends the spectral theory of Arveson. The concept of a continuous Arveson spectrum is introduced and the corresponding spectral subspace is defined. The absolutely continuous and singular-continuous parts of this spectrum are specified. Conditions are given, in terms of the transposed action of the group of isometries, which guarantee that the pure-point and continuous subspaces span the entire Banach space. In the case of a unitarily implemented group of automorphisms, acting on a C*-algebra, relations between the continuous spectrum of the automorphisms and the spectrum of the implementing group of unitaries are found. The group of spacetime translation automorphisms in quantum field theory is analyzed in detail. In particular, it is shown that the structure of its continuous spectrum is relevant to the problem of existence of (infra-)particles in a given theory.