Size Effect of the Immediate Surround for the Border between the Natural and Unnatural Object Color Appearance

The border luminance of the test stimulus between the natural and unnatural object color, y_ynB_u was obtained for different spatial sizes of the immediate surround to prove that _nB_u can be determined based on a new recognized visual space of illumination (RVSI) that is assumed to be constructed for the immediate surround separately from the RVSI for the subjects room itself. The _nB_u of five test stimuli were determined for six different sizes covering from zero to 1866 cm² with four different lightnesses, N4, N6 and N8, while keeping the room illuminance constant at 100 or 600 lx. The results showed that luminance of the border _nB_u gradually decreased as the size of the immediate surround was increased and that the decrease was larger for immediate surround with lower lightness. The results were interpreted as showing a new RVSI constructed for the spatial extent of the immediate surround of the test stimulus, and the RVSI was more completely constructed for larger spatial size of the immediate surround. © 2005 The Optical Society of Japan     

具有空间重叠性和时间同步性的双波长TEA CO2激光器研究

提出了一种改进的双波长TEA CO2激光器,不仅具有良好的空间重叠性,而且具有比较理想的时间同步性.该激光器由两个空间上部分重叠的光栅和一个锗镜构成光栅-平面腔,两个光栅前后放置,相互利用,共同建立双频振荡,由锗镜输出双波长激光.通过改变两光栅的有效面积,对两输出脉冲空间重叠性进行调节;通过改变两光栅的角度形成的失谐缩小输出脉冲的时间间隔,达到时间同步性.实验表明,可以在空间重叠性的基础上使两输出脉冲的时间间隔由1 000 ns调整到200 ns.     

NASA lasers probe planets

NASA is engaged in monitoring the health of planet Earth and exploring the other planets. For the former, global measurements of critical Earth parameters including ice sheet thickness, greenhouse gases, oxygen, wind velocity, and aerosols, are required. Highly specialized lasers, sometimes at new laser wavelengths, are needed to measure these variables. There are three approaches for this laser development being pursued by NASA. First, rather than seeking new lasers employing an empirical approach, a quantum mechanical model is used to predict better new lasers. Second, where lasers exist but the wavelength is not quite right, a technique referred to as compositional tuning was developed. Third, innovative laser designs are devised to produce laser sources at the requisite wavelengths.     

空间目标光学特性模拟实验研究

 通过不同材料、形状的空间目标模拟实验测量,研究了几种简单形状目标和卫星缩比模型的光学特性。结果表明：光源 目标 探测器的位置对目标的光学特性起决定作用,对于球体和柱体目标来说,光源和探测器的相位角是影响接收到光辐射的主要因素,而对于立体状目标,它的光学特性则与特定的入射角和观测角有关;对静止卫星而言,其光学特性主要受太阳能电池板对地夹角和观测面积的影响。该研究有助于实际观测数据反演空间目标的姿态,便于对空间目标特性数据进行归类和分发。     

Performance enhancement on mechanical and electrical effects for on-line fiber-optic bending loss measurement

For an automatic testing of the fiber bending loss parameter, we proposed an on-line fiber optic bending loss measurement system. Many impact factors from the supporting systems, free space coupling alignment, external spatial perturbation device and the other automatic testing systems may degrade the on-line fiber-optic bending loss measurement system. We reduce those impact factors and show the mechanical and electrical improvement in this paper. The accuracy can be improved by 3–5 dB for the proposed on-line bending loss measurement system. Development of an on-line fiber-optic bending loss measurement system can provide a fast-checking solution for jump-line quality improvement on fiber-from-the-desk (FFTD) access network.     

Might Dark Matter and Energy be Intrinsic Properties of?Space?

It is shown that if a volume element V, of space is assumed to have intrinsic energy E, then basic principles of mechanics, thermodynamics and special relativity lead to the equation of state: E=pV, where p is the pressure. When this equation of state is incorporated in the Einstein equations it leads to the prediction that the orbital speed of matter circling a visible galaxy embedded in a spherical galactic halo should be relativistic, in disagreement with observations. However, it also leads directly to the interesting notion that the inertial mass of such a medium can be understood as a resistance to being compressed via Lorentz contraction. It is then shown that the mathematical structure of thermodynamics suggests another plausible definition of pressure if we allow for the possibility that the intrinsic energy of spacetime may not be described by the same work-energy relationship as ordinary matter. This additional possibility leads to the equation of state: E=−pV. While both of these equations of state describe forms of energy that are quite unlike ordinary energy, neither alone is able to account for observed rotational velocity curves of matter orbiting visible galaxies. Therefore, the possibility that space has two distinct components of energy is investigated. This results in a plausible, two-component equation of state in which the former equation of state is tentatively identified as the “dark matter” (DM) component, the latter as the “dark energy” (DE) component. The effective equation of state of space, accounting for the presence of both components, may then be written in the form: p=w ε, where ε is the total energy density, p the total pressure, and w represents the fractional excess of DM over DE (and therefore satisfies: −1≤w≤+1). Given the wide range of possible spacetime properties implied by this equation it appears to be a viable candidate for explaining observations presently attributed to the presence of both DM and DE. Specifically, the static, spherically symmetric solution of Einstein’s field equations, neglecting effects of ordinary matter, predicts the inverse r ² distribution of intrinsic space energy required to explain observed constant rotational velocity curves for matter in circular orbits around visible galaxies embedded within spherically symmetric galactic halos. The proposed equation of state is also capable of describing regions of space undergoing accelerated expansion as regions where DE is dominant (i.e., w<−1/3).     

直线阵光学综合孔径成像中的子孔径尺寸效应

光学综合孔径阵列中的子孔径的位置和直径的大小对成像质量有着重要的影响。详细分析了几种不同优化排列的光学综合孔径直线阵列的无像差点扩展函数、光学传递函数和衍射成像特性．结果表明,子孔径的位置不同．光学传递函数的空间频率覆盖有很大的差异。增大子孔径的直径可以增大空间频率覆盖程度．但子孔径直径过大时义会产生空间频率冗余度和增加制造成本。直线阵光学综合孔径的衍射成像是多重像,子孔径直径的增大还可以减小重影的程度,提高成像质量。结果说明,在进行光学综合孔径阵列优化排列时必须考虑子孔径的直径大小这个重耍的因素。     

无箔二极管强流电子束空间密度分布初步研究

通过在强磁场条件下,利用环形刀口石墨阴极(刀口尺寸38~39mm)开展电子束轰击收集极内表面铜箔和垂直轰击金属靶片实验,对无箔二极管中电子束的空间密度分布进行了初步研究,并对其产生原因进行了分析。研究结果表明,电子束径向分布在37.2~40.2mm,存在密度较高区域(38.8~39.4mm)和密度最大值点(39.2mm),且均偏向于阴极外侧。无箔二极管环形阴极爆炸发射产生电子束的径向密度分布可用偏态分布近似。     

Low dimensional chaos in the AT and GC skew profiles of DNA sequences

This paper investigates the existence of low-dimensional deterministic chaos in the AT and GC skew profiles of DNA sequences. It has taken DNA sequences from eight organisms as samples. The skew profiles are analysed using continuous wavelet transform and then nonlinear time series methods. The invariant measures of correlation dimension and the largest Lyapunov exponent are calculated. It is demonstrated that the AT and GC skew profiles of these DNA sequences all exhibit low dimensional chaotic behaviour. It suggests that chaotic properties may be ubiquitous in the DNA sequences of all organisms.     

Background Independent Quantum Mechanics, Classical Geometric Forms and Geometric Quantum Mechanics—I

The geometry of the symplectic structures and Fubini-Study metric is discussed. Discussion in the paper addresses geometry of Quantum Mechanics in the classical phase space. Also, geometry of Quantum Mechanics in the projective Hilbert space has been discussed for the chosen Quantum states. Since the theory of classical gravity is basically geometric in nature and Quantum Mechanics is in no way devoid of geometry, the explorations pertaining to more and more geometry in Quantum Mechanics could prove to be valuable for larger objectives such as understanding of gravity.