航天光学遥感器在轨调制传递函数神经网络评价方法

通过对航天光学遥感器在轨调制传递函数模型和遥感图像的分析,找出遥感图像中与调制传递函数有关的特征信息,采用神经网络为工具,完成利用遥感器传输下来的任意一幅地面景物图像进行调制传递函数的评价。首先模拟出包含不同调制传递函数等级的遥感图像,组成训练样本集,再从图像中分别提取出直接与调制传递函数有关的特征参量和与景物结构有关的特征参量,作为神经网络的输入,网络通过对训练样本集中模拟出的大量调制传递函数已知的遥感图像训练后,当再次输入一幅调制传递函数未知的遥感图像时,便能够正确估计出其调制传递函数值。这种方法不需要在地面铺设靶标或预先获得调制传递函数已知的同一地面景物的航空图像作为参考,只需获得任意一幅地面景物图像即可完成对遥感器调制传递函数的评价。实验结果表明,当不考虑噪声对调制传递函数的影响时,对调制传递函数的评价误差约为6%,而在考虑噪声时,评价误差约为9%。     

A Facile and Highly Efficient Approach to Obtain a Fluorescent Chromogenic Porous Organic Polymer for Lymphatic Targeting Imaging

Porous organic polymers have an open architecture, excellent stability, and tunable structural components, revealing great application potential in the field of fluorescence imaging, but this part of the research is still in its infancy. In this study, we aimed to tailor the physical and chemical characteristics of indocyanine green using sulfonic acid groups and conjugated fragments, and prepared amino-grafted porous polymers. The resulting material had excellent solvent and thermal stability, and possessed a relatively large pore structure with a size of 3.4 nm. Based on the synergistic effect of electrostatic bonding and π–π interactions, the fluorescent chromogenic agent, indocyanine green, was tightly incorporated into the pore cavity of POP solids through a one-step immersion method. Accordingly, the fluorescent chromogenic POP demonstrated excellent imaging capabilities in biological experiments. This preparation of fluorescent chromogenic porous organic polymer illustrates a promising application of POP-based solids in both fluorescence imaging and biomedicine applications.     

On the non-Riemannian quantity H in Finsler geometry

In this paper, we study a new non-Riemannian quantity H defined by the S-curvature. We find that the non-Riemannian quantity is closely related to S-curvature. We characterize Randers metrics of almost isotropic S-curvature if and only if they have almost vanishing H-curvature. Furthermore, the Randers metrics actually have zero S-curvature if and only if they have vanishing H-curvature.     

无机化学实验室危险废物减量化

高校化学实验室每年要产生大量危险废物,对学校及周边环境造成了严重危害.该文就消除和/或减少废物的产生以及废旧材料的再利用、回收或循环等方面介绍高校无机化学实验室危险废物减量化的成果与进展.     

Indium trichloride mediated intramolecular Prins-type cyclization

[reaction: see text] Intramolecular Prins-type reactions of compounds having both functionalities of homoallyl alcohol and acetal moiety are described. The intramolecular Prins cyclizations were performed using indium trichloride in chloroform or 25% aqueous THF. Both 9-oxabicyclo[3.3.1]nonane and 3,9-dioxabicyclo[3.3.1]nonane compounds were successfully obtained in moderate yields.     

飞秒非线性光学的最新进展——几个周期超短超强激光脉冲的非线性光学

 本文介绍了飞秒非线性光脉冲研究的最新进展。超快技术的发展已经能够产生仅含几个振荡周期的超强脉冲,其强度梯度使电子可以存在于比库仑束缚场高许多倍的外场产生的原子束缚态,并产生了同光频相差不大的电离率,从而导致了非线性光学的一些新的特点。     

Low tropospheric wind measurement with Mie Doppler Lidar

A double edge Mie Doppler lidar at 1064 nm was developed in Hefei, China in 2005 for low tropospheric wind measurement. Intercomparison experiments with a wind profiler and a wiresonde were held. Intercomparisons of concurrent lidar and other instrument observations show good agreement with expected measurement accuracy. The examples of validated lidar wind profiles obtained during these experiments as well as an example of continuous wind observations are presented. The instrument has demonstrated the capability of atmospheric wind field measurement from 0.2 to 5 km altitude, achieving below 2 m/s accuracy with 1 min averaging and 21.2 m vertical resolution.     

Comparison of nonlinear effects in amplitude and phase holograms recorded in photographic materials

Beam amplitudes of successive orders diffracted on holographic gratings are calculated and thus nonlinear effects in amplitude, bleached phase and reversal bleached phase holograms are compared. Then values of intermodulation noise are compared for the above three types of Fourier hologram of two circular holes.     

Rotational Raman lidar for obtaining aerosol scattering coefficients

Two-channel lidar signals that are composed of total rotational scattering and elastic signals provide good information about aerosol scattering coefficients. We can calculate the aerosol backscattering coefficient and extinction coefficient directly, without making any assumption or calibration. Generally, a high-spectral-resolution lidar is used for aerosol monitoring, but we have designed a new low-spectral-resolution lidar system that contains both kinds of scattering information simultaneously, and we have retrieved the aerosol scattering coefficient. The results show that there is no need to assume any relation between aerosol backscattering and extinction or to consider any wavelength calibration to determine the aerosol scattering coefficient.