基于旋转相位编码与照明光束匹配的叠层衍射成像算法研究

在传统的叠层成像算法中引入一种旋转相位编码与照明光束相匹配.采用分块均匀分布的旋转相位调制器对衍射光进行调制,在探测面获得了相应的衍射图样.这种照明光束与相位匹配的方式有效地增加了解的约束条件,具有收敛速度快、抗噪声及抗位置偏差能力强等优点.与随机相位调制相比,本算法所引入的旋转相位调制器构造简单、使用便捷,因而在实时显微成像、超分辨成像等领域将具有更高的实用价值.     

Perturbations of frames

In this paper, we give some sufficient conditions under which perturbations preserve Hilbert frames and near-Riesz bases. Similar results are also extended to frame sequences, Riesz sequences and Schauder frames. It is worth mentioning that some of our perturbation conditions are quite different from those used in the previous literatures on this topic.     

How should process capabilities be combined to leverage supplier relationships competitively?

Two process capabilities have been identified in the operations management literature to leverage supplier relationships for competitive performance: the ability to continuously improve processes with suppliers (process alignment) and the ability to make changes to these relationships (partnering flexibility). While firms may need both capabilities to be successful, it is unclear what strategy should be used to combine these two seemingly contradictory process capabilities. Using data collected from 318 manufacturing firms on a focal firm’s process capabilities to manage supplier relationships, we examine the performance impacts of two dimensions of a particular strategy: balancing (focusing on achieving a close match between the two process capabilities) and complementing (focusing on creating synergy between the two process capabilities). Our results indicate that the balancing dimension has a much stronger effect on a firm’s competitive performance than the complementing dimension. Also, when a firm pursues a high balance and strong complements strategy (combining high levels of both process capabilities), it is able to reduce its competitive performance risks more than when it pursues a high balance and weak complements strategy (combining low levels of both capabilities) or when it implements unbalanced strategies that emphasize either process alignment or partnering flexibility (combining low levels of one capability with high levels of the other). We conclude by discussing the theoretical contributions and practical guidelines.     

Impedimetric aptasensor for Staphylococcus aureus based on nanocomposite prepared from reduced graphene oxide and gold nanoparticles

We describe here an aptasensor for the ultrasensitive detection of Staphylococcus aureus by electrochemical impedance spectroscopy (EIS). Single-stranded DNA was linked to a nanocomposite prepared from reduced graphene oxide (rGO) and gold nanoparticles (AuNP). Thiolated ssDNA was covalently linked to the AuNPs linked to rGO, and probe DNA was immobilized on the surface of an AuNP-modified glassy carbon electrode to capture and concentrate Staph. aureus. The probe DNA of the aptasensor selectively captures the target bacteria in its three-dimensional space, and these results in a dramatic increase in impedance. Scanning electron microscopy, cyclic voltammetry and EIS were used to monitor the single steps of the electrode assembly process. The effect was utilized to quantify the bacteria in the concentration range from 10 to 10⁶ cfu mL^?1 and with a detection limit of 10 cfu mL^?1 (S/N?=?3). The relative standard deviation of Staphylococcus aureus detection was equal to 4.3 % (10⁵ cfu mL^?1, n?=?7). In addition to its sensitivity, the biosensor exhibits high selectivity over other pathogens.

Study on the saturation characteristics of high-speed uni-traveling-carrier photodiodes based on field screening analysis

A back-illuminated mesa-structure InGaAs/InP charge-compensated uni-traveling-carrier(UTC) photodiode(PD) is fabricated,and its saturation characteristics are investigated.The responsivity of the 40-μmdiameter PD is as high as 0.83 A/W,and the direct current(DC) saturation current is up to 275 mA.The 1-dB compression point at the 3-dB cutoff frequency of 9 GHz is measured to be 100 mA,corresponding to an output radio frequency(RF) power of up to 20.1 dBm.According to the calculated electric field distributions in the depleted region under both DC and alternating current(AC) conditions,the saturation of the UTC-PD is caused by complete field screening at high optical injection levels.     

铂基氧还原催化剂在活性和稳定性方面的挑战

在质子交换膜燃料电池（PEMFC）中,由于阴极氧还原反应（ORR）速率缓慢,因此开发高效的ORR催化剂是实现燃料电池商业化的关键. 世界各地的研究人员在提高催化剂活性和耐久性方面做出了不懈的努力. 目前,铂基催化剂仍然是商业应用上的首选,为开发实用的低铂氧还原催化剂,研究人员开展了大量的研究. 本文说明了ORR反应遇到的挑战,并介绍了近年来铂基氧还原催化剂的研究进展,具体包括ORR机理、铂核壳结构、一维纳米Pt催化剂和其他的代表性工作.     

毛细管黏度计自动检定/校准系统的研制

利用自动控温系统、测温电桥、自动计时系统和计算机控制平台组成一种毛细管黏度计自动检定/校准系统,该系统具有自动吸液、自动计时以及数据自动处理功能,可用于标准黏度液定值和毛细管黏度计检定/校准。     

扰动色谱方程黎曼解的极限-delta激波的行成和转换

本文主要讨论扰动色谱方程delta激波解的行成和转换,并讨论上述方程的黎曼问题.当扰动参数趋于零时,通过研究黎曼解的极限,我们可以观察到如下两个重要现象:激波和接触间断重合行成delta激波,一类激波(一个变量含有delta函数).     

一般罚分(或得分)矩阵下的SPA算法

本文在一般罚分（或得分）矩阵条件下推广SPA（Super Pairwise Alignment）算法，该算法是一种次优算法，与Smith-Waterman算法比较，计算速度有明显改进（计算复杂度随序列长度线性增长）．     

Identification of tartrazine and sunset yellow by fluorescence spectroscopy combined with radial basis function neural network

The fluorescence spectra of synthetic food dyes of sunset yellow and tartrazine are analyzed. The fluorescence peak wavelengths of sunset yellow and tartrazine are 576 and 569 nm, respectively, while the fluorescence spectra widths are 480-750 and 500 750 nm induced by ultraviolet light between 310-400 nm. The fluorescence spectra of sunset yellow overlap heavily with those of tartrazine, so it is difficult to distinguish them. Based on the principle of radial basis function neural network, a neural network is obtained from the training of the 14 groups of experimental data. The results show that the species of sunset yellow and tartrazine could be recognized accurately. This method has potential applications in other synthetic food dyes detection and food safety inspection.