Theoretical study of proton coupled electron transfer reaction in the light state of the AppA BLUF photoreceptor

The BLUF (blue light sensor using flavin adenine dinucleotide) domain is widely studied as a prototype for proton coupled electron transfer (PCET) reactions in biological systems. In this work, the photo-induced concerted PCET reaction from the light state of the AppA BLUF domain is investigated. To model the simultaneous transfer of two protons in the reaction, two-dimensional potential energy surfaces for the double proton transfer are first calculated for the locally excited and charge transfer states, which are then used to obtain the vibrational wave function overlaps and the vibrational energy levels. Contributions to the PCET rate constant from each pair of vibronic states are then analyzed using the theory based on the Fermi's golden rule. We show that, the recently proposed light state structure of the BLUF domain with a tautomerized Gln63 residue is consistent with the concerted transfer of one electron and two protons. It is also found that, thermal fluctuations of the protein structure, especially the proton donor-acceptor distances, play an important role in determining the PCET reaction rate. © 2018 Wiley Periodicals, Inc.     

Electroformation and collection of giant liposomes on an integrated microchip

In this work, a microchip was developed for the electroformation and collection of giant liposomes. On the chip, a reactor chamber array was expressly designed so that the influences of multiple parameters could be explored rapidly and efficiently to screen for a suitable condition. Furthermore, in order to overcome the difficulty in the collection of giant liposomes, a tailor-made collection chamber was also integrated on this chip.     

A multifunctional integrated simultaneously online screening microfluidic biochip for the examination of “efficacy-toxicity” and compatibility of medicine

A multifunctional integrated microfluidic biochip device was engineered to estimate the activity-toxicity and composition principle of medicine in a cell model in vitro.     

热解吸低温等离子体质谱技术直接快速筛查蔬菜中的有机磷农药

在传统低温等离子体质谱技术的基础上引入热解吸装置,建立了一种直接快速筛查蔬菜中有机磷农药的新方法。白菜样品经乙腈提取,离心取上清液进行质谱检测,在正离子检测模式下,将承载样品的载玻片置于加热块上进行解吸,被低温等离子体射流离子化后进入质谱检测。结果表明,在优化实验条件下,8种有机磷农药在0.005～0.200 mg/L质量浓度范围内线性良好,相关系数均大于0.99,检出限为0.001～0.010 mg/L,加标回收率为90.5%～119%,相对标准偏差(RSD,n=6)为12%～17%。与无热解吸条件相比,检测灵敏度提高了9.3～41.7倍。该方法操作简单,无复杂的样品前处理,灵敏度高、准确性好,可用于蔬菜中8种有机磷农药残留的同时测定,在大批量样品的非靶向分析中有较大的应用前景。     

Unsymmetrically substituted ethane as a new and efficient initiator for the polymerization of methyl methacrylate and styrene

In this paper, we present a compound, 2,3-diphenyl butyronitrile (DPBN), which can be used as a new and efficient radical initiator for the polymerization of methyl methacrylate (MMA) and styrene (St). Very different from other compounds as a carbon-carbon initiator, DPBN is an unsymmetrically substituted ethane and works with high initiation reactivity at lower temperatures. This new compound as an initiator exhibits various advantages, such as easy preparation, high initiation reactivity, safe use and storage, and convenient handling.     

Optical properties of Er:SrMoO4 single crystal

Er³⁺:SrMoO₄ crystal of high optical quality was grown by the Czochralski method. The room temperature polarized absorption and emission spectra together with the lifetime decay curve were measured. Based on the Judd-Ofelt theory, three intensity parameters, radiative transition rates, radiative lifetimes and fluorescent branching ratios, were obtained. Emission cross-section and gain cross-section around 1.54 μm were also obtained.     

Role of interference between localized and propagating surface waves on the extraordinary optical transmission through a subwavelength-aperture array

We report in this Letter that when radiation is incident on a metal surface perforated with an array of ring-shaped subwavelength apertures, the phase difference between the propagating surface Bloch wave and the localized surface wave can be tailored by the geometrical parameters of the array so as to affect the shape of the transmission spectrum. Above the resonant frequency of the aperture, interference between the two kinds of surface waves leads to a minimum in the transmission spectrum, whereas below it, the interference leads to a maximum. We suggest that this feature provides flexibility in engineering surface-wave-based all-optical devices.     

Phase retrieval using multiple illumination wavelengths

An iterative phase retrieval method is proposed, which uses a sequence of diffraction intensity patterns recorded at different wavelengths. This method has a rapid convergence, and a high immunity to noise and environmental disturbance. The wrap-free phase measurement range is also extended based on the principle of two-wavelength interferometry. Simulation and experimental results are presented to demonstrate the approach.     

Synergetic behavior in the cascading failure propagation of scale-free coupled map lattices

In this paper, the whole dynamical process of cascading failures in a class of scale-free coupled map lattices (CML’s), from the occurrence of attack to the end of failure propagation, is investigated. A dynamical model of cascading failures, based on synergetic theory, is constructed. Numerical simulations show that the macroscopic properties of the scale-free CML’s during cascading failure propagation are governed by the general laws of synergetics. This result will be useful in furthering the studies of the prediction and prevention of cascading events in many real-life complex networks.     

合成反铁磁Ni81Fe19/Co90Fe10/Ru/Co90Fe10/Ni81Fe19的研究

采用直流磁控溅射方法制备了一系列的合成反铁磁及以其为自由层的自旋阀.研究发现,在Ni81,Fe19与Ru层之间插入适当厚度的Co90Fe10层后,可有效地提高合成反铁磁两磁性层间的反铁磁耦合强度,得到具有饱和场日.更高、饱和磁化强度M.更低、热稳定性更好的合成反铁磁.另外,以这种合成反铁磁作自旋阀的自由层时,可有效提高自旋阀的稳定性.