Spiking patterns of a hippocampus model in electric fields

We develop a model of CA3 neurons embedded in a resistive array to mimic the effects of electric fields from a new perspective. Effects of DC and sinusoidal electric fields on firing patterns in CA3 neurons are investigated in this study. The firing patterns can be switched from no firing pattern to burst or from burst to fast periodic firing pattern with the increase of DC electric field intensity. It is also found that the firing activities are sensitive to the frequency and amplitude of the sinusoidal electric field. Different phase-locking states and chaotic firing regions are observed in the parameter space of frequency and amplitude. These findings are qualitatively in accordance with the results of relevant experimental and numerical studies. It is implied that the external or endogenous electric field can modulate the neural code in the brain. Furthermore, it is helpful to develop control strategies based on electric fields to control neural diseases such as epilepsy.     

液体表面张力系数测定实验的几点分析

用拉脱法测定水的表面张力系数实验中，用焦利氏秤测定（Ｆ—Ｗ）时，确定焦利氏秤标尺读数Ｌ１、Ｌ２的位置有两种方法。本文旨在详细分析这两种方法隐含的实验条件和对实验结果的影响．并进行比较，得出结论。     

一种基于新型查表方法的统一计算设备架构并行计算全息算法

为解决点源法计算全息速度较慢的问题,提出了一种新的查表算法,命名为三角函数查表法(T-LUT算法)。该算法是基于点源法基本的数学公式,通过一系列数学近似与恒等变换,生成了一种纯相位查找表,该查找表具有三维特性,并具有生成速度快、精度高、占用内存少等特点,克服了点源法重复计算相位的缺点。同时采用统一计算设备架构(CUDA)并行计算在图形处理器(GPU)上加以实现,并进行了三次并行优化。在算法的验证与对比实验中,采用单显卡(GPU显卡)实现T-LUT算法,在不牺牲全息图再现像质量的前提下,成功地将点源法计算全息的速度大幅度提升。实验发现在不同的物空间采样点数量的情况下,速度相对于点源法GPU运算提升30倍至近千倍不等。     

第三族金属氧化物离子对二氧化碳转化的红外光谱研究

本文利用红外光解离光谱研究了第三族金属氧化物离子对二氧化碳分子的转化机制. 研究表明,对于[ScO(CO₂)_n]⁺体系,在n≤4时,形成了溶剂化结构;在n=5时,形成了碳酸盐结构,实现了二氧化碳的转化. 对于[YO(CO₂)_n]⁺体系,需要4个二氧化碳分子就可以实现二氧化碳的转化. 而在[YO(CO₂)_n]⁺体系中,只发现了溶剂化结构,没有观察到碳酸盐结构. 理论计算表明,[YO(CO₂)_n]⁺体系拥有最小的溶剂化结构向碳酸盐结构转化能垒,[LaO(CO₂)_n]⁺体系拥有最大的溶剂化结构向碳酸盐结构转化能垒. 本文从分子水平揭示了不同金属氧化物离子对二氧化碳分子转化的影响规律.     

5,15-二（二茂铁基）-卟啉酞菁钇的结构和振动光谱的密度泛函理论研究

本文选用混杂的B3LYP密度泛函理论方法,在Lanl2dz水平上,对5,15-二（二茂铁基）-卟啉酞菁钇[Por(Fc)2]Y(Pc)的结构进行了优化,结果表明,5,15-二（二茂铁基）-卟啉酞菁钇呈现出三明治型构型,卟啉环与酞菁环呈穹型围绕在金属钇原子周围。对分子内主要的键长与键角进行了理论计算,通过频率计算,得到了5,15-二（二茂铁基）-卟啉酞菁钇[Por(Fc)2]Y(Pc)的红外光谱图,与实验所得的红外光谱图进行比对,将理论计算和实验所得的光谱主要振动峰进行了线性回归拟合,相关系数为0.992,标准偏差为16.96。理论计算与实验所获得的红外光谱图基本一致,说明本文所选用的DFT理论计算方法是可行的。通过GaussView软件对5,15-二（二茂铁基）-卟啉酞菁钇的红外谱带简正振动模式进行了指认。此外,分析讨论了5,15-二（二茂铁基）-卟啉酞菁钇[Por(Fc)2]Y(Pc)的分子静电势,确定了极大值与极小值的位置。对于研究5,15-二（二茂铁基）-卟啉酞菁钇分子的性质,提供了相应的理论基础。     

Efficient and stable wireless power transfer based on the non-Hermitian physics

As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric vehicles.However,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit model.Here,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance WPT.From the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time symmetry.Based on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time symmetry.Moreover,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection.Therefore,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.     

Identify real gravitational wave events in the LIGO-Virgo catalog GWTC-1 and GWTC-2 with convolutional neural network

In recent years, machine learning models have been introduced into the field of gravitational wave (GW) data processing. In this paper, we apply the convolutional neural network (CNN) to LIGO O1, O2, O3a data analysis to search the released 41 GW events which are emitted from binary black hole (BBH) mergers (here we exclude the events from binary neutron star (BNS) mergers, and the events that are not detected simultaneously by Hanford (H) and Livingston (L) detectors), and use time sliding method to reduce the false alarm rate (FAR). According to the results, the 41 confirmed GW events of BBH mergers can be classified successfully by our CNN model. Furthermore, through restricting the number of consecutive prewarning from sequential samples intercepted continuously in LIGO O2 real time-series and vetoing the coincidences of noise from H and L, the FAR is limited to be less than once in 2 months. It is helpful to promote LIGO real time data processing.     

全反射棱镜式激光陀螺自适应稳频技术

针对全反射棱镜式激光陀螺在稳频过程中相敏信号易受噪声干扰的现象,研究了全反射棱镜式激光陀螺自适应稳频技术。理论分析了全反射棱镜式激光陀螺的稳频特性,结合自适应噪声对消原理,建立了全反射棱镜式激光陀螺自适应稳频系统的数学模型。通过硬件电路设计,搭建了基于递归最小二乘算法的自适应稳频控制系统。分别对原有稳频技术与自适应稳频技术进行了实验测试,实验结果表明,自适应稳频能有效消除噪声对相敏信号的干扰,稳频精度提高了近一个数量级,陀螺精度相应提高了60%以上。此分析结果为提高全反射棱镜式激光陀螺的性能提供了重要参考。     

Radiation Vulcanization of Magnetorheological Elastomers Based on Silicone Rubber

介绍了两种制备磁流变弹性体的硫化方法即高温硫化和辐射硫化. 研究中采用动态力学分析仪(DMA)测量了样品的动态力学特性.特别是对样品的磁流变效应和耐久性进行了详细的测试. 实验结果表明,经过辐射硫化的样品具有更大的零场模量和磁致模量,以及更好的磁流变效应和耐久性. 为了解释这些结果,文章对样品的体积形变和增塑剂渗出都作了详细的分析. 在硫化过程中样品的体积保持稳定是辐射硫化样品具有大磁致模量的重要原因,而增塑剂渗透性小也是辐射硫化样品具有高磁流变效应和耐久性的重要因素.     

First-principles calculations for transition phase and thermodynamic properties of GaAs

The transition phase of GaAs from the zincblende (ZB) structure to the rocksalt (RS) structure is investigated by ab initio plane-wave pseudopotential density functional theory method, and the thermodynamic properties of the ZB and RS structures are obtained through the quasi-harmonic Debye model. It is found that the transition from the ZB structure to the RS structure occurs at the pressure of about 16.3\,GPa, this fact is well consistent with the experimental data and other theoretical results. The dependences of the relative volume V/V₀ on the pressure P, the Debye temperature \Th and specific heat C_V on the pressure P, as well as the specific heat C_V on the temperature T are also obtained successfully.