Vanishing Viscous Limits for 3D Navier–Stokes Equations with a Navier-Slip Boundary Condition

In this paper, we investigate the vanishing viscosity limit for solutions to the Navier–Stokes equations with a Navier slip boundary condition on general compact and smooth domains in R ³. We first obtain the higher order regularity estimates for the solutions to Prandtl’s equation boundary layers. Furthermore, we prove that the strong solution to Navier–Stokes equations converges to the Eulerian one in C([0, T]; H ¹(Ω)) and ${L^\infty((0,T) \times \Omega)}$ , where T is independent of the viscosity, provided that initial velocity is regular enough. Furthermore, rates of convergence are obtained also.     

Laser-induced Fluorescence Spectroscopy of NiCl in 12900-15000 cm-1

Laser-induced fluorescence excitation spectra of jet-cooled NiCl molecules were recorded in the energy range of 12900-15000 cm^-1. Six vibronic bands with rotational structure have been observed and assigned to the [13.0]²П^3/2(v'=0-5)-X²П^3/2(v"=0) transition progres-sion. The relevant rotational constants, significant isotopic shifts, and (equilibrium) molecu-lar parameters have been determined. In addition, the lifetimes of the observed bands have also been measured.     

空间激光跟瞄中指向驱动电机运动特性研究

设计了一种深空非合作目标的激光扫描、捕获、跟踪地面实验装置,通过模拟深空同轨道运动的两颗卫星跟瞄过程,在理论上计算了跟瞄装置中光束指向驱动电机的最小加速度和其在跟踪过程中的运动特性。理论分析与仿真结果表明,当卫星偏离光斑中心一定距离时,指向驱动电机先加速后减速,补偿这个偏心,重新捕获跟踪卫星;重新捕获到跟踪所需时间受电机加速度和望远镜探测精度以及探测器响应处理时间影响,其中探测器精度对重新捕获到跟踪所需时间影响较大,探测器响应处理时间要减小到最小;为了使从捕获到跟踪过程中卫星始终在扫描光斑范围内,经纬仪驱动电机的最小角加速度为25.5°/s2。     

原位被动采样技术*

本文介绍了近些年来环境监测中三种新的原位被动采样技术-透析装置（Dialysis peepers）法、薄膜扩散平衡 (DET) 技术和薄膜扩散梯度 (DGT) 技术。综述了三种技术的原理、装置和特点。着重论述了三种技术在环境中的应用研究,包括透析装置以及DET 技术和DGT联用技术测量水体和沉积物孔隙水中可溶性金属的浓度;DGT技术可以作为一种预测重金属生物可利用性的新方法。DGT技术与其他技术（如DET、高离子选择电极、配体交换法、HPLC-ICP-MS等）联用可以更好地测量环境中重金属的形态。最后展望了原位被动采样技术未来的发展。     

Excitation Wavelength Dependent Fluorescence of an ESIPT Triazole Derivative for Amine Sensing and Anti‐Counterfeiting Applications

Excitation wavelength dependent (Ex‐De) emission materials have potential applications in anti‐counterfeiting labels and bioimaging. Nevertheless, few purely organic chromophores are used in these areas. In this study, multiple excited states were incorporated into a molecule that was excited state intramolecular proton transfer (ESIPT) active, with the goal of manipulating the relaxation pathways of the excited states. The triazole derivative exhibits Ex‐De photoluminescence (PL), and the maximum PL wavelength is located at 526 nm and 593 nm under a series of excitation wavelengths. Spectral identification indicates that the excimer and ESIPT processes are responsible for the green (526 nm) and orange (593 nm) fluorescence, respectively. Importantly, the quick response code and test strip prepared with this triazole derivative can be used for anti‐counterfeiting and food spoilage detection applications, respectively. This research opens the door for developing novel Ex‐De materials for anti‐counterfeiting purposes.     

基于可调谐激光吸收光谱技术的二硫化碳中红外光谱参数测量

采用4.6μm附近的量子级联激光器作为光源,搭建了一套二硫化碳(CS2)吸收光谱测量系统,结合可调谐二极管激光吸收光谱技术,对光谱范围为2178.99—2180.79 cm-1的CS2吸收光谱展开了深入研究,重点测量了2180.5—2180.74 cm~(-1)的四条吸收谱线,利用基于非线性最小二乘的多元线性回归算法对CS2吸收光谱进行拟合,精确得到了该范围内谱线的中心波长、线强以及空气展宽系数等光谱参数.经计算,对应谱线线强不确定度小于5%,空气展宽系数不确定度小于15%,这个结果可作为免标定CS2红外光谱探测的基础光谱参数,对痕量CS2气体传感具有重要意义.未来我们将进一步开展2170—2200 cm-1整个谱段的CS2谱线参数的测量,以期填补其在HITRAN和GEISA数据库光谱参数的空白.     

Fabrication of homogenous three‐dimensional biomimetic tissue for mass spectrometry imaging

Reference samples are essential for mass spectrometric method optimization, data quality control, and target analyte quantitation. However, it is highly challenging to prepare an ideal homogeneous, standard‐spiked tissue sample for mass spectrometry imaging (MSI) research. Herein, we present a standard‐spiked 3D biomimetic tissue model fabricated with native cells, homogenate matrix, and biocompatible polymer. Unlike traditional homogenized tissue surrogates or those constructed with “on‐tissue” or “under‐tissue” micropipetting strategies, this simulated tissue shares both structural integrity of cells and homogeneous properties of matrix. As a result, analyte standards could undergo more in‐depth incorporation and has a more comparable native status with a real tissue. Series of tissue sections made from the 3D tissue model were proven to be feasible and useful for the parameter optimization, analyte quantitation, and calibration curve fitting for the air‐flow assisted desorption electrospray ionization MSI. Additionally, by analyzing the quality control model sections, we proposed a median principal component score calibration and demonstrated that this method can normalize instrumental fluctuations to stable levels in a large‐scale untargeted MSI experiments for the reliable metabolomic biomarker discovery. Thus, these results indicated that the standard‐spiked 3D biomimetic tissue has convincing significance in MSI analysis     

A high-performance bio-tissue imaging method using air flow-assisted desorption electrospray ionization coupled with a high-resolution mass spectrometer

An air flow-assisted desorption electrospray ionization (AFADESI) MSI device was combined with a highresolution mass spectrometer to optimize the system parameters and achieve more accurate spatial distribution characteristics for compounds of interest while investigating bio-tissue sections. Finally, the parameter conditions that can provide optimal ionic intensity and enhanced resolution were confirmed.