Unsupervised cell identification on multidimensional X‐ray fluorescence datasets

A novel approach to locate, identify and refine positions and whole areas of cell structures based on elemental contents measured by X‐ray fluorescence microscopy is introduced. It is shown that, by initializing with only a handful of prototypical cell regions, this approach can obtain consistent identification of whole cells, even when cells are overlapping, without training by explicit annotation. It is robust both to different measurements on the same sample and to different initializations. This effort provides a versatile framework to identify targeted cellular structures from datasets too complex for manual analysis, like most X‐ray fluorescence microscopy data. Possible future extensions are also discussed.     

Observations of the atmospheric boundary layer across the land-sea transition zone using a scanning Mie lidar

Optical properties of the atmospheric boundary layer (ABL) above the land-sea transition interface were measured using a scanning Mie lidar located 30 km away from the Adriatic coast. Based on the two-dimensional range-height-indicator scans, detailed information on the ABL was obtained, including parameters such as atmospheric optical depth, aerosol extinction coefficient and the height of the ABL. The presented case study indicates that the height of the ABL in the land-sea transition zone and the adjacent mountainous region was changing rapidly due to highly variable atmospheric conditions.     

A novel monochromator for experiments with ultrashort X‐ray pulses

Aiming at advancing storage‐ring‐based ultrafast X‐ray science, over the past few years many upgrades have been undertaken to continue improving beamline performance and photon flux at the Femtoslicing facility at BESSY II. In this article the particular design upgrade of one of the key optical components, the zone‐plate monochromator (ZPM) beamline, is reported. The beamline is devoted to optical pump/soft X‐ray probe applications with 100 fs (FWHM) X‐ray pulses in the soft X‐ray range at variable polarization. A novel approach consisting of an array of nine off‐axis reflection zone plates is used for a gapless coverage of the spectral range between 410 and 1333 eV at a designed resolution of E/ΔE = 500 and a pulse elongation of only 30 fs. With the upgrade of the ZPM the following was achieved: a smaller focus, an improved spectral resolution and bandwidth as well as excellent long‐term stability. The beamline will enable a new class of ultrafast applications with variable optical excitation wavelength and variable polarization.     

Growth and optical characterization of organic nonlinear optical crystal: indole-3-aldehyde

The metastable zone width for the solution of organic nonlinear material: indole-3-aldehyde (IA) has been determined for the various solvents of acetone, methanol and ethyl acetate and the corresponding IA crystals have been grown by temperature lowering technique. The surface analysis on different planes of the grown crystals has been carried out. The range of transmission and powder second harmonic generation efficiency of IA have been reported.     

H2/air旋流预混燃烧的流场特性和火焰结构分析

本文采用完全可压缩的N-S方程,对当量比为1.0的H₂/air旋流预混火焰进行了直接数值模拟研究。氢气和空气的化学反应采用9种组分19步的详细机理。模拟结果表明,强旋流流场中存在回流区,碗形旋流火焰稳定在回流区的外围。在火焰面上沿火焰法向提取了局部火焰结构,将局部湍流火焰结构与层流预混火焰的火焰结构进行了比较,发现局部湍流火焰比层流预混火焰更薄,燃烧强度更高。     

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the\"wellbore skin zone\",play a pivotal role in determining flow dynamics and the resulting formation deformation.Existing models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir interface.This paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic medium.Analytical solutions are derived using the Laplace transform method,addressing both positive and negative skin zones.Numerical results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a wellbore.The results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.     

毛细管区带电泳激光诱导荧光间接检测环腺苷单磷酸和环鸟苷单磷酸

研究了影响毛细管区带电泳激光诱导荧光间接检测环腺苷单磷酸和环鸟苷单磷酸的实验条件.cAMP和cGMP的线性范围分别为30～500mg/L和15～500mg/L,其最低检测限分别为9.0mg/L和0.5mg/L;当浓度为125mg/L时,cAMP和cGMP峰面积的RSD为4.45%和6.21%(n=4);其迁移时间的日间RSD分别为2.92%和2.04%(n=5)     

Identification and determination of aesculin and aesculetin in ash barks by capillary zone electrophoresis

Summary A capillary zone electrophoresis method for identification and determination of aesculin and aesculetin has been established using borate-phosphate buffer containing 30% ethanol with on-column UV detection. A detailed investigation of the influence of changes in borate concentration, pH, applied voltage, temperature and organic modifier was then carried out. For both aesculin and aesculetin, a linear plot of migration time (MT) against borate concentration was obtained, and ln[measured peak area (MA)] and lnMT both gave linear plots against ln(applied voltage) with correlation coefficient r>0.999, which also resulted in a linear correlation between MA and MT (r≥0.9998) under varied voltage. Ethanol as organic modifier to the background electrolytes helped in separating aesculin and aesculetin from other components in ash barks. The reproducibility with relative standard deviation in MT and in normalized peak area(NA) and linearity based on NA against concentration were evaluated. Finally, the method was successfully applied to monitor the quality of different ash barks and to compare the effect of sample preparation on content of bioactive components in ash bark. Results indicate that CZE promises to be applicable to quality control of traditional Chinese medicines containing aesculin and aesculetin.     

Optimization of capillary zone electrophoresis parameters for selenium speciation

The behaviour of four biologically relevant selenium compounds (Se(VI), Se(IV), selenomethionine and selenocystine) in capillary zone electrophoresis (CZE) was investigated. Parameters which affect the separation, detection and sample introduction were investigated to improve the sensitivity of the analysis. Short-term repeatability was evaluated and detection limits were found to be in the g·l^–1 range.