凝胶改性基底微藻细胞黏附特性及热力学分析

为强化微藻生物膜成膜过程中藻细胞与基底黏附,同时解决藻细胞残留造成的基底重复利用性差的问题,用聚N-异丙基丙烯酰胺(PNIPAAm)温缩型凝胶修饰基底.傅里叶红外光谱分析改性表面化学特性;结合微藻培养温度给出适宜藻细胞黏附的基底浸润特性;通过构建热力学模型,明晰温度对藻细胞与温缩型凝胶改性基底界面作用自由能的影响规律,...     

Packed-Fiber Solid Phase-Extraction Coupled with HPLC-MS/MS for Rapid Determination of Lipid Oxidative Damage Biomarker 8-Iso-Prostaglandin F2α in Urine

The 8-iso-prostaglandin F_2α (8-iso-PGF_2α) biomarker is used as the gold standard for tracing lipid oxidative stress in vivo. The analysis of urinary 8-iso-PGF_2α is challenging when dealing with trace amounts of 8-iso-PGF_2α and the complexity of urine matrixes. A packed-fiber solid-phase extraction (PFSPE)–coupled with HPLC-MS/MS–method, based on polystyrene (PS)-electrospun nanofibers, was developed for the specific determination of 8-iso-PGF_2α in urine and compared with other newly developed LC-MS/MS methods. The method, which simultaneously processed 12 samples within 5 min on a self-made semi-automatic array solid-phase extraction processor, was the first to introduce PS-electrospun nanofibers as an adsorbent for the extraction of 8-iso-PGF_2α and was successfully applied to real urine samples. After optimizing the PFSPE conditions, good linearity in the range of 0.05–5 ng/mL with R² > 0.9996 and a satisfactory limit of detection of 0.015 ng/mL were obtained, with good intraday and interday precision (RSD < 10%) and recoveries of 95.3–103.8%. This feasible method is expected to be used for the batch quantitative analysis of urinary 8-iso-PGF_2α.     

离子交换聚合物固定三联吡啶钌电玫化学发光传感器的研究进展

将可电化学再生的电致化学发光试剂-三联吡啶钌固定于电极表面制备得到可再生的电致化学发光(ECL)传感器.综述了近年来使用离子交换聚合物膜固定三联吡啶钌ECL传感器的研究进展,简要介绍了不同离子交换聚合物的固定方法及其相关的应用情况.同时展望了该领域未来的发展方向和前景.     

微波烧结Al_2O_3陶瓷的研究

简要介绍了微波烧结的特点,对 Ａｌ２ Ｏ３ 陶瓷的微波烧结过程进行了介绍和分析,并同常规烧结进行了对比实验,在此基础上得出了一些结论,为陶瓷微波烧结提供了实验依据     

基片光学特性对薄膜光强透过谱的影响

在考虑基片与空气界面反射率以及基片吸收不能忽略的情况下，对常见的基片上薄膜的光强透过率公式进行了修正，导出了该情况下的透过率公式．以非晶硅薄膜为研究对象，采用模拟计算说明基片光学特性对薄膜光强透过谱的影响．     

Oscillation of coercivity between positive and negative in MnxGe1-x：H ferromagnetic semiconductor films

Amorphous MnxGe1-x :H ferromagnetic semiconductor films prepared in mixed Ar with 20% H2 by magnetron cosputtering show global ferromagnetism with positive coercivity at low temperatures. With increasing temperature, the coercivity of MnxGe1-x :H films first changes from positive to negative, and then back to positive again, which was not found in the corresponding MnxGe1-x and other ferromagnetic semiconductors before. For Mn0.4Ge0.6 :H film, the inverted Hall loop is also observed at 30 K, which is consistent with the negative coercivity. The negative coercivity is explained by the antiferromagnetic exchange coupling between the H-rich ferromagnetic regions separated by the H-poor non-ferromagnetic spacers. Hydrogenation is a useful method to tune the magnetic properties of MnxGe1-x films for the application in spintronics.     

氧化光栅型垂直腔面发射激光器的研究

通过分析矩形出光孔径和亚波长金属光栅结构,发现大孔径高功率垂直腔面发射激光器(VCSEL)的偏振控制的难点在于横模非常复杂。因此提出一种新型的氧化光栅型VCSEL结构,不仅能够很好地在有源区内引入各项异性的增益结构,并且最大的优势还在于能够完美地控制大孔径VCSEL的横模。通过有限元软件对器件有源区的电流分布进行了模拟,发现当光栅脊的宽度为1.8 μm时,载流子在光栅两端聚集的现象基本上可以消除,而且其电流密度分布差可以达到很高。     

Current and frequency modulation characteristics for continuous-wave quantum cascade lasers at 9.06 μm

We report the characteristics of current induced frequency modulation (FM) for two continuous-wave quantum cascade lasers (QCLs) at 9.06 μm. Both the frequency tuning rate and the phase shift between intensity modulation and FM are measured at different modulation frequencies from 10 Hz to 200 kHz. The frequency tuning rate of the QCLs depends on both the modulation frequency and amplitude. The tested QCL has been used to detect ambient water vapor with wavelength modulation spectroscopy for validation with a numerical model.     

In situ measurement on nonuniform velocity distributionin external detonation exhaust flow by analysis ofspectrum features using TDLAS

Instantaneous and precise velocity sensing is a critical part of research on detonation mechanism and flow evolution.This paper presents a novel multi-projection tunable diode laser absorption spectroscopy solution,to provide a real-time and reliable measurement of velocity distribution in detonation exhaust flow with obvious nonuniformity.Relations are established between overlapped spectrums along probing beams and Gauss velocity distribution phantom according to the frequency shifts and tiny variations in components of light-of-sight absorbance profiles at low frequencies analyzed by the fast Fourier transform.With simulated optical measurement using H2O feature at 7185.6 cm-1 carried out on a phantom generated using a simulation of two-phase detonation by a two-fluid model,this method demonstrates a satisfying performance on recovery of velocity distribution profiles in supersonic flow even with a noise equivalent absorbance up to 2×10^-3.This method is applied to the analysis of rapidly decreasing velocity during a complete working cycle in the external flow field of an air-gasoline detonation tube operating at 25 Hz,and results show the velocity in the core flow field would be much larger than the arithmetic average from traditional tunable diode laser doppler velocimetry.This proposed velocity distribution sensor would reconstruct nonuniform velocity distribution of high-speed flow in low cost and simple operations,which broadens the possibility for applications in research on the formation and propagation of external flow filed of detonation tube.     

Prospective study on observations of γ-ray sources in the Galaxy using the HADAR experiment

The High Altitude Detection of Astronomical Radiation (HADAR) experiment is a refracting terrestrial telescope array based on the atmospheric Cherenkov imaging technique. It focuses the Cherenkov light emitted by extensive air showers through a large aperture water-lens system for observing very-high-energy γ-rays and cosmic rays. With the advantages of a large field-of-view (FOV) and low energy threshold, the HADAR experiment operates in a large-scale sky scanning mode to observe galactic sources. This study presents the prospects of using the HADAR experiment for the sky survey of TeV γ-ray sources from TeVCat and provids a one-year survey of statistical significance. Results from the simulation show that a total of 23 galactic point sources, including five supernova remnant sources and superbubbles, four pulsar wind nebula sources, and 14 unidentified sources, were detected in the HADAR FOV with a significance greater than 5 standard deviations (σ). The statistical significance for the Crab Nebula during one year of operation reached 346.0 σ and the one-year integral sensitivity of HADAR above 1 TeV was ~1.3%–2.4% of the flux from the Crab Nebula.