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The objective of this study was to determine whether light backscatter response from fresh pork meat emulsions is correlated to final product stability indices. For that, a specially designed fiber optic measurement system was used in combination with a miniature fiber optic spectrometer to determine the intensity of light scatter within the wavelength range 300-1100 nm at different radial distances (2, 2.5 and 3 mm) with respect to the light source in fresh pork meat emulsions with two fat levels (15, 30%) and two levels (0, 2.5%) of hydrolyzed potato protein (HPP), a natural antioxidant. Textural parameters (hardness, deformability, cohesiveness and breaking force), CIELAB colour coordinates and TBARS (1, 2, 3, and 7 days of storage at 4?C) of cooked emulsions were also measured. Several optically derived parameters were found to be significantly correlated with emulsion stability parameters. The light backscatter was directly correlated with breaking force, colour and TBARS. Based on the strongest correlations developed, an optical configuration is proposed that would compensate for the emulsion heterogeneity, maximizing the existing correlation between the optical signal and the emulsion quality metrics.


为实现对LED色度的快速、准确测量,开发一种LED色度检测软件系统。该系统采用美国澳门美高梅光学公司HR4000微型光纤光谱仪作为光电传感器,基于Borland C++Builder开发平台,分为数据采集层、数据处理层、数据分析层,各层之间既相互独立又有机的组成一个整体。使用数据库技术存储相关参数和测试结果。系统色度测量符合标准,并且具有快速、稳定等特点。

对淀积在玻璃衬底上厚度约60 nm的金银合金溅射薄膜进行硝酸腐蚀脱银处理, 得到纳米多孔金薄膜. 利用自建的波长检测型表面等离子体共振(SPR)传感装置研究了腐蚀时间对纳米多孔金薄膜SPR特性的影响, 结果发现纳米多孔金薄膜与水溶液接触后在400-900 nm光谱范围内不具有SPR效应, 而当薄膜置于空气中时会产生明显的传播等离子体共振吸收峰, 其共振波长随腐蚀时间增加逐渐红移. 纳米多孔金薄膜在空气气氛中的SPR效应使其能够用于原位监测气相分子在孔内的吸附, 还可对在液相中吸附的生化分子进行离位测试. 本文对L-谷胱甘肽、L-半胱氨酸、2-氨基乙硫醇三种含巯基的生化小分子在纳米多孔金薄膜内的吸附进行了离位分析, 结果表明与传统的致密金薄膜SPR芯片比较, 纳米多孔金薄膜对这些分子显示出更高的灵敏度和更低的检测下限, 这归功于多孔金的大比表面积使其能够吸附大量的生化小分子. 实验还对乙醇蒸气在纳米多孔金薄膜内的吸附进行了原位监测, 发现吸附平衡所用时间较长, 约为160 min.

日光诱导叶绿素荧光( Solar-Induced Fluorescence,SIF) 与植被光合作用关系密切,可能成为研究植物光合作用及相关参数的新型遥感手段。总结了SIF 的提取算法、遥感模型、传感器以及在植被早期胁迫探测和光能利用率估算等领域应用的最新进展,并提出了SIF 遥感有待解决的关键问题。

We present the results of a study of highly linear polarized light emissions from an Organic Light-Emitting Device (OLED) that consisted of a flexible Giant Birefringent Optical (GBO) multilayer polymer reflecting polarizer substrate. Luminous Electroluminescent (EL) emissions over 4,500 cd/m2 were produced from the polarized OLED with high peak efficiencies in excess of 6 cd/A and 2 lm/W at relatively low operating voltages. The direction of polarization for the emitted EL light corresponded to the passing (ordinary) axis of the GBO-reflecting polarizer. Furthermore, the estimated polarization ratio between the brightness of two linearly
polarized EL emissions parallel and perpendicular to the passing axis could be as high as 25 when measured over the whole emitted luminance range.

Since the early pioneering work on efficient Organic Light-Emitting Devices (OLEDs) that was based on both small molecules and polymers, OLEDs have attracted a great deal of research interest due to their promising applications in full-color flat-panel displays and solid-state lighting [1-5]. Intensive research has been conducted into the development of OLEDs for realizing strong and efficient electroluminescent (EL) emission. To date, almost all previous work carried out on organic EL emission has involved unpolarized EL emission. Nevertheless, a number of researchers have reported the results of experiments in which linearly polarized EL emissions have been observed [6-17]. This particular avenue of research has been considered to be important because polarized EL emission from OLEDs is of potential use in a range of applications, not just those limited to high-contrast OLED displays, but also in efficient backlight sources in liquid crystal (LC) displays, optical data storage, optical communication, and stereoscopic 3D imaging systems [17].

We have conducted experiments exploring pulsed laser deposition of thin films using the high average power Thomas Jefferson National Accelerator Facility Free Electron Laser. The combination of parameters of this laser, including subpicosecond pulses, high average power, high repetition rate, and tunability, makes it a unique tool for the study of the effects of laser characteristics on thin-film quality. When compared to ablation and deposition with an ultrafast, high energy per pulse, low repetition rate laser ~amplified Ti:sapphire!, we find that the lower energy per pulse with high repetition rate of the free electron laser leads to very different plasma emission and produces films with high quality with the potential of very high deposition rates. This is demonstrated in the optical spectroscopy of plasma emission from Ti and the growth of Ni80Fe20 thin films.

A new spectroscopic parameter is used in this paper for on-line arc-welding quality monitoring. Plasma spectroscopy applied to welding diagnostics has typically relied on the estimation of the plasma electronic temperature, as there is a known correlation between this parameter and the quality of the seams. However, the practical use of this parameter gives rise to some uncertainties that could provoke ambiguous results. For an efficient on-line welding monitoring system, it is essential to prevent the appearance of false alarms, as well as to detect all the possible defects. In this regard, we propose the use of the root mean square signal of the welding plasma spectra, as this parameter will be proven to exhibit a good correlation with the quality of the resulting seams. Results corresponding to several arc-welding field tests performed on Inconel and titanium specimens will be discussed and compared to non-destructive evaluation techniques.

The purpose of this paper is to determine the emission coefficient radial distribution from the measured intensity distribution emitted by an extended source of radiation, particularly an application to plasma spectroscopy (He-Ne plasma). The plasma was produced inside a gas tube by a DC electrical discharge. The source was assumed to be optically thin and axially symmetrical. This problem is solved by inverting Abel’s integral equation. A smoothing procedure is made on the experimental curve in order to attenuate the random errors before computing the derivative. Abel’s integral equation is frequently applied in the study of extended radiation sources with cylindrical symmetry. A measurement of the transverse distribution I(y) of the intensity emitted perpendicularly to the source axis allows the calculation of the emission coefficient radial distribution, F(r). F(r) can be deduced from I(y) by the inverse formula known as Abel’s integral equation. I(r) and F(r) need not necessarily be the transverse intensity and the local emission coefficient respectively; they can also represent other physical quantities such as the optical thickness and the absorption coefficient of cylindrical absorbing plasma, and the optical path and the refractive index of cylindrical plasmas. The integral is calculated using a polynomial of second degree for the approximation of dI(y)/dy in a small interval on the right of the discontinuity point; the other part is calculated using an approximate numerical method made with a Mathcad program.