微弱光度标准问题探讨

探讨基于标准探测器建立弱光光度标准中的主要问题，介绍为标定弱光光度计专门研制的弱光度测试台。

太阳光度计定标方法和西安地区气溶胶光学特征的研究

利用西安理工大学2015~2018年的太阳光度计观测资料,在传统Langley法定标的基础上,利用期望平均法和拟合平均法获得了更为稳定的仪器定标系数,分析了西安地区气溶胶光学厚度和Angström波长指数的变化特征。研究结果表明:(1)仅用Langley法对仪器进行定标带来的误差较大,引入期望平均法与拟合平均法后,得到的仪器定标值更合理,有效解决了Langley法定标值波动较大的问题;(2)西安地区气溶胶光学厚度日变化呈现5种特征:平稳型、上升型、下降型、凹型和凸型,其中平缓型出现频率最低(3.55%),凸型出现频率最高(34.25%);(3)500 nm气溶胶光学厚度季节均值为0.60±0.36,0.59±0.33,0.62±0.40,0.68±0.36,呈春夏低、秋冬高的季节变化趋势。Angström波长指数季节均值在夏季最大(1.06±0.33),春季最小(0.81±0.32)。

CCD光度定标对星像精确测量的影响(英文)

近年来,在用CCD器件进行恒星星像的位置和光度的精确测量中,有些研究者考虑了器件的光度定标(或称平场)的改正,有些人却不加说明地忽略之。在今后对恒星或行星星像的精确测量中是否需要考虑这种定标影响呢?为回答这一问题,我们利用在云南天文台1m望远镜上配备的CCD拍摄的实际图像进行了分析处理。当假定CCD每一像素光度的响应与输入光度具有线性关系的模型时,试验表明:对于暗星(约16mag),由光度定标引起的光度影响和位置影响分别约为0.2mag和0.02pixel,而对于亮星(约10mag),相应的改正在光度和位置方面分别约为0.02mag和0.002pixel。明显地,我们应该重视暗星星像的光度改正效应,而星像位置方面的效应则可以忽略不计。

面向光环境亮度测量的彩色成像系统光度定标方法

成像系统光度定标是影响其应用于光环境测量的主要因素。本文研究了包括动态范围延展、颜色空间特性化和光亮度绝对定标的彩色成像系统光度定标方法。研究首先通过变积分时间实现成像系统响应函数的相对定标曲线估计,其次基于相对定标曲线对系统进行线性化和动态范围延展,最后使用sRGB到CIE XYZ颜色空间特性化转换矩阵,结合测量数据点对实现了图像Y值与场景亮度之间的映射关系定标。对定标方法进行了实验验证,结果表明的基于本文定标方法的成像测量亮度与实际测量亮度之间的误差低于1.8%。系统定标方法可以有效匹配场景动态范围,对于光环境评估具有重要意义。

ON THE DESIGN OF A NEW HUMAN COMFORT INDEX

In designing the human comfort index (CI) used in Guangzhou, a Gaussian curve was adopted as the fundamental profile to develop a traw hat?model of comfort index. The model projects low or high temperatures into low index values and the moderate temperatures into high index values. Air temperature was chosen as a basic factor in the model. Other factors such as humidity, sunshine and wind speed were introduced by considering them as temperature departures to an equivalent apparent temperature (EAT). Since the index is a relative index, 25C was chosen as an ideal apparent temperature (the most comfortable state) and a maximum CI value of 100 was assigned at this temperature. While in other circumstances, the index would be lower than 100. By utilizing this model, the daily comfort index values had been calculated for Guangzhou city for 1998-1999, using mean temperature, mean humidity, mean wind speed and total hours of sunshine. Results show that the new model was reasonable and practicable. Not only could it reflect the monthly variation of human comfort in Guangzhou, but also was sensitive to short-term changes of weather conditions.

A Comparative Study of Flavonoid Water-Ethanol Extraction Process in Planted Trollius Chinensis

With rutin standard sample as the comparison, flavonoid extraction rate as an indicator, UV-2450 ultraviolet visible light spectrophotometer to measure flavonoid content in planted Trollius chinensis through orthogonal experiment, this experiment optimizes process condition of flavonoid in Trollius chinensis through water extraction and ethanol extraction. The result shows that flavonoid extraction rate of Trollius chinensis through ethanol extraction method is obviously higher than water extraction, and the optimal extraction process condition is： ethanol concentration is 75%, extraction time is 90min, extraction times are 3, and fluid material ratio is 20：1.

Spectrophotometer standardization in UV-Vis spectral region

Ultraviolet-visible（UV-Vis）spectrophotometry is commonly used in analytical laboratories for qualitative and quantitative analyses.To make the data obtained reliable,an experimental instrument must be calibrated.National Institute for Standards（NIS）in Egypt builds up aphotometric method to ensure the competence of absorbance and transmittance to the standard international and national requirements.This paper presents an instrument for UV-Vis measurement,discusses the factors affecting measurement reliability and estabishes the uncertainty model including correspoding measurement parameters.

Simulations of Aerosol Optical Properties to Top of Atmospheric Reflected Sunlight in the Near Infrared CO_2 Weak Absorption Band

Over the Asian continent,high aerosol loading is critical to ensure the high accuracy of CO_2 retrieval in the near infrared absorption band.Simulations were performed to explore the effect of light path modification by aerosol son the atmospheric CO_2 near infrared band(6140-6270 cm^(-1)).The Vector LInearized Discrete Ordinate Radiative Transfer(VLIDORT) model and the Line-By-Line Radiative Transfer Model(LBLRTM) were used for forward calculations.The U.S.standard atmosphere was used for atmospheric profiles.The results indicate that the aerosols caused similar effects to increases in CO_2 in the planetary boundary layer and became more significant with aerosol layer rising while aerosol optical depth was 0.1.This effect will cause an over estimation of the CO_2 mixing ratio in the retrieval process and an under estimation in the aerosol layer.The results also indicate that the effect of urban and industrial aerosols is smaller than that of non-absorbing and dust aerosols because of the nearly constant absorption properties in the near infrared band.

Will harmful dinoflagellate Karenia mikimotoi grow phagotrophically?

We studied the phagotrophic ability of dinoflagellate strain Karenia mikimotoi KM-Lu （isolated from the South China Sea）, using fluorescent microspheres, bacteria isolated from the culture of K. mikimotoi and a marine microalgae lsochrysis galbana. We found that K. mikimotoi cultured under conditions of high light intensity could ingest fluorescent microspheres （diameters 0.5 and 2.0 lain） and fluorescence-labeled bacteria and microalgae. Under a low light intensity, however, only fluorescent microspheres （diameter 0.5 μm） and fluorescence-labeled microalgae were ingested. K. mikimotoi showed better growth by ingesting living marine bacteria or microalgae I. galbana than the controls, either in nutrient-depleted or nutrient-replete conditions. In nutrient-depleted conditions, the growth ofK. mikirnotoi was more significant with L galbana as the prey item. In conclusion, the harmful dinoflagellate K. mikimotoi from the South China Sea has apparent phagotrophic ability, and some marine bacteria and microalgae may promote the growth of K. mikimotoi.

Membrane preconcentration of iron in seawater samples and on-site determination in spectrophotometry

A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe（II）-ferrozine complex was reacted with cetyltrimethylammonium bromide （CTAB） to form a Fe（II）-ferrozine-CTAB paired compound, which was collected on a membrane by filtration under vacuum. The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis. Various factors affecting the iron collection and determination were investigated. With different sample preconcentration volumes, the range of determination was broadened to 0.5-120 ~tg/L. The detection limit of this method reached 0.19 ktg/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45. The relative standard deviation （n = 7） was 1.9% for samples containing 10 ~g/L Fe. Twelve seawater samples were analyzed on-site using the proposed method, and two were also analyzed in inductively coupled plasma mass spectrometry. No significant difference was shown between the two methods by the Student＇s t-test. The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple, accurate and inexpensive.

The Study on the determination method of Aluminum and its salts

This paper reviews the standard methods for the determination of the Aluminum and its salts, and makes comparative analyses from the operation conditions and its characteristics. The current national standard and the industry standard methods include： the inductively coupled plasma atomic emission spectrometry, the inductively coupled plasma mass spectrometry, the atomic absorption spectrometry, the spectrophotometric method, the potential analysis and the titration analysis.

Measurement of Trace Manganese(Ⅱ) by the Catalytic Kinetic Spectrophotometric Method

A new kinetic spectrophotometric method is developed for the measurement of manganese(Ⅱ) in water. The method is based on the catalytic effect of manganese(Ⅱ) with the oxidation of weak acid brilliant blue dye(RAWL) by KIO4 using the Nitrilo triacetic acid(NTA) as an activation reagent. The optimum conditions obtained are 40 mgL-1 RAWL,1×10-4molL-1 KIO4,2×10-4 molL-1 Nitrilo triacetic acid(NTA),pH = 5.8,the reaction time of 3.00 min and the temperature of 20.0 ℃. Under the optimum conditions,the proposed method allows the measurement of manganese(Ⅱ) in a range of 0-50.0 ng mL-1 and with a detection limit of down to 0.158 ng mL-1. The recovery efficiency in measuring the standard manganese(Ⅱ) solution is in a range of 98.5%-102%,and the RSD is in a range of 0.76%-1.25%. The new method has been successfully applied to the measurement of manganese(Ⅱ) in both fresh water and seawater samples with satisfying results. Moreover,few cations and anions interfere with the measurement of manganese(Ⅱ). Compared with other kinetic catalytic methods and instrumental methods,the proposed method shows fairly good selectivity and sensitivity,low cost,cheapness,low detection limit and rapidity. It can be applied on boats easily.

Study on the Determination of Trace Ni(II) by the Catalytic Kinetic Spectrophotometric Method

A new kinetic spectrophotometric method has been developed for the determination of trace Ni （Ⅱ in natural water. The method is based on the catalytic effect of Ni （Ⅱ） on the oxidation of weak acid brilliant blue dye （RAWL） by KIO4 in acid medium. The concentration of nickel （Ⅱ） can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ = 626 nm using the fix-time method. The influencing factors are investigated by the orthogonal experimental design. The obtained optimum analytical conditions are： pH = 2.00, CRAWL = 5.00×10^-5 mol·L^-1, c KlO4 = 2.00× 10^-5 mol·L^-1, the reaction time t= 10min and the temperature T = 25 ℃. Under the optimum conditions, the developed method allows the measurement of Ni （Ⅱ） in a range of 0 - 40.0ngmL1. The standard deviation of eleven independent measurements of blank reaction is S = 3.08× 10^-3 and the limit of detection is 2.20ng·mL^-1. The relative standard deviations （RSDs） in six replicate determinations of 5 ngmL-1 and 8 ngmL1 Ni （Ⅱ） are 2.87% and 1.11%, respectively. Moreover, the experiments show few cations and anions can interfere with the measurement of Ni （Ⅱ）. The recovery efficiencies of this method are in a range of 97.0%-102.5% in freshwater samples. But there is a decreasing effect, which is about 0.2 times the added Ni （Ⅱ） in seawater medium. After reasonable calibration this processing method is used for the determination of Ni （Ⅱ） in seawater samples successfully. The results show this developed method has high accuracy and precision, high sensitivity, large range of linearity and high speed. The method can, therefore, be employed at room temperature.

The definition analyses of radiation temperature measurement area

In the research of primary spectrum pyrometry, this paper discussed the definition problem of radiation temperature measurement area based on the measurement coordinates. For the linear spectrum emissivity model and improved monotonic spectrum emissivity model, the characteristics of radiation temperature measurement area restricted by the measurement coordinates were theoretically analyzed, through the investigations of the temperature and emissivity coordinate axes. Choosing the specific primary spectrum pyrometer as an example in applications, the theoretical area of radiation temperature measurement of this pyrometer was given and it was verified through blackbody experiments. The discussions of this paper will provide the necessary foundation for the theory research development of primary spectrum pyrometry and the realization of technical applications.

An automated fluorescent single strand conformation polymorphism technique for high throughput mutation screening

Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.

NIR-induced highly sensitive detection of latent finger- marks by NaYF4：Yb,Er upconversion nanoparticles in a dry powder state

The most commonly found fingermarks at crime scenes are latent and, thus, an efficient method for detecting latent fingermarks is very important. However, traditional developing techniques have drawbacks such as low detection sensitivity, high background interference, complicated operation, and high toxicity. To tackle this challenge, we employed fluorescent NaYF4：Yb, Er upconversion nanoparticles （UCNPs）, which can fluoresce visible light when excited by 980 nm human-safe near-infrared light, to stain the latent fingermarks on various substrate surfaces. The UCNPs were successfully used as a novel fluorescent label for the detection of latent fingermarks with high sensitivity, low background, high efficiency, and low toxicity on various substrates including non-infiltrating materials （glass, marble, aluminum alloy sheets, stainless steel sheets, aluminum foils, and plastic cards）, semi-infiltrating materials （floor leathers, ceramic tiles, wood floor, and painted wood）, and infiltrating materials such as various types of papers. This work shows that UCNPs are a versatile fluorescent label for the facile detection of fingermarks on virtually any material, enabling their practical applications in forensic sciences.

Time distribution characteristics of cat-eye reflected light from moving optical target

By using the Collins diffraction formula and expanding the aperture function into a fmite sum of complex Gaussian functions, an analytical formula of the time light intensity distribution for oblique Gaussian beams passing through a moving cat-eye optical lens and going back along the entrance way is deduced. By numerical computation, the variation laws of the time intensity distributions of the cat-eye reflected light with the viewing angle, imaging distance, aperture and instantaneous field of view are given. The results show that the relationship between the light intensity at the return place and the detection time is linear, and it is of inverse proportion only when the viewing angle is very large. For the staring imaging optical lens, the nonlinear extent of the time distribution curve becomes larger with the decrease of the viewing angle. For the instantaneous imaging optical lens, there is still some cat-eye reflected light when the detection system is out of the viewing field of the target lens.

Single and Joint Multifractal Analysis of Soil Particle Size Distributions

It is noted that there has been little research to compare volume-based and number-based soil particle size distributions （PSDs）. Our objectives were to characterize the scaling properties and the possible connections between volume-based and number-based PSDs by applying single and joint multifractal analysis. Twelve soil samples were taken from selected sites in Northwest China and their PSDs were analyzed using laser diffractometry. The results indicated that the volume-based PSDs of all 12 samples and the number-based PSDs of 4 samples had multifractal scalings for moment order -6 〈 q 〈： 6. Some empirical relationships were identified between the extreme probability values, maximum probability （Pmax）, minimum probability （Pmin）, and Pmax/Pmin, and the multifractal indices, the difference and the ratio of generalized dimensions at q = 0 and 1 （Do - D1 and D1/Do）, maximum and minimum singularity strength （αmax and OZmin） and their difference （αmax - αmin, spectrum width）, and asymmetric index （RD）. An increase in Pmax generally resulted in corresponding increases of Do - D1, αmax, αmax - αmin, and RD, which indicated that a large Pmax increased the multifractality of a distribution. Joint multifractal analysis showed that there was significant correlation between the scaling indices of volume-based and number-based PSDs. The multifractality indices indicated that for a given soil, the volume-based PSD was more homogeneous than the number-based PSD, and more likely to display monofractal rather than multifractal scaling.