邻氯苯基荧光酮胶束增溶分光光度法测定岩石矿物中的锡

本文介绍了在阳离子表面活性剂存在下锡[Sn(Ⅳ)]与邻氯苯基荧光酮(O-Cl-PF)胶束增溶显色反应的研究结果,发现在溴化十六烷基三甲基铵(CTMAB)存在下,Sn(Ⅳ)与O-Cl-PF可形成深颜色的络合物,其最大吸收在534nm处,络合物的摩尔吸收系数为1.83×10~5lmol~(-1)·cm~(-1)在0—8μgSn(Ⅳ)/25范围内符合比尔定律,采用等摩尔连续变换法确定了络合物的组成为Sn(Ⅳ):O-Cl-PF=1:4、本文提出了不经分离其伴生元素而快速测定铀矿石中微量Sn(Ⅳ)的新方法,所得结果令人满意。     

南极地区UV-B气候学现状与展望

自１９８５年发现南极春季臭氧洞以来，对于臭氧大幅度减少所引起的可能后果与危害引起了国际关注。臭氧减少的直接后果之一是到达地表的ＵＶ－Ｂ辐射增强，从而引起生态系统的不利变化。因此，围绕南极地区ＵＶ－Ｂ辐射变化的测量和研究开始得到重视，并逐步建立南极地区ＵＶ－Ｂ气候学。本文评述了国际上在这方面工作的进展，提出了需要进一步解决的问     

Exploration of faint absorption bands in the reflectance spectra of the asteroids by method of optimal smoothing: Vestoids

An optimization method of smoothing noisy spectra was developed to investigate faint absorption bands in the visual spectral region of reflectance spectra of asteroids and the compositional information derived from their analysis. The smoothing algorithm is called “optimal” because the algorithm determines the best running box size to separate weak absorption bands from the noise. The method is tested for its sensitivity to identifying false features in the smoothed spectrum, and its correctness of forecasting real absorption bands was tested with artificial spectra simulating asteroid reflectance spectra. After validating the method we optimally smoothed 22 vestoid spectra from SMASS1 [Xu, Sh., Binzel, R.P., Burbine, T.H., Bus, S.J., 1995. Icarus 115, 1-35]. We show that the resulting bands are not telluric features. Interpretation of the absorption bands in the asteroid spectra was based on the spectral properties of both terrestrial and meteorite pyroxenes. The bands located near 480, 505, 530, and 550 nm we assigned to spin-forbidden crystal field bands of ferrous iron, whereas the bands near 570, 600, and 650 nm are attributed to the crystal field bands of trivalent chromium and/or ferric iron in low-calcium pyroxenes on the asteroids' surface. While not measured by microprobe analysis, Fe³⁺ site occupancy can be measured with Mössbauer spectroscopy, and is seen in trace amounts in pyroxenes. We believe that trace amounts of Fe³⁺ on vestoid surfaces may be due to oxidation from impacts by icy bodies. If that is the case, they should be ubiquitous in the asteroid belt wherever pyroxene absorptions are found. Pyroxene composition of four asteroids of our set is determined from the band position of absorptions at 505 and 1000 nm, implying that there can be orthopyroxenes in all range of ferruginosity on the vestoid surfaces. For the present we cannot unambiguously interpret of the faint absorption bands that are seen in the spectra of 4005 Dyagilev, 4038 Kristina, 4147 Lennon, and 5143 Heracles. Probably there are other spectrally active materials along with pyroxenes on the surfaces of these asteroids.     

时间分辨紫外脉冲荧光法测定锆矿中的铀

基于前人研究工作,开展时间分辨紫外脉冲荧光法测定天然伴生放射性锆矿样品中铀含量的方法研究。与电感耦合等离子体质谱法相比,该法正确度好、精密度高、抗干扰能力强、适应性强。实验表明体系酸碱度影响荧光强度显著,但当pH值在6.85～9.10范围时,荧光强度较高且相对稳定。对31种阳离子干扰进行实验,结果表明Sn、Cr、Sb、Tl、Rh、Mn、Ag、Bi等阳离子可使荧光强度显著降低;溶液中Zr元素质量浓度低于200μg·mL^-1时,对荧光强度影响不明显,Zr元素质量浓度为200～500μg·mL^-1时,荧光强度随Zr元素质量浓度的增加而逐渐减弱。采用过氧化钠碱熔-硝酸提取天然伴生放射性锆矿样品,样品能够消解完全。采用标准加入法,用紫外脉冲荧光法测定铀含量,检出限为0.05μg·g^-1,测定范围为0.15～4500μg·g^-1;铀含量在40～735μg·g^-1时,RSD为2.1%～7.7%;铀含量为288μg·g^-1的锆矿样品,正确度为5.2%。     

Dynamics of the transition region

In this review, we consider the problem of the apparent redshifts of the UV lines in the transition region and review the basic observations made over the last decades, especially the observations of the last few years from satellite observatories. Moreover, we revise the most popular theoretical explanations for the motions in the transition region. This review is a contribution to the understanding of the physical processes in this important layer of the solar atmosphere and it points out the pending problems.     

All you ever wanted to know about optical long baseline stellar interferometry, but were too shy to ask your adviser

I try to present a small view of the properties and issues related to astronomical interferometry observations. I recall a bit of history of the technique, give some basic assessments to the principle of interferometry, and finally, describe physical processes and limitations that affect optical long baseline interferometry and which are, in general, very useful for everyday work. Therefore, this text is not intended to perform strong demonstrations and show accurate results, but rather to transmit the general “feeling” one needs to have to not be destabilised by the first contact to real world interferometry.     

Near-infrared spectrophotometry of Asteroid 25143 Itokawa from NIRS on the Hayabusa spacecraft

A photometric analysis of the S-type Asteroid 25143 Itokawa is performed over multiple wavelengths ranging from 0.85 to 2.10 μm based on disk-resolved reflectance spectra obtained with the Hayabusa near-infrared spectrometer (NIRS). We derive the global photometric properties of Itokawa in terms of Hapke's photometric model. We find that Itokawa has a single-scatter albedo that is 35-40% less than that of Asteroid 433 Eros. Itokawa also has a single-particle phase function that is more strongly back-scattering than that of Eros. Despite its hummocky surface strewn with large boulders, Itokawa exhibits an opposition effect. However, the total amplitude of the opposition surge for Itokawa was estimated to be less than unity while Eros and other S-type asteroids have been found to have model values exceeding unity. The wavelength dependence of the opposition surge width reveals that coherent backscatter contributes to the opposition effect on Itokawa's surface. The photometric roughness of Itokawa is well constrained to a value of 26° ± 1° which is similar to Eros, suggesting that photometric roughness models the smallest surface roughness scale for which shadows exist.     

meso-四(对-三甲铵基苯基)卟啉与铋显色反应的研究

研究了在催化剂苯羟乙酸的存在下,me so-四(对-三甲铵基苯基)卟啉与Bi(Ⅲ)的显色反应。在pH 5.7的HAc-NaAc介质中,于沸水浴中反应5min完成,配合物的最大吸收波长为464mn,表现摩尔吸光系数为3.15×10~5L·mol~(-1)·cm~(-1),Bi(Ⅲ)含量在0～0.48μg/ml范围内呈线性关系,配合物的组成为Bi(Ⅲ):T(4-TAP)P=2:3。方法可用于矿样中痕量Bi的测定。     

沙棘树干茎流液中总氮总磷联合消解的测定方法

对于总氮和总磷的测定,国家标准HJ636—2012和GB11893—89规定总氮用碱性过硫酸钾消解,紫外分光光度法测定,总磷用中性过硫酸钾消解,分光光度法测定,两种方法分别取样、消解,分析效率低。本文对国家标准方法进行改进,建立了在一份样品中用过硫酸钾作为氧化剂一次消解,分光光度法联合测定树干茎流液中总氮、总磷含量的方法。样品中的含氮化合物在碱性过硫酸钾溶液中,在高温下氧化分解转化为硝酸盐氮(NO-3-N),其吸光度与总氮浓度成正比;含磷化合物在酸性过硫酸钾溶液中,在高温下氧化分解转化成正磷酸盐(PO3-4-P),其吸光度与正磷酸盐浓度成正比。经实际样品验证,方法精密度(RSD,n=5)为总氮2%,总磷4%,加标回收率为98.0%~104.2%(总氮)和94.0%~107.0%(总磷)。本方法将国家标准方法中配制两条标准系列、两次高压消解改进为配制一条标准系列、一次消解,可以节省50%的样品使用量,且提高了分析效率。由于有机质含量较高时,在本法条件下样品不易消解清亮,影响总氮、总磷的测定,该方法适用于有机质含量较低的树干茎流样品分析。