基于0级数据的星载大气痕量气体差分吸收光谱仪在轨衰变监测

大气痕量气体差分吸收光谱仪(EM I)是一种紫外可见成像光谱仪,主要用于实现高空间分辨率的全球每日大气痕量气体浓度反演.EM I在轨运行期间,受空间环境影响,元器件性能随时间推移会不断衰变.为有效监测其衰变状况,利用载荷对地各轨0级数据解析出在轨温度,实现长期在轨温度监测;通过计算各轨道星下点黑暗时的暗背景图像噪声的均...     

Isotopic Exchange of Hydrogen between the Fluids of the Hydrocarbon Fields

It is presented the isotopic exchange of hydrogen in natural gas, crude oil, and underground water. The general behaviour of the isotopic exchange occuring in a system with a large number of components is given. A good agreement between the calculated and the experimental isotopic distribution factors is obtained in the case of the isotopic exchange of hydrogen between methane and underground water. The deuterium concentration of the crude oil samples inserts between the values obtained for methane and underground water. This fact is due to the presence of the isotopic exchange between these fluids.     

Systematic and Regularities in the Origin of 2H Patterns in Natural Compounds

Abstract

Deuterium patterns of natural compounds and their synthetic analogues, preferably obtained by NMR-measurements, are routinely determined in context with authenticity checks and origin assignments. So far, the use of the data is nearly exclusively empirically, and systematic correlations between the patterns and isotope effects on or mechanisms of the reactions involved have not yet been established.     

A Novel Method for the Detection of Trace Gases Based on Photo-Acoustic Spectroscopy

We study quartz tuning fork (QTF) characteristics using a 532 nm semiconductor laser with a power of 39 mW and calculate QTF vibrations caused by thermal noise and disturbance of the air using the equipartition theorem; the vibration value is about 1.152 Pm. The signal-to-noise ratio and QTF resonance amplitude acquired experimentally are 104.56 and 214.75 Pm, respectively. In addition, we develop a new photo-acoustic spectroscopic system for detection of trace acetylene using a CW diode laser source with distributed feedback operating near 1,532 nm, measure the absorption spectrum of acetylene employing this system, and show that the method elaborated is more sensitive than photoelectric detectors that provides new directions for research in photo-acoustic spectroscopy.     

European Minor Constituent Radiometer: A New Millimeter Wave Receiver for Atmospheric Research

EMCOR is a heterodyne receiver for the frequency range of 201 to 210 GHz. It has been designed for ground-based measurements of various minor constituents of the stratosphere involved in ozone chemistry. Since the aim was the detection of faint spectral lines, a superconducting tunnel junction has been chosen as mixer element and special care has been taken in developing the calibration unit of the system. The front-end is completed by a quasi-optical system, a solid state local oscillator with electronic tuning and a HEMT pre-amplifier. In the back-end an acousto-optical spectrometer is employed to analyse the signal. A PC controls the whole system. The instrument has been installed at a high mountain site in the Swiss Alps.     

算法融合的差分吸收光谱法烟气SO2浓度在线监测研究

过去几十年中差分吸收光谱技术(differential optical absorption spectroscopy,DOAS)在大气污染物监测方面取得了成功应用.文章提出了根据差分吸光度最大值(OD'm)设定阈值的思想,将传统DOAS算法与基于卡尔曼滤波的DOAS算法相结合,利用两种算法在相同信噪比下具有不同反演精度的特点,在保证测量精度的前提下提高了DOAS系统的检测极限,较好地解决了短光程下低浓度气体的测量精度问题.在常温常压和流动状态下,对烟气中的SO2浓度测量进行了理论和实验研究.研究结果表明,改进的DOAS算法在OD'm＜0.048 1时,SO2浓度测量精度较高,测量下限可低于28.6 mg·m-3,零点漂移低于2.9 mg·m-3传统DOAS算法在0.048 1＜OD'm＜0.927 2时,SO2浓度测量精度较高;两种算法对OD'm＞0.927 2时的SO2浓度测量都存在较大的误差,必须进行线性度校正.     

相干振动动力学和高分辨非线性光谱学：空气/二甲亚砜液体界面的比较

研究了空气/二甲亚砜界面C?H伸缩振动的自由诱导衰减的相干振动动力学和亚波数高分辨宽带和频振动光谱．对于特定分子体系,频率域光谱测量和时间域动力学测量原则上应获得相同的信息．但对具有耦合或者重叠在一起的若干振动模式的分子体系,通过时域或者频域测量以获取光谱和动力学信息细节均非易事．对于振动光谱并非过于复杂的空气/二甲亚砜界面,基于亚波数高分辨宽带和频振动光谱的频域测量较超快时域测量更有益于获取界面结构和相干动力学定量信     

A Wall Effect in the Photothermal Beam Deflection Response of Infrared-Absorbing Gases

FTIR photothermal beam deflection (PBD) spectroscopy was used to record PBD spectra of IR-absorbing gases in presence of IR-absorbing and non-absorbing solids. The presence of the solid, IR-absorbing or not, causes asymmetry at the juncture of the IR and probe laser     

Ion Optical Methods - Means to Improve Performance of Mass Spectrometers Designed for Isotopic or Chemical Analysis

Abstract

To improve performances of mass spectrometers dedicated to isotopic or chemical analysis, the methods of the ion optics are to be used. To apply the transfer matrix method of ion optics in mass spectrometer design, the matrix elements of various mass analyzers as Wien filters and crossed field sectors, of energy analyzers as electric prisms, were presented. These elements result from ion trajectory calculations representing solutions of the Euler–Lagrange equations. The basic parameters of an unconventional double focusing mass spectrometer were calculated and compared with those of classical design instruments.     

充分发展槽道湍流的小波数值分析

数值计算了高斯子波变换Navier Stokes(N-S)方程后得到的积分方程.在利用高斯子波得到的以弯曲度为基本量的无穷域中N-S方程的基础上,得到了有界区域内的以弯曲度为基本量的N-S方程.将此N-S方程看作一个特殊的扩散方程,将压力项与对流项看作是源项,得到一个积分方程.利用特征线法对该方程求解,得到通解.并将所得结果运用于对称槽道湍流和非对称槽道湍流的研究中.将计算与实验所得的平均量与实验结果进行了对比.     

Theoretical Exploration of the Isotopic Effect on Molecular High-Order Harmonic Generation

The isotopic effect on the generation of the molecular high-order harmonics is studied by numerically solving the one-dimensional time-dependent Schrödinger equation when the model hydrogen molecule ions/hydrogen deuterium molecule ions are exposed to an intense laser pulse. To explain the effect more clearly, not only the ionization probabilities but also the electron–nuclear probability density distributions and time-frequency profiles are calculated. The results show that more intense harmonics are generated in the asymmetric diatomic molecule ions/hydrogen deuterium molecule ions than those of hydrogen molecule ions. Moreover, the interference minimum in the harmonic spectra is investigated by adjusting the laser intensity and the initial vibrational state. It is shown that the interference minimum is sensitive to the laser intensity and the initial vibrational level for hydrogen molecule ions; in contrast, it is only dependent on the initial vibrational level for hydrogen deuterium molecule ions.     

温室效应对温室气体浓度变化的敏感性分析

工业革命以来人类活动排放到大气中的主要温室气体有CO₂、CH₄、N₂O等,其在大气中的含量增加引起吸收地表辐射能量的增加,改变了地表-大气辐射平衡,造成了地表温度升高。本文研究了温室气体含量增加同其吸收地表辐射能量的关系;比较了不同温室气体含量引起的吸收地表辐射能量变化的差异,提出了温室效应对不同温室气体浓度变化的敏感性的概念。通过对敏感性的分析,得出了不同温室气体含量的变化对温室效应影响的强弱关系。     

Influence of Polarization of Exciting X-Radiation on Sensitivity of Energy Dispersive X-Ray Fluorescence Trace Analysis at Rocks and Soils

The application of polarized X-rays in energy dispersive X-ray fluorescence analysis (EDXRF) is prooved to be one method for improvement the sensitivity of trace analysis at rock- and soil-samples. The use of a high power X-ray tube in connection with an amorphous Barkla-scattering target for polarization makes possible the increase of peak-to-background ratios in a wide energy range (5 keV < E < 40 keV) in comparison to direct excitation. The influence of the polarization on the peak-to-background ratios at trace analysis at geological samples will be shown.     

A New Entropy Function to Analyze Isentropic Processes of Ideal Gases with Variable Specific Heats

A new entropy function s⁺ is defined in terms of the existing entropy function s° and temperature as s⁺ = s° − R lnT to facilitate the analysis of isentropic processes of ideal gases with variable specific heats. The function s⁺ also makes it possible to calculate the entropy changes of ideal gases during processes when volume information is available instead of pressure information and the variation of specific heats with temperature is to be accounted for. The introduction of the function s⁺ eliminates the need to use the dimensionless isentropic functions relative pressure P_r and relative specific volume v_r of ideal gases and to tabulate their values. The P_r and v_r data are often confused with pressure and specific volume, with an adverse effect on the study of the second law of thermodynamics. The new s⁺ function nicely complements the existing s° function in entropy change calculations: the former is conveniently used when volume information is given while the latter is used when pressure information is available. Therefore, the introduction of the new entropy function s⁺ is expected to make a significant contribution to the thermodynamics education and research by streamlining entropy analysis of ideal gases.     

A High Precision Thermostat for the Isotopic Analysis of Water by the Falling Drop Method

An a.c. bridge thermostat, using two thermistors mounted in two opposite arms as temperature sensing elements, is described. The unbalanced bridge voltage is rectified, after a previous amplification, by a phase sensitive detector, and it is applied to the input of the final stage which controls the heater. The thermostat can be used to maintain the temperature of a liquid bath with a 0.0005°C precision and can be easily reset to different temperatures in the operational range of the thermistors.     

A Calculation of the Electron Temperature of Complex Plasma of Noble Gases Mixture in CCRF Discharge

In this paper the results of studying of the electron temperature of buffer and complex plasmas in mixtures of noble gases (helium + argon) in capacitively coupled radiofrequency (CCRF) discharge are presented. The optical properties of dusty plasma in argon, helium and their mixtures have been studied using optical diagnostic methods. Based on spectral lines of plasma forming gases, the dependence of the electron temperature on gas pressure and discharge power has been determined. The axial distribution of electron temperature in the interelectrode gap has been measured. Measurements have been made using an RF compensated electric probe. The comparison of the experimental results shows that admixture of a small amount of argon to helium leads to a decrease in the electron temperature of buffer plasma. The presence of dust particles in the plasma causes an increase in the electron temperature. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

激光诱导击穿光谱技术定量分析SF_6中的痕量O

六氟化硫(SF_6)气体因其优良的绝缘和灭弧性能,被广泛应用于高压绝缘设备中。然而,当存在H_2O和O_2等杂质时,SF_6气体在局部放电等作用下分解成的低氟化物会进一步与杂质发生反应生成稳定的氟硫氧化物和氢化物,使得设备绝缘性能下降,危害电网安全,因此检测和分析SF_6中微水、微氧及其分解产物具有重要意义。采用激光诱导击穿光谱技术测量了SF_6中的痕量O含量。利用CaF2作为窗口材料,解决了窗口材料在不断腐蚀作用下引起的激发能量逐渐衰减以及窗口材料与SF_6气体击穿产物反应引入的污染影响测量结果的问题,消除了由激发条件改变引起的等离子体状态的变化;通过测量不同O含量的SF_6气体激光诱导击穿光谱,结合迭代小波分析对实测光谱进行基线校正和降噪处理,通过定标曲线获得了O元素检测限为38ppm。利用偏最小二乘法建立了稳定的定量分析模型,改善了定量分析模型的稳定性和精度。     

A Novel Measurement Method of the Emission Rules of Greenhouse Gases from Fertilized Soil Based on Fourier Transform Infrared Spectrometry with Long Optical Path

Farm soil is the main source of greenhouse gas emission. We developed an optical system for measuring nitrous oxide and carbon dioxide from soil using infrared spectrometer and long optical path gas cell based on multi-reflecting mirrors. The spectral characteristics of nitrous oxide at 2198–2223 cm^?1 and of carbon dioxide at 2258–2283 cm^?1 were observed with the system. We studied the rules of greenhouse gas emission and found that nitrous oxide increased with soil moisture whereas carbon dioxide showed no obvious relationship with moisture. We also studied the diurnal variation rules of nitrous oxide and carbon dioxide from fertilized soil. These results are consistent to the previous results obtained with other analytical methods. The results indicate that the infrared spectroscopy with long optical path is an effective way to measure greenhouse gas emission from soil.     

高温空气热化学物理计算模型研究

对于大气层内高速飞行器,其周围空气受到强激波压缩而温度急剧升高,引起空气分子发生激发、离解、电离、复合等作用形成多组元混合气体,这种多组元混合气体的热物性参数是气动力热和电磁仿真的基础。本文针对N2-O2-Ar空气体系,在局域热动和局域化学平衡假设下,建立了考虑18种化学反应22组元的混合体系热化学物理计算模型,模拟了高温空气的组分浓度以及焓和比热等热力学性质,研究了高温空气的离解、电离、复合等化学反应以及焓和热容等物性参数随温度和密度的演化规律,发现了空气稀薄程度的增加有利于化学反应的发生以及因高温引起化学反应导致的热容和比热比波动变化现象,并对飞行器高速飞行时驻点处的空气组分、压缩比、温度、热容以及比热等参数随飞行速度的变化给出了预测。这些结果和规律性的认识有助于更好地了解高速飞行器周围稀薄空气因强激波压缩产生高温诱导发生的物理化学反应、现象及作用机理。     

Rotational Analysis of the 383.8 nm Band of the GeBr Molecule

Abstract

The 383.8 nm band of the GeBr molecule, recorded at high resolution, has been rotationally analyzed. Rotational constants of the upper and lower states have been determined from lines of six, main isotopic molecules of GeBr. The band has been proposed to be assigned as the ⁴σ^??X²π_3/2 0–0 transition.