多道激光Raman光谱检测系统

设计了一种多道激光Ｒａｍａｎ光谱检测系统,由Ａｒ＾＋激光器、外光路、多色仪和光学多道分析仪（ＯＭＡⅡ）组成,通过对ＣＣｌ４、Ｃ６Ｈ６、Ｃ６Ｈ１２的Ｒａｍａｎ光谱的检测表明,与单道激光Ｒａｍａｎ光谱检测系统相比,多道系统大大缩短记录Ｒａｍａｎ光谱的时间,但每道的积分时间可延长至１０－５０ｓ,将多道探测器的工作温度降低到５℃,可获得信噪比高、灵敏度高、质量好的Ｒａｍａｎ光谱。采用微分软件处理Ｒａｍａｎ     

A Complete Frequency-Field Chart for the Antiferromagnetic Resonance in MnF2

Antiferromagnetic resonance (AFMR) measurements on a well characterized single crystal sample of MnF₂ have been performed using various kinds of millimeter and submillimeter sources up to 570 GHz and a superconducting magnet up to 20 T. All the AFMR modes predicted from the theory have been observed. We report a complete frequency-field chart for these AFMR modes.     

Optoacoustic gas analyzer based on a13C16O2 laser for multicomponent pollution of air

A computer-aided optoacoustic gas analyzer based on a continuous¹³C¹⁶C₂ laser for multicomponent pollution of atmospheric air is described. The analyzer has the ability to detect absorption of radiation by detected substances at the level of ∼1·10⁻⁹ cm⁻¹ at a time resolution of 30 sec. Results of an experiment on simultaneous detection of H₂O, CO₂, NO₂, NH₃, HNO₃, OCS, and C₂H₄ in the atmospheric air using 40 laser lines are presented. B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 345–350, May–June, 1999.     

流动注射分析法测定铁的价态

本文根据Fe(Ⅲ)-DCS-偶氮胂和Fe(Ⅱ)-邻菲啰啉体系的显色反应,采用自动化流动注射分析装置进行了铁两种价态的测定,不同比例的Fe(Ⅲ)和Fe(Ⅱ)混合物相对标准偏差在5％以内,分析速度为120试样/h。     

InGaAs探测器中的双孔法非线性校正技术

探测器的非线性误差是影响光谱仪器精度的主要因素,采用双孔法解决InGaAs探测器的非线性校正问题,消除了InGaAs探测器非线性误差对水红外分析仪吸光度示值的影响。实验结果表明,水红外分析仪经非线性校正后的吸光度偏差明显小于校正前的吸光度偏差,提高了仪器测定结果的准确度。     

直接测汞仪计量校准方法探讨

介绍了直接测汞仪的原理和结构,对其校准方法和主要计量校准项目如线性误差与相关系数、检出限、测量重复性,以及具体技术指标进行了探讨。技术指标如下:线性误差在±10%之内,线性相关系数r≥0.997,检出限不大于0.02 ng,重复性不超过5%(n=7)。提出了直接测汞仪校准过程中应注意的事项。     

近十年来流动测量技术的新发展

流动是一种跨行业、跨部门、跨学科的现象。现代空气动力学、流体力学、热力学、水力学以及航空航天工程、水利水电工程、热能工程、流体机械工程都提出了一系列复杂流动问题，其中包括高速流、低速流、管道流、燃烧流、冲击流、振荡流、涡流、湍流、旋转流、多相流等等。这些流动都需要人们提供新的测量方法和新的量测仪器、使之能够适应单点向多点、平面向空间、稳态向瞬态、单相向多相方向发展，这就促使人们不断利用新技术，发展新原理，采用新结构和新工艺，以改善食品性能，增强讯号处理能力，提高仪器的测量精度。同时简化操作技术，使之便于推广应用。近10年来，伴随着光纤技术、芯片技术、激光技术、数字信号处理技术，图形、图像处理技术以及计算机技术的日益成熟和完善，流速测量技术也随之得到了新的发展。本文就这些发展作一扼要介绍。     

Infrared filters and analyzers of the composition of substances based on them

Results of investigations on designing band dispersion and dispersion-interference filters for the 4–30 μm IR range and cutoff filters for the 50–300 μm region are presented. Analyzers of the composition of a substance that are designed on the basis of band IR filters and analysis procedures are described. Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 734–744, September–October, 1998.     

GC-MS/MS multi-residue method for the determination of organochlorine pesticides,polychlorinated biphenyls and polybrominated diphenyl ethers in human breast tissues

In this work, a multiresidue method for the quantification and confirmation of around 30 organohalogenated compounds in human breast tissue samples has been developed. Analytes tested included organochlorine (OC) (pesticides and polychlorinated biphenyls) and organobromine (OBr) (polybrominated diphenyl ether) compounds. The approach is based on a simple extraction with hexane, followed by a SPE clean-up using silica cartridges and final measurement by GC coupled to triple quadrupole MS. Analyses were performed in both ionizations, electron impact (EI) (selected reaction monitoring (SRM) mode) and negative chemical ionization (NCI) (selected ion recording (SIR) mode). Three isotopically labeled standards were added before extraction and used as surrogates: HCB-¹³C₆, lindane-D₆ and p,p′-DDE-D₈. The method was validated in terms of accuracy, precision, LOQ and LOD and confirmation reliability, using breast tissue spiked at three concentration levels in the range 1–100 ng/g for OC compounds and at two levels 0.1 and 10 ng/g for OBr compounds (0.5 and 50 ng/g for BDE 209). The usefulness of the developed method was tested by the analysis of real human samples, giving as a result the detection of several OC and OBr compounds in different samples analyzed. The acquisition of at least two SRM transitions (in EI) or ions (in NCI) per analyte allowed positive findings to be confirmed by accomplishment of ion ratios between the quantification and the confirmation transitions or ions.     

Development of a new experimental setup for studying collisions of keV-electrons with thick and thin targets

Development of a new lectron-recoil ion/photon coincidence setup for investigating some of the electron induced collision processes, such as electron bremsstrahlung, electron backscattering, innershell excitation and multiple ionization of target atoms/molecules in bombardment of electrons having energies from 2.0 keV to 30.0 keV with solid and gaseous targets is described. The new features include the use of a compact multipurpose scattering chamber, a time-of-flight spectrometer for detection of multiply charged target ions, a 45°-parallel plate electrostatic analyzer for measuring energy and angle of the ejected electrons, a room temperature high resolution Si-PIN photo diode X-ray detector for counting the collisionally induced photons, a coincidence data acquisition system consisting of a 200 MHz Pentium based 8K-multichannel analyzer and a standard network of a fast/slow coincidence electronics. In particular, the details of design, fabrication and assembly of indigenous components employed in the setup are presented. Selected experiments planned with the setup are mentioned and briefly discussed. A report on performance, optimization, efficiency, time resolution etc. of the time-of-flight (TOF) spectrometer and that of the 45°-parallel plate electrostatic analyzer (PPEA) is presented. Test spectra of electron-recoil ion coincidences, energy distribution of ejected electrons and characteristic plus non-characteristic X-ray spectrum are illustrated to exhibit the satisfactory performance of the developed setup.