氧化铁对石灰中温烟气脱硫活化机理的流化床实验分析

运用小型热态流化床对石灰与氧化铁混合物的中温烟气脱硫反应特性再次进行了分析。研究表明:在石灰中掺入一定比例的氧化铁可以显著提高钙利用率,氧化钙晶粒以氧化铁颗粒为核心进行固硫反应,破坏了形成表层致密产物层的条件,改变了石灰表层孔隙结构,使更多的内部孔隙暴露,为同硫反应向纵深发展创造了条件。     

氧化铁浆液脱硫的实验研究与理论分析

本文实验研究了氧化铁浆液在酸性环境下脱除烟气中的二氧化硫气体。实验在一自制的脱硫塔中进行。通过燃烧液化石油气来产生烟气,将氧化铁的超细粉加入水中作为脱硫介质。实验中研究了二氧化硫初始浓度、水气比对脱硫效率的影响。从实验结果可以看出,脱硫率随着水气比的增加而增大;随二氧化硫的初始浓度的增加,其脱硫率呈降低趋势。在文中同时分析了氧化铁浆液的脱硫机理和此方法脱硫的优点以及目前存在的问题。     

高温燃气脱硫的Mossbauer谱研究：氧化铁脱硫,失活与再生机理探讨

本文采用＾５＾７ＦｅＭｏｓｓｂａｕｅｒ谱学方法，跟踪考察氧化铁在高温（９７３Ｋ）燃气脱硫过程中的转化演变，取得有关其脱硫，失活与再生机理的明确信息。     

氧化铁薄膜制备方法的改进

氧化铁薄膜具有很高的极限磁记录密度．然而，单相四氧化三铁薄膜的制备却对工艺条件十分敏感，并且成膜的饱和磁化强度也远低于块状样品．在溅射过程中引入水蒸气、氧气和氩气的混合气体，一方面可以大大拓宽单相四氧化三铁薄膜的制备条件，另一方面也使得饱和磁化强度增加到４５０ ｅｍｕ／ｃｍ~３以上．本文对不同的氧化铁薄膜制备方法及磁性等进行了比较．     

湿法液柱喷射烟气脱硫反应的实验研究

湿法液柱烟气脱硫技术是基于简易湿法石灰-石膏烟气法开发的新型湿法脱硫技术,本套设备在2000-2001年问进行了工业级示范实验运行,得到了湿法液柱脱硫反应的一些基本数据与规律。本文主要探讨了湿法液柱脱硫系统中液气比、吸收塔浆液pH值、烟气温度和烟气中SO2含量等工艺参数对系统脱硫效率的影响规律,并进行了初步的机理分析,为进一步的改进湿法液柱烟气脱硫系统的工艺奠定了基础。     

中温烟气脱硫过程中CO2对脱硫剂钙利用率的影响

本文在300～600℃的中温区段,实验研究了CO2在烟气脱硫过程中与钙基脱硫剂发生碳酸盐还原反应,削弱脱硫效果的规律,发现石灰钙利用率随温度升高呈跳跃式变化,并因碳酸盐反应程度的迅速增加而在500℃附近出现低谷.由此明确了减小碳酸盐反应效应,提高脱硫剂钙利用率的途径,为进一步发展中温烟气脱硫工艺提供了重要依据.     

NO2对中温干法脱硫反应影响的实验研究

利用鼓泡床反应器对NO2对中温干法脱硫反应的影响开展了实验研究.分别采用分析纯CaO和工业级石灰两种物质作为吸收剂,在250℃和350℃两个反应温度下研究NO2对吸收剂转化率的影响.结果表明,NO2的存在可以提高吸收剂转化率;250℃下NO2的作用显著高于350℃;250℃下NO2浓度的增加对吸收剂转化率基本没有影响;在350℃时,对于分析纯CaO,NO2浓度的增加降低了吸收剂转化率,这主要是由于SO2与NO2的竞争反应引起的;工业级石灰内含杂质较多,对一些反应有催化作用,因而其反应现象与分析纯CaO略有不同.     

纳米氧化铁吸附脱除单质汞的实验研究

在固定床反应器上研究了N_2气氛下纳米氧化铁对单质汞的吸附脱除特性,探讨了吸附剂颗粒尺寸,反应床温度,停留时间及表面羟基基团对纳米氧化铁除汞性能的影响。研究表明,与普通氧化铁颗粒瞬间到达穿透相比,纳米氧化铁具有更强的汞吸附能力,相同条件下其80%穿透时间达到45 min,XPS分析表明,纳米氧化铁表面85%以上均为氧化态的汞。汞在纳米氧化铁上的吸附过程中化学反应起重要作用。在试验温度范围内,随着反应床温度增加,纳米氧化铁对汞的吸附性能提高幅度显著。反应前后样品的红外光谱分析结果表明,纳米氧化铁表面主要是游离态的羟基参与了汞吸附反应。     

喷钙脱硫系统中增湿活化器的作用以及液滴和固体颗粒的碰撞实验研究

本文介绍了喷钙脱硫系统的实验研究结果，在调试工况和Ｃａ／Ｓ＝２．１３下采用增湿活化器能增加脱硫率１２．２％；此值和液滴蒸发所需时间有关。本文还利用多脉冲激光全息冷态试验台，对雾化液滴与固体颗粒的碰撞做了初步研究，证实了碰撞的存在，为增湿脱硫机理中的碰撞模型提供了依据。     

水溶液中Ca(OH)2粒径分布研究

本文利用激光粒度分析仪研究了石灰产地、石灰尺寸和液固质量百分比对石灰水合所得浆液中Ca(OH)2粒径的影响.结果显示,石灰尺寸和液固质量百分比对浆液中Ca(OH)2粒径分布影响较小,而产地对粒径有一定影响.将平均粒径为5μm的分析纯Ca(OH)2粉末制备成浆液,其粒径增大到13μm,表明Ca(OH)2在水中发生团聚.因此,单纯依靠改变制备条件或石灰来源,对于减小Ca(OH)2的粒径作用不大,必须采用其它措施如添加分散剂来减轻团聚并减小粒径.     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.