氯化钾异相硫化机理的试验研究

生物质燃烧释放的碱金属氯化物蒸气会在受热面上冷凝,并在烟气中SO_2/O_2/水蒸汽等共同作用下发生异相硫化反应,从而影响碱金属对受热面的腐蚀。本文利用固定床反应器研究了反应温度、停留时间、氯化物及SO_2/O_2/H_2O等浓度等对固相KCl硫化的影响,实验结果表明:KCl非均相硫化的主要产物是K_2SO_4,在O_2和H_2O较低是KCl异相硫化较慢,KCl异相硫化速率随SO_2/O_2和H_2O浓度增大而提高,随停留时间的延长呈线性递增,并随反应温度的升高呈指数关系升高。     

KCl对含有纳米银的[Ru(bpy)3]2+荧光性能影响

通过吸收光谱、荧光光谱等手段研究了KCl对含有纳米银的金属钌联吡啶配合物([Ru(bpy)3]2 )的荧光性能的影响.结果表明,KCl与纳米银粒子间存在较强的相互作用,这种强的相互作用破坏了[Ru(bpy)3]2 与纳米银粒子间的链状网络结构,形成大颗粒和团聚体.同时,在吸收光谱的长波段处观察到明显的新的吸收带,随着KCl量的增加,新吸收带峰值逐渐红移并展宽.随着KCl量的增加,[Ru(bpy)3]2 荧光强度先猝灭而后逐渐增强,直至达到一个定值.文章从分子间的相互作用、能量传递等方面探讨了KCl对含有纳米银的[Ru(bpy)3]2 荧光性能影响机理.     

掺质KCl晶体F_A色心电子能级

在计算KCl晶体中的F_A心电子能级时,本文认为是基质和掺质对色心电子云束缚的松紧程度之差确定了电子云分布,据此对三种典型的掺质:Li:KCl:F_A(II);Cu:KCl:F_A(III);Ti:KCl:F_A(III),采用不同的出发点进行计算,结果和实验值比较,误差在5%以内.     

三氢异氰尿酸红外光谱测绘方法探讨

本文对KBr压片法、KCl压片法以及萨特勒图谱采用的，糊剂法所绘制的三氯异氰尿酸的红外光谱进行了分析、对照。KCl压片法克服了溶剂的影响，简单、直观地体现了物质的精细结构。同时，将三氯异氰尿酸分别与KCl、KBr研磨，和三氯异氰尿酸纯品进行了紫外－可见吸收光谱对照。实验发现，与KBr研磨的三氯异氰尿酸和纯品的吸收峰有差异，而与KCl研磨后的三氯异氰尿酸和纯品一致，说明结构未发生变化。因此，认为KCl压片法是绘制三氯异氰尿酸红外光谱较好的方法。     

KCl中FH(CN)-的吸收、发射光谱及e-v能量转换机理研究

以扩展离子处理方法(SLC)从理论上研究了KCl中F_H(CN)^-缺陷中心的基态和激发态的特性,理论计算值与F_H(CN)^-在KCl中的吸收、发射光谱的实验值符合得很好。计算了(CN)^-分子在KCl中的本征振动频率,解释了F_H(CN)^-的振动荧光光谱及相应的Raman谱,指出Raman振动谱中峰的劈裂应该来源于(CN)^-分子在KCl中的 关键词：     

KCI对银胶形态影响的电子显微镜研究

借助透射电子显微镜研究了银胶中加入KCl时对银胶的影响。发现KCl的加入引起了银原子的输运,使胶体颗粒变大,表面上覆上一层疏松原子集团。同时引起胶体发生链状凝聚。和加入吡啶引起的银胶的变化做了比较,表明KCl和吡啶对银胶的作用结果有很大差异。同时也讨论了这些差异对表面增强喇曼散射信号的影响。 关键词：     

添加KCl对银胶光吸收的影响

本文研究了添加KCl对两种银胶光吸收谱的影响,并与添加吡啶的情形进行了比较。结果表明KCl的加入,由于造成银颗粒表面的覆盖层而使整个光谱区的光吸收增加,消弱了原银颗粒的等离振子共振吸收,同时因银胶发生链状凝聚,原等离振子共振吸收峰发生劈裂和红移。讨论了这些变化对表面增强喇曼散射强度的影响。 关键词：     

KCl添加剂对激光诱导土壤等离子体辐射强度的影响

为了提高激光诱导击穿光谱技术对低含量物质成分的检测能力,实验研究了KCl添加剂对土壤样品发射光谱的增强效应。利用高能量钕玻璃脉冲激光器烧蚀样品,由组合式多功能光栅光谱仪和CCD数据采集处理系统记录等离子体光谱,并通过测量光谱线的强度和Stark展宽分别计算了等离子体的电子温度和电子密度。实验结果证明,随着KCl加入量的增加,激光等离子体的光谱强度、信背比、电子温度和电子密度均呈现出先增大而后减小的规律。当KCl加入量为15%时,等离子体辐射最强,元素Mn,Fe,和Ti的谱线强度分别比无添加剂时提高了2.23,1.13和2.04倍,信背比分别提高了1.33,0.89和0.94倍;而等离子体的温度和电子密度比无添加剂时分别提高了14%和38%。     

H2O+KCl(饱和)+NaCl+NH4Cl的等压研究

在298.15K条件下采用等压实验方法对KCl饱和的四元水溶液体系H2O+KCl(饱和)+NaCl+NH4Cl及其两个三元亚系H2O+KCl(饱和)+NaCl和H2O+KCl(饱和)+NH4Cl进行了研究.以NaCl或CaCl2水溶液为参考溶液,测定了不同水活度条件下该四元水溶液的渗透系数及水活度.实验结果表明,该四元系与其两个三元亚系之间存在着简单的共性,在实验误差允许范围之内,该四元系的等压行为符合类理想溶液模型.     

应用ICP—MS测定KCl肥料中重金属元素含量

肥料是重金属的重要污染源之一,重金属可以通过作物直接进入人类食物链对人体产生危害,研究肥料中重金属含量对于农产品安全溯源意义重大。文章选用北京市场上销售的进口KCl肥料作为实验材料,全面分析了其中的10种重金属元素含量,分别为,Cr0.00,Ni65.54,Cu238.85,As190.60,Cd0.98,Sn14.98,Sb2.97,Hg10.04,Tl1.28,Pb97.42ng·g-1。上述结果表明,KCl肥料中重金属含量普遍比较低,特别是Cr没有检测到,其余四中主要重金属(As,Cd,Hg,Pb)的含量除了As(190.60ng·g-1)以外,也都在100ng·g-1以下,不会对土壤环境造成重大污染,含量最高的重金属是Cu,为238.85ng·g-1。由此看来,KCl肥料与磷肥相比重金属含量较低,对农产品是相对安全的。     

Output couplers of ultra-transparent KCl and NaCl in a pulsed CO2 laser

Uncoated plane parallel windows made from ultra-transparent KCl and NaCl crystals, which were grown by ‘injecting the reactive atmosphere’ (IRA) technique, have been tested as output windows in a high-power, high-repetition TEA CO₂ laser, in various resonator configurations. Output power densities per pulse of 2 to 6 MW cm^-2, which are 40% to 60% less than with 50% reflective coated ZnSe, have normally been obtained. The laser performances did not change after one year of operation and more than 10⁷ pulses per window. No laser damage has been observed.     

Identification of recombination centers in wide-band-gap crystals and related nanostructures from spin-dependent tunneling afterglow

The centers involved in the spin-dependent recombination in KCl: AgCl insulator-semiconductor wide-band-gap crystal structures, bulk ZnO crystals, and quantum dots based on ZnO nanocrystals have been identified by detecting electron paramagnetic resonance from tunneling afterglow. Long tunneling after-glow has been excited by short-term UV irradiation of the sample at liquid-helium temperatures. The observed magnetic quenching of the afterglow at low temperatures results from the Boltzmann polarization of spins of recombination centers. The revealed giant increase in the afterglow intensity is induced by the reorientation of spins of these centers at electron paramagnetic resonance. A new technique for recording the spectra at a high frequency of 94 GHz has been developed and used with the aim of increasing the sensitivity and spectral resolution. This technique has made it possible to separate electron and hole centers in the KCl: AgCl structures and to demonstrate that ZnO: Al quantum dots contain two types of deep acceptors.     

Optical properties and stable,broadly tunable cw laser operation of new FA-type centers in Tl+-doped alkali halides

A new group of complex color centers with F_A-type properties, involving simple center production and high thermal and optical stabilities, has been found in six Tl⁺-doped alkali halides: NaCl, KCl, RbCl, KBr, RbBr and RbI. In its first tested examples, KCl and KBr, broadly tunable cw laser operation over the 1.4 to 1.7 μm range has been obtained, with output powers in the 100 mW range. In contrast to already existing F⁺₂ and F⁺₂-like centers, operating in the same wavelength range, the new F_A(Tl⁺) lasers are optically stable and do not show any bleaching effects under laser operation.     

Pulsed first-overtone CO laser: effective source of IR radiation in spectral range of 2.5–4.0 μm

Spectral properties of radiation of a pulsed electron-beam controlled discharge laser operating on the first-overtone transitions (Δv=2) of CO molecules have been studied both experimentally and theoretically. Various sets of dielectric mirrors with high reflectivity in the wide range of overtone spectrum have been used for the laser resonator. Multiwavelength lasing has been obtained in the wide spectral range of 2.5–4.0 μm. Efficiency of the laser operating on few vibrational transitions within a relatively narrow spectral range comes up to 5% at entirely suppressed fundamental band (Δv=1) lasing. Spectral characteristics of the overtone laser operating on a selected set of vibrational transitions have been analyzed theoretically. A comparison of the experimental and theoretical data has been made.     

Coloration under two-phonon excitation of KCl crystals containing halogen impurities

Color centers induced in KCl:I and KCl:Br crystals by N₂ laser irradiation have been studied at 9 K. It is found that the absorption spectra observed in both crystals are similar to that obtained in undoped KCl X-rayed at low temperatures. Resulting color centers are of the intrinsic lattice involving the F- and the H-centers in host KCl.     

Emission Spectrochemical Analysis of Metals Using a Nitrogen Laser

Comparative studies of the possibilities of using pulsed nitrogen and Nd:YAG lasers for emission spectrochemical analysis of copper-zinc alloys have been made. The nitrogen laser developed on the basis of the commercial excimer laser provided an energy of radiation pulses of 5 mJ with an error of less than 0.8% at a repetition frequency of 100 Hz. The high stability and the high pulse repetition frequency of the nitrogen laser were attained due to the additional high-speed fan inside the laser chamber, which provided agitation and circulation of the gas mixture. It has been shown by experiment that the spectral emission of the plasma formed by means of the nitrogen laser is characterized by intensity fluctuations with a root-mean-square deviation of 1.4%, whereas in the case of using an Nd:YAG laser it was 14.3%. The advantages of the nitrogen laser that are due to the increased signal-to-background ratio and the suppression of the selective evaporation effect have been revealed.     

Positron annihilation studies in the mixed crystals of KCl:KBr

Positron annihilation line shape studies have been made in five mixed crystals of KCl:KBr with varying concentrations. The annihilation line shape parameter S shows a minimum for the 50 mole% KCl/50 mole% KBr specimen indicating an orderly behaviour of the system. At other concentrations, the mixed crystals appear to have defects.     

Modeling the thermomechanical processes in the output window of a high-power СО<Subscript>2</Subscript> laser

A mathematical model of thermomechanical processes in the output window of a high-power continuous gas laser is developed and used to examine the windows of a СО₂ laser. The dependence of the maximum allowed output radiation power on the beam diameter and the distributions of temperatures and mechanical stresses are obtained, and the divergence of radiation is studied for windows made from ZnSe, KCl, and polycrystalline diamond (PD). In addition, the damage threshold of a composite output window made from PD with a single-crystalline region at the center is considered.     

Effect of pumping light polarization on the IR emission of a FA(II) colour-centre laser

Orientational behaviours of the axial F_A(II) centres in alkali halides due to polarized light pumping strongly influence the performance of a laser using such centres. A nearly tenfold increase of the KCl:Li laser output was obtained by properly choosing the orientation of the pumping beam polarization with respect to the crystal axis. A periodic switch of the pumping polarization has been performed in an attempt to produce a pulsed colour-centre laser.     

激光二极管相干长度的压缩

激光二极管的相干长度在高频调制的驱动电流下可以减小，在实验中对一个９８０ｎｍ的激光二极管进行了测量，表明要干长度已减小了近２０倍。