酚醌类化合物振动基频的计算,归属和讨论

本文对４,５－二羟基１,２－苯醌和２,５－二羟基－１,４－苯醌 的振动基频进行了量化计算和实验测定,应用Ｇａｕｓｓｉａｎ９４和ＭＯＰＡＣ计算相结合的方法,取长补短,归属了其振动光谱,并对两者的差异做了讨论。     

β方石英的振动光谱和方石英的相变

利用价力场模型计算了β方石英振动光谱横模的全部基频和简正模式。基频的计算值与β方石英的喇曼和红外光谱的观测值符合得很好。由此提供了一组甚好的β方石英的力常数。讨论了方石英αβ相变，并提出α方石英的软模Ｂ２６ｃｍ－１在此相变中起着基本作用     

几种金属吡啶络合物红外振动基频的归属和讨论

本文对八种金属吡啶络合物的振动基频进行了归属，并对其中络合敏感的两个吡啶振动基频与吡啶合物烷基化反应活性相关联做了讨论。     

周界固定带裂纹薄圆板的振动基频

在将裂纹板挠度表示为正交多项式的基础上，用分区技术的瑞利一里兹方法求解了含不同长度径向裂纹和弧向裂纹的周界固定圆板的振动基频。实验上用小球撞击法测定了裂纹圆板的辐射声场频谱，并得出了谱的基频。此外用有限元法对裂纹板作了理论计算。三项结果基本符合。探究了裂纹长度对圆板基频的影响规律。     

用频谱分析法研究弦振动实验

用频谱分析法,通过计算机实测实验研究弦的线性自由振动和线性受迫振动规律,得到了弦振动的基频和谐频的量值关系,与理论计算结果一致.该实验方法有利于加深学生对机械振动和机械波理论的深入理解,以及掌握用频谱分析法测量物体振动频谱的方法.     

α方石英振动光谱的计算

在价力场模型和已公布的α方石英喇曼光谱和红外光谱不完全的观测数据基础上，计算了α方石英振动光谱横模的全部基频和简正模式。基频的计算值和观测值符合较好。预言了至今尚未观测到的对称类Ａ２、Ｂ１各两个基频和Ｂ２的５个基频的位置。给出了α方石英的一组１０个力常数     

硫酸铵溶液的拉曼光谱特征及其产生机理研究

实验研究了硫酸铵溶液的拉曼光谱特征,得到了硫酸铵溶液中SO2-4的几种典型拉曼特征峰,发现SO2-4浓度和对应的拉曼峰强度间存在线性关系,根据实验结果建立了拉曼光谱参数与离子浓度间的关系数据库。理论上通过Gaussian 03和Hartree-Fock方法(从头计算)对SO2-4的几何结构进行优化并计算出该离子的振动基频,将得到的理论振动基频与实验结果进行比较,发现实验与理论计算结果吻合较好。研究结果证实了利用拉曼光谱技术对硫酸铵进行定量分析的可行性,对工业上鉴别铵盐类别、精确测量不同铵盐含量、生产铵盐等均具有一定的参考价值。     

近三相点氮分子固体的低温红外吸收特性研究

利用自主研制的低温液体/固体制备系统制备出了均匀、透光性好的氮分子固体冰层, 测量了其近三相点的红外吸收谱, 在频率2222–2439 cm^-1处观察到了一个宽的吸收带, 且最强峰位位于2288 cm^-1.基于非谐振子模型计算了氮分子的振动频率, 解释了实验中得到的固体中氮分子的红外吸收带主要由氮分子的基频振动及基频振动与转动耦合引起.     

邻羟基苯腈的双色共振增强多光子电离光谱及Franck-Condon模拟

在自制直线式飞行时间质谱仪上进行了双色共振增强双光子电离实验,获得了振动分辨的邻羟基苯腈的共振增强多光子电离(resonance enhanced multiphoton ionization, REMPI)光谱,结合高精度密度泛函理论计算和Franck-Condon光谱模拟,详细分析了光谱特征,发现了大量基频、泛频和组合振动,并进行了光谱归属.大部分苯环的基频振动归属为环在平面内的畸变或平面内的摇摆,这与分子激发过程中苯环的扩张有关.理论和实验结果都表明, REMPI光谱的低频段信号强,背景低,谱带少,分辨率好.随着振动频率的增加,信号向相反的方向变化.这是由于低频段光谱主要来自于低频的基频振动、少量泛频的贡献.随着振动频率增加,泛频和各种模的组合振动逐渐增多,导致了高频区谱带稠密,分辨率变差.高阶振动和多模的组合振动通常有较低的Franck-Condon因子,因此信号随频率增大逐渐变弱,信噪比变差.     

液体水中O-H 弯曲振动能量弛豫的数值

应用分子动力学模拟方法研究了液相水中水分子O-H弯曲振动能量弛豫的机理. 采用刚性和柔性溶剂模型来探讨振动能量弛豫的不同通道. 研究发现，刚性溶剂中O?H弯曲振动泛频的弛豫时间为174 fs而柔性溶剂中为115 fs. O-H 弯曲振动泛频振动能量弛豫的主要途径是跃迁O?H 弯曲振动基频. O-H弯曲振动基频的弛豫时间为204 fs，与实验值170 fs符合得较好.     

Dynamics of a waveguide pulsed-periodic CO2 laser with loss modulation

The nonlinear dynamics of a waveguide CO₂ laser with combined periodic loss and pumping modulation is investigated theoretically and experimentally. The possibilities of controlling time and energy parameters of the output radiation using the corresponding selection of the detuning of the cavity's longitudinal mode from the center of the amplification line, the amplitude, and the frequency of loss modulation are demonstrated. The observed asymmetric dependence of the lasing-radiation density on the detuning of the cavity frequency is explained by the attendant modulation of the refractive index of the loss modulator. To whom correspondence should be addressed. 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. 4, pp. 471–478, July–August, 1999.     

FAAS测定垃圾渗滤液中的铜、铅、锌、铬、镉和镍

建立了火焰原子吸收光谱法测定垃圾渗滤液中铜、铅、锌、铬、镉和镍含量的方法.铜、镉、铬在0.01-0.05μg/mL呈现良好的线性关系,锌、镍、铅的线性范围为0.10-0.50μg/mL,相关系数分别为0.9987、0.9968、0.9993、0.9999、0.9995、0.9974.铜、铅、锌、铬、镉、镍的加标回收率范...     

ICP-AES扩展通道法测定稀土镁合金中稀土总量、镁、钙、锰、铁

本文介绍了用ICP－AES测定稀土镁合金中稀土总量、钙、镁、锰、铁的方法，其中，稀土总量以铈的量进行换算，而铈 的测量通道通过扩展手段来设置。文中对样品的处理、测定的条件进行了较详细的研究，并对测量的精密度、准确度进行了考查。实验证明，该方法简便、结构可靠。     

基于高光谱技术的酸奶中常见致病菌的快速鉴别及计数

酸奶是一种发酵型乳制品饮料,因其特殊的功能性和良好的口感而广受欢迎。但由于商业链的不正当运行,如奶源非法获取、灭菌不充分等原因,导致酸奶中致病菌大量滋生,酸奶中毒事件频繁发生。酸奶中常见的致病菌主要有大肠杆菌、金黄色葡萄球菌和沙门氏菌,这三种致病菌由人体摄入并达到一定的数量时会产生腹痛、腹泻等严重的消化道疾病,并且会破坏人体肠道内的正常菌群平衡,因此国标对奶制品中这三种致病菌的数量已有明确的限量规定。由于酸奶的主要消费对象为老人和小孩,故其潜在危害不容小觑。传统菌落检测方法虽具有简单,灵敏、可操作性强等优点,但当不同菌落混杂在一起时无法同时进行定性定量的检测,且具有试剂成本高,检测周期长,人为因素影响较大等缺点。因此开发一种快速、简单、准确的混合鉴定计数方法为避免致病菌对酸奶的潜在危害提供了有效的途径。高光谱技术同时包含样本的光谱信息与图像信息,既能够根据化学组分的微小变化进行精确识别（光谱信息）,又能够反映出菌株在外部多层次的变化（图像信息）。因此该研究尝试对比高光谱图像技术和光谱技术,采用模式识别的方法,对比不同的模型识别结果,优选出最佳识别率的识别模型作为计数模型,最后通过最佳鉴别计数模型的识别分类结果来达到对酸奶中常见致病菌鉴定计数的目的。首先,购买酸奶中常见的乳酸菌种（保加利亚乳杆菌、嗜热链球菌、嗜酸乳杆菌、干酪乳杆菌、植物乳杆菌）和潜在污染的致病菌种（金黄色葡萄球菌、大肠杆菌、沙门氏菌）等标准菌株进行培养,提取经过48 h培养后的菌落图像信息和光谱信息。采用几种不同的预处理方式（SNV,MC,MSC,1stDER,2ndDER）对所提取的光谱数据进行预处理,并应用遗传算法筛除光谱数据中冗余的波段,保留有效波段。利用图像处理技术对图像信息中的菌株与培养基背景进行去除,然后采用主成分分析法从每幅图中优选出3个特征波长,并运用图像处理技术从特征波长所对应图像中提取菌株的18个基于GLCM的纹理特征信息。挑选合适的主成分分别建立不同的鉴别模型（LDA,KNN,BP-ANN,LS-SVM）,通过其最终的鉴别模型的识别率来确定最佳鉴别计数模型。最后从标准菌株中分别挑选出30株进行计数测试,通过比较模式识别的分类数量结果与菌株的实际数量来验证模式识别效果的准确率。研究表明,运用SNV预处理后光谱数据在提高信噪比效果上明显优于其他几种预处理方式。745.790 8,773.098 4和779.207 0 nm为图像信息中方差贡献率最大的三个波长,运用从特征波长所对应的图像中所提取的纹理特征信息建立图像识别模型。通过对比图像信息和光谱信息的模式识别结果发现,光谱特征鉴别模型普遍优于图像纹理特征鉴别模型,且当主成分数为9时,运用光谱特征所建立的LS-SVM模型的校正集识别率为96.25%,预测集的识别率为91.88%,为最优模型。采用优选的最优模型对菌株进行识别计数,大肠杆菌计数的相对误差为3.33%,金黄色葡萄球菌和沙门氏菌计数的相对误差均为0,验证了高光谱技术应用于酸奶中常见致病菌的鉴别计数的可行性。     

Principles of demineralization: modern strategies for the isolation of organic frameworks. Part I. Common definitions and history

In contrast to biomineralization phenomena, that are among the most widely studied topics in modern material and earth science and biomedicine, much less is systematized on modern view of demineralization. Biomineralized structures and tissues are composites, containing a biologically produced organic matrix and nano- or microscale amorphous or crystalline minerals. Demineralization is the process of removing the inorganic part, or the biominerals, that takes place in nature via either physiological or pathological pathways in organisms. In vitro demineralization processes, used to obtain mechanistic information, consist in the isolation of the mineral phase of the composite biomaterials from the organic matrix. Physiological and pathological demineralization include, for example, bone resorption mediated by osteoclasts. Bioerosion, a more general term for the process of deterioration of the composite biomaterials represents chemical deterioration of the organic and mineral phase followed by biological attack of the composite by microorganisms and enzymes. Bioerosional organisms are represented by endolithic cyanobacteria, fungi, algae, plants, sponges, phoronids and polychaetes, mollusks, fish and echinoids.In the history of demineralization studies, the driving force was based on problems of human health, mostly dental caries. In this paper we summarize and integrate a number of events, discoveries, milestone papers and books on different aspect of demineralization during the last 400 years. Overall, demineralization is a rapidly growing and challenging aspect of various scientific disciplines such as astrobiology, paleoclimatology, geomedicine, archaeology, geobiology, dentistry, histology, biotechnology, and others to mention just a few.     

Fluorescence of free complex molecules

A number of phenomena that determine the nature of the fluorescence of free complex molecules and the possibility of its analytical application are considered. Attention is specially paid to the specific features of the energetics of radiationless transitions, the role of statistical factors in the formation of spectral properties and the interrelationship among the luminescence-spectrum characteristics of rarefied vapors of complicated molecules, and the processes of energy transfer in collisions. The properties of polarized fluorescence of hot and jet-cooled vapors, the processes of relaxation of anisotropy in time and during collision reorientation, and transfer of anisotropy in photodisintegration are analyzed. 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. 620–634, September–October, 1998.     

手印纳米显现效果的评价研究进展

近些年来,将量子点、金属及金属氧化物纳米材料、稀土上转换及下转换发光纳米材料、荧光碳点、金属-有机框架材料、聚集诱导发光材料等新型材料应用于手印显现领域的研究日益增多,由此衍生出一类新兴的手印显现技术--手印纳米显现技术。手印纳米显现技术具有操作简单、方法灵活、效果显著、适用广泛等突出优势,已经成为传统手印显现技术的重要补充。国内外研究人员对手印纳米显现技术的探索主要集中在显现材料的推陈出新和显现方法的交叉融合两方面,而对手印显现效果的影响因素及综合评价等研究却较为分散且缺乏系统性。准确客观地评价手印纳米显现效果对于显现方法的合理选择和物证价值的客观评估都具有非常重要的意义。该综述从对比度、灵敏度、选择性、毒害性等四方面对手印显现特别是手印纳米显现的效果评价方法进行梳理总结,并对影响手印纳米显现效果的诸多因素分别进行讨论。纳米材料的发光性质主要决定了手印显现的对比度,纳米材料的微观形貌和颗粒尺寸主要决定了手印显现的灵敏度,纳米材料的吸附性能和表面性质主要决定了手印显现的选择性,因此可通过调整显现材料的诸多性质来提升改善手印纳米显现的效果。最后,对手印纳米显现未来的发展方向提出全新展望。纳米显现材料必然由单一发光性能向多元发光性能过渡,由现有材料的借鉴使用向形貌尺寸的精细操控过渡,由表面简单处理向靶向分子修饰过渡,由潜在毒害材料向绿色环保材料过渡;纳米显现方法必然由强背景干扰向弱背景干扰发展,由细节特征的清晰显现向汗孔特征的清晰显现发展,由物理吸附向靶向识别发展,由痕迹物证的高效显现向生物物证的微观无损发展。同时建议科研人员在注重提升手印显现效果的同时,更加重视对手印显现效果的定量评价研究,进而促进手印纳米显现技术体系的完善,也可使手印纳米显现技术在刑事科学技术领域中发挥出重要的作用。     

Influence of nonplanar distortions of the tetrapyrrole macroring on the electronic states of porphyrin dications

Quantum-chemical calculations of the excited electronic states of a porphyrin dication have been performed by the CNDO/S method for different angles determining the saddle-like and ruffled distortions of the porphyrin macroring. It is shown that saddle-like distortions arising as a result of a tilt of the pyrrole rings have a significant influence on the energies of the molecular orbitals and energies of the excited electronic states of porphyrin molecules, especially on the oscillator strength of the G→Q transition. The results of the calculations performed are in good agreement with the experimental spectra of porphyrin dications. To whom correspondence should be addressed. Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998. 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. 66, No. 4, pp. 559–562, July–August, 1999.     

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.     

Nature of the impurity bands of the edge luminescence of highly doped compensated ZnSe:N

A modification of the model of potential fluctuations is suggested to explain the experimentally observed dependences of the form and position of the maxima in the impurity luminescence spectra of ZnSe specimens, highly doped with an acceptor nitrogen impurity, on the degree of doping, excitation level, temperature, and decay time. In this model, analysis of the recombination of donor-acceptor pairs is replaced by consideration of transitions from localized and delocalized states of the donor impurity band and density tail of the conduction-band states, which appear in strong doping because of the overlapping of wave functions of the donor states, to the acceptor levels. The influence of the parameter of the electron-phonon interaction on the spectrum shape is considered. The model allows one to offer a consistent explanation at the qualitative level for the features observed experimentally. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 86–90, January–February, 2000.