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1.
以两种不同结构的羧酸苯乙酸和苯基羟基乙酸与氯化铽为原料,采用低温固相反应合成了两种羧酸铽配合物。经元素分析、稀土络合滴定、摩尔电导确定了配合物的组成为: Tb(L1)3·H2O,Tb(L2)3·4H2O(L1= C6H5 CH COO- ,L2=C6H5CH(OH)COO-)。测定了配体及配合物的IR谱、1H NMR及配体的磷光光谱和铽配合物荧光激发和发射光谱。根据磷光发射光谱数据计算了配体的三重态能级值。比较两个配合物的荧光发射主峰5D4→7F5强度: 苯基羟基乙酸铽为苯乙酸铽的5倍。由此可见在配体亚甲基上引入拉电子基团羟基,将会扩大共轭体系π电子的离域范围,提高能量传递效率,提高稀土离子的发光强度。  相似文献   

2.
建立了一套针板电极交流放电微等离子发生装置,以氮气作为载气,甲烷为分析气体,放电电压为1.32 kV, 放电距离为3 mm, Pt丝和Pt/MWNT复合纳米粒子修饰FTO电极为放电电极,放电频率为30 kHz,功率消耗为13 W,利用发射光谱法检测放电过程中产生的微等离子体发射光谱,用于在室温下检测甲烷气体。在交流电压下,检测到甲烷的谱线有CH,C2和Hα,以C2谱线作为甲烷分析线,发现C2谱线强度与甲烷浓度在0.5%~4.0%(φ)的范围内呈线性,检出限(S/N=3)为0.19%。以Hα谱线为分析线,Hα谱线强度与甲烷浓度在0.1%~3.0 %(φ)范围内呈线性, 检测限(S /N=3)为0.03%(φ)。对于3.2%的甲烷气体,平行测定11次,在Pt/MWNT/FTO电极上以C2谱线为分析线和以Hα谱线为分析线的相对标准偏差分别为 1.3%和1.9%。说明Pt/MWNT 纳米复合材料修饰电极提高了分析方法的重现性和精密度。以空气混合气体为稀释气体,甲烷气体放电行为与纯氮气中放电行为有较大差异,C2峰消失,只有Hα峰存在。Hα峰强度与甲烷浓度在0.5%~4%范围内有线性相关性。与其他的光发射光谱检测系统相比,该系统装置尺寸小,制备简单且在室温下操作。  相似文献   

3.
离子液体在甲烷等离子体转化中作用机理的光谱研究   总被引:1,自引:0,他引:1  
在直流等离子体甲烷转化反应体系中分别引入C6MIMBF4,C6MIMCF3COO,C6MIMHSO4三种离子液体,采用光谱在线技术检测反应中活性物种的种类和光谱谱峰相对强度的变化,研究了离子液体在气液等离子体甲烷转化反应中的作用机理。结果表明:向甲烷等离子体体系中引入离子液体可得到稳定的气液界面,并提高了甲烷转化率和C2烃产物收率,C6MIMCF3COO和C6MIMBF4有助于提高C2烃选择性,而C6MIMHSO4则导致C2烃选择性下降。在气液等离子体甲烷放电体系中检测到了C,C2,C3,CH,H等活性物种的发射光谱,与未引入离子液体时相比大多数活性物种的谱线强度均有增加。核磁共振研究表明反应后离子液体C6MIMBF4结构稳定,可认为离子液体作为液体导电介质提高了等离子体放电强度,促进等离子体区气相反应过程,同时离子液体在气液表面反应过程起催化作用。  相似文献   

4.
在B3LYP/6-31G(d, p)水平下优化了四种姜黄素类似物的几何构型,并通过振动分析验证了其构型稳定性。在B3LYP/6-311G(d, p)水平下计算了该类化合物的核磁共振谱,研究结果表明:四种化合物主体结构共平面性较好,为一较大共轭体系。由于羟基及甲氧基的引入,使Compound-B/C/D中C3,C4以及Compound-A/D中C5均具有较大δ值,Compound-A中C4和C6δ值相对较小,C3δ值相对较大。而在羰基与碳碳双键所形成的共轭羰基化合物中,羰基C13δ值(183 ppm)相对于乙醛中的δ值(201ppm)有所减小,C11, 15(α碳)的δ值(122 ppm)相对减小,而C9, 17(β碳)的δ值(145 ppm)相对增大。最后,通过线性回归方法,利用相关系数值r研究了1H NMR δ值的实验和理论计算值的相关性,结果表明相关性较好,实验值和理论值基本吻合。  相似文献   

5.
研究了TRPO-D3520萃淋树脂从碱性氰化液中固相萃取Au(CN)-2的性能,并借助傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)和扫描电镜(SEM)等方法对固相萃取Au(Ⅰ)的机理进行了讨论。结果表明:阳离子表面活性剂CTMAB在固相萃取中起到了关键的作用,当待萃水相中加入的CTMAB与Au(CN)-2的摩尔比达到1∶1时,TRPO-D3520萃淋树脂即对金具有良好的萃取性能;萃淋树脂负载金后,FTIR分析表明Au(CN)-2中的C≡N伸缩振动吸收峰位于2 144 cm-1,TRPO中的PO伸缩振动峰由1 153 cm-1向低频移至1 150 cm-1;N(1s),Au(4f7/2)和Au(4f5/2)XPS谱揭示了树脂中金的价态和配位环境未发生变化,仍以Au(CN)-2形态存在于萃淋树脂中;O(1s) XPS谱图表明,经固相萃取后,树脂中化学结合水的含量明显增加,化学结合水的峰面积由30.74%增加至42.34%;固相萃取后,P(2p)XPS谱图峰位由132.15 eV增加至132.45 eV,说明PO基团与水分子存在一定的氢键作用,生成P=O…H—O—H。综上可推测,TRPO-D3520树脂固相萃取Au(CN)-2的过程为:离子对扩散至树脂孔内,被孔内的TRPO借助水分子为桥的氢键作用溶剂化而固相萃取。  相似文献   

6.
基于光纤消逝场传感原理,发展一种集固相微萃取和表面增强拉曼散射(SERS)技术于一体的快速、超灵敏检测技术。采用具有光传导功能的光纤作为载体,首先通过层层组装技术,将具有选择性吸附的氧化石墨烯(GO)键合到光纤纤芯侧面作为固相微萃取层,然后通过原位组装技术,将具有SERS活性的贵金属纳米粒子构建到GO表面作为SERS基底,开发出固相微萃取-SERS技术于一体的双功能光纤。利用光纤耦合器将功能光纤与便携式拉曼光谱仪耦合,实现固相微萃取和SERS光纤技术有效集成。结合传统顶空固相微萃取和内标法进行分析,实现水体中超痕量芳环类化合物快速半定量分析。该技术在食品快检、环境在线监测、预警等领域有着广泛的应用。  相似文献   

7.
TCNQ脂类衍生物及其铜复合物的合成与红外光谱研究   总被引:1,自引:0,他引:1  
首次合成了7,7,8,8-四氰基对苯醌二甲烷的脂类衍生物: TCNQ(C2H4COOR)2(R=CH3, C2H5, C3H7)及其铜电子转移复合物。通过元素分析确定这些化合物的组成, 对这些化合成物在4 000~400 cm-1范围内的主要红外光谱吸收峰进行了归属,并讨论了取代基对TCNQ类衍生物红外光谱的影响及其规律。  相似文献   

8.
瓦斯浓度影响下水合物晶体结构Raman光谱特征   总被引:1,自引:0,他引:1  
在初始温压2 ℃,5 MPa条件下开展了三种瓦斯混合气(CH4—C2H6—N2,G1=54∶36∶10,G2=67.5∶22.5∶10,G3=81∶9∶10)水合实验,利用可见显微拉曼光谱仪获取水合产物拉曼光谱,通过水合物相中C2H6 C—C键伸缩振动特征峰拉曼位移判断水合物晶体结构,利用谱图特征峰分峰拟合方法计算出瓦斯水合物孔穴占有率、水合指数等。研究发现:气样G1和G2水合产物为I型水合物、G3为Ⅱ型,气样中C2H6浓度改变导致水合物晶体结构转变;Ⅰ型结构水合物相中CH4和C2H6含量受气样浓度影响较小,G1和G2体系中CH4含量分别为34.4%和35.7%、C2H6含量分别为64.6%和63.9%,而G3体系中CH4和C2H6含量分别为73.5%和22.8%,晶体结构对水合物相客体分子含量控制作用明显;G1~G3体系水合物相大孔穴的CH4—C2H6占有率分别为98%,98%和92%,小孔穴的CH4占有率分别为80%,60%和84%,N2由于分压较低且吸附能力较弱其小孔穴占有率不高于5%。  相似文献   

9.
为了解决变压器气相色谱分析法故障诊断中存在的操作繁琐、消耗待测气体和载气、检测周期长等缺点,提出了利用光声光谱技术检测变压器油中CH4,C2H2,C2H4,C2H6,H2五种特征气体的含量并计算C2H2/C2H4,CH4/H2,C2H4/C2H6三对比值数据。将五种SVM类型和四种核函数采用交叉组合建立20种不同的支持向量机模型,并采用启发式算法对于惩罚因子c和g的取值进行参数寻优,以建立变压器故障诊断准确率最高、最快运行速度的支持向量机模型。启发式算法主要对比研究了粒子群算法和遗传算法在寻优精度与速度上的效果。仿真实验结果表明C-SVC模型、RBF核函数、遗传算法寻优构成的支持向量机模型对变压器故障的诊断准确率最高,测试集达到97.5%,训练集达到98.333 3%,并且遗传算法的寻优速度快于粒子群算法2倍左右。该方法具有操作简单、非接触性测量、不消耗载气、检测周期短、稳定性和灵敏度高等优点。可以代替传统的气相色谱分析法进行变压器故障诊断,满足变压器故障诊断的实际工程需要。  相似文献   

10.
原子吸收光谱法间接研究组氨酸锌的配合反应   总被引:1,自引:0,他引:1  
编程计算了不同pH条件下的组氨酸和锌离子的各种存在形式并分析了拟合分布图,研究了在硫化锌法原子吸收间接测定组氨酸时的pH值对原子吸收响应的影响及络合反应的机理。指出在pH 9.5左右最佳测定条件下,所形成的可溶性组氨酸锌配合物是由电中性的组氨酸基His+- 和带负一价电荷形态的组氨酸基His-与Zn(OH)2共同形成的Zn(OH)2·(C6N3O2H9)2,Zn(OH)2·[(C6N3O2H8)-]2,Zn(OH)2·(C6N3O2H9)·[(C6N3O2H8)-]。结果表明,理论计算分析的结果与实验数据基本吻合,确定了硫化锌法原子吸收间接测定组氨酸时的配合物反应机理及配合物的组成结构。  相似文献   

11.
气相色谱-红外光谱联用技术结合了气相色谱法良好的分离能力和红外光谱法结构鉴定的优势,适合复杂未知物成分分离及其定性定量分析。本文综述了气相色谱-红外光谱联用技术(GC-IR)、数据处理方法及其应用研究进展。介绍了GC-IR同其他检测器联用的连接方式。重点综述了GC-IR谱图和数据处理方法及其在石油化工、日用化工、有机反应等领域的应用研究进展,并对气相色谱-红外光谱联用技术及应用进行了展望。  相似文献   

12.
Room‐temperature phosphorescence (RTP) has been exploited for analytical research for over 30 years now due to the widespread recognition of its unique properties as a selective and sensitive technique, complementary to fluorescence. Recent years have seen the awakening of medical, geological, industrial, and technological interest in its application. The trend continues, driven by the achievements that have already been made and the promise of future achievements. This review attempts to cover specifically emerging applications of RTP in areas such as medicine, geological dating, forensics, and technology, illustrating the advantages that can be derived from the use of the technique and stressing its potential for novel applications.  相似文献   

13.
白光干涉在保偏光纤测量与对轴中的应用   总被引:4,自引:1,他引:3  
张靖华  王春华 《光学学报》1994,14(12):308-1311
本文根据白光干涉原理,研究了保偏光纤偏振色散和耦合系数的测量,保偏光纤连接时主轴夹角的调整,并获得了满意的实验结果,还对白光干涉技术在保偏光纤传感和器件方面的应用作了初步的讨论。  相似文献   

14.
固相萃取-气相色谱-质谱法测定水中的19种多氯联苯   总被引:2,自引:0,他引:2  
建立了固相萃取-气相色谱-质谱联用选择离子扫描法同时检测水样中19种多氯联苯(PCB s)的方法。该法对水样中PCB s的检测具有较高的灵敏度和较好的线性,其相关性r≥0.9970,检出限为2.34—7.33ng/L、回收率为82.3%—103.2%,适用于水样中多氯联苯的测定。  相似文献   

15.
Abstract

The general principles and technical implementations of traditional time-of-flight ion mobility spectrometers and analyzers with field-dependent mobilities were reviewed in our last article in this journal. Recent advances in instrumentation and new applications since 2006 are highlighted in this review. In addition to traditional applications as military chemical-agent detectors, ion mobility techniques have become popular for different purposes. Though ion mobility spectrometry was solely used as vapor sensor in the past decades, further developments in ionization techniques (especially electrospray ionization) now permit its routine use for the analysis of liquid samples. The coupling of ion mobility spectrometry with selective sample preparation techniques such as molecular-imprinted polymers, coupling with chromatographic techniques, the use of dopants, and application of selective ionization sources has led to an expanded number of applications in industrial and environmental analysis with complex sample matrices due to an improved selectivity in comparison with traditional stand-alone spectrometers. Furthermore, new developments in hyphenated techniques, especially ion mobility–mass spectrometry couplings, has resulted in an increased number of new applications for the analysis of biomolecules and pharmaceutical samples and in clinical diagnostics.  相似文献   

16.
Abstract

Luminescence spectroscopy has been extensively applied in the fields of clinical chemistry, biochemistry, and environmental chemistry. Proteins, nucleic acids, enzymes, drugs, and pollutants all show characteristic luminescence properties. The unexcelled sensitivity, selectivity, ease of sampling, and breadth of application of this method is of considerable interest to every analytical researcher and analyst. Whereas fluorimetry has become a well-established method for analysis [11, phosphorimetry has been used during the past decade only for a limited number of quantitative analyses, including the analysis of poly-nuclear aromatic compounds [2–41, coal tar fractions [5], air pollutants [6-8], impurities in petroleum fractions [9–111, detection of pesticides, and fungicides in foods [12–17], and the analysis of amino acids and pharmaceutical compounds in biological fluids [18–26]. Only recently has phosphorimetry been extensively developed into a practical qualitative and quantitative analytical method. Several papers have appeared in which the progress in instrumentation and methodology as well as the analytical uses of phosphorimetry were given [27–30]. In the 1960s the lack of use of phosphorimetry for quantitative analysis was primarily due to the great complexity and time needed to prepare and carry out an analysis at low temperature, and the poor precision and accuracy of measurements of snowed, opaque, or cracked inhomogeneous samples. In the early 1970s, improvements were achieved with techniques to enable the measurement of opaque matrices of organic solvents [31] and the development of time-resolved and phase-resolved phosphorimetry [32-361. However, in most phosphorimetric studies, the analysis still had to be performed using either low temperature rigid solvents of organic glasses, polymer matrices, or carefully degassed and purified solutions in order to minimize collisional triplet quenching. These requirements still are the main disadvantages which make this spectro-chemical method less-widely used than fluorimetry. Recently, the observed phenomenon of intense phosphorescence at room temperature (RTP) from ionic organic compounds adsorbed on a variety of supports, such as silica, alumina, paper, and asbestos [36, 37], has been proposed as a new analytical technique [38–42]. A large variety of ionic compounds of biological and clinical interest [38-40] has been investigated by this new method. The use of external heavy atom perturbers has also been investigated for the determination of trace nonionic compounds, such as the polyaromatic hydrocarbons [41]. Significant progress has been achieved with the development of a simple device for automated RTP measurement [42].  相似文献   

17.
A new optical system for an augmented reality(AR) display is proposed in this paper.The optical system mainly includes a ray deflector, coupling input grating, optical waveguide, and coupling output grating.Both the ray deflector and the coupling input grating are designed based on the diffraction characteristics of the polarization grating, and the coupling output grating is the Bragg reflection grating.Compared with other AR schemes, this AR optical system not only reduces the number of projections from two to one, but also improves the efficiency of light coupling into the optical waveguides.The energy loss is reduced by utilizing the single-order diffraction characteristics of the polarization grating in its coupling input structure.The light deflector uses the polarization selectivity of the polarization grating and the characteristics of the rotating light of the twisted nematic liquid crystal layer to realize beam deflection.The working principle of the optical system is experimentally and theoretically demonstrated.  相似文献   

18.
饶竹  王海霞  江林 《光谱实验室》2001,18(3):290-293
建立了以CO2为超临界流体的超临界萃取地质样品中有机物的分析方法,讨论和优化了超临界萃取条件,测定了茂名油页岩中的n-C13-n-C34,并与索式抽提结果作了对比,该方法测定茂名油页岩中的n-C15-n-C34链烷烃,相对标准偏差为(n=4)4.9%-23.8%,n-C13的相对标准偏差为9.2%(n=4),而传统经黄的索式抽提法测得的n=C15-n-C34链烷烃的相对标准偏差为11.2%-37.7%(n=4),n-C13的相对标准偏差为46.4%(n=4),本法与传统方法相比,具有高效,无热降解,无毒,选择性好,精密度好等优点,可直接用于GC,GC-MS的测定。  相似文献   

19.
We report on an injection seeded 1 kHz single frequency pulsed Nd:YAG ring laser with pulse energy of 5.2 mJ and pulse width of 9.9 ns. The ramp-fire technique is used to maintain single frequency operation and the cavity length is modulated by an intracavity RbTiOPO_4(RTP) crystal. The frequency stability(rms) of the output pulse is 1.99 MHz over 1 min and the linewidth is 64 MHz.  相似文献   

20.
One-dimensional methods for the determination and assignment of heteronuclear 1H-X (X = rare spin-z) coupling constants based on the semiselective polarization transfer via INEPT pulse sequence are proposed. Here the selectivity of the polarization transfer plays a positive role with respect to the sensitivity of the measurement and purity of the observed multiplets. In nonrefocused experiments the acquired antiphase multiplets enable an unambiguous assignment of long-range couplings of a preselected proton. The analysis of such multiplets is also discussed. In the refocused version the purging pulse (INEPT+) was used to provide pure in-phase multiplets. The spectral editing technique DISCO was applied to simplify the spectra and to extract the couplings from complex multiplets. Finally, the modified INEPT experiments which combine semiselective polarization transfer with selective proton decoupling are proposed.  相似文献   

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