土壤环境监测中原子吸收光谱法的应用

对原子吸收光谱法的理论进行阐述,并在此基础上,论述了目前较为常见的原子吸收光谱法类型,在对土壤环境监测中,使用原子吸收光谱法之前需要对土壤采取的处理方式进行介绍,最后对原子吸收光谱法在土壤环境监测中的具体应用路径进行了概述。     

原子吸收光谱技术在微量元素研究方面的应用

微量元素如铁、锌、铜、锰、铅等虽然在人体内的含量不多,却与人的健康息息相关。本文通过原子吸收光谱的原理,原子吸收光谱特点和原子吸收光谱应用等方面简单介绍了原子吸收光谱技术在微量元素研究方面的应用。     

浅谈紫外吸收光谱在有机化学中的应用

本文简单介绍了紫外吸收光谱的原理以及紫外光谱仪的组成,介绍了紫外吸收光谱在有机化合物结构分析中应用的一些实例,通过这些实例可以理解紫外吸收光谱在有机化合物结构解析中应用的重要性。     

光谱技术发展现状及趋势

阐述了光谱学光谱的分类,对原子发射光谱、原子吸收光谱、红外吸收光谱、拉曼光谱、X射线吸收光谱、X射线荧光光谱、紫外-可见吸收光谱、分子发光光谱这8种光谱方法的原理与发展现状作出了介绍,对光谱分析方法可能用到的数据处理方法进行了简要的概括。最后对光谱学与光谱分析技术的发展趋势进行了归纳。     

光谱技术发展现状及趋势

阐述了光谱学光谱的分类,对原子发射光谱、原子吸收光谱、红外吸收光谱、拉曼光谱、X射线吸收光谱、X射线荧光光谱、紫外-可见吸收光谱、分子发光光谱这8种光谱方法的原理与发展现状作出了介绍,对光谱分析方法可能用到的数据处理方法进行了简要的概括。最后对光谱学与光谱分析技术的发展趋势进行了归纳。     

火焰原子吸收光谱法测定痕量铅的研究与应用

综述了近年来火焰原子吸收光谱法测定痕量铅的研究进展。从火焰原子吸收光谱法在环境、食品及其它样品中铅的测定分析进行了归纳和评述,展望了火焰原子吸收光谱法测定痕量铅未来的研究方向和发展前景。     

紫外光固化中常用引发剂对紫外可见光（UV-VI）吸收的影响因素研究

以紫外光固化体系中引发剂对紫外可见光(UV-VI)吸收的研究,以0.1%(质量分数)引发剂浓度研究了常见10余种引发剂的吸收光谱图。通过对吸收光谱的实验,考察了不同极性环境、不同浓度对吸收光谱的影响,以及吸收光谱对有色体系、LED固化体系固化配方设计的指导作用。     

原子吸收光谱分析中的干扰因素及消除方法

原子吸收光谱分析法是现今广泛使用的一种测定样品中金属含量的分析方法,但是在原子吸收光谱分析的过程中可能存在几大干扰:光谱干扰、化学干扰、物理干扰和电离干扰。本文阐述了原子吸收光谱分析法的的优缺点,论述了原子吸收光谱分析法中常见的几种干扰产生的原因,并说明了其相应的抑制和消除的方法。     

紫外吸收光谱在有机化合物结构解析中的应用

本文总结了紫外吸收光谱在有机化合物结构解析中应用的一些实例,通过这些实例可以使学生理解紫外吸收光谱在有机化合物结构解析中应用的重要性,同时使学生初步了解紫外吸收光谱在有机化合物结构解析中应用的一般方法,通过教学实践表明:利用应用实例进行紫外吸收光谱的教学,其效果是非常好的。     

原子吸收光谱法在土壤环境监测中的应用

土壤环境的监测是保护土壤环境的关键步骤,原子吸收光谱法在土壤环境监测应用中占有举足轻重的地位。对原子吸收光谱法的技术和应用优势进行分析,阐述了原子吸收光谱法在土壤环境检测中的具体应用。     

笨骈噻吩酮衍生物甲川型分散染料的研究(Ⅱ)染料分子结构与固色性能

本文对苯骈噻吩酮衍生物甲川型分散染料不同的结构品种,进行了热熔固色率测定;研究了染料分子结构与染料在涤纶上的固色性能,染料的溶解度参数与固色率的关系.     

合成纤维及其混纺织物用染料的研究——Ⅱ.用于涤棉混纺织物的含β-羟乙基砜硫酸酯基活性分散染料

本文综合分析了含β-羟乙基碸硫酸酯基活性染料的染棉机理和聚酯纤维用非离子型分散染料的结构特点,提出了一类用于涤棉混纺织物的含β-羟乙基碸硫酸酯基活性分散染料。并介绍了这类染料的分子结构特点。探讨了这类染料与涤棉混纺织物两种不同纤维的结合问题。     

Oxidative addition of Se–X bonds and reductive elimination of Se–C bonds in platinum compounds containing hydrocarbyl ligands

The oxidative addition of PhSe–X molecules (X=Cl or Br) to Pt(II) complexes of formula [PtR(R^′)(N,N-chelate)] [R, R^′=Me, CH(CO₂Me)₂, CH(CO₂Me)(CN); N,N-chelate=4,4^′-(tert-butyl)₂-2,2^′-bipyridine] is described. The reaction quantitatively affords octahedral products [PtR(R^′)(SePh)(X)(N,N-chelate)], and is highly selective, since only the isomers with -X and -SePh in trans position are obtained. When R=R^′=CH(CO₂Me)₂ or R=R^′=CH(CO₂Me)₂(CN) an irreversible reductive elimination takes place in solution, giving rise to Pt(II) compounds [PtR(X)(N,N-chelate)] and organoselenium molecules PhSeR^′.     

Bond strengths of toluenes, anilines, and phenols: to hammett or not

The Hammett equation correlates the effects of Y on many different chemical properties of YC(6)H(4)ZX families of compounds. One of the most surprising is that the Z-X bond dissociation enthalpy (BDE), a homolytic property, can be correlated for some 4-YC(6)H(4)ZX families with electrophilic substituent constants, sigma(p)(+)(Y), which were largely derived from the rates of the heterolytic S(N)1 solvolyses of para-substituted cumyl chlorides. Although there is no Hammett correlation of the C-X BDEs in 4-YC(6)H(4)CH(2)X (X = H, halide, OPh) families, there are good correlations of N-X BDEs with sigma(p)(+)(Y) in 4-YC(6)H(4)NHX (X = H, CH(3), OH, F) and excellent correlations of O-X BDEs with sigma(p)(+)(Y) in 4-YC(6)H(4)OX (X = H, CH(3), CH(2)Ph) families. The reasons for this varied behavior are discussed.     

水溶液中木质素磺酸的臭氧氧化降解作用研究

在低浓度水溶液中 ,木质素磺酸可被臭氧 ( O3 )氧化降解。其氧化产物的紫外吸收光谱、1H核磁共振谱和红外光谱有明显改变。在臭氧作用下木质素磺酸大分子中的芳香结构被破坏 ,转化为CH3CO RO;R CO CH3O;CH3SO2 R三类链状化合物 ,原木质素大分子中的磺酸基主要被转化为 SO2 -4     

由4-氨基二苯醚合成三苯二噁嗪荧光染料

以4-氨基二苯醚为原料合成了10个新结构三苯二口恶嗪型荧光染料,测定了它们在甲苯、氯仿、DMF、丙酮和乙醇中的吸收光谱和荧光光谱。结果表明,这些染料发色强度大(εm ax>7×104),荧光强度高(在甲苯中Ф=0.43~0.78),染料的摩尔消光系数、荧光量子产率和Stokes位移与溶剂极性参数ET之间呈线性变化关系。     

Intracluster ion molecule reactions following the generation of Mg+ within polar clusters

In this work we investigated the intracluster ion molecule reactions following the generation of Mg(+) within the polar clusters (water, methanol, ether and acetonitrile), using time of flight mass spectrometry. In the case of Mg(+)/water and Mg(+)/methanol, dehydrogenation reactions are observed after the addition of five molecules. However, no dehydrogenation reactions are observed in the case of Mg(+)/ether or Mg(+)/acetonitrile clusters. This confirms the role of the H atom in (O-H) in the dehydrogenation reaction, and rules out any contribution from the H atom in the CH(3) group. In addition, the magic numbers in the time of flight (TOF) mass spectra of the Mg(+)X(n) clusters (X = H(2)O, CH(3)OH, CH(3)OCH(3) and CH(3)CN) have been investigated. Finally, the role of ground electronic magnesium ion Mg(+)((2)S(1/2)), and excited electronic magnesium ion Mg(+)((2)P(1/2)) in the dehydrogenation reaction were investigated using Ion Mobility Mass spectrometry. The results offer direct evidence confirming the absence of the electronically excited, Mg(+)((2)P(1/2)).     

配合物[CuL2（ClO4）2]·2CH3CN的晶体结构及表征

以3-乙基-4-对甲氧苯基-5-（2-吡啶基）-1,2,4-三唑为配体合成了配合物[CuL2（ClO4）2]·2CH3CN,测定了其X-射线单晶结构,并用电子自旋共振谱（ESR）及电子光谱对[CuL2（ClO4）2]·2CH3CN进行了表征。晶体学数据：P-1空间群,a=0．83286（11）nm,b=0．91266（14）nm,c-1．4225（2）nm,α-100．516（7）°,β=101．067（4）°,γ=98．780（4）°,V-1．0234（3）nm3,Z-1,s=1．163,最终残余因子（I〉2σ（I））R1=0．0391,wR2=0．1163;对于全部数据R1=0．0430,wR=0．1202。     

Synthesis,characterization and spectroscopic properties of some new azo disperse dyes derived from 4-hydroxybenzo[h]quinolin-2-(1H)-one as a new synthesized enol type coupling component

4-Hydroxybenzo[h]quinolin-2-(1H)-one (IV) was synthesized from the cyclocondensation of 3-(naphthalen-1-ylamino)-3-oxopropanoic acid (I) or N,N′-di(naphthalen-1-yl)malonamide (II) and subsequently coupled with diazotized p-substituted aniline derivatives. The structures of the synthesized dyes were determined by spectroscopic and analytical methods. Solvent effects on the ultraviolet–visible absorption spectra of these novel azo dyes were studied in six pure organic solvents with different polarities. The color of the dyes is discussed with respect to the nature of substituents on the benzene ring. The tautomeric structures of the azo compounds were studied by ¹H NMR spectroscopy in DMSO-d₆ and CDCl₃. The effects of acid and base on the visible absorption spectra of the dyes were also reported. Ionization constants, pK_a, for these dyes were determined in 80 vol. % ethanol–water medium at room temperature and correlated with the substituent constant, σ_p.     

NMR-study of the stereochemistry and dynamic behaviour of thioacrylamides

Several model thioacrylamides, Me₂N CH = C(R) C(S) NMe₂ (R = H, Ph — 2a, b ) and (p)MeO C₆H₄ NH CHC(R) C(S) NMe₂ (R = H, Ph — 3a, b ) have been synthesized. The ¹H-n.m.r. spectra have been taken for discussing the E/Z-isomerism of the thioacrylamides and the assignment further strengthened by an added LIS-study. The 2-unsubstituted compounds have been found to exist exclusively in preferred configurations/conformations: 2a — E(s-cis); 3a — Z(s-cis); the 2-phenylsubstituted analogs are of divergent behaviour: in 2b the C(S) NMe₂ moiety is found to be twisted out of the common plane, and 3b prefers the flat s-trans conformations (E(s-trans) ⇌ Z(s-trans)). The compounds show restricted rotations about C¹, N- and C³, N-partial double bonds. The corresponding rotational barriers, determined as ΔG-values by dynamic n.m.r. spectroscopy, are discussed with respect to (i) the resonance branch at C¹, (ii) the influence of substituents, and (iii) the effect of steric hindrance in the thioacrylamide moiety generally.