ICP-AES测定铜合金中的磷

采用ICP-AES测定铜合金中的磷元素。通过实验探讨了铜合金中基体元素,共存元素对磷元素分析谱线的光谱干扰情况,确定了合适的分析谱线。对一系列不同牌号不同含量的铜合金中的磷进行测定,通过实验探讨了铜合金中基体元素铜对磷元素测定的干扰情况。方法的检出限为0.00084%,Z-15铍青铜和铅黄铜测定结果的相对标准偏差分别为2.06%和2.89%。加标回收率为85.3%—98.2%。     

基于飞秒激光等离子体丝诱导击穿光谱探测土壤重金属Cr元素含量

本文基于飞秒激光等离子体丝诱导击穿光谱对土壤重金属Cr元素含量进行了实验研究.利用荧光法对等离子体丝的长度进行测量,给出了在不同焦距聚焦透镜作用下土壤中Cr425.5 nm的谱线强度空间分布,实验给出了Cr元素的定标曲线.实验结果表明,土壤中Cr元素浓度分析测量的相对标准偏差小于5%,土壤中重金属Cr元素的检测极限为7.85 ppm.表明飞秒激光等离子体丝诱导击穿光谱技术在土壤重金属Cr元素含量的定量探测方面是完全可行的.     

尝试合成110号元素

在目前的超重元素研究中,合成110号元素是最激动人心的课题之一。本文以如何探索合成110号元素为线索,讨论了核质量和稳定性、由实验和理论得到的启示以及尝试合成它的最新实验。     

土壤重金属铬元素的激光诱导击穿光谱定量分析研究

利用Nd ∶YAG脉冲激光器(波长:1064 nm)作为光源,在实验室自然大气环境下诱导产生土壤激光等离子体,通过等离子体原子发射光谱法定量分析了国家标准土壤样品中元素Cr的含量.实验上研究了在最佳实验条件下土壤中Cr的LIBS分析谱线,测定了Cr元素的定标曲线.实验结果表明,Cr元素浓度在(60—400)×10^-6范围内,元素含量与光谱线强度之间有较好的线性关系;元素Cr浓度分析测量的相对标准偏差(RSD)为7.89%,定量分析结果与标准值的相对偏差为5.3%,Cr元素的检测限为1 关键词： 土壤污染 定量分析 激光诱导击穿光谱 定标曲线     

溶液阴极辉光放电光谱信号的内标法定量分析研究

溶液阴极辉光放电-原子发射光谱是一种新颖的快速、高效、实时在线的元素分析方法,它可用于水体金属元素的检测。为提高其测量精确度和稳定性,将内标法应用于溶液阴极辉光放电-原子发射光谱技术。对K元素建立了标准定标曲线和以H_β为内标元素的定标曲线,内标法测得样品的相对误差和相对标准偏差分别为1.11%,2.14%,精确度和稳定性较之标准曲线法有一定的提高。实验考察了元素谱线强度在同一时段的波动情况,发现元素K和H_β的谱线强度变化趋势稍有不同,而同主族元素K和Rb,Ca和Mg的谱线强度有相同的变化趋势,提出选择与待测元素同主族且谱线强度变化趋势较为一致的元素作为内标元素能更大化校正实验波动的观点。同时探讨了K以Rb为内标元素、Ca以Mg为内标元素以及Mg以Ca为内标元素时的内标法测量的精确度和稳定性,得其相对误差分别为0.49%,0.02%和0.30%,相对标准偏差分别为1.11%,1.13%和0.87%,与标准曲线法和以H_β为内标元素的内标法相比效果更佳。测得自来水样品中Ca元素以Mg为内标的相对误差和相对标准偏差为0.58%,1.03%,Mg元素以Ca为内标的相对误差和相对标准偏差为1.57%和1.10%。研究结果表明,将溶液阴极辉光放电-原子发射光谱技术应用于水体金属元素检测时,内标法可以有效校正实验波动的影响,提高测量的精确度和稳定性。     

水体重金属LIBS多元素测量参数优化方法研究

激光诱导击穿光谱(LIBS)方法的优势之一就是可多元素同时检测。为获得水体重金属LIBS多元素测量时的综合最佳信号输出,本文利用BP神经网络拟合Pb,Cu和Ni三种元素特征谱线信背比(S/B)与延时门宽之间的数值关系,同时采用DM设计实验数据作为校验样本,保证BP神经网络模型的泛化能力。基于上述数值模型利用遗传算法优化延时门宽两个测量参数,定义了适应度函数,得到延时门宽为(15.5和21.5 μs)时,取最小值0.102 4,此时三种元素综合信背比最大,对比实验进一步验证了优化效果。神经网络结合遗传算法的优化方法提高了水体重金属LIBS多元素测量时的综合信背比,研究方法也为更多参数更多响应的实验系统优化提供了参考。     

不同季节的虎杖根茎中8种矿质元素的光谱测定

采用空气-乙炔火焰原子吸收法,测定虎杖根茎的K,Ca,Na,Mg,Fe,zn,Mn,Cu等8种矿质元素的含量。对测定条件进行了实验,选择了最佳电离抑制剂和酸性介质。实验以氯化铯为电离抑制剂,盐酸浓度控制在2％以内,用氯化锶消除磷对Ca的干扰,使吸光值稳定,用标准曲线法进行测定,获得了满意效果。该方法简单、快速、准确,加标回收率为90．5％～108．2％,相对偏差为0．3％～0．7％,适合于植物矿质元素的分析。实验结果表明：虎杖根茎中含有丰富的矿质元素,其中以K,Ca元素含量最高。这与虎杖的药用效果相符。同时,每种元素含量随季节变化而变化,与其生长发育密切相关。     

内标法在土壤重金属镍元素X荧光分析中的应用研究

利用能量色散型XRF重金属实验平台,在实验室自然大气环境下获取土壤的X射线荧光,通过X射线荧光光谱法定量分析了国家标准土壤样品中元素Ni的含量。实验研究了土壤中Ni元素的X荧光特征分析谱线,采用加入内标法测定了Ni元素定标曲线,并依据实验结果分析了内标元素选取方法。实验结果表明,对土壤样品进行内标法分析时,可选取基体中适宜元素作为内标元素;使用Pb的Lα线,Cu和Fe的Kα线作内标线时相对标准偏差(RSD)分别为6.24%,5.24%和5.22%,说明选择合适基体主量元素的特征谱线作为内标线,可有效提高测量结果的准确性。     

微波消解-火焰原子吸收光谱法测定蕨麻中8种矿物元素

利用微波消解,空气-乙炔火焰原子吸收光谱法对蕨麻中钾、钠、钙、镁、铜、锌、铁、锰8种人体必需矿物元素进行了测定。对样品的预处理方法、仪器的测定条件、共存元素的干扰及消除进行了研究,并对各测定元素进行了加标回收率实验。结果表明,在选定的实验条件下,该法的相对标准偏差均小于2.5%(n=8),各元素加标回收率为96.5%—103.2%。     

通过二次回归正交设计对激光诱导击穿光谱实验参数优化建模

激光诱导击穿光谱(LIBS)为多元素同时分析提供了一种简单、快速的分析工具。对LIBS多元素同时分析时实验参数优化,提出了一个"综合信背比(ISBR)"的优化目标函数。基于二次回归正交设计(QROD)构建了激光脉冲能量、检测延时、样品距透镜距离、积分时间这些因素对目标函数影响的多因素模型。结果表明,目标函数可以顾及多条谱线性能,为多元素同时分析提供参数优化的依据。利用QROD方法建立多因素模型,可以获得比单因素逐个优化更优的实验条件,并大大减少了实验次数。     

2D-Mueller-matrix tomography of optically anisotropic polycrystalline networks of biological tissues histological sections

A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined.     

Spectroscopic and nano-molecular modeling investigation on the binary and ternary bindings of colchicine and lomefloxacin to Human serum albumin with the viewpoint of multi-drug therapy

Combination of several drugs is often necessary especially during long-term therapy. The competitive binding drugs can cause a decrease in the amount of drug bound to protein and increase the biological active fraction of the drug. The aim of this study is to analyze the interactions of Lomefloxacin (LMF) and Colchicine (COL) with human serum albumin (HSA) and to evaluate the mechanism of simultaneous binding of LMF and COL to protein. Fluorescence analysis was used to estimate the effect of drugs on the protein fluorescence and to define the binding and quenching properties of drugs-HSA complexes. The binding sites for LMF and COL were identified in tertiary structure of HSA with the use of spectrofluorescence analysis. The analysis of fluorescence quenching of HSA in the binary and ternary systems show that LMF does not affect the complex formed between COL and HSA. On the contrary, COL decreases the interaction between LMF and HSA. The results of synchronous fluorescence, resonance light scattering and circular dichroism spectra of binary and ternary systems show that binding of LMF and COL to HSA can induce micro-environmental and conformational changes in HSA. The simultaneous presence of LMF and COL in binding to HSA should be taken into account in the multi-drug therapy, and necessity of using a monitoring therapy owning to the possible increase of the uncontrolled toxic effects. Molecular modeling of the possible binding sites of LMF and COL in binary and ternary systems to HSA confirms the spectroscopic results.     

陕北侏罗纪富镜煤和富惰煤分子结构的FTIR，XPS和13C NMR表征

侏罗纪优质煤炭资源为煤制油、制气等清洁高效利用提供了丰富的物质基础,其显微组分以富集惰质组为特征,而镜质组与惰质组大分子结构在很大程度上决定了煤的物理化学性质和工艺性能,进而决定了煤炭资源的综合利用效率及附加值。采集并制备了陕北侏罗纪煤田小保当煤矿和柠条塔煤矿的原煤(XR)、富镜质组煤(XV、NV)和富惰质组煤(XI、NI)样品,利用傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、固体13C核磁共振谱(13C NMR)等手段,结合煤质分析结果,定量表征了不同显微组分富集物分子结构的差异。研究结果表明：XI和NI煤中芳烃结构芳环取代程度低,主要以3个相邻、4~5个相邻的氢原子形式存在,苯环上氢原子较少被其他官能团取代,同时其结构中芳烃C═C骨架振动明显,脂肪结构中亚甲基伸缩振动强度较低,并且甲基含量略高于富镜煤,C═O基团相对含量略高,表明富惰煤有较多含氧桥键相连的芳香结构,其结构中脂族链、脂环基团脱落、断裂以及芳烃富集,支链相对较少且长度较短,芳碳率、芳香度、芳环缩合程度及成熟度较高。XV和NV煤中表面结构中碳的赋存形态“C—C,C—H”,“C—O”的相对含量高于富惰煤,反映其结构中应含较多的芳环取代的脂肪族侧链,XI和NI煤表面结构中氧的赋存形态以“C—O”为主,“C═O”和“COO—”明显高于富镜煤。XV和XI煤的芳碳率分别为57.91%和66.02%,脂甲基碳分别为10.02%和7.84%,质子化芳碳为非质子化芳碳的两倍,XV煤的羰基和羧基碳相对含量较高,两者桥碳和周碳之比分别为0.25和0.40,芳香核结构平均缩合环数分别为2.68和3.03,平均尺寸分别为0.448和0.676 nm,XI煤结构中芳香核以萘和蒽为主,支链化度L_γ分别为0.22和0.19,表明XV比XI存在较多脂肪侧链、饱和环结构,生烃(油)潜力大。     

Mechanism and properties of thermally biological effect of Micro waves

水在生命体中是大量存在的,它是维持生命的必要物质.它能促进细胞的繁殖和血液的循环,促进和参与生物化学反应,为生物大分子的功能发挥提供适当条件.由于它是具有一定偶极矩的微观小分子,其转动频率是处在微波范围内,所以我们判定生物体中的液态水能吸收一定频率和强度的微波,并可以将所吸收的微波能量转化为水分子无规运动的热能,使水温升高.我们的实验结果应证了这个机制,从而可导致血液循环,细胞繁殖和一些生化反应的加快和增强DNA,蛋白质和酶的生物活性等生物功能.这就是毫米波的生物热效应的机理和特性.     

地黄饮湿法提取与煎煮法提取效率的比较

以地黄饮中两味君药山茱萸肉及肉苁蓉的主要成分马钱苷、松果菊苷的提出量及出膏率为指标,对湿法粉碎提取法与煎煮法的提取效率进行了比较研究。结果显示,湿法粉碎提取法所得马钱苷、松果菊苷的量、出膏量较煎煮明显提高。湿法粉碎提取法提取效率高,方法简便,时间短,可用于地黄饮提取。     

Stargazing Basics: Getting Started in Recreational Astronomy,by P.E. Kinzer

Soil has its origin in physical processes of comminution and abrasion of rock masses and in chemical processes of solution and recrystallization of rock minerals. After formation it is transported and distributed by a variety of agencies before subaerial or subaqueous deposition. Generally, soils experience a number of cycles of sedimentation, uplift, erosion and redeposition. Their mechanical behaviour under the stresses imposed by engineering structures varies with the type of soil. Both the deformation and failure of soils are of interest in the design of structures and these properties must be studied by special laboratory tests. The solution of a soil engineering problem therefore involves a field investigation and sampling programme to define the boundaries of the soil involved, laboratory testing of the soil, and analytical or computer calculations to determine the displacements and stresses which will occur in the soil and structure. Problems of particular interest include slope failures, the design of earth dams, retaining walls and piled structures, the displacement and failure of soil under buildings and the determination of soil properties on the surface of the moon and other planets.     

Menopausal hot flashes: Randomness or rhythmicity

Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.     

发射光谱法测定乳浊料中的锆和铪

研究了用碳粉和二氧化钛作缓冲剂同时测定乳浊料中的锆和铪的发射光谱法,选择钛作内标线,不需分离、不需化学处理,直接压样于杯形的石墨电极中,具有简便、快速、准确的特点。对测定条件、干扰因素进行了研究,从而建立测定锆和铪的新方法。锆和铪的分析线分别为327.3和286.6 nm,内标线选择为钛的308.8 nm线,锆和铪的线性范围分别为0～0.50%和0～0.25%。锆和铪的检测限分别为0.001%和0.010%,其回收率为96.67%～105.0%,当n=9时,锆的RSD为3.61%;铪的RSD为4.82%;用于样品的测定取得了满意的结果。     

Low-temperature spectroscopy of organic molecules in solids by photochemical hole burning

Characteristic features of photochemical hole-burning (PHB) in the impurity spectra of low-temperature solids and PHB applications in molecular spectroscopy are considered. The evolution of a no-phonon hole and a phonon sidehole in excitation and fluorescence spectra is analysed on the basis of model calculations. Some more complex models for PHB are considered, which take into account reverse reactions, the optical thickness of the sample, the inhomogeneous dispersion of both homogeneous linewidths and transition energies of the photoproduct and quasi-static impurity-impurity interactions. The effects of PHB on fluorescence line narrowing are discussed. By PHB homogeneous linewidths of purely electronic and vibronic no-phonon lines in the spectra of some porphine and phthalocyanine derivatives in various matrices are measured and their temperature dependence is studied. The latter is found to be essentially different in polycrystalline and glassy matrices. Line-broadening mechanisms are discussed. By PHB the existence of an inhomogeneous distribution of vibrational frequencies in molecular impurities is established. The applications of PHB in the studies of photochemical reactions in solid solutions of phthalocyanine derivatives and tetracene are regarded and the mechanisms of these reactions are discussed. The results obtained by PHB for chlorophyll and its derivatives are presented.     

Surface chemistry of nanodiamonds

The experimental data available in the literature and the results obtained by the author in research into the structure of nanodiamonds and the physicochemical and chemical properties of their surface are generalized. An account is given of the problems concerning the chemical state and modification of the nanodiamond surface in gaseous and liquid media and the infiuence of modification on the sorption and catalytic properties of nanodiamonds, their compactibility, and sintering. The similarity and difference in the behavior of nanodiamonds and diamond macrocrystals in oxidation processes are discussed. The activation energies of oxidation of nanodiamonds by different reagents are determined in the absence and presence of catalysts.