多组分体系同时定性定量测定的逐步回归分析法

阐述了逐步回归分析法用于多组分体系同时定性定量分析的原理、实验及数据处理方法。分析了硝基酚类人工样、未知样及合成样。该法可用于仅知可能含有的组分范围的样品分析。     

原子吸收光谱法检测中的质量控制

介绍原子吸收光谱法检测过程中实验准备、标准溶液和样品制备方法、样品分析及数据处理等几个环节的质量控制措施。     

地质样品中氯的测定方法的近期进展

对地质样品中氯的测定方法,包括其样品的前处理方法在近十年中的研究进展作了综述。涉及的样品前处理方法有浸提法、碱熔融法、半熔法、水蒸气蒸馏法及高温水解法等;涉及的测定方法包括分光光度法、离子选择性电极法、离子色谱法、X射线荧光光谱法、原子吸收光谱法、电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法及中子活化法等。并对这方面的发展前景作了简要的展望(引用文献91篇)。     

农、兽药及工业化学物残留量分析中样品前处理微量化学法技术研究

建立了一种用于残留物分析样品处理的微量化学法(MICCM)体系,提出了该体系的基本概念、原理、单元操作,选择了一套基本系列设备和器具,并将这一体系用于检测不同样品中的农药、兽药、工业化学物残留量及食品添加剂。实例中,各方法检测限、回收率、变异系数的实验数据均达到了国际上对残留量分析方法的技术要求。该体系与经典常量化学法(MaCCM)样品处理体系相比,具有快速、简便、工效高,节省人力、试剂材料、能源以及占用场地小等多种优点。残留物分析可广泛用该体系取代经典法样品处理体系。     

环境中锑的形态分析研究进展

评述了环境样品中痕量锑的形态分析概况及近年来的发展趋势，主要包括分光光度法、电化学方法、原子光谱法和色谱法等。     

直观推导式演进特征投影法及其在复杂体系分析中的应用

对直观推导式演进特征投影法(HELP)的原理及主要步骤作了简要介绍。综述了HELP的研究情况及其在中草药分析、环境样品分析等领域中的应用，并对该法的优势和发展趋势作出了讨论。     

用于食品安全分析样品前处理的共价有机聚合物的制备及应用进展

食品安全关系身体健康和生命安全,是全球关注的热点之一。食品基质复杂,痕量有毒有害物质分析之前必须经过有效的前处理。目前发展的前处理技术如固相萃取、磁固相萃取、固相微萃取等,其关键是吸附介质。共价有机聚合物是一类通过共价键连接而成的有机多孔材料,具有质轻、稳定性好、比表面积大、结构可控、易于修饰等特性,是一类优异的新型吸附材料。该文综述了近年来共价有机聚合物(COPs)在食品安全分析前处理中的应用进展。共价有机聚合物及其功能化复合材料通过简单的装填、聚合反应或化学键合固定到小柱或毛细管柱中用作固相萃取的吸附介质;通过一锅法、原位还原法、原位生长法或共沉淀法生成具有磁性的固相萃取吸附介质;或者通过物理涂覆、化学键合、溶胶凝胶法及原位生长法制备固相微萃取纤维。基于以上高吸附容量共价有机聚合物的样品前处理技术,食品中农残兽残、添加剂、环境污染物及生物毒素等得到了有效富集。最后,展望了COPs在食品分析样品前处理应用中的发展方向:简单高效绿色制备方法的开发,功能化COPs的设计合成;萃取机理的研究;高通量、高灵敏度分析方法研究。这些研究将促进COPs在样品前处理领域获得更广泛的应用。     

ESR测年法中样品总剂量的测定

ESR(电子自族共振)方法测定第四纪地质样品的总剂量在ESR测年法中占有重要的地位。该法为ESR谱仪的研究和应用开辟了一个新的领域。本文通过作者近几年来对化石、沉积物、石笋、黄土石英等样品的ESR研究,以及对ESR测年法所进行的一些基础研究,较详细地介绍了ESR测年法中测定总剂量TD方法和可能导致误差产生的各种因素及解决办法。     

环境样品分析

本文是“分析试验室”定期评述“环境试样分析”的第７篇评述。它全面评述了１９９８年１对１９９９年１２月间我国环境分析的进展,内容包括：概述,大气样品分析,水样品分析,土壤和沉积物样品分析,生物样品分析,放射性监测,标准、质量控制和质量保证,展望。     

生物,环境样品和食品中铅的痕量分析

主要根据近七年来发表的有关论文，综述了我国生物、环境样品和食品中铅和痕量分析技术进展，内容包括分子光谱、原子光谱、电化学和其他分析方法，以及联用技术和前处理等方面，收集文献３９３篇。     

Fabrication and characterization of core-shell photonic crystals via a dipping process

High-quality polystyrene (PS) colloidal photonic crystals in large area were fabricated in 24 h via a capillary-enhanced process. Then, the photonic crystals with core-shell structure were obtained by incorporating silica nanoparticles into the interstitial space of opal template via a dipping process. The filling ratio (V_silica) of interstitial space could be manipulated by dipping colloidal crystals into suspensions with different concentrations of silica nanoparticles, which in turn renders the obtained core-shell photonic crystals. The absorptive peak of opal without dipping process is at 445 nm as measured by UV–vis spectrometry. The filling ratios of 0.130, 0.167 and 0.253 can be calculated according to the modified Bragg's Law, which corresponds to the absorptive peaks for core-shell opals at 453, 463 and 469 nm obtained from suspensions with silica nanoparticles of 0.017, 0.122, and 0.244 wt%, respectively. Therefore, by using this dipping process, the characteristic absorption wavelength for photonic crystal will be varied easily, efficiently and cost effectively than that by traditional methods for constructing opal from monodispersed colloids of different diameters.     

两个新颖原子簇化合物的合成及三价非线性光学吸收性质

通过低热固相反应,我们合成了蝶型簇合物[MoOS~3Cu~2(PPh~3)~2(Py)~2](1),该簇合物与PPh~3反应,可以得到另一个新的簇合物[MoOS~3Cu~2(PPh~3)~3(Ph)](2)。使用Z-扫描方法测试这两个化合物的三阶非线性光学性质,发现它们都有较强的非线性光学吸收性质,非线性光学吸收系数分别是1.5×10^-^1^1mW^-^1和3.3×10^-^1^0mW^-^1。     

1,3-二氮杂薁类衍生物电子结构和光谱性质的理论研究

对1,3-二氮杂薁类衍生物采用密度泛函理论(DFT)在B3LYP/6-31G(d)的水平上进行了几何构型的全优化, 在此基础上探讨了分子结构和前线分子轨道能量等性质的变化规律, 采用含时密度泛函理论(TD-DFT)计算了分子的电子跃迁性质, 采用二维平面图和三维立体图来直观表示激发态的性质, 研究分子内电子转移特性. 跃迁密度矩阵的二维等高线图反映了电子-空穴相干性, 三维跃迁密度图反映了跃迁偶极矩的方向和强度, 三维电荷差异密度图说明了激发过程中分子内电子转移性质.     

MnO_x-CeO_2上表面氧性质及其催化碳烟燃烧性能

运用TPO,XRD,BET,O2-TPD,H2-TPR,XPS等技术,研究了在CeO2中引入不同Mn含量对催化剂表面氧性质的影响,并重点探讨了吸附于氧空位上的原子吸附氧O-与催化碳烟燃烧活性的关联。结果表明:将Mn中引入CeO2后,MnOx-CeO2晶格中可形成较CeO2更多的氧空位,并有利于氧的活化和迁移,生成了较多原子吸附氧O-;MnOx(0.4)-CeO2在碳烟起燃温度区间有最多的原子吸附氧O-,其碳烟起燃活性最高,对应的起燃温度是346℃,比无催化剂时降低了111℃,比CeO2降低了35℃。     

Calculation of circular dichroism spectra from optical rotatory dispersion, and vice versa, as complementary tools for theoretical studies of optical activity using time-dependent density functional theory

A comparison of two theoretical methods based on time-dependent density functional theory for the calculation of the linear dispersive and absorptive properties of chiral molecules has been made. For this purpose, a recently proposed computational method for the calculation of circular dichroism (CD) spectra from the imaginary part of the optical rotation parameter has been applied to six rigid organic molecules. The results have been compared to the CD spectra obtained from the rotatory strengths and from the Kramers-Kronig transformation of optical rotatory dispersion (ORD) curves. We have also investigated a criterion based on the Kramers-Kronig integration formula to determine a number of excitations in truncated CD spectra which may yield a reasonable low frequency resonant ORD. It has been tested by calculating the ORD from the sum-over-states formula both in the nonresonant and resonant regions. Finally, we have applied these methods to model the resonant optical activity of proline at low pH.     

Preparation of Silver Nanoparticles Incorporated Electrospun Polyurethane Nano-fibrous Mat for Wound Dressing

Polyurethane foam is currently used as an exudate absorptive wound dressing material. In this study silver (Ag) nanoparticles were incorporated into electrospun polyurethane (PU) nanofiber to enhance the antibacterial as well as wound healing properties. The electrospinning parameters were optimized for PU with and without silver nanoparticles. Silver nanoparticles were synthesized by aqueous and organic methods. The water absorption, antibacterial and cytocompatibility of the PU-Ag nanofibers were studied and compared to that of conventional PU foam. The results indicated that the PU-Ag nanofibers could be used for wound dressing applications.     

新固相微萃取—气相色谱法分析大气中芳烃物质

用石墨吸附质棒固相微萃取装置吸附、富集大气芳烃污染物，于气相以谱中解吸并分析。实验表明此法具有无溶剂、快速、简便、灵敏等优点，具有很大的实用性。     

Cyclodextrins in innovative engineering tools for risk-based environmental management

Experimental results, which may serve as basis for innovative applications of cyclodextrins (CDs) in environmental technologies, are presented here. Some newly developed CD-aided tools are used in sampling, measuring the concentration or testing the effect of contaminants in water and soil. The innovative methods such as the bacterial bioassays with CD-increased sensitivity or the CD-filled absorptive samplers for air and water sampling are utilised in environmental exposure, hazard and risk assessment. Technological developments aim the reduction of the risk of chemical substances in waters and soils. CD-aided environmental remediation is introduced through examples for the elimination of organic contaminants from water by CD-filters, and for the enhancement of the mobility and availability of soil contaminants in this way increasing the efficiency of soil remediation by water extraction, chemical oxidation, biodegradation, etc.     

The Damping of Balances

The paper gives a survey of the history of damping methods for balances. Representation on Egyptian drawings demonstrate that the person performing the weighing shortened the measuring time by holding the suspension cords and touching the beam. By means of delimiters, the Romans constricted the deflection amplitudes. In the 19th century, the movements of precision balances were damped with a brush. For analytical balances, locking mechanism were developed, often combined with levers lifting the weighing scales and the beam in order to relieve the knife-edges. Half-arresting was used to curtail weighings. Air damping was invented by Arzberger in 1875, and eddy current damping by Marek in 1906. In electronic balances, lag, lead and filter elements and absorptive attenuators are used. For digital balances, the fast-reacting nullification of eddy signals is applied. This revised version was published online in July 2006 with corrections to the Cover Date.     

Excited state absorption dynamics in metal cluster polymer [WS4Cu3I(4-bpy)3]n solution

The nonlinear absorptive property of a novel metal cluster [WS(4)Cu(3)I(4-bpy)3]n in DMF solution is studied by using an open-aperture Z-scan technique with picosecond and nanosecond laser pulses at the wavelength of 532 nm. The experimental results show that the cluster has strong nonlinear absorption under the 8 ns pulse excitation and a relatively weak nonlinear absorptive property under the picosecond pulse excitation. The picosecond pump-probe response of the metal cluster is similar to that of C60 solution, which implies that the nonlinear mechanisms are the same for the two materials. By using the rate-equation model, the experimental data are theoretically simulated; several optical parameters of the cluster, especially the lifetime of the higher excited singlet state of the cluster, are obtained.