ICP—AES法测定钢铁样中硅,磷,锰,铬,镍,铜,铝

详细地研究了钢铁样中主量铁对７种被测定元素的干扰和被测定元素间的干扰情况，并研究了不同酸分解样品的效果，确定了用电感耦合等离子体发射光谱测定钢铁样中硅、磷、锰、铬、镍、铜和铝的方法。     

线性规划—导数分光光度法同时测定钴,镍,铜,锌,铁的研究

1 引言 近年来,随着计算机的普及和发展,用化学计量学方法来解析光谱数据,实现毋需分离的多组分同时测定的报道迅速增加,但一般仅限于用来解析基本光谱数据。本文提出用线性规划算法解析一阶导数光谱数据的新方法,对以PAR为显色剂的Co、Ni、Cu、Zn、Fe五组分混合体系的同时测定进行了研究,结果表明,该法既保持了导数分光光度法的高灵敏度,又利用了线性规划算法解决了普通导数光谱难以解析的5组分同时测定问题,对标准合成样品进行了测定,结果令人满意。     

预还原氢化物发生—原子荧光光谱法快速测定化探样品中的As,Sb,Bi,Hg

通过对化探样品进行王水密闭溶解,饱和的硫脲-抗坏血酸预还原,运用氢化物发生-原子荧光光谱法实现了地质样品中As、Sb、Bi、Hg元素的任意配对以及连续快速测定。实验确定了原子化器高度为14mm,最佳溶样时间为1h。在优化条件下,结果显示还原剂(硫脲-抗坏血酸)对Hg、Bi测定结果无影响,且Hg、Bi测定结果在预还原20min至48h内都很稳定,测定结果良好,Cu、Co、Ni、Au、Ag、Cd、As、Sb、Bi、Se、Ge等金属离子对预还原测定汞均无干扰,对比实验表明还原剂体系下汞荧光强度值基本不变。方法的检出限低、精密度好、准确度高、操作简便,有效避免了元素污染问题,可满足大批量地质样品分析测定的需要。     

王玉功,倪能 ,杨发旺

采用电感耦合等离子体发射光谱法(ICP-AES)测定地表水和地下水中的全S、P、B来近似代替水中的SO42-、PO43-、H3BO3。结果表明,ICP-AES可同时测定地表水和地下水的SO42-、PO43-、H3BO3,方法检出限分别为0.0265mg/L、0.0320mg/L、0.0192mg/L。方法的精密度(RSD,n=6)为0.53﹪～6.09﹪,加标回收率为91.9﹪～102.2﹪,经与单个项目分别测定的方法比对实验,测定值无明显系统偏差。方法快速、准确,经国家标准物质验证,结果与标准值相符。     

电感耦合等离子体原子发射光谱法(ICP-AES)测定N18锆合金中Nb,Sn,Fe,Cr元素含量

建立了电感耦合等离子体原子发射光谱法(ICP-AES)测定N18锆合金中Nb,Sn,Fe和Cr含量的分析方法。对溶样方法、基体影响、谱线选择等进行了讨论,结果表明,锆基体对测定结果有一定的影响,在实验中采用基体匹配法消除基体干扰,并对实验条件进行了优化。在优化的实验条件下,该方法用于样品中Nb、Sn、Fe、Cr的测定,测定结果与化学法测定结果基本一致,加标回收率为96.7%~101.0%,相对标准偏差(RSD,n=11)均小于3%。     

电感耦合等离子发射光谱法测定镍铁中Si,Mn,P,Ni

建立ICP–AES法测定新型材料镍铁中的Si,Mn,P,Ni元素的方法。考察了镍铁基体和共存元素对测定结果的影响。通过基体匹配消除基体干扰,确定各待测元素谱线为Mn 293.930 nm,P 178.280 nm,Ni 231.604 nm,Si251.611 nm。Si,Mn,P,Ni的检出限分别为0.06,0.04,0.08,0.04 mg/L,测定结果的相对标准偏差均小于5%(n=11),加标回收率在95%~105%之间。该方法操作简便、测定结果准确可靠,可用于镍铁中Si,Mn,P,Ni的含量测定。     

裂解气中NO,AsH_3,COS等杂质的色/质联用测定研究

 以气相色谱 /质谱 (GC/MS)的选择离子监测 (SIM )测定方式对裂解气中的一氧化氮、砷化氢、羰基硫、硫醚、硫醇等杂质进行了测定。针对一氧化碳、二氧化碳、乙烷、乙烯及氮气对一氧化氮测定的干扰 ,分别采取色谱分离和扣除响应的方法对其予以排除。考察了裂解工艺气物流对所选择离子的测定的干扰情况。对实际工艺气中的上述杂质进行了测定 ,结果一氧化氮的检出限为 10 0nL/L。     

HG-ICP-MS同时测定生物样品中痕量As,Se,Hg

以HNO3为介质,采用自行研制的二级气液分离器代替易消耗的膜分离器,在优化的实验条件下,采用HG-ICP-MS实现了As,Se,Hg的同时测定,分别获得了0.022,0.016,0.009 ngmL的检出限。实验研究了二级气液分离器中的气液分离行为、样品酸度、NaBH4质量浓度和引入方式等因素对测定灵敏度和精密度的影响。实验的结果表明,HG-ICP-MS同时测定As,Se,Hg的主要干扰来自于Fe,cu等过渡金属离子,样品溶液中抗坏血酸-硫脲的加入可以掩蔽这些离子的干扰。利用所建立的方法测定了人发、灌木叶和大米粉标样中痕量的As,Se,Hg,结果与标准参考值相符。     

化学蒸气发生-四通道原子荧光光谱法同时测定高纯金中的痕量As,Sb,Bi,Te

采用化学蒸气发生-四通道原子荧光光谱法测定了高纯金中的痕量砷、锑、铋和碲。用乙酸乙脂萃取分离金,水相还原后采用化学蒸气发生-四通道原子荧光光谱法测定高纯金中的痕量砷、锑、铋和碲。在最佳条件下,方法对As,Sb,Bi,Te的检出限分别为0.04,0.05,0.04,0.03 ng/mL(3σ);测定精密度分别为0.98,0.89,0.94,0.99%(对10 ng/mL As,Sb,Bi和Te混合标准,n=7)。方法对实际样品中的As,Sb,Bi,Te进行了同时测定,测定结果与标准方法无明显差异,各元素的加标回收率为95%～105%。     

电位溶出分析法同时测定锡, 铅, 铜

本文应用电位溶出分析法进行同时测定锡、铅和铜的研究。结果发现在草酸溶液中锡、铅和铜有分离清晰的平台,其溶出讯号与浓度呈线性关系,可用于定量分析。用这一方法测定了某些罐头食品中痕量锡、铅和铜,获得满意的结果。     

MECHANICS AND THE EVOLUTION AND FUNCTIONAL MORPHOLOGY OF CONCHOSTRACAN CARAPACE MECHANICS AND THE EVOLUTION AND FUNCTIONAL MORPHOLOGY OF CONCHOSTRACAN CARAPACE

Conchostracans, with a laterally compressed body enclosed between two symmetric valves, live swimming in fresh or brackish water. The carapace valve has a number of growth bands with various sculptures. The general trend of sculptural evolution is from smooth to punctate-minute polygon-medium reticulation-large reticulation, while these punctate, polygonal and various reticulate patterns may separately develop into various radial ridges. The development of sculpture can be well explained by mechanical principle. Functional morphology of carapace is discussed in the light of mechanics in this paper.     

混甲酚甲醛炭气凝胶的制备及表征

以混甲酚和甲醛为原料,经溶胶－凝胶民、酸洗老化、超临界干燥得有机气凝胶,密度０．１５０７ｇ／ｃｍ＾３,进一步炭化得炭气凝胶。采用正交试验方法重点考察了炭化工艺条件对炭气凝胶结构和性能的影响,并用ＴＥＭ、ＴＧ、低及附等手段进行了表征。结果表明,炭化工艺条件影响因素顺序为：升温速率〉炭化终温〉维温时间,最佳炭化条件下炭气凝胶密度为０２６０ｇ／ｃｍ＾３,幽静面积人１０２２ｍ＾２／ｇ,平均戏５．６ｍｍ。Ｔ     

Si、Zr取代磷酸铝沸石的合成与表征(英文)

利用水热法合成了 Ｓｉ、Ｚｒ取代型的ＡＰＯ－１１分子筛,井利用ＸＲＤ、ＳＥＭ、ＤＧ－ＤＴＡ等多种手段表征了其晶体结构、表面形貌、孔分布等特性。研究结果显示,ＡＰＯ－ｌｌ、ＳＡＰＯ－１１与ＺＡＰＯ－１１具有相同的晶体结构,不同的表面形貌－ＡＰＯ－１１与ＳＡＰＯ－１１为球形颗粒,而ＺＡＰＯ－１１为棒状晶体,推测这可能与ｐＨ对晶体生长的导向作用有关;三种分子筛除了具有为０．４５ ｎｍ的特征微孔孔径外,还形成了３．８ ｎｍ～３．９ ｎｍ的中孔;ＥＤＸ与孔分布结果显示,Ｚｒ主要以氧化物的形式沉积在分子筛的孔道内,而Ｓｉ部分进入了 ＡＰＯ－１１分子筛的骨架;三种分子筛的热稳定性良好,分解温度超过１０００℃。     

PHOTOLYSIS AND RADIOLYSIS OF NITROMETHANE AND NITROETHANE

Abstract— Prolonged photolysis of nitromethane and nitroethane in liquid and vapour phases, with simultaneous photolysis of the nitrogen dioxide formed, was studied in the absence and presence of cupric oxide. A high-pressure quartz immersion lamp providing the full range of visible and u.v. spectrum, with a high output of radiation at 366 and 313 mμ, was employed as source of light. The products of photolysis were detected by microanalytical methods, infrared-absorption spectrum analysis and gas chromatography. Photolysis of liquid nitro-alkanes resulted in formation of many compounds; saturated hydrocarbons, and in the case of nitroethane, ethylene, were submitted to detailed examination. Photolysis in the vapour phase was carried out in a specially designed glass apparatus. The main products were nitrogen dioxide, aldehydes and polyaldehydes; hydrocarbons were not estimated.
Liquid nitromethane and nitroethane were also irradiated with γ-rays from a ⁶⁰Co source. The radiolysis products were similiar to those obtained on photolysis. The mechanism of photolytic decomposition of nitroalkanes is proposed and discussed.     

DIFFRACTION AND HOLOGRAPHY WITH PHOTOELECTRONS AND FLUORESCENT X-RAYS

We consider studies of the atomic and magnetic structure near surfaces by photoelectron diffraction and by the holographic inversion of both photoelectron diffraction data and diffraction data involving the emission of fluorescent x-rays. The current status of photoelectron diffraction studies of surfaces, interfaces, and other nanostructures is first briefly reviewed, and then several recent developments and proposals for future areas of application are discussed. The application of full-solid-angle diffraction data, together with simultaneous characterization by low energy electron diffraction and scanning tunneling microscopy, to the epitaxial growth of oxides and metals is considered. Several new avenues that are being opened up by third-generation synchrotron radiation sources are also discussed. These include site-resolved photoelectron diffraction from surface and interface atoms, the possibility of time-resolved measurements of surface reactions with chemical-state resolution, and circular dichroism in photoelectron angular distributions from both non-magnetic and magnetic systems. The addition of spin to the photoelectron diffraction measurement is also considered as a method for studying short-range magnetic order, including the measurement of surface magnetic phase transitions. This spin sensitivity can be achieved through either core-level multiplet splittings or circular-polarized excitation of spin-orbit-split levels. The direct imaging of short-range atomic structure by both photoelectron holography and two distinct types of x-ray holography involving fluorescent emission is also discussed. Both photoelectron and x-ray holography have demonstrated the ability to directly determine at least approximate atomic structures in three dimensions. Photoelectron holography with spin resolution may make it possible also to study short-range magnetic order in a holographic fashion. Although much more recent in its first experimental demonstrations, x-ray fluorescence holography should permit deriving more accurate atomic images for a variety of materials, including both surface and bulk regions.     

POLYMER SCIENCE AND TECHNOLOGY IN THE PAST AND THE FUTURE:HEROISM,EXPLORATION AND ENLIGHTENMENT

The scientific and technical history of polymerization can be divided into three periods, which will be illustratedfor emulsion polymerization. The first period was when emulsion polymers were originally produced, and was developed asan attempt to copy natural rubber latex. Indeed, the natural process is quite different from the synthetic process of emulsionpolymerization, which in fact does not even need an emulsion to be present: the term is a misnomer! The results werefunctional but limited. In the second period, the first theories appeared, and a huge range of products was madefor surface coatings, adhesives, commodity polymers such as SBR, neoprene, etc. The work of the outstanding pioneers wasbased on limited types of experimental data, and some suppositions are now seen to be incorrect. Nevertheless, manyexcellent products were made and have evolved to many materials currently in everyday use. The third period of emulsionpolymerization is now dawning. The scientific efforts of many teams over previous decades, aided by the advent of newphysical techniques for investigation, have resulted in better understanding of the fundamentals of emulsion polymerizations.Some examples from the author's group involve creating novel materials using controlled seeded emulsion polymerizationfrom natural rubber latex and other polyenes. Latex topology and controlled free-radical chemistry can be combined toproduce a) a comb polymer with hydrophobic backbone and hydrophilic "teeth", or b) with sufficient in situ compatibilizerbetween two otherwise incompatible polymers to yield a spatially uniform material down to the nanostructure level, and c) toproduce controlled nanostructures.     

DLVO AND NON-DLVO SURFACE FORCES AND INTERACTIONS IN COLLOIDAL DISPERSIONS

Some aspects of DLVO and non-DLVO forces in colloidal systems are over-viewed. The influence of long range interactions on some kinetic properties of dispersions, as Brownian diffusion, is discussed. It is shown, both theoretically and experimentally, that the electrostatic repulsion increases the collective diffusivity. The film stratification and oscillatory structure forces in colloidal suspensions are considered within the framework of an uniform approach The presence of small colloidal species (e. g. micelles or polymer molecules) may lead to several maxima and minima in the disjoining pressure isotherm. The particular case of interacting emulsion droplets is examined accounting for the interfacial deformability. The droplet deformation acts as a soft repulsion but affects also the remaining contributions to the interaction energy due to changes of the droplet shape. A general procedure for calculating the inter-droplet interaction energy, as well as the equilibrium film radius and thickness in a doublet of droplets, is suggested. The energy of interaction between charged colloidal particles, due to correlations of the density fluctuations in the electric double layer is also studied. It is found that this effect may lead to attraction greater than the van der Waals contribution, especially when multivale counter ions are present.     

SURFACE ENTHALPY AND ENTROPY AND THE PHYSICO-CHEMICAL NATURE OF HYDROPHOBIC AND HYDROPHILIC INTERACTIONS

The attractive Interactions between typically hydrophobic molecules such as hexane or CCl₄, and the repulsive Interactions between extremely hydrophilic molecules such as poly(ethylene oxide) (PEO), when immersed in water, as well as the interactions between these molecules and water, have been examined from a surface thermodynamic viewpoint, taking the changes in surface free energy into account, as a function of temperature. It was found that attractive hydrophobic Interactions are not, as vas generally believed up to now, invariably entropic. Hydrophobic Interactions can be mainly enthalpic or mainly entropic, or more or less equal mixtures of both, depending on each individual case; however, all hydrophobic interactions are polar (in the sense of Lewis acid-base) in nature. Repulsive hydrophilic interactions are enthalpic, and also polar in nature. The interaction between hydrophobic solutes and water is mainly enthalpic, and is apolar in nature.     

比密粘度和特性粘数的计算及改正

本文导出毛细管粘度计的比密粘度方程: v=η/ρ=At-Bt~(-1)+C 式中-Bt~(-1)和C分别代表动能改正和残液改正。方程在宽的粘度范围内有良好精度。本文提出,准确的特性粘数[η]与忽略任何改正的特性粘数[η]~*之间存在简单的线性关系。例如从以上方程可写出[η]=(1+k_e-k_v)[η]~*+δρ式中k_e=2Bt_o~(-1)/At_0+Bt_0~(-1)+C), k_v=C/(At_0-Bt_0~(-1)+C), δρ=(ρ_1-ρ_0)/(c_1ρ_0), 它们分别是代表动能改正、残液改正和密度改正的常数。利用以上特性粘数改正公式, 可在确保准确性的前提下极大地简化特性粘数的改正计算。     

高效离子交换色谱法分离和测定氯溴碘

用国产高效离子交换色谱仪及国产阴离子交换树脂研究了分离Cl^-、Br^-、Ⅰ^-的条件,以硝酸钠为洗脱液,在三十五分钟内完全分离了上述三种离子。进行了一些样品的定量测定。用无换向阀的予柱富集测定了去离子水中ppb级的Cl^-。从软硬酸碱理论的观点讨论了Cl^-、Br^-.Ⅰ^-的色谱行为,得出了用结构参数及实验条件估算分配系数的经验式:1gD=0.24φg[B]-1g[B]+0.49φ+0.61。