扫描型X射线荧光显微分析仪测定汽车零部件及内饰材料中铅、镉、汞、铬和溴

建立扫描型X射线荧光显微分析仪测定汽车零部件及内饰材料中铅、镉、汞、铬和溴等元素的方法。通过改变测量条件与测量方式选择最佳试验方法,采用成像图判断样品中是否存在目标元素。结果表明,5种元素的含量在0~300 mg/kg范围内与荧光强度成良好的线性关系,相关系数均大于0.993,样品加标回收率为82.3%~106.0%,测定结果的相对标准偏差为2.86%~6.63%(n=6)。该方法简单、快速,测定结果准确、可靠,适用于汽车零部件和内饰材料中有毒有害物质的筛选。

切片电镜方法对炸药粒子内部结构的研究

将炸药粒子用树脂包埋固定,切片,然后溶解脱除包埋剂,并对其进行电镜检测,研究了炸药重结晶粒子的内部结构。探讨了类球形3-硝基-1,2,4-三唑-5-酮(NTO)粒子的生长方式;研究了γ-丁内酯、环己酮和丙酮等三种溶剂重结晶RDX粒子内部均存在的裂纹、孔洞等微缺陷,比较了三种重结晶粒子内部结构的规整性;制备了两种膨化硝铵粒子的切片,电镜测试表明质量较好的膨化硝铵样品晶粒内部存在着非常多的孔洞,呈蜂窝状,多数孔洞的孔径小于10μm,而参照样内部孔洞数量较少,孔径在数微米至十几微米之间。

钢渣粉/聚酯纤维沥青混合料水稳定性研究

为了实现钢渣粉在沥青路面中的可持续利用,同时结合河南省冬季冰雪天气下路面的除冰情况,研究了掺有聚酯纤维与钢渣粉沥青混合料的水稳定性。制备4种聚酯纤维掺量(0、0.3%、0.4%、0.5%)AC-13沥青混合料开展复盐(掺量配比为NaCl∶CaCl2∶CH2COONa=1∶1∶2)冻融循环劈裂试验,结果表明聚酯纤维掺量为0.4%时,沥青混合料水稳定最好;在最佳纤维掺量下制备5种替代率(0、25%、50%、75%、100%)钢渣粉沥青混合料,采用冻融劈裂抗拉强度比(freeze-thaw splitting tensile strength ratio,TSR)确定最佳钢渣粉替代率为75%,混合料水稳定性最佳;通过冻融腐蚀因子K评价沥青混合料的抗侵蚀性能,结果表明:聚酯纤维/钢渣粉沥青混合料的抗侵蚀性能最强,聚酯纤维沥青混合料次之,普通石灰岩沥青混合料最弱。通过电镜扫描(scanning electron microscope,SEM)、X射线衍射(X-ray diffraction,XRD)技术探索钢渣粉/聚酯纤维沥青混合料界面黏附作用的改性机理。微观分析表明:掺量为0.4%的聚酯纤维形成的纤维网状结构以及沥青、钢渣粉(75%的替代率)和矿粉三者存在界面能量作用可以很好地改善沥青混合料的水稳定性。

The Morphology, Phase Composition and Effect of Corrosion Product on Simulated Archaeological Iron

The immersion corrosion of archaeological iron in solution(0.06mol·L- 1NaCl+0.03mol·L -1 Na2SO4+ 0.01mol·L- 1 NaHCO3)simulating soil water composition was presented.The evolution of archaeological iron from iron to iron oxide and to iron oxy-hydroxides compounds was investigated by scanning electron microscope(SEM) and X-ray diffraction(XRD)analysis.According to the morphology,phase composition,and transformation proc- ess,the contributions of each corrosion product to archaeological iron were discussed.

Electrochemical characterization of Ni-Co and Ni-Co-Fe for oxidation of methyl alcohol fuel with high energetic catalytic surface

Non Pt based metals and alloys as electrode materials for methyl alcohol fuel cells have been investigated w ith an aim of finding high electrocatalytic surface property for the faster electrode reactions.Electrodes w ere fabricated by electrodeposition on pure Al foil,from an electrolyte of Ni,Co,Fe salts.The optimum condition of electrodeposition w ere found out by a series of experiments,varying the chemistry of the electrolyte,pH valve,temperature,current and cell potential.Polarization study of the coated Ni-Co or Ni-CoFe alloy on pure Al w as found to exhibit high exchange current density,indicating an improved electro catalytic surface w ith faster charge-discharge reactions at anode and cathode and low overvoltage.Electrochemical impedance studies on coated and uncoated surface clearly show ed that the polarization resistance and impedance w ere decreased by Ni-Co or Ni-Co-Fe coating.X-ray diffraction(XRD),energy dispersive X-ray spectroscopy(EDX)and atomic absorption spectroscopy(AAS)studies confirmed the presence of alloying elements and constituents of the alloy.The morphology of the deposits from scanning electron microscope(SEM)images indicated that the electrode surface w as a three dimensional space w hich increased the effective surface area for the electrode reactions to take place.

Characterization of a Rarely Encountered Sericite with Earthy Luster

A rarely encountered sericite was investigated using X-ray diffraction,differential thermal analysis,and scanning electron microscopy.XRD analysis shows that the pattern of the sericite in the sample is similar to that of illite.DTA (TG) analyses show that only a weak heat absorption reaction takes place at 566℃,which is contributed to the polymorphic transformation of quartz,and no change in mass was detected in the range from ambient temperature to 800℃.These reveal that no water escapes from the crystal structure of the clay mineral during heating and therefore indicated that the clay mineral is obviously sericite in species instead of illite.SEM observations show that the sericite particles are significantly small in size and growth steps and irregular structures develop on the crystal surfaces as well as the colored mineral inclusions,which might suggest some loss of optical properties of the sample and thus lead to the variance,with earthy luster of the aggregate,from typical sericite in optical characters.

Antimicrobial silver nanoparticle induces organ deformities in the developing Zebrafish (Danio rerio) embryos

Silver Nanoparticles were synthesized by Esche- richia coli using Silver nitrate in the growth me-dium and characterized in X-Ray Diffraction, UV-Vis Spectrophotometer and Scanning Electron Microscope. They exhibited antimicrobial activity against human pathogens except Escherichia Coli. Nanoparticles were impregnated in yarn and ana-lyzed for their inhibition in the broth culture. The Minimal Inhibitory Concentratio was calculated for the human pathogens in Microtitre plate. The toxicity assessment of the nanoparticles in the embry-onic Zebrafish showed many organogensis deformi-ties like cardiac malformations, eye and head edema, tail and trunk flexure were observed in the organ system of the developing embryos for 1 to 5 day post fertilization in different concentrations of Ag Nanoparticles. The Organogenesis disruptive effects were found in 14 - 20 ng/ml of silver nanoparticles but the inhibition was found in 4-10ng/ml for the pathogens in vitro and 10ng/ml in embryos. Nevertheless, in Cardiac assay, the Heart Beat rates were calculated as 42 - 45 for 15 Sec in the concentrations ranging from 10 - 20 ng/ml of Silver nanoparticles. The blood flows, rhythmicity, contractility of heart beat rates were observed normal. The Mean value of blood Cell counting did not showed any notable effects in the Nanoparticle treated Zebrafish embryos and control. The LC50 value for the Biosynthesized nanoparticle was at 22 ng/ml in all the developmental stages of the em-bryos. Our results shows silver nanoparticles dis-rupts the normal organogenesis during development and further detailed studies are needed to prove silver nanopartcles are an antimicrobial agent for use in humans.

羊绒与羊毛纤维的鉴别检测综述

文章简单介绍了羊绒与羊毛纤维的形态特点和物理、化学特性,总结并比较了传统光学显微镜法、扫描电镜法、溶液法、计算机图形分析法和基因分析法等鉴别羊绒、羊毛纤维的检测方法。

Wear Resistances of CO_2 Corrosion Product Films in the Presence of Sand Particles

Wear resistances of CO2 corrosion product films formed on P110 carbon steel at different CO2 partial pressures were investigated in water sand two-phase flow by weight loss method, and the microstructures and compositions of corrosion product films were analyzed by scanning electron microscope(SEM) and X-ray diffraction(XRD), respectively. The results showed that the wear rate of CO2 corrosion product films increased until a maximum and then decreased with the increasing of the film-forming pressure, and the maximum occurred at 2 MPa. However, the maximal corrosion rate and the loose and porous CO2 corrosion product films were obtained at 4 MPa. And the wear rate decreased and then went to be flat with increasing test time. Furthermore, the microstructures and compositions of corrosion product films and the impact and wear of sand particles played an important role on wear resistances. In addition, the wear rate and corrosion rate were fitted by cubic polynomial, respectively, which were well in accordance with the measured results.

A STUDY OF PET TIRE CORD TREATED BY LOW TEMPERATURE PLASMA

The process of treating the PET tire cord (210D/3×2) by low temperature nitrogen and airlow temperature plasma and dipping in RFL (resorcinol-formaldehyde-latex) adhesive system wasstudied.The H-pull test value can be improved from about 35 N/cm of untreated sample to 55N/cm of nitrogen plasma treated sample.The photograph of SEM demonstrates that the adhe-sion between nitrogen plasma treated tire cord and rubber has reached the strength of rubber.Airplasma treatment has bad effect on adhesion improvement.The mechanism of plasma treatment on the surface of the PET tire cord and the mechanism ofadhesion improvement are investigated by diffuse reflection infra-red spectrum and XPS (X-rayphotoelectron spectroscopy).From the spectral analysis,it is believed that the contribution to im-provement of the adhesion of the tire cord is the oxidation on the surface.The serious breaking ofthe chemical bonds on surface can cause the adhesion inferior.

Synthesis and characterization of pure mesoporous zirconia thin film with two-dimensional hexagonal framework

Pure mesoporous ZrO2 thin film with two-dimensional hexagonal framework mesostructure has been successfully prepared by using a nonionic triblock copolymer as the structure-directing agent and ZrCl4 as the zireonia source through evaporation-induced self-assembly approach. The resulting materials were characterized by X-ray diffraction, scanning electron microscope, and nitrogen adsorption ,neasurenlents. The obtained mesoporous ZrO2 thin film has a nanocrystalline inorganic framework （tetragonal zirconia） and narrowly distributed mcsopore size （6. 7 nm in diameter].

Loose Sand Particles Cemented by Chem/Bio-BaHPO_4 Powder

Bacillus subtilis was selected as the suitable microorganism,which could produce alkaline phosphatase and constantly hydrolyzed phosphate monoester in the mixture solution of bacteria with substrate,and then the PO4^3-was obtained.Bio-phosphate cement was prepared by alkaline earth element（Ba）ions reacting with PO4^3-in the mixture solution.Structure,size and thermal properties of the bio-phosphate cement were characterized by energy dispersive X-ray spectroscopy（EDS）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and particle size analysis.The average crystallite sizes of chem-BaHPO4 and bio-BaHPO4corresponded to 11.99 and 24.13μm,respectively.Chem-BaHPO4 and bio-BaHPO4 were then adopted to bind loose sand particles.The results indicated that loose sand particles can be well cemented by the bio-BaHPO4powder into a bio-sandstone with a certain mechanical properties,and the average compressive strength of the bio-sandstones can be up to 0.83 MPa when the curing time was 14 d.Along with the method in future studies,there will be multiple new opportunities for engineering applications,for instance,the treatment of sandy soil foundation,remediation of heavy metals in contaminated soil,and so on.

Semiconductor ZnO Nano-Rods Thin Film Grown on Silver Wire for Hemoglobin Biosensor Fabrication

Wurtzite hexagonal ZnO semiconductor nano-rods (NRs) thin films were grown on silicon substrates and silver wire with diameter equal 68 nm. Sol gel (SG) and aqueous chemical growth (ACG) methods by two steps of preparation (seed layers and nano-rod growth) are used for samples preparation. The structural and morphological properties are evaluated using X-ray diffraction (XRD) and scanning electron microscope (SEM). The proposed iron ion sensor has shown good linearity for a wide concentration range from 0.078 M/L to 0.26 M/L of iron ions. The results show that the electrode is highly sensitive to iron ions with a slope around 47.8 mV/decade with a regression coefficient R2 = 0.96.

Applying SEM-EDX and XRD Techniques to Demonstrate the Overgrowth of Atmospheric Soot and Its Coalescence with Crystal Silicate Particles in Delhi

Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and X-ray diffraction (XRD) systems were used to demonstrate the overgrowth of soot to fractal like structure and its subsequent coalescence with crystal shaped silicate particles. Sample was obtained from a very clean area of Delhi at a height of 16 m from ground with the help of a five stage cascade impactor in the winters of 2006. Impactor collects particles in five different size ranges (i.e. ≥10.9, 10.9 - 5.4, 5.4 - 1.6, 1.6 - 0.7 and ≤0.7 μm). In the present investigation only the particles collected in the size range 1.6 - 0.7 μm (D50 = 0.980 μm) have been considered. It has clearly been observed that the soot particles tend to grow or rather agglomerate in a fractal like structure. During this process they incorporate other chemically and structurally different particles (crystal silicate in the present investigation) to make multi phase and multi chemical amorphous aggregates. These aggregates are formed during/after its collection on the sampling substrate and may be as many as hundred times more than the expected size interval (D50 or cut off range).

Comparison of Antioxidant Activities of Silver Nanoparticles and Methanol Extracts of Three Indigenous Nigeria Herbal Seeds

The antioxidant of seeds was carried out using extracts from methanol and Silver Nanoparticles from the spice. The SEM shows the shapes, dispersion and agglomeration of the sample, while the EDX confirms the SEM and the presence of some compounds. The FT-IR reveals the AgNPs capping and reducing the particular biomolecule from the functional group for identification. Compounds found in the FT-IR seeds of Capsicum annum are Ag L (Silver iodide), C K (Cyanogen chloride), P K (Phenol). Monodora myristica are Mo L (Molybdenum), Ag L (Silver iodide), C K (Cyanogen chloride), P K (Phenol), Mg K (Magnesium). Piper guineense are Ag L (Silver iodide), Ci K (Potassium chloride), C K (Cyanogen chloride), P K (Phenol). The seeds show that the AgNPS of CA and MM has a better antioxidant activity than the methanol of CA and MM, while the PG methanol has a better activity than the AgNPS PG. The control (Catechin and Galic acid) has a slight overall better DPPH activity than the AgNPS. It is important to note that there is a concentration dependency in CA, MM AgNPS, PG methanol respectively. Notably, at CA methanol, the conc. at 125 was higher than the conc. at 250. Hence, there is need to create a great part in using plant samples for making tabulated or capsulated drugs for treatment of diseases and using plant silver nanoparticles to develop a healthy food/drug preservative package material “smart packaging” that will enhance shelf-life.

水稻中硅元素的分布及存在状态

利用UV-Vis分光光度计、X线分析显微镜及扫描电子显微镜(Scanning electron microscope,SEM)对水稻不同器官中硅元素的含量、分布及存在状态进行观察和分析,研究水稻中硅酸的化学性质,为水稻硅元素的综合利用提供科学依据.结果表明:水稻以可溶性原硅酸的形式吸收土壤中的硅酸,同样以可溶性原硅酸的形式输送到各器官中.不同的生长期,水稻导管液内的可溶性原硅酸的含量不同,成熟期最高可达到912 mg/L(以SiO2表示).通过比较导管汁液和土壤溶液的硅酸浓度可知,水稻选择性地吸收和浓缩硅酸,最高浓缩率可达85倍.X线分析显微镜观察发现,硅酸普遍存在于水稻各器官中,越是坚硬的部位硅酸分布得越多.SEM图像表明,沉积在水稻各器官中的硅胶体具有一定的形状且不溶于强酸.对水稻干燥组分中硅酸含量的分析结果表明,稻壳中硅酸含量最高,达到13.3%,是生产硅单质及碳化硅材料的最有效的资源之一.

Influence of ash composition on the sintering behavior during pressurized combustion and gasification process

To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer （XRD） analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer （FE-SEM/EDS） analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe203 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe203 additive show consistent results with the XRD measurements. The CaO and Na20 can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures.

Mechanism of flue gas simultaneous desulfurization and denitrification using the highly reactive absorbent

Fly ash,industry-grade lime and a few oxidizing manganese compound additive were used to prepare the“Oxygen-riched”highly reactive absorbent for simultaneous desulfurization and denitrification.Experiments of simultaneous desulfurization and denitrification were carried out using the highly reactive absorbent in the flue gas circulating fluidized bed(CFB)system.Removal efficiencies of 94.5%for SO_(2)and 64.2%for NO were obtained respectively.The scanning electron microscope(SEM)and accessory X-ray energy spectrometer were used to observe micro-properties of the samples,including fly ash,common highly reactive absorbent,“Oxygen-riched”highly reactive absorbent and spent absorbent.The white flake layers were observed in the SEM images about surfaces of the common highly reactive absorbent and“Oxygen-riched”one,and the particle surfaces of the spent absorbent were porous.The content of calcium on surface was higher than that of the average in the highly reactive absorbent.The manganese compound additive dispersed uniformly on the surfaces of the“Oxygen-riched”highly reactive absorbent.There was a sulfur peak in the energy spectra pictures of the spent absorbent.The component of the spent absorbent was analyzed with chemical analysis methods,and the results indicated that more nitrogen species appeared in the absorbent except sulfur species,and SO_(2)and NO were removed by chemical absorption according to the experimental results of X-ray energy spectrometer and the chemical analysis.Sulfate being the main desulfurization products,nitrite was the main denitrification ones during the process,in which NO was oxidized rapidly to NO_(2)and absorbed by the chemical reaction.

Effect of Heat Input on Fume Generation and Joint Properties of Gas Metal Arc Welded Austenitic Stainless Steel

The effect of heat input on fume and their compositions during gas metal arc welding （GMAW） of AISI 316 stainless steel plates are investigated. Fume generation rate （FGR） and fume percentage were determined by ANSI/AWS F1.2 methods. Particle characterization was performed with SEM-XEDS and XRF analysis to reveal the particle morphology and chemical composition of the fume particles. The SEM analysis reveals the morphology of particles having three distinct shapes namely spherical, irregular, and agglomerated. Spherical particles were the most abundant type of individual particle. All the fume particle size falls in the range of less than 100 nm. Mechanical properties （strength, hardness and toughness） and microstructural analysis of the weld deposits were evaluated. It is found that heat input of 1.15 kJ/mm is beneficial to weld stainless steel by GMAW process due to lower level of welding fume emissions and superior mechanical properties of the joints.

Effect of Copper Content on the Direct Process of Organosilane Synthesis from Silicon and Methyl Chloride

The effect of copper concentration on the performance of the catalytic reaction between silicon and methyl chloride was investigated using online gas chromatogram. The catalyst concentration greatly influences various aspects of the direct organosilane synthesis process, including the reaction rate, the selec- tivity, and the silicon conversion. The reaction activity and the silicon conversion increase as the catalyst concentration increases. However, the reaction selectivity decreases for the catalyst concentrations more .than 9 wt.%. The cross-sections of deactivated contact mass particles were observed by optical microscopy and analyzed by scanning electron microscope combined with energy dispersive X-ray detector （SEM-EDX） The observations showed that a textured substance formed on the original flat surface of the silicon particles after deactivation with copper only in a shallow surface layer of the contact mass. This indicates that the copper diffusion is the rate limiting step which causes the reaction deactivation.