Investigation of Glasses Using Surface Profiling by Spectrochemical Analysis of Sputter-Induced Radiation: I, Surface Profiling Technique with High In-Depth Resolution

Experimental equipment was developed to investigate concentration gradients in solid surface layers; the radiative de-excitation of elements and molecules which are ejected from the ion beam-bombarded solid and the luminescence excitation within the surface layer are recorded spectrographically. Examples show how elemental composition profiles can be calibrated with respect to depth. An in-depth resolution of a few nanometers can be obtained. The original profiles are distorted by energy and charge transfer and by other peculiarities connected with ion-beam etching; the extent to which these distortions must be taken into consideration in interpreting the results is discussed. Interdiffusion-controlled solid-state reactions of thin oxide films with a glass substrate were investigated. Advantages and disadvantages of the method for analysis and concentration profiling of glass surfaces and oxide layers on glasses in glass research and industry are discussed.     

铁磷酸盐玻璃析晶的拉曼光谱及显微分析

为研究热效应对铁磷酸玻璃结构的影响,对40Fe2O3-60P2O5玻璃样品在600～800℃进行热处理,获得了结晶样品.利用XRD、Raman等研究了玻璃结晶化过程中的结构变化,指认了铁磷酸盐玻璃微结构的振动模式的归属.结果表明,在600℃,铁磷酸盐玻璃析出的结晶相主要为:Fe(PO3)3和Fe4(P2O7)3,在700℃、800℃玻璃析出的结晶相主要为Fe4(P2O7)3.利用SEM观察了玻璃样品的微观形貌,结晶相的微观形貌为片状,保温时间延长,片层厚度增加.     

Interpretation of Hydrated States of Sodium Silicate Glasses by Infrared and Raman Analysis

Infrared spectra of thin films (a few micrometers) of hydrated sodium silicate glasses after heating at temperatures from 100° to 400°C were measured in the spectral region from 400 to 4300 cm⁻¹. Also, Raman spectra of hydrated glasses were measured in the region from 100 to 1400 cm⁻¹. Water molecules in hydrated glasses were classified into three types by the bonding configuration: water molecules interacting with Si–OH groups, nonbridging oxygens, and bridging oxygens. On the basis of the fundamental bands observed here, we calculated the wave numbers of the combination-overtone bands of water molecules and SiOH groups in hydrated glasses. The calculated wave numbers satisfactorily agreed with observed wave numbers in the nearinfrared region.     

Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis

The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays.     

Investigation of Glasses Using Surface Profiling by Spectrochemical Analysis of Sputter-Induced Radiation: II, Field-Driven Formation and Electrochemical Properties of Protonated Glasses Containing Various Proton Concentrations

The ion-sputtering technique for measuring concentration profiles in glass surfaces provides a method for studying ionic transport in solids. Simultaneous field-driven lithium ion and proton transfer from solutions into, and migration of these ions within, several lithium silicate glasses was investigated quantitatively. This work leads to the new field of protonated glasses which are distinguished by the availability of all sites to both cationic species. Conductivity and mobilities reported as a function of concentration (50°C) do not exhibit the typical features of the mixed-alkali effect. Mechanisms are proposed for ionic transfer across solution-glass interfaces and for migration of ions within protonated glasses. Small proton mobilities at low proton concentrations are explained in terms of specific sites which function as proton traps and are identified by infrared spectroscopy. The condition for stability of boundaries between migrating ions is discussed.     

具有高比表面积的稻壳灰的制备及其化学活性的研究

Preparation of rice husk ash with high specific surface area and chemical reactivity of the product are reported in this paper. The amorphous rice husk ash with high specific surface area of 311 m^2.g^-1 was produced by heating acid treated rice husk at 700~C for 4 h. The isotherms of rice husk ash are similar in shape to type Ⅱ of Brunaner‘s classification with mesopores being predominant. The rice husk ash has a high chemical reactivity, especially that pretreated with acid. This chemical reactivity depends on ashing temperature and pretreatment conditions. There is an exponential relation between the specific surface area of rice husk ash and the change in the conductivity of saturated Ca(OH)2 solution with rice husk ash, from which the specific surface area can be known according to the conductivity change.     

On-Line Chemical Analysis of Individual Alkali-Containing Aerosol Particles by Surface Ionization Combined with Time-of-Flight Mass Spectrometry

An aerosol mass spectrometer for measurements of the alkali metal content in individual submicron aerosol particles is presented. The instrument combines surface ionization of individual particles on a hot platinum surface with orthogonal acceleration time-of-flight mass spectrometry. The instrument simultaneously provides the content of different alkali metal elements in single particles with high sensitivity. The instrument is characterized in laboratory experiments, and determination of the alkali metal content is demonstrated for particle diameters of 50–500 nm. The technique is demonstrated in ambient air measurements at an urban background site, and sea spray particles and particles originating from biomass burning are identified based on their content of sodium and potassium. Possible further improvements and applications of the technique are discussed.     

The Chemical Differentiation between Sinapis arvensis and Brassica napus Seeds by Surface Wax Analysis

The hydrocarbons were extracted and isolated from the surface of both Sinapis arvensis and Brassica napus seeds. The major hydrocarbon of the weed seed was found to be hentriacontane (C₃₁H₆₄) whereas nonacosane (C₂₉H₆₀) was the predominant hydrocarbon in rapeseed. This can be used as a criterion upon which differentiation can be made. Total “wax” extracts of the two seed types were analysed by gas chromatography. The waxy material extracted from the weed seed was found to have a major peak at 3320 Kovats retention indices which was absent in all rapeseed varieties. By studying a series of known composites of rapeseed and wild mustard, the level of wild mustard contamination could be accurately determined down to a level of 1 % using a ratio of two peaks at 2900 and 3320 Kovats retention indices.     

Structural and nanostructural behavior of deuterium implanted Highly Ordered Pyrolytic Graphite investigated by combined High Resolution Transmission Electron Microscopy,Scanning Electron Microscopy and Raman microspectrometry

This work aims at studying the impact of D⁺ ion implantation and thermal annealing on the organization of Highly Ordered Pyrolytic Graphite (HOPG). Raman microspectrometry, High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy (SEM) were used to characterize the multiscale organization of HOPG. For the first time, HRTEM images were processed, allowing a better estimation of structural parameters such as size of the graphene layers, mean interlayer spacing, distribution of the relative orientations of the graphene layers, defined as the spatial orientation of the stacked layers. Ion implantation induces a strong disordering of the HOPG reflected by a decrease of the length of graphene layers, and an increase of both angular dispersion and interlayer distance and a significant decrease of the Basic Structural Unit (BSU) diameter. Thermal annealing up to 1000 °C leads to partial reordering of the HOPG, with increase of the mean length of the graphene layers, decrease of their angular dispersion and interlayer distance and larger and increasingly parallel oriented BSUs. Even if the conservation of the lamellar nanostructure favors reordering, the latter is only partial since annealing temperature is far from 2000 °C, temperature above which stiff and perfect layers may be obtained.     

努力打造有国际竞争力的精品化工园区--初析南京化学工业园区的开发和建设

简要介绍了设立南京化学工业园的必要性，优势特点，阐述了化工园区建设对石化工业及地区经济发展的促进作用和现实意义。     

Mass Spectral Filtering by Mass-Remainder Analysis (MARA) at High Resolution and Its Application to Metabolite Profiling of Flavonoids

Flavonoids represent an important class of secondary metabolites because of their potential health benefits and functions in plants. We propose a novel method for the comprehensive flavonoid filtering and screening based on direct infusion mass spectrometry (DIMS) analysis. The recently invented data mining procedure, the multi-step mass-remainder analysis (M-MARA) technique is applied for the effective mass spectral filtering of the peak rich spectra of natural herb extracts. In addition, our flavonoid-filtering algorithm facilitates the determination of the elemental composition. M-MARA flavonoid-filtering uses simple mathematical and logical operations and thus, it can easily be implemented in a regular spreadsheet software. A huge benefit of our method is the high speed and the low demand for computing power and memory that enables the real time application even for tandem mass spectrometric analysis. Our novel method was applied for the electrospray ionization (ESI) DIMS spectra of various herb extract, and the filtered mass spectral data were subjected to chemometrics analysis using principal component analysis (PCA).     

Barium Borosilicate Sealing Glasses Synthesized by a Sol–Gel Process: Chemical Interactions with a Stainless Steel and Gas‐Tightness of a SOFC

Several glasses synthesized by sol–gel route and based on the BaO–B₂O₃–X–Al₂O₃–SiO₂ (X = CaO, MgO) glass system have been investigated to evaluate their applicability as sealant for solid oxide fuel cell (SOFC). Chemical interactions with K41X stainless steel and hydrogen‐tightness of these materials were evaluated after operations at high temperatures over 1,000 h in air atmosphere. Formation of a new phase at the steel–glass interface and formation of porosity in the glass were observed and determined as critical problems over mid‐term operations. The role of MgO is important to obtain a gas‐tight sealing. Application of the glass paste without binder addition was performed in order to avoid possible residual porosity related problems. The best glass was finally used as sealant between anodic and cathodic compartments in complete SOFCs operated at 760 and at 800 °C. Open circuit voltages and power densities of the cells were recorded during the first hours of operation.     

Surface Analysis of Cr2O3‐, CoO‐, and Al2O3‐Doped Iron–Phosphate Glasses at High Temperature

Surface structures of iron–phosphate glasses were examined using X‐ray photoelectron spectroscopy (XPS). Cr₂O₃, CoO, and Al₂O₃ were introduced to the glass by the replacement of a part of Fe₂O₃, and the simulated fission products are also added. The obtained glasses showed high chemical durabilities by MCC‐1 test. In situ high‐temperature and room‐temperature XPS measurements were conducted on the polished sample surfaces and also those after 1‐week chemical durability test. Unique trends were observed in XPS spectra on heating and after the chemical durability test, respectively. Nature of the glass surface of iron–phosphate glasses was explained from the point of view of surface energy, and the origin of high chemical durability and the effect of chromium ions were discussed based on the changes on surface composition and valence states of transition‐metal ions.     

Synthesis of Si-N and B-N Preceramic Coatings on Silica Gel by Chemical Surface Coating: A Porosity Study

Silica gel has been modified by successive gas reactions with (SiCl₄-NH₃) and (BCl₃-NH₃) in order to obtain Si-N and B-N preceramic polymers, which are chemically bound to the substrate surface. The effect of the polymer synsthesis on the porosity characteristics of the substrate is determined as a function of the number of applied modification cycles, using N₂ adsorption-desorption isotherms recorded at 77 K. The elemental analysis data in combination with the adsorption isotherms yield a more detailed picture of the density and the homogeneity of the coatings. Using the pore size distributions, the contribution of pore blocking and pore narrowing can be calculated as a function of the amount of reaction cycles. A new calculation method for the pore blocking and pore narrowing, which is not based on any pore shape model, is also presented and compared with the former calculation method.     

Synthesis of Nanocrystalline CeO2 with High Surface Area by the Taguchi Method and its Application in Methanation

Mesoporous nanocrystalline cerium(IV) oxide (CeO₂) with high surface area was synthesized by precipitation using a cationic surfactant and employed as support for a nickel catalyst in CO methanation. The preparation factors of CeO₂ were optimized by the Taguchi method to achieve a sample with high surface area. The obtained results reveal that the sample prepared under optimized conditions has a mesoporous structure with high surface area and crystallite size. The addition of a surfactant significantly influences the structural properties of CeO₂ and improves the specific surface area. The optimized sample was employed as support for a nickel catalyst in CO methanation reaction. The prepared catalyst possessed a high activity compared to a commercial methanation catalyst.     

气体多元共渗与化学镀复合处理试样的性能分析

研究了Q235钢经气体多元共渗加化学镀复合处理后，试样表面复合处理层的结构与形貌、显微硬度和抗盐雾腐蚀特性。实验结果表明，复合处理层的结构由Ni-P、NiaP3、NiP4、Fe3N、Fe2N、Fe3O4、Fe2O3和少量的FeS、Fe2C构成，其硬度是气体多元共渗处理后表层硬度的1．6-1．7倍，抗蚀性能相对于单一气体多元共渗或化学镀技术处理大约提高了3．7-5．5倍。     

Druids' Knowledge in Chemical Engineering: Analysis of the Illustrated Literature by Goscinny and Uderzo

The illustrated literature series Asterix (and Obelix) is commonly known as entertainment and distraction, but behind that mask, case studies for chemical production in small medium enterprises and the crucial role of research and development can be discovered. The series rightly puts chemistry and chemical engineering at the heart of success and prosperity. Overall, the motives exemplified are of high relevance today for chemical industry.