A program package for data analysis in extended x-ray absorption fine-structure spectroscopy

A computer program package is described for the evaluation of atomic local structure parameters from extended x-ray absorption fine-structure measurements. It was compiled for the IBM-PC microcomputer and use successfully in structure determination of many samples from different fields. It consists of twelve relatively independent modules; data-processing procedures are programmed in IBM FORTRAN and parts of the graphic procedures are written in IBM Advanced BASIC language. The whole process takes about 20 min.     

关于变动边界的热传导问题

In this paper, a kind of heat conduction problem subject to a moving boundary condition is studied, in which its equation has form of quasilinear parabolic e-quation with vaviable coefficients, under some assumptions, we have defined and provided existence of solution of this problem in domain Ω by singular perturbation methods, where Ω denotes the domain:{σ₁(t)≤x≤ σ₂(t), 0≤t相似文献   

Propagator for a charged particle in a time-dependent electromagnetic field

We first show that the propagator of a charged particle in a time-dependent electromagnetic field, obtained by choosing the vector and scalar potentials to be in static symmetric gauge, is related to the propagator of a one-dimensional particle under a time-dependent perturbative force and with generalized memory. For the case of a constant magnetic field, the latter can then be evaluated exactly with the help of a gaussian integral. Our new results are in agreement with the well-known results of simpler cases.     

Copolymerisation mit Depolymerisation. 10. Mitt. Beschreibung von reversiblen Copolymerisationen durch irreversible Reaktivit?ts-Verh?ltnisse

Ohne Zusammenfassung     

Superhydrophobic CFx coating via in-line atmospheric RF plasma of He-CF4-H2

Stable superhydrophobic coatings on various substrates are attained with an in-line atmospheric rf plasma process using CF4, H2, and He. The coating layer is composed of CFx nanoparticulates and has an average roughness of approximately 10 nm. This roughness is much smaller than other surfaces reported for superhydrophobicity in the literature. The superhydrophobic coatings are produced on both metallic and insulating substrates without any need of separate microroughening or vacuum lines.     

Biflavone glucosides from Ginkgo biloba yellow leaves

Phytochemical investigation of Ginkgo biloba (Ginkgoaceae) has resulted in the isolation of two new biflavone glucosides, ginkgetin 7'-O-beta-D-glucopyranoside (1) and isoginkgetin 7-O-beta-D-glucopyranoside (2). The structures were determined on the basis of chemical and spectroscopic evidences.     

Interaction between cationic surfactants and montmorillonites under nonequilibrium condition

Surfactant adsorption by two different montmorillonites was characterized by examining the time dependence of surfactant behavior on clay surfaces. Surfactants with different micelle concentrations were conducted in our experiment to observe a nonequilibrium activity of cationic surfactant on the clay over reaction periods ranging from 0.1 min to 11 days. Compared with Ca-montmorillonite (SAz), a more active intrusion of surfactant molecules into the interlayers was found in Na-montmorillonite (SWy). During a short "initiation" stage, the basal spacing of SWy montmorillonite increased rapidly with logarithmic time. For SAz montmorillonite, however, the abrupt basal spacing increase occurred at a later stage of the reaction. From the results, it is assumed that the difference in the adsorption behavior exhibited by the two montmorillonite types partly arises from their intrinsic nature; that is, inorganic cations originally existed on the clay surfaces. Additionally, the micelle concentration of the surfactants affects the development of organomontmorillonite, especially in the intercalant formation and stabilization under nonequilibrium.     

Obesity and genetic polymorphism of ERCC2 and ERCC4 as modifiers of risk of breast cancer

To evaluate the relationship of genetic polymorphisms of ERCC2 and ERCC4 genes, both involved in nucleotide excision repair (NER), and the risk of breast cancer, a hospital-based case-control study was conducted in Korea. Histologically confirmed breast cancer cases (n = 574) and controls (n = 502) with no present or previous history of cancer were recruited from three teaching hospitals in Seoul during 1995-2001. Information on selected characteristics was collected by interviewed questionnaire. ERCC2 Asp(312)Asn (G>A) was genotyped by single-base extension assay and ERCC4 Ser(835)Ser (T>C) by dynamic allele-specific hybridization system. Although no significant association was observed between the genetic polymorphisms and the risk of breast cancer, women with both ERCC2 A allele- and ERCC4 C allele-containing genotypes showed a 2.6-fold risk (95% CI: 1.02-6.48) of breast cancer compared to women concurrently carrying the ERCC2 GG and ERCC4 TT genotypes. The breast cancer risk increased as the number of "at risk" genotypes increased with a borderline significance (P for trend = 0.07). Interactive effect was also observed between ERCC4 genotype and body mass idnex (BMI) for the breast cancer risk; the ERCC4 C allele containing genotypes posed a 1.7-fold (95% CI: 0.96-2.93) breast cancer risk in obese women (BMI>25 kg/m(2)) with a borderline significance. Our finding suggests that the combined effect of ERCC2 Asp(312)Asn and ERCC4 Ser(835)Ser genotypes might be associated with breast cancer risk in Korean women.