Numerical analysis of multicomponent responses of surface-hole transient electromagnetic method

We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.

Mechanical Analysis and Measurements of a Multicomponent NbTi/Cu Superconducting Magnets Structure for the Fully Superconducting Electron Cyclotron Resonance Ion Source

A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further

Progress and prediction of multicomponent quantification in complex systems with practical LC-UV methods

Complex systems exist widely,including medicines from natural products,functional foods,and biological samples.The biological activity of complex systems is often the result of the synergistic effect of multiple components.In the quality evaluation of complex samples,multicomponent quantitative analysis(MCQA)is usually needed.To overcome the difficulty in obtaining standard products,scholars have proposed achieving MCQA through the“single standard to determine multiple components(SSDMC)”approach.This method has been used in the determination of multicomponent content in natural source drugs and the analysis of impurities in chemical drugs and has been included in the Chinese Pharmacopoeia.Depending on a convenient(ultra)high-performance liquid chromatography method,how can the repeatability and robustness of the MCQA method be improved?How can the chromatography conditions be optimized to improve the number of quantitative components?How can computer software technology be introduced to improve the efficiency of multicomponent analysis(MCA)?These are the key problems that remain to be solved in practical MCQA.First,this review article summarizes the calculation methods of relative correction factors in the SSDMC approach in the past five years,as well as the method robustness and accuracy evaluation.Second,it also summarizes methods to improve peak capacity and quantitative accuracy in MCA,including column selection and twodimensional chromatographic analysis technology.Finally,computer software technologies for predicting chromatographic conditions and analytical parameters are introduced,which provides an idea for intelligent method development in MCA.This paper aims to provide methodological ideas for the improvement of complex system analysis,especially MCQA.

THE DEGREE OF CRYSTALLINITY OF MULTICOMPONENT POLYMERS BY X-RAY DIFFRACTION ANALYSIS

Based on the X-ray scattering intensity theory,the correction factors of the degree of crystallinity formulae of the multicomponent polymers have been clearly defined.The formula of degree of erystallinity of the multicomponent polymers was derived in terms of the WAXD theory ahd improved graphic multipeak resolution methods.The results calculated are compatible with the density measurement.

PARTIAL LEAST-SQUARES(PLS)REGRESSION AND SPECTROPHOTOMETRY AS APPLIED TO THE ANALYSIS OF MULTICOMPONENT MIXTURES

The UV absorption spectra of o-naphthol,α-naphthylamine,2,7-dihydroxy naphthalene,2,4-dimethoxy ben- zaldehyde and methyl salicylate,overlap severely;therefore it is impossible to determine them in mixtures by traditional spectrophotometric methods.In this paper,the partial least-squares(PLS)regression is applied to the simultaneous determination of these compounds in mixtures by UV spectrophtometry without any pretreatment of the samples.Ten synthetic mixture samples are analyzed by the proposed method.The mean recoveries are 99.4%,996%,100.2%,99.3% and 99.1%,and the relative standard deviations(RSD) are 1.87%,1.98%,1.94%,0.960% and 0.672%,respectively.

Simultaneous Determination of Rare Earth Elements by Dual-System Iterative Target Transformation Factor Analysis

Dualcolor systems were used to reduce the collinearity of multicomponent spectra, which is described by the angles between spectra vectors. Combined with iterative target transformation factor analysis, single rare earth element was determined in its mixture. The calculated results show that the average angle between rare earth spectra in one color system(trichloroarsenazorare earths, pH 34) is 45, and that in two color systems(trichloroarsenazorare earths, pH 34, 14) is 215. This technique makes it easy to select the real number of the components in mixtures, and the determination results show dualcolor system method is an effective technique in rare earth mixture analysis.

Comprehensive Quality Evaluation of ShuXueNing Injection Employing Quantitative High-Performance Liquid Chromatography Fingerprint and Chemometrics

Objective:In this study,a comprehensive and effective quality method for evaluating the efficacy of ShuXueNing injection(SXNI)was developed.Materials and Methods:Quantitative high-performance liquid chromatography fingerprint,the quantitative analysis of multicomponents by a single marker(QAMS)method,hierarchical cluster analysis(HCA),and orthogonal partial least squares discrimination analysis(OPLS-DA)were used to distinguish 53 batches of SXNI samples from 7 manufacturers.Results:A total of 53 batches of samples were analyzed to establish antithesis fingerprint of SXNI,and 12 peaks of the common model were collected and used for the similarity analysis.Meanwhile,six index flavonoid components were determined by the QAMS method,using rutin as internal reference substance.The accuracy of the QAMS method was confirmed by investigating the relative deviation between the QAMS method and the traditional external standard method.The results demonstrated that there was no significant difference(RE<1%),suggesting that QAMS was a reliable and convenient method for the content determination of multiple components.The HCA and OPLS-DA methods drew a similar conclusion.The 53 batches of SXNI samples from 7 manufacturers were categorized into five groups,indicating that chemometrics could reveal the quality differences of SXNI between the manufacturers.Conclusions:The method established herein was efficient and successful in assessing the quality of SXNI,and that it may be potentially employed in the quality control of related products composed of Ginkgo biloba extract.