Improved concept models for straight thin-walled columns with box cross section

This paper focuses on developing improved concept models for straight thin-walled box sectional columns which can better predict the peak crushing force that occurs during crashworthiness analyses. We develop a nonlinear translational spring based on previous research and apply such a spring element to build the enhanced concept models. The work presented in this article is developed on the basis of the publication of the author (Liu and Day, 2006b) and has been applied in a crashworthiness design issue, which is presented by the author in another paper (Liu, 2008).

Lycopodine-Type Alkaloids from Lycopodium japonicum

Three new lycopodine-type alkaloids,4a-hydroxyanhydrolycodoline(1),4a,6a-dihydroxyanhydrolycodoline(2),and 6-epi-8b-acetoxylycoclavine(3),and an artifact,lycoposerramine G nitrate(4),along with seventeen related known compounds,were isolated from the club moss Lycopodium japonicum Thunb.ex Murray(Lycopodiaceae).Their structures were elucidated by extensive spectroscopic methods as well as X-ray analysis.Compounds 1–4 were evaluated for their acetylcholine esterase inhibitory activity.

Carinatines A and B,Lycopodium Alkaloids from Phlegmariurus carinatus

Carinatine A(1),a C16N2-type Lycopodium alkaloid possessing a 5/6/6/6 ring system formed by a new C-4/C-12 bond,and carinatine B(2),the first derivative of lycojaponicumin C,along 16 known compounds,were isolated from the whole plant of Phlegmariurus carinatus.Their structures were elucidated based on the spectroscopic data.The two new isolates were no inhibitory activity for the acetylcholinesterase(AChE).

Large eddy simulation of cavitating flows with dynamic adaptive mesh refinement using OpenFOAM

Cavitating flows are dominated by large gradients of physical properties and quantities containing complicated interfacial structures and lots of multi-scale eddies that need to be accurately characterized using a high-resolution mesh.The present work,within OpenFOAM,proposes an effective modeling framework using the large eddy simulation(LES)approach along with the volume of fluid(VOF)method to simulate the two-phase flow system and applies the Schnerr-Sauer model to calculate the mass-transfer rate between water and vapor.The adaptive mesh refinement(AMR)which is a powerful tool for allocating high-resolution grids only to the region of the greatest concern is adopted for improving the solution of interfacial structures.The effect of grid size is firstly investigated and the time-averaged quantities are verified against the experimental data,and then simulations of cavitating flows are successfully achieved to precisely characterize the features of cavitation with automatically and dynamically refining the mesh.As the refinement only takes place in the interfacial region,high-precision simulations can be achieved with limited computational resources,and the method shows promising prospects for modeling of the multi-scale,time-critical and computationally intensive cavitating flows.

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.