A study for quality evaluation of Taxilli Herba from different hosts based on fingerprint-activity relationship modeling and multivariate statistical analysis

In this study, a fingerprint-activity relationship modeling between chemical fingerprints and antirheumatic activity was established, and multivariate statistical analysis was used to evaluate the quality of Taxilli Herba (TH) from different hosts. Characteristic fingerprints of 20 batches of TH samples were generated by high-performance liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (HPLC-Triple TOF-MS/MS), and the similarity analysis was calculated based on thirteen common characteristic peaks by hierarchical clustering analysis (HCA). Subsequently, nine efficacy markers were discovered by combining fingerprints and antirheumatic activity through grey correlation analysis (GCA) and bivariate correlation analysis (BCA). Meanwhile, the content of 5 constituents in 9 markers was determined by high-performance liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (HPLC-QTRAP-MS/MS). The comprehensive quality of TH was assessed using multivariate statistical analysis, including principal components analysis (PCA) and technique for order preference by similarity to ideal solution (TOPSIS). The results showed that a high dose of TH extract could markedly ameliorate arthritis damage compared to other doses, with flavonoids playing an important role in the antirheumatic activity. The comprehensive quality of samples from Morus alba L. (SS) was superior to those from Liquidambar formosana Hance (FXS). The present study will demonstrate the markers associated with efficacy, and provide an applicable strategy for more comprehensive quality control and evaluation of TH.     

STUDY ON THE PROPERTIES OF BLEND OF NATURAL RUBBER LATEX/METHYL METHACRYLATE GRAFTED RUBBER LATEX BY GAMMA RADIATION

Natural rubber latex(NRL)and methyl methacrylate(MMA)grafted rubber latex were blended in different ratios and irradiated at various absorbed doses by gamma rays from Co-60 source at room temperature.The tensile properties, swelling ratio and permanent set were measured.The maximum tensile strength and modulus at 500% elongation were obtained at an absorbed dose of 8 kGy.Modulus increases from 6.99 MPa to 9.87 MPa for an increase in proportion of MMA grafted rubber from 40% to 60% in the blend at similar absorbed dose.Elongation at break and swelling ratio decrease with increasing absorbed dose as well as the MMA grafted rubber content in the blends.The decreasing trend of permanent set is high up to 5 kGy absorbed dose,and beyond that dose,it becomes almost flat.     

Evaluation of ion mobility in capillary electrophoresis coupled to mass spectrometry for the identification in metabolomics

Currently, feature annotation remains one of the main challenges in untargeted metabolomics. In this context, the information provided by high-resolution mass spectrometry (HRMS) in addition to accurate mass can improve the quality of metabolite annotation, and MS/MS fragmentation patterns are widely used. Accurate mass and a separation index, such as retention time or effective mobility (μ_eff), in chromatographic and electrophoretic approaches, respectively, must be used for unequivocal metabolite identification. The possibility of measuring collision cross-section (CCS) values by using ion mobility (IM) is becoming increasingly popular in metabolomic studies thanks to the new generation of IM mass spectrometers. Based on their similar separation mechanisms involving electric field and the size of the compounds, the complementarity of ^DTCCS_N2 and μ_eff needs to be evaluated. In this study, a comparison of ^DTCCS_N2 and μ_eff was achieved in the context of feature identification ability in untargeted metabolomics by capillary zone electrophoresis (CZE) coupled with HRMS. This study confirms the high correlation of ^DTCCS_N2 with the mass of the studied metabolites as well as the orthogonality between accurate mass and μ_eff, making this combination particularly interesting for the identification of several endogenous metabolites. The use of IM-MS remains of great interest for facilitating the annotation of neutral metabolites present in the electroosmotic flow (EOF) that are poorly or not separated by CZE.     

Electrophoresis and electric conduction in a salt-free suspension of charged particles

The electrophoresis and electric conduction of a suspension of charged spherical particles in a salt-free solution are analyzed by using a unit cell model. The linearized Poisson-Boltzmann equation (valid for the cases of relatively low surface charge density or high volume fraction of the particles) and Laplace equation are solved for the equilibrium electric potential profile and its perturbation caused by the imposed electric field, respectively, in the fluid containing the counterions only around the particle, and the ionic continuity equation and modified Stokes equations are solved for the electrochemical potential energy and fluid flow fields, respectively. Explicit analytical formulas for the electrophoretic mobility of the particles and effective electric conductivity of the suspension are obtained, and the particle interaction effects on these transport properties are significant and interesting. The scaled zeta potential, electrophoretic mobility, and effective electric conductivity increase monotonically with an increase in the scaled surface charge density of the particles and in general decrease with an increase in the particle volume fraction, keeping each other parameter unchanged. Under the Debye-Hückel approximation, the dependence of the electrophoretic mobility normalized with the surface charge density on the ratio of the particle radius to the Debye screening length and particle volume fraction in a salt-free suspension is same as that in a salt-containing suspension, but the variation of the effective electric conductivity with the particle volume fraction in a salt-free suspension is found to be quite different from that in a suspension containing added electrolyte.     

Effective moisture diffusivity and activation energy during convective drying of bread containing clove oil/orange oil

The aim of present study was to investigate the characteristic drying behaviour of bread with the convective drying method for increasing bread shelf life. Effective moisture diffusivity and activation energy were compared in detail. According to the results, bread samples were dried between 0 and 450 min for 40 °C, 0–180 min for 50 °C and 60 °C, respectively. The experimental data with high coefficient of determination (R²) changed between 0.889 and 0.998. The values of D_eff were obtained between 1.21 × 10^?9-1.22 × 10^?8 m²/s. Also, E_a values were found to be in range of 82.47–100.49 kJ/mol for bread samples which had additive-free and additive. When the bread samples without additives and the breads with essential oils were compared, it was found that the activation energy increased with the use of additives. Moisture content values decreased with the increase in time. Drying rate and moisture content relation showed the expected behaviour, thermally and morphologically.     

三氮宾分子的磁性设计

采用量子化学ＧＡＵＳＳＩＡＮ９４ａｂｉｎｉｔｉｏＵＨＦ方法和ＳＴＯ－３Ｇ基组设计一系列三氮宾分子，讨论分子的几何结构和取代基对其磁性的影响，计算结果表明，这些分子都具有铁磁性并有高自旋基态，有效交换积分值随代基的变化而变化，其中一种具有较代的总能量和高的有效交换积分值的分子，可期望被合成。     

Validity of the One and One-Half Layer Quasi-Geostrophic Model and Effective Topography

ABSTRACT

We rigorously justify the so-called one and one-half layer quasi-geostrophic model from the two layer model as the ratio of the depth of the bottom layer over that of the top layer approaches infinity. The effective dynamics is given by the classical barotropic quasi-geostrophic dynamics for the bottom layer without topography, and the one layer quasi-geostrophic dynamics with the stream function of the bottom layer serving as an effective (possibly time-dependent) topography for the the top layer. Such a one and one-half layer model is utilized in successful quantitative prediction of the Great Red Spot on Jupiter (see Turkington et al., 2001 Turkington , B. , Majda , A. J. , Haven , K. , DiBattista , M. ( 2001 ). Statistical equilibrium predictions of jets and spots on jupiter. Proc. Natl. Acad. Sci. USA 98 ( 22 ): 12346 – 12350 . [PUBMED] [INFOTRIEVE] [CSA] [CROSSREF] [Crossref] , [Google Scholar]).     

Effects of defects on the effective thermal conductivity of thermal barrier coatings

It is difficult to establish structure-property relationships in thermal barrier coatings (TBCs) because of their inhomogeneous-geometry microstructures caused by defects. In the current research, the effects of pores and cracks on the effective thermal conductivity of TBCs are studied. Based on the law of the conservation of energy, mathematical formulations are proposed to indicate the relationship between defects and the effective thermal conductivity. In this approach, detailed equations are illustrated to represent the shape and size of defects on the effective thermal conductivity of TBCs. Different from traditional empirical analyses, mixture law or statistical method, for the first time, our results with the aid of finite element method (FEM) and strict analytical calculation show the influence of pore radius and crack length on effective thermal conductivity can be quantified. As an example to a typical microstructure of plasma sprayed TBCs, the effects of defects on the effective thermal conductivity of TBCs are expressed by the influence parameter, which indicating that the longest transverse crack dominates the contribution of the effective thermal conductivity along the spray direction compared with any individual defect.     

渗流对岩体高边坡位移的影响

根据渗流场和位移场耦合机理 ,结合某大型船闸工程 ,采用有限元法进行计算分析和对比 ,结果表明船闸在开挖过程中 ,渗流作用力对开挖边坡的稳定性影响很大。并指出对高边坡进行稳定分析时 ,正确考虑渗流作用力的影响十分重要。