“课程思政”融入研究生课程口腔分子生物学与实验动物模型的教学实践初探

将思想政治教育融入口腔分子生物学与实验动物模型教学中,实现知识教育和德育的有机结合具有重要意义。阐述该课程蕴含的思政元素,提出在专业课教学中开展“课程思政”的具体方法,并分析存在的问题及解决措施。

Experiment and Modeling of Pure and Binary Adsorption of n-Butane and Butene-1 on ZSM-5 Zeolites with Different Si/Al Ratios

Four ZSM-5 zeolite catalysts with different Si/Al ratios for the catalytic cracking of C4 fractions to produce ethylene and propylene were prepared in this study.First,the adsorption isotherms of pure n-butane and butene-1 and their mixtures on these catalysts at 300K and p=0—100kPa were measured using the intelligent gra- vimetric analyzer.The experimental results indicate that the presence of Al can significantly affect the adsorption of butene-1 than that of n-butane on ZSM-5 zeolites.Then,the double Langmuir(DL)model was applied to study the pure gas adsorption on ZSM-5 zeolites for pure n-butane and butene-1.By combining the DL model with the ideal adsorbed solution theory(IAST),the IAST-DL model was applied to model the butene-1(1)/n-butane(2)binary mixture adsorption on ZSM-5 zeolites with different Si/Al ratios.The calculated results are in good agreement with the experimental data,indicating that the IAST-DL model is effective for the present systems.Finally,the adsorp- tion over a wide range of variables was predicted at low pressure and 300K by the model proposed.It is found that the selectivity of butene-1 over n-butane increases linearly with the decrease of Si/Al ratio.A correlation between the selectivity and Si/Al ratio of the sample was proposed at 300K and p=0.08MPa.

A Fully Flexible Potential Model for Carbon Dioxide

A fully flexible potential model for carbon dioxide has been developed to predict the vapor-liquid coexistence properties using the NVT-Gibbs ensemble Monte Carlo technique(GEMC).The average absolute deviation between our simulation and the literature experimental data for saturated liquid and vapor densities is 0.3% and 2.0%,respectively.Compared with the experimental data,our calculated results of critical properties(7.39 MPa,304.04 K,and 0.4679 g?cm-3) are acceptable and are better than those from the rescaling the potential parameters of elementary physical model(EPM2).The agreement of our simulated densities of supercritical carbon dioxide with the experimental data is acceptable in a wide range of pressure and temperature.The radial distribution function estimated at the supercritical conditions suggests that the carbon dioxide is a nonlinear molecule with the C O bond length of 0.117 nm and the O C O bond angle of 176.4°,which are consistent with Car-Parrinello molecular-dynamics(CPMD),whereas the EPM2 model shows large deviation at supercritical state.The predicted self-diffusion coefficients are in agreement with the experiments.

Numerical and Experimental Research on the Influence of the Centrifugal Pumps Rotor Damage on Their Natural Frequency Response

The paper presents process of creating a centrifugal pump rotor model in CAD environment. Modeling of a virtual object was divided into two stages, modeling of the efficient pump and the simulated failure of one of the impeller＇s blades. Comparison of the results of the resonance frequency obtained from the model analysis, with those obtained from measurements on the actual object was shown. Measurements and simulations were conducted on the pump before and after the simulated damaged of the rotor. In order to verify the model the rotor of pump was weighted and compared with the masses of the respective components obtained from the virtual object. In the second stage genuine rotor was subjected to the experimental modal analysis.

Carbon dioxide sorption and diffusion in coals:Experimental investigation and modeling

CO2 sorption and diffusion in coal are closely related to the occurrence of coal and gas outburst,geological sequestration of CO2 in coalbeds,and enhancing coalbed methane recovery by injecting CO2.Hence,it is significant to investigate the sorption properties and diffusion models of CO2 in coal.Here we used a newly designed experimental apparatus at Peking University to investigate the sorption and diffusion properties of CO2 in natural coal samples from Dashucun Mine and Wutongzhuang Mine in Handan city,Hebei province,and Jinhuagong Mine in Datong city,Shanxi province,and obtained CO2 sorption isotherms and diffusivity models.The results indicate that,in a certain pressure range,CO2 sorption isotherms for the coal samples are consistent with the Langmuir model,which assumes that monolayer sorption occurs at the interface between coal matrix and CO2 molecules,and the sorption isotherms feature nonstandard hyperbolas in mathematics.At the same pressure and temperature,as the vitrinite content increases,coal adsorbs more CO2 molecules.The relation between the sorption capacity and the coal rank may be described as a "U-type" trend,and medium rank coal has the least sorption capacity.The bulk diffusivity of CO2 in coal is not constant;in the range of CO2 mass fraction greater than 1%,it increases roughly linearly with increasing mass fraction of CO2 adsorbed(or CO2 partial pressure) in coal.CO2 diffusivity in coal is approximately 10-4 to 10-2 mm2/s in magnitudes,and the diffusivity ranges in coal samples are 3×10-4 to 8×10-3 mm2/s from Dashucun Mine,2×10-4 to 4×10-3 mm2/s from Wutongzhuang Mine,and 2×10-4 to 4×10-3 mm2/s from Jinhuagong Mine.The results of the CO2 sorption and diffusion study can be applied to help predict and prevent coal and gas outburst as well as to evaluate the feasibility in geological sequestration of CO2 and to enhance coalbed methane recovery.

Electron Transfer Between Molecules: Study with Langevin Equations

In this paper, we investigate the electron transfer(ET) in donor-acceptor model. The Langevin equation with random forces is used. The oscillations of the primary states observed in experimental data have been shown with this approach. And other features on the dependence of the rate of ET on temperature, free energy, and reorganization energy have also been clearly shown.

Effects of Wenxiao Ⅱ Decoction on the expression of MCP-1 and VCAM-1 in atherosclerotic rabbits

OBJECTIVE:To observe the effects of different doses of Wenxiao Ⅱ Decoction on the expression of monocyte chemoattractant protein-1(MCP-1) and vascular cell adhesion molecule-1(VCAM-1) in an experimental model of atherosclerosis in rabbits and to explore the mechanism by which it alleviates atherosclerosis.METHODS:Sixty 3-4 month-old New Zealand rabbits of both sexes were randomly divided into six groups:simvastain;model;blank;and high-dose,mid-dose,and low-dose Wenxiao Ⅱ Decoction groups.Except for those in the blank group,all rabbits were fed a high-cholesterol diet.Carotid atherosclerosis was established by balloon-induced injury to the endothelium of the carotid artery in conjunction with consumption of a high-cholesterol diet.After 8 weeks,all rabbits were killed to evaluate the expression of MCP-1 and VCAM-1 by immunohistochemical staining.RESULTS:Expressions of MCP-1 and VCAM-1 were significantly decreased in all groups except the blank group compared with the model group(P<0.05).When compared with the simvastain group only variation of MCP-1 expression in low-dose group was not appreciable,and the differences were indistinct(P<0.05).When comparing among Wenxiao Ⅱ Decoction groups,MCP-1 expression in the mid-and high-dose groups was significantly lower than that seen in the low-dose group(P<0.01),but there were no differences among three dosage groups with respect to VCAM-1 expression(P>0.05).CONCLUSION:These data suggested that high,mid,and low doses of Wenxiao Ⅱ Decoction can inhibit the expression of MCP-1 and VCAM-1,which may prevent the formation of or stabilize atherosclerotic plaques.There may be a direct relationship between the dosage of Wenxiao Ⅱ Decoction and its therapeutic efficacy.