The Selection and Breeding of a Novel Microorganism Strain I and Investigation of Core Model Experiment for MEOR

This paper introduces the results of selecting and breeding a micro-organism, Strain I, and its core model experiment investigation for microbial enhanced oil recovery (MEOR). Strain I was separated from the formation water of the Dagang oil field, with analytical results showing that Strain I is a gram-positive bacillus. A further study revealed that this strain has an excellent tolerance of environmental stresses: It can survive in conditions of 70℃, 30 wt% salinity and pH3.5-9.4. Strain I can metabolize biosurfactants that could increase the oil recovery ratio, use crude oil as the single carbon source, and decompose long-chain paraffin with a large molecular weight into short-chain paraffin with a small molecular weight. The core model experiment shows that Strain I enhances oil recovery well. Using 2 vol% of the fermentation solution of Strain I to displace the crude oil in the synthetic plastic bonding core could increase the recovery ratio by 21.6%.

Mathematical simulation of hot metal desulfurization during KR process coupled with an unreacted core model

A three-dimensional mathematical model was established to predict the multiphase flow,motion and dispersion of desulfurizer particles,and desulfurization of hot metal during the Kanbara reactor(KR)process.The turbulent kinetic energy-turbulent dissipation rate(k-ε)turbulence model,volume-of-fluid multiphase model,discrete-phase model,and unreacted core model for the reaction between the hot metal and particles were coupled.The measured sulfur content of the hot metal with time during the actual KR process was employed to validate the current mathematical model.The distance from the lowest point of the liquid level to the bottom of the ladle decreased from 3170 to2191 mm when the rotation speed increased from 30 to 110 r/min,which had a great effect on the dispersion of desulfurizer particles.The critical rotation speed for the vortex to reach the upper edge of the stirring impeller was 70 r/min when the immersion depth was 1500 mm.The desulfurization rate increased with the increase in the impeller rotation speed,whereas the influence of the immersion depth was relatively small.Formulas for different rotation parameters on the desulfurization rate constant and turbulent energy dissipation rate were proposed to evaluate the variation in sulfur content over time.

APPLICATION OF THE SHRINKING CORE MODEL TO THE KINETICS OF ZINC OXIDE DESULFURIZATION

The kinetics of H2S removal by zinc oxide desulfurizer was studied through thermogravimetricanalysis.The experimental results show that desulfurization rate was controlled,at high temperatureand low conversion,by the chemical reaction rate,and at low temperature and high conversion by thegrain diffusion rate.The reaction is first order with respect to H2S concentration in the differentcontrolled stages.The kinetic behavior can be modeled through the employment of the shrinking coremodel.The values of the model parameters were determined.The variation tendencies with temperatureand concentration of H2S at the controlled stages were discussed.

The Physics of Rotational Flattening and the Point Core Model

The effect of rotation on the shape (figure) and gravitational quadrupole of astronomical bodies is calculated by using an approximate point core model: A point mass at the center of an ellipsoidal homogeneous fluid. Maclaurin’s analytical result for homogenous bodies generalizes to this model and leads to very accurate analytical results connecting the three observables: oblateness (ò), gravitational quadrupole (J2), and angular velocity parameter (q). The analytical results are compared to observational data for the planets and a good agreement is found. Oscillations near equilibrium are studied within the model.

Mathematical Model for Growth of Inclusion in Deoxidization on the Basis of Unreacted Core Model

Controlling inclusion composition, from the point of view of thermodynamics, only explains the probability and limit of reaction. However, kinetics makes the nucleation and the velocity of growth of inclusions clear, and these kinetic factors are very important to the quality of slab. The basic kinetic theory of unreacted core model was used to build the mathematical model for the growth of inclusions and the concerned software was developed through Visual Basic 6.0. The time that different radius inclusions attain saturation was calculated to determine the controlling step of reaction between steel and inclusions. The time for the growth of inclusion obtained from the model was in good agreement with the data measured by Japanese Okuyama G, which indicated that the model is reasonable.

Establishment and verification of a shrinking core model for dilute acid hydrolysis of lignocellulose

The kinetics oflignocellulose hydrolysis under the conditions of high temperature and dilute acid （mass fraction 0.05%） was investigated in this paper. By studying the reducing sugar concentration versus reaction tempera ture （170℃-220℃） and reaction time （150-1800 s） during the hydrolysis process of five kinds of crop straw （rice, wheat, cotton, rape and corn）, the shrinking core model was established, and the differential equation of the model and its analytical solution were obtained. With a numerical calculation method, the kinetic equation was estimated, and the degradation of reducing sugar obeyed firstorder kinetics was obtained. The calculated results from the equations agreed well with the original experimental data. The calculation by the model showed that the reducing sugar concentration increases as the size of the particles decrease, and the uniform particles increase.

基于CORE模型的古街文旅体验产品设计

目的 古街需要形成浓郁的人文氛围和商业环境,通过开发具有优良体验感的文旅产品,为现有文旅产品增加更多互动体验的环节。这不仅可以让游客充分感受古街的地域特色,增强出行动机,也可以使游客有节奏地体验到古街文旅产品中传达的信息,从而对产品体验形成获得感、满足感、认同感等感受,以促进古街文旅产业发展。方法 基于CORE模型,采用观察法、文献研究法、探索性研究法收集当下古街文旅产品体验的趣味点,结合头脑思维风暴,借鉴游戏、玩具、劳动实践中体验感好的部分,组织设计行动及体验活动,重视产品体验心理过程的反馈。结果 设计创新性体验产品及体验流程,通过李克特量表及Kano模型对产品方案进行评估。结论 在设计新产品时,重点展现文旅产品的趣味体验,对在售产品提供体验活动思路及行动方案,从而提升游客对地域特色文化的感受力。

Simulation of double cold cores of the 35°N section in the YellowSea with a wave-tide-circulation coupled model

Based on the MASNUM wave-tide-circulation coupled numerical model, the temperature structure along 35°N in the Yellow Sea was simulated and compared with the observations. One of the notable features of the temperature structure along 35°N section is the double cold cores phenomena during spring and summer. The double cold cores refer to the two cold water centers located near 122°E and 125°E from the depth of 30m to bottom. The formation, maintenance and disappearance of the double cold cores are discussed. At least two reasons make the temperature in the center (near 123°E) of the section higher than that near the west and east shores in winter. One reason is that the water there is deeper than the west and east sides so its heat content is higher. The other is invasion of the warm water brought by the Yellow Sea Warm Current (YSWC) during winter.This temperature pattern of the lower layer (from 30m to bottom) is maintained through spring and summer when the upper layer (0 to 30m) is heated and strong thermocline is formed. Large zonal span of the 35°N section (about 600 km) makes the cold cores have more opportunity to survive. The double cold cores phenomena disappears in early autumn when the west cold core vanishes first with the dropping of the thermocline position.

Overall Features of EAST Operation Space by Using Simple Core-SOL-Divertor Model

A simple Core-SOL-Divertor （C-S-D） model has been developed to investigate qualitatively the overall features of the operational space for the integrated core and edge plasma. To construct the simple C-S-D model, a simple core plasma model of ITER physics guidelines and a two-point SOL-divertor model are used. The simple C-S-D model is applied to the study of the EAST operational space with lower hybrid current drive experiments under various kinds of trade-off for the basic plasma parameters. Effective methods for extending the operational space are also presented, From this study for the EAST operational space, it is evident that the C-S-D model is a useful tool for understanding qualitatively the overall features of the plasma operational space.

Shell and shrinking core kinetics model of Mg-based hydrogen storage alloys

The kinetics equation of the Mg-based hydrogen storage alloys (Mg-Ni-MO) was established by the shell and shrinking core model. The total coefficients of the kinetics equation of the hydrogen absorption and desorption process with shell diffusion as the controlling step were determined by semi-empirical and semi-theoretical methods, and the apparent activation energy of the hydrogen absorption process was obtained. The calculation results can well accord with the experimental data, and can well forecast the hydrogen storage capacity and absorption rate at different times. By using the kinetics equation, the effects of temperature and pressure on the hydrogen storage process can also be well understood. The kinetics equation is helpful for the design of the hydrogen storage container.

Poroelastic finite-difference modeling for ultrasonic waves in digital porous cores

Scattering attenuation in short wavelengths has long been interesting to geophysicists. Ultrasonic coda waves, observed as the tail portion of ultrasonic wavetrains in laboratory ultrasonic measurements, are important for such studies where ultrasonic waves interact with smallscale random heterogeneities on a scale of micrometers, but often ignored as noises because of the contamination of boundary reflections from the side ends of a sample core. Numerical simulations with accurate absorbing boundary can provide insight into the effect of boundary reflections on coda waves in laboratory experiments. The simulation of wave propagation in digital and heterogeneous porous cores really challenges numerical techniques by digital image of poroelastic properties, numerical dispersion at high frequency and strong heterogeneity, and accurate absorbing boundary schemes at grazing incidence. To overcome these difficulties, we present a staggered-grid high-order finite-difference （FD） method of Biot＇s poroelastic equations, with an arbitrary even-order （2L） accuracy to simulate ultrasonic wave propagation in digital porous cores with strong heterogeneity. An unsplit convolutional perfectly matched layer （CPML） absorbing boundary, which improves conventional PML methods at grazing incidence with less memory and better computational efficiency, is employed in the simulation to investigate the influence of boundary reflections on ultra- sonic coda waves. Numerical experiments with saturated poroelastic media demonstrate that the 2L FD scheme with the CPML for ultrasonic wave propagation significantly improves stability conditions at strong heterogeneity and absorbing performance at grazing incidence. The boundary reflections from the artificial boundary surrounding the digital core decay fast with the increase of CPML thick- nesses, almost disappearing at the CPML thickness of 15 grids. Comparisons of the resulting ultrasonic coda Qsc values between the numerical and experimental ultrasonic S waveforms for a cylindrical rock sample demonstrate that the boundary reflection may contribute around one-third of the ultrasonic coda attenuation observed in laboratory experiments.

Study on the judgment model of dyeing and weaving corporation's core competence

On the basis of the dyeing and weaving corporations’ characters,this paper put forward the dimensionality and index system to analyze the core competence. This paper divided the core competence into three layers and gave out the Dimensional-Hierarchical structure of core competence through combining the analysis dimensionalities with the competence layers. The model was described to evaluate,analyze and judge the dyeing and weaving corporation’s competence.

Mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate reverse micelles

The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds,which have become increasingly popular in recent years.However,there are few studies on mass transfer processes and models,which are helpful to better control the extraction process of oils and proteins.In this paper,mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate(AOT)/isooctane reverse micelles was investigated.The effects of stirring speed(0,70,140,and 210 r/min),temperature of extraction(30,35,40,45,and 50℃),peanut flour particle size(0.355,0.450,0.600,and 0.900 mm)and solidliquid ratio(0.010,0.0125,0.015,0.0175,and 0.020 g/mL)on extraction rate were examined.The results showed that extraction rate increased with temperature rising,particle size reduction as well as solid-liquid ratio increase respectively,while little effect of stirring speed(P>0.05)was observed.The apparent activation energy of extraction process was calculated as 10.02 kJ/mol and Arrhenius constant(A)was 1.91 by Arrhenius equation.There was a linear relationship between reaction rate constant and the square of the inverse of initial particle radius(1/r_(0)^(2))(P<0.05).This phenomenon and this shrinking core model were anastomosed.In brief,the extraction process was controlled by the diffusion of protein from the virgin zone interface of particle through the reacted zone and it was in line with the first order reaction.Mass transfer kinetics of peanut protein extracted by reverse micelles was established and it was verified by experimental results.The results provide an important theoretical guidance for industrial production of peanut protein separation and purification.

Mathematical modeling for dynamic stability of sandwich beam with variable mechanical properties of core

The paper is devoted to mathematical modelling of static and dynamic stability of a simply supported three-layered beam with a metal foam core. Mechanical properties of the core vary along the vertical direction. The field of displacements is for- mulated using the classical broken line hypothesis and the proposed nonlinear hypothesis that generalizes the classical one. Using both hypotheses, the strains are determined as well as the stresses of each layer. The kinetic energy, the elastic strain energy, and the work of load are also determined. The system of equations of motion is derived using Hamilton＇s principle. Finally, the system of three equations is reduced to one equation of motion, in particular, the Mathieu equation. The Bubnov-Galerkin method is used to solve the system of equations of motion, and the Runge-Kutta method is used to solve the second-order differential equation. Numerical calculations are done for the chosen family of beams. The critical loads, unstable regions, angular frequencies of the beam, and the static and dynamic equilibrium paths are calculated analytically and verified numerically. The results of this study are presented in the forms of figures and tables.

考虑PWM波形特征的纳米晶磁心损耗模型的研究及验证

磁心损耗精确预测对于电力电子变压器的优化设计至关重要。然而,传统的磁心损耗模型在复杂激励下适用性较差,尤其对于占空比可调、高次谐波含量丰富的PWM波磁心损耗预测,计算精度显著下降。基于Jordan损耗分离模型,建立了一种考虑PWM波形特征的磁心损耗计算方法。首先,该方法根据激励波形特征,推导出相应的波形系数及等效频率来计算PWM波激励下的动态涡流损耗,将Jordan模型的适用范围从正弦拓展到PWM波激励下的磁心损耗计算;然后,分析了不同占空比激励下激励波形有效频率及高次谐波含量变化对损耗系数的影响,并对其进行数学表征,实现了整个占空比范围内磁心损耗的精确预测;最后,搭建了高频非正弦激励下软磁材料磁特性测量平台,针对1K107B纳米晶材料,测量了两种典型PWM波激励下的损耗数据。实验结果表明,所建立的磁心损耗模型具有较高的计算精度,相比于传统的Steinmetz改进公式,整体精度提高了25%。

MVSim:面向VLIW多核向量处理器的快速、可扩展和精确的体系结构模拟器

设计了一个面向VLIW多核向量处理器的快速、可扩展、精确的体系结构模拟器MVSim。设计了可扩展的VLIW多核向量处理器模型、多级存储体系结构模型和多核性能模型;实现了指令集架构的节拍精准模拟,Cache、DMA和多核同步部件的高效功能模拟,采用多线程技术实现了多核处理器的高效和可扩展模拟。实验结果表明,MVSim能够准确模拟多核处理器的目标程序执行,模拟结果完全正确,具有良好的可扩展性。MVSim的平均模拟速度分别是RTL模拟和CCS的227倍和5倍,平均性能误差约为2.9%。

“三核心”教学模式改革提升文科研究生科研创新能力研究

研究生课程教学不仅应关心知识的获得,更应关注知识的探索过程和方法,理解分析问题、解决问题的思路和要领,并培养批判性和创新性理论精神。“三核心”教学模式由核心专题、核心研讨、核心实践三大板块构成,与既有的教学改革相比较,“三核心”教学改革在实践中应坚持专题性、协作性与独立性等主要原则。“三核心”教学模式能够在很大程度上弥补传统课程教学的缺陷,激发文科研究生自主学习的潜能,培养其勇于批判、积极创新的学术精神,提升文科研究生的科研创新能力。

基于波特五力模型的中外合作办学竞争态势研究

随着国际形势的深度演变和调整,中外合作办学在推动国内国际双循环相互促进的高等教育新发展格局方面将发挥独特且重要的作用。通过引入“波特五力模型”,基于举办方、用户、潜在新增办学体、其他类型办学体、同类内部等五个方面,从宏观维度全面系统分析当前中外合作办学面临的系统性竞争态势。主要表现为:举办方投入呈现出政府财力与外方师资的双重聚集效应;用户评价呈现差异化诉求与认可度提升并存;替代品竞争呈现市场细分背景下的“错位竞争”格局;新进入者竞争呈现国家政策引导与高校发展需求助推市场扩充态势;同类内部竞争表现为举办方办学实力及社会声誉辐射衍生的分层现象。研究认为,中外合作办学应实施差异化竞争策略,彰显中外合作办学独特优势及特色;推进集中型战略,形成多元化办学格局;广泛吸纳各方资源,构建办学投入长效机制;有效提升社会发展贡献度,广泛提高认可度和知名度。