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降雨和地震共同作用下高填方边坡稳定性研究

交通科技 2024年第4期 50-55,140页

作者：张虎彭小勇马康贵州省交通规划勘察设计研究院股份有限公司贵阳550081

为研究降雨和地震共同作用对高填方边坡稳定性影响,利用降雨时长、降雨强度,以及地震加速度3个主要因子进行叠合分析,基于GeoStudio数值软件进行稳定性分析计算,并采用正交试验法对因素敏感性进行评价。结果表明,降雨主要影响边坡浅层... 详细信息

为研究降雨和地震共同作用对高填方边坡稳定性影响,利用降雨时长、降雨强度,以及地震加速度3个主要因子进行叠合分析,基于GeoStudio数值软件进行稳定性分析计算,并采用正交试验法对因素敏感性进行评价。结果表明,降雨主要影响边坡浅层土体孔隙水压力,降雨强度和时间对高填方边坡稳定性影响程度有限;地震作用对边坡稳定影响很大,边坡稳定系数随地震峰值加速度增大而降低;降雨和地震共同作用下,填方边坡稳定性明显小于降雨或地震单一作用,叠合作用效果明显;在考虑的边坡稳定性影响因素中,地震作用影响最大,降雨时间次之,降雨强度最小。

关键词：高填方边坡降雨地震稳定性数值分析正交试验

Yb^(3+)-doped Fluorophosphate Glass with High Cross Section and Lifetime

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Journal of Materials Science & Technology 2010年第10期26卷 921-924页

作者： Liyan zhang Yuxin Leng Junjie zhang Lili hu Key Laboratory of Materials for High Power Laser Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China

Yb3＋ doped fluorophosphate （FP/Yb） glasses with emission cross section and fluorescence lifetime as high as 0.8388×10-20 cm 2 and 2.3 ms were developed,and AlF3 content is proved to decrease the lifetime *** scale glass casting procedure shows high Tx-Tg doesn t make better casting crystallization stability in *** Yb laser is difficult to be obtained in FP glass,a 230 mw laser was still achieved from 2 mm thick samples under 976 nm LD excitation because of the large gain parameter（σemiτf） of the FP/Yb *** test also proved the relationship between laser output and gain *** with its wide and flat effective gain property,this FP/Yb glass is a practical new potential material for low power ultra-short pulse application.

关键词： FP15/Yb glass Crystallization stability Gain parameter

Adropin as an indicator of T2DM and its complications

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Food Science and human Wellness 2022年第6期11卷 1455-1463页

作者： hu zhang Ning Chen Graduate School Wuhan Sports UniversityWuhan 430079China Tianjiu Research and Development Center for Exercise Nutrition and Foods Hubei Key Laboratory of Exercise Training and MonitoringCollege of Health ScienceWuhan Sports UniversityWuhan 430079China

Type 2 diabetes mellitus(T2 DM)is one of metabolic diseases with the major inducer of *** to the change in lifestyle and dietary structure,more and more people are being suffered from T2 ***,the prevention and treatment of T2 DM and its complications has become an urgent problem to be *** a secreted peptide,adropin is identifi ed as a useful regulator associated with insulin sensitivity and energy *** has the potential for regulating metabolic diseases including obesity and T2 *** should be noted that the secretion of adropin can be induced by diets,aerobic exercise and other *** this article,the underlying mechanisms of adropin for regulating obesity,T2 DM and its complications including diabetic nephropathy,diabetic retinopathy,diabetic encephalopathy,diabetic vascular disease and diabetic cardiovascular disease were ***,the strategies for promoting the secretion of adropin were also discussed,which will provide a target for the prevention and targeted treatment,or a candidate of novel and effective functional food or drug for metabolic diseases in the future.

关键词： Adropin Metabolic disease Obesity T2DM Diabetic complications

Effects of interstitial H and/or C atoms on the magnetic and magnetocaloric properties of La(Fe, Si)_(13)-based compounds

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Science China(Physics,Mechanics & Astronomy) 2013年第12期56卷 2302-2311页

作者： zhang hu hu FengXia SUN JiRong SHEN BaoGen Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of Sciences

La（Fe, Si）13-based compounds have been considered as promising candidates for magnetic refrigerants particularly near room temperature. Herein we review recent progress particularly in the study of the effects of interstitial H and/or C atoms on the magnetic and magnetocaloric properties of La（Fe, Si）13 compounds. By introducing H and/or C atoms, the Curie temperature Tc increases notably with the increase of lattice expansion which makes the Fe 3d band narrow and reduces the overlap of the Fe 3d wave functions. The first-order itinerant-electron metamagnetic transition is conserved and the MCE still remains high after hydrogen absorption. In contrast, the characteristic of magnetic transition varies from first-order to second-order with the increase of C concentration, which leads to remarkable reduction of thermal and magnetic hysteresis. In addition, the introduc- tion of interstitial C atoms promotes the formation of NaZnl3-type （1：13） phase in La（Fe, Si）13 compounds, and thus reducing the annealing time significantly from 40 days for LaFe11.7Sil.3 to a week for LaFell.7Sil.3C0.2. The pre-occupied interstitial C atoms may depress the rate of hydrogen absorption and release, which is favorable to the accurate control of hydrogen content. It is found that the reduction of particle size would greatly depress the hysteresis loss and improve the hydrogenation process. By the incorporation of both H and C atoms, large MCE without hysteresis loss can be obtained in La（Fe, Si）13 compounds around room temperature, for instance, La0.7Pr0.3Fe115Si15C0.2H12 exhibits a large IASM[ of 22.1 J/（kg＇K） at Tc = 321 K without hysteresis loss for a field change of 0-5 T.

关键词： H atom C atom La(Fe Si)13

A Polynomial Prediction Filter Method for Estimating Multisensor Dynamically Varying Biases

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Chinese Journal of Aeronautics 2007年第3期20卷 240-246页

作者： GAO Yu zhang Jian-qiu hu Bo Department of Electronics Fudan University Shanghai 200433 China

The estimation of the sensor measurement biases in a multisensor system is vital for the sensor data fusion. A solution is provided for the estimation of dynamically varying multiple sensor biases without any knowledge of the dynamic bias model parameters. It is shown that the sensor bias pseudomeasurement can be dynamically obtained via a parity vector. This is accomplished by multiplying the sensor uncalibrated measurement equations by a projection matrix so that the measured variable is eliminated from the equations. Once the state equations of the dynamically varying sensor biases are modeled by a polynomial prediction filter, the dynamically varying multisensor biases can be obtained by Kalman filter. Simulation results validate that the proposed method can estimate the constant biases and dynamic biases of multisensors and outperforms the methods reported in literature.

关键词： signal processing dynamic bias estimation simulation multisensor Kalman filter

基于DPS的双有源桥DC-DC变换器回流功率优化控制

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电工电气 2024年第1期 10-15页

作者：许宇安张晓虎湖南工业大学电气与信息工程学院湖南株洲412007

针对双有源桥(DAB)DC-DC变换器进行回流功率优化研究,在运用传统双重移相控制(DPS)进行调制,变压器两侧的输入电压跟输出电压不匹配时,回流功率会显著增大。提出一种双重移相的多目标优化控制方法,对双重移相控制的工作原理进行分析,推... 详细信息

针对双有源桥(DAB)DC-DC变换器进行回流功率优化研究,在运用传统双重移相控制(DPS)进行调制,变压器两侧的输入电压跟输出电压不匹配时,回流功率会显著增大。提出一种双重移相的多目标优化控制方法,对双重移相控制的工作原理进行分析,推导出对应的输出功率和回流功率的关系式,以此搭建数学模型,并基于该模型对回流功率进行优化;以KKT作为条件,针对回流功率的最小化问题,解出内外移相角的最优组合;为了迅速改变当前的传输功率,通过虚拟电压补偿方法来实现,从而达到优化系统回流功率的目标;通过MATLAB/Simulink仿真对该方案与传统SPS(单移相控制)方案、传统DPS方案进行对比分析,验证了该方案的有效性及优越性。

关键词：双有源桥变换器双重移相回流功率优化控制

CFD simulation of particle suspension in a stirred tank

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Particuology 2013年第3期11卷 317-326页

作者： Nana Qi hu zhang Kai zhang Gang Xu Yongping Yang State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University School of Chemical Engineering The University of Adelaide

Particle suspension characteristics are predicted computationally in a stirred tank driven by a Smith turbine. In order to verify the hydrodynamic model and numerical method, the predicted power number and flow pattern are compared with designed values and simulated results from the literature, respectively. The effects of particle density, particle diameter, liquid viscosity and initial solid loading on particle suspension behavior are investigated by using the Eulerian-Eulerian two-fluid model and the standard k-ε turbulence model. The results indicate that solid concentration distribution depends on the flow field in the stirred tank. Higher particle density or larger particle size results in less homogenous distribution of solid particles in the tank. Increasing initial solid loading has an adverse impact on the homogeneous suspension of solid particles in a low-viscosity liquid, whilst more uniform particle distribution is found in a high-viscosity liquid.

关键词： Stirred tank Smith turbine Particle suspension CFD simulation

Improvement and application of Y2O3 directional solidification crucible

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Chinese Journal of Aeronautics 2016年第2期29卷 554-559页

作者： Ma Limin zhang Jiazhen Yue Guangquan zhang huarui Zhou Li zhang hu Beijing Aeronautical Science & Technology Research Institute of COMAC Bering 102211 Chinab School of Materials Science and Engineering Beihang University Beijing 100191 China

In order to satisfy the drastic temperature change and high chemical activity in direc- tional solidification of Nb Si based alloys, Y2O3 crucible is demanded to possess high thermal shock resistance and erosion resistance. This paper improved the sintering degree and density of Y2O3 crucible by optimizing the sintering temperature and time, and its practical application per- formance was investigated. Y2O3 grains gathered with the increase of sintering temperature and time, and the contact area enlarged, resulting in the open pores being changed into closed pores. The higher density caused the improvement of erosion resistance of Y2O3 crucibles. However, exces- sive density weakened the thermal shock resistance. Considering high-temperature strength, erosion resistance, thermal shock resistance and costs, optimum sintering temperature and time of Y2O3 directional solidification crucible were 1800 ℃ and 120min, respectively, and the porosity was 20%. Improved Y2O3 crucible has been successfully applied to directional solidification of Nb Si based alloys, and significantly reduced the oxygen contamination. Slight interaction occurred between Hf and Y2O3, but no obvious dissolution, penetration or erosion was found, showing good erosion resistance and thermal shock resistance.

关键词： Directional solidification Erosion resistance Microstructure Nb-Si based alloy Thermal shock resistanceY2O3 crucible

Bi-variable damage model for fatigue life prediction of metal components

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Acta Mechanica Sinica 2011年第3期27卷 416-425页

作者： Miao zhang Qing-Chun Meng Xing zhang Wei-Ping hu Division 508 School of Aeronautic Science and Engineering Beihang University 100191 Beijing China

Based on the theory of continuum damage mechanics,a bi-variable damage mechanics model is developed,which,according to thermodynamics,is accessible to derivation of damage driving force,damage evolution equation and damage evolution criteria. Furthermore,damage evolution equations of time rate are established by the generalized Drucker＇s postulate. The damage evolution equation of cycle rate is obtained by integrating the time damage evolution equations,and the fatigue life prediction method for smooth specimens under repeated loading with constant strain amplitude is constructed. Likewise,for notched specimens under the repeated loading with constant strain amplitude,the fatigue life prediction method is obtained on the ground of the theory of conservative integral in damage mechanics. Thus,the material parameters in the damage evolution equation can be obtained by reference to the fatigue test results of standard specimens with stress concentration factor equal to 1,2 and 3.

关键词： Bi-variable damage model - Damage evolution equation . Life prediction - Fatigue . Damage mechanics