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Chinese Journal of Polymer Science 2010年第6期28卷 903-911页

作者： Nan-xi Chen jun-hua Zhang State Key Laboratory of Polymer Materials Engineering of China Sichuan UniversityChengdu 610065China

The aim of this work is to investigate the hydrogen-bonding interaction in poly(vinyl alcohol)(PVA)/poly(acrylic acid)(PAA) blending system and its influence on rheological properties in solution and the physical properties in solid state. Introducing PAA into PVA solutions resulted in a thickening behavior of blend *** viscosity of the solutions increased with PAA content increasing,and a maximum viscosity could be obtained when the ratio of PVA/PAA was 70/30. The intermolecular hydrogen-bonding and miscibility between PVA and PAA in solid state were investigated by differential scanning calorimetry(DSC),Fourier transform infrared spectroscopy(FTIR) and mechanical *** results displayed the great influence of introducing PAA on the properties of blending *** tensile strength increased from 89.31 MPa to 119.8 MPa and Young’s modulus improved by over 300%with increasing PAA concentration compared with those of pure PVA *** systematically studying the rheological behaviors of solutions and the physical properties of films,the influence of hydrogen-bonding in solutions and solid states were discussed.

关键词： Polymer blending Rheology Hydrogen-bonding Molecular network Miscibility

Routing the asteroid surface vehicle with detailed mechanics

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Acta Mechanica Sinica 2014年第3期30卷 301-309页

作者： Yang yu He-xi Baoyin School of Aerospace N931 Mengminwei Research BuildingTsinghua University

The motion of a surface vehicle on/above an irregular object is *** for a potential interest in the insitu explorations to asteroids of the solar system. A global valid numeric method, including detailed gravity and geo- morphology, is developed to mimic the behaviors of the test particles governed by the orbital equations and surface cou- pling effects. A general discussion on the surface mechanical environment of a specified asteroid, 1620 Geographos, is presented to make a global evaluation of the surface vehicle＇s working conditions. We show the connections between the natural trajectories near the ground and differential features of the asteroid surface, which describes both the good and bad of typical terrains from the viewpoint of vehicles＇ dynamic performances. Monte Carlo simulations are performed to take a further look at the trajectories of particles initializing near the surface. The simulations reveal consistent conclusions with the analysis, i.e., the open- field flat ground and slightly concave basins/valleys are the best choices for the vehicles＇ dynamical security. The dependence of decending trajectories on the releasing height is studied as an application; the results show that the pole direction （where the centrifugal force is zero） is the most stable direction in which the shift of a natural trajectory will be well limited after landing. We present this work as an example for pre-analysis that provides guidance to engineering design of the exploration site and routing the surface vehicles.

关键词： Asteroid exploration Numeric model Morphodynamics 1620 Geographos Path planning

A survey on orbital dynamics and navigation of asteroid missions

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Acta Mechanica Sinica 2014年第3期30卷 282-293页

作者： He-xi Baoyin jun-Feng Li School of Aerospace Tsinghua University

Asteroid exploration is currently one of the most concerned topics among international space agencies. Or- bital dynamics and navigation are obviously crucial for asteroid exploration. This paper aims to give a brief review on the dynamics, control and navigation of asteroid reconnaissance orbits, including the heliocentric transfer orbit and near as- teroid orbit. The developments in optimization techniques of the transfer segment are discussed in detail. We surveyed global researches in this field and made comments on several important progresses. The final section proposed a prospec- tive of future studies with emphasis on the key techniques of these issues in the asteroid exploration missions.

关键词： Asteroid Orbital dynamics Navigation Control Guidance

Evaluation and Model of Performance of A Tubular Solid Oxide Fuel Cell

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Chemical Research in Chinese Universities 2005年第5期21卷 577-582页

作者： JIA jun-xi SHEN Sheng-qiang Department of Power Engineering Dalian University of Technology Dalian 116024 P. R. China

A simulation model was developed to analyze the steady state and transient operation of a tubular solid oxide fuel cell. The model covers both the electrochemical and the heat transfer models. The electrochemical model deals with the Nernst potential, ohmic polarization, activation polarization, and concentration polarization, while the heat transfer model concerns the heat transfer by conduction, convection and radiation. The numerical results show that the ohmic loss is the dominant one among the three polarizations in a cathode-supported solid oxide fuel cell and in the middle part of a solid oxide fuel cell the temperature is higher than those at both the ends. When the inlet temperature and the flow rates of the fuel and the oxidant are kept constantly, the temperature of the solid structure of the cell will increase due to the increase of power output of the cell from the initial state to the new one.

关键词： Tubular solid oxide fuel cell Polarization Electrochemical reaction Heat and mass transfer

Analysis of structural response under blast loads using the coupled SPH-FEM approach

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第9期9卷 1184-1192页

作者： jun-xiang XU xi-la LIU Department of Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

A numerical model using the coupled smoothed panicle hydrodynamics-finite element method （SPH-FEM） approach is presented for analysis of structures under blast loads. The analyses on two numerical cases, one for free field explosive and the other for structural response under blast loads, are performed to model the whole processes from the propagation of the pressure wave to the response of structures. Based on the simulation, it is concluded that this model can be used for reasonably accurate explosive analysis of structures. The resulting information would be valuable for protecting structures under blast loads.

关键词： Smoothed particle hydrodynamics (SPH) Finite element method (FEM) Reinforced concrete structure Explosion

A nonlocal Burgers equation in atmospheric dynamical system and its exact solutions

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Chinese Physics B 2019年第1期28卷 189-194页

作者： xi-Zhong Liu jun yu Zhi-Mei Lou xian-Min Qian Institute of Nonlinear Science Shaoxing UniversityShaoxing 312000China yuanpei College Shaoxing UniversityShaoxing 312000China

From a two-vortex interaction model in atmospheric and oceanic systems, a nonlocal counterpart with shifted parity and delayed time reversal is derived by a simple AB reduction. To obtain some approximate analytic solutions of this nonlocal system, the multi-scale expansion method is applied to get an AB-Burgers system. Various exact solutions of the AB-Burgers equation, including elliptic periodic waves, kink waves and solitary waves, are obtained and shown *** show the applications of these solutions in describing correlated events, a simple approximate solution for the two-vortex interaction model is given to show two correlated dipole blocking events at two different places. Furthermore, symmetry reduction solutions of the nonlocal AB-Burgers equation are also given by using the standard Lie symmetry method.

关键词： AB–BA equivalence principle nonlocal Burgers equation periodic waves

Yield and Quality Response of Cucumber to Irrigation and Nitrogen Fertilization Under Subsurface Drip Irrigation in Solar Greenhouse

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Agricultural Sciences in China 2011年第6期10卷 921-930页

作者： ZHANG He-xi CHI Dao-cai WANG Qun FANG jun FANG xiao-yu College of Water Resources Shenyang Agricultural University Shenyang 110161 P.R. China Guizhou Academy of Hydraulic Sciences Guiyang 550002 P.R.China

The aims of this research were to compare subsurface drip irrigation scheduling and nitrogen fertilization rates in cucumber, and evaluate yield and quality of cucumber fruit, water （WUE）, irrigation water （IWUE）, and nitrogen use （NUE） efficiencies in the solar greenhouse in Southwest China. The irrigation water amounts were determined based on the 20 cm diameter pan （Ep） placed over the crop canopy, and cucumber plant was subjected to three irrigation water levels （I1, 0.6 Ep; I2, 0.8 Ep; and I3, 1.0 Ep） in interaction with three nitrogen fertilization levels （N1, 300 kg ha-1; N2, 450 kg ha-1; and N3, 600 kg ha-1）. The results showed that the cucumber fruit yield increased with the improvement of irrigation water. Irrigation water increased yields by increasing the mean weight of the fruits, and also by increasing fruit number. But the highest values of IWUE and WUE were obtained from I2 treatment. NUE significantly decreased with the improvement of N application, but increased by irrigating more water. The quality of cucumber fruit decreased with the improvement irrigation water and nitrogen fertilization. In conclusion, the optimum irrigation level and nitrogen fertilizer application level for cucunber under subsurface drip irrigation in the solar greenhouse in Southwest China were 0.8 Ep and 450 and 600 kg ha-1, respectively.

关键词： subsurface drip irrigation cucumber water use efficiency nitrogen use efficiency fruit quality

Characterization and tribological investigation of self-assembled trimethoxysilyl-functionalized poly(phthalazinone ether ketone)thin films on glass substrates

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Chinese Chemical Letters 2010年第8期21卷 973-975页

作者： Qi Feng Jin Gong xiong Liao Shi jun yu xi Gao Jian State Key Laboratory. of Fine Chemicals Dalian University of Technology Dalian 116012 Liaoning China College of Chemistry and Chemical Engineering Liaoning Normal University Dalian 116029 China Liaoning High Performance Resin Engineering Research Center Dalian 116012 China Department of Polymer Science and Materials Dalian University of Technology Dalian 116012 China

Trimethoxysilyl-functionalized PPEK（PKGS） films had been designed to serve as wear resistant coatings for silicon surfaces. These surface films were formed by a dip-coating technique applied to self-assembled monolayers（SAMs）.The formation and wetting behavior of PKGS films were characterized by means of contact angle *** friction coefficient of the film prepared is very low（about 0.1）,and the anti-wear behavior is good,with a lack of failure after sliding over 1800 s.

关键词： Phthalazinone Poly(aryl ether ketone) Self-assemble film Friction and wear

Response Surface Optimization of Nigella glandulifera Freyn Seed Oil Yield by Supercritical Carbon Dioxide Extraction

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Journal of Integrative Agriculture 2012年第1期11卷 151-158页

作者： ZHANG jun-ping HOU xi-lin yu Tian LI Ying DONG Hai-yan State Key Laboratory of Crop Genetics ＆ Germplasm Enhancement Nanjing Agriculture University Nanjing 210095 P.R. China Key Laboratory of Southern Vegetable Crop Genetic Improvement Ministry of Agriculture Nanjing 210095 P.R. China

Supercritical carbon dioxide （SC-CO2） extraction was employed to extract oil from Nigella glandulifera Freyn seed in this study. Response surface methodology （RSM） was applied to evaluate the effects of the process parameters （pressure, temperature, and CO2 flow rate） on oil yield of N. glandulifera seed. A Box-Behnken design was used to optimize the extraction parameters. The analysis of variance indicated that the linear coefficients of pressure and CO2 flow rate, the quadratic term coefficients of pressure and temperature and the interactions between pressure and temperature, as well as temperature and CO2 flow rate, had significant effects on the oil yield （P〈0.05）. The optimal conditions to obtain the maximum oil yield from N. glandulifera seed were pressure 30.84 MPa, temperature 40.57°C, and CO2 flow rate 22.00 L h-1. Under these optimal conditions, the yield of oil was predicted to be 38.19%. The validation experiment results agreed with the predicted values. The fatty acid composition of N. glandulifera seed oil extracted using SC-CO2 was compared with that of oil obtained by Soxhlet method. The results showed that the fatty acid compositions of oil extracted by the two methods were similar. Identification of oil compounds with gas chromatography-mass spectrometry （GC-MS） showed that the contents of unsaturated fatty acids linoleic acid （48.30%）, oleic acid （22.28%） and saturated fatty acids palmitic acid （16.65%）, stearic acid （4.17%） were the most abundant fatty acids in seed oil from N. glandulifera.

关键词： supercritical carbon dioxide extraction Nigella glandulifera Freyn seed oil response surface methodology,gas chromatography-mass spectrometry fatty acids

Real-Time Investigation of the Growth Kinetics of an Organometallic Complex Crystal ATMB

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Chinese Physics Letters 1996年第8期13卷 606-609页

作者： SUN Yi yu xi-ling HOU Wen-bo ZHANG Shu-jun GUO Shi-yi The State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100

This paper reports the growth kinetics of a new kind of organometallic complex crystal triallylthiourea mercury bromide(ATMB),investigated by in situ microscopic *** step trains formed by the layer growth mechanism have larger width(ranged from 2 to 15μm) and lower height(40-250nm).The relationship between the growth rate R and the relative supersaturationσwas obtained by directly measuring the movement of step trains of ATMB crystal in aqueous *** variation of growth mechanism with supersaturationσis also discussed.

关键词： solution crystal saturation