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A Detailed View of PLGA-m PEG Microsphere Formation by Double Emulsion Solvent Evaporation Method

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Chinese Journal of Polymer Science 2015年第7期33卷 955-963页

作者： Shui-bin Feng De-hao fu Lei Nie Peng Zou 索进平 State Key Laboratory of Material Processing and Die and Mould Technology College of Materials Science and Engineering Huazhong University of Science and Technology Department of Orthopedics Union Hospital Tongji Medical College Huazhong University of Science and Technology

PLGA, m PEG diblock copolymer was synthesized by bulk ring-opening polymerization method. The double emulsion solvent evaporation method was used to prepare bovine serum albumin（BSA）-loaded microspheres. Optical microscopy was used to observe the whole microsphere fabrication process. It is confirmed that the proportion of inner aqueous phase is one of the most critical factors that determines the morphology of microspheres. Double emulsion droplets which have appropriate amount of inner aqueous phase can form closed and dense microspheres, while, too much inner aqueous phase will cause a collapse of the double emulsion droplets, resulting in a loss of drug. The proportion of inner aqueous phase was varied to prepare microspheres of different morphology. The results show that with increasing the amount of inner aqueous phase, a higher percent of broken microspheres and lower encapsulation efficiency appeared, and also, a more severe initial burst release and faster release rate.

关键词： Microspheres PLGA-m PEG Morphology Encapsulation efficiency Release profile

Improved fault location method for AT traction power network based on EMU load test

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Railway Engineering Science 2022年第4期30卷 532-540页

作者： Guosong Lin Xuguo fu Wei Quan bin Hong School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China

The autotransformer(AT)neutral current ratio method is widely used for fault location in the AT traction power *** the development of high-speed electrified railways,a large number of data show that the relation between the AT neutral current ratio and the distance from the beginning of the fault AT section to the fault point(Q-L relation)is mostly ***,the linear Q-L relation in the traditional fault location method always leads to large *** solve this problem,a large number of load-related current data that can be used to describe the Q-L relation are obtained through the load test of the electric multiple unit(EMU).Thus,an improved fault location method based on the back propagation(BP)neural network is proposed in this *** this basis,a comparison between the improved method and the traditional method shows that the maximum absolute error and the average absolute error of the improved method are 0.651 km and 0.334 km lower than those of the traditional method,respectively,which demonstrates that the improved method can effectively eliminate the influence of nonlinear factors and greatly improve the accuracy of fault location for the AT traction power ***,combined with a shortcircuit test,the accuracy of the improved method is verified.

关键词： Fault location EMU load test BP neural network AT traction power network High-speed electrified railway

Flow hydrogen absorption of LaFe_(10.9)Co_(0.8)Si_(1.3) compound under constant low hydrogen gas pressure

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Rare Metals 2018年第3期37卷 243-248页

作者： bin fu Jun He Jie Han Jie Hu Li-Wei Pang Tianjin Key Laboratory for Photoelectric Materials & Devices School of Materials Science and EngineeringTianjin University of Technology Division of functional Material Research Central Iron and Steel Research Institute College of Science Tianjin University of Technology School of Materials Science and Engineering Shijiazhuang Tiedao University

The hydrogen absorption of the LaFe（10.9）-Co（0.8）Si（1.3） compound under constant 1.01 × 10-5 Pa H2 gas in a flow hydrogen atmosphere was studied. The effects of hydrogen absorption on structure, Curie temperature, phase transition and magnetic property were investigated by X-ray diffraction（XRD）, differential scanning calorimeter（DSC） and superconducting quantum interference device,respectively. The hydrides of LaFe（10.9）Co（0.8）Si（1.3） crystallize into NaZn（13）-type structural phase after hydrogen absorption at temperature from 548 to 623 K. Lower hydrogen absorption temperature is of no advantage for pure 1：13 phase formation in a flow H2 atmosphere. The Curie temperature（TC） of LaFe（10.9）Co（0.8）Si（1.3） compound increases by70 K or more after hydrogen absorption. For LaFe（10.9）-Co（0.8）Si（1.3）H（1.8） compound, the maximum magnetic entropy change and the relative cooling power under a magnetic field change of 0-2 T are 6.1 J·kg^-1·K^-1 and 170 J·kg^-1,respectively. Large refrigerant capacity, low hysteresis loss and wide temperature span of magnetic entropy change peak make it a competitive practical candidate for magnetic refrigerant.

关键词： La(FexSi1-x)13 compounds Magnetic refrigerant Hydrogen absorption Magnetic entropy change

Simultaneous determination of 4-tert-octylphenol, 4-nonylphenol and bisphenol A in Guanting Reservoir using gas chromatography-mass spectrometry with selected ion monitoring

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Journal of Environmental Sciences 2004年第5期16卷 825-828页

作者： JINXing-long HUANGGuo-lan JIANGGui-bin ZHOUQun-fang LIUJmg-fu CollegeofEnvironmentalScienceandEngineering NankaiUniversityTianjin300071China ofEnvironmentalChemistryandEcotoxicology ResearchCenterforEco-EnvironmentalSciencesChineseAcademyofSciencesBeijing100085China

The wide occurrence of estrogenic compounds 4-tert-octylphenol, 4-nonylphenol, bisphenol A in surface water of Guanting Reservoir was successfully determined. The target compounds in water samples were preconcentrated by liquid-liquid extraction with dichloromethane, derivatized by trifluoroacetic anhydride, and quantified by gas chromatography-mass spectrometry(GC-MS) with selected ion monitoring(SIM). In the selected seven sampling sites(S1\_S7), the concentration of NP in sample S7 was significantly higher than the other in reservoir. The status of pollution in S3 and S7 were much more serious. The concentrations of OP, NP and BPA were in the range of 44.5—48.8, 221.6—349.6 and 30.2—82.7 ng/L, respectively. The pollutants were mainly inputted from the upper river and released from sediments in Guanting Reservoir.

关键词： 4-tert-octylphenol 4-nonylphenol bisphenol A Guanting Reservoir GC-MS-SIM

Low-cost (ZrCu)50-xTax high temperature shape memory alloys showing excellent shape memory effect

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Progress in Natural Science:Materials International 2022年第3期32卷 369-374页

作者： Weihong Gao Xiaoyang Yi bin Sun Yudong fu Xianglong Meng College of Materials Science and Chemical Engineering Harbin Engineering University College of Nuclear Equipment and Nuclear Engineering Yan Tai University School of Materials Science and Engineering Harbin Institute of Technology

ZrCu-based alloys, as one of the most potential high-temperature shape memory alloys, show quite high martensitic transformation temperature, relatively low price for the raw materials, and good casting fluidity. In this work, the martensitic transformation(MT) and shape memory effect of (ZrCu)50-xTaxhigh-temperature shape memory alloys were systematically investigated. Both X ray diffraction and SEM backscattered electron image demonstrated the coexistence of the main phase monoclinic martensite phase and the second phase Ta2Cu. SEM results also revealed that increasing Ta content resulted in a larger volume fraction of Ta2Cu phase. Differential scanning calorimetry results showed that the MT temperatures remarkably increased with Ta addition. The ductility of the (ZrCu)50-xTaxalloys was reduced to some degree with increasing Ta content. The shape memory effect was improved significantly, in which(ZrCu)98Ta2alloy showed the 6.19% maximum recovery strain during 8% pre-strain under compression at 25℃.

关键词： ZrCu-Based alloys High-temperature shape memory alloys Microstructure Shape memory effect Martensitic transformation

Phase decomposition behavior and its effects on mechanical properties of TiNbTa0.5ZrAl0.5 refractory high entropy alloy

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Journal of Materials Science & Technology 2021年第7期66卷 10-20页

作者： Yuankui Cao Weidong Zhang bin Liu Yong Liu Meng Du Ao fu State Key Lab of Powder Metallurgy Central South UniversityChangsha410083China School of Materials Science and Engineering Hunan UniversityChangsha410083China

The mechanical properties of refractory high entropy alloys(RHEAs) strongly depend on their phase structures. In this work, the phase stability of a BCC TiNbTa0.5ZrAl0.5 refractory high entropy alloy subjected to thermomechanical processing was evaluated, and the effects of phase decomposition on room/high temperature mechanical properties were quantitatively studied. It was found that, the thermomechanical processing at 800℃and 1200℃ leads to phase decomposition in the TiNbTa0.5ZrAl0.5 alloy. The phase decomposition is caused by the rapid rising of free energy of the primary BCC phase. The effect of the precipitates on room temperature strength is determined by the competition between the increasing in precipitation strengthening and the decreasing in solid solution strengthening. But at high temperatures(800-1200℃), the phase decomposition causes significant reduction in strength, mainly due to the grain boundary sliding and the decreasing in solid solution strengthening.

关键词： High entropy alloy Thermomechanical processing Precipitation Mechanical property Strengthening mechanism

PetroKG: Construction and Application of Knowledge Graph in Upstream Area of PetroChina

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Journal of Computer Science & Technology 2020年第2期35卷 368-378页

作者： Xiang-Guang Zhou Ren-bin Gong fu-Geng Shi Zhe-Feng Wang PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China Huawei Technologies Hangzhou 310007China

There is a large amount of heterogeneous data distributed in various sources in the upstream of PetroChina. These data can be valuable assets if we can fully use them. Meanwhile, the knowledge graph, as a new emerging technique, provides a way to integrate multi-source heterogeneous data. In this paper, we present one application of the knowledge graph in the upstream of PetroChina. Specifically, we first construct a knowledge graph from both structured and unstructured data with multiple NLP (natural language progressing) methods. Then, we introduce two typical knowledge graph powered applications and show the benefit that the knowledge graph brings to these applications:compared with the traditional machine learning approach, the well log interpretation method powered by knowledge graph shows more than 7.69% improvement of accuracy.

关键词： knowledge graph natural language processing oil and gas industry

Dynamic deformation behavior of a FeCrNi medium entropy alloy

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Journal of Materials Science & Technology 2022年第5期100卷 120-128页

作者： Ao fu bin Liu Zezhou Li bingfeng Wang Yuankui Cao Yong Liu State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Department of Mechanical and Aerospace Engineering University of CaliforniaSan DiegoUnited States School of Materials Science and Engineering Central South UniversityChangsha 410083China

Deformation behavior of a FeCrNi medium entropy alloy(MEA)prepared by powder metallurgy(P/M)method was investigated over a wide range of strain *** FeCrNi MEA exhibits high strain-hardening ability,which can be attributed to the multiple deformation mechanisms,including dislocation slip,deformation induced stacking fault and mechanical *** shear localization behavior of the FeCrNi MEA was also analyzed by dynamically loading hat-shaped specimens,and the distinct adiabatic shear band cannot be observed until the shear strain reaches~*** microstructures within and outside the shear band exhibit different characteristics:the grains near the shear band are severely elongated and significantly refined by dislocation slip and twinning;inside the shear band,the initial coarse grains completely disappear,and transform into recrystallized ultrafine equiaxed grains by the classical rotational dynamic recrystallization ***,microvoids preferentially nucleate in the central areas of the shear band where the temperature is very high and the shear stress is highly *** microvoids will coalesce into microcracks with the increase of strain,which eventually leads to the fracture of the shear band.

关键词： Medium entropy alloys Mechanical response Dynamic shear properties Grain refinement Adiabatic shear band

Path planning of the fruit tree pruning manipulator based on improved RRT-Connect algorithm

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 177-188页

作者： Yaya Chen Yuxing fu bin Zhang Wei fu Congju Shen Mechanical and Electrical Engineering College Hainan UniversityHaikou 570228HainanChina School of Information and Communication Engineering Hainan UniversityHaikou 570228HainanChina College of Mechanical and Electrical Engineering Shihezi UniversityShihezi 832003XinjiangChina

Aiming to realize the obstacle avoidance of the fruit tree pruning manipulator in unstructured complex natural environment,an improved bidirectional fast extended random tree(RRT-Connect)algorithm was presented in this *** manipulator and obstacles were properly simplified based on their geometrical characteristics to build collision detection models taking account of the obstacles,ground,and manipulator itself and to carry out the obstacle avoidance path ***-biased strategy and adaptive step size adjustment principle were introduced to accelerate the path search *** pruning optimal strategy and cubic non-uniform B-spline interpolation method were adopted to optimize the path generated by *** simulation path planning experiment was carried out in the simulation system of the fruit tree pruning manipulator and the practical obstacle avoidance path planning experiment was carried out on the real fruit tree pruning manipulator path planning experiment *** results showed that the path planning time and the path length of the improved RRT-Connect algorithm reduced by about 55%and 60%respectively compared with the basic RRT-Connect *** path planning success rate of the improved RRT-Connect algorithm was 100%,and the planned path was smooth,continual and executable,which could effectively guide the manipulator to avoid obstacles and lead the end effector of the manipulator to the goal *** proposed improved algorithm not only has certain application value for obstacle avoidance of the fruit tree pruning manipulator in fruit tree pruning environment,but also has theoretical reference value for path planning of other types of robots.

关键词： manipulator path planning RRT-Connect jujube pruning obstacle avoidance non-uniform B-spline