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Pyraclostrobin-loaded poly(lactic-co-glycolic acid) nanospheres: Preparation and characteristics

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Journal of Integrative Agriculture 2018年第8期17卷 1822-1832页

作者： yin ming-ming ZHENG Yu CHEN Fu-liang Institute of Plant Protection Chinese Academy of Agricultural SciencesBeijing 100193P.R.China

We used poly(lactic-co-glycolic acid)(PLGA) as a carrier polymer for pyraclostrobin-loaded nanospheres. Using the ultrasound emulsification-solvent evaporation method, the physicochemical characteristics and release properties of the pyraclostrobin-loaded nanospheres were studied by dialysis. The optimal nanospheres prepared had a diameter of 0.6 μm, an active ingredient loading of 17.2%, and a loading rate of 89.7%. Infrared spectroscopy data and differential scanning calorimetry revealed that pyraclostrobin was successfully embedded in the carrier PLGA, and photostability tests indicated enhanced ultraviolet resistance of pyraclostrobin-loaded PLGA nanospheres nanospheres. Release property testing indicated that smaller particles had a faster release rate. Nanospheres also had a faster release rate in slightly acidic and slightly basic environments than in a neutral condition. Agitated nanospheres had a faster release rate than immobile nanospheres. The cumulative release kinetics of pyraclostrobin-loaded nanospheres was consistent with the first order kinetic equation and the Weibull equation.

关键词： nanospheres pyraclostrobin PLGA physical and chemical properties slow release

Thermal conductivity model of filled polymer composites

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International Journal of Minerals,Metallurgy and Materials 2011年第5期18卷 623-631页

作者： ming-xia Shen yin-xin Cui Jing He Yao-ming Zhang College of Mechanics and Materials Hohai University Nanjing 210098 China

Theoretical and empirical models for predicting the thermal conductivity of polymer composites were summarized since the *** effects of particle shape,filler amount,dispersion state of fillers,and interfacial thermal barrier on the thermal conductivity of filled polymer composites were investigated,and the agreement of experimental data with theoretical models in literatures was *** with high thermal conductivity was chosen to mix with polyvinyl-acetate （EVA） copolymer to prepare SiO2/EVA *** data of the co-films＇ thermal conductivity were compared with some classical theoretical and empirical *** results show that Agari＇s model,the mixed model,and the percolation model can predict well the thermal conductivity of SiO2/EVA co-films.

关键词： polymer matrix composites thermal conductivity mathematical models polyvinyl acetates silica filled polymers.

Release performance and sustained-release efficacy of emamectin benzoate-loaded polylactic acid microspheres

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Journal of Integrative Agriculture 2018年第3期17卷 640-647页

作者： yin ming-ming ZHU Xin-yan CHEN Fu-liang Institute of Plant Protection Chinese Academy of Agricultural Sciences

High-performance liquid chromatography （HPLC） was employed to determine drug release rates based on emamectin benzoate concentrations in the medium. Release kinetics equations were used to fit the drug release behavior. The effects of particle size and release medium pH on the release rate were also investigated. The indoor toxicity of emamectin benzoate-loaded polylactic acid microspheres on the diamondback moth larva （Plutella xylostella） was studied to explore drug sustained-release performance. In acidic and neutral media, the drug release behavior of the microspheres was in accord with the first-order kinetics equation. Increasing the spray dosage of emamectin benzoate-loaded polylactic acid microspheres initially resulted in an equivalent insecticidal efficacy with the conventional emamectin benzoate microemulsion. However, the drug persistence period was four-fold longer than that observed using the conventional formulation. The developed emamectin benzoate-loaded polylactic acid microspheres showed dramatic sustained-release performance. A treatment threshold of greater than 35 mg mL-1 was established for an efficient accumulated release concentration of emamectin benzoate-loaded microspheres.

关键词： emamectin benzoate polylactic acid microspheres release performance kinetics equation sustained-release efficacy

On parametric approach of aerial robots' visual navigation

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Journal of Systems Engineering and Electronics 2008年第5期19卷 1010-1016页

作者： Zhou Yu Huang Xianlin Jie ming yin Hang Harbin Inst. of Technology Harbin 150001 P. R. China

In aerial robots＇ visual navigation, it is essential yet very difficult to detect the attitude and position of the robots operated in real time. By introducing a new parametric model, the problem can be reduced from almost unmanageable to be partly solved, though not fully, as per the requirement. In this parametric approach, a multi-scale least square method is formulated first. By propagating as well as improving the parameters down from layer to layer of the image pyramid, a new global feature line can then be detected to parameterize the attitude of the robots. Furthermore, this approach paves the way for segmenting the image into distinct parts, which can be realized by deploying a Bayesian classifier on the picture cell level. Comparison with the Hough transform based method in terms of robustness and precision shows that this multi-scale least square algorithm is considerably more robust to noises. Some discussions are also given.

关键词： parametric model aerial robots visual navigation multi-scale least square.

New Approach for Measured Surface Localization Based on Umbilical Points

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Chinese Journal of Mechanical Engineering 2017年第5期30卷 1203-1215页

作者： Xiao-Ping Xiao ming yin Liang Heng Guo-Fu yin Zi-Sheng Li School of Manufacturing Science and Engineering Sichuan University Center of Engineering and Technology Southwest University of Science and Technology School of Manufacturing Science and Engineering Southwest University of Science and Technology

Measured surface localization （MSL） is one of the key essentials for the assessment of form error in pre- cision manufacturing. Currently, the researches on MSL have focused on the corresponding relation search between two surfaces, the performance improvement of localization algorithms and the uncertainty analysis of localization. However, low efficiency, limitation of localization algo- rithms and mismatch of multiple similarities of feature points with no prior are the common disadvantages for MSL. In order to match feature points quickly and fulfill MSL efficiently, this paper presents a new localization approach for measured surfaces by extracting the generic umbilics and estimating their single complex variables, describing the match methods of ambiguous relation at umbilics, presenting the initial localization process of one pair matched points, refining MSL on the basis of obtained closet points for some measured points by the improvement directed projection method. In addition, the proposed algorithm is simulated in two different types of surfaces,two different localization types and multiple similar sur- faces, also tested with the part of B-spline surface machined and bottle mould with no knowledge, finally the initial and accurate rigid body transformation matrix, localization errors between two surfaces and execution time are got. The experimental results show that the pro- posed method is feasible, more accurate in localization and high in efficiency. The proposed research can not only improve the accuracy and performance of form error assessment, but also provide an effective guideline for the integration of different types of measured surfaces.

关键词： Measured surface localization Umbilicalpoints and complex variable Similar surface patchesInitial and accurate localization

Synergistic effect of Zr and Mo on precipitation and high-temperature properties of Al-Si-Cu-Mg alloys

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China Foundry 2024年第1期21卷 71-81页

作者： Chao Gao Bing-rong Zhang yin-ming Li Zhi-ming Wang Xiang-bin Meng Faculty of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Hebei Ounai Machinery Mould Co.Ltd. Xingtai 054500HebeiChina

This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg *** synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were *** show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the *** can improve the strength of the alloy by hindering dislocation movement and crack *** addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain *** addition of Mo greatly improves the heat resistance of the *** extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy.

关键词： Al-Si-Cu-Mg alloy high-temperature properties Zr-Mo-rich intermetallics nano-strengthening phases

Study on the thermally induced spindle angular errors of a five-axis CNC machine tool

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Advances in Manufacturing 2023年第1期11卷 75-92页

作者： Ji Peng ming yin Li Cao Luo-Feng Xie Xian-Jun Wang Guo-Fu yin School of Mechanical Engineering Sichuan UniversityChengdu610065People’s Republic of China

Thermally induced spindle angular errors of a machine tool are important factors that affect the machining accuracy of *** is critical to develop models with good generalization abilities to control these angular thermal ***,the current studies mainly focus on the modeling of linear thermal errors,and an angular thermal error model applicable to different working conditions has rarely been ***,the formation mechanism of the angular thermal error remains to be *** this study,an analytical modeling method was proposed by analyzing the formation and propagation chain of the spindle angular thermal errors of a five-axis computer numerical control(CNC)machine *** effects of the machine tool structure and position were considered in the modeling *** angular thermal error equations were obtained by analyzing the spatial thermoelastic deformation *** analytical model of the spindle angular thermal error was established based on the geometric relation between thermal *** model parameters were identified using the trust region least squares *** results showed that the proposed analytical model exhibited good generalization ability in predicting spindle pitch angular thermal errors under different working conditions with variable spindle rotational speeds,spindle positions,and environmental temperatures in different *** average mean absolute error(MAE),root mean square error(RMSE)and R2 in twelve different experiments were 4.7μrad,5.6μrad and 0.95,*** study provides an effective method for revealing the formation mechanism and controlling the spindle angular thermal errors of a CNC machine tool.

关键词： Machine tool Angular thermal errors Thermal error modeling Analytical model

Synthesis of Novel Bisoxazoline Ligands for the Enantioselective Diels-Alder Reaction

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Chinese Chemical Letters 2006年第8期17卷 1033-1036页

作者： Qing Hua BIAN Jun LIU ming ming yin Min WANG College of Science China Agricultural University Beijing 100094

Four novel bisoxazoline ligands 8a-d were synthesized from （S）-amino alcohols and could be formed effective catalysts （up to 77% ee for endo isomer） with Cu（OTf）2 for enantioselective Diels-Alder addition. The f... 详细信息

关键词： Asymmetry catalytic bisoxazoline Diels-Alder reaction ligand.

Measurement of Secondary Electron Energy Spectra of Polymethyl Methacrylate

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Chinese Physics Letters 2018年第4期35卷 108-112页

作者： ming Weng Wan Liu ming yin Fang Wang Meng Cao Key Laboratory for Physical Electronics and Devices (Ministry of Education) Department of Electronic Science and Technology Xi'an Jiaotong University

We report on a novel and convenient method of measuring secondary electron spectra for insulators in a secondary electron yield measurement system with a planar grid analyzer configuration and a metal mesh probe. In this measurement, the planar grid is negatively biased to force some emitted secondary electrons to return to the sample surface and to neutralize charges accumulated on the sample during the previous beam irradiation. The surface potential of the sample is then measured by use of a metal mesh probe. The grid bias for neutralization corresponding to the zero surface potential is determined based on the linear relationship between the surface potential and the grid bias. Once the surface potential equals zero, the secondary electron spectra of polymethyl methacrylate（PMMA） are studied experimentally by measuring the -curve and then fitting it to Everhart＇s formula. The measurement results show that the peak energy and the full width at half maximum of the spectra are 4.26 eV and 14.06 eV, respectively.

关键词： SE In Measurement of Secondary Electron Energy Spectra of Polymethyl Methacrylate