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The Stereocomplex Crystallites Improve the Stability of Biodegradable Poly(L-lactic acid)/Poly(D-lactic acid) Melt-Blown Nonwovens

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CHINESE JOURNAL OF POLYMER SCIENCE 2025年第2期43卷 368-379页

作者： Yu, Jin-Shuo Huan, Yue-Wei Pan, Hong-Wei Liu, Zhi-Gang Zhao, Yan Tan, Zhi-Yong bian, jun-Jia Yang, Hui-Li Zhang, Hui-Liang Chinese Acad Sci Changchun Inst Appl Chem Key Lab Polymer Ecomat Changchun 130022 Peoples R China Changchun Univ Technol Coll Mat & Engn Engn Res Ctr Synthet Resin & Special Fiber Sch Chem EngnMinist Educ Changchun 130012 Peoples R China Shandong Fufeng Fermentat Co Ltd Linyi 276600 Shandong Peoples R China Jilin COFCO Biochem Co Ltd Natl Engn Res Ctr Corn Deep Proc Changchun 130033 Peoples R China

Poly(lactic acid) (PLA) is a biodegradable and eco-friendly polymer that is increasingly being incorporated into various applications in contemporary society. However, the limited stability of PLA-based products remains a significant challenge for their broader use in various applications. In this study, poly(L-lactic acid)(PLLA)/poly(D-lactic acid) (PDLA) melt-blown nonwovens were prepared by melt spinning. The structure, thermal properties, thermal stability, biodegradability and crystalline morphology of the melt-blown nonwovens were investigated. DSC and WAXD confirmed the formation of stereocomplex (SC) crystallites in the PLLA matrix. The storage modulus (G '), loss modulus (G ''), and complex viscosity (divided by eta*divided by) of the PLLA/PDLA blend increased with an increase in SC crystallite content. The thermal degradation temperatures of PLLA/PDLA melt-blown nonwovens increased with the incorporation of SC crystallites, and the maximum rate of decomposition increased to 385.5 degrees C, thus enhancing the thermal stability. Compared with neat PLLA melt-blown nonwovens, the hydrophobicity of PLLA/PDLA melt-blown nonwovens was improved, and WCA increased to 139.7 degrees. The SC crystallites were more resistant to degradation by proteinase K compared to neat PLLA. However, the degradation rate of PLLA/PDLA melt-blown nonwovens remained at a high level. This work provides an effective strategy to obtain high-performance PLLA melt-blown nonwovens.

关键词： PLLA PDLA Melt-blown nonwovens Stereocomplex crystallites Thermal stability Enzymatic degradation

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A Series of Exact Solutions for a New （2＋1）-Dimensional Calogero KdV Equation

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Communications in Theoretical Physics 2005年第5X期44卷 815-820页

作者： bian Xue-jun Department of Mathematics Hulunbeier Educational College Hulunbeier 021000 China

An algebraic method is proposed to solve a new (2+1)-dimensional Calogero KdV equation and explicitly construct a series of exact solutions including rational solutions, triangular solutions, exponential solution, lin... 详细信息

关键词： (2+1)-dimensional Calogero KdV equation exact solutions algebraic method computerized symbolic computation

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Hot-Dip Galvanized Sheet Production and Application

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Journal of Iron and Steel Research International 2003年第1期10卷 55-58页

作者： bian jun LIU Xiang-hua WANG Guo-dong Northeastern University

Hot-dip galvanized sheet is wildly used in construction,household appliances,ship,vehicle and vessel building and machinery,*** last ten years,with the development of automobile industry,the anti-eorrosion requirements for car body are increasingly strict,by which the rapid development in technology has been *** application of hot-dip galvanized sheet,technological progress in production and some Chinese large units were introduced.

关键词： hot-dip galvanized sheet technological progress application

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RESEARCH PROGRESS IN NONLINEAR ANALYSIS OF HEART ELECTRIC ACTIVITIES

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Chinese Science Bulletin 2006年第4期51卷 385-393页

作者： NING Xinbao bian Chunhua WANG jun CHEN Ying State Key Laboratory of Modem Acoustics Institute for BiomedicalElectronic Engineering Department of Electronic Science & Engineering Nanjing University Nanjing 210093 China

Nonlinear science research is a hot point in the world. It has deepened our cognition of determinism and randomicity, simplicity and com-plexity, noise and order and it will profoundly influ-ence the progress of the study of natural science, including life science. Life is the most complex nonlinear system and heart is the core of lifecycle system. In the late more than 20 years, nonlinear research on heart electric activities has made much headway. The commonly used parameters are based on chaos and fractal theory, such as correlation dimension, Lyapunov ex-ponent, Kolmogorov entropy and multifractal singu-larity spectrum. This paper summarizes the commonly used methods in the nonlinear study of heart electric signal. Then, considering the shortages of the above tradi-tional nonlinear parameters, we mainly introduce the results on short-term heart rate variability (HRV) signal (500 R-R intervals) and HFECG signal (1-2s). Finally, we point out it is worthwhile to put emphasis on the study of the sensitive nonlinearity parameters of short-term heart electric signal and their dynamic character and clinical effectivity.

关键词：心电图心率非线性分析混沌信号研究进展

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Dynamic interplay between dislocations and precipitates in creep aging of an Al-Zn-Mg-Cu alloy

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Advances in Manufacturing 2019年第1期7卷 15-29页

作者： Heng Li Tian-jun bian Chao Lei Gao-Wei Zheng Yu-Fei Wang State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 People's Republic of China

Abstract Creep age forming (CAF) is an advanced forming technology used for manufacturing large complex integrated panel components. However, in creep aging (CA), unlike in sole creep or aging procedure, the dislocation movement and the precipitation process occur simultaneously, leading to difficulty in understanding of the dynamic interplay between these two phenomena. In this work, taking 7050 Al alloy, a typical Al-Zn-Mg-Cu alloy, as the test material, an experimental scheme combining pre-deformation, artificial aging (AA), and tensile/ compressive CA is designed to decouple and reveal the dynamic interaction mechanism of both phenomena. From AA experiments, the static interaction between dislocations and precipitates is studied, and then their dynamic interactions in CA and each evolution are comparatively investigated. The research shows that both total strain and strain rate increase with the increase in pre-deformation in tensile and compressive CA. However, the total creep strain in compressive CA is larger than that in tensile CA. In additional, the more the dislocations are induced, the sparser and more heterogeneous the overall distribution of precipitates becomes. For dynamic interplay, in the first stage of CA (I), under thermal-mechanical loading, the GP zones and η phases gradually nucleate and grow, while the effect of dislocation multiplication is dominant compared with dislocation annihilation, leading to an increase in total dislocation density. Soon, the dislocation movement is gradually hindered by tangling, pile-up, and the precipitates that have grown on the dislocation lines, this decreases the mobile dislocation density and results in a significant decrease in creep rate. In the second stage (II), the precipitates grow further, especially those lying on the dislocation lines;the effects of pinning and hindrance are enhanced until the dislocation multiplication and annihilation reach a dynamic equilibrium, and the total and mobile dislocatio

关键词： Creep aging (CA) Dynamic interplay Dislocation Precipitate Pre-deformation Al-Zn-Mg-Cu alloy

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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.

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Graphene nanosheet as support of catalytically active metal particles in DMC synthesis

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Chinese Chemical Letters 2011年第1期22卷 57-60页

作者： jun bian Xiao Wei Wei Ling Wang Zheng Ping Guan Key Laboratory of Special Materials and Preparation Technologies School of Materials Science & Engineering Xihua University Chengdu 610039 China Department of Chemistry National University of Singapore Singapore 117543 Republic of Singapore

Novel graphene nanosheet （GNS） supported Cu-Ni bimetal catalysts were firstly synthesized and used for the direct synthesis of dimethyl carbonate （DMC）. The experimental results demonstrated that GNS was an effect... 详细信息

关键词： Graphene nanosheet (GNS) Dimethyl carbonate Carbon dioxide Cu-Ni bimetal catalyst Catalysis

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Microstructures and properties evolution of Al-Zn-Mg-Cu alloy under electrical pulse assisted creep aging

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Advances in Manufacturing 2022年第4期10卷 596-609页

作者： Tian-jun bian Heng Li Chao Lei Chang-Hui Wu Li-Wen Zhang State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072People’s Republic of China School of Materials Science and Engineering Xi’an University of TechnologyXi’an710048People’s Republic of China

Creep aging(CA)is a promising forming technology for integral panels with complex ***,how to balance excellent corrosion resistance and strength is still a challenge for CA *** synchronously applying electrical pulse(300 Hz,15 A/mm^(2))in the middle of steady-state CA of Al-Zn-Mg-Cu alloy,the electrically assisted CA(ECA)is proposed to induce retrogression rapidly for realizing a three-step aging(retrogression and re-aging,RRA)in CA to tailor the needed properties *** is compared with conventional CA with one-step aging(peak aging,T6 or over aging,T7),two-step aging(over aging,T73)and RRA in hardness,intergranular corrosion and *** the ECA of pre-aging and re-aging for 20 h plus electropulsing for 10 min,the hardness is 10.5%,20.5%and 18.9%higher than those of CA with T6,T7 and T73 processes,respectively,while the corrosion resistance is higher than T6 process and lower than T7 and T73 *** the hardness and corrosion resistance are comparable to those of the CA with the RRA process,ECA takes one hour less due to the accelerated effect of the electropulsing and is not limited by the thick *** improved comprehensive performance of the ECA sample is due to both fine intragranular precipitatesη′and large discontinuous grain boundary precipitatesη.

关键词： Creep aging(CA) Electrical pulse Retrogression Corrosion Hardness Al-Zn-Mg-Cu alloy

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Development of Hot Dip Galvanized Steel Strip and Its Application in Automobile Industry

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Journal of Iron and Steel Research International 2006年第3期13卷 47-50页

作者： bian jun ZHU Yun LIU Xiang-hua WANG Guo-dong Dalian Hongda Metallurgical Integral Equipment Co Ltd Dalian 114023 Liaoning China State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

Hot dip galvanized product is widely used in architecture, household electric appliance, ship vehicle, vessel, mechano-electronic device and other fields including clothing, food, housing, and travel. The history, development, market need, and technological advancement of hot dip galvanized strip, production situation, and development tendency in China are briefly introduced. The fact that it is necessary to build new and auto galvanized strip line with the development of the iron and steel industry in China.

关键词： hot dip galvanizing development technological advancement new galvanizing line

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Chinese Medicine Rescues Acute Respiratory Dyspnea Syndrome Caused by COVID-19:A Case Report

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Chinese Journal of Integrative Medicine 2022年第1期28卷 76-80页

作者： LIU Shi-xu XIA Kun bian Yong-jun LI Guang-xi Department of Respiratory Guang'anmen HospitalChina Academy of Chinese Medical SciencesBeijing(100053)China Graduate School of Beijing University of Chinese Medicine Beijing(100053)China

The novel coronavirus disease 2019(COVID-19)pandemic has struck a devastating blow to our global *** its over 100 million reported cases and 2 million death tolls across over 200 countries,every country is seeking eff... 详细信息

关键词： Medicine Acute death

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