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Crosslinked Colorless Polyimide Films via Oxazole Groups as Crosslinking Agent:Preparation and Properties

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Chinese Journal of Polymer Science 2024年第12期42卷 1905-1914,I0007页

作者： He Wang Zhen-Chao Liu xue Shang Li-Dong Feng Xin-Chao Bian xue-si Chen School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China Key Laboratory of Polymer Ecomaterials Changchun Institute of APPlied ChemistryChinese Academy of SciencesChangchun 130022China

A series of transparent crosslinked colorless polyimide(CPI)films are prepared from 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),2,2'-bis(trifluoro-methyl)benzidine(TFMB),and 4,4'-oxydianiline(ODA)by thermal imidization,incorporating varying contents of 2,2'-(1,3-phenylene)bis(2-oxazoline)(1,3-PBO)as the crosslinking *** the incorporation of the crosslinking structure,the CPI films show good optical transparency(approximately 85%winthin visible light range),enhanced glass transition temperature(from 325℃to 341℃),and improved thermal stability,and tensile ***,compared with the pristine uncrosslinked CPI,these crosslinked CPI films significantly increase in elongation at break(from 5.4%to 44.2%).Furthermore,the new approach ensures that crosslinked CPIs improve heat resistance and mechanical properties,while avoiding the embrittlement of *** study also offeres straightforward preparation methods for optically transparent crosslinked polyimides without additional processing *** these results make this approach can effectively improve the competitive performance of the CPI films for potential applications in microelectronic and optoelectronic fields.

关键词： Polyimide Colorless transparent film Crossking structure Optical property Thermal property Mechanical property

Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County, Shaanxi Province, China

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Journal of Mountain Science 2018年第12期15卷 2730-2740页

作者： WANGYao ZHANG Mao-sheng xue Qiang WU si-duo Development Research Center of China Geological Survey Beijing 100037China Xi'an Center of Geological Survey China Geological SurveyXi'an jiooooChina East China Normal University Shanghai 200062China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle(UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.

关键词： Mountain cities Risks Geological environment Carrying capacity Evaluation

Nanocrystalline Ni(OH)_2 Preparation by Electrolysis in an Aqueous Solution of Nickel Nitrate

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Chemical Research in Chinese Universities 2002年第3期18卷 334-336页

作者： ZHANG Heng bin LI xue yin CAO xue jing LI Shu jia College of Chemistry Jilin UniversityChangchun 130023P.R.China

Nanocrystalline Ni(OH) 2 was prepared by cathode deposition in an aqueous solution of nickel nitrate. The structure and the morphology were characterized by means of XRD and TEM. The electrode performances were exami... 详细信息

关键词： Nanocrystal Nickel hydroxide Electrolysis

Poly(β-cyclodextrin)-mediated Polylactide-cholesterol Stereocomplex Micelles for Controlled Drug Delivery

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Chinese Journal of Polymer Science 2017年第6期35卷 693-693,694-699页

作者： Xiang-ru Feng 丁建勋 Ruxandra Gref xue-si Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry Chinese Academy of Sciences Institute of Molecular Sciences CNRS Université Paris-Sud Université Paris Saclay

A series of host-guest interaction-adjusted polylactide stereocomplex micelles was prepared via the self-assembly of 4-armed poly（ethylene glycol）-block-poly（L-lactide/D-lactide）-cholesterol （4-armed PEG-b-PLLA/PDLA-CHOL） and poly（β-cyclodextrin）（PCD） with the molar ratios of CHOL/β-CD at 1：0.5, 1 ：l, and 1：2 in an aqueous environment. The hydrodynamic diameters of the micelles ranged from 84.1 nm to 107 nm depending on the molar ratio of CHOL/β-CD. It was shown that the micelle with the largest proportion of PCD possessed excellent abilities in drug release, cell internalization as well as proliferation inhibitory effect toward human A549 lung cancer cells. The results demonstrated that the stereocomplex and host-guest interactions-mediated PLA micelles exhibited great potential in sustained drug delivery.

关键词： Polylactide Stereocomplex micelle Poly(β-cyclodextrin) Host-guest interaction Controlled drug delivery

Challenges and Suggestions of Ethical Review on Clinical Research Involving Brain-Computer Interfaces

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Chinese Medical Sciences Journal 2024年第2期39卷 131-139页

作者： xue-Qin Wang Hong-Qiang Sun jia-Yue si Zi-Yan Lin Xiao-Mei Zhai Lin Lu Peking University sixth Hospital Peking University Institute of Mental HealthNHC Key Laboratory of Mental Health(Peking University)National Clinical Research Center for Mental Disorders(Peking University Sixth Hospital)Chinese Academy of Medical Sciences Research Unit(No.2018RU006)Beijing 100191China Department of Psychology University of CaliforniaDavis 95616USA Department of Psychology University of TorontoToronto M5S 1A1Canada School of Population Medicine and Public Health Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Academy for Advanced Interdisciplinary Studies Peking-Tsinghua Centre for Life Sciences and Peking University-International Development Group/McGovern Institute for Brain ResearchPeking UniversityBeijing 100871China

Brain-computer interface(BCI)technology is rapidly advancing in medical research and *** an emerging biomedical engineering technology,it has garnered significant attention in the clinical research of brain disease diagnosis and treatment,neurological rehabilitation,and mental ***,BCI also raises several challenges and ethical concerns in clinical *** this article,the authors investigate and discuss three aspects of BCI in medicine and healthcare:the state of international ethical governance,multidimensional ethical challenges pertaining to BCI in clinical research,and suggestive concerns for ethical *** the great potential of frontier BCI research and development in the field of medical care,the ethical challenges induced by itself and the complexities of clinical research and brain function have put forward new special fields for ethics in *** ensure"responsible innovation"in BCI research in healthcare and medicine,the creation of an ethical global governance framework and system,along with special guidelines for cutting-edge BCI research in medicine,is suggested.

关键词： brain-computer interface clinical research bioethics ethical governance ethical review

Effect of rotation curvature correction and inviscid spatial discretization scheme on the aerodynamics of vertical axis wind turbine

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JOURNAL OF HYDRODYNAMICS 2024年第5期36卷 828-842页

作者： Ma, Kai-fang Wang, jia-song xue, Lei-ping Shanghai jiao Tong Univ Sch Ocean & Civil Engn Shanghai 200240 Peoples R China Shanghai jiao Tong Univ MOE Key Lab Hydrodynam Shanghai 200240 Peoples R China Shanghai jiao Tong Univ Yazhou Bay Inst Deepsea Sci & Technol Sanya 572024 Peoples R China

The effect of rotation-curvature correction and inviscid spatial discretization scheme on the aerodynamic performance and flow characteristics of Darrieus H-type vertical axis wind turbine (VAWT) are investigated based on an in-house solver. This solver is developed on an in-house platform HRAPIF based on the finite volume method (FVM) with the elemental velocity vector transformation (EVVT) approach. The present solver adopts the density-based method with a low Mach preconditioning technique. The turbulence models are the Spalart-Allmaras (SA) model and the k-omega shear stress transport (SST) model. The inviscid spatial discretization schemes are the third-order monotone upstream-centered schemes for conservation laws (MUSCL) scheme and the fifth-order modified weighted essentially non-oscillatory (WENO-Z) scheme. The power coefficient, instantaneous torque of blades, blade wake, and turbine wake are compared and analyzed at different tip speed ratios. The extensive analysis reveals that the density-based method can be applied in VAWT numerical simulation;the SST models perform better than the SA models in power coefficient prediction;the rotation-curvature correction is not necessary and the third-order MUSCL is enough for power coefficient prediction, the high-order WENO-Z scheme can capture more flow field details, the rotation-curvature correction and high-order WENO-Z scheme reduce the length of the velocity deficit region in the turbine wake.

关键词： Rotation-curvature correction spatial discretization scheme turbulence model power coefficient wake

Iron oxide nanoparticles:A promising approach for diagnosis and treatment of cardiovascular diseases

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Nano Research 2023年第11期16卷 12453-12470页

作者： xue Bao Yu Mao Guangxiang si Lina Kang Biao Xu Ning Gu Cardiovascular Disease Research Center Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolMedical SchoolNanjing UniversityNanjing 210093China State Key Laboratory of Bioelectronics Jiangsu Key Laboratory for Biomaterials and DevicesSchool of Biological Sciences and Medical EngineeringSoutheast UniversityNanjing 210096China

Despite advances in diagnostic and therapeutic technologies for cardiovascular diseases(CVDs),it remains a leading cause of mortality and morbidity *** underscores the urgency for innovative approaches aiming at early and precise detection and treatment of CVDs to reduce the disease *** oxide nanoparticles(IONPs),with their unique magnetism and bioproperties,have shown great potential in this *** this review,we will begin with a brief overview of the synthesis and properties of *** will then focus on the latest applications of IONPs in CVDs,including diagnosis and *** use of IONPs in the integration of diagnosis and treatment for CVDs is a promising field,and will be addressed in a separate *** translational potential and challenges of IONPs will also be *** conclusion,ongoing research and development of IONP-based strategies are highly likely to address current challenges effectively,and offer more personalized and efficient options for the diagnosis and treatment of CVDs.

关键词： atherosclerosis cardiovascular disease diagnosis iron oxide nanoparticles theranostic treatment

Hybrid genetic algorithm for a type-Ⅱ robust mixed-model assembly line balancing problem with interval task times

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Advances in Manufacturing 2019年第2期7卷 117-132页

作者： jia-Hua Zhang Ai-Ping Li xue-Mei Liu School of Mechanical Engineering Tongji University Shanghai 201804 People's Republic of China Department of Mechatronics Engineering Wuxi Vocational Institute of Arts and Technology Yixing 214206 Jiangsu People's Republic of China

The typemixed-model assembly line balancing problem with uncertain task times is a critical problem. This paper addresses this issue of practical significance to production efficiency. Herein, a robust optimization model for this problem is formulated to hedge against uncertainty. Moreover, the counterpart of the robust optimization model is developed by duality. A hybrid genetic algorithm (HGA) is proposed to solve this problem. In this algorithm, a heuristic method is utilized to seed the initial population. In addition, an adaptive local search procedure and a discrete Levy flight are hybridized with the genetic algorithm (GA) to enhance the performance of the algorithm. The effectiveness of the HGA is tested on a set of benchmark instances. Furthermore, the effect of uncertainty parameters on production efficiency is also investigated.

关键词： Mixed-model assembly line Assembly line balancing Robust optimization Genetic algorithm (GA) Uncertainty

Rejuvenation Heat Treatment of the Second-Generation single-Crystal Superalloy DD6

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Acta Metallurgica sinica(English Letters) 2015年第10期28卷 1278-1285页

作者： Zhen-xue Shi Shi-Zhong Liu jia-Rong Li Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

The second-generation single-crystal superalloy DD6 with [001] orientation was prepared by screw selecting method in the directionally solidified furnace. The long-term aging of the alloy after full heat treatment was performed at1100 °C for 400 h. Then the rejuvenation heat treatment 1300 °C/4 h/AC ？ 1120 °C/4 h/AC ？ 870 °C/24 h/AC was carried out. The stress rupture properties were investigated at 760 °C/800 MPa, 850 °C/550 MPa, 980 °C/250 MPa and1100 °C/140 MPa after different heat treatments. The microstructures of the alloy at different conditions were studied by SEM. The results show that c0 phase of the alloy became very irregular and larger after long-term aging at 1100 °C for 400 h. A very small amount of needle-shaped TCP phase precipitated in the dendrite core. The coarsened c0 phase and TCP phase dissolved entirely after rejuvenation heat treatment. The microstructure was restored and almost same with the original microstructure. The stress rupture life of the alloy decreased in different degrees at various test conditions after long-term aging. The stress rupture life of the alloy after rejuvenation heat treatment all restores to the original specimen more than 80%at different conditions. The microstructure degradation of the alloy during long-term aging includes coarsening of the c0 phase,P-type raft and precipitation of TCP phase, which results in the degeneration of stress rupture property. The rejuvenation heat treatment succeeds in restoring the original microstructure and stress rupture properties of the alloy.

关键词： single-crystal superalioy DD6 Rejuvenation heat treatment Stress rupture properties