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Long-Range Ordered Nanostructures of Assembling Macromolecules via Rational Design of Kinetic Pathways:A Computational Perspective

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Chinese Journal of Polymer Science 2023年第9期41卷 1318-1328,I0004页

作者： liang-Shun zhang Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Designing the kinetic pathways of assembling macromolecules such as block copolymers and DNA strands is crucial not only for an achievement of thermodynamically equilibrium nanostructures over macroscopic areas,but also for a better understanding of formation process of higher-level superstructures where well-tailored assemblies act as mesoscopic building units.Theoretical analysis and computer simulations provide excellent opportunities to microscopically reveal the kinetics and mechanism of structural evolution as well as the collective behaviors of building units.In this perspective,we summarize our efforts of theoretical and computational modelling to understand the long-range ordering mechanisms and the organization kinetics of assembling macromolecules along designable pathways.First,we present the computational modelling and recent strategies of designable pathways for the achievement of long-range ordering.Then,from the computational views,we give the applications of pathway-designed strategies to explore the ordering mechanism and kinetics in the course of structural evolution,covering the block copolymers and their nanocomposites under zone annealing as well as the hierarchical self-assembly of mesoscopic building units(e.g.,patchy micelles and DNA-functionalized nanoparticles).Finally,we outlook future directions in the field of designable pathways for the achievement of long-range ordered nanostructures.This perspective could promote further efforts towards the wide applications of theoretical and computational modelling in the construction of soft hybrid metamaterials.

关键词： Dynamic self-consistent field theory Structural evolution Block copolymers Hierarchical self-assembly Polymerization

Probabilistic-Ellipsoid Hybrid Reliability Multi-Material Topology Optimization Method Based on Stress Constraint

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 757-792页

作者： Zibin Mao Qinghai Zhao Liang Zhang College of Mechanical and Electrical Engineering Qingdao UniversityQingdao266071China National Engineering Research Center for Intelligent Electrical Vehicle Power System Qingdao UniversityQingdao266071China

This paper proposes a multi-material topology optimization method based on the hybrid reliability of the probability-ellipsoid model with stress constraint for the stochastic uncertainty and epistemic uncertainty of mechanical loads in optimization design.The probabilistic model is combined with the ellipsoidal model to describe the uncertainty of mechanical loads.The topology optimization formula is combined with the ordered solid isotropic material with penalization(ordered-SIMP)multi-material interpolation model.The stresses of all elements are integrated into a global stress measurement that approximates the maximum stress using the normalized p-norm function.Furthermore,the sequential optimization and reliability assessment(SORA)is applied to transform the original uncertainty optimization problem into an equivalent deterministic topology optimization(DTO)problem.Stochastic response surface and sparse grid technique are combined with SORA to get accurate information on the most probable failure point(MPP).In each cycle,the equivalent topology optimization formula is updated according to the MPP information obtained in the previous cycle.The adjoint variable method is used for deriving the sensitivity of the stress constraint and the moving asymptote method(MMA)is used to update design variables.Finally,the validity and feasibility of the method are verified by the numerical example of L-shape beam design,T-shape structure design,steering knuckle,and 3D T-shaped beam.

关键词： Stress constraint probabilistic-ellipsoid hybrid topology optimization reliability analysis multi-material design

Challenges and opportunities of machine learning control in building operations

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Building Simulation 2023年第6期16卷 831-852页

作者： Liang Zhang Zhelun Chen Xiangyu zhang Amanda Pertzborn Xin Jin The University of Arizona 1209 E 2nd StTucsonAZUSA Drexel University 3141 Chestnut StPhiladelphiaPAUSA National Renewable Energy Laboratory 15013 Denver W PkwyGoldenCOUSA National Institute of Standards and Technology 100 Bureau DrGaithersburgMDUSA

Machine learning control(MLC)is a highly flexible and adaptable method that enables the design,modeling,tuning,and maintenance of building controllers to be more accurate,automated,flexible,and adaptable.The research topic of MLC in building energy systems is developing rapidly,but to our knowledge,no review has been published that specifically and systematically focuses on MLC for building energy systems.This paper provides a systematic review of MLC in building energy systems.We review technical papers in two major categories of applications of machine learning in building control:(1)building system and component modeling for control,and(2)control process learning.We identify MLC topics that have been well-studied and those that need further research in the field of building operation control.We also identify the gaps between the present and future application of MLC and predict future trends and opportunities.

关键词： machine learning building operation control building energy system reinforcement learning

Profiling biotoxicities of hexafluoropropylene oxide trimer acid with human embryonic stem cell-based assays

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Journal of Environmental Sciences 2022年第6期34卷 34-42页

作者： Shengxian liang Guoqiang liang Yue zhang Xiufang zhang Li Zhong Institute of Life Sciences and Green Development College of Life SciencesHebei UniversityBaoding 071000China Western University of Health Sciences PomonaCalifornia 91766USA

Hexafluoropropylene oxide trimer acid(HFPO-TA), an emerging replacement of perfluorooctanoic acid(PFOA), has recently been reported to be a potential environmental contaminant.Due to the similar structure to PFOA, HFPO-TA may cause comparable adverse effects on human health. Therefore, evaluating the toxic profiles of HFPO-TA has become an urgent task.In this study, we investigated the cytotoxicity and hepatoxicity of HFPO-TA using human embryonic stem cell(h ESC)-based assays. Results showed that HFPO-TA reduced h ESCs’ viability in a dose dependent manner, and the calculated IC50 for 24, 48 and 72 hr were 222.8,167.4, and 80.6 μmol/L, respectively. Significant intracellular ROS accumulation and mitochondrion membrane potential reduction were detected with HFPO-TA exposure, and increased apoptotic/necrotic cells were also observed in high dose of HFPO-TA treated group.Moreover, HFPO-TA at noncytotoxic concentrations also significantly impaired the functions of induced hepatocytes by diminishing cell glycogen storage ability and deregulating specific functional genes. Transcriptome sequencing analysis identified a set of hepatic associated biological processes responding to HFPO-TA exposure. PPAR was the most significantly enriched pathway. Genes including FGA, FGB, FGG, AHSG, HRG, ITIH2, ALB were characterized as hub genes by cyto Hubba plug-in. These data indicated that HFPO-TA is a potential hepatotoxicant, and may not be a safe replacement for PFOA.

关键词： Hexafluoropropylene oxide trimer acid(HFPO-TA) Stem cell toxicology Hepatoxicity Transcriptional analysis

Insights into the provenance implication of leaf wax n-alkanes along the lower Yellow River

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Science China Earth Sciences 2024年第6期67卷 2001-2018页

作者： Liang Zhang Jinzhao LIU Chong JIANG Fei zhang Zhisheng AN School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710054China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China National Observation and Research Station of Earth Critical Zone on the Loess Plateau of Shaanxi Xi’an 710061China

Serving as one of the largest rivers in terms of both sediment and organic carbon transport fluxes in the world,the Yellow River plays a crucial role in regional biogeochemical process as well as in the global carbon cycle.However,although a large number of studies have been carried out on the flux,composition,source and seasonal variation of total particulate organic carbon in the Yellow River so far,studies on molecular biomarkers at different spatial and temporal scales are still scarce.In this study,we focus on the molecular and hydrogen isotopic properties of leaf wax n-alkanes among different types of samples which obtained from different seasons(flood vs.non-flood)along the lower Yellow River.The molecular distribution of n-alkanes show that the riparian topsoils are subject to inputs from the overlying vegetation,while the suspended sediments from the flood season are characterized by the mixing of soil materials which originate from various stratigraphy with different ages on the Chinese Loess Plateau.Due to the contrasting hydrodynamic conditions,the n-alkanes in suspended sediments also show distinct molecular composition between flood and non-flood seasons.Additionally,considering the effect of climatic factors,the proportion of monocots in flood-season suspended sediments is calculated from a semi-quantitative perspective using δ^(2)H_(wax).Our findings may bring to light new considerations for the interpretation of leaf wax proxies in studies of organic matter sources of Yellow River.

关键词： Molecular distribution Hydrogen isotopic composition Leaf wax n-alkanes Suspended sediments Lower Yellow River

Gel-state polybenzimidazole proton exchange membranes with flexible alkyl sulfonic acid side chains for a wider operating temperature range(25–240 ℃)

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Journal of Energy Chemistry 2023年第10期85卷 91-101,I0005页

作者： Taizhong Zhu Danyi Zhu Jiazhen liang Liang Zhang Fei Huang Lixin Xue Center for Membrane Separation and Water Science&Technology College of Chemical EngineeringZhejiang University of TechnologyHangzhou 310014ZhejiangChina College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035ZhejiangChina Received 18 April 2023Revised 30 May 2023Accepted 31

High-temperature proton exchange membrane fuel cells(HT-PEMFC) possess distinct technical advantages of high output power, simplified water/heat management, increased tolerance to fuel impurities and diverse fuel sources, within the temperature range of 120–200 ℃. However, for practical automobile applications, it was crucial to broaden their low-temperature operating window and enable cold start-up capability. Herein, gel-state phosphoric acid(PA) doped sulfonated polybenzimidazole(PBI) proton exchange membranes(PEMs) were designed and synthesized via PPA sol-gel process and in-situ sultone ring-opening reactions with various proton transport pathways based on absorbed PA, flexible alkyl chain connected sulfonic acid groups and imidazole sites. The effects of flexible alkyl sulfonic acid side chain length and content on PA doping level, proton conductivity, and membrane stability under different temperature and relative humidity(RH) were thoroughly investigated. The prepared gel-state membranes contained a self-assembled lamellar and porous structure that facilitated the absorption of a large amount of PA with rapid proton transporting mechanisms. At room temperature, the optimized membrane exhibited a proton conductivity of 0.069 S cm^(-1), which was further increased to 0.162 and 0.358 S cm^(-1)at 80 and 200 ℃, respectively, without additional humidification. The most significant contribution of this work was demonstrating the feasibility of gel-state sulfonated PBI membranes in expanding HT-PEMFC application opportunities over a wider operating range of 25 to 240 ℃.

关键词： Wide temperature range Proton exchange membrane Fuel cell Gel-state Polybenzimidazole

Addressing the strength-ductility trade-off in a cast Al-Li-Cu alloy—Synergistic effect of Sc-alloying and optimized artificial ageing scheme

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Journal of Materials Science & Technology 2022年第1期96卷 212-225页

作者： Jinshuo zhang Guohua Wu Liang Zhang Xiaolong zhang Chunchang Shi Xin Tong National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites School of Materials Science andEngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Innovation Institute for Materials Shanghai200444China

A dramatic improvement of strength and ductility of cast Al-2.5Li-1.5Cu-1Zn-0.5Mg-0.15 Zr alloy was obtained by the collaboration of Sc-alloying and optimized ageing scheme.Joint and independent influence of Sc-alloying and different ageing temperatures were investigated.The results revealed that a substantial increase was realized in the hardness of Sc-containing alloy,and the ageing response time was only influenced by ageing temperature.Coarse and heterogeneousδ'(Al_(3)Li),wideδ'-precipitation free zones(δ'-PFZs),and a large amount of T_(1)(Al_(2)CuLi)precipitates were observed in Sc-containing alloy aged at 175℃,which resulted in superior yield strength and poor elongation.The Sc-containing alloy obtained an excellent combination of ductility(elongation=8.2%)and tensile strength(ultimate strength=565 MPa)suffered to 150℃ ageing for 64 h.The increase in the elongation was mainly due to the combined effect of grain refining,much finerδ',and extremely narrowδ'-PFZs(<10 nm),while the higher strength was mainly attributed to the formation of Al_(3)(Sc,Zr,Li)composite particles and a large amount of S'(Al_(2)CuMg)phase.However,the enhancement of the different ageing temperature(150℃ and 175℃)on the mechanical properties of the alloys without Sc addition was not obvious.

关键词： Cast Al-Li-Cu alloy δ’-PFZs Mechanical properties Cu-containing phases Microstructure evolutions

On Treatment Patterns for Modeling Medical Treatment Processes in Clinical Practice Guidelines

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China Communications 2021年第11期18卷 197-209页

作者： Liqin Yang Liang Zhang School of Computer Science Fudan UniversityShanghai 200438China Shanghai Key Laboratory of Data Science Shanghai 200438China Institute of Intelligent Electronics and Systems Shanghai 200438China Computer Teaching and Research Section Shanghai University of Traditional Chinese MedicineShanghai 201203China

Clinical practice guidelines(CPGs)contain evidence-based and economically reasonable medical treatment processes.Executable medical treatment processes in healthcare information systems can assist the treatment processes.To this end,business process modeling technologies have been exploited to model medical treatment processes.However,medical treatment processes are usually flexible and knowledge-intensive.To reduce the effort in modeling,we summarize several treatment patterns(i.e.,frequent behaviors in medical treatment processes in CPGs),and represent them by three process modeling languages(i.e.,BPMN,DMN,and CMMN).Based on the summarized treatment patterns,we propose a pattern-based integrated framework for modeling medical treatment processes.A modeling platform is implemented to support the use of treatment patterns,by which the feasibility of our approach is validated.An empirical analysis is discussed based on the coverage rates of treatment patterns.Feedback from interviewed physicians in a Chinese hospital shows that executable medical treatment processes of CPGs provide a convenient way to obtain guidance,thus assisting daily work for medical workers.

关键词： clinical practice guidelines treatment patterns process modeling BPMN DMN CMMN

Multimodal Pretraining from Monolingual to Multilingual

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Machine Intelligence Research 2023年第2期20卷 220-232页

作者： Liang Zhang Ludan Ruan Anwen Hu Qin Jin School of Information Renmin University of ChinaBeijing 100872China

Multimodal pretraining has made convincing achievements in various downstream tasks in recent years.However,since the majority of the existing works construct models based on English,their applications are limited by language.In this work,we address this issue by developing models with multimodal and multilingual capabilities.We explore two types of methods to extend multimodal pretraining model from monolingual to multilingual.Specifically,we propose a pretraining-based model named multilingual multimodal pretraining(MLMM),and two generalization-based models named multilingual CLIP(M-CLIP)and multilingual acquisition(MLA).In addition,we further extend the generalization-based models to incorporate the audio modality and develop the multilingual CLIP for vision,language,and audio(CLIP4VLA).Our models achieve state-of-the-art performances on multilingual vision-text retrieval,visual question answering,and image captioning benchmarks.Based on the experimental results,we discuss the pros and cons of the two types of models and their potential practical applications.

关键词： Multilingual pretraining multimodal pretraining cross-lingual transfer multilingual generation cross-modal retrieval