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Exploring the effect of cooling rate on non-isothermal crystallization of copolymer polypropylene by fast scanning calorimetry

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China Foundry 2024年第4期21卷 379-386页

作者： Yang Liao ye-yuan Hu Kosuke Ikeda Ryoji Okabe Rui-fen Wu Ryota Ozaki qing-yan Xu Key Laboratory for Advanced Materials Processing Technology School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Composite Laboratory Research&Innovation Center Mitsubishi Heavy Industries Ltd.Nagasaki 8510392Japan

Polypropylene is commonly used as a binder for ceramic injection molding,and rapid cooling is often encountered during ***,the crystallization behavior of polypropylene shows a strong dependence on cooling rate due to its semi-crystalline ***,the influence of cooling rate on the quality of final product cannot be *** this study,the fast differential scanning calorimetry(FSC)test was performed to study the influence of cooling rate on the non-isothermal crystallization behavior and non-isothermal crystallization kinetics of a copolymer polypropylene(PP BC03B).The results show that the crystallization temperatures and crystallinity decrease as the cooling rate *** addition,two exothermic peaks occur when cooling rate ranges from 30 to 300 K·s^(-1),indicating the formation of another crystal ***,Ozawa and Mo equations were used to explore the non-isothermal crystallization kinetics,and it can be concluded that the Mo method is suitable for this study.

关键词： cooling rate crystallization temperature crystallinity non-isothermal crystallization kinetics FSC copolymer polypropylene

Enhancing Generic Reaction Yield Prediction through Reaction Condition-Based Contrastive Learning

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Research 2024年第3期 685-702页

作者： Xiaodan Yin chang-Yu Hsieh Xiaorui Wang Zhenxing Wu qing ye Honglei Bao Yafeng Deng Hongming Chen Pei Luo Huanxiang Liu Tingjun Hou Xiaojun Yao Dr.Neher’s Biophysics Laboratory for Innovative Drug Discovery State Key Laboratory of Quality Research in Chinese MedicineMacao Institute for Applied Research in Medicine and HealthMacao University of Science and TechnologyMacao 999078China Innovation Institute for Artificial Intelligence in Medicine of Zhejiang University College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China. Faculty of Applied Sciences Macao Polytechnic UniversityMacao 999078China. CarbonSilicon AI Technology Co.Ltd HangzhouZhejiang 310018China Center of Chemistry and Chemical Biology Guangzhou Regenerative Medicine and Health Guangdong LaboratoryGuangzhou 510530China.

Deep learning(DL)-driven efficient synthesis planning may profoundly transform the paradigm for designing novel pharmaceuticals and ***,the progress of many DL-assisted synthesis planning(DASP)algorithms has suffered from the lack of reliable automated pathway evaluation *** a critical metric for evaluating chemical reactions,accurate prediction of reaction yields helps improve the practicality of DASP algorithms in the real-world ***,accurately predicting yields of interesting reactions still faces numerous challenges,mainly including the absence of high-quality generic reaction yield datasets and robust generic yield *** compensate for the limitations of high-throughput yield datasets,we curated a generic reaction yield dataset containing 12 reaction categories and rich reaction condition ***,by utilizing 2 pretraining tasks based on chemical reaction masked language modeling and contrastive learning,we proposed a powerful bidirectional encoder representations from transformers(BERT)-based reaction yield predictor named *** achieved comparable or even superior performance to the best previous models on 4 benchmark datasets and established state-of-the-art performance on the newly curated *** found that reaction-condition-based contrastive learning enhances the model’s sensitivity to reaction conditions,and Egret is capable of capturing subtle differences between reactions involving identical reactants and products but different reaction ***,we proposed a new scoring function that incorporated Egret into the evaluation of multistep synthesis *** results showed that yield-incorporated scoring facilitated the prioritization of literature-supported high-yield reaction pathways for target *** addition,through meta-learning strategy,we further improved the reliability of the model’s prediction for reaction types with limited data and lower data *** r

关键词： synthesis generic holds

Synthesis of Planar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine Ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

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Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang qing-Xian Xie Xiang Li chang-Bin Yu Yong-Gui Zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The planar-chiral ligands have been widely applied as a class of unique and significant ligands in asymmetric *** them,chiral[2.2]paracycyclophane has emerged as a privileged type of planar-chiral framework and has been utilized as an important toolbox due to their structural ***,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and large steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%***,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Planar chirality Nickel Hydroboration Asymmetric synthesis

Potential effects of aerosol generation and transmission during bedside endoscope cleaning

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第7期25卷 628-632页

作者： Tingting SHENG Xin WU Li CEN ye LU Chenying ZHOU qing GU Nursing Department the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Department of Gastroenterology the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Zhejiang Provincial Center for Disease Control and Prevention Hangzhou 310051China

Airborne transmission is among the most frequent types of nosocomial *** years have witnessed frequent outbreaks of airborne diseases,such as severe acute respiratory syndrome(SARS)in 2002,Middle East respiratory syndrome(MERS)in 2012,and coronavirus disease 2019(COVID-19),with the latter being on the rampage since the end of 2019 and bringing the effect of aerosols on health back to the fore(Gralton et al.,2011;Wang et al.,2021).An increasing number of studies have shown that certain highly transmissible pathogens can maintain long-term stability and efficiently spread through aerosols(Leung,2021;Lv et al.,2021).As reported previously,influenza viruses that can spread efficiently through aerosols remain stable for a longer period compared to those that *** World Health Organization(WHO)has stated that aerosol-generating procedures(AGPs)play an important role in aerosol transmission in hospitals(Calderwood et al.,2021).AGPs,referring to medical procedures that produce aerosols,including dental procedures,endotracheal intubation,sputum aspiration,and laparoscopic surgeries,have been reported to be significantly associated with an increased risk of nosocomial infection among medical personnel(Hamilton,2021).

关键词： Endoscopy Endoscopic surgery Aerosol transmission Bedside endoscope precleaning

Monitoring Multi-Temporal changes of Lakes on the Tibetan Plateau Using Multi-Source Remote Sensing Data from 1992 to 2019: A Case Study of Lake Zhari Namco

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Journal of Earth Science 2024年第5期35卷 1679-1691页

作者： Juan Wu chang-qing Ke Yu Cai Zheng Duan Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural ResourcesSchool of Geography and Ocean ScienceNanjing University Collaborative Innovation Center of Novel Software Technology and Industrialization Guangxi Water and Power Design Institute Co. Ltd Collaborative Innovation Center of South China Sea Studies Department of Physical Geography and Ecosystem Science Lund University

Lake level, area and volume are sensitive indicators of climate change. At present, many studies have focused on the interannual water balance of lakes, but lake level and area can change remarkably with seasons, especially for lakes with seasonal ice cover. Zhari Namco, a seasonal frozen lake, was selected as an example to investigate its seasonal water balance. Multi-source altimetry and Landsat data were used to obtain the seasonal lake level and area from 1992 to 2019, and seasonal lake volume variations were also estimated. The results indicated the average lake level, area and volume in autumn were the largest. The lake level, area, and volume experienced three turning points approximately in 2000, 2010, and 2016, and showed an overall increasing trend from 1992 to 2019, with slopes of 0.15 m/year, 2.17 km2/year, and 0.14 km3/year, respectively. The lake area expanded significantly in autumn, which was related to the abundant precipitation. Delay time of land surface runoff, increased temperature, and evaporation may be the reason for the low lake level and volume in summer. The precipitation was the dominant factor of water balance, which explained 62.09%, 62.43%, and 62.10% of the variations in lake level, area, and volume, respectively.

关键词： lake level lake area lake volume satellite altimetry landsat Zhari Namco hydrogeology

Research on the Icing Diagnosis ofWind Turbine Blades Based on FS–XGBoost–EWMA

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Energy Engineering 2024年第7期121卷 1739-1758页

作者： Jicai Guo Xiaowen Song chang Liu Yanfeng Zhang Shijie Guo JianxinWu chang Cai qing’an Li College of Mechanical Engineering Inner Mongolia University of TechnologyHohhot010051China Inner Mongolia Key Laboratory of Special Service Intelligent Robotics Hohhot010051China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China

In winter,wind turbines are susceptible to blade icing,which results in a series of energy losses and safe operation ***,blade icing detection has become a top *** methods primarily rely on sensor monitoring,which is expensive and has limited ***-driven blade icing detection methods have become feasible with the development of artificial ***,the data-driven method is plagued by limited training samples and icing samples;therefore,this paper proposes an icing warning strategy based on the combination of feature selection(FS),eXtreme Gradient Boosting(XGBoost)algorithm,and exponentially weighted moving average(EWMA)*** the training phase,FS is performed using correlation analysis to eliminate redundant features,and the XGBoost algorithm is applied to learn the hidden effective information in supervisory control and data acquisition analysis(SCADA)data to build a normal behavior *** the online monitoring phase,an EWMA analysis is introduced to monitor the abnormal changes in features.A blade icing warning is issued when themonitored features continuously exceed the control limit,and the ambient temperature is below 0℃.This study uses data fromthree icing-affected wind turbines and one normally operating wind turbine for *** experimental results reveal that the strategy can promptly predict the icing trend among wind turbines and stably monitor the normally operating wind turbines.

关键词： Wind turbine blade icing feature selection XGBoost EWMA

Ultraconformable Integrated Wireless Charging Micro-Supercapacitor Skin

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Nano-Micro Letters 2024年第7期16卷 46-58页

作者： chang Gao qing You Jiancheng Huang Jingye Sun Xuan Yao Mingqiang Zhu Yang Zhao Tao Deng School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044People’s Republic of China School of Microelectronics Tianjin UniversityTianjin 300072People’s Republic of China Key Laboratory of Cluster Science Ministry of Education of China Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081People’s Republic of China

Conformable and wire-less charging energy storage devices play important roles in enabling the fast development of wearable,non-contact soft ***,current wire-less charging power sources are still restricted by limited flexural angles and fragile connection of components,resulting in the failure expression of performance and constraining their fur-ther applications in health monitoring wearables and moveable artificial ***,we present an ultracompatible skin-like integrated wireless charging micro-supercapacitor,which building blocks(including electrolyte,electrode and substrate)are all evaporated by liquid *** to the infiltration and permeation of the liquid,each part of the integrated device attached firmly with each other,forming a compact and all-in-one *** addition,benefitting from the controllable volume of electrode solution precursor,the electrode thickness is easily regulated varying from 11.7 to 112.5μ*** prepared thin IWC-MSC skin can fit well with curving human body,and could be wireless charged to store electricity into high capacitive micro-supercapacitors(11.39 F cm-3)of the integrated *** believe this work will shed light on the construction of skin-attachable electronics and irregular sensing microrobots.

关键词： Micro-supercapacitor Electronic skin Supercapacitor skin Wireless charging energy storage device

Targeted multi-agent communication algorithm based on state control

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Defence Technology（防务技术） 2024年第1期31卷 544-556页

作者： Li-yang Zhao Tian-qing chang Lei Zhang Jie Zhang Kai-xuan Chu De-peng Kong Department of Weaponry and Control Army Academy of Armored ForcesBeijing100072China Unit 92942 Beijing100161China

As an important mechanism in multi-agent interaction,communication can make agents form complex team relationships rather than constitute a simple set of multiple independent ***,the existing communication schemes can bring much timing redundancy and irrelevant messages,which seriously affects their practical *** solve this problem,this paper proposes a targeted multiagent communication algorithm based on state control(SCTC).The SCTC uses a gating mechanism based on state control to reduce the timing redundancy of communication between agents and determines the interaction relationship between agents and the importance weight of a communication message through a series connection of hard-and self-attention mechanisms,realizing targeted communication message *** addition,by minimizing the difference between the fusion message generated from a real communication message of each agent and a fusion message generated from the buffered message,the correctness of the final action choice of the agent is *** evaluation using a challenging set of Star Craft II benchmarks indicates that the SCTC can significantly improve the learning performance and reduce the communication overhead between agents,thus ensuring better cooperation between agents.

关键词： Multi-agent deep reinforcement learning State control Targeted interaction Communication mechanism

Morphological and Sulfur-Isotopic Characteristics of Pyrites in the Deep Sediments from Xisha Trough,South China Sea

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Journal of Ocean University of China 2024年第1期23卷 138-148页

作者： chang Jingyi LIU Yujia LU Hailong LU Jing’an SU Xin ye Jianliang XIE Wenwei College of Engineering Peking UniversityBeijing 100871China Beijing International Center for Gas Hydrate School of Earth and Planetary SciencesPeking UniversityBeijing 100871China School of Marine Science Nanjing University of Information Science and TechnologyNanjing 210044China MLR Key Laboratory of Marine Mineral Resources Guangzhou Marine Geological SurveyMinistry of Land and ResourcesGuangzhou 510075China School of Ocean Sciences China University of GeosciencesBeijing 100083China

Pyrite is one of the common authigenic minerals in marine *** studies have shown that the morphological and isotopic characteristics of pyrite are closely related to the geochemical environment where it is *** better understand the for-mation mechanism of authigenic pyrite,we analyzed the isotopic composition,morphology,and distribution of pyrite in the sediment at 500m below the seafloor from Xisha Trough,South China *** morphologies were observed by scanning electron micros-copy and Raman spectrography.X-Ray computed tomography was applied to measure the particle size of *** size of pyrite crystals in the matrix sediment mainly ranged between 25 and 65µm(***.40µm),although crystals were larger(***.50μm)in the *** pyrites had a fine-grained truncated octahedral shape with occasionally well-developed growth steps,which implies the low growth rate and weak anaerobic oxidation of methane-sulfate reduction when pyrite was ***δ^(34)S values of pyrites ranged from+20.8‰Vienna-defined Canyon Diablo Troilite(V-CDT)to+33.2‰V-CDT and from+44.8‰V-CDT to+48.9‰,which suggest two growth *** the first stage,with the continuous low methane flux,the pyrite possibly formed in an environment with good access to *** the second stage,the pyrites mainly developed in sediment fractures and appeared in veins,probably due to the limited availability of *** less exposure of pyrite to the environment in the second stage was probably caused by sediment accumulation or *** this study,an episodic pyritization process was identified,and the paleoenvironment was reconstructed for the sediment investigated.

关键词： pyrite sulfur isotope AOM methane flux Xisha Trough South China Sea