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Effect of Star-shaped Chain Architectures on the Polylactide Stereocomplex Crystallization Behaviors

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Chinese Journal of Polymer Science 2017年第8期35卷 974-991页

作者： Ke-yu Zhou 李建波 han-xuan wang 任杰 Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and Engineering Tongji University Shanghai 200092 China Institute of Nano and Bio-Polymeric Materials School of Material Science and Engineering Tongji University Shanghai 201804 China

Linear and star-shaped polylactides（PLA） with similar molecular weights of each arm are synthesized via ringopening polymerization of LA with 3-butyn-1-ol and pentaerythritol as initiators,*** solution blending of equivalent mass of poly（L-lactic acid）s（PLLAs） and poly（D-lactic acid）s（PDLAs）,perfect PLA stereocomplexes（sc PLAs） are prepared and confirmed by WAXD and FTIR *** of chain architectures on stereocomplex crystallization is investigated by studying the non-isothermal and isothermal crystallization of linear and star-shaped polylactide *** dynamic DSC and POM test,star-shaped PLLA（4s PLLA）/PDLA and PLLA/star-shaped PDLA（4s PDLA） stereocomplexes reach rapid crystallization and higher crystallinity due to larger spherulite density of star-shaped chain and excellent chain mobility of linear *** isothermal crystallization test,much faster crystallization and less crystallization half-time is obtained with the increase of star-shaped ***,4s PLLA/PDLA and PLLA/4s PDLA are found to have the highest crystallinity,suggesting limitation of too much star-shaped chain for 4s PLLA/4s PDLA and restriction of linear chain in nucleation capacity for PLLA/*** results reveal that star-shaped chain has an important influence on the crystallization of sc PLAs.

关键词： shaped PLLA crystallinity nucleation WAXD lactic polymerization heating isothermal perfect

Characterizations of gas-liquid interface distribution and slug evolution in a vertical pipe

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Petroleum Science 2023年第5期20卷 3157-3171页

作者： Hai-Yang Yu Qiang Xu Ye-Qi Cao Bo Huang han-xuan wang Lie-Jin Guo State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi’an710049ShaanxiChina

Large vertical pipes are key structures connecting subsea wells to offshore ***,existing studies mainly focus on small vertical *** a vertical acrylic pipe with 80 mm inner diameter and 11 m height,a high-speed camera was used to visually research the influences of pipe diameters,liquid properties and inlet effect on air-water co-flow *** flow regime maps of vertical pipes(diameters are in the range of 50e189 mm)were compared and the critical gas velocity of the transition boundary from bubble to slug flow tended to increase with the increase of diameters at D≥80 ***-flux models were established in different flow regimes and liquid properties have a significant effect on drift coefficients of bubble flow and slug flow(void fraction a≤0.4).The influence of inlet turbulent effect on the gas-liquid interface distribution gradually weakened and disappeared from the pipe base to 85D,where the flow was fully *** frequency has a trend of increase first and then decrease with the gas Weber numbers increasing at low liquid superficial velocities(J_(L)≤0.31 m/s).And on the basis of this law,a new slug frequency correlation was *** was found that there was an exponential relationship between the ratio of lengths of Taylor bubble to slug and the void fraction.

关键词： Void fraction Flow regime Drift coefficien Slug frequency Taylor bubble length

Protective Effects of Different Hypothermal Preservation Solutions on Structure and Function of Isolated Rat Arteries

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当代医学科学(英文) 2023年第4期43卷 768-778页

作者： Zhang-yong REN Shao-cheng LYU han-xuan wang Jing wang Lin ZHOU Qiang HE Ren LANG Department of Hepatobiliary and Pancreaticosplenic Surgery Beijing Organ Transplant CenterBeijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China

Objective:With the increasing application of vascular reconstruction in surgical procedures,allogeneic vessels are becoming more popular in clinical practice due to their abundant sources,precise diameter matching,improved histocompatibility,and higher long-term patency *** study aimed to investigate the protective effect of various preservation solutions on the function and structure of the isolated rat abdominal aorta preserved under hypothermal ***:The study utilized a total of 150 Sprague-Dawley(SD)rats,with 144 rats allocated to the experimental groups and 6 rats allocated to the control *** abdominal aorta of the rats was chosen as the subject of our *** aorta in the experimental groups were randomly assigned to 4 groups:University of Wisconsin(UW)solution group,histidine-tryptophan-ketoglutarate(HTK)solution group,normal saline(NS)group,and sodium lactate Ringer's solution(RS)*** were subjected to examination after preservation periods of 1 day,3 days,5 days,7 days,14 days,30 days,and 90 *** of vascular physiological function involved detecting and assessing vasoconstriction ability and measuring cell viability through the MTT *** of the vascular wall structure involved tension tolerance tests and pathological ***:The pathogen-positive rate in the HTK group and NS group at 1 month was 16.7%.Regarding the vascular skeleton structure,both the UW group and HTK group exhibited intact structures after 2 weeks of preservation,with slightly edematous collagen and elastic fibers,which was significantly better than that of the NS group and RS *** terms of cell activity and contractile function,all preservation groups showed similar effects within 2 ***,after 2 weeks,the UW group showed the most favorable preservation effect(P<0.05).In terms of vascular tension,different groups exhibited similar effects within 1 ***,after 2 weeks,the UW group showed the best pres

关键词： rat model allogeneic artery preservation solution vascular preservation technique vascular reconstruction

Clinical value of extended lymphadenectomy in radical surgery for pancreatic head carcinoma at different T stages

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World Journal of Gastrointestinal Surgery 2022年第11期14卷 1204-1218页

作者： Shao-Cheng Lyu han-xuan wang Ze-Ping Liu Jing wang Jin-Can Huang Qiang He Ren Lang Department of Hepatobiliary and Pancreaticosplenic Surgery Beijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China School of Biomedicine Bejing City UniversityBeijing 100084China

BACKGROUND As the lymph-node metastasis rate and sites vary among pancreatic head carcinomas(PHCs)of different T stages,selective extended lymphadenectomy(ELD)performance may improve the prognosis of patients with *** To investigate the effect of ELD on the long-term prognosis of patients with PHC of different T *** We analyzed data from 216 patients with PHC who underwent surgery at our hospital between January 2011 and December *** patients were divided into extended and standard lymphadenectomy(SLD)groups according to extent of lymphadenectomy and into T1,T2,and T3 groups according to the 8 th edition of the American Joint Committee on Cancer’s staging *** data and prognoses were compared among *** factors associated with prognoses were identified through univariate and multivariate *** The 1-,2-and 3-year overall survival(OS)rates in the extended and SLD groups were 69.0%,39.5%,and 26.8%and 55.1%,32.6%,and 22.1%,respectively(P=0.073).The 1-,2-and 3-year disease-free survival rates in the extended and SLD groups of patients with stage-T3 PHC were 50.3%,25.1%,and 15.1%and 22.1%,1.7%,and 0%,respectively(P=0.025);the corresponding OS rates were 65.3%,38.1%,and 21.8%and 36.1%,7.5%,and 0%,respectively(P=0.073).Multivariate analysis indicated that portal vein invasion and lymphadenectomy extent were risk factors for prognosis in patients with stage-T3 *** ELD may improve the prognosis of patients with stage-T3 PHC and may be of benefit if performed selectively.

关键词： Pancreatic head carcinoma Extended lymphadenectomy T stage Surgical treatment Risk factor Long-term prognosis

Recent progress in carbene-catalyzed fluoroalkylation

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Science China Chemistry 2024年第8期67卷 2448-2460页

作者： Bei Zhang xuan Zhang Jian wang Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China

The fluoroalkyl fragment plays a vital role in various fields such as pharmaceuticals and materials science, and has a significant impact on human life not only on the present but also in the future. The insertion of fluoroalkyl groups into the chemical skeletons can cause considerable alternations in the chemical, physical and biological properties of molecules, which has attracted numerous scientists from different fields. This review focuses on N-heterocyclic carbene(NHC)-catalyzed fluoroalkylation reactions, providing a detailed analysis and summary of the achievements in the past two decades. Many successful examples clearly indicate that NHCs can catalyze the tranformation of fluoroalkylation reagents with various electronic characteristics, whether electrophilic, nucleophilic, or radical precursors. Herein, the fluoroalkylation reactions are classified based on different catalytic modes of NHCs: Lewis base catalysis, Umploung catalysis, radical catalysis and others. Meanwhile, by refining and systematically studying the contribution of NHC catalysis in fluoroalkylation reactions, this review is expected to provide valuable insights and enlightenment for related fields.

关键词： N-heterocyclic carbene fluoroalkylation radical catalysis

Features and formulae of sediment incipient motion in vegetated flow environment

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Journal of Hydrodynamics 2024年第2期36卷 331-339页

作者： Yu-xuan Xu Wei-jie wang Shi-bao Zhang han-qing Zhao Xue-kai Chen Hai-ping Zhang School of Water Conservancy North China University of Water Resources and Electric PowerZhengzhou450045China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing100038China China Three Gorges Corporation Wuhan430010China

Aquatic vegetation is a vital component of natural river ecosystems,playing a crucial role in maintaining ecological balance,providing habitat and improving water ***,the presence of vegetation results in increased resistance in vegetated channels compared with non-vegetated channels,rendering traditional sediment movement predictions inadequate for the ***,the concept of a vegetation influence factor,denoted by CDah,has been proposed by previous researchers to represent the effect of vegetation on sediment movement in *** this study,we focus on exploring the vegetation resistance coefficient(CD)among the vegetation influence factors,evaluating two different calculation methods for vegetation resistance coefficient,and presenting two expressions through genetic algorithm analysis to predict the incipient flow velocity of sediment in vegetated *** predicted values from the new formulae show excellent agreement with measured data,highlighting the high accuracy of the proposed methods in predicting the incipient flow velocity of *** results provide a solid theoretical basis for understanding the influence of aquatic vegetation on sediment particle movement.

关键词： Vegetation flow vegetation resistance coefficient genetic algorithm sediment initiation

Effective Activation of Melamine for Synchronous Synthesis of Catalytically Active Nanosheets and Fluorescence-Responsive Quantum Dots

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Transactions of Tianjin University 2024年第3期30卷 284-296页

作者： Jie xuan Guijian Guan Ming-Yong han Institute of Molecular Plus Tianjin UniversityTianjin 300072China

Because of the low reactivity of cyclic nitrides,liquid-phase synthesis of carbon nitride introduces challenges despite its favorable potential for energy-efficient preparation and superior *** this study,we demonstrate a strong interaction between citric acid and melamine through experimental observation and theoretical simulation,which eff ectively activates melamine-condensation activity and produces carbon-rich carbon nitride nanosheets(CCN NSs)during hydrothermal *** a large specific surface area and increased light absorption,these CCN NSs demonstrate significantly enhanced photocatalytic activity in CO_(2) reduction,increasing the CO production rate by approximately tenfold compared with hexagonal melamine(h-Me).Moreover,the product selectivity of CCN NSs reaches up to 93.5%to generate CO from CO_(2).Furthermore,the annealed CCN NSs exhibit a CO conversion rate of up to 95.30μmol/(g h),which indicates an 18-fold increase compared with traditional carbon *** the CCN NS synthesis,nitrogen-doped carbon quantum dots(NDC QDs)are simultaneously produced and remain suspended in the supernatant after *** QDs disperse well in water and exhibit excellent luminescent properties(QY=67.2%),allowing their application in the design of selective and sensitive sensors to detect pollutants such as pesticide 2,4-dichlorophenol with a detection limit of as low as 0.04μmol/***,the simultaneous synthesis of CCN NSs and NDC QDs provides a cost-eff ective and highly efficient process,yielding products with superior capabilities for catalytic conversion of CO_(2) and pollutant detection,respectively.

关键词： Carbon nitride Hydrothermal reaction Photocatalysis Carbon dioxide Quantum dots

Escape probability for isotropic emitters near Kerr black hole with astrometric

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Communications in Theoretical Physics 2024年第5期76卷 128-133页

作者： Yu-xuan han Qing-Hua Zhu Qing-Guo Huang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesNo.19A Yuquan RoadBeijing 100049China Department of Physics Chongqing UniversityChongqing 401331China School of Fundamental Physics and Mathematical Sciences hangzhou Institute for Advanced Study UCASHangzhou 310024China

The paper investigates the escape probability for isotropic emitters near a Kerr black *** propose a new approach to obtain the escape probability in a general manner,going beyond previous case-by-case *** approach is based on studies of the black hole shadow with astrometric observable and can be applied to emitters with an arbitrary 4-velocities and locations,even to the emitters outside of the equatorial *** also consider representative examples illustrating how escape probabilities vary with distance,velocity,and inclination ***,this new approach provides an effective method for studying escape probabilities near Kerr black holes.

关键词： Kerr black hole photon escape probability isotropic emitters

When Does Sora Show:The Beginning of TAO to Imaginative Intelligence and Scenarios Engineering

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 809-815页

作者： Fei-Yue wang Qinghai Miao Lingxi Li Qinghua Ni xuan Li Juanjuan Li Lili Fan Yonglin Tian Qing-Long han School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory for Management and Control of Complex Systems Chinese Academy of SciencesBeijing 100190China Faculty of Innovation Engineering Macao University of Science and TechnologyMacao 999078China Department of Electrical and Computer Engineering Indiana University-Purdue University IndianapolisIndianapolisIN 46202USA Faculty of Innovation Engineering Macao University of Science and TechnologyMacao 999078China Virtual Reality Fundamental Research Laboratory Department of Mathematics and TheoriesPeng Cheng LaboratoryShenzhen 518000China State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia

DURING our discussion at workshops for writing“What Does ChatGPT Say:The DAO from Algorithmic Intelligence to Linguistic Intelligence”[1],we had expected the next milestone for Artificial Intelligence(AI)would be in the direction of Imaginative Intelligence(II),i.e.,something similar to automatic wordsto-videos generation or intelligent digital movies/theater technology that could be used for conducting new“Artificiofactual Experiments”[2]to replace conventional“Counterfactual Experiments”in scientific research and technical development for both natural and social studies[2]-[6].Now we have OpenAI’s Sora,so soon,but this is not the final,actually far away,and it is just the beginning.

关键词： something Intelligence replace