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Synthesis of Fluorene-Bridged Arylene Vinylene Fluorophores： Effects of End-Capping Groups on the Optical Properties, Aggregation Induced Emission

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Chinese Journal of Chemistry 2015年第8期33卷 939-947页

作者： guo-Feng Zhang Tao chen ze-Qiang chen Matthew P. Aldred Xianggao Meng Ming-Qiang Zhu Wuhan National Laboratory for Optoelectronics School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan Hubei 430074 China Department of Chemistry Durham University South Road Durham DH1 3LE UK Key Laboratory of Pesticide and Chemical Biology of Ministry of Education College of Chemistry Central China Normal University Wuhan Hubei 430079 China

We have synthesized a series of fluorene-based fluorophores, in which a central fluorene core has been modified with different peripheral arylene vinylene substituents that are able to activate aggregation-induced emission （AIE） characteristics. 9,9-Dioctylfluorene doubly end-capped at the 2,7-positions with triphenylethene groups, such as 4-（2,2-diphenylvinyl）phenyl （F1-（2,2）-HTPE） and 4-（1,2-dipbenylvinyl）phenyl （F1-（1,2）-HTPE） were synthesized and compared to the tetraphenylethene analogue （F1-TPE）. Both FI-（2,2）-HTPE and F1-（1,2）-HTPE glow with a deep blue fluorescence in THF solution with emission maxima （λem） of 426 and 403 nm, respectively. The λem slightly red-shifts in the solid-state to 458 nm for F 1-（2,2）-HTPE and 437 nm for F 1-（1,2）-HTPE. The fluorescence quantum yields （ΦF） of F1-（2,2）-HTPE （ΦF=35.1%） and FI-（1,2）-HTPE （ΦF=26.2%） were found to be higher in solution compared to the near quenching of F 1-TPE （ΦF = 0.1%）. Consequently, this results in weaker AIE-stability of F1-（2,2）-HTPE （αAIE= 1.5） and F1-（1,2）-HTPE （αAIE=1.9） compared to F1-TPE （αAIE=125）, suggesting that four phenyl groups are necessary for efficient AIE-activity of these fluorene bridged arylene vinylene type materials In addition, decreasing the steric hindrance around the arylene vinylene moiety by removal of a phenyl ring is an- other method to decrease the AIE characteristics, in a similar manner to the commonly known ＂phenyl-locking＂. Non-polar triphenylethenes are poorer AlE materials than their tetraphenylethene analogues. Replacing the hydro- gen atom of F1-（2,2）-HTPE with a cyano group affords fluorene end-capped with 2,3,3-triphenylacrylonitrile （F1-TPAN）, which boosts the AIE-effect to αAIE=90.5 and red-shifts the solid-state emission （λem=528 nm） with near quenching in THF solution （ΦF= 0.12%）. X-ray crystallographic analysis of F1-TPAN indicates that the intro- duction of cyano groups can not only diminish the intramolecular steric hindrance in comparison of F1-TPE, but

关键词： aggregation-induced emission fluorene triphenylethene tetraphenylethene 2,3,3-triphenylacrylonitrile

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Potential Benefits of Green Tea in Prostate Cancer Prevention and Treatment:A Comprehensive Review

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Chinese Journal of Integrative Medicine 2024年第11期30卷 1045-1055页

作者： LIU Gui-hong YAO ze-qin chen guo-qiang LI Ya-lang LIANG Bing Department of Urology Sanya Central Hospital(The Third People's Hospital of Hainan Province)Sanya CityHainan Province 572000China Department of Urology Yuzhou People's HospitalXuchang CityHenan Province 461670China

Prostate cancer is a prevalent and debilitating disease that necessitates effective prevention and treatment *** tea,a well-known beverage derived from the Camellia sinensis plant,contains bioactive compounds with potential health benefits,including catechins and *** comprehensive review aims to explore the potential benefits of green tea in prostate cancer prevention and treatment by examining existing *** tea possesses antioxidant,anti-inflammatory,and anti-carcinogenic properties attributed to its catechins,particularly epigallocatechin *** studies have reported an inverse association between green tea consumption and prostate cancer risk,with potential protection against aggressive forms of the *** studies demonstrate that green tea components inhibit tumor growth,induce apoptosis,and modulate signaling pathways critical to prostate cancer development and *** trials and human studies further support the potential benefits of green *** tea consumption has been found to be associated with a reduction in prostate-specific antigen levels,tumor markers,and played a potential role in slowing disease ***,challenges remain,including optimal dosage determination,formulation standardization,and conducting large-scale,long-term clinical *** review suggests future research should focus on combinatorial approaches with conventional therapies and personalized medicine strategies to identify patient subgroups most likely to benefit from green tea interventions.

关键词： green tea prostate cancer prevention treatment epigallocatechin gallate review

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Thermodynamics and phase transformations in the recovery of zinc from willemite

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1373-1379页

作者： Feng chen Wei chen Yu-feng guo Shuai Wang Fu-qiang Zheng Tao Jiang ze-qiang Xie Ling-zhi Yang School of Minerals Processing and Bioengineering Central South University

Willemite is a common component of zinc and lead metallurgical slags that, in the absence of effective utilization methods, cause serious environmental problems. To solve this problem and increase zinc recovery, we proposed a novel extraction method of zinc from willemite by calcified roasting followed by leaching in NH_4 Cl–NH_3·H_2 O solution. The thermodynamics and phase conversion of Zn_2 Si O_4 to zinc oxide(ZnO) during calcified roasting with CaO were investigated. The mechanism of mineralogical phase conversion and the effects of the CaO-to-Zn_2 Si O_4 mole ratio(n(Ca O)/n(Zn_2 Si O_4)), roasting temperature, and the roasting time on zinc-bearing phase conversion were experimentally investigated. The results show that Zn_2 Si O_4 was first converted to Ca_2 Zn Si_2 O_7 and then to ZnO. The critical step in extracting zinc from willemite is the conversion of Zn_2 Si O_4 to ZnO. The zinc percent leached in the ammonia leaching system rapidly increased because of the gradual complete phase conversion from willemite to ZnO via the calcified roasting process.

关键词： willemite zinc residues calcified-roasting thermodynamics mineralogical phase conversion

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Ultra-broadband metamaterial absorber using slotted metal loops with multi-layers and its anti-reflection analysis

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The Journal of China Universities of Posts and Telecommunications 2015年第5期22卷 41-44页

作者： Yu ze Lu Guizhen guo Qingxin School of Telecommunication Engineering Communication University of China

An ultra-thin and broadband absorber which consists of periodic rings with gaps is proposed in this paper. The periodic rings are printed on the middle metallic layers in a four-layer substrate of total thickness is only 3.4 mm. Simulation results, which are gotten by using finite element method(FEM) and finite-difference time-domain(FDTD), show that the absorption is higher than 90% cover the frequencies range from 7.8 GHz to 22.2 GHz. The measurement results of the absorption agree with simulated ones very well. We also discuss the working mechanism according to the anti-reflection theory in the paper.

关键词： metamaterial broadband anti-reflection periodicstr

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Spraying Arginine at 5 Days before Harvest Delays Postharvest Broccoli Senescence via Nutrient Accumulation

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食品科学 2025年第1期46卷 131-141页

作者： SUN Yupeng chen Ying SHANG Qingwen guo Yanyin ZHANG Yuxiao WANG Yunqiao XUE Qingyue College of Agricultural Engineering and Food Science Shandong University of TechnologyZibo 255049China Zichuan District Agricultural and Rural Affairs Service Center Zibo 255049China

To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before *** appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of *** results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli ***,during the growth stage,total sugar accumulation was higher in the 5-ARG *** addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest *** conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of ***,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.

关键词： arginine broccoli preharvest spraying nutrient accumulation storage quality postharvest senescence

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Some Explorations on Two Conjectures About Rademacher Sequences

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Acta Mathematicae Applicatae Sinica 2021年第1期37卷 1-16页

作者： ze-chun HU guo-lie LAN Wei SUN College of Mathematics Sichuan UniversityChengdu 610065China School of Economics and Statistics Guangzhou UniversityGuangzhou 510006China Department of Mathematics and Statistics Concordia UniversityMontreal H3G 1M8Canada

In this paper,we explore two conjectures about Rademacher ***(εi)be a Rademacher sequence,i.e.,a sequence of independent{-1,1}-valued symmetric random *** Sn=aiε1+…+anεn for a=(a1,…,an)∈*** first *** says that P(|Sn|≤‖a‖)>1/2 for all a∈Rn and n∈*** second conjecture says that P(|Sn|>‖a‖)≥7/32 for all a∈Rn and n∈*** the first conjecture,we present several new equivalent *** include a topological view,a combinatorial version and a strengthened version of the *** the second conjecture,we prove that it holds true when n<7.

关键词： Rademacher sequence Tomaszewaki’s constant Hitczenko and Kwapien’s constant

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Optimizing Strength and Ductility of Titanium Alloys by Oxygen: Review and Prospect

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Chinese Journal of Structural Chemistry 2020年第4期39卷 615-622页

作者： CAI ze-Yun LI Kun XIE guo-Qiang School of Materials Science and Engineering Harbin Institute of TechnologyShenzhen 518055China

The traditional strengthening elements of titanium alloys include Al,Mo,V,etc.,however,the high cost and toxicity of these elements put a limit on their further applications for *** light elements such as oxygen are hopeful replacement due to high *** is recognized that the oxygen enhances the strength but pays the price of brittleness,thus the amount of oxygen is ***,recent study results indicated that excess oxygen can keep high ductility together with high strength of *** paper reviews the influence and the mechanism of oxygen on the strength and ductility of titanium alloys,and provides a new perspective for the strengthening method of titanium alloys.

关键词： oxygen strength ductility titanium alloy

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Asymmetric multilayered MXene-Ag NWs/cellulose nanofiber composite films with antibacterial properties for high-efficiency electromagnetic interference shielding

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Journal of Materials Science & Technology 2022年第34期129卷 181-189页

作者： Fudong Zhang Penggang Ren Zhengzheng guo Jin Wang Zhengyan chen ze Zong Jie Hu Yanling Jin Fang Ren The Faculty of Printing Packaging Engineering and Digital Media TechnologyXi’an University of TechnologyXi’an 710048China School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China

Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films containing cellulose nanofiber(CNF) layers, CNF/MXene layers, and CNF/silver nanowires(CNF/Ag NWs)layers were fabricated by an efficient and easy-to-use vacuum filtration method. Compared with a uniformly mixed film, the resultant layered composite films that loaded with a low MXene and AgNWs content exhibit superior mechanical properties with a tensile strength of 137 MPa, a strain at break of 5.7%, excellent EMI shielding effectiveness(EMI SE) of 61.9 d B, and higher EMI SE/t of 20,653 d B cm^(-1).This is attributed to the high-performance CNF substrate, the highly efficient layered structures, and extensive hydrogen-bonding interactions. In particular, a high degree of ohmic loss of multiple interfaces and polarization relaxation of local defects, as well as an abundance of terminal groups, favor the loss of electromagnetic waves(EMW) within the material. In addition, the prepared multifunctional layered composite films also show good antibacterial properties. As a result, the obtained new kind of flexible layered structure EMI shielding composite films with excellent EMI shielding performance, and mechanical properties present promising application prospects in the fields of EMI shielding and protection for aerospace, portable, and wearable flexible electronic devices.

关键词： MXene AgNWs Laminar structure Electromagnetic interference shielding Flexibility

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Design and preparation of aluminum alloy with high thermal conductivity based on CALPHAD and first-principles calculation

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China Foundry 2022年第3期19卷 225-237页

作者： Ye Wang Hui-jun Kang Yu guo Hong-tao chen Mao-liang Hu ze-sheng Ji School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150004China Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Dalian University of Technology)Ministry of EducationDalian 116024LiaoningChina Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024LiaoningChina School of Science and Engineering Huzhou CollegeHuzhou 313000ZhejiangChina

To obtain the aluminum alloy with high thermal and mechanical properties,the effects of alloying elements and the second phases on the thermal conductivity of Al alloys were investigated by CALPHAD and first-principles calculation,*** properties of the second phases,including Young's modulus,Poisson's ratio and minimum thermal conductivity,were systematically *** show that the ranking order of the effects of the alloying elements on the thermal conductivity is Mg>Cu>Fe>Si,and for Al-12Si alloys,the mathematical model of the relationship between the alloying elements and the thermal conductivity can be expressed as λ=ax^(2)-bx+c when the second phase precipitates in the *** kinds of ternary phases of Al-Fe-Si have higher deformation resistance,rigidity,theoretical hardness,Debye temperature and thermal conductivity than the other phases which possibly exist in the Al-12Si *** on the guidance of CALPHAD and first-principles calculation,the optimized chemical composition of Al alloy with high conductivity is Al-11.5Si-0.4Fe-0.2Mg(wt.%)with a thermal conductivity of 137.50 W·m^(-1)·K^(-1)and a hardness of 81.3 HBW.

关键词： design and preparation CALPHAD first-principles calculation thermal conductivity aluminum alloy

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Investigation of Maxima Assumptions in Modelling Tropical Cyclone- Induced Hazards in the South China Sea

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China Ocean Engineering 2024年第3期38卷 491-504页

作者： WEN ze-guo WANG Fu-ming WAN Jing YANG Fan School of Civil Engineering Sun Yat-sen University&Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Academy of Safety Science and Technology Guangzhou 510060China Guangdong Key Laboratory of Oceanic Civil Engineering Guangzhou 510275China Advanced Energy Science and Technology Guangdong Laboratory(Yangjiang Offshore Wind Energy Laboratory) Yangjiang 529500China

The present study aims to examine the suitability of two commonly used assumptions that simplify modelling metoceanconditions for designing offshore wind turbines in the South China Sea (SCS). The first assumption assumes thatjoint N-year extreme wind and wave events can be independently estimated and subsequently combined. The secondone assumes peak wind and waves can be modelled as occurring simultaneously during a tropical cyclone (TC) *** better understand the potential TC activity, a set of 10000 years synthetic TC events are generated. The wind fieldmodel and the Mike 21 spectral wave model are employed to model the TC-induced hazards. Subsequently, theeffect of the assumptions is evaluated by analyzing the peak structural response of both monopile and semisubmersibleoffshore wind turbines during TC events. The results demonstrate that the examined assumptions are generally *** assessing the implications of these assumptions, valuable insights are obtained, which can inform andimprove the modelling of TC-induced hazards in the SCS region.

关键词： tropical cyclone numerical wave modelling hazards offshore wind turbines structural response

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