检索结果-南通市图书馆

Moment Redistribution Effect of the Continuous Glass Fiber Reinforced Polymer-Concrete Composite Slabs Based on Static Loading Experiment

在线全文

学校读者我要写书评

暂无评论

Structural Durability & Health Monitoring 2025年第1期19卷 105-123页

作者： zhao-Jun Zhang Wen-Wei wang Jing-Shui Zhen bo-Cheng Li De-Cheng Cai yang-yang Du hui huang Offshore Oil Engineering Co.Ltd. Tianjin300461China Department of Bridge Engineering School of TransportationSoutheast UniversityNanjing211189China

This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment *** experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was *** composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab *** methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel *** experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal *** contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading *** the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan *** the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span *** GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span *** test specimens experienced compressive failure of concrete at the mid-span *** results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support *** proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.

关键词： Moment redistribution GFRP-concrete composite slabs bending moment experimental study analysis model

Unraveling the significance of cobalt on transformation kinetics,crystallography and impact toughness in high-strength steels

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 380-390页

作者： Yishuang yu Jingxiao zhao Xuelin wang hui Guo Zhenjia Xie Chengjia Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic *** results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without ***,the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to *** improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant ***,the addition of Co induces a larger transformation driving force and a lower bainite start temperature(BS),thereby contributing to the refinement of blocks and the increase of the V1/V2 variant *** findings would be instructive for the composition,microstructure design,and property optimization of high-strength steels.

关键词： high-strength steel cobalt transformation kinetics crystallography impact toughness

Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu Yan-bo Li Qi Zhang Jun-zhao Xiao Yi-Fan wang Tian-yu Wei Jia-Wei Jiang Ye wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

关键词：

Laser direct writing of flexible multifunctional airflow sensors on the Kevlar fabric

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2025年第1期18卷 443-454页

作者： Wei wang Zi-Qing Chen Yong-Qi Li yu-Long wang Mei-Chen Liu yun-bo Ruan yang Zhang Shu-Juan Liu Qiang zhao College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China State Key Laboratory of Organic Electronics and Information Displays and Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and TelecommunicationsNanjing 210023China Zhe Jiang Topsun Logistic Control CO. LTD.Yuhuan 317600China Department of Rehabilitation Medicine School of Acupuncture-Moxibustion and Tuina and School of Health Preservation and RehabilitationNanjing University of Chinese MedicineNanjing 210023China

The growing interest in flexible devices has emerged as a global trend due to their advantages in flexibility,lightweight structure,and wearability,addressing the limitations of traditional *** wearable airflow sensors have been previously reported,the development of flexible fabric-based airflow sensors capable of functioning in environments with open flames—critical for fire rescue operations—has yet to be explored,largely due to the poor fire resistance of conventional *** this work,we first present a flexible,wearable,and multifunctional airflow sensor with excellent fire-resistant properties,fabricated through a simple direct laser writing *** sensor maintains airflow detection capabilities even in the presence of open ***,the fabrication of fabric-based sensors involves complex procedures such as carbon materials doping or vapor-phase deposition,leading to lengthy preparation cycles and high ***,fabric-based devices are inherently prone to *** address these challenges,we introduce twice-vertical laser-induced graphene(TVLIG)as a sensitive and reliable component for fire-resistant airflow *** resulting TVLIG/Kevlar fabric can be integrated into various garments,particularly protective suits,to form sensitive and fire-resistant airflow sensors capable of detecting airflow velocity and direction in both two-dimensional(2D)and three-dimensional(3D)spaces during fire ***,the TVLIG patterns can be expanded to multifunctional platforms,such as glucose detection for injured individuals,offering further applications in rescue *** functional expansion reduces the burden on rescue personnel and streamlines device *** its outstanding sensing capabilities,fire resistance,and expandability,the developed flexible airflow sensor shows great potential for various real-world rescue scenarios,promising advancements in wearable sensing technology for rescue enginee

关键词： flexible airflow sensor direct laser writing twice-vertical laser-induced graphene fire accident rescue Kevlar fabric

Porous carbon/Fe composites from waste fabric for high-efficiency electromagnetic wave absorption

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第31期126卷 266-274页

作者： Jin-bo Cheng Hai-bo zhao Ai-Ning Zhang Yan-Qin wang yu-zhong wang Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) State Key Laboratory of Polymer Materials EngineeringNational Engineering Laboratory for Eco-Friendly Polymer Materials(Sichuan)College of ChemistrySichuan UniversityChengdu 610064China

Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation ***,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave *** this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high ***,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon ***,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption ***,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 *** work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.

关键词： Up recycling Microwave absorption Waste fabrics Thin thickness

Hierarchical Ti_(3)C_(2)T_(x)@ ZnO Hollow Spheres with Excellent Microwave Absorption Inspired by the Visual Phenomenon of Eyeless Urchins

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第5期14卷 62-76页

作者： Yan‑Qin wang Hai‑bo zhao Jin‑bo Cheng bo‑Wen Liu Qiang Fu yu‑zhong wang Collaborative Innovation Center for Eco‑Friendly and Fire‑Safety Polymeric Materials(MoE) State Key Laboratory of Polymer Materials EngineeringNational Engineering Laboratory for Eco‑Friendly Polymer Materials(Sichuan)College of ChemistrySichuan UniversityChengdu 610064People’s Republic of China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065People’s Republic of China

Ingenious microstructure design and rational composition selection are effective approaches to realize high-performance microwave absorbers,and the advancement of biomimetic manufacturing provides a new *** nature,urchins are the animals without eyes but can“see”,because their special structure composed of regular spines and spherical photosensitive bodies“amplifies”the light-receiving ***,inspired by the above phenomenon,the biomimetic urchin-like Ti_(3)C_(2)T_(x)@ZnO hollow microspheres are rationally designed and fabricated,in which ZnO nanoarrays(length:~2.3μm,diameter:~100 nm)as the urchin spines are evenly grafted onto the surface of the Ti_(3)C_(2)T_(x) hollow spheres(diameter:~4.2μm)as the urchin spherical photosensitive *** construction of gradient impedance and hierarchical heterostructures enhance the attenuation of incident electromagnetic *** the EMW loss behavior is further revealed by limited integral simulation calculations,which fully highlights the advantages of the urchin-like *** a result,the Ti_(3)C_(2)T_(x)@ZnO hollow spheres deliver a strong reflection loss of−57.4 dB and broad effective absorption bandwidth of 6.56 GHz,superior to similar *** work provides a new biomimetic strategy for the design and manufacturing of advanced microwave absorbers.

关键词： Bioinspired Hierarchical heterostructures Ti_(3)C_(2)T_(x)MXene ZnO nanoarrays Microwave absorption

Stress-induced Solid-Solid Crystal Transition in Trans-1,4-polyisoprene

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2022年第3期40卷 256-265,I0006页

作者： Chun-bo Zhang Lei wang bo yang hui zhao Guo-Ming Liu Du-Jin wang Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China CAS Key Laboratory of Engineering Plastics Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Materials Science&Engineering Beijing Institute of Fashion TechnologyBeijing 100029China

The polymorphic transition of trans-1,4-polyisoprene(TPI) during stretching was investigated by in situ wide-angle X-ray diffraction and Fourier transform infrared spectroscopy. The influences of the initial structure, stretching temperature, and strain rate on the contents of different crystal modifications(α, β) were explored. The results confirm that the α-β transition occurs during stretching of TPI that only contains αcrystal(α-TPI). When the stress is relaxed, the β crystal formed during stretching remains, which indicates that the transition is irreversible. On the other hand, stretching of TPI that only contains β crystal(β-TPI) results in orientated β crystal. No β-α transition occurs during stretching. The different structures of stretched α-TPI and β-TPI exclude the previously proposed "melting-recrystallization mechanism". The α-β transition depends significantly on temperature and strain rate, indicating the transition is governed both by thermodynamics and kinetics. Our results support a solid-solid transition mechanism rather than a melting-recrystallization mechanism. The irreversible nature of the transition is attributed to the metastability of the β phase in the unstretched state. Different from the "β phases" that appear in polymers with stress-induced reversible transitions, e.g. poly(butylene terephthalate) and poly(butylene succinate), the stability of β phase in TPI is high that can be *** strain rate dependence of α-β transition hinders the determination of critical stress for the transition. It further indicates that the local stress within the sample is more heterogeneous at higher strain rates.

关键词： Trans-1 4-polyisoprene Crystal transition Deformation Crystallization

Growth and alkaline phosphatase activity of Chattonella marina and Heterosigma akashiwo in response to phosphorus limitation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2015年第2期27卷 1-7页

作者： zhao-hui wang yu Liang College of Life Science and Technology Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education InstitutesJinan University

The growth and alkaline phosphatase activity（APA） of two raphidophyceae species Chattonella marina and Heterosigma akashiwo were investigated in response to P-limitation and subsequent addition of dissolved inorganic phosphorus（DIP, Na H2PO4） and two dissolved organic phosphorus（DOP） compounds： guanosine 5-monophosphate（GMP） and triethyl phosphate（TEP）. APA levels increased greatly after P-starvation as the decrease of the cellular phosphorus quotes（Qp）. C. marina responded to P-limitation quickly and strongly, with 10-fold increase in APA within 24 hr after P-starvation. The larger difference between maximal and minimal QP values in C. marina indicated its high capacity in P storage. APA of H. akashiwo was maximally enlarged about 2.5 times at 48 hr of P-starvation. After the addition of nutrients, cell numbers of C. marina increased in all treatments including the P-free culture, demonstrating the higher endurance of C. marina to P-limitation. However, those of H. akashiwo increased only in DIP and GMP cultures. APA increased only after the addition of the monophosphate ester GMP. The results suggest that quick responses of C. marina to P-limitation, high capacity in P storage as well as endurance for P-depletion provide this species an ecological advantage in phytoplankton community competition under DIP-limited conditions.

关键词： Alkaline phosphatase Dissolved inorganic phosphorus Dissolved organic phosphorus Growth Phytoplankton

Multifunctional protective aerogel with superelasticity over−196 to 500℃

在线全文

学校读者我要写书评

暂无评论

Nano Research 2022年第9期15卷 7797-7805页

作者： bo-Wen Liu Min Cao Yi-Ying Zhang yu-zhong wang Hai-bo zhao The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu 610064China

Protective materials that possess superelasticity and multifunctionality over a broad temperature range are urgently needed in various advanced ***,under harsh work conditions,the performance of current materials may largely deteriorate to lose protective ***,we report a bidirectionally oriented multi-walled carbon nanotubes(MWCNTs)-reinforced chitosan carbon aerogel(CS-MWCNT)that possesses superelasticity,high electromagnetic interference shielding,thermal insulation,and infrared stealth at both low temperatures(such as liquid nitrogen)and high temperatures(such as alcohol flames).Highly oriented lamellar arch structures combined with an MWCNTs-reinforced carbon skeleton act as elastic segments to disperse the stress during compression and endow CS-MWCNT with the ability to recover to almost the original size after being compressed at−196-500℃.The lamellar structures make CS-MWCNT thermally insulating and infrared stealth with a low thermal conductivity of~0.03 W/(m·K).Furthermore,a high electromagnetic interference(EMI)shielding effect of 64 dB is realized via an absorption-dominant EMI shielding mechanism derived from the successive inherently conductive carbon lamella,and the EMI shielding performance is largely maintained after treatment under extreme conditions like low temperature,high temperature,as well as cyclic *** work provides a new strategy for the development of temperature-invariant multifunctional aerogels for harsh environment applications.

关键词： superelasticity electromagnetic interference shielding heat insulation infrared stealth extreme environment