检索结果-南通市图书馆

Rare Metals 2017年第6期36卷 501-511页

作者： Somasundaram Praveen Kumar Kathiresan Sakthipandi Ramamurthy Gayathiri Mathu Sridhar Panday Arumugam Karthik Venkatachalam Rajendran centre for nano Science and Technology K.S. Rangasamy College of Technology Anna University Research and Development centre Bharathiar University

Series of bulk and nanostructured La0.7SrxCa0.3-xMnO3（x = 0.10, 0.15, and 0.20） manganites were synthesized and characterized using different techniques. In the series, both the bulk and nanostructured La0.7Sr0.10Ca0.20MnO3 and La0.7Sr0.20Ca0.10MnO3 manganites have orthorhombic and rhombohedral structures, whereas La0.7Sr0.15Ca0.15MnO3 manganite has rhombohedral and orthorhombic structures, respectively. Online ultrasonic velocity and attenuation measurements were taken through an indigenously designed ultrasonic setup, and the analysis was done from 300 to 400 K during the aging of the samples to explore the structural/phase transitions. The bulk and nanocrystalline La0.7SrxCa0.3-xMnO3 perovskite samples show the particle size distribution in the range of 197-943 and 24-93 nm, respectively. The addition of Sr^2＋ alters the size of particles, which decrease in size. The observed anomaly in ultrasonic velocities, attenuations, and elastic moduli is correlated with the ferromagnetic-paramagnetic（FM-PM） transition temperature（TC） in both bulk and nanocrystalline perovskites. In addition, the shift in TC and the magnitude and width of observed anomaly are correlated with the value of x to study the behavior of TC.

关键词： Magnetic material Ultrasonic measurements Elastic properties Phase transition

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2022年第8期16卷 1198-1210页

作者： Vinayak Hegde Parimal Pandit Pranita Rananaware Varsha PBrahmkhatri centre for nano and Material Sciences Jain UniversityJain Global CampusBengaluru 562112India

Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and *** synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscopeenergy dispersive X-ray spectroscopy,Fourier transform infrared spectroscopy,Brunauer–Emmett–Teller surface area,thermogravimetric analysis and n-butylamine *** shape of catalysts particles plays an important role in its *** sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel *** catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid,oleic acid with *** effect of various reaction parameters such as catalyst concentration,acid/alcohol molar ratio,catalyst amount,reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum *** was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica ***,the catalyst was regenerated and reused up to three cycles without any significant loss in *** present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

关键词： solid acid catalyst mesoporous silica sulfonic acid biodiesel esterification oleic acid

Electrospun MgO/Nylon 6 Hybrid nanofibers for Protective Clothing

在线全文

学校读者我要写书评

暂无评论

nano-Micro Letters 2014年第1期6卷 46-54页

作者： Nattanmai Raman Dhineshbabu Gopalu Karunakaran Rangaraj Suriyaprabha Palanisamy Manivasakan Venkatachalam Rajendran centre for nano Science and Technology K.S. Rangasamy College of Technology

Magnesia(MgO) nanoparticles were produced from magnesite ore(MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction analysis, transmission electron microscopy and Brunauer-Emmett-Teller method, respectively. MgO nanoparticle-incorporated nylon6 solutions were electrospun to produce nanofiber mats. Surface morphology and internal structure of the prepared hybrid nanofiber mats were examined by scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The fire retardancy and antibacterial activity(Staphylococcus aureus and Escherichia coli) of coated fabrics made from MgO/nylon 6 hybrid nanofiber are better than those from nylon6 nanofiber.

关键词： MgO/nylon 6 hybrid nanofibers Cotton fabrics Fire retardancy Antibacterial activity

Microscopic growth mechanism and edge states of monolayer 1T'-MoTe_(2)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 605-611页

作者：赵海鹏刘隐杨胜国林陈昉陈明星 Kai Braun 罗心仪李思宇潘安练王笑 Key Laboratory for Micro-nano Physics and Technology of Hunan Province School of Physics and ElectronicsCollege of Materials Science and EngineeringHunan UniversityChangsha 410082China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Synergetic Innovation Centre for Quantum Effects and Applications (SICQEA) Hunan Normal UniversityChangsha 410081China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Institute of Physical and Theoretical Chemistry and LISA+ University of TubingenAuf der Morgenstelle 1872076 TubingenGermany

Transition metal ditellurides(TMTDs)have versatile physical properties,including non-trivial topology,Weyl semimetal states and unique spin *** growth of high-quality and large-scale monolayer TMTDs with preferred crystal phases is crucial for their ***,we demonstrate the epitaxial growth of 1T'-MoTe_(2) on Au(111)and graphitized silicon carbide(Gr/SiC)by molecular beam epitaxy(MBE).We investigate the morphology of the grown1T'-MoTe_(2) at the atomic level by scanning tunnelling microscopy(STM)and reveal the corresponding microscopic growth *** is found that the unique ordered Te structures preferentially deposited on Au(111)regulate the growth of monolayer single crystal 1T'-MoTe_(2),while the Mo clusters were preferentially deposited on the Gr/SiC substrate,which impedes the ordered growth of monolayer MoTe_(2).We confirm that the size of single crystal 1T'-MoTe_(2) grown on Au(111)is nearly two orders of magnitude larger than that on Gr/*** scanning tunnelling spectroscopy(STS),we observe that the STS spectrum of the monolayer 1T'-MoTe_(2) nano-island at the edge is different from that at the interior,which exhibits enhanced conductivity.

关键词： transition metal ditellurides 1T'-MoTe_(2) microscopic growth mechanism scanning tunneling microscopy/spectroscopy(STM/S)

Controlled synthesis of porous spinel cobalt manganese oxides as efficient oxygen reduction reaction electrocatalysts

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

nano Research 2016年第1期9卷 207-213页

作者： Hongchao Yang Feng Hu Yejun Zhang Liyi Shi Qiangbin Wang Department of Chemistry Shanghai University 99 Shang-Da Road Shanghai200444 China Key Laboratory of nano-bio Interface Division of Nanobiomedicine and i-Lab Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou 215123 China

In this article, we report a facile precursor pyrolysis method to prepare porous spinel-type cobalt manganese oxides （CoxMng-xO4） with controllable morphologies and crystalline structures. The capping agent in the reaction was found to be crucial on the formation of the porous spinel cobalt manganese oxides from cubic Co2MnO4 nanorods to tetragonal CoMn2O4 microspheres and tetragonal CoMn204 cubes, respectively. All of the prepared spinel materials exhibit brilliant oxygen reduction reaction （ORR） electrocatalysis along with high stability. In particular, the cubic Co2MnO4 nanorods show the best performance with an onset potential of 0.9 V and a half-wave potential of 0.72 V which are very close to the commercial Pt/C. Meanwhile, the cubic Co2MnO4 nanorods present superior stability with negligible degradation of their electrocatalytic activity after a continuous operation time of 10,000 seconds, which is much better than the commercial Pt/C electrocatalvst.

关键词： porous nanostructure cobalt manganese oxides electrocatalyst oxygen reduction reaction

Volcanically Driven Terrestrial Environmental Perturbations during the Carnian Pluvial Episode in the Eastern Tethys

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

Acta Geologica Sinica(English Edition) 2024年第3期98卷 753-770页

作者： Naveed Ur RAHMAN XIAN Benzhong FANG Linhao CHEN Sirui CHEN Peng Zaheen ULLAH WANG Pengyu National Key Laboratory of Petroleum Resources and Engineering Beijing 102249China College of Geosciences China University of PetroleumBeijing 102249China centre for Earth and Space Sciences University of SwatSwat 19120Pakistan

The Carnian Pluvial Episode(CPE)fingerprints global environmental perturbations and biological extinction on land and oceans and is potentially linked to the Wrangellia Large Igneous Province(LIP).However,the correlation between terrestrial environmental changes and Wrangellia volcanism in the Ordos Basin during the CPE remains poorly *** of negative carbon isotopic excursions(NCIEs),mercury(Hg),Hg/TOC,and Hg enrichment factor(HgEF)from oil shales in a large-scale terrestrial Ordos Basin in the Eastern Tethys were correlated with marine and other terrestrial *** three significant NCIEs in the study section were consistently correlated with those in the CPE successions of Europe,the UK,and South and North *** U-Pb geochronology indicates a Ladinian-Carnian age for the Chang 7 Member.A comprehensive overview of the geochronology,NCIE correlation,and previous bio-and chronostratigraphic frameworks shows that the Ladinian-Carnian boundary is located in the lower part of Chang 7 in the Yishicun *** may be a more reliable proxy for tracing volcanic eruptions than the Hg/TOC ratio because the accumulation rates of TOC content largely vary in terrestrial and marine *** records of Hg,Hg/TOC,HgEF,and NCIEs in the Ordos Basin aligned with Carnian successions worldwide and were marked by similar anomalies,indicating a global response to the Wrangellia LIP during the ***,a warm-humid climate,enhancement of detrital input,and NCIEs are synchronous with the CPE interval in the Ordos Basin,which suggests that the CPE combined with the regional Qinling Orogeny should dominate the enhanced rate of terrigenous input and paleoenvironmental evolution in the Ordos Basin.

关键词： Chang 7 Member oil shale Carnian Pluvial Episode volcanism environmental perturbations

Carbon fiber reinforced liquid crystalline elastomer composites:a dual exploration in strength augmentation and transformation flexibility through 4D printing

在线全文

学校读者我要写书评

暂无评论

International Journal of Smart and nano Materials 2024年第2期15卷 312-329页

作者： Yuliang Xia Tong Mu Yanju Liu Jinsong Leng centre for Composite Materials and Structures Harbin Institute of Technology(HIT)HarbinPeople's Republic of China Department of Astronautical Science and Mechanics Harbin Institute of Technology(HIT)HarbinPeople's Republic of China

Liquid Crystal Elastomers(LCEs)are renowned for their reversible deformation ***,enhancing their mechanical strength while retaining such flexibility has posed a considerable *** overcome this,we utilized 4D printing to develop an innovative composite of LCE with carbon fiber fabric(LCEC).This approach has notably increased the tensile strength of LCE by eightfold,all the while maintaining its exceptional capacity for reversible *** adjusting the alignment angle between carbon fiber and the LCE printing direction from 0°to 90°,the LCEC demonstrates an array of new deformation patterns,including bending,twisting,wrapping,and S-shaped transformations,which are distinct from pure LCE *** study unveils that LCE composites exhibit deformation processes markedly different from their pure material counterparts,with the ability of pure LCE to sustain tensile strains exceeding 1900%.These findings,previously undocumented and unexplored,represent a substantial contribution to the field of smart *** finite element analysis,we explored the carbon fiber and LcE matrix dynamics,revealing bending mechanics in *** combined experimental and simulation approach yields crucial insights for crafting durable,high-strength LCECs with diverse deformational properties,advancing smart material technology.

关键词： Liquid crystal elastomer composites 4D printing Smart materials

Research on magnetic metallization of microorganism cells using electroplating technique

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

Science China(Technological Sciences) 2011年第6期54卷 1525-1531页

作者： CAI Jun ZHANG DeYuan LAN MingMing LIAN ZhiYang bionic and Miero/nano/bio Manufacturing Technology Research Center School of Mechanical Engineering and Automation Beihang University Beijing 100191 China

Spirulina platensis were chosen as templates to produce microscopic helical soft-core magnetic particles by way of depositing ferromagnetic alloy onto their surface using electroplating technique,and the process of electroplating ferromagnetic alloy onto microorganism cells was *** morphology and appearance of the coated Spirulina platensis were analyzed with optical microscopy and scanning electron microscopy,respectively,and the ingredients and phase structure of the alloy coating were analyzed with energy dispersive X-ray detector(EDX) and X-ray diffractive analysis(XRD),*** result showed that the particles were successfully coated with uniform metal coating and their initial helical shape was perfectly *** coating was NiFe alloy,and its phase structure was face-centered cubic *** magnetic properties of the coated particles were tested with vibrating sample magnetometer(VSM),and the result showed that the particles were ferro-magnetic,which means the magnetic electroplating of the microorganism cells was successfully *** electrochemical reaction mechanism of the magnetic plating process was also analyzed;the result showed that the deposition of NiFe on the microorganism cells was anomalous codeposition,and that Fe2+ ion was preferential deposited when magnetic stirring was applied.

关键词： bio-limited forming microorganism helical particles electroplating magnetic metallization

Jetting-based bioprinting:process,dispense physics,and applications

在线全文

学校读者我要写书评

暂无评论

bio-Design and Manufacturing 2024年第5期7卷 771-799页

作者： Wei Long Ng Viktor Shkolnikov Singapore centre for 3D Printing(SC3DP) School of Mechanical and Aerospace EngineeringNanyang Technological University(NTU)Singapore 639798Singapore HP Inc. Palo AltoCA 94304USA

Jetting-based bioprinting facilitates contactless drop-on-demand deposition of subnanoliter droplets at well-defined positions to control the spatial arrangement of cells,growth factors,drugs,and biomaterials in a highly automated layer-by-layer fabrication *** to its immense versatility,jetting-based bioprinting has been used for various applications,including tissue engineering and regenerative medicine,wound healing,and drug development.A lack of in-depth understanding exists in the processes that occur during jetting-based *** review paper will comprehensively discuss the physical considerations for bioinks and printing conditions used in jetting-based *** first present an overview of different jetting-based bioprinting techniques such as inkjet bioprinting,laser-induced forward transfer bioprinting,electrohydrodynamic jet bioprinting,acoustic bioprinting and microvalve ***,we provide an in-depth discussion of various considerations for bioink formulation relating to cell deposition,print chamber design,droplet formation and droplet ***,we highlight recent accomplishments in jetting-based *** present the advantages and challenges of each method,discuss considerations relating to cell viability and protein stability,and conclude by providing insights into future directions of jetting-based bioprinting.

关键词： 3D bioprinting biofabrication Jetting-based Dispense physics Machine learning

Sodium Nitrate/Formamide Deep Eutectic Solvent as Flame-Retardant and Anticorrosive Electrolyte Enabling 2.6 V Safe Supercapacitors with Long Cyclic Stability

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第3期7卷 374-383页

作者： Huachao Yang Yiheng Qi Zifan Wang Qinghu Pan Chuanzhi Zhang Jianhua Yan Kefa Cen Zheng Bo Kostya(Ken)Ostrikov State Key Laboratory of Clean Energy Utilization College of Energy EngineeringZhejiang UniversityHangzhou Zhejiang 310027China School of Chemistry and Physics and QUT centre for Materials Science Queensland University of Technology(QUT)Brisbane QLD 4000Australia

Safe operation of electrochemical capacitors(supercapacitors)is hindered by the flammability of commercial organic ***-flammable Water-in-Salt(WIS)electrolytes are promising alternatives;however,they are plagued by the limited operation voltage window(typically≤2.3 V)and inherent corrosion of current ***,a novel deep eutectic solvent(DES)-based electrolyte which uses formamide(FMD)as hydrogen-bond donor and sodium nitrate(nano_(3))as hydrogen-bond acceptor is *** electrolyte exhibits the wide electrochemical stability window(3.14 V),high electrical conductivity(14.01 mScm^(-1)),good flame-retardance,anticorrosive property,and ultralow cost(7%of the commercial electrolyte and 2%of WIS).Raman spectroscopy and Density Functional Theory calculations reveal that the hydrogen bonds between the FMD molecules and NO_(3)^(-)ions are primarily responsible for the superior stability and *** developed nano_(3)/FMD-based coin cell supercapacitor is among the best-performing state-of-art DES and WIS devices,evidenced by the high voltage window(2.6 V),outstanding energy and power densities(22.77 Wh kg^(-1)at 630 W kg^(-1)and 17.37 kW kg^(-1)at 12.55 Wh kg^(-1)),ultralong cyclic stability(86%after 30000 cycles),and negligible current collector *** nano_(3)/FMD industry adoption potential is demonstrated by fabricating 100 F pouch cell supercapacitors using commercial aluminum current collectors.

关键词： cyclic stability deep eutectic solvents electrical conductivity electrochemical stability window supercapacitors