检索结果-南通市图书馆

Earthquake Engineering and Engineering Vibration 2024年第3期23卷 713-726页

作者： m.A.Najafgholipour s.Heidarian Radbakhsh E.Erfani Department of Civil and Environmental Engineering Shiraz University of TechnologyShiraz ***Iran Department of Building Civiland Environmental EngineeringConcordia UniversityMontréal H3G 1M8Canada

This paper presents an investigation of the seismic behavior of reinforced concrete(RC)structures in which shear walls are the main lateral load-resisting elements and the participation of flat slab floor systems is not considered in the seismic design *** this regard,the behavior of six prototype structures(with different heights and plan layouts)is investigated through nonlinear static and time history analyses,implemented in the Opensees *** results of the analyses are presented in terms of the behavior of the slab-column connections and their mode of failure at different loading ***,the global response of the buildings is discussed in terms of some parameters,such as lateral overstrength due to the gravity flat slab-column *** to the nonlinear static analyses,in structures in which the slab-column connections were designed only for gravity loads,the slab-column connections exhibited a punching mode of failure even in the early stages of ***,the punching failure was eliminated in structures in which a minimum transverse reinforcement recommended in ACI 318(2019)was provided in the slabs at joint ***,despite neglecting the contribution of gravity flat slab-column frames in the lateral load resistance of the structures,a relatively significant overstrength was imposed on the structures by the gravity frames.

关键词： RC flat slab-column frames seismic behavior nonlinear analysis time history analysis

Kinematic analysis of flexible bipedal robotic systems

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2024年第5期45卷 795-818页

作者： R.FAZEL A.m.sHAFEI s.R.NEKOO Department of mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic muscles and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of *** most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

sodium nitroprusside as a signal molecule for up-regulating membrane characteristics,antioxidant defense system to improve flax productivity under water stress

在线全文

学校读者我要写书评

暂无评论

Oil Crop science 2024年第3期9卷 160-169页

作者： N.m.Al-Ashkar B.A.Bakry H.m.s.El-Bassiouny m.m.s.Abdallah m.s.sadak Botany Department Agricultural and Biological Research InstituteNational Research Centre33 El Bohouth Street P.O.12622DokkiGizaEgypt Field Crops Research Department Agricultural and Biological Research InstituteNational Research Centre33 El Bohouth Street P.O.12622DokkiGizaEgypt

Water stress is a critical environmental adversity that significantly impacts the growth,development,and yield of flax *** this study,flax seeds were cultivated under different water irrigation requirements(WIR)(100%,75%,and 50%)to investigate the effects of exogenously supplied nitric oxide(NO)donor sodium nitroprusside(sNP)as foliar treatments at concentrations of 0.0 mmol/L,0.5 mmol/L,1.0 mmol/L,and 2.0 mmol/*** stress led to a significant decrease in plant growth,photosynthetic pigments,yield components such as oil and total carbohydrate *** also resulted in an increase in leaf H2O2 production,lipid peroxidation levels and activities of enzymatic antioxidants including polyphenol oxidase,superoxide dismutase,and nitrate reductase ***,foliar application of sNP improved photosynthetic pigments and antioxidant defense system which mitigated the negative impact of water stress on growth and yield productivity by reducing oxidative damage caused by reactive oxygen species *** use of sNP also decreased H_(2)O_(2) accumulation levels,lipid peroxidation levels,and improved membrane *** treatment at concentration of 2 mmol/L showed superior results compared to other concentrations with extremely significant increases observed in yield characteristics such as oil content,total carbohydrate percentages,and unsaturated fatty acids to saturated fatty acids ratio.

关键词： Flax Fatty acid sodium nitroprusside Antioxidant enzymes Yield

Enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.sardar m.D.Hossain m.s.sikder m.N.I.Khan m.R.Rahman Physics Discipline Khulna UniversityKhulna9208Bangladesh Department of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Department ofComputer science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh material science Division Atomic Energy CentreDhaka1000Bangladesh

spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FEsEm),energy dispersive X-ray(EDX),vibrating sample magnetometer(Vsm),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XRD patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FEsEm images,and it is increased from 121 to 198 *** analysis confirms that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped samples is greater than that of the mother alloy(x=0.00).The EDX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the Eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Permeability EDX Resistivity

Impact of carbimazole combined with vitamin E on testicular injury induced by experimental hyperthyroidism in adult albino rats:oxidative/inflammatory/apoptotic pathways

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2024年第4期26卷 396-401页

作者： Ramadan s Hussein moustafa m Eyada Rashad m mostafa samah m Elaidy shereen H Elsayed Hany m saad Department of Dermatology College of Medicine Prince Sattam Bin Abdulaziz UniversityAl-Kharj 16242Saudi Arabia Department of Dermatology Andrology and STDsAssiut Police HospitalAssiut 71525Egypt Department of Dermatology Venereology and AndrologyFaculty of MedicineSuez Canal UniversityIsmailia 41522Egypt Department of Andrology and sexology Faculty of MedicineSuez Canal UniversityIsmailia 41511Egypt Department of Clinical Pharmacology Faculty of MedicineSuez Canal UniversityIsmailia 41511Egypt Department of Rehabilitation sciences Faculty of Health and Rehabilitation SciencesPrincess Nourah bint Abdulrahman UniversityRiyadh 12271Saudi Arabia.

Thyroid hormones play essential roles in spermatogenesis,but their effects on infertile males remain poorly *** study aimed to evaluate the impact of combining carbimazole(CBZ)with vitamin E(VE)on testicular injury induced by experimental hyperthyroidism in adult albino rats,focusing on oxidative,inflammatory,and apoptotic *** this experimental study,64 adult male albino Wistar rats were divided into eight groups:Group I(control-untreated),Group II(CBZ-control),Group III(VE-control),Group IV(CBZ+VE-control),Group V(levothyroxine-induced testicular injury),Group VI(levothyroxine+CBZ-treated),Group VII(levothyroxine+VE-treated),and Group VIII(levothyroxine+CBZ+VE-treated).The study was conducted in the Faculty of medicine,suez Canal University(Ismailia,Egypt).After cervical decapitation,both testes and epididymis were examined histopathologically and *** differences were observed among groups concerning malondialdehyde(mDA),glutathione(GsH),superoxide dismutase(sOD),and catalase(CAT;all Pmerase chain reaction analysis showed significant differences in tumor necrosis factor-α(TNF-α),interleukin-10(IL-10),Bcl-2-associated X protein(BAX),B-cell lymphoma 2 protein(Bcl2),p53,Caspase-3,Caspase-8,Caspase-9,and nuclear factor-kappa B(NF-κB)mRNA levels(all Psticular side effects,affecting seminiferous tubules and ***,the Group VIII showed improved spermatogenesis and a decrease in testicular side *** addition of VE to the treatment of hyperthyroid rats with CBZ reduced testicular side effects and seminiferous tubular affection when potentially improving *** research is needed to elucidate the underlying mechanisms fully.

关键词： antithyroid drugs testicular injury thyroid gland vitamin E

mgO-attached graphene nanosheet(mgO@GNs)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance

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 2024年第9期31卷 2062-2076页

作者： s.Abazari A.shamsipur H.R.Bakhsheshi-Rad m.s.soheilirad F.Khorashadizade s.s.mirhosseini Department of materials and metallurgical Engineering Amirkabir University of TechnologyTehran ***Iran Iranian National standards Organization of Hormozgan HormozganIran Advanced materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of materials and metallurgical Engineering Iran University of Science and TechnologyTehranIran

magnesium(mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and ***,they suffer from low corrosion resistance and antibacterial *** this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(mgO@GNs/mg)composite to improve mechanical,corrosion and cytocompatibility *** have revealed that the incorporation of mgO@GNs nanohybrids into mg-based composite enhanced microhardness and compressive *** vitro,osteoblast cell culture tests show that using mgO@GNs nanohybrid fillers enhances osteoblast adhesion and apatite *** presence of mgO@GNs nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the *** demonstrated that the mgO@GNs/mg composite possesses excellent antibacterial properties because of the combination of the release of mgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid ***,the mgO@GNs/mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a promising material for load-bearing implant applications.

关键词： metal matrix composites mgO@GNs nanohybrid strengthening mechanisms antibacterial activity biocompatibility

Isochrone Fitting of Galactic Globular Clusters—Ⅵ.High-latitude Clusters NGC 5024 (m53),NGC 5053,NGC 5272 (m3),NGC 5466,and NGC7099 (m30)

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期24卷 170-190页

作者： G.A.Gontcharov s.s.savchenko A.A.marchuk C.J.Bonatto O.s.Ryutina m.Yu.Khovritchev V.B.Il'in A.V.mosenkov D.m.Poliakov A.A.smirnov Central(Pulkovo)Astronomical Observatory Russian Academy of SciencesPulkovskoye chaussee 65/1St.Petersburg 196140Russia saint Petersburg state University Universitetskij pr.28St.Petersburg 198504Russia special Astrophysical Observatory Russian Academy of Sciences369167 Nizhnij ArkhyzRussia Departamento de Astronomia Instituto de FísicaUFRGSAv.Bento Gonçalves9500Porto AlegreRSBrazil saint Petersburg University of Aerospace Instrumentation Bol.Morskaya ul.67ASt.Petersburg 190000Russia Department of Physics and Astronomy Brigham Young UniversityN283 ESCProvoUT 84602USA

We fit various color–magnitude diagrams(CmDs) of the high-latitude Galactic globular clusters NGC 5024(m53),NGC 5053,NGC 5272(m3),NGC 5466,and NGC 7099(m30) by isochrones from the Dartmouth stellar Evolution Database and Bag of stellar Tracks and Isochrones for α–enrichment [α/Fe] = +*** the CmDs,we use data sets from Hubble space Telescope,Gaia,and other sources utilizing,at least,25 photometric filters for each *** obtain the following characteristics with their statistical uncertainties for NGC 5024,NGC 5053,NGC 5272,NGC 5466,and NGC 7099,respectively:metallicities [Fe/H] =-1.93 ± 0.02,-2.08 ± 0.03,-1.60 ± 0.02,-1.95 ± 0.02,and-2.07 ± 0.04 dex with their systematic uncertainty 0.1 dex;ages 13.00 ± 0.11,12.70 ± 0.11,11.63 ± 0.07,12.15 ± 0.11,and 12.80 ± 0.17 Gyr with their systematic uncertainty 0.8 Gyr;distances(systematic uncertainty added) 18.22 ± 0.06 ± 0.60,16.99 ± 0.06 ± 0.56,10.08 ± 0.04 ± 0.33,15.59 ±0.03 ± 0.51,and 8.29 ± 0.03 ± 0.27 kpc;reddenings E(B-V) = 0.023 ± 0.004,0.017 ± 0.004,0.023 ± 0.004,0.023 ± 0.003,and 0.045 ± 0.002 mag with their systematic uncertainty 0.01 mag;extinctions AV= 0.08 ± 0.01,0.06 ± 0.01,0.08 ± 0.01,0.08 ± 0.01,and 0.16 ± 0.01 mag with their systematic uncertainty 0.03 mag,which suggest the total Galactic extinction AV= 0.08 across the whole Galactic dust to extragalactic objects at the North Galactic *** horizontal branch morphology difference of these clusters is explained by their different metallicity,age,mass-loss efficiency,and loss of low-mass members in the evolution of the core-collapse cluster NGC 7099 and loose clusters NGC 5053 and NGC 5466.

关键词： (stars:)Hertzsprung Russell and C-m diagrams (Ism:)dust extinction (Galaxy:)globular clusters:general (Galaxy:)globular clusters:individual(NGC 5024,NGC 5053,NGC 5272,NGC 5466,NGC7099)

Descriptors-based machine-learning prediction of cetane number using quantitative structure–property relationship

在线全文

学校读者我要写书评

暂无评论

Energy and AI

Energy and AI 2024年第3期17卷 168-178页

作者： Rodolfo s.m.Freitas Xi Jiang school of Engineering and materials science Queen Mary University of LondonMile End RoadLondonE14NSUK

The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develop quantitative structure–property relationship models. The fuel chemical structure is represented by molecular descriptors, allowing the linking of important features of the fuel composition and key properties of fuel utilization. Feature selection is employed to select the most relevant features that describe the chemical structure of the fuel and several machine learning algorithms are tested to construct interpretable models. The effectiveness of the methodology is demonstrated through the development of accurate and interpretable predictive models for cetane numbers, with a focus on understanding the link between molecular structure and fuel properties. In this context, matrix-based descriptors and descriptors related to the number of atoms in the molecule are directly linked with the cetane number of hydrocarbons. Furthermore, the results showed that molecular connectivity indices play a role in the cetane number for aromatic molecules. Also, the methodology is extended to predict the cetane number of ester and ether molecules, leveraging the design of alternative fuels towards fully sustainable fuel utilization.

关键词： Chemical descriptors Quantitative structure-property relationship machine learning Cetane number Fuel design

Enabling Technologies for Autonomous Robotic systems in manufacturing

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

Transactions of Nanjing University of Aeronautics and Astronautics 2024年第4期41卷 403-431页

作者： erdŐs Gábor ABAI Kristóf BEREGI Richárd CsEmPEsZ János CsERTEG Tamás GODÓGábor HAJÓs mátyás HÁY Borbála HORVÁTH Dániel HORVÁTH Gergely JUNIKIÁdám KEmÉNY Zsolt KOVÁCs András NACsA János PANITI Imre PEDONE Gianfranco TAKÁCs Emma TIPARY Bence ZAHORÁN László VÁNCZA József Institute for Computer science and Control Hungarian Research Network(HUN-REN SZTAKI)BudapestHungary Department of manufacturing science and Technology Budapest University of Technology and Economics(BME)BudapestHungary EPIC InnoLabs Nonprofit Ltd. BudapestHungary Eötvös Loránd University(ELTE) BudapestHungary

Research of autonomous manufacturing systems is motivated both by the new technical possibilities of cyber-physical systems and by the practical needs of the *** operation in semi-structured industrial environments can now be supported by advanced sensor technologies,digital twins,artificial intelligence and novel communication *** enable real-time monitoring of production processes,situation recognition and prediction,automated and adaptive(re)planning,teamwork and performance improvement by *** paper summarizes the main requirements towards autonomous industrial robotics and suggests a generic workflow for realizing such *** case studies will be presented from recent practice at HUN-REN sZTAKI in a broad range of domains such as assembly,welding,grinding,picking and placing,and *** various solutions have in common that they use a generic digital twin concept as their *** making general recommendations for realizing autonomous robotic solutions in the industry,open issues for future research will be discussed.

关键词： industrial robotics autonomy digital twin enabling technology

structural effects induced by dialysis-based purification of carbon nanomaterials

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 materials science 2024年第4期6卷 475-483页

作者： A.D.Veloso A.m.Ferraria A.m.Botelho do Rego A.s.Viana A.J.s.Fernandes A.J.Fielding R.A.Videira m.C.Oliveira CQ-VR and Chemistry Department University of Trás-os-Montes e Alto Douro BsIRG iBB-Institute for Bioengineering and BiosciencesDepartment of Chemical Engineeringand Associate Laboratory i4HB-Institute for Health and BioeconomyInstituto Superior TécnicoUniversidade de Lisboa Centro de Química Estrutural Institute of Molecular SciencesDepartamento de Química e BioquímicaFaculdade de CiênciasUniversidade de Lisboa I3N and Physics Department University of AveiroCampus de Santiago Faculty of science Pharmacy and Biomolecular SchoolLiverpool John Moores University REQUImTE/LAQV Laborat orio de FarmacognosiaDepartamento de QuímicaFaculdade de Farm aciaUniversidade do Porto

Dialysis plays a crucial role in the purification of nanomaterials but its impact on the structural properties of carbon nanomaterials was never ***,a carbon-based nanomaterial generated electrochemically in potassium phosphate buffer,was characterized before and after dialysis against pure *** is shown that dialysis affects the size of the carbon domains,structural organization,surface functionalization,oxidation degree of carbon,and grade of ***,dialysis drives the nanomaterial organization from discrete roundish carbon domains,with sizes ranging from 70 to 160 nm,towards linear stacking structures of small nanoparticles （m）.In parallel,alcohol and ether （epoxide） surface groups evolve into more oxidized carbon groups （e.g.,ketone and ester groups）.Investigation of the as-prepared nanomaterial by electron paramagnetic resonance （EPR） revealed a resonance signal consistent with carbon-oxygen centred ***,this study brings to light the selective affinity of the carbon nanomaterial under study to capture Na+ions,a property greatly enhanced by the dialysis process,and its high ability to trap oxygen,particularly before *** findings open new perspectives for the application of carbon-based nanomaterials and raise awareness of the importance of structural changes that can occur during the purification of carbon-based nanomaterials.

关键词： Nanocarbon surface functionalization NmR XPs Hydrophilic carbon Paramagnetic