检索结果-南通市图书馆

Kinematic analysis of flexible bipedal robotic systems

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Parametric investigation on the novel and cost-effective nano fly ash impregnated geopolymer system for sustainable construction

引用

Frontiers of structural and Civil Engineering 2024年第2期18卷 170-183页

作者： r.mOHANA s.m.Leela BHArATHI Department of Civil Engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environmental effects of greenhouse gas emissions and climate change demand alternative sources for cementitious materials in the construction *** development of geopolymer structures provides a way of producing 100%cement-free *** this research work,a novel and simple way of deriving nano particles from waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler medium in geopolymer mortars was investigated by considering strength and durability *** optimization was done by using regression analysis on the geopolymer mortar and the impact of adding nano fly ash particles was studied by varying different percentages of addition ranging from 0 to 7.5%by weight of binder *** the results,it was observed that 1%nano fly ash acted not only as a filler but also as nano-sized precursors of the polymerization process,resulting in denser geopolymer *** can explain the extraordinary gain in strength of 72.11 mPa as well as the denser core with negligible level of chloride ion penetration,making the material suitable for the development of structures susceptible to marine environment.

关键词： geopolymer nano fly ash chloride ion penetration durability polymerization fillers

来源：

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

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

引用

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cr-induced fusion reactions to synthesize superheavy elements

引用

Nuclear science and Techniques 2024年第5期35卷 122-130页

作者： s.madhu H.C.manjunatha N.sowmya B.m.rajesh L.seenappa r.s.susheela Department of Physics R V College of EngineeringBangalore 560074India Visvesvaraya Technological University BelagaviKarnataka 590018India Department of Physics Government First Grade CollegeSrinivasapurKarnataka 563135India Department of Physics Government First Grade CollegeDevanahallyKarnataka 562110India Department of Physics Government First Grade CollegeMulbagalKarnataka 563131India Department of Physics Government First Grade collegeNanjangudOoty RoadMysore 571301India

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 *** cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior *** estimated cross sections from this analysis are consistent with the findings of prior *** the current study,the predicted cross section was found to be 42fb at 236 meV for ^(53)Cr+^(243)Am,23.2 fb at 236 meV for ^(54)Cr+^(247)Cm,95.6 fb at 240 meV for ^(53)Cr+248Bk,and 1.33 fb at 242 meV for ^(53)Cr+***,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.

关键词： Fusion cross sections Compound nucleus formation probability survival probability Evaporation residue cross sections

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Astrophysical s-factor and reaction rate for 15N(p,γ)16O within the modified potential cluster model

引用

Chinese Physics C 2024年第4期48卷 130-145页

作者： s.B.Dubovichenko A.s.Tkachenko r.Ya.Kezerashvili N.A.Burkova B.m.Yeleusheva Fesenkov Astrophysical Institute 050020 AlmatyKazakhstan New York City College of Technology City University of New YorkBrooklyn11201 New YorkUSA Graduate school and University Center City University of New York10016 New YorkUSA al-Farabi Kazakh National University 050040 AlmatyKazakhstan

We study radiative p^(15)N capture on the ground state of ^(16)O at stellar energies within the framework of a modified potential cluster model(mPCm)with forbidden states,including low-lying *** investigation of the ^(15)N(p,γ0)^(16)O reaction includes the consideration of ^(3)s_(1) resonances due to E1 transitions and the contribution of the ^(3)P_(1) scattering wave in the p+^(15)N channel due to the ^(3)P_(1)→^(3)P_(0)m1 *** calculated the astrophysical low-energy s-factor,and the extrapolated s(0)turned out to be within 34.7−40.4 keV·*** important role of the asymptotic constant(AC)for the ^(15)N(p,γ0)16O process with interfering ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances is elucidated.A comparison of our calculation for the s-factor with existing experimental and theoretical data is addressed,and a reasonable agreement is *** reaction rate is calculated and compared with the existing *** has negligible dependence on the variation of AC but shows a strong impact of the interference of ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances in reference to the CNO Gamow windows,especially at low *** estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data from ***.C.85,065810(2012).The reaction rate enhancement due to the cascade transitions is observed from T_(9)>0.3 and reaches the maximum factor~1.3 at T_(9)=*** present the Gamow energy window and a comparison of rates for radiative proton capture reactions ^(12)N(p,γ)^(13)O,^(13)N(p,γ)^(14)O,^(14)N(p,γ)^(15)O,and ^(15)N(p,γ)^(16)O obtained in the framework of the mPCm and provide the temperature windows,prevalence,and significance of each process.

关键词： low and astrophysical energies p^(15)N system thermonuclear reaction rate potential cluster model CNO-cycle

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Complexed amino acid minerals ***-glycinate chelated minerals:Impact on the performance of old laying hens

引用

Animal Nutrition 2024年第1期16卷 395-408页

作者： marcos J.B.santos maria C.m.m.Ludke Leandro m.silva Carlos B.V.rabello mércia r.Barros Fabiano s.Costa Clariana s.santos Jamille s.s.Wanderley Department of Animal science Rural Federal University of PernambucoRecifePEBrazil Department of Veterinary science Rural Federal University of PernambucoRecifePEBrazil

The present study was to evaluate the effect of trace minerals(Zn,mn,and Cu)from complexed amino acid minerals(ZmCAA)and bis-glycinate chelated minerals(ZmCGly)in laying hen diets on performance,internal and external egg quality,yolk mineral deposition,intestinal morphometry,and bone *** 78 to 98 weeks of age,400 White LsL-Lite strain laying hens were distributed in a randomized design with 4 treatments with 10 replicates per *** were distributed in a 2×2 factorial arrangement using either Zn,mn,and Cu of ZmCAA or ZmCGly source at 2 levels:low(20,20,and 3.5 mg/kg of Zn,mn,and Cu,respectively)or high(40,40,and 7 mg/kg of Zn,mn,and Cu,respectively).The analysis of variance was performed,and in cases where differences were observed,the means were compared using Tukey?s test(Psource and level of trace mineral supplementation had a significant impact on the performance of laying *** fed ZmCAA had higher egg production(P=0.01),egg weight(P=0.02),egg mass(P=0.01),and lower feed conversion ratio(P=0.05)compared to those fed *** ZmCAA supplementation showed higher albumen height(P=0.01),albumen weight(P=0.01),and eggshell thickness(Psition of Zn(Pmn(Ps greater for hens received *** weight(P=0.04)and bone densitometry(Pre higher with ZmCAA *** the small intestine,ZmCAA resulted in longer villi(P=0.02)and shorter crypt depth(P=0.01)in the *** and ileum measurements were influenced by the level and source of trace minerals(Ps fed ZmCAA exhibited superior performance,egg quality,deposition of trace minerals in the egg yolk,and bone density compared to hens fed *** this study,older laying hens supplemented with ZmCAA at lower levels demonstrated adequate levels of supplementation.

关键词： Bis-glycinates metal-amino acids radiodensity Trace minerals

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Large magnetocaloric effect and magnetic properties of EurhO3

引用

Journal of rare Earths 2024年第9期42卷 1724-1729页

作者： m.Lassri m.sajieddine A.Elouafi A.El Hachmi s.El Ouahbi r.moubah Laboratory of Energy and materials Engineering (LGEm) University of Sultan Moulay SlimaneFaculty of Science and Technology (FST) Institute of Applied Physics (IAP)-school of Industrial management (EmINEs) Mohammed Ⅵ Polytechnic University National school of Applied sciences (ENsA) University of Sultan Moulay Slimane Laboratory of mechanics Production and Industrial Engineering (LMPGI)Higher School of Technology of Casablanca (ESTC)University of Hassan Ⅱ Casablanca Laboratory of radiation on matter and Instrumentation (LrmI) Faculty of Science and Technology (FST) SettatHassan Ⅰ University Laboatory of Physics of Advanced materials and Thermic (LPmAT) Faculty of Science Ain Chock (FSAC)University of Hassan Ⅱ Casablanca

We report on the structural,magnetic,and magnetocaloric properties of *** oxidation states of Eu and rh ions were studied using X-ray photoelectron spectroscopy（XPs）.It is found that the Eu ions are mainly in the divalent oxidation state while the rh ions have+4 ***3powders are found to be antiferromagnetic with a second order magnetic transition at Neel temperature（TN=2.9 K）.Analysis of the magnetic susceptibility versus temperature data in terms of the Curie=Weiss law:(χ=C/（T-θW）) for T>TN,yields θW=-3.1 K and effective magne tic moment ■,which is close to the theoretical value ■.The magnetic entropy change(-Δsm),was determined by em ploying the thermodynam ic maxwell's *** μ0H=5 T and near TN,■ and relative cooling power（rCP） exhibit large values of 33.7 J/（kg·K） and 238 J/kg,*** large magnitude of-Δsmand rCP show that the EurhO3compound could be a potential candidate to be used in cryogenic magnetic refrigeration.

关键词： X-ray photoelectron spectroscopy Cryogenic magnetic refrigeration magnetic properties magnetocaloric effect rare earths

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Provenance and depositional setting of the Late miocenePleistocene clastic sediments in the eastern Arabian Peninsula and western Iraq using rare earth elements geochemistry

引用

Acta Geochimica 2024年第2期43卷 399-410页

作者： salih m.Awadh Zinah s.Al-Ankaz mohanad r.A.Al-Owaidi John s.Armstrong-Altrin Department of Geology College of ScienceUniversity of BaghdadBaghdadIraq Department of Geology College of ScienceUniversity of WasitWasit 52011Iraq Department of Applied Geology College of ScienceUniversity of BabylonBabylon 51001Iraq Unidad de Procesos Oceanicos y Costeros Instituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autonoma de MexicoCiudad Universitaria04510 Mexico CityCDMXMexico Department of marine sciences Bharathidasan UniversityTiruchirapalliTamil Nadu 620024India

The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements(rEE) and trace elements(sc, Co, V, and Th) concentrations in these sandstones revealed that they likely derived from a single source. The steep light rare earth elements(LrEE) and flat, heavy rare earth element(HrEE) patterns, negative Eu anomaly, and high ΣrEE contents in sandstones suggest its derivation from a suggests that a passive continental margin environment and originated from felsic source rocks. The average concentration of ΣrEE is 93.5 ppm, which is lower than that of the average crustal compositions like Upper Continental Crust and Post Archean Australian shale. The higher proportion of LrEE compared to HrEE implies that these sandstones were recycled and derived from a distal source. The Th/Co, Th/sc, La/sc, La/Co, Eu/Eu*and(La/Lu)cn elemental ratios indicated that these Late miocene–Pliocene sandstones were derived from felsic rocks located in the marginal region of the Arabian shield.

关键词： rEE Dibdibba formation Clastic sediments Passive continental margin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

引用

Journal of rare Earths 2024年第3期42卷 497-505,I0003页

作者： s.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on sEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm Cr dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm Cr dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： semiconductor TiO_(2) rare earths Congo red methylene blue solar spectrum Photodegradation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：