检索结果-南通市图书馆

Olefin Polymerization Behavior of Titanium(IV) Complexes with Fluorinated and Non-fluorinated Aliphatic Phenoxyimine Ligands

引用

Chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： Vladislav A.Tuskaev Kasim F.magomedov Svetlana Ch.gagieva Dmitry A.Kurmaev Yulia V.Nelyubina Evgenii K.golubev maria D.Evseeva Viktor g.Vasil'ev galina g.Nikiforova mikhail I.Buzin Vyacheslav S.Bogdanov Boris m.Bulychev Department of Chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(mmAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(m_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHmWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： FI catalysts Titanium(IV) (Co)polymerization Al/mg co-catalyst Ultra-high molecular weight polyethylene

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

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

Autoantibodies against beta cells to predict early insulin requirements in pediatric patients with clinically diagnosed type 2 diabetes

引用

World Journal of Diabetes 2024年第8期15卷 1717-1725页

作者： Jorge m molina Patricia g medina Rita A gomez Julia R Herrera Nancy L martínez Brenda Hernández Yesenia garcía Department of Endocrinology Children’s Hospital Federico GomezMexico 06720Mexico National medical Center"Siglo XXI" UMAE Hosp EspecialidadesUnidad Invest Med Epidemiol ClinMexican Social Security InstituteMexico 06720Mexico Research Division UMAE Hospital de EspecialidadesCentro Médico Nacional Siglo XXIMexican Institute of Social SecurityMexico 06720Mexico Epidemiology Research Unit in Endocrinology and Nutrition Federico Gómez Children’s HospitalMexico 06720Mexico Department of Endocrinology Comprehensive Health Unit for Trans PersonsMexico 11340Mexico

BACKgROUND Autoimmunity has emerged as a probable disease modifier in patients with clinically diagnosed type 2 diabetes mellitus(T2Dm),that is,patients who have insulin resistance,obesity,and other cardiovascular risk factors,suggesting that the presence of glutamic acid decarboxylase(anti-gAD65),islet antigen 2(anti-IA2),and zinc transporter 8(anti-Zn8T)antibodies could have deleterious effects on beta cell function,causing failure and earlier requirement for insulin *** To evaluate anti-gAD65,anti-IA2 and anti-Zn8T as predictors of early insulin requirement in adolescents with a clinical diagnosis of *** This was a case–control study in patients with clinically diagnosed with T2Dm(68 cases and 64 controls with and without early insulin dependence respectively),male and female,aged 12–18 ***,blood pressure,glucose,insulin,C-peptide,glycated hemoglobin A1c,and lipid profiles were *** was used to measure anti-gAD65,anti-IA2,and anti-Zn8T *** statistics,Pearson'sχ2 test,Student's t test,and logistic regression was performed.Pmale),with a mean age was 15.9±1.3 years,and there was a disease evolution time of 4.49±0.88 *** presence of anti-gAD65,anti-IA2,and anti-Zn8T positivity was found in 29.5%,18.2%,and 15.9%,*** the groups by early or no insulin dependence showed that the group with insulin had a higher frequency of antibody positivity:anti-gAD65 odds ratio(OR):2.42(1.112–5.303,P=0.026);anti-IA2:OR:1.55(0.859–2.818,P=0.105);and anti-Zn8T:OR:7.32(2.039–26.279,P=0.002).CONCLUSION Anti-gAD65 positivity was high in our ***-gAD65 and anti-Zn8T positivity showed a significantly depleted beta cell reserve phenotype,leading to an increased risk of early insulin dependence.

关键词： Diabetes Obesity Adolescents Autoimmunity Beta cell Insulin requirements

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

Transmission of amyloid-βpathology in humans:a perspective on clinical evidence

引用

Neural Regeneration Research 2024年第2期19卷 390-392页

作者： Celso S.g.Catumbela Rodrigo morales Department of Neurology McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTXUSA Centro Integrativo de Biologia y Quimica Aplicada(CIBQA) Universidad Bernardo O’HigginsSantiagoChile

Transmission of misfolded amyloid-β(Aβ)aggregates between human subjects:Protein misfolding disorders are a family of diseases characterized by the accumulation of misfolded protein *** proteinaceous structures,also known as amyloids,are key drivers of fatal neurodegenerative disorders such as prion diseases,Alzheimer’s disease(AD),Parkinson’s disease,and others.

关键词： amyloid diseases Aβ

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

Features of sampling stream sediments of large river valleys under cryolithogenesis conditions in the Balygychan-Sugoy trough,North-East of Russia

引用

Acta geochimica 2024年第4期43卷 638-660页

作者： Artem S.makshakov Raisa g.Kravtsova A.P.Vinogradov Institute of geochemistry Siberian Branch of the Russian Academy of SciencesFavorskiy Str 1AIrkutskRussia 664033

Comprehensive research has been implemented to raise the efficiency of the geochemical survey of stream sediments(SSs)that formed under the cryolithogenesis *** authors analysed the composition,structure and specific features of the formation of exogenous anomalous geochemical fields(AgFs)identified through SSs of large river valleys of IV *** our case,these were the valleys of maly Ken,Ken and Tap *** rivers are located in the central and southern parts of the Balygychan-Sugoy trough enclosed in the magadan region,North-East of *** authors proposed a new technique to sample loose alluvium of SSs in the large river valleys along the *** profiles were located across the *** AgFs of Au,Ag,Pb,Zn,Sn,Bi,mo and W were *** between elements have been *** elements are the main indicator elements of Au-Ag,Ag-Pb,Sn-Ag,mo-W and Sn-W mineralization occurring on the sites under *** results obtained were compared with the results of geochemical surveys of *** is concluded that the AgFs recognized along the profiles reflect the composition and structure of eroded and drained ore zones,uncover completely and precisely the pattern of element distribution in loose sediments of large water *** alluvium fractionmm seems to be most significant in a practical sense,as it concentrated numerous ore *** of this fraction in the river valleys of IV order does not cause any difficulty,for this kind of material is *** developed technique of alluvium sampling within large river valleys is efficient in searching for diverse mineralization at all stages of prognostic *** is applicable for geochemical survey of SSs performed at different scales both in the North-East of Russia,as well as other regions with similar climatic conditions,where the SSs are formed under the cryolithogenesis conditions.

关键词： Stream sediments Large river valleys geochemical fields mineralization Indicator elements geochemical survey

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

Resident immune responses to spinal cord injury:role of astrocytes and microglia

引用

Neural Regeneration Research 2024年第8期19卷 1678-1685页

作者： Sydney Brockie Cindy Zhou michael g.Fehlings Division of genetics and Development Krembil Research InstituteUniversity Health NetworkTorontoONCanada Institute of medical Science University of TorontoTorontoONCanada Division of Neurosurgery and Spine Program Department of SurgeryUniversity of TorontoTorontoONCanada

Spinal cord injury can be traumatic or non-traumatic in origin,with the latter rising in incidence and prevalence with the aging demographics of our *** r,as the global population ages,individuals with co-existent degenerative spinal pathology comprise a growing number of traumatic spinal cord injury cases,especially involving the cervical spinal *** makes recovery and treatment approaches particula rly challenging as age and comorbidities may limit regenerative *** these reasons,it is critical to better understand the complex milieu of spinal cord injury lesion pathobiology and the ensuing inflammatory *** review discusses microglia-specific purinergic and cytokine signaling pathways,as well as microglial modulation of synaptic stability and plasticity after ***,we evaluate the role of astrocytes in neurotransmission and calcium signaling,as well as their border-forming response to neural *** the inflammatory and reparative roles of these cells have eluded our complete understanding and remain key therapeutic targets due to their extensive structural and functional roles in the nervous *** advances have shed light on the roles of glia in neurotransmission and reparative injury responses that will change how interventions are *** key processes and existing knowledge gaps will allow future research to effectively target these cells and harness their regenerative potential.

关键词： astrocytes glial signaling microglia spinal cord injury synaptic transmission

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

ground-based and additional science support for SmILE

引用

Earth and Planetary Physics 2024年第1期8卷 275-298页

作者： J.A.Carter m.Dunlop C.Forsyth K.Oksavik E.Donovon A.Kavanagh S.E.milan T.Sergienko R.C.Fear D.g.Sibeck m.Connors T.Yeoman X.Tan m.g.g.T.Taylor K.mcWilliams J.gjerloev R.Barnes D.D.Billet g.Chisham A.Dimmock m.P.Freeman D.-S.Han m.D.Hartinger S.-Y.W.Hsieh Z.-J.Hu m.K.James L.Juusola K.Kauristie E.A.Kronberg m.Lester J.manuel J.matzka I.mcCrea Y.miyoshi J.Rae L.Ren F.Sigernes E.Spanswick K.Sterne A.Steuwer T.Sun m.-T.Walach B.Walsh C.Wang J.Weygand J.Wild J.Yan J.Zhang Q.-H.Zhang Planetary Sciences group School of Physics and AstronomyUniversity of LeicesterUniversity RoadLeicesterLE17RHUK Rutherford Appleton Laboratory Space Science Technology Facilities CouncilOxfordshireUK School of Space and Environment Beihang UniversityBeijing 100191China Key Laboratory of Space Environment monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100017China Department of Space and Climate Physics UCLMullard Space Science LaboratoryHolmbury St.MaryDorkingSurreyRH56NTUK Birkeland Centre for Space Science Department of Physics and Technology.University of BergenBergenNorway Department of Physics and Astronomy University of Calgary2500 University DriveCalgaryAlbertaCanada T2N 1N4 British Antarctic Survey CambridgeUK Swedish Institute of Space Physics KirunaSweden West Highfield Campus University of SouthamptonUniversity RoadSO171BJUK goddard Space Flight Center NASAGreenbeltMarylandUSA Athabasca University AthabascaCanada ESTEC European Space AgencyNetherlands University of Saskatchewan SaskatoonCanada The Johns Hopkins University Applied Physics Laboratory LaurelMarylandUSA Swedish Institude of Space Physics UppsalaSE 75121Sweden Tongji University Shanghai 200092China Center for Space Plasma Physics Space Science Institute4765 Walnut Street Suite BBoulderColorado80301USA Polar Research Institute of China Shanghai 200136China Finnish meteorological Institute(FmI) Finland Department of Earth and Environmental Sciences(geophysics) Ludwig Maximilian University of Munich(LMU)MunichTheresienstr.41MunichD-80333Germany Canadian Space Agency MontrealCanada gFZ german Research Centre for geosciences PotsdamGermany Nagoya University Institute for Space Earth Environment ResearchCenter for Integrated Data ScienceNagoyaAichiJP 464-8601 Northumbria University Newcastle upon TyneTyne and WearUK NE18ST National Space Science Center Chinese Academy SciencesBeijing 100190China Arctic geophysics University Centre in Svalbard

The joint European Space Agency and Chinese Academy of Sciences Solar wind magnetosphere Ionosphere Link Explorer(SmILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere *** these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SmILE ***,we describe current community efforts to prepare for SmILE,and the benefits and context various experiments that have explicitly expressed support for SmILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the ground-based and Additional Science Working group,is facilitating these *** include constructing an online SmILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft *** anticipate growing interest and community engagement with the SmILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.

关键词： magnetosphere ionosphere magnetosphere-ionosphere coupling ground-based experimentation SmILE conjunctions missions

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

Proton-neutron symplectic model description of ^(106)Cd

引用

Chinese Physics C 2024年第3期48卷 169-179页

作者： H.g.ganev Joint Institute for Nuclear Research DubnaRussia Institute of mechanics Bulgarian Academy of SciencesSofiaBulgaria

In this study,a microscopic shell-model description of the low-lying collective states in the weakly deformed nucleus ^(106)Cd within the recently proposed microscopic version of the Bohr-mottelson model is provided.A good description of the excitation energies of the lowest ground,γ,andβquasibands is obtained without the adjustable kinetic energy ***,γdegrees of freedom are shown to play a crucial role in the description of spectroscopy of this nucleus.A modified SU(3)SU(3)preserving high-order interaction is used to produce aγ-unstable type of odd-even staggering,observed experimentally between the states of the quasi-γ*** current approach enables the characterization of observed intraband and interband quadrupole *** findings of this study propose an alternative interpretation of the fundamental question regarding the nature of low-energy vibrations,as well as the emergence of deformation and collectivity in weakly deformed atomic nuclei.

关键词： shell-model version of the Bohr-mottelson model proton-neutron symplectic model Sp(12,R)dynamical algebra quadrupole dynamics

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

Facile synthesis of samarium and cerium doped double perovskite cobaltite with enhanced dielectric response

引用

Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kamran m.Anis-ur-Rehman Applied Thermal Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm-Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm_(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specimens were synthesized by a facile synthesis technique named the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice parameters,lattice strain,unit cell volume,and bulk density were determined using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional *** and experimental values discrepancy is less than 1%.A scanning electron microscope was used for performing a microstructural *** SEm images demonstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,and tangent loss were also studied as a function of frequency(20 Hz-3 mHz)at different temperatures(100-500℃).All synthesized samples were examined using non-linear Debye's function to determine their spreading factor and relaxation *** specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechanism was examined in the studied samples with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 compositions follow non-overlapping polaron *** studied specimen Bi_(2)Ca_(1.9)0Sm_(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm^(3))displays a high electrical conductivity(∼46.1 S/cm).These findings correspond to those published for ceramics made from calcium cobaltite using solid-state reactions(5.0-26.0 S/cm).

关键词： Bismuth calcium samarium cerium cobaltite (BCSCCO) Spreading factor Conduction mechanism Rare earths

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

Coupled Inversion of Pressure and Tiltmeter Data for mapping Hydraulic Fracture geometry

引用

Acta mechanica Solida Sinica 2024年第3期37卷 396-405页

作者： Zuorong Chen Xiaofang Jiang Zhejun Pan Robert g.Jeffrey National Key Laboratory of Continental Shale Oil Northeast Petroleum UniversityDaqing163318China SCT Operation Pty.Ltd. PO Box 824WollongongNSW2520Australia

Pressure and tilt data are jointly inverted to simultaneously map the orientation and dimensions of a hydraulic *** deformation induced by a fracture under internal pressure is modeled using the distributed dislocation *** planar fracture is represented by four quarter ellipses,joined at the center and sharing *** configuration provides a straightforward model for characterizing asymmetric fracture *** inverse problem of mapping the fracture geometry is formulated using the Bayesian probabilistic method,combining the a priori information on the fracture model with updated information from pressure and tilt *** the nonlinear inverse problem is achieved by pseudo-randomly sampling the posterior probability distribution through the markov chain monte Carlo *** resulting posterior probability distribution is then explored to assess uncertainty,resolution,and correlation between model *** experiments are conducted to verify the accuracy and validity of the proposed analysis method in mapping the fracture geometry using synthetic pressure and tilt data.

关键词： Hydraulic fracture mapping Coupled inversion Tilt Treating pressure

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

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：