检索结果-南通市图书馆

International Journal of Digital Earth 2008年第2期1卷 196-220页

作者： b.k.wylie L.Zhang N.bliss L.Ji L.L.Tieszen W.M.Jolly SAIC USGS Earth Resources Observation and Science(EROS)CenterSioux FallsSD 57198USA.Work performed under USGS contract 03CRCN0001 USGS EROS Center Sioux FallsSD 57198USA USDA Forest Service Fire Sciences LaboratoryMissoulaMT59808

High-latitude ecosystems are exposed to more pronounced warming effects than other parts of the *** develop a technique to monitor ecological changes in a way that distinguishes climate influences from *** this study,we account for climatic influences on Alaskan boreal forest performance with a datadriven *** defined ecosystem performance anomalies(EPA)using the residuals of the model and made annual maps of *** areas(88%)did not have anomalous ecosystem performance for at least 6 of 8 years between 1996 and *** with underperforming EPA(10%)often indicate areas associated with recent fires and areas of possible insect infestation or drying soil related to permafrost *** areas(2%)occurred in older fire recovery areas where increased deciduous vegetation components are *** EPA measure was validated with composite burn index data and Landsat vegetation indices near and within burned areas.

关键词： climate change anomaly performance boreal Alaska Yukon River

Neuroinflammation revisited through the microglial lens

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

Neural Regeneration Research 2025年第7期20卷 1989-1990页

作者： Renato Socodato João b.Relvas Institute of Research and Innovation in Health(i3S)and Institute for Molecular and Cell biology(IbMC) University of PortoPortoPortugal Department of biomedicine Faculty of Medicine of the University of Porto(FMUP)PortoPortugal

Neuroimmunology is emerging as a pivotal field,shedding light on the intricate dialogues between the central nervous system(CNS)and the immune *** exploration is particularly significant in understanding microglia,the CNS’s innate immune cells,beyond the conventional conflation of“neuroinflammation”and“microglial activation.”This conflation has clouded the true complexity of these processes,potentially stalling scientific progress and the development of new *** challenge the long-standing perspectives that have oversimplified these interactions,advocating for a deeper exploration of the dynamic relationship between neuroinflammation and microglial *** dissecting specific molecular pathways,we aim to illuminate their elaborate roles in neuroinflammatory responses,especially in the context of Alzheimer’s disease(AD).Here,neuroinflammation is not merely a passive observer or a direct antagonist but a complex agent in the disease’s *** article calls for a significant paradigm shift towards an integrative,multi-omics approach to *** such a comprehensive framework is crucial for advancing our understanding of neuroinflammatory conditions and paving the way for targeted therapeutic strategies for brain diseases.

关键词： inflammation simplified activation

Synthesis, spectroscopic characterization, and thermal decomposition kinetics of some lanthanide(III) nitrate complexes of 2-(N-o-hydroxyacetophenone) amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2008年第4期26卷 463-468页

作者： k. Mohanan M. Thankamony b. Sindhu kumari Department of Chemistry University of Kerala Kariavattom Campus Trivandrum-695 581. Kerala India

Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb（Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） formed by the condensation of o-hydroxyacetophenone and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesized and characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility data, UV-Visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to the metal ion through ONO donor sequence. A coordination number nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and kinetic parameters were calculated using Coats-Redfem equation. The decomposition reactions followed random nucleation mechanism with one nucleus on each particle.

关键词： lanthanides o-hydroxyacetophenone molar conductance magnetic susceptibility thermal study rare earths

THEORETICAL ANALYSIS OF A HIGH-MACH-NUMbER DILUTE INELASTIC GAS IMPINGING ON A SURFACE

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2010年第2期30卷 633-644页

作者： Yu Hui Deng Jonathan J. wylie Qiang Zhang Department of Mathematics City University of Hong Kong 83 Tat Chee Avenue Kowloon Tong Hong Kong China Center for applied Mathematics and Statistics New Jersey Institute of Technology Newark NJ 07102 U.S.A.

We consider a problem of a 2-dimensional high-Mach-number dilute inelastic gas originating from infinity impinging on an oblique surface of infinite length. by analyzing probabilities of particle-particle collisions, we derive an analytical formula for the mean force experienced by the surface when the system is dilute. We also derive conditions for the validity of our theory.

关键词： dilute inelastic gas high-Mach-number force

Nonsmooth Semi-Infinite Minmax Programming Involving Generalized(Φ, ρ)-Invexity

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2015年第4期28卷 857-875页

作者： UPADHYAY b b MISHRA S k Department of basic Sciences & Humanities National Institute of Technology

This paper introduces some new generalizations of the concept of （~, p）-invexity for non- differentiable locally Lipschitz functions using the tools of Clarke subdifferential. These functions are used to derive the necessary and sufficient optimality conditions for a class of nonsmooth semi-infinite minmax programming problems, where set of restrictions are indexed in a compact set. Utilizing the sufficient optimality conditions, the authors formulate three types of dual models and establish weak and strong duality results. The results of the paper extend and unify naturally some earlier results from the literature.

关键词： Duality, generalized invexity locally Lipschitz functions, minmax programming, semi-infinite programming.

Microstructure and Mechanical Properties of Mg–7.4% Al Alloy Matrix Composites Reinforced by Nanocrystalline Al–Ca Intermetallic Particles

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 444-448页

作者： A.k.Chaubey b.b.Jha b.k.Mishra Institute of Minerals and Materials Technology (IMMT)

Mg-7.6% Al （in mass fraction） alloy matrix composites reinforced with different volume fractions of nano- crystalline Al3Cas particles were synthesized by powder metallurgy, and the effect of the volume fraction of reinforcement on the mechanical properties was studied. Room temperature compression test reveals considerable improvement on mechanical properties as compared to unreinforced matrix. The compressive strength increases from 683 MPa for unre- inforced alloy matrix to about 767 and 823 MPa for the samples having 20 and 40 vol% of reinforcement, respectively, while retaining appreciable plastic deformation ranging between 12 and 24%. The specific strength of the composites increased significantly, demonstrating the effectiveness of the low-density AlaCas reinforcement.

关键词： Intermetallics Consolidation Dispersion strengthening Powder metallurgy Mechanicalproperty Electron microscopy

Rare earth-doped mixed Ni-Cu-Zn ferrites as an effective photocatalytic agent for active degradation of Rhodamine b dye

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第3期42卷 488-496,I0003页

作者： Swapnil A.Jadhav Sandeep b.Somvanshi Sudarshan S.Gawali kranti Zakde k.M.Jadhav Department of Physics Dr.Babasaheb Ambedkar Marathwada UniversityAurangabad431004MaharashtraIndia School of Materials Engineering Purdue UniversityWest Lafayette 47906USA University Department of basic and Applied Sciences MGM UniversityAurangabad431003MaharashtraIndia

In this study, a series of Gd^(3+)-doped mixed Ni-Cu-Zn ferrites with composition of Zn_(0.5)Ni_(0.3)Cu_(0.2)Fe_(2-x)Gd_(x)O_(4)(x = 0, 0.025, 0.05, 0.075, 0.1) was prepared using self-ignition sol-gel method. The prepared nanoparticles with an average size ranging from 22 to 26 nm show a single-phase cubic structure belonging to the spinel matrix. A rise in the Gd^(3+)concentration leads to an increase in crystallite size and lattice parameter. In Fourier transform infrared spectra, two main absorption bands belonging to the spinel structure are observed. The high-frequency bands(v_(1)) represent the tetrahedral complex, while the lowfrequency bands(v_(2)) signify the octahedral complex. The optical bandgap of the nanoferrites is found within the range of 2.91 to 2.41 eV, depending on their size. The magnetic characteristics of the material,such as saturation magnetization and coercivity are significantly altered with the concentration of Gd^(3+)in the solution. Using Rhodamine b(Rhb) as a model organic pollutant, an in-depth investigation of the photocatalytic activity of the compounds was carried out. The present outcomes show that adding an adequate amount of Gd^(3+)significantly enhances the number of hydroxyl radicals produced by the ferrite,in turn, increasing the photocatalytic activity of the material. Mechanism elucidated by scavenger studies reveals that ·OH and holes are the primary reactive radicals responsible for the degradation *** photocatalysts show an insignificant performance loss in five consecutive cycles. Thus, it is concluded that these photocatalysts are highly suitable for the remediation of dye-contaminated wastewater.

关键词： Gd^(3+)substitution Spinel ferrite Structural properties Magnetic properties Photocatalysis Rare earths

Structural and photoluminescence studies on europium-doped lithium tetraborate(Eu:Li2b4O7)single crystal grown by microtube Czochralski(μT-Cz)technique

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2016年第5期25卷 429-433页

作者： A kumaresh R Arun kumar N Ravikumar U Madhusoodanan b S Panigrahi k Marimuthu M Anuradha GRD Centre for Materials Research PSG College of TechnologyCoimbatoreIndia Department of Physics PSG College of TechnologyCoimbatoreIndia Radiation Safety Division Indira Gandhi Centre for Atomic ResearchKalpakkamIndia Department of Physics Gandhigram Rural UniversityDindigulIndia PSG Institute of Advanced Studies CoimbatoreIndia

Rare earth europium（Eu（3＋））-doped lithium tetraborate（Eu：Li_2b_4O_7） crystal is grown from its stoichiometric melt by microtube Czochralski pulling technique（μT-Cz） for the first time. The grown crystals are subjected to powder x-ray diffraction（PXRD） analysis which reveals the tetragonal crystal structure of the crystals. UV–vis–NIR spectral analysis is carried out to study the optical characteristics of the grown crystals. The crystal is transparent in the entire visible region, and the lower cutoff is observed to be at 304 nm. The existence of bO_3 and bO_4 bonding structure and the molecular associations are analyzed by Fourier transform infrared（FTIR） spectroscopy. The results of excitation and emission-photoluminescence spectra of europium ion incorporated in lithium tetraborate（LTb） single crystal reveal that the observations of peaks at 258,297, and 318 nm in the excitation spectra and peaks at 579, 591, 597, 613, and 651 nm are observed in the emission *** chromaticity coordinates are calculated from the emission spectra, and the emission intensity of the grown crystal is characterized through a CIE 1931（Commission International d＇Eclairage） color chromaticity diagram.

关键词： crystal growth optical material growth from melt photoluminescence study

Properties of cement grout modified with ultra-fine slag

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2018年第1期12卷 58-66页

作者： Sowmini GOPINATHAN k b ANAND Department of CiviI Engineering Amrita School of Engineering Coimbatore Amrita ~Tshwa Vidyapeetham Amrita University Pincode 641 112 India

The purpose of the study is to obtain a cement grout with improved performance. The grout mixes of the present study contain cement, ultra-fine slag （UFS）, super plasticizer and water. Properties like flowability, bleeding, compressive strength and shrinkage of cement grouts have been studied. Rheological parameters were also studied in order to explain the grout workability. The results show that, cement replacement with slag in grouts could reduce bleeding substantially without affecting the workability of the mixes. Introduction of slag enhanced the compressive strength and reduced shrinkage reasonably. Ultra-fine slag can be used as a supplementary cementitious material in cementitious grouts in order to improve the grout behavior.

关键词： cement grout ultra-fine slag flowability bleeding viscosity

Analysis of non-symmetrical flapping airfoils

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 Mechanica Sinica 2009年第4期25卷 433-450页

作者： W.b.Tay k.b.Lim Department of Mechanical Engineering National University of Singapore

Simulations have been done to assess the lift, thrust and propulsive efficiency of different types of non-symmetrical airfoils under different flapping configurations. The variables involved are reduced frequency, Strouhal number, pitch amplitude and phase angle. In order to analyze the variables more efficiently, the design of experiments using the response surface methodology is applied. Results show that both the variables and shape of the airfoil have a profound effect on the lift, thrust, and efficiency. by using non- symmetrical airfoils, average lift coefficient as high as 2.23 can be obtained. The average thrust coefficient and efficiency also reach high values of 2.53 and 0.61, respectively. The lift production is highly dependent on the airfoil＇s shape while thrust production is influenced more heavily by the variables. Efficiency falls somewhere in between. Two-factor interac- tions are found to exist among the variables. This shows that it is not sufficient to analyze each variable individually. Vorticity diagrams are analyzed to explain the results obtained. Overall, the S1020 airfoil is able to provide relatively good efficiency and at the same time generate high thrust and lift force. These results aid in the design of a better ornithopter＇s wing.

关键词： Flapping Non-symmetrical Design ofexperiments Ornithopter Airfoil