检索结果-南通市图书馆

Synthesis,characterization and thermolysis of lanthanide metal nitrate complexes with 1,10-phenanthroline,Part-95

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2014年第6期32卷 545-552页

作者： Nibha B.P.Baranwal Gurdip Singh Constantin G.Daniliuc Department of Chemistry DDU Gorakhpur University organisch–chemisches institut Universitat Munster

The nitrate complexes of cerium, praseodymium and neodymium with 1,10-phenanthroline （phen） of general formula [Ln（phen）2（NO3）2（H2O）2]·NO3 （where, Ln=Ce, Pr and Nd） were prepared and characterized by X-ray crystallography. Thermolysis of these complexes was investigated by simultaneous thermogravimetry （TG） and differential thermal analysis （DTA）. Isothermal TG was taken to evaluate the kinetic parameters using model fitting as well as model free isoconversional methods. The thermolytic pathways were also suggested, which involves decomposition followed by ignition. All the three complexes had coordination number ten and showed multistep decompositions. In order to evaluate the response of rapid heating, ignition delay （Di） measurements were undertaken. The activation energies for ignition were found to decrease in the order： Nd〉Pr〉Ce.

关键词： crystal structure metal nitrate kinetics isoconversional model fitting ignition delay rare earths

Dependence of impact regime boundaries on the initial temperatures of projectiles and targets

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 49-57页

作者： Stefano Signetti Andreas Heine Fraunhofer-institut für Kurzzeitdynamik Ernst-Mach-InstitutEMIErnst-Zermelo-Str.479104 Freiburg im BreisgauGermany

Towards higher impact velocities,ballistic events are increasingly determined by the material *** effects might range from moderate thermal softening to full phase *** particular,it is of great interest to quantify the conditions for incipient or full melting of metals during impact interactions,which result in a transition from still strength-affected to hydrodynamic material *** this work,we investigate to which extent the respective melting thresholds are also dependent on the initial,and generally elevated,temperatures of projectiles and targets before *** is studied through the application of a model developed recently by the authors to characterize the transition regime between high-velocity and hypervelocity impact,for which the melting thresholds of materials were used as the defining *** obtained results are expected to be of general interest for ballistic application cases where projectiles or targets are *** conditions might result,for example,from aerodynamic forces acting onto a projectile during atmospheric flight,explosive shapedcharge-jet formation or armor exposure to environmental *** performed analyses also broaden the scientific understanding of the relevance of temperature in penetration events,generally known since the 1960s,but often not considered thoroughly in impact studies.

关键词： Ballistic impact Thermal effects Metallic targets Energy partitioning Homologous temperature

Clustering of voltage-gated ion channels as an evolutionary trigger of myelin formation

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第8期19卷 1631-1632页

作者： Henrike Ohm Simone Rey Christian Klambt institut fur Neuro-und Verhaltensbiologie MunsterGermany

Neurons carry apical dendrites that perceive information and a basal axon that transmits the computed information towards its to *** axon originates at the axon hillock which is followed by the axon initial ***,action potentials are initiated that are based on millisecond long openings of specific voltagegated sodium and potassium channels that are conserved in all parahoxozoa(Placozoa,Cnidaria,Bilateria)(Li et al.,2015).

关键词： initiated carry potassium

Easy access to pharmaceutically relevant heterocycles by catalytic reactions involving a-imino gold carbene intermediates

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2020年第3期14卷 317-349页

作者： Ximei Zhao Matthias Rudolph Abdullah M.Asiri A.Stephen K.Hashmi organisch-chemisches institut Heidelberg University69120 HeidelbergGermany Chemistry Department Faculty of Science21589 JeddahSaudi Arabia

This review summarizes recent advances in the field of gold-catalyzed synthesis of pharmaceutically relevant aza-heterocycles via in situ generated a-imino gold carbene complexes as intermediates.

关键词： gold heterocycles alkynes

The current status and future development of high-temperature conventional superconductivity

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

National Science Review 2024年第7期11卷 18-20页

作者： Mikhail I.Eremets High Pressure Chemistry and Physics Group Max-Planck-Institut für Chemie

This survey highlights key advancements in high-temperature superconductivity in hydrogen-rich materials, emphasizing the robust evidence and reproducibility of superconductivity under challenging experimental conditions of megabar pressures. In the near future, achieving room-temperature superconductivity is highly probable, and the field is expected to transition towards near-ambient-pressure superconductivity.

关键词：

Virtual brain twins: from basic neuroscience to clinical use

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第5期11卷 72-86页

作者： Huifang E.Wang Paul Triebkorn Martin Breyton Borana Dollomaja Jean-Didier Lemarechal Spase Petkoski Pierpaolo Sorrentino Damien Depannemaecker Meysam Hashemi Viktor K.Jirsa Aix Marseille Université Institut National de la Santéet de la Recherche Médicale Institut de Neurosciences des Systèmes(INS) UMR1106 Service de Pharmacologie Clinique et Pharmacosurveillance AP–HM

Virtual brain twins are personalized, generative and adaptive brain models based on data from an individual's brain for scientific and clinical use. After a description of the key elements of virtual brain twins,we present the standard model for personalized whole-brain network models. The personalization is accomplished using a subject's brain imaging data by three means:(1) assemble cortical and subcortical areas in the subject-specific brain space;(2) directly map connectivity into the brain models, which can be generalized to other parameters; and(3) estimate relevant parameters through model inversion, typically using probabilistic machine learning. We present the use of personalized whole-brain network models in healthy ageing and five clinical diseases: epilepsy, Alzheimer's disease, multiple sclerosis, Parkinson's disease and psychiatric disorders. Specifically, we introduce spatial masks for relevant parameters and demonstrate their use based on the physiological and pathophysiological hypotheses. Finally, we pinpoint the key challenges and future directions.

关键词： virtual brain twin personalized modeling inference neuroscience brain disorder

Inertial mixing of acoustically levitated droplets for time-lapse protein crystallography

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Droplet 2024年第3期3卷 91-101页

作者： Soichiro Tsujino Yohei Sato Shichao Jia Michal W.Kepa Sofia Trampari Takashi Tomizaki Division of Biology and Chemistry Paul Scherrer InstitutVilligenSwitzerland Swiss Nanoscience institute University of BaselBaselSwitzerland Division Scientific Computing Theory and DataPaul Scherrer InstitutVilligenSwitzerland Biozentrum University of BaselBaselSwitzerland Photon Science Division Paul Scherrer InstitutVilligenSwitzerland

Varying the chemical consistency of acoustically levitated droplets opens up an in situ study of chemical and biochemical reactions in small ***,the opti-mization of the mixing time and the minimization of the positional instability induced by solution dispensing are necessary for practical applications such as the study of the transient state of macromolecules crystallography during the ligand binding *** this purpose,we study the inertial mixing in a configuration compatible with the room-temperature crystallography using the acoustic levitation diffractometer,therein solution drops ejected at high velocity collide and coalesce with droplets dis-pensed on acoustically levitated and rotating polymer thin-film sample *** the proposed method,we are able to achieve the mixing time of∼0.1 s for sub-micro and a few microliter *** observed short mixing time is ascribed to the rapid penetration of the solution into the droplets and confirmed by a computational fluid dynamic *** demonstrated accelerated solution mixing is tested in a pilot time-lapse protein crystallography experiment using the acoustic levitation *** results indicate the detection of transient ligand binding state within 2 s after the solution dispensing,suggesting the feasibility of the proposed method for studying slow biochemical processes.

关键词： mixing droplets transient

Spectroscopic Observations of Ten Galactic Wolf-Rayet Stars at Bosscha Observatory:Determination of Stellar Parameters and Mass-loss Rates

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

Research in Astronomy and Astrophysics 2024年第9期24卷 7-27页

作者： Hakim Luthfi Malasan Bakuh Danang Setyo Budi Department of Astronomy Faculty of Mathematics and Natural SciencesInstitut Teknologi BandungBandung 40132Indonesia Bosscha Observatory Institut Teknologi BandungLembang 40391Indonesia Master Program in Astronomy Faculty of Mathematics and Natural SciencesInstitut Teknologi BandungJl.Ganesha No.10Bandung 40132Indonesia

We present optical spectra of 10 Galactic Wolf-Rayet(WR)stars that consist of five WN and five WC *** optical observation was conducted using a low-resolution spectrograph NEO-R1000(λ/Δλ~1000)at GAO-ITB RTS(27.94 cm,F/10.0),Bosscha Observatory,*** implemented stellar atmosphere Postdam Wolf-Rayet(PoWR)grid modeling to derive stellar *** normalized optical spectrum can be used to find the best model from the available PoWR grid,then we could derive stellar temperature and transformation *** derive luminosity,stellar radius and color excess,we conducted a Spectral Energy Distribution(SED)analysis with additional data on the near-ultraviolet spectrum from the International Ultraviolet Explorer(IUE)database,and UBV and 2MASS JHK broadband filter *** analysis to derive asymptotic terminal wind velocity was conducted from the P-Cygni profile analysis of the high-resolution IUE ultraviolet *** previously derived parameters,we could determine the mass loss rate of the WR ***,we compared our results with previous work that used PoWR code and the differences are not more than 20%.We conclude that the PoWR spectral grid is sufficient to derive WR stellar parameters quickly and could provide more accurate initial parameter input to the PoWR program code.

关键词： stars:massive stars:mass-loss stars:Wolf-Rayet stars:atmospheres stars:winds outflows

Experimental and numerical investigation on alternatives to sandy gravel

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 130-141页

作者： V.Denefeld H.Aurich Fraunhofer institute for High-Speed Dynamics Ernst-Mach-Institut(EMI)Ernst-Zermelo-Str.479104FreiburgGermany Fraunhofer institute for High-Speed Dynamics Ernst-Mach-Institut(EMI)Am Christianswuhr 279400KandernGermany

The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored *** Allied Engineering Publication,AEP-55,Volume 2 document outlines the test conditions for underbelly improvised explosive device(IEDs),which must be buried in water-saturated sandy *** use of sandy gravel has some drawbacks,for instance reproducibility,time consumption,and *** paper focuses on the investigation of four alternatives to sandy gravel,which could produce similar specific and cumulative impulses:a concrete pot filled with water,a concrete pot filled with quartz sand,a steel pot without filling and a concrete pot filled with glass spheres(diameter 200μm—300μm)and different water *** impulses are measured with a ring technology developed at the Fraunhofer EMI.A numerical soil model based on the work of Marrs,2014 and Fi serov a,2006 and considering the soil moisture was used to simulate the experiments with glass spheres at different water contents,showing much better agreement with the experiments than the classical Laine&Sandvik model,even for high saturation *** results can be used to create new test conditions at original scale that are more cost-effective,more reproducible and simpler to manage in comparison to the current tests carried out with STANAG sandy gravel.

关键词： Improvised explosive device(IED) Specific impulse Momentum transfer Sandy gravel Glass spheres Numerical model Soil moisture