检索结果-南通市图书馆

Rare Metals 2024年第7期43卷 3356-3369页

作者： Aydar Rakhmatullin frantisek Simko Didier Zanghi Zuzana Netriová Ilya BPolovov Ayrat Dimiev Konstantin V.Maksimtsev Catherine Bessada Michal Korenko Conditions Extrêmes et Materiaux:Haute Température et Irradiation CEMHTIUPR 3079-CNRS Univ Orleans45071 OrleansFrance Department of Molten Systems Institute of Inorganic ChemistrySlovak Academy of Sciences84536 BratislavaSlovakia Centre of Excellence for Advanced Materials Application-CEMEA Slovak Academy of Sciences84511Bratislava.Slovakia Department of Rare Metals and Nanomaterials Institute of Physics and TechnologyUral Federal UniversityUral Federal University620002 EkaterinburgRussia Alexander Butlerov Institute of Chemistry Kazan Federal University420008KazanRussia

For the first time,the mechanism of metal aluminum dissolution in NaF-ScF_(3) eutectic melts and the chemical interaction between the constituents of this mixture have been thoroughly studied by a combination of differential thermal analysis(DTA),high temperature and solid-state nuclear magnetic resonance(NMR),and X-ray diffraction(XRD) coupled with the molecular dynamic *** formation of an insoluble Al_(3)Sc alloy in molten(NaF-ScF_(3))_(eut)system was proven,and the chemical mechanism of this aluminothermic Al_(3)Sc alloy production was *** ex situ examinations bring to light the formation of NaScF_4 and solid solution of Na_(3)(Al,Sc)F_(6) in cooled *** molecular dynamics calculations of the bath allow us to construct the structural model and to predict viscosity,density and electrical conductivity of the reagent melt to help to optimize the conditions of the alloy synthesis.

关键词： Scandium Alloy Molten salts NMR Molecular dynamics

同方期刊数据库

Electrical conductivity and viscosity of cryolite electrolytes for solar grade silicon(Si-SoG) electrowinning

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2014年第12期24卷 3944-3948页

作者： Michal KORENKO Zuzana VASKOV frantiek imko Michal IMURDA Marta AMBROV 石忠宁 Institute of Inorganic Chemistry Slovak Academy of SciencesDúbravská cesta 9SK–84536 Bratislava Slovakia Institute of Inorganic Chemistry Technology and Materials Slovak University of TechnologyRadlinskeho 9SK–81237 Bratislava Slovakia 东北大学材料与冶金学院

Electrical conductivity of molten binary and ternary mixtures based on the system NaF-AlF3-SiO2 was investigated by means of a tube–cell （made of pyrolytic boron nitride） with stationary electrodes. Viscosity of the binary system Na3AlF6-SiO2 was measured by computerized torsion pendulum method. It was found that conductivity and viscosity varied linearly with temperature in all investigated mixtures. Obtained content dependence of electrical conductivity （isotherms） was divided into two parts. First, one represented the content region up to 10%（mole fraction） of SiO2;second, the region was with a higher content of SiO2 （from 10%up to 40%）. While the conductivity considerably decreased with content of SiO2 in the second part; it surprisingly rose in the low content range. A small addition of SiO2 to the molten cryolite （up to 10%） could slightly increase viscosity, but had no influence on the slope of this dependence since it is responsible for a glassy-networks formation in the melt. Further addition of SiO2 to the molten cryolite had a huge effect on the viscosity.

关键词： electrical conductivity viscosity solar grade silicon molten salts molten cryolite-silica melts

Sex differences in the risk of retinopathy of prematurity:a systematic review,frequentist and Bayesian meta‑analysis,and meta‑regression

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第4期20卷 340-352页

作者： Tamara M.Hundscheid Silvia Gulden Mohamad F.Almutairi františek Bartoš Giacomo Cavallaro Eduardo Villamor Division of Neonatology Department of PediatricsMosaKids Children’s HospitalMaastricht University Medical Center(MUMC+)School for Oncology and Reproduction(GROW)Maastricht UniversityP.Debyelaan 25.P.O.Box 58006202 AZ MaastrichtThe Netherlands Neonatal Intensive Care Unit Sant’Anna HospitalComoItaly Department of Psychology University of Amsterdam1001 NK AmsterdamThe Netherlands Neonatal Intensive Care Unit Fondazione IRCCS Ca’Granda Ospedale Maggiore PoliclinicoMilanItaly

Background Retinopathy of prematurity(ROP)is generally considered to be more frequent in males than in ***,it is not known whether sex differences in ROP affect all degrees of the condition,are global and have changed as neonatology has *** aimed to conduct a systematic review and meta-analysis of studies addressing sex differences in the risk of developing *** PubMed/MEDLINE and Embase databases were *** frequentist,random-effects risk ratio(RR)and 95%confidence interval(CI)were *** model averaged(BMA)meta-analysis was used to calculate the Bayes factors(BFs).The BF10 is the ratio of the probability of the data under the alternative hypothesis(H1)over the probability of the data under the null hypothesis(H0).Results We included 205 studies(867,252 infants).Frequentist meta-analysis showed a positive association between male sex and severe ROP(113 studies,RR=1.14,95%CI=1.07–1.22)but no association with any ROP(144 studies,RR=1.00,95%CI=0.96–1.03).BMA showed extreme evidence in favor of H1 for severe ROP(BF10=71,174)and strong evidence in favor of H0 for any ROP(BF10=0.05).The association between male sex and severe ROP remained stable over time and was present only in cohorts from countries with a high or high-middle sociodemographic *** Our study confirms the presence of a male disadvantage in severe ROP but not in less severe forms of the *** are variations in the sex differences in ROP,depending on geographical location and sociodemographic level of the countries.

关键词： Oxidative stress Retinopathy of prematurity Sex characteristics

Introducing a New Tool for Studying Unstable Systems

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 Automation and computing 2014年第6期11卷 580-587页

作者： frantiek Gazdo Tomas Bata University in Zlín Faculty of Applied Informatics nam.T.G.Masaryka 5555760 01 Zlin Czech Republic

This paper presents the starting project of a web site focussed on unstable systems. It is a web-based database in a bilingual version(English/Czech), which can be used as an information database for models of unstable processes. The web site contains the mathematical models of such systems, including their simulation files together with basic information about the stability of dynamic systems. The paper outlines the motivation for the development of this database, presents its basic structure, and discusses several models from the site. The areas of prospective usage are also suggested together with the possible directions of further development of this project. The contribution ends with a case study using the database for control system analysis and design of the Amira inverted pendulum. The systematic polynomial approach is fruitfully utilised for the task together with some useful tools from the robust control theory.

关键词： Unstable systems stability modelling simulation database robust control polynomial approach

Effects of no mating on the female adults and embryonic development of Schistocerca gregaria (Orthoptera: Acrididae)

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2013年第26期58卷 3244-3247页

作者： WANG FangHai SEHNAL frantiek Institute of Entomology & State Key Laboratory for Biocontrol Sun Yat-sen University Institute of Entomology Academy of SciencesBranisovská 31 370 11 eské Budějovice Czech Republic

The newly emerged adult females of Schistocerca gregaria were separated and kept in the rearing conditions without males to examine the detailed developmental characteristic of the no mating females and carefully observed the developmental progress of non-fertilised eggs laid by virgin females. The results showed that the females kept without males survived in average 43 d, i.e. 58% of the life span of mated controls, and laid correspondingly fewer egg pods. The size of egg batches, the weight of eggs, and their content of ecdysteroids were normal but the hatch rate was reduced to 18.27%. Blocks of early embryogenesis (58.43%) and hatching failures (23.29%) were the major causes of death. Moreover, most of the hatched insects died during the postembryonic development and only a few females reached the adult stage. All insects that developed until the penultimate or last larval instar or reached the adult stage were females.

关键词：胚胎发育女性交配沙漠直翅目孵化率降低蝗科成人

From individual elements to macroscopic materials: in search of new superconductors via machine learning

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2023年第1期9卷 1640-1648页

作者： Claudio Pereti Kevin Bernot Thierry Guizouarn františek Laufek Anna Vymazalová Luca Bindi Roberta Sessoli Duccio Fanelli Dipartimento di Fisica e Astronomia Universitàdi FirenzeINFN and CSDCVia Sansone 150019 Sesto FiorentinoFirenzeItaly Univ.Rennes Universitéde Rennes 1INSA RennesCNRSISCR(Institut des Sciences Chimiques de Rennes)UMR 6226F-35000 RennesFrance Institut Universitaire de France 1 rue DescartesParisFrance Czech Geological Survey Geologická615200 Praha 5Czech Republic Dipartimento di Science della Terra Universitàdi FirenzeVia G.La Pira450121 FirenzeItaly Dipartimento di Chimica U.Schiff-DICUS and INSTM Research Unit Universitàdi FirenzeVia della Lastruccia 3-13Sesto Fiorentino 50019 FirenzeItaly

An approach to supervised classification and regression of superconductive materials is proposed which builds on the DeepSet *** enables us to provide the chemical constituents of the examined compounds as an input to the algorithm,while avoiding artefacts that could originate from the chosen ordering in the *** performance of the method are successfully challenged for both classification(tag a given material as superconducting)and regression(quantifying the associated critical temperature).We then searched through the International Mineralogical Association list with the trained neural *** the obtained superconducting candidates,three materials were selected to undergo a thorough experimental *** has been indeed confirmed for the synthetic analogue of michenerite,PdBiTe,and observed for the first time in monchetundraite,Pd2NiTe2,at critical temperatures in good agreement with the theory *** latter is the first certified superconducting material to be identified by artificial intelligence methodologies.

关键词： artificial Deep neural

The significance of cherts as markers of Ocean Plate Stratigraphy and paleoenvironmental conditions:New insights from the Neoproterozoic-Cambrian Blovice accretionary wedge,Bohemian Massif

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2023年第1期14卷 162-180页

作者： LukášAckerman Jirízák Václav Kachlík Jan Pašava KarelZák Andreas Pack františek Veselovsky Ladislav Strnad Institute of Geology of the Czech Academy of Sciences Rozvojová269CZ-16500 Prague 6Czech Republic Czech Geological Survey Klárov3CZ-11821 Prague 1Czech Republic Institute of Geology and Paleontology Faculty of ScienceCharles UniversityAlbertov 6Prague 12843Czech Republic Geowissenschaftliches Zentrum Universität GöttingenGoldschmidtstraβe 1D-37077 GöttingenGermany Laboratories of the Geological Institutes Faculty of ScienceCharles UniversityAlbertov 6Prague 12843Czech Republic

The Ediacaran to early Cambrian Blovice accretionary complex,Bohemian Massif,hosts abundant chert bodies that formed on an oceanic plate and were involved in subduction beneath the northern margin of *** relationships of cherts to their host,their microstructure and elemental as well as isotopic compositions revealed diverse processes of chert petrogenesis reflecting depositional environment and position on the oceanic *** deep-water cherts formed through a hydrothermal precipitation of silica-rich gels on outer trench swell of the subducted slab with none or only minor addition of terrigenous *** the contrary,the shallow-water cherts formed in lagoons on seamount slopes,and at least some of them represent a product of hydrothermal replacement of former carbonate and/or evaporite *** both chert types,the hydrothermal fluids were of low temperature and continuous pervasive hydrothermal alteration of oceanic crust,together with an elevated Si content in Neoproterozoic seawater,served as the major source of *** the other hand,minor carbon enrichment in chert is mostly linked to variable incorporation of organic matter that was deposited on the *** earth element(REE)systematics of the cherts indicate predominantly oxygenated environment for the shallow-water cherts whereas the deep-water cherts were deposited in diverse redox conditions,depending on their distance from hydrothermal *** these data,we demonstrate that the cherts once formed a part of Ocean Plate Stratigraphy(OPS)now dismembered and mixed with terrigenous siliciclastic material to form OPS mé*** our data with those from the existing literature,we show that cherts can serve as significant markers of OPS since the Archean,recording a complex interplay between seafloor-related volcanic(production of MORB-and OIB-like magmas)and sedimentary processes,hydrothermal activity at mid-ocean ridges and seamount chains as well as at outer slopes o

关键词： Chert Accretionary wedge Ediacaran Triple oxygen isotopes Strontium isotopes Ocean Plate Stratigraphy

No more blind dates with calcite:Fluid-flow ***-slip along the O?kov thrust,Prague Basin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第4期12卷 167-178页

作者： Nick M.W.Roberts Ji?í ?ák franti?ek Vacek Ji?í Sláma Geochronology and Tracers Facility British Geological SurveyEnvironmental Science Centre Institute of Geology and Paleontology Faculty of ScienceCharles University Department of Mineralogy and Petrology National Museum Institute of Geology Czech Academy of Sciences

Dating of fracture-filling calcite with U-Pb geochronology is becoming a rapidly adopted technique for determining the absolute timing of brittle deformation in the upper *** calcite is a desirable target,as it precipitates between individual fault slip displacement events,and provides additional kinematic *** we present a case study of slickenfibres formed on the O?kov thrust in the Lower Palaezoic Prague Basin,Bohemian Massif,utilising a combination of petrographic and in situ *** demonstrate that slickenfibre external textures can be preserved,whilst internally primary textures are removed by fluid infiltration and recrystallization,leading to variable U and Pb *** slickenfibre yielded a date of ca.250 Ma,which we interpret as recording fault slip along the O?kov *** cross-cutting slickenfibre yielded more scattered U-Pb data,with an imprecise apparent age around ca.95 *** slickenfibre is recrystallised,destroying the primary textures,and exhibits element *** meaning of this younger apparent age is therefore questionable;whereas it likely reflects Cretaceous U and Pb mobility assisted by fluid-flow along the fault plane,it may not reflect a period of fault *** results demonstrate that slickenfibre-based U-Pb dates do not unequivocally relate to fault motion,and that petrographic and elemental analyses are important requirements for interpreting calcite U-Pb data.

关键词： U-Pb geochronology Calcite Fault dating Fluid-flow Prague Basin LA-ICP-MS

Life is more than a computer running DNA software

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Biological Chemistry 2014年第3期5卷 275-278页

作者： frantiek Baluka Guenther Witzany IZMB University of Bonn Telos-Philosophische Praxis

In his recent interview for the Guardian Craig Venter is elaborating about a household appliance for the future, Digital Biological Converter(DBC). Current prototype, which can produce DNA, is a box attached to the computer which receives DNA sequences over the internet to synthesize DNA; later in future also viruses, proteins, and living cells. This would help the household members to produce, e.g., insulin, virus vaccines or phages that fight antibiotic resistant bacteria. In more distant future, Craig Venter's hope is that the DBC will generate living cells via so-called "Universal Recipient Cell". This platform will allow digitally transformed genomes, downloaded from the internet, to form new cells fitted for the particular needs such as therapeutics, food, fuel or cleaning water. In contrast to this, the authors propose that DNA sequences of genomes do not represent 1:1 depictions of unequivocal coding structures such as genes. In light of the variety of epigenetic markings, DNA can store a multitude of further meanings hidden under the superficial grammar of nucleic acid sequences.

关键词： DNA Genome Information Life Non-coding RNA Synthetic biology Virus

At the dawn of a new revolution in life sciences

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Biological Chemistry 2013年第2期4卷 13-15页

作者： frantiek Baluka Guenther Witzany IZMB University of Bonn Telos-Philosophische Praxis

In a recently published article Sydney Brenner argued that the most relevant scientific revolution in biology at his time was the breakthrough of the role of "information" in *** fundamental concept that integrates this new biological "information" with matter and energy is the universal Turing machine and von Neumann's self-reproducing *** this article we demonstrate that in contrast to Turing/von Neumann machines living cells can really reproduce *** current knowledge on the roles of noncoding RNAs indicates a radical violation of the central dogma of molecular biology and opens the way to a new revolution in life sciences.

关键词： History of science Paradigm shift Information Non-coding RNAs