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Structural and optical properties of nanostructured copper sulfide semiconductor synthesized in an industrial mill

Frontiers of Chemical Science and Engineering 2019年第1期13卷 164-170页

作者： marcela Achimovicova Erika Dutkova Erika Tothova Zdenka Bujnakova Jaroslav Briancin Satoshi Kitazono Institute of Mineral and Waste Processing Waste Disposal and Geomechanics Clausthal University of Technology Clausthal 38678 Germany Institute of Geotechnics Slovak Academy of Sciences Kosice 04001 Slovakia Nakase Refinery Nihon Seiko Co. Ltd. Yabu-shi Hyogo 667-1111 Japan

Chalcogenide nanostructured semiconductor, copper sulfide (CuS) was prepared from copper and sulfur powders in stoichiometric ratio by a simple, fast, and convenient one-step mechanochemical synthesis after 40 min of milling in an industrial eccentric vibratory mill. The kinetics of the mechanochemical synthesis and the influence of the physical properties of two Cu powder precursor types on the kinetics were studied. The crystal structure, physical properties, and morphology of the product were characterized by X-ray diffraction (XRD), the specific surface area measurements, particle size distribution and scanning electron microscopy. The XRD analysis confirmed the hexagonal crystal structure of the product-CuS (covellite) with the average size of the crystallites 11 nm. The scanning electron microscopy analysis has revealed that the agglomerated grains have a plate-like structure composed of CuS nanoparticles. The thermal analysis was performed to investigate the thermal stability of the mechanochemically synthesized CuS. The optical properties were studied using UV-Vis and photoluminescence spectroscopy. The determined optical band gap energy 1.80 eV responds to the value of the bulk CuS, because of agglomerated nanoparticles. In addition, a mechanism of CuS mechanochemical reaction was proposed, and the verification of CuS commercial production was performed.

关键词： copper sulfide industrial mechanochemical synthesis thermal analysis optical properties

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Friction Sensitivity of Nitramines. Part Ⅰ:Comparison with Impact Sensitivity and Heat of Fusion

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含能材料 2011年第6期19卷 603-606,589页

作者： marcela Jungová Svatopluk Zeman Adéla Husarová Institute of Energetic Materials Faculty of Chemical TechnologyUniversity of PardubiceCZ-532 10PardubiceCzech Republic

Fractions of β-HMX(β-1,3,5,7-tetranitro-1,3,5,7-tetrazocane) have been used to demonstrate the mutual relationship between friction and impact *** of an additional twelve nitramines into this scenario resulted in a series of partial relationships,which were determined from the molecular structure of these *** was also found that there is a relation between increasing heats of fusion of the nitramines studied and their decreasing friction *** of friction sensitivity with heats of fusion,ΔHm,tr of the studied nitramines shows that the increase in ΔHm,tr values is more or less connected with a decrease in friction sensitivity.

关键词： explosives friction heat of fusion impact nitramines

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Friction Sensitivity of Nitramines. Part Ⅲ:Comparison with Detonation Performance

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含能材料 2011年第6期19卷 610-612页

作者： Svatopluk Zeman marcela Jungová Adéla Husarová Institute of Energetic Materials Faculty of Chemical TechnologyUniversity of PardubiceCZ-532 10 PardubiceCzech Republic

The friction sensitivities(FS) of five linear and eight cyclic nitramines have been *** FS values were compared with the respective detonation velocities,D,and with the dimensionless ratio created by relating the heat of explosion,Qreal,to the activation energy,Ea,of non-autocatalyzed thermal decomposition of the explosives *** the nitramaines studied,these comparisons show a general trend of FS decreasing with increasing energy content.

关键词： friction detonation heat of explosion nitramines

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Friction Sensitivity of Nitramines. Part Ⅱ:Comparison with Thermal Reactivity

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含能材料 2011年第6期19卷 607-609页

作者： marcela Jungová Svatopluk Zeman Adéla Husarová Institute of Energetic Materials Faculty of Chemical TechnologyThe University of PardubiceCZ-532 10PardubiceThe Czech Republic

The friction sensitivity(FS) of five linear and eight cyclic nitramines has been *** parameters of non-autocatalyzed thermal decomposition of these nitramines were used for comparison of the FS values with thermal ***,increasing values of activation energies of non-autocatalyzed decomposition of the studied nitramines are connected with decreasing FS values.A similar trend was found in the relation between FS and hypothetical initiation temperature for 5% conversion of the nitramines after 50 μs of their thermolysis,however,if in the given series of nitramines their initiation reactivity is predominantly determined by the energy content of their molecules and closer similarity of their molecular structures,then the above-mentioned trend may be *** found relationships were used for prediction and verification of the activation energy of non-autocatalyzed thermal decomposition of 2,5-dinitro-2,5-diazahexane.

关键词： physical chemistry friction,thermal decomposition,nitramines

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Homotypic Vacuole Fusion Requires VTI11 and Is Regulated by Phosphoinositides

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Molecular Plant 2014年第6期7卷 1026-1040页

作者： Sang Won Han Maria Fernanda Rodriguez-Welsh marcela Rojas-Pierce Department of Plant and Microbial Biology North Carolina State University Raleigh NC 27695 USA

Most plant cells contain a large central vacuole that is essential to maintain cellular turgor. We report a new mutant allele of VTI11 that implicates the SNARE protein VTI11 in homotypic fusion of protein storage and lytic vacuoles. Fusion of the multiple vacuoles present in vtill mutants could be induced by treatment with Wortmannin and LY294002, which are inhibitors of Phosphatidylinositol 3-Kinase （PI3K）. We provide evidence that Phosphatidylinositol 3-Phosphate （Ptdlns（3）P） regulates vacuole fusion in vtill mutants, and that fusion of these vacuoles requires intact microtubules and actin filaments. Finally, we show that Wortmannin also induced the fusion of guard cell vacuoles in fava beans, where vacuoles are naturally fragmented after ABA-induced stomata closure. These results suggest a ubiquitous role of phosphoinositides in vacuole fusion, both during the development of the large central vacuole and during the dynamic vacuole remodeling that occurs as part of stomata movements.

关键词： vacuole SNARE phosphoinositides membrane fusion Wortmannin.

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Relative Explosive Strength of Some Explosive Mixtures Containing Urea and/or Peroxides

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火炸药学报 2016年第5期39卷 22-27,34页

作者： Ahmed K.HUSSEIN Svatopluk ZEMAN Muhamed SUCESKA marcela JUNGOVA Institute of Energetic Materials Faculty of Chemical Technology University of Pardubice Czech Republic Brodarski Institute-Marine Research and Special Technologies ZagrebCroatia

Several mixtures,based on urea derivatives and some inorganic oxidants,including also alumina,were studied by means of ballistic mortar techniques with TNT as the reference *** detonation pressure(P),detonation velocity(D),detonation energy(Q),and volume of gaseous product at standard temperature and pressure(STP),V,were calculated using EXPLO5V6.3 thermochemical *** performance of the mixtures studied was discussed in relation to their thermal reactivity,determined by means of differential thermal analysis(DTA).It is shown that the presence of hydrogen peroxide in the form of its complex with urea(*** UHP)has a positive influence on the explosive strength of the corresponding mixtures which is linked to the hydroxy-radical formation in the mixtures during their initiation *** radicals might initiate(at least partially)powdered aluminum into oxidation in the CJ plane of the detonation *** containing UHP and magnesium are dangerous because of potential auto-ignition.

关键词： ballistic mortar TNT DTA peroxides perchlorates nitrates urea

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The Top 100 Twitter Influencers in Infectious Diseases

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Infectious Microbes & Diseases 2023年第1期5卷 36-40页

作者： marcela Araujo de Oliveira Santana Saira Butt Department of Medicine Federal University of UberlândiaUberlândiaBrazil Department of Infectious Disease Indiana University School of MedicineIndianapolisUSA

Healthcare professionals in infectious diseases have been using Twitter to disseminate knowledge and interact with other *** study aimed to identify and characterize the top 100 Twitter influencers in infectious diseases and to analyze the correlation between Twitter and academic *** Right Relevance Application Programming Interface was used to search for the term“infectious diseases,”producing a Twitter topic score for the top 100 infectious disease *** influencers'Hirsch index(h-index)was compared with their Twitter topic score for a possible *** identified that 46%of the infectious disease influencers were physicians.A correlation between the Twitter topic score of the infectious disease influencers and their h-index was not identified(r=0.123,P=0.22).The study also provides a list of the infectious disease influencers for those who have an interest in engaging and interacting with them on Twitter.

关键词： infectious diseases medical education social media

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cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5-d]imidazole(BCHMX)as a part of explosive mixtures

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Defence Technology（防务技术） 2018年第5期14卷 380-384页

作者： Svatopluk Zeman Ahmed K.Hussein Ahmed Elbeih marcela Jungova Institute of Energetic Materials Faculty of Chemical TechnologyUniversity of PardubiceCZ-532 10PardubiceCzech Republic Military Technical College Kobry ElkobbahCairoEgypt

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5-d]imidazole(BCHMX) is a relatively available bicyclic nitramine in the present. Due to the high energetic content of its molecule(deformation of valence angles) it has heat of formation higher than β-1,3,5,7-tetranitro-1,3,5,7-tetrazocane(β-HMX) by nearly three times. As a result, it has heat of explosion and relative explosive strength exceed that of β-HMX including their corresponding PBXs. However, penetration abilities of PBXs based on HMX are higher than those based on BCHMX. The relatively high initiation reactivity of BCHMX could be modified in a wide range by its incorporation in a suitable polymeric matrices. Regarding to the performance, coating of BCHMX crystals by 5 wt% Viton A produces the maximum performance while the mixture of BCHMX with polydimethylsiloxane(PDMS) seems to be the optimum composition for the development of PBX with low sensitivity.

关键词： BCHMX Initiation Sensitivity Explosive strength Penetration

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Effectiveness of traffic light system on Brazilian consumers perception of food healthfulness

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Food Science and Human Wellness 2019年第4期8卷 368-374页

作者： Mayara Lima marcela de Alcantara Amauri Rosenthal Rosires Deliza IT/DTA–Federal Rural University of Rio de Janeiro BR 465–Km 07CEP 23.890-000SeropédicaRJBrazil Nutrition and Dietetics Department–Federal Fluminense University Rua Mário Santos Braga30CEPNiteróiRJBrazil PDJ-CNPq/Embrapa Agroindústria de Alimentos Av.das Américas29501CEP 23.020-470Rio de JaneiroRJBrazil Embrapa Agroindústria de Alimentos Av.das Américas29501CEP 23.020-470Rio de JaneiroRJBrazil

Front-of-package(FOP)nutrition labelling schemes were developed to improve consumer’s comprehension about the food nutrients associated with non-communicable diseases(NCDs).Several FOPs have already been developed,and Brazil is in the process of evaluating a scheme to introduce in the *** aim of this study was to investigate the impact of TLS,the scheme proposed by the food industry,on the product healthfulness perception.A study with 141 participants was carried out.A conjoint task was designed considering three categories and levels:types of dairy products(light yogurt,prato cheese,and chocolate flavoured milk),Traffic Light System(yes ***)and brand(well-known ***).The effect of TLS on perceived healthfulness was evaluated using a 9-point scales(1:not healthy;9:very healthy).Results showed that the inclusion of TLS did not influence the perceived healthfulness of the products by consumers,even among consumers with higher interest in healthy *** findings suggest that the proposal supported by the food industry does not seem to be the most appropriate,being recommended the development of further studies to compare the efficacy of TLS and other FOP schemes.

关键词： Front of pack Traffic light system Healthfulness perception Food products

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Crystal lattice free volume in a study of initiation reactivity of nitramines:Friction sensitivity

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Defence Technology（防务技术） 2018年第2期14卷 132-136页

作者： Svatopluk Zeman Ning Liu marcela Jungová Ahmed K.Hussein Qi-long Yan Institute of Energetic Materials Faculty of Chemical TechnologyUniversity of PardubiceCZ-532 10PardubiceCzech Republic Xi'an Modern Chemistry Research Institute Xi'anShaanxi710065China School of Astronautics Northwestern Polytechnical UniversityXi'an 710072ShaanxiChina

The relationship between friction sensitivity(FS) and the crystal lattice free space per molecule, △V. of thirteen nitramines is described by a linear equation, divided into a number of the partial relationships with strong limitations by their molecular structure characteristics. Increasing FS due to raising of the △V values is not clearly confirmed. The influence of the △V values on friction sensitivity of nitramines is similar to that of their aza atoms which influence the mutual orientations of nitro groups in neighboring molecules. The dipole-dipole interaction of the oxygen and nitrogen atoms of nitro groups in neighboring nitramine molecules has a major effect on their own FS. In accordance with this interaction, a directly proportional relationship was derived between FS and the intrinsic gas phase molecular volume, V_(int), of the nitramines mentioned, which is divided also into several straight lines according to relatively tight molecular structure similarity. The relationships found again confirm a level of disorder in the distribution of the forces in the crystal lattice of the "common" quality of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, in comparison with its reduced sensitivity(RS) or chemically pure analogue.

关键词： Crystal lattice Friction Initiation reactivity Nitramines

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