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Disproportionation of ethylbenzene in the presence of C_8 aromatics

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Journal of Natural Gas Chemistry 2009年第3期18卷 369-374页

作者： N.Sharnappa S.Pai v.v.Bokade Catalysis Division National Chemical Laboratory

The selective synthesis of p-diethylbenzene （p-DEB） by disproportionation of ethylbenzene （EB） in the presence of aromatics like m- and p- xylene isomers has been studied over a pore size regulated HZSM-5 catalyst. The industrial feed having different compositions of ethylbenzene and xylene isomers was used for the experimentation. Hence, they were expected to hinder the movement of reactant molecules both on the external surface and within the zeolite channels. It was observed that irrespective of the different feed compositions the concentration of the xylene isomers was intact in the product. There is no other byproducts formation like para-ethylmethyl benzene. The effects of varying the concentration of aromatic compounds in the feed on ethylbenzene conversion and product distribution over the parent and modified H-ZSM-5 catalyst have been discussed. Ethylbenzene disproportionation reaction follows the pseudo first order reaction with an activation energy of 8.6 kcal/mol.

关键词： ethylbenzene xylene isomers catalyst disproportionation diethylbenzene

Cladophora mats in a Crimean hypersaline lake:structure,dynamics,and inhabiting animals

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Journal of Oceanology and Limnology 2018年第6期36卷 1930-1940页

作者： Alexandr v.PRAZUKIN Elena v.ANUFRIIEvA Nickolai v.SHADRIN The A.O.Kovalevsky Institute of Marine Biological Research of RAS 2 Nakhimov Av.Sevastopol 299011Russia

Filamentous green algae play an important functional role in element cycling and productivity in the diff erent water bodies. In hypersaline lakes and lagoons of the Crimea, filamentous green algae are present and form bottom and floating mats that occupy large areas with high biomass, up to 4–5 kg(wet biomass)/m2. Cladophora spp. dominated in those mats. Five species of filamentous green algae(Chlorophyta) in Lake Chersonesskoye: C ladophora vadorum(Aresch.) Kütz., C. siwaschensis C. Meyer, C. echinus(Biasol.) Kütz., Ulothrix implexa(Kütz.) Kütz., Rhizoclonium tortuosum(Dillw.) Kütz., and seagrass(Angiospermae) R uppia cirrhosa(Petagna) Grande were found. Cladophora spp. and R. cirrhosa were found in the lake throughout the year, other types of algae were encountered episodically. In most cases the biomass of bottom mat exceeded that of the floating mat. In general, the total biomass of the bottom and floating mats in the lake areas at depths up to 30 cm was in a stable range of values from 100 to 290 mg(dry weight)/cm2. Animal and infusorian average abundance in mats reach high values: infusorians—up to 15 000 000 ind./m2, Cletocamptus retrogressus(Copepoda, Harpacticoida)—up to 730 000 ind./m2, Eucypris mareotica(Ostracoda)—up to 91 000 ind./m2 and Chironomidae larvae(Insecta, Diptera)—up to 140 ind./m2. Those values were much higher than in the plankton.

关键词： green algae mats hypersaline lake photosynthesis invertebrates

Influence of Zr and Mn additions on microstructure and properties of Mg-2.5wt%Cu-Xwt%Zn(X=2.5,5 and 6.5)alloys

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International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1733-1745页

作者： A.v.Koltygin v.E.Bazhenov I.v.Plisetskaya v.A.Bautin A.I.Bazlov N.Y.Tabachkova O.O.voropaeva A.A.Komissarov v.D.Belov Foundry Department National University of Science and Technology(MISiS)Moscow 119049Russia Department of Metallurgy Steel New Production Technologies and Protection of MetalsNational University of Science and Technology(MISiS)Moscow 119049Russia Laboratory of Advanced Green Materials National University of Science and Technology(MISiS)Moscow 119049Russia Department of Materials Science of Semiconductors and Dielectrics National University of Science and Technology(MISiS)Moscow 119049Russia Fianit Laboratory(Laser Materials and Technology Research Center at GPI) Prokhorov General Physics Institute RASMoscow 119991Russia Laboratory of Hybrid Nanostructured Materials National University of Science and Technology(MISiS)Moscow 119049Russia Laboratory of Medical Bioresorption and Bioresistance Moscow State University of Medicine and DentistryMoscow 127473Russia

This work studied the effects of adding Zr and Mn in amounts less than 1wt%on the microstructure,mechanical properties,casting properties,and corrosion resistance of Mg-Zn-Cu alloys containing 2.5wt%Cu and 2.5wt%-6.5wt%*** hardness and electrical conductivity measurements were used to find an optimal heat treatment schedule with the best mechanical *** has been established that Zr significantly increases the yield strength of the alloys due to a strong grain refinement ***,the presence of Mn and Zr has a detrimental effect on alloy’s elongation at *** was shown that the precipitation of the Mg_(2)Cu cathodic phase in the alloy structure negatively affects the corrosion ***,the addition of Mn decreases the corrosion rate of the investigated *** best combination of the mechanical,casting,and corrosion properties were achieved in the alloys containing 2.5wt%Cu and 5wt%***,the Mn or Zr addition can improve the properties of the alloys;for example,the addition of Mn or Zr increases the fluidity of the alloys.

关键词： magnesium alloy Mg-Zn-Cu casting alloy Mn addition Zr addition

Magnetic nanoparticles and concentrated magnetic nanofluids:Synthesis,properties and some applications

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China Particuology 2007年第1期5卷 43-49页

作者： Ladislau vks Doina Bica Mikhail v. Avdeev Lab Magnetic Fluids CFATR Romanian Academy-Timisoara Division Timisoara Romania National Center for Engineering of Systems with Complex Fluids Univ. Politehnica Timisoara Timisoara Romania Lab Magnetic Fluids CFATR Romanian Academy-Timisoara Division Timisoara Romania Frank Laboratory of Neutron Physics Joint Institute for Nuclear Research Dubna Russia

This paper reviews some recent results concerning chemical synthesis of magnetic nanoparticles and preparation of various types of magnetic nanofluids. Structural properties and behaviour in external magnetic field of magnetic nanofluids will be emphasized with relation to their use in leakage-free rotating seals and in biomedical applications.

关键词： Magnetic nanoparticle Magnetic nanofluid Rotating seal Biomedical application Chemical co-precipitation Structural characterization

Joining and machining of(ZrB2-SiC)and(Cf-SiC)based composites

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Defence Technology（防务技术） 2018年第5期14卷 385-395页

作者： R.v.Krishnarao G.Madhusudan reddy v.v.Bhanuprasad Defence Metallurgical Research Laboratory KanchanbaghHyderabad500058India

Filler materials of(ZrB_2-SiC-B_4C-YAG) composite were developed for gas tungsten arc welding(GTAW) of the ZrB_2-SiC and Cf-SiC based composites to themselves and to each other. Reaction with filler material,porosity and cracks were not observed at weld interfaces of all the joints. Penetration of filler material in to voids and pores existing in the Cf-SiC composites was observed. Average shear strength of 25.7 MPa was achieved for joints of Cf-SiC composites. By incorporation of Cf-SiC(CvD) ground short fibre reinforcement the(ZrB_2-SiC-B_4C-YAG) composite was machinable with tungsten carbide tool. The joint and machined composites were resistance to oxidation and thermal shock when exposed to the oxy-propane flame at 2300℃ for 300s. The combination of(ZrB_2-SiC-B_4C-YAG) and Cf-SiC based composites can be used for making parts like thermal protection system or nozzles for high temperature applications.

关键词： ZrB2-SiC Composite Sintering Machining Gas tungsten arc welding

Multiscalar B-L extension based on S_(4)flavor symmetry for neutrino masses and mixing

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Chinese Physics C 2021年第4期45卷 181-191页

作者： v.v.vien H.N.Long Institute of Research and Development Duy Tan University182 Nguyen Van LinhDa Nang CityVietnam Department of Physics Tay Nguyen University567 Le DuanBuon Ma ThuotDakLakVietnam Theoretical Particle Physics and Cosmology Research Group Advanced Institute of Materials ScienceTon Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Applied Sciences Ton Due Thang UnivesityHo Chi Minh CityVietnam

A multiscalar and nonrenormalizable B-L extension of the standard model(SM)with S_(4)symmetry which successfully explains the recently observed neutrino oscillation data is *** tiny neutrino masses and their hierarchies are generated via the type-I seesaw *** model reproduces the recent experiments of neutrino mixing angles and Dirac CP violating phase in which the atmospheric angle(θ_(23))and the reactor angle(θ_(13))get the best-fit values while the solar angle(θ_(12))and Dirac CP violating phase(δ)are in 3σrange of the best-fit value for the normal hierarchy(NH).For the inverted hierarchy(IH),θ13 gets the best-ft value andθ_(23)together withδare in the lσrange,whileθ12 is in 3δrange of the best-fit *** effective neutrino masses are pre-dicted to be(m_(ee))=6.81 mev for the NH and(m_(ee))=48.48 mev for the IH,in good agreement with the most re-cent experimental data.

关键词： neutrino mass and mixing extensions of electroweak Higgs sector flavor symmetries

Conditions for formation and trapping of the two-ion Coulomb cluster in the dissipative optical superlattice

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Chinese Physics B 2015年第6期24卷 305-313页

作者： I.v.Krasnov Institute of Computational Modeling Siberian DivisionRussian Academy of Sciences

Conditions have been studied under which a polychromatic optical superlattice can form and trap the Coulomb cluster of two strongly interacting ions. In our previous work （Krasnov I v and Kamenshchikov L P 2014 Opt. Comm. 312 192） this new all-optical method of obtaining and confining the Coulomb clusters was demonstrated by numerical simulations for special values of the optical superlattice parameters and in the case of Yb ions. In the present paper the conditions are explicitly formulated, under which the long-lived two-ion cluster in the superlattice cell is formed. The peculiarity of these conditions is the renormalization of the ion-ion Coulomb interaction. Notably, the renormalized Coulomb force is determined by the effective charge which depends on the light field parameters and can strongly differ from the ＂bare＂ ion charge. This result can be accounted for by the combined manifestation of the quantum fluctuations of optical forces, nonlinear dependence of these forces on the velocity, and non-Maxwellian （Tsallis type） velocity distribution of the ions in the optical superlattice. Explicit analytical formulas are also obtained for the parameters of the optical two-ion cluster.

关键词： optical trap ion trap rectified gradient force Coulomb clusters

Unravelling-based (auto)control of back-action in atomic Bose–Einstein condensate

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Frontiers of physics 2024年第4期19卷 287-295页

作者： v.A.Tomilin L.v.Il’ichov Institute of Automation and Electrometry SB RAS 630090 NovosibirskRussia

We present a novel feedback control method for quantum *** does not affect the controlled system ***,it controls the unravelling of the quantum channel of interaction between the system and its *** interaction can be represented as a history of *** their informational content is changed,their back-action on the system is also *** action is trigged by the events,thus granting the system the degree of control over its own *** efficiency of the proposed scheme is demonstrated on the example of two-mode atomic Bose-Einstein condensate,with one of its modes subject to phase-contrast imaging in a Mach–Zehnder *** histories of photocounts in the output channels of the interferometer are used for *** capabilities of state engineering are studied for different settings of the feedback loop and different numbers of events in the recorded histories.

关键词： quantum feedback control quantum measurements twomode Bose-Einstein condensates

Polarization patterns of light enable geolocalization in oceans

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Light(Science & Applications) 2023年第11期12卷 2264-2265页

作者： Lihong v.Wang Caltech Optical Imaging Laboratory Andrew and Peggy Cherng Department of Medical EngineeringDepartment of Electrical EngineeringCalifornia

The deep ocean,characterized by its immense depths and absence of global positioning system(GPS)functionality,presents considerable challenges for search and rescue *** by the geolocalization capabilities of migratory marine animals,Bai et *** a novel method for underwater geolocalization using the polarization patterns of light in the underwater *** a sextant using these underwater polarization patterns,the study determines geolocation in underwater *** prior skepticism,even in low-visibility waters,these patterns,learned through a deep neural network,provide geolocation accuracies of 55 km at 8m and 255 km at 50 *** pioneering approach offers implications for search and rescue and hints at navigation mechanisms in marine animals.

关键词： underwater enable visibility