检索结果-南通市图书馆

The lacustrine sedimentary records of coal-burning atmospheric pollution

在线全文

学校读者我要写书评

暂无评论

Science China earth Sciences 2005年第10期48卷 1740-1746页

作者： e. Appel v. Hoffmann Institut für Geowissenschaften Universitt Tübingen 72076 Tübingen GermanyInstitut für Geowissenschaften Universitt Tübingen 72076 Tübingen Germany

Based on the studies on diatom, ostracods and magnetism on a core acquired from lacustrine sediments, as well as correlation analysis between concentration of acid diatom and the instantaneous lowest pH value, the processes of environment evolution in Lake Yangzonghai were reconstructed. The lacustrine environment was favorable in the 1950s, and began to be polluted by a coal-burning power plant since 1960. During 1965―1980, the instantaneous lowest pH value of lake water decreased to 5―6 when heavily polluted. There was a decrease trend in the pollution from 1983 to 1999, but coal-burning atmospheric pollution was still a main problem for environmental retrieving. As acid precipitated, acid-tolerant species overspread, and shellfish disappeared, as well as ferromagnetic particulates dissolved because of the consequent change of pH-eh values in the interface of water and soil, which results in the change of environmental proxies versus depth. Thus, the environmental evolution of Lake Yangzonghai is reconstructed in this paper based on the inferences mentioned above.

关键词： atmospheric pollution, proxies, environmental reconstruction, lacustrine sediment, Lake Yangzonghai.

SCIeNTIFIC PRINCIPLeS FOR MODIFICATION OF WATeR-SOLUBLe POLYMeRS. FORMATION OF MACROMOLeCULAR COMPLeXeS

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

Chinese Journal of Polymer Science 1998年第3期16卷 268-278页

作者： PAUTOv v.D. ANUFRIevA e.v. KRAKOvYAK M.G. Institute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 Russia

The study of nanosecond dynamics of macromolecules with the lumines-cent methods make it possible to investigate the formation and functioning of polymericcomplexes, polymeric conjugates and macromolecular metal complexes, which are widelyused for solving many practical tasks. The nanosecond dynamics of macromolecules are ahighly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solvethe problems of studying IPC formation and stability and to investigate the interpolymerreactions of exchange and substitution. The investigation of changes in the rotational mo-bility of globular protein molecules as a whole makes it possible to determine the complexcomposition and its stability, and to control the course of polymer-protein conjugate forma-tion reaction. The nanosecond dynamics of polymers interacting with surfacants' ions (S)are the sensitive indicator of the S-polymer complex formation. A method for determin-ing the equilibrium constants of the S-polymer complex formation was developed on thebasis of the study of polymer chains mobility. It is established that nanosecond dynamicsinfluences the course of chemical reactions in polymer chains. Moreover, the marked effectof the nanosecond dynamics is also revealed in the study of photophysical processes (theformation of excimers and energy migration of electron excitation) in polymers with pho-toactive groups. It was found that the efficiency of both processes increases with increasingthe mobility of side chains, the carriers of photoactive groups.

关键词： Modification of water-soluble polymers Formation of complexes

Processes underlying the laser photochromic effect in colloidal plasmonic nanoparticle aggregates

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第3期29卷 412-419页

作者： A e ershov v S Gerasimov I L Isaev A P Gavrilyuk S v Karpov Institute of Computational Modeling SB RAS 660036KrasnoyarskRussia Siberian Federal University Krasnoyarsk660041Russia Kirensky Institute of Physics Federal Research Center KSC SB RAS660036KrasnoyarskRussia Siberian State University of Science and Technology Krasnoyarsk 660014Russia

We have studied the dynamic and static processes occurring in disordered multiparticle colloidal Ag aggregates with natural structure and affecting their plasmonic absorption spectra under pico-and nanosecond pulsed laser radiations, as well as the physical origin responsible for these processes. We have shown that depending on the duration of the laser pulse,the mechanisms of laser modification of such aggregates can be associated both with changes in the resonant properties of the particles due to their heating and melting(picosecond irradiation mode) and with the particle shifts in the resonant domains of the aggregates(nanosecond pulses) which depend on the wavelength, intensity, and polarization of the *** mechanisms result in formation of a narrow dip in the plasmonic absorption spectrum of the aggregates near the laser radiation wavelength and affect the shape and position of the dip. The effect of polydispersity of nanoparticle aggregates on laser photochromic reaction has been studied.

关键词： nanoparticle surface plasmon resonance photochromic process pulsed laser radiation

effects of mechanical activation on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation tailings

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2016年第6期26卷 1043-1049页

作者： ermolovich e.A. ermolovich O.v. Faculty of Mining and Natural Resource Management Belgorod State National Research University Geo Stroy Monitoring Bel GU LTD

The effects of mechanical activation in a planetary mill on the structural changes and microstructural characteristics of the components of ferruginous quartzite beneficiation railings generated by wet magnetic separation process were studied using X-ray and laser diffraction methods. The results revealed the relationship between variations in the mean particle size of activated powders and the milling time. The crystallite size, microstrain, lattice parameters and unit cell volumes were determined for different milling times in powder samples of quartz, hematite, dolomite, and magnetite from the beneficiation tailings. The main trends in the variation of the crystallite size of quartz, hematite, dolomite, and magnetite as a function mean particle size of powder samples were revealed. Changes in the particle shape as a function of the activation time was also investigated.

关键词： Ferruginous quartzite beneficiation tailings Mechanical activation Crystallites Planetary mill Microstructure Structural changes

Review on high repetition rate and mass production of the cryogenic targets for laser IFe

在线全文

学校读者我要写书评

暂无评论

High Power Laser Science and engineering 2017年第2期5卷 28-51页

作者： I.v.Aleksandrova e.R.Koresheva Lebedev Physical Institute Russian Academy of SciencesMoscow119991Russia National Research Nuclear University MePhl(Moscow engineering Physics Institute) Moscow115409Russia

In inertial fusion energy(IFe) research, a considerable attention has recently been focused on the issue of large target fabrication for MJ-class laser facilities. The ignition and high-gain target designs require a condensed uniform layer of hydrogen fuel on the inside of a spherical shell. In this report, we discuss the current status and further trends in the area of developing the layering techniques intended to produce ignition, and layering techniques proposed to high repetition rate and mass production of IFe targets.

关键词： free-standing and line-moving targets high-repetition-rate fuel supply inertial fusion energy target mass production

High-Strength Nanostructured Cold-Resistant Steels for Continental Shelf Development

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 66-71页

作者： Oryshchenko A S Khlusova e I Orlov v v FSUe CRISM PROMeTeY St.PetersburgRussia

The article describes principles of developing steels for maritime structures and main *** scientific approach lies in forming an ultra fine-grained and submicrocrystal structure through thermomechanical treatment of low-carbon low-alloyed steels,providing higher strength and resistance to brittle *** article presents results of assessing the operability characteristics and introducing new steels.

关键词： low-alloyed steels microstructure mechanical properties thermomechanical treatment

Growth of 4＂ diameter polycrystailine diamond wafers with high thermal conductivity by 915 MHz microwave plasma chemical vapor deposition

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第3期19卷 93-97页

作者： A F POPOvICH v G RALCHeNKO v K BALLA A K MALLIK A A KHOMICH A P BOLSHAKOv D N SOvYK e e ASHKINAZI v Yu YUROv Institute of Radio engineering and electronics of Russian Academy of Sciences Fryazino 141190 Russia General Physics Institute of Russian Academy of Sciences Moscow 119991 Russia Harbin Institute of Technology Harbin 150001 People's Republic of China National Research Nuclear University MePhI Moscow 115409 Russia Central Glass and Ceramic Research Institute Kolkata 700 032 India

Polycrystalline diamond（PCD） films 100 mm in diameter are grown by 915 MHz microwave plasma chemical vapor deposition（MPCvD） at different process parameters,and their thermal conductivity（TC） is evaluated by a laser flash technique（LFT） in the temperature range of230-380 *** phase purity and quality of the films are assessed by micro-Raman spectroscopy based on the diamond Raman peak width and the amorphous carbon（a-C） presence in the *** and increasing dependencies for TC with temperature are found for high and low quality samples,***,as high as 1950 ± 230 W m-1 K-1 at room temperature,is measured for the most perfect material.A linear correlation between the TC at room temperature and the fraction of the diamond component in the Raman spectrum for the films is established.

关键词： thermal conductivity polycrystalline diamond microwave plasma chemical vapordeposition Raman spectroscopy

Development of Zeff diagnostic system on the Globus-M（M2） tokamak and the first experimental results

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第10期21卷 33-39页

作者： e A TUKHMeNevA S Yu TOLSTYAKOv G S KURSKIev v K GUSev v B MINAev Yu v PeTROv N v SAKHAROv A Yu TeLNOvA N N BAKHARev P B SHeGOLev e O KISeLev Ioffe Institute

Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the ASTRA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.

关键词： tokamak effective ion charge magnetic confinement

Second-Harmonic Response in Magnetic Nodal-Line Semimetal Fe_(3)GeTe_(2)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2022年第9期39卷 62-66页

作者： v.D.esin A.A.Avakyants A.v.Timonina N.N.Kolesnikov e.v.Deviatov Institute of Solid State Physics of the Russian Academy of Sciences ChernogolovkaMoscow District2 Academician Ossipyan Str.142432Russia

We experimentally investigate second-harmonic transverse voltage response to ac electrical current for a magnetic nodal-line semimetal Fe_(3)GeTe_(2)(FGT).For zero magnetic field,the observed second-harmonic voltage behaves as a square of the longitudinal current,as it should be expected for nonlinear Hall *** magnetic field behavior is found to be sophisticated:while the first-harmonic response shows the known anomalous Hall hysteresis in FGT,the second-harmonic Hall voltage is characterized by the pronounced high-field hysteresis and flat(B-independent)region with curves touching at low *** high-field hysteresis strongly depends on the magnetic field sweep rate,so it reflects some slow relaxation *** the lowest rates,it is also accomplished by multiple crossing *** shape of the second-harmonic hysteresis is known for skyrmion spin textures in nonlinear *** skyrmions have been demonstrated for FGT by direct visualization techniques,we can connect the observed high-field relaxation with deformation of the skyrmion ***,the second-harmonic Hall voltage response can be regarded as a tool to detect spin textures in transport experiments.

关键词： harmonic relaxation hysteresis