检索结果-南通市图书馆

Journal of Energy Chemistry 2018年第3期27卷 843-853页

作者： Michael A.Smirnov Maria P.Sokolova Natalya v.Bobrova alexander M.Toikka Pierfrancesco Morganti Erkki Lahderanta Lappeenranta University of Technology 53850 LappeenrantaFinland Institute of Macromolecular compounds Russian Academy of Sciences199004 Saint PetersburgRussia St.Petersburg State University PeterhofSaint Petersburg 198504Russia Dermatological Institute II University of Naples80138 NaplesItaly

Development of simple methods for preparation of polymeric electrode materials with nanofibrous network structure is a perspective way toward cheap supercapacitors with high specific capacitance and energy density. In this work one-pot synthesis of electroactive ternary composite based on polypyrrole, polyacrylamide and chitin nanofibers with beneficial morphology was elaborated. Ternary system demonstrates better electrochemical performance in comparison with both polypyrrole–polyacrylamide and polypyrrole–chitin binary composites. Possible mechanism of synergistic effect of simultaneous influence of polyacrylamide and chitin nanofibers on the formation of composite＇s structure is *** highest attained specific capacitance of electroactive polypyrrole in ternary composite reached 249 F/g at 0.5 A/g and 150 F/g at 32 A/g. Symmetrical supercapacitor was assembled using the elaborated electrode material. High specific capacitance 89 F/g and good cycling stability with capacitance retention of 90% after 3000 cycles at 2 A/g were measured.

关键词： Energy materials Nanocomposites Natural fibers Electrical properties

Trapped on the Roof of the World:taxonomic diversity and evolutionary patterns of Tibetan Plateau endemic freshwater snails(Gastropoda:Lymnaeidae:Tibetoradix)

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2022年第5期17卷 825-848页

作者： Maxim v.vINARSKI Parm viktor vON OHEIMB Olga v.AKSENOvA Mikhail Yu.GOFAROv alexander v.KONDAKOv Ivan O.NEKHAEv Ivan N.BOLOTOv Laboratory of Macroecology and Biogeography Saint-Petersburg State UniversitySaint-PetersburgRussia Museum für Naturkunde-Leibniz Institute for Evolution and Biodiversity Science BerlinGermany N.Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences ArkhangelskRussia Department of Applied Ecology Saint-Petersburg State UniversitySaint-PetersburgRussia Northern(Arctic)Federal University ArkhangelskRussia

The high-elevation Tibetan Plateau(western China)is inhabited by a unique,though not particularly species-rich,community of *** explored the species content and evolutionary history of the Tibetan Plateau endemic freshwater snail genus *** relationships within the genus were reconstructed based on available sequence *** used a single-rate Poisson Tree Processes approach for species delimitation and compared putative species-level clades with already described *** found that the genus consists of at least 6 species,of which we described 4 as new to *** and soft body morphology was examined and the radula in Tibetoradix was described for theﬁrst *** on ourﬁndings,the diversiﬁcation of the genus did not result in a prominent morphological differentiation and a number of species can be regarded as morphologically *** species found in different drainage areas indicate relatively good passive dispersal abilities of the *** allopatric distribution of the species could result from competitive exclusion between *** absence of Tibetoradix *** the Tibetan Plateau could be explained by a scenario of an“evolutionary trap”,where adaptations to high elevation conditions prevented the taxa from a successful colonization of lower elevations.

关键词： biogeography High Asia molecular phylogenetics morphology species delimitation

Peculiarities of Ethylene Polymerization Reactions with Bis(imino)pyridyl Complexes of CoCl_(2) and FeCl_(2)

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 2024年第4期42卷 492-500页

作者： Laura A.Rishina Yury v.Kissin Svetlana S.Lalayan Artem A.Antonov vadim G.Krasheninnikov alexander A.Gulin N.N.Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences4 Kosygin St.Moscow119991Russia Department of Chemistry and Chemical Biology RutgersThe State University of New Jersey123 Bevier Rd.PiscatawayNJ08854USA Boreskov Institute of Catalysis Russian Academy of Sciences5 Lavrentieva Prosp.Novosibirsk630090Russia

The article describes ethylene polymerization reactions with transition metal catalysts based on complexes of CoCl_(2) and FeCl_(2) with an N,N,N-tridentate ligand 2,6-bis[1-(2,6-dimethylphenylimino)ethyl]pyridine. The complexes are converted into polymerization catalysts by reacting them either with polymethylalumoxane (MAO) or with a combination of Al(C2H5)2Cl and Mg(C4H9)2 at an [Al]:[Mg] ratio of ~3. Both MAO-activated complexes readily polymerize ethylene at 35 ℃ with the formation of linear, low molecular weight polymers with a narrow molecular weight distribution. The same complexes, when activated with the Al(C2H5)2Cl-Mg(C4H9)2 combination, form multi-center catalysts and generate polyethylenes with a broad molecular weight distribution.

关键词： Ethylene polymerization Bis(imino)pyridyl complexes of CoCl_(2)and FeCl_(2) Molecular-weight distribution Polymer chain structure

Effects of low temperatures on strength and power input into rock failure

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2014年第5期6卷 455-460页

作者： Evgenii v.Zakharov alexander S.Kurilko Federal State Academic Institution "Chersky Mining Institute of the North" Siberian Branch of the Russian Academy of Sciences

Study results of low temperature effects on the strength index and specific power input into rock failure are *** has been experimentally determined that within the range of-5 °С to-15 °С,there is a local minimum at which the compression strength and specific power input into failure of some rocks are 10%-50% lower than those at positive temperatures.

关键词： strength power input into failure low temperatures carbonate rocks kimberlite porosity

Tunable chemical complexity to control atomic diffusion in alloys

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2020年第1期6卷 1360-1367页

作者： Yuri Osetsky alexander v.Barashev Laurent K.Béland Zhongwen Yao Keyvan Ferasat Yanwen Zhang Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Department of Nuclear Engineering and Radiological Sciences University of MichiganAnn ArborMI 48109USA Department of Mechanical and Materials Engineering Queen’s UniversityKingstonON K7L 3N6Canada Department of Materials Science and Engineering University of TennesseeKnoxvilleTN 37996USA

In this paper we report a new fundamental understanding of chemically-biased diffusion in Ni–Fe random alloys that is tuned/controlled by the intrinsic quantifiable chemical *** of radiation-tolerant alloys has been a long-standing *** we show how intrinsic chemical complexity can be utilized to guide the atomic diffusion and suppress radiation *** influence of chemical complexity is shown by the example of interstitial atom(IA)diffusion that is the most important defect in radiation *** useμs-scale molecular dynamics to reveal sluggish diffusion and percolation of IAs in concentrated Ni–Fe *** develop a mean field diffusion model to take into account the effect of migrating defect energy properties on diffusion percolation,which is verified by a new kinetic Monte Carlo approach addressing detailed *** demonstrate that the local variations in the ground state energy of IA configurations in alloys,reflecting the chemical difference between alloying components,drives the percolation effects for atomic ***,chemically-biased and sluggish diffusion are phenomena that are directly related to the chemical complexity intrinsically to multicomponent alloys.

关键词： alloys alloying diffusion

Hepatoprotective actions of melatonin:Possible mediation by melatonin receptors

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 Gastroenterology 2010年第48期16卷 6087-6097页

作者： alexander M Mathes Department of Anesthesiology Critical Care and Pain MedicineSaarland University Hospital

Melatonin,the hormone of darkness and messenger of the photoperiod,is also well known to exhibit strong direct and indirect antioxidant properties. Melatonin has previously been demonstrated to be a powerful organ protective substance in numerous models of injury; these beneficial effects have been attributed to the hormone's intense radical scavenging capacity. The present report reviews the hepatoprotective potential of the pineal hormone in various models of oxidative stress in vivo,and summarizes the extensive literature showing that melatonin may be a suitable experimental substance to reduce liver damage after sepsis,hemorrhagic shock,ischemia/reperfusion,and in numerous models of toxic liver injury. Melatonin's influence on hepatic antioxidant enzymes and other potentially relevant pathways,such as nitric oxide signaling,hepatic cytokine and heat shock protein expression,are evaluated. Based on recent literature demonstrating the functional relevance of melatonin receptor activation for hepatic organ protection,this article finally suggests that melatonin receptors could mediate the hepatoprotective actions of melatonin therapy.

关键词： Antioxidant enzymes Hemorrhagic shock Hepatoprotection Ischemia Liver Liver function Melatonin Melatonin receptor Ramelteon Reperfusion Sepsis Toxic liver injury

Pericyte Plasticity in the Brain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2019年第3期35卷 551-560页

作者： Gabryella S.P.Santos Luiz A.v.Magno Marco A.Romano-Silva Akiva Mintz alexander Birbrair Departamento de Patologia Universidade Federal de Minas GeraisBelo HorizonteMG 31270-901Brazil Department of Mental Health Federal University of Minas GeraisBelo HorizonteMG 30130-100Brazil Department of Radiology Columbia University Medical CenterNew YorkNY 10032USA

Cerebral pericytes are perivascular cells that stabilize blood vessels. Little is known about the plasticity of pericytes in the adult brain in vivo. Recently, using stateof-the-art technologies, including two-photon microscopy in combination with sophisticated Cre/loxP in vivo tracing techniques, a novel role of pericytes was revealed in vascular remodeling in the adult brain. Strikingly, after pericyte ablation, neighboring pericytes expand their processes and prevent vascular dilatation. This new knowledge provides insights into pericyte plasticity in the adult brain.

关键词： Pericytes Brain Blood vessel Plasticity

Blood–brain barrier and laser technology for drug brain delivery

在线全文

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2017年第5期10卷 27-38页

作者： Oxana v.Semyachkina-Glushkovskaya Arkady S.Abdurashitov Elena I.Saranceva Eketerina G.Borisova alexander A.Shirokov Nikita v.Navolokin Saratov State University 83 Astrakhanskaya Str.Saratov 410012 Russia Institute of Electronics Bulgarian Academy of Sciences TsarigradskoChaussee 72 Sofia 1784Bulgaria Institute of Biochemistry and Physiology of Plants and Microorganisms Russian Academy of Sciences 13 Prospekt EntuziastovSaratov 410049Russia Saratov State Medical University Saratov 410010 Russia

Here,we discuss an important problem in medicine as development of efctive strategies for brain drug *** problem is related to the blood-brain barrier(BBB),which is a“customs”controlling the entrance of different molecules from blood into the brain protecting the normal function of central nervous system(CNS).We show three interfaces of anatomical side of BBB and two functional types of BBB一physical and transporter *** this protective mechanism is essential for health of CNS,it also creates a hindrance to the entry of drugs into the *** BBB was discovered over 100 years ago but till now,there is no efective methods for brain drug *** ane more than 70 approaches for overcoming BBB incuding physical,chenical and biological techniques but all of these tools have limitation to be widely used in clinical practice due to invasi venes,challenge in performing,very costly or lim-itation of drug *** therapy(PDT)is usual clinical method of surgical navigation for the resection of brain tumor and anti-cancer ***,the application of PDT is considered as a potential promising tool for brain drug delivery via opening of ***,we show the first sucoessful experimental results in this field discussing the adventures and disadv antages of PDT-related BBB disruption as well as altematives to overcome these limitations and possi ble mechanisms with new pathways for brain clearance via gly mphatic and lymphatic systems.

关键词： Blood-brain barrier laser technologies photodynamic therapy brain drug delivery

Lakes of the Jom-Bolok volcanoes valley in the East Sayan Mts., Baikal region: Morphogenesis and potential for regional paleoenvironmental studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2019年第11期29卷 1823-1840页

作者： alexander SHCHETNIKOv Elena v. BEZRUKOvA Institute of the Earth’s Crust SB Russian Academy of Sciences Irkutsk 664033Russia vinogradov Institute of Geochemistry SB Russian Academy of Sciences Irkutsk 664033Russia Irkutsk State University Irkutsk 664033Russia Institute of Archaeology and Ethnography SB Russian Academy of Sciences Novosibirsk 630090Russia

This article describes the lake basins of the Jom-Bolok volcanic region in the East Sayan (the largest manifestation of the Holocene eruptions in Central Asia).The geomorphological position,origins,aspects of the structure and development are reviewed considering its sedimentary *** limnic morphogenesis here develops under the conditions of contrasting relief,high energy of neotectonic and exogenous *** established that Lake Khara-Nur,formed as a result of lava-damming of the Jom-Bolok river valley,emerged in its present form approximately 6500 years ago.A complex record on the environment and climatic changes,acquired from its sediments,made it possible to determine for the first time in this region the long-term trends in the development of the Middle and Late Holocene mountain geosystems and also the distinction of several paleogeographic stages of the formation of the natural *** average geochemical record resolution for the bottom sediments of the lake was made uniquely for the East Siberian lake records and is equal to 35 years,while the palynological record approximates 110 years.

关键词： lake morphogenesis Holocene volcanism lava-dammed lakes environmental change

Mesoscopic Models of Plants Composed of Metallic Nanowires

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2013年第3期10卷 368-376页

作者： Galina K. Strukova Gennady v. Strukov Evgeniya Yu. Postnova alexander Yu. Rusanov Ivan S. veshchunov Institute of Solid State Physics Russian Academy of Sciences 142432 Chernogolovka Russia

various metallic structures of complex shape resembling living plant organisms （biomimetics） are produced as a result of self-assembly of nanowires growing on porous membranes in the course of pulse current electrodeposition. These structures occur if the electroplating is continued after the nanowires appear on the membrane surface. By varying the membrane ge- ometry, pulse current electroplating parameters, and alternating electrodeposition from two baths composed of a variety of electrolytes, diverse models were fabricated, including a hollow container with a wall thickness of 10 nm 20 nm. This biomimetic method suggests an analogy between the shape-forming processes of plants and their metallic models. Nanostruc- tured mesostructures of various metals （Ag, Pd, Ni）, alloys （PdNi, Pbln） and hybrid structures .（PdNi/Pb, PdNi/Pbln） were obtained. They can be of interest for fundamental research （self-assembly, morphogenesis） as well as for applications in nanotechnology （catalysis, nanoplasmonics, medicine, superhydrophobic surfaces）.

关键词： templated growth pulse electroplating self-assembly metallic mesostructures nanowires fractal branching biomimetic method