检索结果-南通市图书馆

Kinetics and mechanism of the low-energy β-a phase transition of the second kind in 2,4-dinitroanisole

Defence Technology（防务技术） 2024年第10期40卷 210-224页

作者： Aleksandr v.Stankev.ch Nikolay A.Rasputin Anisa KhRudina Gennady L.Rusinov.vera I.Filyakov. v.lery N.Charushin I.Ya. Postov.ky Institute of Organic Synthesis Ural Branch of the Russian Academy of Sciencesekaterinburg 620108russia Russian Federal Nuclear Center-Zababakhin All-Russia Research Institute of Technical Physics snezhinsk 456770russia Kazan National Research Technological Univ.rsity kazan 420015russia

In this work, comprehensiv. studies of 2,4-dinitroanisole(2,4DNAN) were carried out using powder thermorentgenography of the internal standard. The time of the complete polymorphic transition in the solid phase β→a in 2,4DNAN under v.rious combinations of conditions has been determined. It has been established that, regardless of the season of manufacture of the substance, when it is stored for 8-9months, with a change in ambient temperature from minus 30℃ to plus 30℃, a complete polymorphic transition β→a occurs. When stored in conditions below minus 5℃, polymorphic transition does not occur. When stored in conditions abov. plus 30℃ in a closed container, polymorphic transition occurs within 3 weeks. The polymorphic transition is accompanied by a decrease in density by 1.3%-1.5% and an increase in melting temperature by 10-12℃, depending on the degree of purity of the starting substance. The activ.tion energy of the molecular rearrangement was 68-70 k J/mol(16.5 ± 3 kcal/mol). The mechanism of polymorphic transition has been ev.luated, which is presumably based on internal homodiffusion and energy transfer to the surface of the mass of powder particles and the product. The average activ.tion energy of the polymorphic transition process was 110 ± 6.2 k J/mol(26.2 kcal/mol). In an open container, reactions proceed by a homogeneous mechanism, and in a closed container by a heterogeneous mechanism inv.lv.ng the gas phase.

关键词： Energetic materials Melt-castable 2,4-Dinitroanisole Polymorphic transition Kinetics Mechanism Homodiffusion Sublimation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

COMPARATIv. TREATMENT OF ACNE v.LGARIS USING PALOMAR LUX APPLIQU´E TECHNIQUE AND DIRECT INTRALESIONAL INJECTION

引用

Journal of Innov.tiv. Optical Health Sciences 2009年第3期2卷 279-287页

作者： ELINA A.GENINA ALEXEY N.BASHKATOv.v.LERY v.TUCHIN GEORGY v.SIMONENKO vera N.SHERSTNEv. ILYA v.YAROSLAv.KY GREGORY B.ALTSHULER Department of Optics and Biophotonics Saratov.State Univ.rsity 83 Astrakhanskaya str. Saratov 410012Russia Saratov.State Medical Univ.rsity 112 B.Kazachya str. Saratov 410012Russia Palomar Medical Technologies Inc. 82 Cambridge St.Burlington 01803MAUSA

Intralesional injection of triamcinolone(TMC)preparations is an effectiv. therapy for cystic acne ***,inv.siv. deliv.ry techniques limit the use of this modality to a relativ.ly narrow class of *** permeability can be enhanced through creating a lattice of microzones(islets)of light-induced limited thermal damage in the upper layers of *** this paper,we directly compared safety and efficacy of deliv.ring TMC acetonide with this nov.l technique v.rsus conv.ntional intralesional injection for treatment of inflammatory acne lesions.A combination of an intense pulsed light system and a specially designed appliqu´e with a pattern of absorbing centers has been used to create the lattice of islets of damage(LID).Quantitativ. analysis has included estimation of the following parameters:redness,diameter,and height of acne *** photography has been used to document dynamics of lesion dev.lopment at successiv. v.sits(two hours,24 hours and one week post-treatment).Sev.n subjects hav. participated in the *** difference in lesion dynamics between the treatment and control groups was observ.d at two-hours *** 24-hours/one-week follow-ups,TMC-injected and TMC-LID-deliv.red groups hav. demonstrated 82%/93%and 80%/89%improv.ment in height of lesions in comparison to control(60%/68%).Deliv.ry of TMC with the newly proposed LID technique is at least as effectiv. as intralesional injection for treating inflammatory acne *** of skin permeability using LID approach is a promising technique for accelerating deliv.ry of v.rious compounds to their target areas in the skin.

关键词： Acne v.lgaris drug deliv.ry skin permeability enhancement.

来源：

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

Stabilization for a Fourth Order Nonlinear Schrödinger Equation in Domains with Mov.ng Boundaries

引用

Journal of Partial Differential Equations 2021年第3期34卷 268-283页

作者： vera v.LLAGRAN Octav.o Paulo Mathematics Department University of TarapacaArica-Chile

In the present paper we study the well-posedness using the Galerkin method and the stabilization considering multiplier techniques for a fourth-order nonlinear Schrödinger equation in domains with mov.ng *** consider ... 详细信息

关键词： Nonlinear Schrödinger equation mov.ng boundary stabilization

来源：

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

Biodiv.rsity, dynamics, and impact of chakras on the Ecuadorian Amazon

引用

Journal of Plant Ecology 2019年第1期12卷 34-44页

作者： Roy R.vera v.J.Hugo Cota-Sánchez Jorge E.Grijalv. Olmedo Univ.rsity of Saskatchewan Department of Biology112 Science PlaceSaskatoon SK S7N 5E2Canada Univ.rsity of Saskatchewan Department of Biology and W.P.Fraser Herbarium(SASK)112 Science PlaceSaskatoon SK S7N 5E2Canada Univ.rsidad Central del Ecuador Facultad de Medicina Veterinaria y ZootecniaJerónimo Leiton y Gatto SobralQuito 170521Ecuador Estación Experimental Santa Catalina Panamericana Sur Km1Instituto Nacional de Investigaciones AgropecuariasMejía 171101Ecuador

Aims Deforestation and biodiv.rsity loss are two alarming,closely related problems,and the main factors triggering changes in land *** agricultural practices in the western Amazon Basin are known as chakras,and their structure and dynamics are seemingly optimal for forest ***,the v.riability in tree spe-cies and the degree of forest recov.ry after abandonment is poorly documented in this agroforestry system(AFS).The goals of this study were:(i)to inv.stigate whether the different AFSs(chakras)preserv. similar lev.ls of forest div.rsity,(ii)to determine the effect of trans-formation of mature forests(MF)to chakras,in particular,forest alpha and beta div.rsity lev.ls,and(iii)to inv.stigate whether nativ. tree species recov.ry leads to the original forest structure following chakra *** We assessed the floristic composition in three AFSs(cassav.,corn,and cocoa),the secondary forest(SF),and the forest remnants in the buffer zone of the Northern Ecuadorian Amazon(NEA).All tree spe-cies with a diameter at breast height(dbh)≥10 cm were inv.ntoried in 61 plots(0.28 ha average)representing 17.44 *** div.rsity was calculated in all systems to determine the lev.ls of v.riabil-ity using species richness and the Shannon div.rsity ***,beta div.rsity was examined to ev.luate the degree of dissimilarity among all AFSs with the MF in order to analyze changes in floristic *** div.rgence between the SF and the MF was ana-lyzed to ascertain forest recov.ry after chakra *** Findings A total of 4,060 trees(dbh≥10 cm)representing 109 species,96 genera,and 43 plant families were inv.ntoried in 17.44 ha sampled in fiv. systems in the buffer zone of the *** most dominant plant families were Arecaceae,Myristicaceae,Fabaceae,Meliaceae,and Malv.ceae,and the most representativ. genera included Iriartea,v.rola,Guarea,Ocotea,Cordia,Chrysophyllum,and *** MF in this zone is composed of 81 tree species circums

关键词： agroforestry biodiv.rsity chakra climate change tropical forest

来源：

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

Same or different?Abstract relational concept use in juv.nile bamboo sharks and Malawi cichlids

引用

Current Zoology 2021年第3期67卷 279-292页

作者： Theodora Fuss Leonie John vera Schluessel Institute of Zoology Rheinische Friedrich-Wilhelms-University BonnMeckenheimer Allee 169Bonn53115Germany

Sorting objects and ev.nts into categories and concepts is an important cognitiv. prerequisite that spares an indiv.dual the learning of ev.ry object or situation encountered in its daily ***,specific items are classified in general groups that allow fast responses to nov.l *** present study assessed whether bamboo sharks Chiloscyllium griseum and Malawi cichlids Pseudotropheus zebra can distinguish sets of stimuli(each stimulus consisting of two abstract,geometric objects)that meet two conceptual preconditions,i.e.,(1)"sameness"v.rsus"difference"and(2)a certain spatial arrangement of both *** two alternativ. forced choice experiments,indiv.duals were first trained to choose two different,v.rtically arranged objects from two different but horizontally arranged *** discriminations were followed by extensiv. transfer test *** tests using stimuli consisting of(a)black and gray circles and(b)squares with nov.l geometric patterns prov.ded conflicting information with respect to the learnt rule"choose two different,v.rtically arranged objects",thereby inv.stigating(1)the indiv.duals'ability to transfer prev.ously gained knowledge to nov.l stimuli and(2)the abstract relational concept(s)or rule(s)applied to categorize these nov.l *** results suggest that the lev.l of processing and usage of both abstract concepts differed considerably between bamboo sharks and Malawi *** sharks seemed to combine both concepts-although not with equal but hierarchical prominence-pointing to adv.nced cognitiv. ***,Malawi cichlids had difficulties in discriminating between symbols and failed to apply the acquired training knowledge on new sets of geometric and,in particular,gray-lev.l transfer stimuli.

关键词： v.sual concept learning spatial arrangement relational abstract concept Malawi cichlid bamboo shark

来源：

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

Phylogenetic relationship and v.riation of alarm call traits of populations of red-cheeked ground squirrels(Spermophilus erythrogenys sensu lato)suggest taxonomic delineation

引用

Integrativ. Zoology 2019年第4期14卷 341-353页

作者： vera A.MATROSOv. Anastasia D.Iv.NOv. Elena v.v.LODINA Ilya A.v.LODIN Dmitry Yu.ALEXANDROv.Olga v.SIBIRYAKOv. Oleg A.ERMAKOv Engelhardt Institute of Molecular Biology RASMoscowRussia Lomonosov.Moscow State Univ.rsity MoscowRussia Moscow Zoo MoscowRussia Sev.rtsov.Institute of Ecology and Ev.lution RASMoscowRussia Department of Zoology and Ecology Penza State UniversityPenzaRussia

Distribution area and taxonomic borders within the species complex Spermophilus erythrogenys sensu lato remain *** ev.dence suggests that red-cheeked ground squirrels of Southeast Kazakhstan are remarkably different in terms of the acoustic structure of their alarm calls from the red-cheeked ground squirrels of the Kurgan region in *** this study,we analyzed the differences in the acoustic structure of the alarm call and mitochondrial DNA(complete control region,1005-1006 bp and complete cytochrome b gene,1140 bp)in 3 populations of red-cheeked ground squirrels(Tara,Altyn-Emel and Balkhash),all located within areas isolated by geographical barriers in Southeast *** found that the alarm call v.riables were similar between the 3 study populations and differed by the maximum fundamental frequency(8.46±0.75 kHz)from the v.lues(5.62±0.06 kHz)reported for the red-cheeked ground squirrels from the Kurgan region of Rus*** in mtDNA control region was only 3%and v.riation in cytochrome b gene was only 2.5%.Phylogenetic trees based on cytochrome b gene polymorphism of 44 indiv.duals from the study area and adjacent territories indicated 3 clades with high(98-100%)bootstrap support:“intermedius,”“brev.cauda”and“iliensis”).We conclude that the 3 study populations in Southeast Kazakhstan belong to the clade intermedius and suggest a taxonomical rev.sion of the species complex Spermophilus erythrogenys sensu lato,including analyses of nuclear DNA and alarm calls for populations of the brev.cauda and iliensis clades.

关键词： alarm call control region cytochrome b mitochondrial DNA v.cal communication

来源：

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

Adrenocortical system activ.ty in alloxan-resistant and alloxan-susceptible Wistar rats

引用

Journal of Diabetes Mellitus 2012年第2期2卷 165-169页

作者： vera G. Selyatitskaya Natalya A. Palchikov. Natalya v. Kuznetsov. Siberian Branch of Russian Academy Medical Sciences Scientific Centre of Clinical and Experimental Medicine Novosibirsk Russia

In the dynamics of the disease dev.lopment, diuresis and glycosuria increase in alloxan-susceptible rats, while in alloxan-resistant rats the increase in the v.lues of these indices is expressed to a lesser extent, and they begin to decrease by day 8 of the disease. In alloxan-susceptible rats, the mass index of adrenal gland is increased, and that of thymus is decreased and corticosterone concentration in blood, adrenal gland and urine as well as alanine and aspartate aminotransferase activ.ties in liv.r are increased;in alloxan-resistant rats the v.lues of these indices do not differ from those of rats of the control group.

关键词： Experimental Diabetes Alloxan-Resistant and Alloxan-Susceptible Rats Adrenocortical System Activ.ty Corticosteroids Concentration in Urine

来源：

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

Effect of poly(3-hydroxyalkanoates) as natural polymers on mesenchymal stem cells

引用

World Journal of Stem Cells 2019年第10期11卷 764-786页

作者： vera v.inov. Garina Bonartsev. Anton Bonartsev Faculty of Biology M.V.Lomonosov Moscow State UniversityMoscow 119234Russia A.N.Bach Institute of Biochemistry Research Center of Biotechnology of the Russian Academy of SciencesMoscow 119071Russia

Mesenchymal stem cells(MSCs)are stromal multipotent stem cells that can differentiate into multiple cell types,including fibroblasts,osteoblasts,chondrocytes,adipocytes,and myoblasts,thus allowing them to contribute to the regeneration of v.rious tissues,especially bone *** are now considered one of the most promising cell types in the field of tissue *** petri dish-based culture of MSCs generate heterogeneity,which leads to inconsistent efficacy of MSC *** and biocompatible polymers,poly(3-hydroxyalkanoates)(PHAs),are activ.ly used for the manufacture of scaffolds that serv. as carriers for MSC *** growth and differentiation of MSCs grown on PHA scaffolds depend on the physicochemical properties of the polymers,the 3D and surface microstructure of the scaffolds,and the biological activ.ty of PHAs,which was discov.red in a series of *** mechanisms of the biological activ.ty of PHAs in relation to MSCs remain insufficiently *** suggest that this effect on MSCs could be associated with the natural properties of bacteria-deriv.d PHAs,especially the most widespread representativ. poly(3-hydroxybutyrate)(PHB).This biopolymer is present in the bacteria of mammalian microbiota,whereas endogenous poly(3-hydroxybutyrate)is found in mammalian *** possible association of PHA effects on MSCs with v.rious biological functions of poly(3-hydroxybutyrate)in bacteria and eukaryotes,including in humans,is discussed in this paper.

关键词： Mesenchymal stem cells Polyhydroxyalkanoates Poly(3-hydroxybutyrate) Tissue engineering Differentiation Natural functions Microbiota Bone Intestine

来源：

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

Fatty acids composition of erythrocytes in arterial hypertension associated with dyslipidemia

引用

Health 2013年第4期5卷 73-77页

作者： Tatyana P. Nov.orodtsev. Yulia K. Karaman Tatyana A. Gv.zdenko Marina v. Antonyuk vera v. Knyshov. v.adiv.stok Branch of the Far Eastern Center of Physiology and Pathology of Respiration SB RAMN Institute of Medical Clima-tology and Rehabilitative Treatment Vladivostok Russia

Studied the fatty acid (FA) composition of erythrocyte membranes in patients with arterial hypertension associated with dyslipidemia. The fatty acid composition of erythrocyte membranes was studied by gaz chromatography. In all hypertensiv. patients are disturbed lipid FA composition of erythrocytes: increase in saturated fatty acids (15:0, 16:0), monoenic fatty acids (18:1n9, 18:1n7), polyunsaturated fatty acids (PUFA) family n6 (20:4n6), decrease in polyunsaturated fatty acids family n3:22:5n3, 22:6n3, the total v.lue of n3 PUFA. Cells endogenous deficiency of n3 PUFA leads to the changes of the plasmatic membranes physicochemical properties, activ.tion of eicosanoids synthesis with proinflammatory and v.soconstriction activ.ty, the formation of the systemic inflammatory syndrome and conditions for the atherogenesis. Thus, structural and functional changes in erythrocyte membranes in hypertension dev.loped as a part of the common systemic disorder of lipid metabolism.

关键词： Fatty Acids Arterial Hypertension Dyslipidemia

来源：

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

Aromatic Bromination in Concentrated Nitric Acid

引用

Open Journal of Synthesis Theory and Applications 2014年第2期3卷 15-20页

作者： Alexander M. Andriev.ky vera I. Lomzakov. Mikhail K. Grachev.Mikhail v. Gorelik Departament of Chemistry Moscow State Pedagogical University Moscow Russia Research Institute of Organic Intermediates and Dyes (NIOPIK) Moscow Russia

Action of bromine in concentrated nitric acid allows carrying out mono- and polybromination of moderately deactiv.ted aromatic compounds. 4-Chloronitrobenzene and isophthalic acid turnes into 3-bromo-4-chloronitrobenzene and 5-bromoisophthalic acid at reaction with bromine in concentrated nitric acid at 20°C whereas in absence of bromine in the same conditions 4-chloro-1, 3-dinitrobenzene and 5-nitroisophthalic acid are formed accordingly. Presence of bromine in concentrated nitric acid changes nitrating capacity to brominating one. Terephthalic acid and phthalic anhydride at heating with bromine in concentrated nitric acid can be transformed to appropriating tetrabromo substituted compounds.

关键词： Bromination Nitration Aromatic Compounds 3-Bromo-4-chloronitrobenzene 5 Bromoisophthalic Acid 2 3 5 6-Tetrabromoterephthalic Acid 4 6 Tetrabromophthalic Anhydride

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：