bluuebunny/crossref_metadata_2025 huggingface dataset:
Policy Integration and Coherence for Conservation Agriculture Initiatives in Malawi
Authors: Chinseu Edna , Stringer Lindsay , Dougill Andrew
Published: August 2018

In sub-Saharan Africa, development and dissemination of perceived new agricultural innovations dominate the development agenda yet hunger and poverty remain widespread. A conducive policy environment is essential to support these efforts. Despite that national policies are a critical component in the functioning of an agricultural innovation system, studies have often overlooked their relevance in farmers’ adoption of agricultural innovations. There is an urgent need to enhance understanding of how policies affect long-term adoption of agricultural innovations aimed at increasing productivity and incomes of smallholder farmers. This study utilises thematic content analysis to examine the extent of integration of Conservation Agriculture (CA) and coherence in Malawi’s national agricultural policies, and their implication for CA adoption among smallholder farmers.Results indicate that inadequate integration of CA in the National Agricultural Policy (NAP), coupled with a lack of coherence of agricultural department policies, undermines farmers’ CA adoption. While inadequate integration constrains resource allocation for supporting CA activities, lack of coherence of agricultural policies radiates conflicting and confusing agricultural extension messages to smallholder farmers. We argue that inadequate CA integration and incoherence of policies are institutional constraints which prevent farmers’ sustained adoption. To facilitate long-term adoption of CA among smallholders, there is need to: (1) strengthen CA integration in agricultural policies; (2) improve departmental coordination to enhance coherence of agricultural strategies and extension messages disseminated to farmers; and (3) strengthen government’s role in supporting multi-disciplinary research to generate and disseminate best practices capable of sustaining CA adoption.
Assessment of pupils’ physical activity during diverse types of teaching lessons
Authors: Trávníček Marek , Svobodová Hana , Durna Radek
Published: August 2018

This paper focuses on the physical activity of pupils of early school age during different types of school lessons, i.e. 45 minutes – a frontal teaching lesson, a physical education lesson, and an integrated fieldwork education (IFE) lesson. In the research, we analysed each method of teaching in terms of the number of steps the pupils made and their metabolic rate in MET units. The minor aim was to verify the use of ActiGraph accelerometers by teachers at schools and to provide basic information about the devices to the potential users.The physical education class had the highest volume of movement – 1,202 steps in 45 minutes. However, the IFE with 1,118 steps in 45 minutes may be compared to a class of physical education in terms of the number of steps. The weakest in terms of the steps made and the amount of physical activity was a habitual education class, where students walked an average of 218 steps in 45 minutes. We also tried to find out the intensity of the physical load of pupils of early school age. Again, the physically most demanding form of teaching was the physical education lesson, during which pupils achieved medium physical load above 3 MET. For integrated fieldwork education, the metabolic output was below 3 MET, namely 2.63. The lesson of habitual teaching was characterized by a low-intensity motoric load of 1.81 MET.
Comparison of selected anthropometric parameters and motor tests in male gravity cyclists and high school students
Authors: Siriški Damjan
Published: August 2018

The objective of our study was to compare selected parameters of body composition and motor tests results obtained with measuring of two diverse groups – elite gravity cyclists and a control group of high school students. The study was conducted in 31 male gravity cyclists (16 technical gravity disciplines, 15 downhill gravity disciplines) and 14 male school students. Matiegka protocol was used to estimate body composition and somatotype, a battery of specific motor skills was used to determine motor skills of the two test groups.Downhill gravity cyclists proved significantly higher mesomorphy than the control group - downhill disciplines 5,3 (σ = 0,43), control group 4.7 (σ = 1,05),  and significantly higher values of test results than control group in broad jump (downhill disciplines 228,2 cm σ = 20,1 cm; control group 192,4 cm, σ = 15,1 cm), back-broad jump test (downhill disciplines 118,6 cm, σ = 12,8 cm; control group 98,3 cm, σ = 13,5 cm) and high jump (downhill disciplines 61,1cm, σ = 11,9 cm; control group 51,5 cm, σ = 12,5 cm). Technical disciplines cyclists proved significantly higher values of test results than control group in broad jump (technical disciplines 214,5 cm σ = 18,2 cm; control group 192,4 cm, σ = 15,1 cm), rotation jump  (technical disciplines 510°, σ = 25,4°; control group 430,2°, σ = 39,4) and high jump test (technical disciplines  112,6 cm, σ = 10,9 cm; control group 98,3 cm, σ = 13,5 cm).Differences in somatotype, body constitution and motoric tests relate with characteristics of training and use of specific training methods. In this study high level performance athletes were tested, therefore it could be helpful for riders and coaches to increase the efficiency of the training process.
Chi Square Test Correlation of Physical Activity of Obese Children of Three Libyan Cities
Authors: Elabani Fawzi
Published: August 2018

Background-The highest prevalence of childhood obesity have been observed in developed countries, however its prevalence is increasing in developing countries as well.Objectives-To evaluate demographic variation in the prevalence of overweight and obesity among 1361 children and adolescents of three Libyan cities Tripoli, Zawia, and Geryan (Tripoli- girls; n =369, boys; n = 290, Zawia- girls; n =250, boys; n = 89, and Geryan- girls; n =230, boys; n = 133) aged 3-19 years. Methods-The study was carried out at Central Tripoli Pediatric Hospital during a year 2016/17.The researcher took the anthropometric measurements inside the nurse's room of the out-patient department (OPD), and gave a questionnaire to children to be answered by one of the child's parents. The questionnaire included questions related to the socioeconomic status, life style (physical activity and eating habits) and family history of overweight and obesity.In this paper a Chi square test of independence is used to measures whether there is a relationship between gender and physical activity.The results shows that there is a significant relationship between the physical activity and the gender for all three cities.
The Character of the Hypocrite
Authors: Bloomfield Paul ,   Philosophy Documentation Center
Published: August 2018

A distinction is made between acting hypocritically and the character trait of being a hypocrite. The former is understood as resulting from the employment of a double standard in order to obtain a wrongful advantage, while a particular problem with the latter is that hypocrites do not give trustworthy testimony.
The influence of aqueous extracts on curd-type cheese quality
Authors: Šlapkauskaitė Jūratė , Žalnieraitė Kristina , Šlapkauskas Algimantas , Sekmokienė Dalia
Published: August 2018

The aim of this study was to evaluate the effect of aqueous extracts from different parts of plants such as berries of guelder rose (Viburnum opulus), seeds of cardamom (Elettaria cardamomum), musk (Myristica fragrans) and indian cumin (Cuminum cyminum), rootstock of ginger (Zingiber officinale) and liquorice (Glycyrrhiza glabra) on the quality of curd-type cheese.
We produced organoleptically acceptable aqueous plant extracts (1.5% concentration) and evaluated their antimicrobial activity. According to the standard methodology we manufactured curd-type cheese. During the storage we identified physico-chemical properties (pH and colour coordinates), the number of lactic acid bacteria (LAB) and sensoryprofile properties of the final product.
The experiment shows that plant extracts extended the shell-life of curd-type cheese, and the substances contained there act as natural preservatives. Curd-type cheese supplemented with plant extracts compared to the control sample is microbiologically safe.
The study proves that curd-type cheese can be improved by adding plants rich in biological active substances, to improve the sensory properties, increase the biological value and extend the shell-life as safety by natural means. The effect of plant extracts has shown sensory properties of curd-type cheese – colour, taste, odour and acceptability.
Intégration de l'évaluation de l'émergence de l'écrit au jeu symbolique en milieu préscolaire
Authors: Drainville Roxanne
Published: August 2018

Actuellement, l’utilisation de tests standardisés est répandue dans le milieu préscolaire au Canada et aux États Unis, notamment pour évaluer le développement des habiletés en lecture et en écriture. Cette pratique évaluative serait toutefois inappropriée au soutien des jeunes enfants dans leurs apprentissages. En s’appuyant sur l’approche vygotskienne, il apparaîtrait que l’intégration de l’évaluation au jeu symbolique serait plus appropriée. Dans la littérature recensée, peu d’études empiriques montrent des pratiques effectives de l’évaluation de l’émergence de l’écrit combinée au jeu symbolique dans les classes préscolaires. Cet article présente donc l’étude de cas que nous réaliserons afin de décrire ces pratiques évaluatives telles qu’elles sont présentement appliquées par des enseignants. Cette recherche pourrait avoir des retombées dans le milieu scolaire en offrant aux enseignants du préscolaire des modèles où l’évaluation de l’émergence de l’écrit a été intégrée au jeu symbolique.
André Gorz, de l'existentialisme au salut par les TIC
Authors: Flipo Fabrice
Published: August 2018

A l'occasion des dix ans de sa disparition, cet article revient sur l’ensemble de l'oeuvre d’André Gorz (1923‑2007), en proposant une périodisation en quatre volets: l'analytique existentialiste (1946/1955), la tentative de refonder le socialisme (1959/1969), puis de le dépasser (1973/1983) avant de revenir au marxisme au travers du motif des Grundrisse et des technologies de l'information (1983/2007). Nous montrons la cohérence et l’exigence d'un philosophe qui n’a jamais renoncé à évaluer les possibles offerts par son temps. Gorz a cependant laissé de côté ce que l'écologie impliquait de remise en cause à propos de la modernité.
Engagement radical, extrême ou violent
Authors: Guibet Lafaye Caroline
Published: August 2018

L'interprétation de la violence politique est placée, de façon récurrente, par les media comme par le discours politique institutionnel sous le paradigme du "basculement". Les sciences sociales y voient un engagement à "haut risque" (McAdam, 1986). Afin d'éprouver la validité de ces interprétations, nous avons mené une enquête par entretiens approfondis auprès de l'extrême gauche française. À partir de ces entretiens, nous proposons une détermination de l'engagement radical, nourrie de la parole des acteurs. Il s'avère alors présenter la double caractéristique d'être coextensif à la vie de l'individu et indissociable du fait d'être acteur de ses convictions politiques, en réponse à une injonction morale à l'action. Ces caractéristiques appellent une relecture critique de la thèse de l'entrée en radicalité comme "basculement", montrant que, concernant l'extrême gauche française au moins, il s'agit plutôt d'une prise de conscience, perçue par l’acteur comme irréversible, mais s'inscrivant cependant dans la continuité d'un parcours de vie. Une nouvelle détermination de l'engagement, décrit comme radical, émerge alors en référence à ces deux caractéristiques non psychologisantes mais de nature descriptive. Elle constitue une interprétation renouvelée de l'engagement radical, formulée par Doug McAdam (1986) et reprise jusqu’alors dans la littérature (Sommier, 2012), en termes de haut coût et de haut risque.
Vivre la transparence
Authors: Barbisan Léa
Published: August 2018

Au début du XXe siècle, la maison de verre fascine nombre d'artistes et d'écrivains de
l'avant-garde européenne. Dans le contexte de la densification urbaine, l'idéal d'un habitat
aux murs transparents interroge la valeur de l'intime et l'attachement au foyer. Le rêve
d'un espace entièrement ouvert, où s'aboliraient les frontières entre l'intérieur et
l'extérieur, le local et l'universel, le privé et le commun, traverse les textes de Paul
Scheerbart, d'André Breton et de Walter Benjamin. D'utopie esthétique, la maison de verre
devint, au gré de ses évolutions, utopie politique, pour finalement basculer dans le
cauchemar de la surveillance totalitaire. Cet article met au jour les fantasmes qui se
cristallisèrent autour de cette utopie insolite, et tente d'élucider les raisons de son
déclin.
Imaginer les chorégraphies technicisées présentes et à venir
Authors: Uhl Magali , Duchesneau Catherine
Published: August 2018

Les programmes des nouvelles machines du quotidien, comme le téléphone intelligent, la
tablette et l’ordinateur portable, contribuent à écrire nos gestes, mouvements et
interactions quotidiennes, engendrant une incorporation de la technique. Par l’analyse de
l’œuvre chorégraphique de Julien Prévieux, What Shall We Do Next ?, c’est l’influence de ces
écritures technologiques du corps sur les gestes et interactions sociales à venir, tel
qu’imaginé par l’artiste, que notre article vise à aborder.
« La violence n'est pas un concept »
Authors: Jahier Adrien
Published: August 2018

Gérard Chaliand, géopolitologue, explique les raisons qui ont mené, d'une part, aux
échecs occidentaux dans les guerres irrégulières et, d'autre part, à la chute actuelle de
l'État islamique. Il critique également les inconsistances de la politique étrangère
américaine et française, ainsi que le rapport que cultive l'Occident avec la violence. Cet
entretien, effectué le 26 avril 2017, est l’occasion de revenir sur le parcours atypique
d’un homme. Né en 1934, Gérard Chaliand a arpenté le globe et ses conflits en étant
observateur-participant : de la Guinée-Bissau au Nord Viêt Nam, en passant par la Colombie,
il a également passé beaucoup de temps au Moyen-Orient, se rendant régulièrement en
Afghanistan, en Irak et en Syrie. Au-delà de la figure du géopolitologue « aventurier », il
y a également celle, moins connue, du poète, qui trouve refuge dans l’écriture face à
l’atrocité du conflit. Pour Gérard Chaliand, la violence n’est pas un concept, mais avant
tout une expérience de terrain, forcément dure.
Dieu n’a pas inventé le webdocumentaire : Réflexion ontologique sur la représentation du réel à l’écran
Authors: Beauparlant Sophie
Published: August 2018

La question qui fonde notre réflexion est la suivante : de quelle façon le numérique affecte-t-il le statut ontologique du documentaire ? Afin de saisir les conditions d’existence du webdocumentaire, cet article interroge la nature indicielle de l’interface numérique et son impact sur l’interprétation des contenus documentaires. En prenant comme référence la notion de degré de documentarité de Gaudreault et Marion, nous cherchons à voir comment le dispositif interactif interfère dans la représentation du réel à l’écran.
Une ontologie ou une esthétique numérique ?
Authors: Roy Lucie
Published: August 2018

Afin de mettre au jour l’être-image ou le caractère relationnel des images argentique
et numérique, l’auteure reproblématise un ensemble de réflexions proposées par André Bazin
(sur l’ontologie) et Roland Barthes (à propos du punctum). Elle suppose que les images
numériques ont contribué au dévoilement de la-réalité-des-images. Ayant trait à la
perception et à la pensée, les images numériques, de même que les images argentiques, ne
manquent pas d’être soumises à des ouvragements et à des transformations. Perception,
pensée, ouvragement et transformation satisfont la-réalité-des-images ou participent de leur
ontologie.
La littérature à la dérive numérique
Authors: Agostini-Marchese Enrico
Published: August 2018

L’opposition millénaire entre réel et imaginaire, inaugurée par Platon, est-elle
encore valable à l’époque du numérique ? Nous entendons questionner le positionnement
platonicien en nous appuyant paradoxalement sur l’art le moins réel d’après Platon
lui-même : la littérature. Nous montrerons, à travers un bref parcours historique de la
filiation qui de la flânerie baudelairienne en passant par la pratique situationniste de la
dérive, mène jusqu’à la littérature numérique contemporaine portant sur l’espace, comment
cette typologie de littérature, avec ses stratégies d’écriture, ses poétiques et ses
pratiques, peut déjouer cette opposition gravée dans notre pensée.
Poeticizing Ecology/Ecologizing Poetry: Reading Elizabeth Bishop’s “Poem” Ecologically
Authors: Spicer Kevin Andrew , McDermott Beth
Published: August 2018

In “Poeticizing Ecology/Ecologizing Poetry: Reading Elizabeth Bishop’s ‘Poem’ Ecologically,” we argue that ecological poetry is a kind of ecopoetry that undergirds “nature poetry” and environmental/activist poetry.  Ecological poetry is also best put into conversation with deconstruction.  This argument, informed by Timothy Morton’s claim that “deconstruction and ecology should talk to one another,” entails challenging previous arguments about what counts as ecopoetry but also the status of the lyric in general.  We synthesize James Longenbach’s position in The Resistance of Poetry with Nick Selby’s argument in “Ecopoetries in America” to examine the relationship between close reading and reading ecologically.  Rather than an ethical stance perceived in the content of the poem, to read ecologically requires attention to form and linguistic indeterminacy, not only because deconstruction and ecology are alike, but also because poetry is comprised of language, the usage of which “revels in duplicity and disjunction.” Deconstruction is the best approach to divergent perspectives on nature, or the way a poem offers, in Nick Selby’s view, not a clear purchase or single overarching view, but “a struggle to get nature right.”  We contend that to give space to alterity, to allow the otherness not only of nature but also of language itself in its capacity for referentiality is to expand the “marked” space of ecology (in the terms set forth by G. Spencer Brown’s Laws of Form).  We support this claim with a reading of Bishop’s “Poem,” which we acknowledge as an atypical choice for what constitutes ecological poetry.  A borderline ekphrastic poem, “Poem” allows us to talk not only about the space inherent in nature and language but between text and image, or poem and painting.  What we find in our reading of Bishop’s “Poem” is a contingency between the poem and the painting, rather than a classical attempt of one to overpower the other, to speak for the other as the more authoritative sign.  We find the uncanny or strange quality of Bishop’s ekphrastic approach to an amateurish painting that she calls “sketch” a way to further substantiate Morton’s claim about the relevance of deconstruction to ecology.  Through our reading of the poem we argue that no entity completely coincides with itself because ecological thinking has helped us to see how every entity is shot-through with traces of the other; we ourselves are made up of other lifeforms; life is made up of nonlife.  To think ecologically is to think the other within the self (especially including all the nonhuman others), within any entity whatsoever.
Genome-wide discovery of local RNA structural elements in Zika virus
Authors: Andrews Ryan J , Roche Julien , Moss Walter N
Published: August 2018

In addition to encoding RNA primary structures, genomes also encode RNA secondary and tertiary structures that play roles in gene regulation and, in the case of RNA viruses, genome replication. Methods for the identification of functional RNA structures in genomes typically rely on scanning analysis windows, where multiple partially-overlapping windows are used to predict RNA structures and folding metrics to deduce regions likely to form functional structure. Separate structural models are produced for each window, where the step size can greatly affect the returned model. This makes deducing unique local structures challenging, as the same nucleotides in each window can be alternatively base paired. In the presented approach, all base pairs from all analysis windows are considered and weighted by favorable folding metrics throughout all windows. This results in unique base pairing throughout the genome and the generation of local regions/structures that can be ranked by their propensity to form unusually thermodynamically stable folds.

This approach was applied to the Zika virus (ZIKV) genome. ZIKV is linked to a variety of neurological ailments including microcephaly and Guillain-Barré syndrome and its (+)-sense RNA genome encodes two, previously described, functionally essential structured RNA regions. Our approach is able to successfully identify and model the structures of these regions, while also finding additional regions likely to form functional RNA structures throughout the viral polyprotein coding region. All data for the ZIKV genome have been archived at the RNAStructuromeDB, a repository of RNA folding data for humans and their pathogens.
Missing, delayed, and old: The status of ESA recovery plans
Authors: Malcom Jacob , Li Ya-Wei
Published: August 2018

Recovery planning is an essential part of implementing the U.S. Endangered Species Act (ESA), but conservationists and government agencies recognize challenges with the current planning process. Using data from all U.S. domestic and transboundary ESA-listed species, we quantify the completeness, timeliness, age, and other variation among ESA recovery plans over the past 40 years. Among eligible listed taxa (n = 1,548), nearly 1/4 lack final recovery plans; half of plans have taken >5 years to finalize after listing; half of recovery plans are more than 20 years old; and there is significant variation in planning between agencies, and among regions and taxonomic groups. These results are not unexpected given dwindling budgets and an increasing number of species requiring protection, but underscore the need for systematic improvements to recovery planning. We discuss solutions—some already underway—that may address some of the shortcomings and help improve recovery action implementation for threatened and endangered species.
A quantitative approach for analyzing the spatio-temporal distribution of 3D intracellular events in fluorescence microscopy
Authors: Pécot Thierry , Zengzhen Liu , Boulanger Jérôme , Salamero Jean , Kervrann Charles
Published: August 2018

Analysis of the spatial distribution of endomembrane trafficking is fundamental to understand the mechanisms controlling cellular dynamics, cell homeostasy, and cell interaction with its external environment in normal and pathological situations. We present a semi-parametric framework to quantitatively analyze and visualize the spatio-temporal distribution of intracellular events from different conditions. From the spatial coordinates of intracellular features such as segmented subcellular structures or vesicle trajectories, QuantEv automatically estimates weighted densities that are easy to interpret and performs a comprehensive statistical analysis from distribution distances. We apply this approach to study the spatio-temporal distribution of moving Rab6 fluorescently labeled membranes with respect to their direction of movement in crossbow- and disk-shaped cells. We also investigate the position of the generating hub of Rab11-positive membranes and the effect of actin disruption on Rab11 trafficking in coordination with cell shape.
Structure of the human volume regulated anion channel
Authors: Kefauver Jennifer M , Saotome Kei , Dubin Adrienne E , Pallesen Jesper , Cottrell Christopher A , Cahalan Stuart M , Qiu Zhaozhu , Hong Gunhee , Crowley Christopher S , Whitwam Tess , Lee Wen-Hsin , Ward Andrew B , Patapoutian Ardem
Published: August 2018

SWELL1 (LRRC8A) is the only essential subunit of the Volume Regulated Anion Channel (VRAC), which regulates cellular volume homeostasis and is activated by hypotonic solutions. SWELL1, together with four other LRRC8 family members, potentially forms a vastly heterogeneous cohort of VRAC channels with different properties; however, SWELL1 alone is also functional. Here, we report a high-resolution cryo-electron microscopy structure of full-length human homo-hexameric SWELL1. The structure reveals a trimer of dimers assembly with symmetry mismatch between the pore-forming domain and the cytosolic leucine-rich repeat (LRR) domains. Importantly, mutational analysis demonstrates that a charged residue at the narrowest constriction of the homomeric channel is an important pore determinant of heteromeric VRAC. Additionally, a mutation in the flexible N-terminal portion of SWELL1 affects pore properties, suggesting a putative link between intracellular structures and channel regulation. This structure provides a scaffold for further dissecting the heterogeneity and mechanism of activation of VRAC.
Vulnerability of diatom communities in the Peace–Athabasca Delta to environmental change
Authors: Connor Stephanie J. , Alexander-Trusiak Alexa C. , Baird Donald J.
Published: August 2018

Habitat degradation associated with resource development is a major ecological concern, particularly in Canada’s boreal zone where limited information on biodiversity is available. Habitat degradation can lead to reductions in biodiversity and ecosystem function, especially when drivers of variability and diversity patterns have not been identified for a region of interest. In this study, the distribution of diatom genera in the Peace–Athabasca Delta in northeastern Alberta was examined in relation to seasonal, geographic, and alkalinity gradients. Grab samples of six abiotic variables (total dissolved nitrogen, total dissolved phosphorus, dissolved iron, turbidity, pH, and specific conductance (SPC)) were taken from 12 remote wetlands over three sampling periods, and regressed against an ordination of diatom community composition to identify key environmental drivers of diatom community variation. Indirect gradient analysis identified two major gradients among sites. First, separation of sites among sampling periods showed successional seasonal changes in diatom community composition. Second, separation of sites from the Peace sub-delta and Birch sub-delta showed a gradient of geographic separation. Direct gradient analysis failed to explain the underlying drivers of these two gradients, but did show that alkalinity is a key driver of diatom community composition in the Embarras sub-delta, and that these sites could be particularly vulnerable to community changes associated with acidification.
ДИНАМИКА ФАЗОВЫХ ПРЕВРАЩЕНИЙ В СНЕЖНОЙ МАССЕ, СОДЕРЖАЩЕЙ ЧАСТИЦЫ ВОДОРАСТВОРИМЫХ СОЛЕЙ, "Журнал физической химии"
Authors: Зеленко В. Л. , Хейфец Л. И. , Орлов Ю.Н. , Воскресенский Н. М.
Published: August 2018

Предлагаемая работа основывается на макрокинетическом подходе к описанию динамики фазовых превращений в снежной массе, содержащей частицы водорастворимых солей. Получены уравнения, описывающие скорость растворения гранул соли, изменение фазового состава снежной массы и температуры в условиях теплообмена с термостатированной поверхностью. Для проверки теоретических выводов была создана экспериментальная установка, моделирующая изменение состояния снежной массы, расположенной на изотермической поверхности. Экспериментальные наблюдения за изменением температуры снежной массы сопоставлены с теоретическими расчетами. Разработанная математическая модель может использоваться для прогнозирования состояния снежной массы на дорогах, обработанных противогололедным материалом, или для анализа состояния снежных масс на склонах, содержащих включения водорастворимых солей.
ГЕТЕРОГЕННАЯ НУКЛЕАЦИЯ ГИДРАТА МЕТАНА В ЭМУЛЬСИИ, "Журнал физической химии"
Authors: Шестаков В.А. , Косяков В.И. , Манаков А.Ю. , Стопорев А.С. , Грачев Е.В.
Published: August 2018

Гетерогенная нуклеация в дисперсных системах с метастабильной дисперсной фазой играет сущест­венную роль в механизмах природных и технологических процессов. В работе рассмотрено влияние концентрации и степени активности частиц, стимулирующих образование новой фазы, на процессы нуклеации в таких системах. Предложен подход, позволяющий на основе данных по зависимости доли закристаллизовавшихся капель от величины переохлаждения с использованием распределения Вейбулла построить спектр активности частиц, характеризующий особенности нуклеации в образце. Предложенный метод использован для описания экспериментральных данных по гетерогенной нук­леации гидрата метана в эмульсии в системе вода-декан-метан.
ЭНТАЛЬПИИ РАСТВОРЕНИЯ ДИКЛОФЕНАКА НАТРИЯ В ВОДЕ И В ВОДНЫХ РАСТВОРАХ КОН ПРИ 298.15 К, "Журнал физической химии"
Authors: Лыткин А.И. , Черников В.В. , Крутова О.Н. , Бычкова С.А. , Волков А.В. , Крутов П. Д.
Published: August 2018

Измерены энтальпии растворения кристаллического диклофенака натрия в воде и в водных растворах КОН при 298.15 К прямым калориметрическим методом в широком концентрационном интервале. Спектрофотометрическим методом изучены кислотно-основные свойства диклофенака натрия при ионной силе I ~ 0 и I = 0.1 (KNO3) и температуре 298.15 К. Определены концентрационные и термодинамические константы диссоциации. Рассчитаны стандартные энтальпии образования диклофенака натрия и продуктов его диссоциации в водном растворе.
ОПРЕДЕЛЕНИЕ БАЗИСА ГОМОДЕСМОТИЧЕСКИХ РЕАКЦИЙ ЦИКЛИЧЕСКИХ ОРГАНИЧЕСКИХ СОЕДИНЕНИЙ С ИСПОЛЬЗОВАНИЕМ ТЕОРИИ ГРАФОВ, "Журнал физической химии"
Authors: Хурсан С.Л. , Исмагилова А.С. , Ахметьянова А. И.
Published: August 2018

Метод сравнительного расчета, основанный на использовании гомодесмотических реакций (ГДР)?-?изодесмических процессов, дополненных условием группового баланса, использован для анализа термохимических характеристик циклических органических соединений (на примере бицикло[2.1.0]пентена-2). Для преодоления неоднозначности при выборе ГДР разработан алгоритм определения базиса ГДР, т.е. всех возможных независимых гомодесмотических реакций. Алгоритм конструирования базисного набора ГДР основан на анализе и трансформациях графа связи групп исследуемого химического соединения. Использование теории графов позволяет автоматизировать процедуру выделения базиса гомодесмотических реакций, а также получить наглядную геометрическую интерпретацию базиса, что важно для последующего физико-химического анализа. С помощью предлагаемого подхода исследовано энергосодержание бицикло[2.1.0]пентена-2, независимый базис ГДР для которого включает 19 формальных превращений. Стандартные энтальпии исследуемого соединения и участников гомодесмотических реакций вычислены с помощью композитного метода G3. Термохимический анализ полученного массива данных позволил определить стандартную энтальпию образования бицикла (DfH° = = 336.4 кДж/моль), а также DfH° ряда циклических и ациклических алкенов и алкадиенов?-?продуктов теоретической декомпозиции исследуемого соединения. Показано, что предлагаемый подход исключительно удобен для анализа невалентных эффектов строения органических молекул. Для исследуемого соединения вычислена энергия напряжения бицикла, ES = 295.2 ± 2.2 кДж/моль.
КАТАЛИТИЧЕСКИЕ СВОЙСТВА НАНОЧАСТИЦ СУЛЬФИДА КАДМИЯ, ПОЛУЧЕННЫХ ОСАЖДЕНИЕМ ИЗ РАСТВОРОВ, "Журнал физической химии"
Authors: Федяева О.А. , Пошелюжная Е.Г. , Тренихин М.В.
Published: August 2018

Изучены каталитические свойства наночастиц сульфида кадмия в реакции фотохимического разложения пероксида водорода. Показано, что в водных растворах H2O2 любой концентрации сульфид кадмия ускоряет реакцию и не изменяет ее порядка. Квантовый выход реакции равен единице и не зависит от концентрации пероксида водорода. Рассеяние света частицами и увеличение их концентрации понижает квантовый выход.
ОКИСЛЕНИЕ ВОДЫ СОЕДИНЕНИЯМИ ЦЕРИЯ(IV) В ПРИСУТСТВИИ ТРЕХЪЯДЕРНЫХ КОМПЛЕКСОВ РУТЕНИЯ, "Журнал физической химии"
Authors: Джабиева З.М. , Добрыгин В. А. , Джабиев Т.С. , Ткаченко Л.И.
Published: August 2018

Изучены кинетика и механизм реакции окисления воды соединениями Ce(IV) в присутствии рутениевого комплекса(NH3)5Ru-O-Ru(NH3)4-O-Ru(NH3)5Cl6. Показано, что этот комплекс является катализатором окисления воды, если реагируют одноэлектронные окислители Се4+, причем четыре комплекса рутения самоорганизуются в активный двенадцатиядерный кластер. Установлено. что с появлением в смеси биядерных, тетраядерных и др. кластеров церия, в катализаторе 4 лиганда NH3 замещаются на 4 иона кислорода, и это уже другая биомиметическая каталитическая система окисления воды.
МЕХАНИЗМ РАСПАДА РАДИКАЛА CH3CO3 ПРИ ЭНЕРГООБМЕНЕ С ВОЗБУЖДЕННОЙ МОЛЕКУЛОЙ CH2O, "Журнал физической химии"
Authors: Саргсян Г.Н. , Арутюнян А.Б.
Published: August 2018

С использованием компьютерных расчетных программ молекулярной механики, Gaussian, возможностей программного комплекса ChemBio 12.0, а также на основе фундаментальных концепций квантовой механики смоделирован процесс спонтанного распада радикала CH3CO3, играющего важную роль в реакциях окисления органических соединений, в частности ацетальдегида. Моделирование позволило рассчитать вероятности активации радикала, образования переходного состояния и его распада вследствие поглощения энергии возбужденных молекул формальдегида, являющегося промежуточным продуктом окисления ацетальдегида. Показано, что лимитирующей стадией распада радикала CH3CO3 является стадия активации.
ГАЗОВАЯ ХРОМАТОГРАФИЯ И ТЕРМОДИНАМИЧЕСКИЕ ХАРАКТЕРИСТИКИ СОРБЦИИ МОДЕЛЬНЫХ СОРБАТОВ НА НОВЫХ СТАЦИОНАРНЫХ ФАЗАХ НА ОСНОВЕ ПОЛИ[(ОЛИГОЭТИЛЕНГЛИКОЛЬ)ДИАКРИЛАТОВ], "Журнал физической химии"
Authors: Ширяева В.Е. , Попова Т.П. , Королев А.А. , Канатьева A.Ю. , Курганов А.А.
Published: August 2018

Термодинамические параметры сорбции тестовой смеси углеводородов на новом типе ПЭГ-подобных стационарных фаз определены из температурной зависимости удерживания сорбатов в диапазоне температур от 35 до 110?°С. Найденные величины энтропии и энтальпии сорбции оказались близкими для всех стационарных фаз, изученных в этой работе, несмотря на различное соотношение этиленгликольных и акрилатных фрагментов в структуре полимерной фазы. В то же время изученные фазы заметно отличаются по их разделяющей способности, что, вероятно, связано с кинетическими свойствами фаз, на что указывают различия в эффективности колонок с этими фазами и в коэффициентах диффузии сорбатов на этих фазах.
АНАЛИЗ АДСОРБЦИОННОЙ АКТИВНОСТИ УГЛЕРОДНОГО ВОЛОКНА УВИС-АК ПО ОТНОШЕНИЮ К РАСТВОРЕННЫМ В ВОДЕ ФЕНОЛАМ, "Журнал физической химии"
Authors: Валинурова Э.Р. , Шаймухаметова Г. Ф. , Хамитов Э.М. , Шаяхметова Р. Х.
Published: August 2018

Исследованы адсорбционные свойства углеродных волокон марки УВИС-АК и углей БАУ-А, СПДК-27МД по извлечению фенолов из воды в статических условиях. Из построенных изотерм адсорбции рассчитаны константы адсорбционного равновесия, емкость монослоя, характеристическая энергия адсорбции, изменение энергии Гиббса.
ЗАВИСИМОСТЬ МЕЖФАЗНОГО НАТЯЖЕНИЯ В СИСТЕМЕ ВОДА-Н-ГЕПТАН ОТ ТЕМПЕРАТУРЫ И КОНЦЕНТРАЦИИ СТЕАРИНОВОЙ КИСЛОТЫ, "Журнал физической химии"
Authors: Атаев Г. М.
Published: August 2018

В системе вода-н-гептан исследована зависимость межфазного натяжения от температуры и концентрации примеси (стеариновой кислоты). Исследования проводились в диапазоне температур от комнатных до 100 °C без примеси и при четырех различных концентрациях примеси. На основе полученных экспериментальных результатов определена зависимость избыточного поверхностного химического потенциала молекул стеариновой кислоты от температуры и концентрации.
ОТЕЧЕСТВЕННАЯ ИСПАНИСТИКА НА СТРАНИЦАХ ПЕРИОДИЧЕСКОГО ИЗДАНИЯ «СРЕДНИЕ ВЕКА»: ПОПЫТКА КОЛИЧЕСТВЕННОГО АНАЛИЗА, "Средние века"
Authors: Свешников Антон Вадимович , Стеблевская Екатерина Вадимовна
Published: August 2018

В статье предпринята попытка создания количественного анализа публикаций, ­посвященных истории средневековой Испании на страницах периодического издания «Средние века». На основании проведенного анализа авторы пытаются выявить основные тренды тенденции репрезентации отечественной испанистики в ведущем академическом издании отечественной медиевистики.
ГИДРОФОБНЫЕ СВОЙСТВА ТОНКИХ ПЛЕНОК ГРЕБНЕОБРАЗНЫХ СОПОЛИМЕРОВ ПЕРФТОРГЕКСИЛЭТИЛМЕТАКРИЛАТА С ПОЛИДИМЕТИЛСИЛОКСАНОМ, НАНОСИМЫХ ИЗ РАСТВОРОВ В СВЕРХКРИТИЧЕСКОМ ДИОКСИДЕ УГЛЕРОДА, "Высокомолекулярные соединения. Серия А"
Authors: Кондратенко М.С. , Анисенко С. А. , Эльманович И.В. , Стаханов А.И. , Галлямов М.О. , Хохлов А.Р.
Published: August 2018

Радикальной полимеризацией в среде сверхкритического диоксида углерода синтезированы гребнеобразные сополимеры перфторгексилэтилметакрилата и метакрилоксипропил-терминированного полидиметилсилоксана, исследована растворимость сополимеров в сверхкритическом диоксиде углерода, изучены гидрофобные свойства тонких пленок, получаемых осаждением сополимеров на подложки из растворов в трифтортрихлорэтане и сверхкритическом диоксиде углерода. По результатам измерения краевых углов смачивания водой и диметилсульфоксидом рассчитана удельная свободная поверхностная энергия формируемых пленок. Показано, что тонкие пленки сополимеров имеют более низкую поверхностную энергию и характеризуются меньшим гистерезисом краевого угла смачивания водой, чем пленки гомополимера поли(перфторгексилэтилметакрилата). Проведено сравнительное тестирование покрытий на основе гомополимера и сополимера, наносимых из растворов в сверхкритическом диоксиде углерода на поверхность нейлоновых тканей. Установлено, что ткани с покрытием на основе сополимера имеют в среднем более высокие краевые углы смачивания водой.
ВСПЕНИВАЕМЫЙ С ПОМОЩЬЮ СВЕРХКРИТИЧЕСКОГО СО2 ПОЛИСТИРОЛ КАК ВОЗМОЖНАЯ МОДЕЛЬНАЯ СИСТЕМА ДЛЯ МАТЕРИАЛОВ МЕМБРАН ПРОТОЧНЫХ БАТАРЕЙ, "Высокомолекулярные соединения. Серия А"
Authors: Галлямов М.О. , Николаев А.Ю. , Никитин Л.Н.
Published: August 2018

Рассмотрены возможные перспективы использования пористых полимерных матриц с закрытыми порами в качестве селективных протонпроводящих мембран. Такие системы хорошо известны, однако их применение для приложений, связанных с массопереносом, традиционно недооценено. Тем не менее, именно подобные структуры привлекательны в качестве мембран окислительно-восстановительных проточных батарей. В работе показаны возможные подходы к получению таких систем с помощью сверхкритического диоксида углерода, в том числе на основе полистирола.
The simultaneous assessment of and relations between children's sympathetic and parasympathetic psychophysiology and their reactive and proactive aggression
Authors: Moore Christina C. , Hubbard Julie , Morrow Michael T. , Barhight Lydia R. , Lines Meghan M. , Sallee Meghann , Hyde Christopher T.
Published: August 2018

The goal of the current study was to examine the link between children's psychophysiology and aggression when both constructs were assessed simultaneously in scenarios designed to provide the opportunity to aggress for either a reactive reason or a proactive reason. Both sympathetic nervous system (SNS) activity (skin conductance) and parasympathetic nervous system (PNS) activity (respiratory sinus arrhythmia or RSA), as well as their interaction, were included as physiological measures. Participants were 35 5th‐grade children who were placed in two virtual‐peer scenarios; one scenario provided the opportunity to aggress in response to peer provocation (i.e., reactive aggression) and the other scenario provided the opportunity to aggress for instrumental gain (i.e., proactive aggression). Both skin conductance and RSA were assessed at the time that children were given the opportunity to aggress; this simultaneous assessment of psychophysiology and aggression allowed for an examination of in‐the‐moment relations between the two constructs. For the reactive scenario, RSA moderated the in‐the‐moment relation between skin conductance and aggression such that the association was positive at low RSA but negative at high RSA. For the proactive scenario, skin conductance negatively predicted aggression in‐the‐moment, and RSA positively predicted aggression in‐the‐moment, but their interaction was not a significant predictor of aggression. Theoretical implications for reactive and proactive aggression and underlying physiological processes are discussed.
Versatile Antibacterial Materials: An Emerging Arsenal for Combatting Bacterial Pathogens
Authors: Ding Xiaokang , Duan Shun , Ding Xuejia , Liu Runhui , Xu Fu‐Jian
Published: August 2018

Antibacterial materials that prevent bacterial infections and mitigate bacterial virulence have attracted great scientific interests. In recent decades, the bactericidal polymers have been presented as promising candidates to combat bacterial pathogens, mainly based on the construction of bactericidal cationic polymers, functionalization with biocidal agents, and formation of bacterial‐repelling layers. However, these established strategies have inherent disadvantages because they often overlook important features such as their biocompatibility and biosafety, especially for biomedical applications. In recent years, many efforts have been made focusing on the development of multifunctional antibacterial materials to meet the elaborate requirements for medical devices and public hygiene products. Herein the recent advances in developing multifunctional materials for their antibacterial activities together with other functions including “kill‐and‐release” capability, hemocompatibility, cell proliferation promoting properties, and coagulation promoting ability for wound dressing are highlighted. In addition, the outlooks on the remaining challenges that should be addressed in the field of multifunctional antibacterial materials are also described.
Stability of Polymer:PCBM Thin Films under Competitive Illumination and Thermal Stress
Authors: Pont Sebastian , Foglia Fabrizia , Higgins Anthony M. , Durrant James R. , Cabral João T.
Published: August 2018

The combined effects of illumination and thermal annealing on the morphological stability and photodimerization in polymer/fullerene thin films are examined. While illumination is known to cause fullerene dimerization and thermal stress their dedimerization, the operation of solar cells involves exposure to both. The competitive outcome of these factors with blends of phenyl‐C61‐butyric acid methyl ester (PCBM) and polystyrene (PS), supported on PEDOT:PSS is quantified. UV–vis spectroscopy is employed to quantify dimerization, time‐resolved neutron reflectivity to resolve the vertical composition stratification, and atomic force microscopy for demixing and coarsening in thin films. At the conventional thermal stress test temperature of 85 °C (and even up to the PS glass transition), photodimerization dominates, resulting in relative morphological stability. Prior illumination is found to result in improved stability upon high temperature annealing, compatible with the need for dedimerization to occur prior to structural relaxation. Modeling of the PCBM surface segregation data suggests that only PCBM monomers are able to diffuse and that illumination provides an effective means to control dimer population, and thus immobile fullerene fraction, in the timescales probed. The results provide a framework for understanding of the stability of organic solar cells under operating conditions.
Hydraulic Power Manufacturing for Highly Scalable and Stable 2D Nanosheet Dispersions and Their Film Electrode Application
Authors: Jeong Jae‐Min , Kang Heon Gyu , Kim Hyung‐Jin , Hong Seok Bok , Jeon Hyeonyeol , Hwang Sung Yeon , Seo Donghyuk , Kwak Byeong Eun , Han Young‐Kyu , Choi Bong Gill , Kim Do Hyun
Published: August 2018

As 2D‐nanosheet dispersions greatly facilitate solution‐based processes, the preparation of 2D nanosheets in various solvents offers considerable potential in many applications, from electronics to energy storage and conversion. However, significant improvements are required in production cost, scalability, yield, and processability to realize the full potential of 2D nanosheets. Herein, a fast, scalable, and versatile hydraulic power process for the large‐scale production of 2D nanosheets (graphene, MoS2, and boron nitride) dispersed in water is presented. A controlled, wavy Taylor‐vortex flow allows for a high‐shear mixing process with efficient mass transfer. The use of an ionic liquid dramatically improves the exfoliation of 2D materials, resulting in an extremely high yield (76.9%), a high concentration (20 mg mL−1), and a high production rate (8.6 g h−1). The computational fluid dynamics simulations reveal that the improved exfoliation performance originates from the high‐shear mixing process, and the first‐principles calculations rationalize this performance via the high adsorption energies of ionic liquids on 2D nanosheets. The highly stable 2D nanosheet dispersions efficiently facilitating the postprocesses of vacuum filtration and inkjet printing, resulting in highly conductive circuits and high‐performance film electrodes for energy‐storage applications, are also demonstrated.
Graphene Oxide Quantum Dots Based Memristors with Progressive Conduction Tuning for Artificial Synaptic Learning
Authors: Yan Xiaobing , Zhang Lei , Chen Huawei , Li Xiaoyan , Wang Jingjuan , Liu Qi , Lu Chao , Chen Jingsheng , Wu Huaqiang , Zhou Peng
Published: August 2018

Memristors as electronic artificial synapses have attracted increasing attention in neuromorphic computing. Emulation of both “learning” and “forgetting” processes requires a bidirectional progressive adjustment of memristor conductance, which is a challenge for cutting‐edge artificial intelligence. In this work, a memristor device with a structure of Ag/Zr0.5Hf0.5O2:graphene oxide quantum dots/Ag is presented with the feature of bidirectional progressive conductance tuning. The conductance of proposed memristor is adjusted through voltage pulse number, amplitude, and width. A series of voltage pulses with an amplitude of 0.6 V and a width of 30 ns is enough to modulate conductance. The impacts of pulses with different parameters on conductance modulation are investigated, and the potential relationship between pulse amplitude and energy is revealed. Furthermore, it is proved that the pulse with low energy can realize the almost linear conductance regulation, which is beneficial to improve the accuracy of pattern recognition. The bidirectional progressive conduction modulation mimics various plastic synapses, such as spike‐timing‐dependent plasticity and paired‐pulse facilitation. This progressive conduction tuning mechanism might be attributed to the coexistence of tunneling effect and extrinsic electrochemical metallization effect. This work provides one way for memristor to attain attractive features such as bidirectional tuning, low‐power consumption, and fast speed switching that is in urgent demand for further evolution of neuromorphic chips.
Muscle‐Inspired Highly Anisotropic, Strong, Ion‐Conductive Hydrogels
Authors: Kong Weiqing , Wang Chengwei , Jia Chao , Kuang Yudi , Pastel Glenn , Chen Chaoji , Chen Gegu , He Shuaiming , Huang Hao , Zhang Jianhua , Wang Sha , Hu Liangbing
Published: August 2018

Biological tissues generally exhibit excellent anisotropic mechanical properties owing to their well‐developed microstructures. Inspired by the aligned structure in muscles, a highly anisotropic, strong, and conductive wood hydrogel is developed by fully utilizing the high–tensile strength of natural wood, and the flexibility and high‐water content of hydrogels. The wood hydrogel exhibits a high–tensile strength of 36 MPa along the longitudinal direction due to the strong bonding and cross‐linking between the aligned cellulose nanofibers (CNFs) in wood and the polyacrylamide (PAM) polymer. The wood hydrogel is 5 times and 500 times stronger than the bacterial cellulose hydrogels (7.2 MPa) and the unmodified PAM hydrogel (0.072 MPa), respectively, representing one of the strongest hydrogels ever reported. Due to the negatively charged aligned CNF, the wood hydrogel is also an excellent nanofluidic conduit with an ionic conductivity of up to 5 × 10−4 S cm–1 at low concentrations for highly selective ion transport, akin to biological muscle tissue. The work offers a promising strategy to fabricate a wide variety of strong, anisotropic, flexible, and ionically conductive wood‐based hydrogels for potential biomaterials and nanofluidic applications.