bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring Teachers Practices of Classroom Assessment in Secondary Science Classes in Bangladesh
Authors: Rahman Md. Mehadi
Published: July 2018

The study investigates teachers’ classroom assessment practices of secondary schools in Bangladesh. The study is mainly quantitative with some integration of qualitative approach. Secondary science teachers and their science classrooms were main data source of the study, which were selected randomly. Data sources were secondary science teachers and their science classrooms. The study used a lesson observation protocol to understand their classroom assessment practice, and pre-lesson and post-lesson observation interview protocols as main sources of data collection. Qualitative data from interview were used to triangulate the quantitative data from observation. A total of thirty teachers (twenty male and ten female) were chosen randomly from six secondary schools in Dhaka. The study explored that teachers’ current practice of classroom assessment was to only assess students learning achievement and they followed traditional methods to assess students. The dominated assessment activity was oral questioning and very few students take part in the assessment activities by answering the questions. The classroom questions are basically focused very specific responses and encouraged rote learning; even students’ didn’t get enough time for thinking and answering the questions. Therefore the study suggests changing current practices by using different assessment strategies like self and peer assessment and focus on assessment for learning to ensure effective teaching-learning and quality education. These findings can inform the classroom teachers as well as o relevant stakeholders in making necessary changes in the present classroom assessment practices in Bangladesh.
The Socially Accountable Professor in Higher Education
Authors: Ross Brian
Published: July 2018

Social accountability has become an important philosophy driving the development of health professional education which is responsive to the needs of the wider community. Although the inention to be socially accountable is usually expressed at the level of the institution, the institution’s educational mission is carried out largely by its faculty. Moreover, while the actions of a socially accountable educational institution have been well described, what individual faculty should do to support such a mission is much less clear. This paper summarises the literature surround community-responsive education and makes recommendations regarding how faculty should act to support social accountability including a commitment to community-service as a professional value, seeing oneself as part of the wider community rather than distinct from it, being actively community engaged, measuring success by means of community impact, and being involved in the internal governance and leadership of the institution.
De stand van de stelselherziening: een nieuwe fase
Authors: Palm C.D. (Lidia) , de Vos H.W. (Wilco)
Published: July 2018

De stand van de stelselherziening: een nieuwe fase

In deze bijdrage geven auteurs een weergave van de stand van de stelselherziening omgevingsrecht begin 2018.
Ruimtelijk beleid voor de energietransitie: centraal wat moet?
Authors: van der Linden A.M.J.R. (Fons) , Akerboom S. (Sanne)
Published: July 2018

Ruimtelijk beleid voor de energietransitie: centraal wat moet? Een studie naar het omgevingsrechtelijk overheidsinstrumentarium in de energietransitie

In deze bijdrage onderzoeken auteurs de connectie tussen energietransitie en het omgevingsrecht. Hierbij staat de vraag centraal hoe de keuze voor groot- of kleinschalige maatregelen het omgevingsrechtelijk kader en de ruimte voor een lokale ruimtelijke afweging kan beïnvloeden. Daarbij worden twee transitiepaden nader bekeken: windenergie op land (als onderdeel van het verduurzamen van de elektriciteitsproductie) en de verduurzaming van ruimteverwarming en warm tapwater in de gebouwde omgeving.
Simultaneous Determination of 15 Flavonoids in Scutellaria barbata–Hedyotis diffusa Herb Pair by HPLC Q-TOF MS
Authors: Yang Wei , He Shiyong , Xiao Nan , Qiao Yanling , Sui Hua , Liang Lina , Chen Jing , Li Weiling , Zhang Lin
Published: July 2018

Background: The Scutellaria barbata – Hedyotis diffusa herb pair has appeared in classical prescriptions and has usually been used for the treatment of cancer and inflammatory conditions. Objective: For quality control of this herb pair, a rapid and reliable HPLC-quadrupole-time-of-flight(Q-TOF)-MS method was used for the simultaneous determination of alpinetin, apigenin-7-O-β-D-glucopyranoside, scutellarein, apigenin, quercetin-3-O-β-D-glucopyranoside, wogonoside, quercetin, amentoflavone, wogonin, chrysin, luteolin, rutin, naringenin, baicalein, and baicalin in the S. barbata–H. diffusa herb pair. Methods: LC-MS analysis was performed on a Shimadzu HPLC 20ADXR LC system in-line with an AB-SCIEX 5600 Triple TOF mass spectrometer. Results: The calibration curves showed good linearity in a relatively wide concentration range (r >0.996). The LOD and LOQ were less than 20 and 68 ng/mL, respectively. The relative standard deviation (RSD) values of intraday and inter-day precision were <3.31% for all the analytes. The recoveries of the method were in the range of 94.6–106.0%, with RSD <4.72%. The RSD values of peak areas in the stability study were not more than 4.28% for all analytes within 2 days. These results revealed that the method exhibited good sensitivity, precision, accuracy, and stability. Conclusions: This method could be applied to the quantitative determination of 15 flavonoids in the S. barbata – H. diffusa herb pair. Highlights: (1) The established method of HPLC-Q-TOF-MS is simple, fast, sensitive, and reliable. (2) 15 Flavonoids in the S. barbata–H. diffusa herb pair were simultaneous determined.
Truth, Touch, and the Order of Inquiry in Aristotle’s Metaphysics
Authors: Oldfield James ,   Philosophy Documentation Center
Published: July 2018

A surprising feature of Aristotle’s thought is the fact that he does not offer a single, extended account of truth. He makes passing references to the meaning of truth in various texts, and his comments at times seem hard to reconcile. A preponderance of these comments occur in the Metaphysics, where he seems to adopt two quite different models for thinking about truth: truth is on the one hand a kind of touching or contact, and on the other a matter of joining or dividing subjects and predicates correctly. This paper proposes a reading that reconciles these two models with one another, one that assigns to each model its appropriate place in what Aristotle thinks of as the process of inquiry, a process exemplified by the text of the Metaphysics itself.
The Relevance of Medieval Philosophy
Authors: Falque Emmanuel ,   Philosophy Documentation Center
Published: July 2018

The “phenomenological practice of medieval philosophy” actualizes its relevance. This method, undertaken substantially in the author’s God, the Flesh, and the Other: From Irenaeus to Duns Scotus (2015) finds its full justification here. The fruitfulness of a method is not found in its theorization, but in its practical application. An examination of authors as diverse as St. Augustine, John Scotus Eriugena, and Meister Eckhart (for “God”), Sts. Irenaeus, Tertullian, and Bonaventure (for the “flesh”), and Origen, Thomas Aquinas, and Duns Scotus (for the “other”), actualizes the relevance of medieval philosophy—an actualization of relevance understood in the first place as the realization of these thinkers’ “potentialities” (actualitas).
Deletion analysis of the flagellum‐specific secretion signal in Salmonella flagellin
Authors: Kovács Noémi , Jankovics Hajnalka , Vonderviszt Ferenc
Published: July 2018

The export signal recognized by the flagellum‐specific export machinery is harbored within the highly conserved 26–47 segment of the disordered N‐terminal part of Salmonella flagellin. In this work, we aimed to further localize the essential part of the export signal by deletion analysis and investigated how the length of the spacer segment preceding the signal affects export efficiency. Export signal variants were attached to a reporter protein, the CCP2 domain of human C1r protein, and export efficiency of the fusion constructs was studied. Our results suggest that almost any continuous oligopeptide of 8–10 residues within the 26–47 segment can efficiently direct flagellar export if preceded by a spacer segment of at least 15 amino acids without any specific sequential requirement.
Continuous, Free‐Formable Sandwich Design with 3D Fiber Reinforced Core for Increased Lightweight Level of Applications in Large‐Scale Production
Authors: Schäfer Kay , Stiller Jonas , Tröltzsch Jürgen , Nestler Daisy , Kroll Lothar
Published: July 2018

The object in this research is the development of a hybrid sandwich structure, which can be produced in large scale and substitute metals to reduce the weight of moving parts. The development uses a generic demonstrator in a complex shape. The innovative sandwich core consists of spacer fabric reinforced polyurethane flexible foam. The facings are thermoplastic composites. An additional spacer fabric linked to the outside of one facing serves as an extra feature like silencer, filter, or human‐machine‐interface. The large‐scale production of such complex structures according to the current state of the art is challenging and shall be realized in this topic in an injection molding environment. The realization of the process needs several differential examinations of the individual lightweight materials and process steps, which are presented in this paper.
Self‐Protective Room‐Temperature Phosphorescence of Fluorine and Nitrogen Codoped Carbon Dots
Authors: Long Peng , Feng Yiyu , Cao Chen , Li Yu , Han Junkai , Li Shuangwen , Peng Cong , Li Zeyu , Feng Wei
Published: July 2018

The unstable triplet excited state is a core problem when developing self‐protective room temperature phosphorescence (RTP) in carbon dots (CDs). Here, fluorine and nitrogen codoped carbon dots (FNCDs) with long‐lived triplet excited states, emitting pH‐stabilized blue fluorescence and pH‐responsive green self‐protective RTP, are reported for the first time. The self‐protective RTP of FNCDs arises from n–π * electron transitions for CN/CN bonds with a small energy gap between singlet and triplet states at room temperature. Moreover, the interdot/intradot hydrogen bonds and steric protection of CF bonds reduce quenching of RTP by oxygen at room temperature. The RTP emission of FNCDs shows outstanding reversibility, while the blue fluorescence emission has good pH stability. Based on these FNCDs, a data encoding/reading strategy for advanced anticounterfeiting is proposed via time‐resolved luminescence imaging techniques, as well as steganography of complex patterns.
Scale‐Up Biomass Pathway to Cobalt Single‐Site Catalysts Anchored on N‐Doped Porous Carbon Nanobelt with Ultrahigh Surface Area
Authors: Zhu Youqi , Sun Wenming , Chen Wenxing , Cao Tai , Xiong Yu , Luo Jun , Dong Juncai , Zheng Lirong , Zhang Jian , Wang Xiaolu , Chen Chen , Peng Qing , Wang Dingsheng , Li Yadong
Published: July 2018

Porous CoNC catalysts with ultrahigh surface area are highly required for catalytic reactions. Here, a scale‐up method to synthesize gram‐quantities of isolated Co single‐site catalysts anchored on N‐doped porous carbon nanobelt (Co‐ISA/CNB) by pyrolysis of biomass‐derived chitosan is reported. The usage of ZnCl2 and CoCl2 salts as effective activation–graphitization agents can introduce a porous belt‐like nanostructure with ultrahigh specific surface area (2513 m2 g−1) and high graphitization degree. Spherical aberration correction electron microscopy and X‐ray absorption fine structure analysis reveal that Co species are present as isolated single sites and stabilized by nitrogen in CoN4 structure. All these characters make Co‐ISA/CNB an efficient catalyst for selective oxidation of aromatic alkanes at room temperature. For oxidation of ethylbenzene, the Co‐ISA/CNB catalysts yield a conversion up to 98% with 99% selectivity, while Co nanoparticles are inert. Density functional theory calculations reveal that the generated CoO centers on isolated Co single sites are responsible for the excellent catalytic efficiency.
Programmable 3D Shape Changes in Liquid Crystal Polymer Networks of Uniaxial Orientation
Authors: Yu Li , Shahsavan Hamed , Rivers Geoffrey , Zhang Che , Si Pengxiang , Zhao Boxin
Published: July 2018

3D programmable materials are highly interesting and have a great potential to enable smart robotic devices. Stimuli‐responsive liquid crystal polymer networks (LCNs) offer an attractive platform for the design and fabrication of 3D programmable materials. To date, extensive efforts have been devoted to the design of 3D programmable LCNs by spatially modulating the orientation of liquid crystals. However, the practical application of LCN actuators has been elusive, partly due to tedious orientation technology and monotonous geometry. To resolve this issue, programmable 3D shape changes achieved in LCNs with uniaxial orientation and homogenous composition using a mechanical programming process inspired by the “programming process” of shape‐memory polymers are reported. The mechanical programming process is suitable for LCNs with distinct geometries, for example, the film and fiber, suggesting a promising way for the design of 3D programmable LCN actuators with complex geometries, and deformation profiles (buckle, helix, horn).
Binder‐Free Nanoparticulate Coating of a Polyethylene Separator via a Reactive Atmospheric Pressure Plasma for Lithium‐Ion Batteries with Improved Performances
Authors: Qin Sicheng , Wang Ming , Wang Chaoliang , Jin Yichao , Yuan Nana , Wu Zhuangchun , Zhang Jing
Published: July 2018

A reactive atmospheric pressure plasma containing Ar/O2/hexamethyldisiloxane is applied to coat polyethylene (PE) separators for lithium‐ion batteries. The PE separator moves through the plasma region roll‐to‐roll, and its top and internal fiber surface is coated with a thin SiOxCyHz film composed of nanoparticulates with an average size of ≈100 nm. The nanoparticulate film has relatively high heat resistance, which provides a PE separator capable of structural support with improved thermal stability. Meanwhile, the polar functional groups on the PE surface improve its crucial properties such as wettability, electrolyte uptake, and ionic conductivity. A mere 3 min of coating endows the lithium‐ion battery with a lower interface resistance and improved C‐rate and cycling performances. Most importantly, the binder‐free coating method provides a new, eco‐efficient way to improve the performances of polyolefin separators for lithium‐ion batteries.
Bifunctional Molecular Modification Improving Efficiency and Stability of Inverted Perovskite Solar Cells
Authors: Zhang Yanjun , Zhang Shasha , Wu Shaohang , Chen Chuanliang , Zhu Hongmei , Xiong Zhenzhong , Chen Weitao , Chen Rui , Fang Shaoying , Chen Wei
Published: July 2018

Kinds of interfacial engineering technologies are explored in perovskite solar cells (PSCs), which are proved to be benefit for the devices to achieve higher efficiency, less hysteresis, and/or better stability. In this work, in an inverted p–i–n structured PSC, a monolayer of 5‐aminovaleric acid (5‐AVA) molecules with bifunctional groups is introduced to modify the surface of p‐NiMgLiO compact hole transport layer (HTL). This key surface modification is not only improving the resultant perovskite film's quality, but also facilitating efficient charge extraction at the HTL/perovskite interface, which result in improved power conversion efficiency (PCE) from 18.0 to 19.4%. Furthermore, the 5‐AVA‐modified device can withstand much higher poling bias (>1.8 V) for a longer time than the pristine one, showing little nonsteady state current and excellent consistency of forward and reverse photocurrent–voltage curves after high bias poling. Benefitting from the exceptionally stable interface, the 5‐AVA‐modified device shows much improved long‐term stability, which can maintain over 90% of its initial PCE after 300 h continuous light soaking at maximum power point tracking condition.
Actuating Textiles: Next Generation of Smart Textiles
Authors: Persson Nils‐Krister , Martinez Jose G. , Zhong Yong , Maziz Ali , Jager Edwin W. H.
Published: July 2018

Smart textiles have been around for some decades. Even if interactivity is central to most definitions, the emphasis so far has been on the stimuli/input side, comparatively little has been reported on the responsive/output part. This study discusses the actuating, mechanical, output side in what could be called a second generation of smart textiles—this in contrast to a first generation of smart textiles devoted to sensorics. This mini review looks at recent progress within the area of soft actuators and what from there that is of relevance for smart textiles. It is found that typically still forces exerted are small, so are strains for many of the actuators types (such as electroactive polymers) that could be considered for textile integration. On the other side, it is argued that for many classes of soft actuators—and, in the extension, soft robotics—textiles could play an important role. The potential of weaving for stress and knitting for strain amplification is shown. Textile processing enables effective production, as is analyzed. Textile systems are made showing automatic actuation asked for in stand‐alone solutions. It is envisioned that soft exoskeletons could be an achievable goal for this second generation of smart textiles.
Progress on Black Phosphorus Photonics
Authors: Deng Bingchen , Frisenda Riccardo , Li Cheng , Chen Xiaolong , Castellanos‐Gomez Andres , Xia Fengnian
Published: July 2018

Recent years have witnessed the rapidly growing interests in the rediscovered black phosphorus (BP), an elemental group‐V layered material with very high carrier mobility among all semiconducting layered materials. As a layered semiconductor, the bandgap of intrinsic BP varies from ≈0.3 to 2 eV depending on the thickness. This bandgap value can be tuned to below 50 meV by a moderate external electric field. Adsorption doping and external pressure can also effectively modify its bandgap. The largely tunable bandgap of BP makes it a promising material for infrared optics. Moreover, its unique puckered structure leads to the anisotropic in‐plane properties, making it ideal for the exploration of exotic physical phenomena and the realization of novel devices. Here, the fundamental optical properties are reviewed and latest developments on BP photonic and optoelectronic devices are discussed.
Rapid and Scalable Synthesis of Zeolitic Imidazole Framework (ZIF‐8) and its Use for the Detection of Trace Levels of Nitroaromatic Explosives
Authors: Prathap Mylamparambil Udayan Anu , Gunasekaran Sundaram
Published: July 2018

A facile and inexpensive approach for scalable synthesis of highly porous zeolite imidazolate framework nanoparticles (ZIF‐8) is described. The synthesis, done in an aqueous solution at room temperature, takes just 2 min compared to hours or days in nonaqueous conditions. The structural integrity and phase purity of ZIF‐8 are studied through X‐ray powder diffraction and are of sodalite topology, and its surface nature and composition are determined with X‐ray photoelectron spectroscopy. ZIF‐8 has high crystallinity, large Brunauer–Emmett–Teller surface area (1398.7 m2 g−1) and pore volume (0.62 cm3 g−1). Images of ZIF‐8 show hexagonal nanocrystals, whose growth is observed with atomic force microscopy (AFM). Thermogravimetric analysis data testify the thermal stability of the material (490 °C in air). Zeta potential measurement confirms that trinitrotoluene (TNT) molecules adsorb onto ZIF‐8. The interaction between the electron‐deficient aromatic core of TNT and the electron‐rich ZIF‐8 is considered to favor the formation of donor–acceptor electron‐transfer mechanism, and the electron conductivity of ZIF‐8 facilitates the effective reduction of TNT. Using the prepared ZIF‐8, an electrochemical sensor is fabricated to detect TNT and other nitroaromatic explosives in aqueous phase. The sensor performance is highly linear, with very low limit of detection (346 × 10−12m), and is unaffected by the presence of various interferents.
Reliable and General Route to Inverse Opal Structured Nanohybrids of Carbon‐Confined Transition Metal Sulfides Quantum Dots for High‐Performance Sodium Storage
Authors: Hu Xiang , Jia Jingchun , Wang Genxiang , Chen Junxiang , Zhan Hongbing , Wen Zhenhai
Published: July 2018

Sodium‐ion batteries (SIBs) have recently attracted increasing attention as the promising alternative to lithium‐ion batteries due to their multiple advantages of abundant reserves and low cost. However, the development of highly desirable anode materials suitable for SIBs is still hampered by a rather low capacity, poor rate capability, and cycling stability. Herein, a deliberate design to implement reliable and simple fabrication of an inverse opal structured nanohybrid of carbon‐confined various transition metal sulfides quantum dots (QDs) is presented. Comprehensive characterizations demonstrate that the hybrids hold a 3D architecture with uniform dispersion of QDs in a conductive carbon matrix that in turn encapsulates these quantum dots. With Co9S8 as an example, such a unique architecture, when applied as the anode of SIBs, endows the hybrids with multiple advantages including a high reversible specific capacity, extraordinary high rate capability, and excellent durability over 2000 cycles charging–discharging process.
Neuropathology of holoprosencephaly
Authors: Fallet‐Bianco Catherine
Published: July 2018

Holoprosencephaly (HPE) is a primary disorder of neural induction and patterning of the rostral neural tube resulting in noncleavage of the forebrain with failure to form two separate distinct hemispheres. The spectrum of HPE is very broad and encompasses various neuropathological phenotypes of different severity. The recent literature has demonstrated that the phenotypic variability of HPE ranges from aprosencephaly–atelencephaly, at the most severe end, to milder forms such as the “middle interhemispheric variant” of HPE at the less severe end of the spectrum. Between them, different intermediate forms demonstrate a continuum in a wide phenotypic spectrum rather than well‐defined categories. Although the term “HPE” suggests a disorder affecting only the prosencephalon, other brain structures are involved, underlining the complexity of the malformation. Because of close spatiotemporal interactions and common signaling pathways contributing to the development of both brain and face, concomitant facial and ocular anomalies are associated with brain malformation. In this review, the characteristic neuropathological features of the various forms of HPE are described as well as their associated brain, face, and ocular malformations, to delineate the different phenotypes.
Challenging issues arising in counseling families experiencing holoprosencephaly
Authors: Hadley Donald W. , Kruszka Paul , Muenke Maximilian
Published: July 2018

The provision of information and support to families experiencing holoprosencephaly (HPE) in a loved one is unequivocally challenging, even for the most experienced clinicians. It deserves the balance of pertinent information coupled with medical guidance that forms the basis for shared decision‐making; all of which is ideally contained within a supportive environment. It requires a willingness to carefully listen to the specific concerns of the parents and family allowing them to revisit challenging issues as much as needed to encourage existing road blocks to be resolved. It necessitates that professionals see each and every family as unique, without preconceived notions about what is or is not important and being prepared to accept thoughts and decisions that may not fit with the professional's own beliefs. To some, this may sound impractical, inefficient, or even impossible within the time constrained models of modern day clinical services. However, in practice, this patient‐focused approach is arguably the most essential step in providing “personalized medicine” to the populations we encounter. This manuscript is intended to provide a brief review of relevant literature and case discussions to highlight issues for families learning of the diagnosis of HPE during a pregnancy, at birth, during childhood or more rarely, in adolescence.
Catalytic Stereoselective SN1‐Type Reactions Promoted by Chiral Phosphoric Acids as Brønsted Acid Catalysts
Authors: Gualandi Andrea , Rodeghiero Giacomo , Cozzi Pier Giorgio
Published: July 2018

In recent years, the field of organocatalysis has extensively explored the use of carbenium ions for practical C−C bond forming reactions. In order to control the formation of new stereocenters, the generation of carbenium ions was investigated by exploring asymmetric Brønsted acid catalysis. Oxocarbenium ions, iminium ions, and other carbenium ions stabilized by heteroatoms could also be generated by Brønsted acid catalysis, through the departure of suitable leaving groups. The aforementioned reactivity has recently been exploited leading to remarkable achievements. The application of chiral Brønsted acids in the generation of heteroatom stabilized carbenium ions has recently been investigated, with the demonstration of important results. Although diverse architectural arrays of Brønsted acid catalysts were conceived, BINOL‐derived phosphoric acids have played a dominant role in this area of research. Their low pKa values combined with the possibility to alter their architecture, and their ability to assemble ordered transition states was exploited in different SN1‐type reactions allowing the formation of a variety of products with high enantiomeric excesses. In addition, the generation of highly stabilized chiral counter anions allowed the exploitation of counterion asymmetric catalysis with various nucleophiles.
Triphenylamine Functionalized Unsymmetrical Quinoxalines
Authors: Bijesh S. , Misra Rajneesh
Published: July 2018

A family of unsymmetrical quinoxalines 11–18 of types D‐A‐π‐D and D‐A‐A′‐D′ have been designed and synthesized by the Suzuki, Heck, Sonogashira, Ullmann coupling and [2+2] cycloaddition−retroelectrocyclic ring opening reactions. A systematic study was performed to explore the effect of donor, acceptor and π‐linker on the triphenylamine functionalized quinoxalines. The electronic absorption spectra of the ethynyl bridged quinoxaline 14 show red shifted absorption in the high‐energy region compared to quinoxaline 13. The quinoxalines 17 and 18 exhibit red shifted absorption in the near–infrared (NIR) region due to the incorporation of strong TCNE/TCNQ acceptor units. The TGA data reveals that triphenylethylene substituted quinoxaline 15 shows higher thermal stability compared to other quinoxalines. The electrochemical data exhibit strong electronic communication in quinoxalines 11–18. The incorporation of TCNE/TCNQ acceptor units results in greater stabilization of LUMO levels and low HOMO−LUMO energy gap in 17 and 18 which was supported by computational studies.
Synthesis and Reversible Hydration of a Pseudoprotein, a Fully Organic Polymeric Desiccant by Multiple Single‐Crystal‐to‐Single‐Crystal Transformations
Authors: Mohanrao Raja , Sureshan Kana M.
Published: July 2018

A diphenylalanine derivative, N3‐Phe‐Phe‐NHCH2CCH, was designed for topochemical azide–alkyne cycloaddition (TAAC) polymerization. This dipeptide adopted β‐sheet arrangement as designed, in its crystals, but the azide and alkyne were not fitly aligned for their topochemical reaction. However, the voids present around these groups allowed them to attain a reactive geometry upon heating and their consequent TAAC polymerization to a pseudoprotein in a single‐crystal‐to‐single‐crystal (SCSC) fashion. This motion led to the creation of channels in the product crystal and it absorbed water from the surroundings to fill these channels as H‐bonded water wire. The pseudoprotein undergo reversible hydration/dehydration in SCSC fashion many times under mild conditions: hydration at low relative humidity and dehydration at low temperature. Vapor sorption analyses suggest that this fully organic polymer might be useful as an energy‐efficient desiccant material for controlling indoor humidity.
Ein rotaxanartiges Käfig‐im‐Ring‐Strukturmotiv für ein metallosupramolekulares Pd6L12‐Aggregat
Authors: Käseborn Matthias , Holstein Julian J. , Clever Guido H. , Lützen Arne
Published: July 2018

Ein BODIPY‐basierter Bis(3‐pyridyl)‐Ligand bildet in einem Selbstorganisationsprozess bei der Koordination an tetravalente Palladium(II)‐Ionen ein metallosupramolekulares Pd6L12‐Aggregat mit einem neuartigen Strukturmotiv, das als ein rotaxanartiges Käfig‐im‐Ring‐Arrangement beschrieben werden kann. In diesem Assemblat nimmt der Ligand zwei unterschiedliche Konformationen ein – eine C‐förmige, um einen Pd2L4‐Käfig aufzubauen, der sich im Zentrum eines Pd4L8‐Rings befindet, welcher aus Liganden in einer W‐förmigen Konformation zusammengesetzt ist. Dieses Aggregat ist nicht im Sinne einer Katenierung mechanisch ineinander verschlungen, sondern es wird lediglich durch attraktive π‐Stapelwechselwirkungen zwischen den BODIPY‐Chromophoren in der Peripherie und den Rückgraten der Liganden sowie den Van‐der‐Waals‐Wechselwirkungen zwischen den langen Alkoxyketten stabilisiert. Durch dieses Arrangement beider Komponenten kommt es zu einem sehr effektiven Ausfüllen des Raumes. Die gesamte Struktur kann daher als ein rotaxanartiges Assemblat beschrieben werden, in dem ein metallosupramolekularer Käfig die Achse in einem metallosupramolekularen Ring bildet. Dieses einzigartige Strukturmotiv konnte mittels ESI‐Massenspektrometrie, NMR‐Spektroskopie und Einkristall‐Röntgenbeugungsexperimenten charakterisiert werden.
Heteroatom‐Doped Carbon Dots (CDs) as a Class of Metal‐Free Photocatalysts for PET‐RAFT Polymerization under Visible Light and Sunlight
Authors: Jiang Jingjie , Ye Gang , Wang Zhe , Lu Yuexiang , Chen Jing , Matyjaszewski Krzysztof
Published: July 2018

A key challenge of photoregulated living radical polymerization is developing efficient and robust photocatalysts. Now carbon dots (CDs) have been exploited for the first time as metal‐free photocatalysts for visible‐light‐regulated reversible addition–fragmentation chain‐transfer (RAFT) polymerization. Screening of diverse heteroatom‐doped CDs suggested that the P‐ and S‐doped CDs were effective photocatalysts for RAFT polymerization under mild visible light following a photoinduced electron transfer (PET) involved oxidative quenching mechanism. PET‐RAFT polymerization of various monomers with temporal control, narrow dispersity (Đ≈1.04), and chain‐end fidelity was achieved. Besides, it was demonstrated that the CD‐catalyzed PET‐RAFT polymerization was effectively performed under natural solar irradiation.
Dissipative Selbstassemblierung photolumineszierender Siliciumnanokristalle
Authors: Grötsch Raphael K. , Angı Arzu , Mideksa Yonatan G. , Wanzke Caren , Tena‐Solsona Marta , Feige Matthias J. , Rieger Bernhard , Boekhoven Job
Published: July 2018

Lösungen von Siliciumnanokristallen (SiNCs) werden z. B. wegen ihrer einstellbaren Photolumineszenz, Biokompatibilität und der Verfügbarkeit von Si in zahlreichen Anwendungen eingesetzt. In dissipativen supramolekularen Materialien wird die Selbstassemblierung von Molekülen oder Nanopartikeln durch ein chemisches Reaktionsnetzwerk angetrieben, das irreversibel Brennstoff verbraucht. Die Eigenschaften der entstehenden Strukturen werden durch die Kinetik des zugrunde liegenden chemischen Reaktionsnetzwerkes gesteuert. Hier wird die dissipative Selbstassemblierung von photolumineszierenden SiNCs demonstriert, die von einem chemischen Brennstoff angetrieben werden. Eine chemische Reaktion setzt die Selbstassemblierung der wasserlöslichen SiNCs in Gang. Allerdings sind die Strukturen transient, und wenn dem chemischen Reaktionsnetzwerk der Brennstoff ausgeht, deassemblieren sich die SiNCs. Die Lebensdauer der Strukturen ist durch die zugegebene Brennstoffmenge steuerbar. Die Plattform kann für die gesteuerte, verzögerte Aufnahme der Nanokristalle durch Säugetierzellen genutzt werden.
Dynamic Coupling at Low Reynolds Number
Authors: Dey Krishna Kanti
Published: July 2018

Collective and emergent behaviors of active colloids provide useful insights into the statistical physics of out‐of‐equilibrium systems. Colloidal suspensions containing microscopic active swimmers have been intensively studied to understand the principles of energy transfer at low Reynolds number conditions. Studies on active enzymes and Ångström‐sized organometallic catalysts have demonstrated that energy can even be transferred by molecules to their surroundings, thereby influencing the overall dynamics of the systems substantially. By monitoring the diffusion of non‐reacting tracers in active solutions, it has been shown that the nature of energy transfer in systems containing different swimmers is surprisingly similar—irrespective of their size, modes of energy transduction, and propulsion strategies. This Review discusses research results obtained so far in this direction, highlighting the common features observed in the dynamic coupling of swimmers with their surroundings.
Modulation of Hydrophobic Interaction by Mediating Surface Nanoscale Structure and Chemistry, not Monotonically by Hydrophobicity
Authors: Cui Xin , Liu Jing , Xie Lei , Huang Jun , Liu Qi , Israelachvili Jacob N. , Zeng Hongbo
Published: July 2018

The hydrophobic (HB) interaction plays a critical role in many colloidal and interfacial phenomena, biophysical and industrial processes. Surface hydrophobicity, characterized by the water contact angle, is generally considered the most dominant parameter determining the HB interaction. Herein, we quantified the HB interactions between air bubbles and a series of hydrophobic surfaces with different nanoscale structures and surface chemistry in aqueous media using a bubble probe atomic force microscopy (AFM). Surprisingly, it is discovered that surfaces of similar hydrophobicity can show different ranges of HB interactions, while surfaces of different hydrophobicity can have similar ranges of HB interaction. The increased heterogeneity of the surface nanoscale structure and chemistry can effectively decrease the decay length of HB interaction from 1.60 nm to 0.35 nm. Our work provides insights into the physical mechanism of HB interaction.
Access to P‐ and Axially Chiral Biaryl Phosphine Oxides by Enantioselective CpxIrIII‐Catalyzed C−H Arylations
Authors: Jang Yun‐Suk , Woźniak Łukasz , Pedroni Julia , Cramer Nicolai
Published: July 2018

An enantioselective C−H arylation of phosphine oxides with o‐quinone diazides catalyzed by an iridium(III) complex bearing an atropchiral cyclopentadienyl (Cpx) ligand and phthaloyl tert‐leucine as co‐catalyst is reported. The method allows access to a) P‐chiral biaryl phosphine oxides, b) atropo‐enantioselective construction of sterically demanding biaryl backbones, and also c) selective assembly of axial and P‐chiral compounds in excellent yields and diastereo‐ and enantioselectivities. Enantiospecific reductions provide monodentate chiral phosphorus(III) compounds having structures and biaryl backbones with proven importance as ligands in asymmetric catalysis.
Chloromethylated polystyrene supported copper (II) bis–thiazole complex: Preparation, characterization and its application as a heterogeneous catalyst for chemoselective and homoselective synthesis of aryl azides
Authors: Dehbanipour Zahra , Moghadam Majid , Tangestaninejad Shahram , Mirkhani Valiollah , Mohammadpoor‐Baltork Iraj
Published: July 2018

This work deals the synthesis of aryl azides catalyzed by heterogeneous copper (II) complex of 3,5–bis (2–benzothiazolyl) pyridine, [Cu (II)(BTP)(OTf)2], immobilized on chloromethylated polystyrene, [Cu (II)(BTP)(OTf)2]@CMP. The prepared catalyst was characterized by different analytical techniques such as X‐ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (SEM), energy dispersive X–ray spectroscopy (EDX), elemental analysis, and FT‐IR and UV–Vis spectroscopic methods. This catalytic system showed excellent activity in the synthesis of aryl azides by the reaction of aryl halides with sodium azide in the presence of catalytic amounts of [Cu (II)(BTP)(OTf)2]@CMP. Moreover, this unique catalyst could be recovered easily and reused several times without any considerable loss of its catalytic activity.
The effect of electric field and Al doping on the sensitivity of hexa‐peri‐hexabenzocoronene nanographene to chloropicrin
Authors: Hosseinian Akram , Gharachorloo Arezoo , Mohazzab Lighvani Tarlan , Delir Kheirollahi Nezhad Parvaneh , Vessally Esmail
Published: July 2018

It has been previously reported that the recently synthesized hexa‐peri‐hexabenzocoronene (HBC) nanographene cannot detect toxic chloropicrin (CP) gas. To overcome this problem, we examined the effect of Al doping and applying an electric field on the sensitivity of HBC towards CP gas by means of density functional theory calculations. We found that the Al‐doping process significantly increases the adsorption energy of CP gas from −7.1 to −39.9 kcal mol−1 but decreases the sensitivity of HBC. By applying an electric field, the HBC is polarized with two different electrostatic potentials on its different surfaces, which increases the adsorption energy. By increasing the electric field strength, the adsorption energy and electronic sensitivity of HBC are increased. We predicted that in the presence of an electric field of about −0.025 au, HBC can act as an electronic senor or a work function‐type sensor with a short recovery time. At this field, the electrical conductivity of HBC is significantly increased on CP adsorption which generates an electrical signal. Increasing the electric field to higher intensities is not favourable because of increasing recovery times, and decreasing it to lower intensities reduces the sensitivity of HBC.
p‐Toluate‐bridged dinuclear Cu(II) complexes in combination with tridentate chelating ligand: Crystal structure, density functional theory calculation, DNA/protein binding and catecholase activity
Authors: Dolai Samar , Das Kalipada , Bhunia Apurba , Bertolasi Valerio , Manna Subal Chandra
Published: July 2018

The dinuclear Cu(II) complexes [Cu2(L1)2(mb)]⋅ClO4 (1) and [Cu2(L2)2(mb)]⋅ClO4 (2) (HL1 = 2‐[(2‐diethylaminoethylimino)methyl]phenol; HL2 = 2‐[1‐(2‐diethylaminoethylimino)propyl]phenol; mb = 4‐methylbenzoate) were synthesized and characterized using X‐ray crystal structure analysis and spectroscopic methods. Complexes 1 and 2 are dinuclear with distorted square pyramidal Cu (II) geometries, where Schiff base coordinates with tridentate (N,N,O) chelating mode and mb bridges two metal centres. Optimized structures and photophysical properties of ligands and complexes were calculated using density functional theory and time‐dependent density functional theory methods using B3LYP functional with 6‐31G (d,p) and LanL2MB basis sets. Interactions of the complexes with bovine serum albumin (BSA) and human serum albumin (HSA) were studied using UV–visible absorption and fluorescence spectroscopies and the calculated values of association constants (M−1) are 1.7 × 105 (1–BSA), 5.7 × 105 (2–BSA), 1.6 × 105 (1–HSA) and 6.9 × 105 (2–HSA). Interactions of the complexes with calf thymus DNA were also investigated and the binding affinities are 1.4 × 105 and 1.6 × 105 M−1 for 1 and 2, respectively. Both complexes catalytically oxidize 3,5‐di‐tert‐butylcatechol to 3,5‐di‐tert‐butylbenzoquinone in the presence of molecular oxygen.
Visible‐light‐driven photocatalytic degradation of fenpyroximate in rotating packed bed reactor using Fe3O4@PbS@Ni2P magnetic nanocomposite photocatalyst: Response surface modelling and optimization
Authors: Mosleh Soleiman , Rahimi Mahmood Reza , Ghaedi Mehrorang , Asfaram Arash , Javadian Hamedreza , Sadeghfar Fardin , Jannesar Ramin
Published: July 2018

A highly efficient rotating packed bed photocatalytic reactor based on Fe3O4@PbS@Ni2P composite for the degradation of fenpyroximate (FP) as an acaricide in agriculture is described. The visible‐light‐driven photocatalyst was characterized using various techniques. The interaction of operational parameters consisting of rotational speed (400–1200 rpm), photocatalyst dosage (0.20–0.40 g l−1), solution flow rate (0.10–0.50 l min−1), aeration rate (15–35 l min−1), FP initial concentration (5–45 mg l−1), pH (2–10) and irradiation time (20–100 min) for FP degradation was examined via central composite design under response surface methodology. Accordingly, under the suggested optimum conditions, namely rotational speed of 950 rpm, Fe3O4@PbS@Ni2P dosage of 0.30 g l−1, solution flow rate of 0.30 l min−1, aeration rate of 25 l min−1, pH of 6.0 and irradiation time of 85 min, more than 99% of 45 mg l−1 FP was degraded. The Langmuir–Hinshelwood kinetic model was the best equation for the description of the experimental data. According to the rate constant, the contribution of photocatalytic degradation, adsorption and photolysis to the reduction of FP concentration and, subsequently, the efficiency of water treatment were studied.
Adaptive Robust Motion Control for Linear Induction Motor with Electromagnetic Nonlinearity Compensation
Authors: Lu Linlin , Sun Peng , Xu Linsen , Luo Minzhou
Published: July 2018

This paper presents an adaptive robust motion control algorithm for linear induction motor (LIM) with electromagnetic nonlinearity compensation to suppress nonlinear magnetic thrust reduction due to the end effect. The electromagnetic compensation adaptive robust control (ECARC) algorithm is developed to deal with the parametric uncertainties and uncertain nonlinearities that are widely present in LIM. This algorithm employs a discontinuous projection‐type method to estimate the system parameters. The disturbance is bounded by a critical value, which guarantees that the system is exponentially stable. However, due to the magnetic field distortion caused by the opening of primary ends, the relationship between the driving current and the resultant motor thrust is nonlinear. Consequently, electromagnetic thrust and flux are calculated and used for feedback compensation. Different from the traditional vector control and direct torque control, the control algorithm employs electromagnetic thrust and magnetic flux to compensate torque current and magnetic field. Simulation results and comparative experimental results show that current control algorithm is accurate and efficient.
Sulfur‐Doped Rhenium Selenide Vertical Nanosheets: A High‐Performance Electrocatalyst for Hydrogen Evolution
Authors: Xia Yufei , Huang Jianwen , Wu Wenqi , Zhang Yadong , Wang Hao , Zhu Juntong , Yao Junjie , Xu Li , Sun Yinghui , Zhang Li , Lu Ruifeng , Xiong Jie , Zou Guifu
Published: July 2018

Developing highly efficient electrocatalysts for hydrogen generation from water has been a crucial option for future energy conversion and storage. Rhenium dichalcogenides (ReX2, X=S or Se) have attracted tremendous research interests due to their unique distorted‐1T phase and anisotropic electronic structure. So far, there is no report about S doped ReSe2 electrocatalyst. In this work, we present a three‐dimensional nanosheets electrocatalyst derived from sulfur‐doped rhenium selenide (ReSe2(1–x)S2x) grown on carbon fiber paper (CFP) for water splitting. It is noting that the catalytic activity could be significantly fine‐tuned by controlling quantity of sulfur dopant. ReSe1.78S0.22/CFP cathode exhibits the best performance with a Tafel slope of 84 mV dec−1, an overpotential of 123 mV to drive the current density of 10 mA cm−2 as well as a long‐term stability of 30 h. The X‐ray photoelectron spectroscopy and density functional theory calculations confirm that sulfur‐doped structure, especially the dangling sulfur atoms adsorbed on the surface Se atom kars, achieves a more thermoneutral hydrogen adsorption energy, conducing an optimized catalytic activity of the basal plane. This study demonstrates that S doped ReSe2 could be a promising candidate electrocatalyst for hydrogen evolution.
Interaction of Single Cells with 2D Organic Monolayers: A Scanning Electrochemical Microscopy Study
Authors: Bartolini Luca , Malferrari Marco , Lugli Francesca , Zerbetto Francesco , Paolucci Francesco , Pelicci Pier Giuseppe , Albonetti Cristiano , Rapino Stefania
Published: July 2018

Cell shape is a valuable indicator of cell health status and interactions with the extracellular materials. With the aim to investigate how individual cells respond to chemical microenvironments, we employed 2D monomolecular layers of small organic molecules, characterized by very low roughness. MCF10A cells were grown on these surfaces and characterized by using scanning electrochemical microscopy. The single cell morphologies were analyzed to define a “figure of merit” for the different cell–surface interactions. Such “figure of merit” quantifies the interaction with the microenvironment. This method is applicable to any cell state (metastatic, physiological or pathological) and any surface.
The Impedance Response of a Passive Film Revisited by a Double Modulation Technique
Authors: Antaño‐López René , Keddam Michel , Turmine Mireille , Vivier Vincent
Published: July 2018

The interfacial capacitance measured in electrochemical experiments is usually considered to be independent of the faradaic processes involved at the electrode surface. In this work, we report on the use of a double modulation technique, which allows the simultaneous measurement of electrochemical impedance spectroscopy (EIS) and modulation of the interfacial capacitance transfer function (MICTF). We show that the capacitance ascribed to the response of passive films formed on pure iron electrodes in phosphoric acid solution exhibits two different time‐constants in low frequency domains, namely the response of intrinsic properties of the film linked to charge carriers and a relaxation ascribed to the thickness relaxation of the oxide film. Interestingly, the low frequency limit of MICTF is in good agreement with the capacitance obtained from EIS measurements. A detailed data analysis allows determination of both, the capacitance of the oxide film and the double layer capacitance to the overall capacitance to be measured. This technique thus provides a unique way of analysing the different contributions ascribed to the relaxation of the interfacial capacitance.
Self‐Integrated Porous Leaf‐like CuO Nanoplate Array‐Based Anodes for High‐Performance Lithium‐Ion Batteries
Authors: Li Zhi , Li Gangyong , Xu Wenyuan , Zhou Minjie , Xu Chenxi , Shi Mengting , Li Fangyi , Chen Liang , He Binhong
Published: July 2018

Developing high‐energy‐density lithium‐ion batteries (LIBs) is of great significance for their wider commercialized application. The design of self‐integrated electrodes can be treated as a valid approach to achieve this goal. In this work, a facile and low‐cost wet chemical oxidation strategy is put forward to prepare self‐integrated porous leaf‐like CuO nanoplates on Cu foil substrates in situ. These nanoplates are then directly used as the anode for LIBs. The morphology, structure, and composition of the resultant CuO/Cu hybrid foils are characterized, and the relevant lithium storage properties of this anode are also investigated by using standard electrochemical tests. The results show that the CuO/Cu hybrid‐based anode possesses a porous leaf‐like morphology and self‐integrated architecture. Benefitting from this unique morphology and favorable architecture, the CuO/Cu hybrid‐based anode exhibits outstanding electrochemical performance, including excellent cycling stability and remarkable rate capability, demonstrating great potential in the application of high‐energy‐density LIBs.