bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanically Tunable Bilayer Composite Grating for Unique Light Manipulation and Information Storage
Authors: Meng Yancheng , Zhang Suna , Wu Kunjie , Li Jie , Li Liqiang 
Published: December 2018

AbstractComposite gratings play important roles in modern information technology. However, such gratings are generally based on the same structural pattern with limited types, and their structural parameters are difficult to tune, which greatly limit their application. A mechanically tunable composite grating in bilayer film, which orthogonally couples a sinusoidal phase grating and a rectangular phase grating, is developed here. The structural parameters of the grating can be well tuned by mechanically stretching or releasing the grating in the uniaxial direction. Naturally, this property allows tunable light manipulation: that is, a single incident laser beam can be split into a 2D diffraction beams array, and the intensity and propagation angle of each diffraction beam can be precisely controlled via mechanical manipulation of the grating. A theoretical model based on scalar diffraction theory that can quantitatively describe and accurately predict this light manipulation is further established. In addition, after treatment with an electron beam, the tunable structures can be immobilized, which enables the storage of information in the bilayer film. This work may open up new pathways for composite grating fabrication and further extend the applications of composite gratings in diverse fields.
Large Area Three‐Dimensional Photonic Crystal Membranes: Single‐Run Fabrication and Applications with Embedded Planar Defects
Authors: Chang Bingdong , Zhou Chen , Tarekegne Abebe Tilahun , Yang Yuanqing , Zhao Ding , Jensen Flemming , Hübner Jörg , Jansen Henri 
Published: December 2018

AbstractThree‐dimensional photonic crystals (3D PhCs) enable light manipulations in all three spatial dimensions, however, real world applications are still faced with challenges in fabrication. Here, a facile fabrication strategy for 3D silicon PhCs with a simple cubic (SC) lattice structure is presented, which exhibits a complete photonic bandgap at near‐infrared wavelengths of around 1100 nm. The fabrication process is composed of standard deep ultra‐violet stepper lithography, followed by a single‐run modified plasma etch process. By applying a direct dry etch release step at the end of the 3D structural etch process, the fabricated 3D PhCs can be released and transferred in the form of a membrane onto other substrates such as glass, polymers, or even substrates with engineered surface. The thickness of the demonstrated membranes is around 2 µm and the size can be up to a few millimeters. A high reflectivity is observed at the stop band frequency, and a planar defect is introduced during the etching process resulting in an optical resonance mode with a small linewidth of around 30 nm. The structure constitutes an optical bandpass filter and can be used as a sensor for organic solvents.
Embossing Reactive Mesogens: A Facile Approach to Polarization‐Independent Liquid Crystal Devices
Authors: Wahle Markus , Snow Benjamin , Sargent Joe , Jones J. Cliff 
Published: December 2018

AbstractReactive mesogens (RMs) are used in a wide variety of applications, from retardation plates for organic light‐emitting display screens, liquid crystal phase stabilization, optical or electrically active elastomers to novel optic components. They can be processed as standard liquid crystals and subsequently polymerized to stabilize both shape and anisotropic properties. However, creating complex shapes while maintaining good alignment of the RM optical axis can be a challenge. In the present work, embossing is used to replicate a wide variety of RM structures in several electro‐optic devices. A novel device geometry is proposed where a polarization‐independent lens is formed by opposing birefringent Fresnel zone plates embossed in aligned RM. The RM forms the optical elements and alignment layers for an index‐matched liquid crystal, arranged to produce the twisted nematic configuration. Low voltages switch the device between nonfocusing and focusing states. After characterizing lens efficiency and beam properties, the method is used to fabricate a switchable multilevel Fresnel zone plate with optical efficiencies beyond 50%, and theoretically able to produce polarization‐independent lenses with efficiencies approaching 100% from a single structure. Finally, manufactured polarization‐independent gratings and microlens arrays are presented using the method to illustrate the wide range of applicability.
Direct Photoassisted α‐Trifluoromethylation of Aromatic Ketones with Trifluoroacetic Anhydride (TFAA)
Authors: Das Somnath , Hashmi A. Stephen K. , Schaub Thomas 
Published: December 2018

AbstractDirect α‐Trifluoromethylation of acetophenone derivatives was achieved by using trifluoroacetic anhydride (TFAA) as the trifluoromethyl source and pyridine‐N‐oxide (Py−O) as activator and oxidant under visible light irradiation and tris‐(2,2′‐bipyridine)ruthenium(II) hexafluorophosphate (Ru(bpy)3(PF6)2) as the photocatalyst. Different acetophenone derivatives could be converted to the corresponding α‐CF3 derivatives with high selectivity. Extensive mechanistic investigation revealed the formation of vinyl trifluoroacetate as the key intermediate for this transformation.magnified image
Three‐Mode Modulation Electrochromic Device with High Energy Efficiency for Windows of Buildings Located in Continental Climatic Regions
Authors: Cardoso Marita A. , Pereira Rui F. P. , Pereira Sónia , Gonçalves Helena , Silva Maria M. , Carlos Luís D. , Nunes Sílvia C. , Fortunato Elvira , Ferreira Rute A. S. , Rego Rosa , de Zea Bermudez Verónica 
Published: December 2018

AbstractA sustainable use of energy in buildings demands energy‐efficient windows. A new design concept for electrochromic (EC) smart windows, easy to implement at the industrial level, is introduced here. It enables simultaneous control of visible and near‐infrared (NIR) solar radiation, thus contributing to reduce heating and cooling loads especially in buildings located in areas experiencing wide daily temperature ranges. The EC device comprises amorphous indium zinc oxide, a conducting oxide transparent in the visible and NIR spectral regions, as nonactive layer, and a sol–gel protonic ionic liquid‐doped di‐ureasil electrolyte displaying high transparency and proton conductivity. The device offers three voltage‐operated modes: bright hot (+3.0 V: transmittances of 70/83% at 555/1000 nm), semi‐bright warm (−2.0 V: transmittances of 37/35% at 555/1000 nm), and dark cold (−2.5 V: transmittances of 6/4% at 555/1000 nm). Its main figures of merit are: high switching efficiency (transmittance variations of 64/79% at 555/1000 nm), high optical density modulation (1.1/1.3 at 555/1000 nm), high optical contrast ratio in the visible region (lightness variation of ≈43), good cycling stability, and unprecedented coloration efficiency (−12538/−14818 cm2 C−1 and +2901/+3428 cm2 C−1 at 555/1000 nm), outstanding optical memory (transmittance variation loss of only 24% more than 4 months after coloration), and self‐healing ability following mechanical stress.
A Percolation Model for Piezoresistivity in Conductor–Polymer Composites
Authors: Wang Mingyi , Gurunathan Ramya , Imasato Kazuki , Geisendorfer Nicholas R. , Jakus Adam E. , Peng Jun , Shah Ramille N. , Grayson Matthew , Snyder G. Jeffrey 
Published: December 2018

AbstractInsulating polymer composites with conductive filler particles are attractive for sensor applications due to their large piezoresistive response. Composite samples composed of a polymer matrix filled with particles of doped semiconductor that gives a piezoresistive response that is 105 times larger than that of bulk semiconductor sensors are prepared here. The piezoresistance of such composite materials is typically described by using a tunneling mechanism. However, it is found that a percolation description not only fits prior data better but provides a much simpler physical mechanism for the more flexible and soft polymer composite prepared and tested in this study. A simple model for the resistance as a function of applied pressure is derived using percolation theory with a conductivity exponent, s. The model is shown to fit experimental piezoresistive trends with the resistance measured both perpendicular and parallel to the pressure direction.
Nanostructured Silicon‐Based Heterojunction Solar Cells with Double Hole‐Transporting Layers
Authors: Shen Suling , Zhang Jie , Zhou Shuang , Han Yujie , Gao Peng , Sun Baoqun , Zhao Ni , Wong Ching‐Ping 
Published: December 2018

AbstractHybrid nanostructured silicon–organic solar cells have been pursued as a low‐cost solution for silicon photovoltaic devices. However, it is difficult for the organic semiconductor, typically poly(3,4‐ethylenedioxythiophene):polystyrene (PEDOT:PSS), to fully cover the nanostructured silicon surface due to the high surface tension of the polymer solution and the small size of the cavities in nanostructured silicon. As a result, the performance of the hybrid solar cells is limited by the defect‐induced surface recombination and poor hole extraction. In this work, an inorganic hole‐transporting layer, copper(I) thiocyanate (CuSCN), is introduced between silicon nanowire (SiNW) and PEDOT:PSS to improve the junction quality. The effect of CuSCN on as‐fabricated SiNW and tetramethylammonium hydroxide (TMAH)‐treated SiNW structures is examined, and it is shown that in both cases CuSCN can well cover the SiNW surface due to the easy penetration of its solution into the silicon nanostructure. As a result, the power conversion efficiency of the solar cells has been dramatically improved from 7.68% to 10.5% for as‐fabricated SiNW‐based‐hybrid cells, and from 10.75% to 12.24% for TMAH‐passivated SiNW‐based‐hybrid cells, suggesting that the double hole‐transporting layer approach can effectively improve the junction quality in hybrid organic‐nanostructured silicon‐based devices.
Probing the Electronic Properties of Monolayer MoS2 via Interaction with Molecular Hydrogen
Authors: Rezende Natália P. , Cadore Alisson R. , Gadelha Andreij C. , Pereira Cíntia L. , Ornelas Vinícius , Watanabe Kenji , Taniguchi Takashi , Ferlauto André S. , Malachias Angelo , Campos Leonardo C. , Lacerda Rodrigo G. 
Published: December 2018

AbstractThis work presents a detailed experimental investigation of the interaction between molecular hydrogen (H2) and monolayer MoS2 field effect transistors (MoS2 FET), aiming for sensing application. The MoS2 FET exhibits a response to H2 that covers a broad range of concentration (0.1–90%) at a relatively low operating temperature range (300–473 K). Most important, H2 sensors based on MoS2 FETs show desirable properties such as full reversibility and absence of catalytic metal dopants (Pt or Pd). The experimental results indicate that the conductivity of MoS2 monotonically increases as a function of the H2 concentration due to a reversible charge transferring process. It is proposed that such process involves dissociative H2 adsorption driven by interaction with sulfur vacancies in the MoS2 surface (VS). This description is in agreement with related density functional theory studies about H2 adsorption on MoS2. Finally, measurements on partially defect‐passivated MoS2 FETs using atomic layer deposited aluminum oxide consist of an experimental indication that the VS plays an important role in the H2 interaction with the MoS2. These findings provide insights for future applications in catalytic process between monolayer MoS2 and H2 and also introduce MoS2 FETs as promising H2 sensors.
Steric Engineering of Alkylthiolation Side Chains to Finely Tune Miscibility in Nonfullerene Polymer Solar Cells
Authors: Xue Xiaonan , Weng Kangkang , Qi Feng , Zhang Yu , Wang Zaiyu , Ali Jazib , Wei Donghui , Sun Yanming , Liu Feng , Wan Meixiu , Liu Juan , Huo Lijun 
Published: December 2018

AbstractMorphology and miscibility control are still a great challenge in polymer solar cells. Despite physical tools being applied, chemical strategies are still limited and complex. To finely tune blend miscibility to obtain optimized morphology, chemical steric engineering is proposed to systemically investigate its effects on optical and electronic properties, especially on a balance between crystallinity and miscibility. By changing the alkylthiol side chain orientation different steric effects are realized in three different polymers. Surprisingly, the photovoltaic device of the polymerPTBB‐m with middle steric structure affords a better power conversion efficiency, over 12%, compared to those of the polymers PTBB‐o and PTBB‐p with large or small steric structures, which could be attributed to a more balanced blend miscibility without sacrificing charge‐carrier transport. Space charge‐limited current, atomic force microscopy, grazing incidence wide angle X‐ray scattering, and resonant soft X‐ray scattering measurements show that the steric engineering of alkylthiol side chains can have significant impacts on polymer aggregation properties, blend miscibility, and photovoltaic performances. More important, the control of miscibility via the simple chemical approach has preliminarily proved its great potential and will pave a new avenue for optimizing the blend morphology.
Structure Distortion Induced Monoclinic Nickel Hexacyanoferrate as High‐Performance Cathode for Na‐Ion Batteries
Authors: Xu Yue , Wan Jing , Huang Li , Ou Mingyang , Fan Chenyang , Wei Peng , Peng Jian , Liu Yi , Qiu Yuegang , Sun Xueping , Fang Chun , Li Qing , Han Jiantao , Huang Yunhui , Alonso José Antonio , Zhao Yusheng 
Published: December 2018

AbstractPrussian blue analogs with an open framework are ideal cathodes for Na‐ion batteries. A superior high‐rate and highly stable monoclinic nickel hexacyanoferrate (NiHCF‐3) is synthesized via a facile one‐step crystallization‐controlled co‐precipitation method. It gives a high specific capacity of 85.7 mAh g−1, nearly to its theoretical value. It also exhibits an excellent rate capability with a high capacity retention ratio of 78% at 50 C and a stable cycling performance over 1200 cycles. Through the ex situ X‐ray diffraction and pair distribution function measurements, it is found that the monoclinic structure with distorted framework is greatly related to the high Na content. The electronic structure studies by density functional theory (DFT) calculation demonstrate that NiHCF‐3 deformation promotes the framework conductivity and improves the electrochemical activity of Fe, which results in an ultrahigh‐rate performance of monoclinic phase. Furthermore, the high‐quality monoclinic (NiHCF‐3) exhibits excellent compatibility with both hard carbon and NaTi2(PO4)3 anodes in full cells, which shows great prospects for the application in the large‐scale energy storage systems.
Reproductive heat tolerance in a Mojave Desert annual plant,Trianthema portulacastrum
Authors: Branch Haley A. , Sage Rowan F. 
Published: December 2018

Premise of the StudyReproduction in many crop species is impaired above 30° to 35°C; however, the sensitivity of reproduction in the natural flora remains uncertain. Studies focusing on the effect of high temperature on plant reproduction in wild species are necessary to improve our understanding of how rising global temperatures will impact global plant reproductive success and may ultimately inform models of plant distribution in the future. Additionally, these studies may highlight candidates for thermotolerance that could be further explored for crop improvement.MethodsWe studied reproductive heat tolerance inTrianthema portulacastrum, a weedy species found in hot microsites throughout the tropics and subtropics. Plants were grown at seven day/night temperature combinations: 30°/24°C, 33°/24°C, 36°/24°C, 40°/24°C, 44°/24°C, 24°/40°C, and 40°/40°C to study the effect of both high‐day and high‐night temperatures. The reproductive parameters measured include anther dehiscence, pollen viability, germination, ovule number, and seed set.Key ResultsPollen viability and germination declined with increasing daytime temperature up to 44°C, but this did not affect fruit production or seed set. Seed set was reduced under high night temperature. Continuous high temperature over the day and night (40°C day/40°C night) decreased pollen viability by half and reduced seed set by two‐thirds.ConclusionsOur results demonstrateTrianthema portulacastrumhas much higher reproductive thermotolerance than commonly identified in crop species, and though inhibited, can retain fecundity at 40°C. Through a combination of night escape and increased thermal tolerance, it maintains fertility in the hot microsites of its natural environment.
Teaching about Decoloniality: The Experience of Non‐Indigenous Social Work Educators
Authors: Hendrick Antonia , Young Susan 
Published: December 2018

AbstractThis paper provides a way to theorize and practice Decoloniality in teaching and learning within higher education. Two social work academics develop a framework for teaching about decoloniality which they hope is useful for other academics from different “helping” professions who also work with First Nations peoples. Rather than a fixed and firm framework it is intended to be used to inform practice and assist students in developing their own framework for practice. The article begins by offering how the authors define decoloniality, then presents a theory for practice/practice to theory framework and explanation of how we use this framework for teaching/learning and practice.
Unsettling the Settlers: Principles of a Decolonial Approach to Creating Safe(r) Spaces in Post‐secondary Education
Authors: Mitchell Terry L. , Thomas Darren , Smith Jackson A. 
Published: December 2018

AbstractIn this paper we discuss the ongoing colonial relationship between Indigenous and non‐Indigenous peoples in Canada with a consideration of how to align the principles and core values of community psychology in relation to Indigenous rights, decolonization, and social justice. In working with Community Psychology values to address issues of social justice it is necessary to recognize that empowerment alone is only one half of the solution. While our discipline focuses on oppression and the empowerment of vulnerable and disenfranchised populations we generally fail to consider the relational aspects of power and justice. Specifically, in recognizing power inequities the focus is often placed on empowerment among vulnerable or subjugated communities while neglecting the requisite counterbalance of consciousness‐raising and de‐powerment of dominant populations. The authors provide three personal accounts from a non‐Indigenous faculty member, an Indigenous doctoral student, and a recently graduated non‐Indigenous Masters student. We share our experiences of conscientization and decolonization within the post‐secondary and graduate education systems. We describe an educational context, a pedagogical praxis, and our efforts to bridge the theories of Settler colonialism and community psychology. From our individual and collective reflections of engagement with decolonization in the education system we present an emergent framework that highlights four principles for decolonization. In implementing these principles we discuss the co‐creation of safe(r), decolonized spaces within post‐secondary institutions through deconstructing dominant narratives and illuminating Indigenous narratives of self‐determination with attention to the de‐powerment of non‐Indigenous faculty and students.
Decolonizing Community Psychology by Supporting Indigenous Knowledge, Projects, and Students: Lessons from Aotearoa New Zealand and Canada
Authors: McNamara Rita Anne , Naepi Sereana 
Published: December 2018

AbstractCommunity psychology has long stood as a social justice agitator that encouraged reformation both within and outside of the academy, while keeping a firm goal of building greater well‐being for people in communities. However, community psychology's historically Euro‐centric orientation and applied, interventionist focus may inadvertently promote colonial agendas. In this paper, we focus on the example of Indigenous Pacific peoples, drawing upon experience working among Indigenous iTaukei Fijian communities and with Indigenous frameworks for promoting student success in Aotearoa New Zealand and Canada. We outline how community psychology curricula can strive toward decolonization by (a) teaching students to respectfully navigate complexities of Indigenous knowledge and traditions that contest colonial ways of being and doing, (b) act as facilitators who build toward collaborative community projects and model this research practice to students, and (c) boost Indigenous student success by fostering relationships with instructors and fellow students that are embedded within the relational model of self that is often absent in individualistic‐oriented Western academic settings.
Validation of the Prediction of Delirium for Intensive Care model to predict subsyndromal delirium
Authors: Azuma Kazunari , Mishima Shiro , Shimoyama Keiichiro , Ishii Yuri , Ueda Yasuhiro , Sakurai Masako , Morinaga Kentaro , Fujikawa Tsubasa , Oda Jun 
Published: December 2018

AimSubsyndromal delirium is associated with prolonged intensive care unit stays, and prolonged mechanical ventilation requirements. The Prediction of Delirium for Intensive Care (PRE‐DELIRIC) model can predict delirium. This study was designed to verify if it can also predict development of subsyndromal delirium.MethodsWe undertook a single‐center, retrospective observation study in Japan. We diagnosed subsyndromal delirium based on the Intensive Care Delirium Screening Checklist. We calculated the sensitivity and specificity of the PRE‐DELIRIC model and obtained a diagnostic cut‐off value.ResultsWe evaluated data from 70 patients admitted to the mixed medical intensive care unit of the Tokyo Medical University Hospital (Tokyo, Japan) between May 2015 and February 2017. The prevalence of subsyndromal delirium by Intensive Care Delirium Screening Checklist was 31.4%. The area under the receiver operating characteristic curve was 0.83 of the PRE‐DELIRIC model for subsyndromal delirium. The calculated cut‐off value was 36 points with a sensitivity of 94.3% and specificity of 57.1%. Subsyndromal delirium was associated with a higher incidence of delirium (odds ratio, 8.81; P < 0.01).ConclusionThe PRE‐DELIRIC model could be a tool for predicting subsyndromal delirium using a cut‐off value of 36 points.
Astaxanthin from Haematococcus pluvialis Microencapsulated by Spray Drying: Characterization and Antioxidant Activity
Authors: Zhao Xiaoyan , Liu Hongkai , Zhang Xiaowei , Zhang Guixiang , Zhu Haitao 
Published: December 2018

AbstractAstaxanthin (AX) is an unstable functional food ingredient. A stable AX powder was developed and its characteristics (such as moisture content, bulk density, solubility, repose angle, and morphology) and antioxidant activity were evaluated. The microencapsulated AX powder was produced by spray drying using maltodextrin (MD)–gelatin and the parameters were optimized by response surface methodology. The results revealed that an optimal microencapsulation process has a ratio of MD to gelatin of 2.1:1, a ratio of wall to core materials of 5.9:1, and a ratio of glycerol monostearate to sucrose fatty‐acid ester of 1.1:1. The AX encapsulation yield and encapsulation efficiency were 38.02% and 71.76%, respectively. AX microcapsules had a lower moisture content and bulk density, greater solubility, and good flowability. AX microcapsules showed antioxidant activities greater than Vitamin C, which indicated that the antioxidant activity of AX was not lost. AX microcapsule micrographs showed almost no cracks or fissures on the surface of microcapsules produced by spray drying under the optimal conditions.