bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Magnetic Properties of L‐Alanine Capped CoFe2O4 Nanoparticles
Authors: Serrano‐García Raquel , Purcell‐Milton Finn , McCarthy Sarah , Gun'ko Yurii K. 
Published: May 2018

AbstractHere we report a low cost scalable synthesis of L‐alanine capped CoFe2O4 magnetic nanoparticles, with excellent size tunability and magnetic properties. Samples were analyzed in details using electron microscopy, X‐ray powder diffraction and vibrational sample magnetometry. The magnetic nanoparticles have demonstrated excellent size distribution, uniformity and phase purity. It was found that the presence and concentration of L‐alanine ligand dramatically affects the size and morphology of the resulting CoFe2O4 nanoparticles, enabling size tunability from 120.5 to 11.3 nm. The magnetic moments of nanomaterials are ranging from 74 to 41 Am2kg−1, they are easily manipulated by an external magnetic field and show the onset of superparamagnetic behavior in the smaller nanoparticles prepared.
Structural Effects on Guest Binding in Cucurbit[8]uril‐Perylenemonoimide Host‐Guest Complexes
Authors: Aryal Gyan H. , ViK Ryan , Assaf Khaleel I. , Hunter Kenneth W. , Huang Liming , Jayawickramarajah Janarthanan , Nau Werner M. 
Published: May 2018

AbstractA series of water‐soluble fluorescent perylene dyes (perylenemonoimides PMI1, PMI2, and PMI3) with two aromatic binding units (a perylene‐core and a phenyl group) as guest molecules for binding with cucurbit[8]uril (CB8) were synthesized. The guest structure was varied by modifying the phenyl group and the spacer between the two binding units. Differences in binding, self‐assembly, and optical properties of the corresponding host‐guest complexes were observed. At low micromolar concentrations, a highly emissive 1:1 CB8•PMI1 complex with high binding affinity (Ka=1.5 x 107 M–1) was formed in water. Interestingly, at higher concentrations of the CB8•PMI1 complex (e. g., >10–4 M), non‐emissive self‐assembled nanowires were formed. In comparison, the binding affinity of CB8•PMI2 and CB8•PMI3 was determined to be only 5.0 x 105 M–1 and 1.7 x 104 M–1, respectively. The host‐guest complexes with various binding affinities could serve as fluorescent displacement probes for the detection of a range of CB8‐binding guest analytes.
Catalytic Selective Hydrogenation and Cross Coupling Reaction Using Polyvinylpyrrolidone‐Capped Nickel Nanoparticles
Authors: Bathla Aadil , Pal Bonamali 
Published: May 2018

AbstractThis study signifies the size‐dependent catalytic activity of Ni‐nanocatalyst for the selective hydrogenation of cinnamaldehyde and Suzuki‐Miyaura cross‐coupling reaction. A series of polyvinylpyrrolidone capped nickel nanoparticles (NPs) with variation in their size are synthesized by polyol method. The morphological studies revealed that average size of Ni‐NPs (Ni‐NP1, Ni‐NP2, and Ni‐NP3) lies in the range of 10–12, 7–9, and 3–5 nm respectively. The optical measurements showed a significant blue shift in the absorption spectra for Ni‐NPs with decreasing particle size. The magnetic hysteresis loop revealed that the remanent magnetization (MR) decreases and coercivity (HC) increases with the decrease in particle size demonstrating a distinct size effect. The Ni‐NP3 was observed to possess higher surface area (79 m2g−1) and efficient activity for the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol and also in the biphenyl formation via C−C cross‐coupling reaction relative to Ni‐NP1, Ni‐NP2, and commercially available Raney Ni.
Combining Whispering‐Gallery Mode Optical Biosensors with Microfluidics for Real‐Time Detection of Protein Secretion from Living Cells in Complex Media
Authors: Chen Ying‐Jen , Schoeler Ulrike , Huang Chung‐Hsuan (Benjamin) , Vollmer Frank 
Published: May 2018

AbstractThe noninvasive monitoring of protein secretion of cells responding to drug treatment is an effective and essential tool in latest drug development and for cytotoxicity assays. In this work, a surface functionalization method is demonstrated for specific detection of protein released from cells and a platform that integrates highly sensitive optical devices, called whispering‐gallery mode biosensors, with precise microfluidics control to achieve label‐free and real‐time detection. Cell biomarker release is measured in real time and with nanomolar sensitivity. The surface functionalization method allows for antibodies to be immobilized on the surface for specific detection, while the microfluidics system enables detection in a continuous flow with a negligible compromise between sensitivity and flow control over stabilization and mixing. Cytochrome c detection is used to illustrate the merits of the system. Jurkat cells are treated with the toxin staurosporine to trigger cell apoptosis and cytochrome c released into the cell culture medium is monitored via the newly invented optical microfluidic platform.
High‐Contrast SEM Imaging of Supported Few‐Layer Graphene for Differentiating Distinct Layers and Resolving Fine Features: There is Plenty of Room at the Bottom
Authors: Huang Li , Zhang Dan , Zhang Fei‐Hu , Feng Zhi‐Hong , Huang Yu‐Dong , Gan Yang 
Published: May 2018

AbstractFor supported graphene, reliable differentiation and clear visualization of distinct graphene layers and fine features such as wrinkles are essential for revealing the structure–property relationships for graphene and graphene‐based devices. Scanning electron microscopy (SEM) has been frequently used for this purpose where high‐quality image contrast is critical. However, it is surprising that the effect of key imaging parameters on the image contrast has been seriously undermined by the graphene community. Here, superior image contrast of secondary electron (SE) images for few‐layer graphene supported on SiC and SiO2/Si is realized through simultaneously tuning two key parameters—acceleration voltage (Vacc) and working distance (WD). The overlooked role of WD in characterizing graphene is highlighted and clearly demonstrated. A unified model of Vacc and WD dependence of three types of SE collected by the standard side‐attached Everhart‐Thornley (E‐T) SE detector is conceptually developed for mechanistically understanding the improved mass thickness contrast for supported few‐layer graphene. The findings reported here will have important implications for effective characterizations of atomically thick 2D materials and devices.
Ferroelectric Localized Field–Enhanced ZnO Nanosheet Ultraviolet Photodetector with High Sensitivity and Low Dark Current
Authors: Wang Peng , Wang Yang , Ye Lei , Wu Mingzai , Xie Runzhang , Wang Xudong , Chen Xiaoshuang , Fan Zhiyong , Wang Jianlu , Hu Weida 
Published: May 2018

AbstractZinc oxide (ZnO) nanosheets have demonstrated outstanding electrical and optical properties, which are well suited for ultraviolet (UV) photodetectors. However, they have a high density of intrinsically unfilled traps, and it is difficult to achieve p‐type doping, leading to the poor performance for low light level switching ratio and a high dark current that limit practical applications in UV photodetection. Here, UV photodetectors based on ZnO nanosheets are demonstrated, whose performance is significantly improved by using a ferroelectric localized field. Specifically, the photodetectors have achieved a responsivity of up to 3.8 × 105 A W−1, a detectivity of 4.4 × 1015 Jones, and a photocurrent gain up to 1.24 × 106. These device figures of merit are far beyond those of traditional ZnO ultraviolet photodetectors. In addition, the devices' initial dark current can be easily restored after continuous photocurrent measurement by using a positive gate voltage pulse. This study establishes a new approach to produce high‐sensitivity and low‐dark‐current ultraviolet photodetectors and presents a crucial step for further practical applications.
Mineral‐Templated 3D Graphene Architectures for Energy‐Efficient Electrodes
Authors: Zhang Mingchao , Chen Ke , Wang Chunya , Jian Muqiang , Yin Zhe , Liu Zhenglian , Hong Guo , Liu Zhongfan , Zhang Yingying 
Published: May 2018

Abstract3D graphene networks have shown extraordinary promise for high‐performance electrochemical devices. Herein, the chemical vapor deposition synthesis of a highly porous 3D graphene foam (3D‐GF) using naturally abundant calcined Iceland crystal as the template is reported. Intriguingly, the Iceland crystal transforms to CaO monolith with evenly distributed micro/meso/macropores through the releasing of CO2 at high temperature. Meanwhile, the hierarchical structure of the calcined template could be easily tuned under different calcination conditions. By precisely inheriting fine structure from the templates, the as‐prepared 3D‐GF possesses a tunable hierarchical porosity and low density. Thus, the hierarchical pores offer space for guest hybridization and provide an efficient pathway for ion/charge transport in typical energy conversion/storage systems. The 3D‐GF skeleton electrode hybridized with Ni(OH)2/Co(OH)2 through an optimal electrodeposition condition exhibits a high specific capacitance of 2922.2 F g−1 at a scan rate of 10 mV s−1, and 2138.4 F g−1 at a discharge current density of 3.1 A g−1. The hybrid 3D‐GF symmetry supercapacitor shows a high energy density of 83.0 Wh kg−1 at a power density of 1011.3 W kg−1 and 31.4 Wh kg−1 at a high power density of 18 845.2 W kg−1. The facile fabrication process enables the mass production of hierarchical porous 3D‐GF for high‐performance supercapacitors.
Light Sources and Photodetectors Enabled by 2D Semiconductors
Authors: Shang Jingzhi , Cong Chunxiao , Wu Lishu , Huang Wei , Yu Ting 
Published: May 2018

AbstractThe emerging 2D semiconductors have aroused increasing attention due to their fascinating fundamental properties and application prospects. Technical investigation of 2D semiconductor–based electronics and optoelectronics is paving the way to realizing practical applications, which opens up new opportunities to reshape the current semiconductor industry. Particularly, 2D semiconductor–based optoelectronics can be extensively utilized in the promising semiconductor and information industries, such as solid‐state lighting, on‐chip optical interconnects, quantum computing, and communication. Here, the research progress regarding the fabrication and characterization of rapidly growing light‐emitting devices and photodetectors enabled by 2D semiconductors is reviewed. According to different emission mechanisms, 2D semiconductor–activated light sources are classified into four types: excitonic light‐emitting diodes (LEDs), quantum LEDs, valley LEDs, and lasers. Moreover, photodetecting devices based on atomically thin MoS2, other 2D semiconductors, and van der Waals heterostructures are discussed, where diverse device structures, performance parameters, and working principles are compared. Furthermore, the remaining challenges in the realization of practical devices with desirable features are outlined and new research opportunities for 2D semiconductor optoelectronics are proposed.
Influence of Synthesis Conditions on Electrochemical Properties of P2‐Type Na2/3Fe2/3Mn1/3O2 for Rechargeable Na Batteries
Authors: Zhao Wenwen , Tsuchiya Yuka , Yabuuchi Naoaki 
Published: May 2018

AbstractP2‐type Na2/3Fe2/3Mn1/3O2 samples are synthesized by solid‐state calcination with different conditions and the influence of synthesis conditions on the structural and electrochemical properties is systematically studied. By controlling the synthesis conditions, a fraction of O3‐type impurity phase is effectively decreased, and nearly stoichiometric P2 Na2/3Fe2/3Mn1/3O2 is successfully obtained by a two‐step calcination method. A voltage plateau of 2.5 V, which is attributed to the oxidation of Mn3+ to Mn4+, appears in initial charge profiles for quenched and one‐step calcined samples. In contrast, for the initial charge process, the voltage plateau of 2.5 V is not observed in the sample prepared in the two‐step calcination process, suggesting that Mn3+ is not contained in this sample. Charge/discharge mechanisms of nearly stoichiometric Na2/3Fe2/3Mn1/3O2 are also examined by X‐ray absorption spectroscopy and X‐ray diffractometry, and it is found that reversible redox reaction of Fe3+/Fe4+ and Mn3+/Mn4+ proceeds on electrochemical cycles. Moreover, stacking faults associated with metal layer glide on charge are more pronounced for P2 Na2/3Fe2/3Mn1/3O2 in comparison to the P2‐type Mn‐rich system, Na2/3Fe1/2Mn1/2O2. From these results, factors affecting electrode performance of sodium insertion materials are discussed.
Cobalt@Nitrogen‐Doped Porous Carbon Fiber Derived from the Electrospun Fiber of Bimetal–Organic Framework for Highly Active Oxygen Reduction
Authors: Bai Qing , Shen Feng‐Cui , Li Shun‐Li , Liu Jiang , Dong Long‐Zhang , Wang Zeng‐Mei , Lan Ya‐Qian 
Published: May 2018

AbstractThe exploitation of high‐efficiency, cost‐effective, and stable oxygen reduction reaction (ORR) electrocatalysts is extremely critical for energy storage and conversion technology. The transition metal carbonitrides have been investigated as an alternative to precious metal‐based catalysts. Here, a series of uniform Co nanoparticles encapsulated in nitrogen‐doped porous carbon fibers (Co@N‐PCFs for brevity) are designed and synthesized by directly carbonizing the ZnxCo1–x‐zeolitic imidazolate frameworks@polyacrylonitrile (ZnxCo1–x‐ZIFs@PAN) electrospun nanofibers. By precisely controlling the Zn/Co molar ratio in the ZnxCo1–x‐ZIFs precursor and carbonization temperature, a higher activity and stability ORR catalyst of Co@N‐PCF‐3 is prepared. The results reveal that Co@N‐PCF‐3 exhibits outstanding ORR activity outperformed commercial Pt/C with more positive half‐wave potential of −134 mV versus Ag/AgCl, high selectivity to four‐electron pathway (n ≈ 3.9), as well as remarkable stability and methanol tolerance. Remarkably, it is one of the highest ORR catalysts among the cobalt carbonitrides reported in the literature.
An integral boundary layer engineering model for vortex generators implemented in XFOIL
Authors: De Tavernier Delphine , Baldacchino Daniel , Ferreira Carlos 
Published: May 2018

AbstractTo assess and optimize vortex generators (VGs) for flow separation control, the effect of these devices should be modelled in a cost and time efficient way. Therefore, it is of interest to extend integral boundary layer models to analyse the effect of VGs on airfoil performance. In this work, the turbulent boundary layer formulation is modified using a source term approach. An additional term is added to the shear‐lag equation, to account for the increased dissipation due to streamwise vortex action in the boundary layer, forcing transition at the VG leading edge where applicable. The source term is calibrated and a semi‐empirical relation is set up and implemented in XFOIL. The modified code is capable of addressing the effect of the VG height, length, inflow angle, and chordwise position on the airfoil's aerodynamic properties. The predicted polars for airfoils with VGs show a good agreement with reference data, and the code robustness is demonstrated by assessing different airfoil families at a wide range of Reynolds numbers.
The existence results for a new 2‐D compressible fluid model with the horizontal thermal gradient effect
Authors: Yang Jiayan , Liu Ruikuan 
Published: May 2018

AbstractBased on the Newton second law, the energy conservation law, the mass conversation law and the equation of state, a new 2‐D model for the motion of fluid flows with the horizontal thermal gradient effect is established. By using the characteristic method, the classic prior estimates and iterative technique, the local existence and uniqueness of strong solution for the new 2‐D model are proved.
Subleading Regge limit from a soft anomalous dimension
Authors: Brüser Robin , Caron-Huot Simon , Henn Johannes M. 
Published: May 2018

AbstractWilson lines capture important features of scattering amplitudes, for example soft effects relevant for infrared divergences, and the Regge limit. Beyond the leading power approximation, corrections to the eikonal picture have to be taken into account. In this paper, we study such corrections in a model of massive scattering amplitudes in$$ \mathcal{N}=4 $$N=4super Yang-Mills, in the planar limit, where the mass is generated through a Higgs mechanism. Using known three-loop analytic expressions for the scattering amplitude, we find that the first power suppressed term has a very simple form, equal to a single power law. We propose that its exponent is governed by the anomalous dimension of a Wilson loop with a scalar inserted at the cusp, and we provide perturbative evidence for this proposal. We also analyze other limits of the amplitude and conjecture an exact formula for a total cross-section at high energies.
Fish–prey interactions in, and associated data from, a temperate stream of the Yura River, Kyoto, Japan
Authors: Nakagawa Hikaru , Takemon Yasuhiro 
Published: May 2018

AbstractAlthough quantitative data on interspecific interactions within complex food webs are essential for evaluation of assumptions, hypotheses, and predictions of ecological theories; empirical studies yielding quantitative data on complex food webs are very limited. Ecological information on body size, habitat use, and seasonality of the component species of food webs aids in determining the mechanisms of food web structures. Ideally, ecological information on component species should be obtained contemporaneously when used to describe quantitative food webs, but such observations and sampling strategies are labor intensive and thus have been rarely described. We conducted year‐round samplings of, and performed observations on, a temperate stream: the upper reaches of the Yura River, Kyoto, Japan. We derived quantitative data on the abundance, biomass, body mass, microhabitat use, and those seasonality of 7 fish species and 167 invertebrate taxa of the temperate stream food web. In addition, we estimated the per mass consumption rates of 7 predatory fish species, consuming 183 prey invertebrates, and the ratios between the per mass consumption rates of the 7 predatory fish species and the production rates of 78 prey invertebrates in each trophic link. All fishes and aquatic invertebrates were identified to species or lowest possible taxon. Our data may contribute to the construction of mathematical models explaining the behavior of stream communities/ecosystems.
Sources of Fluoride Contamination in Singrauli with Special Reference to Rihand Reservoir and its Surrounding
Authors: Usham A. L. , Dubey C. S. , Shukla D. P. , Mishra B. K. , Bhartiya G. P. 
Published: May 2018

ABSTRACT
The Singrauli region is known for fluoride contamination and its effect on human population. In this work the possible sources of fluoride contamination in Rihand reservoir water is constrained. They include slurry water, fly ash and coal samples of various thermal power plants, coal seams and granites of the region. Petrographic study depicted the presence of fluoride bearing minerals - flour apatite in pink granite. Preliminary scanning electron microscope studies revealed presence of fluorine peak in coal samples. The chemical analysis confirmed the presence of fluoride in fly ash (12.6 mg/kg), drain water (5.34 mg/l), soil (6.1 mg/kg), coal (3.1 mg/kg). They confirmed the source of fluoride from coal of thermal power plant which utilized coal from Singrauli coal seam (1.6 mg/kg). Further the Rihand reservoir water is also enriched by fluoride contaminant (upto 4.7 mg/l). This contaminates groundwater of the area as well. The contaminated water used for drinking and agriculture affects health of inhabitants in the area. It is concluded that the main source of fluoride contamination in the study area is due to coal burnt in thermal power plant and pink granite formation of the area, both anthropogenic and geogenic sources are implied.
Assessment of Potential Alkali Aggregate Reactivity for Siliceous and Carbonate Aggregates: A Case Study
Authors: Ahmad M. , Ansari M. K. , Singh Rajesh , Sharma L. K. , Singh T. N. , Pires Sandra 
Published: May 2018

ABSTRACT
Alkali-aggregate reactivity (AAR) involves a reaction between the pore solution of concrete and certain minerals found in some aggregates. To assess the potential AAR various physical and chemical tests are available and extensively used. The petrographic examination is the initial assessment that decides the further investigation for potential reactivity of an aggregate. A chemical approach is another option to assess the aggregate for potential AAR. The accelerated mortar bar method and concrete prism tests are other very important tests for determination of potential AAR of aggregates samples. However, a combination of the results of all the techniques provides most reliable results for potential AAR in aggregates. Moreover, each test represents the stepwise investigation and provides the decision for the test of next approach. Petrographic examination and chemical test methods are the quick decision-making methods for the estimation of potential AAR. In some cases, by these two methods, the aggregate can be selected and rejected confidently. However, for critical values or doubtful aggregates, further tests are necessary to develop a higher confidence level of the results. The present study comprises of the assessment of the alkali-reactivity of siliceous and carbonate aggregates using petrographic and chemical approaches. X-ray diffraction analysis was used as a complementary method to the petrographic evaluation. Moreover, under chemical approach, two separate test methods were used for siliceous and carbonate aggregates. The study also included a comparison between the petrographic examination and chemical analysis for the same aggregate samples and found significant results.
Hydrogeochemistry and Groundwater Quality Assessment for Drinking and Irrigation Purpose of Raipur City, Chhattisgarh
Authors: Khan Rubia , Jhariya D. C. 
Published: May 2018

ABSTRACT
Groundwater is an important source of drinking and irrigation purpose and the greater part of the total populace relies on groundwater for survival. Present study investigates the hydrogeochemistry and groundwater quality of the study area for drinking and irrigation purpose. In this study, total 100 numbers groundwater samples were collected and analyzed using standard methods (APHA, 1995) during pre-monsoon period (May, 2016). In the study area, there is occurrence of mainly Ca+2–Mg+2–HCO3 and Ca+2-M+2-SO4–2 water type and the dominant cations and anions are Ca&gt;Mg&gt;Na&gt;K&gt;Fe=HCO3&gt;Cl&gt;CO3&gt; SO4&gt;Fe&gt;F&gt;NH3. The Gibbs plot shows that, hydrogeochemistry of ground-water is depending upon rock-water interaction. Present study, indicate that groundwater quality in the study area is suitable for irrigation and drinking purpose except some groundwater sample, which are showing high Nitrate, Iron, Sulphate, Ammonia and Calcium concentration.