bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of silver sulfide nanoparticles and their photodetector applications
Authors: Kang Myung Hyun , Kim Sung Ho , Jang Seunghun , Lim Ji Eun , Chang Hyunju , Kong Ki-jeong , Myung Sung , Park Joung Kyu
Published: August 2018

Silver sulfide nanoparticles (Ag2S NPs) are currently being explored as infrared active nanomaterials that can provide environmentally stable alternatives to heavy metals such as lead.
Graphitic carbon-wrapped NiO embedded three dimensional nitrogen doped aligned carbon nanotube arrays with long cycle life for lithium ion batteries
Authors: Deng Weina , Chen Xiaohua , Hu Aiping , Zhang Shiying
Published: August 2018

NACNTs@NiO@graphitic carbon composites were synthesized with the help of nebulizing. The outstanding performances are attributed to the original structure of NACNTs@NiO@graphitic carbon.
Rotating-disk electrode analysis of the oxidation behavior of dissolved Li2O2 in Li–O2 batteries
Authors: Ren Jing , Huang Zhimei , Kalambate Pramod K. , Shen Yue , Huang Yunhui
Published: August 2018

The RDE method introduced in this study is a facile and informative technique to screen for high performance electrolytes for LOB.
OpenFlowChem – a platform for quick, robust and flexible automation and self-optimisation of flow chemistry
Authors: Cherkasov Nikolay , Bai Yang , Expósito Antonio José , Rebrov Evgeny V.
Published: August 2018

OpenFlowChem – an open-access platform for automation of process control and monitoring optimised for flexibility.
Porous 3D graphene-based biochar materials with high areal sulfur loading for lithium–sulfur batteries
Authors: Liu Daoqing , Li Qianwei , Hou Jinbao , Zhao Huazhang
Published: August 2018

A novel pomelo peel biochar integrated graphene composite was applied as a cathode host for Li–S batteries with high sulfur loading.
Recent advances in the preparation, characterization, and applications of two-dimensional heterostructures for energy storage and conversion
Authors: Das Pratteek , Fu Qiang , Bao Xinhe , Wu Zhong-Shuai
Published: August 2018

This review summarizes recent advances in the preparation and characterization of 2D heterostructures for energy storage and conversion.
Heterometallic metal–organic framework nanocages of high crystallinity: an elongated channel structure formedin situthrough metal-ion (M = W or Mo) doping
Authors: Wei Jinxin , Cheng Niancai , Liang Zhiyu , Wu Yufeng , Zou Zhigang , Zhuang Zanyong , Yu Yan
Published: August 2018

Incorporation of WO42−or MoO42−finely caved the inside of UiO-66 single crystals, creating W or Mo doped UiO-66 nanocages with a channel structure.
Impregnation of sulfur into a 2D pyrene-based covalent organic framework for high-rate lithium–sulfur batteries
Authors: Meng Yi , Lin Guiqing , Ding Huimin , Liao Huaping , Wang Cheng
Published: August 2018

By loading 70 wt% sulfur into a pyrene-based COF (Py-COF), we constructed Li–S batteries with high-rate capacity and long-term stability.
A novel WS2/NbSe2 vdW heterostructure as an ultrafast charging and discharging anode material for lithium-ion batteries
Authors: Liu Huating , Huang Zongyu , Wu Guang , Wu Yanbing , Yuan Guanghui , He Chaoyu , Qi Xiang , Zhong Jianxin
Published: August 2018

Through the calculation of the first principle, the diffusion barrier of Li atoms inserted the WS2/NbSe2 heterostructure is low, so it has an ultrafast charging and discharging for lithium-ion batteries.
Solution-derived glass-ceramic NaI·Na3SbS4 superionic conductors for all-solid-state Na-ion batteries
Authors: Park Kern Ho , Kim Dong Hyeon , Kwak Hiram , Jung Sung Hoo , Lee Hyun-Jae , Banerjee Abhik , Lee Jun Hee , Jung Yoon Seok
Published: August 2018

The solution-derived glass-ceramic NaI·Na3SbS4 showing high Na+ conductivity (0.74 mS cm−1 at 30 °C) is developed, demonstrating promising electrochemical performances for FeS2/Na–Sn all-solid-state Na-ion batteries.
Na0.97KFe(SO4)2: an iron-based sulfate cathode material with outstanding cyclability and power capability for Na-ion batteries
Authors: Ko Wonseok , Park Teahoon , Park Hyunyoung , Lee Yongseok , Lee Kang Eun , Kim Jongsoon
Published: August 2018

Na0.97KFe(SO4)2 was successfully prepared via slow evaporation and a low-temperature process, and its outstanding electrochemical performance was demonstrated.
An indole-based conjugated microporous polymer: a new and stable lithium storage anode with high capacity and long life induced by cation–π interactions and a N-rich aromatic structure
Authors: Wei Wenxuan , Chang Guanjun , Xu Yewei , Yang Li
Published: August 2018

An indole-based conjugated microporous polymer, poly(bisindolylmaleimide) (PBIM), with superior electrochemical performance as an anode material for LIBs has been obtained by FeCl3-promoted oxidative coupling polymerization.
Interwoven V2O5 nanowire/graphene nanoscroll hybrid assembled as efficient polysulfide-trapping-conversion interlayer for long-life lithium–sulfur batteries
Authors: Guo Yi , Zhang Yin , Zhang Yun , Xiang Mingwu , Wu Hao , Liu Huakun , Dou Shixue
Published: August 2018

An advanced lithium–sulfur battery interlayer configuration has been developed by engineering a lightweight, self-standing, and flexible hybrid film assembled from interwoven 1D V2O5 nanowires and graphene nanoscrolls.
Doubling the ZT record of TiS2-based thermoelectrics by incorporation of ionized impurity scattering
Authors: Wang Yifeng , Pan Lin , Li Chao , Tian Ruoming , Huang Rong , Hu Xiaohui , Chen Changchun , Bao Ningzhong , Koumoto Kunihito , Lu Chunhua
Published: August 2018

TiS2–xAgSnSe2 composites showed an ionized impurity scattering as indicated by the growth of exponent m in electrical conductivity σ ∝Tm (400–580 K), which favored a new record ZTmax ∼ 0.8 for TiS2-based TEs.
Dielectric domain distribution on Au nanoparticles revealed by localized surface plasmon resonance
Authors: Luo Yi , Zhou Yadong , Zou Shengli , Zhao Jing
Published: August 2018

The LSPR of Au nanospheres shows almost no shift in the extinction spectrum with attachment of a silica domain but considerable shift with a uniform layer of silica, indicating LSPR can be used to differentiate the segregated/uniform dielectric distribution.
Ferromagnetism in a semiconducting Janus NbSe hydride monolayer
Authors: Zhou Xiaocheng , Sun Xu , Zhang Zhuhua , Guo Wanlin
Published: August 2018

NbSeH2 monolayers are a new group of 2D ferromagnetic semiconductors exhibiting robust ferromagnetism, desirable bandgaps and electrically tunable spin-polarization.
Arsenic aggravated reproductive toxicity in male rats exposed to lead during the perinatal period
Authors: Sai Siva Ram A. K. , Pratap Reddy K. , Girish B. P. , Supriya Ch. , Sreenivasula Reddy P.
Published: August 2018

The aim of this study was to assess the reproductive toxic effects of arsenic on adult Wistar rats exposed to lead during the perinatal period.
A 3D human lung-on-a-chip model for nanotoxicity testing
Authors: Zhang Min , Xu Cong , Jiang Lei , Qin Jianhua
Published: August 2018

The prevalent application of nanoparticles (NPs) has drawn intense concerns about their impact on the environment and human health.
Substrate‐integrated waveguide triple‐band filter with improved frequency and bandwidth allocations
Authors: Zhou Kang , Zhou Chunxia , Wu Wen
Published: August 2018

Substrate‐integrated waveguide triple‐band bandpass filter composed of two dual‐mode (TE101 and TE201) rectangular cavities coupled with two single‐mode (TE101) ones is synthesised and designed based on dual‐mode resonances and split‐type dual‐band symmetrical frequency response. By applying the dual‐mode frequency and coupling controlling techniques, the centre frequencies and fractional bandwidths (FBWs) of the three passbands can be allocated more flexibly. An experimental prototype centred at 11.578, 12.468 and 14.985 GHz with respective FBWs of 2.21, 2.21 and 2.3% is synthesised, designed, fabricated and measured for demonstration, showing good agreement between the measured and simulation results.
Laplacian controllable graphs based on connecting two antiregular graphs
Authors: Hsu Shun‐Pin , Yang Ping‐Yen
Published: August 2018

The Laplacian controllability of combined graphs are studied. It is shown that an antiregular graph, namely, a connected simple graph with exactly two vertices having the same degree, can be connected to another antiregular graph by a newly added edge, and becomes a Laplacian controllable graph under one controller. The methods to identify the vertices connected by the new edge and to assign the control vectors that render the resulting graph Laplacian controllable are presented. Numerical examples are given to illustrate the authors work.
Restraining effect of film thickness on the behaviour of amplified spontaneous emission from methylammonium lead iodide perovskite
Authors: Qaid Saif M.H. , Khan M. Naziruddin , Alqasem Abdulaziz , Hezam Mahmoud , Aldwayyan Abdullah
Published: August 2018

The authors report amplified spontaneous emission (ASE) behaviour from methylammonium lead iodide (CH3NH3PbI3) perovskite films of different thicknesses. The ASE threshold carrier density noticeably decreased with thickness, indicating the existence of different traps with perovskite films of smaller thicknesses. We attribute this behaviour to the presence of surface states, whose origin can result from different practical fabrication steps with samples of small thicknesses. The ASE threshold carrier density increased from 3.29 × 1018 cm−3 at a film thickness of 650 nm to 7.73 × 1018 cm−3 at a film thickness of 80 nm. This work warns that while decreasing the film thickness is of practical importance to reduce the ASE threshold pump current, e.g. in electrically driven light‐emitting diodes, the solution processing of perovskites, newly re‐discovered for their potential photonic and photovoltaic applications, can be a restraining factor. Band gap renormalisation (BGR) is also observed in the prepared films as a redshift in the ASE peak with increasing the pump power, and the BGR coefficient is estimated to be ∼ 6.3 × 10−8 eV cm.
Application of Doppler beam sharpening for azimuth refinement in prospective low‐THz automotive radars
Authors: Daniel Liam , Stove Andrew , Hoare Edward , Phippen Dominic , Cherniakov Mike , Mulgrew Bernie , Gashinova Marina
Published: August 2018

In this study, the authors investigate the application of the Doppler beam sharpening (DBS) technique for angular refinement to the emerging area of low‐terahertz (THz) radar sensing. Ultimately this is to improve radar image quality in the azimuth plane to complement the excellent range resolution and thus improve object classification in low‐THz radar imaging systems for autonomous platforms. The study explains the fundamental theory behind the process of DBS and describes the applicability of DBS to automotive sensing, indicating the potential for synthetic beamwidths of a fraction of a degree. Low‐THz DBS was experimentally tested under controlled laboratory conditions, not only to accurately localised target objects in Cartesian space but also to provide unique object imaging at low‐THz frequencies with wide azimuthal beamwidth antennas. It was shown that a stationary (i.e. non‐scanned) wide beam antenna mounted on a moving platform can deliver imagery at least comparable to that produced by physical beamforming, be that steering arrays or narrow beam scanning antennas as in the experimental case presented.
Surface‐modified quantity of Fe3O4 particles by thermogravimetric analysis
Authors: Yao Lihui , Wang Yajuan , Li Ya , Duan Jingkuan
Published: August 2018

Different Fe3O4 particles are synthesised with silane and carboxylic acid, surface modified by co‐precipitation, and subsequently are characterised by Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction, laser particle size analyser (LPSA) and thermogravimetric analyser (TG). Based on the LPSA results, Fe3O4 particles are micrometre size due to the experimental condition and modifiers. It is therefore suggested that the vacuum freeze‐drying and the long‐chain modifiers tend to obtain small size particles. The modifiers density on the surface of Fe3O4 particles is obtained by TG and formula calculation. It is shown that the silane coupling agent is more effective modifier for Fe3O4 particles compared with carboxylic acid. In accordance with the molecular structure and functional group number of carboxylic acids, different carboxylic acids have different modifiers density.
A state of the art survey of data mining-based fraud detection and credit scoring
Authors: Zhou Xun , Cheng Sicong , Zhu Meng , Guo Chengkun , Zhou Sida , Xu Peng , Xue Zhenghua , Zhang Weishi
Published: August 2018

Credit risk has been a widespread and deep penetrating problem for centuries, but not until various credit derivatives and products were developed and novel technologies began radically changing the human society, have fraud detection, credit scoring and other risk management systems become so important not only to some specific firms, but to industries and governments worldwide. Frauds and unpredictable defaults cost billions of dollars each year, thus, forcing financial institutions to continuously improve their systems for loss reduction. In the past twenty years, amounts of studies have proposed the use of data mining techniques to detect frauds, score credits and manage risks, but issues such as data selection, algorithm design, and hyperparameter optimization affect the perceived ability of the proposed solutions and it is difficult for auditors and researchers to explore and figure out the highest level of general development in this area. In this survey we focus on a state of the art survey of recently developed data mining techniques for fraud detection and credit scoring. Several outstanding experiments are recorded and highlighted, and the corresponding techniques, which are mostly based on supervised learning algorithms, unsupervised learning algorithms, semisupervised algorithms, ensemble learning, transfer learning, or some hybrid ideas are explained and analysed. The goal of this paper is to provide a dense review of up-to-date techniques for fraud detection and credit scoring, a general analysis on the results achieved and upcoming challenges for further researches.
E-sports analysis data acquisition algorithm based on convolutional neural network
Authors: Li Liulei , Zhu Wanning , Yu Cheng , Nong Liqing
Published: August 2018

At present, e-sports has become one of the most important industries. How to analyze e-sports data has become an urgent problem to be solved. Currently, some hot competition items do not provide data interfaces, so that the training set required for data analysis cannot be directly and accurately acquired. Data can only be obtained by watching video games in person. This method is obviously inefficient and the accuracy cannot be guaranteed. This paper proposes a data acquisition algorithm based on convolutional neural network algorithm. It also introduces transfer learning, improves the sample training method and data acquisition method, and finally solves the problem of data acquisition. According to the test, this algorithm achieves about 91% accuracy.
From cloud computing to fog computing in Healthcare big data
Authors: Malik Babur Hayat , Mahmood Faisal , Shahzad Sohail , Arif Muhammad Bilawal , Khan Waseem Ur Rehman , Ilyas Sadaf , Hassan Muhammad
Published: August 2018

In Healthcare big data, data is originated from various heterogeneous sources. Numerous novel base particular healthcare applications offered to handling source of data from electronic health record (EHR) to medical images. Imaging, Electronic Health Report, technology in light of sensor and numerous different procedures created an immense measure of Healthcare data. Cloud computing development was an excellent paradigm to substantiate big data which incited find of imperceptible examples. Cloud computing is a developing new registering design intended to answer different contending administrations on the Web. Fog Computing is a design style in which arrange segments amongst devices and the cloud execute application-particular rationale. We in this paper investigate, characterize, and talk about various application of cloud and fog computing. We talk about the impact of cloud computing and fog computing on healthcare big data. Cloud base framework for Homediagnosis Service, Fog computing architecture and the justification of moving from cloud to Fog presented comprehensively in this paper.
Image classification model based on spark and CNN
Authors: Xu Jiangfeng , Ma Shenyue
Published: August 2018

Convolution neural network is a commonly used image classification model, but when the network nodes of the training process are too many, it will have a great influence on the training complexity. At the same time, when the size of the image data is large, many problems will appear on the single node, such as convergence slowly, frequently disk reading and writing. In order to overcome the above problems, this paper proposes a distributed convolution neural network based on Spark (Distribution Convolution neural network, Dis-CNN) model. The model first improves the initialization mode of convolution kernel parameters, then eliminates the redundancy of feature maps, and finally optimizes the distributed gradient descent by reducing the synchronous traffic between master and slave, so as to improve the convergence speed and performance. The experimental results show that the model not only improves the accuracy and recall of image classification, but also performs excellent in parallelism.
A collaborative caching strategy in contentcentric networking
Authors: Hu Qing , Li Chengming , Hasan Touhidul , Li Chengjun , Jiang Qingshan
Published: August 2018

Content-centric Networking (CCN) is one of the most promising network architectures for the future Internet. In-network caching is an attractive feature of CCN, however, the existing research does not consider the off-path nodes, or gives a large communication overhead for cooperation, which makes the caching utilization lower, and hard to achieve comprehensive performance optimization. To reduce the data redundancy and improve the caching utilization, we propose a Regional Hashing Collaborative Caching Strategy (RHCCS). According to calculate the importance of nodes in the network topology, we divide the network into the core area and edge area. In core area, we select the relevant nodes for cooperation, store the block in the off-path nodes with the hashing algorithm, and add a new table in original data structures for routing in the collaborative areas. As for edge area, we deploy the on-path reversion scheme. By simulating in ndnSIM and comparing with the basic caching strategy in CCN, experimental results indicate that the RHCCS can effectively reduce data redundancy, routing hops, requesting delay, and significantly increase the hit rate.
An image dehazing algorithm based on double priors constraint
Authors: Liu Kun , Wang Shiping , He Linyuan , Bi Duyan , Gao Shan
Published: August 2018

Aiming at the color distortion of the restored image in the sky region, we propose an image dehazing algorithm based on double priors constraint. Firstly, we divided the haze image into sky and non-sky regions. Then the Color-lines prior and dark channel prior are used for estimating the transmission of sky and non-sky regions respectively. After introducing color-lines prior to correct sky regions restored by the dark channel prior, we get an accurate transmission. Finally, the local media mean value and standard deviation are used to refine the transmission to obtain the dehazing image. Experimental results show that the algorithm has obvious advantages in the recovery of the sky area.
Crashworthiness optimization of bionic bumper structure under low-speed impact
Authors: Xu Tao , Liu Nian , Tian Yuan , Xu Tianshuang , Zhang Tianyi , Yu Zhenglei , Li Yiwen
Published: August 2018

By considering the crashworthiness design of bionic bumper structure during frontal impact, the thicknesses are chosen to analysis and optimal design to obtain the lightweight demand. The orthogonal experiment design and radial basis function are employed to construct the response surface for the performances of thin-xwalled components. The multi-objective cuckoo search (MOCS) is applied to perform the optimal design. The results demonstrate that the optimal method and process proposed have high accuracy and validity.
Automatic summarization of medical interviews
Authors: Qiang Jipeng
Published: August 2018

Abstract. The genomic-based targeted therapy (Crizotinib) has been emerged as an alternative option for the treatment of patients with locally advanced or metastatic non-small cell lung cancer, comprising the 85\% of lung cancer. However, Crizotinib is not listed in VA drug formulary- and is not available for VA oncologists to treat lung cancer currently. Therefore, for understanding physicians’ views on using genomic services, semi-structured interviews were collected. In this paper, we will present an innovative method to extract summarization from medical interviews automatically. Different from keyword-based method, automatic summarization can help to understand the intention of physicians. Compared with the existing summarization methods, our work is based on latent Dirichlet allocation and recent results m word embeddings that learn seinantically meaningful representations for words from local cooccurrences in sentences. Experiments on medical interviews demonstrate that the proposed algorithm achieves good results compared with a gold standard file using manual extraction technique.
Demand analysis on the performance of shipboard alert unmanned aerial vehicles
Authors: Zhao Shufan , Shi Liming , Qu Qingbo , Zhu Feixiang , Yang Xinyi
Published: August 2018

Shipboard alert unmanned aerial vehicles (UAV) has great significance to improve early warning detection capability of aircraft carrier formation. This paper first analyzes and summarizes the tactical and technical indicators of the carrier-based air early warning(AEW), then analyzes the tactical and technical indicators of the UAV refer to technical performance of early warning aircraft, and finally determines the performance indicators of the UAV. Its anterior distance is 400km, the stable working height is 9000m, the maximum level flight speed is 670km/h, and flying time in the mission area is more than 6 hours. It provides a reference for the future test of UAV.
Formation control of UAVs based on artificial potential field
Authors: Lv Yongshen , Yang Xuerong , Yang Yajun , Pan Shengdong , Xin Chaojun
Published: August 2018

The problem of UAVs’ formation control in the process of motion is investigated in this paper. A formation control method based on artificial potential field of UAVs is proposed, established on the collision avoidance, aggregation and speed matching rules of UAVs. First establish the UAVs’ kinetic model in accordance to the motion rules, then design the formation control algorithm based on artificial potential field function, which is used to control the formation during the movement of UAVs. Finally, the results of simulation experiment show that the proposed formation control method in this paper is effective and has the advantages of easy realization, good real-time performance and excellent robustness.
Analyze the driving module of spiral robot by FEA and genetic algorithm
Authors: FENG Xi-guang , ZHAO Yu-xia , DI Jie-jian , ZHAO Quan-liang
Published: August 2018

The existing whip tail drive size parameter is obtained in the prototype a number of orthogonal experiments to obtain a value. In this paper, a new method is proposed. According to the resistance theory, a propulsive force calculation model is established, and then the local optimal solution is obtained through the combination of finite element method and genetic algorithm. The calculation is small and the thinking is clear. The obtained parameters are of reference to the prototype experiment.
Research on stock similarity and community division based on user attention sequence
Authors: Zhang Gaowei , Xu Lingyu , Wang Lei
Published: August 2018

We conduct research from the perspective of user groups and analyze the differences in the users' attention and posting order in different time periods to vectorize stocks and build relationships from the generatedx vectors. This provides a new perspective for the complex network cconstruction and community division of network public opinion space. The experiment result show that we can get the community division consistent with reality using our model.
Analysis of influencing factors of civil aviation passenger volume in multi airport area: case study on Yangtze River Delta
Authors: HONG Zhen , WEI Wei
Published: August 2018

In order to analyse the main influencing factors of civil aviation passenger transport volume in multi Airport area. Correlation analysis, stepwise linear regression analysis and Grainger causality test were used to analyse the influence factors of civil aviation passenger traffic volume, to eliminate the invalid factors, a regression model is established to analyse the causal relationship between the various factors and air passenger volume. Through the analysis of the Yangtze River Delta region, it is concluded that the number of inbound tourists, the railway mileage and the volume of railway passenger transport are the main factors affecting the Yangtze River Delta region. Through the Grainger causality test, the air passenger volume of the Yangtze River Delta has one-way influence on the railway passenger traffic volume.
Update Augenheilkunde – Amblyopie und Refraktionsfehler
Authors: Joachimsen Lutz , Gross Nikolai , Lagrèze Wolf
Published: August 2018

Der folgende Beitrag stellt zwei aktuelle Themen der Kinderophthalmologie in den Fokus, die vermutlich auch immer wieder in der kinder- und jugendärztlichen Praxis relevant sein werden: die Amblyopie und ihre Früherkennung inklusive Videorefraktometrie und Refraktionsfehler im Schulkindalter mit Fokus auf Myopie, deren Häufigkeit weltweit zunimmt
Peripher exsudative hämorrhagische Chorioretinopathie: Krankheitsverlauf, Diagnosestellung inklusive Weitwinkelbildgebung der assoziierten Erkrankungen altersabhängige Makuladegeneration und polypoidale Choriovaskulopathie, Therapie
Authors: Seibel Ira , Nürnberg Daniela , Löwen Julia , Winterhalter Sibylle , Zeitz Oliver , Joussen Antonia
Published: August 2018

Die PEHCR (peripher exsudative hämorrhagische Chorioretinopathie) ist eine Erkrankung, die sich klinisch besonders durch subretinale Blutungen, retinale Exsudate, retinale Pigmentepithelabhebungen (RPE-Abhebungen), exsudative Ablatio und Sub-RPE-Blutungen manifestiert. Die PEHCR-Läsion ist oft durch ihr polypoidales Muster charakterisiert, welches den Polypen der PCV (polypoidale Choriovaskulopathie) sehr ähnelt. Die Diagnosestellung erfolgt am besten mit einer Weitwinkel-ICGA (ICGA: Indocyaningrünangiografie). Bei ca. der Hälfte der Patienten werden am betroffenen Auge oder am Partnerauge makuläre Veränderungen in Form von Drusen bis hin zur exsudativen AMD (altersabhängigen Makuladegeneration) detektiert. Da es direkt zur PEHCR nur sehr wenig Literatur gibt, werden in dieser Arbeit zudem die im Rahmen der AMD beschriebenen peripheren Veränderungen, die mit Weitwinkelbildgebung untersucht wurden, diskutiert.
Dual Chronic Ossified Epidural Hematomas Presented with Seizures 23 Years after Head Injury in an Adult Male: Case Report and Literature Review
Authors: Agrawal Vivek , Giri Pramod
Published: August 2018

The authors report a rare case of dual chronic ossified epidural hematomas (EDHs) in a 35-year-old man with complaint of seizures after 23 years of head injury. Ossified EDH is a rare entity, and it commonly presents in pediatric age group. Presenting symptoms include headache and very rarely seizures. Asymptomatic cases may produce symptoms after decades; hence, regular follow-up is required. Treatment includes craniotomy or conservative management.
Acute Lower Gastrointestinal Hemorrhage
Authors: Pietrini Sean , Fitzgerald Zachary , Kogut Matthew , Shin David
Published: August 2018

Acute lower gastrointestinal (GI) hemorrhage is a potentially life-threatening event, which requires efficient work-up and effective management. Interventional radiology has an indispensable role in treatment of this serious condition. We review the major causes of acute lower GI bleeding in adults, available diagnostic modalities, and endovascular interventions.
Revisiting La2MMnO6 (M = Co, Ni, Cu, Zn) perovskites in view of 3d-electron configuration
Authors: Guo Lin , Bai Yijia , Huang Chunming , Ma Wenlu
Published: August 2018

We investigate the impact of 3d-electron configuration on the magnetic and DC conductive properties of La2MMnO6 (M = Co, Ni, Cu, Zn) and offer evidence to an enhanced ionic ordering degree with the increase in the 3d electron number of an M ion. A key role of the 3d electronic configuration that influences the B-site ionic arrangement is revealed by changing both the ionic radii and bond covalency. The position of the valence band edge is shifted away from the Fermi level with the increase in 3d electrons, which reveals a strengthened electron localization behavior. Magnetic characterization indicates that the Co, Ni, and Zn samples present magnetic behaviors with half- and full-filled eg configurations, whereas the Cu sample shows a special Jahn-Teller configuration (t2g6eg3), giving rise to the degenerated eg states and significant change in bond parameters. Consequently, the Goodenough-Kanamori rules are not followed and the ferromagnetic coupling is weakened greatly. Further, DC resistivity measurements of samples M = Co, Ni, and Zn present thermally activated conductive behavior, in good accordance with the position shift of valence band edge. However, due to the Jahn-Teller effect arising from Cu2+ ion, a strong electron-phonon coupling is evidenced. This effect provides a suitable hopping channel for small polarons resulting in a considerable rise of its conductivity. Such changes in magnetization and DC conductivity of La2MMnO6 perovskites by modulating the M elements would inspire us to develop novel spin-electronic devices.
Analytic modeling of conductively anisotropic neural tissue
Authors: Schwartz Benjamin L. , Chauhan Munish , Sadleir Rosalind J.
Published: August 2018

The abdominal ganglion of the Aplysia californica is an established in vitro model for studying neuroelectric behavior in the presence of an applied electrical current and recently used in studies of magnetic resonance electrical impedance tomography (MREIT) which allows for quantitative visualization of spatially distributed current and magnetic flux densities. Understanding the impact the Aplysia geometry and anisotropic conductivity have on applied electromagnetic fields is central to intepreting and refining MREIT data and protocols, respectively. Here we present a simplified bidomain model of an in vitro experimental preparation of the Aplysia abdominal ganglion, describing the tissue as a radially anisotropic sphere with equal anisotropy ratios, i.e., where radial conductivities in both intra- and extra-cellular regions are ten times that of their polar and azimuthal conductivities. The fully three dimensional problem is validated through comparisons with limiting examples of 2D isotropic analyses. Results may be useful in validating finite element models of MREIT experiments and have broader relevance to analysis of MREIT data obtained from complex neural architecture in the human brain.
Wear of diamond in scribing of multi-crystalline silicon
Authors: Kumar Arkadeep , Melkote Shreyes N.
Published: August 2018

A practical challenge in slicing of low-cost multi-crystalline silicon (mc-Si) wafers by the fixed abrasive diamond wire sawing process is increased wire consumption due to greater wear of the diamond compared to slicing of the more expensive mono-crystalline silicon (mono-Si) wafers. In this paper, we present the results of scribing of mc-Si and mono-Si materials with two conical tip diamond indenters of the same geometry to understand the possible reasons for increased diamond wear in cutting of multi-crystalline silicon. Specifically, the scribing forces and the diamond indenter wear produced in scribing of the two silicon materials are analyzed. The results show that the forces generated in scribing of mc-Si are higher than in scribing of mono-Si. The higher forces in scribing of mc-Si are consistent with the corresponding higher tip radius of curvature (due to wear) of the diamond indenter compared to the tip radius produced in scribing of mono-Si. Scanning electron microscopy and confocal microscopy of the diamond indenters show that wear is primarily due to physical micro-fracture and blunting of the diamond. Raman spectroscopy shows evidence of stress-induced phase transformation of the diamond and the formation of compressive residual stress in the diamond. Plausible physical reasons, including the role of material inhomogeneity in mc-Si, for the wear of diamond during scribing are given.
A comparative study of individual influences of suspended multiwalled carbon nanotubes and alumina nanoparticles on Rayleigh-Bénard convection in water
Authors: C Kanchana , Zhao Yi , Siddheshwar P. G.
Published: August 2018

The generalized Lorenz model for studying the Rayleigh-Bénard convection in water-multiwalled carbon nanotubes and water-alumina in the presence of heat source/sink is derived using a tri-modal, Fourier series representation under the assumption of the Boussinesq approximation and small-scale convective motion. On the premise that the multiwalled carbon nanotubes/alumina nanoparticles undergo all motions which water particles undergo the single-phase description of the Khanafer-Vafai-Lightstone model can be adopted. The thermophysical properties of the two nanoliquids are calculated using the phenomenological laws and traditional mixture theory. The transition of the dynamical Lorenz system from stability to chaos followed by periodic motion in a window of periodicity and then a sequence of such motions are explained in detail by calculating the maximum Lyapunov exponent. Specifically, the individual effect of multiwalled carbon nanotubes and alumina nanoparticles on the stability of the dynamical system is investigated from a new perspective of time series solution and attractors of the Lorenz model. We then study the individual influence of multiwalled carbon nanotubes and alumina nanoparticles on the onset of convection and heat transport. The findings of a feasibility study indicate that less expensive spherical alumina nanoparticles are preferable in heat transfer applications over the more expensive multiwalled carbon nanotubes, in spite of the latter having a larger surface area and higher thermal conductivity. It is found that exactly the same amount of heat transfer obtained by using multiwalled carbon nanotubes can be achieved by replacing them with a slightly higher volume fraction of the much cheaper alumina nanoparticles.
Dielectric properties and resistive switching characteristics of lead zirconate titanate/hafnia heterostructures
Authors: Espinal Y. , Alpay S. P. , Howard M. , Hanrahan B. M.
Published: August 2018

We report the dielectric response and resistive switching properties of bilayers of PbZr0.40Ti0.60O3 [PZT (40:60)] and HfO2 of varying thickness on platinized Si substrates. PZT (40:60) and HfO2 films were grown using chemical solution deposition and atomic layer deposition, respectively. We show here that the addition of an interposed linear dielectric layer with a high permittivity between the ferroelectric film and the top electrode modifies the polarization and resistive switching characteristics of the multilayer stack. We observe an increase in the coercive field by 45% for PZT films of 250 nm thickness with a 20 nm HfO2 layer compared to 250 nm thick PZT films grown under identical conditions. Simultaneously, the dielectric constant decreases by 43% from 409 to 175 for a 250 nm PZT film with 20 nm HfO2, accompanied by a significant improvement in the leakage current density from 5.6 × 10−4 A/cm2 to 8.7 × 10−8 A/cm2. Our resistance measurements show that there are two separate resistance states that are accessible with at least an order of magnitude in resistance difference from 5 × 108 to 5 × 109 Ω. We show that the dielectric response and the coercivity of the bilayer system can be explained by a capacitors-in-series model. This indicates that the PZT and the HfO2 layer could effectively be considered decoupled, presumably due to bound/trapped charges at the interlayer interface. This charged ferroelectric/dielectric interface could be the reason for the intermediate resistance states which could be used as multistate resistive memories in neuromorphic computing applications.
Comparison of image properties in full-field phase X-ray microscopes based on grating interferometry and Zernike's phase contrast optics
Authors: Takano Hidekazu , Wu Yanlin , Irwin Jeff , Maderych Stan , Leibowitz Marty , Tkachuk Andrei , Kumar Arjun , Hornberger Benjamin , Momose Atsushi
Published: August 2018

A grating interferometer (GI) system has been installed in an X-ray microscope equipped with a Zernike phase contrast (ZPC) system and a Cu rotating anode X-ray source. The GI and ZPC systems are switchable, and their performances of phase information extraction have been compared. The GI system is based on a Lau interferometer consisting of an absorption grating and a π/2 phase grating, which extracts a magnified phase shift map of a sample via a phase-stepping measurement. The ZPC system generates a phase contrast image by using a phase plate and a corresponding condenser device. The ZPC system and the GI system are compared in terms of detectability of phase objects. By the Fourier analysis of images of a logarithmic ruler pattern, the spatial resolution was found to be identical between the two systems. Although the sensitivity depends on the sample size, the signal-to-noise ratio of polystyrene spheres with a few microns in diameter was used for sensitivity comparison, showing the superior sensitivity of the GI system to that of the ZPC system. The quantitativeness of the GI system with the phase-stepping measurement was also demonstrated over the ZPC system, which generates halo and shade-off artifacts. The GI system exhibits twin image artifacts that need to be resolved for practical applications of the technique.
Inverse magnetostrictive stress sensors based on crossed pinned CoFeB/MgO/CoFeB tunnel junctions
Authors: Dohmeier Niklas , Tavassolizadeh Ali , Rott Karsten , Quandt Eckhard , Meyners Dirk , Reiss Günter
Published: August 2018

The usage of double pinned magnetic CoFeB/MgO/CoFeB tunnel junctions with noncollinear magnetizations as sensors of mechanical stress is shown. For this purpose, tunnel magnetoresistive (TMR) stacks with MnIr based pinning of both electrodes have been prepared. By using different MnIr thicknesses, we were able to realize noncollinear magnetizations. A series of annealing steps with a field perpendicular to the initial exchange bias direction have been performed in order to find the optimum thermal treatment for the best performance of the sensors. On these systems, bending experiments were completed which, show the suitability of our double-pinned TMR elements as stress sensors and their performance in differentiating tensile and compressive stress.
First experimental tests of powerful 250 GHz gyrotron for future fusion research and collective Thomson scattering diagnostics
Authors: Denisov G. G. , Glyavin M. Yu. , Fokin A. P. , Kuftin A. N. , Tsvetkov A. I. , Sedov A. S. , Soluyanova E. A. , Bakulin M. I. , Sokolov E. V. , Tai E. M. , Morozkin M. V. , Proyavin M. D. , Zapevalov V. E.
Published: August 2018

A 250 GHz continuous-wave (CW) gyrotron has been developed at the IAP RAS jointly with GYCOM Ltd., as a prototype of the microwave source for the envisaged prospective nuclear fusion power plants (DEMO). The main applications of such a tube are electron cyclotron resonance heating and electron cyclotron resonance current drive of magnetically confined plasma as well as its diagnostics based on collective Thomson scattering in various reactors for controlled thermonuclear fusion (e.g., tokamaks and stellarators). The results of the preliminary experimental tests in a pulsed mode of operation are presented. The microwave power of up to 330 kW with an efficiency of 30% without collector depression was obtained. At an accelerating voltage of 55 kV and an electron beam current of 12.5 A (which corresponds to the design parameters for CW operation), the measured output power was about 200 kW. The TEM00 mode content evaluated at the tube output is not less than 98.6%.
An alternative explanation for the density depletions observed by Freja and Viking satellites
Authors: Shah K. H. , Qureshi M. N. S. , Masood W. , Shah H. A.
Published: August 2018

In this paper, we have studied the linear and nonlinear propagation of ion acoustic waves in the presence of electrons that follow the generalized (r,q) distribution. It has been shown that for positive values of r, which correspond to a flat-topped electron velocity distribution, the nonlinear ion acoustic waves admit rarefactive solitary structures or density depletions. It has been shown that the generalized (r,q) distribution function provides another way to explicate the density depletions observed by Freja and Viking satellites previously explained by proposing Cairns distribution function.
Spectral, magneto-optical and thermo-optical properties of terbium containing cubic zirconia crystal
Authors: Mironov E. A. , Palashov O. V.
Published: August 2018

This letter presents the investigation of magneto-active media based on a cubic zirconia crystal. We studied spectral, magneto-optical and thermo-optical characteristics of a terbium containing cubic zirconia (TCZ) crystal aiming to estimate its applicability in magneto-optic applications. This crystal has significant advantages over the popular TGG crystal. The value of its Verdet constant for the radiation at the wavelength of 1075 nm is 31% higher than that of a TGG crystal. The value of the absorption coefficient is rather small and typical for commercially available TGG crystals. Its transmission spectrum is typical for terbium containing magneto-active media. The dispersion dependence of the Verdet constant had been measured for visible and near-IR ranges and presented in this paper. The optical anisotropy parameter which shows the distribution of orientations of the axes of thermally induced birefringence in a thermally loaded optical element had also been determined. Unlike a TGG crystal, the optical anisotropy parameter of a TCZ crystal is negative, which means that there exists a dedicated orientation of crystallographic axes, at which the axes of thermally induced birefringence are arranged in one direction and thermally induced depolarization may be reduced substantially. Such a combination of characteristics makes the TCZ crystal a very promising material for magneto-optical applications, for example, for creating Faraday isolators, including those with a high maximum permissible operating power.
Terahertz metamaterial perfect absorber with continuously tunable air spacer layer
Authors: Schalch Jacob , Duan Guangwu , Zhao Xiaoguang , Zhang Xin , Averitt Richard D.
Published: August 2018

We present a comprehensive investigation of a continuously tunable metamaterial perfect absorber operating at terahertz frequencies. In particular, we investigate a three-layer absorber structure consisting of a layer of split ring resonators and a metallic ground plane, with a central layer consisting of a mechanically tunable air-spaced layer. The absorber was characterized using terahertz time-domain spectroscopy in reflection (at normal incidence) as a function of spacer thickness from 0 to 1000 μm. Our experimental measurements reveal the detailed evolution of the absorption bands as a function of spacing, in excellent agreement with analysis using interference theory and simulation. Our Fabry-Pérot-like structure provides an avenue for achieving massive tunability in metamaterial absorber devices.
Quantifying entropy using recurrence matrix microstates
Authors: Corso Gilberto , Prado Thiago de Lima , Lima Gustavo Zampier dos Santos , Kurths Jürgen , Lopes Sergio Roberto
Published: August 2018

We conceive a new recurrence quantifier for time series based on the concept of information entropy, in which the probabilities are associated with the presence of microstates defined on the recurrence matrix as small binary submatrices. The new methodology to compute the entropy of a time series has advantages compared to the traditional entropies defined in the literature, namely, a good correlation with the maximum Lyapunov exponent of the system and a weak dependence on the vicinity threshold parameter. Furthermore, the new method works adequately even for small segments of data, bringing consistent results for short and long time series. In a case where long time series are available, the new methodology can be employed to obtain high precision results since it does not demand large computational times related to the analysis of the entire time series or recurrence matrices, as is the case of other traditional entropy quantifiers. The method is applied to discrete and continuous systems.
Quasi-static asymmetric magnetization for hemisphere structure
Authors: Zhao Rongzhi , Chen Wenchao , Zhang Xuefeng
Published: August 2018

Understanding the dynamic magnetization for nanoscale structures has been attracting considerable attention; however, it is extremely limited to uncover such a behavior due to the difficulty in experimentally observing the fast magnetization states. Herein, we theoretically demonstrate in-plane magnetization processes of spherical and hemispherical structures with a diameter of 50 nm by using micromagnetic simulation, presenting symmetrical and asymmetrical vortex structures, respectively. It is emphasized that such an asymmetrical vortex structure is only presented in a quasi-static magnetization state when the external field is at nearly 23 mT along with the symmetric axis. This is associated with an instantaneous evolution from the S-shaped vortex to the C-shaped vortex, ascribed to the lower demagnetization energy for the hemisphere structure compared with that for the sphere structure. The present study could thus open up an insight for designing irregular magnetic structures and understanding the nanoscale magnetic behaviors.