bluuebunny/crossref_metadata_2025 huggingface dataset:
Seeking large Seebeck effects in LaX(X = Mn and Co)O3/SrTiO3 superlattices by exploiting high spin-polarized effects
Authors: Li Jingyu , Wang Yuanxu , Zhang Guangbiao , Yin Huabing , Chen Dong , Sun Wei , Shi Beibei , Cheng Zhenxiang
Published: June 2019

SrTiO3-based transition-metal oxide heterostructures with superconducting, ferromagnetic, ferroelectric, and ferroelastic properties exhibit high application potential in the fields of energy storage, energy conversion, and spintronic devices.
Effect of toxic ligands on O2binding to heme and their toxicity mechanism
Authors: Li Renyi , Dai Xianqi , Feng Zhen , Li Yi , Zhao Mingyu , Liu Jing , Li Huiting , Chen Yang , Ma Yaqiang , Tang Yanan
Published: June 2019

Heme, as the cofactor and active site of Hb, enables Hb to carry out the necessary function required for O2management for life, that is, reversible O2binding for transport.
Theory and practice of modeling van der Waals interactions in electronic-structure calculations
Authors: Stöhr Martin , Van Voorhis Troy , Tkatchenko Alexandre
Published: June 2019

Opening the black box of van der Waals-inclusive electronic structure calculations: a tutorial-style introduction to van der Waals dispersion interactions, state-of-the-art methods in computational modeling and complementary experimental techniques.
Structural variation of transition metal–organic frameworks using deep eutectic solvents with different hydrogen bond donors
Authors: Zhao Ming-Yu , Zhu Jian-Nan , Li Peng , Li Wei , Cai Ting , Cheng Fang-Fang , Xiong Wei-Wei
Published: June 2019

Seven transition metal–organic frameworks with structures ranging from one-dimensional chains to three-dimensional networks have been synthesized in deep eutectic solvents.
MOF derived CoP-decorated nitrogen-doped carbon polyhedrons/reduced graphene oxide composites for high performance supercapacitors
Authors: Zhu Jun , Shen Xiaoping , Kong Lirong , Zhu Guoxing , Ji Zhenyuan , Xu Keqiang , Li Baolong , Zhou Hu , Yue Xiaoyang
Published: June 2019

A CoP-NPC/RGO composite prepared through an efficient pyrolysis–phosphidation–assembly strategy exhibits an enhanced electrochemical performance.
Polyoxometalate-based metallogels as anode materials for lithium ion batteries
Authors: Meng Xing , Wang Hai-Ning , Zou Yan-Hong , Wang Lu-Song , Zhou Zi-Yan
Published: June 2019

POM-based metallogels are employed as anode materials for the first time, which exhibit high reversible capacity, high rate capability, and good cycling stability.
Reunderstanding the photoinduced charge transfer process of ammonium polyoxomolybdate
Authors: Li Li , Hua Yang , Li Xiao-Nan , Guo Yu , Zhang Hong
Published: June 2019

Protonation of 4-phenylpyridine can realize photoinduced electron transfer from the carboxyl group to 4-phenylpyridine and photochromism of ammonium polyoxomolybdate without proton transfer.
Effects of interesterified lipid design on the short/medium chain fatty acid hydrolysis rate and extent (in vitro)
Authors: Acquistapace Simone , Patel Leena , Patin Amaury , Forbes-Blom Elizabeth , Cuenoud Bernard , Wooster Tim J.
Published: June 2019

Short/medium chain fatty acids have well known health effects such as gut immune regulation and ketogenesis.
Automatic oxidation threshold recognition of XAFS data using supervised machine learning
Authors: Miyazato Itsuki , Takahashi Lauren , Takahashi Keisuke
Published: June 2019

Oxidation states of materials are characterized by the X-ray absorption near edge structure (XANES) region in X-ray absorption spectroscopy (XAS).
Proteomic response of marine-derived Staphylococcus cohnii #NIOSBK35 to varying Cr(vi) concentrations
Authors: Shah Shruti , Damare Samir
Published: June 2019

Chromium in its hexavalent state is a water-soluble and toxic element to living organisms present in the environment. However, some organisms are resistant and reduce the toxic forms of Cr(vi) to less toxic or non-toxic forms. A global proteomic analysis of Staphylococcus sp. #NIOSBK35 under different chromate concentrations (0, 100, 200 and 300 mg L−1) at different time points in its growth stages (6, 9, 12, 18, 24 and 36 h) resulted in the identification of 878 proteins. Of all the proteins expressed, 13 proteins [23 rDNA (uracil-5-) methyltransferase RumA, multidrug ABC transporter ATP binding protein, dihydroxy acid dehydratase, polysaccharide biosynthesis protein, etc.] were expressed only in the presence of chromium. 14 proteins were up-regulated in response to chromium(vi), namely, alkyl hydroperoxide reductase, ATP-dependent Zn metallopeptidase, hsp90- like protein, NAD (P)-dependent oxidoreductase, etc. Most of the proteins involved in normal cell functioning like 1-pyrroline-5-carboxylate dehydrogenase, ribosomal proteins (30S ribosomal protein S11, 30S ribosomal protein S2, and 50S ribosomal protein L32), aconitate hydratase, DNA primase, serine-tRNA ligase, phosphoenolpyruvate-protein phosphotransferase, enolase, sulfur transferase FdhD, etc. were found to be down-regulated. On grouping these proteins into their COG (cluster of orthologous groups) functional categories, they were found to be involved in translation, carbohydrate metabolism, stress proteins, amino acid transport and membrane transport mechanisms. The proteomic response given by Staphylococcus sp. #NIOSBK35 did not show expression of Cr-specific proteins, indicating a different mechanism of Cr-tolerance as the organism was able to survive and grow at high concentrations of Cr(vi).
Reaction of imidazoline-2-selone derivatives with mesityltellurenyl iodide: a unique example of a 3c-4e Se→Te←Se three-body system embedding a tellurenyl cation
Authors: Aragoni M. Carla , Arca Massimiliano , Blake Alexander J. , Cadoni Enzo , Copolovici Lucian O. , Isaia Francesco , Lippolis Vito , Murgia Sergio , Pop Alexandra M. , Silvestru Cristian , Tidey Jeremiah P. , Varga Richard A.
Published: June 2019

1,2-Bis(3-methyl-4-imidazolin-2-selone)ethane was used to stabilize the first example of an authentic mesityltellurenyl cation, [MesTe]+, as a charge transfer adduct featuring a 3c-4e Se→Te←Se three-body system.
Ni–Fe hybrid nanocubes: an efficient electrocatalyst for non-enzymatic glucose sensing with a wide detection range
Authors: Bao Cancan , Niu Qiangqiang , Cao Xiaowei , Liu Chang , Wang Hui , Lu Wenbo
Published: June 2019

A sensor for the determination of glucose is developed based on Ni–Fe hybrid nanocubes, which exhibit excellent sensing performance.
A concise Friedländer/Buchwald–Hartwig approach to the total synthesis of quindoline, a bioactive natural indoloquinoline alkaloid, and toward the unnatural 10-methylquindoline
Authors: Méndez María V. , Simonetti Sebastian O. , Kaufman Teodoro S. , Bracca Andrea B. J.
Published: June 2019

Friedländer and Buchwald–Hartwig reactions were used to achieve an efficient total synthesis of quindoline and a new synthesis of the unnatural 10-methylquindoline. DFT calculations were employed to explain the outcome of a failed key transformation.
Mixed dysprosium-lanthanide nitride clusterfullerenes DyM2N@C80-Ihand Dy2MN@C80-Ih(M = Gd, Er, Tm, and Lu): synthesis, molecular structure, and quantum motion of the endohedral nitrogen atom
Authors: Schlesier C. , Liu F. , Dubrovin V. , Spree L. , Büchner B. , Avdoshenko S. M. , Popov A. A.
Published: June 2019

The impact of the second metal on the synthesis and molecular structure of Dy–M nitride clusterfullerenes (M = Gd, Er, Tm, Lu) is evaluated systematically.
Effect of soluble sulfur species on the electrochemical behavior of lithium–sulfur batteries with dual-phase electrolytes
Authors: Zhao Chengcheng , Yang Hao , Wang Xiaofei , Li Huilan , Qi Chu , Wang Lina , Liu Tianxi
Published: June 2019

We report a Li–S system with dual-phase electrolytes by taking advantage of the highly soluble lithium polysulfides (Li2Sn, 2 < n ≤ 8), and it shows an improved reaction kinetics associated with a low interfacial charge transfer resistance.
Nitration-induced ubiquitination and degradation control quality of ERK1
Authors: Zhang Yuanya , Huang Xiahe , Wang Jinlong , Wang Xiaorong , Liu Xiaofei , Chen Yuhang , Xu Wu , Wang Yingchun
Published: June 2019

The mitogen-activated protein kinase ERK1/2 (ERKs, extracellular-regulated protein kinases) plays important roles in a wide spectrum of cellular processes and have been implicated in many disease states. The spatiotemporal regulation of ERK activity has been extensively studied. However, scarce information has been available regarding the quality control of the kinases to scavenge malfunctioning ERKs. Using site-specific mutagenesis and mass spectrometry, we found that the disruption of the conserved H-bond between Y210 and E237 of ERK1 through point mutation at or naturally occurring nitration on Y210 initiates a quality control program dependent on chaperon systems and CHIP (C-terminal of Hsp70-interacting protein)-mediated ubiquitination and degradation. The H-bond is also important for the quality control of ERK2, but through a distinct mechanism. These findings clearly demonstrate how malfunctioning ERKs are eliminated when cells are in certain stress conditions or unhealthy states, and could represent a general mechanism for scavenging malfunctioning kinases in stress conditions.
Differential gene expression in articular cartilage between rheumatoid arthritis and endemic Kashin–Beck disease
Authors: Gao Zongqiang , Duan Chen , Yu Fang-fang , Guo Xiong
Published: June 2019

Kashin–beck disease (KBD) is endemic chronic osteoarthrosis and its pathogenesis is still unclear. The present study aimed to explore differential gene expression in articular cartilage between patients with rheumatoid arthritis (RA) and KBD. Articular cartilages were collected from KBD and RA patients, and differentially expressed genes (DEGs) were analyzed by RNA-seq. The signaling pathway and biological process (BP) of the DEGs were identified by enrichment analysis. The protein–protein interaction (PPI) network of DEGs and the key genes of KBD were identified by network analysis with STRING and cytoscape software. We identified 167 immune-related DEGs in articular cartilage samples from KBD patients compared with RA. The up-regulation of MAPK signaling pathway and the down-regulation of signaling pathways such as toll-like receptor, janus kinase-signal transducers and activators of transcription, leukocyte migration, T-cell receptor and chemokine, and antigen processing and presentation were involved in KBD. We identified 137 genes nodes related with immune and mapped the PPI network diagram. BP analysis revealed that immune response, calcium ion homeostasis, blood vessel morphogenesis, inflammatory response, lymphocyte proliferation, and MAPK activation were involved in KBD. In conclusion, gene expression profiling can be used to identify the different mechanism of pathogenesis between KBD and RA.
Spaced Retrieval Using Static and Dynamic Images to Improve Face–Name Recognition: Alzheimer's Dementia and Vascular Dementia
Authors: Viccaro Elizabeth , Sands Elaine , Springer Carolyn
Published: June 2019

Purpose

The primary objective of this study examined whether spaced retrieval (SR) using dynamic images (video clips without audio) is more effective than SR using static images to improve face–name recognition in persons with dementia. A secondary objective examined the length of time associations were retained after participants reached criterion. A final objective sought to determine if there is a relationship between SR training and dementia diagnosis.

Method

A repeated-measures design analyzed whether SR using dynamic images was more effective than SR using static images for face–name recognition. Twelve participants diagnosed with Alzheimer's dementia or vascular dementia were randomly assigned to 2 experimental conditions in which the presentation of images was counterbalanced.

Results

All participants demonstrated improvement in face–name recognition; there was no significant difference between the dynamic and static images. Eleven of 12 participants retained the information from 1 to 4 weeks post training. Additional analysis revealed a significant interaction effect when diagnoses and images were examined together. Participants with vascular dementia demonstrated improved performance using SR with static images, whereas participants with Alzheimer's dementia displayed improved performance using SR with dynamic images.

Conclusions

SR using static and/or dynamic images improved face–name recognition in persons with dementia. Further research is warranted to continue exploration of the relationship between dementia diagnosis and SR performance using static and dynamic images.
Demonstration of a high‐performance SiGe alloy channel considering Ge fraction, Dit and BTB leakage
Authors: Bae D.‐I. , Choi B.D.
Published: June 2019

The electrical properties of a SiGe alloy channel from Si to Ge, for electron and hole mobilities are investigated. Although SiGe NMOS shows degraded electron mobility until 85% because of alloy scattering, abrupt mobility improvement with the high composition SiGe channel is observed because of a band structure modification. A linearly improved hole mobility with Ge and channel strain increase was also observed. Focusing on PMOS, on‐current gain matching off‐current target shows slightly different behavior. Even if the effective current improvement due to strain is similar with that of mobility, the Ge concentration effect is much smaller because of band‐to‐band leakage degradation. In case of strain, relatively smaller band offset compared to the Ge mole fraction is evaluated by simulation. Finally, when measured hardware is compared between Ge 30, 40 and 50%, the highest SiGe alloy channel shows the lowest effective current. As Ge concentration increase, degraded sub‐threshold swing and capacitance reduction which come from high inter‐face trap, negative Vth shift and band‐to‐band leakage via the conduction band offset is observed. In conclusion, sustaining the high strain at channel and low Dit are critical in the development of high‐performance, high concentration SiGe alloy PMOS.
Reconfigurable resonator in decoupled empty SIW technology using liquid crystal material
Authors: Sánchez J.R. , Bachiller C. , Nova V. , Boria V.E.
Published: June 2019

This Letter presents a novel continuously tunable microwave resonator based on liquid crystal (LC) material. The reconfigurable device is implemented in Decoupled Empty Substrate Integrated Waveguide (DESIW) technology. DESIW technology allows both magnetic and electric DC (or low frequency) biasing of the LC. The resonator is continuously tunable in a range of 600 MHz, resulting in a measured tunability range of 8.5% around a centre frequency of 7 GHz. Moreover, the measured insertion loss of the reconfigurable device is between 4.3 and 6.8 dB, thus obtaining a Q‐factor of 190‐172.
Fast background estimation on long video sequence
Authors: Fu Hui‐Ni , Wang Ben‐Zhang , Liu Heng‐Zhu
Published: June 2019

Background estimation is essential in many computer vision applications with video frames. It refers to two important issues: accuracy and efficiency. There are mainly two challenges: how to recover the background image from as few frames as possible, and how to get a background image as fast as possible from a long video sequence. This Letter proposed a fast background estimation approach based on matrix completion to solve the second issue. Considering that matrix completions set all frames to be column vectors in a big matrix. While sequential images are to some extent related and redundant frames exist, the authors’ approach implements a frame selection step to decrease the number of frames before using fast robust principal component analysis (RPCA) to deal with matrix completion problem. Their experiments selected long video sequences from scene background initialisation (SBI) dataset. Results show that compared with existing RPCA matrix completion algorithms and other state‐of‐the‐art methods, their method is much better in processing efficiency while still keeps the same good performance.
Simple method for enlarging positive LE and accelerating calculation speed of chaotic system
Authors: Wang Faqiang
Published: June 2019

Positive Lyapunov exponent (LE) is vital to identify a dynamical system being chaotic or hyperchaotic. A simple method that the right‐hand side of differential equations which can be used to describe the chaotic system, is multiplied by a constant value, is proposed. From the proposed method, it can not only enlarge the positive LE of chaotic or hyperchaotic systems, but also accelerate their calculation speed. Sprott C chaotic system is selected as an example to show its effectiveness. Finally, an electronic circuit model for Sprott C chaotic system is designed and some experimental results are presented for confirmation.
Joint decoder for network and channel coded multi‐way relay systems with MPSK modulation
Authors: Balasuriya Nuwan , Wavegedara Chandika B.
Published: June 2019

In wireless sensor networks, multi‐way relaying is a very common network configuration, where multiple nodes exchange information via a single relay over uncorrelated fading channels. In such configuration, node pair‐wise communication together with physical‐layer network coding (PNC) at the relay node provides a good trade‐off between spectral efficiency and error performance. A joint channel decoding‐PNC algorithm employed at the relay can further improve the bit error rate performance. This study proposes an improved joint channel decoding‐PNC algorithm for M‐ary phase shift keying modulated multi‐way wireless relay systems. The proposed algorithm can achieve an additional diversity gain by exchanging bit‐level or symbol‐level soft information between the constitute decoders decoding different information pairs. Moreover, several schemes are proposed for exchange of the soft information between the parallely operating channel decoders. Simulation results demonstrate improved error and convergence performance of the proposed algorithm over the existing algorithms at the expense of non‐significant increase in computational complexity.
Cooperative Bayesian‐based detection framework for spectrum sensing in cognitive radio networks
Authors: Maleki Alireza , Mirzahosseini Davood , Moghaddam Naser Ahmadi
Published: June 2019

In this study, a cognitive radio network is considered in which multiple secondary users intend to detect a primary user frequency band in order to specify whether it is occupied or not. To this end, a blind Bayesian framework is proposed by which secondary users cooperatively perform spectrum sensing. In practice, it is impossible to estimate the noise variance accurately (noise uncertainty problem) and this can degrade the performance of some previous spectrum sensing algorithms like energy detection (ER). To overcome this issue, unlike the conventional ER, the proposed algorithm utilises marginalisation to eliminate the effect of uncertainty in noise variance estimation. By computer simulations using MATLAB, it can be seen that the authors' algorithm reaches the ideal case for by improving the level of cooperation (increasing the number of secondary users) and yet its is also improved compared to ER in practical situations (presence of noise uncertainty).
Prediction‐based sliding mode control of non‐linear systems with input delay using disturbance observer
Authors: Moosapour Seyed Hamze , Ataei Mohammad , Ekramian Mohsen
Published: June 2019

In this study, stabilisation of input‐delay non‐linear systems in the presence of disturbance based on prediction variable is studied. For both disturbance estimation and delay compensation, an extended prediction variable as well as adaptive sliding mode controller are proposed in which the open‐loop system is not required to be stable. In the proposed prediction variable one needs to estimate disturbance in the future. In order to solve this problem a new non‐linear disturbance observer (NDOB) is proposed. Considering the NDOB in the closed‐loop system, the stability analysis of error dynamic is performed. And the asymptotic stability of non‐linear system with input delay is guaranteed for some class of disturbance. Simulation results finally validate the good performance and robustness of the proposed controller based on disturbance observer.
Adaptive observer‐based integral sliding mode control of a piezoelectric nano‐manipulator
Authors: Zhang Yangming , Yan Peng
Published: June 2019

In this study, the authors propose an adaptive observer‐based integral sliding mode control scheme to support ultra‐precision tracking of a multi‐axis piezoelectric nano‐manipulator. By introducing a modified Dahl model capable of approximating the hysteresis phenomenon, an adaptive observer is developed to compensate the impact of hysteresis, where an adaptive observer‐based integral sliding mode control architecture is further proposed with good robustness against model uncertainties. The gain of the sliding mode controller is adaptively estimated for the purposes of fast convergence, chattering alleviation and controller robustness. Finally, the proposed algorithm is implemented in real time on a PZT‐actuated nano‐manipulating stage, where good robustness and excellent tracking performance are successfully demonstrated, which outperform representative algorithms in the literature.
Event‐based network consensus with antagonistic interactions and communication delay
Authors: Guo Xing , Liang Jinling , Huang Tingwen
Published: June 2019

In this study, the consensus problem is investigated for the multi‐agent systems with antagonistic interactions and communication delay under the event‐triggered control protocol. For the directed signed networks, an event‐based interaction protocol is first proposed. Then it is shown that with the proposed protocol, bipartite consensus can be realised for the structurally balanced signed networks with distributed communication delay. As for the structurally unbalanced signed networks with communication delay, it is proved that consensus can also be reached under the proposed event‐triggered scheme and the final consensus value is zero. It should be emphasised that the proposed event‐triggered controllers depend only on the local information. Furthermore, Zero phenomenon can be excluded, and the positive lower bound of the inter‐event times is simultaneously provided. Finally, the effectiveness of proposed event‐triggered schemes is demonstrated by one numerical example.
Adaptive finite‐time tracking control of 6DOF spacecraft motion with inertia parameter identification
Authors: Zhao Qin , Duan Guangren
Published: June 2019

This study deals with the problem of relative motion control with 6 degrees of freedom (6DOF) for spacecrafts without a priori knowledge of the inertia parameters. Considering the system natural couplings, the integrated rotational and translational dynamics of the spacecraft are achieved. By a series of first‐order filter operations, an expression of the parameter estimation error is derived and then used for the design of an integrated finite‐time tracking controller applying adaptive backstepping technique. Proven by the Lyapunov theory, the proposed controller can guarantee that the errors of trajectory tracking and parameter identification simultaneously converge to zero in finite time. Furthermore, to be applied in practice, the controller is adapted for the spacecraft subject to external disturbance and input saturation. Compared with the previous control designs, the proposed control strategy can realise inertia parameter identification together with tracking of command position and attitude in finite time, in the presence of input saturation and external disturbance. The effectiveness of the control law is finally demonstrated by numerical simulations.
Microgrid planning considering the resilience against contingencies
Authors: Wu Xiong , Wang Zhao , Ding Tao , Wang Xiuli , Li Zhiyi , Li Furong
Published: June 2019

Increasing the redundancy of distribution lines and increasing the penetration of distributed energy resources (DERs) both help microgrids ride through contingencies. However, it remains a challenging problem for how to coordinate these two measures for minimising the deployment cost while guaranteeing a pre‐specified degree of resilience in case of contingencies. Accordingly, this study proposes a novel microgrid planning model to site and size candidate sets of DERs and distribution lines in close coordination, which is mathematically equivalent to a two‐stage robust optimisation problem. In particular, the resilience level of microgrid operations is quantified and maintained such that the load loss is constrained within a given bound under any realisation of N–k contingencies. The proposed model also incorporates a practical strategy to maintain the radial topology of islanding network sections in any N–k contingency. Finally, numerical experiments based on two microgrid test systems are performed. The results show that the system resilience is adaptively enhanced through optimally placing DERs and distribution lines compared with the conventional economics based model. Moreover, the employed robust method is at least ten times faster than the reliability‐based method in identifying the worst contingency.
Model predictive control of induction motor based on amplitude–phase motion equation
Authors: Lu Ziguang , Zhang Ruilin , Hu Likun , Gan Lin , Lin Jingyu , Gong Pingping
Published: June 2019

Tedious adjustment of the weighting factor restricts the wide application of conventional model predictive torque control (MPTC) for induction motors (IMs) in practice. To solve this problem, this study introduces a new variable R (reactive torque) to control the flux of IM, which is the dual of torque T, with radial orientation and in relation to reactive power. Then, a novel MPTC strategy based on variable R and torque T is proposed and named RT‐MPC. Compared with conventional MPTC, RT‐MPC uses a pair of variables with the same dimensions and time scales instead of the torque and flux amplitude in MPTC. This approach eliminates the weighting factor of the cost function, unifies the time scales of control variables, and avoids prediction of rotor flux at the (k + 2) instant. Simulation and experimental results show that RT‐MPC can avoid the weighting factor, reduce switching frequency, and reduce control complexity. RT‐MPC can also maintain excellent dynamic and steady‐state performance similar to conventional MPTC. Hence, the proposed method is expected to be more practical.
Tri‐level decision‐making framework for strategic trading of demand response aggregator
Authors: Jia Yulong , Mi Zengqiang , Yu Yang , Song Zhuoliang , Fan Hui
Published: June 2019

This article presents a new decision‐making framework for strategic trading of demand response aggregator (DRA). The proposed framework consists of three layers. At the first layer, the wholesale energy market operated by independent system operator (ISO), which seeks to maximise the social welfare in day‐ahead (DA) market and to minimise the cost of minimise the cost for maintaining energy balance in real‐time (RT) markets. At the second layer, the DRA act as an intermediate operator between ISO and flexible customers. Profit‐maximising DRA affects the clearing results of market prices by strategic trading in DA energy market, providing reserve capacity in DA reserve market and offsetting energy deviation in RT. At the third layer, customers seek to optimise the trading strategy between earnings incentive reward from the DRA and considering uncomfortable cost of customers. The tri‐layer framework is modelled as two bilevel optimisation models, which capture interaction between different entities. The bilevel model can be transformed to single level linear model through Karush‐Kuhn‐Tucker conditions and dual theory to solve the couple non‐linear problem. The numerical studies using the IEEE 9‐bus and 118‐bus test systems are presented to illustrate the application of the proposed tri‐layer decision‐making framework.
Oblique incidence of a plane wave on an inhomogeneously loaded grating of slots in a screen
Authors: Haddab Abdulaziz H. , Kuester Edward F.
Published: June 2019

In this paper, we demonstrate a new method to control the enhanced transmission due to Fabry–Perot resonances through an array of dielectric-loaded slots in a thick metallic screen. We obtain approximate analytical formulas for each polarization (TM and TE) using a mode-matching technique based on the assumption that the slots are small compared to a free-space wavelength and that the metallic screen is a perfect electric conductor as is appropriate for microwave frequency applications. We show that the bandwidth and locations of enhanced transmission can be controlled by the angle of incidence or by making the material filling the slots inhomogeneous. Computational results are given that demonstrate the influence of the angle of incidence on the enhanced transmission bandwidth. We show that the separation between enhanced transmission frequencies can be controlled by introducing a gap within the slot with a different dielectric constant. Also, we illustrate how the total transmission bandwidth can be increased by adjusting the angle of incidence and the gap size.
Quantitative analysis of the interaction between a dc SQUID and an integrated micromechanical doubly clamped cantilever
Authors: Salman Majdi , Klemencic Georgina M. , Mandal Soumen , Manifold Scott , Mustafa Luqman , Williams Oliver A. , Giblin Sean R.
Published: June 2019

We provide simulations to quantitatively describe the interaction between a dc superconducting quantum interference device (SQUID) and an integrated doubly clamped cantilever. The simulations have been performed using the SQUID equations described by the resistively and capacitively shunted junction model coupled to the equation of motion of a damped harmonic oscillator. We have chosen to investigate an existing experimental configuration and have explored the motion of the cantilever configuration and the reaction of the SQUID as a function of the voltage flux V(Φ) characteristics. We clearly observe the Lorentz force back-action interaction and demonstrate how a sharp transition state drives the system into a nonlinear-like regime and modulates the cantilever displacement amplitude, simply by tuning the SQUID parameters.
Huge impact of compressive strain on phase transition temperatures in epitaxial ferroelectric KxNa1−xNbO3 thin films
Authors: von Helden L. , Bogula L. , Janolin P.-E. , Hanke M. , Breuer T. , Schmidbauer M. , Ganschow S. , Schwarzkopf J.
Published: June 2019

We present a study in which ferroelectric phase transition temperatures in epitaxial KxNa1−xNbO3 films are altered systematically by choosing different (110)-oriented rare-earth scandate substrates and by variation of the potassium to sodium ratio. Our results prove the capability to continuously shift the ferroelectric-to-ferroelectric transition from the monoclinic MC to orthorhombic c-phase by about 400 °C via the application of anisotropic compressive strain. The phase transition was investigated in detail by monitoring the temperature dependence of ferroelectric domain patterns using piezoresponse force microscopy and upon analyzing structural changes by means of high resolution X-ray diffraction including X-ray reciprocal space mapping. Moreover, the temperature evolution of the effective piezoelectric coefficient d33,f was determined using double beam laser interferometry, which exhibits a significant dependence on the particular ferroelectric phase.
Excitation-current-density and temperature dependences of deep UV cathodoluminescence in rocksalt-structured MgxZn1-xO films
Authors: Ono M. , Ishii K. , Kaneko K. , Yamaguchi T. , Honda T. , Fujita S. , Onuma T.
Published: June 2019

Excitation-current-density and temperature-dependent cathodoluminescence (CL) spectra were measured for rocksalt-structured MgxZn1-xO films with x = 0.92–0.61. A deep UV luminescence (DUVL) band was predominantly observed in an energy range of 4.91–5.86 eV for all the films at 6–300 K. The analysis based on a rate equation model confirms that the DUVL band is attributed to the near-band-edge emission. Temperature-dependent CL spectra were quantified in terms of peak energy shifts and full width at half maximum values. Relatively high equivalent internal quantum efficiencies of 2.5%–11% were obtained for the RS-MgxZn1-xO films.
Study of a magnetically driven reconnection platform using ultrafast proton radiography
Authors: Chien Abraham , Gao Lan , Ji Hantao , Yuan Xiaoxia , Blackman Eric G. , Chen Hui , Efthimion Philip C. , Fiksel Gennady , Froula Dustin H. , Hill Kenneth W. , Huang Kai , Lu Quanming , Moody John D. , Nilson Philip M.
Published: June 2019

A novel magnetically driven reconnection platform was created by a pair of U-shaped Cu coils that connect two parallel Cu plates irradiated at a focused laser intensity of ∼3 × 1016 W/cm2 and characterized using ultrafast proton radiography. The proton data show two prolate voids, each corresponding to the coil current, with an inferred maximum magnitude of 57 ± 4 kA. A center “flasklike” feature was also observed in the proton radiographs. By prescribing electromagnetic fields associated with magnetic reconnection in proton ray tracing simulations, characteristics of this center feature were reproduced. These results demonstrate the robustness of the laser-driven capacitor coils for generating strong magnetic fields and provide promise of using such coils as a viable platform for studying magnetically driven reconnection in the laboratory.
Dual-polarization analog optical phase conjugation for focusing light through scattering media
Authors: Cheng Zhongtao , Yang Jiamiao , Wang Lihong V.
Published: June 2019

Focusing light through or inside scattering media by the analog optical phase conjugation (AOPC) technique based on photorefractive crystals (PRCs) has been intensively investigated due to its high controlled degrees of freedom and short response time. However, the existing AOPC systems only phase-conjugate the scattered light in one polarization direction, while the polarization state of light scattered through a thick scattering medium is spatially random in general, which means that half of the scattering information is lost. Here, we propose dual-polarization AOPC for focusing light through scattering media to improve the efficiency and fidelity in the phase conjugation. The motivations of the dual-polarization AOPC are illustrated by theoretical analysis and numerical simulation, and then an experimental system is established to realize the dual-polarization AOPC. By separating and rotating the two orthogonal polarization components of the randomly polarized scattered light, light in all polarization states is recorded and phase-conjugated using the same PRC. Experimental results for focusing through a thick biological tissue show that the intensity of the time-reversed focus from the dual-polarization AOPC can be enhanced by a factor of approximate four compared with the existing single-polarization AOPC.
Large spin-orbit torque observed in epitaxial SrIrO3 thin films
Authors: Wang Hailong , Meng Keng-Yuan , Zhang Pengxiang , Hou Justin T. , Finley Joseph , Han Jiahao , Yang Fengyuan , Liu Luqiao
Published: June 2019

Semimetallic iridate compound SrIrO3 epitaxial films have been deposited by off-axis sputtering, exhibiting excellent crystalline quality as well as smooth surfaces. By performing second-harmonic Hall measurements on a series of SrIrO3/Co1−xTbx bilayers, we quantitatively determined the spin-to-charge interconversion efficiency θSH of SrIrO3 and discovered a systematic temperature and film thickness dependent evolution behavior. Notably, the measured θSH reaches a remarkably large number of ∼1.1 at room temperature, which is significantly larger than the value of 5d transition metals and comparable to the values reported in some topological material systems. Our findings are further corroborated by ferromagnetic resonance-driven spin pumping studies in SrIrO3/Py bilayers, highlighting the significant opportunities offered by the iridate compounds in designing next-generation energy-efficient multifunctional spin Hall devices.
Separating interface magnetoresistance from bulk magnetoresistance in silicon-based Schottky heterojunctions device
Authors: He Xiong , He Bin , Yu Han , Sun Zhigang , He Jun , Zhao Wenyu
Published: June 2019

Nonmagnetic semiconductor based magnetoresistance (MR) devices combining high performance and low cost have attracted a lot of attention. However, it has been a great challenge to separate the interface MR from the bulk MR in the devices composed of Schottky heterojunctions. In this paper, the MR effect of a silicon-based Schottky heterojunction device had been studied, and its mechanisms were investigated by separating the interface MR effects from the bulk MR effects through combining two-probe and four-probe methods. We find that the bulk MR value is significantly smaller than the total MR value in the avalanche breakdown region in the temperature range of 150 K to 300 K, indicating that the total MR effect mainly originates from the interface MR effect. Theoretical analysis shows that the bulk MR effect is a normal one due to the existence of the Lorentz force on the carriers, and the interface MR effect relates to the suppression of the local plasmas by applying magnetic fields, where the local plasmas form due to the avalanche breakdown in the Ag/SiO2/p-Si Schottky heterojunctions. The total MR effect at room temperature can be further enhanced by reducing the distance between electrodes, and the total MR reaches about 1847% under a magnetic field of 1 T and the MR sensitivity is as large as 118.5 T−1 under 0.1 T.
Bursting analysis for the pre-Bötzinger complex with periodic forcing
Authors: Meng Pan , Dong Jianwei , Ji Quanbao
Published: June 2019

Pre-Bötzinger complex is considered to have a closely relationship with the respiratory rhythms. In this paper, we investigate the bursting phenomena of the pre-Bötzinger complex respiratory neuron with periodic slow stimulation. Since the external forcing visit the spiking and rest areas in different ways, thus the system could generate various complex bursting patterns. With the external forcing is taken as a slow variable that modulates the dynamics of the system, different types of bursting are distinguished and the generation mechanism is explored by using the combination of two parameter bifurcation analysis and fast slow decomposition. Our results show that both the external forcing and the neural intrinsic property play an important role in neural activities.
A statistical Seebeck coefficient model based on percolation theory in two-dimensional disordered systems
Authors: Wang Lingfei , Thean Aaron Voon-Yew , Liang Gengchiau
Published: June 2019

In the presence of structural disorders, carrier conduction via localized hopping sites emerges in two-dimensional systems and results in a unique thermopower characteristic with T1/3 dependence. The disorders induced potential differences of hopping sites leading to energy variations along current-carrying paths. A systematic thermoelectric study is presently required in comprehending the statistical effects. Therefore, we proposed a statistical model of the Seebeck coefficient on the basis of percolation theory and hopping mechanisms. With this model, the carrier density and temperature dependences can be practically predicted. Key parameters can be extracted by calibration to molybdenum disulfide and black phosphorus experiments, providing a deeper insight into device physics. Moreover, a Mott-like analytical model is developed to investigate the parametric dependence. The thermopower deviations from the noninteracting Mott picture at high and low temperatures are analyzed. Finally, the temperature dependence on the thermoelectric figure of merit is evaluated in a variable range hopping regime. Our model is essential for a reliable prediction of the disorder induced statistical effects on thermoelectric behaviors, which guides both device optimization and material engineering.
Droplet impact induced large deflection of a cantilever
Authors: Huang Xiaoping , Dong Xiangwei , Li Jing , Liu Jianlin
Published: June 2019

The phenomenon of a droplet impacting on an elastic solid surface exists in wide and versatile natural and industrial areas, which is involved with the interplay between elasticity and droplet dynamics. In the present work, we have made a comprehensive study on the process of a droplet impacting on a cantilever resulting in large deformation. The morphology of the droplet is observed, and the maximum deflection of the cantilever with respect to the initial velocity, apparent contact angle, and surface tension of the droplet is calculated by the developed theoretical model, which matches the experimental results very well. These findings may aid to engineer new energy harvesting devices and microsensors, and are also promising for many agricultural and industrial applications.
Tightrope bubbles
Authors: de Maleprade Hélène , Pautard Matthias , Clanet Christophe , Quéré David
Published: June 2019

Droplets moving along fibers have a mobility limited by viscous dissipation. Here, we discuss the opposite situation of bubbles moving on threads immersed in water. Contrasting with drops, the mobility is generally fixed by a visco-inertial skin friction, which allows them to move at much larger velocity than reported in the dual situation. We conclude by establishing how the friction becomes purely viscous when increasing the bath viscosity.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: June 2019

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials which supersede earlier data or suggest new research applications.
Promising routes to large-scale photonic quantum computing
Authors: Kim Meeri
Published: June 2019

In a new perspective article, researchers outline two recent innovative approaches to large-scale photonic quantum computing that overcome its previous limitations.
Dual-polarization analog optical phase conjugation improves optical focusing through tissue
Authors: Jaycen Amelia
Published: June 2019

A new dual-polarization optical phase conjugation method uses photorefractive crystals to refocus scattered light with improved fidelity.
A Rapid and Sensitive Aptasensor for Cyromazine Detection in Raw Milk Based on a Nanogold Probe and G-Quadruplex Formation
Authors: Dang Xu , Gu Wenchao , Zheng Xiyin , Fei Xuelian , Tian Fuxiang , Xing Haibo , Hu Xiaojun
Published: June 2019

Herein, a rapid, facile, and colourimetric sensor for the detection of cyromazine in raw milk is reported using an aptamer based on gold nanoparticles (AuNPs). A sequence-specific aptamer for cyromazine called Tcyr1 is designed to absorb on the surface of AuNPs and electrostatically interacts with poly(diallyldimethylammonium chloride) (PDDA), which prevents AuNPs from aggregating. It can also self-assemble to form a G-quadruplex-CYR complex with cyromazine. Because of its specificity and stability, the introduction of cyromazine in raw milk would influence the protection thus the following cationic polymer could aggregate AuNPs and cause a remarkable change in colour. According to this, the presence of cyromazine can be determined by the naked eye and means of absorbance. This sensor is selective for the detection of cyromazine in raw milk and has a limit of detection of 200 ppb by the naked eye and of 5.8 ppb by spectrophotometer, and has a detection range from 0.1 to 1 ppm.
Topology on a new facet of bismuth
Authors: Hsu Chuang-Han , Zhou Xiaoting , Chang Tay-Rong , Ma Qiong , Gedik Nuh , Bansil Arun , Xu Su-Yang , Lin Hsin , Fu Liang
Published: June 2019

Significance

We uncover the presence of a new topological crystalline insulator (TCI) state in bismuth, which is protected by a twofold rotational symmetry. In contrast to the recently discovered higher-order topological phase in bismuth, the present TCI phase hosts unpinned Dirac cone surface states that could be accessed directly through photoemission experiments. Our study provides a comprehensive understanding of the rich topological electronic structure of bismuth.
Spotting plants’ microfilament morphologies and nanostructures
Authors: Almeida Ana P. , Canejo João , Mur Urban , Čopar Simon , Almeida Pedro L. , Žumer Slobodan , Godinho Maria Helena
Published: June 2019

Significance

Microfibers existing in the tracheary systems of plants are crucial for the plants to survive. These microfilaments are curled up, forming left-handed helices that make the contour of tubes responsible for the transport of water and nutrients from the roots to the leaves. The microfilaments present mechanical properties that vary from plant to plant despite having similar polygonal-helical shapes and cellulose skeletons. Here we show that the surface morphology of the microfilaments, sensed by nematic liquid crystal droplets, is at the origin of entanglements, which are responsible for the mechanical behavior of microfilaments. This work introduces routes for the accurate characterization of plants’ microfilaments and to produce bioinspired textiles.
HIF-1α is required for development of the sympathetic nervous system
Authors: Bohuslavova Romana , Cerychova Radka , Papousek Frantisek , Olejnickova Veronika , Bartos Martin , Görlach Agnes , Kolar Frantisek , Sedmera David , Semenza Gregg L. , Pavlinkova Gabriela
Published: June 2019

Significance

The sympathetic nervous system plays a critical role in stimulating heart rate and contractility to increase cardiac output and thereby insure adequate tissue O
2
delivery. Altered sympathetic output contributes to cardiac pathologies, such as sudden cardiac death and heart failure. Our data provide insight into the role of the transcription factor hypoxia-inducible factor 1α (HIF-1α) in the development of sympathetic ganglion neurons and cardiac sympathetic innervation. We found that genetic deletion of HIF-1α resulted in increased cell death and decreased proliferation of neuronal progenitors of the sympathetic system. These findings suggest that dysregulated HIF-1α expression may contribute to cardiac dysfunction and disease associated with defects in the cardiac sympathetic system by affecting the function and survival of sympathetic neurons.
Classifier use in Heritage and Hong Kong Cantonese
Authors: Nagy Naomi , Lo Samuel
Published: June 2019

Heritage language speakers have frequently been reported to have language skills weaker than homeland
(monolingual) speakers. For example, Wei and Lee (2001, p. 359), a study of
British-born Chinese-English bilingual children’s morphosyntactic patterns (including classifier use), report “evidence of delayed
and stagnated L1 development.” However, many studies compare heritage speaker performance to a prescriptive standard rather than
to spontaneous speech from homeland speakers. We compare spontaneous speech data from two generations of Heritage Cantonese
speakers in Toronto, Canada, and from Homeland Cantonese speakers in Hong Kong. Both groups are similar in a strong preference for
general and mass classifiers, and classifier choice being primarily governed by the noun’s number. We observe specialization of
go3 個 to singular nouns, a grammaticalization process increasing with each generation. The similarity between
homeland and heritage patterns replicates previous studies utilizing the same corpus.