bluuebunny/crossref_metadata_2025 huggingface dataset:
The eukaryotic translation initiation factor eIF4E elevates steady-state m
7
G capping of coding and noncoding transcripts
Authors: Culjkovic-Kraljacic Biljana , Skrabanek Lucy , Revuelta Maria V. , Gasiorek Jadwiga , Cowling Victoria H. , Cerchietti Leandro , Borden Katherine L. B.
Published: October 2020

Significance

Methyl-7-guanosine (m
7
G) “cap” addition on 5′ ends of RNA impacts virtually all levels of processing. Titrating capping of transcripts impacts on protein-coding capacity and, for noncoding RNAs, biochemical activity. Capping is widely considered a constitutive housekeeping activity with the expectation that ∼100% of transcripts will be capped at steady state. We developed two methods to quantify capping: quantitative CapIP and an enzymatic method, CapQ. Strikingly, steady-state RNA capping ranged from ∼30 to 50%, much lower than anticipated. eIF4E, a cap-binding protein implicated in human malignancy, elevated capping to ∼60 to 100% for selected transcripts, many of which act in cancer. Indeed, capping is elevated in high-eIF4E primary human cancer specimens. Thus, capping is a significant regulatory step in RNA metabolism.
The anomalies and criticality of liquid water
Authors: Shi Rui , Tanaka Hajime
Published: October 2020

Significance

Water is the most essential yet mysterious liquid on our planet. One fundamental question is whether a liquid–liquid critical point (LLCP) exists in liquid water. However, the inevitable crystallization of ice in the region where LLCP might be located makes the experimental search exceptionally challenging. Here we propose to detect the LLCP as the intersection between thermodynamic and dynamical fluctuation maxima lines in the phase diagram. This unique approach suggests that the LLCP of real water is located around 184 K and 173 MPa. However, contrary to the widely spread belief, we find that the criticality has little influence on the anomalous properties of the experimentally accessible liquid state of water because it is too far from the LLCP.
Spatial organization of functional clusters representing reward and movement information in the striatal direct and indirect pathways
Authors: Shin Jung Hwan , Song Min , Paik Se-Bum , Jung Min Whan
Published: October 2020

Significance

The striatum is critically involved in voluntary motor control and reward-based learning. To formulate a nuanced model of the striatum, it would be important to understand how functional ensembles of striatal neurons are organized in the spatiotemporal domain. In this perspective, we monitored ensemble activity of a large number of striatal neurons in mice performing a classical conditioning task and a self-paced open-field test. We found partially overlapping and learning-dependent spatial organizations of striatal neuronal clusters for movement- as well as reward-related variables in both the direct and indirect pathways. These findings provide insights into striatal neural circuit operations underlying reward-based learning and movement control.
Translingual identity
Authors: Tankosić Ana
Published: October 2020

Translingual identity, as a part of the trans-paradigm, refers to linguistic, sociocultural, ethno-racial, and religious
practices, which are negotiable, fluid, and in motion, transcending mainstream boundaries. This paper expands the translingual literature
from the perspective of sociolinguistic disparities of culturally and linguistically diverse Eastern-European immigrant women in Australia,
as they become victims of the perpetual foreigner stereotype in their host communities. Using the linguistic ethnography methods, such as
open ethnographic observation and semi-structured interview, the study reveals that due to biographical accent, name, and the country of
origin, as aspects of translingual identity – Australian-by-passport, those women become the victim of the perpetual
foreigner stereotypes, such as ‘perceived as different’ and ‘Russian bride,’ which led to their feelings of inferiority and social
inequality. By expanding the scope of the translingual identity and how it is perceived in Australia, this study provides a necessary
contribution to the translingual literature, while simultaneously advocating for the quality of life and justice for translingual immigrants
in their new home.
The challenges of developing an irrigation strategy for UK agriculture and horticulture in 2020: industry and research priorities
Authors: Knox Jerry W. , Kay Melvyn G. , Hess Tim M. , Holman Ian P.
Published: October 2020

In many countries, including the UK, water resources are under intense stress with recent droughts highlighting the risks to the security of supplies for different sectors including domestic water supply, industry, agriculture (including horticulture), power generation and the environment. A changing climate with greater rainfall uncertainty, coupled with new regulations, increasing competition for water and demands for sustainable development will only exacerbate the current situation, with major supply-demand imbalances expected over the next few decades. In the UK, irrigated agriculture constitutes a volumetrically small but economically high value use of water, to maximise crop yields and quality. However, the importance of irrigation is also changing; driven by the intensification and transformation of the agricultural sector, the need to recognise water as an ‘essential’ use, policy incentives to increase domestic food production and an industry imperative to increase water use efficiency
1
and ensure agricultural expansion can continue to underpin the rural economy. This review considers the key climate and water-related risks facing the agricultural and horticultural crop sectors, the various environmental, regulatory and business externalities or ‘drivers for change’, and the strategic priorities for action, both from industry and research perspectives.
A new window into large-pore channels
Authors: Short Ben
Published: October 2020

JGP study describes a novel quantitative assay combining fluorescence microscopy and electrophysiology, which reveals that transport of small molecules through CALHM1 and connexin channels is saturable.
Chiral State Conversion in a Levitated Micromechanical Oscillator with In Situ Control of Parameter Loops*
Authors: Yin Peiran , Luo Xiaohui , Zhang Liang , Lin Shaochun , Tian Tian , Li Rui , Wang Zizhe , Duan Changkui , Huang Pu , Du Jiangfeng
Published: October 2020

Physical systems with gain and loss can be described by a non-Hermitian Hamiltonian, which is degenerated at the exceptional points (EPs). Many new and unexpected features have been explored in the non-Hermitian systems with a great deal of recent interest. One of the most fascinating features is that chiral state conversion appears when one EP is encircled dynamically. Here, we propose an easy-controllable levitated microparticle system that carries a pair of EPs and realize slow evolution of the Hamiltonian along loops in the parameter plane. Utilizing the controllable rotation angle, gain and loss coefficients, we can control the structure, size and location of the loops in situ. We demonstrate that, under the joint action of topological structure of energy surfaces and nonadiabatic transitions, the chiral behavior emerges both along a loop encircling an EP and even along a straight path away from the EP. This work broadens the range of parameter space for the chiral state conversion, and proposes a useful platform to explore the interesting properties of exceptional points physics.
Tunable Optical Bandpass Filter via a Microtip-Touched Tapered Optical Fiber*
Authors: Zhang Peng-Fei , Song Li-Jun , Zou Chang-Ling , Wang Xin , Wang Chen-Xi , Li Gang , Zhang Tian-Cai
Published: October 2020

We demonstrate a tunable bandpass optical filter based on a tapered optical fiber (TOF) touched by a hemispherical microfiber tip (MFT). Other than the interference and selective material absorption effects, the filter relies on the controllable and wavelength-dependent mode–mode interactions in TOF. Experimentally, a large range of tunability is realized by controlling the position of the MFT in contact with the TOF for various TOF radii, and two distinct bandpass filter mechanisms are demonstrated. The center wavelength of the bandpass filter can be tuned from 890 nm to 1000 nm, while the FWHM bandwidth can be tuned from 110 nm to 240 nm when the MFT touches the TOF in the radius range from 160 nm to 390 nm. The distinction ratio can reach 28 ± 3 dB experimentally. The combined TOF-MFT is an in-line tunable bandpass optical filter that has great application potential in optical networks and spectroscopy, and the principle could also be generalized to other integrated photonic devices.
Field-Induced Metal–Insulator Transition in β-EuP3*
Authors: Wang Guangqiang , Chang Guoqing , Zhou Huibin , Ma Wenlong , Lin Hsin , Hasan M. Zahid , Xu Su-Yang , Jia Shuang
Published: October 2020

Metal–insulator transition (MIT) is one of the most conspicuous phenomena in correlated electron systems. However such a transition has rarely been induced by an external magnetic field as the field scale is normally too small compared with the charge gap. We present the observation of a magnetic-field-driven MIT in a magnetic semiconductor β-EuP3. Concomitantly, we find a colossal magnetoresistance in an extreme way: the resistance drops billionfold at 2K in a magnetic field less than 3T. We ascribe this striking MIT as a field-driven transition from an antiferromagnetic and paramagnetic insulator to a spin-polarized topological semimetal, in which the spin configuration of Eu2+ cations and spin-orbital coupling play a crucial role. As a phosphorene-bearing compound whose electrical properties can be controlled by the application of field, β-EuP3 may serve as a tantalizing material in the basic research and even future electronics.
Tuning of the Magnetic Damping Parameter by Varying Cr Composition in Fe1–xCrx Alloy*
Authors: Yang Mao , Lu Xianyang , Liu Bo , Ruan Xuezhong , Zhang Junran , Zhang Xiaoqian , Huang Dawei , Wu Jing , Du Jun , Liu Bo , Meng Hao , He Liang , Xu Yongbing
Published: October 2020

We investigate the magnetic damping parameter of Fe1 – x
Cr
x
thin films using the time-resolved magneto-optical Kerr effect technique. It is demonstrated that the overall effective damping parameter is enhanced with the increasing Cr concentration. The effective damping at high field α
0 is found to be significantly enhanced when increasing the Cr concentration with the α
0 = 0.159 in the Fe45Cr55 enhanced by 562% compared with that of α
0 = 0.024 in the pure Fe film. This study provides a new approach of controlling the effective damping parameter with a desired magnitude via varying Cr composition.
Growth of ultra-thin large sized 2D flakes at air–liquid interface to obtain 2D-WS2 monolayers
Authors: Nisar Talha , Balster Torsten , Haider Ali , Kortz Ulrich , Wagner Veit
Published: October 2020

Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising candidates for future electronics. Currently, the growth of TMD large area thin films/flakes is one of the biggest challenges. A novel method for the growth of ultra-thin and large area WS2 monolayer flakes has been developed by introducing a solution-based temperature-dependent process. This two-dimensional WS2 growth process is low cost and environmentally friendly. WO3 flakes are grown at the air–liquid interface using ammonium tetrathiotungstate ((NH4)2WS4, ATTW) as WS2 precursor. The process requires a moderate activation temperature as no flakes are formed at room temperature. Successful growth of flakes was observed in an aqueous solution of the precursor at a temperature between 70 °C and 90 °C. These flakes could be transferred to any substrate by a controlled dip-coating process. Large 2D WS2 flakes with a lateral size of up to 100 μm were obtained after sulfurization. The thickness ranged from a WS2 monolayer to five monolayers, as verified by atomic force microscope. The chemical reaction mechanism behind the formation of the flakes was investigated by FTIR, Raman, UV–Vis and x-ray photoelectron spectroscopy. The initial flakes were found to be made of WO3, which were successfully converted to WS2 by a post annealing step at 500 °C–900 °C. This simple and environmentally friendly growth technique can be used to produce large WS2 flakes for next generation electronics.
Optical spatial filtering readout techniques for IR/THz imaging and their performance analysis
Authors: Jin Yang , Shi Haitao , Zhang Qingchuan
Published: October 2020

Optical spatial filtering readout techniques (OSFRTs), such as knife-edge filtering and circular hole filtering, are broadly used in optomechanical microcantilever focal plane arrays for infrared (IR)/terahertz (THz) imaging. In order to further improve the responsivity of IR/THz imaging, it is important to improve the optical readout responsivity (ORR). However, the shape and location of the optical spatial filter cannot be well optimized for lack of a unified theoretical ORR model of OSFRTs. This paper gives and experimentally validates a unified ORR model of OSFRTs. Based on this model, the influence of the shape and location of the four commonly used spatial filters on the imaging resolution and light utilization efficiency is discussed. Both theory and experiment show that the slit filter has higher optical readout responsivity than the knife-edge filter and better light utilization efficiency than the rectangular or circular hole filters. Therefore, the slit filter should be the best of the four commonly used filters.
Rapid laser nanomanufacturing and direct patterning of 2D materials on flexible substrates—2DFlex
Authors: Ahmadi Zabihollah , Fathi-Hafshejani Parvin , Kayali Emre , Beidaghi Majid , Mahjouri-Samani Masoud
Published: October 2020

Direct synthesis, large-scale integration, and patterning of two-dimensional (2D) quantum materials (e.g. MoS2, WSe2) on flexible and transparent substrates are of high interest for flexible and conformal device applications. However, the growth temperatures (e.g. 850 °C) of the emerging 2D materials in the common gas-phase synthesis methods are well beyond the tolerances limit of flexible substrates, such as polydimethylsiloxane (PDMS). In addition, random nucleation and growth process in most growth systems limits the predicted integration and patterning freedoms. Here, we report a rapid direct laser crystallization and mask-free large-scale patterning of MoS2 and WSe2 crystals on PDMS substrates. A thin layer of stoichiometric amorphous 2D film is first laser-deposited via pulsed laser deposition (PLD) system onto the flexible substrates followed by a controlled crystallization and direct writing process using a tunable nanosecond laser (1064 nm). The influences of pulse duration, number of pulses, and the thickness of the deposited amorphous 2D layer on the crystallization of 2D materials are discussed. Optical spectroscopy and electrical characterizations are performed to confirm the quality of crystallized 2D materials on flexible substrates. This novel method opens up a new opportunity for the crystallization of complex patterns directly from computer-aided design models for the future 2D materials-based wearable, transparent, and flexible devices.
Role of defects and grain boundaries in the thermal response of wafer-scale hBN films
Authors: Bera K , Roy Anushree , Chugh D , Wong-Leung J , Hoe Tan H , Jagadish C
Published: October 2020

With more widespread applications of nanotechnology, heat dissipation in nanoscale devices is becoming a critical issue. We study the thermal response of wafer-scale hexagonal boron nitride (hBN) layers, which find potential applications as ideal substrates in two dimensional devices. Sapphire-supported thin hBN films, 2′′ in size and of different thicknesses, were grown using metalorganic vapour phase epitaxy. These large-scale films exhibit wrinkles defects and grain boundaries over their entire area. The shift of

E

2
g

high

phonon mode with temperature is analysed by considering the cumulative contribution of anharmonic phonon decay along with lattice thermal expansion, defect, and strain modulation. The study demonstrates that during heat treatment the strain evolution plays a dominating role in governing the characteristics of the wrinkled thinner films. Interestingly we find that both defects and strain determine the spectral line-width of these wafer-scale films. To the end, from Raman line-width, the changes in phonon lifetime in delaminated and as-grown films is estimated. The results suggest the possibility of a reduction in thermal transport in these wafer-scale films compared to their bulk counterpart.
Effect of Ga composition on mobility in a-InGaZnO thin-film transistors
Authors: Ahn Minho , Gaddam Venkateswarlu , Park Sungho , Jeon Sanghun
Published: October 2020

Oxide semiconductor TFTs have attracted considerable attention in the recent past due to their excellent mobility, high optical transparency in the visible region, and most importantly their fabrication process at low-temperature. However, charge trapping formation in the gate dielectric and the interfaces in such oxide TFTs leads to serious issues such as their operational stability and reliability. Understanding the charge trapping mechanism is therefore of utmost importance to identify the root cause of the aforesaid problems. In this report, we present a detailed study on the charge trapping and dynamic charge transport of a-IGZO TFTs by examining microsecond fast IV (FIV), pulse IV (PIV), and transient IV measurements. The a-IGZO TFTs have designed and fabricated with various Ga compositions (0, 0.14 and 0.22). It was observed that the charge trapping in the a-IGZO TFT is reliant on the sweeping time and the carrier mobility measured using the FIV technique was found to be higher than that obtained from the conventional DC IV measurement. Mobility values (

μ

m

) was also measured through the PIV technique and are found to be approximately 10%, 16%, and 21% lower than the intrinsic mobility values. Temperature-dependent study reveals that the intrinsic mobility values (18.45, 16.1 and 12.03 cm2 V−1 s−1) are higher than the pulse mobility values for various Ga compositions (0, 0.14 and 0.22) at higher temperature (175 °C) probably due to the formation of free carriers. Suitable optimization of process parameters of a-IGZO TFTs can therefore enhance the device stability and reliability characteristics leading to their potential utilization in flexible and stretchable electronic devices, sensors & detectors and biomedical devices.
Proton beam defocusing in AWAKE: comparison of simulations and measurements
Authors: Gorn A A , Turner M , Adli E , Agnello R , Aladi M , Andrebe Y , Apsimon O , Apsimon R , Bachmann A-M , Baistrukov M A , Batsch F , Bergamaschi M , Blanchard P , Burrows P N , Buttenschön B , Caldwell A , Chappell J , Chevallay E , Chung M , Cooke D A , Damerau H , Davut C , Demeter G , Deubner L H , Dexter A , Djotyan G P , Doebert S , Farmer J , Fasoli A , Fedosseev V N , Fiorito R , Fonseca R A , Friebel F , Furno I , Garolfi L , Gessner S , Goddard B , Gorgisyan I , Granados E , Granetzny M , Grulke O , Gschwendtner E , Hafych V , Hartin A , Helm A , Henderson J R , Howling A , Hüther M , Jacquier R , Kargapolov I Yu , Kedves M Á , Keeble F , Kelisani M D , Kim S-Y , Kraus F , Krupa M , Lefevre T , Liang L , Liu S , Lopes N , Lotov K V , Martyanov M , Mazzoni S , Medina Godoy D , Minakov V A , Moody J T , Morales Guzmán P I , Moreira M , Nechaeva T , Panuganti H , Pardons A , Peña Asmus F , Perera A , Petrenko A , Pucek J , Pukhov A , Ráczkevi B , Ramjiawan R L , Rey S , Ruhl H , Saberi H , Schmitz O , Senes E , Sherwood P , Silva L O , Spitsyn R I , Tuev P V , Velotti F , Verra L , Verzilov V A , Vieira J , Welsch C P , Williamson B , Wing M , Wolfenden J , Woolley B , Xia G , Zepp M , Zevi Della Porta G
Published: October 2020

In 2017, AWAKE demonstrated the seeded self-modulation (SSM) of a 400 GeV proton beam from the Super Proton Synchrotron at CERN. The angular distribution of the protons deflected due to SSM is a quantitative measure of the process, which agrees with simulations by the two-dimensional (axisymmetric) particle-in-cell code LCODE to about 5%. The agreement is achieved in beam population scans at two selected plasma densities and in the scan of longitudinal plasma density gradient. The agreement is reached only in the case of a wide enough simulation box (several plasma wavelengths) that is closer to experimental conditions, but requires more computational power. Therefore, particle-in-cell codes can be used to interpret the SSM physics underlying the experimental data.
Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC® wires
Authors: Wang Xiaorong , Abraimov Dmytro , Arbelaez Diego , Bogdanof Timothy J , Brouwer Lucas , Caspi Shlomo , Dietderich Daniel R , DiMarco Joseph , Francis Ashleigh , Garcia Fajardo Laura , Ghiorso William B , Gourlay Stephen A , Higley Hugh C , Marchevsky Maxim , Maruszewski Maxwell A , Myers Cory S , Prestemon Soren O , Shen Tengming , Taylor Jordan , Teyber Reed , Turqueti Marcos , van der Laan Danko , Weiss Jeremy D
Published: October 2020

Although the high-temperature superconducting (HTS) REBa2Cu3O
x
(REBCO, RE–rare earth elements) material has a strong potential to enable dipole magnetic fields above 20 T in future circular particle colliders, the magnet and conductor technology needs to be developed. As part of an ongoing development to address this need, here we report on our CORC® canted cosθ magnet called C2 with a target dipole field of 3 T in a 65 mm aperture. The magnet was wound with 70 m of 3.8 mm diameter CORC® wire on machined metal mandrels. The wire had 30 commercial REBCO tapes from SuperPower Inc. each 2 mm wide with a 30 µm thick substrate. The magnet generated a peak dipole field of 2.91 T at 6.290 kA, 4.2 K. The magnet could be consistently driven into the flux-flow regime with reproducible voltage rise at an engineering current density between 400–550 A mm−2, allowing reliable quench detection and magnet protection. The C2 magnet represents another successful step towards the development of high-field accelerator magnet and CORC® conductor technologies. The test results highlighted two development needs: continue improving the performance and flexibility of CORC® wires and develop the capability to identify locations of first onset of flux-flow voltage.
Fluorescent paint for determination on the effective thermal conductivity of YBCO coated conductor
Authors: Li Yingbo , Ma Yanbin , Liu Cong , Zhang Xingyi , Yong Huadong , Zhou You-He
Published: October 2020

Recently, YBa2Cu3O7−x coated conductor (YBCO CC) has been developed intensively for different applications including power cables and high-filed magnets. Of all its physical properties, the thermal conductivity of the YBCO CC is considered as one of the most important parameters in guiding the temperature distribution, heat flux, and prediction of quench propagation. To accurately predict this property, a thermometry technique of high-speed fluorescent thermal imaging is introduced to monitor heat diffusion of commercial YBCO CCs in real time based on the Europium tris[3-(trifluoromethylhydroxymethylene)-(+)-camphorate] (EuTFC) in this study. We propose a new imaging process to eliminate the influences of background intensity and non-uniform illumination on the calibration results accompanying with good accuracy of measurement. And the fluorescence performances are evaluated by static and dynamic calibration experiments. The experimental results show that the photoluminescence of EuTFC has excellent photostability and temperature dependence, and there is no hysteresis in the temperature response when comparing with the PT100 measurements. Subsequently, four kinds of commonly used theoretical models of thermal conductivity and the corresponding calculation curves of the YBCO CC are presented. Finally, the numerical simulation based on the theoretical models has been conducted to reproduce the transient heat conduction process. The simulation results show that the transient heat conduction predicted by the Maxwell’s equivalent model show the best agreement compared with experimental results.
Radiative heat transfer enhancement in MHD porous channel flow of an Oldroyd-B fluid under generalized boundary conditions
Authors: Anwar Talha , Kumam Poom , Baleanu Dumitru , Khan Ilyas , Thounthong Phatiphat
Published: October 2020

This study explains the transient free convection phenomenon in a vertical porous channel subject to nonlinear thermal radiation. The infinite vertical channel encloses magnetohydrodynamic (MHD) flow of an Oldroyd-B fluid. The left channel wall possesses time-dependent velocity

u

0

g
(

t

˜

)

, while the right wall exhibits no motion. The momentum and temperature field equations are developed on the bases of momentum conservation law and Fourier’s principle of heat transfer. Laplace transformation technique and Durbin’s numerical inversion method are jointly incorporated to compute the solutions of the formulated problem. The influences of flow and material parameters on heat transfer and fluid velocity are graphically scrutinized with physical aspects. The numerical computations for skin friction and temperature gradient are tabularized to comprehensively examine the wall shear stress and heat transfer rate. Finally, velocity fields for Maxwell fluid, second grade fluid, and viscous fluid are traced out as limiting cases and their comparison is drawn with the velocity field of an Oldroyd-B fluid. Besides this, some newly published results are also deduced from the acquired solutions. It is observed that increasing the magnitude of radiation parameter Rd rapidly enhances the rate of heat transfer at the right channel wall while an inverse behavior of Nusselt number is witnessed at the left channel wall. The Maxwell fluid and second grade fluid indicate the swiftest and slowest channel flow rates respectively. The shear stress specifies dual nature for relaxation and retardation parameters subject to static and moving wall. Additionally, it is found that the flow of an Oldroyd-B fluid is retarded by a magnetic field.
A fast and precise three-dimensional measurement system based on multiple parallel line lasers
Authors: Wang Yao , Lin Bin
Published: October 2020

This paper conducts a trade-off between efficiency and accuracy of three-dimensional (3D) shape measurement based on the triangulation principle, and introduces a flying and precise 3D shape measurement method based on multiple parallel line lasers. Firstly, we establish the measurement model of the multiple parallel line lasers system, and introduce the concept that multiple base planes can help to deduce the unified formula of the measurement system and are used in simplifying the process of the calibration. Then, the constraint of the line spatial frequency, which maximizes the measurement efficiency while ensuring accuracy, is determined according to the height distribution of the object. Secondly, the simulation analyzing the variation of the systemic resolution quantitatively under the circumstance of a set of specific parameters is performed, which provides a fundamental thesis for option of the four system parameters. Thirdly, for the application of the precision measurement in the industrial field, additional profiles are acquired to improve the lateral resolution by applying a motor to scan the 3D surface. Finally, compared with the line laser, the experimental study shows that the present method of obtaining 41220 points per frame improves the measurement efficiency. Furthermore, the accuracy and the process of the calibration are advanced in comparison with the existing multiple-line laser and the structured light makes an accuracy better than 0.22 mm at a distance of 956.02 mm.
Coherent-driving-assisted quantum speedup in Markovian channels*
Authors: Lu Xiang , Zhang Ying-Jie , Xia Yun-Jie
Published: October 2020

As is well known, the quantum evolution speed of quantum state can never be accelerated in the Markovian regime without any operators on the system. The Hamiltonian corrections induced by the action of coherent driving forces are often used to fight dissipative and decoherence mechanisms in experiments. For this reason, considering three noisy channels (the phase-flip channel, the amplitude damping channel and the depolarizing channel), we propose a scheme of speedup evolution of an open system by controlling an external unitary coherent driving operator on the system. It is shown that, in the presence of the coherent driving, no-speedup evolution can be transformed into quantum speedup evolution in the Markovian dynamics process. Additionally, under the fixed coherent driving strength in the above three noisy channels, the best way to achieve the most degree of quantum speedup for the system has been acquired by rotating the system with appropriate driving direction angles, respectively. Finally, we conclude that the reason for this acceleration is not the non-Markovian dynamical behavior of the system but due to the oscillation of geometric distance between the initial state and the target final state.
Reliability of organic light-emitting diodes in low-temperature environment*
Authors: Pan Saihu , Zhu Zhiqiang , Liu Kangping , Yu Hang , Liao Yingjie , Wei Bin , Borsali Redouane , Guo Kunping
Published: October 2020

Organic light-emitting diode (OLED) is an electroluminescent technology that relies on charge-carrier dynamics and is a potential light source for variable environmental conditions. Here, by exploiting a self-developed low-temperature testing system, we investigated the characteristics of hole/electron transport, electro-optic conversion efficiency, and operation lifetime of OLEDs at low-temperature ranging from –40 °C to 0 °C and room temperature (25 °C). Compared to devices operating at room temperature, the carrier transport capability is significantly decreased with reducing temperature, and especially the mobility of the hole-transporting material (HTM) and electron-transporting material (ETM) at –40 °C decreases from 1.16 × 10−6 cm2/V⋅s and 2.60 × 10−4 cm2/V⋅s to 6.91 × 10−9 cm2/V⋅s and 1.44 × 10−5 cm2/V⋅s, respectively. Indeed, the temperature affects differently on the mobilities of HTM and ETM, which favors unbalanced charge-carrier transport and recombination in OLEDs, thereby leading to the maximum current efficiency decreased from 6.46 cd⋅A−1 at 25 °C to 2.74 cd⋅A−1 at –40 °C. In addition, blue fluorescent OLED at –20 °C has an above 56% lifetime improvement (time to 80% of the initial luminance) over the reference device at room temperature, which is attributed to efficiently dissipating heat generated inside the device by the low-temperature environment.
CdS/Si nanofilm heterojunctions based on amorphous silicon films: Fabrication, structures, and electrical properties*
Authors: Li Yong , Ji Peng-Fei , Song Yue-Li , Zhou Feng-Qun , Huang Hong-Chun , Yuan Shu-Qing
Published: October 2020

Shortening the distance between the depletion region and the electrodes to reduce the trapped probability of carriers is a useful approach for improving the performance of heterojunction. The CdS/Si nanofilm heterojunctions are fabricated by using the radio frequency magnetron sputtering method to deposit the amorphous silicon nanofilms and CdS nanofilms on the ITO glass in turn. The relation of current density to applied voltage (I–V) shows the obvious rectification effect. From the analysis of the double logarithm I–V curve it follows that below ∼ 2.73 V the electron behaviors obey the Ohmic mechanism and above ∼ 2.73 V the electron behaviors conform to the space charge limited current (SCLC) mechanism. In the SCLC region part of the traps between the Fermi level and conduction band are occupied, and with the increase of voltage most of the traps are occupied. It is believed that CdS/Si nanofilm heterojunction is a potential candidate in the field of nano electronic and optoelectronic devices by optimizing its fabricating procedure.
Jamming in confined geometry: Criticality of the jamming transition and implications of structural relaxation in confined supercooled liquids*
Authors: Liu Jun , Tong Hua , Nie Yunhuan , Xu Ning
Published: October 2020

In marginally jammed solids confined by walls, we calculate the particle and ensemble averaged value of an order parameter, 〈Ψ(r)〉, as a function of the distance to the wall, r. Being a microscopic indicator of structural disorder and particle mobility in solids, Ψ is by definition the response of the mean square particle displacement to the increase of temperature in the harmonic approximation and can be directly calculated from the normal modes of vibration of the zero-temperature solids. We find that, in confined jammed solids, 〈Ψ(r)〉 curves at different pressures can collapse onto the same master curve following a scaling function, indicating the criticality of the jamming transition. The scaling collapse suggests a diverging length scale and marginal instability at the jamming transition, which should be accessible to sophisticatedly designed experiments. Moreover, 〈Ψ(r)〉 is found to be significantly suppressed when approaching the wall and anisotropic in directions perpendicular and parallel to the wall. This finding can be applied to understand the r-dependence and anisotropy of the structural relaxation in confined supercooled liquids, providing another example of understanding or predicting behaviors of supercooled liquids from the perspective of the zero-temperature amorphous solids.
Mechanism of titanium–nitride chemical mechanical polishing*
Authors: Feng Dao-Huan , Wang Ruo-Bing , Xu Ao-Xue , Xu Fan , Wang Wei-Lei , Liu Wei-Li , Song Zhi-Tang
Published: October 2020

During the preparation of the phase change memory, the deposition and chemical mechanical polishing (CMP) of titanium nitride (TiN) are indispensable. A new acidic slurry added with sodium hypochlorite (NaClO) as an oxidizer is developed for the CMP of TiN film. It has achieved a material removal rate of 76 nm/min, a high selectivity between TiN film and silica (SiO2) films of 128:1, a selectivity between TiN film and tungsten film of 84:1 and a high surface quality. To understand the mechanism of TiN CMP process, x-ray photoelectron (XPS) spectroscope and potentiodynamic polarization measurement are performed. It is found that the mechanism of TiN CMP process is cyclic reaction polishing mechanism. In addition, both static corrosion rate and the inductively coupled plasma results indicate TiN would not be dissolved, which means that the mechanical removal process of oxide layer plays a decisive role in the material removal rate. Finally, the mechanism of TiN polishing process is given based on the analysis of surface potential and the description of blocking function.
What can a heavy

boson do to the muon

anomaly and to a new Higgs boson mass? *
Authors: Morais António P. , Pasechnik Roman , Rodrigues J. Pedro
Published: October 2020

The minimal

extension of the Standard Model (B-L-SM) offers an explanation for neutrino mass generation via a seesaw mechanism; it also offers two new physics states, namely an extra Higgs boson and a new

gauge boson. The emergence of a second Higgs particle as well as a new

gauge boson, both linked to the breaking of a local

symmetry, makes the B-L-SM rather constrained by direct searches in Large Hadron Collider (LHC) experiments. We investigate the phenomenological status of the B-L-SM by confronting the new physics predictions with the LHC and electroweak precision data. Taking into account the current bounds from direct LHC searches, we demonstrate that the prediction for the muon

anomaly in the B-L-SM yields at most a contribution of approximately

, which represents a tension of

standard deviations, with the current

uncertainty, by means of a

boson if its mass is in the range of

to

, within the reach of future LHC runs. This means that the B-L-SM, with heavy yet allowed

boson mass range, in practice, does not resolve the tension between the observed anomaly in the muon

and the theoretical prediction in the Standard Model. Such a heavy

boson also implies that the minimal value for the new Higgs mass is of the order of 400 GeV.
A family of double-beauty tetraquarks: Axial-vector state

*
Authors: Agaev S. S. , Azizi K. , Barsbay B. , Sundu H.
Published: October 2020

The spectroscopic parameters and decay channels of the axial-vector tetraquark

(in what follows,

) are explored using the quantum chromodynamics (QCD) sum rule method. The mass and coupling of this state are calculated using two-point sum rules by taking into account various vacuum condensates, up to 10 dimensions. Our prediction for the mass of this state

confirms that it is stable with respect to strong and electromagnetic decays and can dissociate to conventional mesons only via weak transformations. We investigate the dominant semileptonic

and nonleptonic

decays of

. In these processes,

is a scalar tetraquark

built of a color-triplet diquark and an antidiquark, whereas M is one of the vector mesons

,

,

, and

. To calculate the partial widths of these decays, we use the QCD three-point sum rule approach and evaluate the weak transition form factors

(

), which govern these processes. The full width

and the mean lifetime

of the tetraquark

are computed using the aforementioned weak decays. The obtained information about the parameters of

and

is useful for experimental investigations of these double-heavy exotic mesons.
Modulating and restoring inter-muscular coordination in stroke patients using two-dimensional myoelectric computer interface: a cross-sectional and longitudinal study
Authors: Jian Chuyao , Deng Linchuan , Liu Huihua , Yan Tiebin , Wang Xianyun , Song Rong
Published: October 2020

Objective. Traditional training focuses on improving the motor function level of the limbs or joint levels, while inter-muscular coordination plays an important role in fine motor control and is often overlooked. The purpose of this study was to investigate the changes in inter-muscular coordination induced by the myoelectric-controlled interface (MCI) and the therapeutic effects of MCI-based inter-muscular coordination training on stroke patients. Approach. Eleven stroke patients, twenty young subjects and thirteen age-matched subjects were recruited to determine the dimensionality effect of MCI on inter-muscular coordination in the evaluation test. In addition, a stroke patient participated in a 20-day training session to test the therapeutic effects as a case study analysis in the training test. In these two tests, all subjects performed tracking tasks by flexing/extending their elbows according to the biofeedback from one-dimensional and two-dimensional (2D) MCI. Meanwhile, the electromyography and functional near infrared spectroscopy signals were recorded simultaneously to reflect the muscle and cortical activations. Main results. In all groups, as the MCI dimensionality increased, the antagonist activation decreased significantly, while the involvement in prefrontal cortex and primary motor cortex increased significantly. A significant reduction in muscle activation and an increase in cortical activation were found in the stroke patient, which might be due to a progressive normalization of patient after the training. Significance. These findings suggested that 2D MCI could be an effective tool to directly modulate inter-muscular coordination for stroke patients. Inter-muscular coordination training may restore the ability to coordinate agonist-antagonist muscle of stroke patient and this improvement may be accompanied by cortical reorganization.
Mathematical Theory of Powerful Tornadoes in the Atmosphere
Authors: Gavrikov M B , Taiurskii A A
Published: October 2020

We propose a mathematical theory of powerful tornadoes for which the angular velocity of air in the vortex ring of the mother cloud generating a tornado in the upper layers of the atmosphere is much greater than the angular velocity of air currents near the Earth’s surface. This theory can have practical applications, in particular, it can be used to determine, with any given accuracy, the air velocity within a tornado, as well as the funnel-shaped boundary of the tornado.
Influence of distance between coils with current on the effect of cascade plasma heating in flows injected from the QSPA
Authors: Kozlov A N
Published: October 2020

Research of the interaction of high-speed dense plasma flows generated by the quasi-stationary plasma accelerator with the magnetic field of the set of ring current-carrying conductors located at different distances from each other is presented. The study was based on the model of radiation magnetic gas dynamics, taking into account electrical conductivity, thermal conductivity and radiation transport. It was found that a decrease in the distance between the coils with a current leads to the disappearance of the effect of step-by-step or cascade transformation of kinetic energy into thermal energy of the plasma.
Vortex structure identification for supersonic flows
Authors: Borisov V E , Davydov A A , Konstantinovskaya T V , Lutsky A E
Published: October 2020

This work is devoted to the application of vortex structure identification methods for two counter-rotating wingtip vortices in a supersonic flow. The λ2 criterion and the method of maximum vorticity were used for detection vortex core lines and visualization of vortex sheet and rope. Computational model based on the URANS equations with SA turbulence model was applied. Numerical simulations were performed on the hybrid supercomputing system K-60 at the Keldysh Institute of Applied Mathematics RAS using the developed software package ARES for 3D turbulent flows modeling on high performance computing systems.
Emission from cooling supernova shocks in MHD simulations
Authors: Makarenko E. I. , Walch S. , Clarke S. D. , Seifried D.
Published: October 2020

Each supernova (SN) injects ∼ 1051 erg into the interstellar medium (ISM). The blast wave shocks the gas and heats it up to 107 K; the gas subsequently cools by emitting radiation across the electromagnetic spectrum. Typically, about 70% of the initially injected SN energy is lost by radiative cooling. Thus an understanding of the radiative losses is needed to understand the evolution of supernova remnants, and to allow for comparisons between simulations and observations.

We present a post-processing module for the FLASH code which calculates the cooling radiation from shock-heated gas in different energy bands. Using modern collision excitation data from MAPPINGS V, we produce maps of the SN emission at different wavelengths, allowing for a comparison to real observations of supernova remnants (SNRs) and for testing observational diagnostic tools. Here, we focus on optical line emission arising from the interaction between the shock wave and dense gas of a nearby molecular cloud and on the use of optical line ratios for determining the shock parameters.
Numerical modeling of the convective Kelvin-Helmholtz instabilities of astropauses
Authors: Korolkov Sergey , Izmodenov Vladislav , Alexashov Dmitry
Published: October 2020

In this paper we present the numerical modeling results of the problem of the hypersonic stellar wind interaction with fully ionized interstellar medium that moves with respect to the star with supersonic speed. This is the classical problem that has been firstly studied in 1970 by Baranov et al. [1] under the thin layer approximation.

In this paper we present results of numerical solutions obtained with high spatial resolution of the numerical grid. The computations were performed by using GPU processors with high-performance parallel programming technology CUDA from NVIDIA. It is shown that the stationary solution depends only on two dimensionless parameters - Mach number in the interstellar medium, M∞, and adiabatic index, γ. The stationary solutions were obtained for different values of M∞ for low and medium resolution of the numerical grids. For the numerical grids of high spatial resolution the Kelvin-Helmholtz instability appears at the tangential discontinuities (both primary and secondary) in the tail part of interaction region. The instability is convective as it should be according to the linear analyses by Ruderman et al. [6]. We explore the instability evolution with increasing resolution of the numerical grid. Effects of the numerical scheme are also studied.
Effective Implementation of low thermal conductivity material Yttrium Stabilized Zirconium Coating on a Diesel Engine Components Fuelled with neat Waste Cooking Oil-An Assessment Study
Authors: Sangeethkumar E. , Jaikumar M. , Vijayabalan P. , Sasikumar N. , Ramanathan V.
Published: October 2020

In this study, an attempt was made on the consumption of neat waste cooking oil (WCO) in a thermal barrier coated (TBC) diesel engine. During the first stage of the study, the standard engine fuelled with diesel and WCO with different power outputs (25%, 50%, 75% & 100%) to measure the performance, combustion and emission parameters. In the second stage of the study, the engine components coated with 8% yttrium stabilized zirconium (8%YSZ) ceramic coat and NiCrAl bond coat using plasma spray coating. In the third stage of the study, the base engine convert to TBC mode and fuelled with diesel and neat waste cooking oil and reading were compared. From the experimental study, it came to know that, the brake thermal efficiency of uncoated diesel and WCO, 31.2%, and 25.7% were as for TBC diesel and WCO it was improved to 32.8 % and 27%. In the combustion side, the cylinder peak pressure for uncoated diesel and WCO 62 bar and 55.8 bar were as for TBC diesel and WCO improved to 63 bar and 57 bar. Further on the emission side, the CO, HC, and smoke were decreased in the TBC mode along with the penalty of increase in the NOx for both diesel and WCO. From the experimental study, the TBC mode reduces the heat flux from the combustion chamber and traps the heat inside the cylinder as an effect it reduces the ignition delay and helps to utilize highly viscous fuel like WCO in a diesel engine.
Numerical investigation of fluid flow and heat transfer in an electrical machine cooling system using nanofluids
Authors: Jayakumar S. , Sreekanth M.
Published: October 2020

The numerical simulation of an electric machine (E-machine) used for hybrid electric vehicle, electric vehicle, and plug-in electric vehicle is carried out to explore the impact of distinct kinds of coolants such as water and distinct nanofluids on the bracket housing cooling performance. Nanofluids are stable nanofiber and fluid particle suspensions. Recent research shows that these nanofluids have enhanced thermal conductivity and convection coefficients, are superior to pure fluid. The aim is to understand the heat transfer enhancement brought by different nanofluids. The present study suggests that the use of Ga-In-Sn (Gallium, Indium, and tin) as the coolant leads to higher efficiency of heat transfer compared to other nanofluids agents and base fluid. Results indicate increased heat transfer in the cooling of the electrical machine as shown by a significant reduction of ∼ 30% in the operating temperature when using nanofluids compared to pure fluid implementation. With superior thermal characteristics and countless advantages, nanofluids are promising to meet the cooling requirements of the machine by a reduction in thermal resistance and maximum temperature.