bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of an electrically modifiable artificial synapse based on ferroelectric field-effect transistors using Al-doped HfO2thin films
Authors: Yoon So-Jung , Moon Seung-Eon , Yoon Sung-Min
Published: May 2020

Biological synaptic behaviors such as short-/long-term plasticity were implemented by ferroelectric polarization switching dynamics of Al-doped HfO2ferroelectric gate insulators.
Flagellar nanorobot with kinetic behavior investigation and 3D motion
Authors: Tang Jiannan , Rogowski Louis William , Zhang Xiao , Kim Min Jun
Published: May 2020

Wirelessly controlled nanorobots have the potential to perform highly precise maneuvers within complex in vitro and in vivo environments.
Synthesis of type 1 Lewis b hexasaccharide antigen structures featuring flexible incorporation of l-[U-13C6]-fucose for NMR binding studies
Authors: Long Mark , Ní Cheallaigh Aisling , Reihill Mark , Oscarson Stefan , Lahmann Martina
Published: May 2020

The synthesis and use of a uniformly 13C labelled fucosyl donor as a general building block is demonstrated.
Formation of bis-benzimidazole and bis-benzoxazole through organocatalytic depolymerization of poly(ethylene terephthalate) and its mechanism
Authors: Fukushima Kazuki , Jones Gavin O. , Horn Hans W. , Rice Julia E. , Kato Takashi , Hedrick James L.
Published: May 2020

One-pot syntheses of bis-benzimidazole and bis-benzoxazole from poly(ethylene terephthalate) waste bottles were successful through two-step nucleophilic attacks promoted by TBD.
Protein aggregation nucleated by functionalized dendritic polyglycerols
Authors: Bernhard Samuel P. , Fricke Mackenzie S. , Haag Rainer , Cloninger Mary J.
Published: May 2020

Lactose functionalized dendritic polyglycerols (LdPGs) nucleate the formation of well-ordered aggregatesviaa combination of specific protein/carbohydrate interactions and intermolecular overlaps of the N-terminal domains.
Chi-MIC-share: a new feature selection algorithm for quantitative structure–activity relationship models
Authors: Li Yuting , Dai Zhijun , Cao Dan , Luo Feng , Chen Yuan , Yuan Zheming
Published: May 2020

An algorithm based on an improved maximal information coefficient and a redundant allocation strategy, which can terminate feature selection automatically, is presented.
The selective laser sintering of a polyamide 11/BaTiO3/graphene ternary piezoelectric nanocomposite
Authors: Jin Yipu , Chen Ning , Li Yijun , Wang Qi
Published: May 2020

Polyamide 11/BaTiO3/graphene nanocomposite SLS part with enhanced dielectric and piezoelectric properties due to its special discontinuous graphene network and microspores.
Electronic structure and lattice dynamics of Ba2CuTeO6 single crystals
Authors: Chung Yun Chen , Karna Sunil K. , Chou Fan-Cheng , Liu Hsiang-Lin
Published: May 2020

The electronic structure and lattice dynamics of Ba2CuTeO6 single crystals were investigated through spectroscopic ellipsometry and Raman scattering measurements.
Approximately symmetric electrowetting on an oil-lubricated surface
Authors: Yuan Xi , Tang Biao , Barman Jitesh , Groenewold Jan , Zhou Guofu
Published: May 2020

An attractive oil-lubricated electrowetting (EW) material system which could suppress the charge trapping on the dielectric/water interface and improve consequently asymmetric EW was proved.
Electrochemical and structural characterization of lithiation in spray deposited ordered mesoporous titania as an anode for Li ion batteries
Authors: Símonarson Gunnar , Calcagno Giulio , Lotsari Antiope , Palmqvist Anders E. C.
Published: May 2020

A combination of electrochemical and structural characterization techniques were used to study the lithiation in spray deposited amorphous mesoporous titania.
Fabrication of low-fouling, high-loading polymeric surfaces through pH-controlled RAFT
Authors: Jesmer Alexander H. , Huynh Vincent , Wylie Ryan G.
Published: May 2020

pH-Controlled surface-reversible addition–fragmentation chain-transfer (S-RAFT) polymerization yields a one-pot synthesis for bimodal polymeric surfaces for improved capture agent immobilization.
Application progress of enhanced coagulation in water treatment
Authors: Cui Hongmei , Huang Xing , Yu Zhongchen , Chen Ping , Cao Xiaoling
Published: May 2020

This review summarizes the current situation of enhanced coagulation and looks forward to future development.
Influence of inter- and intramolecular H-bonding on the mesomorphic and photoswitching behaviour of (E)-4-((4-(hexyloxy)phenyl)diazenyl)-N-phenyl benzamides
Authors: Sunil B. N. , Behera Paresh Kumar , Achalkumar Ammathnadu S. , Shanker G. , Hegde Gurumurthy
Published: May 2020

We report on the synthesis, phase behaviour and photoswitching studies of new azo linked rod-shaped molecules.
Effect of polyvinylpyrrolidone (PVP) on palladium catalysts for direct synthesis of hydrogen peroxide from hydrogen and oxygen
Authors: Han Geun-Ho , Lee Seok-Ho , Seo Myung-gi , Lee Kwan-Young
Published: May 2020

Addition of polyvinylpyrrolidone to Pd/SiO2 catalyst improved H2O2 selectivity by adjusting electronic state of palladium active species.
Controlled delivery of a protein tyrosine phosphatase inhibitor, SHP099, using cyclodextrin-mediated host–guest interactions in polyelectrolyte multilayer films for cancer therapy
Authors: Wang Soobin , Battigelli Alessia , Alkekhia Dahlia , Fairman Alexis , Antoci Valentin , Yang Wentian , Moore Douglas , Shukla Anita
Published: May 2020

Controlled delivery of a potent anticancer drug, SHP099, after supramolecular complexation into a versatile multilayer film.
A thermodynamic and kinetic study of the antioxidant activity of natural hydroanthraquinones
Authors: Vo Quan V. , Thong Nguyen Minh , Le Huyen Trinh , Nam Pham Cam , Tam Nguyen Minh , Hoa Nguyen Thi , Mechler Adam
Published: May 2020

Novel hydroanthraquinones isolated from Talaromyces islandicus EN-501 exhibited promising antioxidant properties in preliminary studies, raising the prospect of adapting these compounds for therapeutic use in diseases caused by oxidative stress.
Mussel inspired ZIF8 microcarriers: a new approach for large-scale production of stem cells
Authors: Asadniaye Fardjahromi Mahsa , Razmjou Amir , Vesey Graham , Ejeian Fatemeh , Banerjee Balarka , Chandra Mukhopadhyay Subhas , Ebrahimi Warkiani Majid
Published: May 2020

Mussel inspired ZIF8 microcarriers with high surface area, biocompatibility, and nanoscale surface roughness are applied to enhance mesenchymal stem cell attachment and proliferation in 3D cell culture.
Investigation of cellular uptake mechanism of functionalised gold nanoparticles into breast cancer using SERS
Authors: Kapara Anastasia , Brunton Valerie , Graham Duncan , Faulds Karen
Published: May 2020

Use of sensitive, non-destructive and straightforward 3D SERS for investigating the cellular uptake processes of functionalised nanotags in entire cell volume.
Double annulation of ortho- and peri-C–H bonds of fused (hetero)arenes to unusual oxepino-pyridines
Authors: Shankar Majji , Rit Raja K. , Sau Somratan , Mukherjee Kallol , Gandon Vincent , Sahoo Akhila K.
Published: May 2020

Direct difunctionalization of chemically distinct ortho- and peri-C–H bonds of fused hetero(arenes) is illustrated through an unusual one-pot domino {[4 + 2] & [5 + 2]} double annulation with alkynes for the first time.
The rupture mechanism of rubredoxin is more complex than previously thought
Authors: Scheurer Maximilian , Dreuw Andreas , Head-Gordon Martin , Stauch Tim
Published: May 2020

Using steered molecular dynamics simulations and strain analysis it is shown that, in contrast to previous assumptions, the experimentally found low rupture force of the iron–sulfur-bond in rubredoxin cannot be explained by hydrogen bond networks.
Correction: Tetrafluorinated phenylpyridine based heteroleptic iridium(iii) complexes for efficient sky blue phosphorescent organic light-emitting diodes
Authors: Chen Zhao , Suramitr Songwut , Zhu Nianyong , Ho Cheuk-Lam , Hannongbua Supa , Chen Shuming , Wong Wai-Yeung
Published: May 2020

Correction for ‘Tetrafluorinated phenylpyridine based heteroleptic iridium(iii) complexes for efficient sky blue phosphorescent organic light-emitting diodes’ by Zhao Chen et al., J. Mater. Chem. C, 2020, 8, 2551–2557, DOI: 10.1039/C9TC05779J.
How Athena SWAN has improved research culture
Authors: McKinnon Caroline
Published: May 2020

‘Draw-a-Scientist’ studies have been conducted regularly by educational researchers for several decades. Even today, the stereotype of a ‘Scientist’ as a middle-aged (or older) white male persists. This is a cliché; however, the sad truth is that it retains some resemblance to real life. Although we are getting better at recognizing women and/or ethnicity in science, we are still a long way from achieving equality. The Athena SWAN charter was launched in 2005 in order to help deal with the lack of women in Science, Technology, Engineering, Mathematics and Medicine (STEMM) careers, particularly at higher level roles. In 2015, the Scientific Women’s Academic Network (SWAN) application process changed to encompass a much broader remit, in order to tackle all underrepresentation within the HE sector and provide a positive research culture that benefits everyone.
Quantitative iTRAQ LC-MS/MS reveals muscular proteome profiles of deep pressure ulcers
Authors: Liu Zan , Cui Xu , Hu Yanke , Zhang Pihong
Published: May 2020

Pressure ulcers (PUs) are a common clinical issue lacking effective treatment and validated pharmacological therapy in hospital settings. Ischemia–reperfusion injury of deep tissue, especially muscle, plays a vital role in the formation and development of the overwhelming majority of PUs. However, muscular protein expression study in PUs has not been reported. Herein, we aimed to investigate the muscular proteins profiles in PUs and to explore the pathological mechanism of PUs. The iTRAQ LC-MS/MS was conducted to detect the protein profiles in clinical muscle samples of PUs. The GO and KEGG pathways analyses were performed for annotation of differentially expressed proteins. Protein–protein interaction (PPI) network was constructed by STRING online database, and hub proteins were validated by the immunoblotting. Based on proteomics results, we found a number of proteins that were differentially expressed in PU muscle samples compared with the normal and identified unique proteins expression patterns between these two groups, suggesting that they might involve in pathological process of the disease. Importantly, cathepsin B and D, as well as other autophagy–lysosome and apoptosis associated proteins were identified. Further experiments characterize the expression of these proteins and their regulation in the process of apoptosis and autophagy. These findings may provide novel insights into the mechanisms of lysosome-associated pathways involved in the initiation of PUs. This is the first study linking proteomics to PUs muscle tissues, which indicated cathepsin B and D might be key drug target for PUs.
WITHDRAWN: SIK2 Promotes Cisplatin Resistance Induced by Aerobic Glycolysis in Breast Cancer Cells through PI3K/AKT/mTOR Signaling Pathway
Authors: Zong Shoukai , Dai Wei , Fang Wencheng , Guo Xiangting , Wang Kai
Published: May 2020

The Accepted Manuscript version of this article (published on 27 May 2020) was withdrawn on 12 June 2020 due to concerns over authorship.
Green tea polyphenols ameliorate metabolic abnormalities and insulin resistance by enhancing insulin signalling in skeletal muscle of Zucker fatty rats
Authors: Cheng Jing , Tan Yi , Zhou Jiong , Xiao Linda , Johnson Michael , Qu Xianqin
Published: May 2020

In the present study, we evaluated the metabolic effects of green tea polyphenols (GTPs) in high-fat diet (HFD) fed Zucker fatty (ZF) rats, in particular the effects of GTP on skeletal muscle insulin sensitivity. Body weight, visceral fat, glucose tolerance, lipid profiles and whole-body insulin sensitivity were measured in HFD-fed ZF rats after 8-week-treatment with GTP (200 mg/kg of body weight) or saline (5 ml/kg of body weight). Zucker lean rats were studied as controls. Ex vivo insulin-mediated muscle glucose uptake was assessed. Immunoblotting was used to evaluate the expression of key insulin signalling proteins in skeletal muscle. GTP treatment attenuated weight gain (P<0.05) and visceral fat accumulation (27.6%, P<0.05), and significantly reduced fasting serum glucose (P<0.05) and insulin (P<0.01) levels. Homoeostasis model assessment of insulin resistance (HOMA-IR), a measure of insulin resistance, was lower (P<0.01) in GTP-treated animals compared with ZF controls. Moreover, insulin-stimulated glucose uptake by isolated soleus muscle was increased (P<0.05) in GTP-ZF rats compared with ZF-controls. GTP treatment attenuated the accumulation of ectopic lipids (triacyl- and diacyl-glycerols), enhanced the expression and translocation of glucose transporter-4, and decreased pSer612IRS-1 and increased pSer473Akt2 expression in skeletal muscle. These molecular changes were also associated with significantly decreased activation of the inhibitory (muscle-specific) protein kinase (PKC) isoform, PKC-θ. Taken together, the present study has shown that regular ingestion of GTP exerts a number of favourable metabolic and molecular effects in an established animal model of obesity and insulin resistance. The benefits of GTP are mediated in part by inhibiting PKC-θ and improving muscle insulin sensitivity.
Near‐optimal hybrid precoding for millimeter wave massive MIMO systems via cost‐efficient Sub‐connected structure
Authors: Huang Yu , Liu Chen , Song Yunchao , Yu Xiaolei
Published: May 2020

Millimeter wave (mmWave) massive multiple‐input multiple‐output (MIMO) is a promising technology for next generation wireless communications. The utilisation of traditional full digital precoding techniques for mmWave massive MIMO systems is too costly. Fortunately, the hybrid (analogue/digital) precoding is a better choice. In this study, the authors investigate a near‐optimal iterative approximation hybrid precoding algorithm via cost‐efficient sub‐connected structure for mmWave massive MIMO systems. Based on the minimum mean square error (MSE) criterion, the optimal design of the proposed hybrid precoders is non‐convex. The original problem is reformulated as two optimisation sub‐problems, where one of the sub‐problems is convex and another is non‐convex. First, the authors convert the non‐convex sub‐problem into a convex problem by relaxing the constant modulus constraint from beampattern with interference control method, and eliminating the block diagonal constraint from vector operation with the properties of Kronecker product. Then the two convex sub–problems are solved iteratively. The proposed algorithm can achieve a highly approximate optimal solution, which can be theoretically demonstrated to converge to a Karush‐Kuhn‐Tucker point of the original problem. Simulation results show that the proposed algorithm via both sub–connected and fully connected structure gets favourable performance in terms of MSE and achievable rate.
Image super‐resolution based on conditional generative adversarial network
Authors: Gao Hongxia , Chen Zhanhong , Huang Binyang , Chen Jiahe , Li Zhifu
Published: May 2020

Generative adversarial network (GAN) is one of the most prevalent generative models that can synthesise realistic high‐frequency details. However, a mismatch between the input and the output may arise when GAN is directly applied to image super‐resolution. To alleviate this issue, the authors adopted a conditional GAN (cGAN) in this study. The cGAN discriminator attempted to guess whether the unknown high‐resolution (HR) image was produced by the generator with the aid of the original low‐resolution (LR) image. They propose a novel discriminator that only penalises at the scale of the patch and, thus, has relatively few parameters to train. The generator of cGAN is an encoder–decoder with skip connections to shuttle the shared low‐level information directly across the network. To better maintain the low‐frequency information and recover the high‐frequency information, they designed a generator loss function combining adversarial loss term and L1 loss term. The former term is beneficial to the synthesis of fine‐grained textures, while the latter is responsible for learning the overall structure of the LR input. The experiments revealed that the proposed method could generate HR images with richer details and less over‐smoothness.
300 GHz radar object recognition based on deep neural networks and transfer learning
Authors: Sheeny Marcel , Wallace Andrew , Wang Sen
Published: May 2020

For high‐resolution scene mapping and object recognition, optical technologies such as cameras and LiDAR are the sensors of choice. However, for future vehicle autonomy and driver assistance in adverse weather conditions, improvements in automotive radar technology and the development of algorithms and machine learning for robust mapping and recognition are essential. In this study, the authors describe a methodology based on deep neural networks to recognise objects in 300 GHz radar images using the returned power data only, investigating robustness to changes in range, orientation and different receivers in a laboratory environment. As the training data is limited, they have also investigated the effects of transfer learning. As a necessary first step before road trials, they have also considered detection and classification in multiple object scenes.
General method to mitigate the continuous wave interference and narrowband interference for GNSS receivers
Authors: Lv Qingshui , Qin Honglei
Published: May 2020

A low‐complexity method based on the second‐order direct infinite impulse response (IIR) notch and its cascaded form for global navigation satellite systems (GNSSs) is proposed to mitigate the continuous wave interference (CWI) and narrowband interference (NI) as well as their mixed interference. The number of the cascaded stages is selected by the bandwidth of NI as well as that of the second‐order direct IIR notch. The parameters of the second‐order direct IIR notch and the bandwidth of NI are determined by the fast Fourier transform. To evaluate the performance of the proposed method, the authors conduct the simulation experiment and real‐data experiment. In each experiment, the CWI scenario, the NI scenario and the mixed interference of CWI and NI scenarios are verified. The results of experiments depict the effectiveness of the introduced method.
Polarisation and source structure of solar stationary type IV radio bursts
Authors: Salas-Matamoros Carolina , Klein Karl-Ludwig
Published: May 2020

The reconfiguration of the magnetic field during and after a coronal mass ejection (CME) may be accompanied by radio emission from non-thermal electrons. In particular, stationary type IV bursts (also called storm continua) are emitted by electrons in closed magnetic configurations usually located in the wake of the outward-travelling CME. Although stationary type IV bursts, which stand out by their long duration (up to several hours) and strong circular polarisation, have been known for more than fifty years, there have been no systematic studies since the 1980s. In this work we use the data pool of the Nançay Radioheliograph together with white-light coronagraphy, EUV imaging and magnetography from the SoHO, Proba2, SDO and STEREO spacecraft to revisit the source structure and polarisation of a sample of seven well-defined stationary type IV bursts at decimetre-to-metre wavelengths. The radio sources are most often found in one leg, in one case both legs, of the magnetic flux rope erupting into the high corona during the CME. The cross-correlation of the brightness temperature time profiles in the event with sources in both legs implies that the radiating electrons have energies of a few tens of keV. Comparison with the magnetic field measured in the photosphere and its potential extrapolation into the corona shows that the radio emission is in the ordinary mode. This result was inferred historically by means of the hypothesis that the magnetic field orientation in the radio source was that of the dominant sunspot in the parent active region. This hypothesis is shown here to be in conflict with noise storms in the same active region. It is confirmed that the polarisation of stationary type IV continua may be strong, but is rarely total, and that it gradually increases in the early phase of the radio event. We find that the increase is related to the gradual disappearance of some weakly polarised or unpolarised substructure, which dominates the first minutes of the radio emission.
Effects of mancozeb on the testicular histology of the zebrafish (Danio rerio)
Authors: Abar Gürol Merve , Arman Sezgi , Yön Nazan Deniz
Published: May 2020

Reproduction is a critical and sensitive process for population continuity of the externally fertilizing aquatic organisms. Environmental pollution may adversely effect the reproductive activities of fish. Pesticides are the mobile chemicals that are known to pollute the aquatic ecosystems. Mancozeb is an ethylene-bis-dithiocarbamate (EBDC) fungicide that is frequently used to protect fruits, vegetables, vineyards and field crops against a wide range of fungal diseases. The aim of the current work was to evaluate the acute toxic effects of mancozeb on the testis tissues of zebrafish (Danio rerio). Zebrafish were exposed to 5 ppm and 7.5 ppm of mancozeb concentrations for five days. Testis tissues were removed and fixed in 10% neutral buffered formalin solution. Specimens were embedded in paraffin and 5 μm serial sections were stained with hematoxylin and eosin. The control and the experimental samples were investigated by light microscopy and histopathological changes were evaluated. Mancozeb gave rise to degenerative spermatogenic cells, seminiferous tubule disorganizations, fibrosis, hemorrhage, vacuolization, hypertrophy of spermatocytes, edema, decreased spermatogenic cell clusters and sperms, pyknotic and karyolytic nuclei. These results showed that mancozeb could interrupt the reproductive activity and decrease the fertilization ratio of zebrafish.
A four-field three-phase flow model with both miscible and immiscible components
Authors: Hérard Jean-Marc , Hurisse Olivier , Quibel Lucie
Published: May 2020

A three-phase flow model with hybrid miscibility constraints is proposed: three immiscible phases are considered (liquid water, liquid metal and gas) but the gaseous phase is composed with two miscible components (steam water and non-condensable gas). The modelling approach is based on the building of an entropy inequality for the system of partial differential equations: once an interfacial velocity is given by the user, the model is uniquely defined, up to some relaxation time scales, and source terms complying with the second principle of thermodynamics can then be provided. The convective part of the system is hyperbolic when fulfilling a non-resonance condition and classical properties are studied (Riemann invariants, symmetrization). A key property is that the system possesses uniquely defined jump conditions. Last, preservation of thermodynamically admissible states and pressure relaxation are investigated.
Structure and dynamics of hydrodynamically interacting finite-size Brownian particles in a spherical cavity: Spheres and cylinders
Authors: Li Jiyuan , Jiang Xikai , Singh Abhinendra , Heinonen Olle G. , Hernández-Ortiz Juan P. , de Pablo Juan J.
Published: May 2020

The structure and dynamics of confined suspensions of particles of arbitrary shape are of interest in multiple disciplines from biology to engineering. Theoretical studies are often limited by the complexity of long-range particle–particle and particle–wall forces, including many-body fluctuating hydrodynamic interactions. Here, we report a computational study on the diffusion of spherical and cylindrical particles confined in a spherical cavity. We rely on an immersed-boundary general geometry Ewald-like method to capture lubrication and long-range hydrodynamics and include appropriate non-slip conditions at the confining walls. A Chebyshev polynomial approximation is used to satisfy the fluctuation–dissipation theorem for the Brownian suspension. We explore how lubrication, long-range hydrodynamics, particle volume fraction, and shape affect the equilibrium structure and the diffusion of the particles. It is found that once the particle volume fraction is greater than 10%, the particles start to form layered aggregates that greatly influence particle dynamics. Hydrodynamic interactions strongly influence the particle diffusion by inducing spatially dependent short-time diffusion coefficients, stronger wall effects on the particle diffusion toward the walls, and a sub-diffusive regime—caused by crowding—in the long-time particle mobility. The level of asymmetry of the cylindrical particles considered here is enough to induce an orientational order in the layered structure, decreasing the diffusion rate and facilitating a transition to the crowded mobility regime at low particle concentrations. Our results offer fundamental insights into the diffusion and distribution of globular and fibrillar proteins inside cells.
Validating universal scaling during the sol-gel transition
Authors: Patrick Chris
Published: May 2020

Measurements of two gel forming systems allowed experimental verification of theoretically proposed scaling laws for the sol-gel transition.
Excited state mean-field theory without automatic differentiation
Authors: Zhao Luning , Neuscamman Eric
Published: May 2020

We present a formulation of excited state mean-field theory in which the derivatives with respect to the wave function parameters needed for wave function optimization (not to be confused with nuclear derivatives) are expressed analytically in terms of a collection of Fock-like matrices. By avoiding the use of automatic differentiation and grouping Fock builds together, we find that the number of times we must access the memory-intensive two-electron integrals can be greatly reduced. Furthermore, the new formulation allows the theory to exploit the existing strategies for efficient Fock matrix construction. We demonstrate this advantage explicitly via the shell-pair screening strategy with which we achieve a cubic overall cost scaling. Using this more efficient implementation, we also examine the theory’s ability to predict charge redistribution during charge transfer excitations. Using the coupled cluster as a benchmark, we find that by capturing orbital relaxation effects and avoiding self-interaction errors, excited state mean field theory out-performs other low-cost methods when predicting the charge density changes of charge transfer excitations.
Symmetric fielding of the largest diamond capsule implosions on the NIF
Authors: Kritcher A. L. , Casey D. T. , Thomas C. A. , Zylstra A. B. , Hohenberger M. , Baker K. , Le Pape S. , Bachmann B. , Bhandarkar S. , Biener J. , Braun T. , Clark D. , Divol L. , Döppner T. , Hinkel D. , Kong C. , Mariscal D. , Millot M. , Milovich J. , Nikroo A. , Pak A. , Rice N. , Robey H. , Stadermann M. , Sevier J. , Strozzi D. , Weber C. , Wild C. , Woodworth B. , Edwards J. , Callahan D. A. , Hurricane O. A.
Published: May 2020

We present results for the largest diamond capsule implosions driven symmetrically on the National Ignition Facility (NIF) (inner radius of ∼1050 μm) without the use of cross beam transfer in cylindrical Hohlraums. We show that the methodology of designing Hohlraum parameters in a semi-empirical way using an extensive database resulted in a round implosion. In addition, we show that the radiation flux symmetry is well controlled during the foot of the pulse and that swings in P2 symmetry between the inflight dense shell and hot spot are within ±4 μm and that swings around peak compression are also within the symmetry specification of ±4 μm. We observed a stronger dependence of symmetry on the capsule scale than previously observed and also observed enhanced inner beam propagation for experiments using a gas fill density of 0.3 mg/cm3 and 1000 μm inner radius capsules. We have observed sufficient symmetry and mass remaining at near full NIF power and energy, up to 480 TW and 1.9 MJ, with little laser–plasma interactions (low laser backscattered light) and predict that this design could support extended NIF energy of up to 2.1 MJ.
Z-pinch fusion
Authors: Shumlak U.
Published: May 2020

The Z-pinch configuration offers the promise of a compact fusion device owing to its simple geometry, unity beta, and absence of external magnetic field coils. Increasing the axial current compresses the plasma, resulting in a rapid rise of the fusion reaction rate. Historically, the Z pinch has been plagued by fast growing instabilities that limit plasma lifetimes. Recent progress has resulted from investigating approaches that provide stability. One approach exploits sheared-flow stabilization to produce an equilibrium Z pinch, which sustains the compressed plasma state for durations much longer than other plasma timescales. Recent experimental and simulation results encourage pursuit of the stabilized Z pinch to explore its fusion performance limits.
Dark current analysis of germanium-on-insulator vertical p-i-n photodetectors with varying threading dislocation density
Authors: Son Bongkwon , Lin Yiding , Lee Kwang Hong , Chen Qimiao , Tan Chuan Seng
Published: May 2020

Dark current characteristics of germanium (Ge) vertical p-i-n photodetectors were studied. Ge photodetectors were demonstrated on the germanium-on-insulator (GOI) platforms realized via direct wafer bonding and layer transfer. GOI platforms with two different threading dislocation densities (TDDs) of 3.2 × 106 cm−2 (low TDD) and 5.2 × 108 cm−2 (high TDD) were varied via furnace annealing in oxygen ambient. An ultra-low dark current density of 1.12 mA/cm2 for epi-Ge photodetectors was obtained for a low TDD Ge photodetector. This is reduced by a factor of 53 in comparison with a high TDD Ge photodetector. A dominant leakage contribution component shifts from bulk leakage to surface leakage as TDD decreases to 3.2 × 106 cm−2, suggesting that advanced surface passivation is required to further reduce the leakage current. Through an activation energy study, it is revealed that a primary bulk leakage mechanism shifts from Shockley–Read–Hall (SRH) leakage to diffusion leakage in a temperature range of 323–353 K. The surface leakage performed with plasma enhanced chemical vapor deposition-deposited SiO2 is governed by SRH and trap-assisted tunneling leakage processes. Two orders of magnitude enhancement in the effective carrier lifetime is observed with the reduction in TDD. This work suggests that bulk leakage current density and effective lifetime analysis provide a better understanding of TDD-dependent dark leakage current study.
Goos–Hänchen effect enabled optical differential operation and image edge detection
Authors: Xu Dingyu , He Shanshan , Zhou Junxiao , Chen Shizhen , Wen Shuangchun , Luo Hailu
Published: May 2020

The Goos–Hänchen effect has found many important applications in photonics and optoelectronics since its discovery in 1947. Here, we propose unique applications of the Goos–Hänchen effect in optical differential operation and image edge detection. This Letter describes the theoretical foundation and experimental realization of the proposed scheme. By incorporating with the microscopy technique, our scheme may find important applications in cell and molecular imaging.
Structural changes upon magnetic ordering in magnetocaloric AlFe2B2
Authors: Oey Yuzki M. , Bocarsly Joshua D. , Mann Dallas , Levin Emily E. , Shatruk Michael , Seshadri Ram
Published: May 2020

With a Curie temperature just above room temperature, AlFe2B2 is a useful magnetocaloric material composed of earth-abundant elements. We employ temperature-dependent high-resolution synchrotron X-ray diffraction to establish with high certainty that the paramagnetic to ferromagnetic transition in AlFe2B2 is of second order, showing no discontinuity in lattice parameters or cell volume. Nevertheless, the lattice parameters undergo anisotropic changes across the transition with distinct differences in the thermal expansion coefficients. While the a and b lattice parameters show a positive thermal expansion, c shows a negative thermal expansion. We link these changes to the respective interatomic distances to determine the contribution of magnetism to the anisotropic structural evolution. The work underpins the possible role of magnetostructural coupling in driving the magnetocaloric effect in AlFe2B2.
A novel experimental technique for the fabrication of the vitamin B12 nucleus using quartz crystal microbalance: Statistical physics modeling and new microscopic properties
Authors: Ben Yahia Manel , Ben Yahia Mohamed
Published: May 2020

A novel adsorption model for the description of adsorption isotherms of cobalt nitrate on porphyrins H2TPP and H2TTPP is developed in the present paper. Experimental data were measured at five temperatures using the quartz crystal microbalance technique and were discussed to choose the most reproductive adsorbent for the achievement of the vitamin B12 nucleus. Then, the modeling treatment was established based on the grand canonical formalism in statistical physics by taking into account the lateral interaction between the adsorbate particles. This leads to a six parameter equation describing the complexation process at the molecular level. Actually, there is a good correlation between experimental data and those calculated by using the double-layer L.B.L. model. It was found that cobalt ions were adsorbed via a multi-docking mechanism onto the two adsorbents. The study of the density of receptor sites (PM) confirmed the endothermic nature of the two complexation processes. The van der Waals parameters indicated that the disturbances following the lateral interactions between the adsorbates are the highest in the case of tetraphenylporphyrin. The magnitude of the calculated adsorption energies reveals that cobalt is physisorbed onto tetraphenylporphyrin, whereas chemical forces were found in the case of porphyrins (H2TTPP). In addition, the proposed model allows the prediction of some adsorption thermodynamic functions, which govern the adsorption mechanism, such as entropy, Gibbs free enthalpy, and internal energy.
Fitting potential energy surfaces with fundamental invariant neural network. II. Generating fundamental invariants for molecular systems with up to ten atoms
Authors: Chen Rongjun , Shao Kejie , Fu Bina , Zhang Dong H.
Published: May 2020

Symmetry adaptation is crucial in representing a permutationally invariant potential energy surface (PES). Due to the rapid increase in computational time with respect to the molecular size, as well as the reliance on the algebra software, the previous neural network (NN) fitting with inputs of fundamental invariants (FIs) has practical limits. Here, we report an improved and efficient generation scheme of FIs based on the computational invariant theory and parallel program, which can be readily used as the input vector of NNs in fitting high-dimensional PESs with permutation symmetry. The newly developed method significantly reduces the evaluation time of FIs, thereby extending the FI-NN method for constructing highly accurate PESs to larger systems beyond five atoms. Because of the minimum size of invariants used in the inputs of the NN, the NN structure can be very flexible for FI-NN, which leads to small fitting errors. The resulting FI-NN PES is much faster on evaluating than the corresponding permutationally invariant polynomial-NN PES.
Hugoniot states and optical response of soda lime glass shock compressed to 120 GPa
Authors: Renganathan P. , Duffy T. S. , Gupta Y. M.
Published: May 2020

In contrast to relatively pure silica glass (fused silica—FS), commercial silica-rich glasses contain significant fractions of additional oxide components. In particular, soda-lime glass (SLG) consists of approximately 71% SiO2 by weight, which raises the question: what is the effect of additional cations on the shock compression response of silica-rich glasses? To address this question, plate impact experiments were conducted to determine the high-pressure Hugoniot states for shocked SLG (37 to 120 GPa) and compared with recently reported results on FS. Using laser interferometry, particle velocity profiles were measured at the impact surface and at the SLG/LiF window interface. In all experiments, the transmitted profiles show a single shock wave, with no features indicative of a phase transformation. The Hugoniot states determined from the wave profiles are described well using a linear shock velocity–particle velocity relation. Interferometry measurements (using 1550-nm wavelength laser) at the impact surface show that SLG is transparent when shocked to 55 GPa, transparent for tens of nanoseconds after impact between 55 and 81 GPa, and opaque beyond 81 GPa. From impact surface measurements, a linear relationship between the apparent and true particle velocity was observed, resulting in a linear relationship between the refractive index (at 1550 nm) and density. At 120 GPa, the SLG density is nearly twice its ambient value, indicating that SLG can achieve highly dense amorphous states. When compared to FS, shocked SLG is much less compressible and likely does not transform to a crystalline phase. A plausible explanation for this difference is suggested.
Assessing the impact of disjoining pressure on thin-film evaporation with atomistic simulation and kinetic theory
Authors: Wang Xiaoman , Li Yang , Malen Jonathan A. , McGaughey Alan J. H.
Published: May 2020

Molecular dynamics (MD) simulations are applied to validate the Hertz–Knudsen–Schrage (HKS) relation for the evaporation mass flux in the presence of disjoining pressure. A non-equilibrium MD simulation system is designed to directly extract the evaporation mass flux for a Lennard-Jones fluid. The temperatures, pressures, properties, and disjoining pressure required to evaluate the HKS relation are obtained from the non-equilibrium MD simulation and complementary equilibrium MD simulations. The direct MD evaporation mass flux and that from the HKS relation agree within 10%. We define an evaporation Kapitza length that estimates where the liquid conduction and evaporation thermal resistances are equal. We propose that surface structures that promote film thicknesses comparable to or smaller than the evaporation Kapitza length, but larger than the adsorbed film thickness, will maximize the evaporation rate.
Barrier heights and Fermi level pinning in metal contacts on p-type GaN
Authors: Wahid Sumaiya , Chowdhury Nadim , Alam Md Kawsar , Palacios Tomás
Published: May 2020

In this work, we investigate the current–voltage (I–V) characteristics of various metal contacts such as Ni/Au, Ir/Au, Ru/Au, Mo/Au, and W/Au on p-GaN. For this, we fabricated different bilayer metal contacts on the same epitaxial heterostructure of GaN, which ensures the uniformity of the experimental data. I–V measurements were then carried out for circular and/or linear contact pads with different spacing values. In each case, the Schottky barrier height of the metal contacts is calculated using the reverse I–V method. A strong Fermi level pinning was found in all these structures on p-GaN, with a pinning factor of ∼0.15. In addition, a very low Ohmic contact resistivity of 3.45 × 10−6 Ω cm2 was measured for the Ru/Au contacts on p-GaN.
Patients’ cultural and spiritual explanatory models in health encounters: a focus on the efficacy of cancer prevention strategies in women from South Sudan
Authors: Peterson Paula
Published: May 2020

This qualitative study examined non-clinical factors that affect health, namely the cultural and spiritual beliefs of the patient. The study focuses on women from South Sudan. Although the overt religious adherence of these women is familiar to mainstream Australia (i.e. Christian), they are culturally diverse from the mainstream. The experiences of five women were documented. These women, all regarded as community leaders, were also asked about their assessment of the views of the wider community of women from South Sudan. This study informs targeted health promotion messages for a significant community in Australia. It is anticipated that the findings of this research, although not generalisable to the whole South Sudanese community or to all those with a refugee background, will provide important information to guide the development of culturally appropriate health care into the future. The findings point to the need for enhanced clinical education around communication, especially in relation to understanding the patients’ explanatory models of health. The findings have implications for patient education strategies. Finally, the findings reinforce the importance of engaging the community in the development of those strategies and ensuring their input into further research.
Voltage-dependent structural models of the human Hv1 proton channel from long-timescale molecular dynamics simulations
Authors: Geragotelis Andrew D. , Wood Mona L. , Göddeke Hendrik , Hong Liang , Webster Parker D. , Wong Eric K. , Freites J. Alfredo , Tombola Francesco , Tobias Douglas J.
Published: May 2020

Significance

The Hv1 voltage-gated proton channels are important for various physiological functions that include the extrusion of acid from cells, oxidative bursts in phagocytes, and immune response. A lack of structural information under physiological conditions has left many unanswered questions about the mechanism of proton conduction. We employed molecular dynamics simulations to generate structural models of the open and closed states of the channel in the presence of applied membrane potentials, without any initial assumptions on the position of the voltage sensor and without relying on homology on functional similarities between Hv1 and other voltage-sensitive proteins. We have thus provided molecular-scale insights into the mechanism of voltage-dependent activation that could inform therapeutic strategies for modulating the function of Hv1.
Broadband terahertz solid-state emitter driven by Yb:YAG thin-disk oscillator
Authors: Barbiero Gaia , Wang Haochuan , Brons Jonathan , Chen Bo-Han , Pervak Vladimir , Fattahi Hanieh
Published: May 2020

We report on a table-top, high-power, terahertz (THz) solid-state emitter driven by few-cycle near-infrared pulses at 16 MHz repetition rate in gallium phosphide (GaP) crystals. Two external nonlinear multi-pass cells are used to shorten the output of a home-built, 100 W, 265 fs, 6.2 μJ Yb:YAG thin-disk oscillator, operating at 1030 nm, to 18 fs with 3.78 μJ pulse energy. The broadband spectrum of the THz driver allowed for the extension of the THz cutoff frequency to 5.7 THz at the dynamic range of 104. By employing the high-power Yb:YAG thin-disk oscillator, the low efficiency of the THz generation is circumvented, resulting in the generation of up to 100 μW, multi-octave THz pulses at 5 THz cutoff frequency in a 2 mm thick GaP crystal.
A comparison of consumer-grade electronic radon monitors
Authors: Warkentin Pam , Curry Erin , Michael Oghenekome , Bjorndal Brian
Published: May 2020

Radon is a radioactive gas which is naturally occurring in soil and can accumulate to concentrated levels inside homes and buildings. Exposure to elevated levels of radon leads to an increased risk of developing lung cancer. In recent years there has been a rise in the popularity of consumer-grade electronic radon monitors. The monitors are appealing to homeowners due to the ease of use and the ability to keep track of radon levels during the process of conducting a radon test. However, there is currently no independent process to evaluate the relative performance of these monitors against known levels of radon. In this study, three sample units of six different models representing three different manufacturers of consumer-grade electronic radon monitors were exposed to three different levels of radon in a controlled environment to evaluate their precision and accuracy. Two separate tests were conducted at the Canadian guideline level to accommodate for ‘indoor winter’ and ‘summer’ conditions. The purpose of the study was to compare the performance of the different consumer-grade electronic radon monitors and determine which factors should be considered when using these monitors to inform mitigation decisions. The monitors had a range of uncertainty from 2%–15% with a range of precision from 1%–24%. The monitors performed better at higher radon levels than at levels near the Canadian guideline level of 200 Bq m−3, and slightly better during ‘summer’ conditions than during ‘indoor winter’ conditions. While the monitors provide homeowners with a very specific number indicating their radon level, it was noted that this number should be considered with respect to a ‘confidence ratio’ or ‘range’ which could be done through a publicly available online tool which could provide the radon level range for a given radon level and device grade.
Impact of the capture time on the series resistance of quantum-well diode lasers
Authors: Boni A , Wünsche H J , Wenzel H , Crump P
Published: May 2020

Electrons and holes injected into a semiconductor heterostructure containing quantum wells are captured with a finite time. We show theoretically that this very fact can cause a considerable excess contribution to the series resistivity and this is one of the main limiting factors to higher efficiency for GaAs based high-power lasers. The theory combines a standard microscopic-based model for the capture-escape processes in the quantum well with a drift-diffusion description of current flow outside the quantum well. Simulations of five GaAs-based devices differing in their Al-content reveal the root-cause of the unexpected and until now unexplained increase of the series resistance with decreasing heat sink temperature measured recently. The finite capture time results in resistances in excess of the bulk layer resistances (decreasing with increasing temperature) from 1 mΩ up to 30 mΩ in good agreement with the experiment.
Computation and analysis of light emission in two-bubble sonoluminescence*
Authors: Liang Jin-Fu , Wu Xue-You , An Yu , Chen Wei-Zhong , Wang Jun
Published: May 2020

We perform a computational simulation of light emissions from two sonoluminescent bubbles in water. Our simulation includes the radii of two bubbles, radiation acoustic pressures, and light emission spectra by numerically solving the pulsing equations of a two-bubble system and the equations of gas dynamics. The simulation results demonstrate that the motion of each bubble in the two-bubble system is restrained because of the radiation acoustic pressures from the other pulsing bubble. The restrained oscillation of a bubble with a small ambient radius is stronger than that of a bubble with a large ambient radius under the same driving acoustic pressure. This effect increases when the distance between the two bubbles decreases. When compared to single-bubble sonoluminescence, the interaction between two bubbles leads to generation of different spectral characteristics.
Electrical properties of m × n cylindrical network*
Authors: Tan Zhi-Zhong , Tan Zhen
Published: May 2020

We consider the problem of electrical properties of an m × n cylindrical network with two arbitrary boundaries, which contains multiple topological network models such as the regular cylindrical network, cobweb network, globe network, and so on. We deduce three new and concise analytical formulae of potential and equivalent resistance for the complex network of cylinders by using the RT-V method (a recursion-transform method based on node potentials). To illustrate the multiplicity of the results we give a series of special cases. Interestingly, the results obtained from the resistance formulas of cobweb network and globe network obtained are different from the results of previous studies, which indicates that our research work creates new research ideas and techniques. As a byproduct of the study, a new mathematical identity is discovered in the comparative study.