bluuebunny/crossref_metadata_2025 huggingface dataset:
Distributed balancing energy activation and exchange optimisation
Authors: Håberg Martin , Doorman Gerard
Published: July 2019

European balancing markets are presently fragmented and mostly national. Integrating them on common platforms requires the ability to identify optimal balancing energy volumes to be activated and exchanged to cover imbalances across the interconnected system, but this leads to new challenges. To avoid balancing energy flows compromising operational security, capacity limitations in the transmission network should be taken into account in the optimisation. However, a zonal market structure and limited computational time inhibit using detailed models in the optimisation. This study describes and demonstrates a distributed formulation for optimisation of activation and exchange of balancing energy. Using Benders decomposition, the optimisation is separated into local activation problems that are smaller and less complex, distributing the computational effort. A single exchange problem identifies the optimal exchange volumes between geographical areas using optimality cuts obtained in the local subproblems. The proposed formulation is capable of optimising balancing decisions across a large, interconnected system, while still keeping a zonal market structure and taking detailed network constraints into account.
Design methodology of the fractal annular ring antennas with the wideband operation
Authors: SamadpourHendevari Maryam , Pourziad Ali , Nikmehr Saeid
Published: July 2019

In this paper, a novel annular ring antenna is proposed to achieve a multi‐wideband antenna. The structure is annular ring. For systematic design of the antenna, fractal shape is employed. Each iteration of the structure acts as a matching load for the previous section. Consequently, by increasing the electrical current path, multi‐band and wideband performances can be achieved. For tuning the frequency bands, three slots are cut from the ground plane. The first operating band is from 1.47 GHz to 1.86 GHz (fractional band width (FBW): 23.42%), the second band is from 2.44 GHz to 3.51 GHz (FBW: 35.96%), and the third one is from 4.49 GHz to 5.34 GHz (FBW: 17.29%). Furthermore, the antenna has the ability to cover the ultra‐wideband (UWB) spectrum by inserting two vias in the substrate. Using vias, impedance matching of the antenna is improved in the frequency range from 2.8 GHz to 5 GHz (FBW: 56.4%) with criteria |S11|<−10 dB. Also, it has a noticeable impedance bandwidth (FBW: 117%) from 1.3 GHz to 5 GHz with criteria |S11|<−6 dB. A prototype of the proposed antenna is fabricated and tested. The measurement and simulation results are in good agreement.
Midcarpal Structure Effect on Force Distribution through the Radiocarpal Joint
Authors: Wollstein Ronit , Kramer Aviv , Friedlander Scott , Werner Frederick
Published: July 2019

Background Wrist structure is complicated by distinct anatomical patterns. Previous studies defined radiographic wrist types based on lunate and capitate shape within the midcarpal joint. We hypothesized that these disparate structural patterns will transfer forces differently through the wrist.

Objective This study aims to correlate force transferred to the distal radius and ulna with morphological measurements in cadaver arms.

Methods Radiographs from 46 wrists, previously tested for force transfer between the radius and ulna, were examined. The percentage of compressive force through the distal ulna was determined by mounting load cells to the radius and ulna, while 22.2 Newton (N) tensile forces were individually applied to multiple tendons. Each wrist was tested in a neutral flexion–extension and radial-ulnar deviation position.

Results Wrist type and lunate type were associated with percentage of force transfer through the ulna (p = 0.002, p = 0.0003, respectively). Percentage of force transfer was correlated with capitate circumference (p = 0.02, r = 0.34).

Conclusions This study supports distinct force transfer between morphological wrist types.

Clinical Relevance Understanding the mechanical significance of different structural variations in the wrist bones will improve our ability to understand wrist function and the distinctive development of wrist pathology.

Level of Evidence This is a Level II study.
The large time behavior of the free boundary for one dimensional compressible Navier-Stokes equations
Authors: Ye Yulin , Li Zilai
Published: July 2019

In this paper, we study the large time behavior of the free boundary for both full Navier-Stokes (NS) equations with heat conduction (FNS) and isentropic NS equations in one dimensional space. We find an interesting phenomenon that the interfaces which separate the fluid and vacuum in FNS or NS will expand outward at exactly the same algebraic rates in time for all γ > 1, except γ = 2, just provided that the initial total entropy of the fluid is positive or the mass of the fluid is conserved, respectively. It should be emphasized that the required condition for FNS equations naturally reduces to the one for isentropic NS equations in which the entropy is constant.
A high-pressure visual flow loop for hydrate blockage detection and observation
Authors: Liu Zheyuan , Yang Mingjun , Zhang Hanquan , Xiao Bo , Yang Lei , Zhao Jiafei
Published: July 2019

More than 65% of the worldwide natural gas is transported through pipelines. Gas hydrate formation and blockage in the pipeline are commonly encountered, causing significant problems in safe and efficient transportation. Yet the instrument simulating the high-pressure multiphase flow and demonstrating the hydrate blocking behavior at flowing conditions is not available. In this work, a high-pressure visual flow loop is developed to detect and observe the hydrate nucleation, growth, and deposition during the multiphase flow. The pressure limit is designed to be 8 MPa, and the temperature can go down to −20 °C. This device allows a direct observation of the gas-liquid flow regime during transportation; investigations on the initiation and evolution of hydrate blockage in the dead-leg section, U-shaped region, and rising pipes are now possible. Sensors are distributed along the pipelines to detect the pressure and temperature change; the differential pressure is used to effectively detect the degree of hydrate blockage, which increases upon hydrate formation. The visual flow loop could also help examine the effect of shut-down and restart of the pump on the flow behavior. The system has been verified feasible demonstrating the flow behavior and predict hydrate blockage. The developed device would help understand the mechanism of hydrate blockage in the transportation pipelines and provide guidance to efficiently avoid such problems.
Implications of laser beam metrology on laser damage temporal scaling law for dielectric materials in the picosecond regime
Authors: Ollé A. , Luce J. , Roquin N. , Rouyer C. , Sozet M. , Gallais L. , Lamaignère L.
Published: July 2019

We report on the implications that the temporal and spatial beam metrologies have on the accuracy of temporal scaling laws of Laser Induced Damage Threshold (LIDT) for dielectric materials in the picosecond regime. Thanks to a specific diagnostic able to measure the temporal pulse shape of subpicosecond and picosecond pulses, we highlight through simulations and experiments how the temporal shape has to be taken into account first in order to correctly understand the temporal dependency of dielectrics LIDT. This directly eases the interpretation of experimental temporal scaling laws of LIDT and improves their accuracy as a prediction means. We also give numerically determined benchmark temporal scaling laws of intrinsic LIDT for SiO2 (thin film) based on the model developed for this work. Finally, we show as well what kind of spatial metrology is needed during any temporal scaling law determination to take into account potential variations of the spatial profile.
Quasioptical modeling of wave beams with and without mode conversion. I. Basic theory
Authors: Dodin I. Y. , Ruiz D. E. , Yanagihara K. , Zhou Y. , Kubo S.
Published: July 2019

This work opens a series of papers where we develop a general quasi-optical theory for mode-converting electromagnetic beams in plasma and implement it in a numerical algorithm. Here, the basic theory is introduced. We consider a general quasimonochromatic multicomponent wave in a weakly inhomogeneous linear medium with no sources. For any given dispersion operator that governs the wave field, we explicitly calculate the approximate operator that governs the wave envelope ψ to the second order in the geometrical-optics parameter. Then, we further simplify this envelope operator by assuming that the gradient of ψ transverse to the local group velocity is much larger than the corresponding parallel gradient. This leads to a parabolic differential equation for ψ (“quasioptical equation”) on the basis of the geometrical-optics polarization vectors. Scalar and mode-converting vector beams are described on the same footing. We also explain how to apply this model to electromagnetic waves in general. In the next papers of this series, we report successful quasioptical modeling of radio frequency wave beams in magnetized plasma based on this theory.
Quasioptical modeling of wave beams with and without mode conversion. III. Numerical simulations of mode-converting beams
Authors: Yanagihara K. , Dodin I. Y. , Kubo S.
Published: July 2019

This work continues a series of papers where we propose an algorithm for quasi-optical modeling of electromagnetic beams with and without mode conversion. The general theory was reported in the first paper of this series, where a parabolic partial differential equation was derived for the field envelope that may contain one or multiple modes with close group velocities. In the second paper, we presented a corresponding code PARADE (PAraxial RAy DEscription) and its test applications to single-mode beams. Here, we report quasi-optical simulations of mode-converting beams for the first time. We also demonstrate that PARADE can model splitting of two-mode beams. The numerical results produced by PARADE show good agreement with those of one-dimensional full-wave simulations and also with conventional ray tracing (to the extent that one-dimensional and ray-tracing simulations are applicable).
Experimental confirmation of the nearly power-law relation between macroscopic current and characteristic current density in carbon nanotube-based large-area field emitters
Authors: Popov Eugeni O. , Filippov Sergey V. , Kolosko Anatoly G. , de Assis Thiago A.
Published: July 2019

Carbon nanotube (CNT) films are potential candidates for viable applications in large-area field electron emission based X-ray sources. An important issue in large-area field electron emitters (LAFEs) is the connection between the macroscopic emission current iM and the characteristic current density JC, linking experimental observations to field emission theories. The quantity JC is often associated with the site in the LAFE with the maximum field enhancement factor (FEF). This convention is used in practice because it mimics the one used for single-tip field emitters. Within the mainstream Fowler-Nordheim (FN) theory, a linear relation between iM and JC is expected. However, recent theoretical works within the framework of the standard FN theory have predicted a nearly power-law dependence between these two quantities. This work experimentally confirms those theoretical predictions for CNT-based LAFEs. Experimental studies, supported by glow pattern analysis, were conducted over a wide range of emitted currents and, importantly, confirm the general validity of the two-component FEF for CNT-based LAFEs, which can be viewed as a simple approach to this nearly power-law dependence.
On the moduli spaces of commuting elements in the projective unitary groups
Authors: Adem Alejandro , Cheng Man Chuen
Published: July 2019

We provide descriptions for the moduli spaces Rep(Γ, PU(m)), where Γ is any finitely generated Abelian group and PU(m) is the group of m × m projective unitary matrices. As an application, we show that for any connected CW-complex X with π1(X)≅Zn, the natural map π0(Rep(π1(X), PU(m))) → [X, BPU(m)] is injective, hence providing a complete enumeration of the isomorphism classes of flat principal PU(m)-bundles over X.
Super resolution in depth for microwave imaging
Authors: Wang Peiyu , Li Zhencheng , Liu Peng , Pei Yongmao
Published: July 2019

Microwave imaging has been investigated in various areas involving nondestructive testing, biomedical imaging, and radar ranging imaging. With a lower frequency than THz and visible light, microwaves penetrate deep in dielectric materials, which enables detection in depth and three-dimensional (3D) imaging. High and super lateral resolutions have been obtained with current techniques, while the depth resolution remains in centimeters or millimeters due to the limited bandwidth of microwaves. Therefore, it is a challenging and interesting issue to accomplish microwave super resolution 3D imaging in low frequency and limited bands. Herein, we proposed a zero-padding pseudo pulse algorithm (ZPPA) enabling super resolution in depth for microwave 3D imaging within the limited band. This algorithm was explained and demonstrated through resolving and reconstructing two separate reflection signals of adjacent interfaces that cannot be resolved from conventional time-of-flight profiles. A depth variation of 10 μm and a metal step with a height of 50 μm were accurately identified and reconstructed through both experiment and theoretical simulation, which greatly surpasses the depth resolution limitation of about 11.1 mm within 26.5 ∼ 40 GHz. Besides, a 3D nanometric step pyramid was theoretically simulated and reconstructed with each step of 1 nm-high accurately resolved. In summary, the depth resolution of ZPPA was compared with that obtained through current microwave methods and THz time-domain imaging methods, which verified that the ZPPA is feasible to obtain super depth resolution in 3D imaging for low frequency and narrow band microwaves.
Measurement of spin mixing conductance in Ni81Fe19/α-W and Ni81Fe19/β-W heterostructures via ferromagnetic resonance
Authors: Cao W. , Liu J. , Zangiabadi A. , Barmak K. , Bailey W. E.
Published: July 2019

We present measurements of interfacial Gilbert damping due to the spin pumping effect in Ni81Fe19/W heterostructures. Measurements were compared for heterostructures in which the crystallographic phase of W, either α(bcc)-W or β(A15)-W, was enriched through deposition conditions and characterized using X-ray diffraction and high-resolution cross-sectional transmission electron microscopy. Single-phase Ni81Fe19/α-W heterostructures could be realized, but heterostructures with β-W were realized as a mixed α-β phase. The spin mixing conductances for W at interfaces with Ni81Fe19 were found to be significantly lower than those for similar heavy metals such as Pd and Pt, but comparable to those for Ta, and independent of enrichment in the β phase.
Organic photodetectors with frustrated charge transport for small-pitch image sensors
Authors: Ma Z. , Renshaw C. K.
Published: July 2019

We demonstrate a frustrated organic photodetector (F-OPD) that utilizes frustrated charge-transport to quench forward-bias current and provide a low-current, light-independent OFF state. Photocurrent is collected efficiently with −3 V reverse-bias recovering the sensitive OPD response with >10-bit dynamic range. This intrinsic switching mechanism eliminates the need for thin-film transistors (TFTs) to provide readout control in high-resolution image sensors. Eliminating TFTs simplifies fabrication processing, improves fill-factor, and enables higher resolution image sensors on nonplanar, stretchable, or large-area substrates for a variety of imaging applications. We simulate image sensors and show that the performance is limited by the OFF state uniformity experimentally observed across 45 devices. We simulate performance in a 900-pixel array and show that the demonstrated F-OPDs can scale into megapixel arrays with a noise-equivalent power of <0.6 mW/cm2 and a dynamic range of >6-bits; better uniformity can substantially improve this performance for large arrays.
Theoretical and experimental studies of spin polarized carbon doped Bi2Se3
Authors: Xin Xiaojun , Guo Chunsheng , Pang Rui , Zhang Min , Shi Xingqiang , Yang Xinsheng , Zhao Yong
Published: July 2019

Carbon doped into Bi2Se3 as substitution for Se was reported inducing simultaneous magnetic and hole doping. In this work, based on theoretical and experimental approaches, we find that carbon doped Bi2Se3 is indeed spin polarized, while the magnetic moments are small and hole doping is little. Most carbon atoms energetically favor to be dimer- and trimer-substitutions for Se which induce neither magnetism nor charge doping. A few isolated carbon atoms doped at interstitial sites in the vdW gap or at Se vacancies result in spontaneous spin polarization and charge doping. The diffusion of a single carbon dopant into Bi2Se3 is difficult, while if dopants are close, carbon clusters can easily form, which means that the isolated, pairwise, and trimeric carbon dopants should coexist. These studies suggest that to obtain strong ferromagnetic C-Bi2Se3, experiments need careful design to dope single carbon atoms into bulk dispersedly.
Influence of the conductivity on spin wave propagation in a Permalloy waveguide
Authors: Manago Takashi , Aziz Mustafa M. , Ogrin Feodor , Kasahara Kenji
Published: July 2019

The influence of the electrical conductivity of a Permalloy waveguide on the spin wave propagation was investigated using the finite-element solution of the combined system of quasistatic electromagnetic potential and linearized LLG (Landau–Lifshitz–Gilbert) equations. The difference in the group velocity between the conductive and nonconductive waveguides becomes large for films over 300 nm thick, and the difference is very small for film thicknesses less than 100 nm. The observed enhancement of the group velocity with increasing film thickness is attributed to the damping caused by the electrical conductivity, which leads to narrowing of the spin wave packet envelope and shorter arrival times of propagating waves. The basic characteristics of the dispersion relations do not change between conductive and nonconductive films for small film thicknesses less than 300 nm. The simulated dispersion relations indicate shift of their maximum intensity toward lower wavenumbers and, therefore, increase in the group velocity with increasing thickness. The simulated decay length of the spin waves for conductive films initially increases but then decreases with increasing thickness, which agrees well with the experimental results. The extracted damping coefficients from both simulations and the experiment agree very well and increase proportionally with d2, where d is the film thickness, due to the additional eddy current damping. The observed thickness and conductivity dependence of spin wave propagation is crucial for magnonics research and toward the development of future spin wave devices using metal films.
A neuron based on a single flux qubit
Authors: Klenov N. V. , Kuznetsov A. V. , Schegolev A. E. , Soloviev I. I. , Bakurskiy S. V. , Kupriyanov M. Yu. , Tereshonok M. V.
Published: July 2019

The concept of creating an element base for superconducting quantum neural networks based on only a single flux qubit is presented. The behavior of the activation function is analyzed for different variants of the “quantum neuron” implementation (based on three-contact, two-contact, and five-contact interferometers), and the conditions at which this activation function is close to a sigmoid curve are determined. The prospects of using energy-efficient upgrades to the rapid single-flux-quantum logic to control the transfer and activation functions when operating a quantum neural network based on the proposed elements are discussed.
On the possibility of faster detection of magnetic flux changes in a single-photon counter by RF SQUID with MoRe–Si(W)–MoRe junction
Authors: Shapovalov A. P. , Shaternik V. E. , Turutanov O. G. , Lyakhno V. Yu. , Shnyrkov V. I.
Published: July 2019

The nonhysteretic mode of a RF SQUID with a MoRe–Si(W)–MoRe Josephson junction is analyzed in order to detect the states of a single-photon counter based on a superconducting quantum interferometer with a discrete Hamiltonian. The absorption of a photon with 10 GHz frequency brings the counter to the excited level causing tunnelling into the adjacent potential well and a change in the magnetic flux in the interferometer, which can be detected by the SQUID magnetometer. Measurement of a quantum system requires minimization of the back action of the signal read-out channel at the counter, high sensitivity, and speed of the magnetometer. The MoRe–Si(W)–MoRe contacts are optimized for various concentrations of tungsten (W) in silicon (Si) and barrier layer thickness. It is shown that using MoRe–Si(W)–MoRe contacts with a tungsten concentration of approximately 11% for the RF SQUID at excitation frequencies of ∼1 GHz makes it practically an ideal parametric upward frequency shifter with noise determined by the cooled amplifier.
Adaptability of cotton (Gossypium hirsutum) genotypes analysed using a Bayesian AMMI model
Authors: Teodoro Paulo Eduardo , Azevedo Camila Ferreira , Farias Francisco José Correia , Alves Rodrigo Silva , de Azevedo Peixoto Leonardo , Ribeiro Larissa Pereira , Paulo de Carvalho Luiz , Bhering Leonardo Lopes
Published: July 2019

Cotton (Gossypium spp.) provides ~90% of the world’s textile fibre. The aim of this study was to use the principal additive effects and multiplicative interaction (AMMI) model under the Bayesian approach to recommend cotton genotypes for the Central-West region of Brazil. Eight trials with upland cotton genotypes were conducted during the 2008–09 harvest in the State of Mato Grosso, Brazil. The experiment included a randomised block design with 16 genotypes. The genotypes were evaluated for fibre yield, length and strength. Chains were simulated via the Markov chain Monte Carlo method with 300000 iterations for the parameters of the Bayesian AMMI model. From the chains generated, the first 20000 burn-in observations were discarded and samples were taken by jumping every 20 observations (thin). Bayesian analysis provided additional results to those obtained by the frequentist approach, highlighting the credibility regions in the biplot for the genotypic and environmental scores. Bayesian AMMI model allowed identification of a genotype that can be widely recommended; this genotype has genotypic values above the overall mean for the three evaluated traits and did not contribute to the genotype × environment interactions observed in these traits. In addition, adaptability of genotypes to specific environments was observed, which makes it possible to capitalise the positive effect of the genotype × environment interaction.
Effects of policy-driven hypothetical air pollutant interventions on childhood asthma incidence in southern California
Authors: Garcia Erika , Urman Robert , Berhane Kiros , McConnell Rob , Gilliland Frank
Published: July 2019

Significance

Asthma is one of the leading chronic diseases among children, and there is increasing evidence that air pollution plays a role in the development of this disease. We found that had NO
2
or PM
2.5
concentration in 9 southern Californian communities been lower than observed in the 1990s and early 2000s, there would have been a corresponding reduction in childhood asthma incidence, with larger effect estimates for NO
2
. Our findings may have implications for air quality regulations, as all communities examined in this study had ambient concentrations well below the current US Environmental Protection Agency annual standard of 53 ppb for NO
2
.
The neural representation of facial-emotion categories reflects conceptual structure
Authors: Brooks Jeffrey A. , Chikazoe Junichi , Sadato Norihiro , Freeman Jonathan B.
Published: July 2019

Humans reliably categorize configurations of facial actions into specific emotion categories, leading some to argue that this process is invariant between individuals and cultures. However, growing behavioral evidence suggests that factors such as emotion-concept knowledge may shape the way emotions are visually perceived, leading to variability—rather than universality—in facial-emotion perception. Understanding variability in emotion perception is only emerging, and the neural basis of any impact from the structure of emotion-concept knowledge remains unknown. In a neuroimaging study, we used a representational similarity analysis (RSA) approach to measure the correspondence between the conceptual, perceptual, and neural representational structures of the six emotion categories Anger, Disgust, Fear, Happiness, Sadness, and Surprise. We found that subjects exhibited individual differences in their conceptual structure of emotions, which predicted their own unique perceptual structure. When viewing faces, the representational structure of multivoxel patterns in the right fusiform gyrus was significantly predicted by a subject’s unique conceptual structure, even when controlling for potential physical similarity in the faces themselves. Finally, cross-cultural differences in emotion perception were also observed, which could be explained by individual differences in conceptual structure. Our results suggest that the representational structure of emotion expressions in visual face-processing regions may be shaped by idiosyncratic conceptual understanding of emotion categories.
Developmental topography of cortical thickness during infancy
Authors: Wang Fan , Lian Chunfeng , Wu Zhengwang , Zhang Han , Li Tengfei , Meng Yu , Wang Li , Lin Weili , Shen Dinggang , Li Gang
Published: July 2019

Significance

During the first 2 postnatal years, the human brain undergoes dynamic growth and shows rapid expansions in behavioral and cognitive abilities. Charting the developmental patterns of cortical thickness in healthy infants is important for understanding many neurodevelopmental disorders, which unfortunately remains unexplored. Therefore, we investigate the infantile developmental regionalization of cortical thickness, which describes regions naturally formed during the dynamic development of cortical thickness and differs markedly from conventional anatomical parcellations. Meanwhile, this study delineates the inverted U-shaped developmental trajectory and peak age of cortical thickness, which clarifies the previous ambiguity on the peaking time of cortical thickness during early brain development.
Membraneless polyester microdroplets as primordial compartments at the origins of life
Authors: Jia Tony Z. , Chandru Kuhan , Hongo Yayoi , Afrin Rehana , Usui Tomohiro , Myojo Kunihiro , Cleaves H. James
Published: July 2019

Significance

The prebiotic milieu was likely heterogeneous, consisting of a large number of chemicals and their associated reactions, including those not only of biological compounds, but also nonbiological compounds. Although origins of life research has focused primarily on biological molecules, the nonbiological molecules which were also present may have assisted evolving chemical systems in unforeseen ways. Thus, we synthesized and assembled membraneless polyester microdroplets from drying of pools of simple α-hydroxy acid monomers and showed that they can act as plausible prebiotic compartments. By having the capacity to undergo combinatorial rearrangement, these microdroplets could have developed versatile abilities to host early genetic and metabolic systems critical for the origins of life.
Rebuilding global fisheries under uncertainty
Authors: Memarzadeh Milad , Britten Gregory L. , Worm Boris , Boettiger Carl
Published: July 2019

Significance

Many fisheries that have been historically overexploited are now considered to be rebuilding, with a hope that current best practices could ensure the recovery of most overfished species by mid century. Our analysis suggests this optimism may be premature, as current projections typically assume managers can have perfect measurements of current stock sizes. We demonstrate how such an assumption can undermine rebuilding efforts under current best practices and even drive unintentional stock declines. By borrowing novel decision methods from the field of robotics, we also show how stock rebuilding can be achieved in the face of measurement and environmental uncertainty, while also achieving higher economic returns than expected under current approaches.
RETRACTED: Officer characteristics and racial disparities in fatal officer-involved shootings
Authors: Johnson David J. , Tress Trevor , Burkel Nicole , Taylor Carley , Cesario Joseph
Published: July 2019

Despite extensive attention to racial disparities in police shootings, two problems have hindered progress on this issue. First, databases of fatal officer-involved shootings (FOIS) lack details about officers, making it difficult to test whether racial disparities vary by officer characteristics. Second, there are conflicting views on which benchmark should be used to determine racial disparities when the outcome is the rate at which members from racial groups are fatally shot. We address these issues by creating a database of FOIS that includes detailed officer information. We test racial disparities using an approach that sidesteps the benchmark debate by directly predicting the race of civilians fatally shot rather than comparing the rate at which racial groups are shot to some benchmark. We report three main findings: 1) As the proportion of Black or Hispanic officers in a FOIS increases, a person shot is more likely to be Black or Hispanic than White, a disparity explained by county demographics; 2) race-specific county-level violent crime strongly predicts the race of the civilian shot; and 3) although we find no overall evidence of anti-Black or anti-Hispanic disparities in fatal shootings, when focusing on different subtypes of shootings (e.g., unarmed shootings or “suicide by cop”), data are too uncertain to draw firm conclusions. We highlight the need to enforce federal policies that record both officer and civilian information in FOIS.
A tumor-targeted immune checkpoint blocker
Authors: Zhang Yuhan , Fang Changming , Wang Rongsheng E. , Wang Ying , Guo Hui , Guo Chao , Zhao Lijun , Li Shuhong , Li Xia , Schultz Peter G. , Cao Yu J. , Wang Feng
Published: July 2019

Significance

Current immune checkpoint inhibitors are not tumor specific and induce systemic immune activation in other tissues and organs. Combination immunotherapies further amplify these toxicities, which limit their clinical application. Here, we describe a strategy to direct checkpoint inhibition to the tumor microenvironment while avoiding systemic immune activation. Specifically, we have synthesized a bispecific antibody by conjugating an MSH analog to the αPD-L1 antibody avelumab. This bispecific antibody binds both MC1R and PD-L1 on cancer cells, shows excellent in vitro activities, and has enhanced efficacy in a syngeneic melanoma mouse model as compared to the parental antibody. This work demonstrates that the incorporation of a targeting element into an immune checkpoint blocking antibody could provide a therapeutic advantage.
Methodology and theoretical basis of forward genetic screening for sleep/wakefulness in mice
Authors: Miyoshi Chika , Kim Staci J. , Ezaki Takahiro , Ikkyu Aya , Hotta-Hirashima Noriko , Kanno Satomi , Kakizaki Miyo , Yamada Mana , Wakana Shigeharu , Yanagisawa Masashi , Funato Hiromasa
Published: July 2019

Significance

The network of genes and molecules that govern sleep and wakefulness remains largely unknown. Forward genetics is a powerful approach to elucidate important biological phenomena that cannot be predicted from the function of known genes. We established a large-scale screening system using EEG/EMG-based sleep/wake monitoring with reliable parameters. The search for novel genes has succeeded in identifying several sleep regulatory genes. By furthering the study, a more comprehensive picture of the regulatory pathways of sleep/wakefulness will become clear.
Investigation of the allosteric coupling mechanism in a glutamate transporter homolog via unnatural amino acid mutagenesis
Authors: Riederer Erika A. , Valiyaveetil Francis I.
Published: July 2019

Significance

Glutamate transporters harness ionic gradients for the concentrative uptake of glutamate. Normal function of glutamate transporters is required for rapid removal of glutamate from the synaptic space, which is required for efficient neurotransmission and preventing excitotoxicity. A key question in glutamate transporters is the mechanism by which the ionic gradient is coupled to glutamate uptake. Previous studies have proposed a role for hairpin-2 (HP2) in this coupling mechanism. Here, we use unnatural amino-acid mutagenesis to develop a fluorescence assay for HP2 movement in the archaeal homolog, Glt
Ph
. Using this assay, we show how key residues in the substrate binding site modulate movement of HP2 and thereby identify the sequence of events involved in the coupled binding of sodium and substrate.
Mstn knockdown decreases the trans-differentiation from myocytes to adipocytes by reducing Jmjd3 expression via the SMAD2/SMAD3 complex
Authors: Gao Li , Yang Miaomiao , Wang Xueqiao , Yang Lei , Bai Chunling , Li Guangpeng
Published: July 2019

Myostatin (Mstn) is an important growth/differentiation factor, and knockdown of Mstn reduces fat content. Here, we knocked down Mstn expression in C2C12 myoblasts and then induced adipogenic trans-differentiation in the cells. The effects of Mstn knockdown on lipid droplet contents and H3K27me3 marker expression on adipocyte-specific genes were detected. The results showed that Mstn knockdown reduced the formation of lipid droplets, downregulated the expression of adipocyte-specific genes, and increased H3K27me3 marker expression on adipocyte-specific genes. Chromatin immunoprecipitation analysis showed that the SMAD2/SMAD3 complex could combine with the Jumonji D3 (Jmjd3) promoter and that Mstn regulated Jmjd3 expression through this process. Jmjd3 overexpression removed the H3K27me3 marker and increased the expression of adipocyte-specific genes. Overall, our results showed that Mstn regulated Jmjd3 expression through SMAD2/SMAD3, thus affecting the H3K27me3 marker on adipocyte-specific genes and the trans-differentiation from myocytes to adipocytes.
Effects of layer stacking and strain on electronic transport in two-dimensional tin monoxide*
Authors: Ge Yanfeng , Liu Yong
Published: July 2019

Tin monoxide (SnO) is an interesting two-dimensional material because it is a rare oxide semiconductor with bipolar conductivity. However, the lower room temperature mobility limits the applications of SnO in the future. Thus, we systematically investigate the effects of different layer structures and strains on the electron–phonon coupling and phonon-limited mobility of SnO. The A2uphonon mode in the high-frequency region is the main contributor to the coupling with electrons for different layer structures. Moreover, the orbital hybridization of Sn atoms existing only in the bilayer structure changes the conduction band edge and conspicuously decreases the electron–phonon coupling, and thus the electronic transport performance of the bilayer is superior to that of other layers. In addition, the compressive strain ofε= −1.0% in the monolayer structure results in a conduction band minimum (CBM) consisting of two valleys at theΓpoint and along theM–Γline, and also leads to the intervalley electronic scattering assisted by theEg(−1)mode. However, the electron–phonon coupling regionally transferring from high frequency A2uto low frequencyEg(−1)results in little change of mobility.
Structural, elastic, and electronic properties of topological semimetal WC-type MX family by first-principles calculation*
Authors: Ullah Sami , Wang Lei , Li Jiangxu , Li Ronghan , Chen Xing-Qiu
Published: July 2019

Recently, the non-centrosymmetric WC-type materials (i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological properties. By means of the first-principles calculations, here we have investigated the structural, thermodynamic, elastic, and electronic properties of the WC-type MX compounds (TiS, TiSe, TiTe, ZrS, ZrSe, ZrTe, HfS, HfSe, and HfTe). Among these nine compounds, five of them (TiS, ZrS, ZrSe0.9, ZrTe, and Hf0.92Se) have been experimentally synthesized to crystallize in the WC-type structure and other four members have never been reported. Our calculations demonstrated that they are all structurally, thermodynamically, and dynamically stable, indicating that all of them should be possibly synthesized. We have also derived their elastic constants of single crystalline and their bulk and shear moduli in terms of the R. Hill approximations. Furthermore, in similarity to ZrTe, all these compounds have been theoretically derived to be topological semimetals. Whereas TiS is unique because of the coexistence of the Dirac nodal lines (DNLs) and sixfold degenerate nodal points (sixfold DNPs), the other eight members are revealed to exhibit coexisted Weyl nodes (WPs) and triply degenerate nodal points (TDNPs). Their electronic and topological properties have been further discussed.
A simple rule for finding Dirac cones in bilayered perovskites*
Authors: Chen Xuejiao , Liu Lei , Shen Dezhen
Published: July 2019

A simple rule for finding Dirac cone electronic states in solids is proposed, which is neglecting those lattice atoms inert to particular electronic bands, and pursuing the two-dimensional (2D) graphene-like quasi-atom lattices with s- and p-bindings by considering the equivalent atom groups in the unit cell as quasi-atoms. Taking CsPbBr3 and Cs3Bi2Br9 bilayers as examples, we prove the effectiveness and generality of this rule with the density functional theory (DFT) calculations. We demonstrate that both bilayers have Dirac cones around the Fermi level and reveal that their corresponding Fermi velocities can reach as high as

∼
0.2
×

10

6

m

/

s

. This makes these new 2D layered materials very promising in making new ultra-fast ionic electronic devices.
Scanning tunneling microscopic investigation on morphology of magnetic Weyl semimetal YbMnBi2
*
Authors: Zhu Zhen , Yan Dong , Nie Xiao-Ang , Xu Hao-Ke , Yang Xu , Guan Dan-Dan , Wang Shiyong , Li Yao-Yi , Liu Canhua , Liu Jun-Wei , Luo Hui-Xia , Zheng Hao , Jia Jin-Feng
Published: July 2019

YbMnBi2 is a recently discovered time-reversal-symmetry breaking type-II Weyl semimetal. However, as a representation of the new category of topological matters, the scanning tunneling microcopy (STM) results on such important material are still absent. Here, we report the STM investigations on the morphology of vacuum cleaved single crystalline YbMnBi2 samples. A hill and valley type of topography is observed on the YbMnBi2 surface, which is consistent with the non-layer nature of its crystal structure. Analysis of STM images yields the information of the index of the vicinal surface. Our results here lay a playground of future atomic scale research on YbMnBi2.
Discrete modulational instability and bright localized spin wave modes in easy-axis weak ferromagnetic spin chains involving the next-nearest-neighbor coupling*
Authors: Xie Jiayu , Deng Zhihao , Chang Xia , Tang Bing
Published: July 2019

We report a theoretical work on the properties of modulational instability and bright type nonlinear localized modes in one-dimensional easy-axis weak ferromagnetic spin lattices involving next-nearest-neighbor couplings. With a linear stability analysis, we calculate the growth rates of the modulational instability, and plot the instability regions. When the strength of the next-nearest-neighbor coupling is large enough, two new asymmetric modulational instability regions appear near the boundary of the first Brillouin zone. Furthermore, analytical forms of the bright nonlinear localized modes are constructed by means of a quasi-discreteness approach. The influence of the next-nearest-neighbor coupling on the Brillouin zone center mode and boundary mode are discussed. In particular, we discover a reversal phenomenon of the propagation direction of the Brillouin zone boundary mode.
Thickness-dependent magnetic anisotropy in obliquely deposited Fe(001)/Pd thin film bilayers probed by VNA-FMR*
Authors: Gul Qeemat , He Wei , Li Yan , Sun Rui , Li Na , Yang Xu , Li Yang , Gong Zi-Zhao , Xie Zong-Kai , Zhang Xiang-Qun , Cheng Zhao-Hua
Published: July 2019

The thickness-dependent magnetic anisotropy of obliquely deposited Fe(001)/Pd thin films on Mg(001) is investigated by fitting the field-dependent resonant field curve using the Kittel equation. In this study, three Fe film samples with thicknesses of 50 monolayers (ML), 45 ML, and 32 ML deposited at 0°, 45°, and 55°, respectively, are used. The magnetic anisotropy constant obtained from ferromagnetic resonance (FMR) spectra exhibits a dominant fourfold magnetocrystalline anisotropy (MCA) at the normal deposition angle with larger Fe thickness. However, the in-plane uniaxial magnetic anisotropy (UMA) is induced by a higher oblique deposition angle and a smaller thickness. Its hard axis lies between the [100] and [010] directions. The FMR data-fitting analysis yields a precise measurement of smaller contributions to the magnetic anisotropy, such as in-plane UMA. Due to MCA, when the magnetic field is weaker than the saturated field, the magnetization direction does not always align with the external field. The squared frequency-dependent resonant field measurement gives an isotropic Landé g-factor of 2.07. Our results are consistent with previous experiments conducted on the magneto-optical Kerr effect (MOKE) and anisotropic magnetoresistance (AMR) systems. Thus, a vector network analyzer ferromagnetic resonance (VNA-FMR) test-method for finding UMA in obliquely deposited Fe(001)/Pd bilayer ferromagnetic thin films, and determining the magnetic anisotropy constants with respect to the film normal deposition, is proposed.
Regulating element distribution to improve magnetic properties of sintered Nd–Fe–B/Tb–Fe–B composite magnets*
Authors: Li Zhu-Bai , Zuo Jing-Yan , Wang Dong-Shan , Liu Fei , Zhang Xue-Feng
Published: July 2019

Nd content was varied in

Nd

13.2
−
x

Fe

80.8
+
x

B6 (x = 0, 0.5, 1, and 1.5) to optimize the magnetic properties of sintered Nd–Fe–B/Tb–Fe–B composite magnets, which were prepared by mixing 9 g of Nd–Fe–B with 1 g of Tb17Fe75B8 powder. In conventional magnets, by reducing Nd content, the coercivity of 10.4 kOe in Nd13.2Fe80.8B6 decreases to 7.2 kOe in Nd12.2Fe81.8B6; meanwhile, in Nd–Fe–B/Tb–Fe–B magnets the coercivity does not decrease when reducing Nd content. In the intergranular phase, the Tb content increases owing to the reducing Nd content of the Nd–Fe–B alloy in the sintered composite magnets. Therefore, the excess Tb in Tb17Fe75B8 enters the intergranular phase, and more Tb atoms can substitute for Nd at the grain boundary of the Nd–Fe–B phase, leading to a more significant increase in coercivity. The remanence increases with reducing Nd content, and the energy product of 39.1 MGOe with a high coercivity of 21.0 kOe is obtained in Nd12.2Fe81.8B6/Tb17Fe75B8 magnets. These investigations show that magnetic properties can be further improved by regulating the element distribution in sintered composite magnets.
Field-variable magnetic domain characterization of individual 10 nm Fe3O4 nanoparticles*
Authors: Li Zheng-Hua , Li Xiang , Lu Wei
Published: July 2019

The local detection of magnetic domains of isolated 10 nm Fe3O4 magnetic nanoparticles (MNPs) has been achieved by field-variable magnetic force microscopy (MFM) with high spatial resolution. The domain configuration of an individual MNP shows a typical dipolar response. The magnetization reversal of MNP domains is governed by a coherent rotation mechanism, which is consistent with the theoretical results given by micromagnetic calculations. Present results suggest that the field-variable MFM has great potential in providing nanoscale magnetic information on magnetic nanostructures, such as nanoparticles, nanodots, skyrmions, and vortices, with high spatial resolution. This is crucial for the development and application of magnetic nanostructures and devices.
Progress in recycling of Nd–Fe–B sintered magnet wastes*
Authors: Yue Ming , Yin Xiaowen , Liu Weiqiang , Lu Qingmei
Published: July 2019

Significant efforts have been put into the recycling of bulk Nd–Fe–B sintered magnet wastes around the world in the past decade because bulk Nd–Fe–B sintered magnet wastes are valuable secondary rare-earth resources. There are two major facts behind the efforts. First, the waste magnets contain total rare-earth content as high as more than 30 wt.%, which is higher than most natural rare-earth mines. Second, the waste magnets maintain the physical and chemical properties of the original magnets even with deterioration of the properties on surfaces due to corrosion and contamination. In this review, various techniques for recycling bulk Nd–Fe–B sintered magnet wastes, the overall properties of the recycled Nd–Fe–B sintered magnets, and the mass production of recycled magnets from the wastes are reviewed.
Grain boundary restructuring and La/Ce/Y application in Nd–Fe–B magnets*
Authors: Yan Mi , Jin Jiaying , Ma Tianyu
Published: July 2019

Since the 1980s, Nd–Fe–B with largest energy product (BH)max approaching the theoretical limit has become the landmark of permanent magnetic material. The application spectrum for Nd–Fe–B continues to expand over time both in the industrial and commercial sectors, which leads to growing research interests for solving the long-standing drawbacks of Nd–Fe–B, i.e., poor corrosion resistance, low coercivity, high Dy/Tb and low La/Ce/Y consumption. Concerning the above obstacles, we aim to present the novel grain boundary restructuring (GBR) approach, from GB design, processing, to structure evolution and property evaluation with a focus on the corrosion and coercivity mechanism of the restructured 2:14:1-typed magnets. Starting with an introduction to the fundamental of GBR, two representative examples, high-electrode-potential (Pr, Nd)32.5Fe62.0Cu5.5 and low-melting-point Dy71.5Fe28.5, are given with detailed descriptions of the advantages of GBR to enhance the intrinsic anti-corrosion stability and to strengthen the coercivity at low Dy consumption. Microstructure–property correlations are established to understand the critical importance of regulating the restructured GB phase to maximize the all-round performance of the 2:14:1-typed permanent magnets. Aiming at sustainable and balanced development of rare earth (RE) industry, the proceeding section proposes new prototypes of La–Ce and Y–Ce co-substitutions with dual benefits of stabilizing the 2:14:1 tetragonal phase and strengthening the intrinsic hard magnetism. The findings of additional REFe2 intergranular phase delight that the GBR approach also opens up a new horizon of research and application to develop high-performance La/Ce/Y-rich permanent magnets with deliberately tailored GB phase.