bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of rhein and diacerein: a chemoenzymatic approach using anthrol reductase of Talaromyces islandicus
Authors: Rajput Anshul , Mondal Amit , Pandey Satyendra Kumar , Husain Syed Masood
Published: December 2021

The approach is similar to the probable biosynthetic conversion of emodic acid to rhein in fungi.
Artificial intelligence, molecular subtyping, biomarkers, and precision oncology
Authors: Shen John Paul
Published: December 2021

A targeted cancer therapy is only useful if there is a way to accurately identify the tumors that are susceptible to that therapy. Thus rapid expansion in the number of available targeted cancer treatments has been accompanied by a robust effort to subdivide the traditional histological and anatomical tumor classifications into molecularly defined subtypes. This review highlights the history of the paired evolution of targeted therapies and biomarkers, reviews currently used methods for subtype identification, and discusses challenges to the implementation of precision oncology as well as possible solutions.
Common computational tools for analyzing CRISPR screens
Authors: Colic Medina , Hart Traver
Published: December 2021

CRISPR–Cas technology offers a versatile toolbox for genome editing, with applications in various cancer-related fields such as functional genomics, immunotherapy, synthetic lethality and drug resistance, metastasis, genome regulation, chromatic accessibility and RNA-targeting. The variety of screening platforms and questions in which they are used have caused the development of a wide array of analytical methods for CRISPR analysis. In this review, we focus on the algorithms and frameworks used in the computational analysis of pooled CRISPR knockout (KO) screens and highlight some of the most significant target discoveries made using these methods. Lastly, we offer perspectives on the design and analysis of state-of-art multiplex screening for genetic interactions.
Artificial intelligence unifies knowledge and actions in drug repositioning
Authors: Yin Zheng , Wong Stephen T. C.
Published: December 2021

Drug repositioning aims to reuse existing drugs, shelved drugs, or drug candidates that failed clinical trials for other medical indications. Its attraction is sprung from the reduction in risk associated with safety testing of new medications and the time to get a known drug into the clinics. Artificial Intelligence (AI) has been recently pursued to speed up drug repositioning and discovery. The essence of AI in drug repositioning is to unify the knowledge and actions, i.e. incorporating real-world and experimental data to map out the best way forward to identify effective therapeutics against a disease. In this review, we share positive expectations for the evolution of AI and drug repositioning and summarize the role of AI in several methods of drug repositioning.
Asteroseismology of β Cephei stars: The stellar inferences tested in hare and hound exercises
Authors: Salmon S. J. A. J. , Eggenberger P. , Montalbán J. , Miglio A. , Noels A. , Buldgen G. , Moyano F. , Meynet G.
Published: December 2021

Context. The β Cephei pulsators are massive, ∼8−25 M⊙ essentially on the main sequence, stars. The number of detected modes in β Cephei stars often remains limited to less than a dozen of low radial-order modes. Such oscillation modes are in principle able to constrain the internal processes acting in the star. They probe the chemical gradient at the edge of the convective core, in particular its location and extension. They hence give constraints on macroscopic processes, such as hydrodynamic or magnetic instabilities, that have an impact on the mixing there. Yet, it is not clear to what extent the seismic inferences depend on the physics employed for the stellar modelling or on the observational dataset used. Consequently, it is not easy to estimate the accuracy and precision on the parameters and the nature of the physical processes inferred.

Aims. We investigate the observational constraints, in particular the properties of the minimum set of pulsations detected, which are necessary to provide accurate constraints on the mixing processes in β Cephei stars. We explore the importance of the identification of the angular degree of the modes. In addition, depending on the quality of the seismic dataset and the classical non-seismic constraints, we aim to estimate, in a systematic way, the precision achievable with asteroseismology on the determination of their stellar parameters.

Methods. We propose a method extending the forward approach classically used to model β Cephei stars. With the help of Monte-Carlo simulations, the probability distributions of the asteroseismic-derived stellar parameters were obtained. With these distributions, we provide a systemic way to estimate the errors derived from the modelling. A particular effort was made to include, not only the observational errors, but also the theoretical uncertainties of the models. We then estimated the accuracy and precision of asteroseismology for β Cephei stars in a series of hare and hound exercises.

Results. The results of the hare and hounds show that a set of four to five oscillation frequencies with an identified angular degree already leads to accurate inferences on the stellar parameters. Without the identification of the modes, the addition of other observational constraints, such as the effective temperature and surface gravity, still ensures the success of the seismic modelling. When the internal microscopic physics of the star and stellar models used for the modelling differ, the constraints derived on the internal structure remain valid if expressed in terms of acoustic variables, such as the radius. However, they are then hardly informative on structural variables expressed in mass. The characterisation of the mixing processes at the boundary of the convective core are model-dependent and it requires the use of models implemented with processes of a similar nature.
VLA proper motion constraints on the origin, age, and potential magnetar future of PSR J1734−3333
Authors: Espinoza C. M. , Vidal-Navarro M. , Ho W. C. G. , Deller A. , Chatterjee S.
Published: December 2021

Context.The characteristic age of PSR J1734−3333 estimated from its current spin down rate implies that it is a young pulsar (τc = 8.1 kyr). However, the time derivative of its spin-down rate differs markedly from that assumed for normal radio pulsars, meaning its actual age is uncertain. G354.8−0.8 is a supernova remnant (SNR) whose centre is located 21′ away from the pulsar, and which has a morphology that suggests an association with the pulsar.

Aims.We aim to assess the likelihood of the association between PSR J1734−3333 and G354.8−0.8 or other nearby SNRs quantitatively, with the objective of shedding light on the real age of this pulsar.

Methods.Observations with the Karl G. Jansky Very Large Array were carried out in 2015 and 2019 that allow precise astrometric measurements and consequently a proper motion estimate for the pulsar.

Results.The proper motion was found to beμα = 10 ± 10 mas yr−1andμδ = −29 ± 11 mas yr−1(error bars are 1-σ). Though marginal, this detection rules out the association with G354.8−0.8 because it means the pulsar is not moving away from the centre of the SNR. No SNR consistent with the measured proper motion and an ageτccould be found. We also present the first measurement of the spectral index for this pulsar,α = −1.1 ± 0.3, measured between 1.5 and 3.0 GHz.

Conclusions.The SNR produced by the birth supernova of PSR J1734−3333 could have already faded to undetectable brightness, estimates of which suggest timescales of 10 − 100 kyr. This and other considerations lead us to conclude that the pulsar is possibly older than 45 − 100 kyr. PSR J1734−3333 is a pulsar with rotational properties that place it between standard radio pulsars and magnetars, and we interpret our result in the context of a possible future life as a magnetar for this pulsar.
Mechanical pruning and soil organic amendments in vineyards of ‘Syrah’: effects on wine mineral composition
Authors: Botelho Manuel , Ribeiro Henrique , Cruz Amândio , Martins Miguel , Khairnar Kaushal S. , Pardal Rafaela , Catarino Sofia , de Castro Rogério , Ricardo-da-Silva Jorge
Published: December 2021

The interaction of mechanized pruning systems and soil organic amendment can affect vine vegetative and reproductive growth. However, since organic amendments supply several mineral elements, namely heavy metals, this study aimed to understand the effects of the interaction between these two practices on the mineral composition of wine. Two field trials were implemented in ‘Syrah’ vineyards in two Portuguese wine regions (Lisboa and Tejo). Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested: biochar, municipal solid waste compost, cattle manure and sewage sludge. The nitrogen (N), phosphorus (P) and potassium (K) wine contents were significantly reduced by mechanical pruning while calcium (Ca) and magnesium (Mg) contents were tendentially higher in this pruning system. Mechanical pruning also reduced the content of some minor elements, such as arsenic (As), molybdenum (Mo) and nickel (Ni). In 2014, the year with the higher reproductive growth, some other elements also decreased as a consequence of the mechanical pruning (gallium - Ga; lithium – Li; rubidium - Rb, thallium – Tl; yttrium - Y). Concerning the organic amendments, sewage sludge was associated with the wines with the lowest P and iron (Fe) content. Ca content was tendentially higher in municipal solid waste compost and sewage sludge treatments. Mechanical pruning and organic amendments had different effects on the mineral composition of wine, according to each specific element. However, the legal limits, recommended by OIV and established by European Union, as well as the technical limits, adopted by winemakers, were never exceeded and the interaction of both practices does not seem to be a problem in what concerns to the mineral composition of the produced wines.
Research on the non-point source pollution characteristics and water environmental capacity within small river basin of agricultural areas a case study of the small watershed near Gan village, Tanxia town
Authors: Yang Liya , Zhou Hao , Dai Liyuan
Published: December 2021

A small watershed of a tributary of the Gantang River was chosen as the study object. The water environment capacity and the amount of non-point source pollutants entering the river were calculated by combining field measurements and survey data. The results reveal that the water quality in the basin exceeds the standard severely, with 23.12t of TN, 1.64t of TP, 58t of CODMn, and 12.05t of NH3-N exceed during the plentiful period; The watershed exceeded the TN standard by 14.3t, TP by 1.64t with 17.489t of CODMn remaining in water environmental capacity and 0.71t of NH3-N exceed during the drought period. Finally, suggestions for the prevention and control of the water environment in the watershed were proposed in response to the pollution characteristics, which are of great significance for improving the water environment of the agricultural area.
Research on Formaldehyde Release Rate of Car mats
Authors: Zhao Song , Wang Yanling , Wang Lei , Lu Yanan , Han Xueli , Liu Jin
Published: December 2021

The environmental test cabin method was used to simulate the actual use environment of car mats to collect test gas, The formaldehyde content in the collected gas was measured by ultraviolet spectrophotometer, and the formaldehyde release rate was calculated. The results indicated that formaldehyde was released in all 30 batches of samples at a rate ranging from 0.02 to 0.13mg/ m2 (m2•h).
Efficient resourcezation of sulfanilamide wastewater and A study on this reaction
Authors: Tian Yingying , Wen Kai , Chen Dezhan
Published: December 2021

Sulfanilamide wastewater which is come from the dyestuff plant is characterized by a high content of hardly biodegradable dissolved，high acidity，and organic matter. The dyestuff plant`s wastewater has become a water pollution of the world's attention. Therefore, efficient removal of sulfanilic acid and hydrochloric acid from wastewater before drainage is of great importance. This paper designed a new process engineering containing a recovery of sulfanilic acid and hydrochloric acid, at the same time which can cycle the mother liquor without any wastewater. The experimental results showed that, using this new process engineering is better than that in traditional methods.
Research on Energy Storage Cost Model in Distributed Energy System Environment
Authors: Yin Shuo , Chai Zhe , Chen Xing , Yang Meng , Lu Yao , Georgiou Kyle
Published: December 2021

With the "dual carbon" goal proposed and the direction of building a new power system dominated by new energy sources clarified, the energy storage industry has entered the fast lane of accelerated development. However, due to the imperfect marketization mechanism and the lack of effective power market ancillary service policies, it is difficult to 00EFfectively recover the cost of energy storage construction, which restricts the development of the energy storage industry to a certain extent. Therefore, it is urgent to clarify the development trend and cost recovery mechanism of typical types of energy storage under the distributed energy system, and clarify the impact of the operating cost of the electrochemical energy storage system. This paper systematically analyses the domestic and foreign energy storage investment channelling mechanisms, clarifies the impact of energy storage cost system operation on costs, and helps the development of the energy storage industry.
Structural model splicing method based on well seismic combination
Authors: Sun Dan
Published: December 2021

The use of small blocks with model-building results for overall structural model splicing can unify fault understanding, effectively integrate existing small block model results, and form a unified and continuous overall model. This article focuses on the structural models of two small blocks in the central and western parts of a certain area, and studies the method of splicing structural models at the sedimentary unit level to lay the foundation for the precise tapping of the potential of the fault edge.
Commissioning Analysis and Improvement measures for Biomass Circulating Fluidized Bed Gasifier
Authors: Gu Shan , Liu Maosheng , He Chunxiao , Yang Jicheng
Published: December 2021

This paper presents the debugging test of biomass circulating fluidized bed gasifier in a rice mill factory of Jiangsu Province. The main debugging process of the gasifier system is reported. The typical problems of the gasifier system during the debugging period are analyzed, including the blockage of the primary cyclone separator, blockage of loop seal, bed inventory leakage of blast cap on air distribution plate, feeding tube coking, and large fluctuation of bed pressure. Reasonable improvement countermeasures and implementation plan is provided. The operation characteristics of the gasifier are preliminaries mastered through debugging, which provides reference for the operation and adjustment of the biomass circulating fluidized bed gasifier. These results provide certain guiding significance for the scale application of biomass circulating fluidized bed gasifier.
Feasibility study on infilling of horizontal wells with difficult to recover reserves in Fuyu reservoir
Authors: Zheng Siqi
Published: December 2021

Aiming at the inter well drive immobile remaining oil in Fuyu oil layer of block 1 due to the non densification of surface village coverage, taking into account the undeveloped reserves that can not be produced by vertical wells due to being located in the wetland protection area along the river, the feasibility study of layered densification of horizontal wells in the main oil layer with good reservoir development is carried out to explore a new densification mode of horizontal wells in Fuyu tight oil reservoir.
Study on the boundary of development adjustment policy of B Oilfield
Authors: Sun Simian
Published: December 2021

After more than ten years of water injection development, the water cut in the main block of oilfield B has increased rapidly and the production has decreased significantly. In view of the rapid rise of comprehensive water cut in the current oilfield, it is necessary to carry out the research on the development law of oilfield B and the reasonable boundary of various development adjustment indexes, so as to clarify the different production stages The development status and development index change law of the oilfield under different oil production rates provide an accurate and reliable theoretical basis for the rational development and adjustment of the oilfield. This paper provides theoretical basis and effective technical support for the adjustment in the middle and later stage of B oilfield development, which is of great significance to the stable production and long-term sustainable development of the oilfield.
Life Cycle Carbon Emission Analyzing of Rural Residential Energy Efficiency Retrofit-A Case Study of Gansu province
Authors: Li Qiangnian , Han Tongze , Niu Changlin , Liu Ping
Published: December 2021

Objective To study and analyze the life-cycle carbon emissions of existing rural residential energy retrofit projects to provide theoretical and data support for local rural green development and sustainable construction. Methods Life cycle analysis (LCA) was used to analyze and compare the life cycle carbon emissions (LCE) of a rural residential envelope energy efficiency retrofitting project in central Gansu. Results It was found that rural dwellings have a very high potential for energy efficiency retrofitting, and the contribution of retrofitted homes to CO2 emissions reduction can reach more than 30% over the whole life cycle. Secondly, during the retrofitting process, neglected in previous studies, carbon emissions account for about a quarter of the LCE. It is concluded that introducing LCA into evaluating rural residential energy retrofit projects' energy-saving and emission reduction benefits is more scientific, reasonable, and necessary.
Study on the law of gas desorption under the condition of water flooding of the abandoned block coal in goaf
Authors: Wang Ran , Wu Wenbin
Published: December 2021

China's coal production has formed a large number of goaf, which contains a large amount of coal and coalbed methane resources. If these resources are stored in the goaf, it will not only cause a waste of resources, but also cause environmental pollution if the coalbed methane in the goaf leaks into the atmosphere. Therefore, the utilization of goaf resources is imminent. In order to achieve the purpose of efficient extraction, it is necessary to evaluate the amount of goaf resources. As an important part of goaf resources, the desorption law of abandoned coal is affected by many factors, among which water is an important factor affecting the desorption law of abandoned coal. At present, there are few studies on the desorption law of block coal under different watered-out volumes.
Electric power emergency drill evaluation based on factor analysis
Authors: Sun Xiaoguang , Geng Jianyu , Liu Kai , Wang Yuanzhi , Wang Zhipeng
Published: December 2021

This paper explores an evaluation method to evaluate the performance of participants in electric power emergency drill, expounds various important activities in electric power emergency drill, and summarizes the general mode of emergency drill. This paper introduces the principle of factor analysis and the principal component method, then uses this method to find common factors in a series of evaluation indexes, finally takes factor score as evaluation score directly. This comprehensive evaluation method can reduce the number of evaluation indexes by looking for commonness among many indexes.
Kuzbass mineral raw material base available for applying the method of robot-based roof coal release
Authors: Kuznetsova Ludmila , Anfyorov Boris
Published: December 2021

Coal reserves suitable, in prospect, for underground mining by means of robot-based system of roof coal release are situated in Bachatskey, Yerunakovskey, Kemerovskey, Leninskey, Prokopyevsk-Kiselyevskey and Tom’-Usinskey geological-economic regions of Kuzbass, in the coal seams with the thickness of more than 5 meters and the depth of 600 meters and total about 3 billion tons.
Mathematical model and numerical calculations of disastrous pressure phenomena in rock mass with weakening cavity
Authors: Lavrikov Sergey
Published: December 2021

The study focuses on deformation and stability of structurally nonuniform rock masses in the vicinity of a mined-out void. Rock masses can for a long time accumulate energy of external forces as internal stresses. The accumulated energy can release both as aseismic relaxation of stresses and as rock bumps and rock bursts. The numerical analysis uses the rock mass model including self-balancing stresses and strength loss. The paper gives examples of calculations of standard problems in mining and illustrates feasibility of modeling disastrous pressure phenomena.
Numerical modeling of the stress-strain state of peripheral massif in the vicinity of mine workings
Authors: Nikitina Anastasiya , Borzykh Dmitriy , Rib Sergey , Lesnykh Aleksandra , Zhao Tonglin
Published: December 2021

In the process of numerical studies, the stress-strain state of the rock massif around the mine working driven at a depth of 600 m was determined. The article presents the analysis of the distribution of total vertical and horizontal stresses isolines in the working roof, as well as the ratio of the residual strength of rocks to the initial. The influence of the roof bolting on the displacement of working contour was established. Dangerous zones in the near-contour rocks of preparatory working were identified. The maximum exposure area of unsecured part of the roof during driving the workings in seam 3-3a was established.
Use of industrial waste concrete from steel manufacturing for blastholes casing in open pit mining
Authors: Korneyevа Elena , Korneyev Viktor , Korneyev Petr
Published: December 2021

The article proposes to use grouting mixtures from industrial waste of steel manufacturing for casing blastholes. Its properties, defined in the course of laboratory studies, are given. One of the main features of the proposed casing technology is the production of pipes directly in the hole using a cylindrical formwork moving along the hole.
Digital modeling of geomechanical processes in a structurally heterogeneous geomassif for predicting the parameters of safe underground mining of coal seams
Authors: Pavlova Larisa , Fryanov Viktor , Veksler Julian
Published: December 2021

A digital model of geomechanical processes in a structurally heterogeneous geo-massif with consideration for the influence of natural and technogenic forces was developed. Based on the results of numerical modeling, the regularities of stress change, convergence of roof and soil rocks, stability of coal pillars between production and development workings were revealed with an increase in the depth of development and the thickness of the interbed rocks within the excavation column of a coal mine.
Belt conveyor predictive diagnostics based on the monitoring of the drive motor electrical parameters
Authors: Anikanov Dmitriy , Kipervasser Mikhail , Simakov Vadim , Qi Dabin
Published: December 2021

The study focuses on the main malfunctions of the mechanical components transmitting rotational moment to belt conveyor pulley and the possibility of functional diagnostics of their technical condition. The results of electrical values of the drive were obtained for the modeled emergency modes of the conveyor operation in the Matlab Simulink programming environment.
Estimate of greenhouse gas emissions during coal production
Authors: Zastrelov Denis , Snetova Ekaterina , Lukina Ekaterina
Published: December 2021

The paper discusses the categories of greenhouse gas emissions associated with coal mining enterprises activities. The features and quantitative assessment of greenhouse gas emissions are also considered on the example of a coal mining enterprise. Recommendations are provided for reducing greenhouse gas emissions at coal mining enterprises.
Cellular-automaton modeling of gas sorption kinetics in the finite volume of coal
Authors: Nemtsev Aleksander , Kalashnikov Sergey , Luo Xudong
Published: December 2021

The work is devoted to cellular-automaton modeling based on a class of cellular automata with Margolus neighborhood. Modeling of the gas sorption process by coal particle was carried out. To organize this kind of evolutionary process, the method of cellular automata modeling was supplemented by the Monte Carlo method to implement the boundary conditions at the solid – gas interface.
Die Trochleaplastik als Behandlungsoption bei chronischer Patellainstabilität
Authors: Schmeling Arno
Published: December 2021

Die chronische patellofemorale Instabilität (PFI) ist ein multifaktorielles Geschehen. Bei 85–96 % der Patienten mit PFI liegt eine Trochleadysplasie vor 7. Die hier vorgestellte Technik der Trochleaplastik stellt daher eine kausale Therapieoption dar und zeigt vielversprechende Ergebnisse. Da die Indikationsstellung von bildmorphologischen, klinischen und funktionellen Faktoren abhängig ist, sollten jedoch auch immer alle weiteren Risikofaktoren einer PFI berücksichtigt und evaluiert werden.
Mythbusters! The Truth about Common Misconceptions in Cochlear Implantation
Authors: Woodson Erika A. , Aaron Ksenia , Nguyen-Huynh Ahn , Vargo Jonathan , Mowry Sarah E.
Published: December 2021

Cochlear implantation (CI) is the preferred method of hearing rehabilitation when patients cannot perform well with traditional amplification. Unfortunately, there are still significant misconceptions around this life-changing intervention. The goal of this article is to address some of the most common myths around CI surgery. After reading this article, the learner will be able to explain the utility of CI in patients with residual hearing and recognize that insurance coverage is widespread. The reader will be able to list common risks associated with this well-tolerated procedure including anesthetic risk and the risk of vestibular dysfunction. Additionally, the reader will be able to identify the significant positive impact of CI on patients' quality of life. Finally, the reader will identify that many patients can safely have an MRI scan after implantation, including nearly all contemporary recipients.
2.4 CuAAC in Carbohydrate Conjugation
Authors: Agrahari A. K. , Mishra A. , Tiwari V. K.
Published: December 2021

Copper(I)-catalyzed azide–alkyne cycloaddition reactions (CuAAC), as a versatile, reliable, and modular strategy, have been widely investigated in the area of glycoscience during the last 20 years. Herein, we presented a brief overview of CuAAC click approaches for easy access to diverse simple and complex triazole-appended carbohydrate-containing molecular architectures. Both intermolecular and intramolecular CuAAC conjugation of glycosylated azides and terminal alkynes have been widely employed for the regioselective triazole-forming reaction under standard click conditions.
6.1 Thiol–Ene/Yne Click Reactions: A Powerful Tool Toward Diversity-Oriented Synthesis
Authors: Sinha A. K. , Singh R.
Published: December 2021

The clickable addition reaction between thiols and unsaturated compounds leading to the generation of (branched/linear) thioethers or (branched/linear) vinyl sulfides is known as the hydrothiolation reaction. Based upon the nature of unsaturation, i.e. double bond or triple bond, hydrothiolation reactions are classified as thiol–ene and thiol–yne click reactions, respectively. These reactions have emerged as a powerful and widely used strategy for the generation of carbon–sulfur bonds due to several associated benefits including versatile synthetic procedures, wide functional-group tolerance, high atom economy with few to no byproducts, and simple purification. The hydrothiolation reactions have numerous trapping applications in the fields of polymer chemistry, nanoengineering, pharmaceuticals, natural products, and perhaps most importantly in medicinal chemistry for the synthesis of many drugs and bioactive molecules.
Dealing with stress and intervention models in families with children with autism spectrum disorder
Authors: González-Herrera Ana Isabel , Pérez-Jorge David , Díaz-Fuentes Yesenia , Rodríguez-Jiménez María del Carmen , Ariño-Mateo Eva
Published: December 2021

Many academics working in the field of education have written about children with autism spectrum disorder (ASD) and its variant, specifically Asperger’s Syndrome. This research aims to analyze and assess the studies and psycho-pedagogical actions developed to understand the actual experience of the families around the stress derived from the presence of a child with ASD. To this end, the strategies used by the families to deal with this situation should be assessed. This paper presents a systematic review based on an exhaustive search in key databases involving a total of 16 updated studies, published between 2010 and 2020, and a selection process that looked at results from five perspectives: causes of stress, strategies used by fathers, mothers, and siblings to manage the stress, more frequent intervention models, and the importance of the family–school relationship in coping with the reality and needs of these children.
Axion Dark Matter Experiment: Detailed design and operations
Authors: Khatiwada R. , Bowring D. , Chou A. S. , Sonnenschein A. , Wester W. , Mitchell D. V. , Braine T. , Bartram C. , Cervantes R. , Crisosto N. , Du N. , Rosenberg L. J. , Rybka G. , Yang J. , Will D. , Kimes S. , Carosi G. , Woollett N. , Durham S. , Duffy L. D. , Bradley R. , Boutan C. , Jones M. , LaRoque B. H. , Oblath N. S. , Taubman M. S. , Tedeschi J. , Clarke John , Dove A. , Hashim A. , Siddiqi I. , Stevenson N. , Eddins A. , O’Kelley S. R. , Nawaz S. , Agrawal A. , Dixit A. V. , Gleason J. R. , Jois S. , Sikivie P. , Sullivan N. S. , Tanner D. B. , Solomon J. A. , Lentz E. , Daw E. J. , Perry M. G. , Buckley J. H. , Harrington P. M. , Henriksen E. A. , Murch K. W. , Hilton G. C.
Published: December 2021

Axion dark matter experiment ultra-low noise haloscope technology has enabled the successful completion of two science runs (1A and 1B) that looked for dark matter axions in the 2.66–3.1 μeV mass range with Dine–Fischler–Srednicki–Zhitnisky sensitivity [Du et al., Phys. Rev. Lett. 120, 151301 (2018) and Braine et al., Phys. Rev. Lett. 124, 101303 (2020)]. Therefore, it is the most sensitive axion search experiment to date in this mass range. We discuss the technological advances made in the last several years to achieve this sensitivity, which includes the implementation of components, such as the state-of-the-art quantum-noise-limited amplifiers and a dilution refrigerator. Furthermore, we demonstrate the use of a frequency tunable microstrip superconducting quantum interference device amplifier in run 1A, and a Josephson parametric amplifier in run 1B, along with novel analysis tools that characterize the system noise temperature.
The physical meaning of the magnetic scalar potential and its use in the design of hermetic electromagnetic coils
Authors: Crawford C. B.
Published: December 2021

The magnetic scalar potential U(r⃗) has an intuitive physical interpretation, representing the electric current I = ΔU, which must be directed between any pair of isocontours along the boundary of a region, differing in potential by ΔU, in order to generate the corresponding magnetic intensity H⃗=−∇⃗U inside the region with no tangential component outside the boundary. This physical significance is exploited to invert the design process of hermetic (fringeless) electromagnetic coils from standard iterative techniques (calculating the magnetic field of refined current distributions) to a procedure for calculating the exact surface currents required to generate a given field configuration. A practical construction algorithm is given to produce the prescribed field in a “Target” region (constrained only by Maxwell’s equations) while confining the fringe field to a specified hermetic “Return” region. Example coils are analyzed along with a discussion of the limits of precision of the constructed field.
Normal forms and near-axis expansions for Beltrami magnetic fields
Authors: Duignan Nathan , Meiss James D.
Published: December 2021

A formal series transformation to Birkhoff–Gustavson normal form is obtained for toroidal magnetic field configurations in the neighborhood of a magnetic axis. Bishop's rotation minimizing coordinates are used to obtain a local orthogonal frame near the axis in which the metric is diagonal, even if the curvature has zeros. We treat the cases of vacuum and force-free (Beltrami) fields in a unified way, noting that the vector potential is essentially the Poincaré–Liouville one-form of Hamiltonian dynamics, and the resulting magnetic field corresponds to the canonical two-form of a non-autonomous one-degree-of-freedom system. Canonical coordinates are obtained and Floquet theory is used to transform to a frame in which the lowest order Hamiltonian is autonomous. The resulting magnetic axis can be elliptic or hyperbolic, and resonant elliptic cases are treated. The resulting expansion for the field is shown to be well-defined to all orders, and is explicitly computed to degree four. An example is given for an axis with constant torsion near a 1:3 resonance.
Growth dynamics of nanoplatelet liquid crystals by directionally drying colloidal suspensions in a confined channel
Authors: Sui Jize
Published: December 2021

Unidirectional solvent evaporation has been increasingly concerned as a versatile microfluidic agent in manipulating the self-assembly dynamics of shape anisotropic colloids by precisely governing a confined nanofluid flow in a microcell. Here we develop a theoretical framework upon unidirectional drying-induced growth of nematic liquid crystals (LC) in nanoplatelet suspension confined to a Hele–Shaw (H–S) channel. The nematic order-dependent permeability assembled in modified Darcy's law and the interactions between nanoplatelets for nematic LC are both explicitly incorporated in a confined nanofluid flow. The growth dynamics of nematic LC that is highly correlated with drying rate (drying Peclet number), nanoplatelet aspect ratio, and geometric confinement have been rationalized by our numerical measurements. Unlike the spherical colloids, the nematic LC grows nonlinearly over time indicating a time-dependent instantaneous growth velocity. The final length of LC, when subjected to an enhanced drying rate, is seen to be compressed toward the drying end, but its time-averaged growth velocity increases significantly. Besides, the LC formed by the thicker nanoplatelets gets the shorter final length, while whether its average growth velocity is affected by nanoplatelet types depends on the drying rate. Importantly, we confirm a noticeable promotion in the growth of LC as the enhanced geometric confinement is imposed. A state diagram we produce suggests a universal signature of enhancement in solvent drying flux with enhanced confinement. However, our results highlight the favorable water retention in nanoplatelet nematic LC with compacted layered architecture prevailing over the spherical colloids deposits with the porous percolation architecture.
The value of pastoral ranches for wildlife conservation in the Kalahari
Authors: Van der Weyde Leanne K. , Theisinger Ole , Mbisana Christopher , Gielen Marie-Charlotte , Klein Rebecca
Published: December 2021

Abstract Context Rangelands can play an important role in conservation by providing additional habitat for many threatened species and maintaining global biodiversity. Identifying areas that can integrate both pastoral and conservation activities is important for capturing benefits from wildlife in non-protected areas. Aims To investigate wildlife distribution in a contiguous landscape comprising both pastoral ranches and wildlife-based areas in western Botswana. Methods We deployed motion-activated camera traps to assess mammal richness and occupancy using a multi-species occupancy model. We tested whether environmental factors influenced these parameters in a commercial ranching block in the western Kalahari region of Botswana, and whether species-specific occupancy varied between ranches and neighbouring wildlife management areas. Key results In the ranching block, vegetation, season and distance to wildlife areas influenced species-specific occupancy and species richness, whereas farm type and water availability affected only a few carnivore species. Commercial ranches supported several threatened species such as African wild dog, cheetah and pangolin, and we detected two species, African civet and serval, not previously considered being present in this region. Mammal diversity was similar between ranches and wildlife areas, but species composition varied. Land use affected species-specific occupancy, with many carnivore species occurring close to or in wildlife areas. Conclusions We showed that commercial ranches in the Kalahari are utilised by many mammal species, and these areas may play an important role in the conservation of threatened species. Understanding species-, group- and community-level responses to the impacts of human activities in rangelands is vital as the need for pastoral land increases. Implications We predicted regions of high occurrence of carnivores that can be important for tackling human–wildlife conflict as well as regions with high species diversity that may be useful for increasing integration of conservation endeavours (e.g. eco-tourism) that promote the benefits of wildlife in predominantly livestock regions.
The impact of analogical effects and social factors on the spelling of partially homophonous verb forms in informal social media writing
Authors: Surkyn Hanne , Vandekerckhove Reinhild , Sandra Dominiek
Published: December 2021

The present study examines unintentional spelling errors on past participles produced by Flemish teenagers in private online writing. Previous psycholinguistic research on verb spelling errors in Dutch mainly focused on identical homophones (Bosman 2005; Frisson & Sandra 2002; Sandra et al. 1999). The present study, however, deals with past participles that are only partially homophonous with other forms in the inflectional paradigm and investigates whether the spelling of these verbs is affected by whole-word frequency, paradigmatic and bigram support for the correct spelling and the token frequency of the past participles’ morphological family. The error rates reflect the effect of both paradigmatic and bigram support. Moreover, the unique database makes it possible to analyze the impact of three social factors (Gender, Educational track and Age). Our results reveal an effect on the error rates of all social variables. Finally, these social factors do not interact with paradigmatic and bigram support.
Unambiguously Resolving the Potential Neutrino Magnetic Moment Signal at Large Liquid Scintillator Detectors
Authors: Ye Ziping , Zhang Feiyang , Xu Donglian , Liu Jianglai
Published: December 2021

Non-vanishing electromagnetic properties of neutrinos have been predicted by many theories beyond the Standard Model, and an enhanced neutrino magnetic moment can have profound implications for fundamental physics. The XENON1T experiment recently detected an excess of electron recoil events in the 1–7 keV energy range, which can be compatible with solar neutrino magnetic moment interaction at a most probable value of μν
= 2.1 × 10−11
μ
B. However, tritium backgrounds or solar axion interaction in this energy window are equally plausible causes. Upcoming multi-tonne noble liquid detectors will test these scenarios more in depth, but will continue to face similar ambiguity. We report a unique capability of future large liquid scintillator detectors to help resolve the potential neutrino magnetic moment scenario. With O(100) kton⋅year exposure of liquid scintillator to solar neutrinos, a sensitivity of μν
< 10−11
μ
B can be reached at an energy threshold greater than 40 keV, where no tritium or solar axion events but only neutrino magnetic moment signal is still present.
Effect of Electron Correlation and Breit Interaction on Energies, Oscillator Strengths, and Transition Rates for Low-Lying States of Helium
Authors: Liu Qing , Li Jiguang , Wang Jianguo , Qu Yizhi
Published: December 2021

The transition energies, E1 transitional oscillator strengths of the spin-allowed as well as the spin-forbidden and the corresponding transition rates, and complete M1, E2, M2 forbidden transition rates for 1s
2, 1s2s, and 1s2p states of He I, are investigated using the multi-configuration Dirac–Hartree–Fock method. In the subsequent relativistic configuration interaction computations, the Breit interaction and the QED effect are considered as perturbation, separately. Our transition energies, oscillator strengths, and transition rates are in good agreement with the experimental and other theoretical results. As a result, the QED effect is not important for helium atoms, however, the effect of the Breit interaction plays a significant role in the transition energies, the oscillator strengths and transition rates.
Ab Initio Study of Single- and Double-Electron Capture Processes in Collisions of He2+ Ions and Ne Atoms
Authors: Wang Xiao-Xia , Wang Kun , Peng Yi-Geng , Liu Chun-Hua , Liu Ling , Wu Yong , Liebermann Heinz-Peter , Buenker Robert J. , Qu Yi-Zhi
Published: December 2021

The single- and double-electron capture (SEC, DEC) processes of He2+ ions colliding with Ne atoms are studied by utilizing the full quantum-mechanical molecular-orbital close-coupling method. Total and state-selective SEC and DEC cross sections are presented in the energy region of 2 eV/u to 20 keV/u. Results show that the dominant reaction channel is Ne+(2s2p
6
2
S) + He+(1s) in the considered energy region due to strong couplings with the initial state Ne(2s
22p
6
1
S) + He2+ around the internuclear distance of 4.6 a.u. In our calculations, the SEC cross sections decrease initially and then increase whereby, the minimum point is around 0.38 keV/u with the increase of collision energies. After considering the effects of the electron translation factor (ETF), the SEC cross sections are increased by 15%–25% nearby the energy region of keV/u and agree better with the available results. The DEC cross sections are smaller than those of SEC because of the larger energy gaps and no strong couplings with the initial state. Due to the Demkov-type couplings between DEC channel Ne2+(2s22p
4
1
S) + He(1s
2) and the dominating SEC channel Ne+(2s2p
6
2
S) + He+(1s), the DEC cross sections increase with increasing impact energies. Good consistency can also be found between the present DEC and the experimental measurements in the overlapping energy region.
Topological Properties in Strained Monolayer Antimony Iodide
Authors: Yuan Danwen , Hu Yuefang , Yang Yanmin , Zhang Wei
Published: December 2021

Two-dimensional (2D) topological insulators present a special phase of matter manifesting unique electronic properties. Till now, many monolayer binary compounds of Sb element, mainly with a honeycomb lattice, have been reported as 2D topological insulators. However, research of the topological insulating properties of the monolayer Sb compounds with square lattice is still lacking. Here, by means of the first-principles calculations, a monolayer SbI with square lattice is proposed to exhibit the tunable topological properties by applying strain. At different levels of the strain, the monolayer SbI shows two different structural phases: buckled square structure and buckled rectangular structure, exhibiting attracting topological properties. We find that in the buckled rectangular phase, when the strain is greater than 3.78%, the system experiences a topological phase transition from a nontrivial topological insulator to a trivial insulator, and the structure at the transition point actually is a Dirac semimetal possessing two type-I Dirac points. In addition, the system can achieve the maximum global energy gap of 72.5 meV in the topological insulator phase, implying its promising application at room temperature. This study extends the scope of 2D topological physics and provides a platform for exploring the low-dissipation quantum electronics devices.
Influence of Device Geometry on Transport Properties of Topological Insulator Microflakes
Authors: Gao Fan , Li Yongqing
Published: December 2021

In the transport studies of topological insulators, microflakes exfoliated from bulk single crystals are often used because of the convenience in sample preparation and the accessibility to high carrier mobilities. Here, based on finite element analysis, we show that for the non-Hall-bar shaped topological insulator samples, the measured four-point resistances can be substantially modified by the sample geometry, bulk and surface resistivities, and magnetic field. Geometry correction factors must be introduced for accurately converting the four-point resistances to the longitudinal resistivity and Hall resistivity. The magnetic field dependence of inhomogeneous current density distribution can lead to pronounced positive magnetoresistance and nonlinear Hall effect that would not exist in the samples of ideal Hall bar geometry.
Recent Progress in Presodiation Technique for High-Performance Na-Ion Batteries
Authors: Xie Fei , Lu Yaxiang , Chen Liquan , Hu Yong-Sheng
Published: December 2021

Na-ion batteries (NIBs) have been attracting growing interests in recent years with the increasing demand of energy storage owing to their dependence on more abundant Na than Li. The exploration of the industrialization of NIBs is also on the march, where some challenges are still limiting its step. For instance, the relatively low initial Coulombic efficiency (ICE) of anode can cause undesired energy density loss in the full cell. In addition to the strategies from the sight of materials design that to improve the capacity and ICE of electrodes, presodiation technique is another important method to efficiently offset the irreversible capacity and enhance the energy density. Meanwhile, the slow release of the extra Na during the cycling is able to improve the cycling stability. In this review, we would like to provide a general insight of presodiation technique for high-performance NIBs. The recent research progress including the principles and strategies of presodiation will be introduced, and some remaining challenges as well as our perspectives will be discussed. This review aims to exhibit the basic knowledge of presodiation to inspire the researchers for future studies.
Plane-wave propagation in media with electromagnetic anisotropy
Authors: Romero-Abad David , Reyes-Portales José-Pedro , Suárez-Córdova Roberto
Published: December 2021

The propagation of electromagnetic waves in a medium with electrical and magnetic anisotropy is a subject that is not usually handled in conventional optics and electromagnetism books. During this work, we try to give a pedagogical approach to the subject, using tools that are accessible to an average physics student. In this article, we obtain the Fresnel relation in a media with electromagnetic anisotropy, which corresponds to a quartic equation in the refraction index, assuming only that the principal axes of the electric and magnetic tensors coincide. Additionally, we find the geometric location related to the different situations the discriminant of the quartic equation provides. In order to illustrate our findings, we determine the refractive index together with the plane wave equations for certain values of the parameters that meet the established conditions. The target readers of the paper are students pursuing physics at the intermediate undergraduate level.