bluuebunny/crossref_metadata_2025 huggingface dataset:
A quantum engineer's guide to superconducting qubits
Authors: Krantz P. , Kjaergaard M. , Yan F. , Orlando T. P. , Gustavsson S. , Oliver W. D.
Published: June 2019

The aim of this review is to provide quantum engineers with an introductory guide to the central concepts and challenges in the rapidly accelerating field of superconducting quantum circuits. Over the past twenty years, the field has matured from a predominantly basic research endeavor to a one that increasingly explores the engineering of larger-scale superconducting quantum systems. Here, we review several foundational elements—qubit design, noise properties, qubit control, and readout techniques—developed during this period, bridging fundamental concepts in circuit quantum electrodynamics and contemporary, state-of-the-art applications in gate-model quantum computation.
Modeling L2,3-edge X-ray absorption spectroscopy with linear response exact two-component relativistic time-dependent density functional theory
Authors: Stetina Torin F. , Kasper Joseph M. , Li Xiaosong
Published: June 2019

X-ray absorption spectroscopy (XAS) is a powerful tool that can provide physical insights into element-specific chemical processes and reactivities. Although relativistic time-dependent density functional theory (TDDFT) has been previously applied to model the L-edge region in XAS, there has not been a more comprehensive study of the choices of basis sets and density functional kernels available for variational relativistic excited state methods. In this work, we introduce the implementation of the generalized preconditioned locally harmonic residual algorithm to solve the complex-valued relativistic TDDFT for modeling the L-edge X-ray absorption spectra. We investigate the L2,3-edge spectra of a series of molecular complexes using relativistic linear response TDDFT with a hybrid iterative diagonalization algorithm. A systematic error analysis was carried out with a focus on the energetics, intensities, and magnitude of L2–L3 splitting compared to experiments. Additionally, the results from relativistic TDDFT calculations are compared to those computed using other theoretical methods, and the multideterminantal effects on the L-edge XAS were investigated.
Optical-frequency scanning-rate calibration of external cavity diode lasers using adaptive complex-shifted Morlet wavelets
Authors: Wang Zhiyong , Liu Zhigang , Deng Wen , Zhang Xin , Yan Haihong
Published: June 2019

Real-time measurement of the optical frequency of an external cavity diode laser (ECDL) is very difficult. In this study, a novel adaptive complex-shifted Morlet wavelets method was proposed to accurately determine the instantaneous frequency of the interference signal. The optical frequency scanning rate and the change in the optical frequency trend could then be obtained using the instantaneous frequency. The proposed method was theoretically analyzed, and both simulations and experimental results confirm that the method can accurately obtain the scanning rate and change in the trend of the ECDL optical frequency. The experimental results demonstrate that the maximum single-cycle relative error was less than 2.5‰ and the linearity of output optical frequency with correction was good and R2 was 0.999 98.
The application of harmonic techniques to enhance resolution in mesh-based x-ray phase imaging
Authors: He Congxiao , Sun Weiyuan , MacDonald C. A. , Petruccelli Jonathan C.
Published: June 2019

X-ray phase-contrast imaging produces significantly higher contrast than the conventional attenuation-based imaging. However, phase contrast typically requires small low-power sources or precisely machined and aligned gratings to generate the required spatial coherence. To overcome this limitation, we use a simple wire mesh to produce a periodic intensity pattern in the illumination. Distortions in this pattern upon propagation through an object can be used to produce phase contrast images. Unlike Talbot-grating-based techniques, this directly provides a measure of the phase gradient. Due to periodicity, fast Fourier transforms enable rapid retrieval of the phase contrast image. The high contrast of the mesh pattern allows a significant relaxation of the coherence requirement. However, the resolution of the phase contrast image is normally limited by the mesh period. We demonstrate that employing wider windowing functions during the Fourier processing substantially improves the spatial resolution at the cost of introducing artifacts in the reconstructed images. In order to remove these artifacts, a method is presented to combine images acquired while spatially shifting the mesh. Experimental results demonstrate the successful removal of these artifacts. This offers a method for significant resolution improvement in mesh-based phase-contrast imaging, enabling high resolution phase contrast images with a significant relaxation of source coherence requirements.
An anisotropic magneto-mechanical model of ferromagnetic materials for the magnetic memory testing method
Authors: Zhang Pengcheng , Shi Pengpeng , Jin Ke , Zheng Xiaojing
Published: June 2019

The metal magnetic memory (MMM) method shows great potential in the early damage evaluation of ferromagnetic materials. The MMM signal is affected by the environmental magnetic field because of the magneto-mechanical coupling effect. For instance, the effect of the environmental magnetic field is connected with the angle between the environmental magnetic field and the detected structure, which is referred to as the angle effect. This paper aims to explore the angle effect on the MMM method under the weak magnetic field. An anisotropic nonlinear magneto-mechanical constitutive relationship is proposed based on the magnetic domain theory and the approach law. Compared to the existing model, the present constitutive relationship in this paper can predict the stress-magnetization curve of ferromagnetic materials under the combined action of the loading stress and the environmental magnetic field with different directions. Based on the present constitutive relationship, an anisotropic nonlinear magneto-mechanical model of the MMM method is established, and then the angle effect is discussed in detail. The prediction of the anisotropic nonlinear magneto-mechanical model shows a good agreement with experimental data. The proposed model can clarify the reasons for some complex phenomena of the MMM signal, and thus help in the practical application of the MMM method.
Precise measurement of absolute Seebeck coefficient from Thomson effect using ac-dc technique
Authors: Amagai Y. , Shimazaki T. , Okawa K. , Fujiki H. , Kawae T. , Kaneko N.-H.
Published: June 2019

The Seebeck coefficient is the most widely measured property specific to thermoelectric materials. The absolute Seebeck coefficient S determined from the Thomson effect is highly sensitive to systematic errors incurred in the determination of the material thermal conductivity and geometry and heat loss from the sample to surroundings caused by temperature differences. Here, we report a technique for the precision measurement of S based on the Thomson effect using an ac-dc technique. This technique utilizes accurate equivalent-amplitude ac and dc currents, which can eliminate the need for acquiring accurate thermal conductivity and geometry values. These parameters can be replaced by the precisely and readily measurable parameters of electrical resistance and temperature changes caused by the Joule effect. The correction term of the heat loss owing to heat transfer via the thermocouple vanishes upon calculating the ratio of the measured temperature changes for both ac and dc excitations. We obtain an S value of -4.8 μV/K ± 0.2 μV/K at a temperature of 300 K for platinum, which is most widely used as a reference, with an expanded relative uncertainty of 4% (2σ). The obtained S value of Pt is closely consistent with that obtained from the conventional method using the Thomson effect within the uncertainty, and importantly, the measurement uncertainty improves to an acceptable level, which is four times more precise.
Theoretical study of charge carrier transport in organic molecular crystals using the Nakajima-Zwanzig-Mori generalized master equation
Authors: Yan Yaming , Xu Meng , Liu Yanying , Shi Qiang
Published: June 2019

There has been a long history of applying the generalized master equation (GME) to study charge carrier and exciton transport in molecular systems. Yet exact memory kernels in the GME are generally difficult to obtain. In this work, exact memory kernels of the Nakajima-Zwanzig-Mori GME for a one dimensional Holstein type of model are calculated by employing the Dyson relation for the exact memory kernel, combined with the hierarchical equations of motion method. Characteristics of the exact memory kernels, as well as the transition rate constants within the Markovian approximation, are then analyzed for different sets of parameters ranging from the hopping to bandlike transport regimes. It is shown that, despite the memory effect of the exact kernels, the Markovian approximation to the exact GME can reproduce the diffusion constants accurately. We also investigate the validity of the second and fourth order perturbation theories with respect to the electronic coupling constant in calculating the rate constants and the diffusion constant. It is found that, due to the cancellation of errors, the second order diffusion constant gives a reasonable estimate of the exact one within a wide range of electronic coupling constants.
Intruders in disguise: Mimicry effect in granular gases
Authors: Lasanta Antonio , Vega Reyes Francisco , Garzó Vicente , Santos Andrés
Published: June 2019

In general, the total kinetic energy in a multicomponent granular gas of inelastic and rough hard spheres is unequally partitioned among the different degrees of freedom. On the other hand, partial energy equipartition can be reached, in principle, under appropriate combinations of the mechanical parameters of the system. Assuming common values of the coefficients of restitution, we use kinetic-theory tools to determine the conditions under which the components of a granular mixture in the homogeneous cooling state have the same translational and rotational temperatures as those of a one-component granular gas (“mimicry” effect). Given the values of the concentrations and the size ratios, the mimicry effect requires the mass ratios to take specific values, the smaller spheres having a larger particle mass density than the bigger spheres. The theoretical predictions for the case of an impurity immersed in a host granular gas are compared against both direct simulation Monte Carlo and molecular dynamics simulations with a good agreement.
BaZrSe3: Ab initio study of anion substitution for bandgap tuning in a chalcogenide material
Authors: Ong Marc , Guzman David M. , Campbell Quinn , Dabo Ismaila , Jishi Radi A.
Published: June 2019

Recently, transition metal perovskite chalcogenide materials have been proposed as possible candidates for solar cell applications. In this work, we provide accurate theoretical calculations for BaZrS3 and two phases of SrZrS3, which have been recently synthesized and their optical properties elaborated. In this study, we consider the substitution of S in BaZrS3 with Se to form BaZrSe3. Evolutionary methods are used to find the optimal structure of this compound, and accurate calculations of its optoelectronic properties are presented. Using phonon frequency calculations and ab initio molecular dynamics, we assess the stability of this compound. We find that BaZrSe3 is likely to be stable under typical conditions, with a low bandgap and high optical absorption coefficients. This suggests that BaZrSe3 could be useful for solar cell applications.
Efficient broadband terahertz generation from organic crystal BNA using near infrared pump
Authors: Zhao Hang , Tan Yong , Wu Tong , Steinfeld Gunther , Zhang Yan , Zhang Cunlin , Zhang Liangliang , Shalaby Mostafa
Published: June 2019

We report on terahertz (THz) generation from organic crystal N-benzyl-2-methyl-4-nitroaniline using a 1.15–1.55 μm near infrared pump. We observed a very large emission spectrum extending up to 7 THz, compared to 2.5 THz from a Ti:Sa pump in previous reports. The maximum optical-to-THz conversion efficiency in our experiment was 0.8% at a repetition rate of 1 kHz and without saturation, leading to a peak electric field of 1 GV/m. Our results show pronounced phase matching privilege for intense terahertz generation using a pump in the 1.15–1.25 μm range where high energy near infrared pump sources operate.
Inversion channel mobility and interface state density of diamond MOSFET using N-type body with various phosphorus concentrations
Authors: Matsumoto Tsubasa , Kato Hiromitsu , Makino Toshiharu , Ogura Masahiko , Takeuchi Daisuke , Yamasaki Satoshi , Inokuma Takao , Tokuda Norio
Published: June 2019

We investigated the phosphorus concentration (NP) dependence of the field-effect mobility μFE and interface state density Dit in inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs). The inversion channel diamond MOSFETs are potentially applicable in high-frequency, high-current, and high-voltage devices because of the material's excellent properties such as a wide bandgap, high breakdown electric field, high carrier mobility, and high thermal conductivity. However, the influences of device design parameters, such as NP in an n-type body and the oxide layer material, on the electrical characteristics of inversion channel diamond MOSFETs have not yet been reported. In this study, we fabricated inversion channel diamond MOSFETs using n-type bodies with various NP values. For decreased NP in the n-type body, μFE was increased, while Dit was decreased. Using the n-type body with the lowest NP of 2 × 1015 cm−3, the maximum μFE of 20 cm2/V·s and the minimum Dit of 1 × 1013 cm−2·eV−1 were obtained. In addition, an inverse correlation was found between μFE and Dit. Specifically, in the low-gate-voltage region of the drain current–gate voltage characteristics, μFE and Dit were strongly inversely correlated. The high Dit suggests that most holes are trapped in the interface state as strong scattering factors in the low-gate-voltage region. Lower Dit values are therefore important for obtaining higher μFE values, the same as in Si and SiC.
Gyrokinetic simulations of m = 0 mode in sheared flow Z-pinch plasmas
Authors: Geyko V. I. , Dorf M. , Angus J. R.
Published: June 2019

Axisymmetric stability properties of sheared flow Z-pinch plasmas are studied by making use of the gyrokinetic approximation in the long-wavelength limit. Numerical simulations are carried out with the high-order finite-volume code COntinuum Gyrokinetic Edge New Technology (COGENT) and are analyzed for the parameters characteristic of the FuZE experiment. Reduction of the linear growth rate with increasing shear is observed, and the results are elucidated by making use of a local dispersion relation analysis. In addition, COGENT simulations are compared with fully kinetic particle-in-cell simulations, and with an ideal magnetohydrodynamics (MHD) model. Good agreement between the gyrokinetic and fully kinetic results for the linear stability is found, with the gyrokinetic model requiring much less computational time due to its ability to step over particle gyroperiod. The ideal MHD model is found to be consistent with the kinetic models in the long-wavelength part of the spectra (kρi), while failing to adequately predict short-scale (kρi) stability. Here, k is the axial wavelength vector and ρi is the ion gyroradius.
Growth of quantum dot coated core-shell anisotropic nanowires for improved thermal and electronic transport
Authors: Hou Bo , Jung Su-Ho , Zhang Jingchao , Hong Yang , Kim Byung-Sung , Sohn Jung Inn , Lee Eun Kyung , Choi Byoung Lyong , Whang Dongmok , Cha SeungNam , Kim Jong Min
Published: June 2019

Anisotropic nanowires are promising candidates for electronic thermal management due to their unique electrical and thermal properties. However, eco-friendly solution-processed nanomaterials with an elaborate morphology and microstructure for modulating thermal and charge transfer are still a considerable challenge. Herein, we present a simple but effective approach for synthesizing pseudo core-shell nanowires through quantum dot (QD)-like nanostructure coating (p-NW@QD) to generate exceptional electron-phonon transport properties. With the assistance of diphenyl ether as a coordination solvent, high crystallinity lead sulfide NWs can be fabricated with a large aspect ratio together with uniform QD coating. This p-NW@QD exhibits high electronic mobility (30.65 cm2/Vs) as well as a diameter independent low thermal conductivity (1.53 ± 1 W/m K). Direct charge/heat carrier flow measurements and computational simulations demonstrate that the unusual electrical and thermal transport phenomenon is strongly dependent on the fast charge transport through the QD shell, and a slow phonon migration across the Umklapp process dominated NW cores. These findings indicate a significant step toward colloidal synthesis nanostructures for future high-performance nanoelectronics and thermal energy devices.
Australia – how do we compare as an exploration destination?
Authors: Quinn Matthew
Published: June 2019

A country’s competitiveness as a destination to conduct oil and gas exploration and production operations can be assessed through analysis of key metrics including discovered volumes, new field wildcat success rate, average field size, discovered volumes per new field wildcat, fiscal terms, sanctity of contract, regulatory burden and civil society risk. When compared globally, Australia ranks very high for aboveground risk factors, well for discovered volumes and discovered volumes per new field wildcat but sits towards the lower end of the dataset for fiscal terms. When assigning each metric a score on a scale of 1–10 and appropriately weighting and combining them to produce one overall score for each country, Australia currently ranks fourteenth for offshore and sixth for onshore. Historically, Australia’s rankings have been relatively consistent and have not dropped below twentieth since 2006. Conducting this analysis at a basin level allows the introduction of ‘time to onstream’ and ‘yet to find’ as additional metrics. Of the Australian immature basins, the McArthur Basin has the highest ranking; and for moderately mature basins, the North Carnarvon Basin tops the list.
From initial advice statement to export – a 10 year retrospective of Queensland's liquefied natural gas industry
Authors: Downey Peter , Thomas Jon , Stone Mark
Published: June 2019

A decade on from the submission of project initial advice statements to Queensland Government agencies in 2008, this paper provides a retrospective on the development journey of three integrated coal seam gas (CSG) to liquefied natural gas (LNG) mega-projects currently delivering domestic and international markets. The process from development concept to operating asset is considered from several perspectives including: project rationale, description and delivery, as well as regulatory approvals. Project delivery is further considered in terms of the upstream, midstream and downstream components. The delivery of world first CSG to LNG is discussed in the context of project execution during significant volatility in the global oil, gas and LNG markets. All three projects have successfully completed commissioning and start-up. Although all six trains have been performance tested at name-plate production capacity, current LNG production is below this level. This paper examines their evolution from the initial concepts through to delivery, including current gas reserves and those required to sustain gas supply over expected project life. The paper also considers how these projects and any future expansion of the Queensland LNG industry will be impacted upon by an evolving global LNG market.
LNG production revenue enhancement
Authors: Vines Michael J.
Published: June 2019

Liquefied natural gas (LNG) production involves complex processes that differ from conventional oil and gas production. That complexity, however, can be harnessed to drive improved business performance. Parameters for optimisation include plant reliability, capacity and yield. In combination, these parameters may deliver a non-linear upside to production operations at minimal cost. This paper shall therefore review a method for assessing the existing and potential performance of a hypothetical LNG facility with a focus on maximisation of gross revenue. Drawing on various case studies, several key process steps shall be reviewed in detail using both fundamental engineering and managerial economics. Optimisation of a single LNG train shall be reviewed to show the cumulative impact of executing a combination of individually small process improvements. The improvements reviewed span the spectrum from setpoint and alarm changes to in-depth technical studies and physical modifications. The process for planning, studying and testing enhanced performance is also discussed. The outcomes from a combination of these initiatives are summarised, including a forecast of the potential for further continuous improvement as well as real world examples.
Towards the development of a baseline for surface movement in the Surat Cumulative Management Area
Authors: Masoudian Mohsen S. , Leonardi Christopher , Chen Zhongwei , Underschultz Jim
Published: June 2019

Ground surface movement can result from several natural and anthropogenic processes. Understanding the mechanisms that drive ground surface movement and their contribution to the net movement is crucial in assessing the impact of resource development projects and other human activities. Consequently, there is an interest in understanding ground surface movement in the Surat Cumulative Management Area (CMA), Queensland, and how it is influenced by coal seam gas (CSG) production, if at all. This paper presents the analysis of a large InSAR (interferometric synthetic aperture radar) dataset covering the CMA regions featuring no active CSG wells. These non-production areas were specifically examined in order to develop an understanding of background surface movement and its contributing processes. Of the regional dataset, four focus areas showing measurable changes over time were selected for more detailed investigation. All the focus areas exhibited an overall downward surface movement (subsidence), with three showing cycles of subsidence and uplift that appeared to be very well correlated with rainfall events. The soil types in these three areas were consistent with the hypothesis that the observed surface movement is due to rainfall infiltration-induced consolidation of the shallow soil layers and subsequent moisture-induced shrinkage and swelling. The fourth focus area, however, did not exhibit a strong seasonal fluctuation, and unravelling the mechanisms driving surface movement in this area was more difficult. This investigation resulted in a foundation for further research into the complex problem of surface movement, and in particular, deconvolution of the various contributions that occur at different depths, lengths, and time scales.
Flowing gas material balance – a useful tool to revise subsurface maps
Authors: Haq Bashirul
Published: June 2019

Subsurface geological maps are an interpretation based on limited data, yet they are the most important vehicles used to explore for undiscovered hydrocarbons and to develop proven hydrocarbon reserves. The flowing material balance (FMB) method uses flowing well head pressure, rather than shut in reservoir pressure, to estimate gas in place (GIP) and reserves at any stage of reservoir depletion. In addition, it can be applied to estimating permeability and skin of the reservoir and predicting production problems. However, application of the FMB for revising subsurface maps is not yet well understood and requires further study. The aim of this research was to develop a systematic approach to redraw subsurface maps using FMB with the aid of reservoir simulation and interpretive contouring methods. The Havlena and Odeh interpretation method was applied to identify a drive mechanism and the FMB was used to estimate GIP, which was checked against the volumetric GIP value. The pressure history match technique and interpretive contouring were applied to draw the revised maps. This step-wise technique was applied to the Titas gas field, operated by Petrobangla, and found that the Titas gas reservoir’s drive mechanism was volumetric drive. A review of the literature, including old reports and well drilling data, confirmed that there was no evidence of aquifer drive and gas water contact in the ‘A sand’ layers. Subsurface maps of sands A2, A3 and A4 were redrawn and validated using field data.
Monitoring marine effects of produced formation water discharge in Bass Strait
Authors: Barnes Lachlan , Hall Katrina , Blount Craig , Hooper Madelaine , van Senden David , Costen Andrew , Scraggs Chris , Provis David , Pygas Daniel
Published: June 2019

Esso Australia Pty Ltd (Esso), in a joint venture with BHP Petroleum Pty Ltd, operates 23 oil and gas production platforms and subsea facilities off the Victorian coast near Gippsland, Australia. The underlying reservoirs have multi-darcy sands and a strong aquifer water drive, so in addition to oil and gas, the extraction activities result in substantial amounts of produced formation water (PFW). Following on-platform treatment, PFW containing a variety of hydrocarbons, ions and inorganics, such as calcium, ammonia, sulfate and trace metals, is discharged into the receiving environment. This paper reports on a study undertaken to investigate the potential effects of PFW discharges from two platforms (Tuna (TNA) and West Kingfish (WKF)) on the receiving environment. Four complementary sampling approaches were used to address the objectives of the study: (1) measure and estimate the dilution of Rhodamine FWT dye solution in the receiving environment following injection into the PFW discharge line, (2) collect and analyse undiluted PFW samples before discharge, (3) collect and analyse marine water samples from within the discharge plume and (4) collect and analyse sediment and benthic infauna samples at various distances away from platforms and at reference locations. Results indicate the rate of PFW dilution within the receiving environment is more rapid than predicted by existing numerical models and that the concentration of all analytes present in PFW were below Australian and New Zealand Environment Conservation Council (ANZECC) 2000 guideline trigger values for 80% protection; moreover, with one exception, analytes were not detected above background levels more than 59 m from the platform. With the exception of a few samples containing metals, specifically arsenic, copper, lead, zinc and nickel, concentrations of analytes in the majority of sediment samples collected were below the ANZECC 2000 and revised 2013 sediment quality guidelines. A diverse range of benthic infauna were sampled, with the abundance of a limited number of taxa influenced by distance from individual platforms. No substantial differences in abundances of benthic infauna were detected at distances greater than 1.3 km from TNA and 1.0 km from WKF, compared with reference locations. These results indicate that PFW discharges from TNA and WKF likely represent a low risk to the receiving environment.
A practical fracability evaluation for tight sandstone reservoir with natural interface
Authors: Feng Runhua , Chen Ruijie , Sarmadivaleh Mohammad
Published: June 2019

Hydraulic fracturing has been widely applied to enhance the conductivity in tight sandstone reservoirs, i.e. reservoirs with low porosity and permeability. The interaction between a hydraulic fracture (HF) and a natural fracture (NF), including crossing, arresting and opening (tensile or dilation), are crucial for controlling the fracability of a reservoir. Previous studies have elucidated that shear dilation is the main mechanism for enhancing the permeability of an unconventional reservoir. Moreover, the brittleness index (BI) is considered another critical parameter that controls the fracability of candidates. However, the fracability of candidates with respect to both shear dilation and BI have not been fully investigated. We performed a practical fracability evaluation by integrating the shear dilation mechanism and BI quantification. We obtained the mechanical parameters from mechanical tests conducted on synthetic tight sandstone samples, and we manufactured specimens with different friction coefficients and shear strengths. Next, we performed scaled hydraulic fracturing experiments on 15 identical 10 cm cubic samples using a true tri-axial stress cell, and the interaction mechanisms between HFs and NFs were investigated. We also evaluated the brittleness of each specimen based on a previous BI model and our own novel BI model. We found that a weak interface cohesion with an interaction (between HF and NF) angle of 60° exhibited a shear dilation (or reactivation) mechanism and a higher BI. We thus conclude that such conditions are more favourable for reservoir stimulation (i.e. hydraulic fracturing) in the field.
The effect of vanadium(IV) complexes on development of Arabidopsis thaliana subjected to H2O2-induced stress
Authors: Rojek Joanna , Kozieradzka-Kiszkurno Małgorzata , Kapusta Małgorzata , Aksmann Anna , Jacewicz Dagmara , Drżeżdzon Joanna , Tesmar Aleksandra , Żamojć Krzysztof , Wyrzykowski Dariusz , Chmurzyński Lech
Published: June 2019

The impact of oxydiacetate oxidovanadium(IV) complexes on plants is currently unknown. This report demonstrates the influence of these complexes on Arabidopsis thaliana (L.) Heynh. In the presence of 10−6M vanadium(IV) complexes, plants proceeded through their entire life cycle, with the occurrence of proper morphological and cytological organisation of leaf and root tissues. The addition of 10−1M H2O2 caused root damage, leaf necrosis, and plant death at around the seventh day, due to the destruction of the root system. Pretreatment of the plants with 10−6M of vanadium(IV) compounds: VOSO4 and VO(oda), alleviated the effects of H2O2 to some extent. Plants pretreated with 10−6M vanadium(IV) complexes survived longer despite the presence of H2O2. Considering the higher rate of plant survival in the presence of VOSO4, and the relatively high photosynthetic parameters and anthocyanin contents in the cells, we conclude that this vanadium(IV) compound can have positive effects on plants that are grown under stress conditions.
Stochastic modelling of soil water dynamics and sustainability for three vegetation types on the Chinese Loess Plateau
Authors: Suo Lizhu , Huang Mingbin
Published: June 2019

Soil water dynamics play an active role in ecological and hydrologic processes. Soil water exhibits a stochastic nature because of the large temporal variations in precipitation and evapotranspiration. Objectives of this study were to analyse the probabilistic nature of soil water under three vegetation types, to simulate their probability density functions (PDFs) using a stochastic model, and to determine the most sustainable vegetation types. Soil water data were collected over a 3-year period with a bi-weekly frequency at plots in the Loess Plateau, China, under grass (Bothriochloa ischaemum L., BOI), shrub, sea-buckthorn (Hippophae rhamnoides L., SEB) and tree, Chinese pine (Pinus tabulaeformis Carr, CHP). The data were compared with values simulated using the Laio stochastic model. The results showed that the mean relative soil water contents differed in the order: BOI > CHP > SEB. Soil water was related to the daily rainfall and evapotranspiration. Under the same climate, topography and soil conditions, the soil water PDF was sensitive to a critical water content at which plants begin closing stomata and the mean maximum daily evapotranspiration rate. Based on the shape of the PDFs and their statistical moments, the Laio stochastic model accurately simulated the soil water PDFs under all three vegetation types in the semi-humid area of the Loess Plateau. The soil water PDFs for three vegetation types were simulated with four leaf area index scenarios; BOI and CHP were the most sustainable vegetation types compared with SEB in terms of maintaining soil water availability and soil erosion control.
Marijuana Use, Alcohol Use, and Sexual Intercourse among Truant Adolescents
Authors: Graves Hannah R. , Hernandez Lynn , Kahler Christopher W. , Spirito Anthony
Published: June 2019

Background

Adolescence is a time in development when many initiate problem behaviors, including alcohol use, marijuana use, and sexual intercourse. Although research has shown that these behaviors tend to co-occur, little is known about their daily co-occurrences, particularly among high-risk groups such as truant adolescents. This study investigated the influence of marijuana and alcohol use on the odds of engaging in sexual intercourse on a daily level among a sample of truant adolescents.

Methods

Daily-level data from 76 at-risk, truant adolescents (46 male, 30 female) between the ages of 13 and 19 years who reported alcohol use, marijuana use, and sexual intercourse over a 90-day retrospective recall period were analyzed.

Results

General estimating equations analyzing 6840 days and controlling for age, gender, and school days demonstrated that the use of marijuana and/or alcohol on a given day were associated with significantly increased odds of engaging in sexual intercourse on the same day. A significant interaction suggested that marijuana use on a given day increased the odds of engaging in sexual intercourse on that day among occasional marijuana users, yet not among frequent users. Additionally, a significant interaction suggested that frequent alcohol users had higher odds of engaging in sexual intercourse than those who used alcohol less frequently.

Conclusions

This study suggests that experimenting with marijuana and alcohol increases truant adolescents’ odds of also engaging in sexual intercourse. These results bridge the gap in the literature by investigating the daily-level associations and frequency of substance use and sexual intercourse among truant adolescents. This study demonstrates that among truant adolescents, substance use and sexual intercourse do not function independently; therefore, it is important to address the intersection between substance use and sexual behaviors during intervention development if sustained behavioral change is expected.
Microvesicles: ROS scavengers and ROS producers
Authors: Bodega G. , Alique M. , Puebla L. , Carracedo J. , Ramírez R. M.
Published: June 2019

This review analyzes the relationship between microvesicles and reactive oxygen species (ROS). This relationship is bidirectional; on the one hand, the number and content of microvesicles produced by the cells are affected by oxidative stress conditions; on the other hand, microvesicles can directly and/or indirectly modify the ROS content in the extra‐ as well as the intracellular compartments. In this regard, microvesicles contain a pro‐oxidant or antioxidant machinery that may produce or scavenge ROS: direct effect. This mechanism is especially suitable for eliminating ROS in the extracellular compartment. Endothelial microvesicles, in particular, contain a specific and well‐developed antioxidant machinery. On the other hand, the molecules included in microvesicles can modify (activate or inhibit) ROS metabolism in their target cells: indirect effect. This can be achieved by the incorporation into the cells of ROS metabolic enzymes included in the microvesicles, or by the regulation of signaling pathways involved in ROS metabolism. Proteins, as well as miRNAs, are involved in this last effect.
c-Myc steers translation in lymphoma
Authors: Cargnello Marie , Topisirovic Ivan
Published: June 2019

Members of the MYC family of oncogenes are master regulators of mRNA translation. In this issue of JEM, Singh et al. (https://doi.org/10.1084/jem.20181726) demonstrate that c-Myc governs protein synthesis in lymphoma cells by interfering with SRSF1- and RBM42-mediated suppression of mRNA translation and by altering selection of translation initiation sites.
Lump Solutions for Two Mixed Calogero-Bogoyavlenskii-Schiff and Bogoyavlensky-Konopelchenko Equations*
Authors: Ren Bo , Ma Wen-Xiu , Yu Jun
Published: June 2019

Based on the Hirota bilinear operators and their generalized bilinear derivatives, we formulate two new (2+1)-dimensional nonlinear partial differential equations, which possess lumps. One of the new nonlinear differential equations includes the generalized Calogero-Bogoyavlenskii-Schiff equation and the generalized Bogoyavlensky-Konopelchenko equation as particular examples, and the other has the same bilinear form with different Dp
-operators. A class explicit lump solutions of the new nonlinear differential equation is constructed by using the Hirota bilinear approaches. A specific case of the presented lump solution is plotted to shed light on the charateristics of the lump.
A Consistency Check for the Free Scalar Field Theory Realization of the Doubly Spacial Relativity*
Authors: Khodadi Mohsen , Nozari Kourosh
Published: June 2019

We study a free scalar field theory in the framework of the Magueijo-Smolin model of the “Doubly Special Relativity” (DSR) which is a non-linear realization of the action of the Lorentz group on momentum space admitting an invariant energy cutoff. We show that unlike the standard quantum field theory, the Klein-Gordon equation obtained via Euler-Lagrange field equation and Heisenberg picture equation of motion of the field are not equivalent in this framework, at least up to the first order of the Planck length scale.
Dipole and Combo Optical Solitons in Birefringent Fibers in the Presence of Four-Wave Mixing
Authors: Raza Nauman , Zubair Asad
Published: June 2019

The ultimate theme of this study is to develop dipole and combo optical solitons in birefringent fibers (BF) along with the effect of four-wave mixing (4WM). Two types of rough mediums are used which are Kerr law and parabolic law. Ansatz method of Choudhuri is applied to obtain dark in the bright (dipole) soliton solutions providing bright background for the propagation of optical dark pulse. Ansatz method of Li is applied to obtain combo soliton solutions providing bright solitary wave and dark solitary wave solutions. These results also exist to hold in non-Kerr media with higher order dispersion.
Study on the Perturbation Characteristics of Two-Channel Laser Propagation in Atmospheric Turbulence
Authors: Yang Xiao-Dong , Gao Ming
Published: June 2019

In order to study the influence factors of acquisition detection target information by lidar and understand the influence degree of each factor, the two-channel phase perturbation model and the two-channel eikonal variance model are derived in detail by using the geometrical optics method in this paper, and each factor is discussed in detail. The results show that the transmission distance is the main factor to affect the two-channel perturbation. With the increase of the transmission distance, the disturbing degree will gradually weaken. With the increase of transverse coordinates, the disturbing of two channels will also be weakened. In order to further weaken the disturbing degree, the feature dimension should be far larger than the wavelength, but far less than the transmission distance.
Controlling Airy-Bessel Light Bullets in an Optically Induced Potential*
Authors: Wu Zhen-Kun , Gu Yu-Zong
Published: June 2019

We investigate numerically the curious evolution of self-decelerating Airy-Bessel light bullets carrying different topological charges (TC), launched in the three-dimensional (3D) Schrödinger equation with an induced parabolic potential. We present their spatiotemporal profile during propagation. In our paper, the number of TC, the modulation depth, and the induced potential are considered simultaneously. The propagation properties of light bullets result from a combination of these effects. Our scheme is distinctly different from the linear light bullets in free space, in which the localized wave packets propagate in a self-consistent trapping potential.
Effects of Inhibitory Signal on Criticality in Excitatory-Inhibitory Networks*
Authors: Wang Fan , Wang Sheng-Jun
Published: June 2019

We study the criticality in excitatory-inhibitory networks consisting of excitable elements. We investigate the effects of the inhibitory strength using both numerical simulations and theoretical analysis. We show that the inhibitory strength cannot affect the critical point. The dynamic range is decreased as the inhibitory strength increases. To simulate of decreasing the efficacy of excitation and inhibition which was studied in experiments, we remove excitatory or inhibitory nodes, delete excitatory or inhibitory links, and weaken excitatory or inhibitory coupling strength in critical excitatory-inhibitory network. Decreasing the excitation, the change of the dynamic range is most dramatic as the same as previous experimental results. However, decreasing inhibition has no effect on the criticality in excitatory-inhibitory network.
Insights into the Discrepancy between Single Molecule Experiments*
Authors: Zhou Qian , Zhang Min , Fan Yang-Tao , Wang Yu-Kang , Bao Lin , Zhao Guang-Ju , Chen Hu , Liu Yan-Hui
Published: June 2019

Sharp bending as one of the mechanical properties of double-stranded DNA (dsDNA) on the nanoscale is essential for biological functions and processes. Force sensors with optical readout have been designed to measure the forces inside short, strained loops composed of both dsDNA and single-stranded DNA (ssDNA). Recent FRET single-molecule experiments were carried out based on the same force sensor design, but provided totally contrary results. In the current work, Monte Carlo simulations were performed under three conditions to clarify the discrepancy between the two experiments. The criterion that the work done by the force exerted on dsDNA by ssDNA should be larger than the nearest-neighbor (NN) stacking interaction energy is used to identify the generation of the fork at the junction of dsDNA and ssDNA. When the contour length of dsDNA in the sensor is larger than its critical length, the fork begins to generate at the junction of dsDNA and ssDNA, even with a kink in dsDNA. The forces inferred from simulations under three conditions are consistent with the ones inferred from experiments, including extra large force and can be grouped into two different states, namely, fork states and kink states. The phase diagrams constructed in the phase space of the NN stacking interaction energy and excited energy indicate that the transition between the fork state and kink state is difficult to identify in the phase space with an ultra small or large number of forks, but it can be detected in the phase space with a medium number of forks and kinks.
Synchronization to extreme events in moving agents
Authors: Chowdhury Sayantan Nag , Majhi Soumen , Ozer Mahmut , Ghosh Dibakar , Perc Matjaž
Published: June 2019

Interactions amongst agents frequently exist only at particular moments in time, depending on their closeness in space and movement parameters. Here we propose a minimal model of moving agents where the network of contacts changes over time due to their motion. In particular, agents interact based on their proximity in a two-dimensional space, but only if they belong to the same fixed interaction zones. Our research reveals the emergence of global synchronization if all the interaction zones are attractive. However, if some of the interaction zones are repulsive, they deflect synchrony and lead to short-lasting but recurrent deviations that constitute extreme events in the network. We use two paradigmatic oscillators for the description of the agent dynamics to demonstrate our findings numerically, and we also provide an analytical formulation to describe the emergence of complete synchrony and the thresholds that distinguish extreme events from other intermittent states based on the peak-over-threshold approach.
Universality classes of topological phase transitions with higher-order band crossing
Authors: Chen Wei , Schnyder Andreas P
Published: June 2019

In topological insulators and topological superconductors, the discrete jump of the topological invariant upon tuning a certain system parameter defines a topological phase transition. A unified framework is employed to address the quantum criticality of the topological phase transitions in one to three spatial dimensions, which simultaneously incorporates the symmetry classification, order of band crossing, m-fold rotational symmetry, correlation functions, critical exponents, scaling laws, and renormalization group approach. We first classify higher-order Dirac models according to the time-reversal, particle-hole, and chiral symmetries, and determine the even–oddness of the order of band crossing in each symmetry class. The even–oddness further constrains the rotational symmetry m permitted in a symmetry class. Expressing the topological invariant in terms of a momentum space integration over a curvature function, the order of band crossing determines the critical exponent of the curvature function, as well as that of the Wannier state correlation function introduced through the Fourier transform of the curvature function. The conservation of topological invariant further yields a scaling law between critical exponents. In addition, a renormalization group approach based on deforming the curvature function is demonstrated for all dimensions and symmetry classes. Through clarification of how the critical quantities, including the jump of the topological invariant and critical exponents, depend on the nonspatial and the rotational symmetry, our work introduces the notion of universality class into the description of topological phase transitions.
Quantum repeaters based on two species trapped ions
Authors: Santra Siddhartha , Muralidharan Sreraman , Lichtman Martin , Jiang Liang , Monroe Christopher , Malinovsky Vladimir S
Published: June 2019

We examine the viability of quantum repeaters based on two-species trapped ion modules for long-distance quantum key distribution. Repeater nodes comprised of ion-trap modules of co-trapped ions of distinct species are considered. The species used for communication qubits has excellent optical properties while the other longer lived species serves as a memory qubit in the modules. Each module interacts with the network only via single photons emitted by the communication ions. Coherent Coulomb interaction between ions is utilized to transfer quantum information between the communication and memory ions and to achieve entanglement swapping between two memory ions. We describe simple modular quantum repeater architectures realizable with the ion-trap modules and numerically study the dependence of the quantum key distribution rate on various experimental parameters, including coupling efficiency, gate infidelity, operation time and length of the elementary links. Our analysis suggests crucial improvements necessary in a physical implementation for co-trapped two-species ions to be a competitive platform in long-distance quantum communication.
Landau damping in cilyndrical inhomogeneous plasmas
Authors: Hoyos Jaime H , Valencia Jose A , Ramirez Sebastian
Published: June 2019

We study the Landau damping for electromagnetic waves in a inhomogeneous cylindrical plasma in the presence of a strong axial magnetic field. For this task we use the kinetic theory for plasmas. This kind of phenomena can not be studied using only macroscopic fluid models. The results of our work can be relevant to identify the behavior of different electromagnetic normal modes propagating through the system, in particular, the energy of the damped modes can be transferred to the plasma particles through resonant interactions and according to the mode polarization can be used in modern particle accelerators based in plasmas.