bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Status Quo and Countermeasures of Modern Agriculture Development in Dazhou City
Authors: Sun Yexing , Ma Qianqian , Li Haosheng , Wu Peng , Li Li’an , Xie Zhengwei , Lai Quanhao , Zhao Siyi
Published: November 2019

Developing modern agriculture, promoting the transformation and upgrading of agriculture, and improving the comprehensive benefits of agriculture are important targets for winning the fight against poverty and the inherent requirements and key links for implementing the rural revitalization strategy. As a large agricultural city in northeastern Sichuan, Dazhou City is facing a crucial period of transition from traditional agriculture to modern agriculture. This paper mainly analyzes the status quo of modern agriculture development in Dazhou and the main constraints it faces, and puts forward reasonable suggestions to provide reference for modern agricultural development in Dazhou.
Preliminary Study on The Control Method of Prunus Americanc Fruit Cracking
Authors: Ma Qianqian , Peng Wanyun , Wang Zhide , Xie Zhengwei , Wei Qiwei , Sun Yexing
Published: November 2019

From 2018 to 2019, the control methods of Prunus americanc fruit were tested with Prunus americanc as experimental material. The fruit cracking rate of fruit trees was reduced by using comprehensive technical measures such as orchard grass, plastic film mulching, spraying gibberellin and spraying calcium fertilizer. The results showed that all treatments could reduce the fruit cracking rate of American plum fruit, and the effect of spraying gibberellin was the best.
The Passivation Effect on Cd of Mixing of Hyperaccumulated Plant Straw and Phosphate Rock Powder in Cd Polluted Soil
Authors: Luo Xian , Zhao Zheng , Deng Fafu , Zhu Lin , Zhang Haiyan , Pu Honglin , Jia Yongxia
Published: November 2019

Soil culture experiments were carried out to study the effects of the mixture of cadmium (Cd) hyperaccumulator straw (Solanum nigrum L., Amaranthus chinense L., and Siegesbeckia orientalis L.) and phosphate rock on soil pH, available Cd content and soil nutrients in Cd polluted soil. The results showed that: (1) The soil pH was increased to a certain extent by three kinds of compound materials. (2) The contents of available potassium (AK) and available phosphorus (AP) in soil were increased to a certain extent by the three compounding materials, but there was no significant effect on total nitrogen (TN). And 2% phosphate rock powder and 1% Amaranthus chinense L. had the greatest increase in AP, reaching 49.28%, and 2% phosphate rock powder and 1% Siegesbeckia orientalis L. had the greatest increase in AK, reaching 136.23%. (3) The available Cd content in soil was reduced by three kinds of compound materials. The decrease of available Cd was the greatest in 2% phosphate rock powder and 1% Solanum nigrum L. straw mixed, which was 12.71%. In summary, the combination of Cd hyperaccumulator straw and phosphate rock powder can effectively passivate Cd in soil and improve soil nutrient content, and 2% phosphate rock powder and 1% Solanum nigrum L. straw are the best.
Preliminary Study on Data Fusion Based on Internet of Things of Eucalyptus Plantation
Authors: Guang Deng , Xinwen Yu , Dongpu Fan , Chen Zhu , xu Zhang
Published: November 2019

Eucalyptus is the main fast-growing and high-yielding tree species in southern China and is the main source of wood production. Over the years, there have been many reports that eucalyptus is a water pump and that eucalyptus causes serious damage to understory vegetation. In this paper, a sensor network of eucalyptus plantation has been established in Yinling branch of Gaofeng Forest Farm in Guangxi, the main eucalyptus producing province. The sensor network can monitor the DBH changes, trunk runoff, soil moisture, environmental information and so on of eucalyptus in the stand in real time. The collected data are uploaded to the artificial forest Internet of Things monitoring information cloud management system established in this paper. This paper introduces the functions of the cloud management system in detail. On this basis, this paper discusses the fusion of high-frequency information collected from monitoring points to meet different data requirements. The research on data fusion in this paper is very preliminary. In the conclusion part, the future research on long-term monitoring data fusion of eucalyptus forest is prospected.
Probiotic properties of Lactobacillus strains from traditional fermented yogurt in Xinjiang
Authors: Yi Ruokun , Tan Fang , Zhao Xin
Published: November 2019

In this study, 3 Lactobacillus strains isolated from 5 kinds of traditional fermented yogurt in Xinjiang were identified as Lactobacillus plantarum (LP1, LP2), and Lactobacillus delbrueckii subsp. Bulgaricus (LD). Probiotic properties of Lactobacillus strains have been evaluated by testing the tolerance to artificial gastric juice and bile salt, cell surface hydrophobicity, hydroxyl radicals and DPPH free radicals scavenging rates. As the results, LP1 showed better tolerance to acid, cell surface hydrophobicity and antioxidant ability, LP2 showed better tolerance to bile salt comparing with the other two LAB strains. LP1 showed the best probiotic properties in general. These results provide reference value for the probiotic research in vivo and the development of new functional probiotic products in the future.
Prediction of Developing Modern Agriculture Demands for the Agricultural Scientific Research Institutions Services Based on BP Artificial Neural Network
Authors: Sun Hongyan , Bi Hongwen , Wang Jingyuan , Zhang Yu , Wang Yanqi , Yu Zhigang , Yang Xiuli , Chai Yongshan
Published: November 2019

BP artificial neural network model is used to predict developing modern agriculture demands for the agricultural scientific research institutions services. Starting from the brief introduction of the usages of BP neural network, we analyzed the demand factors of the agricultural scientific research institutions services and the affective elements of the demands, use the BP neural network model to predict, and then run the BP neural network model on the MATLAB platform, and finally carry out the case studies of Heilongjiang Province.
Structure and mechanical properties of GR/UHMWPE nanocomposite ropes
Authors: Yu Wen Wen , Shi Jian Gao , Liu Yong Li , Wang Lei
Published: November 2019

Ultra-high molecular weight polyethylene (UHMWPE) and graphene (GR) was melt compounded by reactive extrusion. Nanocomposite monofilaments were prepared by melt spinning through a co-rotating screw extruder and drawing at hot water. GR/UHMWPE nanocomposite ropes were twisted using nanocomposite monofilaments. A structure and mechanical properties of the GR/UHMWPE nanocomposite monofilaments and its ropes had been characterized by scanning electron microscopy (SEM), and mechanical test. Results showed that the monofilaments surface of monofilaments became rougher with introducing of GR nanosheets, which could be related to stacking of GR. The breaking load of GR/UHMWPE nanocomposite ropes was remarkably improved upon nanofiller addition, with the decrease of the elongation at break.
Recent STAR Results from Heavy-Ion and Polarized Proton Programs
Authors: Nigmatkulov Grigory
Published: November 2019

We present recent physics results from the STAR experiment at Relativistic Heavy Ion Collider (RHIC). The proceedings cover studies of azimuthal anisotropy in small and large systems, global and local hyperon polarization, correlation femtoscopy, antideuteron and J/ψ production from heavyion program as well as the measurements of longitudinal spin asymmetry from polarized proton program.
Correlation femtoscopy at NICA energies
Authors: Mikhaylov Konstantin , Batyuk Pavel , Kodolova Olga , Malinina Lyudmila , Nigmatkulov Grigory , Romanenko Gleb
Published: November 2019

The space-time characteristics of particle production are measured by the correlation femtoscopy with use of quantum statistics (QS) and final state interactions (FSI) effects. Femtoscopy at lower energy was a key of importance at AGS, SPS and in the Beam Energy Scan (BES) physics program at RHIC.

Using femtoscopy observables we investigate possibilities to observe a difference from the first-order phase transition expected, according to some theoretical predictions, at low energies and the cross over one, to be occurred at high energies. The hybrid model vHLLE+UrQM is used as a baseline for this study. The possibilities to use kaon femtoscopy complementary to the usually used pion one are discussed.
LHCb results on rare leptonic decays of B-mesons
Authors: Kurbatov Evgenii
Published: November 2019

A search for the rare leptonic decays was performed, using the proton-proton collision data collected with the LHCb experiment at center-ofmass energies of 8TeV and 13TeV. The following analysis are reviewed in this work:

• Measurements of the B0s → µ+µ− branching fraction and effective lifetime and search for B0 → µ+µ− decays

• Search for the decays B0s → τ+τ− and B0 → τ+τ−

• Search for the lepton-flavour violating decays B0(s) → e±µ∓

• Search for the lepton-flavour-violating decays B0s → τ±µ∓ and B0 → τ±µ∓

• Search for the rare decay B+ → µ+µ−µ+νµ

All results are consistent with the Standard Model. Nearly all results presented are either unique or the most accurate for the time.
Electronically driven neutrons synthesis-generator with the magneto-optical flow seal
Authors: Dolgopolov Mikhail , Gurskaya Albina , Privalov Andrey , Radenko Vitaly , Radenko Alexandr , Svirkov Vasily
Published: November 2019

We develop the description of a neutron generator construction for the synthesis of light nuclei. The design of the neutron generator with plasma target is given together with a description of the types of nuclear reactions that are implemented in it. The brief theoretical description of the ion multiphase flow in the synthesis generator is considered.
Test of the Hypothesis of Realism Using a Modified Version of Wigner Inequality
Authors: Nikitin Nikolay , Toms Konstantin
Published: November 2019

In the current work we present a modified Wigner inequality for test of the hypothesis of realism. This modified Wigner inequality is suitable for test of realism not only in systems that obey the laws of non-relativistic quantum mechanics, but also in systems that obey the laws of quantum field theory. We show how this inequality can be violated in systems of neutral pseudoscalar mesons.
Calculation of the probability of quantum transitions in the system by the method of functional integration
Authors: Biryukov Alexander , Matveev Igor , Shleenkov Mark
Published: November 2019

The probabilities of quantum transitions are described by integrals over trajectories in the space of energy states of a system exposed to an electromagnetic field. We describe quantum transitions in hydrogen atom.
Hyperfine splitting of P-states in light muonic ions
Authors: Dorokhov A.E. , Martynenko A.P. , Martynenko F.A. , Sukhorukova O.S.
Published: November 2019

We calculate hyperfine structure intervals for P–states in muonic ions of lithium, beryllium and boron. To construct the particle interaction operator in momentum space we use the tensor method ofprojection operators on states with definite quantum numbers of total atomic momentum F and total muonmomentum j. We take into account vacuum polarization, relativistic, quadruple and structure corrections of orders α4, α5 and α6. The obtained numerical values of hyperfine splittings can be used for a comparison with future experimental data.
Energy levels in muonic helium
Authors: Eskin A.V. , Korobov V.I. , Martynenko A.P. , Sorokin V.V.
Published: November 2019

The energy spectrum of bound states and hyperfine structure of muonic helium is calculated on the basis of stochastic variational method. The basis wave functions of muonic helium are taken in the Gaussian form. The matrix elements of the Hamiltonian are calculated analytically. For numerical calculation a computer code is written in the MATLAB system. As a result, numerical values of bound state energies and hyperfine structure are obtained. We calculate also correction to the structure of the nucleus, vacuum polarization and relativistic correction.
Hyperfine structure of muonic mesomolecules tdµ, tpµ, dpµ in variational method
Authors: Eskin A.V. , Korobov V.I. , Martynenko A.P. , Sorokin V.V.
Published: November 2019

The hyperfine structure of energy levels of muonic molecules tdµ, tpµ and dpµ is calculated on the basis of stochastic variational method. The basis wave functions are taken in the Gaussian form. The matrix elements of the Hamiltonian are calculated analytically. Vacuum polarization, relativistic and nuclear structure corrections are taken into account to increase the accuracy. For numerical calculation, a computer code is written in the MATLAB system. Numerical values of energy levels of hyperfine structure in muonic molecules tdµ, tpµ and dpµ are obtained.
Rare four leptonic B-mesons decays with a neutrino in final state
Authors: Danilina Anna , Nikitin Nikolay , Toms Konstantin
Published: November 2019

We revisit prediction for the four – leptonic decay of charged B - mesons in the Standard Model and provide an updated results for branching ratios and various differential distributions. We have taken into account relative phase between intermediate ρ0(770) – and ω(782) – resonances contributing to the amplitude in the framework Vector Meson Dominance model approach.
Probing short-range NN-correlations in the reaction 12C + p → p + pN + 10A
Authors: Uzikov Yuriy
Published: November 2019

The exclusive reaction 12C(p, ppN)10A of quasi-elastic knockout of the nucleon from the short-rangecorrelated nucleon pair  in the 12C nucleus by proton with an energy of few GeV is considered in the plane-wave approximation.The two-nucleon spectroscopic factors and momentum distributions of the center of mass motion of NN-pairs are considered by analogy with theory of quasi-elastic knockout of fast deuteron clusters from nuclei (p, Nd) using the translationally-invariant shell model.
MSSM scenarios with a light CP-odd Higgs boson
Authors: Dubinin Mikhail , Fedotova Elena
Published: November 2019

The possibility of the presence of a light pseudoscalar with the mass of 28 GeV in the MSSM Higgs sector extended by dimension-six operators is analyzed. The perturbative unitarity and vacuum stability constraints are discussed. Tree-level production cross sections of a light pseudoscalar in the process gg → µµbb−, and cross sections of a light pseudoscalar production in the topquark decay are evaluated for suitable benchmark points.
Differences in fully differential cross section of single top quark production and its subsequent decay process depending on various anomalous Wtb couplings.
Authors: Boos Edward , Bunichev Viacheslav
Published: November 2019

The fully differential cross sections of t-channel production of a single top quark with its subsequent decay are compared for the case of contributions involving anomalous Wtb couplings. It is shown that the most noticeable differences, for cases corresponding to different anomalous couplings, appear in the shape of two-dimensional distributions, where one of the variables is the energy of a charged lepton and the other is one of the t-quark spin orientation angles.
Probing anomalous off-shell electroweak dipole moment of the top quark in single top quark production associated with Z or W bosons
Authors: Boos Edward , Bunichev Vyacheslav , Dudko Lev , Vorotnikov Georgii
Published: November 2019

An extension of the previous studies of anomalous Wtb interaction with offshell W boson was considered in associated single top quark production with W or Z bosons. More general variant with covariant derivative DµW−µ b−(fLWPL + fRWPR)t for the same processes is considered in this paper.
Recommendations for the search of the Anomalous Wtb interactions in the tW-associated Single Top Quark Production
Authors: Baskakov Alexey , Boos Eduard , Bunichev Viacheslav , Dudko Lev , Perfilov Maxim , Volkov Petr
Published: November 2019

There are no experimental bounds for the anomalous Wtb couplings provided in the tW-associated single top quark production in the final signature with lepton plus jets so far. The main reason for the situation is the difficulties with the modeling of such a process. Different schemes of the tW-associated single top quark production modeling have different sensitivity to the anomalous Wtb couplings and prospective their constraints are strongly scheme-dependent. The most preferable is the usage of the full gauge-invariant set of the diagrams. However one needs to discriminate the different phase space regions in this case anyway. In the article the separation between top pair and tW-associated single top quark production processes with the help of Neural Network technique is presented. The full scheme with the complete gauge invariant set of Feynman diagrams is used.
The Story of a Discovery: How we found the long-sought-after Higgs Boson
Authors: Mariotti Chiara
Published: November 2019

The Higgs boson has been discovered in 2012 by the ATLAS and CMS experiments at the LHC, 50 years after its prediction. The scientific and human adventure of this discovery will be summarized in this article, going back to the search at LEP and to the foundation of the LHC Higgs Cross Section working group.
Advanced instructions for imparting knowledge: Getting scientists heard amidst the noise of fake news
Authors: Plüss Matthias
Published: November 2019

A compacted re-print of an article by science writer Matthias Plüss, Swiss Science Magazine ‘Horizons’ of 05/06/2018 – DOI: https://doi.org/10.1051/epn/2019507

It’s getting more and more difficult for experts to get their arguments across to a broad public. We investigate why, and offer six suggestions for improving things.
Occlusive thrombosis in arteries
Authors: Kim Dongjune , Bresette Christopher , Liu Zixiang , Ku David N.
Published: November 2019

Thrombus formation in major arteries is life threatening. In this review article, we discuss how an arterial thrombus can form under pathologically high shear stresses, with bonding rates estimated to be the fastest Kon values in biochemistry. During occlusive thrombosis in arteries, the growth rate of the thrombus explodes to capture a billion platelets in about 10 min. Close to 100% of all platelets passing the thrombus are captured by long von Willebrand factor (vWF) strands that quickly form tethered nets. The nets grow in patches where shear stress is high, and the local concentration of vWF is elevated due to α-granule release by previously captured platelets. This rapidly formed thrombus has few red blood cells and so has a white appearance and is much stronger and more porous than clots formed through coagulation. Understanding and modeling the biophysics of this event can predict totally new approaches to prevent and treat heart attacks and strokes.
Anode geometry influence on LaB6 cathode discharge characteristics
Authors: Potrivitu G.-C. , Mazouffre S. , Grimaud L. , Joussot R.
Published: November 2019

The characterization of an electric propulsion device cathode is performed in the so-called diode configuration with an external anode. The anode acts as a physical boundary for the cathode plasma discharge; therefore, it influences cathode operation and performances. In this study, four different anodes—namely, a disk, a plate, a long cylinder, and a short cylinder—have been used with a flat disk LaB6 emitter 5 A-class cathode to examine the anode geometry impact on cathode discharge properties. Current–voltage curves, discharge oscillations, electron parameters, and ion velocities have been measured for currents in the 2 A to 12 A range and xenon mass flow rates varied from 0.4 mg/s to 1 mg/s with a fixed cathode-to-anode distance. The set of results clearly supports the fact that the anode geometry strongly influences the cathode characteristics both at the macroscopic and the microscopic scale.
A microfluidic platform for simultaneous quantification of oxygen-dependent viscosity and shear thinning in sickle cell blood
Authors: Valdez José M. , Datta Yvonne H. , Higgins John M. , Wood David K.
Published: November 2019

The pathology of sickle cell disease begins with the polymerization of intracellular hemoglobin under low oxygen tension, which leads to increased blood effective viscosity and vaso-occlusion. However, it has remained unclear how single-cell changes propagate up to the scale of bulk blood effective viscosity. Here, we use a custom microfluidic system to investigate how the increase in the stiffness of individual cells leads to an increase in the shear stress required for the same fluid strain in a suspension of softer cells. We characterize both the shear-rate dependence and the oxygen-tension dependence of the effective viscosity of sickle cell blood, and we assess the effect of the addition of increasing fractions of normal cells whose material properties are independent of oxygen tension, a scenario relevant to the treatment of sickle patients with blood transfusion. For untransfused sickle cell blood, we find an overall increase in effective viscosity at all oxygen tensions and shear rates along with an attenuation in the degree of shear-thinning achieved at the lowest oxygen tensions. We also find that in some cases, even a small fraction of transfused blood cells restores the shape of the shear-thinning relationship, though not the overall baseline effective viscosity. These results suggest that untransfused sickle cell blood will show the most extreme relative rheologic impairment in regions of high shear and that introducing even small fractions of normal blood cells may help retain some shear-thinning capability though without addressing a baseline relative increase in effective viscosity independent of shear.
Laser-driven strong shocks with infrared lasers at intensity of 1016 W/cm2
Authors: Antonelli L. , Trela J. , Barbato F. , Boutoux G. , Nicolaï Ph. , Batani D. , Tikhonchuk V. , Mancelli D. , Tentori A. , Atzeni S. , Schiavi A. , Baffigi F. , Cristoforetti G. , Viciani S. , Gizzi L. A. , Smid M. , Renner O. , Dostal J. , Dudzak R. , Juha L. , Krus M.
Published: November 2019

We present the results of an experiment on laser-driven shock waves performed at the Prague Asterix Laser system (PALS), where the fundamental frequency of the laser (1315 nm) is used to launch a strong shock in planar geometry. The experiment aims to characterize both shock waves and hot electrons generated at intensities of ≃1016  W/cm2. It is shown that, in these interaction conditions, hydrodynamics is strongly impacted by noncollisional mechanisms, and the role of the hot electrons, generated by parametric instabilities, is essential in determining shock dynamics.
Novel implementation of seniority number truncated valence bond methods with applications to H22 chain
Authors: Zhou Chen , Zeng Chenyu , Ma Bo , Ying Fuming , Chen Zhenhua , Wu Wei
Published: November 2019

Both the efficiency and capability of the seniority number truncated valence bond (VB) methods are highly improved by using our recently proposed extension of Malmqvist’s algorithm for the reciprocal transformation of many-electron bases constructed by nonorthogonal orbitals [Zhou, Chen, and Wu, J. Chem. Phys. 149(4), 044111 (2018)] and by the adoption of the direct technique in solving the generalized eigenvalue problem. Due to the compactness of the wave function that benefited from seniority number restriction, the memory need and computational cost for energy evaluation and orbital optimization in valence bond self-consistent field calculation are largely reduced. The last obstacle in nonorthogonal orbital based ab initio VB calculation is thus removed. Consequently, we can accomplish seniority number truncated VB calculation at the same computational scaling as that of the most general configuration selected multiconfigurational self-consistent field with a memory cost much less than the corresponding complete active space self-consistent field (CASSCF). Test on Hn string molecules shows that the seniority number truncated VB calculation maintains the majority of static correlation by using a more compact wave function than CASSCF.
Trap characterization in ultra-wide bandgap Al0.65Ga0.4N/Al0.4Ga0.6N MOSHFET's with ZrO2 gate dielectric using optical response and cathodoluminescence
Authors: Jewel Mohi Uddin , Alam Md Didarul , Mollah Shahab , Hussain Kamal , Wheeler Virginia , Eddy Charles , Gaevski Mikhail , Simin Grigory , Chandrashekhar MVS , Khan Asif
Published: November 2019

Ultrawide bandgap (UWBG) AlGaN-channel metal-oxide-semiconductor heterostructure field-effect transistors (MOSHFETs) with a ZrO2 gate dielectric achieve peak current in excess of 0.4 A/mm and current ON/OFF ratios >106 with subthreshold swings as low as 110 mV/decade. These devices have strong potential for use in power and radio frequency electronics or as true solar-blind photodetectors. In this work, we present the photoresponse analysis in UWBG AlGaN MOSHFETs. Persistent photoconductivity with the decay time above 10 minutes can be quenched by illuminating with strong UV light at 365 nm and 254 nm, suggesting deep traps to be responsible for this behavior. Upon correlating the optical response under various illumination conditions with cathodoluminescence of these devices, we identified two key trap levels at ∼2.48 ± 0.14 eV and 3.76 ± 0.06 eV, controlling the slow response time. By depth-profiling using cathodoluminescence, these traps are identified to be at the AlN/AlGaN interface at the back of the device, due to partial relaxation from the lattice mismatch between AlN and Al0.4Ga0.6N.
Strong thermal conductivity dependence on arsenic-vacancy complex formation in arsenic-doped silicon
Authors: Lee Yongjin , Hwang Gyeong S.
Published: November 2019

High-concentration doping of silicon (Si)-based materials is an effective way to improve their thermoelectric efficiency via thermal conductivity (κ) reduction as well as thermopower and electrical conductivity enhancement. Beyond the solubility limit, a large portion of dopant atoms may undergo clustering mediated primarily by point defects, which may in turn significantly alter the physical properties of host materials. In this work, we investigate the effect of Arsenic-vacancy (AsV) complex formation on κ in heavily As-doped Si using molecular dynamics simulations. The simulation results clearly demonstrate that the presence of AsV complexes, particularly As4V which is the most stable one, may result in a substantially lower κ compared to the case where all As atoms remain substitutional and electrically active. Further analysis reveals that the central vacancy in As4V causes Si lattice softening and thus results in the reduction of phonon group velocity. Our findings highlight the significant effect of dopant clustering on κ and also provide some guidance on how to manipulate Si-based materials to improve their thermoelectric performance via doping combined with defect engineering.
III–V nanowire array telecom lasers on (001) silicon-on-insulator photonic platforms
Authors: Kim Hyunseok , Chang Ting-Yuan , Lee Wook-Jae , Huffaker Diana L.
Published: November 2019

III–V nanowires have recently gained attention as a promising approach to enable monolithic integration of ultracompact lasers on silicon. However, III–V nanowires typically grow only along ⟨111⟩ directions, and thus, it is challenging to integrate nanowire lasers on standard silicon photonic platforms that utilize (001) silicon-on-insulator (SOI) substrates. Here, we propose III–V nanowire lasers on (001) silicon photonic platforms, which are enabled by forming one-dimensional nanowire arrays on (111) sidewalls. The one-dimensional photonic crystal laser cavity has a high Q factor >70 000 with a small footprint of ∼7.2 × 1.0 μm2, and the lasing wavelengths can be tuned to cover the entire telecom bands by adjusting the nanowire geometry. These nanowire lasers can be coupled to SOI waveguides with a coupling efficiency > 40% while maintaining a sufficiently high Q factor ∼18 000, which will be beneficial for low-threshold and energy-efficient operations. Therefore, the proposed nanowire lasers could be a stepping stone for ultracompact lasers compatible with standard silicon photonic platforms.
A new liquid transport model considering complex influencing factors for nano- to micro-sized circular tubes and porous media
Authors: Zhang Xueling , Kuang Songya , Shi Yutao , Wang Xiaofeng , Zhu Weiyao , Cai Qiang , Wang Yanling , Deng Jia
Published: November 2019

A new liquid transport model in wetted nano- to microsized circular tubes is proposed using basic dynamical analyses that comprehensively consider the Lifshitz–van der Waals force (LWF), the electroviscous force, the weak liquid compressibility, and the Bingham-plastic behavior. The model predicts that the average velocity is initially zero and increases nonlinearly with a concave shape before increasing linearly with the pressure gradient (ΔP/L) and is validated using the experimental data. The threshold pressure gradient (TPG) and the lower limit of the movable-fluid radius (Rm) are calculated based on the proposed model, which are mainly determined by the yield stresses from the Bingham plastic behavior and are also affected by the compressibility and LWF. Considering the microstructural complexity of real porous media, the average velocity model is also applicable for tight porous media with a capillary equivalent radius from the permeability. The calculated average velocity is non-Darcy with TPG. The TPG decreases as the permeability increases, and the Rm decreases with the pressure gradient in the low range and remains constant at the higher ranges, which is primarily between 10 and 30 nm. All these results for porous media are compared with the experimental data of core seepage and show good agreement in general. The proposed model has a clear parametric representation compared with previous nonlinear models. It explains the underlying reasons for the nonlinear, low-velocity flow mechanism in nano- to microsized tubes and pores and provides theoretical guidance for liquid transport in porous media and oil recovery from tight oil reservoirs.
The chemical physics of sequential infiltration synthesis—A thermodynamic and kinetic perspective
Authors: Waldman Ruben Z. , Mandia David J. , Yanguas-Gil Angel , Martinson Alex B. F. , Elam Jeffrey W. , Darling Seth B.
Published: November 2019

Sequential infiltration synthesis (SIS) is an emerging materials growth method by which inorganic metal oxides are nucleated and grown within the free volume of polymers in association with chemical functional groups in the polymer. SIS enables the growth of novel polymer-inorganic hybrid materials, porous inorganic materials, and spatially templated nanoscale devices of relevance to a host of technological applications. Although SIS borrows from the precursors and equipment of atomic layer deposition (ALD), the chemistry and physics of SIS differ in important ways. These differences arise from the permeable three-dimensional distribution of functional groups in polymers in SIS, which contrast to the typically impermeable two-dimensional distribution of active sites on solid surfaces in ALD. In SIS, metal-organic vapor-phase precursors dissolve and diffuse into polymers and interact with these functional groups through reversible complex formation and/or irreversible chemical reactions. In this perspective, we describe the thermodynamics and kinetics of SIS and attempt to disentangle the tightly coupled physical and chemical processes that underlie this method. We discuss the various experimental, computational, and theoretical efforts that provide insight into SIS mechanisms and identify approaches that may fill out current gaps in knowledge and expand the utilization of SIS.
Carbon Dioxide Methanation Over Nickel Catalysts Supported on Activated Carbon at Low Temperature
Authors: Cam Le Minh , Ha Nguyen Thi Thu , Khu Le Van , Ha Nguyen Ngoc , Brown Trevor C.
Published: November 2019

The methanation of carbon over nickel catalysts supported on activated carbon was investigated using a continuous flow microreactor. Catalysts with nickel loadings of 5, 7, and 10% were synthesised by incipient wetness impregnation methods and characterised using Brunauer–Emmett–Teller (BET), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), H2-temperature-programmed reduction (TPR), BET, XRD, SEM, TEM and H2-TPR. The methanation reaction was studied over the temperature range 200–500°C with a H2 to CO2 ratio of 4:1 in He and at 1 atm. With an increase in Ni content from 5 to 7% both conversion of CO2 and CH4 selectivity increased. Increasing the nickel content to 10%, however decreased conversion and selectivity due to the larger crystallite size and lower surface area of the catalyst. The most active catalyst with 7% Ni does not deactivate during 15h time on stream at 350°C. The high catalytic activity and stability of the studied catalysts is a consequence of the reducibility of Ni and a synergetic effect between the nickel active sites and the activated carbon surface.
A portrait of wellbore leakage in northeastern British Columbia, Canada
Authors: Wisen Joshua , Chesnaux Romain , Werring John , Wendling Gilles , Baudron Paul , Barbecot Florent
Published: November 2019

Significance

The possibility of leakage from oil and gas wells has raised environmental concerns. There are 2 major environmental consequences of wellbore leakage: 1) the risk of groundwater contamination from hydrocarbons and brines and 2) the risk of greenhouse gas (GHG) emissions. In this study, oil and gas wellbore leakage data from British Columbia (BC) were analyzed in order to quantify the occurrence and pathways of leakage as well as the contribution to GHG emissions. The key results summarize as follows. 1) In total, 2,329 wells in BC (of 21,525 that have been tested for leakage) have had reported leakage during the lifetime of the well. 2) In total, GHG emissions are estimated to reach about 75,000 metric t/y. The study also underlines that the values of leaky wells are likely underreported.
Vertical transmission inCaenorhabditisnematodes of RNA molecules encoding a viral RNA-dependent RNA polymerase
Authors: Richaud Aurélien , Frézal Lise , Tahan Stephen , Jiang Hongbing , Blatter Joshua A. , Zhao Guoyan , Kaur Taniya , Wang David , Félix Marie-Anne
Published: November 2019

Here, we report on the discovery inCaenorhabditisnematodes of multiple vertically transmitted RNAs coding for putative RNA-dependent RNA polymerases. Their sequences share similarity to distinct RNA viruses, including bunyaviruses, narnaviruses, and sobemoviruses. The sequences are present exclusively as RNA and are not found in DNA form. The RNAs persist in progeny after bleach treatment of adult animals, indicating vertical transmission of the RNAs. We tested one of the infected strains for transmission to an uninfected strain and found that mating of infected animals with uninfected animals resulted in infected progeny. By in situ hybridization, we detected several of these RNAs in the cytoplasm of the male and female germline of the nematode host. TheCaenorhabditishosts were found defective in degrading exogenous double-stranded RNAs, which may explain retention of viral-like RNAs. Strikingly, one strain, QG551, harbored three distinct virus-like RNA elements. Specific patterns of small RNAs complementary to the different viral-like RNAs were observed, suggesting that the different RNAs are differentially recognized by the RNA interference (RNAi) machinery. While vertical transmission of viruses in the family Narnaviridae, which are known as capsidless viruses, has been described in fungi, these observations provide evidence that multicellular animal cells harbor similar viruses.
Bone-inspired microarchitectures achieve enhanced fatigue life
Authors: Torres Ashley M. , Trikanad Adwait A. , Aubin Cameron A. , Lambers Floor M. , Luna Marysol , Rimnac Clare M. , Zavattieri Pablo , Hernandez Christopher J.
Published: November 2019

Significance

Microarchitectured materials, such as foams and lattice structures, can achieve high stiffness and strength while remaining extremely lightweight. Applying high-porosity microarchitectured materials to durable devices, such as vehicles, however, will require the materials to also resist failure during cyclic loading. Here, we identify an aspect of microstructure in cancellous bone that greatly influences failure under cyclic loading and show that the effect is generalizable to synthetic microarchitectured materials. Our findings demonstrate that a common design strategy to improve stiffness and strength of microarchitectured materials comes at the cost of impaired service life. Our findings are useful for the design and application of microarchitectured materials and additionally provide insight into human health in situations of osteoporosis.
Dichotomous regulation of group 3 innate lymphoid cells by nongastric
Helicobacter
species
Authors: Bostick John W. , Wang Yetao , Shen Zeli , Ge Yong , Brown Jeffrey , Chen Zong-ming E. , Mohamadzadeh Mansour , Fox James G. , Zhou Liang
Published: November 2019

Intestinal innate lymphoid cells (ILCs) contribute to the protective immunity and homeostasis of the gut, and the microbiota are critically involved in shaping ILC function. However, the role of the gut microbiota in regulating ILC development and maintenance still remains elusive. Here, we identified opposing effects on ILCs by two
Helicobacter
species,
Helicobacter apodemus
and
Helicobacter typhlonius
, isolated from immunocompromised mice. We demonstrated that the introduction of both
Helicobacter
species activated ILCs and induced gut inflammation; however, these
Helicobacter
species negatively regulated RORγt
+
group 3 ILCs (ILC3s), especially T-bet
+
ILC3s, and diminished their proliferative capacity. Thus, these findings underscore a previously unknown dichotomous regulation of ILC3s by
Helicobacter
species, and may serve as a model for further investigations to elucidate the host–microbe interactions that critically sustain the maintenance of intestinal ILC3s.
Local demographic changes and US presidential voting, 2012 to 2016
Authors: Hill Seth J. , Hopkins Daniel J. , Huber Gregory A.
Published: November 2019

Immigration and demographic change have become highly salient in American politics, partly because of the 2016 campaign of Donald Trump. Previous research indicates that local influxes of immigrants or unfamiliar ethnic groups can generate threatened responses, but has either focused on nonelectoral outcomes or analyzed elections in large geographic units, such as counties. Here, we examine whether demographic changes at low levels of aggregation were associated with vote shifts toward an anti-immigration presidential candidate between 2012 and 2016. To do so, we compile a precinct-level dataset of election results and demographic measures for almost 32,000 precincts in the states of Florida, Georgia, Michigan, Nevada, Ohio, Pennsylvania, and Washington. We employ regression analyses varying model specifications and measures of demographic change. Our estimates uncover little evidence that influxes of Hispanics or noncitizen immigrants benefited Trump relative to past Republicans, instead consistently showing that such changes were associated with shifts to Trump’s opponent.
Galnt11 regulates kidney function by glycosylating the endocytosis receptor megalin to modulate ligand binding
Authors: Tian E. , Wang Shengjun , Zhang Liping , Zhang Ying , Malicdan May C. , Mao Yang , Christoffersen Christina , Tabak Lawrence A. , Schjoldager Katrine T. , Ten Hagen Kelly G.
Published: November 2019

Chronic kidney disease (CKD) affects more than 20 million Americans and ∼10% of the population worldwide. Genome-wide association studies (GWAS) of kidney functional decline have identified genes associated with CKD, but the precise mechanisms by which they influence kidney function remained largely unexplored. Here, we examine the role of 1 GWAS-identified gene by creating mice deficient for
Galnt11
, which encodes a member of the enzyme family that initiates protein O-glycosylation, an essential posttranslational modification known to influence protein function and stability. We find that
Galnt11
-deficient mice display low-molecular-weight proteinuria and have specific defects in proximal tubule-mediated resorption of vitamin D binding protein, α
1
-microglobulin, and retinol binding protein. Moreover, we identify the endocytic receptor megalin (LRP2) as a direct target of Galnt11 in vivo. Megalin in
Galnt11
-deficient mice displays reduced ligand binding and undergoes age-related loss within the kidney. Differential mass spectrometry revealed specific sites of Galnt11-mediated glycosylation within mouse kidney megalin/LRP2 that are known to be involved in ligand binding, suggesting that O-glycosylation directly influences the ability to bind ligands. In support of this, recombinant megalin containing these sites displayed reduced albumin binding in cells deficient for
Galnt11
. Our results provide insight into the association between
GALNT11
and CKD, and identify a role for Galnt11 in proper kidney function.
Proof of concept for identifying cystic fibrosis from perspiration samples
Authors: Zhou Zhenpeng , Alvarez Daniel , Milla Carlos , Zare Richard N.
Published: November 2019

The gold standard for cystic fibrosis (CF) diagnosis is the determination of chloride concentration in sweat. Current testing methodology takes up to 3 h to complete and has recognized shortcomings on its diagnostic accuracy. We present an alternative method for the identification of CF by combining desorption electrospray ionization mass spectrometry and a machine-learning algorithm based on gradient boosted decision trees to analyze perspiration samples. This process takes as little as 2 min, and we determined its accuracy to be 98 ± 2% by cross-validation on analyzing 277 perspiration samples. With the introduction of statistical bootstrap, our method can provide a confidence estimate of our prediction, which helps diagnosis decision-making. We also identified important peaks by the feature selection algorithm and assigned the chemical structure of the metabolites by high-resolution and/or tandem mass spectrometry. We inspected the correlation between mild and severe CFTR gene mutation types and lipid profiles, suggesting a possible way to realize personalized medicine with this noninvasive, fast, and accurate method.
The evolution and genomic basis of beetle diversity
Authors: McKenna Duane D. , Shin Seunggwan , Ahrens Dirk , Balke Michael , Beza-Beza Cristian , Clarke Dave J. , Donath Alexander , Escalona Hermes E. , Friedrich Frank , Letsch Harald , Liu Shanlin , Maddison David , Mayer Christoph , Misof Bernhard , Murin Peyton J. , Niehuis Oliver , Peters Ralph S. , Podsiadlowski Lars , Pohl Hans , Scully Erin D. , Yan Evgeny V. , Zhou Xin , Ślipiński Adam , Beutel Rolf G.
Published: November 2019

The order Coleoptera (beetles) is arguably the most speciose group of animals, but the evolutionary history of beetles, including the impacts of plant feeding (herbivory) on beetle diversification, remain poorly understood. We inferred the phylogeny of beetles using 4,818 genes for 146 species, estimated timing and rates of beetle diversification using 89 genes for 521 species representing all major lineages and traced the evolution of beetle genes enabling symbiont-independent digestion of lignocellulose using 154 genomes or transcriptomes. Phylogenomic analyses of these uniquely comprehensive datasets resolved previously controversial beetle relationships, dated the origin of Coleoptera to the Carboniferous, and supported the codiversification of beetles and angiosperms. Moreover, plant cell wall-degrading enzymes (PCWDEs) obtained from bacteria and fungi via horizontal gene transfers may have been key to the Mesozoic diversification of herbivorous beetles—remarkably, both major independent origins of specialized herbivory in beetles coincide with the first appearances of an arsenal of PCWDEs encoded in their genomes. Furthermore, corresponding (Jurassic) diversification rate increases suggest that these novel genes triggered adaptive radiations that resulted in nearly half of all living beetle species. We propose that PCWDEs enabled efficient digestion of plant tissues, including lignocellulose in cell walls, facilitating the evolution of uniquely specialized plant-feeding habits, such as leaf mining and stem and wood boring. Beetle diversity thus appears to have resulted from multiple factors, including low extinction rates over a long evolutionary history, codiversification with angiosperms, and adaptive radiations of specialized herbivorous beetles following convergent horizontal transfers of microbial genes encoding PCWDEs.
High-resolution view of the type III secretion export apparatus in situ reveals membrane remodeling and a secretion pathway
Authors: Butan Carmen , Lara-Tejero Maria , Li Wenwei , Liu Jun , Galán Jorge E.
Published: November 2019

Type III protein secretion systems are essential virulence factors for many important pathogenic bacteria. The entire protein secretion machine is composed of several substructures that organize into a holostructure or injectisome. The core component of the injectisome is the needle complex, which houses the export apparatus that serves as a gate for the passage of the secreted proteins through the bacterial inner membrane. Here, we describe a high-resolution structure of the export apparatus of the
Salmonella
type III secretion system in association with the needle complex and the underlying bacterial membrane, both in isolation and in situ. We show the precise location of the core export apparatus components within the injectisome and bacterial envelope and demonstrate that their deployment results in major membrane remodeling and thinning, which may be central for the protein translocation process. We also show that InvA, a critical export apparatus component, forms a multiring cytoplasmic conduit that provides a pathway for the type III secretion substrates to reach the entrance of the export gate. Combined with structure-guided mutagenesis, our studies provide major insight into potential mechanisms of protein translocation and injectisome assembly.
Spin foam models and the Duflo map
Authors: Finocchiaro Marco , Oriti Daniele
Published: November 2019

We give a general definition of spin foam models, and then of models of 4d quantum gravity based on constraining BF theory. We highlight the construction and quantization ambiguities entering model building, among which the choice of quantization map applied to the B variables carrying metric information after imposing simplicity constraints, and the different strategies for imposing the latter constraints. We then construct a new spin foam model for 4d quantum gravity, using the flux representation of states and amplitudes, based on the Duflo quantization map and the associated non-commutative Fourier transform for Lie groups. The advantages of the new model are the geometrically transparent way in which constraints are imposed, and the underlying mathematical properties of the Duflo map itself. Finally, the presence of a closed analytical formula for the model’s amplitudes is another valuable asset for future applications.