bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inter-frequency code bias handling and estimation for multi-frequency BeiDou-3/Galileo uncombined precise point positioning
Authors: Cao Xinyun , Shen Fei , Ge Yulong , Liu Chao , Zhang Shoujian 
Published: October 2021

Abstract
The development of a global navigation satellite system (GNSS) with multi-frequency signals brings new opportunities for providing high-quality positioning, navigation and timing (PNT) services. Proper inter-frequency code bias (IFB) handling is a prerequisite for multi-frequency uncombined precise point positioning (UC-PPP) to ensure reliable and accurate PNT services. This work focuses on analyzing the mathematical representation of estimated parameters, as well as the relationship between different multi-frequency UC-PPP models, caused by whether to correct the inter-frequency satellite differential code bias (DCB) or the external ionosphere. Multi-GNSS experiment (MGEX) network stations tracking Galileo E1/E5a/E5b/E6/E5ab and BeiDou-3 (BDS-3) B1I/B3I/B1C/B2a signals were used to investigate the positioning performance and parameter estimations of three multi-frequency UC-PPP models. The results show that the loosely constrained ionosphere will make the estimated ionosphere and DCB/IFB parameters unable to effectively separate due to their high linear dependence. The 3D positioning accuracy of UC-PPP using Galileo five-frequency, BDS-3 four-frequency and Galileo/BDS-3 multi-frequency signals in static mode is 1.76, 2.36 and 1.39 cm, while the corresponding accuracy in kinematic mode is 6.40, 7.08 and 4.16 cm, respectively. The consistency of Galileo IFBs with respect to the MGEX DCB files is rather good, and the probability of deviations within 0.3 ns is 96.58%. Compared to Galileo, the agreement of the BDS-3 IFBs with respect to the reference values is worse, with 92.69% of them within 1 ns.
One-step synthesis of vanadium-doped anatase mesocrystals for Li-ion battery anodes
Authors: Boytsova O V , Drozhzhin O A , Petukhov D I , Chumakova A V , Sobol A G , Beltyukov A N , Eliseev A A , Bosak A B 
Published: October 2021

Abstract
Here we report a successful one-step synthesis of vanadium-doped anatase mesocrystals by reactive annealing of NH4TiOF3/PEG2000 mesocrystal precursors with NH4VO3. The formation solid solution Ti1−x
V
x
O2 with vanadium content up to x = 25 at% inheriting the structure of mesocrystals is observed for the first time. The doping mechanism via vapor phase transport of vanadium is proposed. The Ti1−x
V
x
O2 mesocrystals exhibit improved specific capacity of 175 mAh g−1 (compared to 150 mAh g−1 for pure anatase phase) and decreased potential gap between charge and discharge processes.
A versatile modular preparation strategy for targeted drug delivery systems against multidrug-resistant cancer cells
Authors: Wang Huanhuan , Ning Xiaoyue , Wang Xinnan , Ding Fei , Wang Yongjian 
Published: October 2021

Abstract
Nanotechnology is widely used in targeted drug delivery, but different drug delivery systems need to ‘re-determine’ different synthesis schemes, which greatly limits the further expansion of targeted nanomedicine applications. In this study, we propose a facile and versatile modular stacking strategy to fabricate targeted drug delivery systems to enable tailored designs for patient-specific therapeutic responses. The systems were constructed by a pH-sensitive prodrug module and a mitochondrial targeting module via self-assembly. Using this modular strategy, we successfully prepared two targeting nano-drug delivery systems, TPP-DOX and PK-DOX, where the mitochondrial targeting molecules were triphenylphosphonium (TPP) and 1-(2-Chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK11195), respectively. Confocal laser microscopy and flow cytometry tests revealed that TPP-DOX and PK-DOX exhibited high mitochondria targeting capability and greatly improved the drug retention in drug-resistant cells. The antitumor activity tests showed that the IC50 values of TPP-DOX and PK-DOX in MCF-7/ADR cells were 2.5- and 8.2-fold lower than that of free DOX, respectively. These results indicated that PK was more effective than TPP. The studies on their therapeutic effects on human breast cancer resistant cells verified the feasibility of the modular approach, indicated that the two modular targeted drug delivery systems: (1) retain the drug toxicity and cell-killing effect of the prodrug module, (2) have precise targeting capabilities due to mitochondrial targeting module, (3) enhance drug uptake, reduce drug efflux and reverse the multidrug resistance effect to a certain extent. The results show that modular stacking is a practical, effective and versatile method for preparing targeting drugs with broad application prospects. This study provides an easy approach on preparing customizable targeted drug delivery systems to improve precision therapies.
Anodic TiO2 nanotube arrays for photocatalytic CO2 conversion: comparative photocatalysis and EPR study
Authors: Savchuk Timofey , Gavrilin Ilya , Konstantinova Elizaveta , Dronov Alexey , Volkov Roman , Borgardt Nickolay , Maniecki Tomasz , Gavrilov Sergey , Zaitsev Vladimir 
Published: October 2021

Abstract
Titania (TiO2) is a widely used semiconductor for the photocatalytic decomposition of organic impurities in air, water and the conversion of CO2 into hydrocarbon fuel precursors. TiO2 in the form of nanotubes arrays is the most attractive for practical use because of the morphological advantages providing more favorable diffusion of photocatalytic reaction products and a low recombination rate of photogenerated electrons and holes. We have carried out a comparative study of the photocatalytic activity of gas-phase conversion of CO2 to hydrocarbon products and the defect properties of multi-walled and single-walled arrays of TiO2 nanotubes. Methanol and methane have been detected in the CO2 photoreduction process. The photocatalytic evolution rate of multi-walled TiO2 nanotubes is twice as fast for methane as for single-walled TiO2 nanotubes after four hours of irradiation and four times faster for methanol. The type and features of the structural defects have been investigated by EPR spectroscopy. For the first time, it has been shown that Ti3+/oxygen vacancy centers are mainly located inside the outer layer of nanotubes, while carbon dangling bonds have been observed directly on the surface of the inner layer. Carbon defects have been found to be the centers of adsorption and accumulation of photoinduced charge carriers. The results are entirely new; they clarify the role of different types of defects in the photocatalytic conversion of CO2 to hydrocarbon compounds and show good prospects for applying TiO2 nanotube arrays.
Memristively programmable transistors
Authors: Tappertzhofen S , Nielen L , Valov I , Waser R 
Published: October 2021

Abstract
When designing the gate-dielectric of a floating-gate-transistor, one must make a tradeoff between the necessity of providing an ultra-small leakage current behavior for long state retention, and a moderate to high tunneling-rate for fast programming speed. Here we report on a memristively programmable transistor that overcomes this tradeoff. The operation principle is comparable to floating-gate-transistors, but the advantage of the analyzed concept is that ions instead of electrons are used for programming. Since the mass of ions is significantly larger than the effective mass of electrons, gate-dielectrics with higher leakage current levels can be used. We demonstrate the practical feasibility of the device using a proof-of-concept study based on a micrometer-sized thin-film transistor and LT-Spice simulations of 32 nm transistors. Memristively programmable transistors have the potential of high programming endurance and retention times, fast programming speeds, and high scalability.
Stationary coalescing walks on the lattice II: entropy
Authors: Chaika Jon , Krishnan Arjun 
Published: October 2021

Abstract
This paper is a sequel to Chaika and Krishnan, 2016. We again consider translation invariant measures on families of nearest-neighbor semi-infinite walks on the integer lattice

Z

d

. We assume that once walks meet, they coalesce. We consider various entropic properties of these systems. We show that in systems with completely positive entropy, bi-infinite trajectories must carry entropy. In the case of directed walks in dimension 2 we show that positive entropy guarantees that all trajectories cannot be bi-infinite. To show that our theorems are proper, we construct a stationary discrete-time symmetric exclusion process whose particle trajectories form bi-infinite trajectories carrying entropy.
On long-time behavior of solutions of the Zakharov–Rubenchik/Benney–Roskes system
Authors: Martínez María E , Palacios José M 
Published: October 2021

AbstractWe study decay properties for solutions to the initial value problem associated with the one-dimensional Zakharov–Rubenchik/Benney–Roskes (ZR/BR) system. We prove time-integrability in growing compact intervals of sizetr,r< 2/3, centered on some characteristic curves coming from the underlying transport equations associated with the ZR/BR system. Additionally, we prove decay to zero of the local energy-norm in so-called far-field regions. Our results are independent of the size of the initial data and do not require any parity condition.
Scaled pressure of continuous flows*
Authors: Cheng Dandan , Li Zhiming 
Published: October 2021

AbstractIn this paper we introduce the notion ofscaled pressureof continuous flows. It is proved that scaled pressure is preserved under certain reparametrizations of orbits and Lipschitz conjugations of fixed-point free continuous flows. Moreover, for expansive flows, scaled pressure can be described by period-orbits. In particular, a variational principle is obtained by comparing scaled pressures for continuous flows with their time one maps.
Global multiplicity of solutions for a modified elliptic problem with singular terms
*
Authors: Santos C A , Yang Minbo , Zhou Jiazheng 
Published: October 2021

Abstract
We establish global multiplicity results of solutions for the singular nonlinear problem

−
Δ
u
−
u
Δ

u

2

=
λ
a

(

x

)

u

−
α

+
b

(

x

)

u

β

in

Ω
,

u
>
0

in

Ω
,

u
=
0

on

∂
Ω
,

where

Ω
⊂

R

N

is a smooth bounded domain; N ⩾ 3; a, b are bounded continuous functions, 0 < α < 1 < β ⩽ 22* − 1 and λ > 0 is a real parameter. We first prove a comparison principle to prove the existence of a minimal solution by the method of sub and super solutions and then we also obtain the second solution by critical point theory.
IPEM topical report: results of a 2020 UK survey on the use of online treatment monitoring solutions for IMRT/VMAT
Authors: W Stevens Simon , Moloney Stephen , Bangiri Anna , Blackmore Andrew , Hart Clare , Holmes-Smith William , Pooler Alistair , Rixham Philip , Doolan Paul 
Published: October 2021

Abstract
Numerous commercial technologies for online treatment monitoring (OTM) in radiotherapy (RT) are currently available including electronic portal imaging device (EPID) in vivo dosimetry (IVD), transmission detectors and log files analysis. Despite this, in the UK there exists limited guidance on how to implement and commission a system for clinical use or information about the resources required to set up and maintain a service. A Radiotherapy Special Interest Group working party, established by Institute of Physics and Engineering in Medicine was formed with a view to reassess the current practice for OTM in the UK and an aim to develop consensus guidelines for the implementation of a system. A survey distributed to Heads of Medical Physics at 71 UK RT departments investigated: availability of OTM in the UK; estimates of workload; clinical implementation; methods of analysis; quality assurance; and opinions on future directions. The survey achieved a 76% response rate and demonstrated that OTM is widely supported in the UK, with 87% of respondents indicating all patients should undergo OTM. EPID IVD (EIVD) was the most popular form of OTM. An active EIVD service was reported by 37% of respondents, with 84% believing it was the optimal solution. This demonstrates a steady increase in adoption since 2012. Other forms of OTM were in use but they had only been adopted by a minority of centres. Financial barriers and the increase of staff workload continue to hinder wider implementation in other centres. Device automation and integration is a key factor for successful future adoption and requires support between treatment machine and OTM manufacturers. The survey has provided an updated analysis on the use of OTM methods across the UK. Future guidance is recommended on commissioning, adoption of local tolerances and root-cause analysis strategies to assist departments intending to implement OTM.
Electron acceleration using twisted laser wavefronts
Authors: Shi Yin , R Blackman David , Arefiev Alexey 
Published: October 2021

Abstract
Using plasma mirror injection we demonstrate, both analytically and numerically, that a circularly polarized helical laser pulse can accelerate highly collimated dense bunches of electrons to several hundred MeV using currently available laser systems. The circular-polarized helical (Laguerre–Gaussian) beam has a unique field structure where the transverse fields have helix-like wave-fronts which tend to zero on-axis where, at focus, there are large on-axis longitudinal magnetic and electric fields. The acceleration of electrons by this type of laser pulse is analyzed as a function of radial mode number and it is shown that the radial mode number has a profound effect on electron acceleration close to the laser axis. Using three-dimensional particle-in-cell simulations a circular-polarized helical laser beam with power of 0.6 PW is shown to produce several dense attosecond bunches. The bunch nearest the peak of the laser envelope has an energy of 0.47 GeV with spread as narrow as 10%, a charge of 26 pC with duration of

∼
400

as, and a very low divergence of 20 mrad. The confinement by longitudinal magnetic fields in the near-axis region allows the longitudinal electric fields to accelerate the electrons over a long period after the initial reflection. Both the longitudinal E and B fields are shown to be essential for electron acceleration in this scheme. This opens up new paths toward attosecond electron beams, or attosecond radiation, at many laser facilities around the world.
On the realization of WIMPflation
Authors: Garcia Marcos A.G. , Mambrini Yann , Olive Keith A. , Verner Sarunas 
Published: October 2021

Abstract
We consider models for inflation with a stable inflaton. Reheating is achieved through scattering processes such as ϕϕ→ h h, where h is the Standard Model Higgs boson. We consider the reheating process in detail and show that for a relatively large coupling (needed for the late annihilations of the inflaton during freeze-out), reheating is almost instantaneous leading to a relatively high reheating temperature. The process ϕϕ↔ h h brings the inflaton back into equilibrium, leading to a well studied scalar singlet dark matter candidate and Higgs portal model. We argue that such models can be derived from no-scale supergravity.
Assembly bias in quadratic bias parameters of dark matter halos from forward modeling
Authors: Lazeyras Titouan , Barreira Alexandre , Schmidt Fabian 
Published: October 2021

Abstract
We use the forward modeling approach to galaxy clustering combined with the likelihood from the effective-field theory of large-scale structure to measure assembly bias, i.e. the dependence of halo bias on properties beyond the total mass, in the linear (b1) and second order bias parameters (b2 and bK
2) of dark matter halos in N-body simulations. This is the first time that assembly bias in the tidal bias parameter bK
2 is measured. We focus on three standard halo properties: the concentration c, spin λ, and sphericity s, for which we find an assembly bias signal in bK
2 that is opposite to that in b1. Specifically, at fixed mass, halos that get more (less) positively biased in b1, get less (more) negatively biased in bK
2. We also investigate the impact of assembly bias on the b2(b1) and bK
2(b1) relations, and find that while the b2(b1) relation stays roughly unchanged, assembly bias strongly impacts the bK
2(b1) relation. This impact likely extends also to the corresponding relation for galaxies, which motivates future studies to design better priors on bK
2(b1) for use in cosmological constraints from galaxy clustering data.
Morphogen-regulated contact-mediated signaling between cells can drive the transitions underlying body segmentation in vertebrates
Authors: Kuyyamudi Chandrashekar , Menon Shakti N , Sinha Sitabhra 
Published: October 2021

Abstract
We propose a unified mechanism that reproduces the sequence of dynamical transitions observed during somitogenesis, the process of body segmentation during embryonic development, that is invariant across all vertebrate species. This is achieved by combining inter-cellular interactions mediated via receptor-ligand coupling with global spatial heterogeneity introduced through a morphogen gradient known to occur along the anteroposterior axis. Our model reproduces synchronized oscillations in the gene expression in cells at the anterior of the presomitic mesoderm as it grows by adding new cells at its posterior, followed by travelling waves and subsequent arrest of activity, with the eventual appearance of somite-like patterns. This framework integrates a boundary-organized pattern formation mechanism, which uses positional information provided by a morphogen gradient, with the coupling-mediated self-organized emergence of collective dynamics, to explain the processes that lead to segmentation.
Light-weight electrophysiology hardware and software platform for cloud-based neural recording experiments
Authors: Voitiuk Kateryna , Geng Jinghui , Keefe Matthew G , Parks David F , Sanso Sebastian E , Hawthorne Nico , Freeman Daniel B , Currie Rob , Mostajo-Radji Mohammed A , Pollen Alex A , Nowakowski Tomasz J , Salama Sofie R , Teodorescu Mircea , Haussler David 
Published: October 2021

Abstract

Objective. Neural activity represents a functional readout of neurons that is increasingly important to monitor in a wide range of experiments. Extracellular recordings have emerged as a powerful technique for measuring neural activity because these methods do not lead to the destruction or degradation of the cells being measured. Current approaches to electrophysiology have a low throughput of experiments due to manual supervision and expensive equipment. This bottleneck limits broader inferences that can be achieved with numerous long-term recorded samples. Approach. We developed Piphys, an inexpensive open source neurophysiological recording platform that consists of both hardware and software. It is easily accessed and controlled via a standard web interface through Internet of Things (IoT) protocols. Main results. We used a Raspberry Pi as the primary processing device along with an Intan bioamplifier. We designed a hardware expansion circuit board and software to enable voltage sampling and user interaction. This standalone system was validated with primary human neurons, showing reliability in collecting neural activity in near real-time. Significance. The hardware modules and cloud software allow for remote control of neural recording experiments as well as horizontal scalability, enabling long-term observations of development, organization, and neural activity at scale.
The IFMIF-DONES fusion oriented neutron source: evolution of the design
Authors: Królas W. , Ibarra A. , Arbeiter F. , Arranz F. , Bernardi D. , Cappelli M. , Castellanos J. , Dézsi T. , Dzitko H. , Favuzza P. , García A. , Gutiérrez J. , Lewitowicz M. , Maj A. , Martin-Fuertes F. , Micciché G. , Muñoz A. , Nitti F.S. , Pinna T. , Podadera I. , Pons J. , Qiu Y. , Román R. , Toth M. , Zsakai A. 
Published: October 2021

Abstract
IFMIF-DONES is a powerful neutron irradiation facility for the study and qualification of materials planned as part of the European roadmap to fusion-generated electricity. Its main goal is to study properties of materials under severe irradiation in a neutron field similar to the one in a fusion reactor first wall. It is a key facility to prepare for the construction of the DEMO power plant envisaged to follow ITER. The decision to start the construction of IFMIF-DONES is expected imminent. In this paper we present and discuss several key technical studies and decisions to improve and optimize the engineering design of IFMIF-DONES which were carried out as part of the activities in the framework of the EUROfusion Early Neutron Source work package (2015–2020). The following topics are discussed in this paper: the new layout of the IFMIF-DONES SRF LINAC accelerator and high-energy beam transport line, 7Be impurity management approach for the lithium loop, a maintainable test cell concept, a revised layout of the access cell for the remote maintenance operations, and facilities for complementary experiments.
Observation of low frequency electrostatic coherent oscillation in the proximity of the density limit in the TJ-II stellarator
Authors: Fernández-Ruiz D. , Losada U. , Ochando M.A. , Liu B. , Hidalgo C. , the TJ-II Team  
Published: October 2021

Abstract
Turbulence self-regulation mechanisms are widely believed to be partially governed by the non-linear interplay between turbulence and large-scale plasma flows. In this paper, we employ floating potential data recorded via Langmuir probes to study the evolution of long-range correlated structures in plasmas near the operational density limit of the TJ-II stellarator. The results point towards the presence and amplification of low frequency, coherent, global fluctuations with similar properties to those of the zonal flows in the vicinity of this limit.
Isobaric charge-exchange reactions: a tool to study the excitation of baryonic resonances in exotic nuclear matter
Authors: Rodríguez-Sánchez J L , Benlliure J , Haettner E , Scheidenberger C , Vargas J , Ayyad Y , Alvarez-Pol H , Atkinson J , Aumann T , Beceiro-Novo S , Boretzky K , Caamaño M , Casarejos E , Cortina-Gil D , Fernández P Díaz , Estrade A , Geissel H , Itahashi K , Kelić-Heil A , Lenske H , Litvinov Yu A , Paradela C , Pérez-Loureiro D , Pietri S , Prochazka A , Saito T R , Takechi M , Tanaka Y K , Vidaña I , Weick H , Winfield J S 
Published: October 2021

Abstract
Isobaric charge-exchange reactions induced by beams of 112Sn have been investigated at the GSI facility using the fragment separator FRS. The high-resolving power of this spectrometer makes it possible to obtain the isobaric charge-exchange cross sections with an uncertainty of 3.5% and to separate quasi-elastic and inelastic contributions in the missing-energy spectra, in which the inelastic component is associated to the in-medium excitation of baryonic resonances such as the Δ resonance. We report on the results obtained for the (p,n) channel excited by using different targets that cover a large range in neutron excess. In addition, we also compare the missing-energy spectra with an intranuclear cascade model coupled to a de-excitation code to investigate the in-medium effects in the production of baryonic resonances.