bluuebunny/crossref_metadata_2025 huggingface dataset:
Les métasurfaces optiques pour les lidars à large champ et à haute cadence d’imagerie
Authors: Juliano Martins Renato , Marinov Emil , Ben Youssef M. Aziz , Kyrou Christina , Genevet Patrice
Published: August 2022

Le déploiement de solutions d’imageries avancées, susceptibles de fournir aux systèmes robotiques une vision équivalente à celle de l’homme, nécessite l'acquisition rapide et précise d’images avec un large champ de vision. Etant particulièrement adaptées pour les systèmes optiques à grand champ, les métasurfaces offrent de nouvelles perspectives d’intégration et d’optimisation pour réaliser des LiDARs compacts, à bas coûts de production et à hautes performances.
Medikamentöse Therapie der HFrEF – früher Nutzen von Synergien und individuelle Konzepte
Authors: Kempf Tibor , Bavendiek Udo
Published: August 2022

Die aktuellen Leitlinien zur Pharmakotherapie der Herzinsuffizienz mit reduzierter Pumpfunktion empfehlen den frühzeitigen und möglichst simultanen Beginn mit einem Betablocker (BB),
SGLT2-Inhibitor (SGLT2i), Mineralokortikoidrezeptor-Antagonisten (MRA) und ACE-Hemmer (ACEi) bzw. alternativ einem Angiotensin-Rezeptor-Neprilysin-Inhibitor (ARNI). Dabei wird die Sequenz
des Therapiestarts der empfohlenen Wirkstoffklassen und deren Erweiterung und Dosissteigerung im Verlauf unter Berücksichtigung der individuellen Patientenmerkmale und Komorbiditäten bewusst
dem behandelnden Arzt überlassen. Somit wird das bisherige Stufenschema mit einer sequenziellen Initiierung der verschiedenen Wirkstoffklassen verlassen, da diese primär auf der Historie der
zugrunde liegenden klinischen Endpunktstudien basieren und nicht den frühzeitigen und synergistischen prognoseverbessernden Effekt der Wirkstoffklassen berücksichtigen. Die Empfehlung zur
Dosissteigerung auf die in den klinischen Studien verwendeten Zieldosen von BB, SGLT2i, MRA und ACEi bzw. ARNI bleibt aber erhalten. Die Erweiterung um weitere Wirkstoffklassen sollte in
Abhängigkeit von Komorbiditäten, klinischen Parametern, Progress der Herzinsuffizienz und Evidenzlage aus klinischen Studien erfolgen.
Advances in Bifunctional Squaramide-Catalyzed Asymmetric Sulfa-Michael Addition: A Decade Update
Authors: Sunny Steeva , Maingle Mohit , Seth Kapileswar
Published: August 2022

The application of bifunctional organocatalysts in organic chemistry has advanced remarkably owing to their high stability to moisture and air, relatively low toxicity, ease of handling, and recoverability. Among chiral bifunctional organocatalysts, squaramides have emerged as a privileged catalyst in recent years. This review article presents a comprehensive report on fine-tunable bifunctional chiral squaramide-catalyzed sulfa-Michael addition, which is based upon synchronous interplay of synergistic ‘electrophilic–nucleophilic’ dual activation strategies via multiple H-bonding interactions for the construction of both common and complex molecular entities bearing multiple stereocenters. Mechanistic discussions are kept brief, but significant understandings have been recorded. The contribution of squaramide catalyst to the construction of C–S bonds via sulfa-Michael addition has been applied in medicinal, natural, and industrial chemistry. Attention is focused on summarizing the progress made in chiral squaramide-catalyzed asymmetric sulfa-Michael addition and subsequent cascade/domino reaction sequences between 2011 and 2022.

1 Introduction

2 Quinine-Squaramide Organocatalysis

3 Iminophosphorane-Squaramide Organocatalysis

4 Chinchona-Squaramide Organocatalysis

5 trans-1,2-Diaminocyclohexane-Squaramide Organocatalysis

6 Conclusion
α-Metalated Isocyanides Toward a Tangible Reagent Space
Authors: Neochoritis Constantinos G. , Fragkiadakis Michael
Published: August 2022

α-Metalated isocyanides are a versatile class of compounds that can easily be employed in various transformations, affording tangible libraries for screening campaigns. We report the ring-opening reactions of cyclic anhydrides and lactones with three different metalated isocyanides that readily give 4,5-disubstituted oxazoles, including useful drug-like synthetic intermediates with two functional groups as handles for further modifications.
EUS-Guided Rendezvous and Tractogastrostomy: A Novel Technique for Disconnected Pancreatic Duct Syndrome with External Pancreatic Fistula
Authors: Singla Vikas , Arora Anil , Rana Surinder Singh , Kohle Manoj , Khare Shivam , Kumar Ashish , Bansal Naresh , Sharma Praveen
Published: August 2022

Background and Aims External pancreatic fistula occurring in the setting of disconnected pancreatic duct syndrome leads to significant morbidity, often requiring surgery. The aim of this study is to report a new technique of endoscopic ultrasound (EUS)-guided rendezvous and tractogastrostomy in patients with disconnected pancreatic duct syndrome and external pancreatic fistula.

Methods This study is retrospective analysis of the data of the patients with external pancreatic fistula who had undergone EUS-guided rendezvous and tractogastrostomy. Internalization of pancreatic secretions was performed by placing a stent between tract and the stomach. Technical success was defined as placement of stent between the tract and the stomach. Clinical success was defined as removal of external catheter and absence of peripancreatic fluid collection, ascites or external fistula at 3 months after the tractogastrostomy.

Results Four patients, all male, with median age of 33.5 years (range: 29–45), underwent EUS-guided tractogastrostomy. Technical and clinical success was 100%, without any procedure related complication. External catheter could be removed in all the patients. During the median follow-up of 10.5 months (range: 8–12), two patients had stent migration and peripancreatic fluid collection, which were managed by EUS-guided internal drainage.

Conclusions EUS-guided rendezvous and tractogastrostomy are a safe and effective technique for the treatment of external pancreatic fistula.
Negative emotions and consumer behavioural intention to adopt emerging e-banking technology
Authors: Abikari Masoome , Öhman Peter , Yazdanfar Darush
Published: August 2022

Successful implementation of e-banking technology depends on how consumers perceive the technology and how likely they are to adopt it. Although several studies have analysed the impact of some specific negative emotions, few studies examine a broad range of consumers’ negative emotions (i.e. both deterrence and loss emotions) arising from appraisals of e-banking technology. This study investigates the possible relationships between deterrence and loss emotions, and consumers’ behavioural intention to adopt emerging e-banking technology. Based on the unified theory of acceptance and use of technology, partial least squares structural equation modelling was used to analyse a conceptual model and related hypotheses. The empirical evidence draws attention to the relationship between loss emotions and consumers’ behavioural intention to adopt emerging e-banking technology through effort expectancy and performance expectancy, respectively.
Torturing environments and multiple injuries in Mexican migration detention
Authors: Manek Julia , Galán-Santamarina Andrea , Pérez-Sales Pau
Published: August 2022

Mexico’s role in the US-Central American migration regime is threefold: not only is it a country of origin, and a transit country, but also increasingly becoming a receiving country for migrants who flee from violence, insecurity and poverty. The Mexican state responds with detention enforcement. Clinical research usually puts emphasise on the negative impact of detention enforcement on the detainees‘ mental health. Yet, it often disregards the spatial configurations of detention centres and their socio-political context. This study aims to fill this gap by analysing how such factors create harmful environments that affect both the detainees‘ mental health and their social life in Mexico’s migration detention centres. The study’s mixed method approach builds on semi-structured interviews with a sample ofN = 56 migrants of diverse nationalities and varying socioeconomic status of whom 22 were still detained while 34 had been released. The interviews include the Torturing Environment Scale (TES), a novel instrument for the analysis of detention environments, as well as clinical psychological measures of emotional distress. Additionaln = 10 in-depth interviews with human rights advocates to explore the interconnections between the detention environments, their impact on mental health, and Mexican migration politics. Facultative counter-mappings of the detention centres complement the interviews. Without exception, all interviews of detainees underline that the manipulation of detention conditions creates torturing environments that cause harm to basic physiological and psychological needs. A comparison between detained vs. released interviewees revealed lasting feelings of fear and shame. The study emphasises that immigration detention immobilises migrants in a necropolitical limbo, which destroys hope as much as human integrity. It indicates that detention is part of deterrence politics, which perpetuates harm and inequality through detention and deportation. Highlighting structural human rights violations, the findings stress the need to review current migration policies.
Constructivism in Kant’s theoretical philosphy
Authors: Pereira Roberto Horácio de Sá
Published: August 2022

We set forth what one may call a “constitutional reading” in opposition to the traditional widespread “constructivist reading” of the object of cognition. In the light of the so-called one-object view reading of Transcendental idealism, the object of cognition is nothing but the object that exists in itself insofar as it appears to our cognitive apparatus. The objectexists mind-independently, while our cognitionof the same object must be mind-independent. The constructivist reading mistakes the epistemological problemof how we come to cognize mind-dependently that what we represent(“the constitutional view”) are mind-independent objects with the Berkelian ontological problem ofhow we construct objects out of an undifferentiated, unstructured manifold(the constructivist view) My diagnosis is as follows. The first reason is the traditional “two-worlds view” reading of Kant’s idealism: if we take whatexists in itselfandthe objectof cognition as distinct things, then we must conclude that the object of cognition is a mind-dependent construction. Constructivist readers mistakethe mind-dependent nature of our human cognitionof objects for theputative mind-dependent nature of the known object. The second reason is overintellectualization. Constructivist readers mistake the objectifying syntheses of the imagination, below the threshold of self-consciousness, for cognitive conceptual operations by means of which we cognize (erkennen) the objects of cognition, or so I shall argue.
The effect of leave policies on increasing fertility: a systematic review
Authors: Thomas Jac , Rowe Francisco , Williamson Paul , Lin Eric S.
Published: August 2022

Low fertility is set to worsen economic problems in many developed countries, and maternity, paternity, and parental leave have emerged as key pro-natal policies. Gender inequity in the balance of domestic and formal work has been identified as a key driver of low fertility, and leave can potentially equalise this balance and thereby promote fertility. However, the literature contends that evidence for the effect of leave on fertility is mixed. We conduct the first systematic review on this topic. By applying a rigorous search protocol, we identify and review empirical studies that quantify the impact of leave policies on fertility. We focus on experimental or quasi-experimental studies that can identify causal effects. We identify 11 papers published between 2009 and 2019, evaluating 23 policy changes across Europe and North America from 1977 to 2009. Results are a mixture of positive, negative, and null impacts on fertility. To explain these apparent inconsistencies, we extend the conceptual framework of Lalive and Zweimüller (2009), which decomposes the total effect of leave on fertility into the “current-child” and “future-child” effects. We decompose these into effects on women at different birth orders, and specify types of study design to identify each effect. We classify the 23 studies in terms of the type of effect identified, revealing that all the negative or null studies identify the current-child effect, and all the positive studies identify the future-child or total effect. Since the future-child and total effects are more important for promoting aggregate fertility, our findings show that leave does in fact increase fertility when benefit increases are generous. Furthermore, our extensions to Lalive and Zweimüller’s conceptual framework provide a more sophisticated way of understanding and classifying the effects of pro-natal policies on fertility. Additionally, we propose ways to adapt the ROBINS-I tool for evaluating risk of bias in pro-natal policy studies.
A holistic perspective on sickle cell disease
Authors: Thompson Avery
Published: August 2022

Sickle cell disease goes beyond the blood disorder, and examining secondary conditions can lead to better patient outcomes.
Quasi-homogeneous two-body problem
Authors: Deng Yanxia , Ibrahim Slim , Qian Lingjun
Published: August 2022

The quasi-homogeneous two-body problem aims at studying the interaction between two point particles under a prescribed potential in the form of W(r)=−Ara−Brb, where A, B > 0 are constants and r is the mutual distance between two particles. Important examples include the Manev potential (a = 1, b = 2) and the Schwarzschild potential (a = 1, b = 3). It is well known that power two serves as a threshold value for the homogeneous potential: One is able to observe significant differences regarding the solution dynamics as the power of the homogeneous potential exceeds two from below. This phenomenon remains observable for quasi-homogeneous potentials. In this paper, we shall provide a complete characterization of the whole phase space of the quasi-homogeneous two-body problem in terms of global existence and singularity for all the possible b > a > 0. In particular, one is able to generalize the result of the Manev and Schwarzschild two-body problem to all the quasi-homogeneous potentials. Two techniques are presented in this paper: One is the variational method based on the energy, and the other is a direct computation of collision time based on the integrability of two-body systems.
Painlevé/CFT correspondence on a torus
Authors: Desiraju Harini
Published: August 2022

This Review details the relationship between the isomonodromic tau-function and conformal blocks on a torus with one simple pole. It is based on the author’s talk at ICMP 2021.
Nanoscale reaction monitoring using localized surface plasmon resonance scatterometry
Authors: Hwang Hyunsik , Song Hyunjoon
Published: August 2022

Heterogeneous reactions are highly dependent upon the local structure and environment of the catalyst surface within a nanoscale. Among numerous techniques for monitoring heterogeneous reactions, dark-field microscopy offers reliable data regardless of specific reaction conditions. In addition, plasmonic nanoprobes provide high sensitivity in a sub-wavelength resolution due to localized surface plasmon resonances susceptible to the dielectric change of objects and surroundings. By clever reaction cell design and data analysis, nanoparticle signals can be parallelly analyzed under variable reaction conditions in a controlled manner. This technique effectively measures the heterogeneity of individual nanoparticles for reaction monitoring. A wide range of chemical and electrochemical reactions have been monitored in situ and in operando at a single-particle level in this way. The advancement of localized surface plasmon scatterometry with simulation techniques approaches sub-particle accuracy in a high temporal resolution up to microseconds. Combining other in situ spectroscopic methods would make dark-field scatterometry a versatile tool for various reaction monitoring and sensing applications.
Templex: A bridge between homologies and templates for chaotic attractors
Authors: Charó Gisela D. , Letellier Christophe , Sciamarella Denisse
Published: August 2022

The theory of homologies introduces cell complexes to provide an algebraic description of spaces up to topological equivalence. Attractors in state space can be studied using Branched Manifold Analysis through Homologies: this strategy constructs a cell complex from a cloud of points in state space and uses homology groups to characterize its topology. The approach, however, does not consider the action of the flow on the cell complex. The procedure is here extended to take this fundamental property into account, as done with templates. The goal is achieved endowing the cell complex with a directed graph that prescribes the flow direction between its highest-dimensional cells. The tandem of cell complex and directed graph, baptized templex, is shown to allow for a sophisticated characterization of chaotic attractors and for an accurate classification of them. The cases of a few well-known chaotic attractors are investigated—namely, the spiral and funnel Rössler attractors, the Lorenz attractor, the Burke and Shaw attractor, and a four-dimensional system. A link is established with their description in terms of templates.
Polarization of Bi2Se3 thin film toward non-volatile memory applications
Authors: Zhang Kai , Zhu Xinyi , Yang Yafen , Zhu Hao
Published: August 2022

In recent years, topological insulators have drawn growing interest as a unique electronic state of matter toward quantum information technology. Despite the logic devices with magnetization switching through spin–orbit torque or the topological magneto-electric effect, realizing memory devices based on topological insulators has been urged in quantum computing applications. In this work, we report the design and fabrication of a non-volatile memory device that employs polarization of Bi2Se3 thin films achieving fast memory speed, sufficient memory window, and good reliability. The Bi2Se3 film polarizes under an external electrical field with charges accumulated on the top and bottom surfaces separating the electrons and holes. Such polarization is much faster than the carrier tunneling in conventional floating-gate flash memory and ferroelectric-based memory devices. In addition, good memory retention and endurance properties have also been obtained, showing great potential in high-performance memory application in future topological insulator-involved information technology.
Instabilities, anomalous heating, and stochastic acceleration of electrons in colliding plasmas
Authors: Malkov M. A. , Sotnikov V. I.
Published: August 2022

The collision of two expanding plasma clouds is investigated, emphasizing instabilities and electron energization in the plasma mixing layer. This work is not only directly relevant to laboratory experiments with explosively created laser or z-pinch plasmas but may also elucidate naturally occurring plasma collisions in astrophysical or space physics contexts. In the previous publications [Malkov and Sotnikov, Phys. Plasmas 25, 102108 (2018) and Sotnikov et al., Phys. Plasmas 27, 122113 (2020)], we have studied, analytically and numerically, the flow emerging from interpenetrating coronas launched by two parallel wires vaporized in a vacuum chamber. The main foci of the studies have been on the general flow pattern and lower-hybrid and thin-shell instabilities that under certain conditions develop in the collision layer. The present paper centers around the initial phase of the interpenetration of the two plasmas. Two-stream ion–ion instability, efficient electron heating, and stochastic acceleration dominate plasma mixing at this phase. Both the adiabatic (reversible) electron heating and stochastic (irreversible) acceleration and heating mechanisms, powered by unstably driven electric fields, are considered. The irreversibility results from a combination of electron runaway acceleration in the wave electric fields and pitch-angle scattering on ions and neutrals.
Cardiovascular consequences of sickle cell disease
Authors: Palomarez Alexis , Jha Manisha , Medina Romero Ximena , Horton Renita E.
Published: August 2022

Sickle cell disease (SCD) is an inherited blood disorder caused by a single point mutation within the beta globin gene. As a result of this mutation, hemoglobin polymerizes under low oxygen conditions causing red blood cells to deform, become more adhesive, and increase in rigidity, which affects blood flow dynamics. This process leads to enhanced red blood cell interactions with the endothelium and contributes to vaso-occlusion formation. Although traditionally defined as a red blood cell disorder, individuals with SCD are affected by numerous clinical consequences including stroke, painful crisis episodes, bone infarctions, and several organ-specific complications. Elevated cardiac output, endothelium activation along with the sickling process, and the vaso-occlusion events pose strains on the cardiovascular system. We will present a review of the cardiovascular consequences of sickle cell disease and show connections with the vasculopathy related to SCD. We will also highlight biophysical properties and engineering tools that have been used to characterize the disease. Finally, we will discuss therapies for SCD and potential implications on SCD cardiomyopathy.
Time-series forecasting using manifold learning, radial basis function interpolation, and geometric harmonics
Authors: Papaioannou Panagiotis G. , Talmon Ronen , Kevrekidis Ioannis G. , Siettos Constantinos
Published: August 2022

We address a three-tier numerical framework based on nonlinear manifold learning for the forecasting of high-dimensional time series, relaxing the “curse of dimensionality” related to the training phase of surrogate/machine learning models. At the first step, we embed the high-dimensional time series into a reduced low-dimensional space using nonlinear manifold learning (local linear embedding and parsimonious diffusion maps). Then, we construct reduced-order surrogate models on the manifold (here, for our illustrations, we used multivariate autoregressive and Gaussian process regression models) to forecast the embedded dynamics. Finally, we solve the pre-image problem, thus lifting the embedded time series back to the original high-dimensional space using radial basis function interpolation and geometric harmonics. The proposed numerical data-driven scheme can also be applied as a reduced-order model procedure for the numerical solution/propagation of the (transient) dynamics of partial differential equations (PDEs). We assess the performance of the proposed scheme via three different families of problems: (a) the forecasting of synthetic time series generated by three simplistic linear and weakly nonlinear stochastic models resembling electroencephalography signals, (b) the prediction/propagation of the solution profiles of a linear parabolic PDE and the Brusselator model (a set of two nonlinear parabolic PDEs), and (c) the forecasting of a real-world data set containing daily time series of ten key foreign exchange rates spanning the time period 3 September 2001–29 October 2020.
Study on the mechanism of shock wave and boundary layer interaction control using high-frequency pulsed arc discharge plasma
Authors: Ma Xiaogang , Fan Jian , Wu Yunkai , Liu Xiaowei , Xue Rui
Published: August 2022

This paper studies the response characteristics of shock wave and boundary layer interaction (SWBLI) controlled by high-frequency pulsed arc discharge (PAD) in a Mach 2.5 flow. The dynamic evolution of SWBLI disturbed by arc plasma energy deposition was captured, and the controlling mechanism under different exciting power and frequency was explored. The results showed that the blast wave induced by PADs had a strong impact on SWBLI structures and distorted the separation shock wave. During the downstream propagation, the controlling gas bubbles (CGBs) delivered a continuous thermal excitation to the boundary layer and reached the maximum penetration depth near the semi-cylinder. The arc discharge in the SWBLI region induced larger energy deposition, which made the heating zone obtain the highest initial temperature and longest heating duration. Under the plasma condition of 1 × 1011 W/m3/15 kHz, both the upstream part of the shear layer and the foot portion of the reattachment shock wave were removed. When setting the excitation to 2.5 × 1010 W/m3/60 kHz, a thermal exciting surface of merged CGBs was formed and the separation shock wave was completely replaced by an equivalent compression-wave system. A better drag-reduction effect on the flow field would be produced by the actuator with an increased operating power or frequency, and a drag reduction rate of nearly 25.5% was achieved under the 2.5 × 1010 W/m3/60 kHz control condition.
Time-correlation functions for odd Langevin systems
Authors: Yasuda Kento , Ishimoto Kenta , Kobayashi Akira , Lin Li-Shing , Sou Isamu , Hosaka Yuto , Komura Shigeyuki
Published: August 2022

We investigate the statistical properties of fluctuations in active systems that are governed by nonsymmetric responses. Both an underdamped Langevin system with an odd resistance tensor and an overdamped Langevin system with an odd elastic tensor are studied. For a system in thermal equilibrium, the time-correlation functions should satisfy time-reversal symmetry and the antisymmetric parts of the correlation functions should vanish. For the odd Langevin systems, however, we find that the antisymmetric parts of the time-correlation functions can exist and that they are proportional to either the odd resistance coefficient or the odd elastic constant. This means that the time-reversal invariance of the correlation functions is broken due to the presence of odd responses in active systems. Using the short-time asymptotic expressions of the time-correlation functions, one can estimate an odd elastic constant of an active material such as an enzyme or a motor protein.
Reconciling spectroscopy with dynamics in global potential energy surfaces: The case of the astrophysically relevant SiC2
Authors: Rocha C. M. R. , Linnartz H. , Varandas A. J. C.
Published: August 2022

SiC2 is a fascinating molecule due to its unusual bonding and astrophysical importance. In this work, we report the first global potential energy surface (PES) for ground-state SiC2 using the combined-hyperbolic-inverse-power-representation method and accurate ab initio energies. The calibration grid data are obtained via a general dual-level protocol developed afresh herein that entails both coupled-cluster and multi-reference configuration interaction energies jointly extrapolated to the complete basis set limit. Such an approach is specially devised to recover much of the spectroscopy from the PES, while still permitting a proper fragmentation of the system to allow for reaction dynamics studies. Besides describing accurately the valence strongly bound region that includes both the cyclic global minimum and isomerization barriers, the final analytic PES form is shown to properly reproduce dissociation energies, diatomic potentials, and long-range interactions at all asymptotic channels, in addition to naturally reflect the correct permutational symmetry of the potential. Bound vibrational state calculations have been carried out, unveiling an excellent match of the available experimental data on c-SiC2(A11). To further exploit the global nature of the PES, exploratory quasi-classical trajectory calculations for the endothermic C2 + Si → SiC + C reaction are also performed, yielding thermalized rate coefficients for temperatures up to 5000 K. The results hint for the prominence of this reaction in the innermost layers of the circumstellar envelopes around carbon-rich stars, hence conceivably playing therein a key contribution to the gas-phase formation of SiC, and eventually, solid SiC dust.
An assessment of generating quasi-static magnetic fields using laser-driven “capacitor” coils
Authors: Peebles J. L. , Davies J. R. , Barnak D. H. , Garcia-Rubio F. , Heuer P. V. , Brent G. , Spielman R. , Betti R.
Published: August 2022

Over the previous decade, numerous experiments have been performed using a laser to drive a strong, quasi-static magnetic field. Field strength and energy density measurements of these experiments have varied by many orders of magnitude, painting a confusing picture of the effectiveness of these laser-driven coils (LDCs) as tools for generating consistent fields. At the higher end of the field energy spectrum, kilotesla field measurements have been used to justify future experimental platforms, theoretical work, and inertial confinement fusion concepts. In this paper, we present the results from our own experiments designed to measure magnetic fields from LDCs as well as a review of the body of experiments that have been undertaken in this field. We demonstrate how problems with prior diagnostic analyses have led to overestimations of the magnetic fields generated from LDCs.
Perfect double-layer terahertz absorber based on graphene metamaterial
Authors: Jia Haoduo , Tang Xin , Li Hui , Qian Ziwen , Li Ming , Wu Dai , Li Peng , Wang Jianxin , Zhu Xinghua , Yang Dingyu
Published: August 2022

Using bilayer graphene structures (L-type and disk-type structures), we numerically demonstrate a tunable single-band terahertz metamaterial absorber with nearly perfect (100%) absorption by continuously adjusting the graphene Fermi energy parameters to determine the maximum absorption rate, the corresponding center frequency, and bandwidth. Graphene distinct dielectric–metal transition properties make it possible to achieve tunable terahertz absorption. The maximum absorption rate increases from 18% to 100% when the Fermi energy is increased from 0.1 to 1 eV. At 1 eV, the absorption rate exceeds 90% in the range of 0.57–1.03 THz. The incident angle is also tested. When the angle is in the range of 60°, excellent adsorption performance is maintained.
Strain engineering for enhanced hot-carrier photodetection
Authors: Liu Tingting , Zhang Cheng , Li Xiaofeng
Published: August 2022

Hot-carrier devices in metal–semiconductor junctions have attracted considerable attention but still with quantum efficiencies far from expectations. Introducing the lattice strain to the material can effectively modulate the electronic structure, providing a way to control the hot-carrier dynamics. Here, we study how this strain affects the generation, transport, and injection of hot carriers in gold (Au) by using first-principles calculations and evaluate the overall responses of Au-based hot-carrier devices by Monte Carlo simulation. We find that the compressive strain can significantly increase the hot-electron generation from direct transition at E > 1.1 eV for Au. The compressive strain delocalizes the band structure and decreases the electron density of state, which, in turn, reduce electron–electron and electron–phonon scatterings to improve the transport of hot carriers. Taking the Au/TiO2 device as an example, we find that the compressive strain (−6%) can enable a 1.5- to 3-fold enhancement of quantum efficiency and responsivity at a photon energy between 1.2 and 3 eV.
Transport of thin water films: From thermally activated random walks to hydrodynamics
Authors: Gravelle Simon , Holm Christian , Schlaich Alexander
Published: August 2022

Under ambient atmospheric conditions, a thin film of water wets many solid surfaces, including insulators, ice, and salt. The film thickness as well as its transport behavior sensitively depend on the surrounding humidity. Understanding this intricate interplay is of the highest relevance for water transport through porous media, particularly in the context of soil salinization induced by evaporation. Here, we use molecular simulations to evaluate the transport properties of thin water films on prototypical salt and soil interfaces, namely NaCl and silica solid surfaces. Our results show two distinct regimes for water transport: at low water coverage, the film permeance scales linearly with the adsorbed amount, in agreement with the activated random walk model. For thicker water films, the permeance scales as the adsorbed amount to the power of 3, in line with the Stokes equation. By comparing results obtained for silica and NaCl surfaces, we find that, at low water coverage, water permeance at the silica surface is considerably lower than at the NaCl surface, which we attribute to difference in hydrogen bonding. We also investigate the effect of atomic surface defects on the transport properties. Finally, in the context of water transport through the porous material, we determine the humidity-dependent crossover between a vapor-dominated and a thin film-dominated transport regimes depending on the pore size.
Jet penetration characteristics and NO combustion emission process of ammonia/methane fuel in a flue gas environment
Authors: Zhang Qi , Shan Shiquan , Zhou Zhijun , Wang Zhihua , Cen Kefa
Published: August 2022

Ammonia is an alternative fuel that has potential in much industrial equipment such as internal combustion engines, gas turbines, and boilers. In the present study, the influence of flue gas on the injection process of ammonia fuel was analyzed for the first time, and the influences of ammonia/methane fuel ratio and equivalence ratio on the diffusion process were considered. A Schlieren system was used to characterize the characteristics of ammonia jet, including tip penetration and jet angle. Meanwhile, the NO emissions during this progress were calculated based on the GRI 3.0 combustion mechanism. The results showed that the penetration distance was affected by both the diffusion effect and the chemical effect. The time evolution of penetration has three stages. The second stage of penetration in the flue gas environment develops faster with the decrease in the equivalence ratio. The increase in jet angle is accelerated by the flue gas environment and a decrease in equivalence ratio. Furthermore, the theoretical results showed that the emission process of NO is mainly affected by the fuel ratio and equivalence ratio. When the equivalence ratio increased from 0.8 to 1.2, NO emissions decreased by 85.7%. The distribution of NO along the axis is also affected by the fuel ratio. When the volume ratio of NH3 to CH4 decreases from 1 to 0.5, the peak value of NO concentration decreases by 29.4%.
Effects of surface rigidity and metallicity on dielectric properties and ion interactions at aqueous hydrophobic interfaces
Authors: Loche Philip , Scalfi Laura , Ali Amu Mustakim , Schullian Otto , Bonthuis Douwe J. , Rotenberg Benjamin , Netz Roland R.
Published: August 2022

Using classical molecular dynamics simulations, we investigate the dielectric properties at interfaces of water with graphene, graphite, hexane, and water vapor. For graphite, we compare metallic and nonmetallic versions. At the vapor–liquid water and hexane–water interfaces, the laterally averaged dielectric profiles are significantly broadened due to interfacial roughness and only slightly anisotropic. In contrast, at the rigid graphene surface, the dielectric profiles are strongly anisotropic and the perpendicular dielectric profile exhibits pronounced oscillations and sign changes. The interfacial dielectric excess, characterized by the shift of the dielectric dividing surface with respect to the Gibbs dividing surface, is positive for all surfaces, showing that water has an enhanced dielectric response at hydrophobic surfaces. The dielectric dividing surface positions vary significantly among the different surfaces, which points to pronounced surface-specific dielectric behavior. The interfacial repulsion of a chloride ion is shown to be dominated by electrostatic interactions for the soft fluid–fluid interfaces and by non-electrostatic Lennard-Jones interactions for the rigid graphene–water interface. A linear tensorial dielectric model for the ion–interface interaction with sharp dielectric interfaces located on the dielectric dividing surface positions works well for graphene but fails for vapor and hexane, because these interfaces are smeared out. The repulsion of chloride from the metallic and nonmetallic graphite versions differs very little, which reflects the almost identical interfacial water structure and can be understood based on linear continuum dielectric theory. Interface flexibility shows up mostly in the nonlinear Coulomb part of the ion–interface interaction, which changes significantly close to the interfaces and signals the breakdown of linear dielectric continuum theory.
Fragmentation of inviscid liquid and destination of satellite droplets
Authors: Li Dege , Cao Yi , Huang Bingfang , Wu Xinlei , Hu Guofang , Wang Xiaolong , Liu Yonghong , Zhang Yanzhen
Published: August 2022

The breakup process of the inviscid liquid bridge sandwiched between two coaxial and equal-sized rods is investigated by tracking its profile. Here, the focus is on the quasi-static profile of the liquid bridge close to rupture and its influence on the subsequent dynamic breakup behaviors. With the increasing distance between the two rods, the profile of the liquid bridge close to rupture undergoes a transition from symmetry to asymmetry. We found there exists a critical slenderness above which the liquid bridge will be asymmetric and present a profile that can be well fitted by one cycle of the sine wave. It is demonstrated both experimentally and theoretically that the ratio of the length of the bridge to its equivalent radius, defined as geometric mean of the radii at the peak and trough of the bridge, is always 2π for the asymmetric bridge close to rupture. Different with the symmetric evolution of the short bridge, the long asymmetric bridge pinches off first from the side near the bigger sessile drop and then from the other side, which endows the satellite droplet with a lateral momentum, resulting in the satellite re-collected by the sessile drop. The influence of the slenderness on the time interval among the asymmetric pinch-off, velocity, destination, and size of the satellite was investigated. A scaling law was proposed to describe the relationship between the lateral momentum of the satellite and the time interval between two pinch-off. This work is expected to benefit the utilizing or suppressing the satellite in practice.
Review on optical nonlinearity of group-IV semiconducting materials for all-optical processing
Authors: Cheng Chih-Hsien , Fu Cai-Syuan , Wang Huai-Yung , Set Sze Yun , Yamashita Shinji , Lin Gong-Ru
Published: August 2022

Group-IV semiconductor compounds with intense optical nonlinearity have emerged as a new branch of all-optical processing materials benefiting from the manufacturing compatibility with silicon electronic and photonic integrated circuits. Due to the chemical reforming on the bonding or precipitating feature of the compositional atoms in the membrane matrix, either the orbital hybridization or the quantum self-assembly of interstitial composites can be employed to reform the electronic and optical characteristics. The recent development on enhancing the nonlinear refractive indices of the group-IV semiconductor materials has revealed significant progress to accelerate the all-optical switching logic, which greatly reduces the energy consumption to enable the constitution of the advanced multi-logic gating and the entry-level photonic computing circuits. This work not only overviews the group-IV semiconductor photonic data processing elements but also prospects for the future direction of optical quantum computation and communication. To date, the nonlinear refractive indices of the group-IV semiconductor materials can be obtained as 10−8 to 10−16 cm2/W in the range between 300 and 10 000 nm in 2022. The wavelength conversion and data switching with bit rate beyond 25 Gbps have been achieved via nonlinear photonic waveguide components. By taking the non-stoichiometric SiC-made micro-ring waveguide as an example, the n2 as high as 3.05 × 10−14 cm2/W of the resonant SiC micro-ring gate is retrieved from the pump–probe analysis. The eye-diagram of the wavelength converted data in the micro-ring achieves its signal-to-noise and on/off-extinction ratios (SNR and ER) of 5.6 and 11.8 dB, while up to 25-Gbps all-optical data-format inversion with 4.8-dB SNR and 10.2-dB ER is also performed during an ultrafast switching within rising and falling time of less than 22 ps. Such all-optical data processing including both wavelength switching and format conversion in the highly nonlinear optical SiC waveguide resonator can achieve error-free operation with corresponding bit-error-ratios of lower than 1 × 10−5 at 25 Gbps after forward error correction.
Theoretical study on L–H+–L with identical donors: Short strong hydrogen bond or not?
Authors: Feng Wanwan , Li Dan , Cheng Longjiu
Published: August 2022

Short strong hydrogen bonds (SSHBs) play a crucial role in many chemical processes. Recently, as the representative of SSHBs, [F–H–F]− was experimentally observed. [F–H–F]− has a symmetric structure, which can be described as a H+ acid shared by two terminal F− donors (F−–H+–F−). To explore whether two identical donors are bound to result in SSHBs, we performed theoretical studies on a series of compounds (L–H+–L) with two identical electron donors (L corresponds to donors containing group 14, 15, 16, and 17 elements). The results show that identical donors do not definitely lead to SSHBs. Instead, typical hydrogen bonds also exist. Both electronegativity and basicity contribute to the patterns of hydrogen bonds, where more electronegative and weaker donors benefit to SSHBs. In addition, it was found that zero-point energies also respond to the hydrogen bonding systems. This systemic work is expected to provide more insights into SSHBs.
Higher order heat fluxes in a rarefied granular gas
Authors: Hong Andrew , Morris Aaron
Published: August 2022

Despite its general application, the Fourier's law of heat conduction is not always valid in dilute gases. One of the physical shortcomings of Fourier's law is the mismatch at the boundary; the temperature gradient in the Knudsen layer diverges in the boundary, but the heat flux does not. In this paper, we propose a more generalized constitutive relation for the heat flux to match the heat flux with the hydrodynamics in a rarefied granular gas. The proposed modified heat flux relation is then used to derive analytical solutions for the hydrodynamics of a granular gas bounded by equal and unequal temperature walls. The analytical solutions are then compared to direct simulation Monte Carlo simulations.
Coherent excitation energy transfer in model photosynthetic reaction center: Effects of non-Markovian quantum environment
Authors: Fang Jie , Chen Zi-Hao , Su Yu , Zhu Zi-Fan , Wang Yao , Xu Rui-Xue , Yan YiJing
Published: August 2022

Excitation energy transfer (EET) and electron transfer (ET) are crucially involved in photosynthetic processes. In reality, the photosynthetic reaction center constitutes an open quantum system of EET and ET, which manifests interplay of pigments, solar light, and phonon baths. So far, theoretical studies have been mainly based on master equation approaches in the Markovian condition. The non-Markovian environmental effect, which may play a crucial role, has not been sufficiently considered. In this work, we propose a mixed dynamic approach to investigate this open system. The influence of phonon bath is treated via the exact dissipaton equation of motion (DEOM), while that of photon bath is via the Lindblad master equation. Specifically, we explore the effect of non-Markovian quantum phonon bath on the coherent transfer dynamics and its manipulation on the current–voltage behavior. Distinguished from the results of the completely Markovian–Lindblad equation and those adopting the classical environment description, the mixed DEOM–Lindblad simulations exhibit transfer coherence up to a few hundred femtoseconds and the related environmental manipulation effect on the current. These non-Markovian quantum coherent effects may be extended to more complex and realistic systems and be helpful in the design of organic photovoltaic devices.
Plasmon-enhanced electrochemical oxidation of 4-(hydroxymethyl)benzoic acid
Authors: Qiu Jingjing , Boskin Daniel , Oleson Dallas , Wu Weiming , Anderson Marc
Published: August 2022

Plasmon-mediated electrocatalysis based on plasmonic gold nanoparticles (Au NPs) has emerged as a promising approach to facilitate electrochemical reactions with the introduction of light to excite the plasmonic electrodes. We have investigated the electrochemical oxidation of 4-(hydroxymethyl)benzoic acid (4-HMBA) on gold (Au), nickel (Ni), and platinum (Pt) metal working electrodes in alkaline electrolytes. Au has the lowest onset potential for catalyzing the electrooxidation of 4-HMBA among the three metals in base, whereas Pt does not catalyze the electrooxidation of 4-HMBA under alkaline conditions, although it is conventionally a good electrocatalyst for alcohol oxidation. Both 4-carboxybenzaldehyde and terephthalic acid are detected as the products of electrochemical oxidation of 4-HMBA on the Au working electrode by high-performance liquid chromatography . The electrodeposited Au NPs on indium tin oxide (ITO)-coated glass is further utilized as the working electrode for the 4-HMBA electrooxidation. With its broad absorption in the visible and near-infrared range, we show that the Au NPs on the ITO electrode could enhance the electrochemical oxidation of 4-HMBA under green and red LED light illuminations (505 and 625 nm). A possible reaction mechanism is proposed for the electrochemical oxidation of 4-HMBA on Au working electrodes in an alkaline electrolyte.
Efficient computation of
N
-point correlation functions in
D
dimensions
Authors: Philcox Oliver H. E. , Slepian Zachary
Published: August 2022

We present efficient algorithms for computing the
N
-point correlation functions (NPCFs) of random fields in arbitrary
D
-dimensional homogeneous and isotropic spaces. Such statistics appear throughout the physical sciences and provide a natural tool to describe stochastic processes. Typically, algorithms for computing the NPCF components have

O
(

n
N

)

complexity (for a dataset containing
n
particles); their application is thus computationally infeasible unless
N
is small. By projecting the statistic onto a suitably defined angular basis, we show that the estimators can be written in a separable form, with complexity

O
(

n
2

)

or

O
(

n
g

log
 

n
g

)

if evaluated using a Fast Fourier Transform on a grid of size

n
g

. Our decomposition is built upon the
D
-dimensional hyperspherical harmonics; these form a complete basis on the

(
D
−
1
)

sphere and are intrinsically related to angular momentum operators. Concatenation of

(
N
−
1
)

such harmonics gives states of definite combined angular momentum, forming a natural separable basis for the NPCF. As
N
and
D
grow, the number of basis components quickly becomes large, providing a practical limitation to this (and all other) approaches: However, the dimensionality is greatly reduced in the presence of symmetries; for example, isotropic correlation functions require only states of zero combined angular momentum. We provide a Julia package implementing our estimators and show how they can be applied to a variety of scenarios within cosmology and fluid dynamics. The efficiency of such estimators will allow higher-order correlators to become a standard tool in the analysis of random fields.