bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical investigation of distal charge separation in a perylenediimide trimer
Authors: Wang Ke , Xu Yihe , Xie Xiaoyu , Ma Haibo 
Published: April 2024

An exciton–phonon (ex–ph) model based on our recently developed block interaction product basis framework is introduced to simulate the distal charge separation (CS) process in aggregated perylenediimide (PDI) trimer incorporating the quantum dynamic method, i.e., the time-dependent density matrix renormalization group. The electronic Hamiltonian in the ex–ph model is represented by nine constructed diabatic states, which include three local excited (LE) states and six charge transfer (CT) states from both the neighboring and distal chromophores. These diabatic states are automatically generated from the direct products of the leading localized neutral or ionic states of each chromophore’s reduced density matrix, which are obtained from ab initio quantum chemical calculation of the subsystem consisting of the targeted chromophore and its nearest neighbors, thus considering the interaction of the adjacent environment. In order to quantum-dynamically simulate the distal CS process with massive coupled vibrational modes in molecular aggregates, we used our recently proposed hierarchical mapping approach to renormalize these modes and truncate those vibrational modes that are not effectively coupled with electronic states accordingly. The simulation result demonstrates that the formation of the distal CS process undergoes an intermediate state of adjacent CT, i.e., starts from the LE states, passes through an adjacent CT state to generate the intermediates (∼200 fs), and then formalizes the targeted distal CS via further charge transference (∼1 ps). This finding agrees well with the results observed in the experiment, indicating that our scheme is capable of quantitatively investigating the CS process in a realistic aggregated PDI trimer and can also be potentially applied to exploring CS and other photoinduced processes in larger systems.
The Mysteries of Summer Camp, Chronic Illness, and Magic
Authors: Rendlen Chelsea I. 
Published: April 2024

Summary
Never was the dynamic and complexities of living with chronic mystery illness more apparent than in the summer camp setting. My first year as a counselor brought me face-to-face with the realities of my physical state and how I related to my body in the summer camp context. Now, as an Executive Director of a summer camp, spurred on by the memories of what I endured, and committed to making the space different, I weigh the impact of changing camps, and question what parts of the challenge are necessary to preserve “camp magic”?

Information
© CAB International 2024
Quantum geometrodynamics revived: II. Hilbert space of positive definite metrics
Authors: Lang Thorsten , Schander Susanne 
Published: April 2024

Abstract
This paper represents the second in a series of works aimed at reinvigorating the quantum geometrodynamics program. Our approach introduces a lattice regularization of the hypersurface deformation algebra, such that each lattice site carries a set of canonical variables given by the components of the spatial metric and the corresponding conjugate momenta. In order to quantize this theory, we describe a representation of the canonical commutation relations that enforces the positivity of the operators

q
^

a
b

s
a

s
b

for all choices of s. Moreover, symmetry of

q
^

a
b

and

p
^

a
b

is ensured. This reflects the physical requirement that the spatial metric should be a positive definite, symmetric tensor. To achieve this end, we resort to the Cholesky decomposition of the spatial metric into upper triangular matrices with positive diagonal entries. Moreover, our Hilbert space also carries a representation of the vielbein fields and naturally separates the physical and gauge degrees of freedom. Finally, we introduce a generalization of the Weyl quantization for our representation. We want to emphasize that our proposed methodology is amenable to applications in other fields of physics, particularly in scenarios where the configuration space is restricted by complicated relationships among the degrees of freedom.
Quantum geometrodynamics revived I. Classical constraint algebra
Authors: Lang Thorsten , Schander Susanne 
Published: April 2024

Abstract
In this series of papers, we present a set of methods to revive quantum geometrodynamics which encountered numerous mathematical and conceptual challenges in its original form promoted by Wheeler and De Witt. In this paper, we introduce the regularization scheme on which we base the subsequent quantization and continuum limit of the theory. Specifically, we employ the set of piecewise constant fields as the phase space of classical geometrodynamics, resulting in a theory with finitely many degrees of freedom of the spatial metric field. As this representation effectively corresponds to a lattice theory, we can utilize well-known techniques to depict the constraints and their algebra on the lattice. We are able to compute the lattice corrections to the constraint algebra. This model can now be quantized using the usual methods of finite-dimensional quantum mechanics, as we demonstrate in the following paper. The application of the continuum limit is the subject of a future publication.
External defect immune high quality resonances in microwave topological ring resonator
Authors: Jena Geetanjali , Kulkarni Gopal , Varshney R K , Roy Chowdhury Dibakar 
Published: April 2024

Abstract
Recently, topological ring resonators (TRRs) have emerged as a burgeoning platform for exploring the topological aspects of photonic systems and resonator dynamics. Integrating topology into cavity dynamics offers a new paradigm to unveil various fascinating phenomena, including backscattering immune wave propagation, unidirectional transmission, and reflection-free energy transport. With this background, we provide a scheme to achieve robust high Q resonances in a metal-based topological photonic crystal (TPC) exhibiting defect-immune spectral characteristics in the microwave frequency regime. Coupled with a ring resonator, our proposed topological platform demonstrates the excitation of high Q resonances in the range 230–540. Except for the resonances, a robust microwave transmission (

∼

0

dB

) is observed in the investigated frequency regime 7.1–7.6 GHz depicting a minimal scattering loss even around the sharp corners of the ring resonator. Further, the topological robustness of the propagating microwave and the excited resonances are examined by introducing an external Si obstacle at the domain interface. Our study reveals a minimal transmission loss (

<

7

dB

) and negligible perturbation (

<

8
%

) in the Q factors when the Si barrier placed towards the input end of the straight topological waveguide. In addition, we have also demonstrated a novel way of exciting new resonances in the ring resonator that holds considerable promise for designing a TRR-based all-pass notch filter in the microwave regime.
Capillary-based, multifunctional manipulation of particles and fluids via focused surface acoustic waves
Authors: Pei Zhichao , Tian Zhenhua , Yang Shujie , Shen Liang , Hao Nanjing , Naquin Ty D , Li Teng , Sun Lining , Rong Weibin , Huang Tony Jun 
Published: April 2024

Abstract
Surface acoustic wave (SAW)-enabled acoustofluidic technologies have recently attracted increasing attention for applications in biology, chemistry, biophysics, and medicine. Most SAW acoustofluidic devices generate acoustic energy which is then transmitted into custom microfabricated polymer-based channels. There are limited studies on delivering this acoustic energy into convenient commercially-available glass tubes for manipulating particles and fluids. Herein, we have constructed a capillary-based SAW acoustofluidic device for multifunctional fluidic and particle manipulation. This device integrates a converging interdigitated transducer to generate focused SAWs on a piezoelectric chip, as well as a glass capillary that transports particles and fluids. To understand the actuation mechanisms underlying this device, we performed finite element simulations by considering piezoelectric, solid mechanic, and pressure acoustic physics. This experimental study shows that the capillary-based SAW acoustofluidic device can perform multiple functions including enriching particles, patterning particles, transporting particles and fluids, as well as generating droplets with controlled sizes. Given the usefulness of these functions, we expect that this acoustofluidic device can be useful in applications such as pharmaceutical manufacturing, biofabrication, and bioanalysis.
Electronic properties of polyethylene naphthalate as derived from photo-stimulated discharge, luminescence experiments and quantum chemical calculation
Authors: Mendoza Lopez Duvan , Teyssedre Gilbert , Boudou Laurent , Berquez Laurent , Laurent Christian , Iwata Shinya , Takada Tatsuo 
Published: April 2024

Abstract
The electronic properties of thin films of poly(ethylene 2,6-naphthalate)—PEN, are investigated based on their photo-physical (optical absorption, photoluminescence) and electrical (space charge distribution, photo-stimulated discharge) behavior. Photo-stimulated currents are associated with optical absorption of the material leading to space charge dissipation as demonstrated by space charge distribution measurement. Based on this set of experimental results and quantum chemical calculation performed on PEN macromolecular system, we propose a new scheme for the electronic levels of PEN. This scheme allows understanding the mechanisms at play in photo-stimulated discharge. One of the main conclusions of our work is that photo-stimulated current measurements do not probe the energy level of traps. Detrapping of charges results from a two-step process where the photon energy is absorbed by chromophores that restitute a part of this energy to trapped charges through various mechanisms. Moreover, the new scheme allows discussing the components of the luminescence excited under different stresses, being electric field, electronic and UV irradiation, charge recombination and thermal activation.
A versatile method for exploring the magnetooptical properties of polar saturated and unsaturated ferromagnetic metallic thin films
Authors: Patra Rajkumar , Sharma Apoorva , Stöcker Hartmut , Monecke Manuel , Salvan Georgeta , Mattheis Roland , Schmidt Heidemarie 
Published: April 2024

Abstract
Polar unsaturated ferromagnetic thin films are promising for low-power and high-speed nonvolatile resistive and optical memories. Here we measure the magnetooptical (MO) response of polar unsaturated Co90Fe10 and Co40Fe40B20 thin films in the spectral range from 400 nm to 1000 nm using vector MO generalized ellipsometry (VMOGE) in an out-of-plane applied magnetic field of ±0.4 T where magnetization of the ferromagnetic (FM) thin film is not saturated. Using magnetooptical simulation software (MagOpS®), we extract the complex MO coupling constant (
Q
) of the polar unsaturated FM thin films from difference spectra of VMOGE data recorded in a polar configuration at Hz
= +0.4 T and Hz
= −0.4 T. The presented approach opens a path to determine
Q
of both polar saturated and polar unsaturated FM thin films for simulating the MO properties of application-relevant optical memory multilayer structures.
Simulation comparison of the positive and negative surface discharges induced by metal particles in a plate–surface–plate structure under DC excitation in atmospheric air
Authors: Jiang Hui , Lai Yundong , Gong Ziyi , Han Yufei , Shao Tao 
Published: April 2024

Abstract
Surface discharge induced by metal particles is a common insulation failure in many high-voltage equipment. In order to further understand the mechanisms of this surface discharge, a 2D simulation model of a plate–surface–plate structure with a pin is established and verified by experiments in this paper to simulate the actual discharge configurations, and the evolution characteristics of the positive and negative surface discharges are compared. The evolutions of both positive and negative discharges could be divided into two phases: the bridging phase and the expansion phase. As the electric field in the gap between the streamer and the dielectric surface is strengthened by the effect of the space charge, the ionization sources and the secondary electrons excited on the dielectric surface, the dielectric surface presents attraction to the streamer, and subsequently the two streamer routes first touch the dielectric surface and then arrive at the grounding electrode. However, the channel branching is the most distinctive characteristic of the positive and negative discharges. In the positive discharge, the channel first branches, then merges, and finally expands, and the gaps of pin to dielectric surface and pin to grounding electrode are broken down by two slender positive branches, respectively. The negative discharge presents a stout channel without branching, which develops and expands simultaneously. This is ascribed to the thinner space charge layer, the weaker shielding effect of the internal electric field and the more active movement of the internal charges in the positive discharge. Another important factor for the discharge branching is the appropriate matching of the sheath thickness and the curvature radius of the channel’s head.
Analysis of the impact of edge diffraction on the manipulation of photonic nanojets and photonic hooks using an energy-based model in diffraction-based structures
Authors: Xu Ji , Li Sheng , Wang Jun , Zhang Baifu , Yao Han , Chi Tiantian , Cheng Huichao , Pang Ting , Lu Yunqing , Liu Ning 
Published: April 2024

Abstract
Photonic nanojets (PNJs) and photonic hooks (PHs) are two significant effects in Mesotronics. However, it is difficult to analyze and control the two phenomena generated by diffraction-based structures, such as rectangles and right-angled trapezoids, using diffraction theory. This work focuses on the modulation of incident fields by edge diffraction and the reconstruction of energy distribution, and proposes a model based on energy flows and energy reconstruction, called the ‘energy-based model’, to analyze the formation of PNJs and PHs through such structures. This model reveals that the morphology of PNJ and PH originates from the contributions of different regions of the incident energy, especially the crucial influence of edge diffraction, and successfully clarifies the modulation mechanism of the near-field and far-field regions of PNJ, as well as the tailoring mechanism of the two arms of PH. On the one hand, the model provides reasonable and intuitive explanations for the control of energy flow paths resulting from edge diffraction in rectangles and their variants with different parameters on the generation of PNJs and PHs. On the other hand, it also serves as a basis for reverse design. By adjusting energy flow and energy reconstruction through alterations in incident conditions or structural shapes, PHJs and PHs can be tailored easily and flexibly. The model is also been validated to be applicable in explaining many reported works. The results indicate that the ‘energy-based model’, which describes the energy flow paths resulting from edge diffraction, offers intuitive, convenient, and predictive advantages in analyzing the morphological variations of PNJs and PHs generated by diffraction-based structures, such as rectangles, trapezoids, and their variants. This provides a valuable reference for relevant research on Mesotronics.
Atomistic simulations of the interaction of edge dislocations with β-Nb precipitates in Zr-Nb alloys
Authors: Lin Junru , Chen Shuaijie , Bai Yiding , Zhang Shuo , Wang Tieshan , Zhao Jiangtao 
Published: April 2024

Abstract
Experiments have shown that precipitation can affect the mechanical properties of zirconium alloy, but the interaction mechanism between dislocations and Nb precipitates in zirconium alloys is still unclear. Thus, a systematic molecular dynamics study was performed to investigate the interaction between edge dislocations and Nb precipitates. It was found that the dislocation passed through Nb precipitate by shear mechanism or bypass mechanism of forming jogs, and the critical resolved shear stress increased with the diameter of the precipitate. After completion of the interaction, dislocations formed jogs due to climb when the precipitates were larger than 2 or 3 nm. Some atoms in the precipitate were more disordered after dislocation shearing, and dislocation fragments were generated around the precipitate, both of which lead to the precipitate hardening. The calculation of obstacle strength further confirmed that unsheared Nb precipitates until hundreds of nanometers were the weak obstacle for dislocations.
Role of gas composition in weakened nonlinear standing wave excitation and improved plasma radial uniformity in very-high-frequency asymmetric capacitive Ar/CF4 discharges
Authors: Zhou Fang-Jie , Zhang Yu-Ru , Zhao Kai , Wen De-Qi , Wang You-Nian 
Published: April 2024

Abstract
The higher harmonics generated by nonlinear sheath motion would enhance the standing wave effect, and thus lead to center-peaked plasma density profile in very-high-frequency (VHF) capacitive discharges. In this work, a nonlinear transmission line (NTL) model introduced in Zhou et al (2021 Plasma Sources Sci. Technol.
30 125017) has been extended, with radial transport of various particles and nonlinear sheath motion into account, to investigate the effects of CF4 fraction

α

on the nonlinear standing wave excitation and plasma radial uniformity in VHF (60 MHz) capacitively coupled Ar/CF4 plasmas at 3 Pa. The results indicate that for pure Ar discharges (i.e.

α
=

0%), the nonlinearly excited harmonics with short wavelength significantly enhance the electron power absorption at the radial center, resulting in a pronounced central-high plasma density profile. As

α

increases, the high-order harmonics are gradually damped due to the increase of resistance, as well as the longer wavelength caused by thicker sheath thickness. Thus, the radial profile of the electron absorbed power density shifts from center-peak to edge-high. Besides, at the radial center, the electron density and Ar+ ion density decrease with

α

, CF3
+ ion density shows an increasing trend, while F− ion density initially rises and then decreases. Moreover, the density profiles of all the species become more uniform at higher CF4 fraction, due to the suppressed nonlinear standing wave excitation and the longer wavelength of the nonlinear harmonics.
Spatially fractionated radiation therapy: a critical review on current status of clinical and preclinical studies and knowledge gaps
Authors: Prezado Yolanda , Grams Michael , Jouglar Emmanuel , Martínez-Rovira Immaculada , Ortiz Ramon , Seco Joao , Chang Sha 
Published: April 2024

Abstract
Spatially fractionated radiation therapy (SFRT) is a therapeutic approach with the potential to disrupt the classical paradigms of conventional radiation therapy. The high spatial dose modulation in SFRT activates distinct radiobiological mechanisms which lead to a remarkable increase in normal tissue tolerances. Several decades of clinical use and numerous preclinical experiments suggest that SFRT has the potential to increase the therapeutic index, especially in bulky and radioresistant tumors. To unleash the full potential of SFRT a deeper understanding of the underlying biology and its relationship with the complex dosimetry of SFRT is needed. This review provides a critical analysis of the field, discussing not only the main clinical and preclinical findings but also analyzing the main knowledge gaps in a holistic way.
Patient-specific temperature distribution prediction in laser interstitial thermal therapy: single-irradiation data-driven method
Authors: Gao Tingting , Liang Libin , Ding Hui , Wang Guangzhi 
Published: April 2024

Abstract
Laser interstitial thermal therapy (LITT) is popular for treating brain tumours and epilepsy. The strict control of tissue thermal damage extent is crucial for LITT. Temperature prediction is useful for predicting thermal damage extent. Accurately predicting in vivo brain tissue temperature is challenging due to the temperature dependence and the individual variations in tissue properties. Considering these factors is essential for improving the temperature prediction accuracy. Objective. To present a method for predicting patient-specific tissue temperature distribution within a target lesion area in the brain during LITT. Approach. A magnetic resonance temperature imaging (MRTI) data-driven estimation model was constructed and combined with a modified Pennes bioheat transfer equation (PBHE) to predict patient-specific temperature distribution. In the PBHE for temperature prediction, the individual specificity and temperature dependence of thermal tissue properties and blood perfusion, as well as the individual specificity of optical tissue properties were considered. Only MRTI data during one laser irradiation were required in the method. This enables the prediction of patient-specific temperature distribution and the resulting thermal damage region for subsequent ablations. Main results. Patient-specific temperature prediction was evaluated based on clinical data acquired during LITT in the brain, using intraoperative MRTI data as the reference standard. Our method significantly improved the prediction performance of temperature distribution and thermal damage region. The average root mean square error was decreased by 69.54%, the average intraclass correlation coefficient was increased by 37.5%, the average Dice similarity coefficient was increased by 43.14% for thermal damage region prediction. Significance. The proposed method can predict temperature distribution and thermal damage region at an individual patient level during LITT, providing a promising approach to assist in patient-specific treatment planning for LITT in the brain.