bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and reactivity of 9,10-bis(4-trimethylsilylethynylbuta-1,3-diynyl)anthracene derived chromophores
Authors: Frogley Benjamin J. , Hill Anthony F.
Published: March 2023

9,10-Bis(4-trimethylsilylethynyl-butadiynyl)anthracene serves as a convenient building block for the construction of new butadiynyl and hexatriynyl anthracenes terminated by metal complexes, arenes, haloarenes and alkynyl functionalities.
Development and study of a bifunctional photocatalyst based on SAPO-34 molecular sieve
Authors: Wang Run-quan , Chen Wan-ping , Zhang Yue-rong , Song Kai , Tian Yuan , Li Jia-xian , Shi Gao-feng , Wang Guo-ying
Published: March 2023

A new bifunctional photocatalyst was constructed from a modified SAPO-34 molecular sieve successfully connected with BiVO4crystals through O bridges.
Integrating molybdenum into zinc vanadate enables Zn3V2MoO8 as a high-capacity Zn-supplied cathode for Zn-metal free aqueous batteries
Authors: Wang Gang , Kuang Quan , Jiang Pan , Fan Qinghua , Dong Youzhong , Zhao Yanming
Published: March 2023

The mixed transition-metal spinel Zn3V2MoO8 can provide a high capacity of 360.3 mA h g−1 at 100 mA g−1, which is the state-of-the-art in existing Zn-supplied cathodes. The Zn-metal free Zn3V2MoO8||9,10AQ battery reveals decent cycle performance.
Effects of end groups and entanglements on crystallization and melting behaviors of poly(ε-caprolactone)
Authors: Zhu Liuyong , Li Jingqing , Li Hongfei , Liu Binyuan , Chen Jizhong , Jiang Shichun
Published: March 2023

Melting of the metastable semicrystalline structure of PCL with restricted dynamics is a multistep evolution process involving multiple nanoscale crystalline structures.
Surface fully functionalized metal chalcogenide nanowires for highly sensitive H2S sensing
Authors: Jin Ying-Xue , Chen Jie , Chen Yong-Jun , Deng Wei-Hua , Ye Xiao-Liang , Wang Guan-E , Xu Gang
Published: March 2023

Surface fully functionalized one-dimensional nanowire was designed for the highly sensitive and specific detection of H2S under visible light.
A special issue in Essays in Biochemistry on astrocytes—more than a neuronal support network
Authors: Bolaños Juan P.
Published: March 2023

Astrocytes are a type of non-neuronal, glial cells, anatomically placed in the intersection between the brain blood vessels and other neural cells—including neurons. Such a strategic situation confers these cells a unique opportunity to sense circulating molecules and adapt according to different organismal conditions. By acting as sentinel cells, astrocytes thus co-ordinate gene expression profiles, immune responses, signal transduction pathways, and metabolic programs that play essential roles in the formation of brain circuits to modulate neurotransmission and higher-order organismal functions.
THz imaging enhancement based on Noise2Noise algorithm
Authors: Wang Tianhe , Huang Xuejun , Ding Jinshan , Zhang Yuhong
Published: March 2023

Terahertz (THz) imaging has an outstanding advantage of high resolution due to the high frequency and has promising potential in VideoSAR. However, limited to the THz source power and the air absorption, the THz image usually has a low SNR and is susceptible to noise in remote sensing and imaging. In order to improve the quality of THz images, a THz image enhancement method is proposed based on the noise2noise strategy. The THz images are reconstructed using the AFBP algorithm. They are organized as noisy image pairs and filtered with a mask to remove the influence of moving targets. Then, the Noise2Noise network is constructed based on the CNN network and takes the noisy image pair as input and reference. In the training stage, 1000 noisy image pairs are used as the training set and 100 noisy images are used as the test set to verify the performance of the proposed method. The experimental results of real VideoSAR data have demonstrated that the proposed method is capable of suppressing noise and enhancing the THz image.
High temperature energy storage and release properties of polyimide nanocomposites simulated by considering charge trapping effects
Authors: Wang Poxin , Min Daomin , Song Xiaofan , Gao Ziwei , Hao Yutao , Wang Shihang , Liu Wenfeng
Published: March 2023

Dielectric energy storage capacitors with excellent high temperature resistance are essential in fields such as aerospace and pulse power. However, common high‐temperature resistant polymers such as polyimide (PI) and polyether sulfone have low energy storage densities and energy efficiencies at high temperature, which are greatly limited in practical applications. The polymer nanocomposites prepared by doping modification can regulate the charge injection and transport process, and improve the high‐temperature energy storage performance. However, the quantitative relationship between charge injection and charge trapping and the energy storage performance of linear polymer nanocomposites still needs further study. An energy storage and release model considering the charge trapping effects is constructed by the authors. We simulate the high‐temperature energy storage properties of polyimide nanocomposite dielectrics (PI PNCs) with different charge injection barriers and trap parameters at 150°C. A triangular voltage is applied to the electrodes at both sides of the PI PNCs, the electric displacement‐electric field loop is simulated, and the discharged energy densities and energy efficiencies are calculated. The simulation results are consistent with the experimental results. Increasing the charge injection barrier, deep trap energy and deep trap density can effectively reduce the charge injection and the carrier mobility, thereby improving the discharged energy densities and energy efficiencies of dielectric capacitors. In the case of low charge injection barrier (1.3 eV), with the increase of deep trap energy (0.7–1.5 eV) and deep trap density (1 × 1021–1 × 1025 m−3), the discharged energy density changes from 0.20 to 1.44 Jcm−3, the energy efficiency changes from 9.0% to 99.9%, and the high‐temperature energy storage performance improves significantly. This research provides theoretical and model support for the improvement of the high‐temperature energy storage performance of nanocomposites.
Assessment of energy losses in power distribution systems with individual prosumers and energy communities
Authors: Diahovchenko Illia , Petrichenko Lubov
Published: March 2023

Achieving the energy transition target will require the extensive engagement of consumers and the private sector in investment and operation of renewable‐based power systems. Support of individual prosumers and proliferation of energy communities are efficient ways to implement this engagement. To facilitate smooth integration of prosumers with photovoltaic (PV) installations, while satisfying effective operation of the power distribution system (PDS), it is important to fundamentally assess energy losses for different grid development scenarios. In this paper, the energy losses are compared for two alternatives: (a) when prosumers with PV installations act as individual grid users, and (b) when prosumers become participants of a solar energy community. To achieve this goal, modeling of loads, prosumers’ behavior and PV generation was performed. Furthermore, it has been analyzed how the physical topology of the distribution network can be harmonized with the underlying bidirectional power flows for each alternative, while complying with system constraints. The IEEE 123 Node Test Feeder was employed to capture the performance of the PDS and to estimate the energy loss with various penetration levels of prosumers. The results indicate that reduction of energy losses is only possible until a certain PV penetration level, after which additional PV capacities cause increase in energy losses and complicate the PDS's operation. Lower energy losses were supervised for the cases with dispersed PV generation, compared to the cases focused on energy communities. This means that the PDS demonstrates better tolerance to evenly distributed prosumers, rather than to single sources of a larger scale installed in one node. The outputs of this study will help the energy planners and utilities in improving performance of the PDS in terms of loss minimization and loadability maximization.
Accurate modelling of the Lyman-α coupling for the 21-cm signal, observability with NenuFAR, and SKA
Authors: Semelin B. , Mériot R. , Mertens F. , Koopmans L. V. E. , Aubert D. , Barkana R. , Fialkov A. , Munshi S. , Ocvirk P.
Published: March 2023

The measurement of the 21 cm signal from the Cosmic Dawn is a major goal for several existing and upcoming radio interferometers such as NenuFAR and SKA. During this era before the beginning of the Epoch of Reionisation, the signal is more difficult to observe due to brighter foregrounds, but it reveals additional information on the underlying astrophysical processes encoded in the spatial fluctuations of the spin temperature of hydrogen. To interpret future measurements, controlling the level of accuracy of the Lyman-α flux modelling is mandatory. In this work, we evaluate the impact of various approximations that exist in the main fast modelling approach compared to the results of a costly full radiative transfer simulation. The fast SPINTER code, presented in this work, computes the Lyman-α flux including the effect of wing scatterings for an inhomogeneous emissivity field, but assuming an otherwise homogeneous expanding universe. The LICORICE code computes the full radiative transfer in the Lyman-α line without any substantial approximation. We find that the difference between homogeneous and inhomogeneous gas density and temperature is very small for the computed flux. On the contrary, neglecting the effect of gas velocities produces a significant change in the computed flux. We identify the causes (mainly Doppler shifts due to velocity gradients) and quantify the magnitude of the effect in both an idealised setup and a realistic cosmological situation. We find that the amplitude of the effect, up to a factor of ∼2 on the 21 cm signal power spectrum on some scales (depending on both other model parameters and the redshift), can be easily discriminated with an SKA-like survey and can already be approached, particularly for exotic signals, by the ongoing NenuFAR Cosmic Dawn Key Science Program.
A new dynamical modeling of the WASP-47 system with CHEOPS observations
Authors: Nascimbeni V. , Borsato L. , Zingales T. , Piotto G. , Pagano I. , Beck M. , Broeg C. , Ehrenreich D. , Hoyer S. , Majidi F. Z. , Granata V. , Sousa S. G. , Wilson T. G. , Van Grootel V. , Bonfanti A. , Salmon S. , Mustill A. J. , Delrez L. , Alibert Y. , Alonso R. , Anglada G. , Bárczy T. , Barrado D. , Barros S. C. C. , Baumjohann W. , Beck T. , Benz W. , Bergomi M. , Billot N. , Bonfils X. , Brandeker A. , Cabrera J. , Charnoz S. , Collier Cameron A. , Csizmadia Sz. , Cubillos P. E. , Davies M. B. , Deleuil M. , Deline A. , Demangeon O. D. S. , Demory B.-O. , Erikson A. , Fortier A. , Fossati L. , Fridlund M. , Gandolfi D. , Gillon M. , Güdel M. , Isaak K. G. , Kiss L. L. , Laskar J. , Lecavelier des Etangs A. , Lendl M. , Lovis C. , Luque R. , Magrin D. , Maxted P. F. L. , Mordasini C. , Olofsson G. , Ottensamer R. , Pallé E. , Peter G. , Piazza D. , Pollacco D. , Queloz D. , Ragazzoni R. , Rando N. , Ratti F. , Rauer H. , Ribas I. , Santos N. C. , Scandariato G. , Ségransan D. , Simon A. E. , Smith A. M. S. , Steinberger M. , Steller M. , Szabó Gy. M. , Thomas N. , Udry S. , Venturini J. , Walton N. A. , Wolter D.
Published: March 2023

Among the hundreds of known hot Jupiters (HJs), only five have been found to have companions on short-period orbits. Within this rare class of multiple planetary systems, the architecture of WASP-47 is unique, hosting an HJ (planet-b) with both an inner and an outer sub-Neptunian mass companion (-e and -d, respectively) as well as an additional non-transiting, long-period giant (-c). The small period ratio between planets -b and -d boosts the transit time variation (TTV) signal, making it possible to reliably measure the masses of these planets in synergy with the radial velocity (RV) technique. In this paper, we present new space- and ground-based photometric data of WASP-47b and WASP-47-d, including 11 unpublished light curves from the ESA mission CHaracterising ExOPlanet Satellite (CHEOPS). We analyzed the light curves in a homogeneous way together with all the publicly available data to carry out a global N-body dynamical modeling of the TTV and RV signals. We retrieved, among other parameters, a mass and density for planet -d of Md = 15.5 ± 0.8 M⊕ and ρd = 1.69 ± 0.22 g cm−3, which is in good agreement with the literature and consistent with a Neptune-like composition. For the inner planet (-e), we found a mass and density of Me = 9.0 ± 0.5 M⊕ and ρe = 8.1 ± 0.5 g cm−3, suggesting an Earth-like composition close to other ultra-hot planets at similar irradiation levels. Though this result is in agreement with previous RV plus TTV studies, it is not in agreement with the most recent RV analysis (at 2.8σ), which yielded a lower density compatible with a pure silicate composition. This discrepancy highlights the still unresolved issue of suspected systematic offsets between RV and TTV measurements. In this paper, we also significantly improve the orbital ephemerides of all transiting planets, which will be crucial for any future follow-up.
Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Diverse outcomes of binary–disk interactions
Authors: Zhang Yapeng , Ginski Christian , Huang Jane , Zurlo Alice , Beust Hervé , Bae Jaehan , Benisty Myriam , Garufi Antonio , Hogerheijde Michiel R. , van Holstein Rob G. , Kenworthy Matthew , Langlois Maud , Manara Carlo F. , Pinilla Paola , Rab Christian , Ribas Álvaro , Rosotti Giovanni P. , Williams Jonathan
Published: March 2023

Context. Circumstellar disks play an essential role in the outcomes of planet formation. Disks do not evolve in isolation, as about half of solar-type stars were born in binary or multiple systems. The presence of stellar companions modifies the morphology and evolution of disks, potentially resulting in a different planet population. Resolving disks in binary systems provides the opportunity to examine the influence of stellar companions on the outcomes of planet formation.

Aims. We aim to investigate and compare disks in stellar multiple systems with near-infrared scattered-light imaging as part of the Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS) large program. In particular, we present observations of circumstellar disks in three systems, namely, CHX 22, S CrA, and HP Cha.

Methods. We used polarimetric differential imaging with SPHERE/IRDIS at the VLT to search for scattered light from the circum-stellar disks in these multiple systems. We performed astrometric and orbit analyses for the stellar companions using archival HST, VLT/NACO, and SPHERE data to better understand the interplay between disks and companions.

Results. Combined with the age and orbital constraints, the observed disk structures in scattered light provide insights into the evolutionary history and the impact of the stellar companions. The small grains in CHX 22 form a tail-like structure surrounding the close binary, which likely results from a close encounter and capture of a cloudlet. S CrA shows intricate structures (tentative ringed and spiral features) in the circumprimary disk as a possible consequence of perturbations by companions. The circumsecondary disk is truncated and connected to the primary disk via a streamer, suggesting tidal interactions. In HP Cha, the primary disk is less disturbed and features a tenuous streamer, through which the material flows toward the companions.

Conclusions. The comparison of the three systems spans a wide range of binary separation (50–500 au) and illustrates the decreasing influence on disk structures with the distance of companions. This agrees with the statistical analysis of the exoplanet population in binaries, that planet formation is likely obstructed around close binary systems, while it is not suppressed in wide binaries.
Intraoperative Azetabulumfraktur
Authors: Hipfl Christian , Perka Carsten
Published: March 2023

Die intraoperative Azetabulumfraktur ist eine seltene Komplikation in der
Hüfttotalendoprothetik. Sie tritt hauptsächlich als Folge der Impaktion einer zementfreien
Press-fit-Pfanne auf. Risikofaktoren sind eine verminderte Knochenqualität, ein stark
sklerotischer Knochen und ein zu groß gewähltes Press-fit. Der Zeitpunkt der Diagnose bestimmt
das therapeutische Vorgehen. Intraoperativ erfasste Frakturen sollten immer mit einer
entsprechenden Stabilisierung behandelt werden. Postoperativ entscheidet die Stabilität der
Implantate sowie der Fraktur darüber, ob zunächst ein konservatives Behandlungsprozedere
möglich ist. Die meisten intraoperativ diagnostizierten Azetabulumfrakturen sind mit einer
Multi-Hole-Pfanne mit zusätzlichen in den unterschiedlichen Azetabulumregionen verankernden
Schrauben zu versorgen. Bei großen Hinterwandfragmenten oder einer Beckendiskontinuität ist
primär eine Plattenosteosynthese des hinteren Pfeilers indiziert. Alternativ kann eine
Cup-Cage-Rekonstruktion zur Anwendung kommen. Insbesondere beim älteren Patienten muss das
Therapieziel die schnelle Mobilisierung durch eine adäquate Primärstabilität sein, um das
Komplikations-, Revisions- und Mortalitätsrisiko auf ein Minimum zu reduzieren.
John P. Caffey, 1895–1978
Authors: Beighton Peter , Vanhoenacker Filip M.
Published: March 2023

This history page in the series “Leaders in MSK Radiology” is dedicated to the achievements of Dr. John Caffey, whose name is associated with infantile cortical hyperostosis, also known as Caffey's disease.
Addenbrooke's cognitive examination III: diagnostic utility for detecting mild cognitive impairment and dementia in Parkinson's disease
Authors: Sousa Nariana Mattos Figueiredo , Brucki Sonia Maria Dozzi
Published: March 2023

Background Cognitive deficit in Parkinson disease (PD) is an important cause of functional disability in these patients and early detection, with sensitive instruments, can contribute to longitudinal monitoring.

Objective To investigate the diagnostic accuracy, sensitivity, and specificity of the Addenbrooke's Cognitive Examination-III in patients with PD, using the comprehensive neuropsychological battery as reference method.

Methods Cross-sectional, observational, case-control study. Setting: rehabilitation service. A total of 150 patients and 60 healthy controls matched for age, sex, and education. For level I assessment, Addenbrooke Cognitive Examination (ACE-III) was used. Level II assessment used a comprehensive neuropsychological battery of standardized tests for this population. All patients remained in on-state during the study. The diagnostic accuracy of the battery was investigated through the receiver operating characteristic (ROC) analysis.

Results The clinical group was divided into 3 subgroups: normal cognition in Parkinson's disease (NC-PD-16%), mild cognitive impairment due to Parkinson's disease (MCI-PD-69.33%), and dementia due to Parkinson's disease (D-PD-14.66%). ACE-III optimal cutoff scores for detecting MCI-PD and D-PD were 85/100 (sensitivity 58.65%, specificity 60%) and 81/100 points (sensitivity 77.27%, specificity 78.33%), respectively. Age was inversely associated with the performance of the scores (totals and domains of the ACE-III), while the level of education had a significantly positive correlation in the performance of these scores.

Conclusions ACE-III is a useful battery for assessing the cognitive domains and to differentiate individuals with MCI-PD and D-PD from healthy controls. Future research, in a community setting, is necessary to provide discriminatory capacity of ACE-III in the different severities of dementia.
Compartment Syndrome and Its Validation in Skeletal Injuries
Authors: Agrawal Prabhat , Girish M. , Ramanathan Ashok T. , Sudhakaran M. , Murali S.M.
Published: March 2023

Background

Compartment syndrome, a potential limb-threatening condition in acute traumatic situations following different modalities of injury, may lead to irreversible damage or even life risk later. Its differential time-bound clinical presentation with added observer bias on available invasive and noninvasive diagnostic modalities influences the decision-making and undue delay for early intervention toward limb salvage procedure.

Results

Thirty-two patients were included in our study with mean age of 36; males (18; 56.3%) were more injured than females (14; 43.8%) and left limb (17; 53.1%) was more involved than right (15; 46.9%). Mean calf muscle measurement of total injured limb with relation to immediate time was 39.9 cm, after 1 hour was 40.69 cm, after 2 hours was 41.06 cm, and after 3 hours was 41.40 cm; 95% confidence interval was found to be statistically significant. Three patients (9%) underwent emergency decompression fasciotomy, with an average mean of 41.4 cm for injured limbs against 38.5 cm in control limb.

Conclusions

Compartment syndrome is an acute emergency with potential irreversible damage when undiagnosed. Bias on diagnosis evolves around observer skills and clinical invasive and noninvasive methods, with differential statistical results pertaining to its decision-making for emergency fasciotomy.
Society of Gastrointestinal Endoscopy of India Consensus Guidelines on Endoscopic Ultrasound-Guided Biliary Drainage: Part I (Indications, Outcomes, Comparative Evaluations, Training)
Authors: Rai Praveer , Udawat Priyanka , Chowdhary Sudipta Dhar , Gunjan Deepak , Samanta Jayanta , Bhatia Vikram , Singla Vikas , Mukewar Saurabh , Mehta Nilay , Achanta Chalapathi Rao , Dalal Ankit , Sahu Manoj Kumar , Balekuduru Avinash , Bale Abhijit , Basha Jahangir , Philip Mathew , Rana Surinder , Puri Rajesh , Lakhtakia Sundeep , Dhir Vinay ,   India EUS Club
Published: March 2023

Endoscopic management of bile duct obstruction is a key aspect in gastroenterology practice and has evolved since the first description of biliary cannulation by McCune et al in 1968. Over many decades, the techniques and accessories have been refined and currently, the first-line management for extrahepatic biliary obstruction is endoscopic retrograde cholangiopancreaticography (ERCP). However, even in expert hands the success rate of ERCP reaches up to 95%. In almost 4 to 16% cases, failure to cannulate the bile duct may necessitate other alternatives such as surgical bypass or more commonly percutaneous transhepatic biliary drainage (PTBD). While surgery is associated with high morbidity and mortality, PTBD has a very high reintervention and complication rate (∼80%) and poor quality of life. Almost parallelly, endoscopic ultrasound (EUS) has come a long way from a mere diagnostic tool to a substantial therapeutic option in various pancreatico-biliary diseases. Biliary drainage using EUS-guidance (EUS-BD) has gained momentum since the first report published by Giovannini et al in 2001. The concept of accessing the bile duct through a different route than the papilla, circumventing the shortcomings of PTBD and sometimes bypassing the actual obstruction have enthused a lot of interest in this novel strategy. The three key methods of EUS-BD entail transluminal, antegrade, and rendezvous approach. Over the past decade, with growing experience, EUS-BD has been found to be equivalent to ERCP or PTBD for malignant obstruction with better success rates.

EUS-BD, albeit, is not devoid of adverse events and can carry fatal adverse events. However, neither the technique of EUS-BD, nor the accessories and stents for EUS-BD have been standardized.

Additionally, different countries and regions have different availability of the accessories making generalizability a difficult task. Thus, technical aspects of this evolving therapy need to be outlined. For these reasons, the Society of Gastrointestinal Endoscopy India deemed it appropriate to develop technical consensus statements for performing safe and successful EUS-BD.
Sedation Vacation in Neurocritical Care: A Proposal Algorithm
Authors: Moscote-Salazar Luis Rafael , Florez-Perdomo William A. , Janjua Tariq
Published: March 2023

Daily sedation interruption or sedation vacation is a strategy for neurological evaluation, respiratory mechanics, cardiac stability, and eventual weaning to extubation. However, its application has safety aspects such as pulmonary, cardiac, and neurological complications. A protocol-driven sedation vacation in the medical intensive care helps with the reduction in the intensive care length of stay and increase in ventilator-free days.1,2 The same approach can be used in neurointensive care with alterations based upon the neurocritical care progression.
Mass gap in U(1) Higgs–Yukawa model on a unit lattice
Authors: Goswami Abhishek
Published: March 2023

A non-perturbative proof of the mass generation of fermions via the Higgs mechanism is given. This is done by showing an exponential decay of the two point fermionic correlation function in a weakly coupled U(1) Higgs–Yukawa theory on a unit lattice in d = 4. This decay implies that the Higgs boson, the photon, and the fermion all have a non-zero physical mass, and the theory is said to have a mass gap.
Design and prototype test of a high-sensitivity reentrant-cavity based Schottky pickup
Authors: Wang Minwen , Zhuo Xin , Zhao Mingtong , Qiu Mengtong , Chen Wei , Wang Zhongming
Published: March 2023

Schottky diagnostics is an important measure for the debunched beam during the injection phase of the Xi’an Proton Application Facility (XiPAF). The existing capacitive Schottky pickup has a relatively low sensitivity and a poor signal-to-noise ratio for the low-intensity beam. A resonant Schottky pickup based on the principle of a reentrant cavity is proposed. The effects of cavity geometric parameters on cavity properties are systematically studied. A prototype was built and tested to validate the simulation results. The prototype has a resonance frequency of 24.23 MHz, a Q value of 635, and a shunt impedance of 19.75 kΩ. The resonant Schottky pickup has the capability to detect as few as 2.3 × 106 protons with an energy of 7 MeV and a momentum spread of about 1% at the injection phase of XiPAF. The sensitivity is two orders of magnitude higher than the existing capacitive pickup.
Size dependence of second-harmonic scattering from nanoparticles: Disentangling surface and electrostatic contributions
Authors: Chu Bingxin , Marchioro Arianna , Roke Sylvie
Published: March 2023

Polarimetric angle-resolved second-harmonic scattering (AR-SHS) is an all-optical tool enabling the study of unlabeled interfaces of nano-sized particles in an aqueous solution. As the second harmonic signal is modulated by interference between nonlinear contributions originating at the particle’s surface and those originating in the bulk electrolyte solution due to the presence of a surface electrostatic field, the AR-SHS patterns give insight into the structure of the electrical double layer. The mathematical framework of AR-SHS has been previously established, in particular regarding changes in probing depth with ionic strength. However, other experimental factors may influence the AR-SHS patterns. Here, we calculate the size dependence of the surface and electrostatic geometric form factors for nonlinear scattering, together with their relative contribution to the AR-SHS patterns. We show that the electrostatic term is stronger in the forward scattering direction for smaller particle sizes, while the ratio of the electrostatic to surface terms decreases with increasing size. Besides this competing effect, the total AR-SHS signal intensity is also weighted by the particle’s surface characteristics, given by the surface potential Φ0 and the second-order surface susceptibility χs,22. The weighting effect is experimentally demonstrated by comparing SiO2 particles of different sizes in NaCl and NaOH solutions of varying ionic strengths. For NaOH, the larger χs,22 values generated by deprotonation of surface silanol groups prevail over the electrostatic screening occurring at high ionic strengths; however, only for larger particle sizes. This study establishes a better connection between the AR-SHS patterns and surface properties and predicts trends for arbitrarily-sized particles.
Fabrication and performance of a nickel-chromium (NiCr) igniter integrated with TVS diode for ESD protection
Authors: Liu Wei , Ren Xiao-ming , Xie Rui-zhen , Liu Lan , Yu Ke-xin , Ji Xiang-fei , Ren Wei , Chu En-yi
Published: March 2023

The NiCr igniter is a key element of MEMS-based electro-explosive device (mEED), while electrostatic discharge (ESD) may excite the igniter accidentally. To protect the NiCr igniter from damage by ESD, a novel NiCr igniter by integrating the igniter onto a TVS diode based substrate was designed and fabricated through semiconductor technology. The microscope photograph, resistivity, breakdown voltage, firing performance, and ESD protection ability were tested. The results show that the surface of the chip is smooth, the edges of key structures are clear, and there are no major scratches, cracks, and other phenomena on the whole device. The resistivity of all the TVS-mNiCr igniters is between 5 and 7 Ω, and the TVS diode resistance value is normal. The breakdown voltages of the eight types of TVS diodes with different structures are all between 3.5 and 5 V, and the TVS-mNiCr igniters can fire reliably at a constant current of 2 A. After the ESD test, the microscope of the igniter does not change significantly, meaning that the TVS-mNiCr igniter chip has a certain ability of ESD protection. It is of vital importance to guide the design of electrostatic tolerant ability for the MEMS-based electro-explosive device.
Study on flow-induced noise propagation mechanism of cylinder–airfoil interference model by using large eddy simulation combined with vortex–acoustic equation
Authors: Qiaorui Si , Liu Jinfeng , Ali Asad , Jin Zhongkun , Chen Mengfei , Hong Xu , Iqbal Shahzad
Published: March 2023

An innovative numerical prediction method of flow-induced noise is implemented to overcome the defect that the traditional acoustic analogy method cannot reflect the interaction between turbulence vortex and sound. The classical cylindrical–airfoil interference model is used to perform the simulation and compared with the experimental results. To start with the derivation of Powell’s vortex sound equation, an implicit three-dimensional model of the fluid–acoustic coupling field is established to process the unsteady iterative calculation. The large eddy simulation method is adopted to solve the unsteady flow, and the acoustic information is then calculated using the vortex acoustic equation at each iteration step. The vortex structures around the cylinder airfoil are identified and captured by the Q-criterion for further analysis of vortex–noise correlation mechanism. The flow-induced noise prediction results are finally compared with Ffowcs Williams–Hawkings (FW–H) acoustic analogy approach. The results show that the vortex shedding from the cylinder and the interaction between vortex shedding and airfoil have the greatest influence on the acoustic, and the far-field noise of the cylinder airfoil shows a partial “eight” dipole distribution. The calculated results of the vortex sound theory are closer to the experimental ones than the FW–H method. The research helps understand the vortex acoustic coupling mechanism of the cylinder–airfoil model and provides a more accurate numerical prediction of flow-induced noise.
Optimizing the structure of acene clusters
Authors: Elsässer P. , Schilling T.
Published: March 2023

We present a study of the potential energy surface of anthracene, tetracene, and pentacene clusters with up to 30 molecules. We have applied the basin-hopping Monte Carlo algorithm to clusters of acene molecules in order to find their lowest energy states. The acene molecules are described by the polymer-consistent force field–interface force field. We present the structures with the lowest observed energy, and we discuss the relative stability and accessibility of structures corresponding to local energy minima.
An integration design model for a large-scale negative ion accelerator of neutral beam injection system for fusion application
Authors: Wei Jiang-Long , Yang Yu-Wen , Gu Yu-Ming , Cui Qing-Long , Liang Li-Zhen , Jiang Cai-Chao , Xie Yuan-Lai , Xie Ya-Hong , Hu Chun-Dong
Published: March 2023

Design processes of a large-scale negative ion accelerator for neutral beam injection (NBI) application involve a series of physics and engineering issues, which include high voltage holding, background gas and stripping losses, beamlets optics and steering, particle and power flux on the grid electrodes, heat removal, thermal deformation, and stress of the grids. A self-consistent design model covering all these critical issues has been developed, where the results of one design aspect can be directly plugged into another one as the input conditions with little approximation or assumption. This design model has been applied to the negative ion accelerator of the NBI test facility of CRAFT (Comprehensive Research Facility for Fusion Technology), which is designed to produce a negative hydrogen ion beam of 25 A with the particle energy of 400 keV and the pulse duration of 3600 s. The accelerated current density is required to be 210 A/m2 from 768 apertures with a diameter of 14 mm. The evaluated results of the CRAFT accelerator design are quantitatively analyzed. Additionally, the modeling is applied to a large-scale and relatively complete structure of the multi-grid electrodes. Hence, some nonuniformities or special distributions appear in different design issues, which were not noticed in the reference works.
Legume persistence for grasslands in tableland environments of south-eastern Australia
Authors: Hayes Richard C. , Newell Matthew T. , Li Guangdi D. , Haling Rebecca E. , Harris Carol A. , Culvenor Richard A. , Badgery Warwick B. , Munday Neil , Price Andrew , Stutz Rebecca S. , Simpson Richard J.
Published: March 2023

Context Improving the stability of legumes in grasslands in the face of variable seasonal conditions is key to mitigating risks posed by drought. Aims We assessed the persistence of a range of legume species and cultivars in order to inform legume choice for pasture improvement and identify priority species for further development. Methods Twenty field experiments in four series were conducted at sites with contrasting seasonal and soil characteristics in the ‘high-rainfall’ (560–920 mm long-term average) Tablelands and Monaro regions of New South Wales, Australia. Legumes were grown as pure swards and assessed periodically for seedling density, plant frequency and dry matter for up to 5 years. Key results Legume dry matter production was positively correlated with plant frequency. However, most legumes persisted poorly at most sites, particularly on soils of lower fertility. Subterranean clover (Trifolium subterraneum) cv. Goulburn was the best performing cultivar of that species across sites on the Southern Tablelands and Monaro. Yellow serradella (Ornithopus compressus) cvv. Avila and Yellotas showed promising persistence, particularly under drought conditions. White clover (T. repens) was the most broadly adapted of the perennial legumes across a range of soils, but persistence was still inadequate at many sites. Lucerne (Medicago sativa) was approximately twice as productive as the next-most productive species when soil conditions suited its growth, but it failed to persist on acidic, low-fertility soils. Conclusions Serradella species (yellow and French, O. sativus) and white clover, in conjunction with subterranean clover, offer the best near-term prospects for diversifying legume productivity and resilience under variable seasonal conditions in tableland environments. Implications An increased focus on phenology and seed characteristics is suggested to improve the persistence of annual and facultative perennial legume species in grasslands. Serradella and white clover are identified as the highest priorities for cultivar development for tableland environments of south-eastern Australia.
Enrichment of saccharides at the air–water interface: a quantitative comparison of sea surface microlayer and foam
Authors: Jayarathne Thilina , Gamage Dilini Kirindigoda , Prather Kimberly A. , Stone Elizabeth A.
Published: March 2023

Environmental context Saccharides contribute substantially to dissolved organic carbon in the ocean and are enriched at the ocean surface. In this study, we demonstrate that saccharides are more enriched in persistent whitecap foam compared to the sea surface. The maturation of bubbles at the air–water interface is thus expected to enhance the enrichment of organic matter at the ocean surface and ultimately in the sea spray aerosol that forms when bubbles burst at the ocean surface. Rationale Organic matter accumulates at the ocean surface. Herein, we provide the first quantitative assessment of the enrichment of dissolved saccharides in persistent whitecap foam and compare this enrichment to the sea surface microlayer (SSML) during a 9 day mesocosm experiment involving a phytoplankton bloom generated in a Marine Aerosol Reference Tank (MART). Methodology Free monosaccharides were quantified directly, total saccharides were determined following mild acid hydrolysis and the oligo/polysaccharide component was determined as the difference between total and free monosaccharides. Results Total saccharides contributed a significant fraction of dissolved organic carbon (DOC), accounting for 13% of DOC in seawater, 27% in SSML and 31% in foam. Median enrichment factors (EFs), calculated as the ratio of the concentrations of saccharides relative to sodium in SSML or foam to that of seawater, ranged from 1.7 to 6.4 in SSML and 2.1–12.1 in foam. Based on median EFs, xylitol, mannitol, glucose, galactose, mannose, xylose, fucose, rhamnose and ribose were more enriched in foam than SSML. Discussion The greatest EFs for saccharides coincided with high chlorophyll levels, indicating increasing ocean surface enrichment of saccharides during phytoplankton blooms. Higher enrichments of organic matter in sea foam over the SSML indicate that surface active organic compounds become increasingly enriched on persistent bubble film surfaces. These findings help to explain how marine organic matter becomes highly enriched in sea spray aerosol that is generated by bursting bubbles at the ocean surface.
Nonautonomous Breather and Rogue Wave in Spinor Bose–Einstein Condensates with Space-Time Modulated Potentials
Authors: Ding Cuicui , Zhou Qin , Xu Siliu , Triki Houria , Mirzazadeh Mohammad , Liu Wenjun
Published: March 2023

To study controlled evolution of nonautonomous matter-wave breathers and rogue waves in spinor Bose–Einstein condensates with spatiotemporal modulation, we focus on a system of three coupled Gross–Pitaevskii equations with spacetime-dependent external potentials and temporally modulated gain-loss distributions. With different external potentials and gain-loss distributions, various solutions for controlled nonautonomous matter-wave breathers and rogue waves are derived by the Darboux transformation method, such as breathers and rogue waves on arched and constant backgrounds which have the periodic and parabolic trajectories. Effects of the gain-loss distribution and linear potential on the breathers and rogue waves are studied. Nonautonomous two-breathers on the arched and constant backgrounds are also derived.
An attention-based long short-term memory prediction model for working conditions of copper electrolytic plates
Authors: Zhu Hongqiu , Peng Lei , Zhou Can , Dai Yusi , Peng Tianyu
Published: March 2023

Copper is an important source of non-ferrous metals, with electrolytic refining being one of the main methods to produce fine copper. In the electrolytic process, plate states seriously affect the output and quality of the copper. Therefore, timely and accurate prediction of the working states of the plates is of great significance to the copper electrolytic refining process. Aiming at the issues associated with traditional plate state detection algorithms of large lag, poor anti-interference ability and low accuracy, a plate state prediction model based on a long short-term memory (LSTM) neural network with an attention mechanism is here proposed in this paper. The average gray values of the plates in infrared imagery are used to characterize the plates’ working states. To address the problems of large fluctuation and the large amount of time series data required in such a study, a double-layer LSTM neural network structure is used to improve the efficiency and accuracy of model training. Meanwhile, in view of the periodicity of the time series data and the possible correlation between adjacent data, a unique attention mechanism is proposed to enable the model to learn this correlation between the adjacent data so as to improve the accuracy of the model prediction. The experimental results show that the accuracy of the proposed model for plate state prediction reaches 95.11%. Compared with commonly used prediction algorithms, the plate state prediction model proposed in this paper demonstrates stronger prediction ability.
T
2 orientation anisotropy mapping of articular cartilage using qMRI
Authors: Leskinen Henri P P , Hänninen Nina E , Nissi Mikko J
Published: March 2023

Objective. To provide orientation-independent MR parameters potentially sensitive to articular cartilage degeneration by measuring isotropic and anisotropic components of T
2 relaxation, as well as 3D fiber orientation angle and anisotropy via multi-orientation MR scans. Approach. Seven bovine osteochondral plugs were scanned with a high angular resolution of thirty-seven orientations spanning 180° at 9.4 T. The obtained data was fitted to the magic angle model of anisotropic T
2 relaxation to produce pixel-wise maps of the parameters of interest. Quantitative Polarized Light Microscopy (qPLM) was used as a reference method for the anisotropy and fiber orientation. Main results. The number of scanned orientations was found to be sufficient for estimating both fiber orientation and anisotropy maps. The relaxation anisotropy maps demonstrated a high correspondence with qPLM reference measurements of the collagen anisotropy of the samples. The scans also enabled calculating orientation-independent T
2 maps. Little spatial variation was observed in the isotropic component of T
2 while the anisotropic component was much faster in the deep radial zone of cartilage. The estimated fiber orientation spanned the expected 0°–90° in samples that had a sufficiently thick superficial layer. The orientation-independent magnetic resonance imaging (MRI) measures can potentially reflect the true properties of articular cartilage more precisely and robustly. Significance. The methods presented in this study will likely improve the specificity of cartilage qMRI by allowing the assessment of the physical properties such as orientation and anisotropy of collagen fibers in articular cartilage.
Asymmetrical ignition of radio frequency discharge in atmospheric pressure cascade glow discharges
Authors: Zhang Yarong , Fang Junlin , Xu Shaofeng , Guo Ying , Shi Jianjun
Published: March 2023

A two-dimensional self-consistent fluid model was developed to investigate the ignition of radio frequency (RF) discharge in an atmospheric helium cascade glow discharge. In particular, the model considers the case where a pulsed discharge is excited ahead of the RF discharge by applying pulsed DC voltage and RF voltage to two parallel plate electrodes separately. The spatio-temporal distribution of electron, ion, electric field, and mean electron energy demonstrate that the electron and ion localize in the vicinity of RF electrode with the extinguishment of pulsed discharge, whereas a sheath region formed above the pulsed electrode due to the space charge. It explains the experimental findings of asymmetric ignition of RF discharge in the interelectrode gap. With the migration of ion towards the pulsed electrode, the RF discharge achieves the stable operation. Furthermore, the migration time of ion from the RF electrode to pulsed electrode is estimated to be 3.0 μs, which is consistent with the calculated migration time of ions across the discharge gap.
Design and proof-of-concept of an advanced protective system for the dissipation of tangential impact energy in helmets, based on non-Newtonian fluids
Authors: La Fauci Giuseppe , Parisi Mariafederica , Nanni Alessandro , Crosetta Lorenzo , Pugno Nicola M , Colonna Martino
Published: March 2023

We have designed and tested a device based on non-Newtonian fluids for the attenuation of tangential impacts energy in helmets. A shear thickening fluid based on borurated silicones has given the best results in terms of impact energy attenuation in a system that selectively mimics tangential impacts and for this reason it has been used to fill the chamber of a pad, prepared by additive manufacturing, for impact energy dissipation. The pad is composed of a case containing the fluid in which is immersed a rigid pin that is free to move in all direction and therefore is able to absorb energy during its movement inside the fluid. A motorcycle helmet, already composed of two concentrical expanded polystyrene (EPS) liners, has been implemented with seven pads between the two EPS layers. The two layers have only been connected by means of the dissipating pad and are free to rotate and to dissipate energy during the rotation. The results of oblique impacts according to ECE 22.06 with three impact positions, shows a reduction of the brain injury criterion of 14% for the helmet with the pads, compared to the standard helmet, with values well below the threshold imposed by the norm. On the contrary, the maximum of the peak rotational acceleration show a 3% increase. Nevertheless, the rotational acceleration versus time curves indicates that in all three orientations the time of the maximum is shifted towards longer times for the helmets with the pads, indicating that the pads retard the acceleration of the head due to the efficient rotation of the two EPS parts connected by the pads. The described system could be implemented with minimal modifications in existing protective sport and motorcycle helmets.
Emerging (2+1) D massive graviton in graphene-like systems
Authors: Salgado-Rebolledo Patricio , Pachos Jiannis K
Published: March 2023

Unlike the fundamental forces of the Standard Model the quantum effects of gravity are still experimentally inaccessible. Rather surprisingly quantum aspects of gravity, such as massive gravitons, can emerge in experiments with fractional quantum Hall liquids. These liquids are analytically intractable and thus offer limited insight into the mechanism that gives rise to quantum gravity effects. To thoroughly understand this mechanism we employ a graphene-like system and we modify it appropriately in order to realise simple(2+1)-dimensional massive gravity model. More concretely, we employ(2+1)-dimensional Dirac fermions, emerging in the continuous limit of a fermionic honeycomb lattice, coupled to massive gravitons, simulated by bosonic modes positioned at the links of the lattice. The quantum character of gravity can be determined directly by measuring the correlations on the bosonic atoms or by the interactions they effectively induce on the fermions. The similarity of our approach to current optical lattice configurations suggests that quantum signatures of gravity can be simulated in the laboratory in the near future, thus providing a platform to address question on the unification theories, cosmology or the physics of black holes.