bluuebunny/crossref_metadata_2025 huggingface dataset:
Virtual Ophthalmology Fellowship Interviews: Perceptions of U.S. Ophthalmology Fellowship Applicants in 2020
Authors: Patel Samir N. , Cherkas Elliot G. , Shields Charlotte N. , Soares Rebecca R. , Hinkle John W. , Razeghinejad Reza , Hammersmith Kristin M. , Finklea Brenton D. , Shields Carol L. , Cohen Michael N. , Khan M. A. , Kuriyan Ajay E. , Klufas Michael A.
Published: November 2021

Objective This study aimed to evaluate the experiences and preferences of ophthalmology fellowship applicants utilizing a virtual interview format.

Design Present study is a cross-sectional study.

Subjects All fellowship applicants to Wills Eye Hospital during 2020 to 2021 application cycle were included.

Methods A nonvalidated, online survey was conducted, and surveys were distributed at the conclusion of the interview process after rank list submission.

Main Outcome Measures Applicant demographics, application submissions, interview experiences, financial considerations, and suggestions for improvement of the virtual interview process were the primary outcomes of this cross-sectional study.

Results Survey responses were received from 68 fellowship applicants (34% response rate). Thirty (44%) applicants preferred in-person interviews, 25 (36%) preferred virtual interviews, and 13 (19%) would like to prefer the option to choose either. Fifty-five of 68 (80%) applicants attended the same range of interviews for which they received interview invitations. Reduced costs were reported as the highest ranked strength of virtual interviews in 44 (65%) applicants, with a majority of respondents (68%) spending less than U.S. $250 throughout the entire process. The highest ranked limitation for virtual interviews was limited exposure to the culture/environment of the program in 20 (29%) respondents. On a scale of 0 to 100, the mean (standard deviation [SD]) satisfaction level with the fellowship application process was 74.6 (18.3) and mean (SD) perceived effectiveness levels of virtual interviews was 67.4 (20.4).

Conclusion Respondents were generally satisfied with virtual interviews and noted reduced costs and increased ability to attend more fellowship interviews as the strengths of the virtual interview format. Limited exposure to the culture/environment of the program was cited as the most important limitation.
Evolution of a Glaucoma Fellow's Surgical Training: Improvements in Tube Shunt Case Times during the Academic Year
Authors: Robbins Cason B. , Aldaas Khalid , Asrani Sanjay , McKinnon Stuart , Fleischman David , Gupta Divakar
Published: November 2021

Purpose The aim of the study is to report changes in tube shunt placement surgical case times for glaucoma fellows during the course of the academic year.

Patients and Methods Electronic health records were retrospectively reviewed to determine patient demographics, surgical case times (defined as procedure start time to procedure end time), and glaucoma fellow involvement. Only cases with a glaucoma fellow as the primary surgeon were included. Operative case times were compared by first and second halves of the academic year (beginning in July and ending in June) using a two-tailed t-test.

Results Five hundred and seventy-three individual tube shunt surgeries (385 Ahmed, 188 Baerveldt) performed by 28 glaucoma fellows (17 females, 11 males) at Duke University Eye Center and University of North Carolina Medical Center were included. Overall, case times were significantly shorter in the second half of the academic year as compared with the first (55.3 ± 17.1 minutes vs. 61.0 ± 17.4 minutes, p <0.001). Both male (57.3 ± 16.8 minutes vs. 63.2 ± 18.6 minutes, p = 0.008) and female (53.5 ± 17.3 minutes vs. 59.3 ± 16.4 minutes, p = 0.003) fellows demonstrated shorter case times over the academic year; additionally, female fellows trended toward shorter case times than male fellows in both the first half (p = 0.072) and second half (p = 0.053) of the academic year. Fellows also exhibited shorter case times with both Ahmed implants (54.1 ± 16.2 minutes vs. 59.3 ± 15.8 minutes, p = 0.002) and Baerveldt implants (57.8 ± 18.9 minutes vs. 64.2 ± 20.0 minutes, p = 0.025) cases over the academic year. Baerveldt case times were significantly longer than Ahmed cases in the first half (p = 0.028) and trended toward being longer than Ahmed cases in the second half (p = 0.070).

Conclusion Across 5 years at two academic institutions, glaucoma fellows had shorter primary tube shunt surgical case times in the second half of the academic year. These findings reflect improvement in surgical efficiency throughout glaucoma fellowship. These findings should be taken into consideration when scheduling trainee surgeries at academic medical centers at different points in the academic year.
Unusual Congenital Lesion Masquerading as a Lung Mass in an Adult
Authors: Singh Vartika , Sudhesh Kotian Shravya , Prasad HL Kishan , Hosmane Giridhar Belur , Gopalakrishnan Mundayat , Shetty K Jayaprakash
Published: November 2021

Congenital pulmonary airway malformation (CPAM) is a broad spectrum of congenital cystic lung lesions caused by the arrested bronchoalveolar development. Approximately, 80% of CPAMs are diagnosed prenatally or during the neonatal period when patients present with respiratory failure and cyanosis. CPAM is often associated with other organ anomalies and aplasia, and they have poor prognoses. Many CPAMs are detected in infants and school-age children, and infections like pneumonia trigger these diagnoses. It rarely manifests in adults. These often get missed because of the superadded diseases, and hence, it is essential to have a correct approach to their diagnosis to avoid misdiagnosis.
Current Concepts of Surface Topography of Implants: A Review
Authors: Potdar Raksha , Ramesh Amitha
Published: November 2021

Both the rate of osseointegration and its extent depend upon the characteristics of the implant surface.1
2
3
4
5 Depending on the surface of the implant determination of implant–bone contact area, the rate of bone formation around the implant can be done.6 Hence, the implant surface plays an important part in multiple ways in the osseointegration process.
Comparative Evaluation of Post-TURP Complications in Patients with BPH Presenting with and Without Acute Urinary Retention
Authors: Pogula Veda Murthy Reddy , Galeti Ershad Hussain , Ahmad Ifrah , Kanchi Bhargava Reddy
Published: November 2021

Background Benign prostatic hyperplasia (BPH) is a prevalent urological condition affecting men at an older age. Acute urinary retention (AUR) is a severe symptom of men who develop BPH. TURP is the gold standard as the management of BPH is concerned. Our study tried to compare the post-TURP complications between patients presented with and without AUR.

Materials and Methods We enrolled 126 patients, out of which 74 were in the AUR group and 52 in the non-AUR group. The mean age of patients with AUR was 62.51 years, and that for patients without AUR was 61.06 years. Statistical significance was noted in our study in patients with AUR and without AUR regarding the prostate's grading by DRE, the volume of gland, PSA level, post-TURP UTI, recatheterization post TURP, length of hospital stays with p-values 0.000, 0.000, 0.006, 0.004, 0.007, and 0.000, respectively. Statistical significance was not noted in patients with AUR and without AUR with regard to the grading of hypertension, diabetes mellitus, ischemic heart disease, post-op TURP syndrome, post-TURP hematuria, patients needing a blood transfusion, post-TURP sepsis, LUTS, post-TURP stricture, resurgery for clot retention with p values of 0.918, 1.000, 1.000, 1.000, 0.523, 0.642, 1.000, 0.319, 1.000, and 1.000, respectively.

Conclusion Our study shows that post-TURP complications such as hematuria, blood transfusion rate, post-op UTI, sepsis, recatheterization, lower urinary tract stricture, resurgery, TUR syndrome, and the length of hospital stay were higher in patients who presented with AUR than in those without AUR. Post-TURP UTI complications, recatheterization rate, and the length of hospital stay were statistically significant in the AUR group compared with the non-AUR group. Therefore, it is better to intervene earlier before the patients develop AUR to minimize the complications and maximize the outcomes.
Laparoscopic Gastrojejunostomy for the Treatment of SIRT-Induced Duodenal Ulcer Complicated by Gastric Outlet Obstruction
Authors: Arja Walaa El , Eid Sarah B. , Saikaly Elias , Ezzeddine Lynn , Daoud Rayan , Fiani Elias
Published: November 2021

Selective internal radiation therapy (SIRT) is an emerging therapeutic modality in patients with unresectable hepatocellular carcinoma or liver metastases. However, complications can occur due to migration of radiation microspheres such as gastrointestinal ulcer, cholecystitis, bleeding, pancreatitis, and many others. A 50-year-old woman with stage IV breast cancer who underwent radioembolization for unresectable hepatic metastasis 6 months ago presented to our hospital with 1 month history of nausea, vomiting, with food intolerance, and weight loss. Esophagogastroduodenoscopy showed large deep duodenal bulbar ulcer along with antral ulcerations and edematous gastropathy. Biopsies revealed typical black, duodenal yttrium-90 sphere, documenting radiation injury. After she was discharged on proton pump inhibitor, the patient came back 1 month later for exacerbation of symptoms; computed tomography scan of the abdomen showed gastric outlet obstruction. Although there is no consensus in treating radiation-induced ulcers, physicians should be aware of this complication in patient who underwent SIRT presenting for abdominal pain.
Disparities in Obstetric Readmissions: A Multistate Analysis, 2007–2014
Authors: Matthews Kathy C. , Tangel Virginia E. , Abramovitz Sharon E. , Riley Laura E. , White Robert S.
Published: November 2021

Objective Hospital readmissions are generally higher among racial-ethnic minorities and patients of lower socioeconomic status. However, this has not been widely studied in obstetrics. The aim of the study is to determine 30-day postpartum readmission rates by patient-level social determinants of health: race ethnicity, primary insurance payer, and median income, independently and as effect modifiers.

Study Design Using state inpatient databases from the health care cost and utilization project from 2007 to 2014, we queried all deliveries. To produce accurate estimates of the effects of parturients' social determinants of health on readmission odds while controlling for confounders, generalized linear mixed models (GLMMs) were used. Additional models were generated with interaction terms to highlight any associations and their effect on the outcome. Adjusted odds ratios (aOR) with 95% confidence intervals are reported.

Results There were 5,129,867 deliveries with 79,260 (1.5%) 30-day readmissions. Of these, 947 (1.2%) were missing race ethnicity. Black and Hispanic patients were more likely to be readmitted within 30 days of delivery, as compared with White patients (p < 0.001 and p < 0.05, respectively). Patients with government insurance were more likely to be readmitted than those with private insurance (p < 0.001). Patients living in the second quartile of median income were also more likely to be readmitted than those living in other quartiles (p < 0.05). Using GLMMs, we observed that Black patients with Medicare were significantly more likely to get readmitted as compared with White patients with private insurance (aOR 2.78, 95% CI 2.50–3.09, p < 0.001). Similarly, Black patients living in the fourth (richest) quartile of median income were more likely to get readmitted, even when compared with White patients living in the first (poorest) quartile of median income (aOR 1.48, 95% CI 1.40–1.57, p < 0.001).

Conclusion Significant racial-ethnic disparities in obstetric readmissions were observed, particularly in Black patients with government insurance and even in Black patients living in the richest quartile of median income.

Key Points
Krankenhauslandschaft: Eine nachhaltige Therapie ist überfällig
Authors: Ekkernkamp Axel
Published: November 2021

Sechs Milliarden Euro! Das ist der Investitionsrückstand in deutschen Kliniken im Sommer 2021, wie gesetzliche und private Krankenversicherungen in seltener Einmütigkeit zusammen mit der DKG ermittelt haben. Ganz gleich, wer die schwere Aufgabe übernimmt, das Gesundheitsministerium zu führen – der erforderliche Kassensturz wird in jedem Fall ein erschreckendes Ergebnis liefern. Denn neben den Defiziten in der Infrastruktur wird endlich auch Klarheit darüber herrschen, dass kaum oder zumindest zu wenig Geld da ist für die Therapie einer großen Anzahl von Post-Covid-Patienten und dass es keine Reserven mehr zur Finanzierung von Pflegepersonal gibt.
Medizintechnikplanung mit BIM: Konsequent neue Wege beschreiten
Authors: Thalmayr Maria
Published: November 2021

Konsolidierte Planungs- und Baudaten sind Voraussetzung für und gleichermaßen großer Vorteil von Building Information Modeling. Die Medizintechnikausstattung eines Neubaus der Cnopfschen Kinderklinik in Nürnberg ist Teil einer solchen, alle Gewerke einschließenden, digitalen Planungs- und Umsetzungswirklichkeit – mit einigen Besonderheiten.
Critical fluctuations in renewal models of statistical mechanics
Authors: Zamparo Marco
Published: November 2021

We investigate the sharp asymptotic behavior at criticality of the large fluctuations of extensive observables in renewal models of statistical mechanics, such as the Poland–Scheraga model of DNA denaturation, the Fisher–Felderhof model of fluids, the Wako–Saitô–Muñoz–Eaton model of protein folding, and the Tokar–Dreyssé model of strained epitaxy. These models amount to Gibbs changes of measure of a classical renewal process and can be identified with a constrained pinning model of polymers. The extensive observables that enter the thermodynamic description turn out to be cumulative rewards corresponding to deterministic rewards that are uniquely determined by the waiting time and grow no faster than it. The probability decay with the system size of their fluctuations switches from exponential to subexponential at criticality, which is a regime corresponding to a discontinuous pinning–depinning phase transition. We describe such decay by proposing a precise large deviation principle under the assumption that the subexponential correction term to the waiting time distribution is regularly varying. This principle is, in particular, used to characterize the fluctuations of the number of renewals, which measures the DNA-bound monomers in the Poland–Scheraga model, the particles in the Fisher–Felderhof model and the Tokar–Dreyssé model, and the native peptide bonds in the Wako–Saitô–Muñoz–Eaton model.
Theoretical studies on triplet-state driven dissociation of formaldehyde by quasi-classical molecular dynamics simulation on machine-learning potential energy surface
Authors: Lin Shichen , Peng Daoling , Yang Weitao , Gu Feng Long , Lan Zhenggang
Published: November 2021

The H-atom dissociation of formaldehyde on the lowest triplet state (T1) is studied by quasi-classical molecular dynamic simulations on the high-dimensional machine-learning potential energy surface (PES) model. An atomic-energy based deep-learning neural network (NN) is used to represent the PES function, and the weighted atom-centered symmetry functions are employed as inputs of the NN model to satisfy the translational, rotational, and permutational symmetries, and to capture the geometry features of each atom and its individual chemical environment. Several standard technical tricks are used in the construction of NN-PES, which includes the application of clustering algorithm in the formation of the training dataset, the examination of the reliability of the NN-PES model by different fitted NN models, and the detection of the out-of-confidence region by the confidence interval of the training dataset. The accuracy of the full-dimensional NN-PES model is examined by two benchmark calculations with respect to ab initio data. Both the NN and electronic-structure calculations give a similar H-atom dissociation reaction pathway on the T1 state in the intrinsic reaction coordinate analysis. The small-scaled trial dynamics simulations based on NN-PES and ab initio PES give highly consistent results. After confirming the accuracy of the NN-PES, a large number of trajectories are calculated in the quasi-classical dynamics, which allows us to get a better understanding of the T1-driven H-atom dissociation dynamics efficiently. Particularly, the dynamics simulations from different initial conditions can be easily simulated with a rather low computational cost. The influence of the mode-specific vibrational excitations on the H-atom dissociation dynamics driven by the T1 state is explored. The results show that the vibrational excitations on symmetric C–H stretching, asymmetric C–H stretching, and C=O stretching motions always enhance the H-atom dissociation probability obviously.
Theoretical foundations for the evanescent mode oscillator (EMO) as a high-efficiency source of millimeter-wave and terahertz radiations
Authors: Bahman Soltani Hooman
Published: November 2021

Evanescent mode oscillators (EMO) are investigated as high-efficiency sources of millimeter-waves and low-frequency parts of terahertz radiation. EMO can be considered a high-efficiency version of the extended interaction oscillator (EIO) using the evanescent resonance mode (ERM) of a slow-wave structure. It has been shown quantitatively that the efficiency of the EMO is superior to that of the conventional EIO having the same periodic unit cell. The condition to have an evanescent resonant mode in a chain is derived in this article. EMO threshold excitation condition is expressed in terms of the beam and RF mode parameters. A Typical EMO is systematically modeled, and its performance is checked with a particle-in-cell simulation software package. The excitation of the ERM modes is illustrated, with the results being close to the prediction of the non-linear model used in the paper.
Yield stress measurement techniques: A review
Authors: De Kee Daniel
Published: November 2021

This contribution is to add to the timely celebration of Professor R. B. Bird's outstanding career and accomplishments. Following introductory remarks on material/fluid types, the paper reviews the concept of yield stress. Although yield stress has been studied for several decades, it is still very much a topic of current interest. This paper covers phenomenological yield stress models as well as experimental techniques to measure yield stress. It also discusses, in particular, problems associated with very low yield stress measurements that occur with bio-fluids such as blood.
Flow-induced vibration of a flexible splitter-plate in the wake of a stationary cylinder
Authors: Mittal Charu , Sharma Atul
Published: November 2021

The present work is on free-stream flow across a circular cylinder, with a detached flexible-plate. Using a levelset function-based immersed interface method, the effect of Reynolds number Re(75−150), non-dimensional gap G*(0.5−3.5) between the two structures and non-dimensional length L*(0.5−3) of the plate—with constant structural properties and thickness—is numerically studied. The effect of these parameters on the vibration characteristics of the plate along with the accompanying flow structures and engineering parameters are presented. The study demonstrates a correlation between the plate dynamics and the two flow-phenomenon: vortex-formation mode and vortex-interaction mode. Vortex-formation relates to the position of the leading and the trailing edge of the plate relative to the recirculation region behind the cylinder and is classified into three-regimes: pre-vortex formation regime-a, pre-vortex formation regime-b, and post-vortex formation regime, corresponding to smaller, intermediate, and larger plate-amplitudes, respectively. The vortex-interaction mode refers to the nature of interaction between the cylinder and the plate vortices and is classified into two-modes: constructive and destructive interactions, corresponding to larger and smaller amplitudes, respectively. The study shows that the plate oscillates with very large amplitude at larger Re, intermediate G*, and with plate length equal to the cylinder diameter. The flexible plate leads to a large suppression in the hydrodynamic forces and the vortex shedding frequency of the cylinder in the pre-vortex formation regime, with complete suppression in the vortex-shedding for larger plate-length L* at intermediate gap G*. Thus, the present system can be utilized as a plate-based energy harvesting device as well as a vortex-shedding control device.
Cryo kinetics of N2 adsorption onto bimetallic rhodium–iron clusters in isolation
Authors: Ehrhard Amelie A. , Klein Matthias P. , Mohrbach Jennifer , Dillinger Sebastian , Niedner-Schatteburg Gereon
Published: November 2021

We report the N2 cryo adsorption kinetics of selected gas phase mixed rhodium–iron clusters [RhiFej]+ in the range of i = 3–8 and j = 3–8 in 26 K He buffer gas by the use of a cryo tandem RF-hexapole trap–Fourier transform ion cyclotron resonance mass spectrometer. From kinetic data and fits, we extract relative rate constants for each N2 adsorption step and possible desorption steps. We find significant trends in adsorption behavior, which reveal adsorption limits, intermittent adsorption limits, and equilibrium reactions. For those steps, which are in equilibrium, we determine the Gibbs free energies. We conclude on likely ligand shell reorganization and some weakly bound N2 ligands for clusters where multiple N2 adsorbates are in equilibrium. The relative rate constants are transferred to absolute rate constants, which are slightly smaller than the collision rate constants calculated by the average dipole orientation (Langevin) theory. The calculated sticking probabilities increase, in general, with the size of the clusters and decrease with the level of N2 adsorption, in particular, when reaching an adsorption/desorption equilibrium. We receive further evidence on cluster size dependent properties, such as cluster geometries and metal atom distributions within the clusters through the accompanying spectroscopic and computational study on the equiatomic i = j clusters [Klein et al., J. Chem. Phys. 156, 014302 (2022)].
A molecular perspective on induced charges on a metallic surface
Authors: Pireddu Giovanni , Scalfi Laura , Rotenberg Benjamin
Published: November 2021

Understanding the response of the surface of metallic solids to external electric field sources is crucial to characterize electrode–electrolyte interfaces. Continuum electrostatics offer a simple description of the induced charge density at the electrode surface. However, such a simple description does not take into account features related to the atomic structure of the solid and to the molecular nature of the solvent and of the dissolved ions. In order to illustrate such effects and assess the ability of continuum electrostatics to describe the induced charge distribution, we investigate the behavior of a gold electrode interacting with sodium or chloride ions fixed at various positions, in a vacuum or in water, using all-atom constant-potential classical molecular dynamics simulations. Our analysis highlights important similarities between the two approaches, especially under vacuum conditions and when the ion is sufficiently far from the surface, as well as some limitations of the continuum description, namely, neglecting the charges induced by the adsorbed solvent molecules and the screening effect of the solvent when the ion is close to the surface. While the detailed features of the charge distribution are system-specific, we expect some of our generic conclusions on the induced charge density to hold for other ions, solvents, and electrode surfaces. Beyond this particular case, the present study also illustrates the relevance of such molecular simulations to serve as a reference for the design of improved implicit solvent models of electrode–electrolyte interfaces.
Rethinking Maltese English as a continuum of sociolinguistic continua through evaluations of written and oral
prompts
Authors: Caruana Sandro , Mori Laura
Published: November 2021

Scientific literature has tackled Maltese English (MaltE) mainly in the framework of World Englishes in order to
focus on its features compared to other varieties of English around the world. In this paper we shed more light on MaltE by
proposing a sociolinguistic perspective, oriented towards its social stratification, and by referring to it through degrees of
linguistic competence in English. We therefore propose two continua of variation: MaltE as an L2 continuum and as a situational
one. Within this framework, we identify two groups defined as Mainly Maltese Speakers (MMS) and Mainly English Speakers (MES). We
suggest that MaltE can be interpreted both as an L2, and as a variety used according to speech events, domain, participants,
in-groupness etc. To investigate this we carried out a perceptual experiment involving two groups of university students,
specialising in Maltese and English respectively. We discuss the results based on ratings and evaluations of authentic MaltE
written and spoken prompts.
Collocations in learner English
Authors: Kreyer Rolf
Published: November 2021

The present paper analyses the use of V-N collocations with the four ‘light’ verbs do, give, make and take in a corpus representing longitudinal written data from 83 German learners of English in their four final years of secondary school. The paper focuses on the development of correct and incorrect collocation use, the development of L1 interference, as well as intersubjective variability regarding these aspects. Corroborating previous studies, the paper shows that roughly one quarter of collocations is atypical with no significant changes over the four years. Around half of all erroneous collocations can be interpreted as the result of L1-interference. As regards individual paths of acquisition, the paper shows that students show a large degree of variability. The paper argues that collocations need to be taught explicitly, focusing on frequent collocations of medium restrictedness that show incongruity of L1 and L2.
Creating versatility in Thai demonstratives
Authors: Iwasaki Shoichi , Dechapratumwan Parada
Published: November 2021

Beyond their basic function to index exophoric and endophoric referents, Thai demonstratives have a host of pragmatic functions to encode concerns regarding discourse organization, subjectivity, and intersubjectivity. Based on a detailed analysis of demonstratives used in conversation, we attempt to uncover the pattern of grammaticalization for this class of words in Thai, and to propose a mechanism that allows them to develop multiple functions. Since demonstratives are indexical signs and are qualitatively distinct from content words, we must view the grammaticalization process of demonstratives differently from that of content words. In this paper, we use the model of thejoint attention trianglebased on Diessel’s earlier work and thefunctional utterance framebased on the “attractor position” analysis for grammaticalization of nouns and verbs advanced byBisang (1996)to analyze how exactly demonstratives come to acquire pragmatic functions.
La induced Si3 trimer monolayer on Si(111) surface: an ab initio study
Authors: Yang Guang , Chai Jun-Shuai , Xu Li-Fang , Wang Jian-Tao
Published: November 2021

The π-bond Seiwatz chain (SC) is one of the well-known reconstruction induced by alkaline or rare earth metals on Si(111) surface. Here we identify by ab initio calculations a new reconstruction of La induced quasi-two-dimensional Si3 trimer monolayer on Si(111)-

(

3

×

3

)

R
30
°

surface. Its surface unit cell has one La atom and one Si3 trimer with the same La coverage (1/3 monolayer) as SC structure and the Si3 trimer satisfies the electron counting rule with a transfer of valence electrons from La atom, formally as

L
a

3
+

[

S
i

−

]

3

, in correspondence to the milkstool model for Bi trimers on Si(111) surface. Band structure calculations show a semiconducting character with an indirect surface band gap of 0.76 eV. Moreover, a two-stage conversion process between the Si3 trimer and SC structure is verified by the climbing-image nudged elastic band method. These findings pave the way for further exploration of the new surface structure and its outstanding properties.
Typology of defects in DEMO divertor target mockups
Authors: Addab Y , Richou M , Ramaniraka M , Vignal N , Visca E , Dose G , Roccella S , Greuner H , Missirlian M , You J H
Published: November 2021

We analyzed data from ultrasonic testing and infrared thermography non-destructive examinations performed on a subset of 25 small scale water-cooled target mockups of four target designs developed in the 2nd R&D phase of WPDIV. Examinations were performed before high heat flux tests for the 25 mockups and after high heat flux tests for 18 of them. The detected manufacturing defects are various in size and location. Widths of defects range from 0.2 to 12 mm, which is the entire block width. Angular sizes of defects range from few degrees to 360°. Defects having an angular size less than 50° or a width less than 4 mm are likely to be missed by infrared thermography examinations. After high heat flux tests at 20 MW m−2 up to 500 cycles, we noticed no significant evolution of pre-existing defects.
Revisiting the fundamental equations of the mathematical physics in the space of generalised functions
Authors: Nanni Luca
Published: November 2021

A broad class of physical processes is described by second-order differential equations. The equation of waves, the diffusion equation and the stationary equation, which are found both in classical and quantum physics, belong to this class. In this article, these equations are reformulated under the assumption that the source determining the physical phenomenon acts instantaneously, using the formalism of generalised functions. Some particular cases of these equations are precisely solved by applying the Fourier transform. The obtained solutions form a subspace of the singular generalised functions’ space and are mentioned by the product between a step function and a function with at most a finite number of discontinuity points.
Memristor-based multi-synaptic spiking neuron circuit for spiking neural network
Authors: Jiang Wenwu , Li Jie , Liu Hongbo , Qian Xicong , Ge Yuan , Wang Lidan , Duan Shukai
Published: November 2021

Spiking neural networks (SNNs) are widely used in many fields because they work closer to biological neurons. However, due to its computational complexity, many SNNs implementations are limited to computer programs. First, this paper proposes a multi-synaptic circuit (MSC) based on memristor, which realizes the multi-synapse connection between neurons and the multi-delay transmission of pulse signals. The synapse circuit participates in the calculation of the network while transmitting the pulse signal, and completes the complex calculations on the software with hardware. Secondly, a new spiking neuron circuit based on the leaky integrate-and-fire (LIF) model is designed in this paper. The amplitude and width of the pulse emitted by the spiking neuron circuit can be adjusted as required. The combination of spiking neuron circuit and MSC forms the multi-synaptic spiking neuron (MSSN). The MSSN was simulated in PSPICE and the expected result was obtained, which verified the feasibility of the circuit. Finally, a small SNN was designed based on the mathematical model of MSSN. After the SNN is trained and optimized, it obtains a good accuracy in the classification of the IRIS-dataset, which verifies the practicability of the design in the network.
Quantum simulation of lattice gauge theories on superconducting circuits: Quantum phase transition and quench dynamics
Authors: Ge Zi-Yong , Huang Rui-Zhen , Meng Zi-Yang , Fan Heng
Published: November 2021

Recently, quantum simulation of low-dimensional lattice gauge theories (LGTs) has attracted many interests, which may improve our understanding of strongly correlated quantum many-body systems. Here, we propose an implementation to approximate ℤ2 LGT on superconducting quantum circuits, where the effective theory is a mixture of a LGT and a gauge-broken term. By using matrix product state based methods, both the ground state properties and quench dynamics are systematically investigated. With an increase of the transverse (electric) field, the system displays a quantum phase transition from a disordered phase to a translational symmetry breaking phase. In the ordered phase, an approximate Gauss law of the ℤ2 LGT emerges in the ground state. Moreover, to shed light on the experiments, we also study the quench dynamics, where there is a dynamical signature of the spontaneous translational symmetry breaking. The spreading of the single particle of matter degree is diffusive under the weak transverse field, while it is ballistic with small velocity for the strong field. Furthermore, due to the emergent Gauss law under the strong transverse field, the matter degree can also exhibit confinement dynamics which leads to a strong suppression of the nearest-neighbor hopping. Our results pave the way for simulating the LGT on superconducting circuits, including the quantum phase transition and quench dynamics.
Effect of the target positions on the rapid identification of aluminum alloys by using filament-induced breakdown spectroscopy combined with machine learning
Authors: Li Xiaoguang , Lu Xuetong , Zhang Yong , Song Shaozhong , Hao Zuoqiang , Gao Xun
Published: November 2021

Filament-induced breakdown spectroscopy (FIBS) combined with machine learning algorithms was used to identify five aluminum alloys. To study the effect of the distance between focusing lens and target surface on the identification accuracy of aluminum alloys, principal component analysis (PCA) combined with support vector machine (SVM) and K-nearest neighbor (KNN) was used. The intensity and intensity ratio of fifteen lines of six elements (Fe, Si, Mg, Cu, Zn, and Mn) in the FIBS spectrum were selected. The distances between the focusing lens and the target surface in the pre-filament, filament, and post-filament were 958 mm, 976 mm, and 1000 mm, respectively. The source data set was fifteen spectral line intensity ratios, and the cumulative interpretation rates of PC1, PC2, and PC3 were 97.22%, 98.17%, and 95.31%, respectively. The first three PCs obtained by PCA were the input variables of SVM and KNN. The identification accuracy of the different positions of focusing lens and target surface was obtained, and the identification accuracy of SVM and KNN in the filament was 100% and 90%, respectively. The source data set of the filament was obtained by PCA for the first three PCs, which were randomly selected as the training set and test set of SVM and KNN in 3:2. The identification accuracy of SVM and KNN was 97.5% and 92.5%, respectively. The research results can provide a reference for the identification of aluminum alloys by FIBS.
Molecular dynamics simulations on the wet/dry self-latching and electric fields triggered wet/dry transitions between nanosheets: A non-volatile memory nanostructure
Authors: Zhu Jianzhuo , Zhang Xinyu , Li Xingyuan , Peng Qiuming
Published: November 2021

We design a nanostructure composing of two nanoscale graphene sheets parallelly immersed in water. Using molecular dynamics simulations, we demonstrate that the wet/dry state between the graphene sheets can be self-latched; moreover, the wet→dry/dry→wet transition takes place when applying an external electric field perpendicular/parallel to the graphene sheets (E
⊥/E
∥). This structure works like a flash memory device (a non-volatile memory): the stored information (wet and dry states) of the system can be kept spontaneously, and can also be rewritten by external electric fields. On the one hand, when the distance between the two nanosheets is close to a certain distance, the free energy barriers for the transitions dry→wet and wet→dry can be quite large. As a result, the wet and dry states are self-latched. On the other hand, an E
⊥ and an E
∥ will respectively increase and decrease the free energy of the water located in-between the two nanosheets. Consequently, the wet→dry and dry→wet transitions are observed. Our results may be useful for designing novel information memory devices.
Fast-speed self-powered PEDOT:PSS/α-Ga2O3 nanorod array/FTO photodetector with solar-blind UV/visible dual-band photodetection
Authors: Fan Ming-Ming , Xu Kang-Li , Cao Ling , Li Xiu-Yan
Published: November 2021

The α-Ga2O3 nanorod array is grown on FTO by hydrothermal and annealing processes. And a self-powered PEDOT:PSS/α-Ga2O3 nanorod array/FTO (PGF) photodetector has been demonstrated by spin coating PEDOT:PSS on the α-Ga2O3 nanorod array. Successfully, the PGF photodetector shows solar-blind UV/visible dual-band photodetection. Our device possesses comparable solar-blind UV responsivity (0.18 mA/W at 235 nm) and much faster response speed (0.102 s) than most of the reported self-powered α-Ga2O3 nanorod array solar-blind UV photodetectors. And it presents the featured and distinguished visible band photoresponse with a response speed of 0.136 s at 540 nm. The response time is also much faster than the other non-self-powered β-Ga2O3 DUV/visible dual-band photodetectors due to the fast-speed separation of photogenerated carries by the built-in electric field in the depletion regions of PEDOT:PSS/α-Ga2O3 heterojunction. The results herein may prove a promising way to realize fast-speed self-powered α-Ga2O3 photodetectors with solar-blind UV/visible dual-band photodetection by simple processes for the applications of multiple-target tracking, imaging, machine vision and communication.
Efficient and stable wireless power transfer based on the non-Hermitian physics
Authors: Zeng Chao , Guo Zhiwei , Zhu Kejia , Fan Caifu , Li Guo , Jiang Jun , Li Yunhui , Jiang Haitao , Yang Yaping , Sun Yong , Chen Hong
Published: November 2021

As one of the most attractive non-radiative power transfer mechanisms without cables, efficient magnetic resonance wireless power transfer (WPT) in the near field has been extensively developed in recent years, and promoted a variety of practical applications, such as mobile phones, medical implant devices and electric vehicles. However, the physical mechanism behind some key limitations of the resonance WPT, such as frequency splitting and size-dependent efficiency, is not very clear under the widely used circuit model. Here, we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics, which starts from a completely different avenue (utilizing loss and gain) to introduce novel functionalities to the resonance WPT. From the perspective of non-Hermitian photonics, the coherent and incoherent effects compete and coexist in the WPT system, and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity–time symmetry. Based on this basic physical framework, some optimization schemes are proposed, including using nonlinear effect, using bound states in the continuum, or resorting to the system with high-order parity-time symmetry. Moreover, the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological protection. Therefore, the non-Hermitian physics can not only exactly predict the main results of current WPT systems, but also provide new ways to solve the difficulties of previous designs.
X-ray focusing using an x-ray lens composed of multi-square polycapillary slices
Authors: Pan Kai , Yi Tian-Cheng , Wang Zhao , Zhou Mo , Li Yu-De , Liu Zhi-Guo , Lin Xiao-Yan , Sun Tian-Xi
Published: November 2021

A new type of x-ray lens composed of multi-square polycapillary slices (ASPXRL) used in focusing parallel x-ray beam was presented in this paper. Compared with conventional x-ray polycapillary lens, ASPXRL can provide smaller and brighter focus. The effects of the manufacturing imperfections on focusing quality of ASPXRL were evaluated with the values of transmission efficiency and discussed. It is suggested that ASPXRL has application prospects as a condenser lens for x-ray microscopy and flux collectors for x-ray analytical instruments.
Quantum computing for the Lipkin model with unitary coupled cluster and structure learning ansatz *
Authors: Chikaoka Asahi , Liang Haozhao
Published: November 2021

We report a benchmark calculation for the Lipkin model in nuclear physics with a variational quantum eigensolver in quantum computing. Special attention is paid to the unitary coupled cluster (UCC) ansatz and structure learning (SL) ansatz for the trial wave function. Calculations with both the UCC and SL ansatz can reproduce the ground-state energy well; however, it is found that the calculation with the SL ansatz performs better than that with the UCC ansatz, and the SL ansatz has even fewer quantum gates than the UCC ansatz.
Simulation of MRPC performance under different counting rates
Authors: Liu J. , Yu Y. , Wang Y. , Han D. , Li Y.
Published: November 2021

The increasing luminosity of accelerators requires a higher
counting rate capability of detectors. Previous studies have mostly
simulated the detection efficiency of RPCs at a high counting rate
but rarely involved the time resolution. In this paper, Geant4
software is used to simulate the interaction between particles and
detectors, avalanche multiplication (considering the effect of space
charge), and the generation, amplification, and shaping of the
induction signal. A model is used to describe the establishment and
recovery of the internal electric field in an MRPC at a high
rate. We obtain the detection efficiency and time resolution of
MRPCs with different structures at different counting rates. The
simulation results are in good agreement with the experimental
results, which verifies the feasibility of the model. At the same
time, it has been confirmed that MRPCs built with the low
resistivity glass developed by Tsinghua University can achieve a
time resolution of 60–80 ps and a 90% efficiency at a flux up
to 70 kHz/cm2 both in the experimental and simulation results.
Ecological restoration and rising CO2enhance the carbon sink, counteracting climate change in northeastern China
Authors: Huang Binbin , Lu Fei , Wang Xiaoke , Wu Xing , Zhang Lu , Ouyang Zhiyun
Published: November 2021

The impact of climate change, rising CO2, land-use/land-cover change and land management on the carbon cycle in terrestrial ecosystems has been widely reported. However, only rarely have studies have been conducted to clarify the impact of climate change and rising CO2on the carbon sink contributed by ecological restoration projects (ERPs). To better understand the impact of climate change and rising CO2on ERPs, we took the Beijing–Tianjin Sand Source Control Project zone as an example to set up different scenarios to distinguish the confounding effects of these factors on the regional carbon budget based on a remote sensing data-driven model. Compared with business as usual, our results show that climate change caused a carbon loss of 78.97 Tg C. On the contrary, ERPs contributed a carbon sink of approximately 199.88 Tg C in forest and grassland. Furthermore, rising CO2also contributed an additional carbon sink of 107.80 Tg C. This study distinguished the individual effects of different factors, and clarified the net carbon sink contributed by ERPs and rising CO2and their significance for enhancing the regional carbon sink and reversing the adverse effects of climate change on the carbon sink. Furthermore, ERPs can sequester carbon more effectively and faster compared with rising atmospheric CO2concentration.
Inverse cascade anomalies in fourth-order Leith models
Authors: Thalabard Simon , Medvedev Sergey , Grebenev Vladimir , Nazarenko Sergey
Published: November 2021

We analyze a family of fourth-order non-linear diffusion models corresponding to local approximations of four-wave kinetic equations of weak wave turbulence. We focus on a class of parameters for which a dual cascade behavior is expected with an infrared finite-time singularity associated to inverse transfer of waveaction. This case is relevant for wave turbulence arising in the nonlinear Schrödinger model and for the gravitational waves in the Einstein’s vacuum field model. We show that inverse transfer is not described by a scaling of the constant-flux solution but has an anomalous scaling. We compute the anomalous exponents and analyze their origin using the theory of dynamical systems.
The results of the use of gridless technology for the selection and sowing in a forest nursery of 1000 pieces equalized by weight and size (thickness) of Scotch pine seed fractions
Authors: Golev A D , Goleva G G , Ivannikov V A , Bukhtoyarov V N
Published: November 2021

The aim of our research is to analyze the quantitative composition of standard and non-standard Scots pine seedlings grown with all sowing options: calibrated small and large seeds, as well as uncalibrated seeds. As the material for the study, we used a batch of Scots pine seeds, which were divided by weight into two equal parts. Subsequently, one part was calibrated on a sieve-free separator in thickness into small and large fractions, and the second was not calibrated. The size gap in the calibrated fractions was determined experimentally based on the minimum and maximum size of the seed thickness. All the seeds obtained were sown separately from each other in the nursery areas. At the end of the second growing season, using the field method of accounting for the grown planting material, a sample of standard and non-standard seedlings was carried out. As a result, it was found that in crops with calibrated seeds of non-standard seedlings is 25 … 30% less than in crops with non-calibrated seeds. Thus, sowing with Scots pine seeds calibrated in thickness makes it possible to significantly increase the productivity of forest nursery areas in comparison with sowing with uncalibrated seeds.
Modified approach for effective assessment of human resource management in the forest industry
Authors: Zinovyeva I , Kuznetsov S , Stepanova Yu
Published: November 2021

The existing management system in the forest industry complex is not adapted to modern trends and is not integrated into the new practice of human resource management, since even at the stage of personnel selection it is not focused on assessing the skill-set of applicants. The paper identifies the features and factors affecting the human resource management system, and substantiates a modified approach to assessing the effectiveness of human resource management (based on the study of the world experience of management practices). Modern-level indicators based on a person-centered approach have been also defined. The study proposes the incorporation of new architecture of indicators (emotional intelligence, level of transformation of roles in the team, employment of all the roles according to the Belbin model, the coincidence of the company’s goal with the goals of employees, the level of employee skillset) as a part of the modified approach to assessing the effectiveness of human resource management that meets the new requirements. As a result, effective human resource management based on this approach will increase the competitiveness of the Russian forest industry at the international level.