bluuebunny/crossref_metadata_2025 huggingface dataset:
Der Zusammenhang von Persönlichkeitsstruktur, Burnout und
Prokrastination bei Psychologie- und Medizinstudierenden unter Einbeziehung von
sozialer Unterstützung und Entscheidungsspielraum im
Studium
Authors: Derwahl Leonie , Topalidou Christina , Dilba Pia , Buchholz Ines , Strauß Bernhard , Gumz Antje
Published: November 2023

Theoretischer Hintergrund Burnout und Prokrastination sind weit
verbreitete Phänomene bei Studierenden. Die Rolle der
Persönlichkeitsstruktur ist bislang wenig erforscht. Ziel der Studie: Es
wird der Zusammenhang von Persönlichkeitsstruktur und studienbezogenen
Arbeitsstörungen unter Berücksichtigung von Ressourcen und
Anforderungen bei Psychologie- und Medizinstudierenden untersucht.

Methodik Im Rahmen einer Querschnittsuntersuchung wurden Daten online an
61 deutschen Hochschulen und Universitäten erhoben. Erfasst wurden
Persönlichkeitsstrukturvariablen (Strukturniveau, OPD-SFK; Bindung,
ECR-RD 12; Emotionsregulation, ERQ), studienbezogene Arbeitsstörungen
(Burnout, MBI-SS-d; Prokrastination; APSI-d) sowie Ressourcen (soziale
Unterstützung, F-SozU K-6; Entscheidungsspielraum im Studium, selbst
entwickelte Skala) und Anforderungen (Corona-Pandemie, selbst entwickelte
Skala). Die Fragestellung wurde mittels einer hierarchischen Regressionsanalyse
beantwortet.

Ergebnisse Von Februar 2020 bis Dezember 2021 haben 775 Studierende
(49,2% Psychologiestudierende, 50,8% Medizinstudierende; Alter
M=24,1 Jahre, SD=5,1 Jahre; 82,3% weiblich,
17,4% männlich, 0,3% divers) an der Befragung
teilgenommen. Im Gesamtmodell wurde 30.4% der Varianz von
Burnout-Erschöpfung, 16,2% der Varianz von Burnout-Zynismus,
20,9% der Varianz von Burnout-Ineffizienz und 30,1% der Varianz
von Prokrastination erklärt (p<0,001). Das Strukturniveau zeigte
signifikant negative Zusammenhänge mit allen Burnout-Variablen sowie mit
Prokrastination (p<0,001). Die Emotionsregulationsstrategie Neubewertung
ging mit geringerer Burnout-Ineffizienz und Prokrastination (p<0,001),
die Strategie Emotionsunterdrückung mit geringerem Burnout-Zynismus
einher (p≤0,01). Der Entscheidungsspielraum im Studium war mit allen
Burnout-Variablen und Prokrastination (p<0,001), die soziale
Unterstützung mit Burnout-Ineffizienz negativ assoziiert
(p≤0,01). Das allgemeine Belastungsniveau während der
Corona-Pandemie zeigte einen positiven Zusammenhang mit
Burnout-Erschöpfung (p≤0,001).

Schlussfolgerungen Die Persönlichkeitsstruktur (Strukturniveau,
Emotionsregulation) hängt bedeutsam mit studienbezogenem Burnout und
Prokrastination zusammen. Trainingsangebote zur Förderung der
Emotionsregulationsfähigkeit könnten für vulnerablen
Studierendengruppen im Umgang mit Burnout und Prokrastination sehr hilfreich
sein.
Kurse und Weiterbildungen der staatlich und DKG anerkannten WBS-Ulm
Authors: Bundschu Marion
Published: November 2023

Informationen zu den Veranstaltungen finden Sie auf www.wbs-ulm.de.
Study on the spatio-temporal evolution characteristics and driving mechanism of China’s carbon emissions
Authors: Xu Yanqing , Liu Yan , Chen Ruidun , Meng Yifei , Li Kenan , Fu Cong
Published: November 2023

The present study aims to explore the spatial and temporal changes and drivers of carbon emission patterns in China, with the aim of encouraging county-level carbon reduction policies in pursuit of sustainable development. To this end, we have studied the spatial disparities, spatio-temporal patterns, and evolution characteristics of carbon emissions using county-level carbon emissions data from China between 2002 and 2017. Additionally, we have comprehensively considered the dynamic impacts of both county-level and city-level environmental factors on carbon emissions based on an optimized hierarchical random forest model. The results show that the carbon emissions of China’s counties have generally followed an upward trend before stabilizing. Notable characteristics include elevated carbon emissions in the northern regions and reduced carbon emissions in the southern areas. Additionally, there are higher carbon emissions in the eastern regions compared to lower emissions in the western and inland areas, with discernible local clustering patterns. These findings underscore the importance of tailoring the government’s emission reduction strategy to address the phased variations in carbon emissions across different districts and counties. It is essential to emphasize the key role of major urban agglomerations and metropolitan areas in carbon emission reduction, while also addressing potential emission sources in the resource-rich, yet technologically disadvantaged, northwest region. Furthermore, improving energy efficiency through technological innovation should be the primary means of carbon emission reduction at the county level.
The effect of spiritual leadership on proactive customer service performance: The roles of psychological empowerment and power distance
Authors: Zhu Delong , Bahadur Waseem , Ali Muhammad
Published: November 2023

Scholars have consistently demonstrated that spiritual leadership yields positive outcomes for employees. However, it is not clear how spiritual leadership influences proactive customer service performance. The purpose of this research is to develop a model, grounded in social cognitive theory, to identify why and when spiritual leadership promotes proactive customer service performance. Specifically, the focus is on how spiritual leadership through employee psychological empowerment facilitates proactive customer service performance under the condition of power distance. The empirical analysis, conducted through regression analysis using the PROCESS macro, is based on questionnaire data from 263 leaders and employees in the hospitality industry. Findings reveal that spiritual leadership has a positive effect on boosting employees’ psychological empowerment, subsequently nurturing their engagement in proactive customer service performance. Moreover, it is found that within an environment of low power distance, the favorable impact of spiritual leadership on proactive customer service performance is amplified, as employees are more inclined to challenge authority and norms and engage in proactively solving problems related to customer service. Key implications suggest scholars and managers ways to enhance proactive customer service performance.
Numerical study on the cavitation flow characteristics of high-pressure fuel in injector orifices based on compressible non-isothermal model
Authors: Dai Yan-Jun , Shi Ji-Wei , Cheng Xu-Liang , Zhang Zhuo , He Ying-Qi , Tao Wen-Quan
Published: November 2023

The flow inside the orifices in diesel injector largely determines the injection characteristics, which further affects the performance of the diesel engine. In this paper, numerical simulation is conducted to characterize the fuel flow with characteristics of two-phase cavitation, high speed, high pressure, high turbulence intensity, and high viscosity in two crucial orifice locations. The OZ orifice is selected as a benchmark to select the appropriate turbulence model and cavitation model. The simulation results from different turbulence and cavitation models are analyzed, and the combination of the realizable k–ɛ turbulence model and the Zwart–Gerber–Belamri cavitation model proves to be superior. Then, based on the validated models, the compressibility and non-isothermal characteristics of the fuel and two geometric parameters of the nozzles in an injector are emphatically discussed to depict the cavitation flow. The results suggest that the compressibility and non-isothermal characteristics of fuel affect the mass flow rate, fuel flow velocity, and cavitation extent within the orifices with a maximum deviation of the mass flow rate of 7.1%. However, their influence on the orifice flow coefficient is relatively minor with a maximum deviation of 0.8%. The mass flow rate and flow coefficient are both positively correlated with the rounded edge radius and taper coefficient. A greater rounded edge radius and taper coefficient can lead to a better fuel flow capacity in the nozzle orifice.
Effect of Hf alloying on magnetic, structural, and magnetostrictive properties in FeCo films for magnetoelectric heterostructure devices
Authors: Mion Thomas , Staruch Margo , Bussmann Konrad , Karapetrov Goran , van ’t Erve Olaf , Mills Sara , Ryou Heonjune , Goswami Ramasis , Callahan Patrick G. , Rowenhorst David J. , Qadri Syed B. , Lofland Samuel E. , Finkel Peter
Published: November 2023

Materials with high magnetoelectric coupling are attractive for use in engineered multiferroic heterostructures with applications such as ultra-low power magnetic sensors, parametric inductors, and non-volatile random-access memory devices. Iron–cobalt alloys exhibit both high magnetostriction and high saturation magnetization that are required for achieving significantly higher magnetoelectric coupling. We report on sputter-deposited (Fe0.5Co0.5)1−xHfx (x = 0 – 0.14) alloy thin films and the beneficial influence of Hafnium alloying on the magnetic and magnetostrictive properties. We found that co-sputtering Hf results in the realization of the peening mechanism that drives film stress from highly tensile to slightly compressive. Scanning electron microscopy and x-ray diffraction along with vibrating sample magnetometry show reduction in coercivity with Hf alloying that is correlated with reduced grain size and low film stress. We demonstrate a crossover from tensile to compressive stress at x ∼ 0.09 while maintaining a high magnetostriction of 50 ppm and a low coercive field of 1.1 Oe. These characteristics appear to be related to the amorphous nature of the film at higher Hf alloying.
Controllable optical Zitterbewegung in PT-symmetric photonic lattices
Authors: Zhan Kaiyun , Zhao Tingjun , Chen Qixuan , Zhang Qian , Kang Xinyue
Published: November 2023

We present that parity-time-symmetric photonic lattices can support optical Zitterbewegung (ZB) motion with controllable oscillation amplitude. The nonorthogonality of the Floquet–Bloch modes imposed by the non-Hermitian nature of the dynamics substantially affects the wave oscillation dynamics. It is shown that the amplitude of this optical ZB depends on the gain parameter, thus allowing to control the ZB process. The non-reciprocal light propagation induced by the nonorthogonality of the modes can balance the spectral angular broadening of the incident beam and even the strong oscillations with slightly growing amplitude along the propagation can be observed. Robustness of the optical ZB phenomenon to the perturbations of the gain parameter is also demonstrated.
Decoupling topological antiskyrmion and non-topological magnetic phases in D2d symmetric Mn–Ni–Ga single crystalline device
Authors: Jamaluddin Sk , Sen Subir , Chakrabartty Dola , Nayak Ajaya K.
Published: November 2023

Here, we present the finding of two types of distinct Hall signals in the single crystalline Hall devices of a D2d symmetric antiskyrmion host Mn–Ni–Ga sample. The out-of-plane device, where the magnetic field is applied along the [001] direction, exhibits a dip-like anomaly in the Hall resistivity data, signifying the presence of topological Hall signal originating from the antiskyrmion phase. Most importantly, we demonstrate the robustness of the antiskyrmion phase against an oblique field where the topological Hall signal survives up to a tilting angle of 75° with respect to the c-axis. In contrast, the Hall resistivity data for the in-plane device exhibit an aberrant hump-like feature that can be tuned with applying a rotating magnetic field. We show that this hump-like anomaly emerges from the existence of a two-component anomalous Hall effect arising due to the presence of twinning microstructure. The present study provides an important insight into the stability and evolution of the antiskyrmion phase under the oblique magnetic fields and helps in decoupling of anomalous Hall signals in the non-topological magnetic phases.
Experimental characterization of pressure and friction factor in an interior subchannel of a 61-pin wire-wrapped rod bundle with a porous blockage
Authors: Menezes Craig , Kinsky Matthew , Pyle Dalton W. , Hassan Yassin A.
Published: November 2023

Comprehending and counteracting accident conditions presented by impedances of flow in diminutive subchannels of a Liquid Metal Fast Reactor (LMFR) hexagonal rod bundle are imperative toward their development and safety. Scarce experimental research currently exists in the literature to characterize the pressure and friction factor for partial blockages in LMFR assemblies. Experimental pressure measurements were conducted in a 61-pin prototypical LMFR fuel assembly using specialized instrumented wire-wrapped rods with a three-dimensional printed porous blockage installed. The pressure drop was measured for one helical pitch at four distinct interior subchannel locations: two in the blocked subchannel and two unblocked adjacent locations (near-center and near-wall of the assembly). A wide range of Reynolds numbers between 140 and 24 000 were studied to evaluate the blocked subchannel friction factor and to determine the flow regime boundaries for laminar-to-transition and transition-to-turbulent flows. Power spectral density analysis of the pressure fluctuations for three distinct locations (one upstream and two downstream of the porous blockage) revealed the mechanisms of coherent structure formations and transport, and dominant location-dependent Strouhal numbers. One-dimensional continuous wavelet transforms of the pressure fluctuations demarcated temporal instances of flow events with their frequency content. Temporal cross correlation quantified the temporal delay between the blocked subchannel pressure fluctuations in the blockage vicinity. The presented research provides first-of-its-kind datasets and fluid physics based-analyses for the interior LMFR subchannel in the presence of a porous blockage and provides a benchmark for the validation of computational flow models and predictive correlations for the safety enhancement of LMFR rod bundles.
The strength, position, and width changes of the intertropical convergence zone since the Last Glacial Maximum
Authors: Yuan Shufang , Chiang Hong-Wei , Liu Guangxin , Bijaksana Satria , He Shaoneng , Jiang Xiuyang , Imran Andi M. , Wicaksono Satrio A. , Wang Xianfeng
Published: November 2023

The intertropical convergence zone (ITCZ) plays a key role in regulating tropical hydroclimate and global water cycle through changes in its convection strength, latitudinal position, and width. The long-term variability of the ITCZ, along with the corresponding driving mechanisms, however, remains obscure, mainly because it is difficult to separate different ITCZ variables in paleoclimate proxy records. Here, we report a speleothem oxygen isotope (δ
18
O) record from southwestern Sulawesi, Indonesia, and compile it with other speleothem records from the Maritime Continent. Using the spatial gradient of speleothem δ
18
O along a transect across the ITCZ, we constrain ITCZ variabilities over the Maritime Continent during the past 30,000 y. We find that ITCZ convection strength overall intensified from the last glacial period to the Holocene, following changes in climate boundary conditions. The mean position of the regional ITCZ has moved latitudinally no more than 3° in the past 30,000 y, consistent with the deduction from the atmospheric energy framework. However, different from modern observations and model simulations for future warming, the ITCZ appeared narrower during both the late Holocene and most part of the last glacial period, and its expansion occurred during Heinrich stadials and the early-to-mid Holocene. We also find that during the last glacial and deglacial period, prominent millennial-scale ITCZ changes were closely tied to the variability of the Atlantic meridional overturning circulation (AMOC), whereas during the Holocene, they were predominantly modulated by the long-term variability of the Walker circulation.
High sensitivity of summer temperatures to stratospheric sulfur loading from volcanoes in the Northern Hemisphere
Authors: Burke Andrea , Innes Helen M. , Crick Laura , Anchukaitis Kevin J. , Byrne Michael P. , Hutchison William , McConnell Joseph R. , Moore Kathryn A. , Rae James W. B. , Sigl Michael , Wilson Rob
Published: November 2023

The 540s, 1450s, and 1600s represent three of the five coldest decades in the Common Era (CE). In each of these cases, the cause of these cold pulses has been attributed to large volcanic eruptions. However, the provenance of the eruption and magnitude of the volcanic forcing remains uncertain. Here, we use high-resolution sulfur isotopes in Greenland and Antarctic ice cores measured across these events to provide a means of improving sulfur loading estimates for these eruptions. In each case, the largest reconstructed tree-ring cooling is associated with an extratropical eruption, and the high-altitude stratospheric sulfate loading of these events is substantially smaller than previous estimates (by up to a factor of two). These results suggest an increased sensitivity of the reconstructed Northern Hemisphere summer temperature response to extratropical eruptions. This highlights the importance of climate feedbacks and processes that amplify and prolong the cooling signal from high latitudes, such as changes in sea ice extent and ocean heat content.
Evaluating the impact of a street outreach intervention on participant involvement in gun violence
Authors: Ross Marisa C. , Ochoa Erin M. , Papachristos Andrew V.
Published: November 2023

The past several years have witnessed increased calls for community violence interventions (CVIs) that address firearm violence while centering local expertise and avoiding the criminal legal system. Currently, little evidence exists on CVI effectiveness at the individual level. This study presents an evaluation of the impact of a street outreach-based CVI [Chicago CRED (Create Real Economic Destiny)] on participant involvement in violence. We used a quasiexperimental design with a treatment sample of 324 men recruited by outreach staff from 2016 to 2021 and a balanced comparison sample of 2,500 men from a network of individuals arrested in CRED’s service areas. We conducted a Bayesian survival analysis to evaluate CRED’s effect on individual violence-related outcomes on three levels of treatment: All enrolled participants, a subsample that made it through the initial phase, and those who completed programming. The intervention had a strong favorable effect on the probability of arrest for a violent crime for those completing the program: After 24 mo, CRED alumni experienced an 11.3 percentage point increase in survival rates of arrest for a violent crime relative to their comparisons (or, stated differently, a 73.4% reduction in violent crime arrests). The other two treatment levels experienced nontrivial declines in arrests but did not reach statistical significance. No statistically significant reduction in victimization risk was detected for any of the treatment levels. Results demonstrate that completion of violence intervention programming reduces the likelihood of criminal legal involvement for participants, despite the numerous systemic and environmental factors that impede personal success.
Ripple effects of hospital team faultlines on patient outcomes
Authors: Li Ren , Choi Virginia K. , Gelfand Michele J.
Published: November 2023

Medical errors are rampant across healthcare settings, imposing a significant burden on patient safety. Here, we examined the ripple effects of diversity splits, or faultlines, within hospital teams on patient safety and care. Hospitals consist of hierarchical, mixed-gender, and multiracial units that are prone to conflict. Within a diverse unit, faultlines can occur when multiple attributes (e.g., gender and race) of unit members align and divide a unit into two or more homogeneous subgroups. Yet, little is known about how such faultlines influence patients. Hierarchical path modeling of data collected from 1,102 hospital employees and 4,138 patients across 38 hospital units illustrated that when strong faultlines formed through homogenous subgroups within hospital units resulted in decreased civility among staff. This incivility was related to higher rates of medical error and patient deaths. A 10% increase in unit incivility was linked to a maximum 8.87% increase in healthcare-associated infection rates and a maximum 10.59% increase in mortality rates. However, we found patients within units high on collaborative cultures for managing conflicts—that fostered mutual respect, active listening, and openness to differing opinions—experienced fewer medical errors and lower mortality rates, regardless of strong faultlines. These findings offer an evidence-based, culture-focused approach to reducing medical errors and improving the quality of patient care.
Free energies at QM accuracy from force fields via multimap targeted estimation
Authors: Rizzi Andrea , Carloni Paolo , Parrinello Michele
Published: November 2023

Accurate predictions of ligand binding affinities would greatly accelerate the first stages of drug discovery campaigns. However, using highly accurate interatomic potentials based on quantum mechanics (QM) in free energy methods has been so far largely unfeasible due to their prohibitive computational cost. Here, we present an efficient method to compute QM free energies from simulations using cheap reference potentials, such as force fields (FFs). This task has traditionally been out of reach due to the slow convergence of computing the correction from the FF to the QM potential. To overcome this bottleneck, we generalize targeted free energy methods to employ multiple maps—implemented with normalizing flow neural networks (NNs)—that maximize the overlap between the distributions. Critically, the method requires neither a separate expensive training phase for the NNs nor samples from the QM potential. We further propose a one-epoch learning policy to efficiently avoid overfitting, and we combine our approach with enhanced sampling strategies to overcome the pervasive problem of poor convergence due to slow degrees of freedom. On the drug-like molecules in the HiPen dataset, the method accelerates the calculation of the free energy difference of switching from an FF to a DFTB3 potential by three orders of magnitude compared to standard free energy perturbation and by a factor of eight compared to previously published nonequilibrium calculations. Our results suggest that our method, in combination with efficient QM/MM calculations, may be used in lead optimization campaigns in drug discovery and to study protein-ligand molecular recognition processes.
Minimizing the impacts of the ammonia economy on the nitrogen cycle and climate
Authors: Bertagni Matteo B. , Socolow Robert H. , Martirez John Mark P. , Carter Emily A. , Greig Chris , Ju Yiguang , Lieuwen Tim , Mueller Michael E. , Sundaresan Sankaran , Wang Rui , Zondlo Mark A. , Porporato Amilcare
Published: November 2023

Ammonia (NH3) is an attractive low-carbon fuel and hydrogen carrier. However, losses and inefficiencies across the value chain could result in reactive nitrogen emissions (NH3, NOx, and N2O), negatively impacting air quality, the environment, human health, and climate. A relatively robust ammonia economy (30 EJ/y) could perturb the global nitrogen cycle by up to 65 Mt/y with a 5% nitrogen loss rate, equivalent to 50% of the current global perturbation caused by fertilizers. Moreover, the emission rate of nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting molecule, determines whether ammonia combustion has a greenhouse footprint comparable to renewable energy sources or higher than coal (100 to 1,400 gCO2e/kWh). The success of the ammonia economy hence hinges on adopting optimal practices and technologies that minimize reactive nitrogen emissions. We discuss how this constraint should be included in the ongoing broad engineering research to reduce environmental concerns and prevent the lock-in of high-leakage practices.
Male-killing virus in a noctuid mothSpodoptera litura
Authors: Nagamine Keisuke , Kanno Yoshiaki , Sahara Ken , Fujimoto Toshiaki , Yoshido Atsuo , Ishikawa Yukio , Terao Misato , Kageyama Daisuke , Shintani Yoshinori
Published: November 2023

A female-biased sex ratio is considered advantageous for the cytoplasmic elements that inhabit sexually reproducing organisms. There are numerous examples of bacterial symbionts in the arthropod cytoplasm that bias the host sex ratio toward females through various means, including feminization and male killing. Recently, maternally inherited RNA viruses belonging to the family Partitiviridae were found to cause male killing in moths and flies, but it was unknown whether male-killing viruses were restricted to Partitiviridae or could be found in other taxa. Here, we provide compelling evidence that a maternally inherited RNA virus, Spodoptera litura male-killing virus (SlMKV), selectively kills male embryos of the tobacco caterpillarSpodoptera litura, resulting in all-female broods. SlMKV injected into uninfectedS. lituracan also be inherited maternally and causes male killing. SlMKV has five genomic segments encoding seven open reading frames, has no homolog of known male-killing genes, and belongs to an unclassified group of arthropod-specific viruses closely related to Tolivirales. When transinfected into larvae, both male and female recipients allow SlMKV to proliferate, but only males die at the pupal stage. The viral RNA levels in embryonic and pupal male killing suggest that the mechanism of male killing involves the constitutive expression of viral products that are specifically lethal to males, rather than the male-specific expression of viral products. Our results, together with recent findings on male-killing partiti-like viruses, suggest that diverse viruses in arthropods tend to acquire male killing independently and that such viruses may be important components of intragenomic conflict in arthropods.
Mediatorship in the clash of hegemonic and counter publics
Authors: Abdal Göksenin , Yaman Büşra
Published: November 2023

This study discusses how the publication of Alice Oseman’s translation of the Heartstopper
(Kalp Çarpıntısı) series in Turkey became a case of multiple mediatorship, from the stigmatization of the
series as “propaganda of heresy” and the official restrictions of its sales to the support for its dissemination among the target
audience. Closely relating to the mediation processes that turn sanctions into statements against the LGBTQ+ community or
springboards for solidarity in support of equality and inclusion, the concept of multiple mediatorship embodies mediators or
agents acting for or against the dissemination of the series among Turkish readers. In that vein, this study offers a nuanced
understanding of how mediation cannot simply be deemed a collaborative act enabled by alliance, but, rather, of how it involves a
clash of multiple mediators who are in conflict in the public sphere.
SCRIB controls apical contractility during epithelial differentiation
Authors: Boëda Batiste , Michel Vincent , Etournay Raphael , England Patrick , Rigaud Stéphane , Mary Héloïse , Gobaa Samy , Etienne-Manneville Sandrine
Published: November 2023

Although mutations in the SCRIB gene lead to multiple morphological organ defects in vertebrates, the molecular pathway linking SCRIB to organ shape anomalies remains elusive. Here, we study the impact of SCRIB-targeted gene mutations during the formation of the gut epithelium in an organ-on-chip model. We show that SCRIB KO gut-like epithelia are flatter with reduced exposed surface area. Cell differentiation on filters further shows that SCRIB plays a critical role in the control of apical cell shape, as well as in the basoapical polarization of myosin light chain localization and activity. Finally, we show that SCRIB serves as a molecular scaffold for SHROOM2/4 and ROCK1 and identify an evolutionary conserved SHROOM binding site in the SCRIB carboxy-terminal that is required for SCRIB function in the control of apical cell shape. Our results demonstrate that SCRIB plays a key role in epithelial morphogenesis by controlling the epithelial apical contractility during cell differentiation.
Stem cell–like reprogramming is required for leukemia-initiating activity in B-ALL
Authors: Fregona Vincent , Bayet Manon , Bouttier Mathieu , Largeaud Laetitia , Hamelle Camille , Jamrog Laura A. , Prade Naïs , Lagarde Stéphanie , Hebrard Sylvie , Luquet Isabelle , Mansat-De Mas Véronique , Nolla Marie , Pasquet Marlène , Didier Christine , Khamlichi Ahmed Amine , Broccardo Cyril , Delabesse Éric , Mancini Stéphane J.C. , Gerby Bastien
Published: November 2023

B cell acute lymphoblastic leukemia (B-ALL) is a multistep disease characterized by the hierarchical acquisition of genetic alterations. However, the question of how a primary oncogene reprograms stem cell–like properties in committed B cells and leads to a preneoplastic population remains unclear. Here, we used the PAX5::ELN oncogenic model to demonstrate a causal link between the differentiation blockade, the self-renewal, and the emergence of preleukemic stem cells (pre-LSCs). We show that PAX5::ELN disrupts the differentiation of preleukemic cells by enforcing the IL7r/JAK-STAT pathway. This disruption is associated with the induction of rare and quiescent pre-LSCs that sustain the leukemia-initiating activity, as assessed using the H2B-GFP model. Integration of transcriptomic and chromatin accessibility data reveals that those quiescent pre-LSCs lose B cell identity and reactivate an immature molecular program, reminiscent of human B-ALL chemo-resistant cells. Finally, our transcriptional regulatory network reveals the transcription factor EGR1 as a strong candidate to control quiescence/resistance of PAX5::ELN pre-LSCs as well as of blasts from human B-ALL.
New Painlevé Integrable (3+1)-Dimensional Combined pKP-BKP Equation: Lump and Multiple Soliton Solutions
Authors: Wazwaz Abdul-Majid
Published: November 2023

We introduce a new form of the Painlevé integrable (3+1)-dimensional combined potential Kadomtsev--Petviashvili equation incorporating the B-type Kadomtsev–Petviashvili equation (pKP–BKP equation). We perform the Painlevé analysis to emphasize the complete integrability of this new (3+1)-dimensional combined integrable equation. We formally derive multiple soliton solutions via employing the simplified Hirota bilinear method. Moreover, a variety of lump solutions are determined. We also develop two new (3+1)-dimensional pKP–BKP equations via deleting some terms from the original form of the combined pKP–BKP equation. We emphasize the Painlevé integrability of the newly developed equations, where multiple soliton solutions and lump solutions are derived as well. The derived solutions for all examined models are all depicted through Maple software.
The impact of telescope aberrations on the magnitude of tilt to length coupling noise in space based gravitational wave detectors
Authors: Fan Wentong , Fang Sijun , Hai Hongwen , Song Jie , Zhou Jinhang , Wu Yuwei , Zou Rurui , Zhao Kai , Zhang Rui , Li Bohong , Luo Jian , He Bin , Qiu Minyan , Fan Lei , Li Zizheng , Zhao Hongchao , Yan Yong
Published: November 2023

Tilt-to-length (TTL) coupling noise is one of the main noise sources that affect space gravitational wave detection, and the Tianqin project requires that the internal TTL coupling noise of the telescope used be less than 0.4 pm/Hz1/2 within the frequency band from 0.1 mHz to 1 Hz. In order to design a telescope that meets the requirements of TTL coupling noise and carry out preliminary error allocation research, it is necessary to analyze and calculate the TTL coupling noise, and then guide the design and optimization of the telescope system. This paper establishes a computational analysis model for the non-geometric TTL coupling noise inside the telescope using the first 36-order edge Zernike polynomials. A method was proposed to reduce the internal TTL coupling noise of the telescope by reducing the proportion of sensitive aberrations caused by non-geometric TTL coupling noise. Simulation results show that, with the RMS value of wavefront aberration at the telescope exit pupil unchanged, reducing the proportion of sensitive aberrations at the telescope exit pupil can effectively reduce the internal TTL coupling noise of the telescope. By optimizing the telescope optical system to reduce the proportion of noise-sensitive aberrations, the non-geometric TTL coupling noise inside the telescope has been reduced from 0.34 pm/Hz1/2 @ 0.1 mHz ∼ 1 Hz to 0.25 pm/Hz1/2. This result can provide some guidance for the design of telescope optics based on the suppression of internal TTL coupling noise in the telescope.
Online identification of burn-through and weld deviation in sheet lap MIG welding based on YOLOv5
Authors: Wang Jie , Zhang Zhifen , Qin Rui , Wen Guangrui
Published: November 2023

Abstract

Online monitoring of the welding process is very important to the development of the modern manufacturing industry. However, monitoring welding defects in real-time and with high accuracy is challenging because welding is inherently a dynamic, non-linear process. In this paper, the forming defects generated during the melt Inert-gas welding of sheet steel as the object of research. We propose a multi-task simultaneous monitoring system for welding defects based on the YOLOv5 model, which can achieve highly accurate simultaneous detection of burn-through and weld deviation defects. Firstly, a passive vision system has been designed that can filter out strong arc light interference. In combination with a self-made camera bracket with flexible adjustment and repeatable positioning, clear images of the molten pool can be acquired. Compared to common methods that require a laser for weld deviation detection, all monitoring tasks can be performed with just one charge coupled device camera, significantly reducing the cost of deploying the system. Secondly, to obtain experimental data closer to the industrial field environment. We simulated different degrees of local and continuous burn-through by changing three parameters: welding current, plate thickness, and lap width. Four different deviations: left, right, and tilt were designed to obtain rich weld deviation image data. Finally, based on the above data, we compared several aspects such as detection speed, recognition accuracy, and loss function. The YOLOv5s model with the smallest model parameters was finally selected as the base model. The results show that our proposed multi-task simultaneous monitoring system achieves an average accuracy of 98.84% for the identification of four molten pool states. Burn-through defect and weld deviation detection with more than 50 frames per second can be achieved in the online detection state. This paper can provide some guidance for the online monitoring of the welding manufacturing process.
Influence of cooling rate on microstructure and defect evolution in GaAs during solidification
Authors: Wang Siyuan , Chen Qian , Yuan Yongkai , Gao Tinghong , Liang Yongchao , Tian Zean , Yang Anqi
Published: November 2023

The fabrication of high-quality GaAs crystals is essential to approach optimal performance in optoelectronic and microelectronic devices. In this study, a molecular dynamics simulation study was conducted for the solidification of liquid GaAs at three cooling rates (1010 K s−1, 1011 K s−1, and 1012 K s−1) at 300 K. The structural evolution in terms of crystal structure and defect formation in GaAs was thoroughly investigated using pair distribution function, average atomic energy, the largest standard cluster analysis, and visualization techniques. The results showed that the cooling rate of 1010 K s−1 led to the development of the best crystal quality with ease of eutectic twin grain boundary coherent twin boundary formation. Increasing the cooling rates to 1011 K s−1 and 1012 K s−1 resulted in the amorphous structure. Both high and low cooling rates profoundly affected the formation of As8 structure, but a maximum amount of 2.2% of As8 crystal structure was formed at a cooling rate of 1011 K s−1. The reduction in cooling rate to 1010 K s−1 induced the formation of numerous Schottky and Frenkel types of partial dislocations in the GaAs system. Results of this study can serve as potential guidelines to the theory of crystal growth and may be implemented in the fabrication of high-quality GaAs crystals for optimal device performance.
Graphene nanowalls grown on copper mesh
Authors: Reguig Abdeldjalil , Vishal Badri , Smajic Jasmin , Bahabri Mohammed , Deokar Geetanjali , Alrefae Majed A , Costa Pedro M F J
Published: November 2023

Graphene nanowalls (GNWs) can be described as extended nanosheets of graphitic carbon where the basal planes are perpendicular to a substrate. Generally, existing techniques to grow films of GNWs are based on plasma-enhanced chemical vapor deposition (PECVD) and the use of diverse substrate materials (Cu, Ni, C, etc) shaped as foils or filaments. Usually, patterned films rely on substrates priorly modified by costly cleanroom procedures. Hence, we report here the characterization, transfer and application of wafer-scale patterned GNWs films that were grown on Cu meshes using low-power direct-current PECVD. Reaching wall heights of ∼300 nm, mats of vertically-aligned carbon nanosheets covered square centimeter wire meshes substrates, replicating well the thread dimensions and the tens of micrometer-wide openings of the meshes. Contrastingly, the same growth conditions applied to Cu foils resulted in limited carbon deposition, mostly confined to the substrate edges. Based on the wet transfer procedure turbostratic and graphitic carbon domains co-exist in the GNWs microstructure. Interestingly, these nanoscaled patterned films were quite hydrophobic, being able to reverse the wetting behavior of SiO2 surfaces. Finally, we show that the GNWs can also be used as the active material for C-on-Cu anodes of Li-ion battery systems.
Scanning near-field optical microscopy measurements and simulations of regularly arranged silver nanoparticles
Authors: Song M , Fumagalli P , Schmid M
Published: November 2023

Silver nanoparticles on a glass substrate are experimentally investigated by aperture scanning near-field optical microscopy (a-SNOM). To understand the experimental results, finite-element-method simulations are performed building a theoretical model of the a-SNOM geometry. We systematically vary parameters like aperture size, aluminum-coating thickness, tip cone angle, and tip-surface distance and discuss their influence on the near-field enhancement. All these investigations are performed comparatively for constant-height and constant-gap scanning modes. In the end, we establish a reliable and stable optical model for simulating a-SNOM measurements, which is capable of reproducing trends observed in experimental data.
Tungsten accumulation during ion cyclotron resonance heating operation on WEST
Authors: Maget P , Manas P , Dumont R , Angioni C , Artaud J-F , Bourdelle C , Casson F J , Colas L , Devynck P , Fajardo D , Fedorczak N , Goniche M , Hillairet J , Huynh Ph , Koechl F , Moiraf D , Morales J , Vézinet D ,   the WEST Team
Published: November 2023

The observation of radiative collapses during ion cyclotron resonance heating (ICRH) operation on the full tungsten WEST tokamak constitutes a unique opportunity to get a quantitative balance of the sources and sinks in the core region of the plasma. Experimental analysis and numerical modelling evidence a significant reduction of the effective electron heat source delivered by ICRH compared with expectations on the one hand, and a complex interplay of mechanisms acting on the collisional peaking of tungsten on the other hand. Besides providing an explanation for the observed radiative collapses, this work outlines the variety of phenomenon determining the tungsten profile in ICRH operation.
EEG decoding for datasets with heterogenous electrode configurations using transfer learning graph neural networks
Authors: Han Jinpei , Wei Xiaoxi , Faisal A Aldo
Published: November 2023

Objective. Brain-machine interfacing (BMI) has greatly benefited from adopting machine learning methods for feature learning that require extensive data for training, which are often unavailable from a single dataset. Yet, it is difficult to combine data across labs or even data within the same lab collected over the years due to the variation in recording equipment and electrode layouts resulting in shifts in data distribution, changes in data dimensionality, and altered identity of data dimensions. Our objective is to overcome this limitation and learn from many different and diverse datasets across labs with different experimental protocols. Approach. To tackle the domain adaptation problem, we developed a novel machine learning framework combining graph neural networks (GNNs) and transfer learning methodologies for non-invasive motor imagery (MI) EEG decoding, as an example of BMI. Empirically, we focus on the challenges of learning from EEG data with different electrode layouts and varying numbers of electrodes. We utilize three MI EEG databases collected using very different numbers of EEG sensors (from 22 channels to 64) and layouts (from custom layouts to 10–20). Main results. Our model achieved the highest accuracy with lower standard deviations on the testing datasets. This indicates that the GNN-based transfer learning framework can effectively aggregate knowledge from multiple datasets with different electrode layouts, leading to improved generalization in subject-independent MI EEG classification. Significance. The findings of this study have important implications for brain-computer-interface research, as they highlight a promising method for overcoming the limitations posed by non-unified experimental setups. By enabling the integration of diverse datasets with varying electrode layouts, our proposed approach can help advance the development and application of BMI technologies.
Design and Implementation of RISC-V Based Pipelined Multiplier
Authors: Sun Rongxue , Liu Huimin , Zhang Rong , Qu Jiale
Published: November 2023

Among the many microprocessors, RISC-V as an open-source instruction set is gradually gaining popularity among academia and industry. The performance of the multiplier in the microprocessor imposes constraints on the computational power of the processor. In order to improve the efficiency of multiplication instructions, a pipeline multiplier is implemented in this paper. Firstly, the partial product is generated using the Radix-4 booth. Secondly, the Wallace tree structure is used to accelerate the compression of the partial product. Then, a parallel prefix adder is used to calculate the resulting partial product to improve the timing. Finally, registers are added as a pipeline to achieve a high-efficiency multiplication calculation. With the operating voltage and temperature set to typical conditions, the integrated multiplier area is 50260.6 μm2, and the power consumption is 20.41 mW. The final frequency of the multiplier is 1 GHz in gate-level simulation.
Automatic Solder Joints Layout Algorithm Based on Electrostatics Model
Authors: Yang Wangjun , Cui Zihang , Duan Jiayi
Published: November 2023

Currently, there are many automated algorithms for solder joints layout, such as genetic algorithms, ant colony algorithms, and neural network-based algorithms. The goal of these algorithms is to find the best solder joint layout to improve the quality of welding. However, due to the limited space in mobile phones, sandwich boards are widely used, and their structure determines that the number of solder joints should be increased as much as possible to enhance the flexibility of the device layout. This article proposes an automatic solder joint layout algorithm based on the electrostatics model for the solder joint layout problem on PCB frame boards and LGA boards. The solder joint and frame board are mapped as charged bodies. The position of each solder joint is continuously iteratively corrected so that the total potential energy of the system is zero, thereby satisfying the constraints to obtain a reasonable layout of the solder joint and increase the number of solder joint layouts. Experimental results show that this algorithm can achieve the maximum automatic layout of solder joints on PCB frame boards and LGA boards, and the space utilization rate can reach 95.5% of the theoretical maximum value.
An LDO without a Capacitor Required in Applications
Authors: Shi Leilei , Fan Jiaqi , Huang Shengming
Published: November 2023

Linear voltage regulator with low voltage dropout is widely used in DC/DC circuits because of the advantages of simple structure, low noise, high efficiency, and small package size. In this paper, high stability LDO linear voltage regulator with low static current is designed. By using a voltage detection module, the pass transistor in the regulator can be quickly regulated or switched on and off under load transient conditions. In addition, the stability of the LDO is improved by using an NMOS pass transistor and diode clamp architecture. The test results show that the typical values of linear adjustment and load adjustment of the voltage regulator are 20 mV and 200 mV, respectively. The maximum output current is 60 mA, the load current is 20 mA, and the output pressure difference under 4.8 V output voltage is 210 mV. Compared with traditional LDO, although the output current is not the maximum, the difference and stability of output pressure are greatly improved.
Super-Twisting Sliding Mode Active Disturbance Rejection Control of Permanent Magnet Synchronous Motor Based on Vector Control
Authors: Li Runze , Fang Wei , Wang Shuai
Published: November 2023

The vector control speed regulation system of the permanent magnet synchronous motor founded on traditional control has some weaknesses of poor rapidity and robustness, and it is hard to satisfy the current control requirements. A new control method combining active disturbance rejection control technology with improved super-twisting sliding mode control technology (STSM-ADRC) comes up. In active disturbance rejection control, the tracking differentiator is simplified; the extended state observer is designed to observe all internal and exterior disturbances of the system; the improved super-twisting sliding mode control law is going to take the place of the error feedback control law; and the simulation is carried out. Compared with the existing control algorithms, this new control method can overcome the influence of load disturbances and track the given speed effectively. And the responsiveness and robustness of the system are strengthened.
Research on improved sliding mode control of permanent magnet synchronous motor with disturbance compensation
Authors: Cao Jiaxuan , Liu Jun
Published: November 2023

In order to address the shortcomings of traditional sliding mode variable structure control in permanent magnet synchronous motor vector control, such as the state quantity’s inability to converge to 0 in limited time, too large chattering, too large load disturbance, poor dynamic performance, a non-singular fast terminal sliding mode control algorithm in speed loop is proposed. At the same time, a new approach rate is designed by comparing the advantages and disadvantages of different approach rates, which can restrain the natural chattering of sliding mode and improve the approach rate. On this basis, in order to increase response time, lessen chattering, and enhance the observer’s capacity for adaptation, a load torque observer is constructed, load disturbance is added to the speed loop as feedforward compensation, and a new approach rate is added to the observer. The simulation results manifest that the design successfully tracks load torque, enhances the system’s dynamic performance, and lessens the impact of sliding mode chattering.