bluuebunny/crossref_metadata_2025 huggingface dataset:
Sri Lankan Sloth Bear (Melursus ursinus inornatus) Attacks on Humans
Authors: Thalgaspitiya Sujeewa P.B. , Siriwardana Amila , Chenthuran Venkat , Wijerathne Buddhika T.B.
Published: September 2022

The sloth bear ( Melursus ursinus) is an omnivore that has been reported around most parts of South Asia. Although rare, sloth bear attacks can inflict potentially life-threatening injuries. This cross-sectional study analyzed 10 patients who had been mauled by sloth bears and who presented to rural hospitals in the Anuradhapura district of Sri Lanka between 2015 and 2019. All of the patients were male farmers. The human–bear encounters occurred in the jungle during the daytime. Ten victims sustained multiple soft tissue and bone injuries, mainly to the face and arms. The injuries ranged from minor abrasions to extensive deep lacerations and bone fractures. All of the patients were managed in the tertiary care hospital by multidisciplinary surgical teams. Sloth bear-inflicted wounds must be treated as major trauma. There is a need to formulate guidelines and train medical officers in managing animal-inflicted injuries in Sri Lanka.
Connectome-based prediction of eating disorder-associated symptomatology
Authors: Chen Ximei , Dong Debo , Zhou Feng , Gao Xiao , Liu Yong , Wang Junjie , Qin Jingmin , Tian Yun , Xiao Mingyue , Xu Xiaofei , Li Wei , Qiu Jiang , Feng Tingyong , He Qinghua , Lei Xu , Chen Hong
Published: September 2022

Background

Despite increasing knowledge on the neuroimaging patterns of eating disorder (ED) symptoms in non-clinical populations, studies using whole-brain machine learning to identify connectome-based neuromarkers of ED symptomatology are absent. This study examined the association of connectivity within and between large-scale functional networks with specific symptomatic behaviors and cognitions using connectome-based predictive modeling (CPM).

Methods

CPM with ten-fold cross-validation was carried out to probe functional networks that were predictive of ED-associated symptomatology, including body image concerns, binge eating, and compensatory behaviors, within the discovery sample of 660 participants. The predictive ability of the identified networks was validated using an independent sample of 821 participants.

Results

The connectivity predictive of body image concerns was identified within and between networks implicated in cognitive control (frontoparietal and medial frontal), reward sensitivity (subcortical), and visual perception (visual). Crucially, the set of connections in the positive network related to body image concerns identified in one sample was generalized to predict body image concerns in an independent sample, suggesting the replicability of this effect.

Conclusions

These findings point to the feasibility of using the functional connectome to predict ED symptomatology in the general population and provide the first evidence that functional interplay among distributed networks predicts body shape/weight concerns.
A stochastic model for capital requirement assessment for mortality and longevity risk, focusing on idiosyncratic and trend components
Authors: Clemente Gian Paolo , Della Corte Francesco , Savelli Nino
Published: September 2022

This paper provides a stochastic model, consistent with Solvency II and the Delegated Regulation, to quantify the capital requirement for demographic risk. In particular, we present a framework that models idiosyncratic and trend risks exploiting a risk theory approach in which results are obtained analytically. We apply the model to non-participating policies and quantify the Solvency Capital Requirement for the aforementioned risks in different time horizons.
Sympathy for the devil? Voter support for illiberal politicians
Authors: Lewandowsky Marcel , Jankowski Michael
Published: September 2022

Many democracies are witnessing the rise and continuing success of parties and politicians who oppose fundamental principles of liberal democracy. Recent research finds that voters support illiberal politicians, because they trade off policy congruence against attitudes toward liberal democracy. Other studies, however, suggest that authoritarian and populist voters might actually have a preference to vote for illiberal candidates. We argue that both factors interact: Authoritarian and populist voters are more willing to trade off policy representation against support for liberal democracy. To test this mechanism, we rely on a survey experiment conducted in Germany. The results clearly demonstrate that voters indeed trade off policy congruence against liberal democracy. Moreover, this effect is particularly strong for populist and authoritarian voters. Overall, the results have important implications for understanding when and which voters support or oppose liberal democracy.
Fluid‐Like Behavior of Crushed Rock Flows
Authors: Hu Wei , Xu Qiang , McSaveney Mauri , Scaringi Gianvito , Huang Runqiu , Wang Gonghui , Gou Huaixiao , Zheng Yangshuai
Published: September 2022

The puzzle of the unexpectedly high mobility of large geophysical flows has been reported as “solved” many times since Albert Heim drew attention to it after a disastrous landslide at Elm, Switzerland. However, the mechanism of high mobility remains mysterious. A series of high‐speed rotary shear experiments on particles of different minerals was conducted to explore the high mobility flow‐like behavior of crushable dense granular flow. We found that the flow behavior was more explicable when the shear resistance was considered as a viscous resistance rather than as a frictional resistance. We also found that for the crushable material, the viscosity dramatically decreased and reached a constant and relatively low value, which controlled the high fluidity and hypermobility of large geophysical flows such as rock avalanches. More precisely, there are two phases of the flow behavior, that are separated at a weakening point in the accumulating strain for crushable material. The first phase was a simple Newtonian or non‐Newtonian‐like flow. The second phase was more complex, in which the flow viscosity decreased profoundly and reached a constant viscous resistance at a considerable strain. This finding is important for explaining the hypermobility of many large geophysical processes, such as rock avalanche motion, natural faulting and crater collapse. In particular, we demonstrate that the behavior of rock avalanches is similar to that of complicated fluids with extensive weakening and that the viscosity of this special “liquid” is as low as 500 Pa·s. This finding can also help improve the accuracy and reliability of the numerical simulation of rock avalanches by using the viscous model obtained from the experiments.
Wildfire Smoke Influence on Cloud Water Chemical Composition at Whiteface Mountain, New York
Authors: Lee Jamy Y. , Peterson Peter K. , Vear Logan R. , Cook Ryan D. , Sullivan Amy P. , Smith Ellie , Hawkins Lelia N. , Olson Nicole E. , Hems Rachel , Snyder Philip K. , Pratt Kerri A.
Published: September 2022

Wildfires significantly impact air quality and climate, including through the production of aerosols that can nucleate cloud droplets and participate in aqueous‐phase reactions. Cloud water was collected during the summer months (June–September) of 2010–2017 at Whiteface Mountain, New York and examined for biomass burning influence. Cloud water samples were classified by their smoke influence based on backward air mass trajectories and satellite‐detected smoke. A total of 1,338 cloud water samples collected over 485 days were classified by their probability of smoke influence, with 49% of these days categorized as having moderate to high probability of smoke influence. Carbon monoxide and ozone levels were enhanced during smoke influenced days at the summit of Whiteface Mountain. Smoke‐influenced cloud water samples were characterized by enhanced concentrations of potassium, sulfate, ammonium, and total organic carbon, compared to samples lacking identified influence. Five cloud water samples were examined further for the presence of dissolved organic compounds, insoluble particles, and light‐absorbing components. The five selected cloud water samples contained the biomass burning tracer levoglucosan at 0.02–0.09 μM. Samples influenced by air masses that remained aloft, above the boundary layer during transport, had lower insoluble particle concentrations, larger insoluble particle diameters, and larger oxalate:sulfate ratios, suggesting cloud processing had occurred. These findings highlight the influence that local and long‐range transported smoke have on cloud water composition.
Timing and Structure of 10.9 and 10.3 ka BP Events Revealed by Annually Laminated Stalagmite Records From Shihua Cave, Northern China
Authors: Li Miaofa , Wang Fang , Cai Binggui , Cao Qi , Cheng Hai , Shen Chuan‐Chou , Tan Ming , Edwards R. Lawrence
Published: September 2022

Studies have shown that East Asia experienced several abrupt centennial‐scale weak monsoonal events in the early Holocene. However, the timing and structure of these climate events remain unclear due to the lack of precisely dated and highly resolved records. In this study, we present a well‐dated high‐resolution East Asia summer monsoon record from 11.32 to 10 ka BP based on two coeval stalagmites, one of which developed clear annual lamina, from Shihua Cave, northern China. Stalagmite δ18O records show 2 weak summer monsoon events at 10.9 and 10.3 ka. The 10.9‐ka event occurred from 10.93 to 10.79 ka BP for ∼140 years and features a “W”‐shaped structure. The 10.3‐ka event, also known as the ice‐rafted debris event 7 in the North Atlantic, lasted ∼260 years with an asymmetric double‐plunging structure. The two events are concurrent with the cold conditions in Greenland ice core record, indicating a close correlation between East Asia summer monsoon and North Atlantic climate. Spectral analyses on Shihua Cave stalagmite δ18O time series and annually lamina thickness sequence both show a statistically significant periodicity of 200 years, indicating that anomalous climate events may be triggered by solar activity. The 10.3‐ka event also coincides with three small freshwater outbursts in the high‐latitude North Atlantic. This agreement suggests that freshwater outbursts may have played a role in reinforcing this weak 10.3‐ka event in monsoonal China.
High-fat diet induces depression-like phenotype via astrocyte-mediated hyperactivation of ventral hippocampal glutamatergic afferents to the nucleus accumbens
Authors: Tsai Sheng-Feng , Hsu Pei-Ling , Chen Yun-Wen , Hossain Mohammad Shahadat , Chen Pei-Chun , Tzeng Shun-Fen , Chen Po-See , Kuo Yu-Min
Published: September 2022

Comorbidity exists between metabolic disorders and depressive syndrome with unclear mechanisms. To characterize the causal relationship, we adopted a 12-week high-fat diet (HFD) to induce metabolic disorder and depressive phenotypes in mice. Initially, we identified an enhanced glutamatergic input in the nucleus accumbens of HFD mice. Retrograde tracing and chemogenetic inhibition showed that the hyperactive ventral hippocampal glutamatergic afferents to the nucleus accumbens determined the exhibition of depression-like behavior in HFD mice. Using lentiviral knockdown and overexpression approaches, we proved that HFD-induced downregulation of glial glutamate transporters, GLAST and GLT-1, contributed to the observed circuit maladaptations and subsequent depression-like behaviors. Finally, we identified a potential therapeutic agent, riluzole, which could mitigate the HFD-induced behavioral deficits by normalizing the expressions of GLAST and GLT-1 and ventral hippocampal glutamatergic afferents to the nucleus accumbens. Overall, astrocyte-mediated disturbance in glutamatergic transmission underlies the metabolic disorder-related depressive syndrome and represents a therapeutic target for this subtype of depressive mood disorders.
Association of latrine and waste disposal conditions with water and kitchenware contamination in peri-urban Lusaka
Authors: Chua Min-Li , Nyambe Imasiku , Fujii Shigeo , Yamauchi Taro , Harada Hidenori
Published: September 2022

Sanitation facility conditions and waste disposal practices are hypothesized to affect the fecal contamination of drinking water and kitchenware. The present study aimed to examine the physical conditions of sanitation facilities and waste disposal locations as well as determine the concentrations ofEscherichia coliin drinking water, cups, dishes, flies, toilet floors, and kitchen floors. A total of 336 samples were collected from 17 households in peri-urban Lusaka. Generalized linear mixed models showed that six out of seven physical pit-latrine conditions, waste disposal practices, and kitchen hygiene practices had significant effects on the contamination of either kitchenware or drinking water. The results highlighted that improving the physical pit-latrine conditions, dumpsite location, washing water, and kitchenware-drying location may potentially reduce fecal contamination of drinking water, cups, and dishes.
Intrathecal B cell-related markers for an optimized biological investigation of multiple sclerosis patients
Authors: Feki Sawsan , Damak Mariem , Sakka Salma , Ben Ali Yesmine , Mejdoub Sabrina , Bouattour Nadia , Hachicha Hend , Mhiri Chokri , Masmoudi Hatem
Published: September 2022

In multiple sclerosis (MS) disease, the importance of the intrathecal B cell response classically revealed as IgG oligoclonal bands (OCB) in cerebrospinal fluid (CSF) was reaffirmed again in the recently revised diagnostic criteria. We aimed to optimize Laboratory investigation by testing the performance of new B cell-related molecules in CSF (Ig free light chains (FLCκ and λ) and CXCL13 (B-Cell Attracting chemokine1)) for MS diagnosis. 320 paired (CSF-serum) samples were collected from 160 patients with MS (n = 82) and non-MS diseases (n = 78). All patients benefited from IgG index determination, OCB detection, CSF CXCL13 and FLC (κ and λ) measurement in CSF and serum for metrics calculation (κ/λ ratio, FLC-related indexes, and κFLC-intrathecal fraction (IF)). CXCL13 and FLC metrics in CSF were higher in patients with MS and positive OCB. As expected, κFLC metrics—in particular, κFLC index and κFLC IF—had the highest accuracy for MS diagnosis. κ index showed the best performance (sensitivity 83% and specificity 91.7%) at a cut-off of 14.9. Most of the FLC-related parameters were positively correlated with IgG index and the level of CXCL13. In conclusion, the quantitative, standardizable, and technically simple CSF FLCκ metrics seem to be reliable for MS diagnosis, but could not replace OCB detection. CXCL13 appears to be an effective parameter reflecting the intrathecal B cell response. An optimized way for CSF testing combining the conventional and the new B cell-related parameters is proposed in this study.
An analysis of prognostic factors in a cohort of low-grade gliomas and degree of consistency between RTOG and EORTC scores
Authors: Pérez Isaura Fernández , Valverde Diana , Valverde Concepción Fiaño , Iglesias Jenifer Brea , Silva María José Villanueva , Quintela Martín Lázaro , Meléndez Bárbara
Published: September 2022

Due to their rarity and heterogeneity and despite the introduction of molecular features in the current WHO classification, clinical criteria such as those from the European Organization for Research and Treatment of Cancer (EORTC) and the Radiation Therapy Oncology Group (RTOG) are still being used to make treatment decisions in low-grade gliomas (LGG). Patients with diffuse low-grade glioma treated at our institution between 2002 and 2018 were analyzed, retrieving and assessing the degree of consistency between the EORTC and RTOG criteria, as well as the isocitrate dehydrogenase 1 and 2 (IDH) gene mutational status. Likewise, multivariate analyses were performed to ascertain the superiority of any of the factors over the others. One hundred and two patients were included. The degree of consistency between the RTOG and EORTC criteria was 71.6% (K = 0.426; p = 0.0001). Notably, 51.7% of those assigned to low risk by the EORTC were classified as high risk according to the RTOG classification. In multivariate analysis, only complete resection, age > 40 years, size and IDH mutation status were independently correlated with OS. When the RTOG and EORTC scores were entered into the model, only the EORTC model was independently associated with mortality. The degree of consistency between the EORT and RTOG criteria is low. Therefore, there is a need to integrate clinical-molecular scores to improve treatment decisions in LGG.
Single-molecule real-time sequencing of the full-length transcriptome of Halophila beccarii
Authors: Chen Siting , Qiu Guanglong
Published: September 2022

Ecologically, Halophila beccarii Asch. is considered as a colonizing or a pioneer seagrass species and a “tiny but mighty” seagrass species, since it may recover quickly from disturbance generally. The use of transcriptome technology can provide a better understanding of the physiological processes of seagrasses. To date, little is known about the genome and transcriptome information of H. beccarii. In this study, we used single molecule real-time (SMRT) sequencing to obtain full-length transcriptome data and characterize the transcriptome structure. A total of 11,773 of the 15,348 transcripts were successfully annotated in seven databases. In addition, 1573 long non-coding RNAs, 8402 simple sequence repeats and 2567 transcription factors were predicted in all the transcripts. A GO analysis showed that 5843 transcripts were divided into three categories, including biological process (BP), cellular component (CC) and molecular function (MF). In these three categories, metabolic process (1603 transcripts), protein-containing complex (515 transcripts) and binding (3233 transcripts) were the primary terms in BP, CC, and MF, respectively. The major types of transcription factors were involved in MYB-related and NF-YB families. To the best of our knowledge, this is the first report of the transcriptome of H. beccarii using SMRT sequencing technology.
Holistic tool for ecosystem services and disservices assessment in the urban forests of the Real Bosco di Capodimonte, Naples
Authors: Prigioniero Antonello , Paura Bruno , Zuzolo Daniela , Tartaglia Maria , Postiglione Alessia , Scarano Pierpaolo , Bellenger Sylvain , Capuano Anna , Serpe Eva , Sciarrillo Rosaria , Guarino Carmine
Published: September 2022

A tool for urban forest Ecosystem services (ES) and disservices (ED) assessment has been developed to visualize (i) overall ES and ED value, (ii) ES–ED trade-off and (iii) explore principal influences in ES and ED provision. The Real Bosco di Capodimonte (RBC) (Naples, Southern Italy) has been chosen as a case study. ES and ED linked to urban forest plant cover were: biodiversity, carbon storage, gross and net carbon sequestration, lessen runoff, oxygen production, air pollution removal, UV effects reduction, pollen-related allergenicity risk, and volatile organic compounds (VOCs) emissions. A phytosociological survey was conducted and biodiversity value was evaluated. ES and ED were assessed by i-Tree Eco model and Index of Urban Green Zones Allergenicity (IUGZA). Results showed that 441 different plant species occur in the RBC and the most represented genera are Quercus and Trifolium, while the largest family was Asteraceae. Carbon storage and pollution removal were highest in natural forest, while remaining ES were greater in managed forest areas. Highest value for VOCs emission and allergenicity were assigned to managed and natural forest, respectively. Managed forest scored the highest ES–ED value, while managed grassland scored the lowest. Results highlighted the greater influence of plant cover structure in overall ES and ED provision levels, and management influence considering the same type of plant cover. The model could be a valuable tool for ES and ED effective management generally applicable in urban forests.
The RPN12a proteasome subunit is essential for the multiple hormonal homeostasis controlling the progression of leaf senescence
Authors: Boussardon Clément , Bag Pushan , Juvany Marta , Šimura Jan , Ljung Karin , Jansson Stefan , Keech Olivier
Published: September 2022

The 26S proteasome is a conserved multi-subunit machinery in eukaryotes. It selectively degrades ubiquitinated proteins, which in turn provides an efficient molecular mechanism to regulate numerous cellular functions and developmental processes. Here, we studied a new loss-of-function allele of RPN12a, a plant ortholog of the yeast and human structural component of the 19S proteasome RPN12. Combining a set of biochemical and molecular approaches, we confirmed that a rpn12a knock-out had exacerbated 20S and impaired 26S activities. The altered proteasomal activity led to a pleiotropic phenotype affecting both the vegetative growth and reproductive phase of the plant, including a striking repression of leaf senescence associate cell-death. Further investigation demonstrated that RPN12a is involved in the regulation of several conjugates associated with the auxin, cytokinin, ethylene and jasmonic acid homeostasis. Such enhanced aptitude of plant cells for survival in rpn12a contrasts with reports on animals, where 26S proteasome mutants generally show an accelerated cell death phenotype.
Protein phosphatase 1 regulates phosphorylation of gasdermin D and pyroptosis
Authors: Li Ying , Pu Debing , Huang Jian , Zhang Ying , Yin Hang
Published: September 2022

Phosphorylation of GSDMD inhibits pyroptosis by regulating the oligomerization of cleaved GSDMD_NT in the process of forming pores in cell membrane to induce cell death. Protein phosphatase 1 regulates dephosphorylation of GSDMD and pyroptosis.
Unblocking a rigid purine MOF for kinetic separation of xylenes
Authors: Lyndon Richelle , Wang Yuxiang , Walton Ian M. , Ma Yao , Liu Yang , Yu Zhenzi , Zhu Guanghui , Berens Samuel , Chen Yu-Sheng , Wang SuYin G. , Vasenkov Sergey , Sholl David S. , Walton Krista S. , Pang Simon H. , Lively Ryan P.
Published: September 2022

The optimized synthesis of Zn(purine)I led to excellent p-xylene/o-xylene separation performance via molecular sieving in the rigid ultramicroporous framework.
Composition control of alloy nanoparticles consisting of bulk-immiscible Au and Rh metalsviaan ionic liquid/metal sputtering technique for improving their electrocatalytic activity
Authors: Akiyoshi Kazutaka , Watanabe Yumezo , Kameyama Tatsuya , Kawawaki Tokuhisa , Negishi Yuichi , Kuwabata Susumu , Torimoto Tsukasa
Published: September 2022

AuRh alloy nanoparticles, prepared by simultaneous sputter deposition of Au and Rh metals on an ionic liquid, exhibited a surface composition-dependent electrocatalytic activity.
High-resolution continuum source graphite furnace molecular absorption spectrometry for the monitoring of Sr isotopes via SrF formation: a case study
Authors: Bazo Antonio , Garde Raúl , Garcia-Ruiz Esperanza , Aramendía Maite , Nakadi Flávio V. , Resano Martín
Published: September 2022

A new approach for monitoring Sr isotopes via HR CS GFMAS is described.
Hydroxynicotinic acid crystallisation and solubility systematic studies
Authors: Esteves Catarina V.
Published: September 2022

The 2-, 4-, 5-, and 6-hydroxynicotinic acid (HNA) family was used as a model for crystallisation and solubility systematic studies.
Overoxidized polypyrrole/overoxidized poly(3,4-ethylenedioxythiophene)/graphene quantum dots-chitosan as enhanced electrochemical sensing platform for luteolin determination in peanut shells
Authors: Meng Rongqian , Xue Yanfeng , Guo Lijun , Yang Hong , Song Yongbo , Li Qiaoling , Niu Yulan
Published: September 2022

The GQDs-CS, oPPy and oPEDOT can serve as sensitizing elements to improve the sensing performance of a luteolin electrochemical sensor.
A robust and sensitive flexible strain sensor based on polyurethane cross-linked composite hydrogels for the detection of human motion
Authors: Wen Xiao , Wang Haibo , Ren Erhui , Wang Shuang , Xu Junhuai
Published: September 2022

Polyurethane cross-linked composite hydrogel and wireless Bluetooth module were assembled for the detection of human motion.
Reconstructing solar magnetic fields from historical observations
Authors: Virtanen I. O. I. , Pevtsov A. A. , Bertello L. , Mursula K.
Published: September 2022

Context. We apply our recently developed method to reconstruct synoptic maps of the photospheric magnetic field from observations of chromospheric plages and the magnetic polarity of sunspots. Here, we apply the method to an extended time interval from 1915 to 1985.

Aims. Systematic magnetographic observations of the solar photospheric magnetic field were initiated as recently as the 1970s and the lack of earlier observations limits our ability to study and understand the long-term evolution of the Solar global field. This study is aimed at creating synoptic maps of magnetic fields for the pre-magnetograph era and using these maps as input for modern simulation models to investigate the long-term (centennial) evolution of the Sun’s global magnetic fields.

Methods. We reconstructed active Solar regions by identifying chromospheric plages from Ca II K line synoptic maps and assigning magnetic polarities based on the observed polarity of sunspots. We used a surface flux transport (SFT) model to simulate the evolution of the photospheric magnetic field from the reconstructed active regions. We used the potential field source surface (PFSS) model to determine the amount of open magnetic flux from the reconstruction and from magnetographic observations. We also reconstructed the coronal field during two eclipses and compared the result with eclipse drawings.

Results. We successfully reconstructed the photospheric magnetic field from 1915 to 1985. The number and total magnetic flux of the reconstructed active regions shows a realistic cyclic behavior that mostly follows the evolution of the sunspot number, even on relatively short timescales. The polar field strengths of cycles 19 and 20 do not reflect the evolution of the sunspot number very accurately, which may be related to problems related to the calcium data during cycle 19 and the long data gap during cycle 20. The polarity of polar fields and the amount of open field both at high and low latitudes all demonstrate the expected cyclic behavior. The agreement of the modeled coronal structure with eclipse drawings in 1922 and 1923 is fair.
Research on thermomechanical fatigue life prediction of regenerative cooling thrust chamber
Authors: HUANG Junfeng , HE Erming , YI Jinxiang , DU Dahua , WANG Hongjian
Published: September 2022

The ratcheting effect of the liner wall structure in the thrust chamber of liquid rocket engine under cyclic load is studied, and its service life is predicted. Firstly, the 3-D heat transfer analysis of the wall of the thrust chamber is carried out while explaining the mechanism of its "dog room" failure. Based on the results of the heat transfer analysis, the stress-strain evolution of the structure under cyclic load is analyzed by nonlinear plane strain finite element method. According to the finite element analysis results, the ratcheting effect of the liner wall structure is described and the ratcheting damage is calculated. The low cycle fatigue damage is calculated by using modified Morrow model, and the creep damage is also calculated using Norton model. Finally, the total damage of thrust chamber liner wall is calculated by using Miner linear cumulative damage law and the thermomechanical fatigue life of the structure is estimated. The result shows that the middle point of the lower surface of the liner wall will fail first, and the calculated service life is 33 times, which is good agreement with its actual service life. In the total damage of the weak point, ratcheting damage, creep damage and low cycle fatigue damage account for 52%, 32% and 16% respectively, indicating that the ratcheting effect is the main reason for the failure of the thrust chamber structure. The research results of this paper provide important engineering reference for the structural optimization design and rapid life prediction of regenerative cooling thrust chamber of liquid rocket engine and the future reusable aerospace power.
Research on aerodynamics and aeroacoustics of propeller based on panel-vortex particle method
Authors: LIU Qian , LIU Hanru , LI Jiahui , SHANG Xun , CHEN Nanshu , WANG Yangang
Published: September 2022

The highly-efficient and unsteady aerodynamic simulation of turbomachinery is urgently required. The panel-vortex particle method is coupled with a far free field sound model established with the Lowson method and aims to fast predict aerodynamic and acoustic properties. The aerodynamic results show that, compared with the aerodynamic results acquired with the finite volume method, the use of the panel-vortex particle method may obtain appropriate pressure distribution and velocity distribution in the downstream region of a propeller and that the overall thrust prediction is accurate enough. The vortex distribution features show that the panel-vortex particle method has less numerical diffusion. Therefore, the velocity gradient is more accurate near the wake vortex. Compared with the sound pressure level acquired with the finite volume method, the sound pressure level simulated with the panel-vortex particle method has the same directivity pattern. The relative error of sound pressure in the 60° forward direction is 5% under 1BPF(blade passing frequency), which satisfies acoustic analysis requirements. As for time consumption, the use of the panel-vortex particle method consumes 10% of time when the finite volume method is used, proving that the panel-vortex particle method coupled with the Lowson method can satisfy the design and application needs of unsteady aerodynamic and aeroacoustic noise of a distributed electric propulsion system.
Visual judgment approach of isomorphic GUI for automated mobile app testing
Authors: XUE Feng , WU Junsheng , ZHANG Tao , WANG Wei , CHENG Jing
Published: September 2022

Currently, the rapid growth of mobile apps requires automated testing technology to ensure their quality. Automated testing of mobile apps is usually closely related to the recognition and judgment of their graphical user interface (GUI), but there usually are numerous isomorphic GUIs with different styles and contents, and similar structure and function in mobile apps. In automatic testing, isomorphic GUI is easy to cause the issue of state space explosion, which leads to low efficiency or failure of testing. In view of the limitations of traditional automatic recognition of isomorphic GUI, this paper presents a GUI similarity judgment approach based on visual feature information. Firstly, the GUI component elements are identified by object detection, and then the GUI skeleton is abstracted. Secondly, the visual features of the GUI skeleton are extracted by a convolutional autoencoder. Finally, the isomorphic GUI judgment is completed by comparing the similarity of GUI visual features. The experimental results show that the proposed approach can effectively shield the influence of GUI style and content, complete the isomorphic GUI recognition more accurately and optimize the efficiency of automated mobile app testing.
Aero-acoustic performance of a continuous transonic wind-tunnel axial-flow compressor
Authors: LONG Bingxiang , CHEN Jiming , CHEN Zhenhua , LIU Zongzheng , LIAO Daxiong
Published: September 2022

A three-stage axial-flow compressor was developed for a continuous transonic wind tunnel. The rotor-stator spacing and the ratio of number of rotor blades to number of stator vanes were properly chosen for the purpose of aero-acoustic noise suppression. The aero-acoustic performances of the axial-flow compressor were tested and analyzed. The test results show that the first BPF tonal noise is effectively suppressed even though some of it still exists; the noise amplitude frequency spectrum shows that the abnormal tonal noise, which is different from that related to BPF and its harmonics, exists under a wide range of working conditions and plays a dominant role in determining the sound pressure levels of the inlet and outlet of the axial-flow compressor. The comparison of test results shows that vibration is induced by the periodic non-uniform inlet flow condition and that the rotor blade that has a high aspect ratio is one of the main noise sources responsible for the abnormal tonal noise.
Inverse design of aerodynamic configuration using generative topographic mapping
Authors: SONG Chao , LIU Hongyang , ZHOU Zhu , LUO Xiao , LI Weibin
Published: September 2022

The inverse design method of aerodynamic configuration is hard to give a reasonable pressure distribution, and strongly rely on experience of designers. The method has been difficult to adapt to the needs of modern aircraft design. Aiming at the shortcoming of the method, an efficient and robust aerodynamic configuration inverse design method is developed, employing knowledge of machine learning methods and optimization methods. The present method establishes the mapping between the high dimensional data obtained from aerodynamic shape and pressure distribution and the variables in the latent space. Then, the global optimization is carried out in the latent space by using the genetic algorithm. The optimum pressure distribution and the corresponding shape can be obtained. Through the the GTM model with high precision, there is not necessary for the flow solver in the whole iterative process, thus the design efficiency can be enhanced. Besides, by taking the advantage of optimization method, the target pressure distribution can be given in a very flexible way, and does not need to be physically meaningful. This feature can reduce reliance on the design experience. Airfoils in low speed and transonic flow and a three-dimensional laminar nacelle design cases are carried out. It is shown that the method robustly and efficiently converges to the target pressure, and has good engineering application potential.
Emergency evacuation simulation and test research of civil aircraft complex groups based on the social attribute
Authors: FENG Wenchun , LI Wei , ZHANG Tong , YAO Xiangru
Published: September 2022

Based on the basic social model, the social attribute effect factor is put forward. The desired velocity of individual is modified from sex, age, education, ride frequency, safety knowledge and experience. The influence of the individual behavior, group action and adverse attitude of landing are revised through panic parameter, follow force, leaning force and coefficient of speed damping ratio. Based on the dynamic cabin emergency evacuation test environment, the individual evacuation test, multiplayer evacuation test and group evacuation test are performed. The individual speed distributes and the adverse attitude effects on the individual velocity and group evacuation speed are analyzed. The test result show that the individual desired speed is about 1.5 m/s and the maximum desired speed is about 2.86 m/s. During evacuation, the average speed of male is higher than that of female. However, the proportion of panic of female during jump slide is higher than that of male. The fitting coefficient of speed damping ration based on the test data is consist with that from Lowe's Ship Club. Through comparing the simulation result with the test, the revised social model can be exact simulate evacuation process. The maximum deviation is 6.25 percent with group test performed in the test environment. The relative error is 3.7 percent with ARJ21-700 evacuation demonstrate test. The errors conform to the engineering requirement.
Orbital maneuver technology of temporary networked satellites for earth exploration
Authors: ZHAO Jun , LI Wei , GAO Rui , ZHANG Guangde , ZHU Xiaopeng , ZHAN Yuequan
Published: September 2022

It is very difficult to achieve effective coverage of hot-spot target in a short time period by earth perturbation for orbital maneuver, because the coverage gap of the temporary multi-satellites network in certain period of time is too large. In this paper, it is assumed that wave beam type of the satellite-payload sensor is a simple conic, the beam center of the satellite payload under the maximum lateral pendulum is calculated based on the precise ephemeris, and according to the projection ellipse of the payload wave beam on the ground, the coverage ability of the satellite payload on the ground target direction is obtained. Then the satellite is designed to encounter the ground target in the nodal period between the satellite passing the ground target and the latitude circle. The orbital maneuver control variables are calculated from the change of nodal period, and the optimal orbital maneuver control variables are selected from a specified time period. At last, the orbit maneuver in covering the target in a specified time period is achieved and the maximum revisit interval is greatly shortened.
Product information modeling for capturing design intent for computer-aided intelligent assembly modeling
Authors: MO Shancong , XU Zhijia , TANG Wenbin
Published: September 2022

Intelligent assembly is a bottleneck to be broken with urgency in the on-going revolution of manufacturing industry. However, computer-aided assembly modeling as an important supporting technology is still suffering from the problems of too many manual interventions and low-level intelligence. An intelligent assembly modeling technology was previously developed based on design intent (DI), however there lacks systematical and supportive product information model. Consequently, a novel product information model that can capture DI for computer-aided intelligent assembly modeling is established, based on the previously developed concept of interaction feature pair (IFP). The corresponding meta class model is also constructed utilizing the object-oriented technology. On this basis, the implementation process of the product information model, as well as algorithms supporting the process of computer-aided intelligent assembly modeling, is clarified, and the algorithms include IFP identification and intelligent part matching. Computer-aided intelligent assembly modeling prototype system based on the product information model, together with a case study, validated the feasibility of the proposed technology.
A complex machinery design-oriented digital prototype model driven method
Authors: ZHU Wenyue , LIU Yihua , WANG Yongjuan
Published: September 2022

Because of information loss during the conversion between a geometric digital prototype and a performance digital prototype in developing a complex mechanical product, the model-driven architecture of a digital prototype was constructed. By analyzing the constituent elements of a STEP file, the platform independent model based on the digital prototype was established. The platform specific model conversion method from the model-driven platform independent model to the UG software, the Adams software and the Abaqus software was proposed. Based on the heterogeneous software interface and the scripting language, the model-driven modules of the above three types of software were developed and verified with numerical instances. The verification results show that the use of the model-driven method can share the model information on the special software for a mechanical digital prototype and that the model-driven modules thus developed can perform the quick simulation analysis and output its results in time.
Competing failure method for multi-performance mechanism systems based on Copula function
Authors: LIU Jingyi , ZHUANG Xinchen , ZHANG Yugang , PANG Huan
Published: September 2022

A Copula-based competing failure analysis method for multi-performance mechanism systems is studied. Some specific mechanism systems often are under two types of failure modes, the catastrophic failures leading by oversized-load and function degradation failures because of out of operation. Furthermore, these failure modes also compete with each other. Competing failure model is established by catastrophic failure probability expression and drifting Brown motion. Meanwhile Copula functions are used to describe the failure dependence and deduce joint distribution functions, in order to form the competing failure analysis method to analyse the mechanism system reliability and its evaluation law for multi-performance mechanism systems. At last, an airplane cabin door lock system is studied as a case, demonstrating the validity of proposed method.
Research on multi-core scheduling method for Sporadic task by line tree mode
Authors: HUANG Shujuan , LI Tiansen , MA Zhihao , XIAO Feng
Published: September 2022

At present, most of the scheduling models for real-time periodic tasks are established based on independent fixed periodic tasks and few by considering the task model with period allowed to change and the processor model in the scheduling process. In this paper, a task model and processor model based on line tree(LT) for sporadic real-time periodic tasks are designed, and a transformation algorithm from task line tree(TLT) model to processor line tree(PLT) model is proposed. The algorithm takes the least common multiple of all real-time periodic tasks as the benchmark of layer number, and based on the complete job replacement rule, the minimum common multiple of all real-time periodic tasks is used as the reference of layer number. In order to achieve the optimal multiprocessor scheduling result, the method of replacing the empty node of non-migrating job with the node of migrating job and the condition of allowing job to publish tasks ahead of time with variable cycle are used. Experimental results show that comparing with PEDF, GEDF and RMFF, the present method not only has higher core utilization and lower time loss rate, but also reduces the number of context switching and migration.
JDE multi-object tracking algorithm integrating multi-level semantic enhancement
Authors: WANG Jun , WANG Peng , LI Xiaoyan , WANG Liang , SUN Mengyu , GAO Hui
Published: September 2022

In order to solve the problem of target ID switching caused by target occlusion and insufficient ID information and location information extraction in JDE(joint detection and embedding) algorithm, an improved multi-target tracking algorithm based on JDE is proposed in this paper. Firstly, the SPA feature space pyramid attention module is used to expand the receptive field and obtain more abundant semantic information to improve the detection accuracy of the model for different scale targets. Secondly, the FCN network makes the header and ID Embedding task collaborative learning to alleviate the excessive competition and enhance the original semantic information, effectively reducing the number of ID switching. Finally, PCCs-Ma motion measurement can strengthen the connection between Kalman filtering prediction and observation, and improve the reliability of similarity discrimination of motion characteristics. In order to verify the effectiveness of the algorithm, the JDE algorithm and the proposed algorithm are compared in the same experimental environment. The experimental results show that the average accuracy of model detection is improved by 3.94 %. On the MOT16 dataset, the MOTA and IDF1 indexes are increased by 6.9 %, and the number of ID switching of the improved algorithm is significantly reduced, and good tracking results are achieved.
Salt frost scaling of concrete – new insights regarding the damage mechanism
Authors: Mueller Matthias , Ludwig Horst-Michael
Published: September 2022

To achieve the important goal of clinker reduction for concretes in cold and temperate climates, it is important to understand the underlying mechanisms for salt frost scaling. Two conflicting damage theories dominate the current State of the Art – the glue spall theory and the cryogenic suction theory. In this study, important aspects of both theories were evaluated experimentally using salt frost scaling tests on concrete and low temperature differential scanning calorimetry. It was found, that the generation of scaling in a salt frost attack could be better explained by the cryogenic suction theory, which is based on the uptake of highly concentrated brine at sub-zero temperatures. However, this theory cannot account for the pessimal effect of low de-icing salt concentrations in salt frost scaling tests, as it does not consider the moisture uptake during the thawing phase of a freeze-thaw cycle. By expanding the cryogenic suction theory by that aspect, a comprehensive theory for salt frost damage was obtained. In that theory the cryogenic suction of highly concentrated brine during frost is responsible for the generation of scaling. The moisture uptake during the thawing phase balances the de-icing salt concentration in the concrete and accounts for the pessimum effect.
Extending the Service Life of Existing Concrete Structures to Last Beyond 100 Years
Authors: Whitmore David
Published: September 2022

New bridges and other concrete structures are being built using the design concepts presented in SHRP2 R19A (Bridges for Service Life Beyond 100 Years: Innovative Systems, Subsystems, and Components) and FIB Bulletin 34 (Model Code for Service Life Design) to achieve 100+ year service life. Existing concrete structures may not have been built with a specific design service life in mind but the principles of SHRP2 R19A can be used to maintain and extend the service life of existing concrete structures. Application of these principles and methods can extend service life by mitigating corrosion of embedded reinforcing steel by over 80%. Extending the service life of existing reinforced concrete structures provides many benefits to structure owners and society. Direct benefits include cost savings for owners and a general reduction in disruption to the public caused by repair and replacement. Extending service life also provides many indirect benefits including; reduction in the use of materials, reduction in the generation of demolition waste, reduction of environmental emissions, and the protection of sensitive habitat and existing ecosystems. This paper presents case studies which illustrate how the SHRP2 R19A protocol was used to design durable repairs to extend service life of existing concrete structures and the direct and indirect benefits which were achieved. Service life extension of existing reinforced concrete structures is a sustainable practice and should be encouraged.