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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND Robert l.JACKSON German MIllS Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

OptoGPT: A foundation model for inverse design in optical multilayer thin film structures

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Opto-Electronic Advances 2024年第7期7卷 4-16页

作者： Taigao Ma Haozhu Wang l.Jay Guo Department of Physics University of MichiganAnn ArborMichigan 48109USA Department of Electrical Engineering and Computer Science University of MichiganAnn ArborMichigan 48109USA

Optical multilayer thin film structures have been widely used in numerous photonic ***,existing inverse design methods have many drawbacks because they either fail to quickly adapt to different design targets,or are difficult to suit for different types of structures,e.g.,designing for different materials at each *** methods also cannot accommodate versatile design situations under different angles and *** addition,how to benefit practical fabrications and manufacturing has not been extensively considered *** this work,we introduce OptoGPT(Opto Generative Pretrained Transformer),a decoder-only transformer,to solve all these drawbacks and issues simultaneously.

关键词： multilayer thin film structure inverse design foundation models deep learning structural color

Obstetric References in Disadvantaged Environments: Case of References to the University Hospital Center of Kara, in Northern Togo

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Open Journal of Obstetrics and Gynecology 2024年第2期14卷 267-277页

作者： Kossi Edem logbo-Akey Bassowa Akila Kofi Mawoulé Améwouho Ketevi Tina Yendoubé Pierre Kambote Dédé Régine Diane Ajavon Baguilane Djoauguibe Abdoul-Samadou Aboubakari koffi Akpadza Service de Gynécologie-Obstétrique CHU Kara Togo Service de Gynécologie-Obstétrique CHU Campus Lomé Togo Service de Gynécologie-Obstétrique CHU Sylvanus Olympio Lomé Togo Service de Gynécologie-Obstétrique CHR Tomdé Kara Togo

Introduction: References are frequent and most often carried out in emergency situations. The objective of this study was to describe the epidemiological and clinical profile of obstetric referrals to the CHU-Kara. Methodology: This was a retrospective cross-sectional descriptive study conducted from September 1, 2022, to February 28, 2023, at CHU-Kara, focusing on obstetric referrals to the Gynecology-Obstetrics department. Result: 828 patients were referred for obstetric reasons out of 1295 admissions, representing a frequency of 63.9%. The average age was 25.04 years. They were primigravida (38.3%), unemployed (62.7%). Motorcycles were the main means of transportation, accounting for 53.1% of cases. The average distance to reach the referral center was 31.6 km, covered in an average of 71 minutes. In 40.7% of cases, patients had less than 4 prenatal consultations and were referred in peripartum (56.6%) for pre-eclampsia (14%), post-term pregnancy (11.8%), dystocia (10.5%). Eighty-six point nine percent (86.9%) of the referred patients were able to deliver during their stay in the department, of which 61.7% had vaginal deliveries. The maternal and perinatal mortality rates were 0.7% and 14.9%, respectively. Conclusion: Obstetric referrals to Kara University Hospital are frequent during the perpartum period and are often carried out by motorbike.

关键词： Obstetric Referral Epidemiology Prognosis CHU-Kara

Physico-Chemical and Nutritional Properties of a Food Broth Based on Nere (Parkia biglobosa)

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Food and Nutrition Sciences 2024年第5期15卷 377-389页

作者： lassana Bamba Gervais Melaine M’Boh N’Gbésso Amos Ekissi Kipré laurent Séri Gnogbo Alexis Bahi koffi Pierre Valery Niaba Allico Joseph Djaman Grah Avit Maxwell Beugre laboratory of Agro-Valorization Department of Agroforesterie Jean Lorougnon Gu&#233d&#233 University Daloa C&#244te d&#8217Ivoire Medical and Fundamental Biochemistry Department Institut Pasteur of C&#244te d&#8217Ivoire Abidjan C&#244te d&#8217Ivoire laboratory of Biotechnology Agriculture and Valorization of Biological Resources Department of Biosciences Felix Houphouet-Boigny University Abidjan Cote d&#8217Ivoire Biology and Health laboratory Department of Biosciences Felix Houphouet-Boigny University Abidjan C&#244te d&#8217Ivoire

Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposing to infections. This study of the physico-chemical and nutritional properties of a soumara-based food broth was carried out with the aim of promoting the consumption of organic broth made from nere seeds (soumara). That is to alleviate certain metabolic diseases, which is a matter of food safety, and also to limit the risk for the health about the consumption of some cooking stocks on the market. Methods: Several natural ingredients such as nere seeds (soumara), ginger, black pepper, parsley and garlic were used to create a nere-based stock. All these ingredients were freeze-dried and the powder obtained was used to make the broth, regarding their physical and chemical properties. Results: The broth had a good protein content of 17.41 ± 0.367 g/100g, a lipid content of 16.80 ± 0.08 g/100g and a fiber content of 8.66 ± 0.04 g/100g. In terms of nutritional values, the broth showed good levels of calcium 184.21 ± 0.09 mg/100g, potassium 50.04 ± 1.45 mg/100g and iron and zinc. In terms of antioxidant activity, the broth also showed good antioxidant activity. Conclusion: Regarding the properties of our food broth, whose composition is based on natural ingredients, could be recommended for consumption and, its properties, could play an important role in preventing and combating certain metabolic diseases.

关键词： Food Broth Nere Physico-Chemical Properties Nutrition Food Safety

Distributed swarm control for multi-robot systems inspired by shepherding behaviors

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Science China(Technological Sciences) 2024年第7期67卷 2191-2202页

作者： SUN GuiBin GU HaiBo lÜJinHu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Zhongguancun laboratory Beijing 100094China

Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. The core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. Then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.

关键词： swarm control multi-robot system negotiation-control scheme shepherding behavior

Promoting Older Adults' Engagement in Disaster Recovery Through Supportive Relationships, Partnerships, and Collaboration: Perspectives of Social Work Practitioners and Human Service Professionals

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International Journal of Disaster Risk Science 2024年第2期15卷 265-276页

作者： Julie l.Drolet Mahed Choudhury Faculty of Social Work University of CalgaryEdmontonAB T5J 4P6Canada

Shifting demographics—that is, the growing number of older adults in Canada and internationally—and intersecting climatic risks create a complex landscape of aging in place in disaster contexts. Some older adults are vulnerable due to their underlying health conditions and limited physical mobility. Yet they also exhibit resilience in a distinct manner, owing to their wealth of knowledge, wisdom, and ability to navigate adversities. This article elucidates potential avenues for promoting the involvement of older adults in disaster recovery efforts. Our intention is to recognize and foster older adult resilience and mitigate vulnerability by drawing upon insights from the study titled “In the Aftermath of the 2016 Alberta Wildfires: The Role of Social Work Practitioners and Human Service Professionals in long-Term Disaster Recovery.” Employing a qualitative research approach, that study recruited 51 participants for semistructured interviews and focus groups. A thematic analysis of the collected data unveiled the pivotal roles played by social workers and human service practitioners in facilitating recovery from the 2016 wildfires in the research. Notably, three overarching themes emerged concerning the promotion of older adults' involvement in disaster recovery: fostering supportive relationships, building partnerships and enhancing collaboration, and addressing ongoing challenges. These findings offer valuable insights into how social work practitioners and human service professionals can effectively facilitate the engagement of older adults in disaster recovery initiatives. This article emphasizes the significance of actively promoting the participation of older adults in disaster mitigation efforts, thereby fostering greater resilience within communities.

关键词： Alberta wildfires Canada Disaster recovery Older adults Partnerships and collaboration Social work

Recent Advances in Catalytic Carbonylation Reactions in Alternative Reaction Media

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Chinese Journal of Chemistry 2024年第4期42卷 406-429页

作者： Csaba Árvai lászló T.Mika Department of Chemical and Environmental Process Engineering Faculty of Chemical Technology and BiotechnologyBudapest University of Technology and EconomicsMűegyetem rkp.3H-1111 BudapestHungary

Since the discovery of the hydroformylation(oxo-synthesis or Roelen reaction)and the Reppe-reaction,the transition metal-catalyzed carbonylation reactions,providing versatile,facile,and even atom-economic methods for the selective incorporation of C=O functionality to various skeletons,have gained tremendous importance in synthetic organic chemistry from laboratories to industrial *** carbonylation of carbon-carbon multiple bonds,aromatic halides,triflates,etc.,in the presence of various nucleophiles has led the way to produce aldehydes,carboxylic acids,esters,amides,etc.,in the fine chemical ***,these protocols usually proceed in conventional,fossil-based,and usually toxic reaction ***,several attempts have been directed to developing efficient carbonylation methods in alternative,less harmful,non-fossil-based and even in renewable reaction *** this review,we overview the recent applications of alternative solvents such as water,biomass-based alcohols,γ-valerolactone(GVl),2-methyltetrahydrofuran(2-MeTHF),ionic liquids(Ils),deep eutectic solvents(DES),alkyl levulinates,limonene,α-pinene,and dimethyl carbonate as well as fluorous media to improve efficiency,safety and environmentally benign nature of carbonylation protocols.

关键词： Carbonylation Catalysis Solvents Green chemistry Carbon monoxide Transition metals Homogeneous catalysis Palladium

Variational data encoding and correlations in quantum-enhanced machine learning

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Chinese Physics B 2024年第9期33卷 298-306页

作者： Ming-Hao Wang Hua l¨u School of Physics Hubei UniversityWuhan 430062China School of Science Hubei University of TechnologyWuhan 430068China

leveraging the extraordinary phenomena of quantum superposition and quantum correlation,quantum computing offers unprecedented potential for addressing challenges beyond the reach of classical *** paper tackles two pivotal challenges in the realm of quantum computing:firstly,the development of an effective encoding protocol for translating classical data into quantum states,a critical step for any quantum *** encoding strategies can significantly influence quantum computer ***,we address the need to counteract the inevitable noise that can hinder quantum *** primary contribution is the introduction of a novel variational data encoding method,grounded in quantum regression algorithm *** adapting the learning concept from machine learning,we render data encoding a learnable *** allowed us to study the role of quantum correlation in data *** numerical simulations of various regression tasks,we demonstrate the efficacy of our variational data encoding,particularly post-learning from instructional ***,we delve into the role of quantum correlation in enhancing task performance,especially in noisy *** findings underscore the critical role of quantum correlation in not only bolstering performance but also in mitigating noise interference,thus advancing the frontier of quantum computing.

关键词： quantum machine learning variational data encoding quantum correlation

Stability and performance analysis of the compressed Kalman filter algorithm for sparse stochastic systems

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Science China(Technological Sciences) 2024年第2期67卷 380-394页

作者： lI RongJiang GAN Die XIE SiYu lüJinHu Key laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Zhongguancun laboratory Beijing 100049China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

This paper considers the problem of estimating unknown sparse time-varying signals for stochastic dynamic *** deal with the challenges of extensive sparsity,we resort to the compressed sensing method and propose a compressed Kalman filter(KF)*** algorithm first compresses the original high-dimensional sparse regression vector via the sensing matrix and then obtains a KF estimate in the compressed low-dimensional ***,the original high-dimensional sparse signals can be well recovered by a reconstruction *** ensure stability and establish upper bounds on the estimation errors,we introduce a compressed excitation condition without imposing independence or stationarity on the system signal,and therefore suitable for feedback *** further present the performance of the compressed KF ***,we show that the mean square compressed tracking error matrix can be approximately calculated by a linear deterministic difference matrix equation,which can be readily evaluated,analyzed,and ***,a numerical example demonstrates that our algorithm outperforms the standard uncompressed KF algorithm and other compressed algorithms for estimating high-dimensional sparse signals.

关键词： sparse signal compressed sensing Kalman filter algorithm compressed excitation condition stochastic stability tracking performance

Neural-network-based fully distributed formation control for nonlinear multi-agent systems with event-triggered communication

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Science China(Technological Sciences) 2024年第1期67卷 209-220页

作者： ZHU Guoliang lIU KeXin GU HaiBo lÜJinHu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Zhongguancun laboratory Beijing 100094China

This paper investigates the consensus-based formation control problem for multi-agent systems with unknown nonlinear *** achieve the desired formation,we propose two formation controllers to achieve the desired formation,one based on system states and the other on system *** proposed controllers utilize adaptive gains to avoid global information and neural networks to estimate and compensate for *** proposed event-triggered schemes avoid continuous communication among agents and exclude the Zeno *** analysis reveals that formation errors are bounded,and numerical simulations are used to validate the effectiveness of the proposed approaches.

关键词： formation control neural network adaptive control event-triggered communication multi-agent systems