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Customer Joining Behavior and Regulation Strategy in Visible multi-Server Queues with Synchronous Vacations of Partial Servers

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Journal of Systems Science & Complexity 2024年第3期37卷 1209-1232页

作者： sun.Wei WANG Hao XIE Xumeng LI Shiyong School of Economics and management Yanshan UniversityQinhuangdao 066004China

This paper studies customer joining behavior and system regulation strategy in nonexhaustive visible m/m/m queues with synchronous vacations of a part of the *** this part of the servers are idle,they take multiple vacations simultaneously(vacation period).Until there are customers waiting in the queue,they are reactivated and all servers are busy or idle(busy period).The authors call this part of the servers as“partial servers”.In view of the fully visible queue and the almost visible queue,the authors obtain customers’equilibrium joining threshold strategies and their socially optimal joining threshold strategies,respectively,and observe that customer joining behavior in equilibrium generally makes the system overcrowded,which makes the equilibrium social welfare lower than the optimal social *** regulation,interestingly,for optimizing social welfare,the system manager hopes not only customers arriving in vacation period pay attention to the number of partial servers,but also customers arriving in busy period should care about it rather than ***,arranging more servers for vacation does not necessarily lead to the decrease of social welfare on condition that the number of partial servers is close to *** for the information advantage of the fully visible case,it is not obvious for increasing social welfare and even unfavorable to servers’profit unless the number of partial servers is big ***,given the different composition of social welfare,there exists the optimal number of partial servers and the optimal arrival rate of customers for maximizing social welfare.

关键词： Customer behavior non-exhaustive service partial servers regulation strategy synchronous vacations visible queue

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Effect of structural characteristics on the transport characteristics of solid particles in the thermal storage and release system of circulating fluidized bed

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Particuology 2024年第6期89卷 22-31页

作者： Zengcai Ji Guoliang Song Zihua Tang Liwei sun Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Dalian National Laboratory for Clean Energy Dalian116023China

Coal-fired power generation stands as the most economically viable modulating power source in present-day *** holds the potential to offer prospective solutions to the challenges posed by the rapid expansion of intermittent,unpredictable,and unstable renewable energy *** particle thermal storage technology emerges as an effective means to enhance the flexibility of coal-fired circulating fluidized bed power *** attain an optimized structure for the solid particle thermal storage and release system in circulating fluidized bed units,experimental research was conducted on a 0.1 mWth circulating fluidized bed test *** study delved into the impact of ash storage bin geometries and the shapes of their feed-discharge valves on the control properties of solid particle *** experimental outcomes reveal that employing inverted m-shaped valve and dual U-shaped valves for feed control,alongside U-shaped valves and N-shaped valves for discharge control,both enable efficient and rapid storage and release of solid particles within the circulating fluidized *** similar air distribution conditions,the inverted m-shaped valve exhibits lower conveying energy consumption than the dual U-shaped valves,while the N-shaped valve excels in control characteristics over the U-shaped ***,the inverted m-shaped valve and the N-shaped valve demonstrate optimal overflow port heights,and the ash storage bin exhibits an optimum height-to-diameter ratio.

关键词： Solid particle Thermal storage System structure Transport regulation

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Design and Control of an Autonomous Bat-like Perching UAV

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Journal of Bionic Engineering 2024年第3期21卷 1253-1264页

作者： Long Bai Wei Wang Xiaohong Chen Yuanxi sun State key Laboratory of mechanical Transmission Chongqing UniversityChongqing400044China

Perching allows small Unmanned Aerial Vehicles(UAVs)to maintain their altitude while significantly extending their flight duration and reducing ***,current research on flying habitats is poorly adapted to unstructured environments,and lacks autonomous capabilities,requiring ideal experimental environments and remote control by *** solve these problems,in this paper,we propose a bat-like UAV perching mechanism by investigating the bat upside-down perching method,which realizes double self-locking in the perching state using the ratchet and four-link dead point *** on this perching mechanism,this study proposes a control strategy for UAVs to track targets and accomplish flight perching autonomously by combining a binocular camera,single-point LiDAR,and pressure *** perching experiments were conducted for crossbar-type objects *** experimental results show that a multirotor UAV equipped with the perching mechanism and sensors can reliably achieve autonomous flight perching and re-flying off the target *** power consumption is reduced to 2.9%of the hovering state when perched on the target object.

关键词： Bio-inspired design Perching mechanism UAV Autonomous flight

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Prevalence and risk factors for impaired renal function among Asian patients with nonalcoholic fatty liver disease

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Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 241-248页

作者： Chao sun.George Boon-Bee Goh Wan-Cheng Chow Wah-kheong Chan Grace Lai-Hung wong Wai-kay Seto Yi-Hsiang Huang Han-Chieh Lin I-Cheng Lee Hye won Lee Seung Up kim Vincent Wai-sun.wong Jian-Gao Fan Center for Fatty Liver Disease Department of GastroenterologyXinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai Key Lab of Pediatric Gastroenterology and NutritionShanghai 200092China Department of Gastroenterology&Hepatology Singapore General HospitalSingaporeSingapore Gastroenterology and Hepatology Unit Department of MedicineFaculty of MedicineUniversity of MalayaKuala LumpurMalaysia Department of medicine and Therapeutics and State key Laboratory of Digestive Disease The Chinese University of Hong KongHong KongChina Department of medicine The University of Hong KongHong KongChina Institute of Clinical medicine National Yang Ming Chiao Tung University School of MedicineTaipeiTaiwanChina Division of Gastroenterology and Hepatology Taipei Veterans General HospitalTaipeiTaiwanChina Faculty of medicine National Yang Ming Chiao Tung University School of MedicineTaipeiTaiwanChina Department of Internal medicine Yonsei University College of MedicineSeoulKorea

Background:Nonalcoholic fatty liver disease(NAFLD)is associated with impaired renal function,and both diseases often occur alongside other metabolic ***,the prevalence and risk factors for impaired renal function in patients with NAFLD remain *** objective of this study was to identify the prevalence and risk factors for renal impairment in NAFLD ***:All adults aged 18-70 years with ultrasound-diagnosed NAFLD and transient elastography examination from eight Asian centers were enrolled in this prospective *** fibrosis and cirrhosis were assessed by FibroScan-aspartate aminotransferase(FAST),Agile 3+and Agile 4 *** renal function and chronic kidney disease(CkD)were defined by an estimated glomerular filtration rate(eGFR)with value ofmL/min/1.73 m^(2) andmL/min/1.73 m^(2),respectively,as estimated by the CkD-Epidemiology Collaboration(CkD-EPI)***:Among 529 included NAFLD patients,the prevalence rates of impaired renal function and CkD were 37.4%and 4.9%,*** multivariate analysis,a moderate-high risk of advanced liver fibrosis and cirrhosis according to Agile 3+and Agile 4 scores were independent risk factors for CkD(Pmore,increased fasting plasma glucose(FPG)and blood pressure were significantly associated with impaired renal function after controlling for the other components of metabolic syndrome(Pmpared with patients with normoglycemia,those with prediabetes[FPG≥5.6 mmol/L or hemoglobin A1c(HbA1c)≥5.7%]were more likely to have impaired renal function(Pk of *** glycemic control in the prediabetic stage might have a potential renoprotective role in these patients.

关键词： Nonalcoholic fatty liver disease Impaired renal function Agile 3+ Agile 4 metabolic syndrome

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Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

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Earth and Planetary Physics 2024年第1期8卷 204-214页

作者： A.m.Jorgensen TianRan sun.Y.Huang L.Li R.Xu L.Dai Chi Wang New mexico Institute of mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few *** work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch *** the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution *** this paper we explore the reconstruction using,two,three,and four *** show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray imaging SmILE

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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

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mechanism of plant-soil feedback in a degraded alpine grassland on the Tibetan Plateau

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Journal of Plant Ecology 2024年第2期17卷 188-199页

作者： Tiancai Zhou Jian sun.Peili Shi key Laboratory of Ecosystem Network Observation and modelling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State key Laboratory of Tibetan Plateau Earth System Resources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China key Laboratory of Biodiversity and Environment on the Qinghai-Tibet Plateau Ministry of EducationLhasa 850011China Tibet Research Academy of Eco-environmental Sciences Lhasa 850000China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Although biotic and abiotic factors have been confirmed to be critical factors that affect community dynamics,their interactive effects have yet to be fully considered in grassland ***,we tested how soil nutrients and microbes regulated plant-soil feedback(PSF)in a degraded alpine *** results indicated that soil total carbon(STC;from 17.66 to 12.55 g/kg)and total nitrogen(STN;from 3.16 to 2.74 g/kg)exhibited significant(Pm non-degraded(ND)to severely degraded(SD).Despite higher nutrients in ND soil generating significantly(Pmonocots growth when the soil was sterilized,a high proportion of pathogens(36%)in ND non-sterilized soil resulted in a strong negative PSF on *** contrast,the higher phenotypic plasticity of dicots coupled with a higher abundance of mutualists and saprophytes(70%)strongly promoted their survival and growth in SD with infertile *** findings identified a novel mechanism that there was a functional group shift from monocots with higher vulnerability to soil pathogens in the ND fertile soil to dicots with higher dependence on nutritional mutualists in the degraded infertile *** emerging irreversible eco-evolutionary in PSF after degradation might cause a predicament for the restoration of degraded grassland.

关键词： plant-soil feedback plant function groups degradation alpine grassland Tibetan Plateau

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Silvery fullerene in Ag102 nanosaucer

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National Science Review 2024年第7期11卷 158-167页

作者： Zhi Wang Yuchen Wang Chengkai Zhang Yan-Jie Zhu ke-Peng Song Christine m.Aikens Chen-Ho Tung Di sun School of Chemistry and Chemical Engineering Shandong University Department of Chemistry Kansas State University

Despite the discovery of a series of fullerenes and a handful of noncarbon clusters with the typical topology of Ih-C60, the smallest fullerene with a large degree of curvature, C20, and its other-element counterparts are difficult to isolate experimentally. In coinage metal nanoclusters（NCs）, the first all-gold fullerene, Au32, was discovered after a long-lasting pursuit, but the isolation of similar silvery fullerene structures is still challenging. Herein, we report a flying saucer-shaped 102-nuclei silver NC（Ag102） with a silvery fullerene kernel of Ag32, which is embraced by a robust cyclic anionic passivation layer of（kPO4）10. This Ag32kernel can be viewed as a non-centered icosahedron Ag12encaged into a dodecahedron Ag20, forming the silvery fullerene of Ag12@Ag20. The anionic layer（kPO4）10is located at the interlayer between the Ag32kernel and Ag70shell, passivating the Ag32silvery fullerene and templating the Ag70shell. The ~tBuPhS-and CF3COO-ligands on the silver shell show a regioselective arrangement with the 60 ~tBuPhS-ligands as expanders covering the upper and lower of the flying saucer and 10 CF3COO-as terminators neatly encircling the edges of the structure. In addition, Ag102 shows excellent photothermal conversion efficiency（η） from the visible to near-infrared region（η = 67.1% ± 0.9% at 450 nm, 60.9% ± 0.9% at 660 nm and 50.2% ± 0.5% at 808 nm）, rendering it a promising material for photothermal converters and potential application in remote laser ignition. This work not only captures silver kernels with the topology of the smallest fullerene C20, but also provides a pathway for incorporating alkali metal（m） into coinage metal NCs via m-oxoanions.

关键词： silvery fullerene >Ag102 nanosaucer cyclic anionic passivation layer photothermal conversion DFT calculation

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Feasibility Study on Recovering Human-Occupied Vehicle with An Offshore Crane

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China Ocean Engineering 2024年第4期38卷 648-662页

作者： HAN ming-yue XIE Peng XIAN Hao-yi ZHONG Xin-xin CHEN Sheng-lin sun.Tie-rui sun.Feng-lei School of Ocean Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China key Laboratory of Comprehensive Observation of Polar Environment(sun.Yat-sen University) Ministry of EducationZhuhai 519082China Guangzhou marine Engineering Corporation Guangzhou 510250China

Launching and recovering human-occupied vehicles(HOVs)has always been a challenging *** current recovery process requires staff to manually complete the tethering task,which is inefficient and endangers the lives of *** paper suggests moving the recovery position from the surface to underwater at approximately half the wavelength of the water depth(30−50 m underwater),where the HOV experiences less environmental *** ROV equipped with a ultra-short baseline beacon(USBL)and a manipulator was used to complete the tethering ***,a shackle customized to the shape of the manipulator’s gripper is fitted to the end of the cable to simplify the tethering *** investigate the dynamic response of recovering the HOV using this suggested method,a comprehensive numerical model is developed in this *** effects of wind,surface waves,ocean currents,and nonlinear interaction between the installation vessel and the HOV are quantitatively *** results show that the proposed recovery method can reduce the motion amplitude of the HOV and that the wave has the greatest influence on the dynamic response of the HOV during the recovery *** model provides better insight into the proposed HOV recovery method and confirms the effectiveness of the heave compensation *** proposed approach aims to enhance safety and operational efficiency by reducing direct human involvement in the recovery process and mitigating potential *** finding holds particular significance,especially in environmentally sensitive areas,where reducing the impact on the surrounding ecosystem is crucial.

关键词： human-occupied vehicle recovery dynamic response active heave compensation

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Photo-Responsive Carbon Capture over metalloporphyrin-C_(60) metal-Organic Frameworks via Charge-Transfer

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Research 2024年第3期2023卷 233-241页

作者： Shi-Chao Qi Zhen sun.Zhi-Hui Yang Yun-Jie Zhao Jia-Xin Li Xiao-Qin Liu Lin-Bing sun State key Laboratory of materials-Oriented Chemical Engineering Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China.

Great efforts have been devoted to the study of photo-responsive adsorption,but its current methodology largely depends on the well-defined photochromic units and their photo-driven molecular ***,a methodology to fabricate nondeforming photo-responsive sorbents is successfully *** C_(60)-fullerene doping in metalloporphyrin metal-organic frameworks(PCN-m,m=Fe,Co,or Ni)and intensively interacting with the metalloporphyrin sites,effective charge-transfer can be achieved over the metalloporphyrin-C_(60) architectures once excited by the light at 350 to 780 *** electron density distribution and the resultant adsorption activity are thus changed by excited states,which are also stable enough to meet the timescale of microscopic adsorption *** charge-transfer over Co(II)-porphyrin-C_(60) is proved to be more efficient than the Fe(II)-and Ni(II)-porphyrin-C_(60) sites,as well as than all the metalloporphyrin sites,so the CO_(2) adsorption capacity(CAC;at 0°C and 1 bar)over the C_(60)-doped PCN-Co can be largely improved from 2.05 mmol g^(−1) in the darkness to 2.69 mmol g−1 with light,increased by 31%,in contrast to photo-irresponsive CAC over all C_(60)-undoped PCN-m sorbents and only the photo-loss CAC over C_(60).

关键词： porphyrin adsorption excited

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