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Global analysis of daily new COVID-19 cases reveals many staticphase countries including the United States potentially with unstoppable epidemic

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World Journal of Clinical Cases 2020年第19期8卷 4431-4442页

作者： Cheng Long Xin-Miao fu Zhi-fu fu Department of Orthopaedics Sichuan University West China HospitalChengdu 610041Sichuan ProvinceChina College of Life Sciences Fujian Normal UniversityFuzhou 350117Fujian ProvinceChina Anxi AIER Eye Hospital(AIER EYE Hospital Group) Anxi 362400Fujian ProvinceChina

BACKGROUND The coronavirus disease 2019(COVID-19)pandemic is hitting many *** is hypothesized the epidemic is differentially progressing in different *** To investigate how the COVID-19 epidemic is going on in different countries by analyzing representative *** The status of COVID-19 epidemic in over 60 most affected countries was *** data of daily new cases of each country were collected from *** data of daily tests for the United States,Italy,and South Korea were collected from the Website of One World *** of daily positive COVID-19 tests in the two most affected states of the United States(New York and New Jersey)were collected from the website of the COVID Tracking *** were analyzed using Microcal Origin software with ANOVA algorithm,and significance level was set at a P value of *** The COVID-19 epidemic was differentially progressing in different *** analyses of daily new cases as of April 19,2020 revealed that 61 most affected countries can be classified into four types:Downward(22),upward(20),static-phase(12),and uncertain ones(7).In particular,the 12 static-phase countries including the United States were characterized by largely constant numbers of daily new cases in the past over 14 ***,these static-phase countries were overall significantly lower in testing density(P=0.016)but higher in the level of positive COVID-19 tests than downward countries(P=0.028).These findings suggested that the testing capacity in static-phase countries was lagging behind the spread of the outbreak,i.e.,daily new cases(confirmed)were likely less than daily new infections and the remaining undocumented infections were thus still expanding,resulting in unstoppable *** Increasing the testing capacity and/or reducing the COVID-19 transmission are urgently needed to stop the potentially unstoppable,severing crisis in static-phase countries.

关键词： COVID-19 SARS-CoV-2 Coronavirus Pandemic Testing density

Key technologies and applications of agricultural energy Internet for agricultural planting and fisheries industry

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Information Processing in Agriculture 2023年第3期10卷 416-437页

作者： Xueqian fu Haosen Niu College of Information and Electrical Engineering China Agricultural UniversityBeijingChina National Innovation Center for Digital Fishery China Agricultural UniversityBeijingChina Key Laboratory of Smart Farming Technologies for Aquatic Animal and Livestock Ministry of Agriculture and Rural AffairsBeijingChina Beijing Engineering and Technology Research Center for Internet of Things in Agriculture BeijingChina

Energy consumption in the agricultural sector is significant,reaching 20%of the total energy consumption in *** Energy Internet,an important extension of Energy Internet in the agricultural field,significantly contributes to agricultural *** technologies of Agricultural Energy Internet are vital factors supporting its *** article systematically reviews the key technologies of Agricultural Energy Internet for two areas:agriculture and *** working mechanisms and power consumption characteristics of some state-of-the-art new-energy agricultural intelligent equipment are *** addition,the principles and profit methods underlying the agro-industrial complementary operation model are ***,against the Agricultural Energy Internet background,the development trends of some state-of-theart new energy agricultural intelligent equipment,agro-industrial complementary,and carbon–neutral technology are proposed in this paper,providing novel perspectives on the promotion of the development of Agricultural Energy Internet and related technological innovation *** unmanned farm is the main form of the future agricultural system,which is powered by the Agricultural Energy Internet based on smart agriculture and a smart *** will become the inevitable trend of modern agriculture to replace oil agriculture with electric *** electricity in farming is mainly generated by renewable *** energy power generation has low carbon emissions and is the future direction for the development of agricultural energy *** addition,the Internet of Things will be further strengthened to realize automation and intelligence of agricultural energy systems。

关键词： Agricultural Energy Internet Agricultural equipment Agricultural planting Fisheries industry Carbon neutrality

Analysis of nonlinear vibration for symmetric angle-ply laminated viscoelastic plates with damage

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Acta Mechanica Sinica 2005年第5期21卷 459-466页

作者： Yufang Zheng Yiming fu Department ofEngineering Mechanics Hunan University Changsha410082 China

The behavior of nonlinear vibration for symmetric angle-ply laminated plates including the material viscoelasticity and damage evolution is investigated. By employing the von Karman＇s nonlinear theory, strain energy equivalence principle and Boltzmann superposition principle, a set of governing equations of nonlinear integro-differential type are derived. By applying the finite difference method, Newmark method and iterative procedure, the governing equations are solved. The effects of loading amplitudes, exciting frequencies and different ply orientations on the critical time to failure initiation and nonlinear vibration amplitudes of the structures are discussed. Numerical results are presented for the different parameters and compared with the available data.

关键词： Viscoelasticity . Damage evolution. Laminated plates . Structure's failure initiation

Hot workability characteristics of Rene88DT superalloy with directionally solidified microstructure

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Rare Metals 2015年第1期34卷 51-63页

作者： fu-Lin Li Rui fu Di Feng Zhi-Ling Tian Superalloy Department Central Iron & Steel Research Institute

The hot deformation characteristics of Rene88DT superalloy with directionally solidified micro- structure produced by electroslag remelting continuous directionally solidification （ESR-CDS） were studied in the temperature range of 1,040-1,140 ℃ and strain rate range of 0.001-1.000 s-1 by hot compression tests. Flow curves for Rene88DT alloy with initial directionally solidified （DS） microstructure exhibit pronounced peak stresses at the early stage of deformation followed by the occurrence of dynamic softening phenomenon. Rene88DT alloy with DS micro- structure shows higher flow peak stresses compared with HIPed P/M superalloy FGH4096, but the disparities in peak stresses between ESR-CDSed Rene88DT and HIPed P/M superalloy FGH4096 reduce as temperature increases. The improvement of hot workability of DS alloy with columnar grains avoiding the maximum shear stress comes true. A hot deformation constitutive equation as a function of strain that describes the dependence of flow stress on strain rate and temperature is established. Hot deformation apparent acti- vation energy （Q） varies not only with the strain rate and temperature but also with strain. The strain rate sensitivity exponent （m） map is established at the strain of 0.8, which reveals that global dynamic recrystallization （DRX） shows a relatively high m value in a large strain compression. Optimum parameters are predicted in two regions： T = 1,100-1,130 ℃, ε = 0.100-1.000 s-1 and T = 1,080- 1,100 ℃, ε = 0.010-100 s-1, which is based on pro- cessing maps and deformation microstructure observations.

关键词： Rene88DT alloy Directional solidification Isothermal compression Constitutive equation Processingmap

TPM-Based Remote Attestation for Wireless Sensor Networks

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Tsinghua Science and Technology 2016年第3期21卷 312-321页

作者： Donglai fu Xinguang Peng Software School of North University of China Taiyuan 030051China School of Computer Science&Technology Taiyuan University of TechnologyTaiyuan 030051China.

It is essential to design a protocol to allow sensor nodes to attest to their trustworthiness for mission- critical applications based on Wireless Sensor Networks （WSNs）. However, it is a challenge to evaluate the trustworthiness without appropriate hardware support. Hence, we present a hardware-based remote attestation protocol to tackle the problem within WSNs. In our design, each sensor node is equipped with a Trusted Platform Module （TPM） which plays the role of a trusted anchor. We start with the formulation of remote attestation and its security. The complete protocol for both single-hop and multi-hop attestations is then demonstrated. Results show the new protocol is effective, efficient, and secure.

关键词： network security wireless sensor networks remote attestation trusted platform module

Reduction rules-based search algorithm for opportunistic replacement strategy of multiple life-limited parts

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Chinese Journal of Aeronautics 2018年第1期31卷 21-30页

作者： Xuyun fu Shisheng ZHONG Department of Mechanical Engineering Harbin Institute of Technology at Weihai

The opportunistic replacement of multiple Life-Limited Parts （LLPs） is a problem widely existing in industry. The replacement strategy of LLPs has a great impact on the total maintenance cost to a lot of equipment. This article focuses on finding a quick and effective algorithm for this problem. To improve the algorithm efficiency, six reduction rules are suggested from the perspectives of solution feasibility, determination of the replacement of LLPs, determination of the maintenance occasion and solution optimality. Based on these six reduction rules, a search algorithm is proposed. This search algorithm can identify one or several optimal solutions. A numerical experiment shows that these six reduction rules are effective, and the time consumed by the algorithm is less than 38 s if the total life of equipment is shorter than 55000 and the number of LLPs is less than 11. A specific case shows that the algorithm can obtain optimal solutions which are much better than the result of the traditional method in 10 s, and it can provide support for determining tobe-replaced LLPs when determining the maintenance workscope of an aircraft engine. Therefore, the algorithm is applicable to engineering applications concerning opportunistic replacement of multiple LLPs in aircraft engines.

关键词： Aircraft engine Maintenance occasion Opportunistic replacement Reduction rules Replacement of life-limited parts

Contribution of tropical cyclone rainfall at categories to total precipitation over the Western North Pacific from 1998 to 2007

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Science China Earth Sciences 2015年第11期58卷 2015-2025页

作者： CHEN FengJiao fu YunFei School of Earth and Space Sciences University of Science and Technology of China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

Based on 10 years precipitation data from Tropical Rainfall Measurement Mission （TRMM） Multi-satellite Precipitation Analysis （TMPA） 3B42 and the best track data from China Meteorological Administration （CMA）, the seasonal, monthly and annual contribution of tropical cyclone （TC） precipitation to the total rainfall are analyzed over the Western North Pacific （WNP） during 1998 to 2007 from May to December. The results show that：（1） TC seasonal rainfall contribution ranges from 4% in inland regions to above 40% in ocean-regions of 15°N-25°N. TCs at higher categories contribute much more to the total precipitation. （2） On monthly scale, TCs contribute 60% to the total rainfall regionally during whole TC season, which is the maximum contribution. The peak contribution of TC rainfall averaged in multi-months of the ten years occurs in August （28%） over the whole ocean impacted by TC and in December （23%） over the whole land impacted by TC, respectively. （3） On annual scale, the maximum contribution of TC precipitation to the total rainfall are in 2004 （-30%） over ocean and in 1998 （-20%） over land, respectively. （4） The contribution of TC precipitation to the total rainfall increases 6% （decreases 6%） in El Nino （La Nifia） years compared with neutral years.

关键词： tropical cyclone precipitation contribution 3B42 WNP ENSO

RFID Based e-quality Tracking in Service-oriented Manufacturing Execution System

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 974-981页

作者： fu Yingbin JIANG Pingyu State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong UniversityXi'an 710049China

The method of acquiring the real-time data has influenced the implementation of the manufacturing execution system （MES）. Accompanied with turning the MES into service-oriented manufacturing execution system （so-MES）, real-time e-quality tracking （e-QT）, in which real-time data are computed, has played more and more important roles in manufacturing. This paper presents an e-QT model through the study of real-time status data tracking and quality data collecting. An implementing architecture of the e-QT model is constructed on the basis of radio frequency identification devices （RFID） data-tracking network. In order to develop the e-QT system, some key enabling technologies, such as configuration, data collection, and data processing, etc, are studied. The relation schema between hardware is built for the RFID data-tracking network based on the configuration technique. Real-time data are sampled by using data collecting technique. furthermore, real-time status and quality data in a shop-floor can be acquired in terms of using the real-time data computing method. Finally, a prototype system is developed and a running example is given so as to verify the feasibility of methods proposed in this paper. The proposed research provides effective e-quality tracking theoretical foundation through the use of RFID technology for the discrete manufacturing.

关键词： real-time tracking data collection radio frequency identification devices

A Numerical Study on Pressure Drop in Microchannel Flow with Different Bionic Micro-Grooved Surfaces

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Journal of Bionic Engineering 2012年第1期9卷 99-109页

作者： Jing Cui Yabo fu School of Airport Civil Aviation University of China Tianjin 30300 P. R. China College of Physics and electronic engineering Taizhou University Taizhou 318000 P. R. China

The studies of bionics reveal that some aquatic animals and winged insects have developed an unsmoothed surface possessing good characteristics of drag reduction. In this paper, four types of bionic surfaces, placoid-shaped, V-shaped, rib- let-shaped, and ridge-shaped grooved surfaces, are employed as the microchannel surfaces for the purpose of reducing pressure loss. Lattice Boltzmann Method （LBM）, a new numerical approach on mescoscopic level, is used to conduct the numerical investigationsr. The results show that the micro-grooved surfaces possess the drag reduction performance. The existence of the vortices formed within the grooves not only decrease the shear force between fluid and wall but also minimize the contact area between fluid and walls, which can lead to a reduction of pressure loss. The drag reduction coefficient （η） for these four types of micro-structures could be generalized as follows： ηridge_shaped 〉 ηv-shaped 〉 ηplacoid-shaped 〉 ηriblet-shaped. Besides, the geometrical optimizations for the ridge-shaped grooves, which have the highest drag reduction performance, are performed as well. The results suggest that, for the purpose of drag reduction, the ridge-shaped grooves with smaller width to height ratio are recommended for the lower Reynolds number flow, while the ridge-shaped grooves with larger width to height ratio are be more suitable for the larger Reynolds number flow.

关键词： microchannel bionic grooves drag reduction lattice Boltzmann method