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Journal of Plant Ecology 2020年第6期13卷 732-737页

作者： Yi Tang Arshad Ali Li-Huan Feng School of life Science Liaoning UniversityShenyang 110036LiaoningChina Department of Forest Resources Management College of ForestryNanjing Forestry UniversityNanjing 210037JiangsuChina Co-Innovation Center for Sustainable Forestry in Southern China Nanjing Forestry UniversityNanjing 210037JiangsuChina

回归模型可用于预测森林生态系统地上生物量,其中最为常用的是最小二乘回归模型。在预测灌木,尤其是多茎灌木的地上生物量时,最小二乘法与贝叶斯方法的比较很少被研究。我们开发了小叶锦鸡儿(Caragana microphylla Lam.)生物量预测模型... 详细信息

回归模型可用于预测森林生态系统地上生物量,其中最为常用的是最小二乘回归模型。在预测灌木,尤其是多茎灌木的地上生物量时,最小二乘法与贝叶斯方法的比较很少被研究。我们开发了小叶锦鸡儿(Caragana microphylla Lam.)生物量预测模型。小叶锦鸡儿是科尔沁沙地广泛分布的多茎灌木,对减少风蚀、固定沙丘具有重要作用。本研究建立6种表征生物量的异速增长模型,并基于统计标准选择在预测生物量方面表现最佳的1种,然后分别用最小二乘法与贝叶斯方法对模型中的参数进行估计。参数估计过程中用自助法考察样本量大小的影响,同时区分测试集与训练集。最后,我们比较了最小二乘法与贝叶斯方法在小叶锦鸡儿地上生物量预测中的表现。异速增长的6个模型均达到显著水平,其中幂指数为1的模型表现最佳。研究结果表明,采用无先验信息与有先验信息的贝叶斯方法进行估计,得到的均方误差在测试集上低于最小二乘法。另外,基径作为预测变量在最小二乘法与贝叶斯方法中均不显著,表明在生物量预测模型中应谨慎选择合适变量。本研究强调贝叶斯方法、自助法和异速增长模型相结合能够提升沙地灌木生物量预测模型的准确度。

关键词：自助法小叶锦鸡儿科尔沁均方误差先验信息

Joining of dissimilar metals between magnesium AZ31B and aluminum A6061-T6 using galvanized steel as a transition joining layer

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Journal of Iron and Steel Research(International) 2022年第4期29卷 677-686页

作者： Wei li Jing-huan Chang Bao-feng Wen Rui Cao State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metal Lanzhou University of TechnologyLanzhou 730050GansuChina Department of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050GansuChina

A galvanized steel is used to join Mg AZ31B alloy and Al A6061-T6 alloy as a joining transition layer by cold metal transfer(CMT)method.Firstly,to optimize the process variables,extensive welding tests were performed by a design of experiment method.Then,microstructures,joining mechanisms and tensile properties were characterized and analyzed.Results indicated that Mg and Al alloys can be joined by using galvanized steel as a joining transition layer and cold metal transfer welding method.The formed joint is called as a Mg–steel–Al CMT joint.By using galvanized steel transition joining layer,Mg–Al brittle intermetallics Al12Mg17 and Al3Mg2 were inhibited.The properties of Mg–steel–Al CMT joints have been improved after optimizing the welding variables.The strength of Mg–steel–Al CMT joint is comparable to those of Al–Al joint and Mg–Mg joint.The strength of Mg–steel–Al CMT joint can reach 100%that of Al–Al joint and Al–steel joint,and reach 90%that of Mg–Mg joint and Mg–steel joint.The optimized Mg–steel–Al CMT welded joint with galvanized steel transition layer is fractured at the heat affected zone of Al base metal rather than at the weld-brazed interface,due to softening of Al base metal.

关键词： Cold metal transfer Mg alloy Al alloy Galvanized steel Transition joining layer Dissimilar metal joining

Chemical Recycling of Poly(ethylene furanoate)into Value-added Poly(ethylene-co-isosorbide furanoate)

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高分子科学:英文版 2023年第10期41卷 1533-1542页

作者： Jing li Sheng Wang huan-Jun Lu Ying-Jia Lan Xiao-Hong li Ying-feng Tu Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials State and Local Joint Engineering Laboratory for Novel Functional Polymeric MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China Jiangsu Key Laboratory for Micro and Nano Heat Fluid Flow Technology and Energy Application School of Physical Science and TechnologySuzhou University of Science and TechnologySuzhou215009China

We present here a novel strategy for the chemical recycling of bio-based poly(ethylene furanoate)s(PEF)to value-added high-performance bio-based poly(ethylene-co-isosorbide furanoate)(PEIF)copolyesters by the combination of cyclodepolymerization method with rapid cascade polycondensation-coupling ring-opening polymerization(PROP).The solution cyclodepolymerization of commercially available PEF affords cyclic oligo(ethylene 2,5-furandicarboxylate)s(COEFs),and the effects of reaction conditions on the yield of COEFs were studied.PEIF copolyesters with different isosorbide(IS)contents were synthesized via the cascade PROP of COEFs with IS,which show significant enhanced glass transition temperature.By melt spinning,PEIF fibers with different orientation factors were prepared,with excellent thermal stability and mechanical performance.The obtained PEIF fibers can lift a weight∼25000 times higher than its weight.The PEIF fibers are stable under ambient conditions but are biodegradable following the“surface erosion”mechanism.These sustainable value-added biodegradable PEIF fibers offer a solution to the environmentally friendly fibers.

关键词： Bio-based Chemical recycling Fiber PROP Sustainable

RT-Notification: A Novel Real-Time Notification Protocol for Wireless Control in Fog Computing

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China Communications 2017年第11期14卷 17-28页

作者： li feng Jie Yang huan Zhang The Faculty of Information Technology Macao University of Science and Technology College of Intellectualized City Beijing Union University

Fog computing is an emerging paradigm that has broad applications including storage, measurement and control. In this paper, we propose a novel real-time notification protocol called RT-Notification for wireless control in fog computing. RT-Notification provides low-latency TDMA communication between an access point in Fog and a large number of portable monitoring devices equipped with sensor and actuator. RT-Notification differentiates two types of controls: urgent downlink actuator-oriented control and normal uplink access & scheduling control. Different from existing protocols, RT-Notification has two salient features:(i) support real-time notification of control frames, while not interrupting ongoing other transmissions, and(ii) support on-demand channel allocation for normal uplink access & scheduling control. RT-Notification can be implemented based on the commercial off-the-shelf 802.11 hardware. Our extensive simulations verify that RT-Notification is very effective in supporting the above two features.

关键词： fog computing wireless control real-time notification

Reliable Data Storage in Heterogeneous Wireless Sensor Networks by Jointly Optimizing Routing and Storage Node Deployment

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Tsinghua Science and Technology 2021年第2期26卷 230-238页

作者： huan Yang feng li Dongxiao Yu Yifei Zou Jiguo Yu College of Computer Science and Technology Qingdao UniversityQingdao 266071China School of Computer Science and Technology Shandong UniversityQingdao 266237China School of Computer Science and Technology Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Department of Computer Science the University of Hong KongHong Kong 999077China Shandong Computer Science Center(National Supercomputer Center in Jinan) Jinan 250014China

In the era of big data,sensor networks have been pervasively deployed,producing a large amount of data for various applications.However,because sensor networks are usually placed in hostile environments,managing the huge volume of data is a very challenging issue.In this study,we mainly focus on the data storage reliability problem in heterogeneous wireless sensor networks where robust storage nodes are deployed in sensor networks and data redundancy is utilized through coding techniques.To minimize data delivery and data storage costs,we design an algorithm to jointly optimize data routing and storage node deployment.The problem can be formulated as a binary nonlinear combinatorial optimization problem,and due to its NP-hardness,designing approximation algorithms is highly nontrivial.By leveraging the Markov approximation framework,we elaborately design an efficient algorithm driven by a continuous-time Markov chain to schedule the deployment of the storage node and corresponding routing strategy.We also perform extensive simulations to verify the efficacy of our algorithm.

关键词： reliable data storage routing node deployment heterogeneous sensor networks

Modeling and game strategy analysis of suppressing IADS for multiple fighters' cooperation

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Journal of Systems Engineering and Electronics 2018年第2期29卷 296-304页

作者： li Qiuni YANG Rennong li Haoliang ZHANG huan feng Chao Aeronautics and Astronautics Engineering College Air Force Engineering University

This paper addresses the problem of suppression of the integrated air defense system(IADS) by multiple fighters’ cooperation. Considering the dynamic changing of the number of the nodes in the operational process, a profit model for the influence of the mission’s cost for the whole system is developed for both offense and defensive sides. The scenario analysis is given for the process of suppressing the IADS by multiple fighters. Based on this scenario analysis, the modeling method and the specific expression for the payoff function are proposed in four cases for each node. Moreover, a distributed virtual learning algorithm is designed for the n-person and n-strategy game, and the mixed strategy Nash equilibrium(MSNE) of this game can be solved from the n × m × 3-dimensional profit space. Finally, the simulation examples are provided to demonstrate the effectiveness of the proposed model and the game algorithm.

关键词： cooperative suppression non-cooperative game Nash equilibrium virtual learning

Exhumation History and Exploration Potential of Gold Deposits in the NE Jiaodong Peninsula,North China:Evidence from Apatite and Zircon Fission Track Thermochronology

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Journal of Earth Science 2023年第3期34卷 776-789页

作者： Yuanlin Chen huan li Chaoyang Zheng Safiyanu Muhammad Elatikpo liu’an Duan Bo feng Dadou li Rehan Khan Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China Department of Geology Ahmadu Bello University ZariaNigeria Yantai Geological Survey Center of Coastal Zone China Geological SurveyYantai 264004China Xintai Gold and Mining Industry Co.Ltd Yantai 265147China No.1 Institute of Geology and Mineral Resources of Shangdong Province Jinan 250100China

As the most important gold producer in China,the Northwest Jiaodong Peninsula is famous for its large gold deposits.In recent years,the discovery of gold mineralization has reached a depth of 4000 m below the surface in this region.It has attracted significant interest from explorers about the prospecting potential at greater depths.Besides,the current deep drilling shows that the prospecting effect in the west portion is better than the region to the east.Does it imply that there is a difference in prospecting potential between the east and the west?This paper seeks to address the issue through fission track thermochronology on apatite and zircon to reveal the temperature-time evolution relationship of rock mass and to inverts their thermal evolution history.In addition,this study analyzes the transformation of ore deposits after mineralization,quantitatively calculates the uplift-erosion rate of rock mass,and summarizes the preservation law of ore deposits.Based on the thermal history simulation of the apatite fission track,our results show that the Guocheng gold belt has experienced three stages of thermal evolution:108-74,74-27,and 27-0 Ma.The uplift and cooling processes of the threestage tectonic uplift events are the results of multi-stage Pacific plate accretion.The calculated total denudation depth of the gold deposit in the Guocheng gold belt from Cretaceous to the present is about 3.4-5.3 km.The metallogenic depth of the ore body in the gold belt is 5.6-8.0 km,which indicates that the ore body in the Guocheng gold belt has suffered a significant degree of denudation.It is speculated that the location with less denudation in the southwest has greater prospecting potential.Our results quantitatively identify the uplift and denudation of the deposit after mineralization,which provides a new theoretical reference for regional mineralization,deep prospecting and exploration.

关键词： Queshan pluton Muniushan pluton thermal history simulation apatite zircon exhumation magnitude exploration potential gold deposits Guocheng gold belt

Microbial electro-fermentation for synthesis of chemicals and biofuels driven by bi-directional extracellular electron transfer

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Synthetic and Systems Biotechnology 2020年第4期5卷 304-313页

作者： Ziying Gong huan Yu Junqi Zhang feng li Hao Song Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjin300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

Electroactive bacteria could perform bi-directional extracellular electron transfer(EET)to exchange electrons and energy with extracellular environments,thus playing a central role in microbial electro-fermentation(EF)process.Unbalanced fermentation and microbial electrosynthesis are the main pathways to produce value-added chemicals and biofuels.However,the low efficiency of the bi-directional EET is a dominating bottleneck in these processes.In this review,we firstly demonstrate the main bi-directional EET mechanisms during EF,including the direct EET and the shuttle-mediated EET.Then,we review representative milestones and progresses in unbalanced fermentation via anode outward EET and microbial electrosynthesis via inward EET based on these two EET mechanisms in detail.Furthermore,we summarize the main synthetic biology strategies in improving the bi-directional EET and target products synthesis,thus to enhance the efficiencies in unbalanced fermentation and microbial electrosynthesis.Lastly,a perspective on the applications of microbial electro-fermentation is provided.

关键词： Unbalanced fermentation Microbial electrosynthesis Extracellular electron transfer Synthetic biology

Ascending aorta dilatation reduces the influence of elevated pulse pressure on left ventricular hypertrophy:findings from a Chinese elderly hypertensive population

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Journal of Geriatric Cardiology 2023年第2期20卷 100-108页

作者： Yu-Qi JIANG huan-Rui ZHANG Bo-Nan liU Tian-Wen li Jun-feng JIANG Wen TIAN Department of Geriatrics the First Hospital of China Medical UniversityShenyangChina

OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retrospectively studied.Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements.In addition,brachial blood pressure was measured,and total arterial compliance,systemic vascular resistance,arterial elastance,and end-systolic LV elastance were calculated.The participants were divided into four groups according to the status of ascending aortic diameter and PP.RESULTS LV mass index increased in succession in the four groups,i.e.,the group with the normal aorta and lower PP,with the normal aorta and higher PP,with aortic dilatation and lower PP,and with aortic dilatation and higher PP(Ptrendliance−1,arterial elastance,and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation,regardless of PP being lower or higher(P<0.01).Compared to the group with the normal aorta and lower PP,individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy,and higher PP further exacerbated this risk[aortic dilatation with lower PP(OR=1.75,95%CI:1.01–3.04)and aortic dilatation with higher PP(OR=3.42,95%CI:2.03–5.77)].In the relation between PP and LV mass index(β=0.095,P<0.001),-41.3%of the total effect was attributable to mediation by ascending aortic diameter(P<0.0001).CONCLUSIONS In Chinese elderly patients with hypertension,ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.

关键词： elevated hypertensive hypertrophy

Exceptional electrostrain with minimal hysteresis and superior temperature stability under low electric field in KNN-based lead-free piezoceramics

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Journal of Advanced Ceramics 2024年第3期13卷 364-372页

作者： huan liu Yijin Hao Ziqi Yang Tianyi feng Bin Su Xin Zhang Mengping Xue Bo-Ping Zhang Jing-feng li Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Over the past two decades,(K_(0.5)Na_(0.5))NbO_(3)(KNN)-based lead-free piezoelectric ceramics have made significant progress.However,attaining a high electrostrain with remarkable temperature stability and minimal hysteresis under low electric fields has remained a significant challenge.To address this long-standing issue,we have employed a collaborative approach that combines defect engineering,phase engineering,and relaxation engineering.The LKNNS-6BZH ceramic,when sintered at T_(sint)=1170℃,demonstrates an impressive electrostrain with a d_(33) value of 0.276%and 1379 pm·V^(-1)under 20 kV·cm^(-1),which is comparable to or even surpasses that of other lead-free and Pb(Zr,Ti)O_(3)ceramics.Importantly,the electrostrain performance of this ceramic remains stable up to a temperature of 125℃,with the lowest hysteresis observed at 9.73%under 40 kV·cm^(-1).These excellent overall performances are attributed to the presence of defect dipoles involving V′_(A)-V∙∙_(O) and B′_(Nb)-V∙∙O,the coexistence of R-O-T multiphase,and the tuning of the trade-off between long-range ordering and local heterogeneity.This work provides a lead-free alternative for piezoelectric actuators and a paradigm for designing piezoelectric materials with outstanding comprehensive performance under low electric fields.

关键词： lead-free piezoelectric ceramics temperature stability electrostrain potassium sodium niobate low hysteresis