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Stochastic frontiers or regression quantiles for estimating the self-thinning surface in higher dimensions?

Journal of Forestry Research 2021年第4期32卷 1515-1533页

作者： dechao tian Huiquan Bi Xingji Jin Fengri Li Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education School of ForestryNortheast Forestry UniversityNo.26 Hexing RoadHarbin 150040People’s Republic of China Forest Science NSW Department of Primary Industries−ForestryLevel 1210 Valentine AveParramattaNSW 2150Australia School of Ecosystem and Forest Sciences The University of MelbourneParkvilleVIC 3010Australia

Stochastic frontier analysis and quantile regression are the two econometric approaches that have been commonly adopted in the determination of the self-thinning boundary line or surface in two and higher dimensions since their introduction to the field some 20 years ***,the rational for using one method over the other has,in most cases,not been clearly explained perhaps due to a lack of adequate appreciation of differences between the two approaches for delineating the self-thinning *** an adequate understanding of such differences,the most informative analysis may become a missed opportunity,leading to an inefficient use of data,weak statistical inferences and a failure to gain greater insight into the dynamics of plant populations and forest stands that would otherwise be *** data from 170 plot measurements in even-aged Larix olgensis(***) plantations across a wide range of site qualities and with different abundances of woody weeds,*** regenerated non-crop species,in northeast China,this study compared the two methods in determining the self-thinning surface across eight sample sizes from 30 to 170 with an even interval of 20 observations and also over a range of quantiles through repeated random sampling and *** all sample sizes and over the quantile range of 0.90 ≤τ≤0.99,the normal-half normal stochastic frontier estimation proved to be superior to quantile regression in statistical *** parameter estimates had lower degrees of variability and correspondingly narrower confidence *** greater efficiency would naturally be conducive to making statistical *** estimated self-thinning surface using all 170 observations enveloped about 96.5% of the data points,a degree of envelopment equivalent to a regression quantile estimation with aτ of *** stochastic frontier estimation was also more objective because it did not involve the subjective selection of a particular value

关键词： Larix olgensis Normal-half normal distribution Site productivity Woody weeds Sample size Quantile selection

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精准扶贫视阈下参与式帮扶的内在机理和实现路径

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社会科学 2017年第8期 42-50页

作者：孙德超白天吉林大学行政学院行政管理系吉林大学行政学院

在全面建设小康社会的攻坚时期,国家提出精准扶贫战略,具有深刻的政策用意。从精准扶贫的核心要义、目标意涵及时代使命而言,精准扶贫与参与式帮扶之间具有内在的一致性。参与式帮扶能够夯实精准扶贫中多元主体互动的政治基础,可以积极... 详细信息

在全面建设小康社会的攻坚时期,国家提出精准扶贫战略,具有深刻的政策用意。从精准扶贫的核心要义、目标意涵及时代使命而言,精准扶贫与参与式帮扶之间具有内在的一致性。参与式帮扶能够夯实精准扶贫中多元主体互动的政治基础,可以积极促成精准扶贫中主体合作的行动框架,有助于确保精准扶贫过程的公平价值导向,有助于实现扶贫信息的高效共享与整合。而从主体吸纳、协商嵌入和激励相容的角度构建参与式帮扶是较佳的实现路径,即:需要规范长效识别机制,强化对社会贫困和边缘群体的有效吸纳;探索社区主导型扶贫,提升帮扶策略的精准和细化程度;整合社会资源,推进建立多方利益联结机制;健全扶贫考核评估机制,实现多方参与的扶贫成果反馈。

关键词：精准扶贫参与式帮扶内在机理

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依据分位数回归建立的长白落叶松潜在最大冠幅预测模型

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东北林业大学学报 2019年第8期47卷 41-46页

作者：田德超李凤日董利虎东北林业大学

依据吉林省松江河林业局,黑龙江省孟家岗林场、东京城林业局和林口林业的长白落叶松人工林178块固定样地数据,从中选出1166株优势木数据,采用不同的分位点构建不同线性分位数回归模型,初步选取能够模拟潜在最大冠幅的最适分位点,结合人... 详细信息

依据吉林省松江河林业局,黑龙江省孟家岗林场、东京城林业局和林口林业的长白落叶松人工林178块固定样地数据,从中选出1166株优势木数据,采用不同的分位点构建不同线性分位数回归模型,初步选取能够模拟潜在最大冠幅的最适分位点,结合人为选择的数据点和抽样的方法来最终确定最适分位点。在最适分位点模型基础上,采用线性分位数混合效应模型最终确定潜在最大冠幅模型。结果表明:通过对不同分位点0.90、0.95和0.99在随机抽取样本大小为1000,循环分析1000次得到参数估计值的平均值、标准偏差和变异系数的比较,以及利用决定系数、预测平均误差、预测平均绝对误差和预测的均方误差指标对按径阶选取45株优势木数据做线性回归与用全部数据做不同分位点的分位数回归进行比较,发现分位点为0.99为最适分位点。在最适分位点模型基础上,考虑样地之间的差异,构建了线性分位数混合效应模型。线性分位数混合效应模型较好的描述了长白落叶松潜在最大冠幅随胸径变化的趋势,为准确模拟林分竞争和预测林分生长动态提供有效的依据。

关键词：长白落叶松优势木潜在最大冠幅分位数回归混合效应模型

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Overview and Prospect of Distributed Energy P2P Trading

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Energy Engineering 2025年第1期122卷 379-404页

作者： Jiajia Liu Mingxing tian Xusheng Mao School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou730070China

After a century of relative stability in the electricity sector,the widespread adoption of distributed energy resources,along with recent advancements in computing and communication technologies,has fundamentally altered how energy is consumed,traded,and *** change signifies a crucial shift as the power system evolves from its traditional hierarchical organization to a more decentralized *** the heart of this transformation are innovative energy distribution models,like peer-to-peer(P2P)sharing,which enable communities to collaboratively manage their energy *** effectiveness of P2P sharing not only improves the economic prospects for prosumers,who generate and consume energy,but also enhances energy resilience and *** allows communities to better leverage local resources while fostering a sense of collective responsibility and collaboration in energy ***,there is still no extensive implementation of such sharing models in today’s *** on distributed energy P2P trading is still in the exploratory stage,and it is particularly important to comprehensively understand and analyze the existing distributed energy P2P trading *** paper contributes with an overview of the P2P markets that starts with the network framework,market structure,technical approach for trading mechanism,and blockchain technology,moving to the outlook in this field.

关键词： Distributed energy P2P market mechanisms classification and comparison

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Modeling and Capacity Configuration Optimization of CRH5 EMU On-Board Energy Storage System

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Energy Engineering 2025年第1期122卷 307-329页

作者： Mingxing tian Weiyuan Zhang Zhaoxu Su School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou730070China

In the context of the“dual carbon”goals,to address issues such as high energy consumption,high costs,and low power quality in the rapid development of electrified railways,this study focused on the China Railways High-Speed 5 Electric Multiple Unit and proposed a mathematical model and capacity optimization method for an onboard energy storage system using lithium batteries and supercapacitors as storage ***,considering the electrical characteristics,weight,and volume of the storage media,a mathematical model of the energy storage system was ***,to tackle problems related to energy consumption and power quality,an energy management strategy was proposed that comprehensively considers peak shaving and valley filling and power quality by controlling the charge/discharge thresholds of the storage *** optimization adopted a bilevel programming model,with the series/parallel number of storage modules as variables,considering constraints imposed by the Direct Current to Direct Current converter,train load,and *** improved Particle Swarm Optimization algorithm and linear programming solver were used to solve specific *** results show that the proposed onboard energy storage system can effectively achieve energy savings,reduce consumption,and improve power qualitywhile meeting the load and space limitations of the train.

关键词： Electrified railway regenerative braking bi-level programming on-board energy storage power quality capacity configuration

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Research status and prospects of the fractal analysis of metal material surfaces and interfaces

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 20-38页

作者： Qinjin Dai Xuefeng Liu Xin Ma Shaojie tian Qinghe Cui Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China Laboratory for Advanced Materials Processing of Ministry of Education University of Science and Technology BeijingBeijing 100083China School of Mechanical and Electrical Engineering Xinjiang Institute of EngineeringUrumqi 830023China

As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine *** analysis has been used to characterize the shapes of metal materials at various scales and *** methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and ***,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal *** the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear *** relationship between the fractal dimensions and properties of metal material surfaces and interfaces is *** from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be *** is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.

关键词： metal material surfaces and interfaces fractal analysis fractal dimension homogeneity

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Coordinated Control Strategy of New Energy Power Generation System with Hybrid Energy Storage Unit

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Energy Engineering 2025年第1期122卷 167-184页

作者： Yun Zhang ZifenHan Biao tian Ning Chen Yi Fan School of Mechano-Electronic Engineering Xidian UniversityXi’an710071China Electric Power Control Center State Grid Gansu Electric Power CompanyLanzhou730030China Electric Power Control Center State Grid Gansu Electric Power Company Zhangye Power Supply BranchZhangye734000China

The new energy power generation is becoming increasingly important in the power *** as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power *** solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage ***,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage ***,the fuzzy control algorithm is introduced to balance the power between energy *** this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current *** is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.

关键词： Photovoltaic power suppression hybrid energy storage unit variationalmodal decomposition fuzzy control power distribution control

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Smart Gas Sensors:Recent Developments and Future Prospective

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Nano-Micro Letters 2025年第3期17卷 55-86页

作者： Boyang Zong Shufang Wu Yuehong Yang Qiuju Li tian Tao Shun Mao College of Environmental Science and Engineering Biomedical Multidisciplinary Innovation Research InstituteShanghai East HospitalState Key Laboratory of Pollution Control and Resource ReuseTongji University1239 Siping RoadShanghai 200092People’s Republic of China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092People’s Republic of China Microbiome Medicine Center Department of Laboratory MedicineZhujiang HospitalSouthern Medical UniversityGuangzhou 510280People’s Republic of China

Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,*** the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated *** electronicand optoelectronic gas sensors have been developed for high-performancesmart gas *** the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas *** review highlights recent advances of smart gassensors in diverse *** structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are ***,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are ***,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.

关键词： Smart gas sensor Electronic sensor Optoelectronic sensor Flexible and wearable sensor Artificial intelligence

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“Slope-adsorption & plateau-pore filling” mechanism unlocking the potential of hard carbon anodes for “fast-charging & large-sized”batteries

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Science China Materials 2025年第1期 309-311页

作者： tian Liang Xiaoming Zhu Hubei Key Laboratory of Radiation Chemistry and Functional Materials School of Nuclear Technology and Chemistry & Biology Hubei University of Science and Technology

To date, there has been no report on fast-charging and Ahlevel sodium-ion batteries (SIBs) by utilizing thick hard carbon anodes that demonstrate prolonged cycling life and high areal capacity at high rates. Further, the relationship among the complex structure of hard carbon, storage mechanism, and fastcharging performance in alkali-metal ion batteries has been a subject of ongoing debate [1,2].

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Nanocarrier-mediated siRNA delivery:a new approach for the treatment of traumatic brain injury-related Alzheimer's disease

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Neural Regeneration Research 2025年第9期20卷 2538-2555页

作者： Jie Jin Huajing Zhang Qianying Lu Linqiang tian Sanqiao Yao Feng Lai Yangfan Liang Chuanchuan Liu Yujia Lu Sijia tian Yanmei Zhao Wenjie Ren Institute of Disaster and Emergency Medicine Tianjin UniversityTianjinChina Key Laboratory for Disaster Medicine Technology TianjinChina Henan Medical Key Laboratory for Research of Trauma and Orthopedics The Third Affiliated Hospital of Xinxiang Medical UniversityXinxiangHenan ProvinceChina Clinical Medical Center of Tissue Engineering and Regeneration Xinxiang Medical UniversityXinxiangHenan ProvinceChina Institutes of Health Central Plain Xinxiang Medical UniversityXinxiangHenan ProvinceChina School of Public Health Xinxiang Medical UniversityXinxiangHenan ProvinceChina

Traumatic brain injury and Alzheimer's disease share pathological similarities,including neuronal loss,amyloid-βdeposition,tau hyperphosphorylation,blood-brain barrier dysfunction,neuroinflammation,and cognitive ***,traumatic brain injury can exacerbate Alzheimer's disease-like pathologies,potentially leading to the development of Alzheimer's *** offer a potential solution by facilitating the delive ry of small interfering RNAs across the blood-brain barrier for the targeted silencing of key pathological genes implicated in traumatic brain injury and Alzheimer's disease.U nlike traditional approaches to neuro regeneration,this is a molecula r-targeted strategy,thus avoiding non-specific drug *** review focuses on the use of nanocarrier systems for the efficient and precise delive ry of siRNAs,discussing the advantages,challenges,and future *** principle,siRNAs have the potential to target all genes and non-targetable protein s,holding significant promise for treating various *** the various therapeutic approaches currently available for neurological diseases,siRNA gene silencing can precisely"turn off"the expression of any gene at the genetic level,thus radically inhibiting disease progression;however,a significant challenge lies in delivering siRNAs across the blood-brain *** have received increasing attention as an innovative drug delive ry tool fo r the treatment of brain *** are considered a potential therapeutic strategy with the advantages of being able to cross the blood-brain barrier,targeted drug delivery,enhanced drug stability,and multifunctional *** use of nanoparticles to deliver specific modified siRNAs to the injured brain is gradually being recognized as a feasible and effective *** this strategy is still in the preclinical exploration stage,it is expected to achieve clinical translation in the future,creating a new field of molecular tar

关键词： blood-brain barrier cognitive dysfunction exosomes gene silencing immunotherapy inorganic nanomaterials liposome nanoparticles neuroinflammation polymer nanoparticles stem cells

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