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An attention-based prototypical network for forest fire smoke few-shot detection

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Journal of forestry Research 2022年第5期33卷 1493-1504页

作者： Tingting Li Haowei Zhu Chunhe Hu Junguo Zhang School of Technology Beijing Forestry UniversityBeijing 100083People’s Republic of China Key Lab of State forestry and Grassland Administration for forestry Equipment and Automation Beijing 100083People’s Republic of China

Existing almost deep learning methods rely on a large amount of annotated data, so they are inappropriate for forest fire smoke detection with limited data. In this paper, a novel hybrid attention-based few-shot learning method, named Attention-Based Prototypical Network, is proposed for forest fire smoke detection. Specifically, feature extraction network, which consists of convolutional block attention module, could extract high-level and discriminative features and further decrease the false alarm rate resulting from suspected smoke areas. Moreover, we design a metalearning module to alleviate the overfitting issue caused by limited smoke images, and the meta-learning network enables achieving effective detection via comparing the distance between the class prototype of support images and the features of query images. A series of experiments on forest fire smoke datasets and miniImageNet dataset testify that the proposed method is superior to state-of-the-art few-shot learning approaches.

关键词： Forest fire smoke detection Few-shot learning Channel attention module Spatial attention module Prototypical network

Relationship between types of urban forest and PM_(2.5) capture at three growth stages of leaves

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Journal of Environmental Sciences 2015年第1期27卷 33-41页

作者： Thithanhthao Nguyen Xinxiao Yu Zhenming Zhang Mengmeng Liu Xuhui Liu College of Soil and Water Conservation Beijing Forestry University Science and Technology Department College of Nature Conservation Beijing Forestry University

Particulate matter diameter ≤ 2.5 μm（PM2.5） causes direct harm to human health. Finding forms of urban forest systems that with the ability to reduce the amount of particulate matter in air effectively is the aim of this study. Five commonly cultivated kinds of urban forest types were studied in beijing city at three stages of leaf growth. Results show that the urban forest system is capable of storing and capturing dust from the air. The types of shrubs and broadleaf trees that have the ability to capture PM2.5from the air are most effective when leaves have fully developed. In the leafless season, the conifer and mixed tree types are the most effective in removing dust from the air. For all kinds of forest types and stages of leaf growth, the PM2.5concentration is highest in the morning but lower in the afternoon and evening. Grassland cannot control particles suspended in the air,but can reduce dust pollution caused by dust from the ground blown by the wind back into the air.

关键词： Particulate matter PM2.5 Type of urban forest Growth stages of leaves

A Self-assembled Nanoparticle Platform Based on Amphiphilic Oleanolic Acid Polyprodrug for Cancer Therapy

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Chinese Journal of Polymer Science 2020年第8期38卷 819-829,I0006页

作者： Ying-Sa Wang Gui-Liang Li Shang-Bin Zhu Fan-Chen Jing Run-Dong Liu Sai-Sai Li Jing He Jian-Du Lei beijing Key Laboratory of Lignocellulosic Chemistry Engineering Research Center of Forestry Biomass Materials and Bioenergy(Ministry of Education)Beijing Forestry UniversityBeijing 100083China

Oleanolic acid(OA)is a pentacyclic triterpenoid compound with extensive biological effects,such as anti-inflammatory and anticancer ***,the application of OA in chemotherapy is hampered by its poor solubility and severe adverse *** solve the problems,we developed a self-assembled nanoparticle platform based on amphiphilic oleanolic acid polyprodrug,poly[oligo(ethylene glycol)methyl ether methacrylate]-b-poly(oleanolic acid methacrylate)(POEGMA-b-POAMA),encapsulating 10-hydroxycamptothecin(HCPT)to achieve efficient cancer *** polyprodrug was prepared via reversible addition-fragmentation chain transfer polymerization(RAFT),and could selfassemble to prepare POEGMA-b-POAMA/HCPT nanoparticles(NPs).The obtained nanoparticles exhibited appropriate particle size,excellent drug stability,good drug loading capacity,and high drug loading *** vitro drug release indicated that the drug release was prolonged to 132 *** POEGMA-b-POAMA/HCPT NPs enhanced cell cytotoxicity in 4T1 cells and MCF-7 cells and could be efficiently uptaken by 4T1 ***,in vivo antitumor efficiency showed that the POEGMA-b-POAMA/HCPT NPs had great antitumor efficiency with considerably low adverse effects in the treatment of the 4T1 mouse breast tumor xenograft ***,POEGMA-b-POAMA/HCPT NPs provide great potential as a platform for drug delivery applications.

关键词： Self-assemble Nanoparticle Oleanolic acid Amphiphilic polyprodrug Drug delivery

Forest recovery after clear-cutting in Chinese pine(Pinus tabuliformis) plantations of North China

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Journal of Arid Land 2018年第2期10卷 233-248页

作者： DONG Boqian ZHAO Kuangji WANG Zhibin JIA Zhongkui MA Lvyi XIA Xinli Key Laboratory for Silviculture and Conservation of the Ministry of Education College of Forestry Beijing Forestry University College of Biological Sciences and Technology Beijing Forestry University

In Hebei Province of North China, forest was recovered with natural recruitment in plantations with large area of clear-cutting Chinese pine（Pinus tabuliformis）. This study was aimed to demonstrate the dynamic characteristics of recruits during the natural recruitment. Both plot survey and the spatial point-pattern analysis were performed. Five developmental stages of natural recruitment were selected and studied, including 1 year before and 2, 5, 8, and 11 years after clear-cutting. Different slope aspects were also included. Natural recruitment was always dominated by Chinese pine with a proportion of higher than 90%. For plots of 1 year before clear-cutting on east-and north-facing slopes, recruit densities were 7886 and 5036 stems/hm2, the average heights were 0.78（±0.85） and 1.06（±1.15） m, and the average diameters at breast height（DBH） were 3.21（±1.38） and 2.91（±1.38） cm, respectively. After clear-cutting, recruit density was initially increased, then it was gradually declined with time; however, the variation of average DBH was contrary to that of recruit density. Both of them were no longer varied between 8 and 11 years after clear-cutting. The average height of recruits continued to increase after clear-cutting. For the plots of 11 years after clear-cutting on east-and north-facing slopes, average heights of recruits reached 2.00（±1.14） and 2.24（±1.20） m, respectively. The statuses of recruits on north-facing slopes were better than those on east-facing slopes after clear-cutting. Meanwhile, recruits on east-facing slopes were always aggregated at small scales, while spatial pattern of recruits varied with time on north-facing slopes. Moreover, forest was recovered more quickly by natural recruitment than by artificial afforestation after clear-cutting. The structural diversity was higher in naturally regenerated forests than in plantations of the same age. Our results demonstrated that clear-cutting of Chinese pine plantations recovered by natural recruitm

关键词： Chinese pine natural recruitment clear-cutting slope aspect spatial pattern Hebei Province

Eff ects of environmental factors on the temporal and spatial variations in branch and leaf CO_(2)effl ux of Larix gmelinii ***-rupprechtii Mayr

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Journal of forestry Research 2023年第4期34卷 1007-1019页

作者： Longjie Li Xiangzhen Wang Zhongkui Jia Key Laboratory for Silviculture and Conservation of the Ministry of Education College of ForestryBeijing Forestry UniversityBeijing 100083People’s Republic of China

The CO_(2)effl ux of branches and leaves plays an important role in ecosystem carbon *** a carbon fl ux system,the effl ux of Larix gmelinii ***(Dahurian larch)was investigated in 27 years(immature),31 years(near-mature),and 47 years(mature)stands at diurnal,seasonal,and spatial scales(direction and height)as well as its connection with environmental factors from May to October *** variation in effl ux was a single peak,and the maximum occurring between 14:00 and 16:*** variation also exhibited a single peak,with the maximum in late July and the minimum in early *** May to September,effl ux on the south side was the largest among the three stands,and mean values on the south side of 27 year-old,31 year-old,and 47 year-old trees were 0.50,0.97 and 1.05μmol·m^(–2)·s^(–1),*** minimum occurred on the north *** for the maximum in July and September in the 27 year-old stand in the middle of the canopy,the maximum effl ux in the upper canopy,and the means in the 27 year-old,31 year-old,and 47 year-old stands were 0.49,0.96 and 1.04μmol·m^(-2)·s^(-1),respectively;the minimum occurred in the lower *** and relative humidity infl uenced seasonal variations in effl *** variation in temperature sensitivity coeffi cient(Q 10)was opposite that of temperature,increasing with decreasing *** the spatial scale,maximum Q 10 occurred in the mid *** the effl ux and temperature data in diff erent locations,it is possible to better estimate effl ux variations in each stand.

关键词： CO_(2)effl ux Temperature sensitivity coeffi cient(Q 10) Temporal and spatial variations Environmental factors

Nitrogen addition increased resistance of resident plant community to Solidago canadensis invasion by altering allelopathic effect

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Journal of Plant Ecology 2024年第2期17卷 110-121页

作者： Jing-Fang Cai Kai Sun Lin Li Si-Ha A Yi-Luan Shen Hong-Li Li School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing 100083China The Key Laboratory of EcologicalProtection in the Yellow River Basin of National forestry and Grassland Administration Beijing Forestry UniversityBeijing 100083China

Allelopathy plays an important role in the interaction between invasive and resident *** nitrogen(N)deposition has become a global problem,but it is unclear whether N enrichment affects the interaction between invasive and resident plants by affecting their ***,we performed a greenhouse experiment in which the resident plant community was grown under two levels of invasion by ***(invasion *** invasion)and fully crossed with two levels of allelopathy(with or without adding activated carbon)and two levels of N addition(with or without).The resident plant communities were constructed with eight herbaceous species that often co-occur with *** results showed that both allelopathy of *** and the resident plants had obvious positive effects on their own *** addition had more obvious positive effects on the resident plants under invasion than those that were not ***,N addition also altered the allelopathy of resident ***,N addition improved the allelopathy of resident plants when they were invaded but decreased the allelopathy of resident plants when they grew *** nitrogen addition had no obvious effect on ***,it reduced the allelopathy of *** results suggest that N addition could improve the resistance of resident plants to invasion by improving the allelopathy of resident plants and reducing the allelopathy of *** fndings provide a scientifc basis to manage and control the *** invasion.

关键词： allelochemicals biological invasion nutrient input nitrogen addition resident plants Solidago canadensis

Correlation of metabolic changes of infected paulownia tissue culture with PWB-MLO pathogenic mechanism

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Science China Chemistry 1995年第8期38卷 934-943页

作者：田国忠黄钦才袁巧平张锡津 Research Institute of forestry Chinese Academy of ForestryBeijing 100091China

Paulownia *** culture plantlets infected with paulownia witches' broom mycoplasma-like organism (PWB-MLO) expressed a typical witches' broom *** results determined by transmission electron microscopy and DAPI staining fluorescence microscopy showed that the severity of the symptom was directly related with MLO concentration in the sieve tubes of the *** results of the analysis of endogenous hormones and phenolic compounds by HPLC revealed that in all cases,the free IAA content of the diseased plant apparently lower than that of the healthy,and the free IAA concentration had strikingly positive correlation with catechol concentration changes (r=0.90,n= 11).The changes of cytokinin (Z +ZR, iPA),GA_3 and ABA were shown less relation with MLO *** differences of peroxidase and isoenzyme,IAA oxidase and phenylanine ammonia lyase (PAL) between the extract of infected plants and that of uninfected as well as different effects of NAA and catechol additions on MS media could further re- flect the nature of the relationship and the interaction among MLOs,catechol and the free IAA concentration.

关键词： tissue culture of Paulownia sp.,MLO pathogenic mechanism indol-3-acetic acid(IAA) catechol

Object use in insects

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Insect Science 2024年第4期31卷 1001-1014页

作者： Chao Wen Cai Wang Xiaoli Guo Hongyu Li Haijun Xiao Junbao Wen Shikui Dong School of Grassland Science Beijing Forestry UniversityBeijingChina College of forestry and Landscape Architecture South China Agricultural UniversityGuangzhouChina beijing Key Laboratory for Forest Pest Control Beijing Forestry UniversityBeijingChina

Insects are the most diverse group of organisms in the animal kingdom,and some species exhibit complex social *** research on insect object use is still in its early stages,insects have already been shown to display rich object-use *** review focuses on patterns and behavioral flexibility in insect object-use behavior,and the role of cultural evolution in the development of object-use *** use in insects is not widespread but has been documented in a diverse set of *** insects can use objects flexibly and display various object-use *** mammals and birds,insects use objects in diverse activities,including foraging,predator defense,courtship,and ***,pre-existing manipulative behaviors,and anatomical structure affect innovations in object *** addition,learning and imitation are the main mechanisms underlying the spread of object-use behaviors within *** that insects are one of the major animal groups engaging in object use,studies of insect object use could provide general insights into object use in the animal kingdom.

关键词： cognition evolution insects learning object use

Pretreatment of heterocyclic pesticide wastewater using ultrasonic/ozone combined process

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Journal of Environmental Sciences 2011年第5期23卷 725-730页

作者： Zhenglong Xiong Xiang Cheng Dezhi Sun College of Environmental Science & Engineering Beijing Forestry University Beijing 100083 China

Ultrasonic/O3 combined process was employed to pretreat heterocyclic pesticide wastewater for increasing biodegradability and reducing biological toxicity. Influences of ultrasonic frequency, ultrasonic power, probe diameter, initial pH and 03 dosage on the COD removal were studied. The results showed that the ultrasonic/O3 process significantly improved the biodegradability and reduced the biological toxicity of the wastewater. The ratio of BODs/COD was increased from 0.03 to 0.55 and the EC50 increased from 11% to 52% under ultrasonic/O3 treatment. Low ultrasonic frequency brought better COD removal. Initial pH was found to have a high influence on the COD removal and alkaline conditions were more favorable. The influences of ultrasonic power and probe diameter were small. With an increase in O3 dosage, COD removal was effectively improved. The optimal operational parameters for the combined process on COD removal were ultrasonic frequency 20 kHz, initial pH 9.00, ultrasonic power 300 W and dosage of O3 454.8 mg/（***）, under which the efficiency of COD removal reached 67.2%.

关键词： heterocyclic pesticide wastewater ultrasonic O3 BOD5/COD biological toxicity