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Characteristics and Factors Associated with Obesity and Thinness among Children with Developmental Disorders 被引量:1
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作者 Keiko Kasagi Yuko Hayashi Ryoko Ito 《Open Journal of Nursing》 2018年第9期689-696,共8页
Obesity in childhood or adolescence has been recognized to be a risk factor for the onset of lifestyle-related diseases, not only in healthy children, but also in children with developmental disorders. Therefore, this... Obesity in childhood or adolescence has been recognized to be a risk factor for the onset of lifestyle-related diseases, not only in healthy children, but also in children with developmental disorders. Therefore, this study was conducted to examine the characteristics of obesity and thinness as assessed by the body fat percentage among children with developmental disorders during certain growth periods. It was also designed to investigate those factors associated with obesity and thinness based on a lifestyle and behavioral questionnaire. The subjects included 260 children from 5 to 18 years old with developmental disorders. The results of the study showed that a decrease in thinness and increase in obesity with ageing exhibited more noticeable trends among those children with mental retardation. The factors associated with obesity in children with developmental disorders were characterized by the dietary content, eating behaviors, and food preferences particular to such children, as well as low physical activity and a family history of obesity. The results of this study suggested the importance of continuous guidance along with family participation in order to improve obesity among children with developmental disorders, while focusing on the characteristics of certain growth periods. 展开更多
关键词 OBESITY thinness CHILDREN with Developmental Disorders LIFESTYLE FACTORS Body Fat PERCENTAGE
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The Relationships among Perception of Body Image, a Desire for Thinness, and Dieting Behavior in Young Females in Japan
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作者 Tomoki Mase Chiemi Miyawaki +1 位作者 Kumiko Ohara Harunobu Nakamura 《Health》 2015年第1期112-118,共7页
The aim of this study was to investigate the relationship among body image perceptions, a desire for thinness, and dieting behavior in young females in Japan. The subjects were 302 Japanese female university students ... The aim of this study was to investigate the relationship among body image perceptions, a desire for thinness, and dieting behavior in young females in Japan. The subjects were 302 Japanese female university students (age 19.9 ± 1.4 years). An anonymous, self-administered questionnaire survey was conducted between July and August 2011. The questionnaire clarified the subjects’ physical status, perception about personal body shape, desired body shape, the time frame when they first thought about body shape dieting, exercise habits, and eating behaviors. The results revealed that many of the underweight or normal weight subjects perceived themselves as obese, and often the reasons for the perception of obesity were comparisons with others or with themselves in the past. The scores of EAT-26 in those who perceived themselves as obese were higher than the scores in those who did not. Those who perceived themselves as obese had a desire to become slim, were concerned about body shape at an early age, were concerned about dieting, had dieting experience, and were willing to increase daily exercise. These results indicated that incorrect perceptions about body shape have connection to a desire for thinness and dieting behavior. 展开更多
关键词 Female Students PERCEPTION of Body Shape DIETING EATING BEHAVIOR Desire for thinness
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Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei 被引量:2
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作者 Shicheng Su Nianqing Jin Xiaoli Wei 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期12-28,共17页
Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in... Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted. 展开更多
关键词 THINNING Understory light environment Phoebe bournei Photosynthetic performance Growth performance
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Soil properties and not plant factors affect both abundant and rare microbial taxa after thinning in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu
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作者 Wanxia Peng Tongqing Song +5 位作者 Hu Du Feng Wang Fuping Zeng Yang Wang Shulin Chen Yinzhu Chen 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期81-94,共14页
Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communiti... Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communities(i.e.,bacterial,fungal),were evaluated under various thinning treatments in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu using Mi Seq sequencing.Thinning did not significantly change either abundant or rare bacterial and fungal community composition,but affected their alpha diversity.The Shannon–Wiener indexes of rare fungal taxa under medium thinning were significantly lower than in the light thinning(P<0.05 level).Xanthobacteraceae dominated the abundant bacterial taxa,and Saitozyma and Mortierlla the abundant fungal taxa.The most common rare bacterial taxa varied;there was no prevalent rare fungal taxa under different thinnings.In addition,soil available nitrogen,total phosphorus,and p H had significant effects on rare bacterial taxa.Nutrients,especially available phosphorus,but not nitrogen,affected abundant and rare soil fungi.The results indicate that soil properties rather than plant factors affect abundant and rare microbial communities in soils of mixed stands.Thinning,through mediating soil properties,influences both abundant and rare bacterial and fungal communities in the mixed C.lanceolata and S.tzumu stand. 展开更多
关键词 Diversity Abundant taxa Rare taxa THINNING Mixed stand
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Long-term thinning decreases the contribution of heterotrophic respiration to soil respiration in subalpine plantations
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作者 Longfei Chen Zhibin He +7 位作者 Wenzhi Zhao Xi Zhu Qin Shen Mingdan Song Zhengpeng Li Junqia Kong Shuping Yang Yuan Gao 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期189-204,共16页
Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicult... Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicultural practice,the long-term impacts of thinning on R_(S) and its heterotrophic and autotrophic respiration components(R_(h) and Ra,respectively)in subalpine plantations are poorly understood,espe-cially in winter.A 3-year field observation was carried out with consideration of winter CO_(2) efflux in middle-aged sub-alpine spruce plantations in northwestern China.A trench-ing method was used to explore the long-term impacts of thinning on Rs,Rn and R_(a).Seventeen years after thinning,mean annual Rs,Rn and R_(a) increased,while the contribu-tion of R_(h) to R_(s) decreased with thinning intensity.Thinning significantly decreased winter R,because of the reduction in R_(n) but had no significant effect on Ra.The temperature sensitivity(Q_(10))of R_(h) and R_(a) also increased with thinning intensity,with lower Q_(10) values for R_(h)(2.1-2.6)than for Ra(2.4-2.8).The results revealed the explanatory variables and pathways related to R_(n) and R_(a) dynamics.Thinning increased soil moisture and nitrate nitrogen(NO_(3)^(-)-N),and the enhanced nitrogen and water availability promoted R_(h) and R_(a) by improving fine root biomass and microbial activity.Our results highlight the positive roles of NO_(3)^(-)-N in stimulating R_(s) components following long-term thinning.Therefore,applications of nitrogen fertilizer are not recommended while thinning subalpine spruce plantations from the perspective of reducing soil CO_(2) emissions.The increased Q_(10) values of R_(s) components indicate that a large increase in soil CO_(2) emissions would be expected following thinning because of more pronounced climate warming in alpineregions. 展开更多
关键词 Heterotrophic respiration Autotrophic respiration Long-term thinning impacts Cold seasons Subalpine plantations Temperature sensitivity
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Effects of thinning and understory removal on water use efficiency of Pinus massoniana:evidence from photosynthetic capacity and stable carbon isotope analyses
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作者 Ting Wang Qing Xu +4 位作者 Beibei Zhang Deqiang Gao Ying Zhang Jing Jiang Haijun Zuo 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期42-53,共12页
Understanding the relationship between forest management and water use efficiency(WUE)is important for evaluating forest adaptability to climate change.However,the effects of thinning and understory removal on WUE and... Understanding the relationship between forest management and water use efficiency(WUE)is important for evaluating forest adaptability to climate change.However,the effects of thinning and understory removal on WUE and its key controlling processes are not well understood,which limits our comprehension of the physiological mechanisms of various management practices.In this study,four forest management measures(no thinning:NT;understory removal:UR;light thinning:LT;and heavy thinning:HT)were carried out in Pinus massoniana plantations in a subtropical region of China.Photosynthetic capacity and needle stable carbon isotope composition(δ^(13)C)were measured to assess instantaneous water use efficiency(WUE_(inst))and long-term water use efficiency(WUE_(i)).Multiple regression models and structural equation modelling(SEM)identified the effects of soil properties and physiological performances on WUE_(inst)and WUE_(i).The results show that WUE_(inst)values among the four treatments were insignificant.However,compared with the NT stand(35.8μmol·mol^(-1)),WUE_(i)values significantly increased to 41.7μmol·mol^(-1)in the UR,50.1μmol·mol^(-1)in the LT and 46.6μmol·mol^(-1)in HT treatments,largely explained by photosynthetic capacity and soil water content.Understory removal did not change physiological performance(needle water potential and photosynthetic capacity).Thinning increased the net photosynthetic rate(A_n)but not stomatal conductance(g_s)or predawn needle water potential(ψ_(pd)),implying that the improvement in water use efficiency for thinned stands was largely driven by radiation interception than by soil water availability.In general,thinning may be an appropriate management measure to promote P.massoniana WUE to cope with seasonal droughts under future extreme climates. 展开更多
关键词 Stable carbon isotope Water use efficiency THINNING Understory removal Photosynthetic capacity Needle water potential
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Drivers of spatial structure in thinned forests
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作者 Zichun Wang Yaoxiang Li +4 位作者 Guangyu Wang Zheyu Zhang Ya Chen Xiaoli Liu Rundong Peng 《Forest Ecosystems》 SCIE CSCD 2024年第2期202-213,共12页
Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importanc... Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importance of structure-based.Aims:Our objectives were to define the direction of structure-based forest management.Subsequently,we investigated the relationships between forest structure and the regeneration,growth,and mortality of trees under different thinning treatments.Ultimately,the drivers of forest structural change were explored.Methods:On the basis of 92 sites selected from northeastern China,with different recovery time (from 1 to 15years) and different thinning intensities (0–59.9%) since the last thinning.Principal component analysis (PCA)identified relationships among factors determining forest spatial structure.The structural equation model (SEM)was used to analyze the driving factors behind the changes in forest spatial structure after thinning.Results:Light thinning (0–20%trees removed) promoted forest regeneration,and heavy thinning (over 35% of trees removed) facilitated forest growth.However,only moderate thinning (20%–35%trees removed) created a reasonable spatial structure.While dead trees were clustered,and they were hardly affected by thinning intensity.Additionally,thinning intensity,recovery time,and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area.Conclusion:Creating larger DBH and canopy area through thinning will promote the formation of complex forest structures,which cultivates healthy and stable forests. 展开更多
关键词 THINNING Natural secondary forest Spatial structure Dynamic changes Growth factors Structural equation modeling
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Sparse antenna array design methodologies:A review
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作者 Pan Wu Yan-Hui Liu +1 位作者 Zhi-Qin Zhao Qing-Huo Liu 《Journal of Electronic Science and Technology》 EI CAS CSCD 2024年第3期1-15,共15页
Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct ar... Designing a sparse array with reduced transmit/receive modules(TRMs)is vital for some applications where the antenna system’s size,weight,allowed operating space,and cost are limited.Sparse arrays exhibit distinct architectures,roughly classified into three categories:Thinned arrays,nonuniformly spaced arrays,and clustered arrays.While numerous advanced synthesis methods have been presented for the three types of sparse arrays in recent years,a comprehensive review of the latest development in sparse array synthesis is lacking.This work aims to fill this gap by thoroughly summarizing these techniques.The study includes synthesis examples to facilitate a comparative analysis of different techniques in terms of both accuracy and efficiency.Thus,this review is intended to assist researchers and engineers in related fields,offering a clear understanding of the development and distinctions among sparse array synthesis techniques. 展开更多
关键词 Clustered array Nonuniformly spaced array Sparse antenna array Synthesis method Thinned array
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Date of First Thinning in a Very High-Density Eucalyptus Plantation in the Pointe-Noire Region (Republic of Congo)
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作者 Hugues-Yvan Gomat Chrissy Garel Makouanzi Ekomono +4 位作者 François Mankessi Alberdie Saïra Mangoubi Mantala Ulrich Mayinguidi Ruben Pambou Laurent Saint-Andre 《Open Journal of Forestry》 2024年第4期451-461,共11页
Management of the Pointe-Noire Forest requires high-performance tools for simulating tree and stand growth and assessing the sustainability of plantations. Modelling the dynamics of even-aged and mono-species stands i... Management of the Pointe-Noire Forest requires high-performance tools for simulating tree and stand growth and assessing the sustainability of plantations. Modelling the dynamics of even-aged and mono-species stands is a very active research topic. The approaches adopted by researchers vary according to the objectives and species considered: dendrometrical, Eco physiological or architectural. Thanks to the particular nature of these plantations and the trial set-up, it will be possible to explore the various aspects of production, clearly separating the part linked to genetics (three clones tested) from the part linked to the environment (via fertilisation) and the part associated with competition between trees (via planting densities and thinning regimes). This study will make a major contribution to the applicability of the self-thinning line and the RDI (Reineke Density Index) (Reineke, 1933) to fast-growing plantations. This research work will contribute to two points: 1) product diversification, which is a way of coping with international variations in timber markets, and 2) understanding how ecosystems function in exceptionally poor conditions, which will then enable the environmental impacts of the various recommended silvicultural itineraries to be assessed. The results obtained show that competition between trees in a stand of eucalyptus at very high density (10,000 stems/ha) and in two environments of very contrasting fertility is different depending on the clone. The decision on the date of the first thinning with a view to silviculture for timber and energy wood, which aims to ensure sustained and sustainable production of eucalyptus wood in these soils, should be taken between 12 and 14 months. The competition band is strong between 14 and 17 months, when the RDI = 0.8 is double that observed at 12 months. 展开更多
关键词 SILVICULTURE EUCALYPTUS Pointe-Noire THINNING RDI
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Eff ects of thinning on ecosystem carbon storage and tree-shrub-herb diversity of a low-quality secondary forest in NE China 被引量:2
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作者 Baoshan Zhang Xibin Dong +2 位作者 Hangfeng Qu Ran Gao Liangliang Mao 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期977-991,共15页
Thinning is a widely used forest management tool but systematic research has not been carried out to verify its eff ects on carbon storage and plant diversity at the ecosystem level.In this study,the eff ect of thinni... Thinning is a widely used forest management tool but systematic research has not been carried out to verify its eff ects on carbon storage and plant diversity at the ecosystem level.In this study,the eff ect of thinning was assessed across seven thinning intensities(0,10,15,20,25,30 and 35%)in a low-quality secondary forest in NE China over a ten-year period.Thinning aff ected the carbon storage of trees,and shrub,herb,and soil layers(P<0.05).It fi rst increased and then decreased as thinning intensity increased,reaching its maximum at 30%thinning.Carbon storage of the soil accounted for more than 64%of the total carbon stored in the ecosystem.It was highest in the upper 20-cm soil layer.Thinning increased tree species diversity while decreasing shrub and herb diversities(P<0.05).Redundancy analysis and a correlation heat map showed that carbon storage of tree and shrub layers was positively correlated with tree diversity but negatively with herb diversity,indicating that the increase in tree diversity increased the carbon storage of natural forest ecosystems.Although thinning decreased shrub and herb diversities,it increased the carbon storage of the overall ecosystem and tree species diversity of secondary forest.Maximum carbon storage and the highest tree diversity were observed at a thinning intensity of 30%.This study provides evidence for the ecological management of natural and secondary forests and improvement of ecosystem carbon sinks and biodiversity. 展开更多
关键词 THINNING Carbon storage Plant diversity Forest management NE China
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Response of understory plant species richness and tree regeneration to thinning in Pinus tabuliformis plantations in northern China 被引量:1
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作者 Haijiao Yang Chao Pan +3 位作者 Yun Wu Shiqi Qing Zhibin Wang Dihai Wang 《Forest Ecosystems》 SCIE CSCD 2023年第2期215-226,共12页
Background:Chinese pine(Pinus tabuliformis Carr.)is one of the major afforestation species in northern China and plays a key role in restoring forest ecosystems and preserving soil and water.However,most Chinese pine ... Background:Chinese pine(Pinus tabuliformis Carr.)is one of the major afforestation species in northern China and plays a key role in restoring forest ecosystems and preserving soil and water.However,most Chinese pine plantations are experiencing ecological problems such as the low diversity of understory plants and difficulty in natural regeneration.Thinning has been widely used to maintain and improve a variety of forest ecosystem services from plantations.To date,however,few studies have been conducted to systematically determine the effects of thinning on understory plant diversity and the regeneration of Chinese pine in plantations.Methods:We conducted a literature search,and selected 22 publications covering a total of 83 treatments related to thinning effects on the species richness of understory plants and 15 publications covering a total of 43 treatments related to thinning effects on the regeneration of Chinese pine,in tree plantations of northern China.The data from the literature were synthesized and evaluated with meta-analysis approach to determine the treatment effects.Results:Compared with the control stands,thinning increased the species richness of shrubs and herbs by an average of 25.3%and 26.5%,respectively.While the varying thinning intensities all had significantly positive effects on the species richness of understory plants,only moderate thinning(30%–50%)had a positive effect on the density of regenerating seedlings and saplings of Chinese pine(60.2%).The species richness of understory plants was greatest after 14 years of thinning with an increase of 36.3%,whereas the density of regenerating Chinese pine seedlings and saplings reached a maximum after≥11 years of thinning with an increase of 76.5%,compared to that of the unthinned stands.Thinning in the half-mature plantations had the greatest effects on the understory shrub richness(44.1%)and the density of regenerating Chinese pine seedlings and saplings(86.5%).Both single and multiple thinning were found to significantly promote the species richness of understory plants and the density of regenerating Chinese pine seedlings and saplings,and the positive effects of thinning were greater in areas with a humidity index(HI)<30 than in areas with an HI≥30.In general,age group,planting density and recovery time were prominent factors affecting the species richness of understory plants,whereas the slope,HI and recovery time were the dominant controls of the density of regenerating Chinese pine seedlings and saplings,indicating differential effects of thinning on the species richness of understory plants and the regeneration capacity of Chinese pine in plantations.Conclusion:Thinning appears to be a feasible management measure to improve the understory plant diversity and regeneration capacity of Chinese pine in plantations.We postulate that moderate thinning in half-mature forest stands with an HI<30 can help effectively promote the species diversity of understory plants and the natural regeneration of Chinese pine,thereby maintaining a more resilient stand structure and the development of Chinese pine plantations. 展开更多
关键词 Chinese pine plantation Forest thinning META-ANALYSIS Natural regeneration Understory plants
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Thinning intensity aff ects carbon sequestration and release in seasonal freeze–thaw areas 被引量:1
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作者 Tong Gao Xinyu Song +3 位作者 Yunze Ren Hui Liu Hangfeng Qu Xibin Dong 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第4期993-1006,共14页
To explore how to respond to seasonal freeze–thaw cycles on forest ecosystems in the context of climate change through thinning,we assessed the potential impact of thinning intensity on carbon cycle dynamics.By varyi... To explore how to respond to seasonal freeze–thaw cycles on forest ecosystems in the context of climate change through thinning,we assessed the potential impact of thinning intensity on carbon cycle dynamics.By varying the number of temperature cycles,the eff ects of various thinning intensities in four seasons.The rate of mass,litter organic carbon,and soil organic carbon(SOC)loss in response to temperature variations was examined in two degrees of decomposition.The unfrozen season had the highest decomposition rate of litter,followed by the frozen season.Semi-decomposed litter had a higher decomposition rate than undecomposed litter.The decomposition rate of litter was the highest when the thinning intensity was 10%,while the litter and SOC were low.Forest litter had a good carbon sequestration impact in the unfrozen and freeze–thaw seasons,while the converse was confi rmed in the frozen and thaw seasons.The best carbon sequestration impact was identifi ed in litter,and soil layers under a 20–25%thinning intensity,and the infl uence of undecomposed litter on SOC was more noticeable than that of semi-decomposed litter.Both litter and soil can store carbon:however,carbon is transported from undecomposed litter to semi-decomposed litter and to the soil over time.In summary,the best thinning intensity being 20–25%. 展开更多
关键词 Forest carbon cycle Seasonal freeze–thaw THINNING Climate change
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Forest composition and red oak (Quercus sp.) response to elevation gradients across greentree reservoirs
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作者 Cassandra Hug Pradip Saud +1 位作者 Keith McKnight Douglas C.Osborne 《Forest Ecosystems》 SCIE CSCD 2023年第5期607-617,共11页
Elevation gradients within forested wetlands have long been recognized for their role in defining species composition through factors such as hydrology and soil characteristics.Greentree reservoirs(GTRs)are leveeimpou... Elevation gradients within forested wetlands have long been recognized for their role in defining species composition through factors such as hydrology and soil characteristics.Greentree reservoirs(GTRs)are leveeimpounded tracts of bottomland hardwood forest flooded throughout the winter months to provide habitat for overwintering waterfowl.Artificial flooding of GTRs alters the forest composition due to flood frequency,depth,and duration in combination with slight changes in topography.To evaluate the effect of elevation gradients,soil properties,and management techniques in the overstory species composition and red oak(Quercus spp.)species abundance,we inventoried 662 plots across 12 independent GTRs in eastern Arkansas.In the lower elevations ranging from 50.98 to 54.99 m above sea level,the importance value index(IVI)was highest for nuttall oak(Quercus texana)and overcup oak(Quercus lyrata),whereas IVI shifted to cherrybark oak(Quercus pagoda)in the higher elevations ranging from 54.99 to 58.00 m.Alpha diversity did not differ by elevation gradient,soil property,or management technique within GTRs.Beta diversity,using non-metric multi-dimensional scaling(NMDS)analysis,indicated site-specific variability significantly correlated with the environmental predictors,including elevation(R^(2)=0.57),easting(R^(2)=0.47),soil texture(R^(2)=0.21),and pH(R^(2)=0.12).Red oak species-specific mixed-effects modeling of abundance response using Poisson distribution suggested an inverse correlation of nuttall oak and a direct correlation of cherrybark oak abundance with elevation.However,willow oak(Quercus phellos)abundance was not significantly affected by elevation but was by silt loam soil texture and restoration management techniques.These findings will aid management efforts to reduce the dominance of less desirable species that are prominent under specific environmental conditions and promote the dominance of more desirable species.Ultimately GTR sustainability is increasingly important amid the unpredictable impacts of climate change on the preferred red oak species that are economically,ecologically,and environmentally valuable to the sustaining economy of the local community and managing habitats for wildlife. 展开更多
关键词 Bottomland hardwoods DIVERSITY Forested wetland OVERSTORY Red oak Soil Thinning and management
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A novel model to evaluate spatial structure in thinned conifer-broadleaved mixed natural forests
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作者 Hui Liu Xibin Dong +3 位作者 Yuan Meng Tong Gao Liangliang Mao Ran Gao 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第6期1881-1898,共18页
In order to ensure the effective analysis and reconstruction of forests,it is key to ensure the quantitative description of their spatial structure.In this paper,a distance model for the optimal stand spatial structur... In order to ensure the effective analysis and reconstruction of forests,it is key to ensure the quantitative description of their spatial structure.In this paper,a distance model for the optimal stand spatial structure based on weighted Voronoi diagrams is proposed.In particular,we provide a novel methodological model for the comprehensive evaluation of the spatial structure of forest stands in natural mixed conifer-broadleaved forests and the formulation of management decision plans.The applicability of the rank evaluation and the optimal solution distance model are compared and assessed for different standard sample plots of natural mixed conifer-broadleaved forests.The effect of crown width on the spatial structure unit of the trees is observed to be higher than that of the diameter at breast height.Moreover,the influence of crown length is greater than that of tree height.There are nine possible spatial structure units determined by the weighted Voronoi diagram for the number of neighboring trees in the central tree,with an average intersection of neighboring crowns reaching 80%.The rank rating of natural forest sample plots is correlated with the optimal solution distance model,and their results are generally consistent for natural forests.However,the rank rating is not able to provide a quantitative assessment.The optimal solution distance model is observed to be more comprehensive than traditional methods for the evaluation of the spatial structure of forest stands.It can effectively reflect the trends in realistic stand spatial structure factors close to or far from the ideal structure point,and accurately assesses the forest spatial structure.The proposed optimal solution distance model improves the integrated evaluation of the spatial structure of forest stands and provides solid theoretical and technical support for sustainable forest management. 展开更多
关键词 Weighted Voronoi diagram Optimal distance model Spatial structure quantifi cation Thinning intensity Conifer-broadleaved mixed natural forests
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华北克拉通晚中生代壳-幔拆离作用:岩石流变学约束 被引量:18
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作者 刘俊来 纪沫 +5 位作者 夏浩然 刘正宏 周永胜 余心起 张宏远 程素华 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第8期1819-1829,共11页
大陆岩石圈的流变学结构对于岩石圈深部过程(壳/幔过程)有着深刻的影响,直接表现在岩石圈壳-幔结构与浅部构造上。本文注意到华北克拉通晚中生代岩石圈减薄期间地壳的伸展、拆离与减薄在不同地区的宏观、微观构造及地壳岩石流变学等方... 大陆岩石圈的流变学结构对于岩石圈深部过程(壳/幔过程)有着深刻的影响,直接表现在岩石圈壳-幔结构与浅部构造上。本文注意到华北克拉通晚中生代岩石圈减薄期间地壳的伸展、拆离与减薄在不同地区的宏观、微观构造及地壳岩石流变学等方面的差异表现与区域变化,以及现今和晚中生代时期岩石圈厚度的不均匀性。讨论了以水为主体的地质流体的存在对于岩石圈流变性的影响。综合克拉通东部与西部地壳/地幔厚度变化特点以及下地壳和上地幔含水性特点,阐述了晚中生代时期华北克拉通岩石圈内部壳幔耦合与解耦的规律,提出了华北岩石圈壳-幔拆离作用模型以解释华北克拉通晚中生代岩石圈减薄的基本现象与深部过程。提出区域性伸展作用是岩石圈减薄的主要动力学因素,东部地区在晚中生代伸展作用过程中壳-幔具有典型的解耦性,上部地壳、下部地壳和岩石圈地幔的变形具有显著差异性。而西部区壳幔总体具有耦合性,下地壳与岩石圈地幔共同构成流变学强度很高且难以变形的岩石圈根。 展开更多
关键词 华北克拉通 晚中生代 拆离作用 岩石流变学 约束 Late Mesozoic 岩石圈减薄 North China CRATON LITHOSPHERE thinning upper mantle during lower crust 下地壳 LITHOSPHERE structure continental LITHOSPHERE 岩石圈地幔 rheological strength processes Crustal extension 岩石圈深部过程
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车票预售期内旅客购票请求到达过程分析与仿真 被引量:3
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作者 包云 刘军 马敏书 《北京交通大学学报》 CAS CSCD 北大核心 2012年第6期27-32,共6页
准确把握旅客购票请求到达的规律,并对该过程进行仿真,是实施列车动态票额分配和调整的基础.本文基于对历史售票数据的分析得出:旅客购票请求的到达过程属于非齐次泊松过程,每个购票请求的票额数量是一个离散的随机数,因此,旅客的购票... 准确把握旅客购票请求到达的规律,并对该过程进行仿真,是实施列车动态票额分配和调整的基础.本文基于对历史售票数据的分析得出:旅客购票请求的到达过程属于非齐次泊松过程,每个购票请求的票额数量是一个离散的随机数,因此,旅客的购票过程是一个复合非齐次泊松过程.通过对"Thinning"方法进行改进,采用分段"Thinning"方法对该过程进行仿真,结果表明,该方法产生的旅客购票请求的到达过程与实际观测到的旅客购票请求的到达过程符合率达92%. 展开更多
关键词 铁路旅客运输 旅客购票请求 到达过程 非齐次Poisson过程 Thinning方法
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Rheological properties of low consistency TMP from thinning wood of Chinese Fir 被引量:2
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作者 邱仁辉 王克奇 黄祖泰 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第2期145-149,共5页
The rheological behavior of low consistency thermomechanical pulp of Chinese fir harvested by intermediate thinning was analyzed. The results show that the apparent viscosity of pulp changed along with the beating deg... The rheological behavior of low consistency thermomechanical pulp of Chinese fir harvested by intermediate thinning was analyzed. The results show that the apparent viscosity of pulp changed along with the beating degree, pulp consistency and shearing velocity. With the increasing of pulp consistency, the apparent viscosity of pulp increased gradually. Beating degree of pulp had an effect on microstructure of pulp. The apparent viscosity of pulp declined as beating degree of pulp increased, and the apparent viscosity of pulp fell along with the shearing velocity increasing. Based on the results, the rheological models are set up. The models showed that the fluid types of the low consistency pulp could be described as pseudoplastics fluids (non-Newtonian fluids). 展开更多
关键词 Thermomechanical pulp Chinese Fir Thinning wood Low consistency pulp Rheological properties Pseudoplastics fluid
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Nutritional status of children with inflammatory boweldisease in Saudi Arabia 被引量:1
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作者 Mohammad Issa El Mouzan Mohammed Hadi Al Edreesi +4 位作者 Abdulrahman Abdullah Al-Hussaini Omar Ibrahim Saadah Abdulaziz Abdullatif Al Qourain Mohammad Abdullah Al Mofarreh Khalid Abdulrahman Al Saleem 《World Journal of Gastroenterology》 SCIE CAS 2016年第5期1854-1858,共5页
AIM: To assess the prevalence of nutritional disorders in children with inflammatory bowel disease(IBD) in Saudi Arabia.METHODS: The data from a national cohort of children newly diagnosed with IBD between 2003 and 20... AIM: To assess the prevalence of nutritional disorders in children with inflammatory bowel disease(IBD) in Saudi Arabia.METHODS: The data from a national cohort of children newly diagnosed with IBD between 2003 and 2012 were analyzed. The diagnosis of IBD and the differentiation between Crohn's disease(CD) and ulcerative colitis(UC) were confirmed by gastroenterologists according to the standard criteria. The body mass index(BMI) of each child [weight(kg)/height^2(m)] was calculated at the time of diagnosis. The World Health Organization standards and references were used and the BMI for age > +1 and <-2 standard deviation score were used to define overweight and thinness, respectively. Age stratification analysis was performed to investigate any age-related variation in the prevalence of nutritional status between children < 10 years of age and older.RESULTS: There were 374 children from 0.33 to 17 years of age, including 119(32%) children with UC and 255(68%) with CD. All of the children were Saudi nationals, and 68(57%) of the UC and 150(59%) of the CD children were males. A positive history of anorexia at the time of diagnosis was found in 30(25%) patients with UC and 99(39%) patients with CD. The prevalence of thinness was 31%, 35% and 24% in children with IBD, CD and UC, respectively, with a significantly higher prevalence of thinness in children with CD than in children with UC(P = 0.037) only in the age group of 10-17 years(P = 0.030). The prevalence of overweight was 16 %, 15% and 20 % in the children with IBD, CD and UC, respectively, indicating a higher prevalence in UC that was statistically significant only in the age group of 10-17 years(P = 0.020). CONCLUSION: A high proportion of children with IBD presented with overweight instead of the classical underweight. Awareness of this finding is important for patient care. 展开更多
关键词 Overweight thinness ULCERATIVE colitis CROHN disease CHILDREN SAUDI ARABIA
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Prevalence of functional dyspepsia and its subgroups in patients with eating disorders 被引量:6
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作者 Antonella Santonicola Monica Siniscalchi +3 位作者 Pietro Capone Serena Gallotta Carolina Ciacci Paola Iovino 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第32期4379-4385,共7页
AIM:To study the prevalence of functional dyspepsia(FD)(Rome Ⅲ criteria) across eating disorders(ED),obese patients,constitutional thinner and healthy volunteers.METHODS:Twenty patients affected by anorexia nervosa,6... AIM:To study the prevalence of functional dyspepsia(FD)(Rome Ⅲ criteria) across eating disorders(ED),obese patients,constitutional thinner and healthy volunteers.METHODS:Twenty patients affected by anorexia nervosa,6 affected by bulimia nervosa,10 affected by ED not otherwise specified according to diagnostic and statistical manual of mental disorders,4th edition,nine constitutional thinner subjects and,thirtytwo obese patients were recruited from an outpatients clinic devoted to eating behavior disorders.Twentytwo healthy volunteers matched for age and gender were enrolled as healthy controls.All participants underwent a careful clinical examination.Demographic and anthropometric characteristics were obtained from a structured questionnaires.The presence of FD and,its subgroups,epigastric pain syndrome and postprandial distress syndrome(PDS) were diagnosed according to Rome Ⅲ criteria.The intensity-frequency score of broader dyspeptic symptoms such as early satiety,epigastric fullness,epigastric pain,epigastric burning,epigastric pressure,belching,nausea and vomiting were studied by a standardized questionnaire(0-6).Analysis of variance and post-hoc Sheffè tests were used for comparisons.RESULTS:90% of patients affected by anorexia nervosa,83.3% of patients affected by bulimia nervosa,90% of patients affected by ED not otherwise specified,55.6% of constitutionally thin subjects and 18.2% healthy volunteers met the Postprandial Distress Syndrome Criteria(χ 2,P < 0.001).Only one bulimic patient met the epigastric pain syndrome diagnosis.Postprandial fullness intensity-frequency score was significantly higher in anorexia nervosa,bulimia nervosa and ED not otherwise specified groups compared to the score calculated in the constitutional thinner group(4.15 ± 2.08 vs 1.44 ± 2.35,P = 0.003;5.00 ± 2.45vs 1.44 ± 2.35,P = 0.003;4.10 ± 2.23vs 1.44 ± 2.35,P = 0.002,respectively),the obese group(4.15 ± 2.08vs 0.00 ± 0.00,P < 0.001;5.00 ± 2.45vs 0.00 ± 0.00,P < 0.001;4.10 ± 2.23 vs 0.00 ± 0.00,P < 0.001,respectively) and healthy volunteers(4.15 ± 2.08 vs 0.36 ± 0.79,P < 0.001;5.00 ± 2.45 vs 0.36 ± 0.79,P < 0.001;4.10 ± 2.23 vs 0.36 ± 0.79,P < 0.001,respectively).Early satiety intensity-frequency score was prominent in anorectic patients compared to bulimic patients(3.85 ± 2.23 vs 1.17 ± 1.83,P = 0.015),obese patients(3.85 ± 2.23 vs 0.00 ± 0.00,P < 0.001) and healthy volunteers(3.85 ± 2.23 vs 0.05 ± 0.21,P < 0.001).Nausea and epigastric pressure were increased in bulimic and ED not otherwise specified patients.Specifically,nausea intensity-frequencyscore was significantly higher in bulimia nervosa and ED not otherwise specified patients compared to anorectic patients(3.17 ± 2.56 vs 0.89 ± 1.66,P = 0.04;2.70 ± 2.91 vs 0.89 ± 1.66,P = 0.05,respectively),constitutional thinner subjects(3.17 ± 2.56 vs 0.00 ± 0.00,P = 0.004;2.70 ± 2.91 vs 0.00 ± 0.00,P = 0.005,respectively),obese patients(3.17 ± 2.56 vs 0.00 ± 0.00,P < 0.001;3.17 ± 2.56 vs 0.00 ± 0.00,P < 0.001 respectively) and,healthy volunteers(3.17 ± 2.56 vs 0.17 ± 0.71,P = 0.002;3.17 ± 2.56 vs 0.17 ± 0.71,P = 0.001,respectively).Epigastric pressure intensityfrequency score was significantly higher in bulimic and ED not otherwise specified patients compared to constitutional thin subjects(4.67 ± 2.42 vs 1.22 ± 1.72,P = 0.03;4.20 ± 2.21 vs 1.22 ± 1.72,P = 0.03,respectively),obese patients(4.67 ± 2.42 vs 0.75 ± 1.32,P = 0.001;4.20 ± 2.21vs 0.75 ± 1.32,P < 0.001,respectively) and,healthy volunteers(4.67 ± 2.42 vs 0.67 ± 1.46,P = 0.001;4.20 ± 2.21vs 0.67 ± 1.46,P = 0.001,respectively).Vomiting was referred in 100% of bulimia nervosa patients,in 20% of ED not otherwise specified patients,in 15% of anorexia nervosa patients,in 22% of constitutional thinner subjects,and,in 5.6% healthy volunteers(χ 2,P < 0.001).CONCLUSION:PDS is common in eating disorders.Is it mandatory in outpatient gastroenterological clinics to investigate eating disorders in patients with PDS? 展开更多
关键词 Eating disorders Functional dyspepsia Post prandial distress syndrome Epigastric pain sindrome Rome criteria Upper abdominal symptoms Anorexia nervosa Bulimia nervosa Eating disorders not otherwise specified Constitutional thinness
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Study on the Model of Excessive Staminate Catkin Thinning of Proterandrous Walnut Based on Quadratic Polynomial Regression Equation and BP Artificial Neural Network
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作者 王贤萍 曹贵寿 +4 位作者 杨晓华 张倩茹 李凯 李鸿雁 段泽敏 《Agricultural Science & Technology》 CAS 2015年第6期1295-1300,共6页
The excessive staminate catkin thinning (emasculation) of proterandrous walnut is an important management measure for improving yield. To improve the excessive staminate catkin thinning efficiency, the model of quad... The excessive staminate catkin thinning (emasculation) of proterandrous walnut is an important management measure for improving yield. To improve the excessive staminate catkin thinning efficiency, the model of quadratic polynomial regression equation and BP artificial neural network was developed. The effects of ethephon, gibberel in and mepiquat on shedding rate of staminate catkin of pro-terandrous walnut were investigated by modeling field test. Based on the modeling test results, the excessive staminate catkin thinning model of quadratic polynomial regression equation and BP artificial neural network was established, and it was validated by field test next year. The test data were divided into training set, vali-dation set and test set. The total 20 sets of data obtained from the modeling field test were randomly divided into training set (17) and validation set (3) by central composite design (quadric rotational regression test design), and the data obtained from the next-year field test were divided into the test set. The topological struc-ture of BP artificial neural network was 3-5-1. The results showed that the pre-diction errors of BP neural network for samples from the validation set were 1.355 0%, 0.429 1% and 0.353 8%, respectively; the difference between the predicted value by the BP neural network and validated value by field test was 2.04%, and the difference between the predicted value by the regression equation and validated value by field test was 3.12%; the prediction accuracy of BP neural network was over 1.0% higher than that of regression equation. The effective combination of quadratic polynomial stepwise regression and BP artificial neural network wil not only help to determine the effect of independent parameter but also improve the prediction accuracy. 展开更多
关键词 WALNUT THINNING BP artificial neural network Regression PREDICTION
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