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The carrying capacity for vegetation of forest land across China:Near real-time monitoring and short-term forecasting based on satellite observation
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作者 Huiqian Yu Nan Lu +2 位作者 Bojie Fu Lu Zhang Shufen Pan 《Geography and Sustainability》 CSCD 2024年第3期415-429,共15页
Ecological restoration projects implemented over the past 20 years have substantially increased forest coverage in China,but the high tree mortality of new afforestation forest remains a challenging but unsolved probl... Ecological restoration projects implemented over the past 20 years have substantially increased forest coverage in China,but the high tree mortality of new afforestation forest remains a challenging but unsolved problem.It is still not clear how much vegetation can be sustained by the forest lands with given water,energy and soil conditions,i.e.,the carrying capacity for vegetation(CCV)of forest lands,which is the prerequisite for planning and implementing forest restoration projects.Here,we used a simplified method to evaluate the CCV across forest lands nationwide.Specifically,based on leaf area index(LAI)dataset,we use boosted regression tree and multiple linear regression model to analyze the CCV during 2001-2020 and 2021-2030 and explore the contribution of environmental factors.We find that there are three typical regions with lower CCV located in the Loess Plateau and the southern region of the Inner Mongolia Plateau,the Hengduan Mountain region,and the Tianshan Mountains.More importantly,the vegetation in the regions near the dry-wet climate transition zone show excess local carrying capacity for vegetation over the past two decades and they are more susceptible to potential climatic stress.In comparison,in the Greater Khingan Mountains and Hengduan Mountains,there is high potential to improve the forest growth.Temperature,precipitation and soil affects the CCV by shaping the vegetation in the optimal range.This indicates that more consideration should be given to restrictions of regional environmental constraints when planning afforestation and forest management.This study has important implications for guiding future forest scheme in China. 展开更多
关键词 Carrying capacity for vegetation Leaf area index Ecosystem restoration forest management
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Effects of Meat and Phosphate Level on Water-Holding Capacity and Texture of Emulsion-Type Sausage During Storage 被引量:24
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作者 WANG Peng,XU Xing-lian and ZHOU Guang-hong Key Laboratory of Meat Processing and Quality Control,Ministry of Education/Nanjing Agricultural University,Nanjing 210095,P.R.China 《Agricultural Sciences in China》 CSCD 2009年第12期1475-1481,共7页
This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork ... This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork and frozen pork were pre-blended with five levels of phosphate and made into emulsion-type sausage. The yield, hardness and total expressible fluid (TEF) were measured with texture profile analysis machine and pressiometer when emulsion-type sausage was produced. Meanwhile, hardness and purge loss (PL) were measured during 30 d storage. As emusion-type sausage made by pre-rigor meat, higher yield and relatively stable hardness could be found. It indicated that increasing of phosphate level caused an alleviatable effects in increasing of hardness when emulsion-type sausage made by pre-rigor meat, but opposite effects made by ageing meat or frozen meat. The distribution of PL of emulsion-type sausage was found to be affected by phosphate addition. Significant decrease of PL could not be obtained by increasing of phosphate level during storage. Pre-rigor meat improved WHC and texture of emulsion-type sausage. Problem of WHC and texture of emulsiontype sausage during storage could not be resolved by single use of phosphate at relatively higher level (3%) of NaCl. 展开更多
关键词 MEAT emulsion-type sausage water-holding capacity TEXTURE
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Study on Water Conservation Capacity of Litter from Different Types of Forest in Caohai Basin 被引量:5
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作者 Hua Wu Jianli Zhang +3 位作者 Lifei Yu Lingbin Yan Congjun Yuan Tengyong Liu 《Meteorological and Environmental Research》 CAS 2013年第12期17-22,26,共7页
[Objective]The research aimed to understand water conservation capacity of litter from different forest types in Caohai basin. [Method] Current storage amount,water holding capacity and precipitation interception abil... [Objective]The research aimed to understand water conservation capacity of litter from different forest types in Caohai basin. [Method] Current storage amount,water holding capacity and precipitation interception ability of litter from 4 types of forest were investigated and studied. [Result]The order of exist litter amount was grass slope &gt;shrub forest &gt;mixed broad leaf-conifer forest &gt;coniferous forest. The order of natural water holding capacity was mixed broad leafconifer forest &gt; coniferous forest &gt; grass slope &gt; shrub forest. The relevance between water holding capacity of litter and soaking time was in line with this formula: y = kln( x) + b. During 0-120 min of litter soaking,water holding capacity increased rapidly. After 120 min,the increasing trend remained flat until closing to the maximum water holding capacity. The relevance between water absorption rate of litter and soaking time was in line with this formula: y = a + bx-1. In the beginning of soaking,water absorption rates of litter from different woodlands showed great difference. As soaking time went by,water absorption rates of litter from different woodlands all declined sharply. During 0-120 min,declining velocity of water absorption rate was quicker. After 120 min,the declining trend tended to be slow. The maximum water holding capacity of litter presented the order of shrub forest &gt; mixed broad leafconifer forest &gt; grass slope &gt; coniferous forest. The maximum precipitation interception amount of litter presented the order of shrub forest &gt; grass slope &gt; mixed broad leafconifer forest &gt; coniferous forest. Effective impounding capacity of litter presented the order of shrub forest &gt; mixed broad leafconifer forest &gt; grass slope &gt; coniferous forest. [Conclusion]The research could provide support for the construction of water conservation forest in Caohai basin. 展开更多
关键词 Caohai basin forest type LITTER Moisture conservation capacity China
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A STUDY ON BUFFERING CAPACITY OF THE FOREST SOIL AGAINST ACIDIC PRECIPITATION IN SEVERAL AREAS OF CHINA
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作者 林国珍 廖柏寒 丁茹 《Chinese Geographical Science》 SCIE CSCD 1992年第2期32-38,共7页
Soil samples from several forest areas in China were analyzed by X-ray powder diffractometry after mineral separation and enrichment. The density gradient separation method with sequential extraction by acetone-methyl... Soil samples from several forest areas in China were analyzed by X-ray powder diffractometry after mineral separation and enrichment. The density gradient separation method with sequential extraction by acetone-methylene iodide mixtures was applied for the separation of fine sand fraction of soil samples. The clay fraction (【 2μm) was separated from silt fraction of soil samples prior to examination. Mineral components in some fine sand and clay samples were compared, and their weathering potentiality and buffering capacity against acidic precipitation were discussed. 展开更多
关键词 forest soil MINERAL component ACIDIC precipitation BUFFERING capacity WEATHERING POTENTIALITY
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Examining the Level of Service in the Context of Recreational Carrying Capacity in the Erzurum Urban Forest,Turkey
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作者 Tendu Hilal Goktug Nalan Demircioglu Yildiz +1 位作者 Metin Demir Burcu Mestav 《Journal of Environmental Protection》 2015年第9期1014-1028,共15页
Urban forests are confronted with high using pressure because of the increasing demand for recreation and accessibility of these settings. For that purpose, defining and managing recreational carrying capacity is cons... Urban forests are confronted with high using pressure because of the increasing demand for recreation and accessibility of these settings. For that purpose, defining and managing recreational carrying capacity is considered as significant in ensuring ecological value’s and recreational satisfaction’s continuity. The purpose of this paper is to investigate the carrying capacity of Erzurum Urban Forest with respect to Level of Service (LOS) as a new management technique that focuses on service quality and visitor satisfaction. The data were obtained by self-administered questionnaire conducted with 166 visitors on weekends and holidays during summer season of the year 2014. Data were analyzed by dimensions/indicators of recreational satisfaction and socio-demographic characteristics with intent to identify tolerance range of visitors. The contribution and relative importance of each of the indicators to the overall satisfaction were analyzed by using Ordinal Logistic Model (OLM). The results indicated that the four indicators were at the greatest degree;“distance from picnic spot to toilets” and “quantity of children’s playground facilities” were decease of overall satisfaction while “distance from picnic spot to parking” and “level of shade at picnic spot” had a positive contribution to the overall satisfaction. The outputs from these analyses were used to calculate LOS. It was revealed that the level of service (0.40) in Erzurum Urban Forest was below the moderate level. Planning and managing strategies for optimizing the LOS were developed and discussed by considering these results. 展开更多
关键词 Recreational Carrying capacity Level of Service Visitor Satisfaction Recreation Planning and Management Erzurum Urban forest
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The Scavenging of Free Radical and Oxygen Species Activities and Hydration Capacity of Collagen Hydrolysates from Walleye Pollock(Theragra chalcogramma) Skin 被引量:1
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作者 ZHUANG Yongliang LI Bafang ZHAO Xue 《Journal of Ocean University of China》 SCIE CAS 2009年第2期171-176,共6页
Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock (Theragra chalcogramrna) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3... Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock (Theragra chalcogramrna) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries. 展开更多
关键词 walleye pollock COLLAGEN free radical-scavenging activity water-holding capacity
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Study on Quantitative Model of Karst Drainage Basin Water-Holding Based on Principal Component Analysis: A Case Study of Guizhou, China
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作者 Zhonghua He Xiaoxiang Chen +2 位作者 Hong Liang Fasu Huang Fang Zhao 《Advances in Remote Sensing》 2013年第3期205-213,共9页
In Karst drainage basins, there are the ground water and underground water exchanging frequently, and the shortage of water resources due to having the special double aquifer mediums and unique surface and subsurface ... In Karst drainage basins, there are the ground water and underground water exchanging frequently, and the shortage of water resources due to having the special double aquifer mediums and unique surface and subsurface river systematic structure. This paper is to select 20 research sampling areas coming fromGuizhouProvince, and according to the spectral characteristics of the catchment water-holding mediums and vegetations, and using the remote sensing technique, extract the watershed vegetation index. According to the principle of principal component analysis, using the software of Spss and Matlab is to analyze the impacts of watershed vegetation type on the catchment water-holding ability, and establish the principal component analysis function. Studies have shown that: 1) the watershed vegetation coverage rate plays an important role in Karst basin water-holding ability;2) the catchment water-holding ability is the comprehensive reflection and manifestation of the Catchment Water-storing Capacity (CWC);3) it is much better effects and higher accuracy to monitor/forecast the catchment water-holding volume by using the vegetation indices. 展开更多
关键词 KARST Drainage Basin Watershed Vegetation Index CATCHMENT water-holding Ability CATCHMENT Water-Storing capacity QUANTITATIVE Model
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Water holding effect of subalpine dark coniferous forest soil in Gongga Mountain, China 被引量:2
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作者 常志华 陆兆华 关文彬 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第3期205-209,共5页
Because of the distinction of soil property and humus content, soil water content is not ideal to indicate whether it is suitable to the growth of plant. Mainly based on the PF-a numerical value denoting the water reg... Because of the distinction of soil property and humus content, soil water content is not ideal to indicate whether it is suitable to the growth of plant. Mainly based on the PF-a numerical value denoting the water regime of soil and connected with the growth of plant, the study combined the moisture percentage of soil with PF to research in quantity the interrelation between the moisture percentage and PF in different succession phases of subalpine dark coniferous forest in Gongga Mountain. The results showed that: (1) In the same PF value, the moisture percentage in humus horizon increased gradually with the devel-opment of the succession of the dark coniferous forest; The moisture percentage of over-mature forest was the highest and>mature forest>half-mature forest>young growth forest; (2) With the increase of soil depth, the soil bulk density increased and the moisture percentage decreased, but the difference in the percentage of moisture was not notable in different succession phases. (3) In different succession series, the vegetation affected the soil water characteristics by increasing the soil organic matter, improving the soil construction, receding the soil bulk density and enhancing the soil porosity; (4) The humus horizon of the dark coniferous forest soil has the highest water holding capability in this region. 展开更多
关键词 Gongga Mountain Moisture percentage PF value Dark coniferous forest forest soil water-holding capability
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Young and old forest in the boreal:critical stages of ecosystem dynamics and management under global change 被引量:3
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作者 Timo Kuuluvainen Sylvie Gauthier 《Forest Ecosystems》 SCIE CSCD 2018年第4期361-375,共15页
The circumboreal forest encompasses diverse landscape structures, dynamics and forest age distributions determined by their physical setting, and historical and current disturbance regimes. However, due to intensifyin... The circumboreal forest encompasses diverse landscape structures, dynamics and forest age distributions determined by their physical setting, and historical and current disturbance regimes. However, due to intensifying forest utilisation, and in certain areas due to increasing natural disturbances, boreal forest age-class structures have changed rapidly, so that the proportion of old forest has substantially declined, while that of young post-harvest and post-natural-disturbance forest proportions have increased. In the future, with a warming climate in certain boreal regions, this trend may further be enhanced due to an increase in natural disturbances and large-scale use of forest biomass to replace fossil-based fuels and products.The major drivers of change of forest age class distributions and structures include the use of clearcut shortrotation harvesting, more frequent and severe natural disturbances due to climate warming in certain regions. The decline in old forest area, and increase in managed young forest lacking natural post-disturbance structural legacies,represent a major transformation in the ecological conditions of the boreal forest beyond historical limits of variability.This may introduce a threat to biodiversity, ecosystem resilience and long-term adaptive capacity of the forest ecosystem.To safeguard boreal forest biodiversity and ecosystem functioning, and to maintain the multiple services provided to societies by this forest biome, it is pivotal to maintain an adequate share and the ecological qualities of young postdisturbance stages, along with mature forest stages with old-growth characteristics. This requires management for natural post-disturbance legacy structures, and innovative use of diverse uneven-aged and continuous cover management approaches to maintain critical late-successional forest structures in landscapes. 展开更多
关键词 Adaptive capacity BIODIVERSITY Boreal forest Climate change forestRY Ecosystem services forest dynamics forest management RESILIENCE
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Aspects of forest restoration and hydrology:the hydrological function of litter 被引量:5
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作者 Luara Castilho Pereira Leonardo Balbinot +2 位作者 Marcelle Teodoro Lima Julieta Bramorski Kelly Cristina Tonello 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第2期543-552,共10页
Although forests play important roles in the hydrological cycle,there is little information that relates the water retention capacity of litter in areas under passive restoration,especially in Cerrado savannas.This st... Although forests play important roles in the hydrological cycle,there is little information that relates the water retention capacity of litter in areas under passive restoration,especially in Cerrado savannas.This study relates litter levels to water holding capacity and effective water retention among forest fragments under different passive restoration stages:46,11,and 8 years to better understand litter hydrological functions in the Cerrado.Water retention capacity and effective water retention capacity of litters(unstructured materials,branches and leaves)in the field were monitored on a monthly basis.Total litter accumulation at 46 years was significantly higher than that of the other succession stages.Unstructured litter mass was significantly higher than that of leaves and branches.The 46-year stage had the highest water holding capacity in the leaf fraction,followed by unstructured material and branches.Although the water holding capacity was lower in the oldest resto-ration,this site showed the highest efficiency under field conditions.The process was quickly reestablished,as the 11-year restoration showed results closer to that for the 46-year stage in comparison to the area at 8 years.Thus,passive restoration plays a key role in soil water mainte-nance due to the influence of litter in Cerrado savannas.Deforestation and the imminent need of restoring degraded sites,highlight the need for further studies focused on bet-ter understanding of the process of forest restoration and its temporal effect on soil water recovery dynamics. 展开更多
关键词 forest hydrology Litter interception STEMFLOW CERRADO Águas Perenes forest Water holding capacity
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Recreational potential as an indicator of accessibility control in protected mountain forest areas 被引量:4
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作者 Tomasz DUDEK 《Journal of Mountain Science》 SCIE CSCD 2017年第7期1419-1427,共9页
The article presents research findings related to recreational use of forests located in protected mountainous areas with forestage of over 80%. The study was designed to identify recreational potential of the Carpath... The article presents research findings related to recreational use of forests located in protected mountainous areas with forestage of over 80%. The study was designed to identify recreational potential of the Carpathian national parks (Bieszczady National Park, Bahia G6ra National Park, Goree National Park and Magura National Park; southern Poland) and to compare these findings with the actual number of visitors. The information received on the recreational potential of parks is important from the point of view of protection of natural resources and the financial situation of the parks. The calculated ratio may be an effective tool of management for park administration, that allows to reconcile statutory social and protective functions of national parks. The study determined the recreational potential of the forests with the use of recreational valorisation method designed for areas with varied terrain, and the evaluated factors included the stands of trees with their habitat and land relief. The permissible number of national park visitors, expressed as man- hour/ha/year ranges from 19.31 in Bieszczady National Park (BG: 19~ 35' E, 49~ 35' N) to 32.06 in in Bieszczady National Park (B: 22~ 40' E, 49~ lo' N). In 3 out of 4 investigated parks, Magura National Park (M: 21025' E, 49~ 30' N), Gorce National Park (G: 20~ lo' E, 49~ 35' N), B) recreation carrying capacity was not exceeded, whether or not the strictly protected area is taken into account. Only in BG was the recreation carrying capacity exceeded by nearly 24%, or by 85% if the strictly protected area isexcluded from tourism-related exploitation. The presented procedure for monitoring access to mountain forests in national parks, from the viewpoint of natural resources conservation, can be applied in other mountainous areas covered with forests and exposed to tourist and recreational traffic, and in forests facing particular risk of recreational damage, e.g. in urban and suburban forests growing in areas with varied orography. 展开更多
关键词 forest recreation Recreational capacity Protected areas Mountain forests the Carpathians
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Seasonal patterns of light availability and light use of broadleaf evergreens in a deciduous forest understory: Potential mechanisms for expansion
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作者 Sheri A. Shiflett Julie C. Zinnert Donald R. Young 《Open Journal of Ecology》 2013年第2期151-160,共10页
In recent years, expansion of native and exotic evergreen shrubs into forest understories has been documented worldwide. Dense shrub thickets may interfere with tree establishment, suppress herbaceous cover, and contr... In recent years, expansion of native and exotic evergreen shrubs into forest understories has been documented worldwide. Dense shrub thickets may interfere with tree establishment, suppress herbaceous cover, and contribute substantially to total standing crop of leaf biomass. Expansion may occur because evergreen shrubs exploit seasonal variations in irradiance and temperature that are characteristic of temperate understory environments. We quantified leaf-level light environment and photosynthetic activity of three sympatric broadleaf evergreens (Ilex opaca, Kalmia latifolia, and Myrica cerifera) in a deciduous forest understory in Charles City County,Virginia,USAin order to understand seasonal intra- and interspecific ranges of broadleaf evergreen physiology. Two species (K. latifolia and M. cerifera) represent a diverse taxonomic range within broadleaf evergreens, and often form expansive thickets. We measured parameters related to canopy structure (e.g., bifurcation ratio, leaf angle) and photosynthetic performance (e.g., electron transport rate or ETR, chlorophyll content), to identify potential mechanisms facilitating expansion. ETR varied both seasonally and among species. In summer, M. cerifera ETR was nearly double that ofI. opaca or K. latifolia. Additionally, leaf temperature enhanced photosynthetic capacity of expansive species. Evergreen species, though capable of fixing carbon throughout the year, often exhibit slow growth rates and low physiological activity. Yet, we observed that the range of evergreen physiological activity may be broader than previously recognized. Furthermore, our results indicate potential for changes in composition and expansion of the evergreen shrub layer by species that exhibit structural and physiological mechanisms advantageous for future rises in temperature. 展开更多
关键词 CHLOROPHYLL Fluorescence Evergreenness TEMPERATE forest PHOTOSYNTHETIC capacity SEASONAL IRRADIANCE
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Touristic Ecological Footprint of Jiufeng National Forest Park in Beijing Based on Component Method
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作者 ZHANG Ying PAN Jing CHEN Ke 《Journal of Landscape Research》 2017年第5期47-52,共6页
This paper,based on the ecological footprint component method,calculated the touristic ecological footprint of Jiufeng National Forest Park in Beijing.The results showed that in 2013,in Jiufeng National Forest Park,th... This paper,based on the ecological footprint component method,calculated the touristic ecological footprint of Jiufeng National Forest Park in Beijing.The results showed that in 2013,in Jiufeng National Forest Park,the total touristic ecological footprint was 183.08 hm2,the total ecological capacity was 225.16 hm2,the total touristic ecological surplus was 42.07 hm2,and the average touristic ecological surplus was 0.000 4 hm2 per capita,indicating that tourism in Jiufeng National Forest Park was in ecological surplus and ecological security.However,forest parks in Beijing at large were in ecological deficit.This paper suggested that the tourist flow volume of forest parks with a big ecological deficit should be moved to forest parks with an ecological surplus.Besides,forest parks are expected to strengthen the development and management,improve the availability of forest recreation resource,and promote the environmental protection awareness of tourists,so as to boost the sustainable development of forest park tourism. 展开更多
关键词 forest tourism Ecological footprint Ecological capacity Ecological deficit National forest park BEIJING
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Forest biomass density,utilization and production dynamics in a western Himalayan watershed
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作者 Rakesh Kumar Sharma Prem Lall Sankhayan Ole Hofstad 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第3期171-180,共10页
There is enough evidence to show that the forest biomass has decreased significantly in the Indian Himalayan state of Himachal Pradesh. The government has responded through restrictive measures to check this decline. ... There is enough evidence to show that the forest biomass has decreased significantly in the Indian Himalayan state of Himachal Pradesh. The government has responded through restrictive measures to check this decline. Using tree biomass as proxy for degradation, we assessed the current state of biomass within dominant land use types and examined its implications for sustainability. The highest above-ground mean tree biomass density of 1158 t·ha-1 was recorded for the reserved forest followed by 728, 13, 11, 8, 5 and 3 t·ha-1in the protected forest, fallow land, cultivated-unirrigated land, grassland, orchard land and cultivated-irrigated land respectively. Of the total ac- cessible biomass, only 0.31% was extracted annually by the local people for fuel, fodder and other uses. Though, the current level of ex- traction may be sustainable in the short run, insufficient regeneration is observed for long term sustainability. Forest biomass production was simulated for the next 30 years with a logistic growth model and the relative significance of input variables in influencing system be- haviour was analysed through sensitivity analysis. The model results highlighted the declining forest resources in the long run. Positive response through appropriate government policies can, however, change the scenario for the better. 展开更多
关键词 Biomass density Carrying capacity forest degradation Fuel wood Himachal Pradesh Mean annual increment
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Low-temperature combined with high-humidity thawing improves the water-holding capacity and biochemical properties of Portunus trituberculatus protein
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作者 Jiangang Ling Xiaoting Xuan +4 位作者 Zihan Xu Tian Ding Xudong Lin Yan Cui Donghong Liu 《Food Quality and Safety》 SCIE CSCD 2021年第2期152-160,共9页
This study compared the effects of conventional thawing methods(water immersion thawing(WIT,(25±1)℃),natural air thawing(AT,(25±1)℃,relative humidity(RH(65±2)per cent),refrigerator thawing(RT,4℃,RH(8... This study compared the effects of conventional thawing methods(water immersion thawing(WIT,(25±1)℃),natural air thawing(AT,(25±1)℃,relative humidity(RH(65±2)per cent),refrigerator thawing(RT,4℃,RH(80±2)per cent)and low-temperature(LT)combined with high-humidity thawing LT,-1℃to 1℃(LT-1-1),2-4℃(LT2-4),5-7℃(LT5-7)and 8-10℃(LT8-10),RH>95 per cent)on the water-holding capacity,lipid oxidation and biochemical properties of Portunus trituberculatus(P.trituberculatus)myofibrillar protein.The results showed that WIT and AT significantly decreased the water-holding capacity while dramatically increasing lipid oxidation,protein oxidation and degeneration,resulting in serious P.trituberculatus quality deterioration.High humidity was beneficial for P.trituberculatus\.ha\A/\ng.The thawing time of P.trituberculatus under the conditions of LT2-4 was only 39.39 per cent of that of conventional air thawing at 4℃(RT),and the LT2-4 samples not only maintained better water-holding capacity but also had an obviously reduced degree of lipid oxidation,protein oxidation and denaturation.Thawed samples LT2-4 and LT5-7 provided better maintenance of P.trituberculatus quality than the LT-1-1 and LT8-10 samples.The best quality was exhibited after thawing at 2-4℃.The levels of thiobarbituric acid reacting substances,carbonyl content and surface hydrophobicity observably decreased in these samples,while the total sulfhydryl contents dramatically increased compared to those of conventionally thawed samples,indicating lower lipid oxidation and protein oxidation.Moreover,the Ca2+-ATPase activity of the sample thawed at 2-4℃(2.06 μmol Pi/mg prot/h)was markedly higher than that of samples subjected to WIT and AT.The product qualities observed after thawing at-1℃to 1℃,5-7℃and 8-10℃under LT were comparable to that observed by RT.Considering its thawing efficiency and product quality,LT is a suitable method for the thawing of P.trituberculatus,and the ideal thawing conditions were LT at 2-4℃. 展开更多
关键词 Portunus trituberculatus- thawing low temperature combined with high humidity water-holding capacity lipid oxidation biochemical properties of myofibrillar protein
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Influence of Human Resource Needs on Adoption of Forest Innovations in Kenya
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作者 Michael O. Mukolwe Gilbert O. Obwoyere Fredrick U. Ngesa 《Open Journal of Forestry》 2016年第5期460-475,共17页
A combination of factors, including inadequate interactive influence of professional human resource needs, contributes to low adoption of forest innovations. This study was conducted to assess the influence of quantit... A combination of factors, including inadequate interactive influence of professional human resource needs, contributes to low adoption of forest innovations. This study was conducted to assess the influence of quantity of professional human resource needs on adoption of forest innovations across relevant institutions in Kenya. The study considered 51 main institutions involved in, or support conservation activities, of which 33 were public, 14 non-governmental, and 4 private. Purposive sampling was used due to the heterogeneity of the institutions involved in conservation. Primary data were collected using a structured questionnaire. A quartile graph-based quantitative model was used to establish the differences in capacity variation expressed as expected variation region or the common cause and the unexpected variation region or the special cause. The latter should be investigated and acted upon. Statistical analysis involved Levene’s Test of Equality of Variances. Embracing both approaches confirmed the model as an appropriate quantitative analytical framework for assessing and articulating elements of institutional capacity, and that quantity of professional human capital (P < 0.05) is key to influencing adoption of forest innovations in Kenya. The study reiterates that to overcome professional capacity gaps and respond to conservation paradigm shift, quantity was relevant and was an imperative policy issue. 展开更多
关键词 Professional Human Resource Institutional capacity ADOPTION forest Innovations
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Effect of Substituting Plantation Species for Native Shrubs on the Water-holding Characteristics of the Forest Floor on the Eastern Tibetan Plateau 被引量:10
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作者 庞学勇 包维楷 《Journal of Resources and Ecology》 CSCD 2011年第3期217-224,共8页
Although the forest floor plays important roles in water-holding and nutrient cycling, there is not enough knowledge of the functional changes of the forest floor resulting from changes in vegetation. To evaluate the ... Although the forest floor plays important roles in water-holding and nutrient cycling, there is not enough knowledge of the functional changes of the forest floor resulting from changes in vegetation. To evaluate the effect on the hydrological properties of forest floor by the substitution of plantation species for native coppice, we selected four species substituting plantations and one native coppice (secondary native broad-leaved forest, dominated by Quercus liaotungensis and Corylus heterophylla var. sutchuenensis) (QC) as a comparison forest. The substituting plantations were Cercidiphyllum japonicum (Cj), Pinus tabulaeformis (Pt), Pinus armandi (Pa), Larix kaempferi (Lk). These were established in 1987 with a stocking density of approximately 2500 stem ha -1 . Thickness and the amount of floor in coniferous plantations were significantly higher compared to secondary native broad-leaved forest and pure broad- leaved plantation. The maximal water-holding capacity of the floor showed the same trend as thickness and amount of litter. Main contributors to the difference in hydrological characteristics in the plantations were the quantity of forest floor and the maximal water holding capacity per unit weight of the floor. The relationships between water absorption processes, water absorption rate and the immersion time for litter, fitted to logarithmic and exponential regressions, respectively. Water absorption processes differed significantly between the various plantations and different decomposition floor horizons. Water absorption characteristics were influenced by leaf structure in various tree species and the degree of decomposed litter. Our results showed that litter amount in coniferous plantations were significantly higher than in deciduous broad-leaved plantation. This suggests that a large amount of nutrients are held in the litter horizon, delaying return to the soil and utilization by plants. At the same time, maximal water-holding capacity of the forest floor in F [fermentation] and H [hummus] horizons was significantly higher than that in L [fresh litter] horizon. Therefore, improving litter transformation from L horizon to F and H horizons by promoting forest floor environment would be one of the best methods for plantation management. 展开更多
关键词 forest floor plantation substitution water absorption rate water-holding capacity ecology restoration eastern Tibetan Plateau
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采用集成深度森林模型实现退役电池容量估算
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作者 陈琳 陈德乾 +3 位作者 何熳平 赵铭思 吴淑孝 潘海鸿 《电源技术》 CAS 北大核心 2024年第11期2253-2262,共10页
针对退役锂离子电池容量估算面临历史数据缺失,传统机器学习算法存在过拟合和单个模型估算不稳定的问题,提出一种基于集成深度森林的容量估算模型。首先,从退役电池一次满充数据中提取恒流充电时间和充电电流面积特征;然后,利用提取的... 针对退役锂离子电池容量估算面临历史数据缺失,传统机器学习算法存在过拟合和单个模型估算不稳定的问题,提出一种基于集成深度森林的容量估算模型。首先,从退役电池一次满充数据中提取恒流充电时间和充电电流面积特征;然后,利用提取的特征和容量训练多个深度森林建立集成深度森林模型,并设计一种可信状态决策剔除集成模型中波动较大的估算值,取剩余估算值平均值作为最终估算结果。采用自测和公开数据集对所提方法进行验证,结果表明,该方法能实现退役电池剩余容量的准确稳定估算,最大误差仅为0.08 Ah,与传统机器学习算法相比,该方法能获得更高的容量估算精度。 展开更多
关键词 退役锂离子电池 机器学习 深度森林 容量估算 集成模型
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环境承载力中介下森林转型赋能区域生态宜居——作用路径与效应识别
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作者 李超 朱震锋 邹成成 《林业经济问题》 北大核心 2024年第3期324-336,共13页
基于中国1999—2018年4次森林资源清查结果及相关统计数据,对中国31个省域(不含港澳台地区)的森林转型指数、环境承载力和生态宜居水平进行测评,然后借助中介效应模型探索森林转型赋能区域生态宜居的作用路径,并测度环境承载力对森林转... 基于中国1999—2018年4次森林资源清查结果及相关统计数据,对中国31个省域(不含港澳台地区)的森林转型指数、环境承载力和生态宜居水平进行测评,然后借助中介效应模型探索森林转型赋能区域生态宜居的作用路径,并测度环境承载力对森林转型赋能区域生态宜居水平的中介效应。结果显示:1999—2018年中国森林转型指数整体呈现稳中有升的发展态势,但不同地区之间水平差异比较明显,西南、东北地区森林转型效果最为显著;中国环境承载力的“U型”曲线演变特征明显,其中西南、华南、华东地区环境承载力较强,华东、华中、华南、华北地区环境承载力在回升阶段表现突出,东北、西南和西北地区在经济快速发展时期,环境承载力呈现下降趋势,突显出资源环境系统脆弱性;中国生态宜居水平总体呈现波动上升态势,其中西南、华北、华东地区上升态势最为明显;环境承载力在森林转型对区域生态宜居水平影响中具有中介作用,森林转型通过提升环境承载力部分解释了其对区域生态宜居水平的促进作用。 展开更多
关键词 生态宜居 森林转型 环境承载力 城镇化 中介效应
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森林环境文物建筑集中区域灭火救援能力评估
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作者 颜龙 李琪 +2 位作者 郑佳欣 徐志胜 刘顶立 《中国安全科学学报》 CAS CSCD 北大核心 2024年第9期234-240,共7页
针对森林环境文物建筑集中区域环境复杂,难以准确评估区域灭火救援能力等问题,基于层次分析法(AHP),提出耦合森林因素的单体文物建筑灭火救援能力评估方法,涵盖建筑材料、森林防火隔离带、消防水源等19个二级指标;在单体评估基础上,从... 针对森林环境文物建筑集中区域环境复杂,难以准确评估区域灭火救援能力等问题,基于层次分析法(AHP),提出耦合森林因素的单体文物建筑灭火救援能力评估方法,涵盖建筑材料、森林防火隔离带、消防水源等19个二级指标;在单体评估基础上,从区域视角建立一种基于变权法的森林环境文物建筑集中区域灭火救援能力评估模型;并引入惩罚占主导的混合型变权函数,设置评价策略,确定惩罚与激励区间,区分文物建筑保护等级,提出风险等级划分方法;通过实地调研和数据收集,结合定权法和变权法评价森林环境文物建筑集中区域(岳麓山风景名胜区)的灭火救援能力。结果表明:单体文物建筑评级为优、良、中、次、差的数量占比分别为12%、20%、32%、20%、16%。区域定权法得分为75.27(Ⅲ级,不需采取提升措施),变权法得分为69.97(Ⅳ级,需采取提升措施);建议采取增设电气火灾预警系统、增加森林防火隔离带等措施来提升灭火救援能力。 展开更多
关键词 森林火灾 文物建筑 集中区域 灭火救援 能力评估 变权
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