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天山山地森林对河川枯水径流的补给功能
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作者 高新和 姜志林 +1 位作者 张金池 潘存德 《南京林业大学学报(自然科学版)》 CAS CSCD 2000年第4期55-58,共4页
通过对天山北坡山地森林对河流枯水径流量补给功能分析的研究结果表明 ,随着山地河流集水区内林率以及单位面积森林蓄积量的增加 ,河川枯水期径流量增加 3.5× 1 0 8m3,河川径流枯水期缩短 2个月 ,最枯月径流量增加约 0 .7× 1 ... 通过对天山北坡山地森林对河流枯水径流量补给功能分析的研究结果表明 ,随着山地河流集水区内林率以及单位面积森林蓄积量的增加 ,河川枯水期径流量增加 3.5× 1 0 8m3,河川径流枯水期缩短 2个月 ,最枯月径流量增加约 0 .7× 1 0 8m3;林率每增加 1 %,河流最枯月径流量增加 40 0× 1 0 4 m3;森林蓄积量每增加 1 0 0 0m3,河流最枯月径流量增加 2 70 0× 1 0 4 m3。 展开更多
关键词 天山北坡 森林 林率 河川枯水径流 补给功能
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怎样选好树种,做到适地适树?
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作者 陈永密 《农业现代化研究》 1983年第1期48-48,共1页
据统计,我国1949年至1976年,共造林13.2亿亩,成活的4.2亿亩,成林的3亿多亩,成林率为22.7%。为何造的多,活的少,成林的更少呢?主要原因之一,是没有适地适树,选好造林树种。如何做到适地适树呢?下面以湖南省分布的几种土壤类型与适生树... 据统计,我国1949年至1976年,共造林13.2亿亩,成活的4.2亿亩,成林的3亿多亩,成林率为22.7%。为何造的多,活的少,成林的更少呢?主要原因之一,是没有适地适树,选好造林树种。如何做到适地适树呢?下面以湖南省分布的几种土壤类型与适生树种之间的相互关系为例,作一简单介绍。 展开更多
关键词 适生树种 适地适树 青刚 南酸枣 金钱松 香椿 小叶栎 柳杉 油桐 林率
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Effects of Different Types of Pecan(Carya illinoensis) Seedlings on Forestation Survival Rate in Yunnan 被引量:2
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作者 邹伟烈 习学良 +2 位作者 赵廷松 范志远 张雨 《Agricultural Science & Technology》 CAS 2017年第4期696-699,共4页
In order to explore the forestation technique of pecan in Yunan, different types of pecan seedlings, bare-rooted seedlings and container seedlings were plant- ed in Yunnan, and their survival rates were investigated. ... In order to explore the forestation technique of pecan in Yunan, different types of pecan seedlings, bare-rooted seedlings and container seedlings were plant- ed in Yunnan, and their survival rates were investigated. This study will provide im- portant guidance for development of pecan industry in Yunnan Province. 展开更多
关键词 Carya illinoensis Container seedling Forestation survival rate
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Effect of biological agents on survival rate and root growth of Scots Pine seedlings 被引量:4
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作者 唐凤德 梁永君 +2 位作者 韩士杰 宫伟光 丁宝永 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第2期124-126,i002,共4页
Two-year-old Scots pine (Pinus sylvstris var.mongolica) seedlings were treated with Pt mycorrhiza powder, ABT root-growing powder, HRC water-absorbing agent and high-yield powder, and planted on the sandy land in Bali... Two-year-old Scots pine (Pinus sylvstris var.mongolica) seedlings were treated with Pt mycorrhiza powder, ABT root-growing powder, HRC water-absorbing agent and high-yield powder, and planted on the sandy land in Balinyouqi, Inner Mongolia (180°12′13″E and 43°13′05″N). The effect and function of these biological agents on survival rate of seedlings were tested and analyzed by measuring the fine root growth and gross root growth. The results showed that the survival rates of the seedlings treated with Pt3, ABT, and HRC biological agents increased by 29.3%, 23.6%, and 16%, respectively. The regression analysis revealed that the length of fine roots (<2 mm) was positively correlated with seedling survival rate, which means that the Pt3 powder, ABT foot-growing powder and HRC water-absorbing powder increased the survival rates of the seedlings by promoting the growth of fine roots. Keywords Biological agents - Pinus sylvstris var.mongolica - Sandy soil - Roots - Survival rate CLC number S723.1 - S791.253 Document code A Foundation item: This article was supported by the National Natural Science Foundation of China (No. 39970627).Biography: TANG Feng-de (1967-), male, Ph. Doctor in Institute of Applied Ecology. Chinese Academy of Sciences, Shenyang 110016, P. R. China.Responsible editor: Zhu Hong 展开更多
关键词 Biological agents Pinus sylvstris var.mongolica Sandy soil ROOTS Survival rate
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水稻抽穗始期喷施“九二0”新技术
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作者 王冲 张邦定 《农家科技》 1996年第7期9-9,共1页
水稻抽穗始期喷施“九二0”是一项投资少、简便易行、效益较高的实用新技术。一般亩增产11~13%。1.始穗期喷施的作用。①提高上林率。喷施“九二0”
关键词 新技术 水稻 喷施 投资少 抽穗 始穗期 始期 林率 效益 实用
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墨西哥森林破坏速度比政府的预计快两倍
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作者 杨过 《科学之友》 2004年第10期51-51,共1页
关键词 墨西哥 森林破坏 破坏速度 林率 政府职能
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优质小麦新品种99-4
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作者 谭春强 《农家科技》 2001年第11期12-12,共1页
一、综合性状春性早熟,全生育期183天左右,叶色浓绿,叶片直立,植株矮健,株高84.8厘米,抗倒力强,分蘖力强,上林率高,穗层整齐,落黄转色好,易脱粒,籽粒饱满,千粒重46克左右,中抗条锈病。
关键词 性早熟 综合性状 千粒重 小麦新品种 抗条锈病 千克 小麦生育期 林率 叶片 株高
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Theoretical derivation of risk-ratios for assessing wind damage in a coastal forest
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作者 朱教君 松崎健 +1 位作者 李凤芹 権田豊 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第4期309-315,338,共7页
Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio for Pinus thunbergii tr... Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio for Pinus thunbergii trees and stands were de-duced from stem bending theory and coefficients characterizing wind profile, distribution of branches and optical stratification po-rosity. The results showed that if the value of constant b in the branch distribution-model equals the attenuation coefficient s in the wind profile model for a single tree crown, then the parameter H/D1.33 (height over stem diameter cubed) can be used to compare and evaluate the risk-ratio of wind damage for individual trees. The same method can be applied to stands using the coefficient of wind profile in a stand, i.e. attenuation coefficient , the coefficient from distributions of optical stratification porosity, i.e. extinction coefficient , and the parameter D1.33. The application of parameter H/D1.33 and the process of determining risk ra-tios of wind damage for stands were also given in the paper. 展开更多
关键词 Wind damage THINNING Pine forest Risk-ratio CLC number: S761.2 S757.1 Document code: A Article ID: 1007-662X(2002)04-309-07
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Effect of water stress on N_2O emission rate of 5 tree species
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作者 王淼 李秋荣 +1 位作者 肖冬梅 王长科 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第1期19-23,J001,共6页
The N2O emission rates, photosynthesis, respiration and stomatal conductance of the dominant tree species from broadleaf/Korean pine forest in Changbai Mountain were measured by simulated water stress with the closed ... The N2O emission rates, photosynthesis, respiration and stomatal conductance of the dominant tree species from broadleaf/Korean pine forest in Changbai Mountain were measured by simulated water stress with the closed bag-gas chromatography. A total of five species seedlings were involved in this study, i.e.,Pinus koraiensis Sieb. et Zucc,Fraxinus mandshurica Rupr,Juglans mandshurica Maxim,Tilia amurensis Rupr, andQuercus mongolica Fisch. ex Turcz.. The results showed that the stomatal conductance, net photosynthetic rate and N2O emission of leaves were significantly reduced under the water stress. The stoma in the leaves of trees is the main pathway of N2O emission. N2O emission in the trees mainly occurred during daytime. N2O emission rates were different in various tree specie seedlings at the same water status. In the same tree species, N2O emission rates decreased as the reduction of soil water contents. At different soil water contents (MW, LW) the N2O emission rates ofPinus koraiensis decreased by 34.43% and 100.6% of those in normal water condition, respectively. In broadleaf arbor decreased by 31.93% and 86.35%, respectively. Under different water stresses N2O emission rates in five tree species such asPinus koraiensis, Fraxinus mandshurica, Juglans mandshurica, Tilia amurensis, andQuercus mongolica were 38.22, 14.44, 33.02, 16.48 and 32.33 ngN2O·g?1DW·h?1, respectively. Keywords Trees - N2O emission rate - Soil water stress - broadleaf/Korean pine forest - Changbai Mountain CLC number S718.55 Document code A Foundation item: This project was supported by the National Natural Science Foundation of China (No. 30271068), the grant of the Knowledge Innovation Program of Chinese Academy of Sciences (KZ-CX-SW-01-01B-10), and the Special Funds for Major State Basic Research Program of China (No. G1999043407)Biography: Wang Miao (1964-), male, associate professor in Institute of Applied Ecology, Chinese Academy of Science, Shenyang 110016, P. R. China.Responsible editor: Song Funan 展开更多
关键词 Trees N2O emission rate Soil water stress broadleaf/Korean pine forest Changbai Mountain
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Research on the Jilin Oilfield Field Trials of Microbial Enhanced Oil Recovery 被引量:1
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作者 崔吉 张忠智 +3 位作者 宋绍富 李羡春 黄春霞 洪承燮 《Petroleum Science》 SCIE CAS CSCD 2004年第4期30-35,共6页
This paper describes the experience of Jilin oilfield trials for Microbial Enhanced Oil Recovery (MEOR). A new technique to identify microbes with DNA for MEOR has been established, and useful microbes selected f... This paper describes the experience of Jilin oilfield trials for Microbial Enhanced Oil Recovery (MEOR). A new technique to identify microbes with DNA for MEOR has been established, and useful microbes selected for use in field trials. Behaviors of bacteria activated in the reservoir, oil recovery and water cut, and the viscosity of crude oil produced through huff & puff testing and flooding with molasses-injection tests, have been investigated in situ. CJF-002, which produces biopolysaccharide, is the best among the microbes used for field trials, as it can use molasses as nutrient and produce a small quantity of CO2 and a mass of water-insoluble biopolymer. The metabolic behavior in the reservoir showed that CJF-002 had a good potentiality for MEOR. 展开更多
关键词 Microbial enhanced oil recovery BIOPOLYMER TRACER huff & puff flooding with microbes
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Simulating Carbon Sequestration and GHGs Emissions in Abies fabric Forest on the Gongga Mountains Using a Biogeochemical Process Model Forest-DNDC 被引量:5
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作者 LU Xuyang CHENG Genwei +1 位作者 XIAO Feipeng HUO Changfu 《Journal of Mountain Science》 SCIE CSCD 2008年第3期249-256,共8页
The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs (greenhouse gases) fluxes (CO2, NO and N2O) in forest ecosystems was applied to simulate carbon sequestration and GHGs e... The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs (greenhouse gases) fluxes (CO2, NO and N2O) in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production (GPP) of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha^-1 yr^-1 for 2005 and 26,318.8 kg C ha^-1 yr^-1 for 2006, respectively. The annual total net primary production (NPP) was 5,935.5 and 4,882.2 kg C ha^-1 yr^-1 for 2005 and 2006, and the annual total net ecosystem production (NEP) was 4,815.4 and 3,512.8 kg C ha^-1 yr^-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha^-1 yr^-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha^-1 yr^-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and o.12 kg N ha^-1 yr^-1 for 2005 and 2006, respectively. 展开更多
关键词 Carbon sequestration Forest-DNDC GHGs Abiesfabric forest Gongga Mountains
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Optimization of Land Use Structure Based on Ecological GREEN Equivalent 被引量:7
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作者 LIU Yanfang MING Dongping YANG Jianyu 《Geo-Spatial Information Science》 2002年第4期60-67,共8页
Optimization of land use structure consists of economic and social and ecological optimization.Applying the minds of system engineering and principles of ecology,this paper presents such thoughts:the optimal forest_co... Optimization of land use structure consists of economic and social and ecological optimization.Applying the minds of system engineering and principles of ecology,this paper presents such thoughts:the optimal forest_coverage rate calculated according to the reality of a district is set as main standard of ecological rationality in the district;through considering the value of ecosystem services of the land with GREEN equivalent (mainly cultivated land and grassland)and based on the rule,GREEN equivalent,this paper introduces the area conversion between woodland and cultivated land,also between woodland and grassland;this paper establishes a multi_dimension controlling model of optimization of land use structure.In addition,a multi_objective linear programming model for optimization of land use structure is designed.In the end,this paper tests and verifies this theory of ecological optimization,taking Qionghai city in Hainan Province as an example. 展开更多
关键词 land use structure forest_coverage rate GREEN equivalent value of ecosystem services multi_dimension optimization multi_objective linear programming
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Land Use Structure in Wuhai City on Basis of Ecological Green Equivalence
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作者 李萍 孙泰森 《Agricultural Science & Technology》 CAS 2015年第6期1276-1279,共4页
The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimizat... The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program. 展开更多
关键词 Ecological green equivalence Forest coverage rate Land use structure Wuhai city
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Soil N Pools and Transformation Rates Under Different Land Uses in a Subalpine Forest-Grassland Ecotone 被引量:19
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作者 SUNGeng WUNing LUOPeng 《Pedosphere》 SCIE CAS CSCD 2005年第1期52-58,共7页
Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalp... Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5) tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P < 0.05) in the soils, which was in contrast to the significant increases (P <0.05) of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification. 展开更多
关键词 DENITRIFICATION gross nitrification land use subalpine forest-grassland ecotone Tibetan Plateau
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Multi-temporal forest cover dynamics in Kashmir Himalayan region for assessing deforestation and forest degradation in the context of REDD+ policy 被引量:2
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作者 Akhlaq Amin WANI Pawan Kumar JOSHI +1 位作者 Ombir SINGH Sumera SHAFI 《Journal of Mountain Science》 SCIE CSCD 2016年第8期1431-1441,共11页
The role of forests is being actively considered under the agenda of REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus) aimed at reducing emissions related to changes in forest cover and fore... The role of forests is being actively considered under the agenda of REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus) aimed at reducing emissions related to changes in forest cover and forest quality. Forests in general have undergone negative changes in the past in the form of deforestation and degradation, while in some countries positive changes are reported in the form of conservation, sustainable management of forests and enhancement of carbon stock. The present study in the Kashmir Himalayan forests is an effort to assess historical forest cover changes that took place from 1980 to 2009 and to predict the same for 2030 on the basis of past trend using geospatial modeling approach. Landsat data (Multispectral Scanner (MSS), Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+)) was used for the years 1980, 199o and (2001, 2009) respectively and change detection analysis between the dates was performed. The maps generated were validated through ground truthing. The study area (3375.62 km^2) from 1980-2009 has uffered deforestation and forest degradation of about 126 km^2 and 239.02 km^2 respectively which can be claimed under negative options of REDD+, while as the area that experienced no change (1514 km^2) can be claimed under conservation. A small area (23.31 km^2) observed as positive change can be claimed under positive options. The projected estimates of forest cover for 2030 showed increased deforestation and forest degradation on the basis of trend analysis using Cellular Automata (CA) Markov modeling. Despite the fact that country as a whole has registered a net positive change in the past few decades, but there are regions like Kashmir region of western Himalaya which have constantly undergoing deforestation as well as degradation in the past few decades. 展开更多
关键词 DEFORESTATION Degradation Coniferous forests Carbon emission HIMALAYA
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Synthesis of activated carbon from spent tea leaves for aspirin removal 被引量:5
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作者 Syieluing Wong Yowjeng Lee +2 位作者 Norzita Ngadi Ibrahim Mohammed Inuwa Nurul Balqis Mohamed 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期1003-1011,共9页
Adsorption capacity of activated carbon prepared from spent tea leaves (STL-AC) for the removal of aspirin from aqueous solution was investigated in this study. Preliminary studies have shown that treatment with pho... Adsorption capacity of activated carbon prepared from spent tea leaves (STL-AC) for the removal of aspirin from aqueous solution was investigated in this study. Preliminary studies have shown that treatment with phosphoric acid (H3PO4) increased removal efficiency of STL-AC. Characterizations on STL-AC revealed excellent textural properties (1200 m2.g-1, 51% mesoporosity), as well as distinctive surface chemistry (1.08 mmol.g-1 and 0.54 mmol.g-1 for acidic and basic oxygenated groups, pHpzc = 2.02). Maximum removal efficiency of aspirin observed was 94.28% after 60 rain when the initial concentration was 100 mg.L-1, 0.5 g of adsorbent used, pH 3 and at a temperature of 30 ℃. The adsorption data were well fitted to the Freundlich isotherm model and obeyed the pseudo-second order kinetics model. The adsorption of aspirin onto STL-AC was exothermic in nature (△H = - 13.808 kJ.mol-1) and had a negative entropy change, △S (-41.444 J.mol-1). A negative Gibbs free energy, △G was obtained indicating feasibility and spontaneity of the adsorption process. The adsorp- tion capacity of △C-STL (178.57 mg.g-1) is considerably high compared to most adsorbents synthesized from various sources, due to the well-defined textural properties coupled with surface chemistry of STL-AC which fa- vors aspirin adsorption. The results demonstrate the potential of STL-AC as aspirin adsorbent. 展开更多
关键词 Activated carbon Spent tea leaves ASPIRIN ADSORPTION KINETICS ISOTHERM
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Dietary Protein Requirement of Juvenile Turbot(Scophthalmus maximus Linnaeus) 被引量:1
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作者 LIU Xingwang MAI Kangsen +1 位作者 LIUFU Zhiguo AI Qinghui 《Journal of Ocean University of China》 SCIE CAS 2015年第2期325-328,共4页
The dietary protein requirement of juvenile turbot(initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with ... The dietary protein requirement of juvenile turbot(initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with fish meal as protein source, which contained different concentrations of protein(47.2%, 51.0%, 54.6%, 59.3% and 63.6% of dry diet). Three groups of fish with 18 individuals in each, were cultured in 300-L tanks and fed twice a day for 8 weeks. During culture, temperature was controlled between 15.0 and 18.0℃, salinity was controlled between 28.5 and 32.0, acidity was controlled between p H7.8 and p H8.5, and ammonia nitrogen was maintained below 0.03 mg L-1 and dissolved oxygen was maintained about 7 mg L-1. Results showed that the growth of fish was significantly affected by dietary protein content(P < 0.05). Specific growth rate(SGR) of turbot increased when dietary protein content varied between 47.2% and 51.0%(P < 0.05), and then kept stable when dietary protein content was higher than 51.0%. Fish which were fed the diet containing 63.6% protein showed the highest SGR while those fed the diet containing 59.3% protein showed the highest feed efficiency rate. No significant difference of feed intake and protein efficiency ratio was found among experimental diets(P > 0.05). Broken-line regression analysis of SGR showed that the optimal dietary protein requirement of turbot was about 57.0%. 展开更多
关键词 TURBOT Scophthalmus maximus protein requirement feed nutrition
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Colonoscopic polypectomy in anticoagulated patients 被引量:2
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作者 Shai Friedland Daniel Sedehi Roy Soetikno 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第16期1973-1976,共4页
AIM:To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hund... AIM:To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hundred and twenty five polypectomies were performed in 123 patients. Patients followed a standardized protocol that included stopping warfarin for 36 h to avoid supratherapeutic anticoagulation from the bowel preparation. Patients with lesions larger than 1 cm were generally rescheduled for polypectomy off warfarin. Endoscopic clips were routinely applied prophylactically. RESULTS: One patient (0.8%, 95% CI: 0.1%-4.5%) developed major post-polypectomy bleeding that required transfusion. Two others (1.6%, 95% CI: 0.5%-5.7%) had self-limited hematochezia at home and did not seek medical attention. The average polyp size was 5.1 ± 2.2 mm. CONCLUSION: Polypectomy can be performed in therapeutically anticoagulated patients with lesions up to 1 cm in size with an acceptable bleeding rate. 展开更多
关键词 Colon cancer Colonic polyps COLONOSCOPY Early detection of cancer Endoscopy HEMORRHAGE THROMBOSIS WARFARIN
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Araucaria cunninghamii Seedling Response to Different Forms and Rates of ^(15)N-Labelled Fertiliser 被引量:1
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作者 T, J. BLUMFIELD XU Zhi-Hong 《Pedosphere》 SCIE CAS CSCD 2006年第6期745-755,共11页
Nitrogenous fertilisers are under consideration for promoting the growth of nursery-reared hoop pine (Araucaria cunninghamii Alton ex A. Cunn) seedlings in the establishment phase of second rotation (2R) plantatio... Nitrogenous fertilisers are under consideration for promoting the growth of nursery-reared hoop pine (Araucaria cunninghamii Alton ex A. Cunn) seedlings in the establishment phase of second rotation (2R) plantations. Using ^15N- labelled fertilisers, we investigated the effect of different forms (ammonium sulphate, ammonium nitrate, potassium nitrate and urea) and rates of application (0, 150 and 300 mg N kg^-1 dried soil) of fertilisers on the growth, ^15N recovery and carbon isotope composition (δ^13C) of hoop pine seedlings in a 12-month glasshouse trial in southeast Queensland, Australia. The ^15N-labelled fertilisers were applied to nursery-reared hoop pine seedlings, which were then grown in pots, containing ca. 1.2 kg dried soil, under well watered conditions for 12 months. Four seedlings from each treatment were harvested at 4-month intervals, divided into roots, stem and foliage, with a further subdivision for new and old foliage, and then analysed for ^15N, total N, δ^13C and total C. There was no significant response in the seedling growth to the form or rate of application of nitrogen (N) fertiliser within the 12-month period, indicating that the seedlings did not experience N deficiency when grown on second rotation hoop pine soils. While the combined ^15N recovery from soil and plant remained at around 70% throughout the experiment, the proportion of ^15N recovered from the plants increasing steadily over time. Nitrate containing fertilisers at 150 mg N kg^-1 soil gradually increased seedling foliage δ^13C over the 12-month period, indicating an increase in seedling water use efficiency. 展开更多
关键词 hoop pine ^15N recovery nitrogen water use efficiency
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Effectiveness of Nature Reserves for Natural Forests Protection in Tropical Hainan: a 20 Year Analysis 被引量:4
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作者 YU Bowei CHAO Xuelin +2 位作者 ZHANG Jindong XU Weihua OUYANG Zhiyun 《Chinese Geographical Science》 SCIE CSCD 2016年第2期208-215,共8页
The establishment of nature reserves is a key approach for biodiversity conservation worldwide. However, there is a lack of unified methodology to evaluate the effectiveness of nature reserves, particularly in China, ... The establishment of nature reserves is a key approach for biodiversity conservation worldwide. However, there is a lack of unified methodology to evaluate the effectiveness of nature reserves, particularly in China, the world′s most populous nation supporting some of the most valuable biodiversity hotspots in the world. In this study, we conducted a long-term and large-scale analysis of the effectiveness of 20 of the earliest nature reserves established in Hainan Province, an island home to among the highest concentration of plants and animals in China. Remote sensing imagery from 1988, 1998, and 2008 were analyzed to investigate the temporal and spatial changes of natural forests in these nature reserves and surrounding areas. We also conducted transition matrix analysis and principle component analysis to identify the driving factors that affect the protection effectiveness of nature reserves. The results were as follows: 1) During the 20-year period from 1988 to 2008, natural forests coverage of the 20 studied nature reserves dropped 2.34 percentage points, whereas the natural forests coverage dropped 11.31 percentage points in a 0–5 km outside reserve buffer and 9.36 percentage points in a 5–10 km outside reserve buffer, indicating a significant inhibitory effect of the nature reserves on the loss of natural forests. 2) Natural forests coverage dropped in 60% of the studied nature reserves during the 20-year period, suggesting a poor protection effectiveness of these reserves, while the coverage proportion showed some increase(0%/yr–5%/yr) in other reserves. 3) Expansion of rubber and pulp forests as part of a booming economy were the main factors affecting the effectiveness of the nature reserves for conserving natural forests in Hainan Province. The results of this study provide an important empirical basis for the protection of natural forests in Hainan Province, which can be used as a blueprint for nature reserve evaluation in other places in China. 展开更多
关键词 nature reserve natural forests reserve effectiveness Hainan Province China
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