期刊文献+
共找到65篇文章
< 1 2 4 >
每页显示 20 50 100
The Effect of Magnesium on Accumulations of Primary Metabolites and Yield of Blumea balsamifera
1
作者 Dan WANG Huiping LAN +4 位作者 Yingbo ZHANG Xuan HU Xiaolu CHEN Yuxin PANG Fulai YU 《Agricultural Biotechnology》 CAS 2020年第4期56-59,67,共5页
[Objectives]This study was conducted to investigate the effects of magnesium on the yield of Blumea balsamifera(L.)DC.and the accumulation of primary metabolites that affect yield of the medicinal material.[Methods]Th... [Objectives]This study was conducted to investigate the effects of magnesium on the yield of Blumea balsamifera(L.)DC.and the accumulation of primary metabolites that affect yield of the medicinal material.[Methods]The annual seedlings of B.balsamifera were selected as experimental materials.The treatment concentrations of magnesium(Mg)were set as 0,1.5,15 and 150 mg/ml supplied by MgSO4·7H2O.The yield of the medicinal material was measured dynamically.And the content of total sugar was determined by 3,5-dinitrosalicylic acid colorimetry;the content of crude protein was determined by the Kjeldahl method;the ash content was determined by the high-temperature burning method;the crude fat content was determined with a crude fat instrument;and the crude fiber content was determined by the acid-base washing and weighing method.[Results]Mg significantly increased the yield of B.balsamifera medicinal material,especially 15 mg/ml Mg.It was found that in September,October and November,1.5 mg/ml and 15 mg/ml Mg significantly increased the contents of primary metabolites including total sugar,ash,crude protein,crude fat and crude fiber,and 150 mg/ml of Mg increased the accumulation of total sugar,ash,crude protein and crude fiber to different degrees,but had certain inhibitory effect on the accumulation of crude fat.In December,the application of Mg inhibited the accumulation of total sugar,ash and crude protein to different degrees,but significantly promoted the accumulation of crude fat and fiber.[Conclusions]This study provides a theoretical basis for clarifying the effects of different concentrations of magnesium on plant growth. 展开更多
关键词 Magnesium(Mg) Blumea balsamifera yield primary metabolites Total sugar ASH Crude protein
下载PDF
基于同化植被净初级生产力的区域玉米产量估测
2
作者 张月 曾文治 《节水灌溉》 北大核心 2024年第8期61-67,共7页
为了评价植被净初级生产力NPP作为同化变量提高区域玉米产量估测精度的有效性及其应用于区域玉米产量估测的潜力,选择黑龙江省双鸭山市友谊农场玉米种植区为研究对象,以WOFOST为作物生长动态模型,分别以叶面积指数LAI和植被净初级生产力... 为了评价植被净初级生产力NPP作为同化变量提高区域玉米产量估测精度的有效性及其应用于区域玉米产量估测的潜力,选择黑龙江省双鸭山市友谊农场玉米种植区为研究对象,以WOFOST为作物生长动态模型,分别以叶面积指数LAI和植被净初级生产力NPP为同化变量,选用MODIS LAI和NPP产品为遥感观测数据,开展基于遥感观测数据与作物生长模型同化的区域玉米产量估测研究。重点比较了分别以叶面积指数LAI和植被净初级生产力NPP为同化变量的区域玉米产量估测结果精度。结果表明,相较以叶面积指数LAI为同化变量的区域玉米产量估测统计结果(均值为7755 kg/hm^(2),标准差为1303 kg/hm^(2)),以植被净初级生产力NPP为同化变量的区域玉米产量估测统计结果(均值为9214 kg/hm^(2),标准差为190 kg/hm^(2))与研究区域统计结果(均值为8970 kg/hm^(2))更为接近,但在表现玉米产量空间异质性方面稍显不足。以植被净初级生产力NPP为同化变量开展区域作物产量估测是一种可行的数据同化策略,具有较大的应用潜力。 展开更多
关键词 数据同化 作物生长模型 产量估测 叶面积指数 植被净初级生产力
下载PDF
Spatiotemporal variations of ecosystem services and driving factors in the Tianchi Bogda Peak Natural Reserve of Xinjiang,China
3
作者 ZHU Haiqiang WANG Jinlong +2 位作者 TANG Junhu DING Zhaolong GONG Lu 《Journal of Arid Land》 SCIE CSCD 2024年第6期816-833,共18页
Nature reserves play a significant role in providing ecosystem services and are key sites for biodiversity conservation.The Tianchi Bogda Peak Natural Reserve(TBPNR),located in Xinjiang Uygur Autonomous Region,China,i... Nature reserves play a significant role in providing ecosystem services and are key sites for biodiversity conservation.The Tianchi Bogda Peak Natural Reserve(TBPNR),located in Xinjiang Uygur Autonomous Region,China,is an important ecological barrier area in the temperate arid zone.The evaluation of its important ecosystem services is of great significance to improve the management level and ecological protection efficiency of the reserve.In the present study,we assessed the spatiotemporal variations of four ecosystem services(including net primary productivity(NPP),water yield,soil conservation,and habitat quality)in the TBPNR from 2000 to 2020 based on the environmental and social data using the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model.In addition,the coldspot and hotspot areas of ecosystem services were identified by hotspot analysis,and the trade-off and synergistic relationships between ecosystem services were analyzed using factor analysis in a geographic detector.During the study period,NPP and soil conservation values in the reserve increased by 48.20%and 25.56%,respectively;conversely,water yield decreased by 16.56%,and there was no significant change in habitat quality.Spatially,both NPP and habitat quality values were higher in the northern part and lower in the southern part,whereas water yield showed an opposite trend.Correlation analysis revealed that NPP showed a synergistic relationship with habitat quality and soil conservation,and exhibited a trade-off relationship with water yield.Water yield and habitat quality also had a trade-off relationship.NPP and habitat quality were affected by annual average temperature and Normalized Difference Vegetation Index(NDVI),respectively,while water yield and soil conservation were more affected by digital elevation model(DEM).Therefore,attention should be paid to the spatial distribution and dynamics of trade-off and synergistic relationships between ecosystem services in future ecological management.The findings of the present study provide a reference that could facilitate the sustainable utilization of ecosystem services in the typical fragile areas of Northwest China. 展开更多
关键词 net primary productivity(NPP) water yield soil conservation habitat quality Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model geographic detector Tianchi Bogda Peak Natural Reserve
下载PDF
Yield of OH radicals in water under heavy ion irradiation.Dependence on mass,specific energy,and elapsed time 被引量:2
4
作者 Mitsumasa TAGUCHI Takuji KOJIMA 《Nuclear Science and Techniques》 SCIE CAS CSCD 2007年第1期35-38,共4页
Dependence of yields of OH (hydroxyl) radicals on the mass and specific energy of heavy ions and elapsed time after irradiation was investigated,to understand chemical reactions of aqueous solutions.The yields of irra... Dependence of yields of OH (hydroxyl) radicals on the mass and specific energy of heavy ions and elapsed time after irradiation was investigated,to understand chemical reactions of aqueous solutions.The yields of irradiation products of phenol,super-linearly increased with the incident energy of He,C,and Ne ions ranging from 2 to 18 MeV/u.The yields of the OH radicals were estimated by analyzing the yields of the irradiation products of phenol. The yields of the OH radicals increased with the specific energy for each ion,but decreased both with the mass of each ion at the same specific energy and elapsed time after irradiation. 展开更多
关键词 重离子辐射 辐射分解 羟自由基 产率 质量 耗用时间
下载PDF
Agronomic Behavior of a New Cereal (Primary 6x Tritipyrum: AABBEbEb) in Comparison with Modern Triticale and Iranian Bread Wheat Cultivars
5
作者 Maryam Kamyab Hossein Shahsavand Hassani Enayatollah Tohidinejad 《Journal of Agricultural Science and Technology(B)》 2012年第1期38-51,共14页
The novel salt-tolerant cereal, primary Tritipyrnm, is the third artificially synthesized crop plant. The agronomic traits and grain yields of 13 primary 6x Tritipyrum lines were evaluated and compared with five moder... The novel salt-tolerant cereal, primary Tritipyrnm, is the third artificially synthesized crop plant. The agronomic traits and grain yields of 13 primary 6x Tritipyrum lines were evaluated and compared with five modern 6x triticale lines and nine bread wheat cultivars at Bahonar University, Kerman, Iran in a completely randomized block design with three replications. The primary Tritipyrum lines increased the grain yield per plant by 2.8% and 14.1% compared to triticale promising lines and Iranian bread wheat cultivars, respectively. Although the primary Tritipyrum lines were late maturing, they were shorter than the triticale lines and wheat cultivars and superior in many characters such as penultimate leaf area, flag leaf length, penultimate leaf length and time to milky ripeness. Genotypes were divided into four groups for agronomic and morphological traits and four groups for grain yield by cluster analyses. All clusters showed significant differences (a = 5%) for all traits and the first cluster, which comprised primary Tritipyrum lines, had a higher mean grain yield than the other clusters. The results of this first large-scale trial indicated the high adaptation of primary Tritipyrum lines to conditions in Kerman province in South-east of Iran. 展开更多
关键词 Agronomic performance bread wheat TRITICALE primary Tritipyrum yield traits cluster analysis.
下载PDF
Yield of iodine isotopes from interaction of 47 MeV/u ^(12)C with ^(133)Cs
6
作者 YangWei-Fan ZhaoZhi-Zheng 《Nuclear Science and Techniques》 SCIE CAS CSCD 1997年第1期23-25,共3页
Yieldofiodineisotopesfrominteractionof47MeV/u12Cwith133CsYangWeiFan,ZhaoZhiZheng,LiZongWeiandMuWanTong(Insti... Yieldofiodineisotopesfrominteractionof47MeV/u12Cwith133CsYangWeiFan,ZhaoZhiZheng,LiZongWeiandMuWanTong(InstituteofModern... 展开更多
关键词 重离子反应 碘同位素 质量损失
下载PDF
散射辐射对杨树人工林生态系统总初级生产力的影响 被引量:3
7
作者 万家鸣 律江 +2 位作者 石云 许行 张志强 《林业科学》 EI CAS CSCD 北大核心 2023年第5期1-10,共10页
【目的】在量化生态系统阳冠层和阴冠层光合参数的基础上,通过探究其季节动态变化和主要生物物理调控因子,揭示散射辐射变化对杨树人工林生态系统总初级生产力(GPP)的影响,为人工林生态系统服务功能和碳汇能力的准确评估提供参考。【方... 【目的】在量化生态系统阳冠层和阴冠层光合参数的基础上,通过探究其季节动态变化和主要生物物理调控因子,揭示散射辐射变化对杨树人工林生态系统总初级生产力(GPP)的影响,为人工林生态系统服务功能和碳汇能力的准确评估提供参考。【方法】以北京顺义区共青林场的杨树人工林生态系统为研究对象,利用涡度相关技术和微气象观测系统,对生态系统碳循环过程和生物物理因素进行了连续4年(2015—2018年)的定位观测;采用非线性拟合方法将生态系统最大光合速率(A_(max))和表观量子效率(α)拆分为受直接辐射(A_(max),dir、αdir)和散射辐射(A_(max,dif)、α_(dif))影响的两部分。由于直角双曲线模型(Michaelis-Menten model)在模拟GPP时会出现不饱和现象,本研究采用PAR为2000μmol·m^(–2)s^(–1)时的GPP作为最大光合速率(A_(2000))。【结果】采用晴空指数和太阳高度角模拟的散射辐射与实测值接近(斜率为0.82,R^(2)=0.87,RMSE=51.67 W·m^(–2),P<0.01)。2015—2018年生长季杨树人工林的α_(dif)、A_(2000,dir)和A_(2000,dif)呈先增加后减小的变化趋势,α_(dif)和A_(2000,dif)显著高于αdir和A_(2000,dir)(pα=0.02;p A_(2000)=0.03),α_(dif)/αdir和A_(2000,dif)/A_(2000,dir)分别为5.6和6.1,二者的比例在夏季表现出明显差异。生长季GPP呈单峰变化模式,且GPP与A_(2000,dif)显著相关(P<0.01),随着PAR_(dif)/PAR_(dir)的增加,GPP显著增加(P<0.01)。在夏季,A_(2000,dif)主要受Ta的影响,随着Ta的增加而增加(偏相关系数为0.74,R^(2)=0.49,P<0.05);在春季和秋季,LAI主导着A_(2000,dif)的变化(偏相关系数为0.69,R^(2)=0.53,P<0.01),而PrestleyTaylor系数(η)和晴空指数(CI)无论是在春秋还是夏季,对A_(2000,dif)都无显著影响。【结论】α和A_(2000)会随季节发生变化,散射辐射对A_(2000)和α的影响要显著高于直接辐射的影响,且在生长季中期更加明显,A_(2000,dif)在春秋季和夏季的变化分别主要受生物因素(LAI)和环境因素(Ta)主导。A_(2000,dif)是调控GPP变化的最关键因素,因此,散射辐射是影响该人工林生态系统光合生产力的重要环境因素。 展开更多
关键词 散射辐射 表观量子效率 最大光合速率 总初级生产力 杨树人工林
下载PDF
Spatiotemporal characteristics and influencing factors of ecosystem services in Central Asia 被引量:3
8
作者 YAN Xue LI Lanhai 《Journal of Arid Land》 SCIE CSCD 2023年第1期1-19,共19页
Land use/land cover(LULC)change and climate change are two major factors affecting the provision of ecosystem services which are closely related to human well-being.However,a clear understanding of the relationships b... Land use/land cover(LULC)change and climate change are two major factors affecting the provision of ecosystem services which are closely related to human well-being.However,a clear understanding of the relationships between these two factors and ecosystem services in Central Asia is still lacking.This study aimed to comprehensively assess ecosystem services in Central Asia and analyze how they are impacted by changes in LULC and climate.The spatiotemporal patterns of three ecosystem services during the period of 2000-2015,namely the net primary productivity(NPP),water yield,and soil retention,were quantified and mapped by the Carnegie-Ames-Stanford Approach(CASA)model,Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model,and Revised Universal Soil Loss Equation(RUSLE).Scenarios were used to determine the relative importance and combined effect of LULC change and climate change on ecosystem services.Then,the relationships between climate factors(precipitation and temperature)and ecosystem services,as well as between LULC change and ecosystem services,were further discussed.The results showed that the high values of ecosystem services appeared in the southeast of Central Asia.Among the six biomes(alpine forest region(AFR),alpine meadow region(AMR),typical steppe region(TSR),desert steppe region(DSR),desert region(DR),and lake region(LR)),the values of ecosystem services followed the order of AFR>AMR>TSR>DSR>DR>LR.In addition,the values of ecosystem services fluctuated during the period of 2000-2015,with the most significant decreases observed in the southeast mountainous area and northwest of Central Asia.LULC change had a greater impact on the NPP,while climate change had a stronger influence on the water yield and soil retention.The combined LULC change and climate change exhibited a significant synergistic effect on ecosystem services in most of Central Asia.Moreover,ecosystem services were more strongly and positively correlated with precipitation than with temperature.The greening of desert areas and forest land expansion could improve ecosystem services,but unreasonable development of cropland and urbanization have had an adverse impact on ecosystem services.According to the results,ecological stability in Central Asia can be achieved through the natural vegetation protection,reasonable urbanization,and ecological agriculture development. 展开更多
关键词 ecosystem services land use/land cover change climate change net primary productivity water yield soil retention Central Asia
下载PDF
Climate Change Impacts on Agroecosystems in China:Processes,Mechanisms and Prospects 被引量:1
9
作者 BAO Lun YU Lingxue +3 位作者 LI Ying YAN Fengqin LYNE Vincent REN Chunying 《Chinese Geographical Science》 SCIE CSCD 2023年第4期583-600,共18页
Building a more resilient response system to climate change for sustainable development and reducing uncertainty in China’s food markets,requires access to historical research gaps and mapping future research progres... Building a more resilient response system to climate change for sustainable development and reducing uncertainty in China’s food markets,requires access to historical research gaps and mapping future research progress for decision making.However,the lack of quantitative and objective analyses to ensure the stability and development of agroecosystems increases the complexity of agro-climatic mechanisms,which leads to uncertainty and undesirable consequences.In this paper,we review the characteristics of climate change in China(1951–2020),reveal the mechanisms of agroecosystem structure in response to climate,and identify challenges and opportunities for future efforts in the context of research progress.The aim is to improve the scientific validity and relevance of future research by clarifying agro-climatic response mechanisms.The results show that surface temperature,precipitation,and frequency of extreme weather events have increased to varying degrees in major agricultural regions of China in 1951–2020.And they have strong geographic variation,which has resulted in droughts in the north and floods in the south.Moreover,climate change has complicated the mechanisms of soil moisture,Net Primary Productivity(NPP),soil carbon pool,and crop pest structure in agroecosystems.This lends to a reduction in soil water holding capacity,NPP,soil carbon content,and the number of natural enemies of diseases and insects,which in turn affects crop yields.However,human interventions can mitigate the deterioration of these factors.We have also realized that the methodology and theory of historical research poses a great challenge to future agroecosystem.Historical and projected climate trends identified current gaps in interdisciplinary integration and multidisciplinary research required to manage diverse spatio-temporal climate change impacts on agroecosystems.Future efforts should highlight integrated management and decision making,multidisciplinary big data coupling,and numerical simulations to ensure sustainable agricultural development,ecological security,and food security in China. 展开更多
关键词 climate change AGROECOSYSTEM Net primary Productivity(NPP) soil carbon pool risk management crop yield
下载PDF
Impact of Commercial Organic Ameliorants on Nitrogen and Phosphorus Concentrations of Maize Biomass at Ninth Leaf and Silking Growth Stages
10
作者 Tlangelani Cedric Baloyi Funso Raphael Kutu Christiaan Cornelius du Preez 《Journal of Geoscience and Environment Protection》 2023年第5期102-125,共24页
The response of grain yield, biomass yield and harvest index of maize to the application of commercial organic ameliorants was inconsistent and poor. Hence it was hypothesized that the supply of N and P to maize plant... The response of grain yield, biomass yield and harvest index of maize to the application of commercial organic ameliorants was inconsistent and poor. Hence it was hypothesized that the supply of N and P to maize plants was inadequate during vegetative growth, resulting in low concentrations of the two nutrients in maize biomass. The effects of nine ameliorants on the N and P concentrations of maize plants at ninth leaf (V9) and silking (R1) stages of maize were studied over three years at Bothaville (8% clay), Ottosdal (12% clay) and Potchefstroom (34% clay). All ameliorants were applied as prescribed by manufacturers. The N and P concentrations in maize biomass of the ameliorants at V9 and R1 were lower, comparable or higher, showing that the inconsistent and poor response of yield parameters can not be ascribed to inadequate uptake of N and P. A matter of concern that justifies thorough investigation, is the prescribed use of Crop care and Growmor with partial and of Montys and Promis with no NPK fertilization, an unsustainable practice over the long term. Characterization of the active ingredient(s) of the ameliorants is deemed also of importance for better insight. 展开更多
关键词 Field Trials Grain yield primary Nutrients Reproductive Growth Vegetative Growth
下载PDF
测试一次良率提升探析
11
作者 张浩 张进兵 +2 位作者 周旭峰 崔有军 闫进学 《中国集成电路》 2023年第1期87-90,共4页
集成电路测试过程中提高一次测试良品率是节约成本和提高效率最直接的方法。由于测量系统精度的限制以及测试条件的差异,误测时常发生。本文探讨了部分影响一次测试良品率的因素及其解决方法。
关键词 误测 一次良率 良率提升
下载PDF
影响连续重整芳烃收率的因素分析及优化
12
作者 胡海龙 《化工管理》 2023年第35期116-118,共3页
连续重整装置是一套以石脑油为主要原料,在催化剂的作用下,生产高辛烷值汽油和芳烃,同时还副产大量氢气的装置。提高芳烃收率,是对重整装置生产提质增效最有效的手段。文章主要对装置生产中重整进料初馏点、进料组分、催化剂活性以及再... 连续重整装置是一套以石脑油为主要原料,在催化剂的作用下,生产高辛烷值汽油和芳烃,同时还副产大量氢气的装置。提高芳烃收率,是对重整装置生产提质增效最有效的手段。文章主要对装置生产中重整进料初馏点、进料组分、催化剂活性以及再接触温度对芳烃收率的影响进行了分析,并提出改进方法。 展开更多
关键词 芳烃收率 重整进料初馏点 芳潜 催化剂活性
下载PDF
近70年黄河流域水沙情势及其成因分析 被引量:78
13
作者 赵阳 胡春宏 +4 位作者 张晓明 王友胜 成晨 殷小琳 谢敏 《农业工程学报》 EI CAS CSCD 北大核心 2018年第21期112-119,共8页
深入剖析黄河水沙现状及成因是精准预测黄河未来水沙情势的前提与基础。为此,以黄河干流潼关断面以上4个主要干流水文站及7个主要一级支流把口站1950—2016年水沙实测资料为基础,采用双累积曲线等多种统计分析方法,系统剖析了黄河流域... 深入剖析黄河水沙现状及成因是精准预测黄河未来水沙情势的前提与基础。为此,以黄河干流潼关断面以上4个主要干流水文站及7个主要一级支流把口站1950—2016年水沙实测资料为基础,采用双累积曲线等多种统计分析方法,系统剖析了黄河流域水沙演变规律及水沙主要源区变化特征,定量评估了不同环境要素对黄河水沙变化影响。结果表明:1)黄河干流兰州、头道拐、龙门及潼关水文站年径流及年输沙量均呈显著减少趋势(P<0.05),其中,年径流减幅17.93%~40.79%,年输沙量减幅均在46.74%以上。受多种因素影响,黄河水沙在20世纪80—90年代发生减少突变;2)兰州-潼关区间年均径流量沿程变化表现为由总体递增状态向递减趋势转变,年均输沙量递增状态虽未转变,但递增幅度平均减小90%以上;3)黄河泥沙主要来源区由头龙区间向龙潼区间发生转移特征明显,龙潼区间水土流失治理有待进一步加强;4)人类活动对黄河中游水沙锐减占据主导作用,平均贡献率达到90%以上。而上游兰州站年均径流量受气候影响较大,贡献率达到66.57%。研究结果可为深刻认识黄河水沙时空现状及成因提供依据,并对未来水土流失治理区位方向确定提供参考。 展开更多
关键词 径流 评估 水文 黄河 干流 一级支流 水沙
下载PDF
不同密度和调控措施对枣树生长量和产量的影响研究 被引量:7
14
作者 郝庆 樊丁宇 +3 位作者 肖雷 卡德尔.艾山 陈玲 杨磊 《新疆农业科学》 CAS CSCD 北大核心 2013年第11期2067-2071,共5页
【目的】通过研究不同密度和调控措施对枣树生长量和产量的影响,探讨解决直播密植红枣在保证丰产稳产的前提下,逐步降低种植密度的方法。【方法】通过开展植株密度调控试验和主副株差别化修剪试验,调查不同处理枣树的生长量和产量。【... 【目的】通过研究不同密度和调控措施对枣树生长量和产量的影响,探讨解决直播密植红枣在保证丰产稳产的前提下,逐步降低种植密度的方法。【方法】通过开展植株密度调控试验和主副株差别化修剪试验,调查不同处理枣树的生长量和产量。【结果】种植密度逐渐减小,干粗、株高、树冠投影面积等指标的生长量随之增大,枣头数逐渐增多,单株产量逐渐增加,而单位产量显著降低。主副株差别化修剪结果显示,副株的枣头长度和粗度的生长量、产量大于主株,而枣头数少于主株,差异显著。5年生不同密度的枣树在干粗、产量指标上存在显著差异,其它生长量指标差异不明显,但4年生枣树生长量明显较小。【结论】对于幼龄密植枣园,种植密度对枣树生长量及单株产量有明显影响,但对果吊比的影响很小。随着种植密度的降低,生长空间加大,枣树生长量和单株产量逐渐增大。此外,对幼龄枣树进行主副株差别修剪对调节枣树生长量和产量有重要作用。 展开更多
关键词 枣树 密度 主株 副株 生长量 产量
下载PDF
基于净初级生产力的省公顷生态足迹模型参数的计算——以江苏省为例 被引量:22
15
作者 鲁凤 陶菲 +1 位作者 钞振华 胡秀芳 《地理与地理信息科学》 CSCD 北大核心 2016年第2期83-88,共6页
基于传统生态足迹模型,在省域空间尺度下构建了"省公顷"生态足迹模型,基于植被净初级生产力(NPP),对生态足迹的均衡因子和产量因子加以本地化改进,并改进了化石能源土地的计算方法。以江苏省为例,根据省公顷模型参数的计算形... 基于传统生态足迹模型,在省域空间尺度下构建了"省公顷"生态足迹模型,基于植被净初级生产力(NPP),对生态足迹的均衡因子和产量因子加以本地化改进,并改进了化石能源土地的计算方法。以江苏省为例,根据省公顷模型参数的计算形式,采用该区域2000-2010年间MOD17A3遥感数据的年NPP以及土地利用数据,计算了不同年份江苏省各类生物生产性土地的均衡因子和13个地市各类土地的产量因子。结果表明,江苏省各类土地的均衡因子与全球或国家公顷的均衡因子差异显著,各地市的产量因子也存在一定差异,但总体更为符合区域实际情况。基于NPP的省公顷模型使得动态均衡因子和产量因子的计算快速简便,适用于省、市域等中小尺度区域可持续发展生态评估。 展开更多
关键词 省公顷 净初级生产力 均衡因子 产量因子 生态足迹
下载PDF
稻茬套播油菜种植密度与产量及其分枝习性的关系 被引量:13
16
作者 姚月明 沈明星 +2 位作者 孙华 冯瑞兴 刘凤军 《上海农业学报》 CSCD 2005年第1期29-32,共4页
试验研究了稻茬套播油菜种植密度与产量和分枝习性的关系。结果表明 :(1)在较低密度条件下 (1~ 3万株 6 6 7m2 ) ,油菜籽产量随着密度的增加呈递增趋势 ,其适宜的密度为 3万株 6 6 7m2 左右 ;超过3万株 6 6 7m2 ,油菜籽产量随着密... 试验研究了稻茬套播油菜种植密度与产量和分枝习性的关系。结果表明 :(1)在较低密度条件下 (1~ 3万株 6 6 7m2 ) ,油菜籽产量随着密度的增加呈递增趋势 ,其适宜的密度为 3万株 6 6 7m2 左右 ;超过3万株 6 6 7m2 ,油菜籽产量随着密度的增加呈递减趋势。 (2 )主攻油菜籽 14 0kg 6 6 7m2 的产量水平 ,适宜每株有效分枝数为 3~ 4个 ,群体有效分枝数为 10~ 12万个 6 6 7m2 ,分枝结角果数占总角果数的 75 %左右。 展开更多
关键词 套播 稻茬 分枝数 产量 密度 习性 油菜种植 增加 油菜籽 趋势
下载PDF
一些海洋浮游植物量子产值的研究 被引量:15
17
作者 矫晓阳 朱明远 吴宝铃 《生态学报》 CAS CSCD 北大核心 1993年第1期17-24,共8页
现场实验以及用硅藻、金藻和绿藻所做的实验表明,在光饱和深度以下,随着深度的增加,浮游植物的量子产懂具有不变、增加和下降3种垂直变化趋势。偏离理论模式的后两种结果可能是由浮游植物的光强适应(Light-shade adaptation)等原因引起... 现场实验以及用硅藻、金藻和绿藻所做的实验表明,在光饱和深度以下,随着深度的增加,浮游植物的量子产懂具有不变、增加和下降3种垂直变化趋势。偏离理论模式的后两种结果可能是由浮游植物的光强适应(Light-shade adaptation)等原因引起。还探讨了量子产值作为初级生产力模型和光利用效率模型中的参数的问题。 展开更多
关键词 浮游植物 量子产值 初级生产力
下载PDF
生态足迹研究现状及基于净初级生产力的计算方法初探 被引量:14
18
作者 杜加强 王金生 +1 位作者 滕彦国 张桐 《中国人口·资源与环境》 CSSCI 2008年第4期178-183,共6页
生态足迹是一种有效的再生资源更新能力的定量测度方法,其主要用于评估给定年、给定技术条件下生物圈的再生能力能否满足人类消费需求。本研究对国内外生态足迹模型的理论假设、生态足迹、生物承载力、生态盈余、生态赤字进行了简要介绍... 生态足迹是一种有效的再生资源更新能力的定量测度方法,其主要用于评估给定年、给定技术条件下生物圈的再生能力能否满足人类消费需求。本研究对国内外生态足迹模型的理论假设、生态足迹、生物承载力、生态盈余、生态赤字进行了简要介绍;在对国际组织发布的生态足迹报告以及生态足迹文献发表情况进行统计的基础上,回顾了国内外的生态足迹理论以及应用在空间尺度、时间序列、消费分类、产量因子及方法标准化等方面的最新进展;详细介绍了一种较新的生态足迹计算方法——基于净初级生产力的计算方法,并与现有的基于全球农业生态区的计算方法进行了比较,探讨了两种方法的优缺点;最后对生态足迹今后的研究重点提出了一些看法和展望。 展开更多
关键词 生态足迹 研究进展 均衡因子 产量因子 净初级生产力
下载PDF
基于MOD17A3数据集的三江平原低产农田影响因素分析 被引量:10
19
作者 国志兴 王宗明 +2 位作者 刘殿伟 宋开山 宋长春 《农业工程学报》 EI CAS CSCD 北大核心 2009年第2期152-155,共4页
为了提高三江平原的农田生产力,该文基于EOS/MODIS卫星2000~2005年的MOD17A3数据集,采用空间分析方法,结合数字高程模型(DEM)、道路、河流、居民点等空间数据,对三江平原低产农田的空间分布和影响因素进行了分析。结果表明,阴坡农田低... 为了提高三江平原的农田生产力,该文基于EOS/MODIS卫星2000~2005年的MOD17A3数据集,采用空间分析方法,结合数字高程模型(DEM)、道路、河流、居民点等空间数据,对三江平原低产农田的空间分布和影响因素进行了分析。结果表明,阴坡农田低产率(32.16%) 高于阳坡(25.49%),说明阳坡更有利于农田植被生长。随着海拔的升高,旱田低产率呈现低—高—低的变化趋势,在100~200 m高程带,旱田低产率最高,为39.62%。旱田和水田低产率与距居民点的距离(≤5 km)、距道路的距离(≤3 km)、距河流的距离(≤12 km)呈反比,对应的相关系数分别为-0.979(p<0.01)、-0.999(p<0.05)、-0.935(p<0.05)和-0.980(p<0.01)、-0.998(p<0.05)、-0.923(p<0.05)。研究结果为确保区域农业生产、土地资源合理利用和区域可持续发展提供科学依据。 展开更多
关键词 净初级生产力 低产率 空间分析 三江平原
下载PDF
长城湾夏季初级生产力及其光量子产值 被引量:4
20
作者 吕瑞华 朱明远 +1 位作者 夏滨 陈皓文 《黄渤海海洋》 CSCD 1998年第3期52-59,共8页
本文报道了1992~1993年南极长城湾及其邻近水域夏季初级生产力的水平、同化系数及其分布特征,并对影响水域生产力的主要因素进行了分析。同时对该海区的光量子产值和光利用效率进行了测定,结果表明:长城湾夏季光量子产值的... 本文报道了1992~1993年南极长城湾及其邻近水域夏季初级生产力的水平、同化系数及其分布特征,并对影响水域生产力的主要因素进行了分析。同时对该海区的光量子产值和光利用效率进行了测定,结果表明:长城湾夏季光量子产值的变化范围为1.479×10-2~9.028×10-2mol碳/mol光量子,平均值为4.558×10-2mol碳/mol光量子;浮游植物对光的利用效率为0.796×10-2~1.824×10-2。该海区夏季的光量子产值和光利用效率远高于其他海区。 展开更多
关键词 长城湾 初级生产力 光量子产值 夏季 海洋生物
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部