Investigating factors driving phytoplankton growth and grazing loss rates in waters around Peninsular Malaysia     

Lim  Joon Hai  Lee  Choon Weng  Bong  Chui Wei 《中国海洋湖沼学报》2021,39(1):148-159

In tropical waters where temperatures are relatively stable,we investigated whether the relationship between phytoplankton growth and grazing loss rate acros s different habitats around Peninsular Malaysia can be attributed to its eutrophication states.We measured phytoplankton growth(μ) and grazing loss(g) rates in waters off Bachok Marine Research Station(BMRS),located northeast of Peninsular Malaysia.Chlorophyll-a(chl-a) concentration ranged from 2.90 to 15.78 μg/L and was dominated by nanoand micro-phytoplankton(2 μm in size).Using the Landry and Hassett dilution method,μ at BMRS ranged from 1.02 to 1.58/d whereas g varied from 0.07 to 0.88/d.Grazing accounted for 35% of the primary production at BMRS.A systematic review of available data in waters around Peninsular Malaysia,revealed how μ fluctuated over a wide range(0.01-1.80/d) and correlated with chl a distribution(R2=0.181,P0.001).However,the relationship was only significant at 9 μg/L chl a for mesotrophic waters and 16 μg/L chl a for eutrophic waters.In contrast,g ranged from 0.00 to 1.01/d,and correlated with μ at all locations.The g/μslope ranged from 19% to 84%,and was generally similar for waters around Peninsular Malaysia.However,all the g/μ slopes had a positive y-intercept except for BMRS,and this seemed to suggest the availability of alternative prey supporting grazing at the other stations.  相似文献   

大连机场典型低空风切变的成因分析     

翁雪玲  于佳松  徐建文 《气象与环境科学》2020,43(1):81-89

风切变是指空间两点之间的风的矢量差,风切变分为水平风切变和垂直风切变。航空气象学中,低空风切变通常是指近地面600 m高度以下的垂直风切变,低空风切变严重危害航空活动安全,尤其是在飞机起飞和着陆阶段。为了提高对低空风切变的预报准确率和提前预警时间,利用大连机场话音方式航空器报告统计大连机场出现的低空风切变特点。大连机场低空风切变出现最多的季节是秋末和春季,其中以西北大风和偏北大风造成的低空风切变最为典型,这种切变常常出现在地面风向为360°或350°、平均风速9 m·s^-1、阵风风速16 m·s^-1的观测时次附近。选取3个大连机场典型低空风切变的天气个例,利用NCEP/NCAR FNL(1°×1°)资料分析大连机场出现典型低空风切变时的天气形势特点,利用WRF模式输出资料,分析了大连机场出现典型低空风切变时低层的风场特征。分析结果表明,WRF模式输出的风场变化较小,不能体现低空风切变的突变特征,利用模式输出资料计算得到的反映偏差风相对大小的I值与风切变的出现有明显关系,当I大于0.5且逐渐增加时,容易出现低空风切变,当I小于0.5且逐渐减小时,不易出现低空风切变,可以利用I值及其变化情况进行风切变的预报预警。  相似文献   

Treatment of leachate from domestic landfills with three-stage physicochemical and biochemical technology     

Huan-Xin Weng  Feng Zhang  Yang-Ming Zhu  Ya-Chao Qin  Zhong-qiang Ji  Charles Cheng 《Environmental Earth Sciences》2011,64(6):1675-1681

Because domestic landfill leachate concentrates complex organic pollutants, effective treatment of landfill leachate has gained increasing attention in recent years. In this paper, three-stage physicochemical and biochemical technology for treatment of domestic landfill leachate is presented. Based on an eight-month pilot operation, over 96% of the main pollutants, for example COD_Cr, BOD₅, SS, NH₄ ⁺–N, coliform, and chrominance, can be removed, among which the removal efficiency of COD_Cr was 89.5, 8.6, and 1.7% in stages 1, 2, and 3, respectively, and the removal efficiency of BOD₅ was 90.3, 8.3, and 1.4%. In the treatment, the biochemical process played a principal role on the removal of pollutants from the leachate. The treatment efficiency depends on how the syntheses of physicochemical, anaerobic, and hydrolytic procedures pave the way for biochemical treatment. Application of a combined efflux and mixed-flow aerator enhanced the removal efficiency during each procedure.  相似文献   

九寨沟箭竹海沉积物中BSi含量及其环境指示意义     

李世广  胡欣欣  唐亚  黄成敏 《山地学报》2011,29(4)

通过对九寨沟箭竹海沉积物样品中生物硅( BSi)含量的分析,讨论箭竹海沉积物中BSi含量与总有机碳(TOC)及粒度的关系,进而探讨BSi含量反映自然和人类因素对湖泊水体和沉积物的影响.箭竹海沉积物中BSi含量介于5.5～ 15.8 mg/g之间,BSi含量与TOC呈显著正相关关系.BSi含量还较显著地受到粒度影响,较细颗粒沉积物对BSi有较强的吸附作用.箭竹海沉积物中BSi含量变化与气温波动关系不密切,主要反映了森林砍伐和旅游开发等人类活动对湖泊水体和沉积物的影响.  相似文献   

诸暨枫桥高岭土合成4A沸石的研究     

蔡奇雄  翁焕新 《浙江国土资源》1995,(1)

本文记述了由高岭土合成4A沸石的原理与工艺，分析了诸暨枫桥的高岭土物理、化学性质，经过人工合成试验，证明产自诸暨枫桥的高岭土是合成4A沸石较为理想的材料。  相似文献   

大连市暴雨灾害特征及敏感区识别          下载免费PDF全文

徐建文  杨建莹  翁雪玲  王丽娜  王囝囝 《气象与减灾研究》2020,43(4):314-320

利用国家气象站和区域自动气象站的降水观测资料以及暴雨洪涝灾害情况资料,分析了2007—2019年大连地区暴雨气候特征时空分布,并进行了灾害评估和敏感区域识别。结果表明：1） 大连地区年平均暴雨和大暴雨日数在空间分布上东北部多于西南部,大暴雨出现的概率为0—40%。年平均暴雨量和大暴雨量的极大值区域主要集中于庄河地区,年均暴雨强度也呈现从西到东逐渐递增趋势。暴雨变异系数的高值中心出现在瓦房店西部地区,低值区出现在庄河地区。2） 大连市的暴雨灾害近80%为较严重灾害,最严重和严重暴雨灾害各占9%—10%。3） 普兰店西南部、庄河西部与大连市区为大连地区暴雨洪涝灾害相对敏感区域。  相似文献   

渤海海域莱州湾凹陷构造演化对油气成藏的控制作用   总被引：1，自引：0，他引：1       下载免费PDF全文

王亮  周心怀  牛成民  杨波 《地质科学》2011,(3):838-846

莱州湾凹陷近年获重大油气发现,但构造演化特征复杂,烃源岩、沉积体系展布特征以及油气运聚规律认识尚不够深入.本文利用多种钻井资料,结合区域地质研究,首先对本区构造演化所产生的断裂与圈闭特征进行分析,划分出3级断裂体系以及3种类型圈闭,并深入研究了构造演化对油气生成与演化、优质储盖组合的分布以及油气运移与聚集的控制作用,总...  相似文献   

中国建设用地错配时空特征、驱动机制及空间效应     

张俊峰  王聪聪  徐磊  翁煜炜 《热带地理》2021,41(2):217-228

在阐述建设用地错配机制的基础上,构建建设用地错配测度模型和错配机制计量模型,重点探讨中国2001－2016年城市建设用地错配时空特征、驱动机制及其空间效应。结果表明：1）中国建设用地错配呈现先下降后上升的发展趋势和西高东低的空间分布格局;2）中国建设用地错配及其影响因素呈现空间集聚与关联特征,但空间关联效应有减弱态势;3）土地财政依赖、产业结构优化、市场发育完善对建设用地错配具有显著的负向影响;4）政府腐败和经济发展对建设用地错配具有显著的正向影响且存在空间溢出效应。中国建设用地错配普遍存在且有上升态势,转变经济发展方式、加大政府腐败治理力度、完善市场机制和区域一体化建设能够有效缓解区域建设用地错配。  相似文献   

The organization of multimedia information in electronic map     

Cai Zhongliang  Wu Guofeng  Weng Min  Du Qingyun 《地球空间信息科学学报》2013,16(2):56-61

On the basis of an electronic map-based hypermedia data model (EMBHDM), this paper makes a study on the technologies of nonlinear storage, organization, management and browsing of information as well as organization of data on the basis of the relationship between multimedia information of electronic maps.  相似文献   

Spatial Analysis of Urban Growth Impacts on Vegetative Greenness with Landsat TM Data     

Qihao Weng  C. P. Lo 《国际地球制图》2013,28(4):19-28

Abstract

Landsat Thematic Mapper (TM) data have been used to monitor land cover types and to estimate biophysical parameters. However, studies examining the spatial relationships between land cover change and biophysical parameters are generally lacking. With the integration of remote sensing and Geographic Information Systems (GIS), these relationships can be better explored. The research reported in this paper applies this integrated approach for detecting urban growth and assessing its impact on vegetative greenness in the Zhujiang Delta, China. Multi‐temporal Landsat TM data were utilized to map urban growth and to extract and identify changes in vegetative greenness. GIS analyses were conducted to examine the changing spatial patterns of urban growth and greenness change. Statistical analyses were then used to examine the impact of urban growth on vegetative greenness. The results revealed that there was a notably uneven urban growth pattern in the delta, and urban development had reduced the scaled Normalized Difference Vegetation Index (NDVI) value by 30% in the urbanized area.  相似文献