淮河流域春季浮游植物群落结构特征及其水质评价

浮游植物是内陆水体生态系统的主要初级生产者,其群落结构能反映水体的水质状况.为了全面了解淮河流域内浮游植物群落结构及水质现状,于2013年5月在流域内设置217个样点采集浮游植物样品.共鉴定浮游植物244种(含变种和变型),隶属于8门104属,绿藻门和硅藻门的种类最丰富.浮游植物生物量为3.93 mg/L,在0.04~83.62 mg/L之间变动,生物量组成主要为甲藻门、硅藻门和隐藻门.浮游植物种类数和生物量在河流的中游较高,溪流以及下游入江入海河道较低.浮游植物优势种主要为隐藻门的啮蚀隐藻(Cryptomonas erosa)、尖尾蓝隐藻(Chroomonas acuta),硅藻门的梅尼小环藻(Cyclotella meneghiniana),甲藻门的角甲藻(Ceratium hirundinella),其相对生物量均大于5%.淮河流域浮游植物多样性指数较低,流域内多数样点处于中-重污染状态.     

基于多源数据分析维多利亚湖流域水储量变化

本文利用CSR发布的GRACE RL06时变重力场模型,结合两种水文模式、卫星测高、降雨和蒸散等多源数据,从多个角度综合系统地分析维多利亚湖流域2003-01—2017-06的陆地水储量变化.比较了正向建模方法和单一尺度因子对泄漏误差的改正效果,经对比采用正向建模方法在此流域效果更好.基于多源数据得出以下三点与此前研究不同的结论:(1)GRACE RL06版本数据探测到流域内的水储量在2003-01—2017-06呈增加趋势,球谐位系数和Mascon产品得到的变化速率分别为14.9 mm·a^-1和16.7 mm·a^-1,观测误差小于RL05版本的结果,RL05版本低估了流域水储量的变化速率;(2)2013-01—2016-02期间GRACE和测高探测到湖泊水量增长,而水文模式探测到流域内水储量减少,推测这一现象由大坝蓄水造成;(3)受El Ni1o事件影响,2016-03—2017-06流域降雨减少,流域水储量减少,GRACE球谐位系数和Mascon探测到的变化速率分别为-100.3 mm·a^-1和-129.7 mm·a...     

浙江象山港岛屿春、夏季潮间带大型底栖生物的群落结构特征

基于2015年4月(春季)和6月(夏季)象山港主要岛屿潮间带大型底栖生物的生态调查数据,采用优势度、生物多样性指数、次级生产力、聚类、多维尺度排序及丰度/生物量比较曲线等方法,分析了主要岛屿潮间带大型底栖生物的群落特征和季节变化。结果表明:(1)春、夏季共鉴定出大型底栖生物52种,其中底栖动物与底栖藻类各有45和7种,春、夏季共有物种数为34种,短滨螺、中间拟滨螺、齿纹蜒螺、青蚶等11种为春、夏季共有优势种;(2)夏季平均丰度(2074.85g/m²)高于春季(1505.01g/m²),春季平均生物量和次级生产力(2373.75ind./m²,16.31g/(m²·a))高于夏季(2210.17ind./m²,12.17g/(m²·a));(3)春季Shannon-Weiner多样性指数和Pielou’sevenness均匀度指数(2.742,1.679)高于夏季(2.580, 1.623),夏季Margalef丰富度指数(0.716)高于春季(0.667...     

嘉庚蛸(Octopus tankaheei)基础生物学特征的研究

从2003年1月到2003年12月对浙江省象山港内嘉庚蛸的生物学指标进行了测量,共获取样品408头,分析了其基础生物学的周年变化规律和主要体型特征.结果表明,嘉庚蛸长度分布频率具有明显的季节变化,6,7月份长度分布较其他月份广,6月份分布比较均匀具两个峰值(240和360 mm,所占比例分别为13.3%和16.7%);冬季生长缓慢,3,4月份为快速生长期,体长、体重等指标增长明显,4月底即进入了繁殖季节,在6,7月份可采捕到当年孵化的幼体.嘉庚蛸体长与体重以幂函数拟合最佳,而各体征指标与全长、体重和体积的相关关系也较为显著,但相关方程在雌雄间存在着差异.雌体在体型上明显比雄体粗壮,全长/胴长、全长/胴宽以及全长/体积经统计检验发现雌雄间存在着显著差异,主要表现为若全长相等的情况下,雌体的胴长、胴宽和体积明显大干雄体,自然种群的雌体比雄体更强壮、更丰满.     

超新星SN 1987A的热光度演化──内部中子星的贡献

本文介绍了超新星SN1987A爆发六年多来其热光度演化的研究情况．爆发后的前800天，观测的热光度曲线与由超新星爆发时合成的放射性元素的放射衰变加热模型符合得很好．但900天以后，观测的热光度曲线比考虑了所有放射性元素贡献后的理论曲线下降得还要缓慢．这可能表明有新的能源在起作用．我们认为这个新的能源可能是超新星爆发时产生的中子星的吸积．通过吸积超新星爆发时抛射气壳中小于逃逸速度的部分物质而增大SN1987A的热光度．这一模型能很好地解释900天以后的光度曲线的下降变级以及900至1200天之间光度曲线的凸起，这也为内部中子星的存在提供了间接的证据．     

基于相对状态符号信息的分布式优化算法

针对网络化多智能体的分布式优化问题,本文讨论一种只利用邻居相对状态的符号信息的分布式算法.该算法不要求与图相关的权重矩阵是双随机矩阵.首先利用优化理论中的惩罚函数法解释该算法,然后分析算法在静态图上的收敛性以及收敛速度.与现有使用邻居相对状态的完整信息的分布式梯度下降算法相比,所提算法的收敛速度并没有本质上降低.另一方面,将所提算法扩展到确定性和随机性的时变图上,并给出相应的收敛性结论.最后,通过数值仿真实验验证算法的有效性.     

COMPARISON OF PERSIANN AND TMPA DAILY PRECIPITATION ESTIMATES OVER HUNAN PROVINCE OF CHINA

This study presented a detailed comparison of daily precipitation estimates from Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN) and Tropical Rainfall Measuring Mission (TRMM) Multi -satellite Precipitation Analysis (TMPA) over Hunan province of China from 1998 to 2014. The ground gauge observations are taken as the reference. It is found that overall TMPA clearly outperforms PERSIANN, indicating by better statistical metrics (including correlation coefficient, root mean square error and relative bias). For the geospatial pattern, although both products are able to capture the major precipitation features (e.g., precipitation geospatial homogeneity) in Hunan, yet PERSIANN largely underestimates the precipitation intensity throughout all seasons. In contrast, there is no clear bias tendency from TMPA estimates. Precipitation intensity analysis showed that both the occurrence and amount histograms from TMPA are closer to the gauge observations from spring to autumn. However, in the winter season PERSIANN is closer to gauge observation, which is likely due to the ground contamination from the passive microwave sensors used by TMPA.     

Relationship of Stakeholders in Protected Areas and Tourism Ecological Compensation: A Case Study of Sanya Coral Reef National Nature Reserve in China

The first step to defining the rights, responsibilities and interests of stakeholders and constructing a compensation mechanism is to identify the stakeholders and clarify their mutual relationships. Nature reserves are complex ecosystems involving nature, the economy and society. There exists a conflict between the public welfare benefits of ecological conservation and the private gains to be realized from social and economic development. There also exist in a nature reserve complex relationships among stakeholders, involving the utilization of ecological resources, ecological conservation and ecological-economic interests. The introduction of tourism brings substantial changes to the existing stakeholder benefit structure in a nature reserve. The implementation of tourism ecological compensation (tourism payment for ecological service) is a process for redefining the distribution of rights, responsibilities and profits among stakeholders and it is also an essential way to balance the interests of the stakeholders. This paper uses a case study of Sanya Coral Reef National Nature Reserve in China to examine the characteristics of stakeholders and analyze their interests. According to the method for defining basic attributes proposed by Mitchel and other scholars, in cases of tourism ecological compensation, stakeholders can be classified as definitive stakeholders, expectant stakeholders and latent stakeholders. This paper applies these classifications and then analyzes the relationships between the rights and responsibilities of these stakeholders and how these change after the implementation of compensation. Additionally, based on the impact compensation has on different stakeholders, changes in the relationships can be analyzed and the structure of the stakeholders can be modelled. This case study of the Sanya Coral Reef National Nature Reserve illustrates the operationalization of a new mechanism for tourism ecological compensation. The paper illustrates a method for coordinating the relationships among the stakeholders involved with this national-level nature reserve.     

Comparison between control factors of high quality continental reservoirs in Bohai Bay basin and Ordos basin

Bohai Bay basin, a typical extensional rift basin, and Ordos basin, an intra-craton down-warped basin, represent two important basin types in China. Because of their respective features, the main control factors for their high quality reservoirs are different. In Bohai Bay basin, the sandbody shows great variety in types and severely separated distribution and its high quality reservoirs are mostly controlled by the vertical secondary pore and vertical abnormal pressure. On the other hand, the sandbody in Ordos basin features a relative lack of variety, good continuity, indistinct vertical zone, and its reservoirs are mainly controlled by the diagenetic differentiation caused by different sedimentation inside the sandbody. Therefore, in the Bohai Bay basin, the exploration should be based on the analysis of sedimentary facies and the favorable diagenetic zones and formations. The focus in Ordos basin, however, should be put on the relatively high permeability sandstones in a generally low permeable sandstone background. __________ Translated from Geoscience, 2007, 21(2): 376–386 [译自: 现代地质]     

面向“两规合一”的规划现状底图设计与实现——以北京市石景山建成区为例

土地利用总体规划与城市总体规划存在差异与矛盾,本文通过制作规划现状底图,将二者统一在一起。结合北京市"两规合一"背景,设计了行之有效的规划现状底图的制作方案,利于规划国土部门掌握用地现状,可为后续规划分析提供良好的基础资料。