Influence of stratification and irradiance regime on summer phytoplankton composition in coastal and shelf seas of the British Isles

The effect of interaction between stratification and irradiance regimes on phytoplankton community structure was investigated in three shelf/coastal regions of the British Isles, each of which displayed ranges of vertical stability and light attenuation. Relationships between vertical stability, light penetration and community structure were indicated by the ordination of dominance (assessed using cell volume) of the main phytoplankton phyletic groups—diatoms, dinoflagellates and microflagellates—on a surface defined by a bulk stratification index () and water column depth, scaled by transparency (λh). Diatom- and dinoflagellate-dominated communities occupied distinctly different domains on the - λh surface, diatoms being favoured in well-mixed water columns with high values for λh and dinoflagellates dominating where stratification was strong and λh was low. Microflagellates were not abundant in any of the study areas and showed no clear ordination on the - λh surface. The domain of co-dominance of diatom and dinoflagellates on the - λh surface was narrow with small changes in the irradiance or stratification regime resulting in a switch to diatom or dinoflagellate dominance. It is suggested that loss of non-motile diatom communities in strongly stratified water columns might be a strong selective force in favour of dinoflagel-lates. However, in water columns with intermediate stratification and optical properties, the outcome of competition may be decided by physiological attributes of the two groups with respect to growth in low and fluctuating irradiances.     

中国红树林生态系统的植物种类、多样性、功能及其保护

本文从4个方面对中国红树林生态系统的植物进行论述：（1）中国红树林生态系统的红树植物、半红树植物、伴生植物、红树林区的大型藻类和浮游植物种类；（2）中国红树林生态系统植物的物种多样性、红树植物生理和形态适应的多样性、产物的多样性；（3）红树林的生态功能；（4）中国红树林生态系统的主要保护问题及其保护措施。     

Ecology of beach wrack in northern New England with special reference to Orchestia platensis

The northern New England beach wrack community with special reference to the cosmopolitan amphipod crustacean, Orchestia platensis, was examined at estuarine and open coastal habitats. Beach wrack was dominated by the plant genera Ascophyllum, Zostera, Spartina and Chondrus, and was most abundant during spring and late summer. Animal community numbers, biomass and frequency in fresh to moderately decomposed wrack were dominated by O. platensis throughout the year at all habitats; oligochaetes and Collembola were also important. The abundance of O. platensis showed high spatial and temporal variability, with low abundance generally associated with decreased amounts of wrack during colder months. An exception was the winter presence of the species at one estuarine habitat, in patchy aggregations within gravel-cobble refuges. The abundance of O. platensis averaged 1280 (0.04 m²)⁻¹, with a maximum of 7040 (0.04 m²)⁻¹. The life cycle of O. platensis is bivoltine, with summer-hatched young reaching maturity within 1 month. Laboratory studies indicate females with up to 4 broods (30 days)⁻¹, averaging 18 eggs brood⁻¹.Orchestia platensis is omnivorous, eating fresh plant tissue, live oligochaetes, Limulus eggs and diatom ‘fuzz’. The rate of laboratory consumption of algae and Zostera was 0.05 mg plant mg⁻¹ wet body weight day⁻¹. Presumptive predators of O. platensis are juvenile green crab, Carcinus maenus, and the earwig. Anisolabis maritima. The mobility, aggregation and aggressiveness of O. platensis assist the species in establishing and maintaining populations in the rigorous wrack habitat. The general competitive superiority of O. platensis over its congener, O. gammarella, and the co-occurrence of these species on both eastern and western Atlantic shores is discussed.     

A study on benthic community structure in west of the Taiwan Strait and near the Taiwan Shoals

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基于ArcIMS的城市小区信息发布系统的设计与实现

利用ESRI公司新一代Web GIS产品Arc IMS9.0,结合ASP及IIS6.0、SQL Serve、ArcSDE等网络、空间数据库方面技术,建立了城市小区信息发布系统。总结了ArcIMS的特点和体系结构,提出了基于ArcIMS的城市小区信息发布系统的设计思路和方案,阐述了系统的具体实现方法。     

基于工作流技术的社区管理系统的设计

分析了基于工作流技术管理系统软件的优势,阐述了数字社区的应用软件和工作流引擎整合的通用途径,并设计了一个基于工作流的应用系统。实验表明,结合知识库、规则库的应用软件可以极大地提升数字社区管理软件的应用水平。     

抚顺煤层气赋存特征及资源评价研究

抚顺矿区城市下压煤面积6km^2,煤炭储量23901．5万t。通过对矿区地质特征、煤储层特征分析．认为区内煤层气含量高（9．81～24．53m^3／t）,煤层中大空隙多,透气性好,渗透率较高（0．24～3．60mD）。煤层直接顶板为厚100m左右的致密油页岩,底板为泥岩、凝灰岩,具有良好的封闭条件。根据矿区多年测试资料,采用容积法得出区内煤层气资源量为30．53亿m^3。综合开发煤层气资源符合东北老矿区的实际,其将为复苏东北重工业基地提供有效的洁净能源。     

自重湿陷性黄土地区桩基设计探讨

根据自重湿陷性黄土的特点、《湿陷性黄土地区建筑规范》（GB50025—2004）和《建筑桩基技术规范》（JGJ94—94）中关于桩基设计的对比分析，通过自重湿陷性黄土场地工程实例分析计算，依据负摩擦产生的机理——中性点理论，论述了自重湿陷性黄土场地中桩基设计应考虑中性点，而不应全部计入负摩阻的观点。