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Patella rustica Linnaeus, 1758 （Gastropoda, Patellogastropoda） Inhabiting Coast of Skikda （AIgerie）

Journal of Life Sciences 2014年第1期8卷 65-77页

作者： Razika Maatallah Djebar Abdallah Borhane Department of Biology University 20 August 1955 Skikda 21000 Algeria Departement of Marine Sciences Laboratory of Ecobiology Coasts and Marine Environments (EMMAL) University of Badji Mokhtar Annaba 23000 Algeria

The study was undergone on the distribution of abundance of Patella rustica Linnaeus, 1758, with the objective of evaluating of its abundance along the rocky shores of the coast and located sites with high density. A total of twelve sampling sites were selected along the gulf of Skikda. Each station was sampled using quadrats of 25 cm^2. In the present study, two environmental parameters were measured ＂in situ＂ in the water column at each sampling station （water surface temperature, pH）. Biotic communities of the rocky shores are considered to be generally controlled by physical factors such as temperature and desiccation. Therefore, three measurements were made for each abiotic parameter during this survey and mean values were used for statistical analysis. Consequently, the data of abundance （expressed in frequency） of species were calculated based on the distributed individuals along the quadrat. P. rustica is distributed mainly in the East more than in the West particularly from SI to S5. The condition index calculated at 12 stations revealed important seasonal variations, with the maximum during summer season highlighting three stations （S2, S11 and S 12）. This index is also very important in S3 and S4. The factors of pollution at these points had not affected the abundance and index condition.

关键词： Abundance index of condition environmental parameters Patella rustica.

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Optimum Designing of Gas Distribution Networks of Ilam Province by Using GIS Network and Spatial Analysis

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Open Journal of Geology 2016年第8期6卷 801-811页

作者： Hosein Anvari Bakhtiar Feizizadeh Rasool Olyani Nejad Area of Study Geographic Information Systems Tabriz Iran Faculty Member of Tabriz University Tabriz Iran

Undoubtedly, pipeline transport is considered as significant economical artery of country and national valuable resources, so it is necessary to use latest technologies, major standards and instructions and the best human resources in designing, operation and supervision in construction and also protection of it. Also, all authorities and involved of construction and operation of gas industries installation should observe safety criteria, health and environment and aware of them ever. In fact, in designing of these programs, in addition to technical and economical points, environmental characteristics should be considered in order to their construction has minimum damage to environment. On the other hand, common and traditional approaches of pipeline routing are based on using costly and time-consuming methods. In these methods, it is not easily to use all effective parameters in determining optimum way. According to capability of analysis of network spatial information systems in incorporation of spatial data, for using all effective parameters in routing, this environment is used, therefore weighted overlay analysis (Boleyn, index and fuzzy) and shortest path are modeled for finding optimum path of pipeline in GIS environment.

关键词： Designing Optimum Path Hierarchical Analysis environmental parameters Geographical Information System

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environmental Deterioration of the Tecomate Coastal Lagoon, in the Guerrero State, Mexico

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International Journal of Geosciences 2016年第1期7卷 1-10页

作者： Salvador Villerías-Salinas Juan Violante-González Neftalí García-Castro Lorena Alonzo-Guzmán Centro de Estudios y Posgrado en Estudios Socioterritoriales Universidad Autónoma de Guerrero Chilpancingo México Unidad Académica de Ecología Marina Universidad Autónoma de Guerrero Acapulco México Unidad Académica de Ingeniería Universidad Autónoma de Guerrero Chilpancingo México

An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, Mexico. Data of temperature, dissolved oxygen, salinity parameters and depth of the lagoon were interpolated using the Kriging geostatistical method to generate a prediction surface. The lagoon registered a great variation in its saline concentration, which ranged from 8.0 to 65.0 ppt, with the lowest values in November 2011 and the highest at May 2012. The great variability in the salinity throughout the year contributed in significant form to the lagoon’s instability. An average water temperature of 32?C and dissolved oxygen levels of 4.49 to 7.44 mg/L were recorded. The low depth registered in the lagoon (mean = 1 m), is related to fluvial and marine processes, both of which modify depth through the transport of sediment to its interior. Currently, fishing is scarce, with the mangrove forest in some areas in a process of deterioration due to a lack of moisture. The lagoon system is undergoing a process of environmental deterioration, with an advanced ecological succession and non-aquatic vegetable species colonizing the area surrounding the lagoon.

关键词： Tecomate Lagoon environmental parameters Habitat Deterioration Aquatic Ecosystem

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“产业兴旺”的合约基础

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农业经济研究 2023年第4期

作者：马太超

合约选择是考察经济行为的微观基础，对“产业兴旺”的分析离不开对农业合约选择过程的系统观察。构建由环境参数、交易者特性和交易维度3个层次的分析变量所组成的分析框架，能够全面考察现代农业发展过程中合约选择的经济逻辑。环境... 详细信息

合约选择是考察经济行为的微观基础，对“产业兴旺”的分析离不开对农业合约选择过程的系统观察。构建由环境参数、交易者特性和交易维度3个层次的分析变量所组成的分析框架，能够全面考察现代农业发展过程中合约选择的经济逻辑。环境参数是合约选择的逻辑起点，在既定制度安排下作为宏观背景影响农业合约选择；交易者特性指交易参与人具有的经济和社会属性，是合约选择的能动因素，与环境参数相互作用共同影响农业缔约结构；交易维度用以刻画一项具体交易所具有的特征。3个层面的因素相互作用共同决定交易属性，进而决定交易成本。有效的农业合约便是在给定环境参数、交易者特性和交易维度的情况下将交易成本最小化的合约。交易属性与合约安排的最佳匹配是乡村“产业兴旺”的关键。

关键词：合约选择环境参数交易者特性交易维度交易成本 agricultural contract selection environmental parameters trader characteristics transaction dimensions transaction cost

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