全耦合S型铺管动力定位时域分析     

孙丽萍  朱建勋  艾尚茂  刘胜楠 《海洋工程》2015,33(4):1-10

为研究S型铺管船铺管工况下的动力定位系统性能,进行了船体-托管架-管道的耦合作用下的动力定位模拟。采用广义弹性面接触法模拟托管架上托辊,莫里森杆构建托管架模型,集中质量法计算管道受力,并应用PID和Kalman滤波相结合的控制系统和序列二次规划法进行分配的推力系统,进行了全耦合S型铺管动力定位时域分析;研究了船体波频运动对于管道-托管架耦合作用力和动力定位系统的影响;比较分析了铺管工况和非铺管工况下的定位精度影响;同时应用API规范对管道应力进行校核,验证了该耦合模拟的正确性。结果表明,垂荡和艏摇对于管道-托管架-船体之间的耦合作用力对动力定位系统影响很大,在动力定位系统设计时,需要着重考虑。减小纵摇和迎浪铺管是使铺管作业和动力定位系统安全有效的重要方法。  相似文献   

Assessment of Diversity, Distribution, Conservation Status and Preparation of Management Plan for Medicinal Plants in the Catchment Area of Parbati Hydroelectric Project Stage -Ⅲ in Northwestern Himalaya     

S.S. Samlant Jitendra S. Butola Aman Sharma 《山地科学学报》2007,4(1):34-56

The developmental activities, particularly the construction of hydroelectric projects are causing a great loss of biodiversity in the Indian Himalayan Region. The Himachal Pradesh, a part of IHR is well known for the development of hydroelectric projects. The Parbati H.E. Project is amongst the major projects of the State. The different stages of the project are all causing loss of biodiversity of the area. Stage Ⅲ of the Parbati H.E. Project is a run of the river scheme on the Sainj River downstream of Power House of Parbati H.E. Project Stage Ⅱ. The project shall utilize regulated discharge of Parbati H.E. Project Stage Ⅱ and inflow of River Sainj for power generation, and has been contemplated as a peaking station operating in tandem with Stage Ⅱ. The present study has been undertaken to see the impact of hydroelectric project on the biodiversity, particularly on medicinal plants. A total of 104 species of medicinal plants, belonging to different life forms, i.e., trees (23 spp.), shrubs (22 spp.), herbs (57 spp.) and ferns (2 spp.) were recorded. The species have been analyzed and studied for their distribution, classification, altitudinal zones, part (s) used, indigenous uses, nativity, endemism and rarity.Different parts of these species, such as whole plants, roots (including rhizomes and tubers), leaves, flowers, fruits, seeds, stems, barks, spikes, nuts and insect galls are used by the inhabitants for curing various diseases and ailments. 30 species are native to the Himalayan region, 9 species native to the Himalayan region and adjacent countries also and 65 species are non-natives. 9 species are near endemics. Considering the whole Himalaya as a biogeographic unit (sensu lato), the near endemics are endemic to the Himalaya. Among these species, Zanthoxylum armatum is categorized as Endangered and Valeriana wallichii as Vulnerable. Hedychium spicatum, Rhus javanica, Berberis lycium, Thalictrum foliolossum, Salvia lanata, Rubia cordifolia and Bergenia ligulata may be considered as threatened species due to their over exploitation for trade. 90 species are propagated by seeds, 8 species by seeds and rhizomes/roots/tubers, 4 species by seeds and cuttings, and 2 species by sori. A management plan for the cultivation and conservation of the medicinal plants in the dam submergence area, and the commercially viable medicinal plants with high value in the catchment area is suggested.  相似文献   

Using a hybrid genetic algorithm–simulated annealing algorithm for fuzzy programming of reservoir operation     

Yu‐Chen Chiu  Li‐Chiu Chang  Fi‐John Chang 《水文研究》2007,21(23):3162-3172

We present a novel approach for optimizing reservoir operation through fuzzy programming and a hybrid evolution algorithm, i.e. genetic algorithm (GA) with simulated annealing (SA). In the analysis, objectives and constraints of reservoir operation are transformed by fuzzy programming for searching the optimal degree of satisfaction. In the hybrid search procedure, the GA provides a global search and the SA algorithm provides local search. This approach was investigated to search the optimizing operation scheme of Shihmen Reservoir in Taiwan. Monthly inflow data for three years reflecting different hydrological conditions and a consecutive 10‐year period were used. Comparisons were made with the existing M‐5 reservoir operation rules. The results demonstrate that: (1) fuzzy programming could effectively formulate the reservoir operation scheme into degree of satisfaction α among the users and constraints; (2) the hybrid GA‐SA performed much better than the current M‐5 operating rules. Analysis also found the hybrid GA‐SA conducts parallel analyses that increase the probability of finding an optimal solution while reducing computation time for reservoir operation. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

高精度距离等比例线法海洋划界模型研究          下载免费PDF全文

彭认灿  董箭  陈轶  郑义东  陈惠荣 《海洋测绘》2009,29(4):14-18

分析表明，目前国内外只对距离等比例线法海洋划界模型作了初步的研究，所建立的模型仍然停留在欧氏平面或地图投影平面上，无法满足海洋划界对分界线点位精度的要求。为改变这种局面，提出并建立了一种全新的基于地球椭球体缓冲区构建技术的高精度距离等比例线法——椭球面距离等比例水线法海洋划界模型。  相似文献   

高校文学院本科生人才培养方案研究与实践——以广东海洋大学文学院“6613”与“2613”教学改革为例     

姚国军  张学松 《广东海洋大学学报》2009,29(2)

新世纪以来,文学院的本科各专业需要传承和发展。无论是中文系,还是新闻系的专业,都应该培养具有"作家型的流畅文笔"和"学者般的丰富知识"的高质量专门人才。自2005年起,中文系实施"6613"教学改革计划;新闻系实施"2613"教学改革计划。实施四年来,文学院的学生多出成果,出好成果,充分证明"6613"与"2613"教学改革确实起到了"功在当下,利在将来"的作用。  相似文献   

供水井桥式滤水管应用技术初探     

杨建新 《河南国土资源》1999,(4)

供水井桥式滤水管推广应用是近几年的新技术，不少使用者对桥式滤水管的性能指标不十分了解，在选择和下管的过程中出现了不少偏差，导致了桥式滤水管或管井的报废，造成了严重的经济损失。该文从桥式滤水管的性能指标入手，进行了受力分析，提出了桥式滤水管的正确选择和使用方法。  相似文献   

济南市跨河发展与黄河防洪     

杜玉海  薛儒生 《山东国土资源》2005,(Z1)

特殊的地理位置使济南市跨越黄河向北发展提到了议事日程,城市建设与黄河防洪的关系将更加密切。济南河段历来是黄河防洪的重点,目前该段黄河堤防正在进行标准化建设,防御标准相当于30到近千年一遇,可以满足城市防洪的要求。济南市跨河发展,黄河将成为城中河,城市建设与防洪建设将互相促进。由于黄河问题的复杂性,泥沙淤积和地上悬河将长期存在,建议城市规划要考虑给黄河未来的防洪留出足够空间,对跨河交通等过河建筑物应统一进行规划,城市建设要充分利用黄河泥沙资源,同时搞好沿黄生态和风景线建设,以实现人与自然和谐共处。  相似文献   

Optimization of operation rule curves and flushing schedule in a reservoir     

Fi‐John Chang  Jihn‐Sung Lai  Li‐Shan Kao 《水文研究》2003,17(8):1623-1640

Flushing sediment through a reservoir has been practiced successfully and found to be inexpensive in many cases. However, the great amount of water consumed in the flushing operation might affect the water supply. To satisfy the water demand and water consumed in the flushing operation, two models combining the reservoir simulation model and the sediment flushing model are established. In the reservoir simulation model, the genetic algorithm (GA) is used to optimize and determine the flushing operation rule curves. The sediment‐flushing model is developed to estimate the amount of the flushed sediment volume, and the simulated results update the elevation‐storage curve, which can be taken into account in the reservoir simulation model. The models are successfully applied to the Tapu reservoir, which has faced serious sedimentation problems. Based on 36 years historical sequential data, the results show that (i) the simulated flushing operation rule curves model has superior performance, in terms of lower shortage index (SI) and higher flushing efficiency (FE), than that by the original reservoir operation; (ii) the rational and riskless flushing schedule for the Tapu reservoir is suggested to be set within an interval of every 2 or 4 years in the months of May or June. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

山东数字地震台网地震自动定位系统运行分析   总被引：1，自引：0，他引：1  

石玉燕  蔡寅  李铂  颜启  吴丹桐 《地震地磁观测与研究》2009,30(4):78-82

山东数字地震台网自主研制了一套地震自动定位软件系统,2008年5月在山东地震台网中心试运行,运行稳定。本文对该系统运行期间自动定位结果进行了统计与分析,结果表明,山东数字地震台网自动定位系统对于网内天然地震定位结果可靠,震中平均偏差4．09km,震级偏差±0．08,平均速报用时63s。  相似文献   

印度应对气候变化国家方案简析   总被引：2，自引：0，他引：2       下载免费PDF全文

孙振清  刘滨  何建坤 《气候变化研究进展》2009,5(5):298-303

2008年6月印度政府发布了《气候变化国家行动方案》,阐明了印度应对气候变化的原则立场以及减缓和适应措施。方案中明确指出发展中国家是气候变化的最大受害者,发达国家应该承担温室气体减排的责任和义务;由于近年印度排放不断上升,方案也着重提出了提高能效、大力发展可再生能源等措施。与我国发布的《中国应对气候变化国家方案》进行对比,印度国家行动方案中的一些观点和措施值得我国研究和借鉴,该方案为我国进一步提出应对策略、加强国际合作提供了参考。  相似文献