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The Selection of Dry Port Location by Analytic Network Process Model: A Case Study of Dosso-Niger
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作者 Hamadou Tahirou Abdoulkarim Seydou Harouna Fatouma Bomboma Kalgora 《Journal of Transportation Technologies》 2019年第2期146-155,共10页
The aim of this paper is to select the best location for the construction of a dry port in Niger which is a land locked country (LLC). Niger is located in the Sahel and has a land area of 1,267,000 square kilometers [... The aim of this paper is to select the best location for the construction of a dry port in Niger which is a land locked country (LLC). Niger is located in the Sahel and has a land area of 1,267,000 square kilometers [1], with the closest port being port of Cotonou in Benin. The transport corridor from Niamey to Cotonou is approximately 1036 km long [2]. It is estimated that this corridor carries about 40 percent of Niger’s overseas trade traffic [3]. In this work, the Analytic Network Process (ANP) model is used to determine the optimal location of the dry port, among three major cities: Niamey (capital city), Dosso and Gaya. From the application of this selection model, Dosso was selected as the best location for the location of the dry port, while Gaya and Niamey were placed second and third respectively. The results obtained in this work strongly confirm the decision of the government of Niger to construct a dry port in Dosso, a project that commenced in 2010 and is still in progress. 展开更多
关键词 DRY port Localization ANALYTIC network Process (ANP) Model
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The Hub Status and Transportation Network of Kribi Port
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作者 Che Kingsleychenikwi Xuefeng Wang 《Open Journal of Applied Sciences》 2018年第6期226-270,共45页
In this paper, a study on four African ports was taken out that all have the ca-pability to become a hub port that can serve the central African region. The paper sort to determine which port was most suitable and por... In this paper, a study on four African ports was taken out that all have the ca-pability to become a hub port that can serve the central African region. The paper sort to determine which port was most suitable and port indexing was the method that was used to evaluate these ports. The ports evaluated were the port of Kribi, the port of Bata, the port of Libreville and the port of Pointe-Noire. There were other models that were also used which included linear regression and linear programming which all contributed to providing the final results of the port with the most suitable potential to serve as a hub port and meaningful results were obtained. The final results showed that the port of Pointe-Noire was the most suitable port to serve the central African region as a hub port. 展开更多
关键词 HUB port Kribi port Intermodal network SHIPPING network LOGISTICS Transhipment Transportation INDEXING
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REALIZATION OF ARBITRARY TRANSFER MATRIX WITH ACTIVE MULTI-PORT NETWORK
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作者 戴国胜 戴旦前 《Journal of Electronics(China)》 1991年第1期92-96,共5页
A new simple method in which arbitrary transfer function matrix is realized withactive multiple port network instead of computer simulating is proposed. The active multipleport network is carried on through state feed... A new simple method in which arbitrary transfer function matrix is realized withactive multiple port network instead of computer simulating is proposed. The active multipleport network is carried on through state feedback and state cross output for RC ladder network.The main process is to determine coefficients of each adder. Finally, an example is given forillustration. 展开更多
关键词 ACTIVE MULTI-port network STATE feedback STATE cross output
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ANALYSIS OF MICROWAVE N-PORT NETWORK BY A MODIFIED BOUNDARY ELEMENT METHOD
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作者 洪伟 《Journal of Southeast University(English Edition)》 EI CAS 1991年第1期8-15,共8页
A new approach based on resonance technique and modified boundary ele-ment method is presented to calculate the impedance parameter matrix of a microwaveN-port network of waveguide structure.A two port network is take... A new approach based on resonance technique and modified boundary ele-ment method is presented to calculate the impedance parameter matrix of a microwaveN-port network of waveguide structure.A two port network is taken as a numerical ex-ample and the results show that the approach occupys the advantages of high accuracyand less computation effort. 展开更多
关键词 WAVEGUIDE component MICROWAVE technique/boundary element method MULTI-port network WAVEGUIDE DISCONTINUITY
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BP-neural networks预测法在湛江港港口吞吐量预测中的应用
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作者 李萌 陈绍永 《广东造船》 2010年第4期64-66,共3页
本文对港口吞吐量预测的方法进行了研究,分析了传统预测方法在实际应用中存在的问题,利用黑箱模型理论对湛江港近年吞吐量与建设投资额进行定性研究和定量检验,证明了港口吞吐量与建设投资额之间存在显著的正相关关系,并基于此提出基于B... 本文对港口吞吐量预测的方法进行了研究,分析了传统预测方法在实际应用中存在的问题,利用黑箱模型理论对湛江港近年吞吐量与建设投资额进行定性研究和定量检验,证明了港口吞吐量与建设投资额之间存在显著的正相关关系,并基于此提出基于BP-neural networks的预测方法,为湛江港港口吞吐量的预测提供了一种新的方法与途径。 展开更多
关键词 港口发展 港口吞吐量 预测技术 BP神经网络
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A NEW METHOD FOR FINDING THE NATURAL FREQUENCY SET OF A LINEAR TIME-INVARIANT NETWORK
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作者 吴雪 孙雨耕 《Transactions of Tianjin University》 EI CAS 1997年第2期28-35,共8页
This paper presents a new method for finding the natural frequency set of a linear time invariant network. In the paper deriving and proving of a common equation are described. It is for the first time that in the co... This paper presents a new method for finding the natural frequency set of a linear time invariant network. In the paper deriving and proving of a common equation are described. It is for the first time that in the common equation the natural frequencies of an n th order network are correlated with the n port parameters. The equation is simple and dual in form and clear in its physical meaning. The procedure of finding the solution is simplified and standardized, and it will not cause the loss of roots. The common equation would find wide use and be systematized. 展开更多
关键词 n th order linear time invariant networks natural frequencies n ports
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基于Hybrid Port的VLAN实现 被引量:1
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作者 周蓉蓉 陈刚 《现代电子技术》 2005年第16期102-104,共3页
VLAN具有控制网络广播风暴、保障网络安全和简化网络管理等特点,因此在局域网中得到广泛的应用。在某些场合下必须允许特定VLAN之间相互访问,通常实现方式是划分IP子网并通过IP进行路由。但是在某些特定的场合中,由于IP紧缺以及保障IP... VLAN具有控制网络广播风暴、保障网络安全和简化网络管理等特点,因此在局域网中得到广泛的应用。在某些场合下必须允许特定VLAN之间相互访问,通常实现方式是划分IP子网并通过IP进行路由。但是在某些特定的场合中,由于IP紧缺以及保障IP真实等原因,不能采取这样的方案。为此本文提出了一种基于混杂端口(hybridport)的虚拟局域网(VLAN)实现方案。通过这种方式设计,在提高网络安全性的同时,避免了IP地址紧缺的问题。最后给出了基于混杂端口VLAN设计方案。 展开更多
关键词 混杂端口(hybrid port) 虚拟局域网(VLAN) 广播风暴 网络安全
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Possible Sustainability of Intermodal Transportation in Africa 被引量:1
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作者 Che Kingsley Chenikwi Xuefeng Wang 《Open Journal of Applied Sciences》 2019年第4期139-158,共20页
The lack of adequate and modern transport infrastructures makes the cost of transport in Africa higher than the rest of the world. Most of the transport infrastructures that exist were constructed during the colonial ... The lack of adequate and modern transport infrastructures makes the cost of transport in Africa higher than the rest of the world. Most of the transport infrastructures that exist were constructed during the colonial era which makes inter-regional connectivity difficult. The African Union in collaboration with other organization has committed to bridge the transport gap in Africa but still, face some challenges. This paper discusses the main issues that contribute for the weak nature of transportation in Sub-Saharan Africa with regards to the main transport modes and seeks to establish the possibility of sustainable intermodal transport through the integration of the different transport modes. Some policy reforms and other bilateral agreements such as deregulating the transport markets in West and Central Africa have been suggested to facilitate the development of an effective and efficient transport network in the Sub-Saharan African region. 展开更多
关键词 Intermodal Transport Intermodal Integration network INFRASTRUCTURES CORRIDORS GATEWAY port
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An Adaptive Algorithm to Detect Port Scans
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作者 单蓉胜 李小勇 李建华 《Journal of Shanghai University(English Edition)》 CAS 2004年第3期328-332,共5页
Detection of port scan is an important component in a network intrusion detection and prevention system. Traditional statistical methods can be easily evaded by stealthy scans and are prone to DoS attacks. This paper ... Detection of port scan is an important component in a network intrusion detection and prevention system. Traditional statistical methods can be easily evaded by stealthy scans and are prone to DoS attacks. This paper presents a new mechanism termed PSD(port scan detection), which is based on TCP packet anomaly evaluation. By learning the port distribution and flags of TCP packets arriving at the protected hosts, PSD can compute the anomaly score of each packet and effectively detect port scans including slow scans and stealthy scans. Experiments show that PSD has high detection accuracy and low detection latency. 展开更多
关键词 port scan anomaly detection TCP/IP network security.
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利用Nport Express实现单片机上网
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作者 庞林斌 范新南 蒋霞东 《河海大学常州分校学报》 2003年第1期11-15,共5页
就如何利用 MOXA公司的 Nport
关键词 单片机 串行口 Nport EXPRESS IP地址 网络控件 以太网 数据传输 网卡
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Analytical Criteria for Local Activity of CNN with Two Ports and Application to Smoothed Chua's Circuit 被引量:1
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作者 Na Yu, Lequan Min Applied Science School, University of Science and Technology Beijing, Beijing 100083, China E-mail: lqmin@sohu.com 《Journal of University of Science and Technology Beijing》 CSCD 2002年第1期65-73,共9页
Presents analytic criteria for the local activity theory in two-port cellularneural network (CNN) cells with four local state variables, and gives the application to a smoothedChua's circuit (SCC) CNN with two-por... Presents analytic criteria for the local activity theory in two-port cellularneural network (CNN) cells with four local state variables, and gives the application to a smoothedChua's circuit (SCC) CNN with two-port and I 5 S 15 arrays. The bifurcation diagrams of the SCC CNNshow that they are completely the same as those of an SCC CNN with one-port calculated earlier;which do not exist locally passive domain. The evolution of the patterns of the state variables ofthe SCC CNN is stimulated. Oscillatory patterns, chaotic patterns, or divergent patterns may emergeif the selected cell parameters are located in the locally active unstable domains but nearby theedge of chaos domain. 展开更多
关键词 cellular neural network local activity smoothed Chua's circuit two-port CHAOS
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An Evaluation of West and Central African Ports to Serve as a Hub on the Gulf of Guinea Container Ports Range
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作者 Balla Nguele Veronique Youfang Huang 《Open Journal of Applied Sciences》 2019年第4期285-305,共21页
The level of competitions among ports keep increasing as port worldwide keep upgrading and expanding their port infrastructures so as to capture the greater share of the market. Every continent phases these competitio... The level of competitions among ports keep increasing as port worldwide keep upgrading and expanding their port infrastructures so as to capture the greater share of the market. Every continent phases these competitions. This phenomenon is more prominent in developed countries where ports do not only compete among regional ports but also compete with other ports within the same country such as in America, some European countries and part of Asia like in China. However, the situation is a bit different when it comes to African ports. Most African ports have poor infrastructures and limited technological investments and so port competitions in the African continent cannot be compared with that of the western ports. Despite these setbacks, there is a significant amount of competition among these African ports, especially on a regional basis. The aim of this paper is to determine which port can serve as a hub port between the West and Central African ports along the Gulf of Guinea. The method that will be used to evaluate these ports will be a port indexing method. This method considers different indices for port evaluation to determine the most suitable port. The port of Tema appeared as the most suitable port to serve as a hub port. 展开更多
关键词 port Index HUB port COMPETITION Transhipment WCA network Optimization
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Mozambique Ports in the 16th Century: Trade Routes, Changes, and Knowledge in the Indian Ocean Under Portuguese Rule
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作者 Ana C. Roque 《History Research》 2013年第3期188-204,共17页
Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation wit... Arriving to the east African coast in the 16th century, Portuguese faced an important and well-structured commercial network dominated by Muslim merchants. Operating throughout the Indian Ocean and in articulation with the inland African trade routes by way of the coastal settlements from Bazaruto up to the north of Mozambique, this network bustled luxury goods and basic goods benefiting either from a network of inter-personal relationships and kinship that supported the whole business, or from an ancestral knowledge on the techniques and particular procedures indispensable to navigating in the Indian Ocean. This trade made the prosperity of small southern ports, like Sofala or Mozambique long before the Portuguese arrival. However, this trade was so much dependent on the network's capacity of organisation and the supply demand relation of the goods involved, as well as on other factors such as the political stability of the African kingdoms, the environmental changes that shaped flows and trade routes or the actual knowledge of the region and of the different forms of organization of local communities. By focusing in the ports of Sofala and Mozambique and the information provided by the Portuguese documents we intend to analyse its evolution during the 16th century in order to understand its role in the Indian Ocean commercial network under Portuguese rule. 展开更多
关键词 portuguese expansion Mozambique ports African trade routes Indian Ocean trade network
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Application of Random Search Methods in the Determination of Learning Rate for Training Container Dwell Time Data Using Artificial Neural Networks
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作者 Justice Awosonviri Akodia Clement K. Dzidonu +1 位作者 David King Boison Philip Kisembe 《Intelligent Control and Automation》 2024年第4期109-124,共16页
Purpose: This study aimed to enhance the prediction of container dwell time, a crucial factor for optimizing port operations, resource allocation, and supply chain efficiency. Determining an optimal learning rate for ... Purpose: This study aimed to enhance the prediction of container dwell time, a crucial factor for optimizing port operations, resource allocation, and supply chain efficiency. Determining an optimal learning rate for training Artificial Neural Networks (ANNs) has remained a challenging task due to the diverse sizes, complexity, and types of data involved. Design/Method/Approach: This research used a RandomizedSearchCV algorithm, a random search approach, to bridge this knowledge gap. The algorithm was applied to container dwell time data from the TOS system of the Port of Tema, which included 307,594 container records from 2014 to 2022. Findings: The RandomizedSearchCV method outperformed standard training methods both in terms of reducing training time and improving prediction accuracy, highlighting the significant role of the constant learning rate as a hyperparameter. Research Limitations and Implications: Although the study provides promising outcomes, the results are limited to the data extracted from the Port of Tema and may differ in other contexts. Further research is needed to generalize these findings across various port systems. Originality/Value: This research underscores the potential of RandomizedSearchCV as a valuable tool for optimizing ANN training in container dwell time prediction. It also accentuates the significance of automated learning rate selection, offering novel insights into the optimization of container dwell time prediction, with implications for improving port efficiency and supply chain operations. 展开更多
关键词 Container Dwell Time Prediction Artificial Neural networks (ANNs) Learning Rate Optimization RandomizedSearchCV Algorithm and port Operations Efficiency
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韧性视角下的集装箱航运网络脆弱性评估及恢复策略
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作者 张笛 陶嘉乐 万程鹏 《交通信息与安全》 CSCD 北大核心 2024年第3期114-121,共8页
现有航运网络脆弱性评估方法和恢复策略存在一定局限性,主要表现为:评估方法单一,难以全面反映航运网络的复杂性;未综合考虑实际运营能力和空间距离等关键因素,导致恢复策略应对突发事件的效果不佳。针对上述问题,从拓扑结构和实际运营... 现有航运网络脆弱性评估方法和恢复策略存在一定局限性,主要表现为:评估方法单一,难以全面反映航运网络的复杂性;未综合考虑实际运营能力和空间距离等关键因素,导致恢复策略应对突发事件的效果不佳。针对上述问题,从拓扑结构和实际运营这2个方面对航运网络脆弱性进行了综合评价,提出了基于变异系数法多维度航运网络脆弱性评价指标,并设计了1种基于备份港口排序的恢复策略,其中,备份港口排序综合考虑了空间距离、港口运输能力和泊位数量等因素。通过引入了动态评价框架、调整脆弱性指标权重、优化备份港口选择和流量分配策略等,提升了评估与恢复策略的准确性和有效性。以2020年中欧、中地、中美东、中美西集装箱航运网络为例,构建了集装箱航运网络拓扑图,并分析了航线的脆弱性和运力波动,结果表明:采用单港口备份恢复策略时,航运网络韧性提升11.6%;采用双港口备份恢复策略时,航运网络韧性提升31.5%。综上,本文提出了集装箱航运网络脆弱性评估方法和基于备份港口排序的恢复策略,合理确定备份港口数量,实现对失效港口流量的有效重分配,为提高航运网络韧性提供了新的途径,也凸显了脆弱性评估和备份恢复策略在航运网络中的重要性。 展开更多
关键词 航运网络脆弱性 港口备份 网络韧性 恢复策略
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面向6G全域融合的智能接入关键技术综述
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作者 王雪 孟姝宇 钱志鸿 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第5期1613-1631,共19页
针对空天地一体化接入网络,该文在总结相关研究的基础上,阐述了未来空天地一体化接入架构的关键技术,分析了空口技术、多址技术、干扰分析、计算技术和人工智能(AI)技术等几个重点方向的研究进展,提出了多种接入形式并存的灵活性网络架... 针对空天地一体化接入网络,该文在总结相关研究的基础上,阐述了未来空天地一体化接入架构的关键技术,分析了空口技术、多址技术、干扰分析、计算技术和人工智能(AI)技术等几个重点方向的研究进展,提出了多种接入形式并存的灵活性网络架构。针对6G全域融合网络接入的重点研究问题,结合用户的服务质量需求,构建了一体化AI赋能架构,提出了大规模混合多址接入及弹性资源适配策略。基于网络架构立体化、网络协同传输、一体化网络资源管理、未来空天地接入技术以及网络协同计算等未来重点研究方向进行了讨论和展望。 展开更多
关键词 6G 网络架构 接入技术 空天地一体化接入网络 空口技术
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集装箱货运网络优化问题的研究——以宁波舟山港集装箱运输为例
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作者 杨德志 邵杰 《辽东学院学报(自然科学版)》 CAS 2024年第1期70-76,共7页
为优化集装箱货运网络,对进出口货运集装箱装卸中转站的最佳地理位置的选择和集装箱运输计划的设计进行了研究。2个问题同时考虑建设成本、运输成本以及存储、运力等因素,建立了一种集装箱货运网络优化模型。利用国际集装箱货运代理公... 为优化集装箱货运网络,对进出口货运集装箱装卸中转站的最佳地理位置的选择和集装箱运输计划的设计进行了研究。2个问题同时考虑建设成本、运输成本以及存储、运力等因素,建立了一种集装箱货运网络优化模型。利用国际集装箱货运代理公司在宁波舟山港一整年的船期数据,使用LINGO软件对所建模型的效果进行求解。最终从宁波舟山港腹地现有38个存储中转仓中优选出32个中转仓存储集装箱,使大约5%的集装箱通过铁路运输,从而能节省5.74%的运营成本。 展开更多
关键词 宁波舟山港 网络设计 集装箱运输 优化模型
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柔性直流输电系统三端口混合参数建模及其稳定性分析
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作者 刘欣 袁易 +2 位作者 王利桐 贾焦心 孙海峰 《电工技术学报》 EI CSCD 北大核心 2024年第16期4968-4984,共17页
模块化多电平换流器(MMC)与系统网络之间的交互是诱发振荡的主要原因,然而现有MMC单侧阻抗/导纳建模方法往往没有计及对端换流站的动态过程,因此该文重点通过建立可以考虑交直流耦合的换流器三端口混合参数模型实现整个双端柔直系统的... 模块化多电平换流器(MMC)与系统网络之间的交互是诱发振荡的主要原因,然而现有MMC单侧阻抗/导纳建模方法往往没有计及对端换流站的动态过程,因此该文重点通过建立可以考虑交直流耦合的换流器三端口混合参数模型实现整个双端柔直系统的稳定性分析。首先,该文基于谐波状态空间法推导考虑桥臂间谐波动态交互过程的MMC换流器交直流端口功率守恒方程,并据此建立换流器的三端口混合参数模型;其次,基于所建立的三端口混合参数模型和广义奈奎斯特判据,对MMC互联系统的稳定性进行分析,因该方法可避免计算开环传递函数右半平面零极点的数量,与传统单侧阻抗稳定性分析方法相比,可实现系统稳定性的准确判断;再次,推导了特征值相位关于三端口混合参数元素的灵敏度计算公式,揭示了系统振荡的诱因,进一步结合控制参数灵敏度分析,实现了一种用于改善互联系统直流侧稳定性的直流电流前馈附加阻尼控制策略;最后,结合时域仿真算例验证了稳定性分析和改善措施的有效性。 展开更多
关键词 模块化多电平换流器 三端口网络 混合参数模型 稳定性分析 谐波状态空间
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微差爆破在港口工程中的应用
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作者 武政 何军 魏华 《水运工程》 2024年第9期228-232,共5页
考虑到地质条件的复杂性和输油管等重要设施的存在,水下炸礁作为港口建设和航道疏浚中的重要工作手段需要确保工程的安全性。为了减少爆破产生的冲击波、震荡及爆破涌浪对周围环境的危害,对地质条件进行充分分析,并选取合适的爆破自由... 考虑到地质条件的复杂性和输油管等重要设施的存在,水下炸礁作为港口建设和航道疏浚中的重要工作手段需要确保工程的安全性。为了减少爆破产生的冲击波、震荡及爆破涌浪对周围环境的危害,对地质条件进行充分分析,并选取合适的爆破自由面以降低爆破振动的影响。在进行水下炸礁工作时,开展试爆研究,通过调整爆破参数如装药量和引爆时间,达到最佳的效果;通过设计最佳的装药结构,提高爆破的稳定性和安全性。研究成果可为地质坚硬、水深较深、施工条件复杂以及需要确保施工区内重要建筑安全的水下炸礁工程提供技术参考。 展开更多
关键词 微差爆破 水下炸礁 港口航道 爆破网路 装药结构
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宁波象山港蓝色海湾综合治理中的问题及其应对
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作者 龚虹波 龚钱斌 《宁波大学学报(人文科学版)》 2024年第1期124-132,共9页
从治理网络分析的视角出发,分析浙江省宁波市象山港梅山湾蓝色海湾综合治理中的三个项目:湿地保护与修复治理、岸滩整治修复治理、海洋经济可持续发展监测能力建设,可知这三个治理网络具有行动者类型相对单一的特点。这导致参与主体在... 从治理网络分析的视角出发,分析浙江省宁波市象山港梅山湾蓝色海湾综合治理中的三个项目:湿地保护与修复治理、岸滩整治修复治理、海洋经济可持续发展监测能力建设,可知这三个治理网络具有行动者类型相对单一的特点。这导致参与主体在面临较为复杂的项目时,难以调动基层政府和社会的积极性。要应对这种在综合治理中出现的问题,有效提升治理效能,需要优化治理网络,构建出多元主体参与的多中心治理网络、明确海湾环境治理中各级政府的目标内容,并完善跨域治理机制。 展开更多
关键词 象山港 蓝色海湾 治理网络 网络结构特征
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