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电磁扫雷具是主要的非接触扫雷具之一,用于扫除带有磁引信的非触发水雷。为了诱动水雷磁引信,电磁扫雷具产生的磁场必须与水雷磁引信的动作要求相适应。基于实际的工程模型,应用 Ansoft Maxwell 对电极阵电磁扫雷具的磁场分布进行分析,绘制磁感应强度分布图和通过特性曲线,以便对产品进行设计验证和优化设计。同样的方法还可拓展用于其它电磁扫雷具的设计,以提升设计效率和水平。  相似文献   

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针对我国北方浅海地区风电工程多桩承台所耐受环境,通过模拟海洋工况,如冻融循环、氯盐溶液浸泡,并在此模拟环境作用基础上进行抗压强度试验和抗折强度试验,再结合钢筋粘结的拔出试验,探讨不同混凝土强度等级在氯盐侵蚀的情况下,分别进行不同次数的冻融循环,来对比分析各种工况对混凝土物理性能的影响。运用超声波探测技术有效地解释混凝土在冻融循环和氯离子复合作用下强度降低的劣化机理。最后,利用有限元数值模拟多桩承台的作业环境,再一次验证了冻融循环对风机承台混凝土结构的影响规律。此研究可为北方海域冻融环境较为恶劣区域的风电项目建设提供有益参考。  相似文献   

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条斑紫菜的R-藻红蛋白在pH:5.8—8.4的几种缓冲液中保存,经过大约4个星期,其吸收光谱由原有的双峰型转变为三峰型;在pH=8.4的聚丙烯酰胺梯度凝胶电泳后或在微量四甲基乙二胺作用下发生了同样的变化。但在变性剂SDS或尿素存在下,吸收光谱中540nm和565nm的峰强度比逐渐改变,直至565nm吸收峰消失,始终没有从双峰型转变为三峰型的迹象。显然,条斑紫菜R-藻红蛋白吸收光谱类型的转变不是变性引起的。  相似文献   

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以陆地枪械发射内弹道方程组理论为基础,结合水下聚能剪切器动作的技术特点,对动刀运动的能量转化机理和刀架内部组件的动力学响应进行了综合分析,建立归一化数学模型,用于内弹道参量变化特性曲线的数值计算。通过对某型号水下剪切器内弹道仿真求解,定量分析了各参量变化过程,论证了短行程聚能剪切方案的可行性,为后继内弹道设计及装药参量的优化奠定了理论基础。  相似文献   

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挡板透空码头水平波浪力计算方法的探讨   总被引:1,自引:0,他引:1  
隋华  王文鼎  高晨 《海岸工程》2009,28(3):20-26
目前,对透空式高桩梁板码头的桩基和墩柱波浪力的计算,现行《海港水文规范》中有相应的公式,但对一侧增设挡浪板及上部结构构件的透空式高桩梁板码头水平波浪力的计算,规范并没有明确规定相应的计算公式。从挡板透空码头设计中水平波浪力的计算分析入手,说明挡板波浪力采用不同计算方法的差异性,并针对某设计工程进行了实例分析,通过相关文献、现行规范及物理模型试验等三种不同方法所得计算结果的比较,探讨一种适合挡板透空码头的水平波浪力的计算方法,供工程设计时参考。  相似文献   

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All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static or dynamic calculation methods. In this paper, the finite element method (FEM) and theoretical analysis method are combined to analyze the structural property, bearing behavior and failure mode of the all-vertical-piled wharf in offshore deep water, and to establish simplified calculation methods determining the horizontal static ultimate bearing capacity and the dynamic response for the all-vertical-piled wharf. Firstly, the bearing capability and failure mechanism for all-vertical-piled wharf are studied by use of FEM, and the failure criterion is put forward for all-vertical-piled wharf based on the ‘plastic hinge’. According to the failure criterion and P-Y curve method, the simplified calculation method of the horizontal static ultimate bearing capacity for all-vertical-piled wharf is proposed, and it is verified that the simplified method is reasonable by comparison with the FEM. Secondly, the displacement dynamic magnification factor for the all-vertical-piled wharf under wave cyclic loads and ship impact loads is calculated by the FEM and the theory formula based on the single degree of freedom (SDOF) system. The results obtained by the two methods are in good agreement with each other, and the simplified calculation method of the displacement dynamic magnification factor for all-vertical-piled wharf under dynamic loads is proposed. Then the simplified calculation method determining the dynamic response for the all-vertical-piled wharf is proposed in combination with P-Y curve method. That is, the dynamic response of the structure can be obtained through the static calculation results of P-Y curve method multiplied by the displacement dynamic magnification factor. The feasibility of the simplified dynamic response method is verified by comparison with the FEM under different conditions.  相似文献   

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预测和评价了青岛港液体化工码头苯贮罐苯泄漏对大气环境的影响.结果表明,苯罐一旦发生泄苯事故,会对大气环境造成不同程度的影响;在最不利天气条件下,泄漏挥发量为3375kg,会导致22人死亡;泄漏挥发量为1237kg,会导致4人死亡;如果同样的泄苯挥发量,发生在微风条件下,则分别有4人死亡和无人死亡;若发生33kg泄漏挥发量,无论在何种天气条件下,都不会导致人员伤亡。  相似文献   

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There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly affected by wave action. Currently, no systematic studies or simplified numerical methods are available for deriving the dynamic characteristics and dynamic responses of all-vertical-piled wharves under wave cyclic loads. In this article, we compare the dynamic characteristics of an all-vertical-piled wharf with those of a traditional inshore high-piled wharf through numerical analysis; our research reveals that the vibration period of an all-vertical-piled wharf under cyclic loading is longer than that of an inshore high-piled wharf and is much closer to the period of the loading wave. Therefore, dynamic calculation and analysis should be conducted when designing and calculating the characteristics of an all-vertical-piled wharf. We establish a dynamic finite element model to examine the dynamic response of an all-vertical-piled wharf under wave cyclic loads and compare the results with those under wave equivalent static load; the comparison indicates that dynamic amplification of the structure is evident when the wave dynamic load effect is taken into account. Furthermore, a simplified dynamic numerical method for calculating the dynamic response of an all-vertical-piled wharf is established based on the P-Y curve. Compared with finite element analysis, the simplified method is more convenient to use and applicable to large structural deformation while considering the soil non-linearity. We confirmed that the simplified method has acceptable accuracy and can be used in engineering applications.  相似文献   

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使用层次分析法,对青岛港港池浚深挖泥吹填形成的液体化工码头的软基处理方法进行优选。结合土质特点等因素,分区进行不同工艺的分析,建议真空预压法和强夯法进行地基处理。两种方法的地基处理资料对比表明,真空预压法为首选处理工艺。  相似文献   

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桩基属于柔性结构,低频密集,不利于检测.本研究利用小波变换法可以分离高频成份的特点,提出了利用高频成份和曲线相似性理论相结合的腐蚀厚度识别方法,并以天津港某梁板式码头为例进行了应用,具体步骤为:根据目前研究成果,确定五种典型工况,计算其动力反应;采用小波变换获得突出高频成份的特征曲线;借鉴曲线识别思想,根据实测曲线与特征曲线的相似度确定腐蚀厚度.结果表明,该方法具有较好的效果.  相似文献   

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我国码头新结构型式综述   总被引:1,自引:0,他引:1  
雍新  史宏达 《海岸工程》2013,32(1):35-43
对我国近些年出现的几种新型码头结构进行了分析和综述。导管架码头结构型式是一种新型的结构型式,结构的整体刚度大、水平变位小、透空性好、波浪反射小,在开敞式环境下可适当降低码头面高程;椭圆沉箱墩式结构解决前后不均匀沉降的问题,提高了结构的整体稳定性;内河架空直立墩式结构对大水位差适应能力强,结构紧凑,对水流穿行影响小,装卸作业时泊稳条件好,是内河航道未来的发展方向。  相似文献   

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为促进我国海洋渔业"走出去",进一步发展远洋捕捞业,文章调查西南大西洋乌拉圭近海双船拖网捕捞的渔具和渔法等,并提出生产建议。研究结果表明:双船拖网的渔具包括渔船、网具、纲索和属具,网身采用加目和减目编缝的方式缝合而成;渔法包括放网准备、放网、曳网、起网和网具养护等环节;针对渔场、渔期和捕捞对象,应把握捕捞产量、成本和航次的关系,并结合主捕对象的生活习性,合理规划生产。  相似文献   

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大洋铁锰结壳是继大洋多金属结核之后出现的又一极具潜在经济价值的水下固体矿产(王毅民,1992),富含Mn、Fe、Cu、Co、Ni和Pt多种金属元素及非金属元素P,Co含量最高可达2.5%,是大陆含Co矿床的数倍到数十倍,铂的平均含量也是上地壳的80倍。据众多科学家的初步估计,仅太平洋西部火山构造隆起带上,铁锰结壳矿床的潜在资源量就达10亿t,其中Co金属含量可达600万~700万t,经济总价值超过1000亿美元(Klinkhammer et al.,1980;Halbach et al.,1984;DeCarlo et al.,1987;何高文等,2001)。这与全球陆地已探明Co资源总量仅为1 500万t相比,数量极为可观,并且结壳的产出水深多小于3000 m, 易于进行系统的、大量的样品采集,开采风险及开采时对环境的影响也较小。因此,近年来,随着世界经济的蓬勃发展和高新技术的开发, 对Mn、Cu、Co、Ni等元素的需求日益增大及由此所导致的陆地上这些资源的迅速枯竭,使人们纷纷将目光转向深海底矿产,加大了对海底铁锰结壳资源的研究力度和深度,其资源的经济地位也相应进一步提高。据专家预测,大洋铁锰结壳很可能会比大洋的金属结核率先实现商业性开采,并成为21世纪新兴的海洋矿产产业(Hein et al.,1998;潘家华等,1995)。 此外,结壳还有净化空气中SO2与NO2的氧化催化剂等用途,并且铁锰结壳成矿环境的研究,还具有较高的科学价值,可使科学家进一步深入了解和认识地内深部物源、海底水-岩反应、金属成矿富集过程及其中的微生物成矿作用乃至古海洋环境演变等问题,而这些问题迄今仍未得到完善解决,是当前地学和海洋学领域的研究热点。这就使铁锰结壳成矿环境的研究显得尤为重要。  相似文献   

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