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1.
文章首先对灰色预测模型进行了改进,建立了GM(1,1)综合预测模型;其次针对灰色理论和神经网络的互补性,创建了以等维新息GM(1,1)模型+BP神经网络的串联型灰色神经网络预测方法,在此基础上提出了3*3*1*1结构的预测模型,并对其建模过程和算法进行了分析讨论;最后以某型船用柴油机铁谱监测数据为样本,对这种新预测模型的可行性与准确性进行了验证。  相似文献   

2.
(mg+m-1,mf-m+1)-图的(g,f)-因子   总被引:1,自引:0,他引:1  
讨论了(mg m-1,mf-m 1)-图的(g,f)-因子问题,推广了图的因子理论,改进了一些结论,有助于进一步研究(mg m-1,mf-m 1)-图的(g,f)-因子问题。  相似文献   

3.
本文介绍了1/f噪声的含义和原理,依照这些原理,通过白噪声加简化得到的有理1/f数字滤波器的方法,使用Matlab编程,仿真产生了真实1/f噪声.并根据常见的计算功率谱密度的算法,验证了仿真产生的1/f噪声的性能.  相似文献   

4.
《中国船检》2011,(10):I0024-I0025
国际海事组织环保会(MEPC)于2010年10月1日以MEPC194(61)决议通过了MARPOL公约附则VI修正案,对IAPP证书附件进行了修订,该修正案将于2012年2月1日生效。由于此前IMO通过的MEPC1/Circ718通函与该修正案就何时换发IAPP证书附件要求不一致.为协调此事.MEPC62于2011年8月8日发布了新的MEPC.1/Circ757通函,以替代原MEPC.1/Circ718通函。  相似文献   

5.
比较了不同改性剂掺量的SBS改性沥青的技术指标,并采用直剪试验和45°斜剪试验比较了其作为层间粘结材料的抗剪强度,提出了抗剪强度高且适于施工的改性剂掺量;同时比较了粘层沥青洒布量为0、1.2、1.5、1.8、2.1kg/m^2时的抗剪强度,提出了1.8kg/m^2是层间最佳的洒布量。用GTM试验法比较了沥青路面结构在热接、冷接状态时的层间抗剪强度。  相似文献   

6.
第1 5届国际船舶和海洋工程结构大会,于2 0 0 3年8月1 1日至1 5日,在美国圣地亚哥市隆重举行。来自2 6个国家的2 31个专家出席了会议。我国大陆专家1 4人,台湾省专家5人,海外留学生(代表所在国家) 1 3人,共32人出席了这次大会。大会期间,ISSC所属1 6个专业委员会分别作了技术报告。大会讨论确定了新一届ISSC常务委员会和各专业委员会的人员组成。中国自上世纪80年代即是ISSC常委国家之一,并曾于1 988年至1 991年担任第1 1届ISSC主席国,于1 991年9月在江苏无锡成功举办了第1 1届ISSC大会。从1 994年起,吴有生院士已连任三届ISSC的…  相似文献   

7.
袁胜英  应强 《水道港口》2010,31(5):478-482
基于广州港出海航道2008年1月、4月及9月3次航道测量的地形资料,结合相关的水文资料,从边坡稳定性角度分析了试挖槽的回淤情况。通过对比得出了伶仃航段(KP17~KP60)航道东、西两侧边坡坡比的总体变化。结果表明,2008年1月坡比分别为1∶11.1和1∶11.7,4月分别为1∶8.6和1∶8.5,9月分别为1∶8.8和1∶8.4。1月到4月平均坡比变化较大,4月到9月平均坡比变化较小,坡比基本稳定在1∶8.5左右。  相似文献   

8.
环肋圆柱壳稳定性方程式特性探讨   总被引:2,自引:0,他引:2  
武杰 《中国造船》1995,(1):45-53
本文叙述了在各向均匀外压力作用下正交各向异性壳的失稳特征为:周向整波数n总是大于2,mα1值与1为同级。阐明了计算壳失稳临界压力公式的适用范围。如超出适用范围,所得结果就不正确。本文还从理论上论证了环肋圆柱壳丧失稳定性时其纵向半波数m=1的条件,提出潜艇环肋圆柱壳的m值恒等于1。  相似文献   

9.
近日,徐祖远副部长主持召开了交通运输部“防控甲型H1N1流感疫情专题会”,进一步部署甲型H1N1流感联防联控工作。会议决定成立交通运部甲型H1N1流感联防联控领导小组,由翁盂勇副部作长担任组长,冯正霖副部长和徐祖远副部长担任副组长,相关司局(室)作为领导小组成员单位。  相似文献   

10.
“终于上岸了1可以回家过年了1”2月8日下午5时,历尽艰辛的“HAINA”轮23名船员终于踏上青岛港坚实的土地。  相似文献   

11.
家蚕滞育激素(Bombyx mori diapause hormone,BmDH)与滞育激素受体(BmDH receptor,BmDHR)结合,调控其信号通路中的下游基因的表达.在二化性家蚕中,受滞育信号的影响,蛹体卵巢膜上海藻糖酶的活性增强.为了证实 BmDHR对家蚕海藻糖酶基因(Bmtre)表达的调控作用,以 pcDNA3.1为载体,构建了4种由 ie -1启动子驱动的不同 Bmdhr 的表达质粒 pcDNA - ie1- Bmdhr1、pcDNA - ie1- Bmdhr3、pcDNA - ie1- Bmdhr4、pcDNA - ie1- Bmdhr5和(Bmtre 启动子驱动的萤火虫荧光素酶基因(luciferase,luc)报告质粒 p3Z - Bmtre - luc;用脂质体(Lipofectin)包埋1种 Bmdhr 表达质粒或不同摩尔比的 pcDNA - ie1- Bmdhr1/ pcDNA - ie1- Bmdhr5以及报告质粒后,分别共转染源于卵巢的家蚕细胞 BmN,在 DH 作用下体外检测 BmDHRs 对海藻糖酶基因启动子活性的影响.结果表明,4种滞育激素受体 BmDHR -1、BmDHR -3、BmDHR -4和BmDHR -5分别表达时,均能上调海藻糖酶基因启动子的活性;不同摩尔比(1:3,1:1,3:1)的 BmDHR -1/ BmDHR -5也均能上调海藻糖酶基因启动子的活性,由此证明 BmDHR 能上调其信号通路中下游基因 Bmtre 的表达.  相似文献   

12.
沿岸流研究对海岸工程具有重要的应用价值。为了更深入地研究沿岸流特征,文章对1∶100和1∶40两个较缓坡条件下的沿岸流进行了实验研究,弥补了现有实验研究主要针对较陡坡情况,不具有代表性的弊端,并通过数值模拟进一步阐述了缓坡情况下的平均沿岸流不同于陡坡情况下的物理机理。主要特色与创新有:第一、通过物理模型实验研究发现了1∶100坡度地形条件下存在不同于1∶40坡度情况下的平均沿岸流速度分布特征:前者海岸一侧平均沿岸流分布呈下凹趋势,而后者呈上凸的趋势。第二、通过平均沿岸流数值模型对1∶100和1∶40缓坡沿岸流的不同特征进行数值模拟,找出了影响平均沿岸流速度剖面特征的主要因素为破波带内波高分布和水底摩擦力表达式的选取不同,且对后者更为敏感。1∶100坡度海岸沿岸流速度剖面可由水流型水底摩擦力来计算出,而1∶40坡度海岸沿岸流速度剖面可由波浪型水底摩擦力来计算出。第三、在此基础上进一步给出了缓坡情况下二次破碎波高和波浪增减水的分布特征。  相似文献   

13.
The galvanic corrosion behaviour of aluminium 3004 and copper with different area ratios were studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios of AAl : ACu, studied were 1:1, 1:2, 1:4, 1:8, 2:1, 4:1 8:1. The galvanic corrosion behaviour of metals was studied in terms of relative increase in the corrosion rate of aluminium due to galvanic coupling with copper, relative decrease in the corrosion rate of copper due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with copper. The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders and the surfaces of the interface of aluminium in contact with copper. The weathering parameters and the environmental pollutants which have a major role in influencing the galvanic corrosion of metals were also monitored. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium resulting from galvanic corrosion has been highlighted in terms of pit depth, size and density of pit, using a high resolution microscope.  相似文献   

14.
The galvanic corrosion behaviour of aluminium 3004 and copper with different area ratios were studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios OfAAI: Acu, studied were l:l, 1:2, l:4, 1:8, 2:1, 4:1 & 8:1. The galvanic corrosion behaviour of metals was studied in terms of relative increase in the corrosion rate of aluminium due to galvanic coupling with copper, relative decrease in the corrosion rate of copper due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with copper, The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders and the surfaces of the interface of aluminium in contact with copper. The weathering parameters and the environmental pollutants which have a major role in influencing the galvanic corrosion of metals were also monitored. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium resulting from galvanic corrosion has been highlighted in terms of pit depth, size and density of pit, using a high resolution microscope.  相似文献   

15.
浮力材料在ROV上的应用   总被引:1,自引:0,他引:1  
浮力材料是ROV必不可少的基础材料之一,文章系统地简述了浮力材料在ROV上的重要作用、及其国内外发展现状、结构组成及维保程序等内容,为我国水下机器人浮力材料研究及维保提供参考.  相似文献   

16.
王雅山 《港工技术》2012,49(4):14-15,22
在老港区城市化开发改造中,适当的土地一级开发模式能够有效地保证港口企业国有资产的利益最大化.分析沿海港口企业参与老港区土地一级开发的必要性和关键环节,对典型的土地一级开发模式进行比较.建议沿海港口企业应通过设计符合自身情况的土地一级开发模式,积极参与老港区的城市化开发改造.  相似文献   

17.
The present survey covers one spawning season of marine benthic invertebrates in a large geographical area, the inner Danish waters, and includes a wide range of habitats with steep salinity and nutrient load gradients. The loss ratios of soft-bottom marine invertebrates from one development stage to the next is calculated based on average abundances of pelagic larvae, benthic post-larvae and adults of Bivalvia, Gastropoda, Polychaeta and Echinodermata, with planktonic development. This gives a rough estimate of the larval and post-larval mortality. Loss ratios between post-larvae stage and adult stage (post-larval mortality) varies from 3:1 to 7:1 (71.2–84.9%) and loss ratios between larvae and post-larvae (larval mortality) and between larvae and adult, ranging from 7:1 to 42:1 (85.2–97.6%) and from 45:1 to 210:1 (97.8–99.5%), respectively. The results show a remarkable unity in loss ratios (mortality) between the mollusc taxa (Bivalvia and Gastropoda) at the phylum/class level. This similarity in loss ratios among the mollusc taxa exhibiting the same developmental pathways suggests that the mortality is governed by the same biotic and abiotic factors. Larval mortality is estimated to range from 0.10 d− 1 to 0.32 d− 1 for Bivalvia and ranging from 0.09 d− 1 to 0.23 d− 1 for Polychaeta. The species loss ratios combined with specific knowledge of the reproduction cycles give estimated loss ratios (mortality) between the post-larvae and the adult stage of 25:1 and 14:1 for the bivalves Abra spp. and Mysella bidentata. For the polychaete Pygospio elegans the loss ratio (larval mortality) between the larvae and the post-larval stage is 154:1 and between the post-larvae and the adult stage 41:1. For Pholoe inornata the loss ratio between post-larvae and adults is 7:1. The present results confirm that the larval stage, metamorphosis and settlement are the critical phase in terms of mortality in the life cycle for Bivalvia. Assuming steady state based on actual measurements of pelagic larval densities an estimated input to the water column of pelagic bivalve larvae is ranging from 10,930 to 17,157 larvae m− 2 d− 1 and for Polychaeta between 2544 and 3994 larvae m− 2 d− 1. These estimates seem to correspond to the reproductive capacity of the observed adult densities using life-table values from the literature.The potential settlement of post-larvae is 43 post-larvae m− 2 d− 1 for Bivalvia and 56 post-larvae m− 2 d− 1 for Polychaeta. The adult turnover time for Bivalvia is estimated to be 1.5 years and 2.1 years for Polychaeta. This exemplifies that species with short generation times may dominate in very dynamic transitional zones with a high frequency of catastrophic events like the frequent incidents of hypoxia in the inner Danish waters.  相似文献   

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