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1.
高强度聚乙烯菱形网目经编网片的力学性能初步研究   总被引:7,自引:0,他引:7  
给网箱设计与渔用材料的合理选配提供参考,初步研究了渔用高强度聚乙烯菱形网目经编网片(简称HSPE经编网片)的力学性能。研究结果表明,(1)在同等条件下,36股HSPE经编网片网目强力、网片纵向断裂强力分别比36股普通聚乙烯菱形网目经编网片(简称PE经编网片)增加了48.9%,11.6%,而前者的网片纵向断裂伸长率比后者减少了29.4%;(2)在相同网目长度条件下,36股HSPE经编网片网目强力、网片纵向断裂强力分别比42股锦纶菱形网目经编网片(简称PA经编网片)增加了27.2%,37.9%,而前者的网片纵向断裂伸长率比后者减少了33.6%;(3)36股HSPE经编网片较36股PE经编网片和42股PA经编网片具有性能价格比优势;HSPE经编网片在网箱养殖等渔业生产中推广应用上具有可行性。  相似文献   

2.
采用转录组454 GS FLX测序和PCR技术,以海蜇(Rhopilema esculentum)和沙海蜇(Nemopilema nomurai)的基因组DNA为模板,分别克隆了包含EST-SSR和EST-SNP标记的β-连环蛋白基因目的片段。生物信息学分析显示,海蜇和沙海蜇的β-连环蛋白基因目的片段长度分别为166/169 bp和157/160 bp,均没有内含子。海蜇个体之间β-连环蛋白基因目的片段除了微卫星重复差异外,只有一个碱基的差异;沙海蜇个体之间除了微卫星重复差异外,其余完全一致。在海蜇和沙海蜇β-连环蛋白基因目的片段的相同位置均包含微卫星重复,但其重复单元截然不同:海蜇为:(TGC)4-6(TGT)1-2(TGC)4-5,而海蜇为(TGT)5-6。同时两物种间还存在14个单核苷酸多态位点:(T/C)1,(T/C)2,(C/T)3,(C/T)4,(C/T)5,(T/G)6,(G/C)7,(T/G)8,(A/G)9,(C/T)10,(G/A)11,(A/G)12,(C/T)13,(A/T)14。聚丙烯酰胺凝胶电泳图谱也直接客观地反映了两个群体之间目的片段的长度和微卫星多态性差异。上述结果显示,EST-SSR和EST-SNP标记的β-连环蛋白基因目的片段,可以作为一种简单、有效的分子标记,快速、准确地识别不同发育阶段的海蜇和沙海蜇。  相似文献   

3.
为给深水网箱设计与渔用材料的合理选配提供依据,应用ISO1806等对渔用高强度聚乙烯绞捻网片(以下简称HSPE绞捻网片)和普通聚乙烯绞捻网片(以下简称PE绞捻网片)的拉伸力学性能进行了比较研究。结果表明,(1)在同等条件下,36股HSPE绞捻网片的网目连接点断裂强力和网片单线断裂强力分别比52股PE绞捻网片增加了3.1%,3.7%;而前者的目脚直径和网片阻力可较后者减少19.6%。(2)对网片强力进行了再现性研究,36股HSPE和52股PE绞捻网片网目连接点断裂强力的标准偏差分别为35.93N,25.61N,再现性标准偏差分别为31.07N,36.93N;网片单线断裂强力的标准偏差分别为19.91N,13.49N,再现性标准偏差分别为20.48N,15.49N;网片强力测试数据的变异系数均小于4%;表示测试结果的分散性较小。(3)36股HSPE绞捻网片成本可较52股PE绞捻网片减少38.9%,其在渔业生产中进行推广应用具有可行性。(4)GB/T4925作为一个标准,对绞捻网片来说,存在不足,建议对GB/T4925进行修订。  相似文献   

4.
本文对位于现行黄河口深度30.73m的BH6钻孔粒度分布、岩性特征、常量元素、有孔虫介形虫种类及分布、14 C年代进行了分析,讨论了研究区全新世海侵以来的沉积层序和古气候演化。钻孔连续记录了近黄河口区域全新世海侵以来的沉积历史,从上至下可以分为5个沉积相,(1)(0~4.87m)为河口三角洲前缘亚相,(2)(4.87~8.08m)为前三角洲相沉积,(1)(2)共同组成三角洲相沉积,(3)(8.08~12.08m)应为近岸浅海沉积,(4)(12.08~23.85m)为河口边滩至潮坪相沉积,(5)(23.85m~)为陆相湖泊沉积。利用钻孔常量元素特征比值对古气候演化进行讨论,认为全新世海侵期以来BH6钻孔古气候总体经历了相对暖-温凉-暖-温凉的过程。  相似文献   

5.
张家口-蓬莱断裂带渤海段晚第四纪活动特征   总被引:7,自引:0,他引:7  
张家口-蓬莱断裂带是华北地区一条显著的地震带.利用最新获得的高分辨率浅层地震资料研究了渤海海域内该断裂带晚第四纪以来的活动特征.研究表明:在渤海,张家口-蓬莱断裂带主要由沙西断裂、埕北断裂、沙南断裂、沙东北断裂、柏各庄断裂、石臼坨3号断裂、渤中2号断裂和BZ29断裂等一系列NW走向断裂组成,走向在290°~310°之间;在浅层沉积物中各断裂由多条次级小断裂组成;晚第四纪以来主要表现出强烈的垂向运动特征,具有正断性质;海域各断裂的最新活动时代为晚更新世(Q3)末期-全新世(Q4)初期,并具有相同的活动趋势,在20 ka B.P.和60 ka B.P.左右活动强烈,统计计算显示平均垂向活动速率分别为0.15 mm/a和0.1 mm/a,近20 000 a以来的垂向活动速率超过0.06 mm/a.  相似文献   

6.
胶州湾口海区磁力异常特征及构造解释   总被引:1,自引:0,他引:1  
通过对胶州湾湾口海区磁力异常进行的定性和定量解释,并结合其它地质地球物理资料的综合分析认为,测区内存在1条NW向断裂、2条WNW向断裂及3条NE向断裂。其中NW向断裂(F3断裂)是1条新发现的断裂,属右旋断裂构造,并被多种中基性岩脉所填充。根据区内断裂构造的组合交切关系推定,F3断裂比沧口断裂活动时代要早,为非全新世活动断层。  相似文献   

7.
东濮凹陷古近纪断裂活动的幕式特征及控盆作用   总被引:1,自引:0,他引:1  
通过对东濮凹陷古近纪的沉降史分析,揭示了该区古近纪断裂活动的幕式特征,探讨了断裂活动的幕式特征对盆地沉积、构造演化的控制作用。指出古近纪的断裂活动具有明显的五幕式特征,即初始活动期(Es_4)、快速活动期(Es_3~4)、衰减期(Es_3~3)、再活化期(Es_3~2-Es_2~2)及收缩期(Es_2~1-Ed);断裂活动的幕式特征直接控制着盆地古近系的三级层序界面和沉积演化特征;断裂活动的五幕式特征直接控制着盆地构造演化阶段,相应形成初始断陷期(Ek-Es_4)、快速断陷期(Es_3~4)、衰减期(Es_3~3)、再活化期(Es_3~2-Es_2~2)和收缩期(Es_2~1-Ed)。  相似文献   

8.
lCo~nofthe"booarePhicAtheoftheYthewsa"TheOceanographicAtlasoftheYellowSeahasbeencompiledbyChineseandKoreanscientistsbasedmainlyondataobtainedbyl992surveysandthoseaccumu-latedduringthepastyears,particularlythoseofl958-l988inphysicaloceanography,aswel1asthoseobtainedbytheChinesesideintheperiodl958-l959inmarinecheAnstryandbiology,andnewdataofrecenttenyearsinfisheryproductionbybothcountries-TheAtlasconsistsof5mainparts:(l)Marinegeologychartset,(2)Physicaloceanographychartset,(3)Marinechendst…  相似文献   

9.
对采自我国南海海域的蓖麻海绵Biemnasp .的化学成分进行了研究。从中分离出 4个结晶化合物。经FT -IR ,MS ,1 HNMR ,1 3 CNMR ,DEPT等波谱方法鉴定分别为正二十八酸(Ⅰ) ,正十六酸 (Ⅱ) ,穿贝海绵甾醇 (Ⅲ )和biemnamide (Ⅳ )。报道了 (Ⅰ) ,(Ⅱ) ,(Ⅲ )的化学结构和 (Ⅳ )的生理活性  相似文献   

10.
分别于2006年8月,12月和2007年4月,10月采集胶州湾及周边海域大气和海水样品,对氧化亚氮(N2O)和甲烷(CH4)浓度进行了测定,并设置1个连续站进行24 h连续观测.结果表明:大气中N2O春、夏、秋、冬的平均浓度(体积分数)分别为(3.17±0.03)×10-7,(3.24±0.15)×10-7,(3.19±0.02)×10-7和(3.08±0.25)×10-7;大气中CH4春、夏、秋、冬的平均浓度(体积分数)分别为(1.89±0.04)×10-6,(1.79±0.04)×10-6,(2.09±0.21)×10-6和(2.01±0.09)×10-6.胶州湾表、底层海水中N2O和CH4的浓度和饱和度表现出明显的季节变化,其中N2O浓度和饱和度冬季最高,春、秋季次之,夏季最低;CH4浓度和饱和度夏季最高,冬季最低.利用Liss and Merlivat(1986)公式和Wanninkhof(1992)公式估算出胶州湾海域N2O的年平均海-气交换通量分别为(11.16±14.15)和(22.42±27.56)μmol m-2·d-1;CH4分别为(7.75±6.19)和(17.76±14.84)μmol m-2·d-1.胶州湾大部分海域表层海水中N2O和CH4呈过饱和状态,是大气中N2O和CH4的净源.  相似文献   

11.
The seismicity of the northeastern part of the Indian Ocean in connection with the general structural peculiarities of the main tectonic structures of the bottom is presented. The three main ranges of higher seismic activity at the depths of 0–17, 20–27, and 32–35 km divided by aseismic layers are revealed. The seismic activity at depths of more than 35 km is almost not detected both for the ocean and for the Indian peninsula. The nature of the distribution of the seismicity as such in the lithosphere is discussed. Using the results of anomalous au]gravitational field transformations, the prolongation of the East Indian Ridge structure is revealed to 19 degrees north, while the relationship of the Afanasy Nikitin Rise and the 85th Degree Ridge is not reflected at the tranforms. In the Cocos Basin, the mutually perpendicular disturbance zones of northeastern and northwestern strike, as well as the point of their crossing, where the maximal number of earthquake foci are concentrated, are distinguished. A conclusion concerning the substantial disturbance of the strength properties of the lithosphere in this zone as a consequence of the geodynamical processes, which are accompanied by fracture tectonics, is reached.  相似文献   

12.
Calculation of Diversion Ratio of the North Channel in the Yangtze Estuary   总被引:2,自引:0,他引:2  
The circumfluence around the Jiuduan Sandbank is thoroughly studied by means of the princi-ple of least resistance in fluid dynamics.The diversion ratio of the North Channel for 1998 is calculated,which is almost the same as the field survey data.The normal and minimum diversion ratios of the NorthChannel after stages Ⅰ,Ⅱ and Ⅲ regulation works as well as the future phase are obtained.The numeri-cal results and predicted value are accurate.  相似文献   

13.
长江河口北支倒灌盐水输送机制分析   总被引:13,自引:3,他引:13       下载免费PDF全文
吴辉  朱建荣 《海洋学报》2007,29(1):17-25
基于三维数值模式ECOM-si,采用通量机制分析的方法,对长江河口北支倒灌盐水的输送机制进行了定量研究.模式计算了南北支分叉口和南支河段的潮平均单宽盐通量、各叉道上10个断面的潮平均盐通量和上述两者的机制分解项.基于计算结果讨论了北支倒灌盐水输送的动力机制,发现Lagrange余流输送和潮泵输送在倒灌盐水的输送中起主导作用.讨论了南支各叉道输送倒灌盐水的数量关系,给出了北支盐水倒灌输送的主要路径.  相似文献   

14.
研究渤海的可持续发展.根据 1979~1999 年渤海中部断面温度、盐度、溶解氧、营养盐的调查资料,分析了它们的分布结构和20年来的变化趋势.结果显示断面各个要素冬季的垂向分布均匀,夏季有2个冷水中心,盐度、溶解氧、营养盐在冷中心位置也出现了类似的高值或者低值中心.各要素的距平图显示盐度有上升趋势,溶解氧含量下降,无机氮逐年增加,磷酸盐和硅酸盐夏季有下降的趋势,但是冬季没有明显的增加或者减少的趋势.  相似文献   

15.
Multi-beam,sub-bottom and multichannel seismic data acquired from the western Nigerian continental margin are analysed and interpreted to examine the architectural characteristics of the lower parts of the submarine canyons on the margin.The presence of four canyons: Avon,Mahin,Benin,and Escravos,are confirmed from the multi-beam data map and identified as cutting across the shelf and slope areas,with morphological features ranging from axial channels,moderate to high sinuosity indices,scarps,terraces and nickpoints which are interpreted as resulting from erosional and depositional activities within and around the canyons.The Avon Canyon,in particular,is characterised by various branches and sub-branches with complex morphologies.The canyons are mostly U-shaped in these lower parts with occasional V-shapes down their courses.Their typical orientation is NE–SW.Sedimentary processes are proposed as being a major controlling factor in these canyons.Sediments appear to have been discharged directly into the canyons by rivers during the late Quaternary low sea level which allows river mouths to extend as far as the shelf edge.The current sediment supply is still primarily sourced from these rivers in the case of the Benin and Escravos Canyons,but indirectly in the case of the Avon and Mahin Canyons where the rivers discharge sediments into the lagoons and the lagoons bring the sediments on to the continental shelf before they are dispersed into the canyon heads.Ancient canyons that have long been buried underneath the Avon Canyon are identified in the multichannel seismic profile across the head of the Avon Canyon,while a number of normal faults around the walls of the Avon and Mahin Canyons are observed in the selected sub-bottom profiles.The occurrence of these faults,especially in the irregular portions of the canyon walls,suggests that they also have some effect on the canyon architecture.The formation of the canyons is attributed to the exposure of the upper marginal area to incisions from erosion during the sea level lowstand of the glacial period.The incisions are widened and lengthened by contouric currents,turbidity currents and slope failures resulting in the canyons.  相似文献   

16.
利用模糊综合方法评价长江口海水富营养化水平   总被引:8,自引:0,他引:8  
根据2004年4个季度的调查数据,以化学需氧量(COD)、溶解无机氮(DIN)、磷酸盐(PO4-P)、叶绿素a(Chl-a)和溶解氧(DO)作为评价指标,运用模糊综合评价模型对长江口海域海水富营养化水平进行评价。结果表明,约有一半的调查站点呈现富营养化,长江口门及冲淡水区(122.5°E以西)富营养化程度较高,外海(122.5°E以东)富营养化程度较低,富营养程度从外海向近岸增加。富营养化区域全年大部分都分布于盐度小于20的一侧,呈明显的季节分布和区域分布,表明长江口海域的富营养化水平主要受到长江冲淡水的控制。  相似文献   

17.
This paper presents an overview of two new inertial systems that are now in production at the Guidance and Control Systems Division of Litton Systems, Inc. These units are small, lightweight, require little power, and are silent. Data are presented that show long-term performance as well as short-term attitude, position, and velocity reference data for the LN-100 system. Attitude, velocity, and body axis rate data are required for stabilization of such devices as laser line scanners and long baseline side-scan sonars. The relationship between the characteristics of these sensors and inertial type errors is explored. This analysis shows that it is not sufficient to specify the inertial system only in terms of its navigation CEP. The specification of the inertial unit must also be based on the needs of the sensor payload and include such considerations as short-term stability, the noise content, phase, and bandwidth of the stabilization reference  相似文献   

18.
皱瘤海鞘胃肠道中3种内分泌细胞的免疫组织化学定位   总被引:1,自引:0,他引:1  
应用免疫组织化学技术,用5-羟色胺、神经肽Y和胃泌素3种抗血清对皱瘤海 鞘(Styela plicata)胃肠道内分泌细胞进行鉴别和定位.结果表明,皱瘤海鞘的胃、前 肠、中肠和后肠均不同程度地存在5-羟色胺、神经肽Y和胃泌素3种免疫活性内分 泌细胞,且细胞在胃部的分布密度最高,后沿肠道逐渐递减,至后肠密度最低.胃肠道 免疫活性内分泌细胞可分为开放型和封闭型两种类型.开放型细胞多为长柱形或圆 锥形,具有长短不一的胞质突起;封闭型细胞则多为圆形或椭圆形.本文结合内分泌 细胞的分布密度和形态特点对其在皱瘤海鞘胃肠道中的功能进行讨论.  相似文献   

19.
本文基于渤海南部各测站观测风和浪的资料,分析了本海域波候的区域性特征.大浪的季节性变化和地理分布及风浪随风速成长特征等也作了讨论.另外,还指出本海域中大浪区.这些结果可用于制定防灾措施的依据.  相似文献   

20.
This paper covers the topic of marine geodesy, its goals, and applications. Specifically discussed are position determination and establishment of geodetic control on the ocean bottom, ocean surface, and subsurface, and the determination of the geoid, a vertical reference surface. The various techniques used in position determination (including satellite, airborne, radio, inertial and acoustic techniques) are assessed in terms of accuracy, coverage, and contribution to the solution of specific problems associated with position and control. The results of several marine geodetic control experiments are presented. Classical techniques for the determination of the geoid are discussed and assessed, as are new techniques such as satellite altimetry. The outlook for marine geodetic measurements in the ocean is outlined in terms of what is being planned or considered for the next decade, and several recommendations are made.  相似文献   

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