956 resultados para OUTER HELIOSHEATH
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Ocean color and sea surface temperature data from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite are used to study the cross-shelf circulation and transport of suspended sediments in the Yellow and the East China Seas. The ocean color images show a significant turbid water plume extending in the southeast direction from the Subei coasts of China to the shelf edge south of Cheju during fall-winter, suggesting significant cross-shelf currents in the Yellow Sea/East China Sea in winter. The currents transport suspended sediments from the area of the old Huanghe mouth into the Okinawa Trough. Part of the turbid plume joins the Yellow Sea Warm Current to enter the Yellow Sea trough in winter. The satellite images suggest that the time scales of cross-shelf transport and surface-to-subsurface descending of the suspended sediments are a few weeks. The turbid plume grows in fall, reaches its maximum expansion and intensity in winter-spring, and subsides in late spring. In summer, the plume becomes coastally trapped. Substantial interannual variations of the intensity and coverage of the turbid plume are indicated by the observations. In comparison, the Changjiang Diluted Water in summer only transports a small amount of the Changjiang suspended sediment to the outer shelf south of Cheju, which does not enter the Yellow Sea owing to the weak intrusion of the Yellow Sea Warm Current in summer. The dynamics of the cross-shelf circulation in the Yellow Sea in winter are hypothesized to be associated with (1) the convergence of the Yellow Sea Coastal Current and the Taiwan Warm Current off the Changjiang mouth and (2) the time-dependent forcing of the northerly wind bursts that drives the intrusion of the Yellow Sea Warm Current. (C) 2007 Elsevier B.V. All rights reserved.
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研究胶州湾浮游植物的物种组成与时空分布的特点,对于了解该湾生态系统的现状与历史变化趋势以及生态系统对自然条件变化和人类干扰的响应具有重要意义。 本文根据2004年每月一次采集的浮游植物样品,分析了胶州湾浮游植物的物种组成和优势种的时空分布情况。调查发现浮游植物共142种,分属于6门53属,其中硅藻门40属113种,占总物种数的79.6%;甲藻门10属24种,占总物种数的16.9%;其它为金藻门1属2种,裸藻1属1种,绿藻1属2种。浮游植物丰度周年波动范围为11.12-14602.39×104cells/m3,全年平均为1857.55×104cells/m3。全年丰度最高的藻为环纹劳德藻(Lauderia annulata),出现在2月份,而全年的丰度最高值也出现在2月份。在胶州湾中,硅藻所占比例最大,平均为97.44%,最高为99.95%,最低为82.55%。浮游植物的丰度的周年变化:有两个高峰,分别出现在2月份和10月份,是典型的温带海域双高峰的分布形式。 胶州湾浮游植物的优势种分析,采用Kikvidze等(2002)提出的确定优势种数量的计算方法,再依据各物种的优势度排序最终确定优势种。其中在多样性最低的6月和10月,优势种数目均为1种,分别为丹麦细柱藻(Leptocylindrus danicus)和中肋骨条藻(Skeletonema costatum)。而在多样性指数较低的1月、2月,优势种数目分别为2和3;而在物种多样性比较高的5月、7月、11月,由于分布相对比较分散,所以优势种数量较多。这说明这个方法可以较好地完成对胶州湾浮游植物群落分析时确定优势种的目标。优势种出现频率较多的种类为中肋骨条藻(1、3、4、5、8、10、11、12月)、洛氏角毛藻(Chaetoceros lorenzianus)(7、8、9、11、12月)、尖刺拟菱形藻(Pseudonitzschia pungens)(2、3、5、7月)、加拉星杆藻(Asteronella kariana)(1、2、3、5月)、密联角毛藻(Chaetoceros densus)(5、11、12月)、扭鞘藻(Streptothece thamesis)(7、8、9月)、夜光藻(Noctiluca scintillancs)(4、5、7月)、奇异菱形藻(Nitzschia paradoxa)(5、11、12月),对这些种的时空分布进行了分析。 对2004年胶州湾的浮游植物数据进行分层聚类分析后,发现可以将胶州湾划分为三个海区:湾南与湾外海区、湾中西部海区、湾东海区。
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本论文的目的是研究几种病原菌口服疫苗接种鱼类的免疫效果,并从常见病原菌株中筛选几个具有较好保护效果的蛋白抗原,利用口服免疫的方式,接种养殖动物,并检测免疫效果。 以10号白油为有机溶剂,采用搅拌与均浆方法制备鳗弧菌M3和SMP1的油乳化二价疫苗,用饵料包埋后以口服途径免疫养殖大菱鲆,评价免疫大菱鲆的免疫应答和疫苗的保护效果。结果显示,以油乳化和未油乳化疫苗分别连续口服免疫大菱鲆一周后,在后肠组织,乳化疫苗刺激产生的非特异性活力、特异性抗体水平均高于未乳化疫苗;而在血清,两种疫苗引起的两种酶的活力、SMP1抗体水平没有变化,但在乳化疫苗免疫的大菱鲆检测到明显高于未免疫对照大菱鲆的M3抗体水平。大菱鲆后肠组织原位杂交结果显示,口服免疫的大菱鲆后肠褶皱有IgM抗体的产生和分布。其中,乳化疫苗免疫大菱鲆的IgM抗体的产生和分布水平高于未乳化疫苗免疫的大菱鲆。攻毒实验显示,乳化疫苗免疫的大菱鲆对M3和SMP1的感染分别获得100%和50%的免疫保护率,而未乳化疫苗获得的免疫保护率分别为57.9%和0%,表明乳化疫苗比未乳化疫苗更有效地保护大菱鲆、抵抗病原的感染。在乳化疫苗免疫持续期的研究中,免疫的大菱鲆后肠在免疫后120天仍能检测到抗体效价,在免疫后90天还能观察到一定的免疫保护效果。免疫30天、60天、90天和120天的大菱鲆分别获得100%、66.7%、36.7%和13.3%的免疫保护力。 以鳗弧菌M3和SMP1、链球菌CF、迟缓爱德华菌SMW7作为细菌抗原制备油乳化多价口服疫苗和轮虫携带疫苗,口服途径免疫养殖大菱鲆与大菱鲆初孵仔鱼。结果显示,在免疫大菱鲆后肠可检测到抗M3抗体水平的提高(P<0.05),而在其胆汁、鳃、中肠、体表黏液、前肠与血清中抗体效价变化与对照组没有显示出差异;没有检测到免疫大菱鲆后肠抗SMP1、SMW7、CF抗体效价。M3浸泡攻毒实验显示,口服免疫的大菱鲆获得了100%的免疫保护力;在M3注射攻毒和SMP1、CF、SMW7浸泡攻毒大菱鲆的实验中,在每个攻毒组中,免疫组大菱鲆开始死亡的时间都要比对照组有不同程度的延迟,但攻毒大菱鲆都发生死亡,不能显示出与对照组的差异。轮虫携带免疫的结果显示,免疫的大菱鲆初孵仔鱼并未获得较好的保护效果,与对照大菱鲆没有体现出差异。 从致病性病嗜水气单胞菌(Aeromonas hydrophila)LSA34克隆并表达ahaI基因和gapA基因,从迟缓爱德华菌(Edwardsiella tarda)LSE40克隆并表达eseB,将所得蛋白分别通过腹腔注射途径免疫大菱鲆,检测蛋白的免疫原性和免疫保护。结果在免疫后7天就可以检测到AhaI、GapA蛋白免疫组大菱鲆产生的抗体,至第40天可以检测到明显的保护性抗体,之后抗体效价增加明显,直至第60天时达到最高值。EseB免疫的大菱鲆第一次免疫后15天就有较高的抗体效价产生,明显高于对照组大菱鲆血清抗体效价,到距第一次免疫60天时,抗体效价达到最高值。攻毒实验显示,与对照组相比,AhaI免疫组和GapA免疫组对LSA34感染的免疫保护力分别为80%和100%;AhaI免疫组和GapA免疫组对LSE40感染的免疫保护力分别为30%和10%。,而对照组牙鲆对人工攻毒不具有保护力。以AhaI和GapA作为疫苗免疫大菱鲆,使大菱鲆获得了对嗜水气单胞菌LSA34较高的免疫保护;而对迟缓爱德华氏菌LSE40的交叉保护能力没有明显提高。EseB免疫的大菱鲆在攻毒实验中并没有显示出较好的保护效果,与对照组相比,只是在死亡时间上有所延迟。 以从致病性嗜水气单胞菌中克隆的ahaI和gapA基因表达出的蛋白为蛋白抗原制备油乳化疫苗,用饵料包埋后以口服途径免疫养殖牙鲆,评价免疫牙鲆的免疫应答和疫苗的保护效果。结果显示,以油乳化和未油乳化疫苗分别免疫牙鲆一周后,在后肠组织,AhaI和GapA乳化疫苗免疫组牙鲆检测到抗体,且分别高于AhaI和GapA未乳化疫苗免疫的牙鲆;而在血清,GapA的两种疫苗引起的GapA抗体水平没有变化;但在AhaI乳化疫苗免疫的牙鲆第21天和第35天的血清中检测到高于未免疫对照牙鲆的AhaI抗体水平,AhaI未乳化疫苗免疫牙鲆血清对照组相比没有检测到AhaI抗体水平的变化。
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Based oil the measurements of particulate phosphorus (PP) in the Jiaozhou Bay front May 2003 to April 2004, the spatial distribution, seasonal variation and biogeochemical characteristics of PP Were investigated to Understand the fates and roles of phosphorus in the Jiaozhou Bay ecosystem. The Concentration of the total PP ranged from 0. 07 to 2. 09 mu mol/dm(3). The concentration of POP was from 0. 01 to 1. 83 mu mol/dm(3), with all average of with all average of 0. 33 mu mol/dm(3), which accounted for 50. 4% in total PP. In general, file concentrations of IT in surface water show obvious seasonal variations in the Jiaozhou Bay. POP was the highest in spring, which derived front the accumulation of phyto-detritus and was the lowest ill autumn, which was decomposed into seawaters to participate the recycle of phosphorus. PIP was the highest in spring and summer and Was the lowest in autumn and winter. PLP Was Mainly influenced by river input in the inner bay lint POP derived front autochthonous source in the outer bay. Overkill, the concentrations of IT in the inner bay were higher than those in mouth and the Older bay. In the inner bay. the concentrations of IT with the area near the shore were higher than those in the center of the bay. Totally PP showed the decreasing trend with depth especially in spring and winter. The high value of PP emerged in 20 and 10 in Corresponding to summer and autumn, respectively. The changes of POP showed hysteretic effect compared with the changes of Chl a in the investigated year. However, according to the Change of Chl a, the second high value of POP which should be emerged ill October was missing due to the remineralization of POP and participation in the recycle of phosphorus, which lead to the high concentration of orthophosphate in seawaters.
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The vertical distribution and stage-specific abundance of Calanus sinicus were investigated on three key transects in the southern Yellow Sea and the northern East China Sea in August 1999. The results showed that in summer C. sinicus shrank its distribution area to the central cold (less than or equal to10degreesC) bottom water in the Yellow Sea, i.e. the Yellow Sea Cold Bottom Water, remaining in high abundance (345.7 ind m(-3)). In the northern East China Sea on a transect from the mouth of the Yangtze River to the Okinawa trench, only a few individuals appeared in the inner side and none had been found either in the upper layer or in the deep layer of the outer shelf area. The population of C. sinicus in YSCBW consisted of mainly adults (46.83%) and C5 (37.41%). C1-C4 only accounted for 15.76%. The low proportion of the earlier copepodite stages and the high female:male ratio (11.39) indicated that the reproduction of C. sinicus in YSCBW was at a very low level due to the low temperature and low food concentration. It is concluded that the dramatic decrease of C. sinicus population in the shelf area of China seas in summer is caused by the shrinkage of its distribution area and the YSCBW served as an oversummering site.
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Organic carbon (OC), total nitrogen (TN), and Pb-210 in core sediment were measured to quantify the burial of organic carbon and the relative importance of allochthonous and autochthonous contributions during the past one hundred years in Jiaozhou Bay, North China. The core sediment was dated using Pb-210 chronology, which is the most promising method for estimation of sedimentation rate on a time scale of 100-150 years. The variation of the burial flux of organic carbon in the past one hundred years can be divided into the following three stages: (1) relatively steady before 1980s; (2) increasing rapidly from the 1980s to a peak in the 1990s, and (3) decreasing from the 1990s to the present. The change is consistent with the amount of solid waste and sewage emptied into the bay. The OC:TN ratio was used to evaluate the source of organic carbon in the Jiaozhou Bay sediment. In the inner bay and bay mouth, the organic carbon was the main contributor from terrestrial sources, whereas only about half of organic carbon was contributed from terrestrial source in the outer bay. In the inner bay, the terrestrial source of organic carbon showed a steady change with an increase in the range of 69%-77% before 1990 to 93% in 2000, and then decreased from 2000 because of the decrease in the terrestrial input. In the bay mouth, the percentage of organic carbon from land reached the highest value with 94% in 1994. In the outer bay, the sediment source maintained steady for the past one hundred years.
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The seasonal evolution of dissolved inorganic carbon (DIC) and CO2 air-sea fluxes in the Jiaozhou Bay was investigated by means of a data set from four cruises covering a seasonal cycle during 2003 and 2004. The results revealed that DIC had no obvious seasonal variation, with an average concentration of 2035 mu mol kg(-1) C in surface water. However, the sea surface partial pressure of CO2 changed with the season. pCO(2) was 695 mu atm in July and 317 mu atm in February. Using the gas exchange coefficient calculated with Wanninkhof's model, it was concluded that the Jiaozhou Bay was a source of atmospheric CO, in spring, summer, and autumn, whereas it was a sink in winter. The Jiaozhou Bay released 2.60 x 10(11) mmol C to the atmosphere in spring, 6.18 x 10(11) mmol C in summer, and 3.01 x 10(11) mmol C in autumn, whereas it absorbed 5.32 x 10(10) mmol C from the atmosphere in winter. A total of 1.13 x 10(11) mmol C was released to the atmosphere over one year. The behaviour as a carbon source/sink obviously varied in the different regions of the Jiaozhou Bay. In February, the inner bay was a carbon sink, while the bay mouth and the Outer bay were carbon sources. In June and July, the inner and Outer bay were carbon sources, but the strength was different, increasing from the inner to the outer bay. In November, the inner bay was a carbon source, but the bay Mouth was a carbon sink. The outer bay was a weaker CO2 Source. These changes are controlled by many factors, the most important being temperature and phytoplankton. Water temperature in particular was the main factor controlling the carbon dioxide system and the behaviour of the Jiaozhou Bay as a carbon source/sink. The Jiaozhou Bay is a carbon dioxide source when the water temperature is higher than 6.6 degrees C. Otherwise, it is a carbon sink. Phytoplankton is another controlling factor that may play an important role in behaviour as a carbon source or sink in regions where the source or sink nature is weaker.
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Two new species of Naticidae (Mollusca, Gastropoda) collected from the coast of China are described: Cryptonaitca huanghaiensis sp. nov. and Sinum. vittatum sp. nov. The morphological characteristics between the new species were described and the related information was provided. The similarities and differenees between the new species and related species were also compared and discussed. The new species Cryptonaitea huanghaiensis differed from Cryptonaitca hirasei and Cryptonaitca andoi in outer shape, operculum and radula. The new species Sinum, vittatum is similar to Sinum, japonicum (Lischke, 1869), but the shell of the former is flat-elliptical in shape, spire very small, slightly convex. While the latter is flat-globular in shape, apex light brown in color, without a brown band on the body whorl. The comparison results revealed that Cryptonaitca huanghaiensis and Sinum vittatum were two new species from the coast of China. Specimens studied were obtained from collections in the Marine Biological Museum, Chinese Academy of Sciences.
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Ti and Ti alloys can be applied to steels as a protective coating in view of its excellent resistance to corrosive environment. Cold spraying, as a new coating technique, has potential advantages in fabrication of Ti coating in comparison with conventional thermal spraying techniques. In this study, Ti coatings were prepared on carbon steel substrates by cold spraying via controlling the process conditions. The microstructure of coatings was observed by SEM. The porosity of coatings was estimated by image analysis and the bond strength was tested for comparison of the process conditions. Potentiodynamic polarization and open-circuit potential (OCP) measurements were performed to understand the corrosion behavior of the coatings. The SEM examination shows that the coatings become more compact with the increases of pressure and temperature of driving gas. The potentiodynamic polarization curves indicate that the coating which has lower porosity has lower corrosion current. The polarization and OCP measurement reveal that cold-sprayed Ti coating can provide favorable protection to carbon steel substrate. The polishing treatment of coating surface polishes the rough outer layer including the small pores as well as decreases the actual surface area of the coating, leading to the considerable improvement of corrosion resistance.
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Vision plays an important role in the living habits of animals, especially in feeding. We investigated the postnatal development of retina in root vole Microtus oeconornus. The result shows that the retina of the M. oeconornus is very primitive before postnatal day (PD) 3. The neuroblastic layer does not differentiate and makes up more than half of the retina layer. The outer plexiform layer (OPL) first comes into existence at PDS. At PD6, as the presence of the OPL becomes obvious, the outer nuclear layer (ONL) and inner nuclear layer (INL) are much clearer. At PD18, the retina is similar to an adult retina and each layer becomes distinct. The thickness and cell density of the ganglion cell layer (GCL) and ONL during different postnatal days were also examined. These results show that the thickness and density of ONL increase during ontogeny, while the thickness and density of GCL decrease. Compared with Rattus norvegicus, Apodemus agrarius , Cricetulus triton, Microtus mandarinus , Myospalax cansus , Spermophilus dauricus and Sciurotamias davidianus, the histological structure of the retina of M. oeconornus is between that of nocturnal and diurnal rodents.
A new genus of grasshopper (orthoptera : acridoidea : Catantopidae : Cyrtacanthacridinae) from China
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This paper reports a new genus i.e. Parapachyacris gen. nov and a new species Parapachyacris taiwanensis sp. nov in Cyrtacathacridinae. The new genus is similar to Pachyacris Uvarov, 1923 and differs from the latter in: 1) foveolae lacking; 2) hind tibiae with 10 spines on inner side and 8 spines on outer side; 3) basal part of prostemal process thickened; 4) cross veins right angled with longitudinal veins in apical part of tegmina and 5) the back of body with yellow longitudinal stripe in middle. The new genus is also similar to Patanga Uvarov, 1923 and differs from the latter in: 1) foveolae lacking; 2) basal part of prostemal process thickened; 3) upper side of hind femora with three dark bands and 4) black spots of tegmina lacking. Type specimen is deposited in the National Museum of Natural Science (NMNH), Taichung, Taiwan, China.
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运动目标跟踪技术是未知环境下移动机器人研究领域的一个重要研究方向。该文提出了一种基于主动视觉和超声信息的移动机器人运动目标跟踪设计方法,利用一台SONY EV-D31彩色摄像机、自主研制的摄像机控制模块、图像采集与处理单元等构建了主动视觉系统。移动机器人采用了基于行为的分布式控制体系结构,利用主动视觉锁定运动目标,通过超声系统感知外部环境信息,能在未知的、动态的、非结构化复杂环境中可靠地跟踪运动目标。实验表明机器人具有较高的鲁棒性,运动目标跟踪系统运行可靠。
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对当前移动机器人上常用的激光测距仪的性能研究进行了全面的总结。分析了检测SICK、Perceptron、Explorer等常用激光测距仪各方面特性的各种实验结果。根据影响激光测距仪测量性能的方式,把激光测距仪的时变特性、角度偏移、数据传输影响、混合象素现象、色度亮度干扰现象、辐射干扰现象等,分为内因和外因两大类进行了分类讨论。
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为了研究结构变形对大型六维力传感器精度的影响,基于螺旋理论及影响系数方法,并借助位姿解建立了考虑结构整体变形条件下Stewart平台六维力传感器测量误差模型,推导出并联六维力传感器测量的I,II类误差表达式,分析了在不同外载下,六维力传感器Ⅰ,Ⅱ类误差,总结了结构变形和平台自重对传感器测量精度的影响规律,为具有普通球形铰链大型Stewart平台六维力传感器标定方案的选择和精度的改善提供了理论基础。
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长基线声学定位系统是水下机器人广泛应用的外部导航设备。以对"CR-02"6000m自治水下机器人(简称AUV)技术的深入开发为背景,提出在原有长基线(LBL)定位系统的基础上增加导航功能的方案。由于海水介质非均匀性与复杂的时空变化特性,给基于测距的位置计算带来很大困难。采用平均声速法计算耗时小而误差大,波阵面定位法误差小而耗时大。为解决这个矛盾,根据AUV深度传感器给出的深度信息,采用本征声线快速计算方法解算AUV的水平面位置。与波阵面法、平均声速法进行了综合比较。仿真实验表明该方法具有优良的性能,满足AUV导航需要。