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本文对取自台湾海峡棱鮻 (Lizacarinatus)消化道的弯睾软穴吸虫 (HapalotremaflecterotestisZhukov, 1971)进行重新描述,并对其毛蚴的体外发育进行观察.根据Yamaguti(1971)区分单孔科 (Haploporidae)和叉盘科 (Waretrematidae)的标准,同意李敏敏(1984)将其从单孔科移出并入叉盘科.在与叉盘科已知属比较后,我们发现该吸虫除睾丸形状外,其他主要特征与鲫吸虫属 (CarassotremaPark, 1938)的相似.因此,我们拟将其作为后者的同物异名,并将该吸虫重新命名为弯睾鲫吸虫 [Caras sotremaflecterotestis(Zhukov, 1971)comb. nov. ].实验结果表明:在室温 7~24℃(均值为 15. 3℃)条件下,其虫卵从单个卵细胞到毛蚴孵出共需 12d. 相似文献
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鲻鱼体内单睾椭囊吸虫的种群生态研究 总被引：2，自引：0，他引：2
鲻鱼肠内的单睾椭囊吸虫Elliptobursa singlorchis随着宿主体长的增长，其感染率、感染强度和种群平均密度呈逐渐增加的趋势；其中群平均拥挤度、扩散性指标随着体长的增长亦有显著的增加，而负二项参数则在0．13－0．34之间呈不规划的变动；在春夏秋3季，吸虫在宿主鲻鱼体内的感染率逐渐降低，冬季又显著增加，而感染强度和种群平均密度在一年四季中则变化不大。吸虫种群在不同体长组的鲻鱼体内均为聚集分布，而且聚集强度随种群密度的增加而增强。吸虫种群在一年四季中的鲻鱼体内的时空分布亦为聚集分布，聚集强度变化不大。 相似文献
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转体科吸虫一新属、新种 总被引：1，自引：0，他引：1
Manter (1961)从斐济的鱵鱼( Hemiramphus sp.)肠道内采到一种吸虫,以不具口腹吸盘,睾丸单个,虫体呈横向延长等特征建立了新属转体吸虫属 Treptodemhs ,放在二囊科 Bivesiculides 内。Yamaguti (1971) 将该属提升为转体科 Treptodemidae ,含1属,并以 Treptodemus latus Manter,1961为该科的代表。作者在整理鉴定1992年采自海南省鱵鱼吸虫标本时发现一种吸虫,按其特征应归于转体科,但体形与其内部各器官的形状、位置等均与该属差异很大,故建新属,记述如下。转体科吸虫在我国尚属首次报道。
虫体测量均为mm,卵子为μm,。模式标本保存在中国科学院海洋研究所。 相似文献
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报道寄生于斑点鸡笼鲳Drepanepunctata(Linnaeus)消化道的阿拉伯类腹盘吸虫Par adiscogasterarabi(Hafeezullah＆Siddiqi,1970)Cribb,Anderson＆Bray,1999和寄生于金钱鱼Scatophagusargus(Linnaeus)消化道的福氏类腹盘吸虫ParadiscogasterfarooqiiHafeezullah＆Siddiqi,1970在中国属新发现,并将中国的标本同国外的标本进行比较。首次观察到Par adiscogasterarabi的排泄囊为"V"型;而Paradiscogasterfarooqii的排泄囊形状则与Nahhas,SeyandNishimoto(1998)和Cribb,Anderson＆Bray(1999)所报道的不同。首次绘制出这二种吸虫卵巢复合体的结构。 相似文献
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在国家908专项调查和成果集成工作的基础上,结合对海洋吸虫文献资料的收集,分析研究了中国海洋吸虫的物种多样性.其结果表明中国海洋吸虫有1 184种,其中单殖目吸虫410种,复殖目吸虫774种.单殖目的宿主都是硬骨鱼.复殖目物种成虫的宿主主要是鱼,也有爬行纲和兽纲.吸虫感染宿主有些具有专一性,但也有些具有普遍性.宿主的食性、地理分布和季节分布与吸虫感染密切相关.不同于以往70多年来主要进行的分类研究,本文主要探讨海洋吸虫的生活史及与其宿主的关系,这将为水生生物病虫害的防治和海洋物种多样性的研究提供基础资料,具有重要生物学和生态学的意义. 相似文献
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养殖文蛤体内寄生的一种吸虫幼虫及宿主组织病理学 总被引：3，自引：0，他引：3
作为文蛤吸虫病害研究的基础资料,报道了寄生在文蛤体内的1种复殖吸虫幼虫的形态结构及宿主由此所产生的组织病理学变化。研究表明：该吸虫分别为咆蚴和尾蚴。咆蚴圆筒形,内含不同发育阶段的尾蚴。成熟尾蚴体成扁平舌状,具有口吸盘、腹吸盘,1对眼点和1条细长无刺的尾巴。该吸虫主要侵占生殖腺,少部分幼虫进入附近的消化盲囊、鳃、肾等部位。轻微感染者,生殖滤泡萎缩,生殖细胞发育滞后;严重感染的宿主,生殖腺完全被侵占并耗尽。消化盲囊、鳃、肾等器官组织也因幼虫感染呈现不同程度的病理学变化;严重者上皮细胞水肿或脱落,肌肉组织结构紊乱或溶解等。本工作同时显示,吸虫寄生可诱发宿主血淋巴细胞大量增生,并产生凝集、组织浸润及形成包囊等免疫反应。 相似文献
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厦门颈褶吸虫,新种Tergestia
xiamenensissp.nov.发现于鲈鱼Lateolabrax japonicus靠近肛门处的肠道.它与本属较相似的种有尖颈褶吸虫T.acuta 相似文献
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囊双科Didymozoidae Poche,1907吸虫为鱼类专性寄生虫之一,其体形多变,寄生部位广泛,侵袭宿主体内与体外各种组织与器官,因而引起人们的注意,国外不断有该科的研究报道。我国关于该科的研究,顾昌栋在1965,1983年曾有文章发表,但其中有关东海的种类不多。1975,1976,1979年作者在东海采集鱼类寄生虫,整理后共得囊双科吸虫11种。其中除双枝囊双吸虫Didymosoon biramous Ku et Shen,1965,大眼鲷囊双吸虫Didymozoon priacanthi Ku et Shen,1965;海南合体双吸虫Syncorpozoum hainanensis Ku et Shen,1965鲐囊双吸虫Didymozoon Pneumatophori Gu et Shen,1983和线形线双吸虫Nematobothrium filiforme Yamaguti,1934在我国已作报道外,共发现1新属3新种及3个新记录。本文为新种和新记录描述。测量一律用毫米,卵子用微米。模式(副模式)标本存放于中园科学院海洋研究所。 相似文献
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港口内靠码头系泊船运动的计算 总被引：11，自引：1，他引：11
本文以英国南海岸处Ｓｈｏｒｅｈａｍ港内系泊船为例，研究了港口内靠码头系泊船运动的数值计算问题。该船的实船实验和模型实验已经完成，为验证本文计算结果提供了依据。运动方程在时域内求解。在计算船体脉冲响应函数时，引入了船体阻尼系数在频率很低时的渐近表达式和一迭代算法。分析了港内共振波浪和其对船体的作用力。讨论了靠码头系泊船运动的非线性特征。计算结果与实验结果符合很好。 相似文献
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An elliptic jet and a square jet flowing into a counterflow with different jet-to-current velocity ratios are investigated by using realizable k–ε model. Some computed mean velocity and scalar features agree reasonably well with experimental measurements, and more features are obtained by analyzing the computed results. After fluid issues from a nozzle, it entrains ambient fluid, and its velocity and concentration on the centerline decay with the distance downstream from the potential core (l0). The decay ratio increases with the decreasing jet-to-current velocity ratio α. For an elliptic jet, the evolution of the excess velocity half-width b and the concentration half-width bc merely remains constant near the jet exit on major-axis plane while they increase linearly on the minor-axis plane. However, the half-widths on the major-axis and minor-axis plane become proportional to the axial distance downstream after equaling each other. For a square jet, b and bc increase linearly with the distance downstream from the jet exit, but the spread ratio is larger on the middle plane than that on the diagonal plane before they equal each other. The radial extent of the dividing streamline rs or the mixing boundary rsc increases linearly downstream, and decreases exponentially after reaching a peak at xb. The ratio on the minor-axis plane is larger than that on the major-axis plane for an elliptic jet. The characteristics are the same for the square jet. b, bc, rs, and rsc on two corresponding planes become equal to each other more rapidly for the square jet than for the elliptic jet, because the sharp corner of the square nozzle induces secondary structures that are more intense. The distributions of the excess axial velocity and scalar concentration exhibit self-similarity for either the elliptic jet or square jet in the region of l0 < x < xb. On the cross section, four counter-rotating pairs of vortices, which enhance the entrainment between the jet and counterflow, form at the four corners of the square jet or at the two ends of the major-axis plane of the elliptic jet. The recirculation pattern formed by these axial vortices is more complex for the square jet than that for the elliptic jet. The turbulent kinetic energy k have large value in the region near the jet exit and stagnation point. The maximum value of k for the square jet is larger than that of the elliptic jet near the jet exit. This results in the square jet mixing more strongly than the elliptic jet. 相似文献
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提出一种基于序贯预测误差方法（ＳＰＥ）的多层神经网络（ＭＮＮ）的学习算法。经模拟计算，它比传统的基于最陡下降方法的误差反传（ＳＤＢＥＰ）算法具有更好的收敛性能。并对这两种算法进行了模拟计算的比较． 相似文献
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This paper deals with the study of moisture budget of the typhoon No. 7507. The results show that the mass convergence produced by divergent wind has made the maximum contribution to precipitation, especially at the lower level, accounting for about 70% of the total precipitation, and that the advection term of water vapor is very small. The vertical flux term is to transport water vapor from the lower level to the middle and upper levels, resulting in the increase of water vapor accumulation at these levels. Evaporation term also plays an important role in precipitation, accounting for about 13% of the total precipitation and 23% of the horizontal moisture convergence. The moisture of the typhoon comes mainly from its southern boundary and the secondary inflow of moisture is from its western or eastern boundary. All the inflow layers of these three boundaries are very deep, reaching up to 300 hPa, while the strongest inflow occurs below 700 hPa. In the northern boundary of the typhoon, we obtained that 相似文献
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A Time-Domain Coupled Model for Nonlinear Wave Forces on A Fixed Box-Shaped Ship in A Harbor 总被引：2，自引：1，他引：1
A 2-D time-domain numerical coupled model is developed to obtain an efficient method for nonlinear wave forces on a fixed box-shaped ship in a harbor.The domain is divided into an inner domain and an outer domain.The inner domain is the area beneath the ship and the flow is described by the simplified Euler equations.The other area is the outer domain and the flow is defined by the higher-order Boussinesq equations in order to consider the nonlinearity of the wave motions.Along the interface boundaries between the inner domain and the outer domain,the volume flux is assumed to be continuous and the wave pressures are equal.Relevant physical experiment is conducted to validate the present model.It is shown that the numerical results agree with the experimental data.Compared with the coupled model with the flow in the inner domain governed by the Laplace equation,the present coupled model is more efficient and its solution procedure is more simple,which is particularly useful for the study on the effect of the nonlinear wave forces on a fixed box-shaped ship in a large harbor. 相似文献
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中国隆头鱼之一新属新种——尖尾新丝隆头鱼 总被引：1，自引：0，他引：1
在过去几年的西沙群岛鱼类区系调查中,我们曾在西沙群岛的东岛和永兴岛附近水域,先后三次采到5尾前所未曾见过的隆头鱼类标本,经过比较研究后,认为是一新属、新种,定名为“尖尾新丝隆头鱼”,(Neocirrhilabrus oxyurus gen. et sp. nov.)现描述如下: 相似文献
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王荣良 《中国海洋大学学报(自然科学版)》1988,(1)
本文对J.Maynard Smith提出的物种竞争模式: x=x(a-bx-cy-kxy) y=y(e-fx-gy-lxy)作了定性分析,并给出两物种共存或其中任一物种死亡,而另一物种趋于确定值的条件。 相似文献
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An edge wave is a kind of surface gravity wave basically travelling along a shoaling beach. Based on the periodic assumption in the longshore direction, a second order ordinary differential equation is obtained for numerical simulation of the cross-shore surface elevation. Given parameters at the shoreline, a cross-shore elevation profile is obtained through integration with fourth-order Runge-Kutta technique. For a compound slope, a longshore wavenumber is obtained by following a geometrical approach and solving a transcendental equation with an asymptotic method. Numerical results on uniform and compound sloping beaches with different wave periods, slope angles, modes and turning point positions are presented. Some special scenarios, which cannot be predicted by analytical models are also discussed. 相似文献
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一种来自海洋细菌的血纤维蛋白溶酶的分离纯化及性质研究 总被引：2，自引：0，他引：2
利用硫酸铵分级盐析、DEAE－纤维素阴离子交换层析、Sephadex G-75凝胶层析法对由海洋细菌FE92－8分泌的纤维蛋白溶酶进行了分离纯化，结果得到SDS－聚丙烯酰胺凝胶电泳单一区带。性质研究发现，该酶分子量为12.6kD，等电点为7.45，琼脂糖－纤维蛋白平板法测得该酶作用的最适温度为50℃，最适pH为8.0，在37℃，pH为8.0的情况下表现出很好的稳定性，温度起来50℃热稳定性较差，在碱性环境中稳定性较在酸性环境中稳定性强，阴性平板和阳性平板对比实验发现，该酶只有纤溶活性而无激酶活性，体外实验发现，该酶具有快速溶解血栓的能力。 相似文献