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1.
于 2 0 0 0年 3月提取中华绒螯蟹眼柄总RNA ,以此为模板 ,根据日本对虾的神经肽Pej SG Ⅳ设计兼并引物 ,进行RT PCR扩增 ,在适宜的反应条件下 ,获得一特异性的产物 ,将该片段克隆到载体中进行测序。结果表明 ,中华绒螯蟹特异性cDNA片段由 2 1 3个碱基组成。在生物信息数据库中查找由该cDNA推定的氨基酸序列的相似序列 ,可以发现有大量甲壳动物的CHH家族神经肽与它相似。在所有相似序列中 ,甲壳动物的蜕皮抑制激素 (MIH)与它的相似度最高 ,这一结果提示由中华绒螯蟹的眼柄特异性cDNA片段推定的氨基酸序列可能是它的MIH片段。  相似文献   

2.
该文把增强式学习方法应用于多障碍环境中机器人路径规划 ,并将增强式学习和路径规划相结合 ,通过工作空间势场的自适应优化学习 ,实现机器人的全局路径规划 ,即得到从任何初始位置开始的最优路径。与传统的人工势场方法相比 ,该方法避免了势场中局部极小点所引起的陷阱区域 ,并且所得到的路径具有最优特性。计算机仿真实验结果表明 ,这种学习方法能有效的解决多障碍环境中的机器人路径规划问题  相似文献   

3.
袁贺  孙长征  徐建明  武庆  熊兵  罗毅 《海洋学报》2010,32(10):7239-7244
针对光电子器件端面抗反镀膜的要求,研究了基于等离子体增强化学气相沉积(PECVD)技术的多层抗反膜的设计和制作.首先,对影响SiNx折射率的因素进行了实验研究,确定了具有大折射率差的SiO2/SiNx材料的PECVD沉积条件.根据理论计算分析,设计了四层SiO2/SiNx抗反膜结构,能够在70 nm的波长范围内实现低于10-4的反射率  相似文献   

4.
海岸河口二维潮流可视化数学模型   总被引:12,自引:0,他引:12  
经过多年的不同断的研究,逐步改进和完善了在海岸河口非常适用的,基于不规则三角形网格显式差分法的二维潮流数学模型,研制了潮流场可视化成品实用软件,将二者结合起来即构成了二维潮流可视化数学模,可视化数学模型不仅使数学模型可视化,直观化,而且加快了数学模型的调试速度,方便 了各种工程方案的比选,从而使用数学模型解决实际工程问题的效率大为提高。  相似文献   

5.
A 2D Mathematical Model for Sediment Transport by Waves and Tidal Currents   总被引:12,自引:5,他引:12  
In this study, the combined actions of waves and tidal currents in estuarine and coastal areas are considered and a 2D mathematical model for sediment transport by waves and tidal currents has been established in orthogonal curvilinear coordinates. Non-equilibrium transport equations of suspended load and bed load are used in the model. The concept of background concentration is introduced, and the formula of sediment transport capacity of tidal currents for the Oujiang River estuary is obtained. The Dou Guoren formula is employed for the sediment transport capacity of waves. Sediment transport capacity in the form of mud and the intensity of back silting are calculated by use of Luo Zaosen' s formula. The calculated tidal stages are in good agreement with the field data, and the calculated velocities and flow directions of 46 vertical lines for 8 cross sections are also in good agreement with the measured data. On such a basis, simulations of back silting after excavation of the waterway with a sand bar under complicated boundary conditions in the navigation channel induced by suspended load, bed load and mud by waves and tidal currents are discussed.  相似文献   

6.
针对遥感影像数据大面积覆盖的特性,利用数学形态学提出了一种多目标海岛水边线的同步提取模型,模型包括:利用K-means算法的海岛区域粗分割;基于灰度膨胀算法的海岛初始轮廓曲线确立;利用水平集算法的海岛水边线优化。以福州海域的多目标海岛水边线提取为例,将本文模型与K-means模型、二值化高斯滤波水平集模型(SBGFRLS)和基于改进水平集的海岛边界快速分割模型(ILSM-IBRS)进行了比较。结果表明,本文模型弥补了K-means模型的过分割现象,其计算耗时较SBGFRLS和ILSM-IBRS模型分别节省了96.16%和86.96%;其迭代次数分别减少了97.07%和90.59%。由此可见,本文模型解决了现有提取模型效率低、过分割等现象,实现了多目标海岛水边线的同步提取,为海岛普查等提供了一种快速提取方法。  相似文献   

7.
海滩地表水与地下水间的相互作用对于海岸带的物质循环及生态环境有重要的影响。基于控制体的思想推导出了统一形式的地表水和地下水的控制方程,在此基础上不仅实现了地表水和地下水的全耦合模拟,也简化了动边界的处理。对一些经典算例的模拟结果验证了该模型的有效性。  相似文献   

8.
文章以具有自由表面的三维非线性Navier-Stokes方程组为基本控制方程,垂向采用σ坐标变换后得到三维浅海湍流数学模型。数值模拟求解方法采用具有自动迎风、精度高及稳定性好的混合有限分析法求解,最后,以渤海湾潮流模拟算例验证了文中模型及其混合有限分析解法模拟潮流的正确性和应用于工程实际问题的适用性。  相似文献   

9.
An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%—20% and the piles‘ bearing state is improved greatly.  相似文献   

10.
A 2-D mathematical model of tidal current and sediment has been developed for the Oujiang Estuary and the Wenzhou Bay. This model accomodates complicated features including multiple islands, existence of turbidity, and significant differ-ence in size distribution of bed material. The governing equations for non-uniform suspended load and bed load transport are presented in a boundary-fitted orthogonal curvilinear coordinate system. The numerical solution procedures along with their initial conditions, boundary conditions, and movable boundary technique are presented. Strategies for computation of the critical condition of deposition or erosion, sediment transport capacity, non-uniform bed load discharge, etc. are suggested. The model verification computation shows that, the tidal levels computed from the model are in good agreement with the field data at the 18 tidal gauge stations. The computed velocities and flow directions also agree well with the values measured along the totally 52 synchronously ob  相似文献   

11.
LU  Yongjun 《中国海洋工程》2002,16(1):107-122
A 2-D mathematical model of tidal current and sediment has been developed for the Oujiang Estuary and the WenzhouBay. This model accomodates complicated features including multiple islands, existence of turbidity, and significant differ-ence in size distribution of bed material. The governing equations for non-uniform suspended load and bed load transport arepresented in a boundary-fitted orthogonal curvilinear coordinate system. The numerical solution procedures along with theirinitial conditions, boundary conditions, and movable boundary technique are presented. Strategies for computation of thecritical condition of deposition or erosion, sediment transport capacity, non-uniform bed load discharge, etc. are suggested.The model verification computation shows that, the tidal levels computed from the model are in good agreement with the fielddata at the 18 tidal gauge stations. The computed velocities and flow directions also agree well with the values measuredalong the totally 52 synchronously observed verticals distributed over 8 cross sections. The computed tidal water throughputsthrough the Huangda‘ao cross section are close to the measured data. And the computed values of bed deformation fromYangfushan to the estuary outfall and in the outer-sea area are in good agreement with the data observed from 1986 to 1992.The changes of tidal volumes through the estuary, velocities in different channels and the bed form due to the influence of thereclamation project on the Wenzhou shoal are predicted by means of this model.  相似文献   

12.
To solve problems concerning wave elements and wave propagation, an effective way is the wave energy balance equation, which is widely applied in oceanography and ocean dynamics for its simple computation. The present papaer advances wave energy balance equations considering lateral energy transmission and energy loss as the governing equation for the study of wave refraction-diffraction. For the mathematical model, numerical simulation is made by means of difference method, and the result is verified with two examples.  相似文献   

13.
传统的东、西半球版的多圆锥投影世界地图(经线世界地图),在表示世界海陆分布的格局和世界大洲、大洋等巨大的地理实体的空间关系方面有很好的效果,但两极地区的变形过大和北冰洋不能完整表示也是缺陷。郝晓光首创的纬线世界地图(即南、北半球版世界地图)采用的地图投影,把南、北极置于投影的中心位置,能使南极洲和北冰洋及其周边大陆变形很小和完整表示。纬线世界地图的优点弥补了经线世界地图的缺陷。从地图投影拓扑结构出发,通过引入中央经线对称型曲经线族、闭曲线、邻域、环极纬线族等概念,分析和阐释了经线和纬线世界地图投影的经纬网结构特点,给出了系列世界地图投影的数学模型。  相似文献   

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