黄河口新口门水下三角洲演变特征

黄河口新口门水下三角洲的发育演变影响到国土资源的增长与流失,影响到胜利油田海上油气开发变为陆上开发的战略,影响到黄河三角洲湿地生态系统的保护,其研究的开展具有重要的实际指导意义。现通过采用实测资料分析的方法,对黄河口新口门附近水下三角洲冲淤演变特征进行了研究,研究结果表明:黄河口清水沟流路自1996年改走清8汊河已10余年,黄河口新口门附近的海域由于入海泥沙的沉积扩散,海域地形发生了非常大的变化,通过运用AutoCAD、Surfer等软件对黄河口新口门地形分析可知,黄河口新口门水下三角洲平面呈椭圆形分布,椭圆长轴不超过15 km,短轴不超过10 km,说明黄河入海泥沙的沉积分布,除了新口门的大量淤积和老口门的剧烈冲刷外,其余大部分区域的冲淤厚度都在1 m以内。     

Rumor spreading in social networks

Social networks are an interesting class of graphs likely to become of increasing importance in the future, not only theoretically, but also for its probable applications to ad hoc and mobile networking. Rumor spreading is one of the basic mechanisms for information dissemination in networks; its relevance stemming from its simplicity of implementation and effectiveness. In this paper, we study the performance of rumor spreading in the classic preferential attachment model of Bollobás et al. which is considered to be a valuable model for social networks. We prove that, in these networks: (a) The standard PUSH-PULL strategy delivers the message to all nodes within O(log²n) rounds with high probability; (b) by themselves, PUSH and PULL require polynomially many rounds. (These results are under the assumption that m, the number of new links added with each new node is at least 2. If m=1 the graph is disconnected with high probability, so no rumor spreading strategy can work.) Our analysis is based on a careful study of some new properties of preferential attachment graphs which could be of independent interest.     

Inchworm robot grippers for clothes manipulation

Manipulating deformable objects like clothes, plastic, and paper by a robot is very challenging. This paper focuses on clothes manipulation as an example. A tracing manipulation method is used here to find a corner of the clothes. In this paper, tracing refers to tracing the clothes’ edge, with the robot’s movement based on feedback from sensors. One difficulty during this edge tracing is to make the robot trace smoothly and speedily without dropping the clothes in the process. This is due to the fact that deformable objects are sensitive to contact forces. A solution to this problem is to design a special robot gripper that can trace the clothes without having to worry about the clothes slipping away. In this paper, the development of inchworm-type grippers is proposed. Two sets of grippers inside a robot hand will allow the robot to trace the clothes more freely because there will always be a gripper firmly holding the clothes at any time. A unique tracing method for towel spreading using the inchworm grippers is also discussed. Experimental results have demonstrated the effectiveness of both the proposed grippers and also the algorithm. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

心理词库视角下词汇错误的认知分析

为了解二语学习者词汇使用的心理过程,利用心理词库的组织构建模型对英语作文文本中出现的错误分别从概念层、词目层和词位层做出认知分析.发现学习者受词汇近义关系使用的混乱及写作过程中的母语思维的影响,会造成概念层模糊;母语负迁移、教师归纳性受训迁移及泛化句法结构会引起词目层出现错误;英汉不同的正字法系统会造成词位层的拼写错误.最后认为应该加强学习者词汇的纵聚合和横组合的语义关系,完善其心理词库的语义网络,以提高词汇提取的准确性.     

高效复合肥料硝酸铵钙的生产及市场概况

介绍了硝酸铵钙的物化性能；概述了硝铵熔融液与石灰石混合法生产硝酸铵钙的工艺技术；分析了硝酸铵钙在农作物种植上的施用效果和产品市场前景。     

局部减缩积分曲面展开单元在某汽车翼子板一步成形模拟中的应用

为了进一步提高一步成形模拟的计算精度和避免单元的剪切闭锁,提出改进型曲面展开四节点等参膜单元模型,即在单元内力计算中采用了局部减缩积分技术,对现有算法进行了改进。将该方法用于某汽车翼子板成形模拟,并与增量法模拟结果及实验结果进行了对比。结果表明,改进后的一步成形模拟结果与增量模拟结果非常接近,而计算时间不到增量法的1/30,进而验证了本文方法的有效性和实用性。     

论循环农业的科技服务体系建设

发展循环农业必须有科技创新的支撑，农业科技推广服务是发展循环农业的重要环节。探讨了循环农业科技推广服务机制，分析了我国传统农技推广服务体系存在的问题。并就建设适应循环农业发展的农技推广服务体系提出了对策建议。     

基于优秀基因传播的免疫优化算法

对文献[5]的工作进行改进，改进基因重组策略，增加免疫基因传播操作，使得算法能够更快更好的搜索最优解．核心思想是区分成熟抗体中高层次抗体和低层次抗体，低层次群体不断更新，高层次群体相对稳定，但不断从低层次群体中学习优秀基因完善自身．本文详细介绍了该算法的设计思想和具体实验，实验结果说明本算法具有较好的问题求解能力．     

初始展开面积对一步成形模拟收敛效率的影响

通过典型件方盒，针对一步模拟法初始场预示的截面线展开法和反向变形法，研究了板成形冲压件表面积与初始展开面积之比对收敛性和收敛速度的影响，得出了适当调整该面积比，可以提高收敛速度的结论，并通过某轿车翼子板的一步成形模拟验证了该结论，为进一步提高一步成形模拟的计算效率提供了一个简便而有效的方法．     

热轧窄带钢粗轧强迫宽展孔型的模拟研究

按照现场使用165mm×280mm连铸坯轧制宽度为355mm带钢粗轧孔型尺寸及轧制规程的有关数据,对热轧窄带钢的粗轧强迫宽展孔型进行模拟试验。通过改进粗轧孔型尺寸使展宽系数提高,使用165mm×280mm连铸坯能够轧制宽度约为400mm的窄带钢。