试论电视节目主持人的传播策略

电视节目主持人是电视台及栏目的形象代言人与信息传播者。讲求传播策略与技巧,对于增加主持人的魅力,提升整个栏目乃至媒体的传播水平和效果有着至关重要的意义。     

大花蕙兰原球茎诱导与增殖研究

为研究大花蕙兰（Cymbidium hybridum）原球茎诱导与增殖的最佳配方,用大花蕙兰无菌苗为材料,以MS、1/2MS为基本培养基,应用6-BA、2,4-D、NAA植物生长调节剂对大花蕙兰无菌苗茎段切块进行原球茎诱导和原球茎增殖研究。结果表明：在1/2MS＋6-BA 8.0 mg/L＋2,4-D 0.2 mg/L＋琼脂10g/L＋蔗糖15g/L＋活性炭1.5g/L的培养基（PH=5.8）上诱导出原球茎的效果最好,其诱导率高达77.78%;原球茎接种于MS＋6-BA6.0mg/L＋NAA0.2mg/L＋琼脂10g/L＋蔗糖10g/L＋活性炭1.5g/L＋香蕉泥100g/L（PH=5.8）培养基上原球茎增殖效果最佳。低水平的2,4-D（0.2 mg/L）、较高水平的6-BA（8.0mg/L）对大花蕙兰原球茎诱导具有显著的促进作用。     

深海声传播信道和目标被动定位研究现状

随着我国海洋技术逐渐从近浅海向深远海的战略性转移,深海目标远程探测技术逐渐受到重视。海洋中目前已知的可用于远距离传播的信号是声信号,海洋是"声透明"的。基于水声传播特性的新型水声技术是实现装备探测能力突破的关键。文章主要概述了目前研究比较集中的深海表面波导、表面波导泄露、会聚区、海底弹射和可靠声路径5种深海声传播信道,以及基于可靠声路径的目标被动定位方法。旨在通过梳理深海声传播规律及相关被动定位技术,为水声技术的快速发展提供思路。     

Revisiting the cluster-based paradigm for implicit search result diversification

To cope with ambiguous and/or underspecified queries, search result diversification (SRD) is a key technique that has attracted a lot of attention. This paper focuses on implicit SRD, where the subtopics underlying a query are unknown. Many existing methods appeal to the greedy strategy for generating diversified results. A common practice is using a heuristic criterion for making the locally optimal choice at each round. As a result, it is difficult to know whether the failures are caused by the optimization criterion or the setting of parameters. Different from previous studies, we formulate implicit SRD as a process of selecting and ranking k exemplar documents through integer linear programming (ILP). The key idea is that: for a specific query, we expect to maximize the overall relevance of the k exemplar documents. Meanwhile, we wish to maximize the representativeness of the selected exemplar documents with respect to the non-selected documents. Intuitively, if the selected exemplar documents concisely represent the entire set of documents, the novelty and diversity will naturally arise. Moreover, we propose two approaches ILP4ID (Integer Linear Programming for Implicit SRD) and AP4ID (Affinity Propagation for Implicit SRD) for solving the proposed formulation of implicit SRD. In particular, ILP4ID appeals to the strategy of bound-and-branch and is able to obtain the optimal solution. AP4ID being an approximate method transforms the target problem as a maximum-a-posteriori inference problem, and the message passing algorithm is adopted to find the solution. Furthermore, we investigate the differences and connections between the proposed models and prior models by casting them as different variants of the cluster-based paradigm for implicit SRD. To validate the effectiveness and efficiency of the proposed approaches, we conduct a series of experiments on four benchmark TREC diversity collections. The experimental results demonstrate that: (1) The proposed methods, especially ILP4ID, can achieve substantially improved performance over the state-of-the-art unsupervised methods for implicit SRD. (2) The initial runs, the number of input documents, query types, the ways of computing document similarity, the pre-defined cluster number and the optimization algorithm significantly affect the performance of diversification models. Careful examinations of these factors are highly recommended in the development of implicit SRD methods. Based on the in-depth study of different types of methods for implicit SRD, we provide additional insight into the cluster-based paradigm for implicit SRD. In particular, how the methods relying on greedy strategies impact the performance of implicit SRD, and how a particular diversification model should be fine-tuned.     

公益性图书馆信息网络传播豁免：权利源起与立法选择

文章分析了公益性图书馆网络传播豁免权的源起、赋予公益性图书馆网络传播豁免权的意义和公益性图书馆网络传播豁免的立法选择及其发展趋势。     

实验探究锥形POF的光功率的传输特性

通过实验研究了锥形聚合物光纤(POF)输出端光场强度分布呈现中心强、周边弱的模式分布特征,无论激光从大端输入、小端输出还是从小端输入、大端输出,都观察到小端的高阶模相对光强度明显低于大端,证明了锥形POF可以使大芯径POF和小芯径石英光纤的过渡连接得到良好的匹配.分别以大小端作为输入端口,研究了圆锥角度以及耦合长度对过渡器的光功率传输效率的影响,得出了POF过渡器最佳圆锥角度.yh     

“终身教育”的由来及在中国的传播

“终身教育”的思想源远流长,但它作为一种教育思潮被社会普遍接受还是20世纪的事。关于“终身教育”的含义,说法不尽相同,但其主要精神还是基本一致的,即指“人们在一生中所受到的各种培养的总和”,包括正规教育和非正规教育在内的教育体系的各个阶段和各种方式,包括人从生到死所受到的连续的有系统的教育。“终身教育”被世界各国普遍接受,有其深刻的社会原因,也得益于学者们的呼吁,联合国的倡导和各国政府的支持。     

基于NN的随动系统故障诊断

文章首先介绍了人工神经网络的基本原理,其次讨论了反向传播算法,并针对传统BP算法的不足设计了一种基于参数动态改变的BP算法,最后研究了新的算法在某武器随动系统诊断方面的应用.     

论影视艺术的差异性

着重对影视传播媒介、受者的角度、题材选择、叙述方式、审美心理等方面所表现出来的差异性作一些分析,以期使我们对影视的分流和建设有一个参照性的认识和理解。     

网络文化传播对高校图书馆信息服务的冲击分析

首先阐述了网络文化传播的内涵和基本特点，以及对高校图书馆信息服务的冲击所造成较大负面影响的几种网络文化形式。接着论述了高校网络文化对大学生健康成长的影响和网络文化传播对高校图书馆信息服务冲击的反思与对策。以期望对高校图书馆的信息服务工作有所启示。