A numerical model for predicting the jump of lift force on an oscillating cylinder

The fluid force coefficients on a transversely oscillating cylinder are calculated by applying two- dimensional large eddy simulation method. Considering the ‘‘jump’’ phenomenon of the amplitude of lift coefficient is harmful to the security of the submarine slender structures, the characteristics of this ‘‘jump’’ are dissertated concretely. By comparing with experiment results, we establish a numerical model for predicting the jump of lift force on an oscillating cylinder, providing consultation for revising the hydrodynamic parameters and checking the fatigue life scale design of submarine slender cylindrical structures.

Threat and management strategies of potentially invasive insects in China

The Global Invasive Species Database, GISD, comprises 27 species of the most significant invasive alien insects in the world (through November, 2005), 6 of which are originally native to China, 11 are established in China, and 10 have a potential invasion

The status and causes of alien species invasion in China

Data of classification, origin, pathway and environmental impacts of invasive alien micro-organisms, invertebrates, amphibians and reptiles, fish, birds, mammals, weeds, trees, and marine organisms in terrestrial, aquatic and marine ecosystems of China, were analyzed, based on literature retrieval, field survey and consultation. Some 283 invasive alien species were recorded in China, including 19 invasive alien micro-organisms, 18 aquatic plants, 170 terrestrial plants, 25 aquatic invertebrates, 33 terrestrial invertebrates, 3 amphibians and reptiles, 10 fish, and 5 mammals. Of the invasive alien species, 55.1% originated from North and South America, 21.7% from Europe, 9.9% from Asia, 8.1% from Africa and 0.6% from Oceania. Many institutions and individuals in China lack adequate knowledge of ecological and environmental consequences caused by invasive alien species, with some ignorance of the dangerous invasion in the introduction of alien species. For instance, 50.0% of invasive alien plants were intentionally introduced as pasture, feedingstuff, ornamental plants, textile plants, medicinal plants, vegetables, or lawn plants, 25% of alien invasive animals were intentionally introduced for cultivation, ornament, or biological control, In addition, more efforts are being made in the introduction of alien species, and little attention is paid on the management of introduced alien species, which may cause their escape into natural environment and potential threats to the environment. There were also gaps in quarantine system in China. All microorganisms were unintentionally introduced, through timber, seedling, flowerpot, or soil; 76.3% of alien invasive animals invaded through commodity or transportation facility because of the failure of quarantine. Therefore, quarantine measures should be strictly implemented; and meanwhile the intentional introduction of alien species should be strictly managed and a system of risk assessment should be implemented.

落叶松毛虫防治咨询专家系统

落叶松毛虫是东北林区主要害虫之一，它对松林可以造成毁灭性的破坏，因此，采取及时且必要的综合防治措施，可以带来显著的经济和生态效益。本文依据害虫综合管理的指导思想，采用计算机人工智能程序模型，构建了落叶松毛虫防治咨询专家系统。 落叶松毛虫防治咨询专家系统主要由推理机、知识库、数据库、知识获取机制和用户界面等部分组成。其中知识库和推理机是系统的核心部分。在知识库设计中充分考虑了落叶松毛虫防治的复杂性，结合具体的限定条件，如危害特征、自然环境、地形地貌、害虫的生长阶段等，将知识存储在数据库中形成专家数据库；利用数据库查询语言SQL语句设计了系统的推理机，采用正向推理的方式，增强了知识库的可扩展性和可维护性；知识获取机制面向林业专家，实现知识的获取以及知识库的修改、扩充等任务；数据库用来存放落叶松毛虫的基本信息，用户可以通过数据库来获得落叶松毛虫相应的咨询信息。 落叶松毛虫防治咨询专家系统的目标为：（1）对落叶松毛虫的基本信息、行为特征、生理和生态学特征以及防治方法和施药方法等进行存储和查询。（2）正向推理方式保证专家系统在运行时能方便地选择问题，实现智能推理过程。（3）易用的知识维护。 该系统主要有以下几方面的功能和特点：（1）该系统本着害虫综合管理的指导思想，以落叶松毛虫的种群动态为理论基础，充分考虑不同林地环境条件下的自然控制因素，根据环境、气候和害虫本身的条件推出更加合理的结论，尽量采用生物防治，必要时采用化学防治；（2）系统可向用户提供多种可行的防治方案，经营者可以根据当时当地的实际情况作出决定；（3）系统使用方便；（4）系统具有显示、打印、通过Internet浏览获取信息、显示推理解释等功能。 另外，本文对落叶松毛虫专家系统又进行了有效的评估，评估对象分为三个组别：领域专家、森保人员以及学生。三组人员分别针对系统实用性、友好性、系统提问的简洁程度以及可学习性给出等级分数。通过评估结果，最终认定该系统是可以信赖的。 本系统以落叶松毛虫防治领域专家的经验和知识为基础，有效地将计算机技术和森保专家的知识结合在一起，集落叶松毛虫信息存储浏览、查询、专家系统于一体，对于缓解森林保护专家和人员的不足，提高落叶松毛虫虫害的防治能力，加快科技成果的转化具有重要的意义。

弧焊机器人焊接咨询专家系统

为了推广弧焊机器人的应用，应用ＶｉｓｕａｌＢＡＳＩＣ和Ｃ语言开发了一个弧焊机器人焊接咨询专家系统，可用来帮助弧焊机器人操作者进行焊接工艺的制定和选择。

混流汽车总装配线上的零部件优化配送方案研究

配送车每次配送的利用率大小是提高配送效率的主要因素,因此设计一种启发式算法使配送车一次装载的标准塑料周转箱尽可能多,提高配送车空间利用率。最后的仿真实验验证了上述配送方法的实用性,提出的零部件配送管理方法,只需使用较少的配送工人,同时降低了线旁库存,能为企业节省人力,降低生产成本。

企业组织领导参与决策行为研究

In the processes of Chinese economic and political reforms, making decision democratically and scientifically is one of the most important problems for the managers. Through the investigations of 319 managers from 13 companies in 3 cities of China, the participation or the behavior of influence and power sharing in managerial decision-making was systematically analyzed. The research was concerned with three aspects: (1) the descriptive study of managerial decision-making; (2) the relationship between managerial decision-making and a set of specified contingent situational factors; (3) the relationship between managerial decision-making and various outcome variables, such as job satisfaction and organizational effectiveness. The principal results of the research showed. 1. The managers used different methods of decision-making in different situations. The wildly used method by the managers was "prior consultation with subordinate". 2. Compared with the developed countries, Chinese managers tended to use more centralized methods of decision-making. In the comparisons among the different districts of China, the managers in the districts of the higher level economic and cultural development tended to use more participative methods in the processes of decision-making. 3. The behavior of managerial decision-making was influenced by the various contingent factors, such as the uncertainties of the environments, the job constraints, and the variables related to persons, etc. 4. The behavior of the managerial decision-making correlated significantly with the job satisfaction and organizational effectiveness. The more influence and power managers owned in the processes of decision-making, the more positive they evaluated their job satisfaction and organizational effectiveness.