二阶变系数线性齐次方程的三个可积充分条件

利用变量代换和凑项的方法,给出了二阶变系数线性齐次方程的三个可积充分条件,并得出求解方程的通解公式.     

浅论鲁迅杂文的抒情方式

鲁迅是一个以心发现心的人,在其剑拔弩张的杂文背后,隐含着一股情感的激流,熔铸着他浓烈饱满的爱憎之情,然而这种情感的抒发和表达方式却不尽相同:有的较为外露,有的则倾于内向。无论是溢于言表的悲愤激扬,还是沉郁含蓄的抒而不发无不体现出其“情感中的理性的美”。     

曹雪芹四字对偶句的魅力

本文主要论述曹雪芹如何直接继承诗经四字对偶句传统，在《红楼梦》中塑造人物和刻画意境，使小说具有诗化的魅力。     

Si3N4陶瓷二次部分瞬间液相连接数值模拟

利用热弹塑性有限元方法，通过瞬态热结构直接耦合，模拟Si3N4陶瓷二次部分瞬问液相连接过程，分析了连接接头残余应力分布状态和中间层对此连接接头应力分布的影响。结果表明：陶瓷外表面靠近连接界面的附近存在最大拉伸应力；采用Ti／Cu／Ni／Cu／Ti中间过渡层的接头应力出现大幅度的降低；陶瓷与金属之间热膨胀系数的巨大差异是导致残余应力的主要原因，采用中间过渡层能缓和接头的残余应力，提高接头强度。     

传播学视野中的电视文化

本文主要以传播学的视角展开对电视文化的认识,探讨电视这一媒介及其所承载的文化的特性:本文认为电视创造了人与外界交流的全新方式,它以视听语言的形式发展了人类新的语言平台;电视文化具有高度综合性和兼容性、即时性和普及性、巨大的社会教育效果与示范性导向性。     

“探究教学”与科学素养

随着社会的进步、科技的发展 ,对学生进行科学素养的培养显得非常重要。“探究教学”是科学素养培养的手段 ,而科学素养是“探究教学”的最终目标。“探究教学”的实施 ,能充分调动学生学习科学知识的积极性 ,提高他们的科学意识和科学探究能力 ,养成科学的态度、情感与价值 ,理解科学、技术与社会的关系 ,意识到人类、社会与自然是一个和谐的生态系统     

Use of place information for improved event tracking

The main purpose of topic detection and tracking (TDT) is to detect, group, and organize newspaper articles reporting on the same event. Since an event is a reported occurrence at a specific time and place and the unavoidable consequences, TDT can benefit from an explicit use of time and place information. In this work, we focused on place information, using time information as in the previous research. News articles were analyzed for their characteristics of place information, and a new topic tracking method was proposed to incorporate the analysis results on place information. Experiments show that appropriate use of place information extracted automatically from news articles indeed helps event tracking that identify news articles reporting on the same events.     

对企业生产缓冲的再认识

阐述了企业在当前形势下设置生产缓冲的必要性,划分了生产缓冲的类型,提出建立生产缓冲的木桶原理和替代原理,认为生产缓冲的要素之间存在相互替代的特性,在设置生产缓冲时各要素的水平应相互协调,最后探讨了生产缓冲的经济评价。     

Optimization of some factors affecting the performance of query expansion

This paper examines the factors affecting the performance of global query expansion based on term co-occurrence data and suggests a way to maximize the retrieval effectiveness. Major parameters to be optimized through experiments are term similarity measure and the weighting scheme of additional terms. The evaluation of four similarity measures tested in query expansion reveal that mutual information and Yule's Y, which emphasize low frequency terms, achieve better performance than cosine and Jaccard coefficients that have the reverse tendency. In the evaluation of three weighting schemes, similarity weight performs well only with short queries, whereas fixed weights of approximately 0.5 and similarity rank weights were effective with queries of any length. Furthermore, the optimal similarity rank weight achieving the best overall performance seems to be the least affected by test collections and the number of additional terms. For the efficiency of retrieval, the number of additional terms needs not exceed 70 in our test collections, but the optimal number may vary according to the characteristics of the similarity measure employed.     

企业技术创新中的风险及其控制

论述了企业技术创新是既具有潜在高效益，又具有潜在高风险的科学技术研究活动。分析企业技术创新中的风险，是为了让技术创新成果的持有者、接受者认识到技术创新的风险性及产生的原因，便于双方及时采取有效的措施，把风险控制在最小范围。从企业技术创新过程出发，分析了企业技术创新存在的风险，并根据这些风险产生的原因，探讨了其防范措施。