56K Modem是快速获取信息的重要手段

56KModem技术的不断完善在理论上，实践应用上推动了Modem技术的进步，为用户快速获取所需的信息提供了技术支持。     

K/Na-Mo复合变质对M2高速钢组织和性能的影响

用K／Na-Mo复合变质剂对M2铸造高速钢进行变质处理,对试样进行组织分析及力学性能测试．结果表明,随着K／Na-Mo复合变质剂的加入,M2高速钢中铸态碳化物趋于断网,骨状晶转变为等轴晶,组织得到了优化,同时M2高速钢的韧性明显提高,硬度和红硬性也有所改善．     

Measuring patent assessment quality—Analyzing the degree and kind of (in)consistency in patent offices’ decision making

We argue that consistent decision making in judging a patent's validity and basing this on its underlying technological quality are important elements of patent office service (“assessment”) quality. To understand which level of assessment quality patent offices (can) provide, particularly in new technological areas, we study the concordance of the European Patent Office's (EPO) granting and opposition decisions for individual patents. Using the biotechnology industry in the 1980s (an emerging patenting area then) as an example, we find no empirical evidence that the EPO provided maximal or optimal assessment quality as far as can be told from bibliographic indicators. We discuss research limitations and consequences of this first empirical analysis, and suggest ideas for refinements in future work.     

韩礼德系统功能语法对预科阶段国家通用语言文字教学的启示

系统功能语法重视语言的社会性、语境、功能的研究,韩礼德是系统功能语法的代表人物,他提出的语言层次、语言的元功能、语言的“盖然性”理论帮助人们深入理解了语言的本质和语言的使用过程。随着系统功能语法的不断发展,该理论逐渐被应用于语言研究的各个领域,其中包括母语教学和第二语言教学。母语为非汉语的少数民族学生需要在大学阶段深入学习国家通用语言,预科阶段的国家通用语教学从20世纪80年代发展之初就在不断学习各语言学流派的思想,旨在全面提高学习者运用国家通用语言的能力。对此,韩礼德的系统功能语法理论有一定的指导意义,值得学习和借鉴。     

双模压缩真空态的K次方H压缩效应

本文研究了双模压缩真空态1ξ〉=1/coshr sum from n=0 to(-e~(iθ)tanhr)~n 1n,n)的K次方H压缩效应。数值计算的结果表明:对于双模压缩真空态,光场存在着K次方H压缩效应(K=1,2,3,4,5,Λ);但是,随着方次K的升高,K次方H压缩效应减弱。     

一般载荷下裂纹尖端附近K的一种解法

采用保角变换 ,给出了线弹性状态下裂纹体承受对称和不对称集中载荷以及对称均匀分布载荷时裂纹尖端附近应力场强度因子K的表达式     

PTEN在白血病研究中的新进展

PTEN(Phosphatase and tensin homologue deleted on chromosome 10)是10号染色体缺失,编码与张力蛋白和辅助蛋白同源磷酸酶的抑癌基因.自1997年被正式发现起,越来越多的研究者对其蛋白、生物学活性、参与信号转导途径、药物靶点等相关方面做了极为深入和广泛的研究.研究显示,PTEN可通过多种信号转导通路,广泛参与人类肿瘤细胞的增殖、恶变、趋化、粘附、血管生成、凋亡、耐药、衰老、肌肉收缩、DNA损伤应答等过程,从而在人类肿瘤的治疗中发挥至关重要的作用,成为肿瘤生物学发展中最为重要的分子之一.迄今为止,涉及PTEN功能的相关临床试验已在肿瘤治疗中取得突破性进展,包括在白血病中的应用.但是国内外对于PTEN与白血病发生、进展、治疗的相关性并无针对性的、较为完善的归纳与总结.本综述结合近年来较为前沿的论点对PTEN与白血病发生、发展与治疗相关进展进行阐述,为进一步的科研提供新的思路与展望.     

Teacher Perceptions of Parent Engagement at a Cyber High School

A growing number of adolescents are taking all or most of their courses online. This places a greater responsibility on parents to support and facilitate their students' learning. This case study used teacher surveys and interviews to better understand how teachers perceived and supported parents' attempts to support their online students at a single online charter school. The results indicated that teachers observed multiple ways in which parents supported their students by (a) organizing and managing students' schedules, (b) nurturing relationships and interactions, (c) monitoring and motivating student engagement, and (d) instructing students when necessary. However, teachers believed that parents could act as obstacles to their students' learning by being overly engaged in certain types of learning activities. Additional research is needed that examines parent engagement in a variety of online learning environments. Research that identifies best practices could also be especially valuable to online teachers and administrators wishing to improve the quantity and quality of parental engagement in their programs.     

Students' Acceptance of Tablet PCs in the Classroom

In recent years digital technologies, such as tablet personal computers (TPCs), have become an integral part of a school's infrastructure and are seen as a promising way to facilitate students' learning processes. This study empirically tested a theoretical model derived from the technology acceptance model containing key constructs developed in previous research on the acceptance of technological innovations. On the basis of the research model, it was hypothesized that students' acceptance of tablet PCs could be explained by key constructs and could be distinguished in organizational, individual, and technological factors. The survey research was conducted in three German middle schools, involving a total of 120 students. Overall, participants' attitude toward the TPC positively predicted their behavioral intention to use the TPC and as such had the strongest direct influence. The findings emphasize the importance of understanding factors affecting students' attitudes in order to manage and influence the integration of TPCs in schools.