天门冬药理与临床应用研究进展

天门冬药用价值高、作用明确、毒副作用少,是一种重要的药用植物,为多个民族的常用药,极具开发前景.综述了目前天门冬药理作用与临床应用的研究进展,并对未来的研究作了展望.     

D406A钢K_(Ic)与动态力学性能的相关性研究

为总结D406A钢的静态断裂韧性KIc值与动态力学性能间的关系,分别采用三点弯曲试样以及标准冲击试样对D406A钢进行了KIc测试和仪器化冲击试验,发现室温下该材料的冲击功CVN与断裂韧度KIc存在着相同的变化趋势,两者间的对应关系与修正后的Rolfe-Novak经验公式基本相符,今后可以通过该公式来推断材料的KIc值。利用标准冲击样所获得的动态断裂韧度KId与静态断裂韧度KIc虽遵循相同的变化规律,但相关性不是特别理想,这主要是由于一方面动态加载条件下试样的受力情况远比静态下要复杂,这更容易导致KId的离散;另一方面标准冲击样并不是一个理想的裂纹体,缺口尖端在断裂之前会普遍屈服,这也会给KId的计算带来较大误差。     

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.     

QFD理论在高校创新创业教育课程设计中的应用研究

我国当前高校创新创业教育课程存在一定的不足,尽管有研究提出了改进对策或建议,但其提出过程缺少科学系统的分析工具,且所提出的对策措施千校一面,缺乏针对性。造成这种状况的本质原因在于未对课程对象(顾客)需求期望进行清晰准确的识别。质量功能展开(QFD)立足于顾客,能有效将顾客需求转化为产品/服务设计要求。因此,将QFD与高校双创课程设计相结合,提出创新创业课程质量功能展开模型(ICQFDM),通过"顾客需求—教学规划"与"教学规划—教学管理"两级质量屋,将顾客对于双创课程的要求转化到课程设计要求中。以南京已开展创新创业课程且互为竞争对手的2所财经类院校为例,演示模型的具体运用过程。结果显示:2所高校创新创业课程设计路径存在较大差异。ICQFDM的提出为高校建设创新创业课程提供了可操作的分析框架,各高校可结合不同实际情况,制定适用于自身的课程建设措施。     

Testing and ideology: policy debates about literacy assessments for Colorado’s bilingual students

ABSTRACT

The Colorado Reading to Ensure Academic Development Act requires grade-level attainment in literacy in English for students in grades K-3. Its practical outcome, however, has been to pressure schools with bilingual programs to shift their instructional language allocations towards more English in the early grades. Proposed rule revisions debated by the state Board of Education sought to facilitate testing in students’ language of instruction for those in bilingual programs. Analysis of written and verbal opposition to the proposed rule revisions demonstrates the persistence of insidious ethnoculturalist discourses opposing bilingual education as well as the cooptation of liberal multiculturalist discourses that, while framing bilingualism as an asset, argue that it is underdeveloped in bilingual programs that do not include English instruction from the outset. Given that bilingual instruction has demonstrated time and again that it benefits students acquiring English in schools, such new discursive turns pose a threat that must be recognized to fend off further legislative and regulatory attempts against bilingual education.     

智慧教育转型与变革

智慧教育不仅是智能技术在教育中的应用,更是智能时代教育的全面转型与变革。文章结合智能时代的三大发展趋势:即人机物三元融合、主动智能服务与人机结合的分布式认知,从基础环境、智能形态、培养模式、教育生态、育人目标五个维度提出了智慧教育转型与变革的关键所在,包括拥有主动智能的教育环境、人机协同的教育智能、大规模个性化的人才培养模式、虚实融合的教育新生态和智能时代的创新人才培养。在此基础上,面向智慧教育转型与变革的实践落地,提出了三点关键建议,包括建立数据无缝流转的生态体系、推进教育公共服务模式创新、高度重视专业性的教育服务,期望为智能时代智慧教育的转型与变革提供一定的参考与应用启示。     

A theory of instruction for introductory programming skills

ABSTRACT

Background and Context: Current introductory instruction fails to identify, structure, and sequence the many skills involved in programming.

Objective: We proposed a theory which identifies four distinct skills that novices learn incrementally. These skills are tracing, writing syntax, comprehending templates (reusable abstractions of programming knowledge), and writing code with templates. We theorized that explicit instruction of these skills decreases cognitive demand.

Method: We conducted an exploratory mixed-methods study and compared students’ exercise completion rates, error rates, ability to explain code, and engagement when learning to program. We compared material that reflects this theory to more traditional material that does not distinguish between skills.

Findings: Teaching skills incrementally resulted in improved completion rate on practice exercises, and decreased error rate and improved understanding of the post-test.

Implications: By structuring programming skills such that they can be taught explicitly and incrementally, we can inform instructional design and improve future research on understanding how novice programmers develop understanding.     

广义(3+1)维KPB方程的对称约化、精确解和守恒律

运用李对称方法得到了(3+1)维Kadomtsev Petviashvili Boussinesq(KPB)方程的对称和约化方程。进而,利用齐次平衡原理和椭圆函数方法得到了方程的精确解。最后,给出了该方程的守恒律。     

论21世纪图书馆的发展模式与功能

本文分析了影响决定图书馆发展模式的四个重要因素。即技术、资金、文化心态和制度变迁。认为模式的不同导致图书馆功能在不同时代的差异，并提出了21世纪图书馆的四种发展模式，阐述了它们的主要功能。