对土家族城镇中小学生体表面积调查研究

为了解和建立土家族中小学生这方面的形态学指标,采用适合中国人的Stevenson标准公式,对土家族中小学生的体表面积进行了调查研究.结果显示:1)土家族中小学生体表面积值随着年龄增长而增长,且其增长速度男女生均可分为匀速增长期、快速增长期、速度减缓期3个不同时期;2)男女生体表面积曲线出现双交叉现象,即11岁时女生体表面积值超过男生,14岁时男生的体表面积又超过女生,15岁以后二者体表面积值的差异逐渐增大,表现出显著性差异.     

低应变法检测桥梁嵌岩桩的评价

用低应变法检测嵌岩桩 ,若桩底出现明显同相反射 ,多数因桩底缺陷引起。而区分是桩还是持力层的缺陷 ,主要看反射的起跳时间在 2 L/ C之前还是之后。当桩的变径及入岩反射对测试影响很大时 ,应进一步用钻芯法检验。     

Steps Toward More Effective Implementation of the Standards for Educational and Psychological Testing

The goal of the Standards for Educational and Psychological Testing is to improve testing practices, but their impact on practice appears spotty. Self-regulation clearly fails in some instances. The establishment of an external agency to oversee testing practices and adherence to the Standards would face substantial hurdles, and the ambiguity of many of the Standards would hobble such an organization if one were created. Many of the Standards are general statements of principle, and past controversies make clear that we in the field often disagree about the reasons for them, their applicability to specific cases, and their practical meaning in specific contexts. This paper argues that the field should follow two approaches to lessen this ambiguity. First, using journals, conferences, and other vehicles, we should foster more frequent and more protracted debate about the practical meaning of key Standards, such as 13.6 and 13.7, which mandate that a decision that will have a "major impact" on a student should not be based on a single score. Second, future revisions of the Standards should use concrete examples of testing practices to clarify the meaning of the Standards, much as the legal system uses case law to clarify the meaning of the general principles embodied in statutes .     

投篮质量评价标准建立及应用

分析按命中率评价投篮质量这一方法不利于运动队 (员 )之间投篮水平的变化及技战术水平发挥程度的比较。提出了将投篮按结果不同分为 A、B、C、D四级 ,用于定量分析投篮技术水平的新的投篮质量评价标准 ,介绍了新的投篮质量评价标准在 CBA决赛阶段的应用。     

从事物特性的相互作用本质看运动生物力学研究方法与测试手段的发展

从任何事物的特性都是由相互作用相互联系的的事物双方共同决定的这一哲学原理来看,运动生物力学的研究方法和测试手段发展具有主动性,它能够从运动中的人体引申出这样或那样的特性来,能够引申出何种特性不仅取决于运动中的人体,也取决于研究方法和测试手段,从而推动运动生物力学学科的发展。     

On Applicable Methods in Testing Spoken English

The importance of raising speaking ability of the students is more and more emphasized. But the pity is that, until present time, teachers or testers have to face the perplexity of lacking useful ways to test the students about their ability in speaking. In order to break through the existing perplexity, the author tries, by analyzing the applicability of several methods for testing this ability, to shade a new light in this field, thus facilitate the means of daily teaching and learning evaluation.     

基于点云数据的复杂型面实体建模研究

文章针对复杂型面产品的特点,从工业产品设计的实际应用出发,提出将正向设计的尺寸和定位关系设计方法和逆向设计的复杂曲面设计方法有效结合起来,基于点云数据实现产品的实体模型重建。以摩托车覆盖件为例,利用逆向工程软件从点云数据中提取和重构特征曲线与曲面,然后将这些几何元素信息在正向设计系统中结合特征建模方法创建整体三维CAD模型。     

武汉体育学院学生身体素质测试指标、方法和结果研究

研究分析武汉体育学院学生身体素质测试指标、方法、过程与结果。结合体育院校学生特点,对学生身体素质指标进行了测试,并就选择学生身体素质测试的原则、依据、测试指标的构建和方法的确立等进行探讨。制订身体素质测试指标和评价标准,结果表明:学生身体素质测试指标与评价标准符合在校学生身体素质的实际,达到了预期的目的与效果。     

Creating Better Learners Through Learning Science: A Sample of Methods

This article proposes the incorporation of learning science into the programming and operation of public libraries. Learning science, a multidisciplinary field spanning cognitive science, psychology, neuroscience, economics, anthropology, and linguistics, has identified proven methods for enhancing learning at any age. The article highlights some of the tools and insights that are most relevant to libraries in their role as centers for informal learning.     

Development of a chemically defined medium for Planctopirus limnophila to increase biomass production

BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO₃, 2.318 mM NH₄Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD₆₀₀ of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002.