四个麦芽品质性状的杂种优势和相关分析

本文对四个主要麦芽品质性状—a一淀粉酶活力、麦芽汁粘度、麦芽汁色度和搪化力进行了杂种优势和相关分析.(1)相对优势结果表明，在84个组合次中，呈正向优势的46个，占54.76男，负向优势34个，占40.48男，无显性4个，占4.75男;(2)四个品质性状的中亲优势平均值分别为一6.117、一9.965 40.452和一。.545s a-淀粉酶活力和糖化力的超高亲优势分别为一14.578和一8.201,麦芽汁粘度和色度的超低亲优势分别为5.442和70.455.四个性状杂种优势的变异系数均很大.(3)麦芽汁色度的F，对MP的回归系数(B)和相关系数(r)均达显著水平，分别为。..43和0.50，麦芽汁粘度的相关系数达显著水平，为一。.45,其余均未达显著水平，(4)除麦芽汁色度性状外，另三个性状的中亲优势、超亲优势和特殊配合力的相关均达显著或极显著水平.(5)四个麦芽品质性状间的相关结果表明，仅有a-淀粉酶活力和麦芽汁粘度间呈极显著负相关(r=一0.56').最后，文章根据实验结果，就啤酒大麦麦芽品质改良的遗传育种及其杂种优势应用进行了初步讨论.     

Characterization of Effects of Different Tea Harvesting Seasons on Quality Components,Color and Sensory Quality of “Yinghong 9” and “Huangyu” Large-Leaf-Variety Black Tea

Harvesting seasons are crucial for the physicochemical qualities of large-leaf-variety black tea. To investigate the effect of harvesting seasons on physicochemical qualities, the color and sensory characteristics of black tea produced from “Yinghong 9” (Yh) and its mutant “Huangyu” (Hy) leaves were analyzed. The results demonstrated that Hy had better chemical qualities and sensory characteristics, on average, such as a higher content of tea polyphenols, free amino acids, caffeine, galloylated catechins (GaCs) and non-galloylated catechins (NGaCs), while the hue of the tea brew (ΔE*ab and Δb*) increased, which meant that the tea brew was yellower and redder. Moreover, the data showed that the physicochemical qualities of SpHy (Hy processed in spring) were superior to those of SuHy (Hy processed in summer) and AuHy (Hy processed in autumn), and 92.6% of the total variance in PCA score plots effectively explained the separation of the physicochemical qualities of Yh and Hy processed in different harvesting seasons. In summary, Hy processed in spring was superior in its physicochemical qualities. The current results will provide scientific guidance for the production of high-quality large-leaf-variety black tea in South China.     

Managing differences by focusing on communication qualities: Pupils learning mathematics in pairs at a computer

The article presents a study of face-to-face verbal communication when pupils work with geometry in pairs and share a stand-alone computer with Geoboard software. The work sessions of pairs of 9th grade pupils are video recorded, and a screen recorder is used to capture their computer activity. The study focuses on identifying and characterizing good communication practices that enhance mathematics learning through joint research reflections between the pupils, the teacher, and the researcher. The major finding concerns how two of the pupils have diverging perspectives on how to communicate mathematics, yet they manage to have productive collaboration. The differences generate collaborative challenges for the pupils and an opportunity to discuss how pupils’ communication qualities can prove important in fruitfully managing such challenges.     

便携式X射线荧光光谱仪快速监测重金属土壤环境质量

便携式X射线荧光光谱仪(PXRF)作为一种新型快速测试手段具有突出的应用前景,但也存在检测范围和检测限的局限,为此本文研究PXRF仪器在快速监测土壤环境质量中Cr,Ni,Cu,Zn,Pb,Cd,As和Hg等8种重金属元素的适用性,筛选仪器可检测元素,评价检测结果准确度。具体方法是使用仪器测试重金属污染土壤样品,测试结果与电感耦合等离子体质谱分析方法(ICP-MS)测试值进行对比,评判检测结果精密度,建立PXRF仪器测试值与ICP-MS仪器测试值的线性回归关系。结果表明：(1)在监测重金属土壤环境质量时,PXRF仪器可用于检测土壤中Pb,Zn,Cr和Cu含量,但不适于检测Ni,Cd,As和Hg含量。(2)Pb和Zn测试值稍低于ICP-MS测试值,Cu偏高,而Cr过高;PXRF仪器测试值需要参照标准分析方法进行线性校正。研究结论为：便携式X射线荧光光谱仪适用于Pb,Zn,Cr和Cu等4种重金属的土壤环境质量监测,是一种简单快速、准确可靠的低成本土壤重金属分析手段。该研究的创新之处是合理规避PXRF仪器的缺点,将仪器应用于土壤环境质量监测,提高了测试结果应用价值。     

基于神经网络的课堂教学质量综合评估

研究了神经网络对课堂教学质量进行综合评估的原理、方法和过程,并成功地应用于实际中,结果表明该方法简洁,准确,并能克服各种人为因素.     

“一体三翼”教学模式在工科无机化学教学中的应用与实践*

为适应当前复合型人才培养需求和提高学生自主学习能力和创新意识,在对大学一年级新生进行无机化学教学时需坚持以学生为主体的教学理念,并努力同时提高他们的思想政治素质、理论联系实际能力和科学研究素养。为此,提出“一体三翼”教学模式。然而,大多数工科院校无机化学课程的授课学时有所压缩,这对任课教师来讲是一种巨大挑战。通过“线上-线下”混合式教学解决学时不足问题,并通过学生课程参与度、学生学习成绩及教学反思等形式检验“一体三翼”教学模式的教学实践成效。     

Lot sizing with random yield and different qualities

This paper considers a production/inventory system where items produced/purchased are of different qualities: Types A and B. Type A items are of perfect quality, and Type B items are of imperfect quality; but not necessarily defective; and have a lower selling price. The percentage of Type A (the yield rate) is assumed to be a random variable with known probability distribution. The electronics industry gives good examples of such situations. We extend the classical single period (newsvendor) and the economic order quantity (EOQ) models by accounting for random supply and for imperfect quality (Type B) items which are assumed to have their own demand and cost structure. We develop mathematical models and prove concavity of the expected profit function for both situations. We also present detailed analysis and numerical results. We focus on comparing the profitability of the novel proposed models with models from the literature (and derivatives of these models) that develop the optimal order quantity based on the properties of Type A items only (and ignore Type B items). We find that accounting for Type B items can significantly improve profitability.     

物理实验教学与科学素养教育

本文简要论述了在物理实验教学中，对学生进行科学素养教育的意义．内容和方法。     

Effect of gamma irradiation on chemical composition,antioxidant activity,antibacterial activity,shelf life,and cytotoxicity in the peels of two mango varieties grown in Bangladesh

Mango (Mangifera indica) is perhaps the most notable sound natural product, however short-lived. A few synthetic compounds like calcium carbide, pesticides, formalin and calcium-based arrangements have been utilizing for its protection, notwithstanding, those synthetic compounds are perilous for our human wellbeing. Besides, mango strip is a food-handling by-product that is discarded since it isn't economically reasonable. For this study, the nutritional, antibacterial, and antioxidant properties of peels from two mango cultivars (Amrapali, and BARI-11) were analyzed with four doses (0.5, 1.0, 1.5, and 2 kGy) of gamma irradiation. The impacts of radiation on storage quality and life span of usability were likewise investigated. Mango peels were found to have many phytochemicals. Be that as it may, radiation altogether impacted tested parameters like fat, protein, carb, fiber, sugar, energy, soluble solids, etc. in both of the mango peels. On the other hand, the peel samples showed 50% DPPH scavenging activity at varied dosages. Moreover, samples exposed to 1.5 kGy of radiation showed higher antioxidant activity. At a radiation dose of 1.5 kGy, amrapali peel proved to be less hazardous to brine shrimp lethality assay than other samples. The widest inhibitory zones against Pseudomonas sp. were obtained at a dosage of 150 µg/disc. After two weeks of storage, the 1.5 kGy radiation dosage left the mangoes' texture firm, indicating that it was extending the fruit's shelf life by greatly reducing the microbial attack. Thus mangoes could be preserved using radiation without significantly affecting their nutritional value.     

全日制化学教育硕士综合素质的调查研究

在调研、访谈的基础上,设计全日制化学教育硕士综合素质调查问卷,以全国20多所高师院校2012级全日制化学教育硕士为对象进行调查研究,旨在深入了解化学教育硕士综合素质现状,发现存在的主要问题,分析可能的成因,提出一些建议,为教育硕士的培养提供借鉴。