基础-任务驱动模式在《微生物学基础》实验教学中的改革初探

任务驱动是高职教育正在推广的"教、学、做"一体化的一种教学模式,能激发学生的思维,发挥学生的主动性及与教师之间的深层次沟通。基础实验则有助于学生掌握微生物学基础实验技术与技能,为任务驱动教学的顺利展开奠定基础。在《微生物学基础》实验教学过程中进行基础-任务驱动模式教学,教学效果显著,学生综合技能大有提高。     

Decision making for contractor insurance deductible using the evolutionary support vector machines inference model

Loss risk during the course of a construction project may be described in terms of frequency (i.e., loss frequency) and severity (i.e., loss severity). This study focused on improving the methodology used to evaluate loss risk. The authors first identified the common attributes of building construction project loss through a review of the literature and interviews with experts. Objective factors adequate to describe loss attributes were selected as model inputs. The loss prediction model was created using the evolutionary support vector machine inference model (ESIM) and deployed to evaluate loss frequency and loss severity. This research combined the deductible efficient frontier curve with the indifference curve of risk versus insurance cost, and developed criteria for optimal insurance deductible decision making.     

Influence of the initial volume fill ratio of the granulator on melt agglomeration behavior in a high-shear mixer

The purpose of this study was to investigate the effects of different initial volume fill ratios of the granulator on granular agglomeration in a high-shear mixer. Calcium carbonate powders, with mean granule sizes of 75–150 μm were used as the raw material. Polyethylene glycol 6000 (PEG 6000) was used as the melting binder. The initial liquid to solid weight ratio was fixed at 0.15. Four different initial granulator fill ratios were used 11%, 14.7%, 18.4% and 22%. The results showed that the granules that formed during the nucleation stage were a little larger when the initial fill ratio was lower than higher. In the rapid-growth stage, the agglomeration growth rate increased as the initial fill ratio increased. The range in granule size at the end of agglomeration also increased as initial fill ratio increased. SEM images of the surface structure of the granules during the nucleation and final stages are shown.     

Oligosaccharides prepared by acid hydrolysis of polysaccharides from pumpkin (Cucurbita moschata) pulp and their prebiotic activities

As a rich source of polysaccharides, pumpkin pulp was used for the production of oligosaccharides. To investigate the prebiotic potential of the oligosaccharides, prepared by acid hydrolysis of polysaccharides from pumpkin pulp, the effect of the oligosaccharides on lactobacilli growth was studied. The oligosaccharides were composed of galactose (99.03%) and glucose (0.97%). The molecular weight distribution of the oligosaccharides showed a larger part of low molecular weight fraction in a range from 5000 to 324 Da than the polysaccharides, which gave the oligosaccharides higher solubility. The oligosaccharides showed good resistance to hydrolysis by artificial human gastric juice and α‐amylase, compared to the reference prebiotic inulin, and considerable capability to stimulate the growth of lactobacilli. In vitro studies showed that the number of lactobacilli was significantly greater than those in control medium when they were cultured in the medium supplemented with the oligosaccharides (P < 0.05), and there was no significant difference at the oligosaccharides group and the inulin group (P < 0.05).     

高频红外碳硫仪法测银石墨合金中的C含量

C是银石墨电触头中的重要组分,对电触头的性能起着决定性的作用。研究了用高频红外碳硫仪测银石墨合金中的C含量的方法,对试样加入量、校正标准样品、空白值、助熔剂等影响因素进行了试验,确定了最佳分析条件,该方法快速准确、实用性强。     

Experimental Study of Bubble Growth and Departure at the Tip of Capillary Tubes with Various Wettabilities in a Stagnant Liquid

In the present paper, the bubble growth and departure at the tip of capillary tubes with different wall wettabilities in a stagnant fluid is experimentally investigated by using a high-speed visual system. The visual experiments show that the bubble growth experienced three typical stages: the initial growth, the speed-up growth, and the speed-down growth, with distinct varying behaviors of tip contact angle and size of bubble. The formation mechanism of each growth stage is discussed individually. It can be deduced from the experimental results that the bubble breakthrough point for a hydrophilic capillary tube is resulting from the triple contact line rapidly advancing from the inner wall slightly beneath tube tip to the inside surface edge of the tube tip when the contact angle of the bubble on the inner wall approaches the receding contact angle. The wall wettability has a significant effect on bubble growth and departure. The departure size and growth cycle period of bubble for a Teflon tube with hydrophobic wall is obviously smaller than these for glass tube with hydrophilic wall. Furthermore, the triple contact line of the bubble locates at the inside surface edge of the tube tip for glass tube, while one locates at the outside surface edge for Teflon tube before bubble departure. The liquid incursion into the tube tip for glass tube has never arisen for the Teflon tube after bubble departing from the tube tip.     

Adaptive fuzzy diagnosis system for dissolved gas analysis of powertransformers

To enhance the fault diagnosis abilities for the dissolved gas analysis (DGA) of the power transformers, this paper proposes a novel adaptive fuzzy system for the incipient fault recognition through evolution enhanced design approach. Complying with the practical gas records and associated fault causes as much as possible, a fuzzy reasoning algorithm is presented to establish a preliminary fuzzy diagnosis system. In the system, an evolutionary optimization algorithm is further relied on to fine-tune the membership functions of the if-then inference rules. To make the diagnosis system intensively compact and the inference process more understandable, a pruning scheme is then developed to filter out the insignificant or redundant rules. The capabilities of the proposed diagnosis system for the transformer DGA decision support have been extensively verified through the practical test data collected from Taiwan Power Company (TPC)     

Improvement of functional properties of acid-precipitated soy protein by the attachment of dextran through Maillard reaction

The functional acid-precipitated soy protein (SAPP)–dextran conjugate was prepared by dry-heated storage at 60 °C under 79% relative humidity (RH) for 5 days through Maillard reaction between the ε-amino of lysine in soy proteins and the reducing-end carbonyl residue in the dextran. The covalent attachment of dextran to SAPP was confirmed by SDS-polyacrylamide gel electrophoresis and gel filtration chromatography. Functional properties of soy protein depend on the structural and aggregation characteristics of their major components (storage globulins 7S and 11S). The conjugate seemed to be predominantly formed by 7S, and the acidic subunits of 11S in soy protein. The emulsifying properties of the SAPP–dextran conjugate were about four times higher than those of SAPP. The solubility of the protein was not enhanced as a result of preheating, but rather it was not decreased when the conjugated protein was heated at 90 °C for 20 min due to the presence of the polysaccharide. The excellent emulsifying properties of SAPP–dextran conjugate were maintained even at pH 3.0 and were further improved at pH 10.0. The object of Maillard reaction is to guarantee the suitable reaction degree, and the resulting soluble conjugate can have excellent emulsifying properties.     

CALCULATION MODEL OF SURFACE TENSION FOR ALLOY MELTS

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