物理实验教学新模式的探索与实践

提出了一种新的物理实验教学模式，论述了建立实验教学模式所遵循的基本原则和基本做法，简要介绍实施新的教学模式所取得的教学成果。     

江西省中华鳖种质状况及养殖方式调查

对江西省中华鳖的主要养殖企业分布、种质情况及养殖模式等进行了调查,结果表明:全省各地均有养殖,有一定规模的养殖企业主要分布于南丰县、黎川县、玉山县、永修县、余干县、进贤县和弋阳县等地;主要的养殖品系有鄱阳湖中华鳖、广东绿卡中华鳖、日本品系中华鳖、黄河中华鳖等;采用的养殖模式主要分为3种:常温养殖模式,控温高产养殖模式和生态化高产养殖模式。测量了不同养殖企业的6个中华鳖养殖类群的13项形态指标,从形态数据方面分析了不同养殖类群的种质。英明养殖类群系黄河中华鳖、日本品系中华鳖和台湾鳖的杂交种;富源养殖类群为鄱阳湖中华鳖,但推测其有广东绿卡中华鳖品系的混杂;进贤养殖类群是鄱阳湖中华鳖、广东绿卡中华鳖、日本品系中华鳖和黄河中华鳖等品系的混杂种;京丰养殖类群、兴初养殖类群和永修养殖类群是鄱阳湖中华鳖,但不排除有其他品系混杂的可能,其种质有待进一步研究。     

大麦幼胚培养的初步研究

大麦幼胚组织培养结果初步表明,两种培养基之间,两个品种之间总出愈率没有显著差异,而不同类型愈伤组织诱导率却存在差异。Ⅱ号培养基中,甲、乙两种类型愈伤组织产生比例多于Ⅰ号培养基,丙型愈伤组织正好相反。因此认为Ⅱ号培养基对大麦幼胚培养中诱导出愈及生长是较理想的。啤酒大麦品种“付8”的甲型愈伤组织比例大于高蛋白品种“Hiproly”。愈伤组织和胚芽的总过氧化物酶活性变化较大,但规律不明显,因此很难作大麦幼胚培养中愈伤组织诱导、生长及分化的指标。过氧化物酶同工酶和酯酶同工酶的电泳分析,表明不同品种,培养基、组织器官之间存在一些差异。改进与扩大试验设计进一步探索提高出愈及分化率的研究正在进行中。     

Multimodal approach for diagnosis of bacterial etiology in brain abscess

Background and purpose

Proton magnetic resonance spectroscopy (PMRS) has high sensitivity and specificity for the detection of pyogenic brain abscess and the categorization of bacteria. But the metabolite patterns failed to evaluate the etiology of disease when the culture results are sterile. The aim of the present study is to compare the multimodality techniques viz., conventional culture, MR spectroscopy and 16S rRNA PCR and sequencing for rapid diagnosis of etiology in brain abscess and evaluate the PMRS in culture sterile samples and also demonstrate the sensitivity and specificity of these techniques.

Methods

Thirty five patients underwent MRI on a 3 T MRI and in-vivo PMRS for the diagnosis and evaluation of various resonances of metabolites such as lipid (LIP), lactate (LAC), acetate (AC), amino acid (AC), succinate (SUC). Pus was collected for identification of etiologic agents by culture and molecular method.

Results

In 35 samples, metabolite patterns were as follows: LIP/LAC/AA, n = 17, LIP/LAC/AA/SUC with or without AC, n = 17 and LIP/LAC/AA/AC, n = 1. Culture showed bacterial growth in 22 samples (18 aerobic/facultative anaerobic, 9 anaerobic) whereas molecular method was detected 26 aerobic/facultative anaerobic, 13 anaerobic, 4 microaerophilic bacteria. Among the 13 sterile samples, molecular method detected 16 microorganisms along with 3 mixed infections and PMRS recognized metabolite patterns as LIP/LAC/AA, n = 5 and LIP/LAC/AA/SUC with or without AC, n = 8. The sensitivity of in-vivo PMRS in sterile samples was 100% and 75%, and specificity was 75% and 100% for aerobic and anaerobic organisms respectively.

Conclusion

Based on metabolite resonances, PMRS can detect slow growing and fastidious organisms and classify them into aerobic and anaerobic bacteria which are difficult to culture by conventional method. It can categorize microorganisms even in culture sterile samples with rational sensitivity and specificity which may allow early choice of targeted therapy.     

Effective radiating area and beam non-uniformity ratio of ultrasound transducers at 5 MHz, according to IEC 61689:2007

This paper discloses results of measuring the effective radiating area (A_ER) and the beam non-uniformity ratio (R_BN) for US transducers at 5.0 MHz. Measurements were carried out at Laboratory of Ultrasound of the Brazilian National Institute of Metrology, Standardization, and Industrial Quality. As reliability proof of system’s adequacy, uncertainties were assessed. The calculation protocol was developed based on standard IEC 61689:2007. Type A uncertainty was estimated after four repetitions of the full procedure for the determination of A_ER and R_BN, and Type B uncertainty was estimated from the mathematical model for both calculations, obtained from IEC 61689:2007 and the guide to the expression of uncertainty in measurement. The procedure presented herein represents the state of the art regarding metrology for testing therapeutic ultrasound devices, and its application results in fundamental aspects to support their evaluation regarding quality assurance, for instance, for a certification process due safety and performance.     

AT&T准则下完全检验的最优设计(英文)

本文研究了完全检验的质量控制问题,将广泛用于X-控制图的AT＆amp;T准则应用于完全检验,并根据完全检验的特点,提出一种新的最优模型,数值实验结果表明AT＆amp;T准则下的完全检验优于传统的完全检验。     

Effects of multi-frequency ultrasound on freezing rates and quality attributes of potatoes

The effects of multi-frequency ultrasound assisted freezing on the freezing rate, microstructure, quality properties (drip loss, firmness, total calcium content, l-ascorbic acid content and total phenol content) of potatoes were studied. The results indicated that the freezing effects of multi-frequency ultrasound was better than those of single-frequency ultrasound. Multi-frequency ultrasound could significantly increase the freezing rate and preserve the quality of frozen samples better. With increase in the number of ultrasonic frequencies, the freezing effect was more obvious. In addition, scan electron microscopy (SEM) images showed that the ice crystals formed by the multi-frequency ultrasonic treatment were fine and uniformly distributed, which caused less damage to the frozen potato samples. From the analysis of the quality attributes, the nutritional values of the samples after multi-frequency ultrasonic treatment was higher, but attention should be paid to the negative influence of the hydroxyl radical generated by the multi-frequency ultrasound.     

ICP-AES结合SVDV技术应用于饮用水品质检测性能诊断

采用电感耦合等离子体原子发射光谱(ICP-AES)技术,通过轴向、径向、同步垂直双向(SVDV)三个视角配置,快速检测生活饮用水样本中的As,Ba,Mg和Ni等微量元素。ICP-AES光谱仪在三个检测视角均能实现快速预热,预热时间仅需2 min,而且,ICP-AES光谱的短期稳定性和长期稳定性表现良好,其相对标准偏差(RSD)均低于2%。以3份商业瓶装饮用水和2份添加标准物的饮用水为检测的对象,利用ICP-AES技术结合SVDV视角,分别从轴向和SVDV两个视角检测As,Ba,Cr,Cu,Mn,Mo,Ni,V和Zn等元素,利用水微量元素含量的国家标准来验证结果的准确性,这两个视角的检测具有较高的准确度和灵敏度。检测所得结果符合国家环境保护总局发布的饮用水微量元素限制标准,并符合国际卫生组织的标准,满足人类所需饮用水标准要求。     

Ultrasound- and microwave-assisted convective drying of carrots – Process kinetics and product’s quality analysis

The aim of these studies was to investigate the influence of airborne ultrasound-assisted convective drying and microwave-assisted convective drying, as well as their combination, on process kinetics, total color change, water activity, content of carotenoids, polyphenols and antioxidant activity of carrots (Daucus carota L.). The global model of drying kinetics based on coupled ordinary differential equations was used to describe the moisture and material temperature profiles during drying. Application of ultrasound and microwave in convective drying reduced drying time in the range of 9–81%, but the shortest drying time was observed for simultaneous action of convection, ultrasound and microwave. The results of qualitative analysis showed a product improvement due to ultrasound as compared to convective drying and microwave-convective drying. The proposed mathematical model of drying kinetics successfully simulated real drying processes. The proposed mathematical model of drying kinetics successfully simulated real hybrid drying processes.