固体表面液滴热毛细迁移的实验研究

首先从理论方面推导了固体表面液滴热毛细迁移速度、临界半径的关系式,然后通过实验的方法系统的研究不同的液滴在二氧化硅底板上的热毛细迁移行为。液滴静置在一个固体表面上时,会出现部分润湿,完全润湿和不润湿的情况。对于部分润湿来说,可用Young方程来描述三相线处的静态接触角。由于固体基底表面非均质性或液滴的热动力学因素等,液滴会出现接触角滞后现象。当固体表面存在温度梯度时,液体的表面张力随温度

Classification method of diabetes based on integration of characteristic classifier

目的:结合医用电子鼻技术,探讨糖尿病患者及其口腔呼气的气味图谱特征。方法:选择180例糖尿病患者和100例健康者,用医用电子鼻采集280例口腔呼气的气味图谱,采用基于数据特征划分的方法,用支持向量机和随机森林集成模型对糖尿病患者进行分类预测。结果:1线性核函数的支持向量机(SVM1)分类结果不是很理想,低于多项式核(SVM2)、径向基函数核(SVM3)和随机森林(RF)3种分类器,说明分类超平面显然是非线性的;2集成分类器对糖尿病患者和健康者的气味图谱特征的识别准确率可达88.04%。结论:基于特征划分的分类器集成方法预测性能明显好于单一分类器,为使用医用电子鼻进行糖尿病诊断分析提供了一种有效手段。Objective: To discuss the proi le features of oral odor of diabetic patients based on medical electronic nose technology. Methods: 180 patients of diabetes and 100 healthy people were selected, and the proi le features of oral odor of 280 volunteers were collected by using medical electronic nose. The classii cation forecasting was carried out on diabetic patients by using support vector machine(SVM) and random forest integration model based on partitioning method of data characteristics. Results: 1The classii cation result of SVM1 was not very good, which was lower than that of SVM2, SVM3 and RF, and the result showed that the classii cation hyperplane is nonlinear. 2The accurate rate of recognition of integrated classii er on diabetic patients and healthy people is 88.04%. Conclusion: The forecasting performance of classii er integration method based on feature division is superior to that of single classii er signii cantly, which provided an ef ective means for the diagnostic analysis of diabetes based on medical electronic nose.国家自然科学基金项目(No.81373552);; 福建省教育厅A类项目(No.JA14212);; 福建工程学院科研启动项目(No.GY-Z12079)~

甲壳素溶致液晶的研究

报道了甲壳素有溶致液晶性．对四种不同分子量的甲壳素的研究结果表明，分子量增大，临界浓度显著降低，胆甾相平均螺距减少，但液晶有序微区平均尺寸却增加．甲壳素分子量为２８４×１０６、１４７×１０６、９４×１０５和５３×１０５时，在二氯乙酸中的临界浓度（Ｗ／Ｗ）分别为０００５、００１５、００３５和００５０．根据理论分析，甲壳素可视为刚性链，与多肽相似．甲壳素的指纹状织构不同于其他溶致液晶体系，在各种分子量甲壳素的两相共存浓度区内，液晶有序存在于内含指纹的不规则微区内，而不是滴状微区内

城乡链接与农民合作

2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

software effort estimation method of optimal linear combining

软件工作量估算的方法和技术众多且各有千秋,没有一种方法被证明在各种情况下的估算都是最精确的.组合估算是一种非常有效的估算方法,它避免了选择单一的最优估算方法这一难题,而是充分利用各种估算方法提供的信息来达到提高估算精确度和稳定性的目的.将系统的"外部"组合预测方法介绍到软件工作量估算领域,基于最具代表性的组合估算方法:最优线性组合方法,提出了软件工作量估算的最优线性组合方法,该方法中即使是估算效果"较差"的技术或者方法也能为估算精度和稳定性的提高做出贡献

提高二极管激光阵列外腔锁相效率的实验研究

采用1/4 Talbot外腔实现宽条二极管激光阵列的锁相,在工作电流是35 A时,获得7.56 W的锁相输出功率,输出光束的远场图像是多瓣结构,锁相前后输出光的光谱宽度从2.0 nm压缩到0.2 nm.腔内插入焦距大约为5倍腔长的柱透镜,在相同电流下获得8.75 W的锁相输出功率,输出光的远场图像是多瓣结构,输出超模的数目有所减少,能量向中部集中,输出光的光谱宽度是0.2 nm

3-MCPD and Glycidyl Esters in Potato Chips Sold in Turkey

3-Kloropropan 1,2-diol (3-MCPD) maddesi gıda kaynaklı bulaşanlardandır. 3-MCPD, Avrupa Komisyonu'nun Gıda Bilimsel Komitesi tarafından genotoksik karsinojen olarak belirlenmiş ve İngiltere Gıda Danışma Komitesi tarafından gıda ve gıda maddelerinde minimum düzeylere indirilmesi önerilen proses tabanlı bulaşan olarak tanımlanmıştır. Bu çalışmanın amacı, piyasadan elde edilen ve farklı markalardan alınan patates cipslerinin 3-MCPD esterleri ve glisidil esterlerinin miktarlarının belirlenmesidir. Patates cipslerinde bulunan 3-MCPD esterleri ve glisidil esterleri miktarları üzerine üretim yönteminin (markanın) ve kızartma amacıyla kullanılan yağ tipinin etkisi istatistiksel olarak incelenmiştir. Ayrıca ortalama vücut ağırlığına sahip bir bireyin, saptanan miktarlarda 3-MCPD esteri içeren patates cipsi tüketim sınırları ve tolere edilebilir günlük alım miktarları üzerinden hesaplanmıştır. Patates cipslerinin toplam 3MCPD esterleri ve glisidil esterleri miktarlarının belirlenmesi için DGF C VI 18(10) standart yöntemi kullanılmıştır. En yüksek 3-MCPD esterleri miktarı 2.97 mg/kg olarak B2 markasında (Örnekleme 1) bulunmuştur. Ayrıca en yüksek glisidil esterleri miktarı B2 markasında (Örnekleme 2) 6.01 mg/kg olarak tespit edilmiştir.3-Chloropropane 1,2-diol (3-MCPD) is a food-based contaminant. 3-MCPD is declared as a genotoxic carcinogen formed in foods by the Scientific Committee on Food of the European Commission and the UK Food Advisory Committee has recommended reducing its level to minimum in foods. The objective of this study is to determine 3MCPD esters and glycidyl esters contents of commercially available potato chips sold in Turkey. For this purpose, various brands of potato chips were obtained from local markets. The effects of production method (brands) and frying oil were investigated statistically based on the formation of 3-MCPD esters and glycidyl esters in various brands of potato chips. Moreover, maximum consumption for potato chips was calculated based on tolerable daily intake of 3MCPD esters for individuals of average body weight. DGF C V 18 (10) standard method was used for determination of 3-MCPD esters and glycidyl esters in potato chips. Maximum value for 3-MCPD esters was 2.97 mg/kg in B2 brand (Sample Block 2). Also, the highest amount of glycidyl esters was determined as 6.01 mg/kg in B2 brand (Sample Block 2)

近十年来赤水河不同江段鱼类群落年际变化特征

赤水河是目前长江上游为数不多的仍然保持着自然流态的大型一级支流,同时也是长江上游珍稀特有鱼类国家级自然保护区的重要组成部分,在长江上游珍稀特有鱼类保护方面发挥着至关重要的作用。文章基于2007—2016年连续十年的渔获物监测数据,对赤水河不同江段鱼类群落结构的年际变化特征进行了分析。调查期间,赤水镇、赤水市和合江县3个调查江段共采集到鱼类7目20科84属133种,其中包括长江鲟Acipenser dabryanus和胭脂鱼Myxocyprinus asiaticus2种国家重点保护野生动物以及36种仅分布于长江上游地区的特有鱼类。鱼类物种数量呈现出随河流梯度向下游延伸而逐渐增加的趋势,其中赤水镇江段采集鱼类47种,赤水市江段采集鱼类90种,合江县江段采集鱼类120种。聚类分析和排序分析显示,赤水河不同江段鱼类群落结构均发生了较为明显的年际变化。主要表现为部分大中型鱼类在渔获物中的比例持续降低,其中赤水镇江段中华倒刺鲃Spinibarbus sinensis和白甲鱼Onychostoma sima的相对丰度由2007—2011的12.19%和14.26%降低至2012—2016年的0.66%和3.25%;赤水市江段中华倒刺鲃的相对丰度由2007—2008年的8.21%下降至2009—2013年的4.31%和2014—2016年的3.47%。此外,部分特有鱼类在渔获物中的比例逐年下降。合江县江段张氏?Hemiculter tchangi的相对丰度由2007年的8.41%下降至2008-2012年的7.98%和2013—2016年的1.51%;圆口铜鱼Coreius guichenoti的相对丰度由2007年的2.08%下降至2008—2012年的0.10%,2013—2016年则完全从渔获物中消失。造成赤水河鱼类群落结构变化的原因是多方面的,不仅包括流域内高强度的商业捕捞和日益增强的人类活动,而且还与整个长江上游的水域生态环境变化密切相关。为切实保护好赤水河鱼类资源,建议加强渔政管理,实施生态修复,同时加强科研监测