国家速滑馆自控施工技术研究

国家速滑馆工程建筑面积9.7万m2,建筑结构复杂,为国内首个全冰面的比赛场馆.智能控制系统特点鲜明、先进且复杂,包括赛事管理平台、楼宇自控、智慧管理平台及下设的23项独立统管理子系统.高效畅通地搭建各层级主系统的框架,解决平台对各子系统控制和监视中存在的问题是工程的亮点.详细论述管理平台对各系统的控制需求和各系统在深化实施中遇到的问题,及如何对整个平台功能进行完善.     

分子动力学模拟聚乙烯在碳纳米管表面的扩散

通过采用分子动力学方法模拟不同链长的聚乙烯分子在单壁碳纳米管表面的扩散,探究了聚乙烯的动力学性质。研究表明随着链长的增加聚乙烯在碳纳米管表面的扩散系数减小,且二者间存在明显的标度关系。聚乙烯在碳纳米管表面扩散的扩散系数和聚乙烯吸附在碳纳米管表面的构象有关,有序结构的聚乙烯比无序结构的聚乙烯在碳纳米管表面扩散的快。此外,由于受到碳纳米管吸附作用的影响,聚乙烯分子在平行于管轴和垂直于管轴2个方向上的扩散系数不同,扩散表现各向异性。     

发芽绿豆多酚提取物对Ⅱ型糖尿病小鼠糖脂代谢的改善作用

目的:探究发芽绿豆多酚提取物对Ⅱ型糖尿病(T2DM)模型小鼠糖脂代谢的改善作用。方法:根据C57BL/6小鼠体重随机分为正常对照组、模型组、发芽绿豆多酚提取物高、中、低剂量组、阳性对照组。通过高脂饮食联合腹腔注射链脲佐菌素(STZ)的方法 建立2型糖尿病小鼠模型。连续灌胃5周后,测定小鼠空腹血糖值、葡萄糖耐量、脏器指数、血脂水平等指标,观察肝脏组织形态。结果:与模型组相比,发芽绿豆多酚提取物能降低小鼠空腹血糖,并显著提高其糖耐量水平(P<0.01);改善T2DM小鼠血清中血脂指标(TC、TG、LDL-C、HDL-C)的浓度(P<0.01);降低小鼠血清ALT、AST的活力,并对STZ诱导的糖尿病小鼠肝脏组织细胞形态有一定的修复作用。结论:一定剂量的发芽绿豆多酚提取液可以有效改善Ⅱ型糖尿病小鼠高血糖和血脂代谢紊乱的症状。     

基于RGB颜色信息聚类的光谱反射率重建

针对光谱反射率研究中因训练样本数据量大造成的冗杂等问题,提出了一种基于RGB信息进行聚类的样本分类方法。首先对颜色进行聚类并确定聚类个数,后对每一类光谱反射率使用BP神经网络分别进行重建。对于实验结果,使用ΔE00、均方根误差（RMSE）以及适应度系数等标准进行评价,同时与主成分分析算法进行对比。从实验分析可得出,在聚类数目为7时光谱反射率重建效果最好,这时的平均CIE2000的色差为0.836,平均RMSE为0.014 9,平均适应度系数为99.82%,并且,在最后对重建色差较大的色块进行了优化处理。实验证明,颜色聚类方法可以很好的应用于光谱反射率重建。     

Nondestructive Prediction of Tilapia Fillet Freshness During Storage at Different Temperatures by Integrating an Electronic Nose and Tongue with Radial Basis Function Neural Networks

This study developed principal component analysis and radial basis function neural networks (PCA-RBFNNs) for predicting freshness in tilapia fillets stored at different temperatures by integrating an electronic nose and electronic tongue. Total volatile basic nitrogen (TVB-N), total aerobic counts (TAC), and K value increased at 0, 4, 7, and 10 °C, while sensory scores decreased significantly. The electronic nose and tongue acquired the volatiles and dissolved chemical compounds in the stored samples. Gas chromatography-mass spectrometry (GC-MS) verified the changes in gas species and contents in fillets stored for different periods of time at different temperatures. PCA-RBFNNs based on data fusion were developed and presented good performance for prediction of TVB-N, TAC, K value, and sensory score in tilapia fillets. The established PCA-RBFNNs based on feature variables of the electronic nose and tongue is a promising method to predict changes in the freshness of fillets stored from 0 to 10 °C in the cold chain.     

海洋真菌Chaetomium globosum G2产麦角甾醇的研究

从连云港近海的沉积物中分离得到一株毛壳霉属真菌Chaetomium globosum G2,发酵后从其菌丝体中分离得到白色固体,经核磁共振谱及质谱分析,确定该化合物为麦角甾醇,并对其产麦角甾醇的条件进行了研究。发现培养条件为GPY培养基、初始pH为8、培养时间11天时麦角甾醇含量最高为8.36 mg/g干菌。     

二次主成分提取高光谱的病害薯叶特征波长

针对马铃薯晚疫病,提出了将病害叶片和健康叶片联合测试并提取有效特征波长的检测方法。对健康和病害叶片的光谱图像进行主成分分析,并从主成分图像的权重系数曲线中提取出6个健康叶片特征波长和病害叶片特征波长。基于健康叶片与病害叶片的6个特征波长做第二次主成分分析,将特征波长优化至712.19 nm、749.70 nm和841.47 nm,再基于这3个特征波长做主成分分析,选用主成分中对比度最明显的图像来识别病害区域。研究表明,采用健康叶片与病害叶片联合使用并结合二次主成分分析可实现马铃薯叶片病害的设别,且识别率可达100%。     

BAF-L Modulates Histone-to-Protamine Transition during Spermiogenesis

Maturing male germ cells undergo a unique developmental process in spermiogenesis that replaces nucleosomal histones with protamines, the process of which is critical for testicular development and male fertility. The progress of this exchange is regulated by complex mechanisms that are not well understood. Now, with mouse genetic models, we show that barrier-to-autointegration factor-like protein (BAF-L) plays an important role in spermiogenesis and spermatozoal function. BAF-L is a male germ cell marker, whose expression is highly associated with the maturation of male germ cells. The genetic deletion of BAF-L in mice impairs the progress of spermiogenesis and thus male fertility. This effect on male fertility is a consequence of the disturbed homeostasis of histones and protamines in maturing male germ cells, in which the interactions between BAF-L and histones/protamines are implicated. Finally, we show that reduced testicular expression of BAF-L represents a risk factor of human male infertility.     

RFC中数字锁相环的设计

本文介绍了以可编程逻辑器件CPLD实现RFC中数字锁相环的设计，分析了设计原理，列出了详细的设计过程并例举数据以及仿真结果。     

Experimental study on clamping pressure distribution in PEM fuel cells

To study the effect of internal pressure distribution on the performance of a PEM fuel cell, a pressurized endplate was designed and fabricated. The endplate had a built-in hydraulically pressurized pocket with a thin wall facing the fuel cell assembly. Pressure sensitive films were used to measure the pressure distribution for both conventional and newly designed end plates. Fuel cell performance tests were conducted under selected conditions. It was found that the pressure distribution for the newly designed endplates was more uniform than for the conventional end plates, and an improved fuel cell performance was obtained with the newly designed end plates as well.