ITS宽带短波信道及其噪声的建模和仿真

文章介绍了宽带短波（WBHF）信道研究的发展历程,根据ITS信道建模的方法,在对信道衰落特征及其噪声干扰统计特性进行分析的基础上建立了适当模型,并设定了特定环境下信道衰落模型及其噪声模型的相关参数。最后通过计算机仿真与实测数据加以比较,从散射函数能量分布、噪声时／频域电平以及噪声电平交叉率（LCR）方面验证了信道模型的合理性。     

GPS系统在交通运营管理中的应用

在国家智能交通系统（ITS）的发展战略和产业化方向的指引下,GPS技术在ITS的发展中得到广泛的应用与发展,随着交通运输规模的不断扩大,它在交通运营中的应用也得到广泛地推广。本文着重介绍了GPS系统在交通运输中的应用,包括在车辆交通管理,军事交通、奥运车辆监控等方面的作用,最后做了总结和展望。     

基于智能终端定位的智能交通疏导系统研发

在城市发展到比较成熟的阶段,缓解交通堵塞可借鉴智能交通系统(Intelligent Transportation System,ITS)的理念,文章在现有的无线通信设施和车辆系统上,通过融合信息与通信技术、移动互联网和智能终端设备构建一套道路交通流量计算和道路交通服务系统。该系统通过车载智能终端的GPS数据进行实时交通流量计算,并且将计算的交通流量信息实时地反馈给驾驶车辆的用户,方便用户出行道路选择,缓解交通阻塞。     

一种基于直方图统计与多帧平均混合的背景提取算法

介绍了背景的提取与自适应更新的算法,提出了一种基于直方图统计与多帧平均混合的算法。这种算法克服单纯的多帧图像在车流量多、车速低时出现拖尾和模糊的现象,且相对于混合高斯模型,其计算复杂度较低。该算法已通过TI DM642DSP硬件平台实现,实验图像结果表明,该背景提取算法的速度快,且符合实际场景。     

基于ARM9的道路交通数据采集系统设计

智能运输系统被公认为是当前解决我国大城市交通拥挤和提高道路安全的有效手段,而交通数据采集是ITS最为基础的环节。分析了国内外数据采集系统发展的现状和存在的问题,论证了交通数据信息采集系统的必要性,提出了交通数据采集系统的基本要求,详细论述了基于ARM9系列的S3C2410嵌入式系统平台来实现数据采集系统的设计,利用TCP/IP协议来实现数据传输及数据共享的实现方法,最后完成应用程序到目标平台的移植。     

高大平房仓稻谷粮层霉菌量与优势霉菌的差异性研究

采用传统培养法对湖南与湖北两省粮库中的稻谷进行研究,对高大平房仓粮仓上中下三层的稻谷霉菌量及优势霉菌进行研究。研究结果表明:湖南省储藏一年稻谷与新入库稻谷中层霉菌数分别为6.4×10~3 CFU/g、1.3×10~3 CFU/g,相比上、下层,中层最多;湖北省储藏一年稻谷下层霉菌数为1.4×10~4 CFU/g,相比上、中层,下层最多,湖北省新入库稻谷上层霉菌数为1.4×10~4 CFU/g,相比中、下层,上层最多。通过传统的菌落培养及菌丝、孢子观察,初步判断上中下三层的优势霉菌,并结合分子生物学的方法对其ITS序列进行分析,通过PCR扩增,将扩增出来的基因序列,在GenBank进行BLAST,最终鉴定优势菌株为黄曲霉、白曲霉、聚多曲霉、内生真菌、黑曲霉。     

A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily

Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based characterization. PCR assays using species-specific primers discriminated between A. niger, A. carbonarius and A. japonicus on the basis of the target sequences for each species. The PCR-based methods matched morphological characterization in identifying all the black aspergilli (BA) isolates tested, whereas RFLP analysis with RsaI of isolates positive to PCRs with A. niger specific primers identified three A. tubingensis isolates. The identification of thirteen isolates was further confirmed by ITS analysis. By this method, each of the isolates was identified and assigned to an Aspergillus species. The fAFLP analysis of 40 isolates highlighted the power of this technique to discriminate different species and single strains, to verify the presence of mixed populations in the same vineyard, through homogeneous species clusters. No correlation was observed between the clusters and OTA production level or origin.     

Chemical and DNA authentication of taste variants of Gynostemma pentaphyllum herbal tea

Gynostemma pentaphyllum Makino (Gp) was once used as a sweetener in Japan and is now widely consumed as an herbal tea worldwide for lowering cholesterol levels. Two taste variants, bitter and sweet, of Gp exist in the commercial market, but they cannot be differentiated morphologically nor by existing chemical analytical methods. This has been creating a problem in quality control of Gp products. In the present study, using HPLC-DAD and HPLC–ESI-MS analysis, we found that the Gp saponins, not flavonoids, from the sweet and bitter variants have distinctly different profiles. In addition, the two variants share only 69.01% homology in the ribosomal ITS-1 region, suggesting a phylogenic gap between these two variants. The combinations of chemical profiling and phylogenic analysis clearly confirm, for the first time, the distinction between these two taste variants. This information has direct application in the authentication and quality assessment of the various Gynostemma tea products.     

桃果实贮藏期间病原真菌的ITS rDNA序列分析与鉴定

目的:对桃果实采后病原菌进行分离与鉴定.方法:采用转接法分离桃果实采后病原真菌,经形态学观察和核糖体rDNA ITS(Internal transcribed spacer)区序列分析,对相关病原菌进行分类鉴定.结果:从采后贮藏过程中发生病害的桃果实分离到2株病原菌,经鉴定分别为美澳型核果链核盘菌(Monilinia fructicola)和葡萄座腔菌(Botryosphaeria dothidea).结论:通过对ITS rDNA序列的相关分析,对分离自采后贮藏果实中的病原真菌进行有效的分类鉴定.     

Comparative study of the phenolics,antioxidant and metagenomic composition of novel soy whey-based beverages produced using three different water kefir microbiota

Water kefir microbiota was used to develop novel soy whey-based beverages that have antioxidant activity. In the present study, comparative phenolics, antioxidant and metagenomic composition of the soy whey beverages fermented using three different water kefir microbiota, named WKFS-A, WKFS-B and WKFS-C were investigated. WKFS-B beverage had the highest concentrations of isoflavone aglycones (208.73 ± 2.78 mg L⁻¹) and phenolic acids (132.33 ± 3.41 mg L⁻¹) compared with WKFS-A (193.88 ± 1.15 mg L⁻¹) and (91.73 ± 2.34 mg L⁻¹) and WKFS-C (160.63 ± 1.76 mg L⁻¹) and (97.13 ± 2.63 mg L⁻¹), respectively. The WKFS-B also showed higher DPPH and ABTS radical scavenging activity and ferric reducing antioxidant power compared with WKFS-A and WKFS-C beverages. Microbial species diversity index analysis showed that a higher concentration of isoflavone aglycones, phenolic acids and increased antioxidant activity in the WKFS-B beverage correlates with the higher relative abundance of Lactobacillus genus. This study thus revealed that Lactobacillus dominated water kefir microbiota produces soy whey beverages with high phenolic acids, isoflavone aglycones and antioxidant activity.