藜草花叶病毒的研究概述

藜草花叶病毒(Sowbane mosaic virus,So MV)是菠菜上的重要有害生物,可通过种子、花粉、昆虫介体和机械等方式传播。随着我国种子、种苗进口量的进一步扩大和产业化种植,藜草花叶病毒传入我国的风险非常大。本文综述了藜草花叶病毒的生物学特性、分布、寄主范围、为害症状、传播途径、检测技术等,论述了藜草花叶病毒传入我国的潜在危害性和风险。     

数字式蜂蜜含水率检测仪设计

对蜂蜜含水率的检测应提供便携、快速、精确、适于在线检测且能克服温度对测量结果影响的仪器。在实验基础上,基于蜂蜜电导率的检测原理,设计了数字式蜂蜜含水率检测仪。以洋槐蜂蜜为对象,通过实验建立了蜂蜜含水率（17%～43%）、温度（5～40℃）和电导率之间的数学模型。以8位单片机为控制器,DJS—1型电极为电导率传感器,DS18B20为温度传感器,设计了检测仪的硬件系统,利用单片机C语言编写程序。检测实验结果表明：每个样品的测量时间在3s内,测量精度为±0.5%。     

饲料中动物源性成分显微近红外光谱检测分析

探讨了应用显微近红外光谱分析技术检测饲料中动物源性成分的可行性.利用12个动物源性成分饲料样品和14个植物源性成分饲料样品建立偏最小二乘定标模型,数学预处理方法为导数+多元散射校正,利用平均光谱来优化模型实现数据压缩,模型的决定系数、交互验证标准差分别为0.969、0.090.4个配合饲料样品作为外部验证未出现误判.结果表明显微近红外光谱分析技术可用于检测饲料中动物源性成分.     

基于小波变换的基波无功实时检测

分析了SVC装置现有的无功功率检测方法，提出了一种基于正交小波变换的基波无功功率实时检测方法。该方法用电力系统电压、电流信号离散采集的数据，可方便地对系统功率因数实时检测，能有效地分解和计算含各次谐波和随机干扰的电压、电流信号中的基波分量，从而得到实时的无功功率数据。通过仿真，验证了实时检测方法的有效性。     

数据融合技术在温室温度检测中的应用

根据温室环境中空间大,温度场分布受到各种参数影响大等特点,提出了采用数据融合方法来处理温室中采集到的传感器数据,采用分布图法剔除疏失误差,采用基于均值的分批估计的融合方法对采集的数据进行处理,提高了温度采集的精度,同时有效地消除了由于传感器失效引起的误差。     

基于可见光机器视觉的棉花伪异性纤维识别方法

为提高皮棉质量和皮棉中异纤的检测精度,提出了一种基于机器视觉的棉花伪异性纤维识别方法。皮棉经过开松装置被制成薄棉层,检测通道两侧的相机对棉层进行拍摄,并将采集到的棉层及异纤和伪异纤图像保存到工控机,通过图像分块及阈值分割等算法,提取伪异纤目标区域,统计获取区域的数个颜色、形状和纹理特征,基于特征数据,分别使用BP神经网络、一对一有向无环图策略线性核函数支持向量机和径向基核函数支持向量机对两大类棉花杂质进行分类识别。实验结果表明,99.15%的伪异纤目标可被准确识别,径向基核函数支持向量机在棉花异纤和伪异纤分类识别中,总分类正确率为95.60%,能够满足在线检测的要求。     

Influence of MUD on the System Capability of CDMA

In CDMA communication system, the relativities between users result in Multiple Access Interference (MAI). With the increase of users, MAI becomes the main jam of broadband CDMA communication system. Multi-User Detection (MUD) is the most important technology of anti-jamming in the broadband CDMA communication system, which can eliminates MAI effectively by using the information of all user signals to detection single. This paper analyze the expression of system capability without MUD and with MUD, and puts forward the way to increase system capability by using MUD. Then the influence of MUD on CDMA system capability is discussed by MATLAB emulation. Basing analysis and emulation, the conclusion is got: the higher the MUD efficiency, the better the improvement of CDMA system capability; under the same MUD efficiency, the lower data rate, the smaller inter-cell interference, the lower the ratio of bit energy to power spectrum, the better the improvement of CDMA system capability.     

猪圆环病毒Ⅱ型PCR检测方法的研究

【目的】建立快速、简便、特异的检测猪圆环病毒II型的PCR方法;【方法】根据已发表的猪圆环病毒II型基因序列设计合成了一对引物,用酚-氯仿法抽提可疑病料中的病毒DNA,应用PCR技术对猪圆环病毒进行基因扩增,PCR产物进行序列测定;以猪瘟病毒、猪伪狂犬病毒、猪细小病毒为对照,进行特异性试验;取部分病料进行重复性试验;【结果】PCR方法扩增出了长度为702bp的片段,扩增产物经测序和序列分析表明扩增的序列为PCV2序列;猪瘟病毒、猪伪狂犬病毒、猪细小病毒的PCR扩增均为阴性,与预期结果一致;部分病料PCR重复检测5次,检测结果完全一致;【结论】PCR检测方法可以对猪圆环病毒病作出敏感、特异、准确地诊断,该方法检测的基因最低模板量为2×10-5ng/ml。     

国内蔓性长豇豆系列品种的抽测与综合评价

通过田间试验对国内31个蔓性长豇豆品种进行重复鉴定。结果表明,约有四分之一的品种质量不合格;约有十分之九的品种不早熟,产量与对照之豇28-2差异不显著,约有二分之一的品种抗病性比对照差。国内虽有众多品种育成,但由于遗传性状的局限性而不能取代老品种之豇28-2。长豇豆虽然是高度自花授粉作物,但忽视选择也极易混杂退化。黑子类品种和柱头外露品种在留种繁殖,更要注意品种间隔离,并要多次进行去杂去劣。     

Using the soil gas radon as an indicator for ground contamination by non-aqueous phase-liquids

1 The Problem  One of the major problems facing risk assessment at polluted industrial sites and military bases is subsurface contamination by non-aqueous phase-liquids (NAPLs), since tracing the extent of a NAPL plume using conventional methods (drive point profiling) is usually associated with difficulties. In an effort to trace subsurface contamination as precisely as possible, monitoring points are placed in the area that might be affected by contaminants, and groundwater and soil samples are taken to the laboratory for analysis. However, the final number of monitoring points is hardly ever sufficient for distinctive contamination mapping, and this may ultimately result in an unsuitable remediation action being taken. 2 Objectives  To obtain a more detailed image of a subsurface NAPL plume and, hence, to facilitate remediation measures that are best suited for the site in question, a denser network of monitoring points is desirable. The aim of the investigation described in this paper was therefore to develop a new detection method for subsurface NAPL contamination, which is based on an easily accessibleindicator for NAPLs rather than on the analysis of soil and groundwater samples taken at the site. Based on the good solubility of radon in NAPLs, the idea was put forward that subsurface NAPL contamination should have an influence on the natural radon concentration of the soil gas. Provided this effect is significant, it would be possible to carry out a straightforward radon survey on an appropriate sampling grid covering the suspected site and thus enabling the NAPL contamination to be detected by the localization of anomalous low radon concentrations in the soil. The overall aim of the investigation was to assess the general suitability of the soil-gas radon concentration as an indirect tracer for NAPL contamination in the ground. 3 Methods  The partitioning coefficient K_NAPL/air is one of the most influential parameters governing the decrease of the radon concentration in the soil gas in the presence of a subsurface NAPL contamination. Since NAPL mixtures such as gasoline, diesel fuel and paraffin are among the most important NAPLs regarding remediation activities, laboratory experiments were performed to determine the radon-partitioning coefficient for these three NAPL mixtures. Field experiments were carried out as well. The aim of the field experiments was to test the use of the soil-gas radon concentration as a tracer for NAPL contamination on-site. For the field experiments, each site was covered with a suitable grid of soil gas sampling points. Finally, the lateral radon distribution pattern achieved on each of the sites was compared to the respective findings of the earlier research performed by conventional means. 4 Results and Discussion  The results of the laboratory experiments clearly show a very strong affinity of radon to the NAPL mixtures examined. The partitioning coefficients achieved correspond to those published for pure NAPLs (Clever 1979) and are thus in the expected range. The results of the field experiments showed that the minimum radon concentrations detected match the respective NAPL plumes traced previously. 5 Conclusions  Both the results of the lab experiments and the on-site findings demonstrate that the soil-gas radon concentration can be used as an indicator for subsurface NAPL contamination. The investigation showed that NAPL-contaminated soil volumes give rise to anomalous low soil-gas radon concentrations in the close vicinity of the contamination. The reason for this decrease in the soil-gas radon concentration is the good solubility of radon in NAPLs, which enables the NAPLs to accumulate and ‘trap’ part of the radon available in the soil pores. 6 Recommendations and Outlook  Further research is required into contamination with rather volatile NAPLs such as BTEX. Further research is also needed to examine whether it is possible to not only localize a NAPL plume, but also to obtain some quantitative information about the subsurface NAPL contamination. The authors also believe that additional investigations should be carried out to study the ability of the method to not just localize a NAPL contamination, but also to monitor on-site, clean-up measures.