食品中瘦肉精常用检测方法及快速检测技术的研究进展

瘦肉精能加速畜禽体内的瘦肉生长，但会对人们健康造成威胁。综述了现有瘦肉精检测方法的研究进展，主要介绍了感官检测法、酶联免疫吸附法、高效液相色谱法的优劣，重点分析了瘦肉精快速检测方法，介绍常见瘦肉精胶体金快速检测卡优化和改进措施，为后续不断深入研发新型快速检测技术提供依据，确保消费者舌尖上肉制品的安全，推动肉类食品加工行业的可持续发展。      

气相和液相色谱法在氟苯尼考残留检测中的应用进展

气相和液相色谱法常用于检测氟苯尼考在动物产品和环境样品中的残留水平。本文比较了气相色谱和液相色谱检测氟苯尼考的优缺点，同时重点对动物产品和养殖场相关环境样品中氟苯尼考的提取和净化方法进行了比较分析。不同类型样品前处理方法有不同，乙腈是良好的蛋白沉淀剂，有助于动物产品的纯化；环境样品的前处理比动物产品更复杂，色谱串联质谱能够有效提高其检测效率。本文旨在归纳氟苯尼考的残留检测的色谱方法，为动物类食品安全和氟苯尼考环境风险评估提供参考。     

逆向云在垩白识别中的应

在云理论的基础上提出了一种无需人工干预的垩白识别方法.在此方法中,把垩白与非垩白定义为两个定性概念,以一个不对称云和一个对称云来表达垩白与非垩白,以两组数字特征分别描述垩白云与非垩白云.首先,利用动态阈值算法获得训练样本,然后设计逆向云发生器实现定量到定性的转换,最后根据两个云的隶属度函数,用极大值判定法来实现垩白区与非垩白区的分离.试验结果表明,云分类法分类精度高于传统的硬分类法.     

手持式X射线荧光光谱快速测定仪的实践应用评价及建议

手持式X射线荧光光谱仪(XRF)作为快速筛选重金属污染的手段在污染地块调查中广泛使用，但目前国内对XRF现场检测结果指导实验室筛选检测样品的可靠性研究缺乏。本文选择两个实际污染地块调查中的Cu、Pb、As、Ni、Cd和Hg6种重金属的XRF现场检测数据和实验室实测数据，采用一元线性拟合、Pearson相关、差异分析等手段对两种测试结果的一致性进行研究。结果表明，土壤中Cu、Pb、As和Ni4种金属的XRF测定值和实验室实测值具有显著相关性。Hg和Cd的XRF测定值显著高于实验室实测值，Cu、Pb、As和Ni XRF测定值较实验室实测值偏小的样品占比超过50%。6种重金属中Cu和Pb XRF测定值和实验室实测值的相关性及一元线性拟合结果更好(相关系数0.5～0.8,R~2>0.7)。Cu在XRF测定值大于1 000 mg/kg时与实验室实测值的拟合结果更好(R~2>0.7),As和Pb分别为XRF测定值在4.0～10 mg/kg和检出限～80 mg/kg范围时更好(R~2>0.8)。采用重金属筛选值的50%作为筛选实验室样品的标准时，XRF结果预测Cu、Pb和As超标样...     

菌根真菌定殖检测技术比较与分析

使用菌根真菌定殖植物这一研究方法,已被大量研究者成功运用在各类植物中,并且得到了使植物促生、抗逆性与抗病害性提高以及改善根际土壤环境等良性结果。因此监测菌根真菌在植物根部的定殖与否和定殖程度,即对其定殖检测技术的掌握具有重要意义。本文根据不同利用方法归类介绍了7种检测技术,同时对比了各自的优点以及详细检测过程,旨在为选择效果优良的检测技术,提高菌根真菌定殖的检测效率提供参考。     

Preliminary investigation and detection based on loop-mediated isothermal amplification (LAMP) of phytoplasmas associated with diseases in B. napus L.

In the last decade, some disease occurred on our experimental farms that had caused serious losses. They were not caused by fungi, bacteria or viruses. By loop-mediated isothermal amplification (LAMP) technique, the detection results pointed to the possible pathogen as phytoplasma. The investigation results implied that phytoplasmas could cause more than 13 kinds of symptoms in almost all parts of plants in B. napus L., including witches’ broom, multi-stems, aggregate main inflorescences, and flat stems. The incidences of these phytoplasma-associated diseases in our experimental farms rose from 1.61% in 2010 to 6.00% in 2021. Some phytoplasma infected plants died without any growing points. These studies would be helpful for detecting phytoplasmas diseases, selecting disease resistant germplasm and improving varieties with disease resistances in B. napus L.     

Occupancy and detectability of African crowned eagles in an urban mosaic landscape: The importance of natural forest areas

Diminishing forests as a result of anthropogenic activities continues to impact the persistence of terrestrial species negatively. Raptors are particularly susceptible to human activities because of their low population densities and large home range sizes. In this study, we investigated the occupancy and detection probabilities of the Near-Threatened African crowned eagle (Stephanoaetus coronatus) in Durban, EThekwini Municipality, South Africa. Using point count surveys, we documented the presence/absence of African crowned eagles in 42 sampling sites in the urban mosaic landscape of Durban. We used the presence/absence data to model their occupancy and detection probability in our surveyed sites. The naïve occupancy of African crowned eagles was 0.6, and the estimated occupancy and detection probability were 0.78 + 0.061 and 0.40 + 0.085, respectively. Based on the best models, the occupancy of African crowned eagles was positively influenced by forests (β = 1.24 + 0.69) and negatively influenced by disturbance (β = −1.69 + 0.78) and roads. The detection probability of these eagles was positively influenced by disturbance (β = 0.34 + 0.29) and the presence of exotic tree plantations (β = 0.33 + 0.47) and negatively influenced by the type of surrounding settlements (i.e., urban or rural) (β = −0.59 + 0.43). Based on the averaged models, occupancy is positively influenced by forests (β = 0.15 + 1.48) and negatively influenced by roads (β = −0.05 + 0.34), building density (β = −0.07 + 0.79) and disturbance (β = −0.24 + 3.36). Detection probability is negatively influenced by surrounding settlement (β = −0.12 + 0.41) and positively influenced by disturbance (β = 0.04 + 3.21) and plantations (β = 0.01 + 0.12). Overall, our results showed the persistence of African crowned eagles in the urban mosaic landscape as a consequence of natural and managed green spaces, especially forests. This highlighted the importance of natural forests and exotic tree plantations in ensuring the survival and thriving of African crowned eagles and the key role these green spaces play in species conservation in this urban mosaic landscape.     

便携式叶绿素、氮素、水分一体化测定仪设计

建立了可以同时检测作物叶片叶绿素、氮素和水分的数学模型.结合光谱学原理,设计了由近红外LED光源、窄带干涉滤光片、光电检测芯片以及单片机系统组成的作物叶片叶绿素、氮素、水分检测一体化便携式仪器,避免现有仪器由于叶片位置和测定时间差异导致的作物养分探测误差,可用于作物养分和水分的精细管理.     

非洲马瘟病毒VP7蛋白原核表达及间接ELISA抗体检测方法的建立

为建立非洲马瘟病毒(African Horse Sickness Virus,AHSV)的血清学诊断方法,本研究构建了非洲马瘟病毒VP7蛋白的原核表达质粒pET-32a-VP7,诱导表达后使用Ni-NTA对可溶性VP7蛋白亲和纯化,以重组VP7蛋白作为包被抗原,优化建立检测血清抗体的间接ELISA方法,并对该方法进行敏感性、特异型和重复性验证,表明该方法的检测效果良好。本研究为非洲马瘟的血清检测试剂盒的开发提供的相关参考。     

The effects of urban greenway environment on recreational activities in tropical high-density Singapore: A computer vision approach

The urban greenway has been increasingly recognised as an important type of green infrastructure especially for land-scarce, densely-populated cities to efficiently provide their residents with continuous public spaces close to nature for recreation. Nevertheless, empirical studies on urban greenways and their recreational use rarely focus on high-density environment. Moreover, most research endeavours in this field are also largely confined to the subtropical climate, whereas much of the world’s future urban growth is projected to occur in the form of high-density mega-cities in much of tropical South and Southeast Asia. In view of these gaps, this study proposes a new approach that employs Computer Vision tools to examine the effects of the greenway’s physical environment on recreational activities, taking tropical Singapore as the test bed. The semantic segmentation model, PSPNet and the action detection model, ACAM are adapted and applied in conjunction with geographical information system tools to measure the greenway’s physical environment and people’s recreational activity at the human scale, and analyse their relationships. The result reveals a pattern that sees the clustering of different types of recreational activities at different time periods. It also reveals the relationships between recreational activities and specific environmental features, which were observed to have influenced the overall spatial distributions of the recreational activities. The finding also corroborates the design strategies for Singapore’s future urban greenways and offers a reference for engaging community groups to participate in the maintenance of urban greenways.