GIS特高频及超声波局部放电测试传感器专用支撑工具

GIS设备超声波及特高压局部放电,高处测点较多,测试耗时费力,测试效率低。QC小组分析找出5条末端因素,并确定了"缺少专用支撑工具"是主要原因。设计了专用支撑工具,包括绝缘杆、传感器固定卡座和附件固定卡座,该工具结构小巧,便于携带,方便操作,绝缘良好,可同时适用于超声波和特高频两种形状完全不同的传感器专用支撑。     

蔬菜标准化嫁接育苗关键技术

中国蔬菜种苗需求量逐年上升,且前景广阔。同时对于种苗质量的要求也越来越高。本文详细介绍茄果类和瓜类标准化嫁接育苗技术与条件。     

太原市农民工市民化水平评价指标体系研究

本研究在建立市民化水平评价指标体系的基础上,对太原市农民工市民化水平进行实证研究,考察太原市农民工市民化特征,评析其水平,为中部地区城市可持续发展提供相应的政策依据和建议。建立了包含居住条件、经济条件、社会公共服务享有、社会融入、政治参与、心理适应6个维度的市民化水平评价指标体系,运用问卷调查法、熵值法和主观意见法确定了各维度一级和二级指标权重,对市民化水平进行了评价和分析。结果表明：太原市农民工市民化总体水平较高,但仍处在初始阶段,物质方面的进程远优于精神方面的进程,农民工未能完成向市民的真正转变;尤其是社会公共服务享有的维度水平较低。这反映了为了有效促进市民化进程,政府部门在农民工市民化进程中需要进一步加大教育、医疗和住房保障等公共服务的提供力度。     

我国小户竹农扶持政策分析

小户竹农人口众多,面临的竹林经营风险多样,其发展状况关系到社会公平,有必要制定专门政策加以扶持。虽然我国开展了集体林权制度改革,但在竹产业政策中,仍缺乏对小户竹农的针对性扶持,有必要完善相关政策。建议取消小户竹农的育林基金和采伐审批、增加对小户竹农的贷款及竹林生态效益补偿额度,设置小户竹农竹林经营奖励项目,并在林地流转、科技推广、森林保险补贴制度、投诉制度等方面加以完善。     

Validation of reference genes for quantitative expression analysis by real-time rt-PCR in four lepidopteran insects

Abstract Quantitative real-time polymerase chain reaction (qPCR) is an efficient and widely used technique to monitor gene expression. Housekeeping genes (HKGs) are often empirically selected as the reference genes for data normalization. However, the suitability of HKGs used as the reference genes has been seldom validated. Here, six HKGs were chosen (actin A3, actin A1, GAPDH, G3PDH, E2F, rp49) in four lepidopteran insects Bombyx mori L. (Lepidoptera: Bombycidae), Plutella xylostella L. (Plutellidae), Chilo suppressalis Walker (Crambidae), and Spodoptera exigua Hübner (Noctuidae) to study their expression stability. The algorithms of geNorm, NormFinder, stability index, and ΔCt analysis were used to evaluate these HKGs. Across different developmental stages, actin A1 was the most stable in P. xylostella and C. suppressalis, but it was the least stable in B. mori and S. exigua. Rp49 and GAPDH were the most stable in B. mori and S. exigua, respectively. In different tissues, GAPDH, E2F, and Rp49 were the most stable in B. mori, S. exigua, and C. suppressalis, respectively. The relative abundances of Siwi genes estimated by 2(-ΔΔCt) method were tested with different HKGs as the reference gene, proving the importance of internal controls in qPCR data analysis. The results not only presented a list of suitable reference genes in four lepidopteran insects, but also proved that the expression stabilities of HKGs were different among evolutionarily close species. There was no single universal reference gene that could be used in all situations. It is indispensable to validate the expression of HKGs before using them as the internal control in qPCR.     

Chloroplast DNA molecular characterization and leaf volatiles analysis of mint (Mentha; Lamiaceae) populations in China

Non-coding chloroplast DNA (cpDNA) was used to evaluate genetic diversity and relationships within the section Mentha collected from China. Leaf volatiles of Mentha spicata accessions and its parent were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). To this end, genetic diversity of 30 Mentha accessions from different geographic origins of China, representing six species and two hybrids, was assessed. Molecular studies grouped the samples mainly according to genetic relationship established by conventional methods. Cluster analysis based on the leaf volatiles chemical composition of M. spicata accessions defined two main chemotypes: 1,8-cineole-piperitenone oxide type and limonene-carvone type. The results suggested that there was a high genetic variability among individuals of Mentha in China. A distinct correlation between cpDNA marker and volatile oils in M. spicata accessions was revealed. Moreover, the chemical composition followed maternal inheritance in M. spicata accessions. In conclusion, the genetic diversity of Mentha populations as shown in this study should play a critical role in future selection and breeding programs.     

Efficacy of a Fructus mume Extract Combination with Stable Chlorine in Preventing Bacterial Contamination in Frozen Mackerel (Scomber japonicus) Fillets

ABSTRACT

A combination composed of Fructus mume extract and stable chlorine dioxide was investigated for its antibacterial activity, mechanism of action, and its application against Escherichia coli and Staphylococcus aureus in mackerel (Scomber japonicus) fillets. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against E. coli and S. aureus ranged from 0.9–1.2 and 1.3–1.6 mg/mL for F. mume extract and 0.004–0.006 and 0.007–0.010 mg/mL for stable chlorine dioxide, respectively. We observed a mechanism of action against E. coli that involved a pore-formation role that led to cell membrane damage. In the case of S. aureus, the mechanism of action is believed to be mediated by the combination’s activity as a metabolite disrupting agent. Here, the amount of bacteria was greatly reduced in mackerel fillets treated with the combination. Moreover, the flavor and texture properties of fillets were not significantly affected by this treatment (p < 0.05). These findings suggested that the combination has promise in being used as an additive to a broader class of foodstuffs.     

连云港市发展农业特色产业的调查与思考

特色农业是连云港市农业的重要组成部分,该文在调查的基础上,分析了其对连云港经济发展的意义,并针对所存在的问题提出了相应的发展策略。      

黄淮地区香樟树引种现状与前景分析之一:气候条件

文中介绍香樟在北方地区的引种栽培现状,以香樟自然分布区北界气候条件为参照,分析北方香樟引种区在气候条件方面的差异及其未来变化趋势,认为从气候角度看香樟在黄淮地区有条件稳步扩大应用。     

高粱靶斑病菌粗毒素对高粱胚根生长及胚根细胞膜透性的影响

为了揭示高粱靶斑病菌的致病机理,用不同浓度病原菌粗毒素处理高粱种子L407B和Tx622B,测定其胚根生长抑制率、电导率和丙二醛(MDA)含量,探讨高粱靶斑病菌粗毒素对高粱不同品种胚根生长及胚根细胞膜透性的影响。结果表明,病菌粗毒素对高粱胚根生长有明显的抑制作用。在同一毒素浓度下,处理后2天,处理组胚根的相对电导率和MDA含量均高于对照组;同一处理时间内,不同浓度毒素处理后胚根相对电导率和MDA含量均高于对照组。说明高粱靶斑病菌毒素能降低高粱胚根细胞膜透性,且不同高粱品种间差异显著。