一次特大暴雨成因及对农业影响的分析

2019年7月在江苏南通出现了一次特大暴雨,此次暴雨过程造成大面积农田被淹、金鱼养殖受灾等,对当地农业造成了极大影响。本文利用NCEP再分析资料、FY-2G风云卫星资料、自动气象观测站等监测数据,对此次农业致灾暴雨的环流背景、内部结构及其演变进行了分析,并探讨了其对农业的影响。结果表明：1)西风槽、中低层切变线和远距离热带风暴是造成特大暴雨的天气背景,2)产生强降水的直接影响系统是一个由γ中尺度对流云团发展成β中尺度对流系统造成,3)低层强锋生导致不稳定能量释放,是特大暴雨发生的触发机制,4)通过分析来提高暴雨预报能力,提出防范应对措施,提前开展防灾减灾工作,减轻暴雨灾害对农业生产的影响。     

Recovering the urban forest: The role of trees,tree culture,and place attachment before and after Hurricane Harvey

Trees can be powerful symbols that contribute to the production and consumption of places. Disaster events, such as hurricanes, alter the physical landscape, causing tree damage and loss. In places with strong tree cultures, the reforestation of damaged landscapes becomes an implicit element of recovery plans; however, less is known about the implications of tree loss to community recovery. In 2017, Hurricane Harvey made landfall near the coastal communities of Rockport and Fulton, Texas. Rockport-Fulton, known for its beach tourism, is home to a remnant live oak (Quercus virginiana) forest shaped by coastal onshore winds. Many of Rockport-Fulton’s windswept oaks were damaged or lost along with native and non-native palm trees. Rockport-Fulton’s history is imbued with stories situated around its oak forest. Drawing from multiple sources and participant observations from repeated site visits, we analyzed references to Rockport-Fulton’s trees in news media, organizational communications, and public exhibits before and after Harvey to understand the area’s tree culture and its associated discourses. We also interviewed tourists, business owners, and community members nine months after Harvey to understand their perceptions of recovery efforts. Our findings show that tree narratives pre- and post-Harvey amplify social-ecological systems definitions of resilience and that tree loss was a dominant theme in the recovery process for all participants. Yet we also found that tourists discussed the damage to palm trees, whereas community members focused on the loss of live oaks. Despite these preferences, trees available through replanting efforts contained few live oak and palm species; furthermore, recovery plans did not amplify trees in recovery strategies. Overall, our findings highlight the importance of replanting trees during the disaster recovery process in a way that not only enhances local biodiversity but also reaffirms place characteristics to meet community members’ and visitors’ expectations.     

认罪认罚从宽制度中量刑辩护问题研究

认罪认罚从宽制度的改革为量刑辩护提供了发展空间，量刑辩护具有提升认罪认罚从宽制度稳定性、平衡各诉讼主体的诉讼利益、保障被追诉人合法权利等重要价值。但目前认罪认罚从宽制度下量刑辩护的推行存在着困境，在量刑指导意见的完善、量刑协商机制的规范化、相对独立量刑程序的落实、强制法律援助制度的实施与量刑辩护的专业化五个方面加以改进是实现认罪认罚从宽制度下有效量刑辩护的重要措施。     

烟粉虱持续取食对棉花叶片防御酶活性、营养物质和代谢产物含量的影响

【目的】研究不同密度与不同为害时间下,棉花植株对烟粉虱持续取食胁迫所产生防御应答响应,分析叶片中防御酶活性,营养物质和代谢产物含量的变化,分析烟粉虱与棉花的互作关系。【方法】在人工气候室内,叶片真叶生长至5叶的棉花植株(NJ-135)上,分别接入0头(对照)、50和500头烟粉虱,单株罩140目尼龙网,在烟粉虱持续取食24、48和72 h后,分别采集棉花叶片,测定总蛋白、可溶性糖、脯氨酸、丙二醛、过氧化氢酶和叶绿素的含量。【结果】50和500头/株处理组,烟粉虱持续取食24、48和72 h,叶片中总蛋白、脯氨酸、过氧化氢酶含量均与取食时间的增长呈正相关,随取食时间和密度的加大而增高(3.23, 4.87和5.55 μg/mL, 3.84, 5.38和5.92 μg/mL; 0.85, 0.92和0.99 μg/g, 0.89, 0.98和1.21 μg/g; 9.81, 10.98和18.45 U/mg prot; 12.42, 15.29和19.16 U/mg prot),叶片中可溶性糖含量随取食时间延长逐渐下降(16.77, 15.83和15.64 mg/g; 18.10, 15.75和7.84mg/g),丙二醛含量随烟粉虱持续取食时间延长先下降后升高(3.76, 3.26和4.44 nmol/mg prot; 4.45, 3.94和5.15 nmol/mg prot),叶绿素含量变化低密度与高密度处理含量动态变化不同,50头/株为先下降后上升(1.27, 0.90和1.92 mg/g),500头/株为逐渐上升(0.50, 0.86和1.98 mg/g)。【结论】 棉花叶片会对烟粉虱取食胁迫产生相应的防御应答,与棉花生理生化性质改变有关。密度与烟粉虱持续取食时间,均是诱导叶片内总蛋白、脯氨酸、丙二醛、过氧化氢酶、可溶性糖和叶绿素含量变化的因素。高密度的烟粉虱会增强这种应答的程度,随着为害时间的延长应答程度也随之增强。     

NaCl胁迫下转入Cu,Zn-SOD基因马铃薯活性氧的代谢及保护酶的变化

以转入Cu ,Zn-SOD基因的马铃薯为材料 ,研究了在不同NaCl浓度胁迫下其活性氧代谢及保护酶活性的变化。结果表明 ,在NaCl胁迫下转基因马铃薯植株体内的超氧阴离子 (O₂^-)含量明显低于对照非转基因马铃薯 ,H₂O₂含量前者略高于后者但差异不大 ;超氧化物歧化酶活性转基因马铃薯显著高于对照 ,过氧化氢酶及抗坏血酸过氧化物酶活性转基因马铃薯高于对照 ;转基因马铃薯体内的脂质过氧化产物丙二醛 (MDA)含量显著低于对照。研究表明 ,转入Cu ,Zn-SOD基因马铃薯具有较强的抗氧化能力 ,具有耐 (抗 )盐的潜力。