中亚天然气C线管道SPS仿真模拟

中亚天然气C线管道属于典型的输送压力高、流量大、管道跨度大、压气站数目多、输送工艺复杂的输气管道。为研究中亚天然气C线管道正常工况和事故工况下水热力参数的变化规律以及各种事故下管道的自救时间,采用SPS软件建立了中亚天然气C线管道仿真模型。模拟了正常工况下管道全线压力和温度参数,模拟结果与实际运行数据最大相对误差分别为1.90%和12.24%,验证了模型的可靠性;在此基础上分析了环境温度和管道粗糙度变化对全线输气效率的影响规律,确定了各种事故工况下管道最长的自救时间,可为中亚天然气长输管道运行管理提供参考。     

富硒区茶树鲜叶中硒累积与土壤因子的相关性分析

茶树是富硒植物,饮用富硒茶是一种安全、有效的补硒途径之一。茶叶的硒含量受多种环境因素影响,但有关富硒茶区茶树硒积累特性及主要影响因子的研究还鲜有报道。以高硒茶区湖北恩施、陕西安康不同地点生产茶园成龄茶树和根际土壤为研究对象,结合土壤及植物样品全硒含量等多种指标,明确了根际土壤硒含量对茶树硒分布特性的影响,分析了富硒区土壤pH、硒含量等9个重要土壤特性相关因子的数值分布规律。通过对186组具有代表性的土壤样品和附生茶树新梢组织检测数据进行分组和整体相关性分析,证实了富硒区茶叶全硒含量与土壤硒含量之间存在极显著相关（相关系数r=0.59,P<0.01）,揭示了茶叶全硒含量与土壤有机质含量、水解性氮、锌含量以及茶叶中硫、锌含量的显著相关,同时对安康和恩施地区的土壤和茶叶硒含量相关因素进行了深入分析。提出了茶叶硒含量对土壤有机质含量、硫含量、硒含量和锌含量的数学模型,模型拟合优度为0.512 6,达极显著水平（P<0.01）。     

关于中国智慧管道发展的认识与思考

智慧管道是覆盖油气长输管道全生命周期的综合管理系统,是SCADA系统、电子管道、数字管道、智能管道在物联网、云计算、人工智能时代的延续和发展。剖析了油气管道行业智慧管道的内涵与外延,梳理了智慧管道技术发展的历史脉络,揭示了数字孪生体技术的实质与应用现状,在此基础上,建议中国智慧管道建设宜坚持需求驱动、问题导向、突出重点、体现特色、开放融合、数据共享、滚动发展、持续改进的原则,以期为中国智慧管道的健康持续发展提供参考。     

西方语境的中国古典园林审美认知历史溯源

中国古典园林审美不仅仅在中国文化体系中进行讨论，随着全球化进程，西方语境学者也逐渐涉及相关的内容。尝试寻找一种跨文化的“他者”视角，梳理近3个世纪以来西方语境的中国古典园林审美认知经历的3个主要阶段。以18世纪为开端，经过19—20世纪借助西译艺术著作和海外园林建设实现对审美理解从印象到真实的转变，到进入21世纪后诞生的跨学科的诸多新观，这个过程中展现出以中国传统园林审美为代表的打破自身线性历史的闭关自守，回归全球语境的未来中国古典园林研究趋势。     

饲草作物对土壤健康与农业可持续发展的作用

饲草作物是指为增加土壤肥力,防止土壤侵蚀,累积和保护土层,增加土壤养分和含水率以及提高土壤质量而种植的植物。饲草作物为农田土壤提供了诸多益处,其还有助于增加和维持土壤中的微生物多样性。本文对多种饲草作物对土壤特性的作用,如土壤含水量、土壤微生物的活动、土壤碳固存、土壤硝态氮淋失、土壤水分和土壤健康等进行综述。饲草作物的选择通常取决于其自身对土壤的作用,其他考虑因素还包括天气条件,播种时间,是否为豆科植物以及杀灭饲草作物的时间和方法。研究表明,饲草作物也可用于减缓气候变化,抑制作物中的杂草,增加可交换的营养物质如Mg2+和K+,具有一定的经济性。另外,覆盖作物也会存在一些问题,包括杀灭覆盖作物的方法,其可能成为病原体的寄主,饲草作物的再生性以及短期收益不明显。尽管有一些局限,饲草作物仍被认为可以明显改善土壤整体健康状况,为主栽作物提供可持续的生态环境。     

分子标记辅助选择改良水稻恢复系香5的病虫抗性

香5是由湖北省农科院选育的优质两系杂交稻恢复系,所配组合广两优5号(广占63-4S/香5)于2013年通过了湖北省审定.利用回交和分子标记辅助选择技术,将供体亲本MD12086-1351中的抗稻瘟病基因Pi9、抗褐飞虱基因Bph14、Bph15和抗白叶枯病基因Xa23渗入到香5背景中,育成了3个同时携带Pi9、Bph14、Bph15和Xa23基因的新株系.鉴定结果表明,新株系的叶瘟抗性明显提高,穗颈瘟抗性部分提高,苗期抗褐飞虱,分蘖盛期高抗白叶枯病;产量、主要农艺性状、香味和稻米品质主要指标与香5相似.新株系所配的组合在产量、主要农艺性状上与香5所配的组合相似.表明新株系可以作为香5的替代系用于培育抗稻瘟病、抗褐飞虱和抗白叶枯病的两系杂交稻新组合.     

舒城县干汊河镇农村集体“三资”管理现状与建议

阐述了舒城县干汊河镇农村集体"三资"管理取得的成效,指出了管理过程中存在的问题,并提出了加强农村集体"三资"管理的建议。     

Influences of sand cover on erosion processes of loess slopes based on rainfall simulation experiments

Aeolian-fluvial interplay erosion regions are subject to intense soil erosion and are of particular concern in loess areas of northwestern China.Understanding the composition,distribution,and transport processes of eroded sediments in these regions is of considerable scientific significance for controlling soil erosion.In this study,based on laboratory rainfall simulation experiments,we analyzed rainfall-induced erosion processes on sand-covered loess slopes(SS)with different sand cover patterns(including length and thickness)and uncovered loess slopes(LS)to investigate the influences of sand cover on erosion processes of loess slopes in case regions of aeolian-fluvial erosion.The grain-size curves of eroded sediments were fitted using the Weibull function.Compositions of eroded sediments under different sand cover patterns and rainfall intensities were analyzed to explore sediment transport modes of SS.The influences of sand cover amount and pattern on erosion processes of loess slopes were also discussed.The results show that sand cover on loess slopes influences the proportion of loess erosion and that the compositions of eroded sediments vary between SS and LS.Sand cover on loess slopes transforms silt erosion into sand erosion by reducing splash erosion and changing the rainfall-induced erosion processes.The percentage of eroded sand from SS in the early stage of runoff and sediment generation is always higher than that in the late stage.Sand cover on loess slopes aggravates loess erosion,not only by adding sand as additional eroded sediments but also by increasing the amount of eroded loess,compared with the loess slopes without sand cover.The influence of sand cover pattern on runoff yield and the amount of eroded sediments is larger than that of sand cover amount.Furthermore,given the same sand cover pattern,a thicker sand cover could increase sand erosion while a thinner sand cover could aggravate loess erosion.This difference explains the existence of intense erosion on slopes that are thinly covered with sand in regions where aeolian erosion and fluvial erosion interact.     

Periplaneta americana peptide decreases apoptosis of pig-ovary granulosa cells induced by H2O2 through FoxO1

Oxidative stress can induce apoptosis of granulosa cells and lead to follicular atresia, thereby reducing the number of pigs giving birth. The aim of this study was to investigate the protective effect of Periplaneta americana peptide (PAP) on the apoptosis of the granulosa cells of pig ovaries (PGCs) induced by hydrogen peroxide (H₂O₂) via FoxO1. PGCs were treated with H₂O₂ to establish a cell apoptosis model. Cell viability was measured using the cell counting kit-8 (CCK-8) assay, and cell apoptosis was detected using flow cytometry. The malondialdehyde (MDA) level and nitric oxide (NO) content were detected to reflect the oxidative stress. Western blotting, qRT-PCR and overexpression were undertaken to determine the expression of FoxO1 and caspase-3, and immunofluorescence was used to detect FoxO1 in the nucleus and cytoplasm. PGCs were treated with 100 μM H₂O₂ for 6 hr, which resulted in oxidative damage and apoptosis and an apoptosis rate for PGCs of 32.95%. Next, PGCs were treated with 400 μg/ml PAP for 24 hr to repair the apoptosis induced by H₂O₂. PAP improved cell viability in H₂O₂-stimulated PGCs, the increased MDA level and NO content caused by H₂O₂ stimulation were reversed and the apoptotic rate of PGCs was reduced. The qRT-PCR and Western blotting results indicated that PAP decreased the H₂O₂-induced apoptosis and the expression of FoxO1 and caspase-3 in PGCs. The effect of PAP was the same following FoxO1 overexpression. FoxO1 was expressed in the nucleus when stimulated by H₂O₂ or overexpression; however, it migrated to the cytoplasm following PAP treatment. PAP decreased the apoptosis of PGCs induced by H₂O₂ by regulating FoxO1 expression and nuclear translocation.