Combining multi-source data to explore a mechanism for the effects of micrometeorological elements on nutrient variations in paddy land water

Paddy land plays a key role in global crop production. Thus, paddy land water is a potential source of nitrogen and phosphorus; both nutrients largely contribute to non-point source pollution because they usually vary closely with micrometeorological elements (MEs) during the growth period. However, few studies have focused on the mechanism of co-variation between nutrients and MEs at the field scale. The relationships between nutrients in the paddy land water and MEs as well as soil water content, soil temperature, and the normalized difference vegetation index (NDVI) are still unclear. In this paper, an in situ experiment was designed to obtain 5 years of meteorological data and nutrient data (nitrogen and phosphorus); the size of the experiment plot is in accordance with the spatial resolution of NDVI data. Multi-source meteorological and satellite data were integrated to explore the mechanism of co-variation. The results show that precipitation, air temperature, and solar radiation are the three MEs significantly affecting the nitrogen concentration in the paddy land water during the growth period. The air temperature is the most important ME influencing the phosphorus concentration. At the same time, the NDVI, as an effective indicator of the photosynthetic potential of rice used to explore the relationship between nutrients, has a prominent influence on soluble nutrients, especially on dissolved phosphorus. These findings could significantly improve our understanding about the responses of paddy land nutrients during the growth period to the surrounding drivers, inclusive of MEs, soil water, soil temperature, and NDVI. Undoubtedly, it is a potentially helpful means to monitor the sources of non-point pollution.     

麻地膜对设施樱桃番茄(Solanum lycopersivon)生长及产量的影响

为了明确麻地膜覆盖在设施大棚内对樱桃番茄生长及产量的影响,本研究采用‘浙樱粉1号’为实验材料,设置3个处理:麻地膜覆盖、塑料地膜覆盖及对照(不覆盖),比较了不同覆盖措施对‘浙樱粉1号’株高、茎粗、单株鲜重、结果数量及樱桃番茄鲜果重的影响。结果表明,在设施大棚内采用麻地膜覆盖增加了‘浙樱粉1号’株高、茎粗、结果数量及樱桃番茄鲜果重。麻地膜覆盖对设施大棚内种植的樱桃番茄有增产作用,麻地膜的推广应用可以减少塑料地膜对环境污染,利于农业的可持续发展。     

秸秆覆盖方式和施氮量对河套灌区夏玉米氮利用及产量影响

为探究夏玉米氮素转运利用规律、产量及土壤NO3－-N含量分布对秸秆覆盖方式和施氮量的响应，在河套灌区开展2a不同秸秆覆盖方式（秸秆表覆B处理、秸秆深埋S处理）和不同施氮水平（不施氮N0、低氮N1、中氮N2、高氮N3）的田间试验，以传统耕作模式为对照（CK处理）。结果表明：在0～100 cm土层，各处理NO3－-N含量随施氮量增加而增大，成熟期B和CK处理随土层加深呈先减后增趋势，而S处理呈先增后减趋势；B处理提高0～20 cm土层NO3－-N含量，而S处理提高20～40 cm土层NO3－-N含量（P<0.05）；秸秆覆盖可减少0～100 cm土层NO3－-N累积损失量，且显著提高氮肥利用率及夏玉米氮素转运量对籽粒产量的贡献率，SN2处理效果较佳。相比CK处理，成熟期的SN2处理2 a平均NO3－-N累积损失量降低39.6%，氮肥利用率较提高28.5%，夏玉米氮素转运量对籽粒产量的贡献率提高32.1%，增产9.3%。综合分析，秸秆深埋配施中氮效果较佳，可实现河套灌区夏玉米提效增产的目标，并减少深层土壤NO3－-N累积损失量，为优化河套灌区夏玉米耕作施氮模式和缓解农业面源污染提供参考。     

耕作方式与秸秆覆盖对夏玉米根系分布及产量的影响

为探究夏玉米根系分布及水分利用效率对不同耕作结合秸秆覆盖模式的动态响应,于2017年和2018年在河套灌区开展不同耕作模式田间试验。试验设置,常规(CK)、秸秆表覆(BF)、深翻结合秸秆深埋(SM)和深翻结合秸秆深埋与表覆(BFSM)4种处理。结果表明,BF处理显著提高水平向根长密度,较CK处理高24.7%,SM、BFSM处理显著提高深层根长密度,较CK处理高23.8%;2017年夏玉米根长密度与标准化根深呈显著的三阶多项式函数关系,用2018年实测值率定效果较好,可较好描述不同耕作模式根长密度分布。BF、SM、BFSM处理较CK处理根冠比显著提高3.8%、20.8%、26.4%(P<0.05),较CK处理夏玉米产量及水分利用效率分别显著提高8.6%、19.5%、19.7%和13.6%、32.3%、34.8%(P<0.05),SM与BFSM处理差异不显著。该研究为河套灌区农业耕作模式提供一定借鉴。     

基于DNA条形码的红翅大小蠹和黄杉大小蠹分子鉴定

外来有害生物的快速准确鉴定有助于提高口岸检疫效率。红翅大小蠹(Dendroctonus rufipennis)和黄杉大小蠹(D. pseudotsugae)作为大小蠹属的非中国种是我国口岸原木检疫中频繁截获的检疫性有害昆虫。本研究以mtDNA COI基因5′端和3′端序列为标记对红翅大小蠹与黄杉大小蠹的11个样本开展分子鉴定有效性评价。结果显示,当以COI基因5′端和3′端为靶标时,两种大小蠹间的平均遗传距离分别为0.181和0.144,是种内遗传距离的60.3和48倍,且种内、种间遗传距离间无重叠现象,在系统发育树上都能聚为独立的分支,表明mtDNA COI基因5′端和3′端序列均可有效区分红翅大小蠹与黄杉大小蠹。     

Detection of full and limited amphidromous migratory dynamics of fish in Caribbean rivers

All native fishes living in the Caribbean island rivers are considered diadromous but few species have been validated as diadromous. In Guadeloupe (Lesser Antilles) as well as in the other tropical islands, the riverine habitats are subject to strong anthropogenic pressure due to resource modifications or dams. The management of fish biodiversity requires knowledge concerning their life history traits and behaviour that are still unknown for most species at a local scale and at the whole distribution area of the species. In a Guadeloupe river, we inferred the migratory patterns of four freshwater fishes common to Caribbean rivers by the analysis of otolith microchemistry. We found two species Eleotris perniger (Eleotridae) and Sicydium plumieri (Gobiidae) to be completely amphidromous with a marine larval phase and a freshwater adult phase. Agonostomus monticola (Mugilidae) was also found to be amphidromous in this system. The fourth species Gobiesox cephalus (Gobiesocidae) showed elemental ratios suggesting an estuarine larval phase and was defined as “limited amphidromous”. The identification of such life history traits, with limited dispersion abilities, argues for specific management measures in tropical island rivers at a basin scale for the conservation of biodiversity.     

基于多结构鲁棒估计的虹膜外边缘定位方法

在Adaboost检测人脸区域的基础上，提出了基于多结构鲁棒估计的虹膜外边缘定位方法．通过对200幅单人脸的图像数据集的仿真实验，结果表明，本方法相比于传统的RANSAC模型生成算法以及Hough变换等方法，能得到更精确的定位结果，而且能加快有效的模型生成，虹膜外边缘定位精度达到94％．     

Application and mechanisms of metal-based nanoparticles in the control of bacterial and fungal crop diseases

Nanotechnology is a young branch of the discipline generated by nanomaterials. Its development has greatly contributed to technological progress and product innovation in the field of agriculture. The antimicrobial properties of nanoparticles (NPs) can be used to develop nanopesticides for plant protection. Plant diseases caused by bacterial and fungal infestations are the main types of crop diseases. Once infected, they will seriously threaten crop growth, reduce yield and quality, and affect food safety, posing a health risk to humans. We reviewed the application of metal-based nanoparticles in inhibiting plant pathogenic bacteria and fungi, and discuss the antibacterial mechanisms of metal-based nanoparticles from two aspects: the direct interaction between nanoparticles and pathogens, and the indirect effects of inducing plant resilience to disease. © 2022 Society of Chemical Industry.     

论节能式炉气体木材干燥室的设计

本文讨论了节能式炉气干燥室设计的一些技术问题，如提高自生风引力增强通风；多种传热方式并用，增强传热，降低热损失的途径等，以达到节能降耗、快速干燥的目的。     

一种含有竹叶黄酮的复配型肉类食品添加剂的开发

通过竹叶黄酮和异Vc钠的系列复配应用试验,得到了一种性能优越的肉类食品添加剂.实验选用中式香肠体系,通过测定过氧化值(POV)、酸价(AV)和亚硝酸盐含量,辅以感官评定等手段,评价此复合抗氧化剂的抗氧性能以及对产品风味和质量的整体影响.结果表明,在原配方的基础上,硝酸盐或亚硝酸盐减半使用,同时添加0.01%的竹叶黄酮和0.05%的异Vc钠,能显著抑制香肠的脂质过氧化,延长产品保质期,降低产品中亚硝酸盐的含量,同时维持并改善中式香肠应有的感官品质.竹叶黄酮在有效发挥抗氧化作用的同时,部分替代了具有潜在致癌作用的发色剂,提高了制品的安全性,是一种十分有前途的肉类食品添加剂.