Agrometeorology and agricultural statistics methods were used to analyze the cases of high temperature heat damage to crab breeding since 2008 in Hongze Lake Beach, finding that the high temperature heat damage was ma...Agrometeorology and agricultural statistics methods were used to analyze the cases of high temperature heat damage to crab breeding since 2008 in Hongze Lake Beach, finding that the high temperature heat damage was mainly under the comprehensive effects of the highest temperature, duration of high temperature weather, amount of precipitation and sunshine hours. Based on the function relation between the high temperature heat damage index and the influence factors, the linear model was used to describe the weight coefficient of each heat damage factor by using the synthesis correlation of multiple factors. The historical values of the influencing factors were used to make statistical calculation of the heat damage index model of crab culture in Hongze Lake Beach, which achieved good effects when applied in the meteorological operation of river crab culture.展开更多
Chinese mitten crab （Eriocheir sinensis） is an indigenous and ecologically and economically important species in the Liao River area, but its identification and genetic diversity remain poorly understood. To evaluat...Chinese mitten crab （Eriocheir sinensis） is an indigenous and ecologically and economically important species in the Liao River area, but its identification and genetic diversity remain poorly understood. To evaluate the germplasm resources of this species, samples were collected from these locations： four sub-populations from the Liao River area and one population from the Yangtze River area; one primer was used to distinguish between the Liao River and the Yangtze River crabs. Thirteen loci were used for crab genetic diversity analysis, and basic statistics showed that the collecting samples were purebred in the Liao River area. The average observed heterozygosity （H0） of the Liao River population was 0.5931, and the expected heterozygosity （He） was 0.8064. The polymorphism information content （PIC） was 0.7753, which showed that the Liao River population had high genetic diversity. The genetic differentiation index （FST） averaged 0.0342, meaning a low degree of differentiation; cluster analysis indicated that Hujia （HJ）, Xinli （XL） and Chenjia （CJ） sub-populations were allocated to the same cluster, while Baqiangzi （BQZ） sub-population was isolated. In summary, these data demonstrated that the crabs in the Liao River had high genetic diversity, but low genetic differentiation. Thus, the Liao River population had the potential for breeding selection. Furthermore, this study also provided valuable genetic information for the conservation of Chinese mitten crab.展开更多
针对目前在水下复杂环境中池塘养殖河蟹与饵料的检测算法存在检测精度低、速度慢等问题,该研究提出了基于改进YOLOv5s(you only look once version 5 small)的河蟹与饵料检测方法。首先,采用轻量化卷积Ghost替换普通卷积,同时利用GhostB...针对目前在水下复杂环境中池塘养殖河蟹与饵料的检测算法存在检测精度低、速度慢等问题,该研究提出了基于改进YOLOv5s(you only look once version 5 small)的河蟹与饵料检测方法。首先,采用轻量化卷积Ghost替换普通卷积,同时利用GhostBottleneck结构替换原主干网络中的残差结构快速提取网络特征,减少模型计算量,满足安卓端的应用要求。其次,为了弥补因网络参数量减少造成网络检测精度稍有降低的问题,借鉴BiFPN(bidirectional feature pyramid network)的思想改进原始YOLOv5s的双向融合骨干网络,以较低的计算成本提高网络对小目标的检测精度。此外,为了帮助网络进一步更好地识别目标,加入了CA(coordinate attention)注意力机制,使得图像中感兴趣的区域能够更准确地被捕获。试验结果表明:该研究改进模型平均精度均值为96.9%,计算量为8.5GFLOPs,与当前主流的单阶段有锚框目标检测算法SSD(single shot multibox detector)和YOLOv3相比,具有更高的检测精度以及更少的计算量。相比于原始YOLOv5s模型,本文改进模型平均精度均值提高了2.2个百分点,计算量和模型内存都降低了40%以上。最后,将改进前后的模型部署到安卓设备上测试。测试结果表明:改进后模型的平均检测速度为148 ms/帧,相较于原始模型检测速度提高了20.9%,并且保持了较好的检测效果,平衡了安卓设备对模型检测精度以及速度的性能需求,能够为河蟹养殖投饵量的精准确定提供参考。展开更多
文摘Agrometeorology and agricultural statistics methods were used to analyze the cases of high temperature heat damage to crab breeding since 2008 in Hongze Lake Beach, finding that the high temperature heat damage was mainly under the comprehensive effects of the highest temperature, duration of high temperature weather, amount of precipitation and sunshine hours. Based on the function relation between the high temperature heat damage index and the influence factors, the linear model was used to describe the weight coefficient of each heat damage factor by using the synthesis correlation of multiple factors. The historical values of the influencing factors were used to make statistical calculation of the heat damage index model of crab culture in Hongze Lake Beach, which achieved good effects when applied in the meteorological operation of river crab culture.
基金Supported by Open Project Program of Key Laboratory of Freshwater Aquatic Biotechnology and Breeding,Ministry of Agriculture,Heilongjiang Fisheries Research Institute,Chinese Academy of Fishery Sciences(FBB2016-01)
文摘Chinese mitten crab （Eriocheir sinensis） is an indigenous and ecologically and economically important species in the Liao River area, but its identification and genetic diversity remain poorly understood. To evaluate the germplasm resources of this species, samples were collected from these locations： four sub-populations from the Liao River area and one population from the Yangtze River area; one primer was used to distinguish between the Liao River and the Yangtze River crabs. Thirteen loci were used for crab genetic diversity analysis, and basic statistics showed that the collecting samples were purebred in the Liao River area. The average observed heterozygosity （H0） of the Liao River population was 0.5931, and the expected heterozygosity （He） was 0.8064. The polymorphism information content （PIC） was 0.7753, which showed that the Liao River population had high genetic diversity. The genetic differentiation index （FST） averaged 0.0342, meaning a low degree of differentiation; cluster analysis indicated that Hujia （HJ）, Xinli （XL） and Chenjia （CJ） sub-populations were allocated to the same cluster, while Baqiangzi （BQZ） sub-population was isolated. In summary, these data demonstrated that the crabs in the Liao River had high genetic diversity, but low genetic differentiation. Thus, the Liao River population had the potential for breeding selection. Furthermore, this study also provided valuable genetic information for the conservation of Chinese mitten crab.
文摘针对目前在水下复杂环境中池塘养殖河蟹与饵料的检测算法存在检测精度低、速度慢等问题,该研究提出了基于改进YOLOv5s(you only look once version 5 small)的河蟹与饵料检测方法。首先,采用轻量化卷积Ghost替换普通卷积,同时利用GhostBottleneck结构替换原主干网络中的残差结构快速提取网络特征,减少模型计算量,满足安卓端的应用要求。其次,为了弥补因网络参数量减少造成网络检测精度稍有降低的问题,借鉴BiFPN(bidirectional feature pyramid network)的思想改进原始YOLOv5s的双向融合骨干网络,以较低的计算成本提高网络对小目标的检测精度。此外,为了帮助网络进一步更好地识别目标,加入了CA(coordinate attention)注意力机制,使得图像中感兴趣的区域能够更准确地被捕获。试验结果表明:该研究改进模型平均精度均值为96.9%,计算量为8.5GFLOPs,与当前主流的单阶段有锚框目标检测算法SSD(single shot multibox detector)和YOLOv3相比,具有更高的检测精度以及更少的计算量。相比于原始YOLOv5s模型,本文改进模型平均精度均值提高了2.2个百分点,计算量和模型内存都降低了40%以上。最后,将改进前后的模型部署到安卓设备上测试。测试结果表明:改进后模型的平均检测速度为148 ms/帧,相较于原始模型检测速度提高了20.9%,并且保持了较好的检测效果,平衡了安卓设备对模型检测精度以及速度的性能需求,能够为河蟹养殖投饵量的精准确定提供参考。
文摘为了解加热对河蟹酶解液(River crab enzymolysis liquid,RCEL)蟹味变化的影响,本试验以河蟹高压浸提液(High pressure extract of low valueriver crab,HPEC)为底物,利用风味蛋白酶进行酶解得到RCEL,将RCEL经真空浓缩后,收集酶解液的浓缩液(Concentration of the enzymatic solution,CES)和蒸发的水(Evaporated water,EW),分别设置不同的真空浓缩温度(20、30、40、50、60、70℃)和浓缩体积(浓缩至原体积的3/4、1/2、1/4)。将收集到的9个CES和9个EW样品分别进行电子鼻PCA分析。采用顶空-固相微萃取和气相色谱-质谱联用技术(HS-SPME-GC-MS)分析HPEC、RCEL和真空浓缩温度为50℃时的50CES和50EW样品的挥发性风味物质变化。电子鼻分析结果表明,河蟹酶解液只要经过真空浓缩处理,无论温度和体积如何变化,CES与RCEL之间的距离都相对较远,即两者整体气味差异越大。相比较而言,真空浓缩温度比浓缩体积的变化对蟹味的影响更大。GC-MS分析结果表明,4组样品中的挥发性风味物质的相对质量浓度大小关系为RCEL>50CES>HPEC>50EW,其值分别为13.9753、8.3862、6.2235、1.0855μg/L,真空浓缩后50CES样品的风味物质明显减少。GC-MS分析表明,形成蟹味的风味物质可能是由醛类(苯甲醛、大茴香醛、3-乙基苯甲醛和2,4,5-三甲基苯甲醛)、酯类(N-苯甲酰基甘氨酸甲酯)、酮类(丁酰基丙酮和苯亚甲基苯乙酮)、烃类(2,2-二甲基十四烷、十一烷、9-辛基-二十烷和正二十烷)、醚类(4-烯丙基苯甲醚)和杂环类(2,5-二甲基吡嗪)等构成的。
