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新形势下的农民减负工作 总被引:1,自引:0,他引:1
刘春红 《山西农业:致富科技版》2008,(12):24-24
减轻农民负担是党在农村的一项基本政策,事关广大农民的切身利益,事关农村大局稳定和党委政府形象。新形势下,减轻农民负担工作遇到了许多新情况、新问题,农民负担呈现点状、散发、地域性、行业性的特点,主要表现在: 相似文献
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一、免疫的目的和种类
通常我们所说的免疫接种是将疫苗或菌苗经过一定途径接种于动物体,使动物在不发病的情况下产生免疫应答,在一定时间内对某种传染病具有抵抗力。免疫力可以分为先天性免疫和获得性免疫两种。 相似文献
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<正>抗病毒药物是一类用于预防和治疗病毒感染的药物。在体外可抑制病毒复制酶,在感染细胞或动物体抑制病毒复制或繁殖,在临床上治疗病毒病有效的药物。病毒与细菌不同,缺乏自身繁殖的酶系统,因而它是细胞内寄生的微生物,依赖宿主细胞代谢系统进行生殖复制。 相似文献
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Quick and accurate assessment of fish freshness is of great significance for intelligent quality monitoring and ensuring the safety of consumers. In the current fish freshness evaluation method based on visual images, the study of fish gills needs to remove the gill cover, which is invasive to the fish body, and the analysis of other parts has a low evaluation accuracy. To solve the above problems, a fish freshness classification method based on color histogram & grey-level co-occurrence matrix-linear discriminant analysis (CHG-LDA) was proposed. Firstly, preprocessing operations such as labeling, image zooming and color space conversion were performed on the collected fish images. Secondly, the extracted color histogram features and grey-level co-occurrence matrix (GLCM) features were fused to constitute the features, and the feature dimension was reduced by LDA. Finally, K-nearest neighbor (KNN) algorithm was used to classify fish freshness. The CHG-LDA method proposed solved the problem of poor classification performance caused by the low quality of the extracted fish image features. The experiment was carried out on a real crucian data set, and the index values of precision, recall, F1-score and accuracy were all 1. Compared with color histogram features, color moment, GLCM features, etc., this method improved the performance of each evaluation index on KNN, RF, ANN, and LightGBM classifiers. Among them, the evaluation time of KNN was the best, which was 0.01s. Experimental results showed that this method can achieve accurate and non-destructive evaluation of fish freshness, and it was feasible for actual production monitoring. 相似文献
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为探讨中国沙棘伐桩萌枝能力对平茬高度的响应规律及其生物量调控机制,以不平茬为对照,平茬高度为0、10、20 cm进行随机排列和拉丁方排列相结合的田间试验,对萌枝数量、萌枝生长、生物量投资格局、生物量分配格局在不同平茬高度之间的差异显著性进行检验,对萌枝能力与生物量投资的相关性状进行比较。结果表明:随平茬高度增大,萌枝数上升而存活率、生长量、生物量先升后降;萌枝数与存活率呈负相关,生长量与存活率具有负相关趋势,生长量与生物量呈正相关。与对照相比,平茬使克隆对根系和叶片的生物量投资与分配增大、树干和枝条生物量投资与分配减小。因此,平茬干扰通过刺激诱导伐桩不定芽和休眠芽萌发,通过加大根系和叶片生物量投资及分配促进萌芽生长,并在萌枝数、存活率、生长量权衡作用下形成不同平茬高度的萌枝格局。其中,平茬10 cm的萌枝存活率和生长量最大,且经过3个生长季生物量积累能力已显著超过对照(未平茬)。 相似文献