农业废弃物两相厌氧处理技术的研究

以两只750mlUASB反应器分别作为酸化相和甲烷相进行农业废弃物厌氧处理的研究,两相中,都培养出了颗粒污泥。酸化相有机负荷达240kgCOD/m³[bed]·d,HRT=1.6h,酸化率66％,COD去除率4％～8％,甲烷相有机负荷达88kgCOD/m³[bed]·d,HRT=3.7h,COD去除率大于85％。两相COD总去除率大于90％,总有机负荷60kgCOD/m³[bed]·d。并结合扫描电镜照片,对两相颗粒污泥的形成,菌体分布规律等进行了探讨。     

母质和微地形条件对变性土形成的影响

福建南亚热带的地带性土壤为砖红壤性红壤。在本地带沿海漳浦、龙海等县的低丘、台地玄武岩风化物上发育的一种暗色粘质土壤,历史上归属于砖红壤性红壤,经研究其性状明显区别于砖红壤性红壤,我们确定它为典型艳色湿润变性土。这种变性土与砖红壤性红壤呈复区分布。     

农业机械化发展水平的概率-灰色评估方法及应用

在建立农业机械化发展水平评估指标体系的基础上，结合不确定性理论及灰色系统理论，提出了评估农业机械化发展水平的新方法——概率－灰色评估法。并用该方法对河南省农业机械化发展水平进行了评估分析。     

我国养猪生产的发展方向

我国养猪生产正处在由传统生产向现代化生产转化阶段。在这个阶段中，养猪生产所面临的主要任务是工作重心由城郊转向农村；引导养猪生产向产业化方向发展；提高宏观调控能力，做到可持续发展。     

Archaeal communities in the sediments of different mangrove stands at Dongzhaigang,China

Purpose

Knowledge of archaeal communities is essential for understanding of the mechanism of carbon and nitrogen cycle in the mangrove sediment ecosystem. Presently, little is known about archaeal communities in the Dongzhaigang mangrove sediments. This study aimed to characterize the archaeal communities in sediments of different mangrove stands and to find out the correlations between archaeal communities and the environmental factors of sediments.

Materials and methods

Sediment samples were collected from the Dongzhaigang mangrove forest for analysis of soil properties and archaeal communities, by national standard methods and Illumina Miseq archaeal 16S ribosomal RNA (rRNA) gene sequencing, respectively.

Results and discussion

The archaeal community in the Dongzhaigang mangrove forest was constituted by some phyla from “TACK” and “DPANN” supergroups, and dominated by Euryarchaeota. Among sediments of the four mangroves in Dongzhaigang, principal coordinates analysis (PCoA) scatter plot showed a trend of difference in the archaeal community structure in the Bruguiera gymnoihiza and Kandelia candel stands from that in the Laguncularia racemosa and Sonneratia apetala stands. The abundance of the order Methanosarcinales was the highest in the sediments of K. candel mangroves, whereas the order of Methanobacteriales dominated in B. gymnoihiza sediments. The highest richness and diversity values of Archaea occurred in K. candel sediments, while the lowest in B. gymnoihiza. Pearson correlation showed the significant relationships between sediment properties and some dominant genera, with a positive and significant correlation between sediment properties and genus Methanobacterium, coinciding with the maximum values of sediment properties and abundance of Methanobacterium in the sediment of B. gymnoihiza. Such results indicated that the difference of archaeal community structure among mangrove sediments may be caused by the different sediment characteristics. Methanogenic communities in the Dongzhaigang mangrove forest sediments were, at the order level, constituted by Methanobacteriales, Methanomicrobiales, Methanosarcinales, and Methanomassiliicoccales.

Conclusions

The investigation indicated that the Dongzhaigang mangrove sediment ecosystems support diverse archaeal communities and methanogenic communities, and that there was a general trend of difference in the archaeal community structure in the B. gymnoihiza and K. candel mangrove sediments from that in the L. racemosa and S. apetala sediments. Such difference may be caused by the difference in sediment characteristics.

     

机械采摘茶园的农艺工程技术研究

茶叶采摘,不但耗工多,且季节性强,在当前是制约茶叶生产发展的一个因素,必须从手工采摘发展到机械采摘。本文系统地论述了机械采摘茶园园地设计、品种选择、树形确定等基础工程技术。同时,以机采茶树的生育性状为依据,提出修剪周期,采摘适期,留蓄秋梢、施肥水平等几种关键栽培技术。试验证明,这些配套技术是必不可少,而又行之有效的。此外,在大量测试各种采茶,修剪机械作业性能的基础上,依据我国茶园现状,提出了采茶,修剪机械的选型原则和配套方案,可以用来指导采茶机生产和推广应用,具有较好的投资效益。     

太湖地区水稻土的发生分类

太湖地区是太湖流域之泛称,包括西起莫干山、北止茅山、南达钱塘江、北到长江右岸的广大地区。在行政上分辖于两省一市(江苏、浙江省与上海市)。除西部与西北部有低山丘陵屏障外,主要是由三角洲形成的平原,故地形平坦开阔,河川纵横,平原上间有残丘兀立,并有众多湖泊,水土资源条件均比较优越。共有土地面积近3万平方公里,其中低山丘陵占20.8%,水面积占20.5%,平原好区占58.7%,可概括为二山二水六分田。     

基于图像处理与人工神经网络的小麦颗粒外观品质评价方法

综合利用计算机视觉、图像处理、人工神经网络技术，实现小麦品质评价自动化。通过比较不同背景，发现在黑色毛面纸板背景下，使用数码像机获得容易处理的小麦图像。应用分水岭算法自主开发了图像分割处理软件，分割小麦图像并识别提取出完整的小麦颗粒，针对每个小麦颗粒，计算了其12个形态学特征、12个色泽参数等图像特征参数。利用所提取的24个小麦图像特征参数，采用人工神经网络BP算法建立起小麦粒径外观品质评价模型，并应用于小麦的品质识别，取得了良好的试验结果。多次建模运算证明，该方法具有较好的稳定性，对小麦粒径外观品质评价的平均识别准确率可达93%。     

Ecdysteroids of quinoa seeds (Chenopodium quinoa Willd.)

Quinoa (Chenopodium quinoa) is a hardy and nutritious Latin American pseudo-cereal. Studies on the seeds led to the isolation of five ecdysteroids using column chromatography. Their structures were determined as ecdysterone, makisterone A, 24-epi-makisterone A, 24(28)-dehydromakisterone A, and 20,26-dihydroxyecdysone by spectroscopic methods. This study demonstrates that quinoa seeds are a source of ecdysteroids, which were reported to be molting hormones in insects.