大棚番茄腐霉茎基腐病的重发原因及防治对策

大棚番茄栽培在徐州铜山栽培历史已久，种植面积常年稳定在133hm^2。由于种植单调，重茬年限长和大棚小气候的适宜性，番茄腐霉茎基腐病暴发流行，造成大量死苗。轻病棚病株率10％～20％，一般40％-60％，重病棚毁棚重植，对番茄生产造成严重威胁．为此笔者从2003年开始，对该病在本地的发生原因进行了调查、研究，并对该病的防治技术开展了多次试验、示范，取得了良好的效果，多项技术正在大面积推广应用，效益较为显著。     

梯形渠道机翼形量水槽试验

基于Hager对圆锥筒及圆柱体量水槽测流原理分析,推求出梯形渠道机翼形量水槽在自由出流时的流量理论计算公式,指出流量校正系数可由相对水头确定.选择6种收缩比进行了一系列室内模型试验,并根据试验数据建立了相对流量与相对水头的无量纲关系式.结果表明,相对流量与相对水头具有良好的相关关系,流量计算最大相对误差为±3.5%,该量水槽临界淹没度可达0.90,控制断面收缩比为0.372～0.585时可得到较好的量水效果.     

日光温室番茄寡照灾害等级指标研究

为了初步确定日光温室番茄苗期及花果期冬季寡照灾害等级指标。基于日光温室内番茄苗期、花果期寡照对比观测试验,将冬季温室番茄生产寡照分为无灾、轻灾、中灾、重灾4个等级。通过1、3、5、7、10、15天寡照及恢复处理,对寡照植株样本及对照植株样本进行光合速率的观测分析,结合试验过程中样本生长性状表征以及经寡照处理后的样本产量统计分析,确定寡照等级指标。结果表明,苗期寡照指标为：无灾（3天及3天以下）、轻灾（4~7天）、中灾（8~10天）、重灾（10天以上）;花果期寡照指标为：无灾（3天及3天以下）、轻灾（4~5天）、中灾（5~10天）、重灾（10天以上）。本研究为开展日光温室番茄寡照预警提供依据。     

土壤腐殖物质形成转化与结构特征研究进展

土壤有机质(SOM)是极为重要和复杂的天然有机物,从化学本质出发,SOM包括腐殖物质(HS)和非腐殖物质两个主要部分。HS是土壤SOM的主体,在土壤养分循环和碳截获方面具有重要作用。SOM的重要性和复杂性共存,这是激励研究者勇于探索的不竭动力。为了能够更好地了解土壤HS,本文对HS及其组分的形成转化及稳定性(包括形成顺序、相互转化、驱动因素、同位素分异、热力学稳定性等),化学组成和结构特征(包括HS组分的提取、分组、纯化、结构表征等),人为措施响应规律(包括耕作、施肥、土地利用的影响)的研究现状进行了回顾和总结,同时提出今后HS研究中要进一步应用先进技术、重新重视HS化学分组研究、进一步认识HS结构特征,以及探索HS形成转化机制及其与农业措施的关系。     

基于图像处理技术的小麦叶面积指数的提取

为了较好地模拟叶面积指数的变化动态,在大田条件下进行试验,获取5个品种5个密度下不同发育期的小麦群体冠层数字图像,并手工测得实际叶面积。通过研究设计了复杂背景下小麦冠层图像叶面指数的有效提取方法,将图像处理得到的叶面积指数数据与实际测得的数据进行拟合建立模型。结果表明：品种、密度和发育期的差异对拟合模型参数影响显著,对模型经过随机抽取样本图像进行假设检验,均能够通过检验。模型的相关系数平方均达到0.86以上,能够实现高精度的小麦冠层叶面积指数的估测。     

Isoflavone profile and biological activity of soy bread

The present study examines the ability of isoflavone extracts from whole soy bread and two soy bread fractions, crumb and crust, to modulate the proliferation of human prostate cancer PC-3 cells. Total isoflavone content in the two fractions of soy bread were similar (3.17 micromol/g dry basis). However, their conjugate patterns were altered. Both fractions of soy bread contained a similar level of isoflavone aglycones ( approximately 24%). Low concentrations of soy bread extracts increased PC-3 cell proliferation as much as 47% compared to untreated control. This proliferative effect in cell growth was reduced at higher extract concentration. Soy bread crust extract (10 mg/mL) reduced PC-3 cell proliferation by 15% compared to untreated control. Interestingly, wheat bread extracts increased cell proliferation at all concentrations tested. Although extracts from both breads possessed biological activity, only soy bread crust extract reduced PC-3 cell proliferation. This observation may be related to the presence of soy in this bread.     

最小二乘法与SVM组合的林果行间自主导航方法

为了提高作业装备在果园与树林行间的自主导航性能,该研究提出一种基于最小二乘法与支持向量机(SupportVector Machine,SVM)融合的树行识别与导航方法.研究采用履带式小型喷雾机为作业平台,通过低成本的单线激光雷达获取果园或树林环境点云数据,融合姿态传感器进行数据校正,利用最小二乘法拟合识别树行,结合SV...     

吉林省乡镇工业发展区划的研究

文章根据乡镇工业发展的特点，研究确定了乡镇工业的分区依据、原则和分区指标，采用模糊聚类和动态聚类分析的数学方法完成了吉林省乡镇工业发展区划，提出了各区域乡镇工业发展的方向、重点、步骤和措施     

谷物识别中对神经网络的优化

主要讨论了在谷物纹理识别中对神经网络的优化。通过比较优化神经网络和非优化神经网络的输入、输出之间的非线性联系,可知优化神经网络能够更迅速、准确地进行纹理识别。同时,该文还评价了优化方法的有效性。     

Responses of soil nitrous oxide production and abundances and composition of associated microbial communities to nitrogen and water amendment

Soil moisture and nitrogen (N) are two important factors influencing N₂O emissions and the growth of microorganisms. Here, we carried out a microcosm experiment to evaluate effects of soil moisture level and N fertilizer type on N₂O emissions and abundances and composition of associated microbial communities in the two typical arable soils. The abundances and community composition of functional microbes involved in nitrification and denitrification were determined via quantitative PCR (qPCR) and terminal restriction length fragment polymorphism (T-RFLP), respectively. Results showed that N₂O production was higher at 90% water-filled pore (WFPS) than at 50% WFPS. The N₂O emissions in the two soils amended with ammonium were higher than those amended with nitrate, especially at relatively high moisture level. In both soils, increased soil moisture stimulated the growth of ammonia-oxidizing bacteria (AOB) and nitrite reducer (nirK). Ammonium fertilizer treatment increased the population size of AOB and nirK genes in the alluvial soil, while reduced the abundances of ammonia-oxidizing archaea (AOA) and denitrifiers (nirK and nosZ) in the red soil. Nitrate addition had a negative effect on AOA abundance in the red soil. Total N₂O emissions were positively correlated to AOB abundance, but not to other functional genes in the two soils. Changed soil moisture significantly affected AOA rather than AOB community composition in both soils. The way and extent of N fertilizers impacted on nitrifier and denitrifier community composition varied with N form and soil type. These results indicate that N₂O emissions and the succession of nitrifying and denitrifying communities are selectively affected by soil moisture and N fertilizer form in the two contrasting types of soil.