小麦蚜虫及黄矮病综合防治研究综述

根据多年来麦蚜及黄矮病发生规律及防治研究成果,总结出麦蚜的防治适期为秋季拌种、春季小麦扬花末期和灌浆初期;防治指标为百株蚜量500头;防治方法为农业防治、生物防治及化学防治相结合。掌握其防治理论,可以准确有效地控制麦蚜及黄矮病为害。     

我国优质水稻发展思路

依据稻谷的质量指标,分析了我国优质水稻生产的现状及存在问题,关键是减少垩白,提高食味值。在此基础上,提出了我国优质水稻的发展思路:采用遗传改良方法选育新品种,利用现代技术改进栽培措施,保护生态环境避免污染,利用先进设备提高加工水平,制定优质稻米标准、实施名牌策略。     

新银合欢林土壤理化性质—微生物量耦合协调关系研究

新银合欢因具有抗旱、速生等特点和良好的水土保持功能，在工程扰动区生态修复中被广泛采用。研究新银合欢林土壤理化性质与微生物量的耦合协调关系，可为现有新银合欢林植被恢复效果的可持续性调控提供科学参考。研究采用空间代替时间序列的方法，通过方差分析、相关性分析和偏最小二乘路径模型探究向家坝工程扰动区6种不同龄级新银合欢林土壤理化性质与微生物量的耦合协调关系。结果表明：①原生草地群落A1土壤含水量、养分水平和微生物量均最高，新银合欢入侵后在草灌阶段土壤含水量、养分水平和微生物量显著下降。新银合欢成为灌丛时A3群落土壤含水率、有机碳、全氮、全磷、微生物碳、氮含量分别下降为A1群落的51.2%、33.9%、31.6%、27.1%、72.8%和61.5%，pH值上升至8.16使得土壤更为碱化。②土壤微生物碳氮含量与土壤含水率的相关性达显著或极显著水平（P<0.05或P<0.01），土壤微生物碳熵也与土壤全氮等含量呈显著相关；土壤含水率、养分水平和微生物量三者之间相互影响且作用显著，高土壤含水率有利于土壤养分与微生物量的存在和转化。③原生样地结构稳定，协调度D较高（0.7162）；新银合欢入侵后，协调度随着新银合欢林龄增大呈现波动下降，至A4群落时协调度降至最小值（0.5012）；在乔木阶段土壤养分与微生物量缓慢增加且趋于稳定，协调度缓慢上升，最终在新银合欢纯林时稳定趋于勉强协调发展类型。因此，针对不同龄级新银合欢林，要根据不同恢复阶段的土壤生境条件采取不同调控措施，在植被恢复的物种搭配选择上应注重草灌结合，促进土壤以及整个生态系统的健康发展。     

水磷耦合对冬小麦幼苗营养元素含量的影响

本文研究了速效水范围内水磷耦合对冬小麦幼苗的N、P、K吸收量的影响。结果表明:不同速效水水平对小麦苗期N、P和K的吸收有明显影响。在不同的P水平处理时最高N、P吸收值都出现在速效水高的处理上,低水时N、P吸收也较低。中P与高水配合有利于N、P的吸收。低速效水时提高P水平可促进P吸收,但不能显著提高N吸收。速效水的水平对K吸收影响不如对P吸收影响明显,品种间差别不大。结果还显示土壤低P处理显著降低植株幼苗对P素的吸收,不同速效水水平时增加土壤P可以提高植株吸P量。土壤缺P对小麦植株K吸收有一定影响,水磷耦合后品种间的K吸收量差异加大。     

Greenway service supply and public demand in Guangzhou city,China

Small-size green spaces contain convenient service capabilities for urban residents and satisfy the daily needs of citizens for high-quality ecological products. A greenway is a kind of linear green space, which can create a beautiful and livable environment in a high-density urban area. This study explored whether the services provided by the greenway can meet the daily needs of urban residents for green space in Guangzhou, a mega city in south China. Based on the Analytic Hierarchy Process (AHP) method and the entropy weight (EW) method, both the coupling coordination degree model and spatial autocorrelation analysis were adopted to quantify and determine the coordination degree of greenway service supply and public demand in Guangzhou. The results showed that the comprehensive score of the greenway service supply (GSS) subsystem and the public demand (PD) subsystem in Guangzhou was 0.3865 ± 0.08 and 0.3778 ± 0.03 (mean±s.e., n = 11), respectively. The GSS subsystem score was slightly higher than that of PD subsystem (P > 0.05), indicating that the two subsystems had no significant differences. The supply and demand subsystem of ten districts (excluding Conghua) in Guangzhou achieved different levels of coordination, and the average coupling coordination degree was 0.5885, suggesting that the districts were barely balanced at the city level. The Moran's I value was 0.580, indicating that the coupling coordination degree had significant positive global spatial autocorrelation and showed a spatial agglomeration effect. Furthermore, the local Moran’s I spatial autocorrelation showed that three districts (i.e., Yuexiu, Haizhu and Liwan) formed a high supply-high demand cluster and a spatial difference was detected when coupling the GSS and PD in Guangzhou. Therefore, we proposed the differentiated optimization strategies based on the results of the coupling coordination degree and the development status of each district and the entire city. This knowledge can better guide the subsequent construction and development of greenway in Guangzhou and may be useful for adjacent cities in Asia-Pacific region.     

两级同轴环式减速机的耦合非线性动态特性

环式减速机在使用过程中常出现振动、噪声、发热等问题，因此设计了一种两级同轴环式减速机，对其结构特点及传动原理进行了分析，在综合考虑齿轮系统时变刚度、齿侧间隙和制造误差的基础上，建立了该减速机的齿轮一转子一支承全系统耦合非线性动力学模型，在考虑系统内部激励的情况下对该耦合系统动态特性进行了研究，验证了该结构的合理性。     

良好农业规范在我国茶业中的应用

介绍了当前国际时兴的良好农业规范( Good Agricultural Practices, GAP) 产生背景和理念, 并在分析GAP 与其他质量安全管理体系关系的基础上, 回顾了 GAP 发展历程及其在国内外的应用现状。基于中国茶叶行业发展情况, 探讨了中国茶叶 GAP 今后一段时间内的研究重点及实施 GAP 对我国茶业的影响。