加快漳州市生态农业发展的探讨

本文分析了漳州市发展生态农业有利的自然条件和社会经济条件,指出其存在耕地资源少、水土流失严重、农产品质量不高、农业环境受到污染等问题,并提出加强生态农业宣传教育力度、加大科技投入、综合防治水土流失等措施加快发展漳州市生态农业。     

Effect of phytocompounds from the heartwood of Acacia confusa on inflammatory mediator production

Acacia confusa Merr. (Leguminosae) is traditionally used as a medicinal plant in Taiwan. In the present study, anti-inflammatory activity of extracts from the heartwood of A. confusa were investigated for the first time. Results demonstrated that ethanolic extracts of A. confusa heartwood strongly suppressed NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Among all fractions derived from ethanolic extracts, the EtOAc fraction exhibited the best inhibitory activity. Following column chromatography and reverse-phase high-performance liquid chromatography, 13 specific phytocompounds including 5 new flavonoids (i.e., 7,8,3',4'-tetrahydroxy-4-methoxyflavan-3-ol, 7,8,3',4'-tetrahydroxyflavone, 7,8,3'-trihydroxy-3,4'-dimethoxyflavone, 7,3',4'-trihydroxyflavone, and 7,3',4'-trihydroxy-3-methoxyflavone) were isolated and identified from the EtOAc fraction. In addition, melanoxetin (3,7,8,3',4'-pentahydroxyflavone), a major compound in the EtOAc fraction, markedly suppressed LPS-induced NO and prostaglandin E 2 (PGE 2) production. Moreover, melanoxetin completely suppressed gene expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at 50 and 100 microM, respectively. This is the first report to identify the inhibitory bioactivities of melanoxetin on iNOS and COX-2.     

Infant feeding practices in Xinjiang Uygur Autonomous Region, People's Republic of China

AIMS: To document infant feeding methods in the first six months of life in Xinjiang Uygur Autonomous Region, People's Republic of China, 2003-2004. Some problems with breast-feeding in the area are explained. METHODS: A longitudinal study of infant feeding practices was undertaken. A total of 1219 mothers who delivered babies during 2003 and 2004 were interviewed in five hospitals or institutes, and after discharge were contacted in person or by telephone at approximately monthly intervals to obtain details of infant feeding practices. Multivariate logistic regression analysis was used to explore factors associated with breast-feeding initiation. RESULTS: 'Any breast-feeding' rates at discharge and at 0.5, 1.5, 2.5, 3.5, 4.5 and 6 months were 92.2, 91.3, 89.9, 88.8, 87.7, 86.0 and 73.0%, respectively. 'Exclusive breast-feeding' rates at discharge and at 0.5, 1.5, 2.5, 3.5, 4.5 and 6 months were 66.2, 47.6, 30.1, 25.8, 22.1, 13.0 and 6.2%, respectively. The main problem of breast-feeding in Xinjiang was the early introduction of formula or water. The average duration of 'exclusive breast-feeding' was 1.8 months (95% confidence interval (CI) 1.7-2.0), of 'full breast-feeding' 2.8 months (95% CI 2.7-2.9) and of 'any breast-feeding' 5.3 months (95% CI 5.2-5.4). CONCLUSIONS: Infant feeding methods in Xinjiang were documented in this study and the main problems with infant feeding in Xinjiang are discussed. Further studies are needed to identify factors associated with 'exclusive breast-feeding' and duration.     

水稻黄叶突变体光合特性的日变化

对水稻黄叶突变体黄玉B及其亲本龙特甫B孕穗期的光合速率和叶绿素荧光参数的日变化所进行的研究表明:(1)在自然日照条件下,当光强上升到1043.4μmol/m2.s时,野生型出现光饱和点并表现出光抑制现象,而突变体没有出现光饱和点;(2)在野生型出现光抑制阶段(12:00—14:00),突变体的光合速率(Pn)、PSⅡ原初光化学效率(Fv/Fm)、PSⅡ光量子效率(фPSⅡ)、非循环光合电子传递速率(ETR)和热耗散(NPQ)均高于野生型。突变体在强光条件下(PFD>1149.2μmol/m2.s)能有效利用光能并耗散过剩光能,其对强光光响应能力优于野生型亲本。     

植物物料的化学组成和腐解条件对新形成腐殖质的影响

植物物料的某些化学组成分与其腐解产物很相似,迄今还没有一种方法能够把两者清楚地分别开来。这为腐解过程的研究带来了很多困难。例如,已经证明,用碱液作为提取剂时,进入溶液的不仅有腐殖物质,而且也有植物物质^[8],因而所得到的样品不具有很好的代表性;另一方面,由于不能将植物物料与其腐解产物加以区分,甚至连单位重量的植物物料分解一定时期后生成了多少腐殖物质也不能较准确地知道,直到现今,人们仍不得不以残留碳量来作为估量不同植物物料对土壤有机质含量贡献大小的指标。     

黄土丘陵沟壑区水土保持综合治理关键措施及其组合的研究

 通过对黄土丘陵沟壑区几条典型小流域和现有治理模式的分析评价,初步确定了该区不同侵蚀类型区水上保持综合治理的关键措施及其组合方案。各区的组合比例如下。第1副区和第2副区:水平梯田18％～25％,人工造林45％～55％,人工种草20％～25％,坝地5.5％～7.5％,水地0.5％～2.7％;第3副区:水平梯田42％～48％,人工造林32％～38％,人工种草18％～22％;第4副区和第5副区:水平梯田28％～35％,人工造林40％～46％,人工种草13％～17％,坝地小于5％,水地小于6％。     

猪粪堆肥臭气产生与调控的研究

通过两次室外中型堆肥试验，研究在相同水分条件(68.8%)，不同调理剂、不同碳氮比(C/N)、不同通气方式以及不同添加剂对猪粪堆肥过程中臭气产生与控制的影响。研究表明：猪粪堆肥中，臭气的主要形式是氨气，主要产生在堆肥的升温及高温期。降低堆肥的pH值、增加微生物对NH⁺₄-N的固定等是控制臭气的有效措施；过磷酸钙添加量为1.5%时，可以降低堆肥的pH值，使NH₃浓度减小，促进NH⁺₄-N向其它形式的氮转变，且不影响堆肥的腐熟；除臭剂试验组堆肥过程中臭味小，堆肥结束后的物理性状最好，不影响猪粪堆肥进程，可在生产中推广。     

滴头性能综合测试平台构建及其在水力特性研究中的应用

在对国内外滴头性能测试系统进行深入分析的基础上，构建了面向滴头性能研究的综合测试平台，并利用该系统对目前中国农业灌溉领域最为典型的8种迷宫式流道滴头水力性能进行了研究，结果表明：测试系统完全符合滴头流量-压力测试要求；升压、降压两种工作方式对滴头出流的有一定影响，但未达到显著水平；经典的流量-压力关系模型完全适合于1.5～15.0 m压力区间；从水力学角度来看，8种滴头能够满足微重力滴灌滴头的要求；滴头流量偏差系数在整个压力区间范围内都在一定数值附近，制造偏差是属于滴头本身的特性，并不随滴头进口压力的变化而变化，用流量偏差系数完全可以反映这种特性。     

不同规格鱼鳞坑坡面侵蚀过程及特征研究

探究不同雨强下鱼鳞坑措施的坡面侵蚀规律及特征,对进一步明晰该措施的径流泥沙调控机制具有重要意义。该研究采用小区模拟降雨试验,研究3种雨强(40,70和100 mm/h)条件下2种规格鱼鳞坑坡面的蓄水保土效益及侵蚀过程,并探讨鱼鳞坑坡面水沙特征及其与细沟形态之间的关系。结果表明,鱼鳞坑的径流泥沙调控作用明显但也存在阈值,在措施被冲垮前,各处理减流效益和减沙效益分别为66.02%~82.20%和85.77%~91.91%;平均径流强度和输沙速率分别为平整坡面的18.87%~33.21%和10.04%~15.38%;当鱼鳞坑被冲垮后,坡面产流量和产沙量分别为平整坡面的1.00~1.22倍和1.39~3.53倍,其平均径流强度和输沙速率分别为鱼鳞坑冲垮前的4.60~7.46倍和13.70~16.75倍。鱼鳞坑坡面径流含沙率在措施冲垮前后的差异较大,水沙关系线性拟合的斜率在措施被冲垮前为0.020和0.035,而冲垮后斜率为0.205和0.231,同时坡面总产沙量和峰值产流产沙量与细沟形态显著相关。因此,鱼鳞坑措施对坡面产流产沙特征及形态的影响在其调控阈值前后有较大差异。研究可为鱼鳞坑坡面水土流失的研究可为区域水土保持措施配置及管理提供相应的依据。     

地下滴灌灌水器堵塞研究

地下滴灌(SDI)是一种高效的节水灌溉技术，但系统易于堵塞，堵塞问题成为影响地下滴灌成败的关键。通过对运行8年的地下滴灌系统堵塞的实地调查，迷宫式、微管式和孔口式等3类型的灌水器均有不同程度的堵塞，堵塞率分别达到16.67%、25%和63.89%。分析3类型灌水器的堵塞状况，引起地下滴灌堵塞的主要原因是进入系统的微粒在流道壁的附着和发育。为此，提出加强过滤、定时冲洗和改变滴头流道设计等解决地下滴灌堵塞的建议。