高含沙水流水轮机转轮的改型与抗磨蚀研究

进行高含沙水流水轮机转轮的改型研究，关键是要从正确确定转轮设计参数和轴面流道型式入手，根据三维水力设计理论，考虑导叶与转轮匹配关系进行叶型设计，针对不同破坏机理选择强磨蚀区采用金属喷涂或非金属保护等综合措施，使水轮机在高舍沙水流中运行时出力增加、抗磨蚀能力提高。     

汽车动力总成液压悬置元件特性研究

液压悬置具有低频大阻尼、高刚度等特点，可以有效隔离和衰减发动机的怠速振动，降低车内噪声，提高乘坐舒适性。为此，应用流体一结构耦合理论的方法建立了某车动力总成悬置系统的动力学分析模型，并运用Adams软件对其动特性进行了仿真。仿真结果与已知实验数据基本吻合，从而证明了该模型建立的正确性。     

A comparison of soil- and canopy temperature-based methods for the early detection of water stress in a simulated patch of pasture

This paper evaluates the sensitivity of two different methods of water stress detection in a simulated patch of pasture grown in a greenhouse. The performance of two indices, based respectively on canopy temperature and soil water content values — the latter gauged by means of a time domain reflectometry (TDR) system, was assessed against actual evapotranspiration, measured by a very accurate weighing system. Both methods were able to detect water shortage by the time transpiration was reduced to some 80% of its potential value. The soil-based index, however, relied on the estimate of root water extraction rate, which may not be known. It is concluded that detection of water shortage by means of a canopy temperature-based stress index is to be preferred to measuring soil water deficits by time domain reflectometry, despite the accuracy of the TDR-based soil water content estimate.     

浅谈如何搞好公益性农机培训工作

就如何在新形势下搞好公益性农机培训工作提出了看法和建议,笔者分别在建立保障机制、队伍和设施设备建设、借力培训与科学培训等方面展开论述。     

Is partial root-zone drying an effective irrigation technique to improve water use efficiency and fruit quality in field-grown wine grapes under semiarid conditions?

We investigated the effects of partial root-zone drying (PRD) applied at different periods on leaf water relations, vegetative development, fruit yield, must and wine quality in wine grapes (Vitis vinifera L. cv. Monastrell) during a 3-year field experiment in order to determine the importance of the timing of PRD application on physiological and agronomical vine response under semiarid conditions. Two irrigation treatments were applied: conventional drip irrigation (CI) and PRD. Both treatments received the same annual water quantity. Each year the PRD treatment was applied at different periods of the growth cycle. In 1999 PRD was applied from veraison to harvest (end July–early September); in 2000 from fruit set to harvest (mid June–early September); and in 2001 PRD from budburst to harvest (mid April–early September). Leaf water relations and gas exchange during the experimental period were not significantly affected by PRD treatment. In 1999 and 2000 there was no significant treatment effect on vegetative development, yield or fruit quality. However, in 2001 (when PRD was applied from budburst to harvest), reproductive and vegetative development was clearly altered in PRD vines. Fruit set percentage and vegetative development (shoot length, pruning weight and primary and lateral leaf area) were significantly increased in PRD vines compared to CI. This resulted in both higher yield (kg per vine) (43%) and water use efficiency (40%) compared to CI vines. Berry number per cluster and cluster weight were also significantly increased in PRD vines. Notwithstanding higher yield in PRD vines and a similar berry size, the must and wine quality was not significantly altered, indicating a higher synthesis and accumulation of photoassimilates and metabolites in the berries of PRD vines. We conclude that there was an positive effect on vegetative and reproductive growth when long-term PRD was applied from the beginning of growing season (budburst), suggesting that early onset of PRD is desirable to intensify PRD response under these semiarid conditions. Nevertheless from these results we need to further investigate the long- and short-term effects of PRD, with moderate water amounts, on vegetative and reproductive development such as flowering and fruit set processes in wine grapes.     

盐碱对水稻生产的危害及防治对策

阐述了凌海市沿海地区水稻遭受盐碱危害的状况,分析了盐碱灾害发生的原因,并提出了选种抗盐品种、培育壮秧、提高田间工程标准、科学用水、适当施肥、调节盐碱、培肥地力等防治措施。     

内部沸腾强化肉桂皮中肉桂醛的提取工艺及机理

用少量乙醇溶液润湿肉桂皮,然后加入热水,使渗透到肉桂皮微孔内的乙醇溶液沸腾,强化提取过程。实验结果表明,肉桂醛提取得率为2.43%,高于传统水提法。提取一次所需时间仅为1~5 m in,达到或者超过微波等非常规手段强化的效果。通过对热水温度的影响分析,发现内部沸腾时,提取速率发生突变,这种突变是由于孔内沸腾时产生对流引起的。     

赭曲霉毒素A对肉鸡毒性作用的研究进展

霉菌毒素污染是影响动物饲料安全的重要因素。赭曲霉毒素A（ochratoxin A,OTA）广泛存在于肉鸡饲料原料中。众多研究表明,OTA对肉鸡具有肾毒性、肝毒性、细胞毒性、遗传毒性、致癌性、致畸性、免疫毒性和肠道毒性等,给肉鸡养殖业带来了巨大的经济损失,也对动物和人类的健康造成威胁。对国内外OTA研究进展进行总结归纳,从诱导机体产生肠毒性、肝毒性、肾毒性和免疫毒性四方面阐述OTA对肉鸡的致毒机制,为深入研究OTA提供参考。     

小麦TaPYL8基因的克隆与抗旱功能分析

脱落酸(ABA)信号通路在植物对干旱胁迫的响应中扮演着至关重要的角色;作为ABA受体,PYL家族蛋白在ABA信号转导中发挥核心作用。小麦TaPYL8是PYL家族的成员。为了明确TaPYL8是否参与小麦干旱胁迫响应,本研究分析了TaPYL8的表达模式,创建过表达TaPYL8拟南芥,并探讨了干旱对拟南芥生理生化及胁迫相关基因表达的影响。结果表明,TaPYL8表达量在干旱胁迫、外源ABA及PEG6000处理后上调。干旱胁迫下,过表达TaPYL8增强了拟南芥的存活率,降低了叶片失水率和MDA含量,提高了SOD、POD和CAT等抗氧化酶活性及AtSOD、AtP5CS1、AtABF3等胁迫相关基因的表达量。推测TaPYL8通过促进胁迫相关基因表达增强植物抗旱能力。     

氮肥减量配施有机肥对苹果产量品质及土壤生物学特性的影响

为改善当前苹果园不合理施肥现状,探究适合苹果园提质增效的施肥方案,以红富士苹果为试材,设置常规施肥、优化减氮、有机肥替代25%氮肥、有机肥替代50%氮肥4个处理,其中后3个处理的总施氮量一致,为常规施肥的一半,试验连续进行两年后测定果实产量、品质、土壤微生物量碳氮以及土壤酶活性。结果表明:优化减氮处理产量与常规施肥差异不显著,氮肥偏生产力是常规施肥的2倍以上;有机肥替代50%氮肥处理的产量最高,比常规施肥处理增加5.4%。优化减氮处理和有机肥替代氮肥处理的果实可溶性糖和糖酸比均显著高于常规施肥;施用有机肥的处理可滴定酸显著低于施化肥处理,糖酸比相反;有机肥替代50%氮肥处理的品质最佳,可溶性固形物、可溶性糖、糖酸比分别比常规施肥高1.8%、2.7%、16.9%。土壤微生物量碳氮、土壤酶活性与土层深度及有机肥的施用有关,特别是在20～40 cm土层深度,有机肥替代氮肥处理的土壤微生物量碳氮、土壤β-1,4-N-乙酰基氨基葡萄糖苷酶、β-1,4-葡萄糖苷酶、纤维二糖水解酶活性均显著高于常规施肥处理,且两两之间呈显著或极显著正相关关系。因此,在陕西省苹果园可以推荐常规施氮量减少一半的情况下用有机肥替代50%氮肥,以节省化肥、增加产量、改善品质、提升土壤质量,促进果园的可持续发展。