雾滴密度与喷雾方式对毒死蜱防治褐飞虱效果的影响

分别选用实心圆锥雾和扇形雾TP6501E两种喷头,以3WP-2000型行走式喷雾塔模拟对水稻植株压顶喷雾和侧向喷雾,探究雾滴密度、喷雾方式对48%毒死蜱乳油防治褐飞虱效果的影响。结果表明：压顶喷雾当底层雾滴密度分别达到99.4个/cm^2和94.9个/cm^2,且48%毒死蜱乳油有效剂量分别高于68.00 mg/m^2和55.64 mg/m^2时,对褐飞虱的防治效果达80%;侧向喷雾当底层雾滴密度分别在10.4～49.0个/cm^2和12.3～55.4个/cm^2范围内,且48%毒死蜱乳油有效剂量分别在41.21～82.42 mg/m^2和72.12～82.42 mg/m^2区间内对褐飞虱的防治效果均高于80%。相同有效剂量条件下,侧向喷雾的防效高于压顶喷雾。采用侧向喷雾方式时,水稻基部较易获得高密度雾滴,药剂在低有效剂量条件下即可取得预期防治效果。     

Influence of flow-equilibrating device on purification of flue gas from MSW incineration

The influences of flow-equilibrating device on flue gas purification by spray drying are studied numerically with RNG k-ε turbulent model and stochastic droplet track model. The effects of flow-equilibrating device on flue gas streamline, droplets distribution, internal resistance, adhering ratio and purification efficiency are investigated. The flow field is more uniform and symmetrical after the flow equalization plate is added. The internal resistance decreases gradually with increasing diameter of the opening area of flow equalization plate. The percentage of droplet adhering on the wall is first increased, and then decreased when opening area diameter increases from 0.2 to 0.7 m. The maximum value reaches 38.2% when the diameter equals to 0.4 m. The purification efficiency for SO2 and HCl has increased after the plate is added. The desulphurization efficiency increases from 60.25% to 68.56%. HCl removal efficiency increases from 93.73% to 97.62%. The results can provide theoretical basis for flue gas purifying system optimization and parameters selection.     

叶面喷施尿素涂膜液对苹果树的影响

为了验证尿素涂膜液在苹果上的喷施效果,在大田试验条件下,采用叶面喷施尿素涂膜液和清水(CK)的方法研究了苹果叶面喷施尿素涂膜液的增产效果。结果表明:苹果叶面喷施尿素涂膜液新梢生长量、叶片厚度、叶片鲜重、叶面积分别比对照增加50.0%、15.0%、6.2%和9.3%,百果重、果型指数分别比对照提高4.4%和3.3%,产量较对照增产9.8%,增产效果明显。     

航空静电喷雾与非静电喷雾沉积效果的比较

利用直升机R44和固定翼飞机Y5B挂载自主研制的航空静电喷雾系统设备进行机场和野外航空静电喷雾与非静电喷雾的比较试验.结果表明:静电喷雾存地面和空中靶标表面、树冠中上部叶片正面的沉积效果明显优于非静电喷雾:雾粒细小、分布均匀、沉积密度提高1倍以上,最高达1.75倍;直升机静电喷雾在叶片背面的沉积率为非静电喷雾的2.15倍,是常规航空喷雾的3.31倍.Y5B静电喷雾在叶片背面的沉积率为非静电喷雾的2.38倍,是常规航空喷雾的3.44倍.     

Cytotoxic, cytoprotective and antioxidant effects of isolated phenolic compounds from fresh ginger

Twenty-nine phenolic compounds were isolated from the root bark of fresh (Yunnan) ginger and their structures fully characterized. Selected compounds were divided into structural categories and twelve compounds subjected to in-vitro assays including DPPH radical scavenging, xanthine-oxidase inhibition, monoamine oxidase inhibition, rat-brain homogenate lipid peroxidation, and rat pheochromocytoma PC12 cell and primary liver cell viability to determine their antioxidant and cytoprotective properties. Isolated compounds were also tested against nine human tumor cell lines to characterize anticancer potency. Several diarylheptanoids and epoxidic diarylheptanoids were effective DPPH radical scavengers and moderately effective at inhibiting xanthine oxidase. An enone–dione analog of 6-shogaol (compound 2) was isolated and identified to be most effective at protecting PC12 cells from H₂O₂-induced damage. Almost all tested compounds inhibited lipid peroxidation. Three compounds, 6-shogaol, 10-gingerol and an enone-diarylheptanoid analog of curcumin (compound 6) were identified to be cytotoxic in cell lines tested, with KB and HL60 cells most susceptible to 6-shogaol and the curcumin analog with IC₅₀ < 10 μM. QSAR analysis revealed cytotoxicity was related to compound lipophilicity and chemical reactivity. In conclusion, we observed distinct compounds in fresh ginger to have biological activities relevant in diseases associated with reactive oxygen species.     

镉污染土壤伴矿景天的萃取强化-螯合剂和植物激素的叶面调控

为提高Cd超富集植物伴矿景天(Sedum plumbizicola)的植物萃取能力,采用盆栽试验研究螯合剂乙二胺四乙酸(EDTA)和植物激素脱落酸(ABA)单独和联合作用的叶面调控对伴矿景天生长和Cd吸收转运的影响,并通过大田试验进行验证。结果表明:盆栽试验叶面喷施EDTA、ABA均能提高伴矿景天对Cd的转运,地下部至地上部的Cd转运系数为EDTA＞ABA,但叶面EDTA处理对生长旺盛期伴矿景天的生长有抑制。伴矿景天各部位Cd富集浓度差异很大,呈现新叶＞地下部＞茎＞老叶,新叶中Cd浓度是老叶的3.6~5.4倍,且主要富集在细胞壁和细胞器中,占总富集量的88%~94%。EDTA处理新叶细胞器中Cd浓度剧增,ABA处理新叶细胞壁中Cd浓度增加,ABA和EDTA联合使用可以缓解EDTA对生长的抑制,且更有利于Cd从根系向地上部转运。大田小区试验叶面诱导强化伴矿景天Cd萃取是可行的,ABA和EDTA联合处理显著增加伴矿景天总Cd积累量,增幅达到37.87%。研究结果为伴矿景天修复Cd污染土壤提供理论指导。     

“空中拖拉机”在复杂山区防治蜀柏毒蛾试验

摘要：本文首次在地形复杂、地势陡峭的四川省梓潼县七曲山国家级森林公园运用AT-504飞机防治蜀柏毒蛾2—3龄幼虫,作业流量2400mL·hm,喷幅80m,平均雾滴密度为15个·cm,雾滴直径140～200μm,喷洒覆盖率达90％以上。结果表明：“空中拖拉机”在复杂山区的喷洒作业质量与在平原地区相比,没有明显差异。喷洒1．2％烟碱·苦参碱乳油和3％苯氧威乳油15天内蜀柏毒蛾虫口减退率达89．5％和88．0％,飞防效果十分显著。“空中拖拉机”不仅适合平原地区农业和林业飞机喷洒作业,而且适合复杂山区林业有害生物的飞防作业,具有效果好,成本低、效率高的优点,可以大面积推广应用。     

外源喷施FeSO4对‘黄金梨’黄化叶片氮代谢相关酶活性及基因表达量的影响

为了探寻供铁水平对梨叶片氮代谢相关酶活性及基因表达量的影响,利用不同浓度FeSO₄喷施‘黄金梨’,分析处理3、6、9 和12 d后‘黄金梨’叶片中N含量,硝酸还原酶（NR）、亚硝酸还原酶（NiR）、谷氨酰胺合成酶（GS）和谷氨酸合酶（GOGAT）的酶活性及其基因表达量差异。结果表明,通过不同浓度FeSO₄处理,‘黄金梨’叶片中N含量均显著性增加,达到正常叶片中含量水平。黄化‘黄金梨’叶片中4种酶活性显著低于正常叶片,供铁显著增强了黄化‘黄金梨’叶片中NR、NiR、GS和GOGAT酶活性。黄化‘黄金梨’叶片4种酶基因表达量显著低于正常叶片;随着喷施水平的提高,NR、Fd-GOGAT和GS基因表达量较黄化叶片有显著性上升;0.10%和0.15%的FeSO₄处理的NiR基因表达量显著高于未处理黄化叶片。该结果说明叶片施Fe增强相关酶活性,提高相关基因表达水平,有效的促进N含量的增加;叶面喷施外源FeSO₄可有效恢复黄金梨叶片黄化的症状,以0.10%~0.15%浓度处理效果最好。     

黑蒜粉喷雾干燥工艺优化

为获得高品质的黑蒜粉,利用喷雾干燥的方法进行制粉,以进风温度、黑蒜浆中固形物含量、进料流量、β-环糊精、羧甲基纤维素和阿拉伯胶为自变量,以集粉率为响应值,运用正交试验对其喷雾干燥条件进行优化,并分析黑蒜粉的总酚和抗氧化活性。结果显示,进风温度200℃、固形物含量18%、进料流量17 mL/min、β-环糊精添加量8%、羧甲基纤维素添加量0.5%和阿拉伯胶添加量2.5%为最优组合工艺参数,在优化得到的喷雾干燥条件下,产品集粉率为51.3%,含水率为4.22%,总酚损失为3.6%,产品稳定性高且品质良好。这表明利用喷雾干燥技术制备高品质黑蒜粉是可行且有效的。     

植保机可变量喷雾鲁棒控制

为了减少农药对环境的污染程度,可变量喷雾技术是当前植保机械研发的重要内容和发展方向,该技术可根据喷药目标的要求,通过提高农药的利用率来减少对环境的污染问题。本文针对植保机变量喷药系统的输出流量进行控制,建立了喷药系统的数学模型,控制电磁阀的输出流量,并设计了最优鲁棒输出跟踪控制器,实现实际输出流量跟踪到目标值。同时,利用Mat Lab对系统进行了仿真,结果表明:采用鲁棒控制方法,能够进行良好的系统跟踪,并能达到很好的控制效果。