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The stability of some diluted emulsifiable concentrate formulations in clear liquid fertilizers, as affected by the nature and concentration of the salt solutions, was checked by a static test. The time-induced changes in the concentration of the dispersed phase were estimated by visual observations and turbidity measurements. For each formulation a specific relationship between the electrical conductivity of all the fertilizer solutions and the emulsion stability was found. This was valid for a pH range between 4.6–6.3; in alkaline conditions the emulsion stability was relatively lower. A critical electrical conductivity range, above which irreversible destabilization occurred, was observed for each formulation: 100-120 dS m?1 for fenamiphos, 60-70 dS m?1 for metolachlor, 30-50 dS m?1 for chlorpyrifos, and about 45 dS m?1 for S-ethyl dipropylthiocarbamate (EPTC). The correlation observed between the emulsion stability and the electrical conductivity could be used in a simple and rapid qualitative test to estimate the physical compatibility between emulsifiable concentrate formulations and liquid fertilizers. 相似文献
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A modified leaf disc buoyancy procedure for the detection of photosynthesis-inhibiting residues in water is described. The modifications proposed, mainly the presence of sodium hydrogen carbonate in the infiltration solution, increased the sensitivity of the method and reduced the time required. The substituted urea and 1,3,5-triazine herbicides diuron, linuron, monuron, atrazine, ametryn and atraton were detected below 0.7 mg litre?1 using cucumber (Cucumis sativus L., cv. ‘Dalia’) leaf discs. A concentration as low as 0.09 mg diuron litre?1 could be detected. Although bean (Phaseolus vulgaris L., cv. ‘Bulgarian’) leaf tissue was less sensitive in this bioassay than cucumber, 0.3 mg diuron litre?1 could still be detected. The test, being very rapid (less than 30 min per determination) and relatively sensitive, could be used for the detection of photosynthesis inhibitors in recycled water used for irrigation. 相似文献
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以通蓖9号、通蓖6号、通蓖5号和中东为试验材料,利用作物生理发育时间恒定的原理,系统构建了蓖麻花芽分化和物候期的机理模型。模型用Bate函数来计算相对热效应,用高斯函数来计算光周期效应,引入温度敏感性、光周期敏感性、品种早熟性和灌浆因子4个参数。运用不同地点和年份试验数据对模型进行检验,结果表明：不同品种蓖麻生长锥伸长膨大期、花梗原基分化期、小花原基分化期、花粉粒和子房形成期、花粉粒充实完成期等花芽分化阶段和出苗期、开花期、结果期和成熟期等物候期的绝对模拟误差大多都在0～5d,根均方差不超过3d。 相似文献
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Reinhard A. Hirt Alexandra Galler Sarina Shibly Andrea Bilek 《Veterinary journal (London, England : 1997)》2011,187(1):54-59
Airway hyperresponsiveness is a key feature of human asthma and chronic bronchitis and response to the indirectly acting agonist adenosine 5′-monophosphate (AMP) is thought to reflect underlying airway inflammation. To examine whether airway responsiveness testing (ART) with AMP may be used to differentiate healthy cats from those with asthma (FA) and chronic bronchitis (CB), 24 cats (9 FA, 6 CB, 9 controls) underwent ART with AMP at concentrations of 0.1, 1, 10, 100 and 500 mg/mL using barometric whole body plethysmography.The defined endpoint of ART, an increase in enhanced pause (Penh) exceeding 300% of the post-saline value (baseline), was reached in 9/15 patients (7 FA, 2 CB), but in none of the controls. Mean Penh (±SD) at baseline (BL) was 0.49 ± 0.16 for cases, and 0.54 ± 0.16 for controls, and was significantly increased after AMP challenge in clinical cases (2.62 ± 2.20), but not in controls (0.63 ± 0.30, P < 0.05). After separating responder (R) and non-responder (NR) cases, a more pronounced difference after challenge was found (R: 3.96 ± 1.84, NR: 0.6 ± 0.21, P < 0.001). The provocative concentration of the agonist that increased Penh to 300% of BL (PC Penh 300) in R cases was 52.98 ± 48.04 mg/mL AMP. Age had no influence on the responder status or PC Penh 300. It was concluded that AMP challenge may offer a new method for the identification of cats with lower inflammatory airway disease, and possibly for monitoring disease progression or response to therapy. 相似文献
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Fumigation is an important crop protection practice employed to control soil pathogens and diseases. Metham sodium and cadusafos are two commonly used soil fumigants for this purpose. However, little information is available on their effects on non-target soil organisms. The aim of the study was to determine the ecotoxicity of these chemical fumigants on earthworms (organismal responses and DNA damage) and soil microbial communities. Changes in soil microbial community function and structure were evaluated by means of Biolog? Ecoplates and phospholipid fatty acid (PLFA) analyses, respectively. Both fumigants had a significant (p < 0.05) negative impact on all earthworm endpoints. Earthworms did not reproduce; biomass was affected negatively and manifested significant DNA damage with metham sodium causing more pronounced effects in comparison to cadusafos. The fumigants had an inhibitory effect on microbial growth. No lasting effects were observed in the community structure but cadusafos had a pronounced effect on the microbial community functional diversity. Metham sodium and cadusafos had varying effects on earthworm and microbial endpoints. This illustrates the importance of using different bioindicators to get a better understanding of the overall effects on the soil ecosystem. 相似文献
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