氯吡脲处理对脐红猕猴桃果实品质的影响

脐红为深受市场欢迎的黄肉红心芽变猕猴桃新品种,研究不同浓度氯吡脲处理对其果实品质的影响,对脐红猕猴桃生产具有重要指导意义。设置5、10 mg/L氯吡脲水溶液2个处理,在谢花后25 d进行浸果,以清水为对照(CK),于果实成熟期测定果实的外观品质、内在品质、矿质元素及水解氨基酸含量。结果表明:10 mg/L氯吡脲水溶液处理后的单果重、横径、侧径、可溶性固形物含量、固酸比均增幅最大,分别提高了32.26%、17.09%、12.45%、9.38%和18.73%;可滴定酸、维生素C、花色苷含量和钙元素含量则显著降低,分别降低了7.75%、17.05%、52.13%和28.30%。在单个氨基酸方面,胱氨酸和精氨酸等2种氨基酸含量随氯吡脲浓度的增加而显著降低,丝氨酸、甘氨酸、脯氨酸等3种氨基酸含量则显著提高,总氨基酸含量有所降低,但差异不显著。在不同类别氨基酸方面,甜味氨基酸含量随着氯吡脲浓度的增加而提高,鲜味氨基酸、芳香氨基酸含量则降低。综上,氯吡脲的施用可促进脐红猕猴桃果实膨大,增加果实风味,如提高可溶性固形物含量、降低可滴定酸含量,但高浓度处理降低了果实营养品质,如维生素C、花色苷、钙元素、鲜味氨基酸和芳香氨基酸含量。建议种植户合理施用氯吡脲,以促进脐红猕猴桃产业健康可持续发展。

HPLC及LC-MS测定榛子中氯吡苯脲和多菌灵残留

本文采用高效液相色谱法(HPLC)和液相色谱-质谱法(LC-MS)对干果榛子中氯吡苯脲和多菌灵残留量进行含量测定.HPLC和LC-MS均使用C18色谱柱,含量测定采取等度洗脱,流动相:甲醇-水(55∶45,体积比);体积流量:1.0 mL·min-1;测定波长:260 nm;柱温:30℃.LC-MS采取电喷雾离子源,梯度洗脱,体积流量:0.6 mL·min-1,柱温:30℃.结果表明,榛子中氯吡苯脲与多菌灵存在残留,氯吡苯脲质量浓度在1.00~10.00μg·mL-1范围内线性关系良好,加样回收率在95.58%~100.58%;多菌灵质量浓度在1.005~15.075μg·mL-1范围内具有良好的线性关系,加样回收率在95.61%~104.39%.实验证明,HPLC与LC-MS相结合的方法具有操作简便、灵敏度高、检出限低等优点,能有效地检测到榛子样品中膨大剂氯吡苯脲及杀菌剂多菌灵的残留,并确定其残留量,线性关系和回收率结果均令人满意.根据被检测的8批样品中氯吡苯脲和多菌灵两项农药残留量推断,作为一般干果食用榛子是安全的.

超高效液相色谱-串联质谱法测定葡萄中氯吡脲的残留

建立利用超高效液相色谱一串联质谱法对葡萄样品中氯吡脲残留的定性和定量方法。样品经溶剂提取后，分别比较3种固相萃取柱的净化富集效果，采用超高效液相色谱分离，串联质谱仪检测，外标法定量。结果表明：乙腈用于氯吡脲的提取效果较好，氨基固相萃取柱具有较好的净化富集效果，回收率为81．2％～96．4％，变异系数为3．7％～4．5％，方法的最低检出限为0．1μg／kg、定量限为0．3μg／kg。该方法灵敏度高、快捷简便，能够满足国家标准对葡萄中氯吡脲残留的测定要求。

Effect of canopy gap size and ecological factors on species diversity and beech seedlings in managed beech stands in Hyrcanian forests

We studied the species diversity of the herb layer and ecological factors in harvest-created gaps in beech stands under a single-tree selection system in Northern Iran. To determine diversity, the number of beech seedlings, and other ecological factors, 16 gaps were selected and subplots of 5 m2 were positioned at the centre and at the cardinal points of each gap. Species richness and Simpson diversity index increased with increasing gap area as did numbers of seedlings. With increasing humus layer thickness, species richness declined but the Hill evenness index increased. Species richness increased with increasing light availability. There was no relationship between crown radii of beech trees and diversity indices. Correlations between environmental factors and numbers of individuals of some species in the herb layer were not significant except in a few cases. The results help explain the effects of man-made gaps on the dynamics of managed beech stands and this benefits evaluation of silvicultural operating plans.

Real-time embedded software testing method based on extended finite state machine

The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.

眉县猕猴桃果品氯吡脲残留量测定

为确定猕猴桃果品氯吡脲含量可靠、简便测定方法,并依其测定眉县果品的含量,实验研究了液相色谱联用质谱法测定猕猴桃果品氯吡脲残留量的方法和眉县猕猴桃果品氯吡脲残留量,结果为两次加乙腈涡旋离心、混合提取液去杂方法的最低检出限为0.4μg·kg^(-1),相对标准偏差1.26%~5.47%,回收率为85%~107%,适于猕猴桃氯吡脲残留分析;眉县猕猴桃主产地,徐香、海沃德、红阳、秦美等主栽品种喷施氯吡脲制剂80、90、100 d后氯吡脲残留量依次为0.025~0.058、0.008~0.033、0.002~0.016 mg·kg^(-1),除80 d后1个样品高于国家标准外,其余批次均符合国家标准要求,食用安全,施药后100 d氯吡脲残留量仅为国家标准4.0%~32.0%;氯吡脲类植物生长调节剂对猕猴桃生产有促进作用。