Sex-specific activity of (R)-(−)- and (S)- (+)-1,7-dioxaspiro[5.5]undecane,the major pheromone ofDacus oleae

1,7-Dioxaspiro[5.5]undecane (olean), the major component of the female sex attractant pheromone blend of the olive fruit flyDacus oleae (Gmelin) was shown to be released as a racemate. The response of males and females to pure (R)-(–) and (S)-(+)-enantiomers was tested under laboratory and field conditions. Males in laboratory and field tests responded only to (R)-(–)-olean, which functions as a sex attractant. Females responded only to (S)-(+)-olean in laboratory tests but not in the field. There are indications that the latter enantiomer fuctions as a short-range arrestant throughout the day and as an aphrodisiac in the process of mating.Diptera: Tephritidae.     

基于IMAQ Vision和PLC的水果大小自动分级系统设计

水果大小是水果分级的一个重要依据,随着计算机技术和图像处理技术的飞速发展,计算机视觉技术被广泛用于水果品质的检测。所设计的水果大小自动分级系统由机器视觉检测系统和基于PLC的水果传送分拣机构组成。使用LabbVIEW软件编写水果大小自动分级系统的监控界面,并实现对CCD摄像机的控制及获取图片;使用IMAQ Vision工具包对所获取的水果图片进行处理,并进行大小分析,根据大小的等级由LabVIEW通过串口通信发送命令给PLC,由PLC控制水果的传送并进入对应的分级口,从而完成水果的自动分级。实际运行证明该系统能实时进行动态采集图片,有效地进行水果大小分析及自动分级。     

氟吗啉对辣椒疫病的防治效果

室内离体试验结果表明:氟吗啉对沈阳、丹东、彰武3地采集的不同菌株辣椒疫病病原菌(PhytophthoracapsiciLeonian)的EC50值分别为0.171、0.137、0.097ìg/ml,与对照药剂烯酰吗啉的抑菌活性基本一致;温室试验结果表明:供试药剂20%氟吗啉可湿性粉剂对辣椒疫病的EC90值为39.51ìg/ml,活性略优于对照药剂50%烯酰吗啉可湿性粉剂(43.38ìg/ml);多点田间小区试验结果表明:氟吗啉及其混剂对辣椒疫病有优异的防治效果,生产上使用50%氟吗·锰锌可湿性粉剂在推荐使用剂量为600～800ga.i./hm2,施药3～4次,间隔8～10d的条件下,对辣椒疫病有良好的防治效果,优于相同剂量72%杜邦克露可湿性粉剂和25%甲霜灵可湿性粉剂的防治效果。     

Polyurethane composites based on oil palm empty fruit bunches: Effect of isocyanate/hydroxyl ratio and chemical modification of empty fruit bunches with toluene diisocyanate and hexamethylene diisocyanate on mechanical properties

This study focuses on the effect of isocyanate (NCO)/hydroxyl (OH) group ratios and chemical modification of oil palm empty fruit bunches (EFBs) with toluene diisocyanate (TDI) and hexamethylene diisocyanate (HMDI) on the mechanical properties of EFB–polyurethane (PU) composites. The tensile, flexural, and impact properties are affected by the NCO/OH ratios. The tensile strengths, flexural strengths, and toughness increase as the NCO/OH increases; however, the modulus decreases. The reduction in the modulus is attributable to the increased flexibility of the PU linkages. Chemical modification of the EFBs increases the tensile strength, flexural strength, and toughness; however, the modulus is lowered as the percentage of treated EFB is increased. Impact strength results show that the strength increases as the NCO/OH ratio is increased. At NCO/OH ratios of 1.0 and 1.1, the composites with HMDI‐treated fibers exhibit higher impact strength than those with TDI‐treated and untreated fibers, respectively. This may be due to the longer and more flexible chain length of HMDI as compared to TDI, which enables the composites to absorb more energy before failure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Enantiospecific synthesis of (R)-1,7-dioxaspiro [5.5]undecane [major component of olive fruit fly (Dacus Oleae) sex pheromone] from d-Fructose

The synthesis of the title compound13 has been carried out through the preparation of its precursor, (3R,4R,5S,6R)-3,4,5-trihydroxy-1,7-dioxaspiro[5.5]undecane (6), obtained fromd-fructose using Wittig's methodology, reduction, and spiroketalation. Compound6 was transformed into13 by a Barton deoxygenation at C-5 followed by a Corey dideoxygenation at C-3,4 of the appropriately protected derivatives.Enantiospecific synthesis of spiroacetals. Part II. For Part I, see Izquierdo and Plaza (1990).     

Attractiveness to mexican fruit flies of combinations of acetic acid with ammonium/amino attractants with emphasis on effects of hunger

Ammonium acetate was more attractive than other ammonium salts to Mexican fruit flies (Anastrepha ludens) in an orchard test. We hypothesized that acetic acid enhanced the attractiveness of ammonia in the orchard test and that acetic acid may similarly enhance attractiveness of AMPu, an attractant consisting of a mixture of ammonium bicarbonate or ammonium carbonate, methylamine HCl, and putrescine. In laboratory experiments, acetic acid was attractive to flies deprived of either yeast hydrolysate or both sugar and yeast hydrolysate but not to flies fed both sugar and yeast hydrolysate. AMPu/acetic acid combinations were more attractive than AMPu alone to flies deprived of both sugar and yeast hydrolysate but not to flies fed sugar, regardless of yeast hydrolysate deprivation status. Acetic acid is the first attractant found that has become more attractive with both sugar and protein deprivation in studies withA. ludens. It is also the first that has enhanced the attractiveness of another attractant type. In orchard tests, yellow sticky panels baited with either AMPu or 17 mg of acetic acid were at least six times more attractive than unbaited panels. However, panels baited with both acetic acid (17–68 mg) and AMPu were less attractive than AMPu alone. These results differed from the laboratory data in which combinations were never less attractive than AMPu alone.     

A novel attractant for Mexican fruit fly,Anastrepha ludens,from fermented host fruit

Chemicals from fermented chapote fruit were identified and evaluated as attractants for hungry adult Mexican fruit flies in laboratory and greenhouse bioassays. Twenty-eight chemicals identified from an attractive gas-chromatography fraction were as attractive as a chapote volatiles extract (CV) when mixed in the same amounts found in CV. Sixteen of the chemicals were slightly attractive to flies when tested individually. A mixture containing 15 of the chemicals by design and the 16th as an impurity, in arbitrary concentrations, was at least as attractive as the original CV. In a series of experiments, the number of chemicals was reduced to three by elimination of unnecessary components. The three-component mixture retained the attractiveness of the 15-component mixture. The three chemicals were 1,8-cineole, ethyl hexanoate, and hexanol (CEH). Attractiveness of the three-chemical mixture was equal to the sum of the attractiveness of the three individual components, suggesting that each chemical binds to a different receptor type that independently elicits partial attraction behavior. Optimal ratios were 1011 of the three chemicals, respectively. Optimal test quantities ranged between 0.4–4g of 1,8-cineole and 40–400 ng each of ethyl hexanoate and hexanol applied to filter paper in the laboratory bioassays. A neat 1011 mixture of the chemicals was 1.8 times more attractive than aqueous solutions ofTorula dried yeast and borax to starved 2-day-old flies when the lures were tested in competing McPhail traps in a large greenhouse cage.Diptera: Tephritidae.     

陕西果业产品出口的现状、问题及策略

陕西是我国水果生产大省之一,水果产业已经成为陕西国民经济的支柱产业和富民产业。论述陕西果业产品出口的现状,分析了在新格局下陕西果业存在的问题,在此基础上,结合当前市场环境提出陕西果业产品的出口策略。     

面向动用计划的车辆装备备件预测研究

针对动用计划下的车辆装备备件的消耗特点,研究了车辆装备维修备件消耗量和库存控制两个预测优化问题。考虑动用计划期内车辆装备的预防性维修和修复性维修,实现定时定程维修和自然随机故障维修下装备维修备件的消耗量的预测。在此基础上,根据备件库存检查方式的特点,建立基于定期检查策略的联合补货库存控制模型,根据模型的结构特点确定决策变量界限,并利用多类种群位置更新方式改进了果蝇优化算法。仿真结果表明,改进的果蝇优化算法具有良好的求解效率,本文所提出的优化方法可为车辆维修保障资源优化提供决策依据。     

苹果梨醋发酵过程中醋酸发酵条件的优化

以甲酚紫培养基中加入乙醇作为分离培养基,从5种水果样品中分离得到20种醋酸菌,然后通过产酸量的测定,筛选出了一株产醋酸度高的醋酸菌AAB13.探讨了乙醇浓度、菌株接种量、发酵液有效体积对醋酸发酵的影响,并在优化的条件下制备了苹果梨醋.