梨汁生产配方的研究

采用L_9(3~3)正交试验研究梨汁的配方,在单因素试验的基础上,确定生产出风味纯正的梨汁的最佳配方为:梨加入量2.5 kg,糖质量分数6.5%,糖水添加量6.0 kg。     

Comparative pharmacokinetics of acetylsalicylic acid and sodium salicylate in chickens and turkeys

1. Pharmacokinetics of acetylsalicylic acid (ASA) and sodium salicylate (SS) were assessed following single intravenous (i.v.) and oral administration at doses of 50 mg/kg body weight to chickens and turkeys. Plasma drug concentrations were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model.

2. The mean residence time (MRT) of salicylate (SA) after i.v. administration of SS was 6.08 ± 0.59 and 3.32 ± 0.27 h and after oral administration was 6.95 ± 0.72 and 4.55 ± 0.71 h in chickens and turkeys, respectively. The elimination half-life (T _{1/2 e}) was shorter in turkeys compared with chickens. The value of body clearance (Cl_B) was higher in turkeys than in chickens, but the apparent volume of distribution (V _ss) was similarly low in both species. The bioavailability of SS was complete and the maximal plasma concentration of SA (C _max) after oral administration was 96.93 ± 8.06 and 91.76 ± 9.64 µg/ml, respectively, in chickens and turkeys.

3. The MRT of ASA after iv administration was 0.24 ± 0.08 and 0.24 ± 0.02 h and after oral administration was 0.78 ± 0.25 and 0.59 ± 0.13 h, respectively, in chickens and turkeys. In both species, T _{1/2 e} was very short, Cl_B and V _ss were similar and markedly higher than those of salicylate. The bioavailability of unchanged ASA was low and C _max after oral administration was 6.9 ± 3.6 µg/ml in chickens and 8.6 ± 1.3 µg/ml in turkeys.     

基于离散元法的果园开沟刀具的仿真与试验研究

为探究自主研制的果园立式单轴开沟机刀片数量对开沟质量及功耗的影响及刀片在作业过程中受力最大的部位,采用离散元法建立了4刀片刀具开沟过程的仿真模型,并运用转速—扭矩测量平台获得了开沟过程中刀具的真实功耗,得出仿真模型的误差为9.3%,从而验证了离散元法对刀具开沟过程进行模拟的可行性。运用该仿真模型分别对刀片数目为3和5的刀具开沟过程进行了仿真研究,结果表明:当刀片数目为3时刀具的功耗最小,刀片数目为4为时开沟效果最好。通过分析4刀片刀具工作时的受力情况,得知其在工作开始时功耗波动较大,底端刃口处始终受到较大力的作用,因而应对其进行耐磨处理。     

中缅油气管道沿线地质灾害分析与防治

中缅油气管道(缅甸段)地质条件复杂,管道穿越若开山区和缅北高原,由于建设期大面积扰动地表,改变了原始地貌,铺设管道后重新回填的土体力学强度低、水敏感性强,受汛期强降雨和洪水的影响,管道沿线出现了大量滑坡、河沟道水毁、坡面水毁、已建水工失效等地质灾害,导致多处露管、悬管,严重威胁了管道的安全运营。重点分析了沿线地质灾害的类型、成因及结构特征,并分别对若开山区和缅北高原的地质灾害提出了防治措施,以期对类似工程提供参考和借鉴。     

Field testing of different synthetic attractants for mass trapping of common European cockchafer (Melolontha melolontha [L.], Coleoptera,Scarabaeidae) adults

Between 2012 and 2014, we tested the efficacy of different synthetic attractants for the purpose of massive trapping of common European cockchafer adults (Melolontha melolontha). The research took place in three different locations in Slovenia (Otlica, ?rni Vrh nad Idrijo, Cesta nad Ajdov??ino) during flight periods of adult beetles. In the period 2013–2014, we used, on the basis of the preliminary test results (2012), the following chemicals: toluquinone, cis–3–hexen–1-ol, ethyl acetate, toluquinone?+?cis–3 hexen–1-ol, and ethanol as a control. M. melolontha adults were most abundant in the location ?rni Vrh nad Idrijo; the traps in this location caught 18 times more of them than those in the first location and more than six times more than those in the third location. Male insects accounted for 73 to 87% of the trapped specimens. We confirmed the highest efficiency of cis–3–hexen–1-ol in 2013 (43.25?±?0.08 males/trap), as well as in 2014 (15.00?±?0.14 males/trap). On the basis of the trapped adult common European cockchafers and the simple economic analysis of applying different synthetic substances for attracting them, we found that independent application of cis-3-hexen-1-ol is the most efficient and cost-effective option for attracting the studied insect pest. Consequently, we recommend it as an attractant in the traps for massive trapping of adult common European cockchafers.     

Randomized control trial to test the effect of a feed additive on Campylobacter contamination in commercial broiler flocks up to slaughter

A randomized controlled trial (RCT) was carried to evaluate the effect of a feed additive on Campylobacter contamination of broilers reared in commercial conditions. Twenty‐four broiler flocks naturally contaminated with Campylobacter were enrolled in the RCT: 12 were assigned to a control group (C) fed with a conventional finishing feed from 4 weeks of age to slaughter (around 35 days), and the other group of 12 flocks (S) was fed with a finishing feed supplemented with 250 ppm of a patented feed additive (an ion‐exchanged clay compound) previously proven to reduce Campylobacter contamination in broiler caeca under experimental conditions. Enumeration of Campylobacter colonies in caeca (8 per flock) was carried out following ISO standards before feed distribution and at slaughter. Before treatment, the caecal Campylobacter load tended to be lower in C flocks (7.1 ± 1.9 log CFU/g, CI_95% [6.6–7.5]) than in S flocks (7.7 ± 1.0 log UFC/g, CI_95% [7.5–7.9]) (p = .05). At slaughter, the bacterial load was similar in the S (7.7 ± 1.0 log CFU/g, CI_95% [7.5–7.9]) and C groups (7.5 ± 1.2 log CFU/g, CI_95% [7.2–7.8]) (p = .73). Therefore, the feed additive had no significant effect on the caecal Campylobacter load at slaughter under the tested conditions. The logistical constraints inherent in field trials and the natural variability of Campylobacter contamination in naturally infected broiler flocks make it difficult to reproduce experimental results in in situ farm conditions. RCT testing of an intervention strategy in commercial situation is therefore a key step in evaluating pre‐harvest interventions against food‐borne pathogens.     

Plant resistance to aphid feeding: behavioral,physiological, genetic and molecular cues regulate aphid host selection and feeding

Aphids damage major world food and fiber crops through direct feeding and transmission of plant viruses. Fortunately, the development of many aphid‐resistant crop plants has provided both ecological and economic benefits to food production. Plant characters governing aphid host selection often dictate eventual plant resistance or susceptibility to aphid herbivory, and these phenotypic characters have been successfully used to map aphid resistance genes. Aphid resistance is often inherited as a dominant trait, but is also polygenic and inherited as recessive or incompletely dominant traits. Most aphid‐resistant cultivars exhibit constitutively expressed defenses, but some cultivars exhibit dramatic aphid‐induced responses, resulting in the overexpression of large ensembles of putative aphid resistance genes. Two aphid resistance genes have been cloned. Mi‐1.2, an NBS‐LRR gene from wild tomato, confers resistance to potato aphid and three Meloidogyne root‐knot nematode species, and Vat, an NBS‐LRR gene from melon, controls resistance to the cotton/melon aphid and to some viruses. Virulence to aphid resistance genes of plants occurs in 17 aphid species – more than half of all arthropod biotypes demonstrating virulence. The continual appearance of aphid virulence underscores the need to identify new sources of resistance of diverse sequence and function in order to delay or prevent biotype development. © 2013 Society of Chemical Industry     

合肥市流浪动物活动规律的初步观察

游牧于城市中的流浪猫流浪狗正在成为一个困扰人们的问题,了解和掌握各个季节和环境中流浪动物的数量、分布与行为是开展流浪动物保护工作的基础和前提.2009年3月17～30日,在合肥市区的主要街道、居民区、垃圾场和公园、学校等环境,进行了流浪猫、流浪狗的春季调查和行为观察.结果表明,春季合肥市区流浪猫的密度为1.204 5只/km2,流浪狗的密度0.812 3只/km2.春季流浪猫主要选择在居民区和学校栖息,大多数流浪狗选择在街道和社区巷道上活动.春季流浪猫的主要行为是觅食与休息.春季流浪猫休息行为的时间分配是26.81%,觅食是15.95%,觅食活动(觅食、走动、跑动和观望)是55.09%,安全防护(警戒、威吓、叫吠和逃逸)是15.12%.春季流浪狗全天行为时间分配中,休息占23.89%,觅食占15.29%,觅食活动占58.61%,安全防护占4.93%;春季流浪狗1 d有3次觅食高峰.     

粉垄栽培木薯增产效果及理论探讨

为木薯等作物粉垄栽培提供依据,利用粉垄栽培技术种植木薯,与常规方法种植木薯相比较,探明2种栽培方法在根系、产量、品质等方面的区别。以‘华南205’、‘新选048’2个木薯品种为试验材料,在同一地点连续2年进行粉垄栽培和常规种植比较试验,在成熟期进行块根、产量、品质等调查测定。结果显示,木薯粉垄栽培比常规栽培单株结薯条数增加23.13%~39.10%,薯长增加6.94%~60.00%,薯径增加8.40%~13.91%,产量增加29.22%~63.78%;鲜薯淀粉含量增加3.23%~18.67%。表明粉垄栽培木薯可以提高产量,改善品质。并在此基础上进行以根系为主导的作物栽培的“根”本理论探讨。