果实贮藏保鲜技术的研究进展

寻找安全有效的果实采后防腐、杀菌技术,已成为果实保鲜领域的重要课题之一。阐述国内外果实采后贮藏保鲜研究的最新进展,详细介绍天然果蔬保鲜剂、采后热处理、气体调控、乙烯拮抗和基因工程等保鲜方法的作用机理及应用效果,以期为延长果实贮藏期提供参考。     

农村污水治理PPP项目风险因素分析--基于ISM-MICMAC模型

当前我国在探索将PPP模式应用于农村污水治理领域时面临诸多挑战,准确识别与分析项目风险因素具有实际意义。基于全寿命周期视角,采用文献研究与德尔菲法识别出农村污水治理PPP项目面临的21个风险因素,运用解释结构模型(ISM)与交叉影响矩阵相乘法(MICMAC)构建了风险因素的六级层次结构模型并分类,以揭示了风险因素间的内在联系,并提出政策建议。研究表明,项目缔约与运营阶段是关键阶段,合作单位选择是最根本的风险因素。此研究可为我国农村污水治理PPP项目风险分担与控制研究提供新思路,同时为政府部门提供投资决策与风险管理的依据。     

Histopathological Changes in Third-Instar and Adult Anastrepha ludens (Diptera: Tephritidae) After in vitro Heat Treatment

The Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), is one of the most harmful pests of mango causing direct damage by oviposition on the fruit pulp. Mango for export is subjected to hydrothermal treatment as a quarantine method for the control of this pest, but exposure to heat for long periods of time reduces considerably the quality and shelf-life of treated fruit. The aim of this work was to study morphological changes of third-instar larvae and adults of A. ludens after in vitro exposure to high temperature at sublethal times. A heating block system was used to expose larvae at 46.1°C for 19.6 and 12.9 min, producing 94.6 and 70% mortality, respectively. Treated larvae were processed for optical microscopy. A fraction of surviving treated larvae was separated into containers with artificial diet to allow development into adults. Adult sexual organs were dissected and processed for transmission electron microscopy analysis. Results showed that 94.6% of the treated larvae died at 46.1°C for 19.6 min and none of the surviving larvae eclosed to adulthood, as they developed as malformed puparia. For the in vitro treatment at 46.1°C during 12.9 min, 70% of the treated larvae died and only 3.75% reached the adult stage, but ultrastructural damage in the male testes and in the female ovaries was observed. Additionally, 11.1% of the adult flies from the in vitro treatment also showed wing malformation and were incapable of flying. The analysis showed that surviving flies were unable to reproduce.     

农村一体化生活污水处理设备评析与研究

农村生活污水污染问题现已成为一个不可忽视的问题,迫切需要解决。一体化污水处理设备具有投资低、能耗少、处理效率高、占地面积小、管理方便等一系列优势,适合在农村地区推广。针对农村生活污水的水质水量特征,介绍了一体化污水处理设备在农村地区推广的优越性,并分析对比了国内一体化污水处理设备常采用的主体工艺,为农村地区采用一体化生活污水处理设备提供了技术经济参考。     

粉煤灰在土壤改良和污染治理中研究进展

从粉煤灰理化性质出发,综述了国内外对粉煤灰在土壤改良和污染治理方面的应用。粉煤灰作为土壤改良剂,可以增加土壤容重,提高土壤持水性能和保温能力,调节土壤pH,改善土壤营养状况。在污染治理方面,粉煤灰主要应用于废水处理、重金属钝化和废气滤除。最后,指出粉煤灰在土壤改良和污染治理方面存在的问题和对策。     

复方中草药对雏鸡感染沙门氏菌的药效学试验

对由白头翁、黄柏、秦皮、坷子等组成复方中草药制剂分别进行体外和体内抑菌试验.体外抑菌试验中复方制剂的抑菌圈直径为16 mm,说明沙门氏菌对其高度敏感;体内抑菌试验中,将复方制剂以高、中、低三个剂量进行治疗试验,结果表明中剂量组明显好于其他剂量组,增重率为25.9%,死亡率为10.0%,治愈率为90.0%,对鸡白痢表现出很好的治疗作用.     

不同水分处理对水稻和旱稻产量及产量构成因子的影响

[目的]研究不同水分处理对水稻和旱稻产量及产量构成因子的影响。[方法]以宁粳16号和旱稻297为试验材料,进行淹水、干湿交替和旱作灌溉处理,观察水稻和旱稻的生长动态变化,研究不同水分处理对其理论产量、实际产量、穗长、穗数、穗粒数、千粒重、结实率、经济系数等的影响。[结果]与淹水灌溉相比,旱作灌溉使水稻和旱稻分蘖期后移,生育期推迟,生长发育缓慢,株高降低,产量降低,穗长变短,穗数不足,穗粒数下降,千粒重降低,结实率下降,经济系数提高;旱稻与水稻相比,旱作灌溉处理对旱稻的影响较小。[结论]该研究结果为水稻抗旱节水栽培提供了参考。     

钢渣在废水处理方面的应用研究

我国每年产生大量的钢渣,钢渣的综合利用关系到环境友好型社会的建设。本文简要介绍了钢渣的基本特性,综述了钢渣在废水处理方面的应用研究。     

桔小实蝇检疫处理及诱杀技术研究

对桔小实蝇进行虫果热处理试验和田间引诱试验,结果表明:卵的耐热力最弱,1龄、2龄幼虫较强,老熟幼虫的耐热力最强;60 ℃,120 min或45 ℃,300min干热处理虫果杀虫效果达到100 %,适用于口岸发现桔小实蝇后的检疫处理.筛选出诱捕效果最好的5种药剂组合,其中甲基丁香酚+多杀霉素组合在成本上具有优势,而水解蛋白+多杀霉素组合、水解蛋白等药剂组合防治效果更显著,适用于新传入种群的消除.     

垂直传播引起的鸡沙门氏菌病的诊断与防治

晋中地区某海兰褐父母代种鸡场的孵化室突然发生孵化率下降10%,孵化出的19 800羽商品蛋雏鸡,在经14个养殖场饲养到5～12日龄时发生以下白色痢、糊肛为特征的疾病,死亡率达16.6%。经流行病学调查、临床诊断和实验室诊断,结果表明,引起该病的病原为沙门氏菌,它来源于种鸡饲料中的鱼粉原料,并对氧氟沙星和头孢噻肟高敏。