不同喷雾助剂对稻田除草剂减量作用的研究

采用田间试验方法开展了β助剂、迈丝、益泽、激健4个喷雾助剂对氰氟草酯和灭草松的减量使用技术研究。结果表明,使用100 g/L氰氟草酯乳油防除稻田杂草稗Echinochloa crusgalli、千金子Leptochloa chinensis时,分别添加β助剂、益泽、激健3个喷雾助剂均可降低其使用量30%,添加迈丝可降低其使用量20%;使用480 g/L灭草松水剂防除多花水苋Ammannia multiflora、丁香蓼Ludwigia prostrata和异型莎草Cyperus difformis等杂草时,添加β助剂可降低其使用量30%,分别添加迈丝、益泽、激健3个喷雾助剂均可降低其使用量至少20%。两种稻田常用除草剂减量20%～30%后添加喷雾助剂施用对水稻生长和产量均无不良影响。     

Meta分析在转基因作物安全性评价中的应用

转基因作物的生态安全性及其科学评价方法一直备受关注。目前，已有大量研究系统评价了转基因作物的生态安全性，但是不同的研究得出的结论并不一致。Meta分析是一种定量分析文献资料的方法，可以对特定研究主题的多个独立研究开展分析，从而获得更为科学合理的结论，已在医学和生态学等领域得到广泛的应用，但在转基因作物安全性评价中的应用还比较少。因此本文从Meta分析的概念、分析步骤及其在转基因作物安全评价中的应用等方面进行了概述，并探讨了其局限性，以促进该方法得到更加广泛的应用。     

Detection of contaminated hazelnuts and ground red chili pepper flakes by multispectral imaging

Mycotoxins are the toxic metabolites of certain filamentous fungi and have been demonstrated to cause various health problems in humans, including immunosuppression and cancer. Among them, the aflatoxins have received greater attention because they are potent carcinogens and are responsible for many human deaths per annum, mostly in non-industrialized countries. Various regulatory agencies have enforced limits on the concentrations of these toxins in foods and feeds involved in international commerce. Hyperspectral and multispectral imaging are becoming increasingly important for rapid and nondestructive testing for the presence of such contaminants. However, the high number of spectral bands needed may render such image acquisition systems too complex, expensive and slow. Moreover, they tend to generate overwhelming amount of data, making effective processing of this information in real time difficult. In this study, a two-dimensional local discriminant bases algorithm was developed to detect the location of the discriminative features in the multispectral data space. The algorithm identifies the optimal passband width and center frequencies of optical filters to be used for a multispectral imaging system. This was applied to a multispectral imaging system used to detect aflatoxin-contaminated hazelnut kernels and red chili peppers. Classification accuracies of 92.3% and 80% were achieved for aflatoxin-contaminated and uncontaminated hazelnuts and red chili peppers, respectively. The aflatoxin concentrations were decreased from 608 to 0.84 ppb for tested hazelnuts and from 38.26 to 22.85 ppb for red chili peppers by removal of the nuts/peppers that were classified as aflatoxin-contaminated. The algorithm was also used to classify fungal contaminated and uncontaminated hazelnut kernels, and an accuracy of 95.6% was achieved for this broader classification.     

引水隧洞掘进爆破对地面工程振动影响与监测

针对九龙江北引二期改造工程引水隧洞开挖爆破施工中爆破振动进行监测,研究爆破地震波给洞口地面工程带来的振动安全影响。通过对振动监测数据的回归分析,得到了隧洞爆破振动传播衰减规律。同时,根据振动监测成果,结合隧洞爆破开挖施工特点,确定了进水口区域地面工程的施工程序,使各重要部位的爆破振动控制在了安全范围以内。在此基础上,对洞口边坡上的实测爆破振动信号进行频谱分析,研究了边坡上爆破振动信号的能量分布特性,并分析了地形地质条件对爆破地震波传播的影响特点。     

Weed control with pre-emergence herbicides in vegetable soybean (Glycine max L. Merrill)

Field and laboratory experiments were conducted in the early and late rainy seasons in Thailand to evaluate the effect of pre-emergence application of herbicides and determine the herbicide residues on vegetable soybean (Glycine max L. Merrill cv. No. 75) production. No visible crop injury was observed after application of alachlor 469 g a.i./ha, clomazone 1080 g a.i./ha, metribuzin 525 g a.i./ha, pendimethalin 1031.25 g a.i./ha, tank-mixed clomazone 960 g a.i./ha + pendimethalin 928 g a.i./ha, or tank-mixed metribuzin 350 g a.i./ha + pendimethalin 928 g a.i./ha. However, acetochlor 1875 g a.i./ha, isoxaflutole 75 g a.i./ha, and oxadiazon 1000 g a.i./ha caused visible crop injury. Plant bioassay of herbicide residues in the soil after harvest showed no phytotoxic effect on baby corn (Zea mays Linn. cv. Suwan 3), cucumber (Cucumis sativus L. cv. Pijit 1), pak choi (Brassica chinensis Jusl. cv. Chinensis), and soybean (G. max L. Merrill cv. CM 60). Gas Chromatography-Mass Spectrometry (GC–MS) analysis showed no significant herbicide residues on crop yield (or MRLs < 0.01 ppm) for all herbicides used in this study. The application of metribuzin at 525 g a.i./ha was sufficient to provide satisfactory full-season control of several weed species and gave the highest crop yield. In addition, pendimethalin at 1031.25 g a.i./ha, and tank-mixed metribuzin at 350 g a.i./ha + pendimethalin at 928 g a.i./ha can provide a similar level of weed control as an alternative to reduce herbicide dosage thereby increasing food and environmental safety in vegetable soybean production.     

基于“减抗、限抗”背景下猪场疾病防控的应对措施

随着国内外对滥用抗生素危害的进一步认识,抗生素将会逐渐在畜禽饲料中禁止添加。近年来,用于猪场疾病防控的各类抗生素替代品研究也取得一定进展,包括发酵饲料、中药活性物质,微生态制剂(复合益生菌)、植物提取物等。文章重点从抗生素在猪场疾病防控中的应用和存在问题,"减抗、限抗"对猪场疾病防控的影响和应对措施等方面进行综述,旨在为"减抗、限抗"时代猪场的疾病防控提供一些理论借鉴。     

活性炭脱色法测定蔬菜中亚硝酸盐含量的研究

[目的]探讨活性炭脱色法检测蔬菜中亚硝酸盐含量的可行性。[方法]以市售12种蔬菜为试材,参考国标法采用分光光度法,研究活性炭加入时间和加入量对蔬菜中亚硝酸盐含量测定的影响。[结果]在国标法的基础上加入活性炭可有效去除色素干扰,以水浴前加入2.0 g活性炭脱色效果最好。在0～10μg范围内,吸光值与硝酸盐含量呈现良好的线性关系,相关系数达0.999 47,方法的相对标准偏差〈1.0%,回收率为97.9%～102.6%。[结论]该方法能够准确检测蔬菜中亚硝酸盐含量。     

Research Progress on Application and Safety of Soybean Isoflavone in Animal Husbandry

Soybean isoflavone is a kind of faint estrogen-like mixture of polyphenols which derived from the leguminous plants.Its active components include genistein,daidzein and glycitein.It is used in animal husbandry for its physiological functions that it can enhances performance,immune function,antioxidant and improves bone metabolism.But some following reports about safety and side effects of soybean isoflavones are also appeared.That is a worthy further research topic how to use it effectively.The article summarizes the types of soybean isoflavones,nutrient metabolism characteristics,physiological characteristics,the promoting effect of livestock and poultry production and security problems about animal and human.     

Bacterial contamination of eggs and behaviour of poultry flocks in the free range environment

The free range production system is becoming more common in Australia and is expected to increase. Free range hens are exposed to more stressors in comparison to hens from barn and cage systems and it is suggested that stress can increase bacterial shedding on eggs. The aims of this study were to examine the level of total bacteria and Enterobacteriaceae populations, as well as the presence of Salmonella and Campylobacter, in eggs collected from two free range flocks on two different farms and to conduct longitudinal observations of the behaviour and welfare of hens in the free range production system. Hen age (weeks) was shown to have a significant effect (increase) on the level of total bacteria on the egg shell surface and in shell pores, as well as having an effect on feather condition score. As the hens aged, the frequency of external visual egg characteristics increased, as did feather condition score (where feather condition was poorer). These observations indicate areas which should be investigated further to improve the food safety of eggs and optimise the welfare of free range hens.     

平安县三合镇寺台等六村人饮安全工程供水规模核定

供水规模包括生活用水量、牲畜用水量、管网漏失与未预见水量之和。即:Q=Q1+Q2+Q3+Q4+Q5=720m3/d据此,平安县三合镇寺台等六村农村饮水安全工程实际供水规模按Q=720m3/d进行核定。