Efficient reduction of biomass,seed and season long pollen production of common ragweed (Ambrosia artemisiifolia L.)

Ragweed (Ambrosia artemisiifolia L.) is a noxious plant that not only is a troublesome agronomic weed that causes economic damage to agricultural crops but also − and even more importantly − causes severe health problems due to its severe allergenicity. The pollen of invasive ragweed has become a major allergenic risk factor in urban areas in newly occupied regions. Many urban areas prohibit herbicide application; thus, mowing is the most widely used control measure. Counting pollen is labour intensive; therefore, pollen production data are mainly based on estimations. Field experiments were conducted to determine the effects of different mowing scenarios, plant density and cutting height on the biomass, pollen production and seed production of common ragweed plants. Ragweed plants were mown twice: just before the flowering of terminal racemes (BBCH 59) and when the flowers of the re-sprouting lateral shoots reached BBCH 59. A 1- to 3-cm cutting height produced the greatest pollen reduction compared to that of intact control plants (94%) based on a season-long pollen collection. The number of female flowers also significantly decreased (97%). Compared to the control, the onset of pollen discharge was delayed by 5 weeks and the length of the pollen discharge period decreased from 9 to 4 weeks. The season-long unique and reproducible pollen production data can be integrated with airborne pollen modelling and population management strategies.     

土壤重金属污染及对生物体影响的研究进展

重金属污染是当今社会世界性的环境生态问题。由于人类社会城市化进程加剧、工业生产中"三废"的不合理排放以及现代农业中各种农药化肥的大量使用,导致土壤中重金属的含量剧增,污染问题严重,其中尤以重金属镉、汞、铅等在生物体内的富集与抗生性的研究日益受到关注。笔者综述了土壤重金属污染及对生物体影响的研究进展,以期为土壤重金属综合治理与污染修复提供科学依据。     

国内湿地重金属污染评价的研究进展

湿地作为地球上重要的生态系统之一,具有稳定环境、物种基因保护及资源利用功能,被誉为自然之肾、生物基因库和人类摇篮。随着近年来湿地面临着面积萎缩、功能下降、污染日趋严重等危机,国内外学者对湿地保持着持续关注与研究,其中对湿地重金属的污染评价就是湿地科学研究领域的重要内容之一。笔者通过对国内十多年来有关重金属污染方面的报道进行整理分析,回顾总结了湖泊、河流、三角洲以及滨海等类型湿地的底泥、水体及土壤中重金属的污染现状与迁移特征,重点对重金属的种类、空间分布以及分析方法等进行总结归纳。在众多研究成果中,对污染物评价的方法以地累积指数法和潜在生态风险指数法使用最多。     

农业面源污染负荷空间分布及风险评价研究进展

为了研究农业面源污染负荷空间分布及风险评估,综述了国内外近10年的最新研究进展,发现在农业面源污染空间分布及风险评估上的研究较多,其中污染的源因子及迁移因子空间分布研究进展颇多,而在综合风险评价上的研究还比较缺乏,对污染负荷的分布特征及其相关性的研究还存在不足,今后还需研究污染负荷分级区划与管理控制措施研究。     

Determination and Analysis of Heavy Metal Content in the Soil from Beef Cattle Farms in Three Regions of Xinjiang

In order to study and evaluate the feeding environment of the beef cattle farms in Xinjiang, the contents of heavy mentals in the soil from 8 beef cattle farms in Xinjiang Aksu, Yili and Tacheng regions were tested according to the Field of Livestock and Poultry Environment Quality Standard (NY/T 388—1999).The atomic absorption spectroscopic method was used to determine the contents of As, Hg, Pb, Cd, and Cr.The mean contents of As, Hg, Pb, Cd, and Cr in 8 beef cattle farms soil were 0.389, 0.568, 22.708, 0.573 and 149.449 mg/kg, respectively, and they were all below the upper limit of NY/T 388—1999.The comprehensive heavy metal pollution index of 8 beef cattle farms were 0.577 to 0.994, and the index were 0.7 to 1 of two observation points in Yili and one observation point in Tacheng.The soil environment quality of these 3 farms were at the level of slight cleaning.The comprehensive heavy metal pollution index of other five observation points were ≤0.7, the soil environment was in a clean level.The soil environment of beef cattle farms in these three regions conformed to the standards of livestock for environment quality and safe products.     

Effects of distillers dried grains with solubles and mineral sources on gaseous emissions

Distillers dried grains with solubles (DDGS), an important ethanol industry co-product, has been used as a high-protein feed in poultry production. Limited studies exist on their effect on air emissions, however. In the current study, 4 diets (2 × 2 factorial design: 0 or 20% DDGS + inorganic or organic mineral sources) were fed to Hy-line W36 hens from 50 to 53 wk of age and the effects of DDGS level and mineral sources on air emissions were monitored continuously for a 23-d period in environmentally controlled chambers. The NH₃, H₂ S, CH₄, nonmethane hydrocarbons, N₂ O, CO₂, and CO₂-equivalent emissions ranged from 0.51 to 0.64 g/day-hen, 0.71 to 0.84 mg/day-hen, 33.9 to 46.0 mg/day-hen, 54.1 to 60.0 mg/day-hen, 66.0 g to 72.2 g/day-hen, and 83.1 to 92.1 g/day-hen, respectively. Feeding DDGS to laying hens resulted in 14% decreased NH₃ emissions but a 19% increase in CH₄ emissions without affecting other gaseous emissions. More than 30% of N, 80% of P, 80% of K, and 50% of Ca was retained in the manure. In conclusion, feeding laying hens a diet containing 20% DDGS may be beneficial for the environment. Substitution for organic trace minerals did not affect hen performance or air emissions.     

基于DLMS/COSEM的嵌入式自动抄表集中器的设计与实现

环境污染责任保险因开展经验及历史数据不足致费率难以合理厘定，引入模糊信息粒及综合评价理论，相对传统方法，更能实现费率厘定的公平合理，保障各方利益.本文以化学原料及化学制品制造业为研究对象，首先运用模糊信息粒理论处理历史数据，克服数据模糊不确定性，得出第三者赔偿额的模糊信息粒X~；其次运用传统精算定价方法得出行业基准费率的模糊信息粒p~；最后运用模糊综合评价二级评价理论，综合追溯期、企业规模等影响因素，得出投保企业风险综合评价集B~，以此修正基准费率.     

哈萨克斯坦渔业主要水域环境现状及保护对策

分析了哈萨克斯坦渔业主要水域的环境现状。伊犁河（Ile River）-巴尔喀什湖（Balhash Lake）、乌拉尔河（Oral River）-里海（Caspian Sea）、锡尔河（Ser River）-咸海（Aral Sea）、额尔齐斯河（Ertis River）-斋桑泊（Zai-sang Lake）均受不同程度的污染,污染物有化肥、农药、石油产物、重金属及含氮化合物、氯化物、硫酸盐,来源包括国内外两个渠道。污染物破坏渔业主要水域生境,对水生物种（鱼类）的安全造成威胁,导致了水生生物资源衰竭。国家有关管理部门应采取相应标准化管理措施,依法执行治理工作,防止国外污染物进入本国渔业水域;并通过和邻国联合对哈国渔业主要水域环境及生物资源开展保护与利用研究,确保本国主要渔业水域生态环境的可持续发展,保护与合理利用人类共有资源。     

贵州尾矿区野生豆科牧草根瘤菌及其抗性测定

为了筛选获得对复合重金属具有耐受能力且能在本地豆科植物根系内定殖共生的抗性根瘤菌,本研究从贵州省内的锰矿区、铅锌矿区采集野生豆科牧草根瘤样品,经分离纯化、菌体形态观察、16S rRNA基因序列比对分析,获得71个根瘤菌保存菌株。系统发育和区系分析结果表明,分离菌株分属7属28种,其中根瘤菌属(Rhizobium)的分布频率高达54.93%,为优势属,木兰根瘤菌(R.indigoferae)的分布频率最高(15.49%),为优势种。选择来自不同尾矿区、不同种类的根瘤菌17株,采用重金属平板法测定各供试菌株对贵州尾矿土分布较多的Pb²⁺,Zn²⁺,Cr⁶⁺,Mn²⁺,Cd²⁺五种重金属的耐受性,结果发现17个菌株对3种或3种以上的重金属都具有不同程度的耐受能力,其中HMZT039-6,HSST042-6,HSST042-1,ZHQT052-1和HXTT050-1对5种重金属离子均有耐受能力,为筛选出的最优抗性根瘤菌株。本研究结果可为本地区土壤重金属污染的修复治理提供共生微生物资源。     

鸡毒支原体灭活疫苗效力检验气囊注射攻毒方法的研究

鸡毒支原体灭活疫苗效力检验采用的喷雾攻毒方法所需菌液量大,结果易受喷雾时间和器械设备影响。为了探索一种简便、易行且结果稳定的新方法,本研究冻干了一批攻毒用菌株鸡毒支原体R株,对其性状、纯粹、真空度、剩余水分、培养特性、特异性、活菌计数和均一性等进行检定,结果全部符合规定。将其稀释成不同活菌数,采用气囊注射方式攻毒,观察试验结果并与《中国兽药典(三部)》中的喷雾方法进行比较。结果表明,建立的气囊注射攻毒法稳定、准确,通过5批次疫苗效力检验试验比较,与喷雾方法结果无显著差异,可为该类疫苗攻毒方法优化提供新思路。