1989~2010年广东沿海牡蛎体镉含量时空分布特征及其健康风险评价     

王学锋  贾晓平  蔡文贵  陈海刚  马胜伟  王增焕 《水产学报》2012,36(12):1910-1916

为评价广东沿海牡蛎体镉(Cd)含量的时空分布特征及其食用健康风险,实验根据2001-2010年广东17个海湾的牡蛎体Cd含量监测结果及1989-1999年的历史数据,分析了广东沿海总体及粤东、珠江口、粤西3大海区牡蛎体镉含量的时空分布特征;并采用风险商法评价其健康风险.1989-2010年广东沿海累计268频次的监测结果表明:牡蛎体Cd含量变化范围为未检出～10.80 mg/kg(均值1.14 mg/kg,以湿重表示,下同),检出率97.01％;其中98.64％符合中国、美国牡蛎体或贝类的Cd含量限量标准(≤4 mg/kg).珠江口海域达标率为三大海域最低(86.5％),是今后生物监测与海洋环境管理的重点.2001-2010年牡蛎体Cd含量的健康风险依次为儿童-青少年(5～17岁)＞老年人(60岁以上)＞成年人(18～59岁);连续食用广东沿海牡蛎10年,其Cd含量在70年内不会对人体构成Cd摄入过量的风险.  相似文献   

Application of natural aminopolysaccharide in seed film-coating for pest control and cotton growth   总被引：1，自引：0，他引：1  

D. F. Zeng  X. Mei 《Russian Agricultural Sciences》2011,37(1):20-24

Cotton suffers attacks of various pests that result in a decreased yield. Until recently, the chemical control of pests was achieved through seed film-coating treatment with toxic insecticides. The natural aminopolysaccharide extracts from crab is a promising candidate as a repellent to protect cotton from Aphis gossypii Glover and Helicoverpa armigera Hubner. Experiments were conducted to study the effect of aminopolysaccharide on pest control, seed germination, plant growth and lint yield. Results indicated that all aminopolysaccharide treatments of different content repelled pests efficiently and increased significantly seed germination, plant growth and cotton yield. The natural aminopolysaccharide extracts from shrimp is a promising candidate as a repellent to protect cotton from Aphis gossypii Glover and Helicoverpa armigera Hubner. The application of the potential aminopolysaccharide by seed coating is an appropriate option for controlling pests and avoiding environmental pollution.  相似文献   

Preparation and study of an environmentally friendly seed-coating agent for cucumber     

Defang Zeng  Renjie Tu 《Frontiers of Agriculture in China》2011,5(3):328-332

Traditional seed-coating agents are widely used, and their accumulative toxicity in soil brings a great hazard to natural environment and human health. In this study, a novel cucumber seed-coating agent was prepared from natural polysaccharide, fertilizer and microelement, etc. Results indicated that the agent had an excellent control effect on pests and increased yield by 8.5% to 9.3%, while the material cost was decreased by 16.7% compared with the traditional toxic seed-coating agent. In addition, the toxicity of the novel agent was also lower than that of traditional ones. Therefore, the application of the novel agent for cucumber is an appropriate option for controlling pests and replacing high toxicity ones.  相似文献   

苜蓿来源的变黑轮枝菌及其致病性     

王明霞  杨继娟  白应文  胡小平 《西北农业学报》2011,20(1):165-169

苜蓿(Medicago sativa L.)是重要的牧草和控治水土流失的重要植被。近年来,苜蓿病害日趋严重,成为苜蓿种植的限制因素。采用常规组织分离法和柯赫氏证病律,从发白矮化的苜蓿病株中分离得到一种病原菌,结合形态学和ITS序列分析,鉴定为变黑轮枝菌(Verticillium nigrescens Pethyhr.),可引起苜蓿叶片发白,节间缩短,植株矮化等症状,但发病植株维管束不变色,不形成黑白轮枝菌引起的典型V字型病斑。该病菌对苜蓿和茄子有一定致病性。  相似文献   

3个构树无性系幼龄材纤维形态和化学成分分析   总被引：1，自引：0，他引：1  

刘飞  刘艳萍  晏增  马永涛  翟晓巧 《河南农业科学》2011,40(10):120-122

以人工培育的3个构树无性系幼龄材为试验材料,对其纤维形态和化学成分进行测定和分析,并揭示不同构树无性系幼龄材纤维形态和化学成分的变化规律.结果表明:构树1号木材的纤维长度和长宽比最大,分别为684.95 μm和57.51,构树3号木材的纤维长度和长宽比最小,分别为482.65 μm和34.73;3个构树无性系木材的纤维...  相似文献   

基于使用后评价探讨广州天河公园园林景观与优化     

曾仪  吴嫣婷  陈章和 《农业科技与信息》2011,(6)

运用使用后评价(POE)研究方法结合模糊综合评价体系,以公众参与为事实基础,从公园总体环境品质、植物景观、水体景观、道路景观、建筑景观、文娱景观以及公共设施7个方面对广州市天河公园进行了调查研究。调查结果表明:广州天河公园园林景观属于良好,公众认可度较好,其中得分最高的为公园总体环境品质,最低的为文娱景观和水体景观;探讨公园景观存在的主要问题并在文化内涵、娱乐设施、水体以及照明设施四个方面提出相对应的优化建议。  相似文献   

7 羟基 4 甲基香豆素钠盐的合成及结构表征     

李振  周乐  宋晓平 《西北农业学报》2011,20(10):173-175

以7-羟基-4-甲基香豆素与氢氧化钠为原料合成标题化合物,并进行重结晶溶剂筛选及纯化精制,采用TLC、UV、IR、1H NMR、13C NMR和MS进行结构表征。结果表明,7-羟基-4-甲基香豆素与氢氧化钠较易形成钠盐,在水-丙酮中易形成结晶,用体积分数为92%丙酮溶液重结晶可得到淡黄色针状晶体,产率75%。该方法操作简单,成本低廉,对规模化生产具有重要指导意义。  相似文献   

Effects of dietary glutamate supplementation on growth performance,digestive enzyme activities and antioxidant capacity in intestine of grass carp (Ctenopharyngodon idella)   总被引：1，自引：0，他引：1       下载免费PDF全文

Y. Zhao  Y. Hu  X.‐Q. Zhou  X.‐Y. Zeng  L. Feng  Y. Liu  W.‐D. Jiang  S.‐H. Li  D.‐B. Li  X.‐Q. Wu  C.‐M. Wu  J. Jiang 《Aquaculture Nutrition》2015,21(6):935-941

A 56‐day feeding trial was carried out to investigate the effect of dietary glutamate (Glu) supplementation on growth performance, digestive enzyme activities and intestinal antioxidant capacity of grass carp (Ctenopharyngodon idella). A total of 540 grass carp with average initial weight of 370 ± 3.8 g were fed three diets supplemented with 0, 8 and 16 g kg^?1 Glu. The per cent weight gain, specific growth rate, feed conversion ratio, and protein and lipid productive value were significantly improved by dietary Glu supplementation. Feed intake, condition factor, visceral somatic index and perivisceral fat ratio were not significantly different between dietary groups. Hepatosomatic index, intestinal somatic index, intestine length index, intestine protein content, trypsin activity in hepatopancreas and intestine, lipase activity in proximal and mid‐intestine (MI) and hepatopancreas, alkaline phosphatase and gamma‐glutamyl transpeptidase activities in intestine, creatine kinase activities in the mid‐ and distal intestine, intestinal folds height in the proximal and MI were significantly increased with increased Glu. Malondialdehyde and protein carbonyl contents in the intestine decreased with increased Glu. Superoxide anion and hydroxyl radical scavenging ability, glutathione reducase, catalase and total superoxide dismutase activities, and glutathione content in the intestine were increased with increased Glu. These results suggested that dietary Glu supplementation increased intestinal antioxidant capacity, digestive and absorptive ability and improved fish growth.  相似文献   

Numerical Analysis of Acoustic Environment with Finite Element Method     

Ma Fei  Zhou Xiaoping  Li Zuwei 《保鲜与加工》2014,(5):61-65

The acoustic environment of highway tunnel is complex and has influences on the driving safety and comfort. In case of emergency, evacuation information is difficult to transfer. Finite element method is used for calculating highway tunnel acoustic modal and attenuation characteristics. The results show that acoustic mode of highway tunnel has symmetry in the horizontal pressure amplitude of symmetry regional is equal and phase is the same or opposite. The higher modal frequency, the greater sound pressure amplitude is, and the effect of tunnel length on modal frequency is smaller. Decay curves of pressure level at each point in the highway tunnel over time are nonlinear. After the source excitation, in 1.5 s, attenuation rate is faster than that of few seconds later and the attenuation time of sound pressure level 30 dB is 5.5 to 7 s.  相似文献   

不同秧龄对双季机插晚稻生长特性与产量形成的影响   总被引：1，自引：0，他引：1  

滕飞  陈惠哲  曾研华  蔡雪青  朱德峰 《中国农学通报》2014,30(30):95-100

为解决长江中下游地区双季机插晚稻移栽秧龄过长的问题,选取温光特性及熟期各不相同的4个代表性品种为材料,研究不同秧龄移栽对双季晚稻生长及产量的影响。结果表明,随着移栽秧龄的增大,感温性水稻穂、成熟期均明显推迟,而感光型水稻生育期受影响较小;感温性迟熟品种25 天、30 天移栽产量显著下降,而感温性中早熟及感光性迟熟品种至30 天移栽产量才发生显著下降。最佳移栽秧龄为感温性晚稻15 天左右,感光性晚稻20 天左右。感温性品种作双季晚稻种植时应选用中早熟品种,而感光性品种可选用高产的中迟熟品种。  相似文献