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991.
生态环境损害鉴定评估业务化技术研究 总被引:11,自引:10,他引:1
随着社会经济的不断发展和人类需求的不断提高,我国生态环境损害事件屡有发生,由于人类活动导致的典型生态系统结构和功能退化、生态系统服务降低等生态环境损害严重威胁到我国的生态安全。系统研究典型生态系统生态环境损害基线、因果关系及损害程度的判定技术方法对保障国家生态安全和实现可持续发展具有重要的理论和实践意义。根据国家"十三五"《典型脆弱生态修复与保护研究专项指南》的要求,中国科学院大学牵头组织6家课题牵头单位联合申报了"生态环境损害鉴定评估业务化技术研究"项目,通过了专业机构组织的评审,获准立项。本文对该项目的研究背景、总体目标、主要内容及预期产出进行了介绍。该项目的开展将对典型生态环境损害评估提供决策支持,为国家在政策层面解决环境损害追责、环境执法与管理提供科学技术和平台支撑。 相似文献
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以鸡粪配方基质(腐熟鸡粪:腐熟玉米秸秆:河沙体积为3:4:3)和牛粪配方基质(腐熟牛粪:腐熟玉米秸秆:河沙体积为3:4:3)为试材,研究了基质中分别添加地福来、酵素菌、EM菌、枯草芽孢杆菌和农用微生物菌剂对基质酶活性和番茄产量及品质的影响.结果表明: 两种配方基质添加微生物菌剂40和60 d时根际基质的脲酶、蔗糖酶和碱性磷酸酶活性均显著提高,番茄植株生长量、果实产量及维生素C含量显著高于对照.鸡粪和牛粪配方基质均以添加地福来效果最好,番茄单株产量分别较各自对照增加14.7%和40.0%,果实维生素C含量分别提高22.2%和39.7%.在不添加微生物菌剂的情况下,鸡粪配方基质栽培的番茄单株产量和果实维生素C含量高于牛粪配方基质;分别添加地福来后,两种基质栽培的番茄单株产量和果实维生素C含量无显著差异. 相似文献
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《Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)》2016,32(10):1368-1374
IntroductionAs hospitalized neonates are radiosensitive and often require numerous X-rays, institutions should investigate the optimal beam parameter combinations to deliver diagnostically acceptable quality images at the lowest possible entrance surface dose (ESD). Using a subjective approach, this study evaluated the effect of different beam parameter combinations on image quality.Methods and materialsFive rabbits simulated the neonatal chest. The ESD was reduced using a variation of voltage, tube current and filtration. Eight radiology registrars, blinded to the dose parameter information, ranked the digital X-ray images of three anatomical regions from best to worst using a variation of the multiple rank order method. T-tests compared the average values, obtained from the scores assigned by each observer to images acquired at different ESDs, for each region. The calculated intraclass correlation coefficient (ICC) assessed observer agreement.ResultsResults showed that a 64% dose reduction was achievable by altering the beam parameters. Large variation among the observers was confirmed by an ICC value <0.5. A 95% confidence interval could not conclude that different ESD values, resulting in a 50–77% dose reduction compared to current practice, would result in different overall observed image quality. This was noted for all three regions indicating that no preference existed towards an image acquired with a specific beam parameter combination.ConclusionsThe large variation in observers’ opinion of acceptable image quality emphasizes the importance of subjective image quality evaluation in the clinical environment. The rabbit phantom and multiple rank order method are considered appropriate for these evaluations. 相似文献
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The effectiveness and credibility of environmental decisions depend on the information provided by scientific assessments. However, the conflicting assessments provided by government agencies, industries, and environmental advocacy groups suggest that biases occur during assessment processes. Sources of bias include personal bias, regulatory capture, advocacy, reliance on volunteer assessors, biased stakeholder and peer review processes, literature searches, standardization of data, inappropriate standards of proof, misinterpretation, and ambiguity. Assessors can adopt practices to increase objectivity, transparency, and clarity. Decision-makers, managers of assessors, and institutions that commission assessments can adopt other practices that reduce pressures on assessors and reduce opportunities for expression of the personal biases of assessors. Environmental assessment should be recognized as a discipline with its own technical and ethical best practices. 相似文献
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Information about male infertility in free‐living bird populations and its underlying causes are poorly documented in the literature. Here, we assessed sperm quality and infertility among males in a wild population of Blue Tits Cyanistes caeruleus, a socially monogamous passerine with frequent extra‐pair mating. One of 30 males (3.3%) studied across two breeding seasons had morphologically abnormal and nearly immotile spermatozoa in combination with zero annual fertilization success. Demonstration of male functional infertility suggests the possibility that socially monogamous females of the study population could obtain a direct fitness benefit by mating polyandrously to increase fertilization success, which could contribute to selection on extra‐pair mating behaviour. 相似文献
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Mathieu Douhard Marco Festa‐Bianchet David W. Coltman Fanie Pelletier 《Evolution; international journal of organic evolution》2016,70(2):358-368
Parents should bias sex allocation toward offspring of the sex most likely to provide higher fitness returns. Trivers and Willard proposed that for polygynous mammals, females should adjust sex‐ratio at conception or bias allocation of resources toward the most profitable sex, according to their own body condition. However, the possibility that mammalian fathers may influence sex allocation has seldom been considered. Here, we show that the probability of having a son increased from 0.31 to 0.60 with sire reproductive success in wild bighorn sheep (Ovis canadensis). Furthermore, our results suggest that females fertilized by relatively unsuccessful sires allocated more energy during lactation to daughters than to sons, while the opposite occurred for females fertilized by successful sires. The pattern of sex‐biased offspring production appears adaptive because paternal reproductive success reduced the fitness of daughters and increased the average annual weaning success of sons, independently of maternal allocation to the offspring. Our results illustrate that sex allocation can be driven by paternal phenotype, with profound influences on the strength of sexual selection and on conflicts of interest between parents. 相似文献