自然富硒土中Se对不同水稻籽粒吸收Cd的影响

通过水稻盆栽试验,在高低两种自然富硒土壤上种植3种水稻。结果发现,水稻籽粒Se含量与土壤中Se含量呈正相关,而土壤硒含量过高会降低水稻籽粒的产量。在添加Cd下,高富硒土种植的博优998、秋优998、金稻优998等水稻籽粒Cd含量比低富硒土分别降低了26.99%、10.28%、13.48%,说明土壤中适量的Se对水稻籽粒吸收Cd有拮抗作用。另外,秋优998富集Se、Cd的能力最强,生物产量最低,金稻优998达到富硒效果,而富集Cd的能力最弱,且生物产量较高,在筛选品种时,应优选金稻优998。     

模拟海洋全浸区环境下A517海工钢的腐蚀机理研究

目的 探究 A517 海工钢在海洋全浸区环境下的腐蚀机理。方法 通过模拟海洋全浸区腐蚀环境,利用失重法、SEM、EDS、XRD、电化学等测试技术,分析A517钢的腐蚀行为历程,并探讨其在全浸区的腐蚀机理。结果A517钢在厚度方向上的最大电位差为 13 mV,小于发生电偶腐蚀的最小电位差50mV,说明材料在厚度方向上的腐蚀敏感性一致。随浸泡时间的延长,腐蚀质量损失量逐渐增加,平均腐蚀速率先降低、后升高、最后趋于稳定,腐蚀速率约为 0.127 mm/a。结论 腐蚀动力初期主要是由溶解氧的极限扩散控制,后期则是腐蚀产物的氧化还原电荷转移控制。腐蚀首先在 Al₂O₃、MgO 等夹杂物处萌生扩展,腐蚀产物出现明显的分层现象,外锈层主要是疏松易脱落的γ-FeOOH,内锈层主要是致密均匀的 Fe₃O₄,同时锈层中还检测到了β-FeOOH和α-FeOOH的存在。锈层中存在大量微裂纹,削弱了产物膜的保护作用,促进了腐蚀的进行。     

高浓度J酸废液资源化技术研究

探讨了Ｎ２５３－煤油－Ｈ２ＳＯ４－ＮａＯＨ化学萃取－反萃取体系提取浓缩Ｊ酸废母液中间体的工艺特性,试验结果表明,通过萃取工艺,Ｊ酸废液中的ＣＯＤｃｒ去除率可达９５％,萃余液ＣＯＤｃｒ在５００￣２０００ｍｇ／Ｌ之间,色度去除率可达９５％,该工艺可使废母液中的回收物浓缩５－１０倍,萃取剂可以循环使用而不改变性质,损失较少。     

Methodological convergence as an issue within environmental cognition research

Two perspectives in the analysis of pointing and mapping tasks as the measure of representations of the large-scale environment are examined. These two perspectives are: (1) an individual difference approach; and (2) a cognitive representational approach. Convergence between methods assessing the same geographical/spatial knowledge is necessary as evidence for the existence of unified cognitive-spatial representations of the environment.Three sets of analyses interrelate performance on pointing and mapping tasks. In the first analysis, a confirmatory factor analytic model is applied to short tests of pointing and mapping accuracy to determine whether one or two factors are needed to account for covariation between the tests. In the second analysis, covariation among errors in pointing and mapping of specific locations is partitioned into general and specific method factors using the Schmid-Leiman procedure. In the third analysis, pointing errors for identical locations within the mapping and pointing tasks are directly compared on the basis of directional errors.The three analyses indicate that: (1) tests of pointing and mapping measure highly related abilities; (2) the targets used in pointing and mapping tasks are of differential importance in identifying general and specific method factors; and (3) there is little or no direct correspondence between directional errors made in pointing tasks and those occurring in mapping tasks for the same locations.When results of the three analyses are examined in relationship to criteria for convergence of pointing and mapping tasks, little evidence is found to suggest that directional errors in these tasks arise from a unified mental representation of the geographical environment. However, substantial predictable individual differences are apparent for both tasks.     

美国机场大气污染物控制途径及效果

随着航空运输业的快速发展,飞机及机场机械排放的污染物越来越受到人们的重视,国内外针对机场污染物排放和环境影响采取了针对性的控制措施。本文主要根据美国环保局针对机场飞机和地面保障机械尾气排放控制措施和效果的评估资料,整理机场大气污染物控制途径及效果,合理的飞机起降安排、地面保障机械的清洁燃料替代和尾气后处理装置的安装使用是主要的控制措施,本文总结了各项控制措施的减排效果,为机场大气污染物排放治理提供参考和借鉴。     

Environmental disaster,pollution and infant health: Evidence from the Deepwater Horizon oil spill

In 2010 the Gulf Coast experienced the largest oil spill affecting U.S. waters in history. Evaporating crude oil and dispersant chemicals can cause major health problems. This paper examines the impact of the Deepwater Horizon oil spill on air quality and infant health outcomes. Using U.S. Environmental Protection Agency (EPA) AirData, vital statistics data from National Center for Health Statistics (NCHS), and a difference-in-difference methodology, we find that the oil spill of 2010 increased concentrations of PM2.5, NO2, SO2, and CO in affected coastal counties, increased incidence of low birth weight (<2500 g) and premature born infants (<37 weeks of gestation). Heterogeneity effects reveal more pronounced adverse infant health outcomes for black, Hispanic, less educated, unmarried, and younger mothers. Results are robust to a wide range of controls and robustness checks.     

改性膨润土对J酸溶液和废母液处理效果

研究了改性膨润土对Ｊ酸溶液和Ｊ酸废母液的处理效果,结果表明,改性膨润土对Ｊ酸溶液的处理效果比Ｊ酸废母液要好,对Ｊ酸废母液的去除效果与ｐＨ和硫酸钠含量有关,在中性或弱碱性条件下,硫酸钠含量越低。对Ｊ酸废母液的去除率越高,最高可达到５０％左右。     

Growth, photosynthesis and antioxidant responses of two microalgal species, Chlorella vulgaris and Selenastrum capricornutum, to nonylphenol stress

The effect of nonylphenol (NP) on growth, photochemistry and biochemistry of two green microalgae, Chlorella vulgaris and Selenanstrum capricornutum, and their ability to degrade NP were compared. The 96 h EC₅₀ of C. vulgaris and S. capricornutum were greater than 4.0 and 1.0 mg L⁻¹ NP, respectively, suggesting that the former species was more tolerant to NP. Both microalgae acclimated to NP stress through down-regulating their photosynthetic activities, including antenna size (chlorophyll a content), maximal photochemistry (Fv/Fm) and the light absorbed by PSII (ABS/CS₀), but the dissipation of energy from reaction centres (DI₀/RC) increased with the increase of NP concentrations. In C. vulgaris, the changes of these parameters were more significant than in S. capricornutum and recovered completely after a 96 h exposure. The antioxidant responses, such as GSH content, CAT and POD activities in C. vulgaris increased with the increase of NP concentrations after a 24 h exposure, but these changes disappeared with exposure time and recovered to the control levels after 96 h. In S. capricornutum, although GSH content, CAT and POD activities also increased when exposed to low- to moderate-NP concentrations, these values were significantly reduced at a high concentration (4 mg L⁻¹) even after a 96 h exposure, indicating its antioxidant responses were significantly delayed. It is clear that the more NP-tolerant species, C. vulgaris, acclimated better with a faster recovery of its photosynthetic activity from the NP-induced damage, and exhibited more efficient and rapid responses to NP-induced oxidative stress. C. vulgaris also had a higher NP degradation ability than S. capricornutum.     

氨基-J酸废水处理及资源化研究

用PCW 5萃取剂对氨基 J酸废水进行了萃取处理 ,废水的CODCr去除率 >95 % ,萃取液用碱液反萃回收氨基 J酸产品 ,每立方米废水回收 2 7 9kg氨基 J酸 ,回收产品符合工业品质量要求     

Climate policies and skill-biased employment dynamics: Evidence from EU countries

The political acceptability of climate policies is undermined by job-killing arguments, especially for the least-skilled workers. However, evidence of the distributional impacts for different workers remains scant. We examine the associations between climate policies, proxied by energy prices, and workforce skills for 14 European countries and 15 industrial sectors over the period 1995–2011. Using a shift-share instrumental variable estimator and controlling for the influence of automation and globalization, we find that climate policies have been skill biased against manual workers and have favoured technicians. The long-term change in energy prices accounted for between 9.2% and 17.5% (resp. 4.2% and 8.0%) of the increase (resp. decrease) in the share of technicians (resp. manual workers).