地层重力分异在改善水锥进油藏开发效果中的应用     

Bowl.  KR 罗水发 《国外石油地质》1999,21(2):35-36,49

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Semipermeable membrane devices link site-specific contaminants to effects: PART II - A comparison of lingering Exxon Valdez oil with other potential sources of CYP1A inducers in Prince William Sound, Alaska   总被引：1，自引：1，他引：0  

Short JW  Springman KR  Lindeberg MR  Holland LG  Larsen ML  Sloan CA  Khan C  Hodson PV  Rice SD 《Marine environmental research》2008,66(5):487-498

We deployed semipermeable membrane devices (SPMDs) on beaches for 28 days at 53 sites in Prince William Sound (PWS), Alaska, to evaluate the induction potential from suspected sources of cytochrome P450 1A (CYP1A)-inducing contaminants. Sites were selected to assess known point sources, or were chosen randomly to evaluate the region-wide sources. After deployment, SPMD extracts were analyzed chemically for persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAH). These results were compared with hepatic CYP1A enzyme activity of juvenile rainbow trout injected with the same extracts prior to clean-up for the chemical analyses. Increased CYP1A activity was strongly associated with PAH concentrations in extracts, especially chrysene homologues but was not associated with POPs. The only apparent sources of chrysene homologues were lingering oil from Exxon Valdez, asphalt and bunker fuels released from storage tanks during the 1964 Alaska earthquake, creosote leaching from numerous pilings at one site, and PAH-contaminated sediments at Cordova Harbor. Our results indicate that PWS is remarkably free of pollution from PAH when nearby sources are absent as well as from pesticides and PCBs generally.  相似文献   

Degradation rates of low molecular weight PAH correlate with sediment TOC in marine subtidal sediments   总被引：3，自引：0，他引：3  

Hinga KR 《Marine pollution bulletin》2003,46(4):466-474

The degradation rate of low molecular weight (LMW) polycyclic aromatic hydrocarbons (PAH) in subtidal marine sediments was found to correlate with sediment total organic carbon (TOC) in stations sampled two or more times after the North Cape No. 2 fuel oil spill. With 2.5-5 months between samplings, stations with lower sediment TOC had lower fractions of LMW PAH remaining at the time of the second sampling. Apparent first-order degradation rate constants calculated for each station varied by nearly an order of magnitude between stations with a range of TOC from 0.4% to 7.3%. The correlation of degradation rate with sediment TOC can be used to provide improved and site-specific predictions of the initial time-course of LMW PAH concentrations in sediments after oil spills.  相似文献   

Toxicity comparison of biosurfactants and synthetic surfactants used in oil spill remediation to two estuarine species   总被引：1，自引：0，他引：1  

Edwards KR  Lepo JE  Lewis MA 《Marine pollution bulletin》2003,46(10):1309-1316

The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbiologically produced surfactants were determined and compared in this study for the estuarine epibenthic invertebrate, Mysidopsis bahia and the inland silverside, Menidia beryllina. The toxicities of the surfactant were determined in standard laboratory static and static-renewal tests of 4-7 d duration. Results were specific to the surfactant, response parameter and test species. The LC50 values (nominal concentrations) for M. bahia ranged from 3.3 mg/l (Triton X-100) to >1000 mg/l (PES-61) and 2.5 mg/l (Triton X-100) to 413.6 mg/l (PES-61) for M. beryllina. Chronic first-effect concentrations (mg/l) for the six surfactants ranged from 2.3 to 465.0 (M. beryllina) and 1.0 to >1000.0 (M. bahia) based on reductions in growth and fecundity. Few generalizations could be made concerning the results due to their variability but M. bahia was generally the more sensitive species and the toxicities of the biosurfactants were intermediate to those of the synthetic surfactants.  相似文献   

连阴雨对玉米的影响研究进展     

王秀萍  刘荣花  詹静 《气象与环境科学》2016,39(4):121-125

概述了玉米连阴雨灾害的研究方法和研究现状,重点对玉米连阴雨灾害研究方法、连阴雨灾害指标、玉米耐阴指标及耐阴机理等进行了总结与评述。目前,研究已初步形成了玉米连阴雨气象灾害指标和玉米品种的耐阴性评价指标,并从玉米生长发育、光合生理、碳氮代谢和分子生物学等角度对玉米耐阴机制进行了有益的探索。但目前尚未有明确的灾损评估指标,品种耐阴性评价指标尚未统一,前人研究多注重阴雨天气带来的光辐射减弱的影响,后续研究需考虑土壤墒情和气温因素与光辐射对玉米产量的协同影响规律。加强玉米品种耐阴性评价指标的研究和耐阴种质的筛选,以减缓连阴雨灾害对玉米生产的不利影响。  相似文献   

圣本多细菌氧化（BIO）计划南美采用细菌氧化作用...     

Sutt.  KR 杨玉波 《世界地质》1992,11(4):109-113

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正向和斜向裂谷作用实验模型     

McCl.  KR 吴李泉 《世界地质》1997,16(1):30-38

砂箱实验模拟了正向和外向裂谷的三维演化过程，裂谷作用的方位角α（α为裂谷轴和伸展方向之间的夹角）分别取90°（正向裂谷）、75°、60和45°（斜向裂谷）。实验模型分别在水平和垂向上做切面。正向裂谷模型以长、直的边界断层和内断层与拉伸方向正交为特征。外向裂谷模型以短、分段的边界断层和内部断层为特征。在科向裂谷模型中，边界断层呈雁行排列，并与基底伸展带平行；裂谷内断层与伸展方向大角度相交。在中度外向和斜向裂谷（α＝60°和45°）中，随着拉伸量的增加，裂谷内断层朝着平行于边界断层方向发生旋转。在所有实验中都没有发现走滑或斜滑断层。所有模型中，裂谷边界断层和内部断层沿走向分段，在断层重叠部位形成中继断坡构造。共轭正断层组成的调节带能够实现裂谷系统走向方向上半地堑不对称性的转变和沉降中心的错开。实验产生的断层样式可与现代年轻裂谷中断层样式进行很好的对比，在这些现代裂谷中，也没有发现由基底控制的走滑或科滑转换断层。实验模型得出断层的几何形态可以作为识别正向和斜向裂谷中断层样式的样板。  相似文献   

中国西南部东北寨和金牙金矿床的矿物成分     

Wang  KR 毛家衢 《山东地质信息》1997,(2):17-23

对中国西南部两个金矿床的矿物成分，进行了考察，这两个金矿床含有全部是显微或次显微颗粒的金或包裹体金。它们含有难以提炼的或低品位矿石，与美国内华达州卡林型相似。对采自两个矿床的矿石样品的矿物成分研究（如质子探针分析、扫描电子显微镜分析、电子探针分析、Ｘ－射线衍射分析、矿石显微镜研究）表明，最主要的含金矿物，在东北寨矿床是黄铁矿，在金牙矿床是毒砂和黄铁矿。两矿床中的金均与Ａｓ、Ｓ和Ｆｅ密切相关。  相似文献   

CO2和温度对皮马棉发育的影响     

Redd.  KR 刘荣花 《气象与环境科学》1997,(1):26-28

预报作物对大气ＣＯ２浓度变化和全球可能变暖的响应，是重要问题。ＣＯ２对作物发育过程的影响，是ＣＯ２和其它主要气候变量对作物发育的相互作用的结果，对此还报道甚少。本项试验的目的是要确定ＣＯ２环境的变化及ＣＯ２与温度间的相互作用对皮马棉发育速度的影响。皮马棉（ＧｏｓｙｐｉｕｍｂａｒｂａｄｅｎｓｅＬ．ｃｖ．ｓ－６）从播种开始就生长于有日光照射的作物生长箱内。白天／夜间气温控制在２０／１２～４０／３２℃，每隔５℃一个处理。白天ＣＯ２保持在３５０或７００μＬＬ－１。在第二个试验中，温度维持在３０／２２℃（白天／夜间），ＣＯ２为３５０、４５０、７００μＬＬ－１。并测定了主茎节发育所需天数、出苗到初现蕾的日数、营养枝和果枝数、座果数、结铃和现蕾数以及为植株所能保持的蕾铃数。发现主茎节的形成速率、现蕾和现花的早晚对大气ＣＯ２浓度不敏感，但对温度很敏感。果枝长出之前节位的发育要比果枝长出之后的节位发育慢。不同ＣＯ２浓度对长出节的快慢没有影响。分枝数目对温度和ＣＯ２都敏感。相比之下，生长在高ＣＯ２下的植株由于提供了一个较大的光合作用汇，其下部果枝上的棉铃数要多些。这也许就是我们观察到生长在高浓度ＣＯ２下的棉株上层节的铃数减少的  相似文献   

Does historical exposure to hydrocarbon contamination alter the response of benthic communities to diesel contamination?     

Carman KR  Fleeger JW  Pomarico SM 《Marine environmental research》2000,49(3):255-278

A microcosm experiment was used to compare the influence of diesel contamination on two benthic salt-marsh communities, one chronically exposed to petroleum hydrocarbons for decades (Louisiana [LA]) and the other relatively uncontaminated (Mississippi [MS]). Initial meiofaunal community composition of the two sites was similar. Higher organic content of MS sediments should have reduced bioavailability, and thus the toxicity of hydrocarbons relative to the LA site. Nevertheless, although responses to diesel contamination at the two sites were generally qualitatively similar, a species-specific and several community-response variables were influenced to a much greater degree in the MS community. In particular, the abundance of total nauplii, ostracods, and copepods were negatively impacted to a greater extent in MS than in LA, as was grazing by ostracods on benthic microalgae. Nematode:copepod ratios in contaminated sediments were much higher in MS than in LA sediments. Pseudostenhelia wellsi (a benthic copepod) nauplii suffered greater adverse effects of diesel in MS than in LA. We conclude that the MS community was more sensitive to diesel contamination than was the LA community. The differential sensitivity is presumably a manifestation of different tolerances to hydrocarbon contaminants, mediated by a higher proportion of more tolerant species and/or increased tolerance among individual species in LA. Although the MS site was more sensitive to diesel contamination, qualitative response of the LA and MS communities were similar, and comparable to previous studies of diesel contamination. The spatial and temporal consistency of diesel impacts on salt-marsh communities suggests that hydrocarbon contamination results in predictable community responses. Specifically, crustacean (e.g. copepods, ostracods, and nauplii) benthos are most sensitive to hydrocarbons. Reductions in abundance and grazing activity of crustaceans leads to enhanced algal biomass, reduced copepod diversity, and alters competitive interactions among meiofauna.  相似文献