The effect of diesel fuel on common vetch (Vicia sativa L.) plants

When petroleum hydrocarbons contaminate soil, the carbon:nitrogen (C:N) ratio of the soil is altered. The added carbon stimulates microbial numbers but causes an imbalance in the C:N ratio which may result in immobilization of soil nitrogen by the microbial biomass, leaving none available for plant growth. As members of Leguminosae fix atmospheric nitrogen to produce their own nitrogen for growth, they may prove more successful at growing on petroleum hydrocarbon contaminated sites. During a wider study on phytoremediation of diesel fuel contaminated soil, particular attention was given to the performance of legumes versus other plant species. During harvesting of pot experiments containing leguminous plants, a recurring difference in the number and formation of root nodules present on control and contaminated Common vetch (Vicia sativa L.) plants was observed. The total number of nodules per plant was significantly reduced in contaminated plants compared to control plants but nodules on contaminated plants were more developed than corresponding nodules on control plants. Plant performance of Common vetch and Westerwold's ryegrass (Lolium multiflorum L.) was compared to illustrate any difference between the ability of legumes and grasses to grow on diesel fuel contaminated soil. Common vetch was less affected by diesel fuel and performed better in low levels of diesel fuel contaminated soil than Westerwolds ryegrass. The total amount of diesel fuel remaining after 4 months in Common vetch planted soil was slightly less than in Westerwolds ryegrass planted soil.     

基于葵花影像中国地区夜间云识别方法研究

目的实现适用于中国地区的夜间云识别。方法根据红外波段云与非云的亮温差异,采用亮温阈值法研究适用于中国地区的夜间云识别算法。中国地形高程差异明显,其地表辐射能量也存在较大差异,影响云检测结果精度,因而提出基于三个高程阶梯的云识别方法。由于云检测结果验证缺少可见光波段,使用MODIS云数据产品和雷达数据CALIPSO分别做定性和定量验证。结果云检测区域与MODIS的MYD06云产品基本一致,CALIPSO雷达数据四个月的平均验证结果为:非云区域的提取精度约77.86%,云区域的提取精度为79.67%,将有云区域错提为非云的误差率为2.76%,而将非云区域误提取为有云区域的错误率为12.31%。结论利用日本静止气象卫星Himawari-8影像数据,根据阈值法提出的基于三个高程阶梯的云检测算法,较好地实现了适用于中国地区的夜间云识别。     

基于8—羟基喹啉与NO^—2—磺胺重氮盐的偶联反应示波极谱法测定NO^—2

研究了８－羟基喹啉与ＮＯ＾－２－碘胺重氮盐偶联反应的条件及其产物的极谱行为。二阶导数波高与ＮＯ＾－２的浓度在０．００２－０．２ｍｇ／Ｌ内呈良好的线性关系,回收率为９８％－１０３％,已用于环境水样中ＮＯ＾－２的测定。     

Mitigating phytotoxicity of tetracycline by metal-free 8-hydroxyquinoline functionalized carbon nitride photocatalyst

Photooxidative removal of pharmaceuticals and organic dyes is an effective way to eliminate growing micropollutants. However, photooxidation often results in byproducts as secondary hazardous substances such as phytotoxins. Herein, we found that photooxidation of common antibiotic tetracycline hydrochloride (TCH) over a metal-free 8-hydroxyquinoline (8-HQ) functionalized carbon nitride (CN) photocatalyst significantly reduces the TCH phytotoxic effect. The phytotoxicity test of photocatalytic treated TCH-solution evaluated towards seed growth of Cicer arietinum plant model endowed natural root and shoot growth. This study highlights the conceptual insights in designing of metal-free photocatalyst for environmental remediation.     

超声、过硫酸钾协同去除水中诺氟沙星的效果

过硫酸钾活化可产生强氧化性硫酸根自由基(SO-4·),采用超声/过硫酸钾体系氧化降解诺氟沙星,考察了过硫酸钾浓度、诺氟沙星初始浓度、溶液初始p H值及自由基淬灭剂甲醇、叔丁醇对降解效果的影响.结果表明,超声/过硫酸钾体系能够显著降解和矿化诺氟沙星,与单独过硫酸钾、超声相比,超声/过硫酸钾对诺氟沙星的去除率分别提高了3.2和8.9倍,降解过程符合一级反应动力学.诺氟沙星的去除率随过硫酸钾浓度的增加趋于平缓.p H对诺氟沙星的降解影响较大,这是因为随p H的升高,体系中的氧化性物种由SO-4·转化为以SO-4·/HO·为主.TOC去除和大肠杆菌抗菌实验表明,反应180 min,超声/过硫酸钾能够实现49.12%的诺氟沙星矿化,且对大肠杆菌的抑菌圈直径由45 mm减小到14 mm(滤纸直径),完全去除其抗菌性.结果表明超声/过硫酸钾能够有效用于诺氟沙星废水处理.     

贵州省典型矿区土壤重金属污染对蚯蚓的毒性效应评估

选取我国贵州省某矿区典型的重金属复合污染土壤开展28 d慢性毒性暴露试验,以蚯蚓体内2种抗氧化酶活性——过氧化氢酶(CAT)和超氧化物歧化酶(SOD)、8-羟基脱氧鸟苷(8-ODHG)和金属硫蛋白(MT)含量为生物指标,评估了以上生物指标与土壤重金属含量的相关性,探讨该研究方法用于矿区土壤重金属生态风险评估的可行性。结果表明,CAT和SOD在暴露周期内均出现先诱导后抑制的动态响应过程,表明蚯蚓通过提高CAT和SOD的活性来清除机体因污染胁迫而产生的自由基,以适应环境变化,在毒性缓解后,蚯蚓体内代谢产物的积累抑制了抗氧化氢酶活性,CAT和SOD活性下降并趋于稳定。暴露于重金属污染亚致死浓度时,蚯蚓体内的8-OHDG含量随着暴露时间的延长显著降低,随着暴露浓度的增加,损伤存在由低到高的转变。在28 d暴露周期内,蚯蚓体内MT在重金属胁迫下发挥了解毒作用,MT含量在蚯蚓暴露后第7天增加,随后逐渐降低。本文基于生物毒性试验综合评估了矿区典型重金属污染土壤的生态风险,研究结果对指导重金属复合污染土壤的修复与再利用具有重要意义。     

产絮菌H8絮凝条件的优化

在实验室条件下对产絮菌H8絮凝条件进行优化,得出所需最佳碳源为葡萄糖;最佳复合氮源为酵母菌+蛋白质;最佳生长环境PH为8;培养温度为10℃,培养时间为20h。最佳絮凝条件:高岭土PH为9.0;助凝剂为Ca2+,加入Ca Cl2的最佳浓度为0.04%,菌液投加量为2%,静沉时间5min。     

A Comparison of Spatial and Spectral Image Resolution for Mapping Invasive Plants in Coastal California

We explored the potential of detecting three target invasive species: iceplant (Carpobrotus edulis), jubata grass (Cortaderia jubata), and blue gum (Eucalyptus globulus) at Vandenberg Air Force Base, California. We compared the accuracy of mapping six communities (intact coastal scrub, iceplant invaded coastal scrub, iceplant invaded chaparral, jubata grass invaded chaparral, blue gum invaded chaparral, and intact chaparral) using four images with different combinations of spatial and spectral resolution: hyperspectral AVIRIS imagery (174 wavebands, 4 m spatial resolution), spatially degraded AVIRIS (174 bands, 30 m), spectrally degraded AVIRIS (6 bands, 4 m), and both spatially and spectrally degraded AVIRIS (6 bands, 30 m, i.e., simulated Landsat ETM data). Overall success rates for classifying the six classes was 75% (kappa 0.7) using full resolution AVIRIS, 58% (kappa 0.5) for the spatially degraded AVIRIS, 42% (kappa 0.3) for the spectrally degraded AVIRIS, and 37% (kappa 0.3) for the spatially and spectrally degraded AVIRIS. A true Landsat ETM image was also classified to illustrate that the results from the simulated ETM data were representative, which provided an accuracy of 50% (kappa 0.4). Mapping accuracies using different resolution images are evaluated in the context of community heterogeneity (species richness, diversity, and percent species cover). Findings illustrate that higher mapping accuracies are achieved with images possessing high spectral resolution, thus capturing information across the visible and reflected infrared solar spectrum. Understanding the tradeoffs in spectral and spatial resolution can assist land managers in deciding the most appropriate imagery with respect to target invasives and community characteristics.     

The relative contribution of visual and auditory cues to environmental perception

This study assesses the relative dominance of vision and hearing in judgments of environments, and examines whether the sound sensitivity of the judge alters relative sensory dominance. Six sets of four composite (auditory-plus-visual) videotaped environmental displays were created from unisensory visual and auditory components with known levels of evoked affect. These displays, in a 2 (high, low) × 2 (high, low) Pleasure and/or Arousal format, were presented to 70 participants. The results indicate that visual cues dominate auditory cues in judgments of Pleasure, but that the degree of dominance is highly variable. Arousal judgments were not consistently related to visual or auditory cues. Sound sensitivity does not appear to influence the relative dominance of vision.     

SCS URBAN CURVE NUMBERS FROM A LANDSAT DATA BASE1

Estimating the Curve Numbers used in the Soil Conservation Service hydrologic models is a tedious and costly task. Recent advances in remote sensing and data processing have led to the development of readily available land cover data bases for many areas of the United States. This study evaluated the potential of using a Landsat data base to make the Curve Number estimation process more cost-effective and less tedious. Ten watersheds in the Washington, D.C., area were evaluated using a Landsat land cover data base developed by the U.S. Geological Survey. Results showed that these data can be useful. Predictions can be improved if ancillary data on residential lot size are included. It was concluded that this type of data base must be examined carefully before implementation.