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Zecong Yu Keke Xiao Yuwei Zhu Mei Sun Sha Liang Jingping Hu Huijie Hou Bingchuan Liu Jiakuan Yang 《Frontiers of Environmental Science & Engineering》2022,16(6):80
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选择单因子指数法、综合指数评价法及模糊综合评价法对漕桥河2008年—2011年的水质进行评价,并结合评价结果对3种评价方法进行分析比较。结果表明,采用模糊综合评价方法可以正确、全面地反映漕桥河的水质状况。 相似文献
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The changes of protein secondary structures in the extracellular polymeric substances(EPS) extracted from activated sludge by four different methods were studied by analyzing the amide I region(1700–1600 cm-1) of the Fourier transform infrared spectra and model protein test. The results showed the molecular weight distribution of organic matter extracted by centrifugation, heating and cation exchange resin(CER) was similar, while the EPS extracted by centrifugation(Control) and CER had similar fluorescent organic matter. The protein secondary structures of extracted EPS by the four methods were different. The similarities of protein secondary structures between the EPS extracted by CER with the Control were the highest among the four extracted EPS. Although the EPS yield extracted by formaldehyde + NaOH method were the highest, its protein secondary structures had the lowest similarity with those extracted by the Control. Additionally, the effects of centrifugation and CER extraction on the secondary structures of bovine serum albumin were also lower than that of other extraction processes. CER enables the second maximum extraction of EPS and maximum retention of the original secondary structure of proteins. 相似文献
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野外调查研究结果表明,安丘-莒县断裂莒县盆地段是一条晚第四纪以来强烈活动的断层.根据断层走向、活动时代及活动性质的变化,可分为两段.董家坡-武家曲坊段和武家曲坊-太湖段,总长度约30km.从滑动速率的分布来看,董家坡-武家曲坊段全新世早期右旋水平滑动速率为1.83mm/a,垂直滑动速率大约为0.37mm/a;全新世晚期右旋水平滑动速率为0.86mm/a,垂直滑动速率大约为0.17mm/a.武家曲坊-太湖段晚更新世早期断裂右旋水平滑动速率为2.78mm/a,垂直滑动速率为0.65mm/a.全新世晚期右旋水平滑动速率为1.37mm/a.垂直滑动速率为0.18mm/a.上述资料表明,安丘~莒县断裂带盆地段的断裂活动无论是时间上还是空间上都有差异,晚更新世以来断裂的活动性有减弱的趋势,全新世时期断裂的活动北段比南段强. 相似文献
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为研究各类型土壤的肥力差异,依据Pallo分组法,初步分析了黑土、草甸土、风沙土、棕壤、暗棕壤、水稻土、黑钙土等7种土壤的腐殖质组成和性质。结果表明:7种土样的腐殖质组成中,均以胡敏素的有机碳的相对数量为最高,风沙土和棕壤中,富里酸的有机碳的相对数量则大于胡敏酸的有机碳的相对数量。7种土样的腐殖化程度从高到底依次为:草甸土>黑土>黑钙土>水稻土>暗棕壤>风沙土>棕壤。各土样胡敏酸的分子复杂程度和化学稳定性的序列为:草甸土>黑土>暗棕壤>黑钙土>风沙土>水稻土>棕壤。各土样中富里酸的分子复杂程度和化学稳定性的序列为:暗棕壤>黑钙土>风沙土>黑土>草甸土>棕壤>水稻土。 相似文献
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西风环流与亚洲季风交互控制下的青海湖流域,对气候变化响应敏感。该区广泛分布的黄土记录了古环境古气候信息,但其在不同时间尺度上的沉积模式和沉积连续性尚不明晰。本文以青海湖西南的黑马河黄土剖面(HMHW)为研究对象,通过高密度光释光(optically stimulated luminescence,OSL)测年,结合粒度、磁化率和色度指标探讨其环境演变特征。结果表明:(1)黑马河黄土的沉积模式以快速堆积为主,集中于较冷的末次冰消期(13—12 ka)和晚全新世(~2 ka);(2)早中全新世(11—4 ka)存在~7 ka的沉积间断;(3)黑马河黄土剖面(HMHW)的土壤粒度组分,以体积占68.68%的粉砂为主,砂次之,黏粒最少;整个剖面的平均粒径和亮度低值对应古土壤层,高值对应黄土层;磁化率的最大值在115 cm处为74.30×10 ?8 m 3·kg ?1,110 cm处的OSL年代为(1.52±0.16) ka,指示晚全新世(~2 ka)有古土壤发育。 相似文献
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Particulate matter exposure has been described to elevate the risk of lung and cardiovascular diseases.An increasing number of recent studies have indicated positive correlations between PM_(2.5)(the fraction of airborne particles with an aerodynamic diameter less than2.5 μm) exposure and the risk of liver diseases.However,research on the effects of PM_(2.5)exposure on liver fat synthesis,secretion,and clearance mechanisms under normal diet conditions is limited,and whether these effects are age-dependent is largely unknown.Female C57BL/6 mice at different ages(4 weeks(4 w),4 months(4 m),and 10 months(10 m))were treated with 3 mg/kg body weight of PM_(2.5) every other day for 4 weeks.Subsequently,the ultrastructural changes of liver,the expression of genes involved in oxidative damage and lipid metabolism in the liver were examined.Observation of hepatic ultrastructure showed more and larger lipid droplets in the livers of 4-week-old and 10-month-old mice exposed to PM_(2.5).Further analysis showed that PM_(2.5) exposure increased the expression of genes related to lipid synthesis,but decreased the expression of genes involved in lipid transport and catabolism in the livers of 10-month-old mice.Our findings suggest that exposure to PM_(2.5) disrupts the normal metabolism of liver lipids and induces lipid accumulation in the liver of female mice in an age-dependent manner,with older mice being more susceptible to PM_(2.5). 相似文献
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不同开垦年限湿地土壤铁变化特征研究 总被引:4,自引:0,他引:4
以三江平原不同开垦年限的湿地土壤为对象,研究了土壤全铁含量、氧化铁游离度、活化度和络合度的时空变化趋势.结果表明,耕层(0~20 cm)土壤较中下层(20~100 cm)土壤、开垦初期(0~1a)较开垦后期(1~25 a)铁所受影响更为显著.土壤全铁与有机质呈极显著负相关,相关系数为-0.620,而与全磷和pH值的相关程度较低.土层1(0~10 cm)全铁含量于开垦前7 a快速增长,13 a后趋于平稳;而土层2(10~20 cm)的快速增长期为8 a,15 a后进入平稳期.土层1比土层2的响应时间更短,规律性更强.土壤氧化铁的游离度在开垦之后迅速升高,而后降低再升高.活化度和络合度随开垦年限的增加都呈指数衰减趋势,其中土层1的活化度在开垦前4 a迅速降低,6 a后趋于平稳,土层2的活化度则在开垦1 a内迅速降低而后一直保持平稳;而络合度的上述年限分别为6 a、14 a和2 a.土壤中全铁的相对含量、氧化铁的活化度和络合度的拟合方程都可反推出土壤的开垦年限,可见铁对土壤环境变迁具有一定的指示作用. 相似文献
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江苏省南通市区3个测点降水组分对比分析 总被引:2,自引:0,他引:2
本文系统分析了2008年度南通市区3个降水监测站位数据,用年、月均值(雨量酸雨频率为累积值)分析了测站之间的差异量,用月均值分析了测站之间的相关性,用每次降水中的PH值分析了4级PH值出现的频率。得出虹桥子站与南郊公园和交巡警支队相比,降水量分别高出337.36mm和289.78mm,酸雨频率分别高出八点八个百分点和减少零点零七个百分点,pH分别低于0.18和0.01,电导率分别低于0.43 ms/m和0.53ms/m,九项阴阳离子年均值均偏低;在50%酸性降水中,pH值分布在≤4.5的频率最高;监测站之间指标具有低度线性相关、显著性相关和高度线性相关3级。说明:降水测站之间指标数据相关性高低,与接受的大气污染物种类和数量、大气扩散条件有关。因此各降水测站酸雨程度高低,与区域大气污染源强度、大气扩散条件密切关联。 相似文献