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为探究浙北地区常见景观树种对大气硫、氟污染物的吸收净化能力,采用典型调查法对嘉兴市北部化工区(污染区)和中央公园(清洁区)共52种景观树种叶片的硫、氟含量进行测定,对其在污染环境中吸收富集硫、氟污染物的能力进行评价。结果表明,浙北地区52种景观树种叶片硫、氟含量差异较大,不同采样点和不同生活型之间的变异也较大。灌木树种叶片硫和氟含量略低于乔木,但高于小乔木;落叶树种叶片硫和氟含量均高于常绿树种。依据叶片对硫、氟的生物富集系数(BCF)和叶片的硫、氟含量,将这52种景观植物分为5大类,筛选出对硫、氟污染的综合修复能力较强的树种,如杨树(Pterocarya stenoptera)、柳树(Salix babylonica)、火棘(Pyracantha fortuneana)、广玉兰(Magnolia grandiflora)、红花继木(Loropetalum chinense)、榉树(Zelkova serrata)、桂花(Osmanthus fragrans)和红枫(Acer palmatum‘Atropurpureum’)等。这些可为浙北地区植物修复化工区硫、氟污染研究提供借鉴。 相似文献
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目的:探讨急性脑梗死患者血清心肌酶学变化与预后的关系及导致急性脑梗死患者心肌酶学变化的相关危险因素。方法:回顾性分析临床及影像资料齐全且确诊的140例急性脑梗死患者(发病14天内),根据有无血清心肌酶学升高分为血清心肌酶学升高的急性脑梗死组A组(43例),血清心肌酶学正常的急性脑梗死组B组(97例),应用美国国立卫生研究院卒中量表评分(NIHSS)比较两组神经功能缺损情况,并对两组病人血清心肌酶学(包括天冬氨酸氨基转移酶(AST)、肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)、血糖、血脂、纤维蛋白原和血压等结果进行分析。结果:A组(31%)患者血清心肌酶学均增高,与B组比较均有显著性差异(P<0.01);发病后1天A、B两组患者临床神经功能缺损程度评分无显著性差异,发病后4、8、10天A、B两组患者临床神经功能缺损程度评分有显著性差异(P<0.01);A组高血压、糖尿病与B组比较有显著性差异(P<0.05);而血脂及纤维蛋白原两组比较无显著性差异。结论:急性脑梗死患者血清心肌酶学升高者预后不良;高血压、糖尿病是急性脑梗死患者血清心肌酶学升高的相关危险因素。 相似文献
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Optimization of methane fermentation from effluent of bio-hydrogen fermentation process using response surface methodology 总被引:1,自引:0,他引:1
The individual effects and interactive effects of substrate concentration, ratio of inoculum to substrate, Ca(2+) concentration on the methane yield from the effluent of bio-hydrogen fermentation of food waste were investigated in this study. A central composite design (CCD) and response methodology (RSM) were employed in designing the experiments, in order to determine the optimum conditions for methane fermentation. The experiment results showed that the effects of substrate concentration, ratio of inoculum to substrate, Ca(2+) concentration were statistically significant at 5% level. The interactive effect of substrate concentration and ratio of inoculum to substrate was significant, however the interactive effect of substrate concentration and Ca(2+) concentration, ratio of inoculum to substrate and Ca(2+) concentration were found to be insignificant at 5% level. A maximum yield of 565.76 ml CH(4)/g VS(added) was estimated under the optimum conditions for substrate concentration 7.77 g of VS/l, inoculum to substrate ratio of 2.81 and calcium concentration of 380.82 mg/l. Verification experiment of the estimated optimum conditions confirmed that the RSM was useful for optimizing the methane yield from effluent of bio-hydrogen fermentation of food waste. 相似文献
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