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351.
Lugu lake is an alpine lake in Yunnan Province in western China. It is famous for its beautiful scenery and the special culture of Mosuo people in this area. The lake is becoming contaminated and eutrophicated because of the huge number of visitors and improvements in agriculture during the last decade. This paper uses the water quality index (WQI) as an indicator to describe trends in contamination of Lugu Lake from 1995 to 2004 and analyses several parameters to determine the causes and consequences of contamination. We found that the dominant cause was pollution from tourism and suggest some feasible measures to prevent further deterioration of the lake water quality. 相似文献
352.
Energy is one of the most important elements required for poverty alleviation and socioeconomic development, and it has a particularly strong impact on households in rural areas. An extensive survey on household energy consumption patterns that interrelates socioeconomic and demographic factors was conducted in the disregarded villages of Lijiang City by using the stratified random sampling technique for 120 households. This study focuses on household energy consumption and the related carbon dioxide (CO2) emissions in the study area. Firewood, biogas, and electricity were identified as the main energy sources of the rural households. This study demonstrates that 100% of the households use firewood, 52% use biogas, and 95% use electricity as fuel types. On average, each household consumed 1752 kg of firewood, 280 m3 of biogas, and 392 kWh of electricity annually. All households generated an annual average amount of CO2 emissions of 3851 kg, of which 85.08% come from firewood, 7.66% from biogas, and 7.26% from electricity. Family size, income, and educational level were found to be the major factors that influence CO2 emissions. The results of this study may be useful in explaining the energy consumption characteristics in the rural areas of Lijiang City and are expected to be useful in policy formulation for energy consumption and environmental protection. 相似文献
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随着越来越多标准化生活垃圾填埋场的建成和投入运行,原有简易生活垃圾填埋场的环境综合治理被各级环境管理部门日益重视,成为改善环境急需解决的问题。以西北某市简易生活垃圾填埋场综合整治工程为例,通过分析简易垃圾填埋场存在的主要环境隐患,有针对性地提出了解决垃圾渗沥液、填埋气、边坡安全等环境和安全问题的具体工程措施,尽量将简易垃圾填埋场对周围环境的影响降到最低程度。 相似文献
355.
2006─2010年环保重点城市主要污染物浓度变化特征 总被引:13,自引:6,他引:7
利用2006─2010年全国环保重点城市的空气质量日报数据,分析了大气ρ(SO2)、ρ(NO2)和ρ(PM10)的变化特征. 结果表明:从年际变化看,ρ(SO2)和ρ(PM10)呈下降趋势,ρ(NO2)变化不显著.从季节变化看,ρ(SO2)、ρ(NO2)和ρ(PM10)均呈冬季高、夏季低的特征.从浓度谱分布看,全国大气中ρ(SO2)、ρ(NO2)和ρ(PM10)分别集中在0~0.150、0~0.100和0~0.250 mg/m3范围内,ρ(SO2)和ρ(PM10)谱峰区间逐渐向低浓度范围偏移,高浓度事件逐渐减少,表明SO2和PM10污染得到较明显的控制,而ρ(NO2)谱峰变化不大.从浓度变化看,山西ρ(SO2)、ρ(NO2)和ρ(PM10)下降最明显,年变化率分别为-11.2、-3.6和-14.2 μg/m3;青海ρ(SO2)、山东ρ(NO2)和ρ(PM10)的上升趋势最明显,年变化率分别为4.4、2.7和4.5 μg/m3. 相似文献
356.
本文利用腈纶纤维(PANF)便于回收、易于修饰、价格低廉等优点,通过不同链长卤代烃的季铵化反应,构建系列极性可调的功能化腈纶纤维,通过红外光谱、扫描电镜、X-射线衍射等技术进行表征,并研究纤维表层极性调控对水体磷酸盐的吸附性能的影响.结果 表明,正溴丁烷修饰的季铵化纤维(PANT-C4F)对磷的吸附能力(25 mg·g-1P)优于正溴己烷和正溴辛烷修饰的季铵盐功能化纤维(PANT-C6F、PANT-C8F).改性纤维材料的吸附动力学更符合准二级动力学模型,吸附等温线采用Langmuir模型拟合更优,说明功能化纤维对磷的去除主要为单分子层化学吸附.PANT-C4F在pH 7左右时,对磷的吸附效果最好,且3 min达到平衡,因此具有较高的吸附效率.此外,PANT-C4F吸附的磷酸盐可以在NaCl溶液中解吸附,至少可以循环5次以上,实现功能化纤维的循环利用和磷的有效回收.研究表明,PANT-C4F是一种高效的水体磷酸盐吸附材料,具有较高的实际应用价值. 相似文献
357.
Monitoring and reporting attacks on education in the Democratic Republic of the Congo and Somalia
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Cyril Bennouna Elburg van Boetzelaer Lina Rojas Kinyera Richard Gang Karume Marius Nshombo Leslie Roberts Neil Boothby 《Disasters》2018,42(2):314-335
The United Nations' Monitoring and Reporting Mechanism is charged with documenting six grave violations against children in a time of conflict, including attacks on schools. Many of these incidents, however, remain unreported across the globe. This study explores whether or not a local knowledge base of education and child protection actors in North and South Kivu Provinces, Democratic Republic of the Congo, and in Mogadishu, Somalia, could contribute to a more complete record of attacks on education in those areas. Hundreds of semi‐structured interviews were conducted with key informants across the three settings, and in total 432 attacks on education were documented. Purposive samples of these reports were verified and a large majority was confirmed. Local non‐governmental organisations and education institutions were most knowledgeable about these incidents, but most never reported them to a monitoring authority. The study concludes that attack surveillance and response were largely insufficient, and recommends investing in mechanisms that utilise local knowledge to address these shortcomings. 相似文献
358.
Chen G Wu X Zhou WL Li L 《Journal of environmental biology / Academy of Environmental Biology, India》2010,31(5):655-660
C-glucosyltransferase (EC 2.4.1.X) is one of the key enzymes for the biosynthesis of puerarin. This paper describes the methodology in purification and assay of the enzyme for the first time in Puerarin lobata (Wild.) Ohwi. C-glucosyltransferase from roots of P. lobata was extracted and partially purified by (NH4)2SO4 saturation. The effects of pH, temperature, and substrate concentration on the activity of the enzyme were investigated. The properties of the puerarin produced by C-glucosyltransferase were studied by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The peak activity of C-glucosyltransferase was detected in fraction of by 80% saturation of (NH4)2SO4 and the optimal conditions for enzymatic reaction were 35.5 micromol l(-1) of isoliquiritigenin and 560 micromol l(-1) of UDP-G at pH 8.1, 28 degrees C for 1 h. Mn2+ at 1 mmol l(-1) and Al3+ at 1 mmol l(-1) increased the enzyme activity, while Mg2+ inhibited its activity. The enzyme activity in Nicotiana tabacum and P. lobata were detected under the above assay conditions. Higher activity was found in roots than in leaves and stems of P. lobata, while no enzyme activity was detected in leaves of N. tabacum. It was the first time that activity of C-glucosyltransferase, which transforms isoliquiritigenin to puerarin, was detected in P. lobata. 相似文献
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