IFC增效微肥对小白菜产量和硝酸盐积累的影响

在江苏省沿江高沙土地区如皋综合试验示范基地进行蔬菜田间试验 ,研究IFC增效微肥对减少小白菜硝酸盐积累的效果。各处理在相同用量磷钾肥和不同用量氮肥的基础上将 30kg·hm-2 的IFC增效微肥拌入蔬菜基肥中一次性施用 ,以不施IFC增效微肥作对照 ,进行成对比较试验。研究表明 :适量施用IFC增效微肥能显著增加蔬菜产量和氮素累积量 ,降低作物体内含氮率和硝态氮含量 ,并降低氮素对土壤及地下水的污染。     

绿色荧光蛋白分子标记在环境微生物学研究中的应用

绿色荧光蛋白(green fluorescent protein,GFP)分子标记是现有遗传标记中最简单方便的一种方法，GFP及GFP突变体在微生物降解污染物、生物膜菌群构架、环境生态学和环境检测生物传感器等研究领域取得了很好的应用效果。     

PM2.5 concentration declining saves health expenditure in China

● Monthly hospitalization expenses are sensitive to increases in PM_2.5 exposure. ● The increased PM_2.5 causes patients with CHD and LRI to stay longer in the hospital. ● The impact of PM_2.5 on total expenses for stroke is greater in southern China. ● Males may be more sensitive to air pollution than females. Air pollution has been a severe issue in China. Exposure to PM_2.5 has adverse health effects and causes economic losses. This study investigated the economic impact of exposure to PM_2.5 pollution using monthly city-level data covering 88.5 million urban employees in 2016 and 2017. This study mainly focused on three expenditure indicators to measure the economic impact considering lower respiratory infections (LRIs), coronary heart disease (CHD), and stroke. The results show that a 10 µg/m³ increase in PM_2.5 would cause total monthly expenses of LRIs, CHD, and stroke to increase by 0.226%, 0.237%, and 0.374%, respectively. We also found that LRI, CHD, and stroke hospital admissions increased significantly by 10%, 8.42%, and 5.64%, respectively. Furthermore, the total hospital stays of LRIs, CHDs, and strokes increased by 2.49%, 2. 51%, and 1.64%, respectively. Our findings also suggest heterogeneous impacts of PM_2.5 exposures by sex and across regions, but no statistical evidence shows significant differences between the older and younger adult subgroups. Our results provide several policy implications for reducing unequal public health expenditures in overpolluted countries.     

论清末的官制改革

1906年的清末官制改革是以慈禧为首的清朝统治者为摆脱内外交困的状况,挽救濒临灭亡的封建专制的政治统治,在“大权统一于朝廷”的前提下进行了一次官僚机构的改革.由于清朝统治者不肯放松手中的权力,其机构的设置与官员的任用都紧紧围绕着加固皇权进行,改革未触及实质,失败势所必然,引人深思.     

我国城市防洪排涝安全研究

分析了我国城市防洪排涝的现状以及存在防洪标准偏低、调蓄雨洪能力衰减、防洪排涝技术落后、防洪排涝应急管理体系不完备、城市居民防灾减灾意识淡薄等方面的主要问题,研究提出我国城市防洪排涝管理的总体对策,并分别从工程保障、行政管理、公众参与监督、法规制度、经济调控和科学技术等6个方面提出包括城市防洪排涝工程建设应与城市建设相结合,考虑泄、排和滞蓄并重,强化防洪排涝应急管理,加强科学研究以及通过宣传教育鼓励公众参与监督管理等具体措施.     

兰州市大气污染对植物中游离脯氨酸含量的影响

对兰州市大气污染对植物叶片中脯氨酸的含量进行测定和分析.结果表明:同一树种在不同污染区中脯氨酸的含量不同,存在极显著性的差异.同一污染区各种绿化植物中脯氨酸的含量也存在显著性的差异.5种树种的抗污染能力为:杨树>小叶黄杨>椿树>国槐>圆柏.根据污染区植物的生理反应,说明兰州市主要功能区的大气污染程度为:兰炼厂区>兰化厂区>橡胶厂>西关>西站>交大>兴隆山.     

化学沉淀法去除稀土废水中氨氮试验

用磷酸铵镁化学沉淀法处理稀土废水中的氨氮,通过对pH值,n(P):n(N),n(Mg):n(N)及反应时间等条件进行试验,结果表明,在PH=12,n(Mg):n(N):n(P)=1.2:1:1.3,反应20min,氨氮去除率可达98%以上.氨氮初始浓度在100-200 mg·1-1左右的废水,处理后出水的残余氨氮浓度达到国家一级废水排放标准.     

电感耦合等离子体质谱法测定土壤中重金属有效态浓度

采用电感耦合等离子体质谱(ICP/MS)法,结合内标技术,高效、快速地测定了土壤中Cu、Zn、Pb、Cd、Ni、Cr、Hg、As和Se 9种元素的有效态浓度.Cu、Zn、Pb、Cd、Ni、Cr、Hg的有效态采用0.1 mol/L NaNO3浸提,所得浸提液上机前预先稀释10倍;As和Se的有效态采用稀HCl浸提.结果表明,在测定所有空白、标准溶液及样品时均在线加入500 靏/L 45Sc/72Ge/209Bi内标溶液,有效地克服了基体效应、接口效应和仪器波动所产生的影响;0.15%(质量分数)NaCl\|1.0%(体积分数)HCl作为Hg标准溶液固定液,可保证1 靏/L Hg标准溶液7 d有效期;9种元素有效态的仪器检出限均在靏/L级以下,方法检出限<0.030 mg/kg,平均加标回收率为81%～121%,相对标准偏差为0.02%～1.21%.     

Difference between selenite and selenate in selenium transformation and the regulation of cadmium accumulation in Brassica chinensis

Environmental Science and Pollution Research - Se can regulate Cd accumulation and translocation in plants; however, such effects can be controversial because of the differences in plant species...     

Circular economy pattern of livestock manure management in Longyou,China

Journal of Material Cycles and Waste Management - The development of biogas programs in rural China has led to great economic, social, ecological and environmental benefits. The focus of this study...