青藏高原年降水量分区及变化特征

利用青藏高原 81个气象台站近 30来年的降水量资料 ,采用EOF、REOF、气候线性趋势分析以及累积距平法等方法 ,对青藏高原年降水量的时空分布特征及其异常进行分析。结果表明 :EOF分解的前三个主向量的累积方差贡献占总方差的 4 2 .8% ,地形特别是高原主体的阻挡和抬升作用对年降水量的空间变化影响显著 ;年降水量的时间变化在缓慢减少的过程中未发生突变现象 ;青藏高原年降水量的空间异常类型可分为高原中部区、西藏北部区、青海东部区、柴达木盆地区、高原东北区、中北部边缘区、高原西北区、西藏南部区、高原东南区共 9个区 ,其分区受地形和低涡影响较明显     

黄明在应急管理部党委会上强调:坚持底线思维 强化系统观念 全力防范化解重大安全风险

2021年3月15日,应急管理部党委书记黄明主持召开部党委会议,学习贯彻习近平总书记关于安全生产重要指示精神,深入剖析近期典型事故案例,研究部署当前重点工作。黄明强调,要深入贯彻新发展理念,强化底线思维,增强忧患意识,紧紧盯住重点行业领域系统施治、标本兼治,举一反三防范化解重大安全风险,推动实现更为安全的发展,有力维护人民群众生命财产安全和社会稳定。     

臭氧层耗损对对流层大气质量的影响和在中国的响应

平流层臭氧损耗导致透射到近地面的UV-B辐射的增加,加强了低对流层的能量来源,增强了大气氧化性和化学反应性,特别是加快O₃、颗粒物、酸性物质等二次污染物的生成和一些有机污染物的光解,加剧如光化学烟雾、酸沉降等城市和区域性的大气污染,从而改变对流层的大气组成和空气质量.在中国,UV-B的增加会对城市和区域的空气质量、酸雨污染以及青藏高原地区的环境产生重要的影响.      

Pollution characteristics and health risk assessment of benzene homologues in ambient air in the northeastern urban area of Beijing, China

Ambient benzene homologues were measured at a site in the northeastern urban area of Beijing, China, from August 24 to September 4, 2012 by SUMMA canister sampling followed by laboratory determination using cryogenic cold trap pre-concentration-GC-MS/FID, and their health risks were also assessed. Daily total benzene homologues ranged from 0.99 to 49.71 μg/m3with an average of 11.98 μg/m3. Benzene homologues showed higher concentrations in the morning and evening than that at noontime. Comparison with previous studies revealed a trend of decrease for ambient benzene homologues probably due to the efective emission control in Beijing in recent years. Vehicular exhaust was the main source while volatilization of paints and solvents also made substantial contributions. Health risk assessment showed that BTEX(benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene) and styrene had no appreciable adverse non-cancer health risks for the exposed population, while benzene has potential cancer risk of 1.34E-05. Available data from cities in China all implied that benzene imposes relatively higher cancer risk on the exposed populations and therefore strict control measures should be taken to further lower ambient benzene levels in China.     

青藏高原表土重金属污染评价与来源解析

为了解青藏高原表层土壤重金属的污染特征、空间分布及污染来源,沿东北-西南方向对青藏高原表土(0～20 cm)样品进行了采集,对土壤中的Ba、Cd、Co、Cr、Cu、Fe、Mn、Mo、Ni、Pb、Sb、Sc和Zn等13种重金属总量进行了分析,并利用主成分分析-绝对主成分分数-多元线性回归(PCA-APCS-MLR)受体模型初步定量解析了重金属的潜在来源.结果表明Cd和Sb均显著超标,分别是20世纪70年代青藏高原土壤背景值的2. 13与1. 52倍.富集因子(EF)、地累积指数(I_(geo))和Nemero综合指数(PN)分析同样表明青藏高原表土主要以Cd和Sb污染为主,但污染程度普遍不高.在空间分布方面,青藏高原中部、东南部及东北部均呈不同程度污染,但中部及东南部污染相对较重. PCA-APCS-MLR分析表明,青藏高原土壤重金属主要有3个来源,分别为自然、交通和采矿等综合因素. Co、Cr、Cu、Fe、Mn、Ni和Sc主要受自然因素影响,Ba、Cd、Mo和Pb主要受交通因素影响,Zn主要受自然和交通因素共同影响,Sb主要受采矿、自然和交通等综合因素影响.青藏高原土壤重金属污染防治过程中应着重考虑受交通、采矿等综合因素影响下的Cd和Sb污染.     

青藏高原纳木错流域水体总汞的时空分布特征

为研究青藏高原纳木错流域水体中总汞的时空分布特征,于2007～2010年对纳木错湖表层水及入湖河水进行了采样,检测了其总汞浓度,并分析了总汞浓度与降水量、河水径流量等的关系.结果表明,纳木错表层湖水和河水中的总汞质量浓度均值分别为(1.09±0.73)ng.L-1和(2.87±2.59)ng.L-1,显著低于受到汞污染的水体.近岸带湖水的总汞浓度在季风期远大于非季风期,而其浓度水平和空间变化明显大于湖心区.河水的总汞浓度季节变化明显,表现为季风盛期最高且波动最大,而季风期后最低,这与降水量变化趋势基本一致.对你亚曲的定点观测表明,河水总汞浓度的时间变化与径流量一致.入湖河流总汞浓度的空间分布特征在不同的时间表现不同,这可能是由河流的流域面积、流域内土壤汞本底值及补给方式的差异引起的.     

Effects of elevated CO2 concentration and nitrogen supply on biomass and active carbon of freshwater marsh after two growing seasons in Sanjiang Plain, Northeast China

An experiments were carried out with treatments differing in nitrogen supply (0, 5 and 15 g N/m²) and CO₂ levels (350 and 700 μmol/mol) using OTC (open top chamber) equipment to investigate the biomass of Calamagrostis angustifolia and soil active carbon contents after two years. The results showed that elevated CO₂ concentration increased the biomass of C. angustifolia and the magnitude of response varied with each growth period. Elevated CO₂ concentration has increased aboveground biomass by 16.7% and 17.6% during the jointing and heading periods and only 3.5% and 9.4% during dough and maturity periods. The increases in belowground biomass due to CO₂ elevation was 26.5%, 34.0% and 28.7% during the heading, dough and maturity periods, respectively. The responses of biomass to enhanced CO₂ concentrations are differed in N levels. Both the increase of aboveground biomass and belowground biomass were greater under high level of N supply (15 g N/m²). Elevated CO₂ concentration also increased the allocation of biomass and carbon in root. Under elevated CO₂ concentration, the average values of active carbon tended to increase. The increases of soil active soil contents followed the sequence of microbial biomass carbon (10.6%) > dissolved organic carbon (7.5%) > labile oxidable carbon (6.6%) > carbohydrate carbon (4.1%). Stepwise regressions indicated there were significant correlations between the soil active carbon contents and plant biomass. Particularly, microbial biomass carbon, labile oxidable carbon and carbohydrate carbon were found to be correlated with belowground biomass, while dissolved organic carbon has correlation with aboveground biomass. Therefore, increased biomass was regarded as the main driving force for the increase in soil active organic carbon under elevated CO₂ concentration.     

向烧烤炉中添酒精烧人更烧心

<正>大学时光本是人生最美好的时刻,然而由于这次意外,她的人生轨迹发生了巨大转变,或许再也无法重返校园。现在再去后悔已毫无意义,悲剧过后,更需反思。烧烤店这样一种行业,明火比较多,隐患无所不在,安全、防范意识应该比其他店铺高才对。对店员的培训应该更具体、更详细,添加酒精更是烧烤店必不可少的,也是安全隐患较大的,烧烤店应该额外注意,多次强调。还要准备更加充分的灭火器材,这样才能保证顾客,还有店     

青海湖会成为第二个罗布泊吗?

被人们誉为青藏高原蓝宝石的青海湖，由于受长期的干暖气候和人类经济活动等的影响，目前正面临着越来越严重的沙漠化威胁。     

青藏高原水体及盐湖沉积物中氟的分布规律

本文主要对青藏高原的各类水体(盐湖、河水、井水、泉水及雪水)和柴达木盆地昆特依盐湖,尕斯库勒盐湖的各类沉积物(石盐、石膏、泥岩、粉砂和砂岩等)中氟的分布规律做了初步研究,发现地表水体中的氟主要受构造地质背景以及气候、水体盐度所制约,沉积物中水溶氟的含量与沉积物颗粒大小成反比,同类沉积物中氟的变化与其沉积时水体的古盐度成正比。