Explosion of lycopodium-nicotinic acid–methane complex hybrid mixtures

With the terms “complex hybrid mixtures”, we mean mixtures made of two or more combustible dusts mixed with flammable gas or vapors in air (or another comburent).In this work, the flammability and explosion behavior of selected complex hybrid mixtures was studied. In particular, we investigated mixtures of nicotinic acid, lycopodium and methane. We performed explosion tests in the 20-L explosion vessel at different overall (nicotinic plus lycopodium) dust concentrations, nicotinic acid/lycopodium ratios, and methane concentrations.An exceptional behavior (in terms of unexpected values of rate of pressure rise and pressure) was found for the complex hybrid mixtures containing lycopodium and nicotinic acid in equal amounts. This mixture was found to be much more reactive than all the other dust mixtures, whatever the dust concentration and the methane content.     

多时间尺度上研究中国近代气温变化规律

应用MODIS数据反演了过去10年中国气温及气温的空间分布特征,并基于气象数据重建了过去60年中国城市、郊区、农村及气象台周边地区冬季气温距平的时间序列,从多时间尺度上,详细分析了20世纪中国气温变化规律。结果发现：气象台气温记录可能受城市热岛效应影响;60年来我国气温呈震荡波动,波动小周期约为7a;从10年尺度上看,近60年来,年代际气温增加幅度最大的是20世纪90年代,21世纪初气温虽然仍处于暖期,但已经出现下降趋势。     

杭州G20峰会空气污染控制状况评估

为了实现杭州G20峰会（二十国集团财长和央行行长会议）期间的环境空气质量目标,2016年初开始长江三角洲地区尤其是浙江省加快推进大气污染防治行动,分区分时间节点实施多种污染控制措施.为了评估这些措施实施成效,利用WRF-Chem（Weather Research and Forecasting Model Coupled to Chemistry）模式对2015—2016年浙江省AQI（air quality index）、PM_2.5、SO₂等污染物浓度观测资料进行了模拟计算及分析.结果表明:①模拟计算显示,G20峰会期间各污控措施减排效果明显,核心区减排比例最大,严控区次之,管控区最小,4种污染物浓度减排比例从大到小顺序依次是SO₂、PM_2.5、NO_x和VOCs.②观测资料分析显示,G20峰会期间浙江省环境空气质量明显改善,但不同控制区改善状况不尽相同.与2015年9月、2016年8月相比,2016年9月核心区月均AQI的降幅约为35和25;严控区次之,AQI降幅约为20和15;管控区最弱,AQI降幅约为8和5.ρ（PM_2.5）情况与AQI相似,观测结果与模拟计算一致.③G20峰会期间日均AQI及各种污染物浓度振荡下降,9月5日降至最低值.9月4—5日杭州市和浙江省日均AQI分别为90、62和77、51,均在GB 3095—2012《环境空气质量标准》的二级标准限值以下;日均ρ（PM_2.5）分别为37、35 μg/m3和20、21 μg/m3,优于GB 3095—2012二级标准.④污控措施改变了大气中的首要污染物.以杭州市为例,2016年6—8月没有出现以PM_2.5为首要污染物的污染天气情况;7—9月没有出现以NO₂为首要污染物的污染天气情况,2015仅8月出现这种情况,10月出现跃升,日数占比高达60%左右;从4月开始以O₃为首要污染物的日数占比较往年呈更快的增长状态,7月出现最大值,并呈现与往年双峰型不同的单峰型结构.研究显示,除有利气象条件外,对污染源所采取的严格控制措施是杭州G20峰会取得良好效果的主要原因.      

Scenarios of large mammal loss in Europe for the 21st century

Distributions and populations of large mammals are declining globally, leading to an increase in their extinction risk. We forecasted the distribution of extant European large mammals (17 carnivores and 10 ungulates) based on 2 Rio+20 scenarios of socioeconomic development: business as usual and reduced impact through changes in human consumption of natural resources. These scenarios are linked to scenarios of land‐use change and climate change through the spatial allocation of land conversion up to 2050. We used a hierarchical framework to forecast the extent and distribution of mammal habitat based on species’ habitat preferences (as described in the International Union for Conservation of Nature Red List database) within a suitable climatic space fitted to the species’ current geographic range. We analyzed the geographic and taxonomic variation of habitat loss for large mammals and the potential effect of the reduced impact policy on loss mitigation. Averaging across scenarios, European large mammals were predicted to lose 10% of their habitat by 2050 (25% in the worst‐case scenario). Predicted loss was much higher for species in northwestern Europe, where habitat is expected to be lost due to climate and land‐use change. Change in human consumption patterns was predicted to substantially improve the conservation of habitat for European large mammals, but not enough to reduce extinction risk if species cannot adapt locally to climate change or disperse.     

Rare chromosome 20 variants encountered during prenatal diagnosis

A case with an uncommon heteromorphism in the centromeric region of chromosome 20, var (20) (cen, CBG 50), and a family with a pericentric inversion of chromosome 20, inv (20) (p11.23q11.21), are reported, both detected in amniotic fluid cell cultures. It appears that small pericentric inversions of chromosome 20 have a low risk of recombination.     

Further examples of trisomy-20 mosaicism in amniotic cell cultures

Amniotic fluid cultures from two patients showed trisomy-20 mosaicism. No trisomy-20 cells were found in a normal full term infant and in multiple tissue biopsies and fetal blood from a fetus after a termination of pregnancy. No definitive advice is yet possible for parents where trisomy-20 amniotic cell mosaicism is detected. Fetoscopy and fetal blood sampling are of no value and termination of pregnancy is not indicated by empirical evidence. Preferential trophoblastic non-disjunction (Kalousek and Dill, 1983) is discussed as a possible partial explanation for the variable occurrence and distribution of this type of mosaicism.     

Trisomy 20 mosaicism in prenatal diagnosis–a review and update

A total of 66 cases with prenatal diagnosis of trisomy 20 mosaicism was reviewed. Since the majority of cases (85 per cent) was associated with grossly normal phenotype and the abnormalities noted in 15 per cent of cases were inconsistent and rather non-specific, no causal relationship between trisomy 20 mosaicism and a specific malformation syndrome can be established. The possiblity of an association between an abnormal phenotype and a high percentage of trisomy 20 cells (> 60 per cent) must be considered preliminary and be viewed with caution. The fact that cells with trisomy 20 have not been recovered from blood cultures and were detected more frequently from specific fetal tissues, (such as kidney, rectum, oesophagus), and from placental tissues, suggests that trisomy 20 is more likely to be confined to certain fetal organs and to extra-embryonic tissues. This review calls for the collection of more data on all cases of trisomy 20 mosaicism diagnosed prenatally, in order to provide more accurate information to the prospective parents.     

Relationships of ozone formation sensitivity with precursors emissions, meteorology and land use types, in Guangdong-Hong Kong-Macao Greater Bay Area, China

Due to the influences of precursors emissions, meteorology, geography and other factors, ozone formation sensitivity (OFS) is generally spatially and temporally heterogeneous. This study characterized detailed spatial and temporal variations of OFS in Guangdong-Hong Kong-Macao Greater Bay Area (GBA) from 2012 to 2016 based on OMI satellite data, and analyzed the relationships of OFS with precursors emissions, meteorology and land use types (LUTs). From 2012 to 2016, the OFS tended to be NO_x-limited in GBA, with the value of FNR (HCHO/NO₂) increasing from 2.04 to 2.22. According to the total annual emission statistics of precursors, NO_x emissions decreased by 33.1% and VOCs emissions increased by 35.2% from 2012 to 2016, directly resulting in OFS tending to be NO_x-limited. The Grey Relation Analysis results show that total column water (TCW), surface net solar radiation (SSR), air temperature at 2 m (T2) and surface pressure (SP) are the top four meteorological factors with the greatest influences on OFS. There are significant positive correlations between FNR and T2, SSR, TCW, and significant negative correlations between FNR and SP. In GBA, the OFS tends to be NO_x-limited regime in wet season (higher T2, SSR, TCW and lower SP) and VOCs-limited regime in dry season (lower T2, SSR, TCW and higher SP). The FNR displays obvious gradient variations on different LUTs, with the highest in “Rural areas”, second in “Suburban areas” and lowest in “Urban areas”.     

Sustainability through system transformation: lessons from Finnish efforts

This special issue of the Journal of Cleaner Production addresses system transformation by examining progress, stumbling blocks and opportunities for sustainable consumption and production in a specific country, Finland, set within a global context. The articles present and analyse top-down policy efforts, bottom-up efforts by municipalities, activities by companies and actions by consumers. They provide material for discussions on the shift from sustainability planning to enhancing system transformation, on the implications of globalisation for system boundaries, on the transformation of complex systems, on learning processes and on methods of assessing transitions. Without providing a singular solution, the articles show that issues of sustainability should be explored in different ways within different contexts, and experimented with. There is a continuous need for transformations and reflexive learning, since conditions are likely to become very different, not least due to climate change. The notion of change and transformation will be high on the agenda of the Rio+20 conference, as will similar efforts to promote large-scale transformations of consumption and production.     

Damos: Twenty Years of Dredged Material Disposal Site Monitoring. Isn'st That Enough?

Since 1977, the US Army Corps of Engineers Disposal Area Monitoring System (DAMOS) has monitored New England's offshore dredged material disposal sites. DAMOS has shown that by using monitoring information to make management decisions, open water disposal of dredged sediments is possible with minimal environmental impact. Over the past two decades, DAMOS has answered many of the key questions about dredged material impacts. Yet the need for such a programme remains strong from both the technical and public interest perspectives. the programme continues to monitor projects that are extending our knowledge in the areas of deeper water capping, geotechnical behaviour of capping and capped materials, and biological response to contaminants. These investigations, along with the need for specific disposal site surveys, will continue to provide valuable technical information needed by the public, policy makers, and regulators to make critical decisions on dredged sediment management.