Prevention and Control of Continuous Cropping Obstacle of Watermelon by Reductive Soil Disinfestation (RSD)

This study aimed to explore whether reductive soil disinfestation (RSD) is an effective method of controlling continuous cropping obstacle of watermelon. Samples of watermelon continuous cropping soils were treated by RSD in laboratory tests and pot experiments in August 2015 and from December 10, 2016 to April 10, 2017. The soil samples for the laboratory test were divided into 16 groups, and each group comprised three parallel samples of 100 g (dry soil weight). Except for the original and control (CK) samples, the 14 other groups of soil samples were treated with different combinations of 1% or 3% alfalfa powder, 1% or 3% ammonia (NH₃) water, and 1% or 3% acetic acid. The soil samples were placed inside size-five self-styled plastic bags and incubated in a constant-temperature biochemical incubator at 35°C for 14 days after blending, flooding, and sealing. Seven groups of soil samples were designed for the pot experiments based on the laboratory test results. Each group consisted of 30 parallel samples of 3 kg (dry soil weight). These samples were incubated outdoors for 4 months after mixing with alfalfa powder and/or NH₃ and/or acetic acid according to the experimental design, blending, flooding, and sealing. Watermelon seedlings were planted in the air-dried soil samples from May to July in 2017. The results showed that the pH of the soil samples treated by RSD were elevated except for those samples with acetic acid. In addition, the electrical conductivities of the soil samples treated by RSD were effectively adjusted. The presence of soil-borne pathogenic Fusarium oxysporum f.sp. niveum was significantly suppressed (p < 0.05) in soil samples treated by RSD, and the incidence and mortality rate of watermelons planted in these samples were remarkably lower than those planted in the CK and flooded CK soil samples. Therefore, continuous cropping obstacle of watermelon can be controlled by RSD.     

东海内陆架EC2005孔重矿物组合特征及其物源指示意义

为探讨东海内陆架17.3ka BP以来的重矿物含量变化及其物源指示意义,对东海内陆架南部泥质沉积中心EC2005孔的沉积重矿物进行了鉴定和分析。结果表明:(1)在0.063—0.25mm粒级沉积物中,重矿物含量平均值为27.3%,变化范围为3.7%—89.6%,重矿物含量较高的部分均出现在自生黄铁矿富集的层位;(2)片状矿物、含铁氧化物、角闪石族矿物、绿帘石族矿物、白云石、辉石族矿物、变质矿物、蚀变矿物和自生黄铁矿占重矿物颗粒总数的96.0%以上,但其含量变化很大;(3)以重矿物分布特征为依据将岩心划分为Ⅰ—Ⅴ五个沉积层段,各层段对应的特征矿物分别为片状矿物、白云石、片状矿物、自生黄铁矿和榍石。结合粒度、AMS14C年代及西太平洋海平面变化等数据对物源进行分析,结果表明:自17.3ka BP以来,EC2005孔沉积物源主要是长江,其次还可能受到瓯江等浙江沿岸河流所输运物质的一定影响。     

Toxic Effects of Copper‐Based and Synthetic Organic Pesticides on Activated Sludge

Toxic effects of five commonly used pesticides on the biomass of a municipal activated sludge system were determined on the basis of the reduction in the oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR). Toxicity levels of the selected pesticides were determined by employing a modified OECD 209 (Organisation for Economic Cooperation and Development) method which was performed as batch experiments using a respirometer. Copper sulphate (CuSO₄ · 5 H₂O), copper oxychloride (Cu₂Cl(OH)₃), copper calcium oxychloride (CaCu₃Cl₂(OH)₆) as copper‐based pesticides and chlorsulphuron (C₁₂H₁₂ClN₅O₄S), 2,4‐dichlorophenoxyacetic acid (2,4‐D) (C₈H₆Cl₂O₃) as synthetic organic pesticides were selected for the experiments. The EC₅₀ values were determined to be 78, 249 and 281 mg/L for CuSO₄ · 5 H₂O, Cu₂Cl(OH)₃ and CaCu₃Cl₂(OH)₆, respectively. Corresponding values for C₁₂H₁₂ClN₅O₄S and 2,4‐D were 860 and 3664 mg/L, respectively. Results indicated that toxicity effects of copper‐based pesticides were higher than that of synthetic organic pesticides. CuSO₄ · 5 H₂O was found to exert the highest toxicity among the copper‐based pesticides, whereas, C₁₂H₁₂ClN₅O₄S was determined to be the most toxic among the organic pesticides on activated sludge biomass.     

中国枢纽机场时间延误成本估算与航线影响分析及中美比较

论文借鉴欧洲控制研究中心以机型为基本单元的延误成本估算模型(简称EC估算模型)及其相关算法,以EC估算模型为基础,补充机型配置比和引入航班执行阶段作为影响参数,估算了24 h中国枢纽机场单位时长延误成本和时间延误总成本,进行了时间延误成本的航线影响分析及中美比较,得到如下结论：① 区域枢纽机场时间延误成本普遍低于复合枢纽机场,但前者中机型单位时长延误成本和登机口成本均高于后者,从中可透视出其分别与中国航线网络中心集聚、航空地理市场(机型配置)需求和航线网络模式应用的密切相关;枢纽机场空中维持成本在时间延误总成本中占比最大,说明中国空中廊道设置存在缺陷。② 枢纽机场间(航线)以及枢纽机场与非枢纽机场之间(航线)时间延误总成本的差异深受航线属性所影响,其根本又在于航空地理市场(机型配置)需求以及空中廊道参与机场位置。③ 中美枢纽机场和枢纽机场间(航线)时间延误成本均有较大差异,主要表现为中国空中维持成本远高于美国,这是由空中廊道特征路径宽度和航迹交叉点数量2个因素造成的。     

T639和EC模式对内蒙古主要天气系统的预报性能检验

利用2012年T639和EC模式500hPa高度场预报产品及ECMWF客观再分析资料,采用天气学检验方法,对内蒙古主要天气影响系统之西风槽、贝加尔湖冷涡、蒙古冷涡和东北冷涡数值产品的预报性能进行检验。检验结果表明:T639和EC模式产品对内蒙古影响系统具有较好的预报性能,36h内的预报性能更为显著。EC模式产品预报准确率优于T639模式产品,但对内蒙古东部地区影响系统的预报稳定性相对较差。T639模式产品在36h的预报能力比较高,对影响系统的生成时间、槽线位置、移动速度及中心强度4项检验指标预报准确率均在80%以上。EC模式预报产品,48h内对影响系统4项检验指标预报准确率均在80%以上。随着预报时效延长,T639和EC模式产品预报能力均有所下降。两套模式产品与实况相关系数空间分布在各时效均具有显著的相关关系,并且对应相关系数空间分布,T639和EC模式产品标准差的大值中心与相关系数的低值中心基本一致。     

一次重秋风天气过程的EC96h500hPa预报场与实况场的对比检验

对2002年一次重秋风天气的EC96h 500hPa预报场及EC的850hPa温度96h预报与实况场进行了对比分析，发现EC500hPa 96h预报场对大的环流形势预报较准确，EC的850hPa温度96h预报除个别时次误差较大外，其余时次的温度场预报均较成功，可以提前4d对一些重大天气过程作出准确地预报，大大提高了中期预报水平。     

The EU as a frontrunner on greenhouse gas emissions trading: how did it happen and will the EU succeed?

The objective of this paper is first to provide empirical evidence of what can be seen as a rather remarkable change in EU’s position on the use of greenhouse gas (GHG) emissions trading (ET) in climate policy, from the role of a sceptic in the run-up to Kyoto towards more of a frontrunner. The paper argues that there is a synergistic and multilevel mix of explanatory factors for this “U-turn”, including developments at the international, EU, Member State, sub-national, and even down to the personal level. Second, the paper explores and discusses the philosophy behind the Commission’s proposal for a directive on GHG ET. Third, the paper examines the prospects for ‘success’ of a scheme for EU-wide ET using a multifaceted set of metrics. In brief, we argue that output success—the chances for having a directive adopted—hinges on the resolution of two key issues. First, whether the preliminary phase is to be mandatory or voluntary, and second, incompatibilities with domestic ET schemes. Outcome success—steering and cost-effectiveness—will in turn depend on factors like the coverage of the scheme and inclusion of project-based credits, while more long-term political implications hinges on the successful adoption and operation of the scheme.

“The Proposal on emissions trading represents a major innovation for environmental policy in Europe. We are de facto creating a big new market, and we are determined to use market forces to achieve our climate objectives in the most cost-conscious way […]. The emissions trading system will be an important cornerstone in our strategy to reduce emissions in the most cost-effective way”.

Environment Commissioner Margot Wallström.     

基于EC细网格数值预报产品的太阳辐照度订正技术

太阳辐照度与光伏电站发电功率密切相关,其预报的准确性直接影响发电功率预报的准确性。根据光伏电站太阳辐照度实况、气象站实况、WRF(Weather Research and Forecast Model)模式辐照度预报、EC细网格数值预报以及太阳理论辐照度,利用逐步回归法开展太阳辐照度预报订正研究,得到以下结论:①太阳辐照度实况与太阳理论辐照度的比值与EC细网格数值预报中气象要素的相关性优于太阳辐照度实况与气象要素的相关性;②不同时刻影响太阳辐照度的气象因子存在差异,通过逐步回归法建立不同时刻太阳辐照度预报模型;③在非晴天情况下,回归预报辐照度相对均方根误差比WRF模式预报辐照度降低10%左右,减小了辐照度预报误差。该研究成果在光伏电站的新能源数值预报服务中有一定的应用价值。     

TRIME-T3用于盐碱地土壤含水量测定的试验研究

以陕西省富平县卤泊滩盐碱地改良区为例,在其上游地段选取两块农田为研究对象,布置典型观测断面并埋设测管,运用TRIME-T3法和烘干法对观测断面土壤剖面含水量进行测定,并同步测定土壤含盐量。对两种方法测得的土壤含水量进行对比分析,研究土壤盐分对TRIME-T3法测定的土壤含水量影响以及该方法在盐碱地农田土壤剖面含水量测试中的应用。研究结果显示：（1）TRIME-T3法测量值较烘干法值偏大,但两者之间有较高的相关性,回归分析结果表明可以用y=0.866 3x+0.754 5的线性函数进行校正,校正后的TRIME-T3测量值中将有94.4%的值接近土壤含水量真实值。（2）通过对校正函数进行实例验证,结果表明TRIME-T3标定曲线值与烘干法测定值非常接近,绝对误差<1 cm³·cm^-3,相对误差在5%以下,表明TRIME-T3法通过一定的校正后可以很好地表达该盐碱地农田土壤剖面含水量信息。（3）通过对TRIME-T3测定的含水量与相应含盐量进行分析,发现两者之间的相关性并不显著,表明该方法可适用于盐碱地农田土壤剖面含水量测定。该研究结果可为类似地区盐碱地土壤剖面水分测定技术（TRIME-T3）的应用提供科学依据和理论参考。