A cointegration and causality analysis of copper consumption and economic growth in rich countries

The paper examines the copper consumption-economic growth nexus for 16 rich economies from the period 1966 to 2010. Various generations of panel unit root and cointegration tests are applied. Both series are found to be integrated of order one. Evidence of cointegration is found especially when controlling for breaks and long-run cross-sectional dependence. Causality is investigated using a vector error-correction mechanism (VECM) framework. At individual level, unidirectional causality running from economic growth to copper consumption is unraveled for Finland, France and UK in the long-run. Unidirectional causality is also found running from copper consumption to economic growth for Spain. Long-run bi-directionality between economic growth and copper consumption is found for Belgium, Greece, Italy, Japan and South Korea. The neutrality hypothesis holds for Australia, Austria, Canada, Netherlands, Portugal, Sweden and USA in the long-run. Taken as a whole, panel causality test reveals a long-run unidirectional causality running from economic growth to copper consumption.     

Iron ore spot price volatility and change in forward pricing mechanism

To examine the impact of the change in forward pricing mechanism on the volatility of iron ore spot prices, we model the iron ore daily price of Platts IODEX from October 7, 2008 to September 21, 2012. The identified iron ore spot price tends to be less volatile after the introduction of quarterly pricing mechanism. Our main approaches are as follows: (i) to decompose the spot price of Platts IODEX into two subsamples and relate the result of the structural break to the date of the switch in the iron ore forward pricing mechanism; (ii) to apply the EGARCH (1, 1) model to simultaneously capture the long memory and the asymmetric effect on the volatility of the iron ore spot price; and (iii) to delineate the news impact curve to further interpret the asymmetric effect.     

紫外诱变选育优势好氧反硝化菌株

采用紫外照射的方法对好氧反硝化菌株进行诱变,从中筛选出一株优势正突变菌株ZR43,并对其形态、生长条件及反硝化能力进行了研究.结果显示,相对于亲本R1,菌株ZR43对亚硝态氮的积累量大幅度降低,从75.05mg·L-1减少到17.42mg·L-1.TN去除率提高了18%.菌株形态为球菌.最佳生长条件:温度为30℃、pH为8、C/N为10、以丁二酸为最佳碳源.C/N对菌株ZR43的好氧反硝化能力影响很大,当C/N大于8时,总氮的去除率均达到32%以上.     

Land-use induced changes in topsoil organic carbon stock of paddy fields using MODIS and TM/ETM analysis: A case study ofWujiang County, China

Topsoil soil organic carbon (SOC) that plays an important role in mitigating atmospheric carbon dioxide (CO_2) buildup is greatly affected by human activities.To evaluate the influence of land-use changes on SOC stocks in paddy soils,a new algorithm was developed by integrating MODIS (moderate resolution imaging spectral-radiometer) and TM/ETM data for timely monitoring the land-use change in Wujiang County.Thereafter,the land-use class-maps derived from MODIS and TM/ETM analyses were further used to est...     

云南白水台现代钙华δ~(13)C的季节和空间变化特征研究

对云南白水台引水渠道中钙华沉积的δ13C值分析发现,白水台引水渠道中钙华δ13C值与降雨量有着较好的线性负相关关系,这一发现为下一步利用当地古钙华的δ13C数据重建古降水量提供了实验与理论基础。而造成雨季钙华δ13C值偏负的原因是雨后形成的低δ13C值的坡面流对高δ13C值的渠道水的稀释效应,降低了渠道水的δ13C值。水中贫13C的CO2逸出至大气是下游方向钙华δ13C偏正的主要原因。     

Fe—C微电解法＋H2O2组合工艺处理硝基苯废水的实验研究

利用废铁屑对硝基苯废水进行预处理,可以使废水中的硝基苯转化为苯胺,然后在废水中加入H2O2,使H2O2与废水中的Fe^2＋构成Fenton试剂,反应生产OH·自由基,OH·自由基具有强烈的氧化性,将苯胺和硝基苯中的苯环打开,形成断链,再进一步将其矿化分解。     

Carbon-14 transfer into rice plants from a continuous atmospheric source: observations and model predictions

Carbon-14 ((14)C) is one of the most important radionuclides from the perspective of dose estimation due to the nuclear fuel cycle. Ten years of monitoring data on (14)C in airborne emissions, in atmospheric CO(2) and in rice grain collected around the Tokai reprocessing plant (TRP) showed an insignificant radiological effect of the TRP-derived (14)C on the public, but suggested a minor contribution of the TRP-derived (14)C to atmospheric (14)C concentrations, and an influence on (14)C concentrations in rice grain at harvest. This paper also summarizes a modelling exercise (the so-called rice scenario of the IAEA's EMRAS program) in which (14)C concentrations in air and rice predicted with various models using information on (14)C discharge rates, meteorological conditions and so on were compared with observed concentrations. The modelling results showed that simple Gaussian plume models with different assumptions predict monthly averaged (14)C concentrations in air well, even for near-field receptors, and also that specific activity and dynamic models were equally good for the prediction of inter-annual changes in (14)C concentrations in rice grain. The scenario, however, offered little opportunity for comparing the predictive capabilities of these two types of models because the scenario involved a near-chronic release to the atmosphere. A scenario based on an episodic release and short-term, time-dependent observations is needed to establish the overall confidence in the predictions of environmental (14)C models.     

广吸力范围内国道G310路基黄土水力力学特性试验研究*

为探讨广吸力范围内国道G310路基黄土水力力学特性,采用WP4C仪、压力板法、滤纸法和蒸汽平衡法对其开展持水特性试验,用全自动直剪仪对具有不同初始干密度和不同吸力的试样进行强度特性试验,并结合压汞试验进行微观分析。根据上述试验数据提出快速预测抗剪强度公式。试验结果表明:随着初始干密度的增加,积聚体间孔隙体积发生收缩,积聚体内孔隙占主要作用。广吸力范围内试样的土水特征曲线随着初始干密度增大而向右上方偏移,而孔隙比随吸力的增加基本不变。抗剪强度随着初始干密度增大而增大,且随着吸力增加而增加。应力-应变曲线低吸力范围呈应变硬化现象,高吸力范围呈应变软化现象。利用Khalili & Khabbaz模型预测的抗剪强度值与实测值非常接近,因此该模型可用于预测广吸力范围内非饱和黄土的抗剪强度。     

复合乳化剂对乳化炸药热安全性影响研究

为了探究复合乳化剂对乳化炸药热分解特性的影响,使用C80微量热仪通过MC法研究了乳化剂A(SP80)和乳化剂B(T152)作为单一乳化剂和复合乳化剂(加入比例为1:1、1:2、2:1)制备的乳化炸药。以升温速率为0.5K/min时的C80热流速曲线为基础来求解5种炸药热分解反应的表观活化能(Ea)、指前因子(lnA)等热安全参数。结果表明,使用复合乳化剂制备的乳化炸药稳定性均高于使用单一乳化剂的乳化炸药。采用复合乳化剂可导致乳化剂分子间排斥作用降低,使分子排列更紧密,增加了界面膜的致密性。当加入的乳化剂比例为m(SP80):m(T152)=1:2时,由于两种乳化剂相互作用形成致密的复合界面膜,其稳定性最高。     

短程反硝化的启动及多参数优化下NO2--N积累特性

采用本实验室长期培养的厌氧（S-A）、好氧（S-O）和交替厌氧/好氧（S-A/O）活性污泥为种泥,分别启动短程反硝化SBR反应器R1、R2和R3,控制进水C/N比为3,缺氧搅拌时间为1h时,在第15d、7d和4d亚硝酸盐积累率（NAR）分别达到75.34%、84.51%和86.23%.选取C/N比、初始pH值、缺氧搅拌时间和初始NO₃^--N浓度对NAR进行四因素三水平响应面实验,方差分析结果表明,以上因素对NAR均有显著影响（P<0.05）,模型R²为0.983.通过模型预测得最佳运行条件：C/N比为3.16,初始pH值为8.51,缺氧搅拌时间为1.27h,初始NO₃^--N浓度为60mg/L的条件下,NAR高达91.32%.