ICP-AES内标法测定铜精矿中的铅、砷、镉含量

以锗为内标,用电感耦合等离子体原子发射光谱法同时测定铜精矿中铅、砷、镉元素的含量,有效地消除了仪器及环境波动等非光谱干扰的影响。被测元素在0.5-10.0mg/L的范围内具有良好的线性;铅、砷、镉元素检出限分别为为10.6μg/L、10.8μg/L、6.0μg/L,测试值相对标准偏差分别为1.31%、0.93%、1.05%。同样条件下,测试结果优于直接法测试结果。     

The King’s currency: Gustav II Adolf and the copper standard (1619–1632)

King Gustav Adolf ruled Sweden from 1611, until his death on the battlefield in 1632. The king was at war in Russia, Poland, and Germany, throughout this period. Sweden was a poor and backward country; the crown struggled to pay and feed its armies. The Swedish crown did, however, operate the largest copper mine in Europe, and enjoyed a near monopoly on exports to the continent. In 1624 the crown began a bimetallic standard by minting copper coins alongside the existing silver standard. Eminent scholars from the last century, including Eli F. Heckscher, wrote that the crown’s intention was to manipulate the copper prices in Europe by restricting supply. The crown planned to consume substantial quantities of copper in the royal mints instead of exporting copper as ingot. I will seek to demonstrate that the king had another, parallel, purpose for establishing the copper standard. In addition to influencing the price of copper abroad, he also sought a rapid and simple means of turning copper into a fungible currency, which he could use to sustain his armies. Alongside manipulation, therefore, the king’s motive was to improve his liquidity and cash flow to fuel his military and political ambitions.     

铜酞菁生产企业生产过程中的废水治理探讨

铜酞菁生产企业生产过程中的废水对环境产生了严重影响,文章就铜酞菁生产企业生产过程中的废水治理进行了探讨。     

逆王水溶样冷原子吸收光谱法测定铜精矿中的汞

研究了一种用逆王水溶样冷原子吸收光谱测定铜精矿中汞的方法.铜精矿用逆王水消化后用测汞仪测定其中的秉含量.测定结果的相对标准偏差小于5%,回收率在91%～106%之间.与GB/T 3884.11-2005测汞方法比,操作简单容易.     

国标短碘量法测定铜精矿中铜含量的方法改进研究

对国家标准GB/T 3884.1-2000中短碘量法测定铜精矿中铜含量的分析方法进行了研究和改进。结果表明：在前处理过程中,盐酸和硝酸可同时加入;在砷含量和锑含量较低时,溴素可不加或少加;在滴定过程中,淀粉指示剂可由更灵敏的聚乙烯醇指示剂代替。采用本文所改进的方法可使分析操作更加方便,减小有毒有害试剂对人员的伤害,还能提高实验的准确度和显色灵敏度。     

Exchange Rate and Inflation Dynamics in a Resource Rich Setting: The Case of Zambia

This paper investigates the relationship between copper prices, the exchange rate and consumer price inflation in Zambia using a structural vector autoregression with quarterly data for 1995–2014 and a combination of sign and zero restrictions to identify relevant global and domestic shocks. The paper makes two contributions. First, it provides new measures of exchange rate pass through (ERPT), based on less restrictive assumptions than previous estimates, to show how changes in the value of the kwacha are reflected in changes in consumer prices (distinguishing food and non‐food inflation). Second, the ERPT is disaggregated to demonstrate that measured ERPT depends on the nature of the shock, with implications for policy responses. Although the price of copper is the most important driver of the exchange rate, the fluctuations it caused are associated with a low pass‐through of about 7% (consistent with a period of relatively low inflation). Exchange rate fluctuations caused by monetary shocks, in contrast, come with a pass‐through of up to 25% (and even more for food prices). A fast response by monetary authorities can mitigate the adverse effects of exchange rate shocks.     

我国农产品出口市场结构及依赖性研究

在农产品出口市场比较集中的情况下,为了有效地降低出口市场风险,需要考察农产品出口与主要进口市场之间的依赖关系,以明确国际市场上的可靠需求者。通过考察中国对某国农产品出口额及中国农产品出口总额、该国从中国进口农产品数量及该国农产品总进口数量及其两国总体贸易的平衡状况,计算出中国对各出口市场的依赖系数,作为我国农产品国际贸易依赖程度分析的参考。     

铜精矿取制样及储存过程中铜含量变化研究

本文用智利、加拿大和秘鲁三个矿山中的九个样品,针对铜精矿取样、制样及储存过程中铜含量的变化情况进行研究。结果表明,在样品取样试验和水分干燥试验中,未发现样品中的铜含量发生氧化,而在样品研磨试验和样品储存试验中,部分样品中的铜含量发生了变化,原因可能是这些样品中的铜与硫发生了氧化反应。通过本实验数据的分析找出铜精矿氧化的可能因素,氧气、水、温度、时间都是必要条件,而硫含量越高,发生氧化的趋势越明显。将这些分析结果应用于铜精矿的检验和贸易中,能更准确地反应铜精矿中计价元素的真实含量,减少贸易双方检验数据偏差以及贸易双方的争议。     

企业规模、市场结构与创新——来自不同行业的经验证据

本文利用2000~2003中国工业统计数据,选取其中的五个行业(电子、纺织、服装、化学和机械行业),研究企业规模、产业集中度等与创新的关系的行业差异。研究发现,企业规模、市场结构与创新之间一般不存在简单的线性关系。在不同的行业,它可以表现为U型或倒U型曲线。这种产业之间的差异表明,我们不能单纯地根据与企业规模有关的特性来解释企业创新。而对于产业结构,我们需要进行更加具体细致的调查和分析。单纯的产业集中度指标不足以完全反映产业的真实状况。     

Estimating Market Power in the US Copper Industry

Before 1978, most of the domestic copper production in the US and an important share of imports were traded at a price set by the major US producers. At the same time, the rest of the world was trading copper at prices determined in auction markets. This two-price system ended in 1978, when the largest US producers began using the Comex price of refined copper as a benchmark for setting their prices. Using this regime shift, I empirically test the competitive behavior of the US copper industry before 1978. The results show that copper prices were close to the levels predicted by a competitive model of the industry.