Industrial sulfur demand: Analysis and prospect

Weak growth in industrial (nonagricultural) U.S. sulfur demand has slowed the growth of total sulfur demand. Evaluating prospects for trend reversal is hampered by inadequate detailed data published by industry, and the lack of an easily measured demand component that reliably depicts total demand. In this article, I try to overcome this data deficiency by constructing an industry-by-industry breakdown of published data on total industrial sulfur consumption. Industrial sulfur consumptions were estimated from data on consuming industry activity, characteristics of relevant industrial processes, and analyses of the conditions affecting choice among alternative industrial processes. Subjective projections of the industry detail data are presented.In addition to cyclical factors, past declines in industrial sulfur demand were due to replacement of sulfur-using industrial processes with alternative processes that use less or no sulfur to achieve production cost economies. In some, but not all, cases, changeovers of process were in response to impositions of environmental-related requirements. The demand for industrial sulfur has good prospects for positive growth as shrinkage of some markets reaches natural limits and total market growth comes increasingly to be dominated by markets with positive growth prospects. Positive growth has been generated by environmentally related regulation in several markets, such as petroleum alkylation and copper production.     

渗透蒸馏浓缩柠檬酸

渗透蒸馏是适用于浓缩生物制品的一种新型膜过程．以ＮａＣｌ—柠檬酸稀溶液为研究体系，对渗透蒸馏的传质过程进行了研究，实验结果表明，水通量大于６７Ｋｇ／ｍ２·ｄ，柠檬酸可由３００ｇ／Ｌ浓缩到５００ｇ／Ｌ以上，同时还探索了渗透蒸馏和膜蒸馏浓缩柠檬酸的集成膜过程．     

永春桃东温泉地震预报效果分析

1986年以来台湾省花莲、菲律宾(?)、福建省南日岛海域及蓬壶发生过几次地震,发震前桃东温泉井的水量、水氡含量均有明显的规律性变化,可作为短期地震预报的重要信息。笔者认为其变因与温泉所处的地质构造及地貌环境密切相关。     

黑龙江省冷硅锶质矿泉水赋存规律和形成机制的探讨

近年来,黑龙江省境内发现了多处含硅质或硅锶质天然矿泉水,这种矿泉水属珍贵的矿泉水类型之一。本文就冷硅或硅锶质矿泉水的赋存规律和形成机制提出初浅认识。     

甲基异丁基酮负载泡塑富集—原子吸收测定岩矿中痕量金银铊镉

研究了多种负载泡塑对Au、Ag、Ti、Cd的富集行为。提出了在HCI-KI-抗坏血酸介质中用甲基异丁基酮(MIBK)负载泡塑同时萃取,然后用2％硫脲-1％HCl解脱的富集方法,并采用火焰原子吸收连续测定地质样品中痕量Au、Ag、Tl和Cd,方法的测定下限(μg/g)分别为:0.2g、0.05、0.20和0.04。     

中国主要类型土壤若干重金属临界含量和环境容量的区域分异

本文通过8年研究结果,归纳、分析了中国的砖红壤、赤红壤、红壤、紫红土、黄棕壤、棕壤、黑土、褐色土、灰钙土等主要类型土壤中Cd、Cu、Pb、As的土壤临界含量和土壤环境容量分布特征,发现他们大多数或在相当大的程度上随土壤类型由南向北、由东向西的分布而分异,具有一定的地带性分异特征。Cd、Cu是由南到北、由东向西增大;而As则相反,由南到北、由东向西减小。     

Nitric oxide concentration near the mesopause as deduced from ionospheric absorption measurements

Nitric oxide concentration in the upper D-region is estimated by comparing empirically derived ratios of Lyman- and X-ray contributions to the total radio-wave absorption (2775 kHz. A3 method) in medium latitudes with model ratios. Typical NO concentrations are about 8.5×10¹³ m^–3, at 90 km and 6.5×10¹³ m^–3 at 78 km. These values are higher than generally accepted model NO concentrations, but lie within the broad range of experimental values.     

Linear spectral unmixing algorithm for modelling suspended sediment concentration of flash floods,upper Tekeze River,Ethiopia

Flash floods are the highest sediment transporting agent,but are inaccessible for in-situ sampling and have rarely been analyzed by remote sensing technology.Laboratory and field experiments were done to develop linear spectral unmixing(LSU) remote sensing model and evaluate its performance in simulating the suspended sediment concentration(SSC) in flash floods.The models were developed from continuous monitoring in the laboratory and the onsite spectral signature of river bed sediment deposits and flash floods in the Tekeze River and in its tributary,the Tsirare River.The Pearson correlation coefficient was used to determine the variability of correlations between reflectance and SSCs.The coefficient of determination(R2) and root mean square of error(RMSE) were used to evaluate the performance of the generated models.The results found that the Pearson correlation coefficient between SSCs and reflectance varied based on the level of the SSCs,geological colors,and grain sizes.The performance of the LSU model and empirical remote sensing approaches were computed to be R2=0.92,and RMSE=±0.76 g/1 in the Tsirare River and R2=0.91,and RMSE=±0.73 g/1 in the Tekeze River and R2=0.81,RMSE=±2.65 g/l in the Tsirare river and R2=0.76,RMSE=±10.87 g/l in the Tekeze River,respectively.Hence,the LSU approach of remote sensing was found to be relatively accurate in monitoring and modeling the variability of SSCs that could be applied to the upper Tekeze River basin.     

Modeling the effect of sediment concentration on the flow-like behavior of natural debris flow

The rheological behavior of natural slurries consisting of fine-grained, reconstituted debris-flow deposits on pyroclastic terrains having different solid concentrations (ranging from 30 to 42%) has been investigated using a rotational rheometer equipped with a vane rotor system. Experiments were done by increasing the applied shear stress step by step; then a decreasing stress ramp was applied following the same shear stress levels. The slurry mixtures exhibit a typical yield-stress fluid behavior with a static yield stress larger than the dynamic yield stress. In the range of the shear rate corresponding to the flow-like behavior the slurry mixtures behave as a dilatant fluid at lower grain concentrations and as a pseudoplastic fluid in correspondence with the higher grain content, showing a strong discrepancy from the Bingham idealization. The rheological behavior is better interpreted by a Herschel-Bulkley model, whose rheological parameters strongly depend on the granular concentration. Therefore, a generalized Herschel-Bulkley model accounting for the bulk sediment concentration effect is proposed.     

基于GMS软件对某矿区松散层孔隙水污染的数值模拟研究

以云南某矿区为研究对象,在详细调查区域水文地质条件和已有资料的基础上,结合调查区监测井,利用GMS软件建立研究区域地下水水流场模型和溶质运移模型。模型计算了在合理误差范围内的水流场模型并预测了硫酸盐在持续泄漏730d、180d后切断泄漏源,硫酸盐的迁移过程。研究结果表明:随着持续泄漏时间的增加,调查区域北部边界附近受到污染的浓度越高、污染范围越广,超标的污染物在北部边界区域进入岩溶含水层,遇到岩溶带会加速污染物向下游运移,破坏下游水质、危及下游村庄饮用水安全。