The crude oil market and the gold market: Evidence for cointegration,causality and price discovery

Given that the gold market and the crude oil market are the main representatives of the large commodity markets, it is of crucial practical significance to analyze their cointegration relationship and causality, and investigate their respective contribution, from the perspective of price discovery, to the common price trend so as to interpret the dynamics of the whole large commodity market and forecast the fluctuation of crude oil and gold prices.     

半干法烟气脱硫中SO2排放控制研究

以某135MW机组循环半干法脱硫系统的SO2控制为例,分析了循环半干法烟气脱硫系统中SO2排放控制问题,提出了一种基于前馈加反馈的SO2排放控制方案。     

Belowground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L./Picea abies [L.] Karst)

The effects of experimentally elevated O₃ on soil respiration rates, standing fine-root biomass, fine-root production and δ¹³C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O₃ under beech and spruce, and was related to O₃-stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O₃ on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O₃ regime. δ¹³C signature of newly formed fine-roots was consistent with the differing g_s of beech and spruce, and indicated stomatal limitation by O₃ in beech and by drought in spruce. Our study showed that drought can override the stimulating O₃ effects on fine-root dynamics and soil respiration in mature beech and spruce forests.     

铁炭复配修复地下水中NO_3~--N的条件研究

采用了铁炭复配修复地下水中NO3--N,探讨了实验条件对修复效果的影响。结果表明,在pH值近中性条件(初始pH 6.42)下,反应时间为1 h时NO3--N修复率达到60.85%;Fe/C=1∶1时介质最佳用量分别为4~5 g;Fe/C=1/1.5时修复率为72.80%;反应速率在高振荡强度下大于低振荡强度;氧化铜的催化效果最好,可使修复率提高7.5个百分点。铁炭复配介质修复地下水中NO3--N是有效可行的,修复率随反应时间的增加而提高,在Fe/C=1∶1时修复率与介质用量呈正相关,无限减小Fe/C比并不能无限提高修复率,振荡强度对修复具有显著影响,低振荡强度下的修复过程较高强度存在滞后现象,并非所有金属氧化物催化剂对铁炭修复NO3--N均有促进作用。     

Chemisorption and Physical Adsorption Roles in Cadmium Biosorption by Chlamydomonas Reinhardtii

The aim of this study was to investigate the mechanism of cadmium (Cd) adsorbed by microalgae Chlamydomonas reinhardtii (C.reinhardtii). The kinetic and adsorption isotherm of the process could be well described by mathematical models. Chemical modification experiments and Fourier transform infrared spectra indicated that carboxyl and amine groups were the important functional groups for adsorption of Cd. The maximum contribution of physical adsorption in the overall adsorption process was evaluated as 5.5%...     

Co-composting of Paper Mill Sludge and Hardwood Sawdust Under Two Types of In-Vessel Processes

Abstract

Recycling of organic residues by composting is becoming an acceptable practice in our society. Co-composting dewatered paper mill sludge (PMS) and hardwood sawdust, two readily available materials in Canada, was investigated using uncontrolled and controlled in-vessel processes. The composted materials were characterized for total C and N, water-soluble, acid-hydrolyzable, and non-hydrolyzable N, extractable lipids, and by Fourier Transform Infrared (FT-IR) spectrophotometry. In the controlled scale process, the loss of organic matter was approximately 65% higher than in the uncontrolled process. After undergoing initial fluctuations in N fractions during the first two days of composting, by the end of the process, concentrations of water-soluble N decreased while those of acid-hydrolyzable and nonhydrolyzable N increased in the controlled process, whereas in the uncontrolled process, water-soluble N increased, but N in the other two fractions decreased continuously, indicating that the biochemical transformations of organic matter were not completed. Data on extractable lipids and FT-IR spectra suggest that the compost produced from the controlled process was bio-stable after 14 days, while the uncontrolled process was not stabilized after 18 days. In addition, FT-IR data suggest the biological activity during composting centered mainly on the degradation of aliphatic structures while aromatic structures were preserved. The co-composting of the PMS and hardwood sawdust can be successfully achieved if aeration, moisture, and bio-available C/N ratios are optimized to reduce losses of N.     

Impact of carbon,oxygen and sulfur content of microscale zerovalent iron particles on its reactivity towards chlorinated aliphatic hydrocarbons

Zerovalent iron (ZVI) abiotically degrades several chlorinated aliphatic hydrocarbons (CAHs) via reductive dechlorination, which offers perspectives for in situ groundwater remediation applications. The difference in reactivity between ZVI particles is often linked with their specific surface area. However, other parameters may influence the reactivity as well. Earlier, we reported for a set of microscale zerovalent iron (mZVI) particles the disappearance kinetic of different CAHs which were collected under consistent experimental conditions. In the present study, these kinetic data were correlated with the carbon, oxygen and sulfur content of mZVI particles. It was confirmed that not only the specific surface area affects the disappearance kinetic of CAHs, but also the chemical composition of the mZVI particles. The chemical composition, in addition, influences CAHs removal mechanism inducing sorption onto mZVI particles instead of dechlorination. Generally, high disappearance kinetic of CAHs was observed for particles containing less oxygen. A high carbon content, on the other hand, induced nonreactive sorption of the contaminants on the mZVI particles. To obtain efficient remediation of CAHs by mZVI particles, this study suggested that the carbon and oxygen content should not exceed 0.5% and 1% respectively. Finally, the efficiency of the mZVI particles may be improved to some extent by enriching them with sulfur. However, the impact of sulfur content on the reactivity of mZVI particles is less pronounced than that of the carbon and oxygen content.     

碘掺杂Ti02可见光光催化性能研究

在低于100℃温度条件下,采用溶胶一凝胶法以钛酸正丁酯为钛源,碘酸钾为碘源,制备了I掺杂纳米TiO2催化剂（I-TiO2）,运用x-射线衍射（XRD）、透射电镜（TEM）及x-射线光电子能谱（XPS）等对催化剂进行表征,结果表明,TiO2及I-TiO2催化剂均为锐钛矿,I吸附并包裹在TiO2表面或以间隙进入的形式存在,并未进入TiO2晶格。通过在可见光照射下（A〉420nm）以罗丹明B（RhodamineB,RhB）的光催化降解为探针反应研究了在不同条件下制备催化剂的催化性能,结果表明,掺杂比为n1：n^ti=0．05：l,焙烧温度为400℃,降解介质条件pH=7时,l-TiO2光催化活性明显优于未掺杂的TiO2。光催化降解过程通过红外光谱（IR）,总有机碳（TOC）跟踪测定,比较了TiO2掺杂前后降解RhB和对氯苯酚（4-CP）的光催化特性差异;同时采用苯甲酸荧光光度法跟踪测定体系中的氧化物种,表明在可见光下,I-TiO2光催化体系中产生·OH高活性氧化物种从而氧化降解目标化合物。     

碳源及反硝化芽孢杆菌强化低C/N比景观水体的生物脱氮

实验探讨了添加碳源及投加反硝化细菌对低碳氮比景观水体生物脱氮的影响。结果表明,有机碳源及B.subtilis FS05均能显著促进实验水体的生物脱氮作用,实验水体在28℃静置72 h后,乙醇添加组的TN、氨氮、硝酸盐及亚硝酸盐的去除率分别达到了62.7%、67.0%、69.8%和29.4%,而同样条件下,B.subtilis FS05投加组的去除率分别达到了66.9%、73.4%、66.0%和82.2%。从水质变化趋势可以看出,投加B.subtilis FS05能在更短时间内完成生物脱氮过程,其中,硝酸盐和亚硝酸盐去除速率最快,分别仅需要18 h和12 h。     

碳源类型及进水量分配对CMICAO工艺脱氮除磷的影响

研究了分别以葡萄糖和乙酸钠为碳源时多点交替进水阶式A2/O(CMICAO)工艺氮磷的去除效果,以及在不同进水C/N比时各进水量分配对脱氮除磷效果的影响.结果表明,在相同的进水COD浓度下,乙酸钠比葡萄糖更适合作为碳源,更能提高脱氮除磷效率.以葡萄糖为碳源时,COD为200 mg/L、C/N比为5、缺氧池与厌氧池进水配比为1∶2时,出水COD、TN、氨氮和TP浓度分别为28.5、10.8、2.1和0.5 mg/L,均达到国家一级A排放标准.若采用葡萄糖作为碳源,投加量以使进水C/N比为5～7.5为宜,外加碳源时缺氧池与厌氧池进水分配比可统一采用1∶1.