秦岭若干重要类型金矿床(体)快速定位预测

本文以西部秦岭地区八卦庙、双王、煎茶岭 3种重要类型金矿床为例 ,在成矿地质背景研究基础上 ,开展若干新方法新技术的找矿试验 ,研究发现 ,八卦庙式金矿岩石的烃含量与其金品位大致成正相关关系 ;而且金矿化强度和规模越大 ,相关系数值也越大 ;据此根据石英脉的烃含量对隐伏金矿床 (体 )和金矿化规模进行预测。双王式金矿原生晕的前缘晕元素为B、As、Sb、Hg,近矿晕元素为Au、Ba(-) ,尾晕元素为Mn、Bi。通过原生叠加晕垂向研究预测 ,双王和八卦庙金矿床现有的金矿体向下延伸还较大 ,在矿床的深部存在有盲矿体。煎茶岭式金矿的矿石铅同位素平均值比围岩要小 ,铅同位素曲线的低峰区往往就指示矿体所在 ;预测区的2 0 6Pb/ 2 0 4 Pb、2 0 8Pb/ 2 0 4 Pb比值变差椭圆图的形状和轴向斜率与已知矿区趋于一致 ,并且两者的变差椭圆图形大部分重叠 ,说明存在有同类型金矿体。以上研究成果为同期或后来的勘探工作或矿山采矿所验证。     

Are current Chinese national ambient air quality standards on 24-hour averages for particulate matter sufficient to protect public health?

With rapid economic development and urbanization in recent decades, China has experienced the worsening of ambient air quality. For better air quality management to protect human health, Chinese government revised national ambient air quality standards(NAAQS) for particulate matter(PM) in 2012(GB3095-2012). To assess the effectiveness of current NAAQS for PM on public health in Chinese population, we conducted a metaanalysis on published studies examining the mortality risk of short-term exposure to PM with aerodynamic diameters less than 10 and 2.5 μm(PM_(10) and PM_(2.5)) in China. The reported24-hour concentrations of PM_(10) and PM_(2.5) in studies ranged from 43.5 to 150.1 μg/m~3 and 37.5 to 176.7 μg/m~3. In the pooled excess, mortality risk estimates of short-term exposure to PM.In specific, per 10 μg/m~3 increase in PM_(10), we observed increases of 0.40%(95%CI: 0.33%,0.47%), 0.57%(95%CI: 0.44%, 0.70%) and 0.49%(95%CI: 0.40%, 0.58%) in total, respiratory and cardiovascular mortality, per 10 μg/m~3 increase in PM_(2.5), we observed increases of 0.51%(95%CI: 0.38%, 0.63%), 0.62%(95%CI: 0.52%, 0.73%) and 0.75%(95%CI: 0.54%, 0.95%) in total,respiratory and cardiovascular mortality. Finally, we derived 125 μg/m~3 for PM_(10) and 62.5 μg/m~3 for PM_(2.5) as 24-hour recommendation values based on the pooled estimates. Our results indicated that current Chinese NAAQS for PM could be sufficient in mitigating the excess mortality risk from short-term exposure to ambient PM. However, future research on longterm exposure cohort studies in Chinese population is also essential in revising annual averages for PM in Chinese NAAQS.     

Efficient adsorption of Mn(Ⅱ) by layered double hydroxides intercalated with diethylenetriaminepentaacetic acid and the mechanistic study

In this study, greatly enhanced Mn(II) adsorption was achieved by as-synthesized diethylenetriaminepentaacetate acid intercalated Mg/Al layered double hydroxides(LDHsDTPA). The adsorption capacity of LDHs-DTPA was 83.5 mg/g, which is much higher than that of LDHs-EDTA(44.4 mg/g), LDHs-Oxalate(21.6 mg/g) and LDHs(28.8 mg/g). The adsorption data of aqueous Mn(II) using LDHs-DTPA could be well described by the pseudosecond order kinetics and Langmuir isotherm model. Thermodynamics study results also showed that the adsorption process of Mn(II) by LDHs-DTPA was exothermic as indicated by the negative ΔH value. Furthermore, based on the structural, morphological and thermostable features, as well as FT-IR and XPS characterizations of LDHs-DTPA and the pristine LDHs, the adsorption mechanism of Mn(II) was proposed. The carboxyl groups of DTPA were proposed to be the main binding sites for Mn(II), and the hydroxyl groups of LDHs also played a minor role in the adsorption process. Among the three common regeneration reagents, 0.1 mol/L Na_2CO_3 was the best for reusing LDHs-DTPA in Mn(II)adsorption. Besides, the Mn(II) adsorption performance could be hindered in the presence of typical inorganic ions, especially cations. Further specific modifications of LDHs-DTPA are suggested to get more selective adsorption of Mn(II) in practical applications.     

One-step synthesis of Cu(II) metal–organic gel as recyclable material for rapid, efficient and size selective cationic dyes adsorption

Efficient removal of non-biodegradable and hazardous dyes from wastewater remains a hot research topic. Herein, a rationally designed a Cu(Ⅱ)-based metal–organic gel(Cu-MOG) with a nanoporous 3 D network structure prepared via a simple one-step mixing method was successfully employed for the removal of cationic dyes. The Cu-MOG exhibited high efficiency, with an adsorption capacity of up to 650.32 mg/g, and rapid adsorption efficiency, with the ability to adsorb 80% of Neutral Red within 1 min. The high adsorption efficiency was attributed to its large specific surface area, which enabled it to massively bind cationic dyes through electrostatic interaction, and a nanoporous structure that promoted intra-pore diffusion. Remarkably, the Cu-MOG displayed size-selective adsorption, based on adsorption studies concerning dyes of different sizes as calculated by density functional theory. Additionally, the adsorption performance of the Cu-MOG still maintained removal efficiency of 100% after three regeneration cycles. These results suggested that the Cu-MOG could be expected to be a promising and competitive candidate to conveniently process wastewater.     

Highly catalytic activity of Mn/SBA-15 catalysts for toluene combustion improved by adjusting the morphology of supports

Rod-like, hexagonal and fiber-like SBA-15 mesoporous silicas were synthesized to support MnO_x for toluene oxidation. This study showed that the morphology of the supports greatly influenced the catalytic activity in toluene oxidation. MnO_x supported on rod-like SBA-15(R-SBA-15) displayed the best catalytic activity and the conversion at 230°C reached more than 90%, which was higher than the other two catalysts. MnO_x species consisted of coexisting MnO_2 and Mn_2O_3 on the three kinds of SBA-15 samples. Large amounts of Mn_2O_3 species were formed on the surface and high oxygen mobility was obtained on MnO_x supported on R-SBA-15, according to the H_2 temperature programmed reduction(H_2-TPR)and X-ray photoelectron spectroscopy(XPS) results. The Mn/R-SBA-15 catalyst with greater amounts of Mn_2O_3 species possessed a large amount of surface lattice oxygen, which accelerated the catalytic reaction rate. Therefore, the surface lattice oxygen and high oxygen mobility were critical factors on the catalytic activity of the Mn/R-SBA-15 catalyst.     

Contribution of the Kodama and 4S pathways to the dibenzothiophene biodegradation in different coastal wetlands under different C/N ratios

Dibenzothiophene (DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation efficiencies were clearly improved with increasing C/N ratio in reed wetland sediments, tidal wetlands sediments and estuary wetland sediments. The quantitative response relationships between DBT degradation rates and related functional genes demonstrate that the Kodama pathway-related gene groups were dominant factors at low C/N ratios, while the 4S-related gene groups mainly determined the degradation rate when the C/N ratio was up to 5. Network analysis also shows that the pathway shifts from the Kodama pathway to the 4S pathway occurred through changes in the connections between functional genomes and rates. Furthermore, there were competition and collaboration between the Kodama and 4S pathways. The 4S pathway-related bacteria were more active in estuary wetland sediments compared with reed wetland sediments and tidal wetland sediments. The higher degradation efficiency in estuary wetland sediments may indicate the greater participation of the 4S pathway in the DBT biodegradation reaction. And the effects of ring cleavage of Kodama pathway caused more complete metabolizing of DBT.     

Detection of polycyclic aromatic hydrocarbons using a high performance-single particle aerosol mass spectrometer

The real-time detection of the mixing states of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs in ambient particles is of great significance for analyzing the source, aging process, and health effects of PAHs and nitro-PAHs; yet there is still few effective technology to achieve this type of detection. In this study, 11 types of PAH and nitro-PAH standard samples were analyzed using a high performance-single particle aerosol mass spectrometer (HP-SPAMS) in lab studies. The identification principles ‘parent ions’ and ‘mass-to-charge (m/z) = 77’ of each compound were obtained in this study. It was found that different laser energies did not affect the identification of the parent ions. The comparative experiments of ambient atmospheric particles, cooking and biomass burning emitted particles with and without the addition of PAHs were conducted and ruled out the interferences from primary and secondary organics on the identification of PAHs. Besides, the reliability of the characteristic ions extraction method was evaluated through the comparative study of similarity algorithm and deep learning algorithm. In addition, the real PAH-containing particles from vehicle exhaust emissions and ambient particles were also analyzed. This study improves the ability of single particle mass spectrometry technology to detect PAHs and nitro-PAHs, and HP-SPAMS was superior to SPAMS for detecting single particles containing PAHs and nitro-PAHs. This study provides support for subsequent ambient observations to identify the characteristic spectrum of single particles containing PAHs and nitro-PAHs.     

恩平市2006年生态足迹计算与分析

位于广东省西南部的恩平市,是珠江三角洲经济较为落后的地区,生态环境较好,为珠三角起着生态屏障、后花园的作用。应用生态足迹理论对恩平2006年的生态足迹进行了实证计算和分析,结果表明,恩平市的人均生态足迹需求为1．5632hm2／cap,生态承载力在扣除12％后为0．32032hm2／cap,人均生态赤字为1．2429hm2／cap。表明该地区的资源利用效率较低,现有的消费量已超出了自然系统的再生产能力,针对恩平实际情况,需要调整产业结构、提高能源利用效率,树立科学发展观等。     

FIA技术在水质监测分析中的应用

通过使用Lachat流动注射分析仪测定环境水样中的四个常规项目总磷、总氮、挥发酚和总氰来介绍兀A技术在水质分析领域的应用。实验结果表明,各项目的标样测定值均在保证值范围之内,相对标准偏差在0．2％-3．7％之间。方法的精密度及准确度较好,加标回收率在91％-102％之间,满足水质监测实验室质量控制的要求。     

流动注射法测定水中高锰酸盐指数的研究

研究了用流动注射分析技术测定水体中高锰酸盐指数。使用新发明的耐腐蚀恒流泵、低记忆高效混合器、不存留气泡流通池等部件,通过高温高压,缩短消解时间,从而建立了一种可用于无人值守的自动在线快速监测水体中高锰酸盐指数的分析方法。通过实验研究了流动注射法测定水中高锰酸盐指数的优越性。对方法的检出限、精密度和准确度进行了测定,并与GB／T11892—89《水质高锰酸盐指数的测定》进行了比对,取得了满意的结果。