华北过渡相页岩气储层微观孔隙结构特征——以山西省文水地区为例(增刊)

为表征过渡相页岩气储层纳米级孔隙发育特征,以山西省文水地区山西组与太原组煤系页岩为研究对象,采用高分辨率成像技术对页岩储层孔裂隙系统发育情况进行观察;利用低温氮吸附实验对页岩气储层孔隙结构加以表征。扫描电镜下页岩孔径多小于1μm,有机质孔含量不多,粘土矿物晶间孔、黄铁矿晶间孔等矿物基质孔较为发育,粒间孔少见。低温氮吸附实验表明,山西组页岩BET比表面积与总孔体积平均为5.4762 m₂/g与0.0088 cm₃/g,太原组页岩分别为6.7462 m₂/g和0.0102 cm₃/g,孔径小于10nm的微孔是比表面积的主要贡献者,中孔孔隙体积在总孔体积中占明显优势。BJH孔径分布曲线可分为两类,一类于2.5nm,4nm,10nm处有明显峰值;第二类除具有前者三个峰值外,于90nm处有相对较弱的峰值出现,该类样品同时具有相对较低的比表面积与总孔体积。     

Asymmetric Hydrogenation of 3‐Amido‐2‐arylpyridinium Salts by Triply Chloride‐Bridged Dinuclear Iridium Complexes Bearing Enantiopure Diphosphine Ligands: Synthesis of Neurokinin‐1 Receptor Antagonist Derivatives

We describe a most straightforward synthetic method for preparing neurokinin‐1 (NK1) receptor antagonist derivatives by asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts using dinuclear iridium complexes with enantiopure diphosphine ligands, affording the corresponding chiral piperidines in high cis‐diastereoselectivity (>95:5) and moderately high enantioselectivity (up to 86%). Deprotection treatments afforded the NK‐1 receptor antagonist (+)‐CP‐99,994 (83% ee). In addition, we observed unique additive effects of 10‐camphorsulfonic acid in the asymmetric hydrogenation of 3‐amido‐2‐arylpyridinium salts.

     

Efficient Hydrogenation of Nitrogen Heterocycles Catalyzed by Carbon‐Metal Covalent Bonds‐Stabilized Palladium Nanoparticles: Synergistic Effects of Particle Size and Water

We reveal here the first hydrogenation of nitrogen heterocycles catalyzed by carbon–metal covalent bonds‐stabilized palladium nanoparticles in water under mild conditions. Using a one‐phase reduction method, smaller metal–carbon covalent bond‐stabilized Pd nanoparticles were prepared with a size distribution of 2.5±0.5 nm, which showed extraordinary synergistic effects with water in the catalytic hydrogenation of nitrogen heterocycles. Water was supposed to accelerate substrate absorption and synergistic activation of molecular hydrogen on the Pd nanoparticles surface. The nanosized Pd catalyst could be easily recovered and reused for 5 runs.

     

煤层注氮模拟实验中的置换-驱替效应及其转化机制分析

为了研究注N_2促排煤层瓦斯过程中驱替和置换效应及其主导作用,利用自研的煤层注气实验装置,进行了单轴应力、分层预压成型条件下煤层注N_2促排瓦斯的模拟实验。实验结果表明:驱替和置换效应始终贯穿整个注气过程,共同作用将煤体中瓦斯排出。在注气初期14 min内,置换解吸效应起主导作用,注入的N_2由于被吸附或充填于煤层孔裂隙等自由空间而被全部滞留煤中,表现为出口并无N_2排出,而煤体中的CH_4则大量解吸排出。在14~200 min注气实验时间内,置换作用的主导地位将逐渐丧失,开始进入置换作用减弱和驱替作用增强的转换阶段;在注气时间大于400 min的后期,处于置换和驱替相互作用、彼此平衡的时期,但置驱总效率处于较低水平。根据注气400 min(6.67 h)后注气促排效率较低的实验结果,建议井下煤层注气时间控制在8 h工作制的一个小班以内为宜。     

A/A/O-MBR组合工艺强化去除氨氮及其硝化速率

将PVDF帘式中空纤维膜组件与A/A/O工艺结合,构建"A/A/O-MBR"强化生物脱氮的中试系统,用于处理太湖流域城镇污水。针对组合工艺的脱氮效果,以组合工艺MBR池内活性污泥的硝化速率为研究对象,分析了溶解氧(DO)浓度、进水氨氮浓度和温度对硝化速率的影响。结果表明,组合工艺在夏季和冬季的氨氮平均去除率分别稳定为96.56%和96.68%;低温(T15℃)条件下,进水氨氮浓度对硝化速率影响不大;温度升高硝化速率加快,温度为30.5℃时组合工艺的硝化速率为11.8℃时的2.6倍;与常规工艺相比,组合工艺的硝化速率是氧化沟工艺的2.3倍。组合工艺两级硝化空间形成的较长水力停留时间和MBR内膜的截留作用补偿了低温对硝化速率的影响。     

水泥基材料超低温冻融循环试验研究

利用液氮作为环境介质进行超低温冻融循环试验,研究了超低温对水泥基材料抗冻性能的影响。观测冻融循环前后试件外观、质量和强度等宏观性能变化,采用扫描电子显微镜(SEM)分析水泥基材料冻融循环前后微观结构变化。试验结果表明:在超低温条件下,混凝土的抗冻性能明显强于砂浆,且随混凝土强度提高其抗冻性能呈增长趋势;SEM分析结果表明超低温冻融循环后泡水融化试件结构内存在明显缺陷;超低温冻融循环试验可以加速水泥基材料破坏进程,明显减少试验周期,能相对较快的评价出水泥基材料的抗冻性能。     

结晶硝铵真空缓冲罐冷凝液回收治理

将结晶硝铵真空缓冲罐含高浓度氨氮冷凝液回收,与硝铵表冷液一并送电渗析膜处理装置进行处理,处理后的浓缩硝铵溶液送结晶硝铵系统回用,氨氮浓度不超过40mg/L的淡水回循环水使用,以达到节能减排、保护环境的目的。     

Formation of carbonaceous and nitrogenous disinfection by-products from the chlorination of Microcystis aeruginosa

Formation of carbonaceous disinfection by-products (C-DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), haloketones (HKs), chloral hydrate (CH), and nitrogenous disinfection by-products (N-DBPs), including haloacetonitriles (HANs) and trichloronitromethane (TCNM) from chlorination of Microcystis aeruginosa, a blue-green algae, under different conditions was investigated. Factors evaluated include contact time, chlorine dosages, pH, temperature, ammonia concentrations and algae growth stages. Increased reaction time, chlorine dosage and temperature improved the formation of the relatively stable C-DBPs (e.g., THM, HAA, and CH) and TCNM. Formation of dichloroacetonitrile (DCAN) followed an increasing and then decreasing pattern with prolonged reaction time and increased chlorine dosages. pH affected DBP formation differently, with THM increasing, HKs decreasing, and other DBPs having maximum concentrations at certain pH values. The addition of ammonia significantly reduced the formation of most DBPs, but TCNM formation was not affected and 1,1-dichloropropanone (1,1-DCP) formation was higher with the addition of ammonia. Most DBPs increased as the growth period of algal cells increased. Chlorination of algal cells of higher organic nitrogen content generated higher concentrations of N-DBPs (e.g., HANs and TCNM) and CH, comparable DCAA concentration but much lower concentrations of other C-DBPs (e.g., THM, TCAA and HKs) than did natural organic matter (NOM).     

Is the association between temperature and mortality modified by age, gender and socio-economic status?

Background

A number of studies have examined the relationship between high ambient temperature and mortality. Recently, concern has arisen about whether this relationship is modified by socio-demographic factors. However, data for this type of study is relatively scarce in subtropical/tropical regions where people are well accustomed to warm temperatures.

Objective

To investigate whether the relationship between daily mean temperature and daily all-cause mortality is modified by age, gender and socio-economic status (SES) in Brisbane, Australia.

Methods

We obtained daily mean temperature and all-cause mortality data for Brisbane, Australia during 1996-2004. A generalised additive model was fitted to assess the percentage increase in all deaths with every one degree increment above the threshold temperature. Different age, gender and SES groups were included in the model as categorical variables and their modification effects were estimated separately.

Results

A total of 53,316 non-external deaths were included during the study period. There was a clear increasing trend in the harmful effect of high temperature on mortality with age. The effect estimate among women was more than 20 times that among men. We did not find an SES effect on the percent increase associated with temperature.

Conclusions

The effects of high temperature on all deaths were modified by age and gender but not by SES in Brisbane, Australia.     

Atmospheric NH3 and NO2 concentration and nitrogen deposition in an agricultural catchment of Eastern China

To assess the atmospheric environmental impacts of anthropogenic reactive nitrogen in the fast-developing Eastern China region, we measured atmospheric concentrations of nitrogen dioxide (NO₂) and ammonia (NH₃) as well as the wet deposition of inorganic nitrogen (NO₃⁻ and NH₄⁺) and dissolved organic nitrogen (DON) levels in a typical agricultural catchment in Jiangsu Province, China, from October 2007 to September 2008_. The annual average gaseous concentrations of NO₂ and NH₃ were 42.2 μg m⁻³ and 4.5 μg m⁻³ (0 °C, 760 mm Hg), respectively, whereas those of NO₃⁻, NH₄⁺, and DON in the rainwater within the study catchment were 1.3, 1.3, and 0.5 mg N L⁻¹, respectively. No clear difference in gaseous NO₂ concentrations and nitrogen concentrations in collected rainwater was found between the crop field and residential sites, but the average NH₃ concentration of 5.4 μg m⁻³ in residential sites was significantly higher than that in field sites (4.1 μg m⁻³). Total depositions were 40 kg N ha⁻¹ yr⁻¹ for crop field sites and 30 kg N ha⁻¹ yr⁻¹ for residential sites, in which dry depositions (NO₂ and NH₃) were 7.6 kg N ha⁻¹ yr⁻¹ for crop field sites and 1.9 kg N ha⁻¹ yr⁻¹ for residential sites. The DON in the rainwater accounted for 16% of the total wet nitrogen deposition. Oxidized N (NO₃⁻ in the precipitation and gaseous NO₂) was the dominant form of nitrogen deposition in the studied region, indicating that reactive forms of nitrogen created from urban areas contribute greatly to N deposition in the rural area evaluated in this study.