Comparison between urban Toronto PM and selected materials: aerosol characterization using laser ablation/ionization mass spectrometry (LAMS)

Laser ablation/ionization mass spectrometry (LAMS) of particulate matter (PM) was undertaken on-line in order to extend and contrast PM characterization. Qualitative on-line LAMS results for certified materials and Toronto source materials demonstrated the versatility and limitations of the technique. The observation of organic and inorganic components of certified materials verified the proper working condition of the in-house on-line LAMS. Organic and inorganic components of Toronto source materials were also observed with the on-line LAMS. Common components identified from both types of materials were Na, Al, Ca, Fe, and K. Other recognized components were compared with marker elements reported for some common PM emission sources. An in-house off-line LAMS was used to analyze urban Toronto PM deposited on glass substrates, while the on-line LAMS analyzed individual urban Toronto PM particles that were introduced directly into the instrument. Scanning electron microscopy (SEM), X-ray spectrometry and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used for confirmatory purposes. Organic and inorganic components of urban Toronto PM at their typical ng/m3 concentrations were successfully observed in mass spectra using both off-line LAMS and on-line LAMS. Identified ions unique to each analyzed material were compared to identified ions of urban Toronto PM. The ability of LAMS to analyze individual respirable PM particles (viz. < 2 microns), both for inorganic trace elements and for organic components, greatly extended our capability to characterize PM and also to achieve estimates of concentration contributions of each material.     

凝聚炸药的冲击起爆

分析了飞片在炸药内产生高压区的行为，导出高压区中热点发生热爆炸的临界条件；讨论了高压区中侧向能量分配对热点传播的影响，得到了适应性更加广泛的凝聚炸药冲击起爆判据；利用这一判据，对实验结果给予了理论解释。     

海船避碰专家系统领域知识的来源和决策流程初探

综述了海船避碰专家系统知识库领域知识的来源;对反映船舶碰撞危险程度的特征值进行了分析,认为取两船距离作为判别值是简明可行的,经比较,提出以王逢辰划分的船舶行动阶段与具体赋值后的动界和船舶领域模型相结合,是知识库判断碰撞危险和避让时机的基础;在考虑了能见度、船舶种类、相对方位和动态的基础上,提出了专家系统避让决策的初步流程。     

Water softening by induced crystallization in fluidized bed

Fluidized bed and induced crystallization technology were combined to design a new type of induced crystallization fluidized bed reactor. The added particulate matter served as crystal nucleus to induce crystallization so that the insoluble material, which was in a saturated state, could precipitate on its surface. In this study, by filling the fluidized bed with quartz sand and by adjusting water p H, precipitation of calcium carbonate was induced on the surface of quartz sand, and the removal of water hardness was achieved.With a reactor influent flow of 60 L/hr, a fixed-bed height of 0.5 m, pH value of 9.5, quartz sand nuclear diameter of 0.2–0.4 mm, and a reflux ratio of 60%, the effluent concentration of calcium hardness was reduced to 60 mg/L and 86.6% removal efficiency was achieved. The resulting effluent reached the quality standard set for circulating cooling water. Majority of the material on the surface of quartz sand was calculated to be calcium carbonate based on energy spectrum analysis and moisture content was around 15.994%. With the low moisture content, dewatering treatment is no longer required and this results to cost savings on total water treatment process.     

水污染源在线设备比对监测问题与解决方案——以长沙市在线监测系统为例

总结了长沙市7年来水污染源在线监测系统开展比对监测工作的情况,对氨氮、p H、重金属比对监测存在的问题进行了剖析,分析了在线监测仪器比对不合格的原因以及目前在线监测仪器部分项目缺乏误差标准等亟待解决的问题,研究出各因子误差的合理区间,提出了切实可行的解决方案:氨氮应该按照检测浓度高低确定误差范围;p H质控样不应使用相对误差,建议采用±0.3 p H的绝对误差;重金属实际水样浓度小于一定量时,用接近水样浓度的低浓度质控样替代。     

佛山市南海城区环境空气中铅污染现状分析研究

为了解佛山市南海城区环境空气中铅污染现状,在南海城区中心设置空气质量监测点,采用重量法和电感耦合等离子体质谱法分别对空气颗粒物及不同粒径颗粒物的铅含量进行定量分析,测定结果为:TSP、PM10、PM2.5平均浓度分别是150 ug/m3、99 ug/m3、67 ug/m3,其中铅平均浓度分别是214 ng/m3、175 ng/m3、156 ng/m3.结论为:南海城区环境空气中的铅浓度达到国家环境空气质量二级标准,铅污染水平处于珠江三角洲的中游;大气中的铅主要分布在PM2.5中,机动车尾气是其主要来源.     

城市生活垃圾治理过程的能源化技术

论述了垃圾多种治理技术以及这些技术中的能源化的关键。这些技术涉及垃圾卫生填埋、垃圾梦烧、垃圾衍生燃料技术、垃圾厌氧发酵和垃圾的热解气化等。针对中国垃圾的具体特点，对中国垃圾能源化提出一些初步方案和建议。     

In vitro effects of metal ions on lipid peroxidation induced by alcohol in mice liver homogenate

The study is aimed to estimate the effect of different heavy metals such as Hg2+, Cd2+, Mn2+, Cr3+, Ni2+, Se2O3(2-), As2O3 water solution and combined effects of Hg2+, Mn2+, Cr3+ on lipid peroxidation in mice liver homogenate in vitro. Lipid peroxidation was determined as thiobarbituric acid-reacting materials (TBA). We select five different concentrations of selected ions for experiments. Correlations used to identify the concentration of ions associated with lipid peroxidation. The rate of lipid peroxide formation in mice liver homogenate increased with the gradual addition of alcohol. When alcohol dose was up to 0.5 ml, the rate of lipid peroxide formation was greatest. At tested concentrations, the effects of metal ions on lipid peroxidation induced by alcohol were classified into three groups, and are as follows: (1) simulative, Hg2+. (2) inhibitory, Mn2+, Cr3+, Ni2+, Se2O3(2-). (3) ambiguous, Cd2+, As2O3 water solution. When Hg2+, Mn2+ and Cr3+ were added to the mice liver homogenate with alcohol at the same time, Hg2+, Mn2+ were the main agents for the rate of alcohol induced lipid peroxidation. The simulative effect of Hg2+ on lipid peroxidation induced by alcohol indicate that alcohol-drinkers will have further health risk when they are exposed in polluted regions than others, and Mn2+, Cr3+, Ni2+, Se2O3(2-) may act as free radical scavengers and preventive remedy for alcoholism in part. Furthermore, analysis of combined effect of Hg2+Mn2+ and Cr3+ provide us a new way to estimate the combined effect of multi-materials.     

博罗县下村农场坡地赤红壤的结构特征及其意义

探讨了博罗县下村农场坡地赤红壤的结构特征及其生产意义。结果表明,下村农场坡地赤红壤的质地较粗,土壤的团聚体含量较高,土壤的孔隙性较差;土壤粘粒、有机质,尤其是后者对土壤结构状况影响很大,土壤结构系数与土壤粘粒含量呈显著正相关,土壤1—0.05mm粗微团聚体含量、10—0.25mm水稳性团聚体及其几何平均直径值,均与土壤有机质含量呈显著正相关。坡地土壤的开发利用,应注意防治水土流失,减少团聚体的破坏,并特别注重提高土壤有机质含量,以改善土壤结构状况。     

Comparative sensitivity to and consumption of methyl eugenol in three <Emphasis Type="Italic">Bactrocera dorsalis</Emphasis> (Diptera: Tephritidae) complex sibling species

Summary. Sensitivities to methyl eugenol of three sibling species in the Bactrocera dorsalis complex were compared. The degree of species sensitivity to methyl eugenol, i.e. B. dorsalis > B. papayae > B. carambolae (in decreasing order), was concomitant with the species age-related response to methyl eugenol as previously reported. The ability to consume methyl eugenol by the three sibling species showed similar trend - the average ME consumption per male was 0.70 ml for B. dorsalis, 0.58 ml B. papayae and 0.18 μl B. carambolae. Results obtained were discussed in relation to area-wide control of fruit fly. Received 21 April 2002; accepted 9 July 2002