Capture of gaseous elemental mercury from flue gas using a magnetic and sulfur poisoning resistant sorbent Mn/γ-Fe2O3 at lower temperatures

A series of Mn/γ-Fe(2)O(3) were synthesized to capture elemental mercury from the flue gas. Mn(4+) cations and cation vacancies on the surface played important roles on elemental mercury capture by Mn/γ-Fe(2)O(3). Furthermore, the reaction route of elemental mercury oxidization was dependent on the ratio of Mn(4+) cations to cation vacancies. As a result, the capacities of 15%-Mn/γ-Fe(2)O(3)-250 for elemental mercury capture were generally higher than those of 30%-Mn/γ-Fe(2)O(3)-400. SO(2) mainly reacted with ≡Fe(III)-OH and only a small amount of ≡Mn(4+) reacted with SO(2), so the presence of a high concentration of SO(2) resulted in an insignificant effect on elemental mercury capture by 15%-Mn/γ-Fe(2)O(3)-250 at lower temperatures. The capacities of 15%-Mn/γ-Fe(2)O(3)-250 for elemental mercury capture in the presence of 2.8 g N m(-3) of SO(2) were more than 2.2 mg g(-1) at <200°C. Meanwhile, 15%-Mn/γ-Fe(2)O(3)-250 can be separated from the fly ash using magnetic separation, leaving the fly ash essentially free of sorbent and adsorbed HgO. Therefore, 15% Mn/γ-Fe(2)O(3)-250 may be a promising sorbent for elemental mercury capture.     

Construction of food and water borne pathogens' dose-response curves using the expanded Fermi Solution

Abstract: Theoretically, the relationship between the number of pathogens that cause acute infection if settling in the gut, N, and that initially ingested, M, can be constructed from the survival probabilities at the different “stations” along the digestive tract. These probabilities are rarely known exactly, but their ranges can be estimated. If for a given N one generates estimates of M using random probabilities within these ranges, the estimates’ distribution will be approximately lognormal and its cumulative (CDF) form will represent the pathogen's dose–response curve. The distribution's logarithmic mean and standard deviation can be calculated from the ranges with a formula and used to plot the curve. The method was used to generate dose–response curves of hypothetical food and waterborne pathogens and calculate their infective dose (ID) at 5%, 50%, and 95% probability. The curves were compatible with the Beta Poisson model and robust against minor perturbations in the underlying probabilities’ ranges. The calculation and plotting procedure was automated and posted on the Internet as a freely downloadable interactive Wolfram Demonstration. It allows the user to generate, modify, examine, and compare dose–response curves, and to calculate their characteristics, by moving sliders on the screen.     

黄酒对实验性铅中毒的拮抗作用研究

为了研究黄酒对小鼠铅水平的影响,建立了小鼠实验性铅中毒模型。将ICR小鼠随机分成空白对照组、模型对照组和黄酒剂量(3个剂量)组。空白对照组饲喂基础饲料,模型对照组连续饲喂高铅饲料,3个剂量组按高、中、低剂量分别饲喂黄酒,并同时饲喂高铅饲料。受试后30d,用等离子体发射光谱法(ICP-AES)测定小鼠血液、肝脏和骨骼的铅含量,结果表明:高、中、低剂量黄酒均能够显著降低小鼠血液和肝脏的铅含量,黄酒对小鼠实验性铅中毒有显著的拮抗作用。     

油脂加氢铜催化剂的硫中毒研究

考察了硫化物对大豆油部分加氢Ｃｕ－Ｃｒ催化剂和ＣｕＯ／ＳｉＯ２催化剂活性的影响。不挥发性硫化物毒性与硫含量基本成正比，挥发性硫化物毒性较小。铜催化剂抗Ｓ性比镍催化剂好。活性高的催化剂抗毒性比活低的强。减小催化剂颗粒度和提高活性组分分散度，有利于提高催化剂活性和抗毒性。     

快速测定米饭中的甲胺磷

用无水硫酸钠吸干米饭中水份,再用乙酸乙酯提取样品中甲胺磷农药,提取液直接上气相色谱仪测定。可达到快速分析,测定结果良好。     

职业苯中毒病因分析的数据处理

本文以处理哈尔滨电缆厂职工医院职防科的职业苯中毒流行病学调查资料为例,介绍了多因素分析研究中的得力工具—Logistic 回归分析模型及苯中毒病例—对照资料的计算机处理结果,可对医疗卫生部门、生产劳动组织部门及有关人士提供参考。     

MODELING OF COMPETITIVE ADSORPTION OF NITROGEN SPECIES IN HYDRODESULFURIZATION

Previously, we developed a simple, one-parameter model reproducing the observed inhibiting effect of nitrogen species in the hydrodesulfurization (HDS) of hindered sulfur heterocycles. The model owes its simplicity to some nontrivial assumptions. Here we develop a full model by relaxing these assumptions, which gives a more quantitative picture of how sulfur, nitrogen, and catalyst surface interact on many widely disparate time scales. Computational results build a strong case for the accuracy of the previous one-parameter theory. As such, the theory should be applicable to reaction systems in which catalyst poisoning is driven by nonequilibrium adsorption. Some of the complexities and subtleties in modeling the competitive adsorption effects in distillate HDS are discussed, giving special attention to the design of robust catalyst-deactivation-compensation operating strategies.     

Axial characterization of oxygen storage capacity in close-coupled lightoff and underfloor catalytic converters and impact of sulfur

The oxygen storage capacity of a 56,000 mile aged warmup and underfloor converter system was characterized as a function of axial location along the converters and compared with fresh samples having the same formulation. Measurements of oxygen storage were made using a titration technique and at conditions expected to be commonly encountered during OBD-II diagnosis of catalyst performance. Vehicle aging resulted in a dramatic loss of oxygen storage in the warmup converter presumably due to the severe thermal sintering, but the significant amount of phosphorus (P) and zinc (Zn) poison accumulation on this converter was found to impact oxygen storage minimally. This is in contrast to the measured impact of P and Zn deposition on warmed-up hydrocarbon conversion, which was found to be significant relative to the impact of thermal sintering. The underfloor converter was found to have retained nearly all of its original oxygen storage after vehicle aging, consistent with operation of this converter at moderate temperatures which do no result in severe thermal sintering of the noble metals and the ceria.

The impact of sulfur on the oxygen storage of both warmup and underfloor converter sections was dramatic. Sections in the forward part of the warmup converter and in the front brick of the underfloor converter had relatively modest oxygen storage capacity which was almost completely blocked as the sulfur concentration reached 75–150 ppm (equivalent in gasoline). Other sections such as the rear of the warmup converter and the rear monolith of the underfloor converter had more oxygen storage capacity, which was significantly decreased as the sulfur concentration reached 150 ppm equivalent in fuel, and was approached complete loss near 500 ppm sulfur equivalent in fuel.     

天然气高温燃烧用催化剂失活的研究进展

简要介绍了天然气高温催化燃烧的特征与机理，分别从催化剂的高温烧结、活性组分的迁移和流失、中毒、催化剂活性组分与载体的强相互作用、高温热震等引起的催化剂失活，概述了各种典型催化剂的高温失活机理，并对制备高温稳定的活泼催化剂提出了建议。     

深圳大学微型反应堆的改进

介绍深圳大学核技术所近年来对微型反应堆进行的一系列改进 ,包括 :采取特殊措施 ,延长微堆安全运行时间 ,从原来的 6～ 8h ,延长至 40h左右 ,成功研制了治疗肝癌的含稀土元素的放射性玻璃微球 ;建立了超热辐照管和计算机控制的循环跑兔装置 ,扩展了微堆活化分析范围和领域 ;研制出一种新颖、简单、准确 ,且无需添置任何设备的测量堆芯绝对中子通量密度的方法———氙中毒法 .尽管深大微堆具有固有的安全性 ,但它目前处于运行后期 .因腐蚀、疲劳等原因 ,核燃料元件包壳破损的可能性将越来越大 ,为此研制了安全监测计算机系统 ,一旦发生核燃料元件包壳破损时 ,系统能很快监测放射性泄漏 ,这对控制核污染起到十分重要的作用 .但这并不说明深大微堆已安全无事 .国外发生的一系列核泄漏事件昭示人们 ,在核安全管理中 ,人员因素至关重要 .不管放射性物质泄漏多与少 ,影响都很大 ,万万不能麻痹大意