PPS覆膜滤料的性能及应用

通过VDI滤料模拟测试装置、SEM等先进仪器对PPS覆膜滤料的性能进行测试分析,比较了常规PPS和PPS覆膜滤料性能,列举了其在燃煤电厂中的应用情况,阐明PPS覆膜滤料优异的过滤性能及工程应用效果。     

基于自碳黑的水化硅酸钙制备及其磷回收特性

以白碳黑、硅灰、硅藻土和硅胶筛选硅质原料,并与钙质原料电石渣制备了水化硅酸钙。借助XRF、BET、FT—IR等表征手段,通过多次重复除磷实验,研究了硅质原料特性对水化硅酸钙回收磷性能的影响。结果表明,白碳黑具有极高的反应活性,因此可作为制备具有磷回收特性的水化硅酸钙的硅质原料。结合XRD等表征发现,白碳黑的有效利用率是影响水化硅酸钙回收磷性能的关键,该利用率取决于白碳黑与电石渣的摩尔配比以及水热反应温度。当电石渣与白碳黑的摩尔比为1．6：1,反应温度为170℃时,白碳黑具有最佳的利用效率。该条件制备的水化硅酸钙可作为晶种,在其表面结晶形成羟基磷灰石,从而达到磷回收的目的,磷回收后固体物质中的磷含量为19．05％。     

铜锰镧铈复合催化剂的制备及其降解对二甲苯的机制

采用溶胶凝胶法制备了镧掺杂的铜锰镧铈催化剂,研究了其对对二甲苯的催化性能.通过BET、SEM、H2-TPR、XRD和XPS等对不同元素比例的催化剂进行表征,探讨了催化剂结构和性能的关系;同时,研究了不同影响因素(初始浓度、空速、O2含量和混合物)对其催化氧化性能的影响;最后,利用FT-IR、XRD和GC-MS对降解产物...     

Natural radionuclides distribution and environmental impacts of ferruginous sand-siltstone (raw material) and their manufactured Ahmer oxide used as wall paints

Commercially known Ahmer oxide paints are prepared from raw material mainly composed of red iron oxides (hematite) and iron oxyhydroxides. The raw material used in manufacturing of Ahmer oxide comes from some localities in southwest Sinai such as Abu Thor, Allouga, and El lehian. The adsorption of uranium and other radioelements on iron oxides could make the raw material (red iron oxides) and their products environmentally hazardous. The studied samples were subjected to radiometric analysis using NaI (Tl) gamma-ray spectrometer. The average activity concentration of U, Th, Ra, and K are 108.7, 458.8, 88.8, and 627.5?Bq?kg^?1, respectively in raw material and 136.4, 14.6, 58.3, and 95.9?Bq?kg^?1 in Ahmer oxide. High values of activity concentrations of ²³⁸U, ²²⁶Ra, and ⁴⁰K were recorded in Allouga and El lehian raw material. High radioactivities of Allouga and El lehian raw material are mainly attributed to the presence of torbernite, zircon, and monazite, in addition to adsorbed elemental uranium in Ahmer oxide. absorbed dose rate (D), annual effective dose equivalent, radium equivalent activity (Ra_eq), external hazard index (H_ex), and internal hazard index (H_in), as well as representative gamma index (Iγ) were determined from the activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K. Some of the studied samples do not satisfy the universal standards.     

Occupational Exposure to Harmful Chemical Substances While Processing Phenol-Formaldehyde Resins

Air pollutants emitted while processing phenol-formaldehyde resins have been investigated. Gas chromatography-mass-selective detection was used to separate and identify chemical compounds. It was determined that workers were exposed to formaldehyde in all workplaces. Besides, phenol, acetaldehyde, acrylaldehyde, 2-furaldehyde, xylene, ethylbenzene, toluene, tetrachlorethene, ethyl acetate, butyl acetate were found during the production of frictional materials; and 2-furaldehyde, phenol, naphthalene, 2-furan-methanol, polycyclic aromatic hydrocarbons (PAHs) during the production of abrasive materials. Quantitative analyses were performed with gas chromatogra-phy and high performance liquid chromatography. Assessment of occupational exposure indicated that chemical compounds emitted during the investigated processes might be dangerous for human health, mainly because of suspected carcinogenic compounds: formaldehyde and PAHs.     

A Whole Body Postural Loading Simulation and Assessment Model for Workplace Analysis and Design

Abstract

This study reports on the development and validation of a new computer model for simulating human postures at work, and assessing the reaction forces and bending moments in 43 human articulation joints. The proposed model estimates the intradiscal pressure in the vertebral column in response to external loading forces encountered during human interactions with work objects or processes. The model was implemented in a self-contained interactive software package. The simulation results compare favorably with the reported experimental data, and provide reasonable confidence in the quality of the model. Its characteristics and its applications in evaluating physical task performance are also discussed     

可用作原料的固体废物进口可行性评价指标体系探索研究

合理利用境外的可用作原料的固体废物,可以弥补我国国内资源的相对不足,但固体废物固有的废物属性仍不可避免地会带来一定的环境负面影响。建立可用作原料的固体废物进口可行性评价体系,对于在合理利用境外废物资源的同时,保护和改善环境具有重要意义。本文论述了我国建立可用作原料的固体废物进口可行性评价体系的理论和原则,并根据影响可用作原料的固体废物进口可行性评价的因素分析,构建了可用作原料的固体废物进口可行性评价指标体系框架。     

The effects of different electrode materials on seed germination of Solanum nigrum L. and its Cd accumulation in soil

The effects of different electrode on Solanum nigrum L.seed germination were determined.The result showe d that germination percentage(GP) of seeds in treatment T2(titanium electrode) was 26.6% higher than in control(CK,without electric field).High potassium and calcium concentrations were beneficial for seed enzymatic activity in treatment T2,which could partly explain the increase in GP.Cd accumulation(μg/pot) in S.nigrum treated with any electric field was significantly higher(p<0.05) than...     

浅埋近距离煤层内错布置采空区自燃危险区域研究

浅埋近距离煤层内错布置开采下部煤层时,地表裂隙易与复合采空区相互贯通,造成地表漏风,使采空区,特别是上部老采空自燃危险区域的分布难以预测。针对此问题,以酸刺沟煤矿6上109工作面至地表空间为研究对象,在漏风测定及束管监测的基础上,建立地表与复合采空区漏风模型,借助FLUENT数值模拟软件,研究地表漏风对复合采空区自燃危险区域的影响。研究表明,地表漏风最终汇入下部采空区回风侧,加大了其自燃危险区域范围;漏风流在向回风侧偏移的过程中,由于煤柱的阻挡,风速逐渐降低,与下部漏入的风流共同作用,使上部老采空区形成了氧浓度中间低四周高的不规则环状自燃危险区域;下部采空区进风侧向上的漏风增加了本煤层采空区的总漏风量,加大了其自燃危险区域宽度,同时增加了上部老采空区局部氧浓度,使其自燃危险性增大。     

三种氧化剂预处理有机物、氨氮和锰复合原水的比较研究

针对中国水源水污染严重,多呈复合污染的问题,因此,对常用的氧化剂氧化复合污染的原水进行了研究。主要包括三种水处理药剂臭氧、高锰酸钾和氯对有机物、氨氮和锰的处理效能及抗污染负荷的研究,并进一步从安全性进行了比较。研究结果表明,高锰酸钾可以部分去除水中消毒副产物前驱物,适合复合污染水体;若利用臭氧预氧化,更适用尤以有机物污染严重的水质;预氯化将导致水中消毒副产物生成量增加。