汽车用材料——PA66及其玻璃纤维复合材料在不同介质中的老化行为研究

在三种介质（二次水，汽油，乙二醇，50℃温度）条件下对PA66及PA66／GF进行95天左右的人工模拟材料在汽车使用环境下的加速试验，对不同老化时间的PA66及PA66／GF试样进行了宏观力学测试及吸湿性测试，并进一步利用示差扫描量热法（DSC），红外光谱及扫描电镜等手段分析老化前后试样的微观结构及组织差异。结合老化前后试样的力学性能变化，揭示了PA66及复合材料的老化规律和机理。实验表明，PA66及PA66／GF在三种介质中拉伸强度呈现下降趋势。其主要机理是介质溶液对试样渗入的结果影响，降低了分子间的相互作用力（范德华力）从而使材料机械性能下降；同时未发现化学作用对材料的力学性能有明显的变化。     

Acid Orange 7 degradation using methane as the sole carbon source and electron donor

• AO7 degradation was coupled with anaerobic methane oxidation. • Higher concentration of AO7 inhibited the degradation. • The maximum removal rate of AO7 reached 280 mg/(L·d) in HfMBR. • ANME-2d dominated the microbial community in both batch reactor and HfMBR. • ANME-2d alone or synergistic with the partner bacteria played a significant role. Azo dyes are widely applied in the textile industry but are not entirely consumed during the dyeing process and can thus be discharged to the environment in wastewater. However, azo dyes can be degraded using various electron donors, and in this paper, Acid Orange 7 (AO7) degradation performance is investigated using methane (CH₄) as the sole electron donor. Methane has multiple sources and is readily available and inexpensive. Experiments using ¹³C-labeled isotopes showed that AO7 degradation was coupled with anaerobic oxidation of methane (AOM) and, subsequently, affected by the initial concentrations of AO7. Higher concentrations of AO7 could inhibit the activity of microorganisms, which was confirmed by the long-term performance of AO7 degradation, with maximum removal rates of 8.94 mg/(L·d) in a batch reactor and 280 mg/(L·d) in a hollow fiber membrane bioreactor (HfMBR). High-throughput sequencing using 16S rRNA genes showed that Candidatus Methanoperedens, affiliated to ANME-2d, dominated the microbial community in the batch reactor and HfMBR. Additionally, the relative abundance of Proteobacteria bacteria (Phenylobacterium, Pseudomonas, and Geothermobacter) improved after AO7 degradation. This outcome suggested that ANME-2d alone, or acting synergistically with partner bacteria, played a key role in the process of AO7 degradation coupled with AOM.     

石油降解菌XD-1产表面活性剂的性能

从含油废水中筛选分离到1株原油降解菌XD-1,鉴定为假单胞菌（Pseuomonas sp.）.初步实验表明菌XD-1具有较强的产表面活性剂乳化原油的作用,对该菌的产表面活性剂性能进行了研究.实验证明,菌XD-1所产表面活性剂为脂肽类物质,菌在生长对数期产表面活性剂,表面活性剂的产生为生长相关型;充足的碳源是产表面活性剂的必需条件,菌利用原油为碳源时能持续大量地产表面活性剂;原油和尿素为产表面活性剂的最适碳源和氮源,菌XD-1产表面活性剂的最佳营养培养基组成为葡萄糖10 g,尿素4 g,磷酸二氢钾1 g,微量元素液4 mL,水1 L,pH 8.0.     

Assessment of popular techniques for co-processing municipal solid waste in Chinese cement kilns

• Municipal solid waste (MSW) was fermented, screened, gasified, then co-processed. • Co-processing MSW in cement kilns could cause excessive pollutant emissions. • Bypass flue gas can be disposed of through the main flue system. • Popular MSW co-processing methods do not affect cement quality. Cement kiln co-processing techniques have been developed in the past 20 years in China, and more than 60 factories now use fermentation, screening, and gasification pre-treatment techniques to co-process municipal solid waste (MSW). There three complete MSW pre-treatment techniques, co-processing procedures, and environmental risk assessments have been described in few publications. In this study, we assessed the effectiveness of each technique. The results suggested that the pollutant content released by each pre-treatment technology was lower than the emission standard. To reveal the mechanisms of pollutant migration and enrichment, the substances in the kiln and kiln products are investigated. The input of co-processing materials (Co-M) produced by fermentation caused formation of polychlorinated dibenzo-p-dioxins and dibenzofuran (PCDD/Fs) in the bypass flue gas (By-gas) in excess of the regulatory standard. The Co-M input produced by the screening and gasifier technologies caused the total organic carbon (TOC) concentration to exceed the standard. In addition, the NO_x, TOC, and PCDD/Fs in the By-gas exceeded the regulatory standard. Raw meal was the primary chlorine and heavy metals input stream, and clinker (CK) and cement kiln dust (CKD) accounted for>90% of the total chlorine output stream. Flue gas and CKD were the primary volatile heavy metal (Hg) output streams. Greater than 70% of the semi-volatile heavy metals (Cd, Pb, Tl and Se) distributed in hot raw meal and bypass cement kiln dust. The low-volatility heavy metals were concentrated in the CK. These results indicated that co-processing techniques used in China still require improvement.     

Study on dust–gas coupling pollution law and selection of optimal purification distance of air duct during tunneling process

During the excavation of high gas mine, gas and dust often exist at the same time. In order to ensure that the gas concentration remains within a safe range and minimize the risk of workers’ pneumoconiosis, we simulated the interaction mechanism of airflow, gas, and dust, explored the pollution law of gas and dust, and obtained the optimal purification distance (L_p) by the CFD method. The reliability of the numerical simulation was verified by field measurements. Firstly, the properties of the gas and dust affected the structure of the airflow field. At the same time, the change in the airflow field affected the concentration distributions of the gas and dust. During the diffusion process, some high-risk regions in which the gas or dust concentrations exceeded 0.80% or 200 mg/m³, respectively, were discovered. Moreover, we have found that the airflow velocity in the top region of the tunnel and at the intersection corner between the cutting face and tunnel wall was the main factor affecting the purification effects. When L_p = 5–8 m, the gas concentration remained below 0.50%. When L_p = 6 m, the dust concentration reached a minimum of 287.5 mg/m³. Therefore, the optimal purification distance was determined to be 6 m; in which case, the gas and dust concentrations decreased by 32.84% and 47.02%, respectively.

     

内陆输送过程中沙尘单颗粒类型及其非均相反应

采用单颗粒分析方法对2004 年2~3 月发生在北京的3 次沙尘暴的样品中沙尘颗粒物的化学成分进行了测定.3 次沙尘暴的反向轨迹图显示,它们主要来自于中国北部、西北部和蒙古的戈壁沙漠地区,且这些沙尘颗粒主要通过高空长距离输送到下游区域.使用带能谱的扫描电镜对481 个沙尘颗粒进行分析,并根据成分特征,把这些沙尘颗粒划分为8 种类型,主要类型有“富Si”、“富Ca”、“富S”、“富Fe”.将北京样品分析结果与呼和浩特、塔克拉玛干和敦煌的结果进行对比,结果显示,长距离输送的沙尘颗粒表面发生了SO₂ 的非均相化学反应,导致部分颗粒局部的表面发生化学修改作用,且“富Ca”的碱性矿物为非均相化学反应提供了更有利的反应界面.     

茂名小良桉树人工林生态经济效益分析与评价

利用模糊数学的方法,通过对小良的实地调杳和专家走访,挑选了30个对小良桉林生态经济影响较大的因子.建立了评价因子指标体系和五个评价等级,采用二个层次的综合评价模型对小良桉林生态经济效益首次进行了定量的综合评价.评价结果是:现在小良桉林生态经济效益为一般.总体态势是:16%为好,26%为较好,31%为一般.23%为较差,4%为差.综合评价得分为79.85分,介于一般和良好之间,这说明在小良桉树人工林的发展过程中存在许多显性的、潜在的问题,如果还不注意合理利用林地资源,就会使森林资源变为不可更新资源,不可持续利用.因此,科学客观地分析与评价小良桉林产业生态经济效益,为区域可持续发展提供科学依据和发展良策,实现生态和经济的综合调控具有现实意义.     

黄土高原马栏林区辽东栎的种子产量

辽东栎种子产量对其种群更新和恢复具有重要意义.调查研究了黄土高原马栏林区天然辽东栎次生林的种子产量,结果表明.该区天然辽东栎次生林处于较成熟阶段,结实植株所占比例高且种子产量丰富.分析发现,辽东栎结实植株数目表现出密度依赖效应,即样地结实植株密度与辽东栎植株的大小呈极显著的负相关,而辽东栎结实植株比例与样地密度呈极显著的负相关.通过埘标准枝上发育良好种子和败育种子数目的分析发现,在植株水平受精胚珠数与其发育种子数呈极显著的正相关;单株理论种子产量与胸径呈极显著的线性关系,表明辽东栎个体大的植株产生更多的种子;而对不同结实枝条,其高度与受精胚珠数、败育种子数和发育种子数均呈饭显著的线性关系,表明传粉或光照可能起到重要作用.此外,阳坡辽东栎林结实植株比例显著低于阴坡,表明样地水平坡向对辽东栎林结实也有一定的影响.图5 表3 参19     

宿根甘蔗产量性状的稳定性分析

利用AMMI模型对13个宿根甘蔗品种的产量性状进行稳定性分析,并以产量性状的表型值和相应的品种稳定性参数为指标,对供试品种进行系统聚类分析和评价.结果表明,6个产量性状在不同品种和环境的差异以及品种与环境互作效应都达到显著水平;但不同品种与不同试点的交互作用不同,每个品种对试点都有其特殊的适应性,综合考虑各产量性状的表现和稳定性,YZ99-596、CK、HoCP92-648、MT96-1409、Q170和Mex105是蔗产量和糖产量高、综合性状好、稳定性强的优良甘蔗新品种,FN98-1103、FR93-435、CP88-1762、Hocp91-555和MT93-730蔗产量和糖产量较低,蔗产量稳定性差.图3表3参20     

构建“水-煤-碳”体系 优化煤化工发展

分析了煤化工行业发展的现状及趋势,提出我国现代煤化工发展瓶颈主要是产业发展存在技术风险、产业发展与资源环境的矛盾突出及面临碳减排压力,并提出通过合理构建"水-煤-碳"三大约束指标体系,引导煤化工实现有序发展。