HMBR法处理某黄金矿山氨氮废水试验研究

针对某黄金矿山外排水氨氮浓度较高的特点,采用复合式膜生物反应器(HMBR)系统进行处理。研究了在好氧区pH为弱酸性及中性条件下,HMBR法对氨氮和COD等典型污染物的去除特征。试验确定了HMBR法最佳工艺参数:好氧区pH值控制为6.80~7.20,DO为2~3 mg/L,动态曝气运行周期6 min(运行-间歇时间4 min^-2 min),在线化学清洗措施为“柠檬酸+水-次氯酸钠”,水力停留时间为2.34 d,HMBR出水中氨氮和COD均达到GB 8978—1996《污水综合排放标准》一级要求。该研究为HMBR法处理氨氮废水的工业化应用提供数据支持。     

耐硫酸露点腐蚀钢09CrCuSb氧化铁皮缺陷的分析与研究

针对耐硫酸露点腐蚀钢09Cr Cu Sb热轧时出现的表面氧化铁皮压入缺陷,通过EPMA进行表面、断面形貌分析,研究了形成原因及控制方法。结果表明:降低加热炉均热段温度、合理控制空燃比和刷漆可有效控制板材表面氧化铁皮压入缺陷。     

Effect of phase boundary on nucleation and propagation of microcrack in nuclear grade Z3CN20-09M stainless steel

Abstract

In order to study the effect of the phase boundary between austenite and ferrite phases on the nucleation and propagation behaviours of microcracks in nuclear grade Z3CN20-09M stainless steel, an in situ scanning electron microscopy (SEM) tensile technique was used to study the deformation, nucleation and propagation of microcracks during tension. The fractography was subsequently observed by SEM. The results indicated that, during tension, the deformation first occurred in the austenitic grains followed by in the ferrite, and the microcracks were subsequently preferential formed at the phase boundary between austenite and ferrite phases. In the case of the phase boundary perpendicular to the loading direction, microcracks nucleated and subsequently propagated along the phase boundary. In the case of the phase boundary parallel to the loading direction, microcacks nucleated at the intersection of slip bands and the phase boundary and propagated perpendicularly to the phase boundary, resulting in deflection of the main crack. The phase boundary played a hindrance effect on crack propagation.     

聚羧酸系减水剂引入聚氧乙烯侧链的新方法

如何接枝聚氧乙烯长侧链已经成为聚羧酸系减水剂合成的核心问题。采用酯基乙氧基化的方法向聚丙烯酸甲酯中引入一定数目的环氧乙烷(EO),得到甲氧基封端的聚氧乙烯侧链。从而为聚羧酸系减水剂引入聚氧乙烯侧链提供了一种新方法。在自制的酯基乙氧基化催化剂MCT-09催化下,对不同分子量的聚丙烯酸甲酯进行了乙氧基化反应。采用红外光谱对产物结构进行了表征,通过测试皂化值来确定其链均EO加合数。     

Bootstrapping confidence intervals for the change‐point of time series

Abstract. We study an at‐most‐one‐change time‐series model with an abrupt change in the mean and dependent errors that fulfil certain mixing conditions. We obtain confidence intervals for the unknown change‐point via bootstrapping methods. Precisely, we use a block bootstrap of the estimated centred error sequence. Then, we reconstruct a sequence with a change in the mean using the same estimators as before. The difference between the change‐point estimator of the resampled sequence and the one of the original sequence can be used as an approximation of the difference between the real change‐point and its estimator. This enables us to construct confidence intervals using the empirical distribution of the resampled time series. A simulation study shows that the resampled confidence intervals are usually closer to their target levels and at the same time smaller than the asymptotic intervals.     

Thermal building simulation using the UKCP09 probabilistic climate projections

This article investigates how to use UK probabilistic climate-change projections (UKCP09) in rigorous building energy analysis. Two office buildings (deep plan and shallow plan) are used as case studies to demonstrate the application of UKCP09. Three different methods for reducing the computational demands are explored: statistical reduction (Finkelstein-Schafer [F-S] statistics), simplification using degree-day theory and the use of metamodels. The first method, which is based on an established technique, can be used as reference because it provides the most accurate information. However, it is necessary to automatically choose weather files based on F-S statistic by using computer programming language because thousands of weather files created from UKCP09 weather generator need to be processed. A combination of the second (degree-day theory) and third method (metamodels) requires only a relatively small number of simulation runs, but still provides valuable information to further implement the uncertainty and sensitivity analyses. The article also demonstrates how grid computing can be used to speed up the calculation for many independent EnergyPlus models by harnessing the processing power of idle desktop computers.     

09Cr2AlMoRE钢在糠醛装置换热设备中的防腐蚀应用

本文通过对糠醛装置换热设备腐蚀的情况、机理进行分析,尝试采用低合金钢09Cr2AlMoRE来提高换热设备的抗腐蚀能力,效果很好。     

海洋放线菌JWH-09代谢产物中农用抗菌组分的分离纯化及结构鉴定

从134株海洋微生物中筛选得到放线菌JWH-09,其发酵代谢产物具有较好的抗植物病原真菌活性.根据生物活性跟踪测试,采用硅胶柱层析、薄层层析以及制备高效液相色谱等技术对JWH-09发酵产物中的抗菌活性组分进行分离纯化,得到了一种抗真菌活性化合物JWH-09-A,经ESI-MS、EI-MS、1H NMR、13C NMR、2D NMR等谱图分析,确定该活性物质的结构为1-菲羧,1,2,3,4,4a,9,10,10a-八氢-1,4a-二甲基-7-(1-甲基乙基),俗名脱氢松香酸(dehydroabietic acid).经盆栽试验证明该化合物对水稻纹枯病、黄瓜白粉病和灰霉病具有较好的防治效果.     

锻造工艺对7A09铝合金锻件晶粒组织的影响

采用7A09铝合金过热处理工艺实验,研究其过热显微组织形态;采用4种锻造温度(440、460、480、500℃)对应3种变形程度ε(45%、68.3%、76.7%)进行了锻造实验,分析了锻造温度和变形程度对锻后晶粒组织的影响。过热处理工艺实验研究表明,随着加热温度的升高、保温时间的延长,晶粒变大;在加热温度440℃保温时间6 h后锻件的显微组织图上出现了织构组织,在加热温度500℃保温时间10 h后过烧现象明显;锻造工艺实验研究表明,获得锻后晶粒细小组织的最佳锻造工艺参数是锻造温度440℃和变形程度76.7%。     

稀土合金钢09Cr2AlMoRE的耐CO2腐蚀性评价

为了评价新型材料09Cr2AlMoRE的CO2腐蚀性能,采用高温高压釜模拟该材料的油田CO2腐蚀环境,考察和分析了其CO2腐蚀速率、腐蚀形貌和腐蚀产物膜的化学成分.结果表明,在CO2腐蚀环境中09Cr2AlMoRE主要发生均匀腐蚀,平均腐蚀速率在0.3～1.5mm/a;其腐蚀产物膜主要成分为FeCO3,不同温度下成分略有差异.