再生粗骨料混凝土柱耐火性能试验与理论分析

为研究再生粗骨料混凝土柱的耐火性能,进行了1个足尺的再生粗骨料混凝土柱和足尺的1个普通混凝土柱在竖向恒定荷载和温度场耦合作用下的耐火性能试验研究,2个试件的混凝土设计强度均为C30,2个柱采用相同的轴压比施加竖向荷载。在试验研究基础上,比较分析了2个试件的耐火极限以及各个测点的温度变化、侧向挠度、轴向变形和破坏过程;用有限元软件ABAQUS对试件截面温度场进行了模拟分析,测点温度增量模拟结果与实测温度增量符合较好。研究表明:相同初始轴压比条件下,混凝土强度接近的再生粗骨料混凝土柱比普通混凝土柱升温速度慢,具有相对较好的隔热性能;再生粗骨料混凝土柱比普通混凝土柱的抗爆裂性能好,耐火极限长;因再生粗骨料混凝土柱比普通混凝土柱的孔隙率相对较高,在高温作用下其内部蒸汽应力可得到一定释放,由此引起的柱子轴向压缩变形相应也较大;一定条件下的再生粗骨料混凝土柱可用于建筑工程。     

Performance of hybrid vertical up- and downflow subsurface flow constructed wetlands in treating synthetic high-strength wastewater

The performance and temporal variation of hybrid vertical-subsurface flow constructed wetlands (VFCWs) in response to two-stage combinations of vertical upflow (VUF) and vertical downflow (VDF) were analyzed in this research. The results of high carbon (C) treatment and high nitrogen (N) treatment were similar. The Lythrum salicaria treatment showed higher removal efficiency than CWs planted with Acorus calamus. Under high C- and N-loading treatments, the optimum two-stage combination was VDF-VUF VFCWs planted with A. calamus. Furthermore, the highest nutrient removal efficiencies were achieved in late summer (July and August) and early autumn (September). The chemical oxygen demand and total nitrogen removal efficiencies were significantly affected (P?<?0.05) by season, system, and wetland plant.     

用味精生产废水培养好氧颗粒污泥

以厌氧颗粒污泥为接种污泥,采用味精生产废水进行培养,在SBR中以逐渐降低污泥沉淀时间的方法成功培养出好氧颗粒污泥。实验结果表明：污泥接种65 d后,出现细小的好氧颗粒污泥,呈黄褐色,95 d后颗粒污泥趋于成熟,粒径达0.6 mm左右,且周围存在大量原生动物;运行95 d后MLSS提高至8.00 g/L,SVI降至30.00 mL/g左右;成熟后的好氧颗粒污泥对味精生产废水中的COD和NH₃-N具有良好的去除效果,出水COD和ρ（NH₃-N）分别为80 mg/L和2 mg/L左右。     

生物絮凝剂产生菌群发酵特性及动力学

从土壤中分离、筛选得到2株具有协同发酵的微生物絮凝剂产生菌。通过单因素实验考察了碳源、氮源、不同C/N等多种发酵条件对复合菌株产絮的影响,并对复合菌株的生长动力学进行了研究。当碳源为蔗糖、氮源为草酸铵、C/N为30∶1,pH=7.0、在30℃,160 r/min的摇床速度下培养24 h,其发酵液对4 g/L的高岭土的悬浊液的絮凝率达到99.3%。根据Logistic方程,得到复合型生物絮凝剂产生菌群的生长动力学模型与实验数据能较好地拟合,基本反映了复合菌群生长的动力学特征。     

PBDD/F impurities in some commercial deca-BDE

The study presented the concentrations and distributions of polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans (PBDD/Fs) as impurities in some commercial decabromodiphenyl ether (DBDE) mixtures that were produced by several manufacturers. The total concentrations of 12 2,3,7,8-substituted tetra- to octa-BDD/F congeners were found to be in the range of 3.4-13.6 (mean 7.8) μg/g, averagely accounting for 99% of total PBDD/Fs. OBDF was the prevailing congener, followed by 1,2,3,4,6,7,8-HpBDF. In addition, OBDD and 1,2,3,4,7,8-HxBDF were also obviously detectable. The total concentrations of PBDD/Fs varied both between the manufacturers and between the lots. On the basis of the global demand for the commercial DBDE in 2001, the annual potential emissions of PBDD/Fs were calculated coarsely to be 0.43 (range: 0.21-0.78) tons. The major dioxin congeners, OBDF and 1,2,3,4,6,7,8-HpBDF, presenting in DBDE, were estimated to be formed from BDE-209, BDE-206, and/or BDE-207 via an intra-molecular elimination of Br₂/HBr.     

The changes of nitric oxide production during the growth of Microcystis aerugrinosa

This study characterized the changes of nitric oxide (NO) production during the growth of Microcystis aerugrinosa, a cyanobacterium which usually cause cyanobacterial blooms. Results showed a drastic NO release accompanying with cell density and Chl-a content sharp rises when M. aerugrinosa grew from fifth day to sixth day. Moreover, high N:P ratio accelerated the cyanobacterial growth and NO burst. Sodium nitroprusside, an exogenous NO donor, promoted M. aerugrinosa growth with the optimal concentration of 0.1 mg/L. Experiments by supplementing with sodium nitrite and l-arginine demonstrated NO production in M. aerugrinosa cells was mainly through nitrate reductase (NR) pathway while minorly through NO synthase pathway. All these data suggested M. aerugrinosa produced increasing NO during its growth mainly by NR pathway, during which NO positively regulated the growth of M. aerugrinosa.     

计算流体动力学在火电厂SCR系统流场优化中应用及研究进展

作为一种设计和分析的工具,计算流体力学（CFD）技术已成功应用于火电厂选择性催化还原（SCR）系统设计中,提供了大量物理模型或现场试验不能得到的数据。介绍了近年来国内外CFD技术在选择性催化还原（SCR）中的研究及应用进展,指出该研究目前存在的问题及发展方向。     

Bioaccumulation and depuration of anthracene in Penaeus monodon (Fibricius) through food ingestion

Understanding on the bioaccumulation and depuration of PAHs (polycyclic aromatic hydrocarbons) in Penaeus monodon is important in seafood safety because it is one of the most popular seafood consumed worldwide. In this study, we used anthracene as the precursor compound for PAHs accumulation and depuration in the shrimp. Commercial feed pellets spiked with anthracene were fed to P. monodon. At 20 mg kg⁻¹ anthracene, P. monodon accumulated 0.1% of the anthracene from the feed. P. monodon deputed the PAH two times faster than its accumulation. The shrimp reduced its feed consumption when anthracene content in the feed exceeded 20 mg kg⁻¹. At 100 mg kg⁻¹ anthracene, P. monodon started to have necrosis tissues on the posterior end of their thorax. The bioaccumulation factor (BAF), uptake rate constant (k₁) and depuration rate constant (k₂) of anthracene in P. monodon were 1.15 × 10⁻³, 6.80 × 10⁻⁴ d⁻¹ and 6.28 × 10⁻¹ d⁻¹, respectively. The depuration rate constant is about thousand times higher than the uptake rate constant and this indicated that this crustacean is efficient in depurating hydrocarbons from their tissue.     

报废家庭用轿车传动零部件的再生利用

家庭用轿车报废后,在传动系统中还有许多没有损坏的零部件。通过实际使用情况和设计寿命分析,发现这些零部件还有较长的使用寿命。对此提出零部件再生利用能够达到节约资源、能源和人力物力的目的。     

基于SSM方法的黑龙江省入境旅游产业结构分析

以相关入境旅游统计数据为基础,运用转移—份额分析法,对2002—2007年黑龙江省入境旅游产业结构进行了分析。结果表明,黑龙江省入境旅游产业发展速度高于全国水平,产业结构较好,但总体竞争力不强。在此基础上,针对产业中的优势部门、增长部门和劣势部门提出了相应的对策和建议。