GIS环境下大区域工程场地地震液化势的二维概率评价方法

用具有概率意义的饱和砂土抗液化强度经验公式来对大区域场地进行地震液化势二维概率评价;在GIS软件ArcGIS的支持下,将取样钻孔处的液化势评价结果等价于数字高程模型(Digital Elevation Model,DEM)中的高程,利用ArcGIS空间分析模块中的Kriging插值法估计大区域场地的地震液化范围。研究表明:将Kriging法应用于岩土工程地质特征的统计推断,有助于揭示勘探孔以外的地层信息,对于大区域场地地震液化范围的判别是一个较好的手段;利用ArcGIS空间分析模块中的Kriging法,通过已勘察点的信息(液化势)来估计未勘测点的土层液化势,能够较好地区划出场地地震液化势的空间分布特征。     

高喷插芯组合群桩竖向承载特性的数值分析

高喷插芯组合桩(简称JPP)是一种新型的复合材料桩,具有承载力高、造价低等优点。利用岩土工程专业软件FLAC3D对JPP群桩竖向承载特性进行了数值模拟分析,讨论了桩数、桩间距、桩长、不同组合形式、不同水泥土弹性模量等对竖向承载特性的影响。结果表明:承载力随着桩数的增加而减小,但16根群桩与25根群桩的承载力相差不多,16根群桩承载力可以代表16根以上群桩的承载力;桩间距越大,承载力越小,桩间距宜采用3倍的JPP组合桩径或4倍的芯桩桩径;承载力随着桩长的增加而增加;分段组合形式承载力效果较好,实际工程施工中宜采用之;水泥土弹性模量对竖向位移没有影响,但水泥土弹性模量越大,芯桩轴力越小。     

鹤岗煤矿开采诱发地震研究

对鹤岗煤矿开采诱发地震的生成环境、活动与破坏特征及震源机制进行了分析，提出鹤岗矿震的孕育和发生受到人为采掘因素和区内构造应力场的双重作用。在特定的构造物理条件和地球动力学环境下，深部采矿使井下断裂构造从稳定状态逐渐活动或蠕动，致使局部活化。矿震具有震源浅、对地表破坏强的特点。震源机制表现出断层的运动方式有走滑断层，也有正断层和逆断层。     

Pollution characteristics of 23 veterinary antibiotics in livestock manure and manure-amended soils in Jiangsu province,China

The aim of this study was to investigate the pollution characteristics of typical veterinary antibiotics in manure and soil of livestock farms in Jiangsu province. This investigation employed solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A total of 53 manure and 50 amended soil samples from 16 livestock farms in Jiangsu province were collected for analysis. In the manure samples, the highest detected frequencies and concentrations were those of tetracyclines (TCs, 54.1 ± 5775.6 μgkg^?1), followed by fluoroquinolones (FQs, 8.4 ± 435.6 μgkg^?1), sulphonamides (SAs, 3.2 ± 5.2 μgkg^?1) and macrolides (MACs, 0.4 ± 110.5 μgkg^?1). Statistical analysis was used to illuminate the pollution characteristics of 23 veterinary antibiotics for various animal types and different regions in Jiangsu province. The results showed that the pollution level in cow manure was relatively lower compared with pig and chicken manure due to the relative restriction of medication. Furthermore, contamination was serious in amended soil from chicken farms. The pollution level in manure among different regions was higher to the south and north compared with the centre of the region. The same outcome was found for soil. Antibiotic residues in organic fertilizer were also investigated in this study. We found that although the detected concentration was lower in organic fertilizer than in fresh manure, detection frequencies (10–90%) were high, especially for roxithromycin (90%) in MACs (30–90%). This finding suggests attention should be paid to the pollution levels in organic fertilizer. This study is the first extensive investigation of the occurrence and distribution of many kinds of typical veterinary antibiotics in manure and soil from livestock farms of Jiangsu province. This investigation systematically assesses veterinary antibiotics usage and related emissions in southeast China.     

序批式生物膜反应器挂膜启动实现短程硝化

常温条件下(20～25℃),以模拟的人工配水为研究对象,采用序批式生物膜反应器(SBBR),在初期挂膜的基础上,笔者运用两种不同的挂膜方式即重新加入新泥和不加新泥而加大进水COD浓度来实现生物膜的快速启动。实验表明,2种挂膜启动通过14 d的培养与富集,NH4+-N与COD的处理效果都能分别达到85%和75%以上。将剩余污泥排尽后,采用第1种挂膜方式的反应器通过连续间歇曝气,达到了比较好的短程硝化效果。调整溶解氧,并且通过先下降后上升曝气量的方式,能进一步提高亚氮的出水。最终在DO为3.6 mg/L时,亚氮的积累率能达到平均74%左右,达到了比较好的亚硝化效果。而第2种挂膜方式培养的生物膜则以好氧反硝化菌为主,去除的氨氮由同化作用和培养的好氧反硝化菌去除,以后者为主。通过比较可以看出,为了实现短程硝化,第1种挂膜方式比第2种更具有优越性,有利于硝化菌种的生长和亚氮的积累,而第2种方式则有利于培养好氧反硝化菌。     

合肥市臭氧及其前体物污染特征及源解析

利用合肥市臭氧和VOCs连续观测数据分析了合肥市臭氧及其前体物污染特征,并使用NAQPMS模型研究了合肥市不同季节臭氧来源情况。结果表明:O₃已经成为影响合肥市环境质量的主要污染因子,O₃高值区主要集中在5—6月和9月。合肥市大气VOCs中烷烃含量最丰富,其次是烯烃、芳香烃和炔烃;主要物种为乙烷、丙烷、乙炔、正戊烷、乙烯、环戊烷、异戊烷、正丁烷、异丁烷和甲苯。合肥市O₃生成主要受VOCs控制,其中,烯烃是合肥市O₃生成贡献最大的关键活性组分,乙烯的OFP贡献率居首位。合肥市不同季节O₃来源差异较大,其中,本地排放是主要来源,夏季占比为50%,其余季节占比为30%~45%,O₃存在跨省长距离输送特征,主导风向的变化是造成合肥市臭氧来源季节性变化的重要因素。     

363kV快速真空断路器电场计算

高电压等级开关设备的绝缘水平严重影响设备的安全运行和开断能力,因此在研发高电压真空断路器时需要分析其电场分布。以363 kV快速真空断路器设计结构为原型,建立三维有限元电场计算模型,分别计算了额定电压下闭合和开断工况下的电场分布,分析了灭弧室、绝缘子以及主要金具表面的电场大小。结果表明:均压环表面电场最大值为1.92 MV/m,绝缘子表面最大值为0.36 MV/m,开距20 mm时灭弧室断口电场最大值为3.5 MV/m,其他部位电场均处于控制范围内,断路器总体结构设计合理,满足绝缘要求。     

地震动关键特性对隔震连续梁桥碰撞响应的影响

为考虑地震动特性对隔震连续梁桥顺桥向主梁与桥台碰撞响应的影响,以某三跨混凝土隔震连续梁桥为例,基于ABAQUS建立了考虑混凝土材料损伤及三维接触碰撞的有限元模型。采用12条典型地震动输入,分析了不考虑碰撞时地震动峰值加速度与峰值速度的比值(PGA/PGV)对主梁顺桥向最大位移的影响;并进一步分析了考虑碰撞效应时PGA/PGV对主梁碰撞响应的影响;在此基础上,以一条典型地震动为例,分析了地震动峰值加速度对碰撞响应的影响。结果表明,当不考虑碰撞效应时,主梁顺桥向最大位移随着PGA/PGV的增大而呈现减小趋势;考虑碰撞时,碰撞次数和最大碰撞力的变化具有一定的相似性,但随PGA/PGV的变化并不明显。随着伸缩缝间隙的不同,最大碰撞力随着峰值加速度的增加既可能表现出线性增加的特征,也可能表现出较大波动。     

长江源区浮游植物群落结构及分布特征

地处青藏高原腹地的长江源区是长江流域的水源涵养地和生态系统的天然屏障,同时也是自然生态系统最敏感、生态环境十分脆弱的地区,浮游植物作为水体生态系统中的初级生产者,其群落结构对反映水体质量具有重要的指示作用。为探究长江源区水环境特性和浮游植物群落特征,于2018年3月份与10月份对长江源区10个典型河段的水环境因子与浮游植物群落组成进行了系统调查。结果显示:10月份各调查河段流速、浊度、水温及电导率等水环境参数均比3月份高;同一月份中,楚玛尔河的浊度、盐度、电导率等水环境参数均显著高于其余河段;两个月份各调查河段的pH、溶解氧以及亚硝酸盐氮等指标差异不显著。采样调查共鉴定出浮游植物4门28属58种,其中以硅藻、绿藻和蓝藻物种数占优,分别占总数的79.3%、10.4%和8.6%。调查期间,长江源区浮游植物密度在6.06×10~4～39.90×10~4 cells·L~(-1)之间,平均生物量为0.59 mg·L~(-1)。浮游植物优势种有美丽颤藻(Oscillatoria formosa)、普通等片藻(Diatoma vulgare)、脆杆藻(Fragilaria sp.)、针杆藻(Synedra sp.)、舟形藻(Navicula sp.)、桥弯藻(Cymbella sp.)、小球藻(Chlorella sp.)等。两个月份Shannon-Wiener多样性指数(H’)均值分别为3.06和3.12,Margalef丰富度指数(D)均值为1.17和1.52,Pielou均匀度指数(J)均值为0.90和0.82。结合水体营养盐指标、浮游植物密度及多样性指数等指标对水质评价,长江源区水质总体呈无污染或轻度污染状态。     

Effects of chemical modification on physicochemical properties and adsorption behavior of sludge-based activated carbon

This study aimed to explore the adsorption performance of sludge-based activated carbon (SBC) towards dissolved organic matters (DOMs) removal from sewage, and investigated the modification effect of different types of chemicals on the structure of synthesized SBC. Waste activated sludge (WAS) was used as a carbon source, and HCl, HNO₃, and NaOH were used as different types of chemicals to modify the SBC. With the aid of chemical activation, the modified SBC showed higher adsorption performances on DOMs removal with maximum adsorption of 29.05 mg/g and second-order constant (k) of 0.1367 (L/mol/sec) due to the surface elution of ash and minerals by chemicals. The surface elemental composition of MSBC suggested that the content of C-C and C-O functional groups on the surface of modified sludge-based activated carbon (MSBC) played an important role on the adsorption capacities of MSBC towards DOMs removal in sewage. Additionally, the residual molecular weight of DOMs in sewage was investigated using a 3-dimension fluorescence excitation-emission matrix (3D-EEM) and high-performance size exclusion chromatography (HP-SEC). Results showed that the chemical modification significantly improved the adsorption capacity of MSBC on humic acids (HA) and aromatic proteins (APN), and both of NaOH-MSBC and HCl-MSBC were effective for a wide range of different AMW DOMs removal from sewage, while the HNO₃-MSBC exhibited poorly on AMW organics of 2,617 Da and 409 Da due to the reducing content of macropore. In brief, this study provides reference values for the impact of the chemicals of the activation stage before the SBCs application.