地震预警系统中的算法研究

通过对地震预警系统中基本算法的研究,在现有方法的基础上提出了一套地震参数快速估算的算法,以应用于地震预警系统中。该算法根据某些噪音的特殊性质,通过引入两个参数:触发时窗与取消阈值,对常用的P波初到判断方法STA/LTA(长时窗平均/短时窗平均)算法进行改进,以消除P波到达前的异常跳动点与脉冲噪音的影响,对P波到达进行识别。在识别到P波到达后,该算法实时的从P波初到后3s时窗内的竖向数据中提取出12类特征性质不同的计算参数作为估算震级,震中距等地震参数的依据,提高了震级、震中距的估算精度,减少了在大震下估算的离散性,取得了较好的结果。该算法可在地震P波到达后的几秒钟内,估算出地震相关参数,在S波到达前发出预警,并为采取相应的措施以及震后求援行动提供判断依据,达到防灾减灾的目的。     

铅处理对茴香植株生长及精油组分的影响

为了揭示铅对茴香（Foeniculum vulgare L.）生长和次生代谢产物-精油组分的影响及茴香植株对铅的吸收累积特性,本试验采用水培方法,在霍格兰营养液中加入铅,设计0（对照）、1 mg·L^-1、5 mg·L^-1、10 mg·L^-1处理,研究了不同铅质量浓度对茴香植株生长、精油组分及茴香植株对铅吸收累积的影响。结果表明：不同铅质量浓度处理对茴香植株的形态、生物量、色素质量分数、碳和氮质量分数、铅的吸收累积及精油组分均有影响。随着铅质量浓度的增加,茴香植株的株高呈降低趋势,且各处理之间差异显著,真叶数大致也呈降低趋势,但仅10 mg·L^-1处理显著低于对照,各处理的最大叶长差异均不显著,最大叶宽仅对照与5 mg·L^-1处理之间差异显著。随着铅质量浓度的增加,地上部鲜质量和干质量均呈逐渐降低趋势,且铅处理后的地上部鲜质量和干质量均显著低于对照,地下部鲜质量和干质量呈逐渐升高趋势,但铅处理后的地下部鲜质量和干质量与对照差异均不显著,根冠比呈逐渐增加趋势,但仅10 mg·L^-1处理显著高于对照。随着铅质量浓度的增加,叶绿素a、叶绿素b、叶绿素a＋b和类胡萝卜素质量分数均呈降低趋势,且均低于对照,叶绿素a/叶绿素b以5 mg·L^-1处理最高,但仅显著高于1 mg·L^-1处理。铅处理后,可溶性蛋白质质量分数均高于对照,但仅1 mg·L^-1处理和5 mg·L^-1处理显著高于对照,全氮质量分数与可溶性蛋白质质量分数的变化趋势基本一致,但各处理之间差异均不显著;随铅质量浓度的增加,可溶性糖质量分数呈降低趋势,除1 mg·L^-1处理显著高于对照外,其余铅处理均显著低于对照,各处理的全碳质量分数与对照差异均不显著。随铅质量浓度的增加,茴香植株对铅的吸收累积显著增加。不同铅质量浓度处理下的反式-茴香脑含量和含氧化合物均显著低于对照,以5 mg·L^-1铅处理最低,而柠檬烯含量和单萜类化合物均显著高于对照,以5 mg·L^-1铅处理最高;随铅质量浓度的增加,倍半萜类化合物含量呈降低趋势,且均低于对照。因此,铅能抑制茴香植株的生长;随铅质量浓度的增加,茴香植株对铅的吸收累积显著增加;铅处理能影响茴香精油组分,显著降低反式-茴香脑和含氧化合物含量,而显著提高柠檬烯和单萜类化合物含量。     

Removal of 17β-estradiol in laccase catalyzed treatment processes

The removal of 17β-estradiol （E2） in laccase catalyzed oxidative coupling processes was systematically studied in this work. We focused on the influence of pH and natural organic matter （NOM） on the performance of the enzymatic treatment processes. It was found that the optimal pH for E2 removal was between 4 and 6. The removal of E2 was slightly inhibited in the presence of NOM. Enzymatic transformation of E2 was second-order in kinetics with first-order to both the concentrations of the enzyme and contaminant. Mass spectrum （MS） analysis suggested that coupling products were formed through radical-radical coupling mechanism. The results of this study demonstrated that laccase catalyzed oxidative coupling process could potentially serve as a treatment strategy to control steroid estrogens.     

Use of different soft tissues of Perna viridis a s biomonitors of bioavailability and contamination by heavy metals (Cd,Cu, Fe,Pb, Ni,and Zn) in a semi-enclosed intertidal water,the Johore Straits

Green-lipped mussels, Perna viridis, were collected from the eastern and western parts of the Johore Straits in September 2004 and January 2005. Based on the heavy metal concentrations in the different soft tissues (gonad, foot, mantle, gills, muscle, and remaining soft tissues) of these mussel samples, the eastern part of the Johore Straits (which is divided into two portions by a causeway), recorded higher levels of bioavailability and contamination by Cd, Cu, Fe, Ni, and Zn when compared to the western part, while Kg. Pasir Puteh in the eastern part was found to record the highest bioavailability and contamination by heavy metals. The use of different soft tissues of P. viridis as biomonitors of bioavailability and contamination by Cd, Cu, Fe, Pb, Ni, and Zn in the semi-enclosed Johore Straits is proposed, since erroneous results due to spawning and the problem of defecation before dissection could be overcome. Hence, a more accurate interpretation of the bioavailability and contamination by heavy metals in coastal waters could be obtained. To our knowledge, this is the most detailed study on the bioavailability and contamination of heavy metals in the Johore Straits on the Malaysian side of the waterway carried out by using the different soft tissues and metal distribution based on the Mussel Watch approach.     

Trichoderma atroviride as a bioremediator of Cu pollution: An in vitro study

Isolated Trichoderma atroviride from Cu-polluted river sediment at the Serdang Industrial Area was studied under in vitro conditions to understand the mechanisms that allowed the fungi to thrive in the Cu-polluted freshwater ecosystem. From this study, adsorption was recognized as the main mechanism of Cu tolerance with 50–85% adsorption during the in vitro experiment. The uptake capacity of the isolate in liquid medium ranged from 0.8 to 11.2 mg g^?1 in the potato dextrose broth medium with increasing Cu concentrations from 25 to 300 mg L^?1. It was found that 2.7–5.0% of Cu was lost due to washing. The high percentage of Cu adsorption and the high uptake capacity of Cu by T. atroviride suggest that it is a potential bioremediator of Cu. However, further studies are needed to confirm its practical use as a bioremediating agent for Cu under field conditions.     

Bioavailability of copper and cadmium in sediment of nanjing section of Changjiang river to aquatic organisms

Bioavailabilities of metals in sediment to aquatic organisms depend on the strength of metal bonding to particulates. The accumulation tests of Cu and Cd in carp and in snails have been studied in vitro with the solution containing semisynthetic sediment samples in which the contents of various speciation of metal in sediment have been extended. For carp, the accumulation of Cu and Cd is related to the concentration of dissolved metal which in turn is affected by the distributions of speciations in sediment under given environmental conditions. It is another pattern for snails, various speciations of metal in sediment can contribute indirectly to metal accumulation. The contribution ratio, or relative importance of various speciations of metal in sediment can be expressed by multiple linear regression formulas. The contribution of ion‐exchangable speciation and coprecipition with carbonate speciation is 10⁵ times larger than that of residue speciation in sediment.     

Essential and nonessential elements in the red-crowned crane Grus japonensis of Zhalong Wetland,northeastern China

The concentrations of four essential (Ca, Mg, Zn, and Cu) and two nonessential elements (Pb and Cd) in feathers and kidneys, livers, gut walls, and muscles of eight carcasses of migratory red-crowned cranes (Grus japonensis) from Zhalong Wetland, northeastern China, were examined. The concentrations of Cd in the feathers were between 0.4 mg kg^?1 dry weight (dw) and 3.1 mg kg^?1 dw, in the livers between 0.4 and 4.4 mg kg^?1 dw, the maximum of which exceeded a level considered to be environmental exposure risk (i.e., 3 mg kg^?1 dw in the liver or kidney). High Pb levels (0.4–3.2 mg kg^?1 dw, with an average of 1.8 mg kg^?1) were also detected in livers, which exceeded a level considered toxicosis in birds (1.7 mg kg^?1 dw). Pb and Cd had the highest scores in principal component analysis. Relatively high Pb and Cd concentrations in the migratory cranes were thought to be associated with their habitat and prey.     

Fluent软件在地表水源热泵系统温排水数值模拟中的运用

运用Fluent软件对重庆市嘉陵江化龙桥段瑞安新天地江水水源热泵系统尾水排入受纳水域的过程进行二维数值模拟,选取Fluent中非耦合、隐式求解器对模型内的定常流动进行求解,得出受纳水域受水源热泵系统温排水影响后的温升面积和温度梯度。结果表明:在温排水流量为2.0×103 m3/h、温差为4℃的条件下,计算该水域沿水流方向温升超过1℃的最大影响距离为150.4 m,温升超过1℃的水域面积约为1 525 m2,为模拟江水面积的8.59%。选取1℃温升值作为温升带的边界控制值,并在热泵系统最大负荷工况下,根据W=Q×ΔT计算研究水域热环境容量为19.402 m3.℃/s,剩余热环境容量为17.736 m3.℃/s。根据地表水环境质量标准,该工程温排水量小于受纳水域的热承载力,不会对受纳水域生态环境造成热污染。     

Community structure and biotic integrity of aquatic plants along the North Canal in Beijing北大核心CSCD

Aquatic plants along the North Canal in Beijing were studied to identify the community structure of aquatic plants and vegetation index of biotic integrity (VIBI), and to provide scientific basis for the management and protection of urban rivers. Aquatic plants from 49 sampling sites along the North Canal were investigated during June 2015. Based on the field data, distributing range analysis, discriminatory power analysis, and correlation analysis were used stepwise to select core metrics from candidate metrics to establish the VIBI assessment system. The VIBI value of each sampling site was calculated as the average of the scaled values of all core metrics. Thirty-six aquatic plant species, including 14 hygrophytes, 13 emergent species, 6 submergent species, 2 floating-leaved species, and 1 floating species were collected. Species diversity was low in the North Canal, and no aquatic plants were recorded in 28 sampling sites, of which 9 sampling sites were dried up. Five sites were in excellent condition (VIBI > 0.60), 5 were good (0.60 > VIBI > 0.38), 7 were fair (0.38 > VIBI > 0.23), and 4 were poor (VIBI < 0.23). Based on the distribution of VIBI, Shahe River and Wenyu River upstream, and Fenghe River located in suburbs had a higher VIBI. Downstream tributaries, such as Qinghe River, Bahe River, and Liangshui River, had a lower VIBI. Correlation analysis showed that habitat quality, habitat complexity, and vegetation diversity along riparian zones were the important factors affecting VIBI along the North Canal, Beijing. Aquatic plants along the North Canal showed low species diversity owing to human disturbance. VIBI along tributaries with limited disturbance from human activities was higher; however, VIBI along tributaries disturbed by frequent human activities was lower. © 2018 Science Press. All rights reserved.     

智能供氧系统在污水领域的应用研究

绍兴污水处理厂二期工程采用的是延时曝气工艺,生物氧化池是其核心工艺所在,在实际运行中,生物氧化池中溶解氧的数值波动大,较难实现稳定控制,通常采用滞后调整的控制方式,易造成能耗增加。为合理控制供气量,降低运行成本,利用欧洲的智能供氧技术,在经过小试的基础上,对二期其中一组生物氧化池进行中试,通过对几个月的试验数据进行对比分析,溶解氧控制较为平稳,供风量有所降低,从而实现了安全供氧和经济供氧,推动污水处理厂的精细化操作向纵深化发展。