Partitioning of Fluoroquinolones on Wastewater Sludge     

Xuefei Zhou  Yalei Zhang  Lu Shi  Jiabin Chen  Zhimin Qiang  Tian C. Zhang 《洁净——土壤、空气、水》2013,41(8):820-827

Laboratory‐scale batch experiments were conducted to investigate the adsorption behavior of eight fluoroquinolones (FQs) on aerobic, anoxic, and anaerobic sludge, under different adsorpiton time, pH, and temperature conditions. Results indicated that adsorption of FQs onto all sludge was a physical sorption process. The relationship of the partitioning coefficient (K_d) and the octanol/water partition coefficient (K_ow) for each FQ was established. The adsorbed fraction of FQs on sludge could then be predicted with the K_d. It was calculated that about 50–72% of the FQs were adsorbed on the sludge. Therefore, the adsorption effect must be considered when studying the fate and occurrence of FQs in wastewater treatment systems.  相似文献   

Development of a data mining method for land control     

Wang Shuliang  Wang Xinzhou  Shi Wenzhong 《地球空间信息科学学报》2013,16(1):68-76

Land resources are facing crises of being misused, especially for an intersection area between town and country, and land control has to be enforced. This paper presents a development of data mining method for land control. A vector-match method for the prerequisite of data mining i. e., data cleaning is proposed, which deals with both character and numeric data via vectorizing character-string and matching number. A minimal decision algorithm of rough set is used to discover the knowledge hidden in the data warehouse. In order to monitor land use dynamically and accurately, it is suggested to set up a real-time land control system based on GPS, digital photogrammetry and online data mining. Finally, the means is applied in the intersection area between town and country of Wuhan city, and a set of knowledge about land control is discovered.  相似文献   

QTPV data model and algorithm and its application to geological exploration engineering     

Cheng Penggen  Shi Wenzhong  Gong Jianya  Zhou Guoqing 《地球空间信息科学学报》2013,16(1):64-71

3D spatial data model and simulating are the core of 3D GIS can be adopted in different domains. A data model based on Quasi Tri-Prism Volume (QTPV) has been proposed. QTPV definition and its special cases have been discussed. Using QTPV and its special cases, irregular natural geological bodies and regular subsurface engineering can be described efficiently. The proposed model is composed of five primitives and six objects. Data structures and topological relationship of the fives primitives and three objects describing stratigraphy are designed in detail. Some schemes are designed for the QTPV modelling of stratigraphy and subsurface engineering according to modelling data. The model manipulation method of QTPV cutting by an arbitrary plane is discussed. Using VC++ 6.0 programming language integrated with SQL database and OpenGL graphic library under windows environment, a system prototype 3DGeoMV has been developed. The experiment result shows that the QTPV model is feasible and efficient in modelling subsurface engineering.  相似文献   

Development of a GIS data model with spatial,temporal and attribute components based on object-oriented approach     

Shi Wenzhong  Zhang Minwen 《地球空间信息科学学报》2013,16(1):17-23

This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model includes two major parts: (a) modeling the signal objects by STA-object elements, and (b) modeling relationships between STA-objects. As an example, the STA-model is applied for modeling land cover change data with spatial, temporal and attribute components.  相似文献   

Interannual variability of the sea surface salinity and its related freshwater flux in the tropical Pacific: A comparison of CMIP5 and CMIP6          下载免费PDF全文

Hai Zhi  Yu Huang  Pengfei Lin  Shiwei Shi  Meng Dong 《大气和海洋科学快报》2022,15(4):100190

This paper assesses the interannual variabilities of simulated sea surface salinity (SSS) and freshwater flux (FWF) in the tropical Pacific from phases 5 and 6 of the Coupled Model Intercomparison Project (CMIP5 and CMIP6). The authors focus on comparing the simulated SSS and FWF responses to El Niño–Southern Oscillation (ENSO) from two generations of models developed by the same group. The results show that CMIP5 and CMIP6 models can perform well in simulating the spatial distributions of the SSS and FWF responses associated with ENSO, as well as their relationship. It is found that most CMIP6 models have improved in simulating the geographical distribution of the SSS and FWF interannual variability in the tropical Pacific compared to CMIP5 models. In particular, CMIP6 models have corrected the underestimation of the spatial relationship of the FWF and SSS variability with ENSO in the central-western Pacific. In addition, CMIP6 models outperform CMIP5 models in simulating the FWF interannual variability (spatial distribution and intensity) in the tropical Pacific. However, as a whole, CMIP6 models do not show improved skill scores for SSS interannual variability, which is due to their overestimation of the intensity in some models. Large uncertainties exist in simulating the interannual variability of SSS among CMIP5 and CMIP6 models and some improvements with respect to physical processes are needed.摘要通过比较CMIP5和CMIP6来自同一个单位两代模式模拟, 表明CMIP5和CMIP6均能较好地模拟出热带太平洋的海表盐度 (SSS) 和淡水通量 (FWF) 对ENSO响应的分布及其响应间的关系. 与CMIP5模式相比, 大部份CMIP6模式模拟的SSS和FWF年际变化分布均呈现改进, 特别是纠正了较低的中西太平洋SSS和FWF变化的空间关系. 但是, 整体上, CMIP6模式模拟的SSS年际变化技巧没有提高, 与SSS年际变率的强度被高估有关. CMIP5和CMIP6模式模拟SSS的年际变化还存在较大的不确定性, 在物理方面需要改进.  相似文献   

Tropical forcing of Australian extreme low minimum temperatures in September 2019     

Lim  Eun-Pa  Hendon  Harry H.  Shi  Li  de Burgh-Day  Catherine  Hudson  Debra  King  Andrew  Trewin  Blair  Griffiths  Morwenna  Marshall  Andrew 《Climate Dynamics》2021,56(11):3625-3641

We explore the causes and predictability of extreme low minimum temperatures (T_min) that occurred across northern and eastern Australia in September 2019. Historically, reduced T_min is related to the occurrence of a positive Indian Ocean Dipole (IOD) and central Pacific El Niño. Positive IOD events tend to locate an anomalous anticyclone over the Great Australian Bight, therefore inducing cold advection across eastern Australia. Positive IOD and central Pacific El Niño also reduce cloud cover over northern and eastern Australia, thus enhancing radiative cooling at night-time. During September 2019, the IOD and central Pacific El Niño were strongly positive, and so the observed T_min anomalies are well reconstructed based on their historical relationships with the IOD and central Pacific El Niño. This implies that September 2019 T_min anomalies should have been predictable at least 1–2 months in advance. However, even at zero lead time the Bureau of Metereorolgy ACCESS-S1 seasonal prediction model failed to predict the anomalous anticyclone in the Bight and the cold anomalies in the east. Analysis of hindcasts for 1990–2012 indicates that the model's teleconnections from the IOD are systematically weaker than the observed, which likely stems from mean state biases in sea surface temperature and rainfall in the tropical Indian and western Pacific Oceans. Together with this weak IOD teleconnection, forecasts for earlier-than-observed onset of the negative Southern Annular Mode following the strong polar stratospheric warming that occurred in late August 2019 may have contributed to the T_min forecast bust over Australia for September 2019.

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DETERMINING GROUNDWATER SUSTAINABLE YIELD IN BASINS:A CASE STUDY OF YINMA RIVER BASIN     

Shi Fengzhi  Chi Baoming  Zhao Chengyi  Lan Shuangshuang 《第四纪研究》2012,32(2)

地下水可持续开采量的确定与评价既是合理开发地下水资源的基础,又是水文地质学研究中的难点.为克服没有统一的评价标准以及对众多约束条件难以定量化计算的难点,本文从提高流域内整体水资源的利用率出发,综合考虑了流域水资源整体开发利用效益和生态环境需水,以及人工调蓄作用对地下水系统的影响作用,提出了流域地下水可持续开采量的概念;论述了所提出概念的内涵;建立了由流域水循环模拟模型、水资源开发综合效益模型和可持续开采量优化模型组成的流域地下水可持续开采量的评价体系,将流域水循环模拟模型作为研究平台,以水资源开发的综合效益模型作为选优依据,以不同生态环境需水条件为约束条件,对施加其上的各种不同调控措施进行模拟,最后通过性价比的综合分析与评估,得到可持续开发方案下的流域地下水可持续开采量.以吉林省饮马河流域为例展开实例应用,确定饮马河流域最满意的开发模式下,即水库高比例供水(水库供水4.850×108m3),保证河道适宜生态需水时,饮马河流域地下水可持续开采量为2.516×108m3/a.  相似文献   

海水热力学方程TEOS-10及其与海水状态方程EOS-80的比较     

孙永明  史久新  阳海鹏 《地球科学进展》2012,27(9):1014-1025

新的2010年海水热力学方程TEOS-10采用1990年国际温标以及考虑世界大洋海水组成空间差异的绝对盐度,与旧的1980年海水状态方程EOS-80相比,具有更高的准确度和更广的适用范围,能够直接计算包括熵、焓、热容量在内的旧方程无法计算的热力学变量,将给海洋学研究带来重要的影响。借助气候态平均数据计算的结果表明,新旧方程计算的密度之差,在全球大多数海域可超过10-2kg/m3。在赤道以北的太平洋和印度洋海域,包括中国东海和南海的深海区域,该差别尤为显著,在精度要求较高的研究中必须予以考虑。新方程对密度计算的这一修正主要归因于其首次提出的绝对盐度,考虑了包括中性溶质在内的所有溶质的作用,弥补了实用盐标的缺陷。新旧方程计算冰点等其他物理量也有相应的修正。应尽快推广应用TEOS-10以及绝对盐度,充分发挥其对海洋学发展的推动作用。  相似文献   

HDD铺管引起地表工后变形的数值模拟分析     

刘耀东  石朋飞  乌效鸣 《岩土钻凿工程》2012,(4):1-5

水平定向钻进（HDD）是一种重要的非开挖铺管技术,在非开挖领域应用非常广泛。由于其会扰动周围地层以及造成地层损失,进而造成一定程度的地表变形,如地表沉降、地表水平变形等。本文采用有限差分数值模拟方法,运用FLAC3D软件分析了HDD铺管的引起的地表工后变形问题;综合考虑了不同地层内聚力、地表荷载及扩孔级数情况下的地表工后变形。  相似文献   

某洞库裂缝原因分析及加固设计     

时卫民  杨智  舒蕴忠 《岩土工程技术》2012,26(4):185-187,191

在分析某洞库裂缝原因的基础上,采用间隔增设二次衬砌的方法对洞库进行了加固设计,提出了以控制原衬砌混凝土不出现裂缝的原则来确定二次衬砌间距的确定方法,并利用叠合构件位移协调的条件推导出了二次衬砌上荷载的计算公式,为洞库的二次衬砌加固提供了一套设计方法。  相似文献