大学英语教学文化渗透的重要性及其方法

目前,大学英语教学中普遍存在着这样的问题:片面强调词汇及语法知识的教学,而忽略了英美文化背景知识的传授.这就使得学生只会单纯的记忆词汇、分析语法结构,对英美文化知识却知之甚少,从而导致了对文章中出现的与文化有关的内容不理解.为了让同行们认识到这个问题给学生的英语学习所带来的不良影响,笔者从四个方面阐述了大学英语教学中文化渗透的重要性,并对文化渗透的5种方法运用课文中的实例,进行了深入详尽的论述.     

IMPLEMENTATION OF BIORETENTION SYSTEMS: A WISCONSIN CASE STUDY1

ABSTRACT: The implementation of various bioretention systems was analyzed, including rain gardens, vegetated swales, trenches, and infiltration basins in the St. Francis subdivision, Cross Plains, Wisconsin. Through the examination of archival data and interviews with key participants, it was found that although regulatory and political pressures encouraged the inclusion of bioretention, current standards for storm water management prevailed. The developers had to meet both existing requirements and anticipated rules requiring infiltration. As a result, bioretention systems simply supplemented, rather than replaced, traditional storm water practices. The confusion surrounding dual standards contributed to substantial delays in the negotiations among relevant stakeholders in the watershed. It is concluded that the St. Francis subdivision serves as both a cautionary tale and a bioretention success story. As a caution, this situation demonstrates the need for careful review and refinement of existing storm water ordinances to incorporate water quality improvement technologies, such as bioretention. The demonstrated success of the St. Francis development, however, is that it became a positive prototype for best management storm water practices elsewhere in the region. In addition, the water quality monitoring data from the site has contributed to development of a new county ordinance, the first in Wisconsin to address both quantity and quality of storm water runoff.     

MODELING INFILTRATION WITH VARYING HYDRAULIC CONDUCTWITY UNDER SIMULATED RAINFALL CONDITIONS1

ABSTRACT: Physically-based models are extensively used to simulate the infiltration process under varied field conditions. Most models are based on the deterministic nature of input parameters related to the flow process (such as hydraulic conductivity). These models yield poor predictions of infiltration rates because they do not include the field-scale variations of flow parameters. The paper presents an approach for integrating the field-scale variability of hydraulic conductivity with an infiltration model to simulate infiltration under the rainfall conditions. A model describing the spatial structure of hydraulic conductivity has been developed using stochastic techniques. The stochastic structure of hydraulic conductivity was then incorporated in the Green-Ampt and Mein-Larson infiltration model. The model outputs on the instantaneous infiltration rates and cumulative infiltration were evaluated using the field infiltration data measured under simulated rainfall conditions. The results show that the combined model is capable of rep. resenting the instantaneous infiltration rates and cumulative infiltration of the study soils. The model may, therefore, be used to simulate the rainfall infiltration process for spatially-variable soils under the field conditions.     

土壤渗滤系统中污染物去除效果分析

在土壤渗滤系统中,水力负荷、有机负荷和碳氮比等因素均对营养盐的处理效率具有显著影响.在实验室控温条件下,分析了不同水力负荷、有机负荷和环境条件对土壤渗滤系统污染物去除效果的影响.结果表明,在水力负荷小于0.15 m3·m^-2·d^-1的条件下,模拟生活污水中CODCr、总氮和总磷去除率分别达到84％、37％和93％以上,土壤（以干土计）亚硝酸盐细菌数量为4.50× 106 g^-1.装置上层产生的滞水对CODCr和磷酸盐的去除影响不大,但是由于处理系统内溶解氧浓度降低,使得氨氮硝化过程受到抑制,氨氮和总氮的处理效果均变差;在通气良好条件下,较高的碳氮比[m（碳）：m（氮）=5：1]对系统中总氮的去除更为有利.     

利用CRI作为人工湿地预处理措施的工艺研究

人工湿地处理系统作为一种对于面源污染有较好针对性的生态型污水处理技术,构建简单,成本低,但也存在诸多缺陷。利用人工快渗(CRI)作为人工湿地的预处理措施,使得系统的氧恢复能力增强,过水速率提高,能有效缓解堵塞问题,改善人工湿地的水力条件。实验研究表明:增加CRI工艺作为预处理措施可以很大程度上改善单一人工湿地的出水水质。     

高羊茅和结缕草对地下渗滤系统中氮磷的去除研究

研究了高羊茅和结缕草覆盖的地下渗滤系统处理生活污水过程两种草坪草对氮、磷的去除作用。研究结果表明:高羊茅含有的总氮浓度在46.8～52.7 g/kg变化,且显著高于结缕草的总氮浓度;高羊茅含有的总磷浓度在4.64～5.89 g/kg之间变化,两种草坪草之间没有显著差异;高羊茅的日平均氮带出量在不同的月份分别为0.237,0.180,0.118 g/(m2.d),显著高于结缕草的日平均氮带出量;高羊茅对生活污水中的氮去除率在2011年9月、10月及11月分别为21.4%,、13.1%和11.8%;高羊茅的日平均磷带出量在不同的月份分别为23.4,15.1,13.8 mg/(m2.d),显著高于结缕草的日平均磷带出量;高羊茅对生活污水中的磷去除率在2011年9月、10月及11月分别为30.2%、24.4%和22.4%。     

高速公路通道集水净化渗透系统及其水质分析

结合河北省大广高速公路衡大段实体工程,针对路表径流污染物的种类及处理机理,提出了通道集水净化渗透系统的好氧兼氧消化-沉淀-人工材料吸附-土壤渗滤一元化的复合工艺,该工艺主要采用蛭石作为过滤材料,将路表径流的污染物控制在饮用水水质标准范围内,不仅有效地解决了通道积水问题,还使得地下水得到补充。     

The Role of Soil Surface Crusting in Desertification and Strategies to Reduce Crusting

Soil crusting decreases infiltration, increases erosion, and impedes vegetation establishment, so reducing the impact of crusting is of major importance in combating desertification. Although surface crusting has been the subject of considerable research over the past 50 years or more, the practical management of soil crusts remains a challenge for many dryland communities. Crusting occurs in two steps, an initial aggregate breakdown period that occurs under rainfall and a subsequent hardening phase during drying. Several factors influence crust development, but the single most important one is soil aggregate stability. Strategies to reduce crusting can be based either on protecting the surface from raindrop impact or improving aggregate stability, or a combination of both. However, crust control is labor and/or capital intensive and must be thought out clearly in terms of the benefits to be achieved.     

EFFECT OF RAINFALL-EXCESS DETERMINATION ON RUNOFF COMPUTATION1

ABSTRACT: Four methods of determining rainfall-excess are considered. They include Ø-index and equations of Horton, Kostyakov and Philip. These methods are utilized in a nonlinear kinematic wave model to predict surface runoff from two natural agricultural watersheds. The effect of determining rainfall-excess on surface runoff response is then examined. It is observed that errors in rainfall-excess constitute a major source of error in runoff prediction. The choice of a method of determining rainfall-excess is thus crucial to runoff computation.     

ASSESSMENT OF SAMPLING ERROR ASSOCIATED WITH SOIL MOISTURE ESTIMATION DESIGNS1

A spectral formalism was developed and applied to quantify the sampling errors due to spatial and/or temporal gaps in soil moisture measurements. A design filter was developed to compute the sampling errors for discrete measurements in space and time. This filter has as its advantage a general form applicable to various types of sampling design. The lack of temporal measurements of the two‐dimensional soil moisture field made it difficult to compute the spectra directly from observed records. Therefore, the wave number frequency spectra of soil moisture data derived from stochastic models of rainfall and soil moisture were used. Parameters for both models were estimated using data from the Southern Great Plains Hydrology Experiment (SGP97) and the Oklahoma Mesonet. The estimated sampling error of the spatial average soil moisture measurement by airborne L‐band microwave remote sensing during the SGP97 hydrology experiment is estimated to be 2.4 percent. Under the same climate conditions and soil properties as the SGP97 experiment, equally spaced ground probe networks at intervals of 25 and 50 km are expected to have about 16 percent and 27 percent sampling error, respectively. Satellite designs with temporal gaps of two and three days are expected to have about 6 percent and 9 percent sampling errors, respectively.