上海市水体中人工放射性水平调查及评价

调查了１９８９－１９９１年不海市各类水体中人工放射性核素的水平。调查共设点１５个，采集枯、丰水期水样４５个，结果表明，上海市各类水体中＾９０Ｓｒ、＾１３７Ｃｓ和总β放射性浓度均低于国家生活饮用水卫生限制标准，属正常本底水平。按调查结果估算的上海市居民从饮水中摄入的人工放射性核素＾９０Ｓｒ、＾１３７Ｃｓ、＾３Ｈ，所致人均年有效剂量为３．８×１０＾－７ＳＶ，与全国均值相吻合。     

声屏障用于室内降噪的技术与经济问题

根据室内声屏障的降噪原理及影响因素,论述了室内声屏障降噪效果的评价与测量方法。通过固定式及活动式声屏障的设计,分析了室内声屏障的技术特点和经济效益。     

湛江港湾海域水质状况调查及其评价

根据 1 998年 1 1月到 2 0 0 1年 5月对湛江港湾海域 6期的监测结果 ,初步探讨了该海域环境因子的变化特征和营养水平。结果表明 ,该海域水质处于高氮状态 ,pH、SS、DO和CODcr的含量符合GB30 97- 1 997第二类海水水质标准 ;DIN和油类超过第二类海水水质标准 ;DRP含量的逐年增高 ,湛江港湾海域目前已处于中度富营养化水平阶段。     

Baseline Study on Essential and Trace Elements in Polished Rice from South Korea

In 2000, 63 (polished) white rice samples were collected in eight administrative areas all over South Korea and analyzed for 16 elements by inductively coupled plasma atomic emission spectrometry (ICP-AES). Potassium had the highest content, next to Mg, Ca, Si, Zn, Na, Al and Fe. Most of the samples contained worldwide average concentrations of essential and trace elements in rice grains reported by various researches. For inter-area differences in those elements in the rice, the statistical analysis showed no significant differences (p > 0.05) among the eight administrative areas, suggesting that inter-area differences were not substantial in most cases. Thus, the present data can be used as national background levels of elements in rice produced in South Korea. Using the published data on daily consumption of rice in South Korea, it was possible to estimate the daily intake of As, Cd, Cu, Pb and Zn via rice. The results showed that a regular consumption of rice produced in Korea plays an important role in accumulation of essential and trace elements in Korean, especially for farm-households consuming relatively large amounts of rice.     

AM真菌和施钾量对烟草植株钾素累积和分布的交互效应

采用盆栽试验，研究了不同施K水平下接种AM真菌摩西球囊霉（Glomus mosseae）对烤烟烟叶生长和植株中K素累积和分布的影响。结果表明，不同施K水平对AM真菌的接种效果有显著的影响，以每公斤土施K2O0.75-1.125g时接种效果最好。接种AM真菌提高了烟草根系菌根侵染率，增加了烟叶总干重，其中对中位烟叶效果明显，上位和下位烟叶因施K量而异，接种AM真菌显著增加了K在叶中的分配比例，减少了K在茎中的分配比例，提高了烟叶中K素的累积量，增加了成熟期烟叶K的含量。表5参8。     

Modeling of oak pollen dispersal on the landscape level with a mesoscale atmospheric model

We present the extension and application of the mesoscale atmospheric meteorology model METRAS for dispersion of oak pollen. We incorporated functions for pollen emission, pollen viability and pollen deposition into METRAS and simulated pollen dispersal on a scale of up to 200 km. The basis of the simulations is a real landscape structure that includes topography, land use, and the location and size of oak stands. We simulated the oak pollen dispersion of one single oak stand with an estimated annual pollen production of 1 billion pollen grains/m² forest surface on two exemplary days of the flowering season in 2000. Depending on the meteorological situation of the simulated days, a pollen cloud with about 10 pollen/m³ may extend up to 30 km from the source. Downstream of the oak stand, approximately 1,000 pollen/m² deposited up to a distance of 25 km, and lower amounts of pollen deposited up to 100 km away. These values of pollen concentration and deposition lay within the range of published field studies. Overall, it is shown that mesoscale atmospheric models are applicable to simulate pollen dispersal on the landscape level.     

环空带压气井保护液液位测试方法研究

为了有效检测环空保护液位,评估气井环空带压情况,在传统回声法检测的基础上,提出了基于频谱分析及自相关分析的2种液位检测方法;搭建了液位检测试验系统,开展了不同环空压力下的液位检测试验,计算了不同压力下的环空声速;设计了FIR低通滤波器对液面回波信号进行滤波处理,同时利用了上述2种方法计算液位值并与实际值及传统液位计算方法对比,得出了声衰减系数并评判了衰减过程对液面回波信号频谱分析的影响程度。研究结果表明:设计的FIR低通滤波器适用于所建液位检测试验的滤波处理过程;频谱分析及自相关分析都能够有效检测液位高度,最大误差分别为1.65%和0.61%,自相关分析方法具有更高的精确度;声衰减系数整体较小,对液面回波信号频谱分析结果影响较小。     

基于直觉模糊集的城市供水安全预警评价模型

为了更好地评价城市供水安全预警的等级,基于直觉模糊集理论,建立城市供水安全预警评价模型。模型选取12个评价指标构成属性集,预警等级划分标准构成评价等级集,再将二者转换为直觉模糊数,以此构成直觉模糊决策矩阵,并综合主、客观权重的优势得到组合权重,以此计算样本综合值,最后分析指标权重变化对于评价结果影响的灵敏度。实例计算结果表明:基于直觉模糊集的城市供水安全预警评价与可拓物元分析法的结果总体接近,2006—2009年供水安全预警等级处于重警或中警等级,2009年以后预警等级降低并基本稳定在无警这一等级。不同指标的敏感性分析有助于提高权重的准确性。     

Predicting retail shrink from performance pressure,ethical leader behavior,and store‐level incivility

Retail shrink, a form of inventory loss due primarily to employee theft and shoplifting, is a growing concern for retailers. Prior work on shrink has taken primarily an individual‐level focus to understanding this problem but has yet to really explore how the business context impacts shrink. The current study addresses this need by delineating and testing a unit‐level (i.e., between‐stores) conceptual model, wherein we examine the influence of performance pressure, ethical leader behavior, and store‐level incivility on shrink in a field study of 111 U.S. retail stores. Results demonstrate that performance pressure and ethical leadership interact to influence store‐level incivility. Further, stores with higher incivility also had higher levels of shrink. A focus on the contextual predictors of shrink provides timely insights into the role of performance pressure and leadership on store‐level incivility and consequently on retail shrink. In light of increasingly thin margins in the retail industry, the evidence on how pressure to perform and ethical leadership influences retail shrink may offer a solution to retailers looking to stem financial losses by promoting civility in the workplace.     

路径-脆弱点最短距离最大化的危险品运输网络设计

为了实现危险品运输网络的有效设计,进而降低危险品运输风险。将分布于公路两侧的医院、学校、居民区、购物中心等人口集聚场所定义为“脆弱点”,并通过计算运输路径和脆弱点间的加权距离来评估路段风险;结合双层理论构建模型,上层规划为政府的网络设计问题,通过关闭部分路段来最大化危险品车辆行驶路径与各脆弱点间的最小加权距离,下层规划则为承运商的车辆路径选择问题;为求解模型,设计1类启发式算法,并对算法的计算时间复杂性进行证明,最后根据算例分析发现,该算法经过有限数量的迭代即可得到风险最小的、次小的、…、第k小的运输路径及对应的路段关闭方案,为寻求兼顾运输风险和运输成本的最优方案提供决策支持。