北京市一日交流圈的空间特征及其动态变化研究

概括北京市一日交流圈的现状特征及其影响因素;通过比较分析发现各等级公路对一日交流圈的贡献大小取决于其等级、密度和分布形式;1990至2005年北京市一日交流圈的拓展受益于高速公路和国道的修建以及整体网络运行速度的提升;对未来重大交通设施建成后的模拟表明,高速铁路将成为北京市一日交流圈最有效的拓展途径。     

Occurrence of major and trace elements in powdered milk from Argentina

The concentrations of major and trace elements in Argentinean commercial powdered milk samples were determined with inductively coupled plasma mass spectrometry. Also the daily intake (DI) was calculated for adults and infants. The concentrations of B, Mg, Na, K and Ca were significantly higher in skimmed milk. Cu, Mo, Fe, Mn and Zn were significantly higher in infant formula. All the DIs were below the tolerable upper intake levels. The mean As concentration (26.0 ± 8.6 ng/g) in the powdered skimmed milk samples was slightly higher than in the others. Mean Pb concentrations ranged from 4.1 ± 2.1 to 13.5 ± 8.2 ng/g. The highest mean U concentration was 7.8 ± 2.6 ng/g for whole milk. This study contributes to the knowledge of major and trace elements in powdered milk and its contribution to the diet in Argentina.     

陕西潼关水坡巷沈氏民居初探

地处陕西潼关水坡巷的沈氏民居是一座保存完好的明代民居,该文通过对沈氏民居的考察测绘,从选址、历史沿革、院落布局、装饰等方面对其建筑形态和特点进行初步的探讨分析,展示出沈氏民居的现状与内涵．对陕西关中的古民居保护与发展具有一定意义。     

钟灵毓秀,越中奇葩——沈园的造园特色分析

沈园是我国古典园林艺术宝库中的一颗明珠,本文按照构图、要素和空间的理论,从布局、造园要素配置、造园理念和意境方面分析其造园特色,为我国的古典园林保护和现代景观建设实践提供借鉴作用。     

《人民日报》和《朝日新闻》气候变化科学类报道新闻框架分析

对《人民日报》和《朝日新闻》1992年以来10次联合国气候大会期间及前后一周的时间范围内的气候变化科学类报道进行了新闻框架分析。从新闻标题、新闻图片、消息来源、引语等分析单元入手,研究了两份报纸气候变化科学类报道的主要议题和科学知识分布特点。     

Determination of ethyl carbamate in some fermented Korean foods and beverages

Ethyl carbamate has been associated with cancer for several decades. It is mainly found in fermented foods and beverages. In view of the importance of fermented foods in the Korean diet and the significant level of ethyl carbamate expected, we determined ethyl carbamate concentrations in some of the staple food items and estimated the daily intake for the Korean population. Ethyl carbamate in commercial samples of kimchi, soy sauce, vinegar, soybean paste, and alcoholic beverages were determined by gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM). Homemade soy sauce and kimchi were also analysed. The maximum ethyl carbamate concentrations observed were 73 mu g/kg in soy sauce, 7.9 mu g/kg in soybean paste, 2.5 mu g/l in vinegar, 16.2 mu g/kg in kimchi and 15.4 mu/l in Korean traditional alcoholic beverages. Combining these values with the average daily food intake data, we estimated that the maximum daily exposure of Korean population to ethyl carbamate is 2.8 mu g/day, which is not a negligible amount considering the 'virtually safe dose' derived by animal experiment ranges between 1.2 and 4.8 mu g/day. It would be desirable to closely monitor ethyl carbamate levels in Korean foods and to find ways to reduce the daily intake.     

A multi-country assessment of compliance with daily disposable contact lens wear

PurposeTo investigate compliance with daily disposable contact lens (DDCL) wear and investigate re-use of lenses according to country and DDCL material worn.MethodsOptometrists invited eligible DDCL patients from their practices to participate in a survey on DDCL wear in Australia, Norway, the United Kingdom (UK) and the United States (US). Eligible participants completed an online or paper version of the survey.Results805 participants completed the survey (96% online): Australia 13%, Norway 32%, UK 17%, US 38%. The median age was 38 years; 66% were female. Silicone hydrogel (SiHy) DDCLs were worn by 14%. Overall, 9% were non-compliant with DDCL replacement; Australia 18%, US 12%, UK 7% and Norway 4%. There were no differences with respect to sex, years of contact lens wear experience or DDCL material (SiHy versus hydrogels). The primary reason for re-use was “to save money” (60%). Re-use of DDCLs resulted in inferior comfort at insertion and prior to lens removal (p = 0.001). 75% reported occasional napping and 28% reported sleeping overnight for at least one night in the preceding month, while wearing their DDCLs.ConclusionNon-compliance with replacement of DDCLs occurred in all countries investigated; the rate was highest in Australia and lowest in Norway. Re-use of DDCLs was associated with reduced comfort. DDCL wearers often reported wearing lenses overnight. It is important for optometrists to counsel their patients on the importance of appropriate lens wear and replacement for DDCLs.     

利用二维积分测试太阳能热水系统热性能的方法

GB/T19141-2011《家用太阳能热水系统技术条件》及GB26969-2011《家用太阳能热水系统能效限定值及能效等级》固化了家用太阳能热水系统的质量性能及强制规范,但这些方法也存在着一些问题,如:由于测试当天的太阳累计辐照度、当天的环境温度等不确定因素的直接或间接的影响,使得不同起始温度测试的集热器的热性能参数不具有可比性,或者规定天数内测试的整机日有用得热量存在误差。为此,我们研究利用数值理论《二维积分法》量化测试结果来解决这些问题。本文将针对该方法进行详细论述,并举例说明应用结果。     

Assessing exposure to phthalates – The human biomonitoring approach

Some phthalates are developmental and reproductive toxicants in animals. Exposure to phthalates is considered to be potentially harmful to human health as well. Based on a comprehensive literature research, we present an overview of the sources of human phthalate exposure and results of exposure assessments with special focus on human biomonitoring data. Among the general population, there is widespread exposure to a number of phthalates. Foodstuff is the major source of phthalate exposure, particularly for the long‐chain phthalates such as di(2‐ethylhexyl) phthalate. For short‐chain phthalates such as di‐n‐butyl‐phthalate, additional pathways are of relevance. In general, children are exposed to higher phthalate doses than adults. Especially, high exposures can occur through some medications or medical devices. By comparing exposure data with existing limit values, one can also assess the risks associated with exposure to phthalates. Within the general population, some individuals exceed tolerable daily intake values for one or more phthalates. In high exposure groups, (intensive medical care, medications) tolerable daily intake transgressions can be substantial. Recent findings from animal studies suggest that a cumulative risk assessment for phthalates is warranted, and a cumulative exposure assessment to phthalates via human biomonitoring is a major step into this direction.     

沈67块聚合物微球调驱技术可行性研究

结合沈67块油藏特征,研究了交联聚合物微球ESsc深部调驱体系封堵性能,进行聚合物微球室内岩心驱油模拟实验。实验结果显示:微球ESsc驱油时,当岩心渗透率在(500～3500)×10-3μm2范围内,微球驱对应采收率相对稳定,能满足化学驱提高采收率要求。另外,针对油藏孔隙吼道的多分布特征,在选择微球作为主调驱段塞时,应对特大孔隙采用过250目延迟体膨型颗粒调剖剂进行先期调剖。2009年在沈67块实施聚合物微球体系深部调驱先导试验,取得了较好效果。