汽车通风盖板发白现象的大数据分析

目的 以某型汽车自然曝露试验过程中通风盖板老化发白现象为例,研究建立影响汽车零部件自然老化的主要环境因素综合作用计算模型.方法 以试验大数据库为基础,利用互信息理论分析方法,确定影响汽车通风盖板发白的主要环境因素,并推导主要环境因素综合作用计算模型.结果 基于不同地区试验过程中每5 min记录1次的汽车通风盖板表面太阳辐照量和温度数据,精确计算了通风盖板出现发白现象的环境综合作用值.计算结果表明,当光热等效辐照值大于1882.8 J/cm2时,该通风盖板就会出现发白现象.结论 依据汽车外饰塑料件在典型地区的自然暴露试验结果,通过该模型可以预估其他地区的服役寿命.     

Driving safety improves after individualized training: An RCT involving older drivers in an urban area

Objective: This study aimed to reproduce the results of a previous investigation on the safety benefits of individualized training for older drivers. We modified our method to address validity and generalizability issues.

Methods: Older drivers were randomly assigned to one of the 3 arms: (1) education alone, (2) education?+?on road training, and (3) education?+?on road?+?simulator training. Older drivers were recruited from a larger urban community. At the pre- and posttests (separated by 4 to 8 weeks) participants followed driving directions using a Global Positioning System (GPS) navigation system.

Results: Our findings support the positive influence of individualized on-road training for urban-dwelling older drivers. Overall, driving safety improved among drivers who received on-road training over those who were only exposed to an education session, F(1, 40) = 11.66, P = .001 (26% reduction in total unsafe driving actions [UDAs]). Statistically significant improvements were observed on observation UDAs (e.g., scanning at intersections, etc.), compliance UDAs (e.g., incomplete stop), and procedural UDAs (e.g., position in lane).

Conclusion: This study adds to the growing evidence base in support of individualized older driver training to optimize older drivers’ safety and promote continued safe driving.     

A BIO ASSAY LABORATORY BOAT WITH COMPARISONS OF CENTRAL VS. BOAT LABORATORY BIOASSAY EVALUATIONS1

ABSTRACT: A laboratory boat designed to investigate toxic effects on site and its use as a bioassay tool in the study of a refinery effluent discharged into the Schuylkill River, a tributary of the Delaware River, is described. Three-hundred thirty-six-hour continuous-flow bioassay s exposing the bluegill sunfish, the channel catfish, the tadpole snail, the grass shrimp, and the sheephead minnow to concentrations of refinery effluent in Schuylkill, Delaware River, and Delaware Bay water, with and without the addition of sediment were performed. Results indicated that the toxicity (lethality) of fresh samples tested aboard the boat (refinery effluent, dilution water, sediment) were considerably higher (i.e., refinery effluent at full strength was 2.2X as lethal to the bluegill, 1.4X as lethal to the channel catfish, 1.5X as lethal to the sheep-head minnow and 100X as lethal to the grass shrimp) than the same test material collected from the refinery outfall and brought to a central laboratory for testing. Chemical analysis and bioassay data is presented showing the effects of aging and irradiation upon the refinery effluent.     

Impacts of sodium hydroxide and sodium hypochlorite aging on polyvinylidene fluoride membranes fabricated with different methods

This study compared the effects of chemical aging on the polyvinylidene fluoride(PVDF)membranes fabricated with the methods of non-solvent induced phase separation(NIPS)(named NIPS-PVDF) and thermally induced phase separation(TIPS)(named TIPS-PVDF). The chemical solutions of sodium hypochlorite(NaClO) and sodium hydroxide(NaOH) were chosen at the concentration of 5000 mg/L. The equivalence of 5 and 10 years was respectively selected as the time of aging. The physicochemical evolutions of membrane aging are characterized on the base of morphology analysis, chemical components, permeation ability and mechanical properties. The aging of NIPS-PVDF membrane led to the elimination of surface hydrophilic additives, while NaO H focused on the dehydrofluorination process resulting in the formation of conjugated chains of polyene on the skeleton structure. The chemical components of the surface of TIPS-PVDF membrane were removed continuously during the aging processes of both NaClO and NaOH, which was caused by the saponification of surface additives and the chain scissions of skeleton structure, but without producing any obvious conjugated chains of polyene. All the aging processes led to the increase of contact angle and the decrease of mechanical properties, and the permeability was reduced first and increased later due to the enlargement of surface membrane pores and membrane block. With the influence of membrane aging, selectivity of membrane was decreased(except coliform bacteria). At the beginning of filtration, the turbidity and particle count were at relatively high levels and declined with the filtration process.     

聚碳酸酯在不同试验方式下的光老化行为研究

目的研究不同试验方式下聚碳酸酯的光老化行为。方法对比聚碳酸酯在自然暴露试验、自然加速光老化试验及实验室光源暴露试验中的缺口冲击强度变化,分析各种加速试验方式对自然暴露试验的模拟性。结果聚碳酸酯在拉萨户外自然暴露中,其缺口冲击强度随试验时间的延长而降低。单轴跟踪暴露和跟踪太阳反射聚能暴露这两种自然加速光老化试验方式对户外自然暴露的模拟性均较好,加速倍率分别约为1.5,6。氙弧灯下的暴露试验对自然暴露试验的模拟性比紫外冷荧灯、金属卤素灯高。结论跟踪太阳反射聚能暴露、氙弧灯下暴露可推荐为评价聚碳酸酯光老化行为的加速试验方式。     

Toxicity evaluation in a paper recycling mill e uent by coupling bioindicator of aging with the toxicity identification evaluation method in nematode Caenorhabditis elegans

Toxicity identification evaluation (TIE) can be used to determine the specific toxicant(s) in industrial e uents. In the current study, the authors have attempted to combine the advantages of the model organism, Caenorhabditis elegans, with the virtues of the TIE technique, to evaluate and identify the toxicity on aging from a paper recycling mill e uent. The results indicate that only the toxicities from mixed cellulose (MC) filtration and EDTA treatment are similar to the baseline aging toxicity, suggesting that the suspect toxicants inducing aging toxicity may largely be the heavy metal substances in this industrial e uent. Examination of the accumulation of intestinal autofluorescence in adult animals further confirms that the short lifespans are actually due to accelerated aging. In addition, exposure to fractions of EDTA manipulations cannot result in severe defects of reproduction and locomotion behaviors in C. elegans. Moreover, high levels of Ca, Al, and Fe in the e uent may account for the severe toxicity on aging of exposed nematodes, by TIE assay. The study here provides a new method for evaluating environmental risk and identifying toxicant(s) from the industrial e uent using C. elegans.     

外源铜锌在我国典型土壤中的老化特征

采用室内培养的方法,研究了我国3种典型土壤——红壤、水稻土和褐土,在铜、锌单一污染和复合污染下的老化过程. 结果表明,有效态铜、锌（0.01 mol·L^-1 CaCl₂提取的金属）随时间先是快速下降,然后缓慢降低,大约90 d是转折点. 无论是在单一污染还是在复合污染土壤中,铜和锌的老化都没有显著差异,预示着这2个金属有相似的化学行为. 铜、锌在红壤、水稻土和褐土中的老化最适合二级动力学方程（R²为0.994 0～0.999 9, p<0.000 1）,而抛物线扩散方程拟合程度较差,说明金属有效形态向无效形态的转化过程（老化）并不完全取决于扩散作用,它是表面聚合/沉淀作用、有机质包裹作用、扩散作用等交互的结果. 铜锌在土壤中的老化显著受pH影响,在低pH土壤（红壤）,金属有效形态比例高,老化速率慢,速率常数k₂为4.36×10^-3～7.05×10^-3 kg·(mg·d)^-1;高pH土壤（褐土）中,金属有效形态比例低,老化速率快,k₂为1.095×10^-2～1.377×10^-2 kg·(mg·d)^-1. 也就是说,随土壤pH升高,金属的老化速率加快.     

铜沉淀提高铸造马氏体不锈钢耐空蚀性能研究

针对普通马氏体铸造不锈钢在含氯离子溶液中耐点蚀和耐空蚀能力不足的问题,自行设计冶炼了一种经铜沉淀硬化的马氏体铸造不锈钢。通过力学性能测试、动电位极化扫描空泡腐蚀试验并结合SEM分析,研究了热处理工艺和铜含量对自行设计冶炼MSB马氏体不锈钢耐空蚀性能的影响。结果表明经铜沉淀的铸造马氏体不锈钢在3％NaCl溶液中的耐点蚀性能优于普通奥氏体不锈铜1Crl8Ni9Ti和高锰铝青铜,铜含量对铸造马氏体不锈钢的耐点蚀性影响不大。热处理工艺对铸造马氏体不锈钢耐空蚀性能有较大影响,时效温度越高,耐空蚀性能越差。当铜的质量分数在1．5％～2．5％之间时可以获得较好的强化效果,不锈钢的耐空蚀性能最好。     

鄱阳湖区农户经济行为变化对农业系统脆弱性的影响——基于农户问卷调查的实证研究

通过对鄱阳湖区7县市17个村子的农业生产活动和耕地流转问卷调查结果分析发现,不同年龄、教育程度、收入来源和谋生能力决定着该区农户从事农业生产的意愿。目前外出打工的农民中年轻人最多,在家从事农业生产的多为年长者;家庭收入的无保障和外出打工的不稳定性,使得大部分农民仍把土地作为重要的生活保障手段;劳动力依然处在低水平状态,而且支撑当地社会经济发展的后续劳动力严重不足,农村社会即将面临老龄化问题,农业生产系统的脆弱性日趋严重。为使当地农业生产可持续发展,确保国家粮食安全,需要在研究区域内实施有效的、具有造血功能的生态补偿机制以增加农户收入,改善恶化的人-地关系,同时还需要采用耕地流转土地管理机制和建立健全农村社会保障体系。     

中国特色养老旅游地功能内涵及体系探讨——基于“五老功能”多样化诉求视角

基于人们日益增长的"老有所养、老有所医、老有所学、老有所为、老有所乐"多样化诉求,依据马斯洛需求层次理论,构建我国养老型旅游地功能体系,提出在已有旅游目的地中融入养老旅游所需元素的"嵌入式"发展路径和在城郊、小城镇、乡村等适宜场地专门建设养老型旅游地的"专业式"发展路径。从日常生活、医疗保健、学习氛围、老年就业、愉悦体验5个维度提出养老型旅游地的发展目标,从健康服务体系、分类医养体系、终身教育体系、科学劳动体系、旅游产品体系5个方面给出发展建议。