渗滤液污染包气带中铁的形态变化

从渗滤液场龄和包气带岩性两方面出发,研究了新、老渗滤液对亚粘土和细砂包气带环境中Fe的含量及存在形态的影响。结果表明：新、老渗滤液分别能使细砂包气带介质中除残渣态以外Fe的含量增加16.68%或降低13.82%。亚粘土比细砂作为包气带介质更能缓冲渗滤液对介质中Fe的影响程度,其受影响范围在包气带0～20 cm深度处。当亚粘土为介质的包气带被新渗滤液污染后,其表层介质中碳酸盐结合态Fe的含量会增加15倍之多,为缓冲渗滤液Fe的污染做出了巨大贡献,但这部分Fe的存在也是潜在的二次污染源,在环境pH急剧变化的情况下,它可能会引起地下水高铁污染。     

秦皇岛山羊寨动物群及其生存环境的研究

1981年,笔者在泰皇岛市抚宁县山羊寨村小南山发现大量动物化石,经鉴定共有32种动物,其中绝灭种7个,时代为新生代第四纪中更新世,绝对年龄为（18±2）万年至（20±2）万年,相当于北京周口店动物群后期。研究发现：其生活在低山丘陵及其河谷;当时的气候是温和湿润的温带气候,但已向凉干转化;植被为温带落叶阔叶林。     

我国消防标准体系分析

为明确我国消防标准体系发展的方向和重点,分别从消防标准的数量、标龄、类型、属性和采标情况等5个方面对我国消防标准体系进行分析,并与国际标准化组织、欧盟标准化委员会和美国的消防标准体系进行了比较。研究结果表明:我国消防标准体系整体适用性在不断增强;需制定周期性标准复审计划;消防基础试验类和管理类标准应成为下一步消防标准制修订的重点;消防强制性标准所占比例有待进一步下调;需建立国际标准动态跟踪机制,同时应注重将我国先进的消防标准转化为国际标准。     

Autonomous emergency braking systems adapted to snowy road conditions improve drivers' perceived safety and trust

Objective: This study investigated drivers' evaluation of a conventional autonomous emergency braking (AEB) system on high and reduced tire–road friction and compared these results to those of an AEB system adaptive to the reduced tire–road friction by earlier braking. Current automated systems such as the AEB do not adapt the vehicle control strategy to the road friction; for example, on snowy roads. Because winter precipitation is associated with a 19% increase in traffic crashes and a 13% increase in injuries compared to dry conditions, the potential of conventional AEB to prevent collisions could be significantly improved by including friction in the control algorithm. Whereas adaption is not legally required for a conventional AEB system, higher automated functions will have to adapt to the current tire–road friction because human drivers will not be required to monitor the driving environment at all times. For automated driving functions to be used, high levels of perceived safety and trust of occupants have to be reached with new systems. The application case of an AEB is used to investigate drivers' evaluation depending on the road condition in order to gain knowledge for the design of future driving functions.

Methods: In a driving simulator, the conventional, nonadaptive AEB was evaluated on dry roads with high friction (μ = 1) and on snowy roads with reduced friction (μ = 0.3). In addition, an AEB system adapted to road friction was designed for this study and compared with the conventional AEB on snowy roads with reduced friction. Ninety-six drivers (48 males, 48 females) assigned to 5 age groups (20–29, 30–39, 40–49, 50–59, and 60–75 years) drove with AEB in the simulator. The drivers observed and evaluated the AEB's braking actions in response to an imminent rear-end collision at an intersection.

Results: The results show that drivers' safety and trust in the conventional AEB were significantly lower on snowy roads, and the nonadaptive autonomous braking strategy was considered less appropriate on snowy roads compared to dry roads. As expected, the adaptive AEB braking strategy was considered more appropriate for snowy roads than the nonadaptive strategy. In conditions of reduced friction, drivers' subjective safety and trust were significantly improved when driving with the adaptive AEB compared to the conventional AEB. Women felt less safe than men when AEB was braking. Differences between age groups were not of statistical significance.

Conclusions: Drivers notice the adaptation of the autonomous braking strategy on snowy roads with reduced friction. On snowy roads, they feel safer and trust the adaptive system more than the nonadaptive automation.     

Performance of IUCN proxies for generation length

One of the criteria used by the International Union for Conservation of Nature (IUCN) to assess threat status is the rate of decline in abundance over 3 generations or 10 years, whichever is longer. The traditional method for calculating generation length (T) uses age‐specific survival and fecundity, but these data are rarely available. Consequently, proxies that require less information are often used, which introduces potential biases. The IUCN recommends 2 proxies based on adult mortality rate, = α + 1/d, and reproductive life span, = α + z^*RL, where α is age at first reproduction, d is adult mortality rate, RL is reproductive life span, and z is a coefficient derived from data for comparable species. We used published life tables for 78 animal and plant populations to evaluate precision and bias of these proxies by comparing and with true generation length. Mean error rates in estimating T were 31% for and 20% for , but error rates for were 16% when we subtracted 1 year ( ), as suggested by theory; also provided largely unbiased estimates regardless of the true generation length. Performance of depends on compilation of detailed data for comparable species, but our results suggest taxonomy is not a reliable indicator of comparability. All 3 proxies depend heavily on a reliable estimate of age at first reproduction, as we illustrated with 2 test species. The relatively large mean errors for all proxies emphasized the importance of collecting the detailed life‐history information necessary to calculate true generation length. Unfortunately, publication of such data is less common than it was decades ago. We identified generic patterns of age‐specific change in vital rates that can be used to predict expected patterns of bias from applying .     

汶川大地震灾后青少年心理援助经验启示

为探索和创新汶川大地震以及其他灾情灾后青少年心理援助提供科学决策依据,通过对四川灾区民众的调查分析及其对收集的信息资料研究,着重揭示了汶川大地震灾后青少年心理援助的经验：“三个加强”——加强方式、方法、机制“三位一体”对青少年心理援助,“三个强化”——社会、学校、家庭“三位一体”对青少年心理援助的启示。     

环境健康价值评估中的年龄效应研究

在环境健康价值评估研究中,统计寿命价值和年龄之间的关系是理论和实证研究焦点之一,也是重要的学术问题。长久以来,环境政策效益评估中是否应该赋予老年人较低的统计寿命价值一直存在广泛争议,且尚未得到一致性结论。通过设计选择实验,对北京市空气质量改善的健康效益进行了抽样调查,并采用MNL模型对北京市约500个居民的调查数据进行回归分析,估算了不同年龄人群对健康风险减少的支付意愿,针对中国人群中统计寿命价值和年龄之间的关系进行实证探讨。结果表明:一方面,在总体样本中设置年龄虚拟变量,回归结果表明年龄变量系数的符号均显著为负,即年龄因素对减少空气污染带来的死亡风险降低的支付意愿具有显著的影响,年龄越大支付意愿相对越小;另一方面,不同年龄人群分组样本结果显示,统计寿命价值与年龄之间呈现"倒U型"关系,统计寿命价值在中国存在"老年折扣"现象。研究结果可为我国环境政策的健康效益分析中如何考虑年龄的影响提供重要依据。     

不同碳源和泥龄对反硝化聚磷的影响

在4个SBR装置(1#~4#)中,对4种不同比例的丙酸/乙酸合成废水采用厌氧/缺氧方式驯化富集反硝化聚磷菌(DPB),研究了碳源浓度和污泥龄对除磷的影响。实验结果表明:(1)厌氧段碳源COD浓度越高,释磷越充分,溶解性正磷酸盐(SOP)去除率越高;但当碳源COD浓度超过某个浓度值时,未反应完全的有机物残留于后续缺氧段对缺氧吸磷产生抑制作用。(2)污泥龄SRT=15 d时,活性污泥的性能较好,达到了较好的除磷效果。(3)在相同碳源浓度和相同的污泥龄下,随着丙酸/乙酸比例的提高,SOP的去除率逐渐的降低。说明在厌氧/缺氧环境下,碳源中丙酸比例的提高不利于系统中磷的去除。高乙酸含量的碳源更适合反硝化除磷系统。     

三峡库区水质和水龄数值模拟研究

三峡水库是我国重要的生态屏障和水资源战略储备库,保护水库的水质安全对于国家经济发展和社会稳定具有重要战略意义.本文基于EFDC模型模拟了2010-2014年三峡库区及主要支流的水动力水质过程,重点研究上游来水和重点支流对库区水质的影响及水龄变化特征,结果表明:①模型可定量研究重点支流输入对库区水质的影响,17条支流中仅...