棉布厚度对辐射式电暖器引燃能力影响研究

实验研究了棉布厚度对辐射式电暖器的引燃能力影响情况。实验用电暖器上加热管向外辐射热通量占电器功率之间的比例(辐射率η值)为65%。辐射式电暖器可以使棉布发生阴燃燃烧,当单面工作功率为400 W的电暖器紧贴棉布且全过程全覆盖的前提下棉布阴燃的临界厚度在0.18 mm～0.48 mm之间,当棉布厚度超过0.48 mm时将发生阴燃,但薄棉布通常难以直接发生有焰燃烧。对于用棉布开始阴燃时间表征的电暖器引燃能力,随着棉布厚度的增大,电暖器对棉布的引燃能力将减弱。     

低压环境对锂电池热失控释放温度影响

为研究锂电池在民航飞行低压特殊环境的安全性及发生热失控灾害后的高温危险性,通过可模拟飞行变动条件的动压变温实验舱开展系列实验,研究锂电池在不同低压环境下的（101,60,30 kPa）多节18650型锂离子电池热失控温度特性,采集电池池体温度及热失控喷射释放温度等参数。研究结果表明:随环境压力降低,圆柱锂电池间的热失控传播并不能被阻断,但锂电池热失控灾害所释放产生的高温区域减少,且高温持续时间变短,释放所产生温度的高温危险性随环境压力的降低而有所降低。     

基于CEEMDAN-SOBI对桥梁监测挠度的分离研究

为实现桥梁挠度监测信号各种效应值的分离,提出1种基于自适应噪声的完备集合经验模态分解（Complete Ensemble Empirical Mode Decomposition with Adaptive Noise,CEEMDAN）结合二阶盲源辨识（Second Order Blind Identification,SOBI）的单通道盲源分离算法。首先利用自适应噪声的完备集合经验模态分解将单通道的桥梁挠度信号分解为一系列线性平稳的本征模函数,计算各子序列的排列熵（Permutation Entropy,PE）并将排列熵值相近的序列相加组成新的序列;然后采用K-L散度的判别法剔除虚假的分量,将真实的分量组成盲源分离模型的输入信号;最后采用二阶盲源辨识对输入信号进行盲源分离,得到桥梁监测挠度的各效应值。结果表明:该方法能有效分离挠度监测信号中的各种效应值。     

中国市政污泥末端处置技术的发展及存在问题

随着中国污水处理行业的高速发展,城市污水处理量显著提高,污水处理的二次产物污泥的产量亦随之剧增.市政污泥是市政废水处理的剩余固态物质,性质复杂,处理难度较大,是当今需要解决的重要问题之一.文章围绕当前主流的市政污泥的产生工艺、末端处置技术加以探讨,介绍了活性污泥法的产生和发展、剩余污泥的危害和主要的末端处置技术,分析了市政污泥处置领域中研究和应用的关键问题,对进一步了解中国当前市政污泥处置领域的发展具有一定借鉴意义.     

基于油松树轮宽度重建河北青龙过去123年平均相对湿度

相对湿度的研究对理解古气候变化有着重要的科学意义,但是目前国内利用树轮资料重建的历史时期相对湿度变化十分有限。本文利用油松树轮宽度重建了河北青龙地区1890—2012年5—7月的平均相对湿度变化,重建序列的方差解释量为39.1%(减少自由度后为38.0%)。重建序列显示出5个湿润期(1895—1899年,1906—1914年,1924—1926年,1950—1955年,1984—2000年)和5个干旱期(1900—1905年,1917—1921年,1927—1949年,1956—1973年,1975—1981年)。重建序列和观测数据均与邻近研究区的PDSI对应良好,表明该序列具有较强的空间代表性,可以反映河北北部地区的平均相对湿度变化情况。本研究表明研究区相对湿度变化不仅受局地气候控制,还可能受到ENSO影响。     

Analysis of risk factors affecting driver injury and crash injury with drivers under the influence of alcohol (DUI) and non-DUI

Objective: The objective of this research was to study risk factors that significantly influence the severity of crashes for drivers both under and not under the influence of alcohol.

Methods: Ordinal logistic regression was applied to analyze a crash data set involving drivers under and not under the influence of alcohol in China from January 2011 to December 2014.

Results: Four risk factors were found to be significantly associated with the severity of driver injury, including crash partner and intersection type. Age group was found to be significantly associated with the severity of crashes involving drivers under the influence of alcohol. Crash partner, intersection type, lighting conditions, gender, and time of day were found to be significantly associated with severe driver injuries, the last of which was also significantly associated with severe crashes involving drivers not under the influence of alcohol.

Conclusions: This study found that pedestrian involvement decreases the odds of severe driver injury when a driver is under the influence of alcohol, with a relative risk of 0.05 compared to the vehicle-to-vehicle group. The odds of severe driver injury at T-intersections were higher than those for traveling along straight roads. Age was shown to be an important factor, with drivers 50–60 years of age having higher odds of being involved in severe crashes compared to 20- to 30-year-olds when the driver was under the influence of alcohol.

When the driver was not under the influence of alcohol, drivers suffered more severe injuries between midnight and early morning compared to early nighttime. The vehicle-to-motorcycle and vehicle-to-pedestrian groups experienced less severe driver injuries, and vehicle collisions with fixed objects exhibited higher odds of severe driver injury than did vehicle-to-vehicle impacts. The odds of severe driver injury at cross intersections were 0.29 compared to travel along straight roads. The odds of severe driver injury when street lighting was not available at night were 3.20 compared to daylight. The study indicated that female drivers are more likely to experience severe injury than male drivers when not under the influence of alcohol. Crashes between midnight and early morning exhibited higher odds of severe injury compared to those occurring at other times of day.

The identification of risk factors and a discussion on the odds ratio between levels of the impact of the driver injury and crash severity may benefit road safety stakeholders when developing initiatives to reduce the severity of crashes.     

A multilevel perspective of interpersonal trust: Individual,dyadic, and cross‐level predictors of performance

While it is generally known that interpersonal trust facilitates individual functioning, few studies have examined the role of specific features of the interpersonal trust network — individual, dyadic, third‐party, and network‐level features — on individual performance. We adopt a multilevel perspective of interpersonal trust to examine how individuals' performance is not only predicted by their individual‐level centrality in the interpersonal trust network but also moderated, at the network level, by the overall centralized nature of that network. Further, we examine whether mutual trust relationships at the dyadic level, as well as shared trust ties to common third parties, can predict individuals' performance. We test our hypotheses with 206 members in 15 professional networking groups and find that interpersonal trust operates at multiple levels to predict members' performance in terms of generating income from business referrals. These findings provide theoretical and practical implications on how interpersonal trust relationships operate and can be managed for performance gains. Copyright © 2016 John Wiley & Sons, Ltd.     

供给侧结构性改革与环境保护的相互影响

在经济增长放缓,市场中高端需求扩大,但有效供给不足的形势下,国家推行供给侧结构性改革,以期调整产业结构,提高生产率.对于具有政策驱动性特点的环保产业,此轮改革既是机遇也是挑战.环保产业的供给侧结构性改革,对于科技、资本、人才、信息和创新等高级要素的投入提出了新的要求.同时,公众对环境保护的需求又会倒逼供给侧结构性改革的推行.文中介绍了供给侧结构性改革的内涵和必要性,阐述了环保约束对供给侧结构性改革的影响和供给侧结构性改革对环保领域的影响,旨在为环保产业在新常态下的大力发展提供借鉴.     

Electroactive polyamide modified carbon paste electrode for the determination of ascorbic acid

Construction electroactive polyamide (EPA) with aniline-pentamer-based in the main chain has been modified on the surface of carbon paste electrode (CPE) for detecting ascorbic acid (AA). Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy studies confirm the well-defined molecular structure of the oligoaniline and EPA. Further, the in situ chemical oxidation of EPA was monitored by UV-Visible absorption spectrum. The electroactivity of the EPA was evaluated by performing electrochemical cyclic voltammetry study. The sensing response studies have revealed that this EPA-modified CPE electrode can detect AA in the range of 0.05–0.7 mM with detection limit of 0.005 mM and sensitivity of 1.5 × 10^–5 AmM^–1. Besides, this EPA-modified CPE electrode shows a minimal relative standard deviation of 1.73%.     

Empirical research on coordination evaluation and sustainable development mechanism of regional logistics and new-type urbanization: a panel data analysis from 2000 to 2015 for Liaoning Province in China

Environmental Science and Pollution Research - As the largest developing country in the world, China has witnessed fast-paced urbanization over the past three decades with rapid economic growth. In...