石河子垦区农业生态环境

对垦区农业环境影响较突出的水污染状况，土壤次生盐渍化及土地沙化等环境问题进行研究分析，认为：垦区农业环境生态保护要兼顾垦区内外，绿洲内制约农业经济发展的重要问题仍然是水资源合理利用和土壤沙漠化问题，城市生态要严格控制工业废水的排放。     

Mobile phone use while riding a motorcycle and crashes among university students

Objective: Motorcycle crashes are a significant road safety challenge, particularly in many low- and middle-income countries where motorcycles represent the vast majority of their vehicle fleet. Though risky riding behaviors, such as speeding and riding under the influence of alcohol, have been identified as important contributors to motorcycle crashes, little is understood about the effect of using a mobile phone while riding on motorcycle crash involvement. This article investigates crash involvement among motorcycle riders with risky riding behaviors, particularly using a mobile phone while riding.

Methods: Data were obtained from an online survey of university students’ risky riding behaviors in Vietnam administered between March and May 2016 (n?=?665).

Results: Results show that 40% of motorcycle riders reported to have experienced a crash/fall and nearly 24% of motorcycle riders indicated that they had been injured in a crash/fall. Effects of mobile phone use while riding on safety of motorcycle riders are highlighted. Specifically, more frequent use of a mobile phone for texting or searching for information while riding is associated with a higher chance of being involved in a crash/fall. The results also show that drink riding is associated with a higher chance of being injured.

Conclusions: Overall this article reveals significant safety issues of using a mobile phone while riding a motorcycle, providing valuable insight for designing education and publicity campaigns.     

基于地震与危化品突发事件耦合影响的人员转移安置点设置

通过对目前人员疏散转移安置点设置研究现状和问题及城镇化工园区集约发展安全隐患的分析,提出了突发事件耦合影响下人员转移安置点综合规划的必要性。首先分析了典型危化品园区内突发事件耦合的典型模式、影响特性,并基于突发事件耦合特性、影响区域提出了耦合突发事件下人员转移安置点规划的安全性、可达性、适宜性的14个关键影响因素,给出了各指标量化的标准。基于加权灰色关联法和事故影响评估方法,提出了一套安置点适宜性评估筛选、新增安置点规划的方法,给出了安置点规划的流程。利用改进的Voronoi图方法确定安置点的覆盖半径和责任服务区,进行安置点容量与责任区内核密度人口容量的对比分析,以确定安置点人口容量缺口。结合安置点可达性、安全性、适宜性进行叠加划分,确定新增安置点规划位置。最后以某区示范应用,阐述其规划应用方法和流程。以区域内安置点最大全覆盖原则,得到了在地震灾害影响下城镇人员可能受危化品泄漏威胁区域,以及区域安置点的缺口及规划方案。     

被控对象动力特性对人操作者手控跟踪效率的影响

人操作者的手动控制能力在人机环境系统的工效研究中具有广泛的应用价值。本文研究了人操作者的手动控制能力，以跟踪时间、跟踪误差和失误率为评价指标；分析不同被控对象动力学特性对人操作者在两自由度跟踪能力的影响。     

人的视觉注意力分配定量测试技术及其应用前景分析

介绍了人的视觉注意力分配的定量测试技术；阐述了实现测试功能的技术手段；举例说明了如何通过测试眼注视点来研究视觉信息获取和分配问题；对其应用前景进行初步分析。     

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments

Matching biological and chemical data were compiled from numerous modeling, laboratory, and field studies performed in marine and estuarine sediments. Using these data, two guideline values (an effects range-low and an effects range-median) were determined for nine trace metals, total PCBs, two pesticides, 13 polynuclear aromatic hydrocarbons (PAHs), and three classes of PAHs. The two values defined concentration ranges that were: (1) rarely, (2) occasionally, or (3) frequently associated with adverse effects. The values generally agreed within a factor of 3 or less with those developed with the same methods applied to other data and to those developed with other effects-based methods. The incidence of adverse effects was quantified within each of the three concentration ranges as the number of cases in which effects were observed divided by the total number of observations. The incidence of effects increased markedly with increasing concentrations of all of the individual PAHs, the three classes of PAHs, and most of the trace metals. Relatively poor relationships were observed between the incidence of effects and the concentrations of mercury, nickel, total PCB, total DDT and p,p′-DDE. Based upon this evaluation, the approach provided reliable guidelines for use in sediment quality assessments. This method is being used as a basis for developing National sediment quality guidelines for Canada and informal, sediment quality guidelines for Florida. The methods and guidelines presented in this report do not necessarily represent the policy of the National Oceanic and Atmospheric Administration, Environment Canada, or Florida Department of Environmental Protection.     

MEASURING THE CONTRIBUTION OF LAND AND WATER TO AGRICULTURE1

ABSTRACT Irrigated land outproduces dryland agriculture, especially in the western United States. Many valuable crops could not be grown without irrigation. A paucity of yield data does not allow direct measurement of the contribution from irrigated crop agriculture, nor does it allow evaluation of the contributions from livestock which are dependent upon irrigated feed. Regression results indicate that 80 percent of Idaho farm income is associated with irrigation, and that 75 percent of the farm income in the 17 western states is associated with irrigation. For the United States as a whole, results indicate that 13.7 percent of the total cropland (irrigated land) produced 41.3 percent of all cash receipts from farming in 1978. If 14 percent of the land can produce 40 percent of the value of production, can 35 percent of our land produce all our food and fiber needs? Such an allegation has several implications in terms of the adequacy of our land and water resources. It also emphasizes the role of technology in future resource use and production.     

有毒化学物质对DNA的损伤——生成DNA加成物

本文涉及了环境中各种重要类型的化学致癌物并着重讨论了潜在致癌物与DNA加成物的化学反应及其生物影响,它包括简单烷化剂、简单非烷化剂以及代谢活化致突剂。不同烷化剂、简单非烷化剂、代谢活化致突剂与DNA的化学致癌反应部位,无论是在试管中试验还是在活体试验都有很大的不同。特别是N-亚硝基化合物和BaP曾作过详细研究,因为它们只在某个体系的特定器官使之成为恶性。尽管N-硝基化合物对人并不意味着致癌,但它很有可能就是致癌物。相反,某些在动物中致癌性很弱的烷化剂却被列为人体致癌物(氯乙烯、芥子气)或者人体可能的致癌物(硫酸二甲酯、乙烯氧化物)。     

短柱气相色谱法研究焚烧炉飞灰上萘的氯化反应及其产物

本文用0.3mBenton-34/OV-1短填充柱气相色谱法研究了萘在焚烧炉飞灰上的氯化反直产物,实验表明,飞灰表面性质对氯化有促进作用,这种促进作用与飞灰的来源或表面性质有强烈关系,文中对有关分析方法和萘在焚烧炉飞灰上氯化反应的结果作了讨论。     

混凝-Fenton法处理采油污水的研究

对采油废水进行混凝预处理后进行了Fenton处理 ,确定了Fenton试剂处理采油废水的最佳配比为H2 O2 ∶Fe2 +=5 0mmol L :1mmol L。同时利用GC MS色谱图探讨了混凝 -Fenton法对有机物的去除机理。结果表明 :混凝工艺去除了75 %的有机污染物 ,碳数低于 2 1的烷烃去除率可达到 80 %以上 ,同时还去除了所有的多环芳烃 ,但是对苯酚类物质的去除率只有 5 0 %。在Fenton过程中 ,铁的水解吸附和OH·的氧化作用并存 ,采油污水经过 12 0min的Fenton处理后 ,其中的烷烃类物质、酚类物质、多环芳烃物质能被完全氧化。