基于2GW-HAZOP与偏离度的输气站降压排污作业风险评估*

为预防输气站降压排污过程中发生事故,提出1种基于2GW-HAZOP与偏离度的作业过程风险评估方法。在HAZOP方法的基础上定义作业偏差,将传统7种工艺参数偏差引导词映射到1个偏差二元组中;通过将作业过程节点功能作为参量,采用节点跨越和节点功能偏离2种引导词,从而构建节点功能偏差;进一步通过定义功能偏离度和控制措施偏离度对偏差进行量化处理,表征风险水平;将方法应用于降压排污作业过程的风险评估中,可分析得到偏离度大的作业过程节点。结果表明:分离器放空不充分、排污池液位过高或过低、排污结束未检查泄漏情况的偏离度较大,需加强风险控制。     

稳健GM(1,1)模型在工业固废产生量预测中的应用

本文提出了稳健灰色模型,并用该模型建立了山东省工业固体废物产生量数学模型。结果表明,稳健ＧＭ（１,１）模型比通常的ＧＭ（１,１）模型更具预测应用价值。     

信效度在安全生产标准化元评估中的应用研究

安全生产标准化评审是根据一定的安全生产标准化评审目标和标准,通过系统地收集信息和科学分析,对企业安全生产标准化工作做出价值判断的过程。为了科学评估评审偏差和统一评审尺度,基于信效度理论,提出在评审单位和评审组织单位进行安全生产标准化元评估时,应用评审者信度和效标关联效度,研究安全生产标准化评审的可靠程度和有效程度;并以危险化学品从业单位安全生产标准化评审为例,从信效度的分析方法选择、信效度的计算和信效度的可接受度,全面探究信效度在安全生产标准化元评估中的实现方式。结果表明,应用信效度方法分析安全生产标准化评审的优势和不足,可以为安全生产标准化评审结果的客观评价提供依据。     

中晚全新世泰国湾Chanthaburi海岸Welu河口区沉积物的敏感粒级组分及其对季风气候变化的指示意义

对泰国湾Chanthaburi海岸Welu河口区三根沉积物柱样（WLE08、WLE10和WLE12）进行了²¹⁰Pb测年分析、AMS¹⁴C测年分析和粒度分析。粒度分析结果表明,研究区三根柱样的沉积物类型均属于粘土质粉砂,包含部分贝壳及生物碎屑,分选差,呈正偏态,属于中晚全新世以来形成的沉积物。通过粒级-标准偏差方法对沉积物敏感粒级进行提取,每根柱样各获得两个敏感粒级,分别为S_A1和S_A2、S_B1和S_B2以及S_C1和S_C2。将S_A2/S_A1、S_B2/S_B1以及S_C2/S_C1作为中晚全新世以来亚洲夏季风相对强度变化的替代指标,比值升高可以指示夏季风强度增强,反之则减弱。结合测年结果得出研究区的亚洲夏季风自中晚全新世以来经历了强盛-减弱-增强-减弱-稳定-波动的过程。其中,8.5～6.5 cal.ka BP期间S_C2/S_C1值较高,表明该时期处于亚洲夏季风强盛期,6.5～3 cal.ka BP期间S_B2/S_B1值较低且变化较小,表明该时期亚洲夏季风处于较弱的稳定期,而1.5 cal.ka BP以来S_A2/S_A1值有升高趋势表明亚洲夏季风在这一时期有所增强。此外,在8.2 cal.ka BP期间敏感粒级S_C2/S_C1值急剧下降,表明夏季风存在一次较大的衰弱期,响应了8.2 cal.ka BP全球范围的气候突变事件,这与阿曼石笋和董歌洞石笋δ¹⁸O记录所显示的结果相一致,体现了气候变化具有区域性乃至全球性的联系。     

大气颗粒物“二重源解析”技术的误差分析

"二重源解析"模型计算结果的误差是采样误差、样品处理误差、化学组分分析误差、数据处理误差以及数学模型误差等所有误差的积累。提出了"二重源解析"解析结果的相对误差和标准偏差表达式,并用之计算了某市利用"二重源解析"模型计算的源贡献值的相对误差和标准偏差,还针对从源排放出来的初始态颗粒物在传输过程中发生的扬尘态变化提出了扬尘转化率的概念和计算方法。     

水质自动监测中的质量保证与质量控制

质量保证与质量控制是水质自动监测中十分重要的技术工作和管理工作,包括人员素质、运行与管理机制、试剂与标准溶液的配制及文件记录等.在实际工作中,监测人员可根据仪器的运行状况,定期时仪器进行校准、标准溶液的核查、比对实验验证及试剂有效性检查,用以检查仪器的基线飘移情况.如果分析中出现一个异常值,它的前后均为正常值,这种数值大多是由仪器的进样、仪器内部试剂传输等原因所致,如果发生原因不明的数据异常,就要及时检查系统的各个环节并采集实际水样进行人工分析,直至查清原因,剔除异常值,并在周报中加以说明,以确保上报数据的准确性、精密性和可比性.     

北沙河上游流域潜在非点源污染风险时空变化分析

非点源污染风险时空分布特征解析和等级分区是有效控制非点源污染的关键.为了弥补PNPI（potential non-point pollution index,潜在非点源污染指数）模型中专家评价法主观赋权的不足,引入均方差决策法,并采用改进后的PNPI模型分析1980-2017年北京市北沙河上游流域潜在非点源污染风险时空变化特征,划分潜在非点源污染风险等级.结果表明:①均方差决策法根据土地利用指标、径流指标和距离指标集的数值离散程度确定各指标权重,其结果可体现各指标权重随土地利用类型动态变化的特点.②1980-2017年土地利用指标、径流指标和距离指标的平均权重分别为0.49、0.18、0.33,说明土地利用类型对非点源污染风险相对影响较大.③受土地利用类型空间分布格局影响,北沙河上游流域潜在非点源污染风险呈西北部山区低、东南部平原区高的分布特征.④随着城镇化的推进,潜在非点源污染极高风险区主要土地利用类型由旱地和园地逐渐演变为城镇用地、农村居民地和建设用地.研究显示,非点源污染风险高低与土地利用类型密切相关,可通过土地利用类型的合理布局,降低流域非点源污染风险.      

Slow eyelid closure as a measure of driver drowsiness and its relationship to performance

Objective: Slow eyelid closure is recognized as an indicator of sleepiness in sleep-deprived individuals, although automated ocular devices are not well validated. This study aimed to determine whether changes in eyelid closure are evident following acute sleep deprivation as assessed by an automated device and how ocular parameters relate to performance after sleep deprivation.

Methods: Twelve healthy professional drivers (45.58 ± 10.93 years) completed 2 randomized sessions: After a normal night of sleep and after 24 h of total sleep deprivation. Slow eye closure (PERCLOS) was measured while drivers performed a simulated driving task.

Results: Following sleep deprivation, drivers displayed significantly more eyelid closure (P < .05), greater variation in lane position (P < .01) and more attentional lapses (P < .05) compared to after normal sleep. PERCLOS was moderately associated with variability in both vigilance performance (r = 0.68, P < .05) and variation in lane position on the driving task (r = 0.61, P < .05).

Conclusions: Automated ocular measurement appears to be an effective means of detecting impairment due to sleep loss in the laboratory.     

Incidence of thyroid disease following exposure to polybrominated biphenyls and polychlorinated biphenyls, Michigan, 1974-2006

Thyroid hormones, which influence body metabolism and development, could be affected by persistent organic pollutants. We sought to examine the relationship between polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) and thyroid disease. We employed incidence density sampling to perform a nested case control analysis of the Michigan Long-Term PBB Cohort. Cohort members (n = 3333) were exposed to PBBs through contaminated cattle feed in 1973-1974 and to PCBs through daily life. Those with detectable serum PBB and PCB concentrations at enrollment were categorized into tertiles of PBB and PCB exposure. Case-patients were cohort members answering “Yes” to “Has a healthcare provider ever told you that you had a thyroid problem?” during follow-up interviews; control-patients were cohort members answering “No”. We used odds ratios (OR) with 95% confidence intervals (CI) to compare odds of thyroid disease by PBB and PCB exposure and by various risk factors. Total cumulative thyroid disease incidence after 33 years was 13.9% among women and 2.6% among men. After adjusting for body mass index, we found no statistically significant differences in odds of any type of thyroid disease among women or men with elevated PBB or PCB exposure. Compared to control-patients, women with thyroid disease had increased odds of being overweight/obese (OR = 2.82, 95% CI: 1.94-4.11) and developing infertility (OR = 1.71, 95% CI: 1.08-2.69), diabetes (OR = 1.61, 95% CI: 1.04-2.51), or arthritis (OR = 1.71, 95% CI: 1.18-2.50) during follow-up. Additional research should explore potential associations between PBBs/PCBs and thyroid disease among children exposed in utero.     

对单项污染评价中污染分界线问题的讨论

根据数理统计的原理，将环境质量标准，平均值，标准偏差以及样本容量综合进行考虑，提出了污染分界线的计算公式，并以表格形式给出了不同显著性水平下，不同的相对标准偏差和样本容量所对应的污染分界线，对污染分界线与样本容量及相对标准的偏差的关系进行了讨论，指出提高监测精度和适当增加监测数据个数，可以使污染分界线接近评价标准。