超声导波技术在长输管道跨越段腐蚀检测中的应用

管道跨越段的检测一直是管道检验检测的难题之一,本文运用英国TWI集团Teletest Focus+MK4导波设备,对某在役的长输管道,综合选择了河流、沟壑、高速公路、水渠等多种不同服役环境管段,管径DN200至DN350不等6个跨越段进行检测,并进行案例分析.实践表明,导波检测技术对跨越段管道的单边检测距离在100m左...     

青藏铁路三岔河特大桥空心薄壁高墩寒季混凝土施工技术

三岔河特大桥地处海拔高、干燥多风的恶劣气候区,是青藏铁路的咽喉工程,按总体部署须跨越寒季施工,依据高墩薄臂特点,优选拆装式大模板施工方法。该项技术采用试验研究、理论计算分析、现场监测分析等手段,使现场量测与设计数据、施工管理等工程信息相结合,并反馈于施工过程中。利用成熟度法对砼早期强度进行预测和估算,以确定下道工序的时间和对混凝土质量进行预测;采用双层保温层及内置供热系统形成高原高寒高墩薄臂负温混凝土保温加热养护技术;选用塔吊配合整体拼装式模板的高墩施工技术,成功解决空心薄臂高墩快速连续施工和寒季砼加热养护的难题,实现了高墩流水化、机械化作业。以温度为主线的信息化监控技术是该技术成果的创新内容,该创新成果对于高寒地区,尤其对青藏铁路、青藏公路桥梁下部结构施工具有广泛应用和借鉴价值。     

LNG加注趸船安全距离确定方法研究

为确定液化天然气(LNG)加注趸船与周边建(构)筑物的安全距离,对趸船LNG储罐和加液臂泄漏后果进行数值模拟计算。利用FLACS软件,计算不同泄漏场景LNG气云扩散距离;采用自主开发的LNG火灾计算软件LNGFHR+计算趸船储罐泄漏和加液臂泄漏池火热辐射强度的影响距离。结果表明:LNG泄漏量、气象条件、风向等均会对LNG气云的扩散距离产生影响;储罐泄漏池火热辐射影响距离大于加液臂的影响距离。根据计算结果,确定LNG加注趸船与重要公共建筑物的安全距离为120~150 m,与民用建筑物的安全距离为85~110 m,与生产厂房、库房和甲、乙、丙类液体储罐的安全距离为90~110 m。     

5种杀虫剂对3种淡水浮游动物的急性毒性

探讨了5种不同类型杀虫剂(毒死蜱(Chlorpyrifos)、三氟氯氰菊酯(Cyhalothrin)、丁硫克百威(Carbosulfan)、阿维菌素(Abamectin)和锐劲特(Fpronil))对3种淡水浮游动物(大型溞(Daphnia magna)、萼花臂尾轮虫(Brachionuscalyciflorus)和尾草履虫(Paramecium caudatum))的急性毒性作用。通过单一急性毒性试验,检测了5种常用杀虫剂对3种淡水浮游动物的24 h(大型溞和萼花臂尾轮虫)和1 h(尾草履虫)半致死浓度(LC50)。结果表明,随杀虫剂质量浓度增加,5种杀虫剂的毒性均明显增强,3种浮游动物的死亡率上升,呈明显的浓度-效应关系。5种杀虫剂对大型溞的24 h-LC50依次为0.001 mg/L、0.000 001 mg/L、0.078 mg/L、0.001 mg/L、0.098 mg/L,毒性均为剧毒;对萼花臂尾轮虫的24 h-LC50依次为0.081 mg/L、0.003 mg/L、0.062 mg/L、0.005 mg/L、0.476 mg/L,毒死蜱、三氟氯氰菊酯、丁硫克百威、阿维菌素为剧毒,锐劲特为高毒;对尾草履虫的1 h-LC50依次为0.434 mg/L、1.904 mg/L、4.851 mg/L、4.024 mg/L、33.393 mg/L,毒死蜱表现为高毒,三氟氯氰菊酯、丁硫克百威、阿维菌素为中毒,锐劲特为低毒。3种淡水浮游动物对杀虫剂的敏感性从大到小依次为大型溞、萼花臂尾轮虫、尾草履虫。从敏感性来说,大型溞和萼花臂尾轮虫均为较好的进行杀虫剂水环境生态效应评价的受试动物;尾草履虫由于时效快,在毒死蜱的检测中可作为优先考虑的受试动物。     

量热式酶生物传感器及其环境监测应用

量热式酶生物传感器应用于环境现场快速检测及实际试样具有优势.介绍了量热式酶生物传感器的量热检测和热放大原理以及组成、测试装置等关键技术,其中热放大的应用可从根本上提高检测的灵敏度和水平;综述了量热式酶生物传感器应用于农药残留和重金属检测涉及的酶源、富集处理等环节;结合最新的研究成果,分析并展望了量热式酶生物传感器在农药残留和重金属等环境监测领域的应用.     

压缩机装置的安全工作条件探讨

机器制造工厂在铸工车间、锻工车间、金工车间广泛地采用2～7大气压力的压缩空气,用于化铁炉、压铸机、起重运输设备、空气锤、风动工具等工作方面。 为此采用单作用或双作用的单级活塞压缩机或双级活塞压缩机,每分钟的空气吸入量在0.5～100立方米不等。 空气进入压缩机汽缸,先经由吸气管和过滤器,在过滤器中排去灰尘。压缩空气冷     

机械回转反吹袋式除尘器清灰能力的研究

为提高机械回转反吹袋式除尘器的清灰能力,改善其性能指标,在对目前广泛应用的该类设备普遍存在清灰效果不佳的原因进行理论分析的基础上,提出了降低旋转臂转速以加大喷吹气量和喷吹时间为主,同时辅以其他改进措施的思路.实验表明,采用加大减速机速比的方法降低反吹机构回转速度以保证喷吹气量和喷吹时间,调整反吹风进口位置等其他措施以改善反吹风参数并有效地避免了二次吸附,在改善清灰效果和提高清灰能力方面取得了令人满意的效果.     

汽车起重机操作中的安全要求

随着汽车起重机在我国生产活动中使用频率明显增加,各类事故呈上升趋势。汽车起重机最常见的事故是翻车和折臂事故,翻车事故的主要起因是起重机丧失稳定性。丧失稳定性的原因有:吊重超載,支承不平、惯性力、离心力、风力等;折臂事故多是由于起重臂仰角过大,再加上惯性力的作用,起重臂下坠所致。要减少     

液化石油气站装卸连接装置改造的安全隐患分析

针对目前液化石油气站内装卸软管已强制要求改装为液体装卸臂的现状,本文梳理了原质监部门和安监部门对液化石油气站内装卸连接装置的不同要求,对在用液体装卸臂改造存在的安全隐患和后续的监管问题进行了分析,并对液体装卸臂的改造和监管提出了几点建议.     

耐油防护鞋耐油体积变化率测试方法分析

检验中发现,国标ＧＢ１６７５６中规定的体积变化测试方法不很准确,经推导其测试原理,提出严密的体积变化测试方法。解决了采用两种类型天平进行测试的试验装置制备和如何排除试样表面气泡两大难题。增强了标准的可操作性和准确性,为检测人员按照ＧＢ１６７５６标准检验提供帮助。     

Gender and career success: A typology and analysis of dual paradigms

Despite women's advancements in the workplace, gender inequality persists. We classify and test two frameworks used to explain gender differences in career success: unequal attributes and unequal effects. The unequal attributes framework suggests that gender is related to other attributes, which result in unequal career outcomes for men and women (i.e., a mediated effect). The unequal effects framework suggests that even when men and women share the same attribute or circumstances, they are rewarded differently, such that individual attributes have unequal effects on career outcomes for men and women (i.e., a moderated effect). We collected survey data from a gender‐balanced sample of 394 business school alumni. Using structural equation modeling to test the unequal attributes framework, we found that work hours, career orientation, having a nonemployed spouse, and working in a predominantly female job were unequal attributes that explained gender differences in career success. Using multigroup path analysis to examine unequal effects, we found that being agentic, married, having children at home, and working in a predominantly female workplace had unequal effects in relation to career success for men and women. We find support for both models across three categories of career success antecedents (i.e., personal, family, and job attributes).     

基于PECT的金属保护层重合处干扰研究

对实际工业现场的有包覆层设备开展脉冲涡流检测(PECT),发现包覆层的外部金属保护层搭接重合处对检测结果造成干扰;利用试验手段,分别在金属保护层采用非铁磁性材质的铝皮及铁磁性材质的白铁皮条件下进行干扰试验;研究结果表明,当金属保护层为铝皮时,各段保护层搭接重合处引起的干扰信号可通过直接观察检测结果的晚期时窗信号直接进行滤除,不影响缺陷的检出;而当金属保护层为白铁皮时,由各段保护层搭接重合处引起的干扰信号无法滤除,故当缺陷位于重合处时则无法检测.     

欧美、日本与中国个体防护标准比对

个体防护装备,以往称劳动防护用品,是以保护劳动者安全和健康为目的,并且直接与人体接触的装备或者用品。从某种意义上讲,它是保障劳动者安全和健康的最后一道防线,在保护劳动者和确保安全生产方面有着重要意义。经过多年努力,我国在个体防护装备的技术标准方面制定并颁布了一系列国家标准和行业标准,并形成了初步的标准体系,本文研究了ISO、CEN、JIS的个体防护标准体系,并着重对其体系和有代表性的标准进行比对分析,从而归纳出我国个体防护及检测技术标准存在的问题,对制定和提高我国个体防护装备的体系建设具有一定的参考意义,并为个体防护及检测领域的相关国际标准的研制工作提出一些建议。     

基于改进YOLOX的变电站工人防护设备检测研究

为解决电气工人防护设备检测问题,通过改进YOLOX算法,提出检测工作人员防护设备的模型。首先在预测部分改进损失函数,为解决损失函数计算存在的缺陷,对IOU损失的计算方法进行改进,根据防护设备任务特性,通过调整各种类型损失函数的权重,增加对模型误判的惩罚,对模型进行优化;其次在算法主干网络中引入CBAM注意力模块提高神经网络对工人防护设备的感知能力;最后在算法Neck部分,将UpSample结构用于多尺度特征融合,加强网络的细节表达能力,从而提升对小目标困难样本的检测精度。研究结果表明：改进后的YOLOX模型平均精度均值达到87.24%,与已有YOLOX模型相比提升2.46%,具备有效性,适用于变电站工人防护设备检测。研究结果可为电气工人提供更高的防护装备检测精度。     

织物抗低速冲击性能测试仪的研制

本文介绍了用于测试织物抗低速冲击过程中对冲击能量吸收性能测定的仪器的设计思路和结构组成。在抗冲击标准的基础上通过自制冲击装置,使用漫反射光电感应设备及利用LabVIEW虚拟仪器软件成功地设计了织物的抗低速冲击性能测试仪。     

基于多模型耦合的化工物料输送管道泄漏检测系统研究

将物料平衡统计模型、信号序列相关分析模型和管道机理模型进行耦合,实现了管道泄漏事故的检测、空间定位和泄漏量估算.多模型耦合的方法降低了利用单一模型进行检测的漏检风险.将模型与GIS紧密集成,实现了泄漏信息的直观显示,可有效提高化工管道泄漏事故的应急反应效率.     

重点行业在用呼吸防护用品质量状况的调查分析

调查重点行业企业在用呼吸防护用品质量状况,发现主要问题并研究对策,促进对呼吸防护用品的监督管理。对106家企业进行问卷调查,并随机抽样37家企业对在用69种呼吸防护用品进行检测。所有企业均配发了呼吸防护用品,样品合格率为40.58%,LA认证率33.33%。防尘口罩过滤效率和泄漏率的合格率较低（40.38%和48.08%）,且国内外品牌差异具有统计学意义（P<0.05）;防毒口罩防护时间合格率35.29%,防护时间、过滤元件通气阻力（30 L/Min和95 L/Min）的国内外品牌差异具有统计学意义（P<0.05）。     

个体防护装备创新研制探析

个体防护装备是保障从业者人身安全的重要保护装备,研制性能优异的保护装备、装具和防护用品,可保障从业人员的作业安全。如何更好的感知危险因素,预防安全事故的发生,实现从业人员快速撤离的主动式个体防护技术及装备将成为研究重点。本文提出主动式个体防护装备的创新研制需立足危险因素及作业人员这两个关键环节,实现危险因素信息与作业人员信息的实时感知、高效互通、快速预警与处置,进而实现个体防护装备从被动防护到主动防护的深刻变革。     

Use of association rules to explore cause–effect relationships in occupational accidents in the Taiwan construction industry

Most models of the incidence of occupational accidents in the construction industry are composed of multiple factors. Although statistical techniques can be used to infer cause-and-effect relationships among these factors, the large number of factors involved and the complexity of the relationships among them make it difficult for managers to identify potential hazards in construction projects and thus develop effective safety procedures. This study addresses this problem by using the association-rule method of data mining in performing an analysis of 1347 accidents in the Taiwan construction industry during the period 2000–2007. The association-rule method enables potential cause-and-effect relationships to be identified among the many factors that play a role in occupational accidents in the construction industry. The study finds that such accidents tend to occur when certain combinations of hazards are present – especially working in high places without protective measures, loss of balance when in motion, failure to use protective equipment, insufficient experience, and injurious contact with unstable structures. These hazards are especially evident in small enterprises with less than 10 persons. The results can help management to formulate effective safety policies with regard to management shortcomings and staff training.     

Assessing gait changes in firefighters due to fatigue and protective clothing

Each year, roughly 11,000 firefighters are injured as a result of slips, trips and falls, which account for over 25% of all fireground injuries. Wearing personal protective equipment (PPE) can increase risk of fall-related injuries due to its weight, restrictiveness, and increased heat stress. Modification of PPE may serve to mitigate firefighter injuries related to loss of balance and falls. We examined the effects of choosing ‘enhanced’ protective clothing (lightweight, breathable, and less restrictive compared to typical firefighting PPE) and simulated firefighting tasks (18-min bout over four activities) on subsequent gait performance. To assess the effect of wearing protective clothing and firefighting activity, seven gait parameters and three movement errors were assessed during level and obstacle-crossing walking tasks. Forty-four firefighters wore one of two types of PPE (‘Standard’, ‘Enhanced’) during three testing conditions (baseline in station uniform, pre-firefighting activity in PPE, and post-firefighting activity in PPE). The effect of donning any PPE was found to significantly impair gait performance. Fatigue may impact effective mobility since more movement errors were observed during post-activity than pre-activity assessments. Although the Enhanced PPE did not lead to any significant differences in gait parameters compared to Standard PPE, participants in Enhanced PPE made twice as many movement errors, potentially attributed to lack of familiarity with the gear. These results suggest that wearing firefighting PPE and heat-stress induced fatigue are associated with reduced gait performance and increased risk for tripping over obstacles.