内蒙古自治区饮用水水源地保护对策

通过对全区21个城市的64个饮用水水源地的状况调查结果表明我区城市饮用水水源地全区城市饮用水源地2007年供水量46457.2万m3,集中式供水服务人口达到546.73万人。水质调查表明,我区水质达标的集中式饮用水水源地数量为45个,占水源地总数量的70.31%。造成内蒙古饮用水源地环境不安全的主要原因在于保护区内污染源未得到有效控制、农业面源的潜在威胁、缺乏保护区划分和管理不到位、法律法制尚不完善和环境监管能力比较薄弱等。本文针对这些问题提出了饮用水源地的环境保护对策。     

洗槽机清洗头升降故障原因分析及对策

针对洗槽机清洗头运行中的升降故障进行了原因分析,找出了解决方法,为今后类似的故障检查和排除提供了借鉴。     

煤巷掘进工作面煤层注水防尘的试验研究

在公司某煤矿一综掘工作面进行现场实验,设计了若干深10m直径42mm注水钻孔,注水压力26-32MPa,时间为15h;而后取芯进行湿润效果检验,注水后降尘效果检验和沿程粉尘浓度、综合降尘效果分析,结果表明:掘进进尺24 m处各个测尘点粉尘浓度都是最低;全尘的降尘率比呼吸性粉尘总体高些;注水后全尘浓度比注水前下降快     

昆明市水源区不同利用类型坡地径流氮和磷的输出特征

采用径流小区法对昆明市松华坝水源区牧羊河中游5种不同利用类型坡地2007年雨季地表径流氮和磷的输出情况进行观测分析.结果表明,随着雨季降雨次数的增加,径流小区产生的水样中,输出的ρ(TN)和ρ(TP)逐渐下降,在7月3日—9月17日的7次采样中,裸地、黄豆地、林地、土豆地和草地径流输出的ρ(TN)分别下降83.2%,79.8%,78.4%,75.9%和75.3%;输出的ρ(TP)分别下降74.6%,62.2%,54.2%,75.3%和72.1%,由此说明氮和磷的输出与地表径流及土壤侵蚀具有一致性.在氮和磷的输出过程中,强降雨对输出影响较大,施肥对输出影响明显.输出的可溶态氮素主要以NO₃--N为主.      

浅谈影响烧结机头电除尘器效率的主要因素

针对烧结机头烟气、烟尘的特点,对影响机头电除尘器运行效率的主要因素进行了分析,并提出了一些应付不利因素的对策,为提高烧结机机头除尘器除尘效率和使用寿命,进一步加强和改善除尘器运行效果,实现达标排放提供了理论依据及技术方案。     

水泥厂窑头多管冷却器及袋除尘技术的应用

介绍了水泥厂窑头篦冷机烟气的特性和袋除尘治理工艺、国外技术现状;国内外窑头烟气调质技术应用和国内窑头袋除尘器技术应用。列举典型案例分别对CXS型反吹风高温玻纤袋式除尘器、FGM气箱脉冲高温袋式除尘器、CDMC新型低压长袋脉冲高温袋式除尘器三种袋式除尘器技术的应用进行详细描述。分析认为,多管冷却器和新型低压长袋脉冲高温袋式除尘器组合是最好的应用技术。     

某桥式起重机主起升系统吊具的探伤检验

本文介绍了使用超声波和磁粉探伤技术对某大吨位铸造用桥式起重机主起升系统吊具金属结构母材及其焊缝探伤检验的一些情况,重点阐述了探伤检验部位确定的方法和依据。     

顶空便携式气相色谱—质谱仪现场测定地表水中苯系物

对顶空便携式气相色谱—质谱仪分析水中的苯、甲苯、乙苯、邻-二甲苯、间-二甲苯、对-二甲苯、异丙苯的方法进行了研究,并讨论了平衡时间、平衡温度、水中含盐量等因素对测定的影响。结果表明,方法的回收率为94.15%~98.67%,相对标准偏差为2.32%~4.88%,最低检出限为0.031~0.094μg/L。该方法快速、准确、重复性好。     

安康中心城市饮用水水源地环境现状调查分析及保护措施

根据安康中心城市两个饮用水水源地环境现状调查和水质监测结果,按照国家《地表水环境质量标准》(GB3838-2002),采用比照法进行了环境质量现状评价。同时,针对目前水源地存在的环境问题,提出了法律法规和制度保护措施、组织保障措施、各级水源保护区的工程治理措施,以及相应的生态修复与建设重点工程和管理能力建设重点工程等,对于改善水源地生态环境系统,有效地保证安康市生活饮用水质量和促进区域水资源可持续利用具有一定的指导作用。     

Role of age and injury mechanism on cervical spine injury tolerance from head contact loading

Objective: The objective of this study was to determine the influence of age and injury mechanism on cervical spine tolerance to injury from head contact loading using survival analysis.

Methods: This study analyzed data from previously conducted experiments using post mortem human subjects (PMHS). Group A tests used the upright intact head–cervical column experimental model. The inferior end of the specimen was fixed, the head was balanced by a mechanical system, and natural lordosis was removed. Specimens were placed on a testing device via a load cell. The piston applied loading at the vertex region. Spinal injuries were identified using medical images. Group B tests used the inverted head–cervical column experimental model. In one study, head–T1 specimens were fixed distally, and C7–T1 joints were oriented anteriorly, preserving lordosis. Torso mass of 16 kg was added to the specimen. In another inverted head–cervical column study, occiput–T2 columns were obtained, an artificial head was attached, T1–T2 was fixed, C4–C5 disc was maintained horizontal in the lordosis posture, and C7–T1 was unconstrained. The specimens were attached to the drop test carriage carrying a torso mass of 15 kg. A load cell at the inferior end measured neck loads in both studies. Axial neck force and age were used as the primary response variable and covariate to derive injury probability curves using survival analysis.

Results: Group A tests showed that age is a significant (P < .05) and negative covariate; that is, increasing age resulted in decreasing force for the same risk. Injuries were mainly vertebral body fractures and concentrated at one level, mid-to-lower cervical spine, and were attributed to compression-related mechanisms. However, age was not a significant covariate for the combined data from group B tests. Both group B tests produced many soft tissue injuries, at all levels, from C1 to T1. The injury mechanism was attributed to mainly extension. Multiple and noncontiguous injuries occurred. Injury probability curves, ±95% confidence intervals, and normalized confidence interval sizes representing the quality of the mean curve are given for different data sets.

Conclusions: For compression-related injuries, specimen age should be used as a covariate or individual specimen data may be prescaled to derive risk curves. For distraction- or extension-related injuries, however, specimen age need not be used as a covariate in the statistical analysis. The findings from these tests and survival analysis indicate that the age factor modulates human cervical spine tolerance to impact injury.