城市供水管网健康监测与诊断:IV.监测点压力在线预测

供水管网运行状态的准确把握,对供水管网的健康监测与诊断至关重要,而监测点压力是管网运行状态最重要的标志之一。提出用于供水管网监测点压力在线预测的EMD(经验模态分解)与自回归模型相结合的方法,并对EMD组合模态所蕴含的物理意义进行了阐述。通过一实际供水管网中某监测点压力的在线预测与实际监测值的比较,验证了方法的有效性,此方法可提高城市供水管网健康的在线监测与诊断的效率。     

Social vulnerability and pneumonic plague: revisiting the 1994 outbreak in Surat,India

The 1994 outbreak of pneumonic plague in Surat, India is revisited and analyzed using the pressure and release (PAR) model. Overviews of the outbreak, of India's experience with plague, and of the disease are provided and the PAR model is used to trace the production of vulnerability via root causes, dynamic pressures, and unsafe conditions and to explain the why, when, and where of the epidemic. The emergence of plague in Surat was an unfortunate amalgam of prior hazard events and of factors generating vulnerability. Root causes include the country's colonial legacy and a complex and pervasive social hierarchy promoting caste and class interests over the common good. Dynamic pressures include: a curative-focused healthcare system; a weak civil society; misplaced spending priorities; and public and private corruption that deprived public health programs of needed funds and which compelled workers to live and labor in unhealthy environments. Unhealthy public, residential and workplace environments; fragile economic conditions; and a lack of surveillance and preparation are immediately linked to the outbreak and to the transmission of pneumonic plague.     

Community pressure for green behavior

The desire to avoid rousing community hostility may encourage firms to behave in an environmentally responsible manner. Firms may engage in corporate social responsibility (CSR) to maintain community support and/or to regain the support of a community where it has been lost. It has been conjectured that such ‘informal regulation’ could effectively replace formal intervention in some settings, and usefully complement it in others. We explore these conjectures with mixed results. Informal regulation is necessarily less efficient than a well-designed formal alternative and the pattern of green behavior induced by the threat of community hostility may increase or decrease welfare. The existence of community pressure may increase or decrease the optimal calibration of a formal intervention (in this case an environmental tax) and may complement or detract from the incentives generated by an optimally calibrated tax.     

不同虫压下转Bt基因水稻与非转基因水稻生态适合度差异

为了解转基因水稻的基因扩散效率和潜在生态风险,以转Bt抗虫水稻Bt63、R1、R2和非转基因常规水稻Ⅱ优838为试材,采用高、低两个不同虫害胁迫水平和转基因与非转基因水稻相间种植方式,通过观察水稻植株营养生长、结实以及对螟虫危害的抗性表现等差异,研究比较了Bt外源基因插入后对水稻植株适合度的影响.结果表明:在低虫害胁迫条件下,转Bt基因水稻在植株分蘖数、生物量鲜重等营养生长指标方面与非转基因对照品系间无明显差异,但株高、穗长、穗重等指标不及对照,且R2和Bt63与对照间差异显著;在高虫害胁迫条件下,3个转Bt基因水稻品系的分蘖数、穗长、穗重等指标明显高于对照.而不同转基因品系株高适合度效应不同,这可能与受体本身的特性相关.3种转基因水稻的单株结实粒数、千粒重与对照在两种虫害胁迫条件下均无显著性差异,Bt基因对受体植株的结实影响不明显.在高虫害胁迫条件下,3种转Bt基因水稻的抗虫能力均显著优于非转基因水稻,表明Bt基因对受体植株的抗虫性影响显著.同时,本研究结果还表明转Bt基因水稻的适合度代价较小,预示了抗虫转基因水稻外源Bt基因在一定环境条件下具有逃逸的可能,但这种风险比较小.     

COPD合并Ⅱ型呼吸衰竭患者无创通气的护理体会

探讨COPD合并Ⅱ型呼吸衰竭神志清楚患者无创通气的护理体会.方法:南华大学附属第一医院呼吸内科2009年1月-2012年2月收治的98例COPD合并Ⅱ型呼吸衰竭应用无创正压通气治疗的清醒患者,随机分为护理干预组(观察组)与对照组各49例,其中观察组给予系统的护理干预;对照组仅采取一般护理措施.比较两组患者治疗后呼吸参数.结果:护理干预组的pH、PaO2、SaO2等参数明显高于对照组,而PaCO2明显低于对照组.表1,参5.     

助剂强化罐底油泥的压滤脱水性能

采用实验室压滤装置对胜利油田某联合站罐底清罐油泥进行压滤脱水研究,采用单独添加助滤剂G、絮凝剂PAM或PAC均可改善过滤效果,提高滤速,降低过滤比阻。但仅使用助滤剂G时滤速的提高尚不够理想,单独使用絮凝剂PAM或PAC时,滤饼含水率偏高,滤饼不易从滤布上剥离;絮凝剂PAM 0.1%与助滤剂G 3.0%复配,滤饼比阻由空白样的18.7×1012 m/kg降低到0.05×1012 m/kg,3 min即可使滤饼含水率降到74.16%,滤液澄清,滤饼成形性好,较仅添加絮凝剂PAM时,更容易从滤布上剥离。     

Comprehensive monitoring technique based on electromagnetic radiation and its applications to mine pressure

Strata pressures are common potential troubles during coal mining, serious ones can cause great catastrophe. This paper presents a new comprehensive electromagnetic radiation (EMR) monitoring technique to monitor and predict these disasters. In this paper, we studied the relationship of EMR emitted by various, uniaxially loaded, coal rock samples (coal, rock, roof-coal-floor composite) in their whole deformation and failure processes to the applied loads, and found that EMR signal is linearly related to the applied loads, while the number of EMR pulses is a third power function of the applied loads. Therefore, EMR signal is capable of reflecting the stress (load) state, deformation and fracture strength, and internal stress state of coal rock mass. Based on the above, we proposed three methods for measuring rock pressure distribution, periodic pressure, and internal stress distribution of coal rock mass on working faces, and conducted field measurements and verifications. The results showed that (i) EMR has a certain correspondence to support resistance of working faces, and can reflect more accurately the face pressure distribution; (ii) in the mining impacted area located within 100 m in the front of working face, the stress distribution has unimodal and bimodal forms; (iii) EMR signal changes periodically with periodic pressure, and can be used to qualitatively observe and evaluate periodic pressure; (iv) tested with antenna in the borehole into coal rock mass, EMR signal can effectively reflect the internal stress distribution and shifting, which was verified by using traditional drilling cuttings method. In addition, EMR can also be used to check the effect of destress blasting as one of the emergency measures. In conclusion, the results are of practical significance for using EMR to monitor rock pressure and guiding safe underground mining.     

复合板压力容器点腐蚀缺陷运行适应性评价

为准确反映含点腐蚀缺陷复合板压力容器的安全状态,在复合结构弹性力学分析的基础上,通过工程实例,采用运行适应性(FFS)评价方法对其进行安全评定与剩余寿命评估。结果表明:复合板压力容器安全评定时应考虑覆材的影响,依据提出的力学模型分别对覆材厚度计入和不计入强度设计2种情况进行应力校核,同时结合蚀孔的分布特征,对其特征尺寸进行统计学平均后计算剩余强度。在剩余寿命预测中,已考虑蚀孔直径和深度随时间变化对剩余强度的影响。通过计算最大工作压力(MAWP)参量,已对某一压力容器进行寿命评估。     

甲烷煤尘燃烧爆炸试验研究

为揭示甲烷煤尘空气混合物爆炸波的传播规律,采用试验分析的方法,建立甲烷煤尘空气混合物燃烧爆炸的3种试验方案,分析不同体积分数的甲烷和不同质量浓度的煤尘消耗不同体积空气时的爆压和爆速等参数的发展趋势,探究爆轰波传播的稳定性,阐明了甲烷煤尘燃烧爆炸的基本特征。试验结果表明,在最优配比条件下,与单一甲烷空气、煤尘空气混合物相比,甲烷煤尘空气混合物的爆压、爆速明显增加。甲烷煤尘空气混合物爆轰比单一的气相、固相混合物爆轰的爆炸压力、爆速明显增加、爆轰更稳定。     

基于微地震监测的华丰煤矿深孔爆破防冲技术

为提高深孔爆破措施对防治华丰煤矿冲击地压的有效性,采用微地震监测技术连续监测其1410工作面围岩破裂情况。根据采场附近岩层"破裂-应力"对应关系,得到工作面前方、侧向及垂直方向上的支承压力峰值区,由此确定深孔爆破卸压的具体参数。结果表明:卸压孔深40 m(倾向投影为4倍采高)时,爆破对煤岩的整体性破坏明显,煤岩体中积聚的弹性能得到释放。监测期间共释放能量9.47 MJ,高应力区向煤岩深部转移,采场附近形成一定的卸载区域,减弱或消除了煤岩体的冲击危险性。