警用防暴装备的研究进展及应用分析

在警员执法过程中,来自刀具、钝器等器材的暴力伤害无处不在。防暴装备作为一种重要的警用防护器材是保护警员的重要手段。本文对各类防暴装备的相关标准和研究进展进行了介绍,分析和比较了各类防暴装备的防暴机理及防暴性能,阐述了各类防暴装备的应用范围,最后对防暴装备的应用和研究提出了建议。     

企业低碳制造战略分类研究:以水泥企业为例

随着气候变化加剧,低碳发展已成为政府和学者关注的重要议题。降低工业碳排放成为实现我国经济可持续发展的当务之急。低碳制造战略是工业企业实现战略转型、应对碳排放约束和提升市场竞争力的可行策略之一,但企业低碳制造战略的研究正处于起步阶段,还缺乏低碳制造战略类型的认识。为此,本文在拓展企业制造战略竞争优先权结构要素的基础上,增加能源利用率和单位产品二氧化碳排放量为竞争优先权结构要素,构建低碳制造战略竞争优先权分类指标,由此探索企业低碳制造战略类型。本文以国内22个省(自治区、直辖市)所辖的137家水泥企业为研究对象,运用聚类分析方法,识别企业低碳制造战略的类型,结果表明:企业低碳制造战略可划分为三种类型,分别是设计者、看守者和低碳践行者。研究结果不仅有助于深入了解水泥企业低碳制造战略特点,为我国水泥企业低碳制造战略制定和实施提供决策依据,而且其理论成果也可推广至其他高耗能产业,创新引导企业有效实施基于产品全生命周期的企业低碳制造战略。     

Chemical and spectroscopic characterization of organic matter during the anaerobic digestion and successive composting of pig slurry

In this work, anaerobic digestion of pig slurry and successive composting of the digestate after centrifugation were studied by means of chemical analysis, FTIR and fluorescence spectroscopy as excitation–emission matrix (EEM). Chemical analysis highlighted the organic matter transformation occurring during the processes. A decrease of volatile solids and total organic carbon were observed in the digestate with respect to the fresh pig slurry as a consequence of the consumption of sugars, proteins, amino acids and fatty acids used by microorganisms as a C source. Water Extractable Organic Matter (WEOM) was obtained for all samples and fractionated into a hydrophilic and a hydrophobic fraction. The highest WEOM value was found in the pig slurry indicating a high content of labile organic C. The digestate centrifuged and the digestate composted showed lower hydrophilic and higher hydrophobic contents because of the decrease of labile C. Total phenolic content was lower in the digestate with respect to fresh pig slurry sample (36.7%) as a consequence of phenolic compounds degradation. The strong decrease of total reducing sugars in the digestate (76.6%) as compared to pig slurry confirmed that anaerobic process proceed mainly through consumption of sugars which represent a readily available energy source for microbial activity. FTIR spectra of pig slurry showed bands indicative of proteins and carbohydrates. A drop of aliphatic structures and a decrease of polysaccharides was observed after the anaerobic process along with the increase of the peak in the aromatic region. The composted substrate showed an increase of aromatic and a relative decrease of polysaccharides. EEM spectra provided tryptophan:fulvic-like fluorescence ratios which increased from fresh substrate to digestate because of the OM decompostion. Composted substrate presented the lowest ratio due to the humification process.     

风电行业安全生产风险特征与对策

系统检索了2000至2012年年底风电行业事故情况,从事故总数、死亡人数及事故类型展开分析。结果表明,风电行业风险具有自身特征,事故一直呈现上升趋势,其中叶片损坏、火灾、结构毁损、抛冰、交通运输、环境破坏等事故比较突出,对从业人员和公众构成威胁。我国风电行业正处于快速扩张期,内在风险较高,需引起行业主管部门和企业的高度重视,开展全产业链系统安全研究和管理手段创建,开发本质安全型工艺和设备,强化施工及运营安全管理。分析结果对指导风电行业安全管理决策和提升企业安全管理水平具有现实意义。     

施工企业安全绩效与社会资本及动态能力的关系的实证研究

为改善施工企业安全绩效,以社会资本理论和安全管理学理论为基础,深层次分析施工企业社会资本对安全绩效的影响机制。引入动态能力为中介变量,构建施工企业安全绩效与社会资本及动态能力间的关系的理论模型。通过98个项目300份有效问卷收集数据,采用因子分析和结构方程模型(SEM)理论验证上述模型。结果表明,施工企业社会资本对动态能力和安全绩效具有显著正向作用,动态能力在社会资本的结构维度、关系维度与安全绩效间起完全中介作用,在认知维度与安全绩效间起部分中介作用。因此,重视施工企业社会资本的培育,加强动态能力的发展是提升企业安全绩效的有效途径。     

ISOLATING THE RANDOM RAMSTORM COMPONENT FROM BASIN RESPONSE FACTORS IN RAINFALLRUNOFF DATA1

ABSTRACT: Gaged watersheds can provide information as to geomorphic, and geologic influence on the spatial variability of rainfall-runoff relationships. However, correlations between raingages distributed throughout the basin, and stream discharge are influenced by both storm patterns and drainage basin characteristics. Factor analysis has been applied to rainfall-runoff relationship to isolate the storm pattern from a basin response factor. Comparing two periods of time separated by eight years reveals relative stability in the rainfall attenuation (basin response) factor, while storm patterns for the two periods of record are quite disparate.     

基于FTA-SVM的车辆发动机故障识别方法

发动机结构日益复杂,其故障具有多样性和频发性的特点,收集大量故障样本存在很多实施障碍。为了提高车辆发动机的故障识别的效率和准确性,提出了一种新的结合故障树(FTA)和支持向量机(SVM)各自特点,从故障模式分析到故障类型识别的FTA-SVM故障识别方法。首先利用故障树在复杂系统故障模式分析中的优势,找出系统的故障模式,建立故障树模型,通过对故障树模型中各故障事件的分析,采集与故障事件状态相关的数据,建立数据与故障树底事件的映射模型,最后利用支持向量机在小样本数据处理中的优势,进行故障类型的识别。以发动机的失火故障为例建立了发动机失火故障树模型及故障数据与故障模式映射模型,验证了FTA-SVM方法的有效性和适用性。     

混凝土结构施工中人因差错的模拟

以施工现场人因差错真实准确的调查实测数据为依据,笔者采用人的可靠性分析方法建立了混凝土结构施工中人因差错发生及其对混凝土强度影响规律的数学模型,并编制了相应的模拟计算程序.将该模拟计算程序所得的考虑人因差错的混凝土强度模拟计算结果与实测的混凝土强度调查结果进行比较,二者具有很好的一致性,说明该数学模型和模拟计算程序是比较符合实际的,也是比较合理的.上述模拟计算结果为考虑人因差错的结构安全性分析以及人因差错的有效控制措施研究提供了参考依据.     

Comparison of the Performance of Statistical Models in Forecasting Monthly Total Dissolved Solids in the Rio Grande1

Abudu, S., J.P. King, Z. Sheng, 2011. Comparison of the Performance of Statistical Models in Forecasting Monthly Total Dissolved Solids in the Rio Grande. Journal of the American Water Resources Association (JAWRA) 48(1): 10‐23. DOI: 10.1111/j.1752‐1688.2011.00587.x Abstract: This paper presents the application of autoregressive integrated moving average (ARIMA), transfer function‐noise (TFN), and artificial neural networks (ANNs) modeling approaches in forecasting monthly total dissolved solids (TDS) of water in the Rio Grande at El Paso, Texas. Predictability analysis was performed between the precipitation, temperature, streamflow rates at the site, releases from upstream reservoirs, and monthly TDS using cross‐correlation statistical tests. The chi‐square test results indicated that the average monthly temperature and precipitation did not show significant predictability on monthly TDS series. The performances of one‐ to three‐month‐ahead model forecasts for the testing period of 1984‐1994 showed that the TFN model that incorporated the streamflow rates at the site and Caballo Reservoir release improved monthly TDS forecasts slightly better than the ARIMA models. Except for one‐month‐ahead forecasts, the ANN models using the streamflow rates at the site as inputs resulted in no significant improvements over the TFN models at two‐month‐ahead and three‐month‐ahead forecasts. For three‐month‐ahead forecasts, the simple ARIMA showed similar performance compared to all other models. The results of this study suggested that simple deseasonalized ARIMA models could be used in one‐ to three‐month‐ahead TDS forecasting at the study site with a simple, explicit model structure and similar model performance as the TFN and ANN models for better water management in the Basin.