碳酸氢钠及其固态分解产物对玉米淀粉爆炸抑制实验研究

为研究NaHCO3对玉米淀粉爆炸的抑制效果,采用20 L球形爆炸装置测试玉米淀粉在添加不同抑制比NaHCO3及其固态分解产物Na2 CO3后爆炸参数变化规律,并分析NaHCO3抑制淀粉爆炸过程.结果表明:NaHCO3及Na2 CO3对玉米淀粉爆炸均有抑制作用,NaHCO3抑制效果优于Na2 CO3;混合粉尘的最大爆炸压...     

二次电池电极材料环境影响计算系统

以生命周期评价理论为基础,建立了电极材料电化学性能与环境影响的内在量化关联关系分析方法。基于Java语言,设计和编写了二次电池电极材料环境影响综合计算系统,协调考虑了二次电池的循环特性、电化学特征等,实现了环境影响评价过程中对材料质量需求的便捷计算,进而实现了整个评价操作过程的综合化、软件化和信息化,提高了评价效率。选用LiFePO_4/C,LiFe_(0.98)Ti_(0.02)PO_4/C,LiFe_(0.98)Mn_(0.02)PO_4/C和FeF_3(H_2O)_3/C 4种正极材料基于此系统进行了实例应用。     

丙二酸二(2-(2,3-二羟基苯甲酰胺)乙基)酯的合成与螯合性能研究

用2,3-二羟基苯甲酸经羟基保护、酰胺化、酯化和去保护4步反应,生成一种新型的四齿丙二酸二(2-(2,3-二羟基苯甲酰胺)乙基)酯配体.采用傅里叶变换红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)、核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)和质谱(MS)对其结构进行了表征.在中性pH值条件下,研究了这种配体对铀酰离子的络合能力.结果表明,丙二酸二(2-(2,3-二羟基苯甲酰胺)乙基)酯配体与铀酰离子的螯合常数为23.2.     

A multilevel investigation of predictors and outcomes of shared leadership

For modern organizations, shared leadership becomes increasingly important. Knowledge on shared leadership may be limited, as past research often relies on cross-sectional data or student samples, and most studies neglect the multilevel nature of shared leadership. Our research model includes transformational leadership, trust, and organizational support as predictors of shared leadership. Furthermore, we analyze the influence of shared leadership on team performance and team creativity. In total, 160 teams with 697 employees participated in our field study. Data collection took place at three time points. To test our hypotheses, we used multilevel modeling with a Bayesian estimator. We found relationships of transformational leadership and trust with shared leadership at the team level and of transformational leadership, trust, and organizational support with shared leadership at the individual level. Furthermore, shared leadership fully mediated the effect of the three input factors on team performance and team creativity. This study contributes to the understanding of the antecedents and outcomes of shared leadership. Furthermore, the dynamic development of team processes based on an input–mediator–output model is explored. On the basis of the results, organizations can increase shared leadership behavior by focusing on transformational leadership and trust building.     

基于模糊评价的VDT系统搜索策略绩效形成机理研究

为优化视觉显示终端（VDT）结构性搜索界面的布局,提高作业绩效和安全,设计了VDT系统搜索实验,构建了搜索目标位置在4个主观偏好指标下的Pythagorean模糊集决策矩阵,运用交互式多准则决策（TODIM）法计算各目标位置偏好的总体优势度并排序;同时对VDT系统搜索实验中各目标位置的绩效进行方差分析并排序,分析系统搜索策略下作业者对目标位置的主观偏好与绩效之间的关系。研究结果表明:基于系统搜索策略的VDT作业绩效在不同目标位置差异显著;导致绩效差异的根本原因是作业者对搜索目标位置的主观偏好度,而不是搜索目标的位置属性;除中心区域外,偏好度高的区域搜索绩效要优于偏好度低的区域。     

隧道内偏置火源顶棚近壁面温度边界层效应研究

基于隧道火灾不同横向火源位置的非对称卷吸影响,通过模拟计算分析了中心火源和偏置火源产生的烟气沿纵向最大温升变化规律,研究了顶棚下方近壁面区域内的不同温度分布,提出偏置火源纵向空间最大顶棚温升公式。结果表明:在壁面黏性作用下,沿纵向蔓延的烟气最高温度在顶棚下方呈现“温度边界层”分布;随着火源位置的偏移,下游出现偏置距离起主导作用影响温度衰减的区域,衰减速度相较于中心火源逐渐降低;火源下游近壁面最高温度位置逐渐远离顶棚后趋于稳定。研究结果对于排烟方式的设计以及空间通风效果的提升有着重要意义。     

基于不同强度等级混凝土的动力学特性研究

基于TAW-2000D电液伺服岩石三轴仪和直径75 mm的霍普金森压杆试验装置,得到了C25,C35和C45混凝土在静、动载荷作用下的应力-应变曲线,探讨了混凝土强度等级、动态峰值强度、峰值应变和应变率之间的变化规律。结果表明:混凝土准静态应力-应变曲线和动态应力-应变曲线在形态上存在明显差异,动态应力-应变曲线的峰值点随应变率的增大向右上方移动,线弹性阶段各曲线斜率变化不明显;动态峰值应力、动态弹性模量和峰值应变均存在不同程度的率相关性,并且混凝土材料的应变率敏感性随其强度等级的提高而增强;混凝土C45的各力学指标对应变率的敏感性最强,C35次之,C25的应变率敏感性最弱;推导了应变率与强度等级和冲击速率之间的经验公式,三者之间存在非线性变化规律。     

Alcohol is a predictor of mortality in motor vehicle collisions

IntroductionIt is well recognized that driving while intoxicated increases the probability of a motor-vehicle collision (MVC). The effect of alcohol on the chance of surviving the MVC is less clear. Method: Using data from the Fatality Analysis Reporting System (FARS) we conducted analyses for the outcome of mortality using alcohol and other variables as predictors. We also selected alcohol positive (AP) and alcohol negative (AN) persons from the same MVC and vehicle to control for confounding characteristics. Results: The odds ratio (OR) for mortality for alcohol positive drivers was 2.57, (p < 0.001 for all the following OR). Other harmful predictive factors were age OR 1.01 per year, vehicle age OR 1.05 per year, male sex OR 1.23, avoidance maneuver OR 1.09, speed related OR 2.89, rollover mechanism OR 2.75, and collision with a fixed object OR 6.70. Protective factors were proper restraint use – OR 0.19 and collision with another moving vehicle, OR 0.21. In the multivariate analysis the OR of mortality for AP vs AN was 1.46. Proper restraint use (OR 0.27) remained protective along with collision with another moving vehicle. When AP and AN persons from the same MVC and the same vehicle were compared, the adjusted OR’s for mortality were 1.46 and 2.08, respectively. Conclusions: Alcohol is an independent predictor of mortality in an MVC. Proper restraint use is the strongest protective factor. This finding allows a more complete understanding of the risks of driving while intoxicated, not only a higher probability of an MVC, but decreased survival once the MVC occurs. Practical Applications: Identification of alcohol as an independent predictor of mortality in an accident may improve risk assessment and influence drivers to avoid driving while intoxicated.     

2014—2018年铁路辖区职工癌胚抗原检测结果与分析

为了解某铁路辖区职工癌胚抗原异常情况,探讨该人群癌胚抗原异常检测结果的影响因素,以提出防控策略,采用全自动电化学发光仪对2014—2018年铁路辖区职工的癌胚抗原进行测定,共检测159 214份。结果表明,癌胚抗原异常率12.1%,56～60岁人群癌胚抗原异常率最高、为14.5%,男性职工癌胚抗原异常率高于女性,血糖偏高人群癌胚抗原异常率为16.5%。最后提出应进一步重视检测结果,充分利用铁路现有卫生资源,采取健康体检、健康宣传、健康休养、健康管理的防控手段。     

Farmers' Willingness-to-Pay for Environment and Human Health and Adoption of IPM

Abstract

Although chemical control of pests increases crop production, it brings a lot of damage to environment and human health. There exist a number of alternative methods that are not so harmful to environment and human health. However, whether and how much in extent these technologies adopted are plausible depends on the comparison of benefit- cost between chemical control and the alternative control methods (such as Integrated Pest Management, IPM) and farmers' willingness-to-pay (WTP) for environment and human health. Using contingent valuation method (CVM), the author investigates farmers' WTP for environment and human health, recognizes the factors influencing WTP, and accordingly points out the importance of pest control technology extension and government regulation of pesticides.