基于化感作用抑制藻华爆发的研究及应用

为了有效预防和控制藻华现象,分析了国内外基于化感作用抑制藻华爆发的研究成果,归纳出该技术的三大主要优势：抑制高效性、选择抑制性及环境友好性,并介绍了化感植物与藻类共培、直接投加化感物质、采用缓释技术投加化感物质3种抑制方式,最后指出目前该技术仍需丰富抑藻条件研究、克服“低促高抑”现象等问题,以期使化感抑藻技术尽快成熟并投入应用。     

芦苇水浸提液对水华微囊藻的化感作用研究

通过测定水华微囊藻(Microcystis flosaquae)细胞密度、叶绿素a、藻胆素质量浓度及SOD活性,研究了不同质量浓度芦苇(Phragmites communis)水浸提液对水华微囊藻的化感抑制作用。结果表明:1)低质量浓度芦苇水浸提液对水华微囊藻生长有促进作用,芦苇水浸提液质量浓度≥20 g/L时对水华微囊藻具有明显抑制作用;2)芦苇水浸提液质量浓度≥20 g/L时,可破坏水华微囊藻的光系统Ⅱ,减少其同化产物,促进叶绿素a的降解,而藻胆素不是主要作用靶点;3)当芦苇水浸提液质量浓度≥20 g/L时,藻细胞受到胁迫,其细胞活性氧的产量增加,抗氧化体系不能及时清除这些活性氧,导致植物细胞内发生过氧化反应,尤其是脂质过氧化反应,破坏细胞内膜系统,使抗氧化体系酶活性降低。     

微囊藻毒素与酚类和脂肪酸类化感化合物相关关系的研究进展

从微囊藻毒素作为化感化合物的角度,简要介绍了微囊藻毒素的合成机理、理化性质和环境特征,重点分析了微囊藻毒素与其他化感化合物的相关关系,详细阐述了微囊藻毒素在藻类群落演替及水华中的作用,以推动人类对藻毒素本质作用的全面、科学的认识进程,从而更好地管理和利用藻毒素。     

安全仪式感生成机制及作用机理研究

为明晰安全仪式感生成机制及其对企业安全管理促进作用机理,基于仪式与仪式感,阐述安全仪式与安全仪式感定义及“安全”核心内涵,厘清安全仪式、安全仪式感与安全管理关系,探讨安全仪式感产生的3个基本条件和4个时期,剖析安全仪式感的5个功能,并构建安全仪式感在安全管理中的功能作用模型。研究结果表明：安全仪式感能正向引导员工安全行为,可提升企业安全管理水平。     

不同溶剂对化感物质抑藻效果的影响

以铜绿微囊藻作为生物材料,邻苯二甲酸二丁酯和没食子酸作为化感物质,研究了这两种化感物质在不同浓度下对铜绿微囊藻生长的影响,对比了不同溶剂中两种化感物质的抑藻效果.结果表明,低浓度的邻苯二甲酸二丁酯对铜绿微囊藻的生长具有一定促进作用.但高浓度时抑制其生长;没食子酸对铜绿微囊藻的生长具有一定的抑制作用,但浓度的影响规律性并不明显;对邻苯二甲酸二丁酯来说,乙醇溶剂可以增强其对铜绿微囊藻生长的抑制作用,而对没食子酸来说,甲醇溶剂可以减弱其对铜绿微囊藻生长的抑制作用.可见,在化感物质发生作用时,化感物质用量和溶剂种类起着极其重要的作用.     

基于惰化降温耦合作用的采空区低温CO2注入位置研究

为了更好的使用低温CO2预防采空区煤自燃事故,利用FLUENT数值模拟的方法,结合宣东二号煤矿Ⅲ3煤层209工作面的实际条件,构建了考虑采空区不同压实程度的低温CO2注入采空区惰化降温耦合作用数值计算模型;分别研究了CO2注入量为540m3/h和720m3/h时,不同注入位置对采空区氧化带内最高温度点和氧化带宽度变化的影响。研究表明,合理的低温CO2注入位置为距工作面支架尾梁20～30m。     

Experimental study on explosion inhibition by heptafluoropropane and its synergy with inert gas

The inhibition effect of heptafluoropropane (CF₃CHFCF₃) on methane explosions under different inhibitor concentrations in a closed vessel was studied. A high-speed camera and a pressure sensor were adopted respectively to record flame propagation characteristics and pressure data. Results indicate that the relationship between flame propagation and pressure rising was correlated. As the equivalent ratio (ϕ)≤1, the pressure presented a trend of rising firstly and then decreasing with increasing CF₃CHFCF₃ concentration, and it was found that there existed a critical concentration for pressure decrease. As ϕ > 1, the pressure exhibited a decreasing trend. Although the pressure appeared to seemingly increase, the moment that the pressure began to rise (t_rise) and the moment that the maximum explosion overpressure appeared (t_Pmax) were obviously delayed. The average rate of pressure rise ((dP/dt)_ave) was decreased as the concentration of CF3CHFCF3 increased. It indicates that CF₃CHFCF₃ can effectively reduce the explosion reaction rate. The critical concentration of CF₃CHFCF₃ for complete inhibition was determined. Meanwhile, the synergy of CF₃CHFCF₃-inert gas can improve the inhibition effect. Compared with CF₃CHFCF₃–N₂, the synergy of CF₃CHFCF₃–CO₂ presented a better inhibition effect, and the inhibition effect was increased with increasing inert gas concentration. And the mechanisms of physical and chemical effects on explosion inhibition were analyzed.     

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...     

温石棉致豚鼠肺泡巨噬细胞酸性磷酸酶释放的干预效应研究

为了探讨几种化合物对温石棉致肺泡巨噬细胞（AM）酸性磷酸酶（ACP）释放的干预效应。本研究用不同浓度的柠檬酸铝、混合稀土或亚硒酸钠溶液浸泡温石棉1小时后，再将其与豚鼠肺泡巨噬细胞共同孵育，测定了细胞培养液中酸性磷酸酶的活性。结果显示，随着石棉剂量的增加和作用时间的延长，细胞培养液中酸性磷酸酶的活性逐渐升高，呈明显的剂量依赖性和时间，效应关系。经3种化合物预处理的石棉组，细胞培养液中酸性磷酸酶的活性均明显低于未处理温石棉组。提示，用3种化合物预处理温石棉，均可减轻温石棉对豚鼠肺泡巨噬细胞的毒性作用。     

Study on the preparation of novel FR-245/MCM-41 suppressant and its inhibition mechanism on oil shale deflagration flame

Oil shale development is of great significance because oil and gas resources are scarce. Research on the prevention of oil shale dust explosion is particularly important for guaranteeing the safe development and utilization of oil shale resources. In this work, the flame morphology and velocity of oil shale dust with and without MCM-41 or FR-245 were compared. Furthermore, the novel green FR-245/MCM-41 inhibitor was prepared by jet mill method and used in oil shale dust explosion for the first time. The best ratio of FR-245/MCM-41 for flame inhibition was obtained, which was 9: 1. The pyrolysis oxidation behavior of oil shale before and after adding FR-245/MCM-41 was analyzed and compared by FWO and KAS methods, respectively. The results showed that the activation energy calculated by FWO and KAS methods greatly increased after adding FR-245/MCM-41, which increased by 95.36% and 115.15% than that before adding inhibitor, respectively. Significantly, the activation energy is particularly high for two methods when α between 0.2 and 0.6, due to that MCM-41 and FR-245 coexisted to limit the oxidation of oil shale. For α between 0.7 and 0.9, the activation energy is still high because of the existence of MCM-41. Combining the oil dust flame propagation behavior with the characterization results before and after explosion, the physical-chemical synergy mechanism of oil dust flame propagation inhibition was revealed.     

菜籽油直接胺解法制备咪唑啉衍生物的缓蚀性能研究

为了降低原料成本,减少三废污染,以菜籽油和羟乙基乙二胺为原料,采用潜溶剂法合成咪唑啉中间体IM-1,再分别与氯化苄和氨基磺酸进行改性,得到阳离子咪唑啉衍生物IM-2和两性咪唑啉衍生物IM-3。应用红外光谱和核磁共振氢谱对合成产物进行鉴定。从中优选出1种与助剂KI(20∶1)复配,得到复配缓蚀体系IM-4。利用挂片法评价了该复配体系IM-4的缓蚀性能,并探究了其在A3钢表面的成膜性能。利用扫描电镜观察了加入IM-4前后A3钢的表面形貌,并与常用缓蚀剂进行了缓蚀性能的比较。结果表明,该缓蚀体系IM-4在盐酸溶液中对A3钢具有较强的缓蚀性能,静态缓蚀率为88.62%~98.98%,动态缓蚀率为86.76%~95.85%。     

煤氧化和阻化机理的红外光谱法研究

利用红外光谱法分析煤氧化和阻化的微观结构变化特征,对研究煤低温氧化和阻化机理有重要意义.采用TENSOR37傅里叶变换红外光谱仪,通过对阳泉无烟煤氧化和阻化的红外光谱图的分析.研究阳泉无烟煤在添加化学阻化剂前后煤分子结构的变化特征.结果表明:红外光谱图中位于高波数的羟基(-OH)吸收峰较弱,吸光度只有0.086～0.122.在加入吸水盐类阻化剂(MgCl2)后,吸光度约为原煤样的1.5倍,谱峰明显加强;在阻化前的低温氧化过程中,酚、醇、醚、酯的C-O吸光度由0.309降到0.207,甲基(-CH3)、亚甲基(-CH2-)的吸光度分别由0.027、0.019、0.042和0.056降到0.012、0.010、0.031和0.047,吸收峰强度逐渐减弱,芳烃C-H吸光度分别由0.031和0.040升高到0.077和0.087;在阻化后的低温氧化过程中,C-O含量基本不变,甲基、亚甲基的吸光度分别由0.017、0.011、0.034和0.040降到0.012、0.009、0.031和0.038,吸收峰减弱的速度明显降低,芳烃C-H的变化并不大.研究表明:在高变质阳泉煤中,含氧官能团和脂肪侧链的含量很低,在低温氧化过程中,很容易被氧化;吸水盐类阻化剂MgCl2可以通过与煤分子间发生取代和络合等作用,增加煤分子的稳定性,提高煤分子氧化的活化能,降低煤的氧化速率.     

Motorcycle helmet visor–related facial injury and its potential mechanism of injury: Evidence-based case study

Objectives: We encountered an unusual facial laceration wound in relation to motorcycle helmet visor use during our clinical practice. We aimed to assess the prevalence of this unusual facial injury among motorcyclists who sustained facial injuries in selected hospitals and to determine the possible mechanism involved.

Methods: We used our prospective cross-sectional substudy involving injured motorcyclists presenting at major trauma hospitals in Southern Klang Valley, Malaysia, between March 2010 and March 2011. of 391 subjects with facial injuries, 2 male motorcyclists sustained this laceration. The wounds were assessed and we believed that each was associated with the helmet visor. One of the visors was collected and the edge was inspected using scanning electron microscopy (SEM).

Results: The prevalence of this unusual injury was 0.51% (95% confidence interval, 0.002–0.012) among motorcyclists who sustained facial injuries. Both cases were involved in a head-on collision with their colliding partners and their helmets were intact throughout the crash. The visor in case 1 was intact, but the visor in case 2 was broken. SEM analysis showed that the visor in case 1 had a potential cutting surface.

We postulated that with helmet rotation in the forward and downward position and with some degree of visor bending or with a dislodged visor, the sharp-edged visor could potentially severely lacerate the face.

Conclusion: This injury affects facial aesthetics and early referral to the facial surgery team is advocated. Documentation of the mechanism of injury, the patient’s helmet and visor is obligatory, so that this information can be delivered to the regional road safety authority for preventive measures.     

2006—2016年我国工亡率趋势变化及其地区差异研究——基于工伤保险数据

为了解决目前国内现有工亡率数据所存在的局限性问题,引入我国工伤保险数据,并在此基础上分析2006—2016年我国及各地区的工亡率变化趋势, 进而运用泰尔指数分析法测算全国及各地区的工亡率地区差异。研究结果表明:2006—2016年,我国总体工亡率呈下降趋势,但整体水平仍偏高;西部明显高于东、中部,但东、中、西部之间的工亡率差异在缩小;东部、中部和西部内部各省市之间的差异还比较大。最后,提出设定管控工亡率指标时要注重追求本质上的进步,各地应采取措施解决不平衡的问题,完善标准化工亡报告制度,选择更高水平的国际对标体系。     

胡敏酸对水泥土强度的影响及机理

针对实际工程中胡敏酸造成水泥土搅拌桩强度降低的问题,利用室内试验研究不同胡敏酸掺入量、不同水泥掺入比制备的水泥土试样以及在不同养护龄期下水泥强度的变化规律,基于扫描电镜(SEM)和能谱分析(EDS)的检测结果,分析胡敏酸对水泥土试样强度的影响机理.结果表明,1)水泥土试样的无侧限抗压强度随着胡敏酸质量分数的增大而减小,其峰值应力处的应变也随着胡敏酸质量分数的增大而降低;水泥土试样的无侧限抗压强度随着养护龄期的增大而增大;水泥土试样的无侧限抗压强度随着水泥质量分数的增加而增大,但随着胡敏酸质量分数的增大,低水泥质量分数的无侧限抗压强度增幅较小.2)通过对扫描电镜观察和能谱结果的分析,添加胡敏酸制备的水泥土试样,微观结构变松散,土颗粒周围的胶结物质减少;水泥质量分数较低时孔隙较多且较大,孔隙随着水泥掺入比的增大而减少,水泥结构变得更为密实;水泥土试样中水泥的水化产物即水化硅酸钙(C-S-H)与水化铝酸钙(C-A-H)随着胡敏酸质量分数的增大而减少,其微观结构中水泥的水化产物减少,能谱分析中水泥土的Ca质量分数减小,其宏观上表现为水泥土无侧限抗压强度降低.     

Effect of pyrolysis and oxidation characteristics on lauric acid and stearic acid dust explosion hazards

The effect of pyrolysis and oxidation characteristics on the explosion sensitivity and severity parameters, including the minimum ignition energy MIE, minimum ignition temperature MIT, minimum explosion concentration MEC, maximum explosion pressure P_max, maximum rate of pressure rise (dP/dt)_max and deflagration index K_st, of lauric acid and stearic acid dust clouds was experimentally investigated. A synchronous thermal analyser was used to test the particle thermal characteristics. The functional test apparatuses including the 1.2 L Hartmann-tube apparatus, modified Godbert-Greenwald furnace, and 20 L explosion apparatus were used to test the explosion parameters. The results indicated that the rapid and slow weight loss processes of lauric acid dust followed a one-dimensional diffusion model (D1 model) and a 1.5 order chemical reaction model (F1.5 model), respectively. In addition, the rapid and slow weight loss processes of stearic acid followed a 1.5 order chemical reaction model (F1.5 model) and a three-dimensional diffusion model (D3 model), respectively, and the corresponding average apparent activation energy E and pre-exponential factor A were larger than those of lauric acid. The stearic acid dust explosion had higher values of MIE and MIT, which were mainly dependent on the higher pyrolysis and oxidation temperatures and the larger apparent activation energy E determining the slower rate of chemical bond breakage during pyrolysis and oxidation. In contrast, the lauric acid dust explosion had a higher MEC related to a smaller pre-exponential factor A with a lower amount of released reaction heat and a lower heat release rate during pyrolysis and oxidation. Additionally, due to the competition regime of the higher oxidation reaction heat release and greater consumption of oxygen during explosion, the explosion pressure P_m of the stearic acid dust was larger in low concentration ranges and decayed to an even smaller pressure than with lauric acid when the concentration exceeded 500 g/m³. The rate of explosion pressure rise (dP/dt)_m of the stearic acid dust was always larger in the experimental concentration range. The stearic acid dust explosion possessed a higher P_max, (dP/dt)_max and K_st mainly because of a larger pre-exponential factor A related to more active sites participating in the pyrolysis and oxidation reaction. Consequently, the active chemical reaction occurred more violently, and the temperature and overpressure rose faster, indicating a higher explosion hazard class for stearic acid dust.