漆酶/HOBT体系对苯胺蓝的脱色条件及机理研究

研究了Pleurotus sp.N3固态发酵所得漆酶对三芳基甲烷类染料苯胺蓝的脱色条件和机理.通过可见光光谱扫描和非变性凝胶电泳的分析发现漆酶能够对苯胺蓝进行脱色,介体可以显著增强脱色效果,提高脱色率.分别考察了介体、酶活和温度对苯胺蓝脱色的影响,结果表明,在酶活为200 U/L、1-羟基苯并三唑(HOBT)浓度为4mmol/L、温度为40℃的条件下,反应6h后苯胺蓝(24 mg/L)的脱色率达到90.42％.对脱色0、4h、11h和23 h的产物进行了超高效液相色谱-质谱(UPLC-MS)分析,推断出漆酶/HOBT体系对苯胺蓝的脱色过程中有显色基团碳氮双键(C=N)的断裂.     

星豹蛛头胸部乙酰胆碱酯酶最佳反应体系及其药剂敏感度

利用正交试验法研究5个因素对测定星豹蛛(Pardosa astrigera)头胸部乙酰胆碱酯酶(AChE)活性的影响,以建立酶活测定的最佳反应体系.结果表明,各因素对AChE的比活力影响由大到小的顺序为反应体系的pH值、反应时间、酶质量浓度、反应温度和底物浓度.测定AChE活性的最佳反应条件是: 酶质量浓度为12 g·L-1,底物浓度为0.6 mmol·L-1,反应体系pH值为7.0,反应温度为30 ℃,反应时间为5 min.此外,4种杀虫剂对星豹蛛头胸部AChE活性的影响试验结果表明,灭多威、辛硫磷、高效氯氰菊酯、毒死蜱对AChE的抑制中浓度(IC50)分别为7.76×10-5 mol·L-1、1.76×10-4 mol·L-1、4.12×10-4 mol·L-1和4.94×10-4 mol·L-1,并且上述4种杀虫剂对AChE的抑制具有明显的剂量关系.     

饮用水中微囊藻毒素臭氧降解效能及影响因素研究

对臭氧氧化去除饮用水中微囊藻毒素RR及LR的降解效能、反应动力学进行了试验研究,讨论了藻毒素初始质量浓度、pH值、羟基自由基(·OH)抑制剂(HCO-3)、溶解性有机碳(DOC)质量浓度对降解的影响.结果表明:整个降解过程符合一级动力学反应方程,降解速率常数与藻毒素初始质量浓度无关;pH值的升高、HCO-3和DOC的存在都会降低藻毒素的降解效率.在液相臭氧质量浓度为8.20 mg·L-1,pH=7.0,温度为(25±1) ℃,反应时间30 min的条件下,MC-RR降解速率常数k=7.80×102 min-1,去除率达90.0%;MC-LR降解速率常数k=1.06×101 min-1,去除率达96.3%.     

铅胁迫对苦草生理生化及氮、磷代谢关键酶的影响

通过研究不同时间(1 d、3 d、5 d、7 d)和不同铅浓度(0、5μmol/L、25μmol/L、50μmol/L、100μmol/L、250μmol/L)胁迫下苦草的生理特性及其氮、磷代谢关键酶的变化,探讨了苦草对铅胁迫的响应。结果表明,叶绿素(Chl)质量比和硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和酸性磷酸酶(ACP)活性在低浓度铅胁迫下5 d内均有所提高,而在高浓度铅胁迫下,叶绿素质量比呈下降趋势。在试验第7 d,各浓度下的酶活性均受到抑制,并且低于对照组。丙二醛(MDA)含量和游离脯氨酸(Fpro)质量比随铅浓度增加呈现先增加后降低的趋势。研究表明,苦草对铅胁迫具有一定的抵抗缓解能力,氮磷代谢关键酶对铅胁迫的响应更为敏感,可以考虑将其作为铅胁迫的响应指标。     

零价铁活化过硫酸盐降解分散剂木质素磺酸钠研究

为研究零价铁(Fe0)通过电子转移对过硫酸盐(PS)降解分散剂木质素磺酸钠(SL)能力的影响,以SL作为目标污染物,对影响SL降解的因素(初始pH值、SL初始质量浓度、PS浓度、Fe0投加量)及降解机理进行探讨.结果表明,1)当pH值小于2时,SL降解率随pH值升高而升高;当pH值在2～5时,SL降解率随pH值升高而降低.当PS浓度在2～4 mmol/L时,SL的降解率随PS浓度的增大而增大;当PS浓度超过4 mmol/L后降解率呈现下降趋势.当固定其他反应条件时,SL的降解率随SL初始质量浓度的升高而降低.2)相比于单一 Fe0体系和单一 PS体系,Fe0-PS体系对SL的降解率有显著提高,对含SL废水可生化性有所改善.在最佳反应条件下(pH值为2,Fe0投加后质量浓度为0.3 g/L,SL初始质量浓度0.5 g/L,PS浓度为4 mmol/L),180 min内SL的降解率能达到75.9％.3)Fe0活化PS产生SO4-·,通过自由基淬灭剂进行淬灭试验,确定降解过程中的SO4-·与·OH为体系活性物质.4)通过红外吸收光谱扫描,比较SL与反应产物的FTIR图谱,推测在氧化作用下,SL的苯环结构断裂,部分磺酸基团被氧化为SO4-.研究表明,Fe0-PS体系与单一 Fe0体系和单一 PS体系相比,Fe0能有效活化PS产生SO4-·,进而对SL有更好的降解效果.     

水体中的微生物对壬基酚聚氧乙烯醚的生物降解

为有效控制水体中壬基酚聚氧乙烯醚的污染 ,以芽孢杆菌、假单胞菌、诺卡氏菌和假丝酵母为试验菌株 ,研究了其对壬基酚聚氧乙烯醚的生物降解特性。试验结果表明 ,4菌株在一定的条件下对水体中的壬基酚聚氧乙烯醚均有一定的降解率。若按体积比 1∶ 2∶ 1∶ 1的比例将四菌株组合成复合菌群 ,可大幅度提高处理效率 ,降解率可达 61 %。应用该复合菌对影响壬基酚聚氧乙烯醚降解的各种主要因素进行了研究 ,发现降解菌在θ为 2 5～ 30℃ ,p H值为 5.5～ 8.5及壬基酚聚氧乙烯醚初始质量浓度ρ(NP1 0 EO)为 0～ 1 0 0 mg/ L范围内保持高活性 ;当底物质量浓度大于 1 0 0 mg/ L 时 ,平均降解速率线性下降 ;当接种量标准为 1× 1 0 8CFU/ m L (即菌悬液 /反应液为1 0 % )时壬基酚聚氧乙烯醚的降解是高效与经济的     

NH3-H2O2气雾对氰化氢气体的消毒

采用NH_3-H_2O_2气雾对1 m3密闭试验舱内氰化氢气体进行消毒,采用单因素试验研究H_2O_2和NH_3质量浓度对消毒率和消毒反应速率的影响规律。结果表明,NH_3-H_2O_2气雾对HCN的消毒符合一级反应动力学特征,NH_3质量浓度对消毒反应速率有一定影响,但当NH_3质量浓度增加至20 mg/m3以上时,对反应速率几乎没有影响; H_2O_2质量浓度对消毒反应速率有显著影响,反应速率随H_2O_2质量浓度的提高明显增大。NH_3-H_2O_2气雾消毒剂的最佳配方为H_2O_2的质量浓度为120 mg/m3、NH_3的质量浓度为20 mg/m3,在此条件下对HCN进行消毒,在28 min时HCN的残余质量浓度为0. 92 mg/m3,可以达到GBZ 2. 1—2007《工作场所有害因素职业接触限值第1部分:化学有害因素》中有关HCN最高容许质量浓度MAC值(1 mg/m3)的规定。分析消毒机理为H_2O_2首先将HCN氧化为氰酸(HCNO),氰酸不稳定,在NH_3和水的作用下可以水解成碳酸铵,也可以进一步被氧化形成CO2和N2。     

钛酸纳米管的光催化性能研究

以Ti0_2(Degussa P25)和NaOH为原料,采用水热法制备钛酸纳米管.以亚甲基蓝溶液(Methylene Blue,简称MB)为模型污染物,研究水热反应条件对所制钛酸纳米管光催化性能的影响,以及钛酸纳米管加入量、溶液pH值和MB初始浓度等光催化反应条件对钛酸纳米管光催化性能的影响.研究表明:水热反应温度为150℃,反应时间为48 h制得的钛酸纳米管对MB的光催化效率最高;钛酸纳米管的加入量、溶液pH值和MB初始浓度等光催化反应条件对钛酸纳米管的光催化性能有较大影响.     

摇蚊乙酰胆碱酯酶最佳反应体系的建立及有机磷类药剂敏感度比较

花翅摇蚊(Chironomus kiiensis)是一种重要的水生昆虫,经常用于水体环境质量的生物学评价.用正交试验方法研究了酶浓度、底物浓度、反应体系pH值、反应温度、反应时间5个因素对花翅摇蚊(Chironomus kiiensis)乙酰胆碱酯酶(AChE)活性测定的影响.通过对正交试验结果进行极差和方差分析,明确了测定摇蚊AChE活性的最适反应条件是酶浓度为5头/mL、底物浓度为6 mmol/L、pH值为8.0、温度为35℃、反应时间为10 min.DDVP、马拉硫磷和甲胺磷对花翅摇蚊的LC50值分别为8.93 mg/L、16.74 mg/L和47.65 mg/L.利用正交试验得到的反应最适条件进一步研究了花翅摇蚊接触上述3种药剂亚致死剂量后对其体内AChE活性的影响.结果表明,无论是时间效应还是剂量效应,3种药剂对花翅摇蚊幼虫体内AChE影响的趋势与生物测定结果是一致的,其对花翅摇蚊幼虫体内AChE的抑制能力依次为DDVP、马拉硫磷和甲胺磷.     

三子汤对水丝蚓铅污染的保护作用研究

为了研究三子汤对铅胁迫下水丝蚓抗氧化酶的保护作用,以探索中药抗重金属污染的特性,采用室内急性毒性的试验方法测定了不同质量浓度的铅离子对水丝蚓6 h、12h、24 h的半致死浓度分别为2. 50 mg/L、2. 00 mg/L、1. 25mg/L;测定了三子汤对水丝蚓的6 h、12 h、24 h半致死浓度分别为45 g/L、24. 75 g/L、22. 50 g/L。然后在反应体系中加入不同质量浓度的三子汤,测定不同质量浓度的三子汤对铅胁迫水丝蚓的SOD酶活性的影响,与未加入三子汤的铅胁迫水丝蚓的SOD酶活性进行检测。结果显示,铅胁迫的水丝蚓体内SOD酶活性为0. 087 U/g;加入1/4致死浓度三子汤的水丝蚓体内SOD酶的活性降低至0. 048 U/g;加入半致死浓度三子汤和1/8致死浓度三子汤的水丝蚓体内的SOD酶活性分别为0. 068 U/g和0. 058 U/g;对照组水丝蚓体内的SOD酶活力为0. 047 U/g。研究表明,1/4致死浓度的三子汤对铅胁迫的水丝蚓有明显的保护作用。     

自然灾害与地质勘探劳动保护

自然灾害和人密切相关,这不仅表现在自然灾害施予的客体是人,人的伤亡和财产损失是自然灾害的标志,而且表现在自然灾害的发生受人类活动的强烈影响。地质勘探活动是人类改造自然获取财富的主要活动之一。它一方面遭受自然灾害的危害,另一方面存在诱发触发自然灾害的危险,自然灾害已成了地质勘探活动的巨大障碍。自然灾害特别是地质灾害(人工诱发触发地质灾害、地方病)和气象灾害的测、报、防、治、救措施和方法研究是地质勘探劳动保护的重要课题。     

聚乙烯醇/氧化石墨插层纳米复合材料的结构和热分析

制备了聚乙烯醇/氧化石墨插层纳米复合材料,并用X-射线衍射仪和高分辨电镜对其结构进行了表征.X-射线衍射仪和高分辨电镜的试验结果表明,氧化石墨和聚乙烯醇插层氧化石墨的层间距分别为0.89 nm和1.4nm.该纳米复合材料的热分析和热失重图说明,氧化石墨的加入有利于提高聚乙烯醇/氧化石墨纳米复合材料的玻璃化转变温度和氧化温度,同时也降低了其热释放速率.     

基于遗传算法的支持向量机预测有机物自燃点的研究

根据定量构效关系(QSPR)原理,研究自燃点(AIT)与其分子结构间的内在定量关系。以265种有机化合物作为样本集,随机选择238种作为训练集,27种作为测试集,用遗传算法(GA)进行变量选择,分别建立多元线性回归(MLR)模型和支持向量机(SVM)模型研究有机物的自燃点与其分子结构间的关系。通过分析,发现造成模型预测效果不佳的原因是试验数据本身存在问题。通过对2个模型的比较,结果为GA-SVM模型明显优于GA-MLR模型,说明自燃点与其分子结构间具有很强的非线性关系。     

Automation design in advanced control rooms of the modernized nuclear power plants

This study evaluated the effects of levels of automation (LOAs) decisions in advanced control rooms of the modernized nuclear power plants. Following advancements in design of digitalized human–system interfaces (HSIs), the roles of human operators have changed significantly. Negative performance and safety consequences may occur as a result of these changes. These problems are viewed as the out-of-the-loop (OOTL) performance problems. This study conducted an experiment to compare the effects of different LOAs under different operating procedures on operating performance. Experimental results indicated that blended decision-making (level 6 LOA) generates the lowest mental workload. Furthermore, the pattern of SA observed in this study is found better SA at intermediate LOA and poorer SA at low level of automation and full automation. Subjective rating results suggest that LOAs distribute the roles of option generation, and selection between human and/or computer servers which significantly impacts automated system performance. This study provides a direction for the HSI designers in nuclear power plants (NPPs). Additionally, based on results obtained by this study, the user interfaces of PCTRAN system and the alarm reset system should be improved to ensure safe operation of NPPs.     

Influence of ATD versus PMHS reference sensor inputs on computational brain response in frontal impacts to advanced combat helmet (ACH)

ABSTRACT

Objective: This study analyzed the influence of reference sensor inputs from anthropomorphic test devices (ATDs) versus postmortem human subjects (PMHSs) on simulations of frontal blunt impacts to the advanced combat helmet (ACH).

Methods: A rigid-arm pendulum was used to generate frontal impacts to ACHs mounted on ATDs and PMHS. An appropriately sized ACH was selected according to standard fitting guidelines. The National Operating Committee on Standards for Athletic Equipment (NOCSAE) head was selected for ATD tests due to shape features that enabled a realistic helmet fit. A custom procedure was used to mount a reference sensor internally near the center of gravity (CG) of the PMHS. Reference sensor data from the head CG were used as inputs for the Simulated Injury Monitor (SIMon). Brain responses were assessed with the cumulative strain damage measure set at 10%, or CSDM(10).

Results: Compared to ATD tests, PMHS tests produced 18.7% higher peak linear accelerations and 5.2% higher peak angular velocities. Average times to peak for linear accelerations were relatively similar between ATDs (5.5?ms) and PMHSs (5.8?ms). However, times to peak for angular velocities were higher by a factor of up to 3.4 for PMHSs compared to ATDs. Values for were also higher by a factor of up to 13.1 when PMHS inputs were used for SIMon.

Conclusions: The preliminary findings of this work indicate that small differences in ATD versus PMHS head kinematics could lead to large differences in strain-derived brain injury metrics such as CSDM.     

TMBR+NF/RO组合工艺处理垃圾渗滤液的工程应用

采用TMBR+NF/RO组合工艺对湖北省宜昌市某垃圾卫生填埋场渗滤液进行处理,介绍了组合工艺的流程、特点、设备规格、技术参数。TMBR系统对可生化降解COD处理后,COD平均质量浓度为822 mg/L,平均去除率为95.8%,对NH_3-N平均去除率为94.9%;经过NF/RO出水的COD平均值为45 mg/L,NH_3-N均小于25mg/L,达到《生活垃圾填埋场污染控制标准》(GB 16889—2008)的排放标准。组合工艺处理成本为29.5元/m3。     

Reliability analysis of subsea blowout preventers with condition-based maintenance using stochastic Petri nets

Blowout Preventer (BOP) has maintained its function as a safety barrier and the last line of defence against oil and gas spills since its development in the early 1900s. However, as drilling and exploration activities move further offshore, challenges pertaining to reliable operation of the subsea BOP systems continue to be a source of concern for stakeholders in the industry. In spite of recent advancements in reliability analysis of safety instrumented systems (SISs), the research on reliability assessment of BOP is still lacking in some regards. There are gaps in the literature with respect to the incorporation of preventive maintenance (PM) strategies as well as dynamic operating conditions into BOP reliability analysis. To address these gaps, this paper develops an advanced analysis method using stochastic Petri nets (SPN) to estimate the reliability of subsea BOP systems subject to condition-based maintenance (CBM) with different failure modes. The BOP system is divided into five subsystems which are connected in series with each other and categorised into degrading and binary units. The performance of the BOP system in terms of availability, reliability and mean-time-between failures (MTBF) is obtained and analysed. A sensitivity analysis is also performed to evaluate the effect of fault coverage factor and redundancy design on system performance. The results show that both the fault coverage factor and redundancy have significant impact on the BOP's reliability, availability and MTBF.     

Safety and kinetic parameters analysis for 1,1,-Di(tert-butylperoxy) cyclohexane mixed with monoammonium phosphate

Runaway reactions by organic peroxides have occurred throughout the world. In this study, we used 1,1,-Di(tert-butylperoxy) cyclohexane (CH) 70 mass% as the main material, which was extensively employed as initiator for styrene in polymerization. Fire extinguishers are the first fire-fighting apparatus when fires occur. If a fire extinguisher has sat idle for a long time, which would cause the extinguishing agent to damp, it cannot achieve the desired effect and be properly handled at the start of the accident, thereby causing more casualties and property losses. CH 70 mass% was employed to mixed with monoammonium phosphate (MAP) for understanding the phenomenon by applying differential scanning calorimetry (DSC). Safety parameters also were carried out for more deeply understanding the basic characteristics for preventing an accident from occurring, in terms of applying CH 70 mass% as the initiator in the manufacturing process.     

引气剂和聚丙烯纤维对高水材料性质的影响研究

为了改变高水材料的破坏特点,采用引气剂和聚丙烯纤维双掺对其进行改性。试验结果表明:随着引气剂掺量的增加,浆体的流动性逐渐降低,混合浆液失流时间延长,试块密度和单轴抗压强度逐渐减小;聚丙烯纤维的掺入,对浆体流动性、失流时间、引气率影响均较小。聚丙烯纤维最佳掺量为2 kg/m3,引气剂和聚丙烯纤维的掺入使硬化体的弹性模量略有减小,且使试块由脆性破坏转变为延性破坏,在保持整体不散的情况下,提高其压缩量。SEM观察表明:钙矾石在气泡壁上集中生成,聚丙烯纤维与基体的界面处有利于针状钙矾石的生成,从而使聚丙烯纤维更好地发挥增强增韧的作用。     

Nonlinear molecular based modeling of the flash point for application in inherently safer design

New chemical process design strategies utilizing computer-aided molecular design (CAMD) can provide significant improvements in process safety by designing chemicals with required target properties and the substitution of safer chemicals. An important aspect of this methodology concerns the prediction of properties given the molecular structure. This study utilizes one such emerging method for prediction of a hazardous property, flash point (FP), which is in the center of attention in safety studies. Using such a reliable data set comprising 1651 organic and inorganic chemicals, from 79 diverse material classes, and robust dynamic binary particle swarm optimization for the feature selection step resulted in the most efficient molecular features of the FP investigations. Apart from the simple yet precise five-parameter multivariate model, the FP nonlinear behavior was thoroughly investigated by a novel hybrid of particle swarm optimization and support vector regression. Besides, 195 missing experimental FPs of the DIPPR data set are predicted via the presented procedure.