X80天然气管道在役焊接应力分析与调控

为了探究X80天然气管道在役焊接的应力分布和变化规律，在考虑天然气介质的作用下，采用有限元方法模拟了X80天然气管道在役焊接应力场分布规律，分析了天然气工况参数和环境温度对X80天然气管道在役焊接应力的影响，并根据应力变化规律提出了降低X80天然气管道在役焊接应力的措施。研究结果表明:X80天然气管道轴向焊接应力和环向应力主要呈对称分布形式，且管道外壁的应力大于管道内壁上的应力；随着天然气压力和流速逐渐增大，轴向应力先增加后降低，而环向应力逐渐增大；当环境温度增大后，管道轴向和环向应力均呈下降趋势；降低天然气压力和流速、采用焊前预热能够有效降低焊接应力。研究结果可为我国X80天然气管道在役焊接安全提供参考。     

过氧化氢异丙苯热稳定性与热安全性研究

为研究过氧化氢异丙苯(CHP)的热稳定性和热安全性,利用C80微量量热仪对CHP在空气中的热分解进行试验研究。利用热分析技术研究CHP的热分解,得到了升温速率对CHP热分解的影响,CHP热分解的活化能,绝热条件下最大反应速率到达时间Tmrad和不同包装下的自加速分解温度。结果表明:随着升温速率的增加,CHP的起始放热温度和最大放热温度随之升高;CHP热分解的活化能范围为52～91 kJ/mol;Tmrad为1,8,24,50和100 h时对应的起始温度分别为118.08,75.41,55.83,44.83和34.52℃;CHP的储罐内径越大,其对应的自加速分解温度越低。     

The ex vivo and in vivo biological performances of graphene oxide and the impact of surfactant on graphene oxide's biocompatibility

Graphene oxide(GO)displays promising properties for biomedical applications including drug delivery and cancer therapeutics.However,GO exposure also raises safety concerns such as potential side effects on health.Here,the biological effects of GO suspended in phosphate buffered saline(PBS)with or without 1% nonionic surfactant Tween 80 were investigated.Based on the ex vivo experiments,Tween 80 significantly affected the interaction between GO and peripheral blood from mice.GO suspension in PBS tended to provoke the aggregation of diluted blood cells,which could be prevented by the addition of Tween 80.After intravenous administration,GO suspension with or without 1% Tween 80 was quickly eliminated by the mononuclear phagocyte system.Nevertheless,GO suspension without Tween 80 showed greater accumulation in lungs than that containing 1% Tween 80.In contrast,less GO was found in livers for GO suspension compared to Tween 80 assisted GO suspension.Organs including hearts,livers,lungs,spleens,kidneys,brains,and testes did not reveal histological alterations.The indexes of peripheral blood showed no change upon GO exposure.Our results together demonstrated that Tween 80 could greatly alter GO’s biological performance and determine the pattern of its biodistribution in mice.     

复合乳化剂对乳化炸药热安全性影响研究

为了探究复合乳化剂对乳化炸药热分解特性的影响,使用C80微量热仪通过MC法研究了乳化剂A(SP80)和乳化剂B(T152)作为单一乳化剂和复合乳化剂(加入比例为1:1、1:2、2:1)制备的乳化炸药。以升温速率为0.5K/min时的C80热流速曲线为基础来求解5种炸药热分解反应的表观活化能(Ea)、指前因子(lnA)等热安全参数。结果表明,使用复合乳化剂制备的乳化炸药稳定性均高于使用单一乳化剂的乳化炸药。采用复合乳化剂可导致乳化剂分子间排斥作用降低,使分子排列更紧密,增加了界面膜的致密性。当加入的乳化剂比例为m(SP80):m(T152)=1:2时,由于两种乳化剂相互作用形成致密的复合界面膜,其稳定性最高。     

工业废水中痕量汞的直接测定

采用DMA-80型直接测汞仪测定工业废水中的痕量汞,优化了干燥时间、分解温度、释放温度等试验条件。方法在0μg/L~600μg/L范围内线性良好,检出限为5.0×10-5mg/L,工业废水样品平行测定的RSD≤0.2%,加标回收率为96.7%~105%。     

供氧条件和水分对煤粉热特性的影响研究

使用C80微量量热仪研究了煤粉在升温条件下的热特性,比较了煤粉在不同供氧条件下的热特性.结果表明,在80℃时探测到煤粉开始放热,供氧量增加能促进煤粉产热增加,根据供氧不足情况下的实验,得出煤粉的耗氧产热量为14.49 J mL-1.研究了少量水分对煤粉热稳定性的影响,当煤粉和水的质量比为10:1时,在71℃时探测到放热,比干燥煤粉的放热开始温度低9℃.这些研究为煤炭的安全存储提供了实验基础.     

Mn2+协同PDS对酸性蓝80的电催化降解性能研究

以酸性蓝80（AB80）模拟染料废水,采用E-Mn²⁺-PDS协同体系,对AB80进行电催化降解实验.对比了不同催化体系的降解效率,探讨了Mn²⁺与PDS浓度、pH值和电流密度等单因素对E-Mn²⁺-PDS体系电催化降解效率的影响,对E-Mn²⁺-PDS体系中的氧化性物质、AB80的分解产物及其在体系中的矿化程度进行了研究,并分析了降解机理.结果表明：与其他催化体系比较,E-Mn²⁺-PDS协同体系最优,对AB80的降解率高达99.9%.pH值是最主要的影响因素,pH=3时,E-Mn²⁺-PDS协同体系的降解率为99.6%;协同体系中的氧化性物质包括硫酸根自由基（SO₄^-×）,羟基自由基（HO×）,还有活性Mn³⁺;AB80在协同体系中经过多种化学反应形成11种主要分解产物.协同体系对AB80的矿化率是直接电催化的2.6倍;降解机理为：PDS被Mn²⁺与电流激发出SO₄^-×后,SO₄^-×与水反应生成HO×,然后HO×与电流将Mn²⁺氧化为活性Mn³⁺,三种氧化性物质协同降解污染物.     

Tween-80和鼠李糖脂对铜绿假单胞菌及枯草芽孢杆菌产蛋白酶的影响

研究了添加表面活性剂Tween-80和生物表面活性剂鼠李糖脂对从堆肥中筛选得到的铜绿假单胞菌和枯草芽孢杆菌生产蛋白酶的影响.用固态发酵的方法,对添加不同浓度的表面活性剂对这2种微生物产蛋白酶能力的影响、2种微生物产蛋白酶能力的差异以及发酵过程中的一些参数(包括菌体数、酶提取液表面张力、pH值和挥发性有机质)进行了考察.结果表明,Tween-80对铜绿假单胞菌和枯草芽孢杆菌产蛋白酶有较大促进作用,添加浓度为0.05%时,能分别使铜绿假单胞菌和枯草芽孢杆菌产蛋白酶最高酶活提高65%和30%;鼠李糖脂对铜绿假单胞菌产蛋白酶有轻微抑制作用,但能将枯草芽孢杆菌产蛋白酶,当添加浓度为0.018%时,鼠李糖脂能将枯草芽孢杆菌产蛋白酶最高酶活提高51%.铜绿假单胞菌产蛋白酶能力明显强于枯草芽孢杆菌,前者对照样的蛋白酶产量是后者对照样蛋白酶产量的6倍多.发酵过程中,铜绿假单胞菌酶提取液的表面张力明显低于枯草芽孢杆菌;添加表面活性剂对菌体生长有一定影响,但对pH值变化影响不大;挥发性有机质变化与微生物酶活成正相关关系.     

日立180/80原子吸收分光光度计汞分析仪附件使用方法的改进

针对日立 1 80 / 80原子吸收分光光度计汞分析仪附件设计的不足之处 ,在理论和实践的基础上提出了 5条具体的改进措施 ,并对改进前后仪器的使用性能作了对比。改进后仪器的灵敏度大大提高 ,所测数据的精密度及精确度均达国家标准     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.