汽车碰撞砼护拦过程的数值模拟

将汽车与砼护拦简化为刚体，给出了描述碰撞过程中车辆三维空间运动的Ｅｕｌｅｒ－Ｌａｇｒａｎｇｅ方程－微分代数方程组，采用半显式外插方法求解上述方程组。数值计算得出的车辆各方向上的最大平均加速度、最大侧倾角、最大俯仰角、车轮沿护拦面的最大爬升值及车辆脱离护拦时的弹出角等结果是从乘员风险和车辆轨迹等多角全面评估砼护拦的安全性能的重要依据。针对美国ＮｅｗＪｅｒｃｙ型砼护拦的实际算例与文献结果吻合较好。     

Lubricated squeezing flow of a Newtonian liquid between elastic and rigid plates

Theoretical force-time relationships were derived for squeezing flow of a Newtonian liquid between lubricated rigid and elastic plates. It is shown how the elastic number, representing the ratio between the elastic plate's rigidity and the specimen's viscosity, affects the force-time curve and under what circumstances the fluid specimen's thickness becomes a significant factor. Potential implications of the analysis in oral sensory evaluations of viscous foods are also considered.     

Development of High Performance Liquid Chromatography Method for Costunolide and Dehydrocostuslactone in Mice Plasma and Tissues:Application to Pharmacokinetic Study

A simple and sensitive high performance liquid chromatographic (HPLC) method for simultaneous determination of costunolide and dehydrocostuslactone in mice plasma and tissues was developed and validated. Costunolide and dehydrocostuslactone were extracted into acetonitrile and separated using an isocratic mobile phase, on a Hypersil ODS C18 column. The effluent was monitored by UV detector at 210 nm and at a flow rate of 1.0 mL· min^?1 and 25°C. The linearity ranges of proposed method were 0.223–8.920 µg·mL^?1 for costunolide and 0.227–9.080 µg·mL^?1 for dehydrocostuslactone. The intra‐day and inter‐day RSD of the assay method for the two components were less than 5%, and mean recovery was within the 86.5% to 101.8% range. The method was found to be precise, accurate, and specific during the study. The method was successfully applied for pharmacokinetic study of costunolide and dehydrocostuslactone after application of ethanol extraction of Muxiang (EEM) in mice.     

高效液相色谱法测定全血中直链烷基苯磺酸钠

提出了高效液相色谱法测定全血中直链烷基苯磺酸钠同系物的含量。全血样品用酸性提取溶液稀释,过Bakerbond SPE C18固相萃取小柱,经甲醇-乙酸-水(49+2+49)混合溶液淋洗后用甲醇-氨水(98+2)混合溶液洗脱。经纯化后的洗脱液在Wakopak WS AS-Aqua(250 mm×4.6 mm,5μm)柱上进行分离,流动相为乙腈与水(60+40)混合溶液,检测波长为228 nm。5种n-ABS同系物的C10~C14的质量分数在10.0~100.0 ng.g-1范围内与其峰面积呈线性关系,全血中各同系物回收率为78%~107%;日内相对标准偏差(n=5)≤10%,日间相对标准偏差(n=5)≤13%。     

Application of in-plasma catalysis and post-plasma catalysis for methane partial oxidation to methanol over a Fe2O3-CuO/γ-Al2O3 catalyst

Methane partial oxidation to methanol (MPOM) using dielectric barrier discharge over a Fe2O3-CuO/γ-Al2O3 catalyst was performed. The multicomponent catalyst was combined with plasma in two different configurations, i.e., in-plasma catalysis (IPC) and post-plasma catalysis (PPC). It was found that the catalytic performance of the catalysts for MPOM was strongly dependent on the hybrid configuration. A better synergistic performance of plasma and catalysis was achieved in the IPC configuration, but the catalysts packed in the discharge zone showed lower stability than those connected to the discharge zone in sequence. Active species, such as ozone, atomic oxygen and methyl radicals, were produced from the plasma-catalysis process, and made a major contribution to methanol synthesis. These active species were identified by the means of in situ optical emission spectra, ozone measurement and FT-IR spectra. It was confirmed that the amount of active species in the IPC system was greater than that in the PPC system. The results of TG, XRD, and N2 adsorption-desorption revealed that carbon deposition on the spent catalyst surface was responsible for the catalyst deactivation in the IPC configuration.     

橡胶及橡胶制品中4种酚类防霉剂的高效液相色谱法测定

建立了橡胶及其制品中硝基苯酚(PNP)、2,3,5,6-四氯苯酚(TeCP)、五氯苯酚(PCP)、邻苯基苯酚(OPP)4种酚类防腐剂的高效液相色谱测定方法。样品冷冻粉碎后,经甲醇超声提取,在Venusil-XBP C18色谱柱(250 mm×4.6 mm,5μm)上以10 mmol/L醋酸铵和甲醇为流动相梯度洗脱,采用二极管阵列检测器,PCP、TeCP、OPP的检测波长为220 nm,PNP的检测波长为320 nm。4种酚类防霉剂的质量浓度在0.5~250mg/L范围内与峰面积呈良好的线性关系,相关系数大于0.999 4。丁苯橡胶、硅橡胶基体的加标回收实验结果表明:TeCP、PCP、OPP、PNP在不同基质中的平均加标回收率分别为82%~95%、68%~90%、85%~98%、87%~98%,相对标准偏差小于5%。     

饮料中红花黄色素的固相萃取/超高效液相色谱-质谱测定

利用超高效液相色谱-电喷雾串联四极杆质谱法对从红花中提取纯化的红花黄色素进行结构分析,其包含对羟基红花黄A(34.0%)、红花黄A(27.4%)、脱水红花黄B(23.2%)和红花黄C(8.3%)4种主要成分。建立了测定碳酸类、果汁类饮料中4种色素成分的SPE/UPLC检测方法。利用大孔吸附树脂作为填料,自制SPE固相萃取柱,对饮料中的红花黄色素进行吸附解吸,通过优化固相萃取条件,使得各组分的回收率为84%~116%,相对标准偏差为0.78%~6.6%。各组分在0.40~17 mg/L范围内具有良好的线性关系,线性系数均不小于0.998 8。     

加速溶剂萃取-高效液相色谱-串联质谱法同时检测鱼肉中喹诺酮、磺胺与大环内酯类抗生素

建立了加速溶剂萃取(ASE)-高效液相色谱-串联质谱联用法同时检测鱼肉中22种抗生素药物残留的分析方法。样品经ASE提取,HLB固相萃取柱净化后进入高效液相色谱-串联质谱仪分析。对ASE的萃取条件进行优化,并采用XTerraMSC18柱对药物进行分离,以甲醇-乙腈(体积比1∶1)为色谱流动相A,以0.3%(体积分数)甲酸水溶液(含0.1%甲酸铵,pH=2.9)为流动相B。22种喹诺酮、磺胺和大环内酯类抗生素药物在加标水平为20、100μg/L时的回收率分别为72%～120%与66%～114%,相对标准偏差(RSD,n=5)分别为1.9%～16%与0.7%～10%,方法的检出限为0.02～0.6μg/kg。结果显示所建立的方法精密度好,准确度高,可满足同时对鱼肉样品中多种喹诺酮、磺胺和大环内酯类抗生素残留进行定性及定量分析的要求。     

Physical and Electrochemical Characterization of Hydrothermal Prepared α'-NaV_2O_5 Crystals

α'-NaV2O5 was prepared by a simple hydrothermal process.X-ray diffraction confirmed the orthorhombic structure of α'-NaV2O5,with preferential growth along the (001) direction.Scanning electron microscopy showed α'-NaV2O5 was composed of flake-shaped crystals.X-ray photoelectron spectroscopy confirmed the co-existence of V4+ and V5+ in α'-NaV2O5,which results in an average V4.5+ oxidation state of α'-NaV2O5.The observed Raman bands are ascribed to different V―O vibrations.α'-NaV2O5 shows a reversible specific capacity of about 100 mA·h·g-1 between 3.5 and 1.0 V,with a good capacity retention.The good electrochemical stability of the material is attributed to its structural stability during Li+ intercalation.     

新型荧光试剂用于土壤中脂肪胺的高效液相色谱-质谱测定

利用新型荧光试剂2-(2-(10-蒽基)-苯并咪唑)-乙酸(ABIA)为柱前衍生化试剂,在Akasil-C18色谱柱上,通过梯度洗脱对12种游离脂肪胺进行了分离和在线质谱定性。以乙腈为溶剂,N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)为缩合剂,在50℃条件下衍生反应20 min后获得稳定的荧光产物。激发波长和发射波长分别为260 nm和430 nm,采用大气压化学电离源(APCI)的正离子模式,实现了土壤中脂肪胺的定性及其含量的测定。脂肪胺的线性相关系数大于0.9990,检出限为11.72~25.63 fmol。