子宫内低铅暴露对婴儿早期神经行为影响的研究

为探讨低铅暴露对婴儿智能发育的影响,随机选择足月顺产新生儿110例,0.48 μmol/L＞脐血铅水平≥0.24 μmol/L,作为观察组;同一时期配对足月顺产新生儿110例,脐血铅水平＜0.24 μmol/L,作为对照组;采用新生儿20项新生儿神经行为、Gesell婴幼儿发育检查量表,在出生24～36 h和3月龄时进行测试.结果表明,观察组神经行为总得分显著性低于对照组;头竖立得分显著低于对照组,头竖立时间较对照组缩短;3月龄观察组适应性、语言能力和个人社会交往显著低于对照组. 提示血铅水平低于0.48 μmol/L时,仍可对婴儿神经行为发育产生不良影响.     

Zr 改性MnOx/MWCNTs催化剂的结构特征与低温SCR活性

以ZrO（NO₃）₂·2H₂O为前驱体对多壁碳纳米管（MWCNTs）进行了改性并负载MnO_x制备了MnO_x/ZrO₂/MWCNTs 催化剂. 考察了Zr 对催化剂低温选择性催化还原（SCR）反应活性的影响,并通过多种分析手段对催化剂的结构进行了表征. 结果表明Zr 的添加对催化剂的低温SCR活性具有显著的促进作用,当Zr 负载量为30%时,催化剂活性最佳. X射线衍射（XRD）、拉曼（Raman）光谱、透射电镜（TEM）、N₂吸附-脱附的表征结果分析表明,适量的Zr 改性促进了MnO_x在载体表面的分散,增强金属氧化物与MWCNTs 之间的作用,也能增加催化剂的比表面积、孔容和孔径. X 射线光电子能谱（XPS）、H₂程序升温还原（H₂-TPR）和NH₃程序升温脱附（NH₃-TPD）的分析结果则显示,Zr 能提高催化剂表面化学吸附氧浓度,促进Mn³⁺转化为Mn⁴⁺,从而使催化剂表面的活性位点增多,氧化还原能力增强,同时还提高了催化剂表面酸性位点的数量和强度,促进了NH₃的吸附,是MnO_x/ZrO₂/MWCNTs 催化剂低温SCR活性提高的主要原因.     

Identification and characterization of supercritical fluid extracts of Rhizoma Chuanxiong by high performance liquid chromatography ion trap mass spectrometry

The main constituents, senkyunolide A, Z-ligustilide, neocnidilide, 3-butylphthalide, and ligustilide dimers, in supercritical CO₂ fluid extracts of Rhizoma Chuanxiong, a popular Chinese traditional medicine, have been identified and characterized by high performance liquid chromatography tandem mass spectrometry. Separations were carried out on an Agilent (ECLIPSE XDB) C18 analytical column by gradient elution with 0.25% acetic acid and methanol (containing 0.25% acetic acid). An Agilent 1100 series LC/MSD XCT system was operated under positive ESI and auto MS/MS modes for mass spectrometric analysis. Collision-induced dissociation (CID) fragmentations of these phthalides have been investigated and elucidated. Phthalides have primarily undergone two ESI CID pathways: side-chain cleavage with losses of alkenes and ring-opening with eliminations of H₂O followed by losses of CO. Direct neutral loss of CO has not been observed. Sodium adduct ions have demonstrated completely different CID pathways. __________ Translated from Journal Instrumental Analysis (in press, in Chinese)     

Zr改性MnO_x/MWCNTs催化剂的结构特征与低温SCR活性

以ZrO(NO3)2·2H2O为前驱体对多壁碳纳米管(MWCNTs)进行了改性并负载MnOx制备了MnOx/ZrO2/MWCNTs催化剂.考察了Zr对催化剂低温选择性催化还原(SCR)反应活性的影响,并通过多种分析手段对催化剂的结构进行了表征.结果表明Zr的添加对催化剂的低温SCR活性具有显著的促进作用,当Zr负载量为30%时,催化剂活性最佳.X射线衍射(XRD)、拉曼(Raman)光谱、透射电镜(TEM)、N2吸附-脱附的表征结果分析表明,适量的Zr改性促进了MnOx在载体表面的分散,增强金属氧化物与MWCNTs之间的作用,也能增加催化剂的比表面积、孔容和孔径.X射线光电子能谱(XPS)、H2程序升温还原(H2-TPR)和NH3程序升温脱附(NH3-TPD)的分析结果则显示,Zr能提高催化剂表面化学吸附氧浓度,促进Mn3+转化为Mn4+,从而使催化剂表面的活性位点增多,氧化还原能力增强,同时还提高了催化剂表面酸性位点的数量和强度,促进了NH3的吸附,是MnOx/ZrO2/MWCNTs催化剂低温SCR活性提高的主要原因.     

Flow pattern transition,pressure gradient,hold-up predictions in gas/non-Newtonian power-law fluid stratified flow

This work focuses on gas/non-Newtonian power-law fluid stratified pipe flow. Two different theoretical approaches to obtain pressure gradient and hold-up predictions are presented: the steady fully developed two-fluid model and the pre-integrated model. The theoretical predictions are compared with experimental data available for horizontal and for slightly downward inclined air/shear thinning fluid stratified flow taken from literature. The predictions of the pre-integrated model are validated showing a good agreement when compared with experimental data. The criteria for the transition from the stratified flow pattern are applied to gas/non-Newtonian stratified flow. The neutral stability analysis (smooth/wavy stratified flow) and the well-posedness (existence region of stratified flow) of governing equations are carry out. The predicted transition boundaries are obtained using the steady fully developed two-fluid model and the pre-integrated model, where the shape factors and their derivatives are accounted for. A comparison between the predicted boundaries and experimental flow pattern maps is presented and shows a good agreement. A comment on the shear stress modeling by the pre-integrated model is provided.     

Optical bistability in gold nano-colloid due to thermal lensing effect

In this study, experimental results are concerning “the optical bistability due to thermal lensing effect”, in colloidal solution of gold nanoparticles (Au Nps) which has been studied under CW laser illuminations. Two different CW laser beams (He–Ne and Nd-Yag) were used to interact with a vertical Fabry–Perot interferometer, containing colloid of the Au Nps. Hysteretic loops have been observed with regard to optical bistability and the results were fitted with theoretical curves. The radiated power to the resonator was elevated up to 50 mW for both the laser beams with the same spot size. Also, new method was defined to precise evaluation of the theoretical hysteretic loop which is describing the relation between nonlinear refractive index and the beam intensity inside the resonator. This dependency is due to thermal lensing effect and numerical simulations of this effect were also performed, in order to better understanding of it.     

Study of the Synergistic Effect Between Corrosion Inhibitors by Using Fractional Free Volume

The fractional free volumes(FFVs) of the adsorption films formed with different ratios of dipropargyl methoxythiourea imidazoline(DPFTAI) and pyridine quaternary ammonium salt(16BD) were calculated by simulation to determine their synergistic corrosion inhibition effect. The results suggest that the composite corrosion inhibitor at the molar ratio between DPFTAI and 16BD of 4:1 gives the best corrosion inhibition effect. This simulation method to predict the synergistic effect between corrosion inhibitors was further validated by mass loss and electrochemical experiments. This finding delivers valuable understandings of inhibition mechanism of corrosion inhibitors.     

A Legendre expansion and some exact solutions basic to the McCormack model for binary gas mixtures

A Legendre expansion of the scattering kernel, a conservation condition and some exact solutions are reported for the McCormack kinetic model that is used to describe a binary mixture of rarefied gases.     

两种铁剂治疗妊娠期缺铁性贫血疗效的研究

目的观察两种铁剂对妊娠期缺铁性贫血的治疗效果。方法80例缺铁性贫血孕妇随机分成两组,多糖铁组40例,每天早餐后给多糖铁复合物胶囊0．3g;多维铁组40例,多维铁口服溶液20mL／d分两次于早晚餐后服。主要观察指标：血红蛋白、平均红细胞容积、血清铁、铁蛋白等。结果两组治疗4周后,患者血红蛋白、平均红细胞容积及血清铁均有升高,且多糖铁组较多维铁组升高更明显,差异均有统计学意义（P〈0．05）。结论两种铁剂治疗妊娠期IDA均有效,多糖铁复合物胶囊升高血清铁效果显著,而且服用方便,患者用药依从性好,是治疗妊娠期缺铁性贫血理想的口服铁剂。     

有负顾客的M/G/1有限源重试排队系统

采用补充变量法，本文研究了有负顾客的M/G/1有限源重试排队系统。与前人的研究相比，本文考虑了干预因素，即负顾客对系统的影响，其中负顾客的机制是带走系统中所有正顾客。文中给出了两种解决系统微分方程组的递归方法，得到了重试组的平均人数，平均等待时间，系统忙期和工作周期分布的L变换等重要指标的递归公式。在特殊情况下，求出以上指标的具体表达式并得到与前人一致的结果。