掺钇锆酸锶-TiO2复合光催化剂的制备及性能研究

SrZrO₃ particles were prepared by a co-precipitation method and Sr(Zr_1-xY_x)O_3-δ -TiO₂ composite particles were then synthesized by Sr(Zr_1-xY_x)O_3-δ and titanium dioxide. The composite particles were characterized by XRD, SEM, FTIR and TG-DTA techniques. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate the photocatalytic activity of the composite particles. The effect of the preparation method for SrZrO₃, doping content of yttrium and TiO₂ amount in the composite particles on the photocatalytic activity of composite particles was also discussed. The results show that the methylene blue solution could be completely degraded by Sr(Zr_1-xY_x)O_3-δ -TiO₂ composite particles under UV-light or visible light irradiation. The photocatalytic activity of composite particles was higher than that of pure TiO₂. The fast recombination of photogenerated electrons and holes were restrained by the heterojunction formed in composite particles. The particle of SrZrO₃ prepared by co-precipitation was small, and the photocatalytic activity of composite particles prepared from this kind of SrZrO₃ was higher than that of particles prepared by solid sintering method. The best doping content of yttrium is 5%. The optimal content of TiO₂ in composite particles is 90wt%, 70wt%, respectively under UV-light and visible light irradiation, the degradation rates of MB are 98.8% and 93.5% , respectively after 50 min irradiation.     

N-(4-磺胺苯基)-2-羟基-5-氯苯甲酰胺的合成及药效

以磺胺为原料,合成了未见文献报道的N-（4-磺胺苯基）-2-羟基-5-氯苯甲酰胺（1）,其结构经^1H NMR,IR及MS确证。杀精和杀钉螺药学研究结果表明,1具有很好的杀精与杀螺作用。     

关于有限向量集的一类三角不等式及应用

本文引入了Ｅⁿ中ｒ阶空间角的概念,建立了有限向量集的一类三角不等式．作为其应用,得到了ｎ维单形的两类三角不等式,推广和改进了一些已有文献中的主要结果．     

Application of emulsion liquid membranes to recover cobalt ions from a dual-component sulphate solution containing nickel ions

Emulsion liquid membranes (ELMs) containing 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) have been applied to recover cobalt II ions from a dilute sulphate solution containing equal amounts of nickel II ions (0.16 g/l). We focused on the study to develop an effective technique to recover cobalt as a target metal. It is found that polyamine (PX 100) membranes allow better permeation rates of cobalt ions than sorbitan monooleate (Span 80) membranes. The separation factor (β_Co/Ni) in polyamine membranes averaged 70 at a carrier concentration of 12 mol/m³ and feed solution pH 5.5. The permeation rate of Co II was found to increase proportionately with feed pH while for Ni II it decreased substantially at pH above 5.5 indicative of slower interfacial reaction rate. We found that short contact time (4–6 min) of feed solution and emulsion improved separation factor (β_Co/Ni) at feed pH above 5.5 and also minimized chances of emulsion break up. We have also observed that Span 80 membranes are hydrolyzed readily in a moderate acidic sulphate solution (pH 4.0–5.5) to form viscous gels. Results have shown that excess carrier [(HR)₂] affects the stability of emulsion and thus the separation factor. The critical ratio of carrier to emulsifier [(HR)₂]/[C_sf] was found to be approximately 0.5. This paper concludes with a discussion on the prospects of ELM system in practical use.     

手性酯类萃取剂萃取拆分α-环己基扁桃酸外消旋体

研究了α-环己基扁桃酸对映体在含有疏水性D酒石酸酯手性选择体的1,2-二氯乙烷和水两相系统萃取分配行为,考察了酒石酸酯烷基链长度、pH值和D酒石酸酯浓度对分配比和分离因子的影响。实验表明：D酒石酸酯与R-α-环己基扁桃酸对映体比与S—α-环己基扁桃酸对映体形成更稳定的非对映体复合物;随着pH值增大,分配比减小,分离因子也随之降低;同时,D酒石酸酯浓度的影响也比较大。     

E2反应中的反式共平面构象

研究总结了E2反应中离去基团L和H的"反式共平面"构象与产物结构、产物组成、反应速度之间的对应关系.提出了让学生在参与中学习有机立体化学的新方法,具体的参与方式为"看、画、做".     

Triangle inequalities associated with the vertex angles and dihedral angles of a simplex and their applications

In this paper, a class of triangle inequalities associated with the vertex angles and dihedral angles of a simplex is given. As an application, we improve an inequality on the volume of the pedal simplex. Received 3 July 2000.     

新墙河区草本植物重金属含量的测定

用HNO3∶HClO4=4∶1(V/V)混酸消解草本植物后,采用原子吸收光谱(AAS)法测定样品中铅、砷、镉、铜、锌。结果表明:方法加标回收率94.7%~100.3%,相对标准偏差0.8%~8.7%。草本植物各不同部分重金属含量有所不同;新墙河流域草本植物重金属含量相对偏高,新墙河的一条支流油港河比另一条支流沙港河重金属污染严重,是新墙河的主要污染来源。该法用于草本植物重金属含量的测定快速、灵敏、重现性好。     

Generalized Hadamard's inequality and r-convex functions in Carnot groups

In this paper, we establish a generalization of Hadamard's inequality to r-convex functions on Carnot groups.     

油酸新戊二醇癸二酸混合酯的合成及其性能研究

以新戊二醇(NPG)和癸二酸(SA)为原料,经酯化反应合成了"寡聚物"(1),测定1的寡聚度(m)。当n(NPG)∶n(SA)=1.4~3.0时,1的m在5.44~1.61,收率95%以上。将1与油酸进行酯化得到混合酯(2),收率83%~89%。测定了2的粘度和热氧化稳定性,结果表明2的粘度随着m的增大而增大,热氧化稳定性随m的增大而提高。2在40℃的粘度为(116~273)mm2.s-1,粘度指数均超过200,凝点低于-40℃。1和2的结构经IR表征。