气动雾化进样微波等离子体炬（MPT）原子荧光光谱法测定锌的研究

本文将水溶液雾化进样与微波等离子体炬原子荧光光谱法联用,建立了HCL-MPT-AFS测定Zn的新方法。讨论了实验条件的选择问题以及溶液中共存离子对测定Zn的影响,本文所推荐的方法具有较高的灵敏度和精密度,并将其用于实际样品分析。     

Detection of metalloproteins in human liver cytosol by synchrotron radiation X-ray fluorescence combined with gel filtration chromatography and isoelectric focusing separation

Synchrotron radiation X-ray fluorescence (SRXRF) spectroscopy is an advanced method of quantitative multielemental analysis with space resolution of several microm and sensitivities in the microg g(-1) range. It can be used for keeping track of trace elements after an electrophoretic separation of biological samples. In this paper, proteins in human liver cytosol were separated with gel filtration chromatography and thin layer isoelectric focusing (IEF). The contents of metal ions in protein bands were determined by SRXRF. The results showed that in the molecular weight (MW) range of 10 approximately 25 kDa, there were at least 2 Zn-containing bands with isoelectric point (pI) of 5 approximately 6 and 6.2 approximately 7, respectively and about 11 Fe-containing proteins with pI of 4.4, 4.6, 4.8, 5.0, 5.2, 5.3, 5.5, 5.6, 6.6, 6.8, and 7.2, respectively, present in human liver cytosol. The Zn-containing band with pI of 5-6 is the dominant species of zinc in this MW range. In addition, the Cu-containing bands with pI of 5.0 and below 4.8 were also detected. It is demonstrated that the procedure could be widely used in further investigations of the chemical species of trace elements in biological samples.     

微孔分子筛纳米晶的控制合成及其催化应用

纳米分子筛因具有高的外表面积和短的孔道结构而显示了独特的催化活性和选择性, 近年来已成为催化界的研究热点.本文就分子筛纳米晶的控制合成、催化基础研究,特别是当前分子筛纳米晶在自组装分级多孔材料和分子筛基纳米复合材料方面的新方向进行了系统的综述,分析了纳米分子筛研究中的机会和应用前景.     

Quantitative study on La~(3+) influx mediated by sodium-calcium exchanger in human lymphocytes

Whether La3+ can enter human peripheral blood lymphocytes by the Na+/Ca2+ exchanger or not and the effect of La3+on the Na+/Ca2+ exchanger activity are examined by fura-2 technique. And that whether La3+ is sequestered by intracellular organelles (mainly endoplasmic reticulum and mitochondria) is studied by this method. La3+uptake is obviously stimulated by pre-treating the cells with ouabain and by removing extracellular Na+, and intracellular La3+concentration ([La3+]i) is directly proportional to its extracellular concentration ([La3+]o). But when [La3+]o exceeds 0.4 mmol/L, the 340/380 nm ratio of fluorescence is no longer varied and the maximum [La3+], is 1.5×10-12 mol · L-1. The higher concentration of La3+ (0.1 mmol/L) increases Na+/Ca2+ exchange-mediated calcium influx, but lower concentration (10 μmol/L) appears to block calcium influx. The results also suggest that cytosolic La3+ is transported by the ATP-dependent Ca2+ pump. Intracellular Ca2+ stores are depleted by ionomycin, and then ion     

Y2O3, La2O3, Sm2O3对氧化铝瓷烧结及力学性能的影响

研究了3种稀土氧化物对氧化铝陶瓷烧结性能和力学性能的影响.结果表明 含Y2O3,La2O3,Sm2O3的添加剂促进了氧化铝瓷的烧结,提高了氧化铝瓷的力学性能.Y2O3和Sm2O3掺量为0.50%,La2O3掺量为0.75%时氧化铝瓷在1600或1620 ℃保温2 h烧结,相对密度达98.9%以上,强度超过439 MPa,断裂韧性达5.15 MPa·m1/2以上.微观结构分析表明,Y2O3,La2O3,Sm2O3抑止氧化铝晶粒生长,细化晶粒,使晶粒尺寸较均匀形成致密化结构.     

川芎嗪的结构修饰及生物活性

介绍了川芎嗪的结构修饰及其衍生物的生物活性、川芎嗪衍生物合成及其在新药开发方面的发展前景。     

Investigation of photoinduced electron transfer in model system of vitamin E-duroquinone by time-dependent density functional theory

Photoinduced electron transfer of the model system composed of vitamin E and duroquinone has been investigated using time-dependent density functional theory. Calculations for the excited states tell that the photoexcitation of the model system can directly yield the charge transfer states in which the vitamin E moiety is positively charged but the duroquinone moiety is negatively charged. Our theoretical investigations indicate that the second charge transfer state of the model system can also be produced through the decay of higher locally excited state S(4). Since S(4) state in the model system corresponds to S(1) state of the isolated duroquinone used as a model for peroxyl radical, and S(2) state has the character of electron transfer from the tertiary amine group of the vitamin E moiety to the duroquinone moiety, the decay from S(4) to S(2) corresponds to the dynamic process following the photoexcitation of the duroquinone moiety of the model system, i.e., the initial stage of antioxidant reaction of vitamin E. Calculations of the kinetic parameters for the electron transfer have been carried out in the framework of the Marcus-Jortner-Levich formalism. Our calculations confirm that the electron transfer from S(4) to S(2) possesses the character of the inverted regime and the barrier is negligibly small.     

室温以上磁制冷材料La(Fe1-xCox)11.7Al1.3化合物的研究

通过X射线衍射分析和超导量子干涉磁强计（SQUID）磁性测量,研究了Co替代Fe含量对居里温度在室温以上的磁制冷材料La（Fe1-xCox）11.7Al1.3（x=0.072,0.081）磁结构和磁性能的影响。La（Fe1-xCox）11.7Al1.3材料的居里温度随Co的含量增加而增加,La（Fe0.919Co0.081）11.7Al1.3的居里温度为311 K。当外场变化为1.9 T时磁熵变达到3.6 J·kg^-1·K^-1,RCP值为168.6 J·kg^-1,虽然它的磁熵变小于具有巨磁熵变的磁制冷材料,但是它在磁场为1.9 T时的制冷能力与这些材料相当。     

Synthesis, crystal structure and equilibrium studies on the bidentate amine adducts of bis(S-methyl-β-N-(4-methyloxyphenyl) methylendithiocarbazide)nickel(II) complex

The crystal structure of the 1,10-phenanthroline bis(S-methyl-β-N-(4-methyloxyphenyl)methylendithiocarbazide)nickel(II) adduct, (Ni(SN)₂phen) [SN = S-methyl-β-N-(4-methyloxyphenyl)methylendithiocarbazide, PHEN = phenanthroline], has been determined by single crystal X-ray diffraction. The nickel atom is in an octahedral environment, surrounded by two chelating SN ligands and one chelating phen molecule. The nitrogen atoms from phen are in the cis configuration. The other chelating diamines adducts of the parent complex (Ni(SN)₂) were also studied, where the chelating diamnies are 5-nitro-1,10-phenanthroline(NO₂phen), 2,2′-bipyridine (bipy), 4,4′-methyl-2,2′-bipyridine (Mebipy). The equilibria were determined by UV-vis spectrometry in dichloromethane. The coordination ability of the added ligands were influenced by substitute groupings and steric factors. From the structure and addition equilibrium studies, the possible addition mechanisms are also discussed.