环状共轭多烯烃简并分子轨道的群论处理

以苯分子为例用群论方法对简并能级进行了处理,得出了用群论方法处理环状共轭多烯烃(CnHn)简并能级分子轨道的一般方法,证明了简并分子轨道的不同表示形式实质上是等价的,介绍了3-8元环状共轭多烯烃的分子轨道。     

一种基于时间序列模型的风速预测方法

分析了美国HMO（Health Maintenance Organization）市场结构主要指标及部分医疗和社会经济指标对美国医疗费用的影响,采用1995-2007年数据,利用主成分分析（PCA）方法与BP神经网络构建预测模型,对美国支出在医院方面的医疗费用进行拟合及预测,预测结果与实际值之间的相对误差小于0.25%,表明可基于该模型考察在HMO市场结构影响下的美国医疗费用.     

氨基取代四苯基卟啉衍生物的结构剖析

用 HMO 方法计算了5个氨基取代四苯基卟啉的能级、净电荷、自由价和共振能,讨论了这些参数之间的线性关系,并预测了这类大环化合物的酸碱性。     

Competitive Scavenging of Trace Metals by HFO and HMO during Redox-driven Early Diagenesis of Ferromanganese Nodules (11 pp)

-  Dedicated to Prof. Dr. Ulrich Förstner on his 65th birthdayBackground   Surface complexation models (SCM) alone have yet less successfully reproduced sorption isotherms of hydrous manganese oxides (HMO). This is in part due to the fact that the HMO structure may vary with pH, and also because microbially formed natural HMO has an oxidation number O/Mn 〈 2, i.e. is of non-stoichiometrical composition. The former effect has often led to severe artefacts, such as an under-prediction of metal sequestration at low pH, and non-comparable pK and pHZPC values in literature. The latter effect is of particular importance for environments of varying redox conditions like sediments.Objectives   We propose therefore a new sorption model comprising of amphoteric site SCM, ion exchange due to permanent charge compensation, and solid solution formation, in order to comply at least in part with the redox complexity of HMO phases of stable birnessite- and buserite-type structures. Methods   The model is run by a new Gibbs energy minimization code which is shown to be particularly suitable for such a sorption continuum approach. Results and Discussion   Initial calibration of the model was performed by experimental literature data on simple laboratory systems. Thus parameterised, we simulated on the basis of available field data the effect of redox-driven dissolution of a ferromanganese nodule on the partitioning of metals between the interacting HMO, HFO, and marine water phases. Our scenario model suggests that significant fraction of Mn and other metals, probably 50% or more, may be recycled to water column from the surface of the ferromanganese nodule upon gradual development of the bottom water stagnation, except of Zn for which a by far stronger net retention was found.Conclusion and Outlook   Our model, even if only a first approximation, clearly shows that stagnation in the marine bottom water, once occurring, can drastically change primary element proxy records in ferromanganese nodules, smoothing out any anomalous patterns in the most recent record.     

双歧杆菌代谢母乳寡糖机制的研究进展

母乳寡糖(human milk oligosaccharides,HMO)结构复杂,其能够选择性地促进母乳喂养婴儿肠道中益生菌双歧杆菌的生长。婴儿肠道相关双歧杆菌具有糖苷酶等分子工具,使其能够代谢HMO,且代谢过程具有菌株特异性。本文总结了HMO的结构特点,探讨了婴儿肠道相关双歧杆菌代谢HMO的机制,重点分析了双歧杆菌代谢HMO的种内差异以及代谢过程涉及到的分子工具的研究进展。