热力学计算模拟对月球镁质岩套源区的约束

镁质岩套是月球上最重要的岩石之一。通常认为该类岩石的母岩浆来自月幔翻转引起的深部物质的减压熔融或者月壳底部的混合杂化。但是,这两类模型分别面对无法重现样品中橄榄石的Cr_(2)O_(3)含量过低等地球化学特征,也无法解释镁质岩套与其他月球样品年龄重合的问题。本文采用热力学计算方法,通过改变源区物质组成、熔融程度、熔融方式及结晶方式等参数,对两种模型进行了一系列的正演研究。结果表明,月球的镁质岩套有多种成因:月幔物质减压熔融形成的熔体通过平衡结晶可以形成镁质岩套,并满足样品中橄榄石Cr_(2)O_(3)含量的制约;减压熔融模型可以解释某些月球样品年龄的重合,但是成分较为单一,而混合杂化模型形成的镁质岩套成分范围较广。

The Study Results of F1 Generation of Washington Navel Orange Obtained Through Distant Hybridization

For a successful selection of citrus plants when mating with cultural forms through the method of distant hybridization it is necessary to choose a promising father component such as： a） a complex hybrid of inchangensis ＂Caucasus＂ obtained using hybrid citrange of American origin _ C. Kinokuni X C.ichanglemon, which gives an eatable lemon with a chemical composition similar to the normal lemon fruit and without any damage it can resist frost at -16 ℃ temperature and b） spontaneous mutations of trifoliata： #1 and #2 which are distinguished among trifoliata species. Their fruits don＇t contain or contain a small amount of the substances that deteriorate the taste： naringin, porcine and so on. They are characterized by high index of frost resistance. In the experiment when obtaining sexual hybrids of the Washington naval orange the above mentioned components were used and hybrid seedlings were obtained, which are distinguished according to their phenotypic hereditary features. Selected seedlings represent the best initial material for a successful future work.

Hybridization and genome evolution I： The role of contingency during hybrid speciation

Homoploid hybrid speciation （HHS） involves the recombination of two differentiated genomes into a novel, func- tional one without a change in chromosome number. Theoretically, there are numerous ways for two parental genomes to recom- bine. Hence, chance may play a large role in the formation of a hybrid species. If these genome combinations can evolve rapidly following hybridization and sympatric situations are numerous, recurrent homoploid hybrid speciation is a possibility. We argue that three different, but not mutually exclusive, types of contingencies could influence this process. First, many of these ＂hopeful monsters＂ of recombinant parent genotypes would likely have low fitness. Only specific combinations of parental genomic con- tributions may produce viable, intra-fertile hybrid species able to accommodate potential constraints arising from intragenomic conflict. Second, ecological conditions （competition, geography of the contact zones or the initial frequency of both parent spe- cies） might favor different outcomes ranging from sympatric coexistence to the formation of hybrid swarms and ultimately hybrid speciation. Finally, history may also play an important role in promoting or constraining recurrent HHS if multiple hybridization events occur sequentially and parental divergence or isolation differs along this continuum. We discuss under which conditions HHS may occur multiple times in parallel and to what extent recombination and selection may fuse the parent genomes in the same or different ways. We conclude by examining different approaches that might help to solve this intriguing evolutionary puz- zle [Current Zoology 59 （5）： 667-674, 2013].

Bifunctional catalysts of Co3O4@GCN tubular nanostructured （TNS） hybrids for oxygen and hydrogen evolution reactions

Catalysts for oxygen and hydrogen evolution reactions （OER/HER） are at the heart of renewable green energy sources such as water splitting. Although incredible efforts have been made to develop efficient catalysts for OER and HER, great challenges still remain in the development of bifunctional catalysts. Here, we report a novel hybrid of Co3O4 embedded in tubular nanostructures of graphitic carbon nitride （GCN） and synthesized through a facile, large-scale chemical method at low temperature. Strong synergistic effects between Co3O4 and GCN resulted in excellent performance as a bifunctional catalyst for OER and HER. The high surface area, unique tubular nanostructure, and composition of the hybrid made all redox sites easily available for catalysis and provided faster ionic and electronic conduction. The Co3O4@GCN tubular nanostructured （TNS） hybrid exhibited the lowest overpotential （0.12 V） and excellent current density （147 mA/cm^2） in OER, better than benchmarks IrO2 and RuO2, and with superior durability in alkaline media. Furthermore, the Co3O4@GCN TNS hybrid demonstrated excellent performance in HER, with a much lower onset and overpotential, and a stable current density. It is expected that the Co3O4@GCN TNS hybrid developed in this study will be an attractive alternative to noble metals catalysts in large scale water splitting and fuel cells.

Hybridization and genome evolution II： Mechanisms of species divergence and their effects on evolution in hybrids

Recent genomic studies have highlighted the importance of hybridization and gene exchange in evolution. We ask what factors cause variation in the impact of hybridization, through adaptation in hybrids and the likelihood of hybrid speciation. During speciation, traits that diverge due to both divergent and stabilizing selection can contribute to the buildup of reproductive isolation. Divergent directional selection in parent taxa should lead to intermediate phenotypes in hybrids, whereas stabilizing se- lection can also produce extreme, transgressive phenotypes when hybridization occurs. By examining existing theory and em- pirical data, we discuss how these effects, combined with differences between modes of divergence in the chromosomal distribu- tion of incompatibilities, affect adaptation and speciation in hybrid populations. The result is a clear and testable set of predic- tions that can be used to examine hybrid adaptation and speciation. Stabilizing selection in parents increases transgression in hy- brids, increasing the possibility for novel adaptation. Divergent directional selection causes intermediate hybrid phenotypes and increases their ability to evolve along the direction of parental differentiation. Stabilizing selection biases incompatibilities to- wards autosomes, leading to reduced sexual correlations in trait values and reduced pleiotropy in hybrids, and hence increased freedom in the direction of evolution. Directional selection causes a bias towards sex-linked incompatibilities, with the opposite consequences. Divergence by directional selection leads to greater dominance effects than stabilizing selection, with major but variable impacts on hybrid evolution [Current Zoology 59 （5）： 675-685, 2013].

Hot water as a mild Brφnsted acid catalyst in ring opening reactions of epoxides

Ring opening of extremely hydrophobic epoxides with water, amines, sodium azide and thiophenol was realized in the mixture solvent of water and 1, 4-dioxane under reflux condition. Hot water was believed to act as a mild Bronsted acid catalyst in the epoxide-opening reactions.

Interaction of epicatechin with bovine serum albumin using fluorescence quenching combined with chemometrics

The interaction between BSA and epicatechin was studied using fluorescence quenching titrations combined with trilinear decomposition method and excitation-emission matrix(EEM)fluorescence.The resolved spectra were highly similar with the actual ones which indicated that the resolved results were reliable.The relevant parameters of the binding process were obtained by quantifying each substance in the complicated mixtures in situ.The quenching was static quenching,epicatechin had a weak interaction with BSA and the binding site was one.The total concentration and the free concentration of quenchers had different effect on the system.The results demonstrated that the method exploited in this article is a useful tool to investigate complicated interactions,avoiding complicated pretreatment and simplify experimental procedure.