苯甲醛1,2-丙二醇缩醛的杂多酸（盐）催化剂研究进展

综述了近二十年来国内采用杂多酸（盐）催化剂催化合成苯甲醛1,2-丙二醇缩醛的实验结果。研究结果表明,杂多酸（盐）能够代替硫酸作为合成苯甲醛1,2-丙二醇缩醛反应的催化剂。     

The Drosophila melanogaster Genetic Reference Panel

A major challenge of biology is understanding the relationship between molecular genetic variation and variation in quantitative traits, including fitness. This relationship determines our ability to predict phenotypes from genotypes and to understand how evolutionary forces shape variation within and between species. Previous efforts to dissect the genotype-phenotype map were based on incomplete genotypic information. Here, we describe the Drosophila melanogaster Genetic Reference Panel (DGRP), a community resource for analysis of population genomics and quantitative traits. The DGRP consists of fully sequenced inbred lines derived from a natural population. Population genomic analyses reveal reduced polymorphism in centromeric autosomal regions and the X chromosome, evidence for positive and negative selection, and rapid evolution of the X chromosome. Many variants in novel genes, most at low frequency, are associated with quantitative traits and explain a large fraction of the phenotypic variance. The DGRP facilitates genotype-phenotype mapping using the power of Drosophila genetics.     

Hafnium isotope evidence for a transition in the dynamics of continental growth 3.2 Gyr ago

Earth's lithosphere probably experienced an evolution towards the modern plate tectonic regime, owing to secular changes in mantle temperature. Radiogenic isotope variations are interpreted as evidence for the declining rates of continental crustal growth over time, with some estimates suggesting that over 70% of the present continental crustal reservoir was extracted by the end of the Archaean eon. Patterns of crustal growth and reworking in rocks younger than three billion years (Gyr) are thought to reflect the assembly and break-up of supercontinents by Wilson cycle processes and mark an important change in lithosphere dynamics. In southern West Greenland numerous studies have, however, argued for subduction settings and crust growth by arc accretion back to 3.8 Gyr ago, suggesting that modern-day tectonic regimes operated during the formation of the earliest crustal rock record. Here we report in situ uranium-lead, hafnium and oxygen isotope data from zircons of basement rocks in southern West Greenland across the critical time period during which modern-like tectonic regimes could have initiated. Our data show pronounced differences in the hafnium isotope-time patterns across this interval, requiring changes in the characteristics of the magmatic protolith. The observations suggest that 3.9-3.5-Gyr-old rocks differentiated from a >3.9-Gyr-old source reservoir with a chondritic to slightly depleted hafnium isotope composition. In contrast, rocks formed after 3.2 Gyr ago register the first additions of juvenile depleted material (that is, new mantle-derived crust) since 3.9 Gyr ago, and are characterized by striking shifts in hafnium isotope ratios similar to those shown by Phanerozoic subduction-related orogens. These data suggest a transitional period 3.5-3.2 Gyr ago from an ancient (3.9-3.5 Gyr old) crustal evolutionary regime unlike that of modern plate tectonics to a geodynamic setting after 3.2 Gyr ago that involved juvenile crust generation by plate tectonic processes.     

A ferromagnet in a continuously tunable random field

Most physical and biological systems are disordered, even though the majority of theoretical models treat disorder as a weak perturbation. One particularly simple system is a ferromagnet approaching its Curie temperature, T(C), where all of the spins associated with partially filled atomic shells acquire parallel orientation. With the addition of disorder by way of chemical substitution, the Curie point is suppressed, but no qualitatively new phenomena appear in bulk measurements as long as the disorder is truly random on the atomic scale and not so large as to eliminate ferromagnetism entirely. Here we report the discovery that a simply measured magnetic response is singular above the Curie temperature of a model, disordered magnet, and that the associated singularity grows to an anomalous divergence at T(C). The origin of the singular response is the random internal field induced by an external magnetic field transverse to the favoured direction for magnetization. The fact that ferromagnets can be studied easily and with high precision using bulk susceptibility and a large variety of imaging tools will not only advance fundamental studies of the random field problem, but also suggests a mechanism for tuning the strength of domain wall pinning, the key to applications.     

三维超分子配合物[Cu(Phen)2NO3](OH)·6H2O的合成、结构和量化研究

由Phen(Phen=1,10-phenanthroline)与铜(Ⅱ)离子反应,合成了标题配合物[Cu(Phen)2NO3](OH)·6H2O.单晶X射线衍射分析表明,晶体属单斜晶系,空间群为P2(1)/c,晶胞参数a=0.994 2(4)nm,b=2.635 8(9)nm,c=1.055 1(4)nm,β=106.045(6)°,V=2.657 2 nm3,Z=4,Dx=1.527 g.cm-3,μ(Moka)=8.88 cm-1,F(000)=1 268,R1=0.044 1,wR2=0.111 0[I＞2σ(I)].配合物中Cu-O、Cu-N键键长分别为0.201 4～0.233 2 nm和0.203 5～0.221 8 nm,中心铜原子与六个配位原子形成变形八面体结构.晶体中结构单元通过分子间氢键和π-π堆积,形成了三维网络结构.对标题配合物进行了量化计算,得原子轨道贡献信息.     

腈基取代脂肪族一元酸的电子结构与化学反应性

为了引导和构建结构决定性质教学思想，对腈基取代直链型脂肪族羧酸化合物的空间构象和电子结构进行了分析，结果表明α-腈基癸酸羧基C1-C2单键旋转构象能量能垒17．4758kJ／mol；腈基使碳原子电荷密度减少，腈基取代使酸性加强，羧基H原子电荷p与n的关系遵从p=0．449-0．0061n（n）（2≤n≤10）规律，腈基取代位置n-C原子与羧基碳电荷遵从p=0．716＋0．123/n（2≤n≤10）关系；腈基取代酸（HA）的体系能随与羧基的距离n增加次降低，遵从E=-631．492-0．0071n（n）（2≤n≤10）规律。     

Entangled quantum state of magnetic dipoles

Free magnetic moments usually manifest themselves in Curie laws, where weak external magnetic fields produce magnetizations that vary as the reciprocal of the temperature (1/T). For a variety of materials that do not display static magnetism, including doped semiconductors and certain rare-earth intermetallics, the 1/T law is replaced by a power law T(-alpha) with alpha < 1. Here we show that a much simpler material system-namely, the insulating magnetic salt LiHo(x)Y(1-x)F(4)-can also display such a power law. Moreover, by comparing the results of numerical simulations of this system with susceptibility and specific-heat data, we show that both energy-level splitting and quantum entanglement are crucial to describing its behaviour. The second of these quantum mechanical effects-entanglement, where the wavefunction of a system with several degrees of freedom cannot be written as a product of wavefunctions for each degree of freedom-becomes visible for remarkably small tunnelling terms, and is activated well before tunnelling has visible effects on the spectrum. This finding is significant because it shows that entanglement, rather than energy-level redistribution, can underlie the magnetic behaviour of a simple insulating quantum spin system.