The mini-review for synthesis of core@Ag nanocomposite

As common noble metal, Ag nanoparticles (Ag NPs) have unique physical and chemical properties and it is widely used in daily life, scientific research, industrial production, environment, medical and healthcare systems. Core/shell of Ag nanocomposite have attracted attention due to the significant properties and wide applications by combination with the core and shell. As a mini-review, it is emphasized the approaches for fabrication Ag shell coating on core nanoparticles as core@Ag nanocomposite, including situ growth method, phenol formaldehyde resin method, silane coupling agent method, ultrasound method, PEI method, dopamine method and other methods. The procedures and mechanism for construction of core@Ag nanocomposite are highlighted. The comparison of those approaches, including their advantages and disadvantages are described in detail. At the same time, the properties and applications of Ag NPs are briefly introduced. The current challenges and perspectives in the future for synthesis of core/shell nanocomposite is proposed. The review is very useful for quickly gaining knowledge and experience for synthesis of core@Ag nanocomposite.     

两例基于相同的含氮及联苯二羧基混合配体构筑的Zn(Ⅱ)/Cd(Ⅱ)配位聚合物:不同的穿插结构和荧光性质

在溶剂热条件下合成了2个锌Ⅱ/镉Ⅱ配位聚合物：{[Zn（1,3-bip）（bpdc）]·0.5H₂bpdc}_n（1）,{[Cd₂（1,3-bip）₂（bpdc）₂]·DMF}_n（2）,H₂bpdc=4,4''-联苯二甲酸,1,3-Bip=1,3-二（咪唑基）丙烷。并通过X射线单晶衍射,粉末XRD、红外光谱、元素分析以及热重分析对其结构进行表征。单晶解析结果表明：配位聚合物1是一个五重穿插3D→3D三维空间网络结构,配位聚合物2是一个二重穿插的2D→2D二维的（4,4）网格层状结构。另外,研究了2个配位聚合物在室温下的热稳定和荧光性能。     

Synthesis,Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd(Ⅱ) coordination polymer, namely, [Cd(1,3-bip)(3,5-pdc)]n(1,3-bip =1,3-bis(imidazol)propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid) has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis,powder X-ray diffraction(PXRD) and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178(7), b = 1.72502(12), c = 1.41635(6) nm, β =92.653(4)o, V = 3.4212(3) nm3, Z = 4, C316H15 Cd N5O4, Mr = 453.73, Dc = 1.762 g/cm, F(000) =1808, μ = 1.310 mm-1, R = 0.0899 and w R = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd(Ⅱ) ions and each Cd(Ⅱ) attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.     

Concise enantiodivergent synthesis of (+)- and (−)-trans-quercus lactones

A concise enantiodivergent total synthesis of (+)- and (−)-quercus lactones from the known tricyclic lactone (+)-1 as a single chiral template was achieved using the diastereoselective nucleophilic addition of organometallic reagents as the key step.     

Three Cu(II) Complexes Constructed by Flexible bis-Imidazole and Different Anions: From 0D Architecture to 2D Layer

Crystallography Reports - Three new Cu(II) complexes, Cu(1,3-bip)(Ac)2 (I), {[Cu(H2O)2(1,3-bip)2] · (NO3)2}n (II), {[Cu(1,3-bip)(1,4-bdc)]2 · H2O · MeOH}n (III), where 1,3-bip is...     

秦巴山区中草药钮子七中微量元素的测定

用ICP-AES测定了秦巴山区独有的中草药钮子七中的2种常量营养性元素(钙、镁)和5种微量元素(铜、铬、铁、锌、锰)含量。钙4790.66μg.g-1、镁55.32μg.g-1、铜18.44μg.g-1、铬2.1μg.g-1、铁264.50μg.g-1、锌56.71μg.g-1、锰17.83μg.g-1,回收率均在96.2%—100.5%之间,结果表明,此方法简便、可靠,具有良好的精确度和准确性。并初步讨论了中草药钮子七中有益元素与治疗疾病的关系,并与中药材汉三七中微量元素含量相比较,二者微量元素含量略有差异。     

三维谐振子Wigner函数的星乘解

Wigner函数作为相空间中的一个准概率分布函数,也是密度矩阵的特殊表示形式,具有十分重要的物理意义。首先介绍了Wigner函数的性质及其计算方法,然后利用星本征方程(Moyal方程)计算了三维谐振子的Wigner函数。最后讨论了在相空间中描述声子与电子(或光子)相互作用的方法,并得到了跃迁几率在相空间中所满足的方程。     

Designing variable height carbon nanotube bundle for enhanced electron field emission

A variable height model has been implemented in order to improve the emission performance from a nanotube bundle. A Gaussian distribution of nanotube heights has been considered. This resulted in a nearly uniform electric field distribution across all the nanotubes and consequently an enhanced emission current in comparison to a nanotube bundle with all the nanotubes having the same height. Simulation results from linear as well as area nanotube bundles are reported. The analysis helped in providing a better understanding of the previously reported experimental results on enhanced field emission from plasma treated nanotube bundles having CNTs of variable heights.     

一例吡嗪羧酸镉配合物的合成、结构及荧光性质研究

吡嗪化合物因其独特的结构及活性被广泛应用于制药、医学、化学等领域。水热法以水作为溶剂，具有绿色无污染、简单易操作等特点，是合成配合物的首选方法。本文以2,6-双(2-吡嗪基)吡啶-4-对苯甲酸(Hbppc)和CdCl₂·2.5H₂O为原料，用水热合成法合成了一例新型的配位化合物[Cd(bppc)(H₂O)Cl]_n,并运用单晶X射线衍射、红外光谱和拉曼光谱分析等手段对配合物的结构进行了表征，结果表明此配合物为一维链状结构。对自由配体2,6-双(2-吡嗪基)吡啶-4-对苯甲酸及配合物[Cd(bppc)(H₂O)Cl]_n进行荧光分析，结果表明所得配合物具有较好的荧光性质。