Multi-functional cotton textiles design using in situ generating zeolitic imidazolate framework-67 (ZIF-67) for effective UV resistance,antibacterial activity,and self-cleaning

Cellulose - In this study, a multifunctional cotton fabric with durable superhydrophobic, antibacterial, and UV resistance properties was prepared by in situ growth of zeolitic imidazolate...     

β‐Functionalization of Carboxylic Anhydrides with β‐Alkyl Substituents through Carbene Organocatalysis

The first NHC‐catalyzed functionalization of carboxylic anhydrides is described. In this reaction, the β carbon behaves as a nucleophilic carbon and undergoes asymmetric reactions with electrophiles. Anhydrides with challenging β‐alkyl substituents work effectively.     

一种新型偶氮染料在扭曲向列相液晶显示取向中的应用

研究了一种新型偶氮材料sy03在光控取向中的应用。将sy03加入聚酰亚胺SE-3310(Nissan)与N,N-二甲基甲酰胺(DMF)的混合溶液中作为90°扭曲向列相液晶显示(Twisted nematic liquid crystal display,TN-LCD)的光取向材料,测量由它作为取向膜的扭曲向列型盒的电光特性与仅用SE-3310取向的扭曲向列型盒电光特性比较,发现sy03偶氮的加入使得扭曲向列型盒的响应时间短到98 ms、阈值电压也降低到1.7 V左右。而且随曝光时间的增加,响应时间和衬比度都有所提高,电光响应曲线也更为陡峭。加热到150℃后,其电光特性并没有明显变化,证明了它良好的热稳定性。最后通过测量偏振紫外吸收光谱,分析得出液晶分子易取向方向与激发光源偏振方向垂直。     

String order in half-integer-spin antiferromagnetic Heisenberg chains

We derive the extended string order parameter O(S) for antiferromagnetic Heisenberg chains with half-integer spin S in the valence-bond-solid picture. We obtain the analytic power-law scaling of O(S) versus the chain length L and show that O(S) scales at an extremely slow pace that decreases rapidly with growing spin magnitude. Furthermore, accurate numerical calculations show that the power-law scaling sets in only when L exceeds a characteristic length scale l(S) which increases very fast with growing S. Consequently, a pseudo-long-range string order exists in half-integer-spin Heisenberg chains. The implications of this result and its relationship to other topological features such as the end-chain states are discussed.     

溶出伏安法测定乌药中的铜铅镉

在KNO3底液下,用线性扫描阳极溶出伏安法同时测定了乌药样品中铜、铅、镉3种金属的含量.结果表明,在最佳实验条件下,铜、铅、镉的峰电位分别为0.067、-0.45和-0.64V(vs ScE);铜、铅、镉金属离子的质量浓度在0-0.8 mg·L-1范围内,呈现良好的线性关系,相关系数分别为0.991 3、0.990 5...     

The Preparation of Enantiopure [6]‐ and [7]Helicenes from Binaphthanol

A general and efficient synthetic methodology for the preparation of enantio‐ and diastereopure [6]‐, and [7]helicenes is developed. Commercially available chiral binaphthanols are utilized to generate the arylene‐vinylene precursors, which undergo helical folding via photocyclization to give enantio‐ and diastereopure [6]‐, and [7]helicenes. These optically pure helicenes could be easily obtained via silica gel column chromatography without the use of expensive HPLC or chiral resolution reagents. The configurations and structures of these helicenes are confirmed by CD spectra and X‐ray crystallographic analysis. This work provides a new method for preparation of enantiopure helicenes.     

Synthesis of Sub‐2 nm Iron‐Doped NiSe2 Nanowires and Their Surface‐Confined Oxidation for Oxygen Evolution Catalysis

Ultrathin nanostructures are attractive for diverse applications owing to their unique properties compared to their bulk materials. Transition‐metal chalcogenides are promising electrocatalysts, yet it remains difficult to make ultrathin structures (sub‐2 nm), and the realization of their chemical doping is even more challenging. Herein we describe a soft‐template mediated colloidal synthesis of Fe‐doped NiSe₂ ultrathin nanowires (UNWs) with diameter down to 1.7 nm. The synergistic interplay between oleylamine and 1‐dodecanethiol is crucial to yield these UNWs. The in situ formed amorphous hydroxide layers that is confined to the surface of the ultrathin scaffolds enable efficient oxygen evolution electrocatalysis. The UNWs exhibit a very low overpotential of 268 mV at 10 mA cm^?2 in 0.1 m KOH, as well as remarkable long‐term stability, representing one of the most efficient noble‐metal‐free catalysts.     

Determination of trace elements in bone crusts of rabbit during healing after fracture by INAA

The radius of rabbits were fractured by operation and the contents of Ca, Na, Mg, Zn, Mn and Sr in bone crusts during the period between the first to seventh week after fracture were determined by INAA. The tests show that all the contents of 6 elements in bone crusts are higher than those in contrast lateral in the same rabbit. The elemental metabolism curves in both laterals are roughly parallel. The content of Ca in the fractured position is almost constant during healing, those of Mn, Mg and Zn change apparently, and that of Sr changes in different way with the other elements.     

广藿香化学成分和指纹图谱研究

采用气相色谱-质谱联用技术(GC-MS),对石牌、高要、湛江3个栽培品种的广藿香挥发性成分进行了研究,分别鉴定了其化学组成,并测定了其相对含量。采用色谱指纹图谱分区法对3个栽培品种广藿香的质量进行分析和比较,把广藿香总离子流色谱图分为4个区,并用相对保留值α和相对峰面积Sr进行分析比较。结果表明,此法简单、快速,为有效地鉴别不同栽培品种的广藿香以及建立其色谱指纹图谱提供了一种新的方法。本研究还讨论了广藿香酮结构的确定。     

用于液晶取向的掺偶氮类染料的光诱导取向膜

介绍了一种使用聚酰亚胺和偶氮类染料进行液晶光诱导取向技术,深入研究了代号为SY04包含两个偶氮基团的新偶氮类染料.通过对取向膜偏振吸收光谱的分析,讨论了这种混合材料光诱导取向机理.由于聚酰亚胺良好的成膜性使得这种光诱导取向膜具有很好的稳定性,偶氮类染料的引入使得液晶表面取向更加有序,从而获得了响应快速,电光特性优良的液晶盒.这种取向膜材料同时具有很好的热稳定性及抗紫外稳定性.