1,5-苯并硫氮杂-α-丁烯二酰亚氨基-β-内酰胺衍生物的合成、晶体结构及其抑菌活性

丁烯二酰亚氨基乙酰氯与1,5-苯并硫氮杂反应, 合成了8个1,5-苯并硫氮杂-α-丁烯二酰亚氨基-β-内酰胺衍生物, 用IR, MS, 1H NMR和元素分析表征了产物的结构, 用单晶X射线衍射法确证了产物的立体结构. 生物活性研究表明, 此类化合物有一定的抑菌作用, 其中对金黄色葡萄球菌和白色葡萄球菌的抑菌效果相对较好.     

Banach空间中同时逼近问题的适定性

研究一般Banach空间X中同时逼近问题的适定性.对严格凸的KadecBanach空间X中的相对有界弱紧闭子集G,建立了关于最佳同时逼近问题适定Bair纲结果.进一步,当X是一致凸空间时,证明了E(G)中使其最佳同时逼近问题不适定的序列在E(G)中是一个σ-多孔集.另外,还研究了关于最佳同时逼近元具有分歧域的集合G的几乎性.     

CHEBYSHEV APPROXIMATION BY FUNCTIONS HAVING RESTRICTED RANGES WITH EQUALITIES

In this paper, we establish a new type of alternation theory for more general restricted ranges Chebyshev approximation with equalities. The uniqueness and strong uniqueness theorems are given. Applying the results, we obtain the alternation theorem and uniqueness theorem for best coposilive approximation.     

几乎K-Chebyshev子集

1978年,Kasing Lau证明了自反局一致凸空间的任何闭子集都是几乎Chebyshev子集,从而解决了Steckin在1963年提出的问题。本文研究了自反K局一致凸空间的类似性质。证明了自反的K局一致凸空间的任何闭子集都是几乎K-Chebyshev子集。     

有界集空间中的几乎Chebyshev子集

研究了有界集关于一般集合的限制Chebyshev中心的存在唯一性。在集合的Hausdorff距离下,引进了有界集空间中的几乎Chebyshev子集的概念。证明了一致凸(自反局部一致凸)Banach空间中的任何闭子集都是关于有界集(紧凸子集)的几乎Chebyshev子集。     

最佳同时逼近的特征

<正> 设X是赋范线性空间(实或复),V、F是X的子集,F有界,如果ν_o∈V满足则称ν_o是V对F的最佳同时逼近,其全体记为P_v(F). 最佳同时逼近近年来已有不少文献进行研究,J.H.Freilich,H.w.Mclaughlin     

基于次磷酸铝的聚丙烯木塑复合材料的阻燃改性研究

本研究以次磷酸铝(AP)为阻燃剂,探讨了其对聚丙烯/木粉复合材料(WPC)的阻燃性能的影响,并阐明了相关的阻燃机理。实验结果证明,当AP的添加量为30 wt%时,可以使木粉含量为30 wt%的WPC通过垂直燃烧V-0级,氧指数达到25. 0%。锥形量热测试结果表明:AP的加入能够有效抑制复合材料的燃烧,30wt%AP的加入能够使木粉含量为30 wt%的WPC的热释放峰值(PHRR)降低至240 k W/m~2,与不含阻燃剂的WPC相比降低了50%;燃烧后所得的残炭的质量高达45. 2%。扫描电子显微镜(SEM),热重-红外联用(TGFTIR)和X射线光电子能谱结果表明:添加AP后,燃烧过程中WPC/AP的气相产物中会有水、二氧化碳及含PO_2-结构的物质等生成,从而赋予WPC/AP气相阻燃作用;此外,WPC/AP在燃烧中能够热解生成内外结构不同的炭层,内部炭层主要为含铝为主的交联稳定炭层,而外部炭层主要含有交联P-O-C结构等,因此,AP能够同时通过气相和凝聚相的双重作用实现WPC的高效阻燃。     

Efficiency-enhanced AlGaInP light-emitting diodes using transparent plasmonic silver nanowires

Silver nanowire(AgNW) networks have been demonstrated to exhibit superior transparent and conductive performance over that of indium-doped tin oxide(ITO) and have been proposed to replace ITO, which is currently widely used in optoelectronic devices despite the scarcity of indium on Earth. In this paper, the current spreading and enhanced transmittance induced by AgNWs, which are two important factors influencing the light output power, were analyzed. The enhanced transmittance was studied by finite-difference time-domain simulation and verified by cathodoluminescence measurements.The enhancement ratio of the light output power decreased as the Ga P layer thickness increased, with enhancement ratio values of 79%, 52%, and 15% for Ga P layer thicknesses of 0.5 μm, 1 μm, and 8 μm, respectively, when an AgNW network was included in Al Ga In P light-emitting diodes. This was because of the decreased current distribution tunability of the AgNW network with the increase of the Ga P layer thickness. The large enhancement of the light output power was caused by the AgNWs increasing carrier spread out of the electrode and the enhanced transmittance induced by the plasmonic AgNWs. Further decreasing the sheet resistance of AgNW networks could raise their light output power enhancement ratio.     

Research of the use of silver nanowires as a current spreading layer on vertical-cavity surface-emitting lasers

Silver nanowire(AgNW) film was proposed to apply on the surface of the vertical-cavity surface-emitting lasers(VCSELs) with large aperture in order to obtain a uniform current distribution in the active region and a better optical beam quality.Optimization of the AgNW film was carried out with the sheet resistance of 28.4 Ω/sq and the optical transmission of 94.8% at 850 nm.The performance of VCSELs with and without AgNW film was studied.When the AgNW film was applied to the surface of VCSELs,due to its better current spreading effect,the maximum output optical power increased from 23.4 mW to 24.4 mW,the lasing wavelength redshift decreased from 0.085 nm/mA to 0.077 nm/mA,the differential resistance decreased from 23.95 Ω to 21.13 Ω,and the far field pattern at 50 mA decreased from 21.6° to 19.2°.At the same time,the near field test results showed that the light in the aperture was more uniform,and the far field exhibited a better single peak characteristic.Various results showed that VCSELs with AgNW on the surface showed better beam quality.     

聚乙烯亚胺功能化石墨烯修饰电极同时测定抗坏血酸、 多巴胺、尿酸和色氨酸

制备了聚乙烯亚胺(PEI)功能化的石墨烯(G)修饰电极以实现抗坏血酸(AA)、 多巴胺(DA)、 尿酸(UA)和色氨酸(Trp)的分离及同时测定. 采用红外光谱(FTIR)、 紫外-可见吸收光谱(UV-Vis)、 X射线粉末衍射仪(XRD)和透射电子显微镜(TEM)对电极修饰材料进行了表征, 并优化了该修饰电极同时测定AA, DA, UA和Trp的实验条件. 在聚乙烯亚胺功能化石墨烯修饰的玻碳电极(PEI-G/GCE)上实现了AA, DA, UA 和Trp氧化峰的分离, AA-DA, DA-UA和UA-Trp的氧化峰电位差分别为298, 130和350 mV. 该修饰电极对AA, DA, UA和Trp的检测线性范围分别为50~5800, 30~2570, 0.05~400和6~1000 μmol/L; 检出限分别为16.67, 10, 0.017和2 μmol/L.