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31.
The wavelet and harmonic filtering method suggested by Zalevsky and Ouzieli is introduced in this paper and adopted in our volume holographic image recognition system. This composite filter combines several scaled versions of the cascaded wavelet and harmonic filter, obtaining high discrimination ability and wide dynamic range of rotation and scale deformations. Optical experiments are conducted to demonstrate the validity and practicability of the algorithm. To the best of our knowledge, this is the first report of using this algorithm in a volume holographic system. Moreover, the separate correlation approach proposed in this paper greatly simplifies the manufacturing process and reduces the cost of the system.  相似文献   
32.
We report herein studies on the liquid crystalline behavior of a series of supramolecular materials that contain different ratios of two complementary symmetrically-substituted alkoxy-bis(phenylethynyl)benzene AA- and BB-type monomers. One monomer has thymine units placed at either end of the rigid mesogenic core, while the other has N6-(4-methoxybenzoyl)-adenine units placed on the ends. Differential scanning calorimetric and polarized optical microscopy studies have been carried out on these systems. These studies show that the material's behavior is strongly dependent on its thermal history. As a result, the materials can exhibit, on heating, either a liquid crystalline phase, a crystalline phase, or the coexistence of crystalline and liquid crystalline regions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5049–5059, 2006  相似文献   
33.
A series of chiral polymers based on poly(N‐acryl) amino acids was synthesized using a convergent synthetic approach. These chiral polymers have been used as chiral additives to induce enantioselective crystallization of racemic or conglomerate amino acids in solutions. These polymeric additives showed strong capabilities to enhance highly enantioselective resolution during the crystallization of amino acids. In addition, these polymers caused unusual modifications of amino acid crystal morphologies. Furthermore, spherical microparticles of those same chiral polymers were also shown active in similar chiral discriminations during amino acid crystallizations occurring on microparticle surfaces. Our study demonstrates the high potential of chiral polymers and microparticles to resolve amino acids throughout crystallization processes. High enantiomeric excesses in one targeted enantiomer of amino acids can also be maximized via time‐dependent kinetic control of crystallizations. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3009–3017, 2006  相似文献   
34.
We present a new algorithm for the identification of ring pairs in Cherenkov detectors. The approach combines linear regression methods for the construction of an appropriate reference quantity, methods from statistics for the evaluation of hypotheses and Monte Carlo simulation runs for the tuning of threshold levels.  相似文献   
35.
Two Kemp's acid diamides were synthesized and applied to chiral amine recognition using 1H NMR analysis. One derivative based on 1-(1-naphthyl)ethylamine had good chiral recognition of six amines and was useful to determine the optical purity for three amines, i.e., methylbenzylamine, 1-(1-naphthyl)ethylamine and 1- henylpropylamine,however, the cyclohexylethylamine derivative showed little discrimination for the amines studied. Together with the results for alkylamines, it was shown that aromatic structure was important for aromatic shielding anisotropy and –– interactions between host and guest. The structure of the 1-(1-naphthyl)ethylamine derivative in solution was also considered based on 1H NMR data and computer simulation.  相似文献   
36.
Summary Chiral recognition of many enantiomeric solutes by a chiral amide stationary phase is based mainly on hydrogen bonding. A chiral-recognition-factor CHI is proposed, given by the difference of the enthalpy change in the enantiomer discrimination, standardized with respect to the specific interaction of the solutes with the diamide core of the stationary phase. The r?le of the entropy part is also discussed. By extrapolation of the retention behaviour to elevated temperature, peak inversion of enantiomers is predicted. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984  相似文献   
37.
孙命  刘小兰 《结构化学》1998,17(6):405-408
合成了标题化合物,并用X-射线衍射法确定了该分子的晶体结构。化合物Δ(λλ),Λ(δδ)-cis-[Co(en)2(NO2)2]2d,l-C4H4O5,Co2C12N12O13H22,Mr=657.94.晶体属单斜晶系,空间群为P21/c,晶胞参数:a=13.969(4),b=6.440(1),c=14.408(4)A,β=94.37(1)°,V=1292.3A3,Z=2,Dc=1.69g/cm3,μ=105.833cm-1,F(000)=668.最终偏离因子R=0.066,Rw=0.085。结构分析表明晶体存在无序现象,其阴离子C4H4O52-有两种排列方式。R-构型和S-构型的几率各为50%,手性识别是通过Δ构型的阳离子与阴离子R-构型C原子上羟基氧形成氢键相互作用;Λ构型的阳离子与阴离子S-构型C原子上羟基氧形成氢键相互作用而实现的。  相似文献   
38.
通过关于“普里昂”蛋白病毒疾病的已有临床、医学生理、免疫和化学等方面的现象,讨论了朊病毒当中的部分蛋白氧化损伤和蛋白自由基化学本质。  相似文献   
39.
40.
设计并合成了2-(2’-羟基-3’-甲氧基苯基)-5,6-二硝基苯并咪唑化合物(1),通过X射线单晶衍射研究了该化合物的固态结构.利用紫外-可见光谱技术研究了其对阴离子的识别,发现化合物1能够在DMSO中对AcO^-,H2PO4^-,OH^-的3种离子进行有效识别,同时溶液由原来的黄色变成红色,实现裸眼检测.  相似文献   
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