脲基苯乙炔4-′(对甲基苯基)-6-苯基-2,2′-二联吡啶铂(II)络合物的合成

本文通过异氰酸酰化反应合成了含有脲基的苯乙炔新型配体及以它作为辅助配体的4′-(对甲基苯基)-6-苯基-2,2′-二联吡啶铂(II)络合物,初步研究了铂(II)络合物的光物理性质,发现由于脲基的存在,当浓度大于3.32×10-5mol/L时铂(II)络合物能够发生分子间簇集.     

Multivariate calibration of near infrared spectra by orthogonal WAVElet correction using a genetic algorithm

Orthogonal WAVElet correction (OWAVEC) is a pre-processing method aimed at simultaneously accomplishing two essential needs in multivariate calibration, signal correction and data compression, by combining the application of an orthogonal signal correction algorithm to remove information unrelated to a certain response with the great potential that wavelet analysis has shown for signal processing. In the previous version of the OWAVEC method, once the wavelet coefficients matrix had been computed from NIR spectra and deflated from irrelevant information in the orthogonalization step, effective data compression was achieved by selecting those largest correlation/variance wavelet coefficients serving as the basis for the development of a reliable regression model. This paper presents an evolution of the OWAVEC method, maintaining the first two stages in its application procedure (wavelet signal decomposition and direct orthogonalization) intact but incorporating genetic algorithms as a wavelet coefficients selection method to perform data compression and to improve the quality of the regression models developed later. Several specific applications dealing with diverse NIR regression problems are analyzed to evaluate the actual performance of the new OWAVEC method. Results provided by OWAVEC are also compared with those obtained with original data and with other orthogonal signal correction methods.     

两亲嵌段共聚物聚乙二醇-聚谷氨酸苄酯纳米粒药物载体的合成研究

用磺酸酯法制备单端氨基聚乙二醇引发剂,引发谷氨酸苄酯羧酸酐开环聚合,生成可生物降解的两亲嵌段共聚物聚乙二醇﹣聚谷氨酸苄酯(PEG-PBLG),用IR,NMR和GPC表征了共聚物。用超微透析法制备PEG-PBLG聚合物纳米粒,荧光芘探针法测定纳米粒的临界聚集浓度(cac)。紫外分光光度计考察纳米粒对疏水性药物的增溶作用,PEG-PBLG可作为亚微粒药物输送系统的载体。     

Photo-induced Charge Separation of p-Tricyanovinyl-N,N-Dialkylanilines

In this paper,p-tricyanovinyl-N,N-dialkylanilines were synthesized as model compounds and through their spectroscopic behavior,the photo-induced electron transfer,charge separation were discussed and the aggregation in DMSO-H_2O system was investigated.     

Size of Micelles Determined by Static Fluorescence Quenching

We developed a new method to measure the average aggregation number of large rod-like micelles using static fluorescence self-quenching of a solubilized fluorophore. The method is based on the increase of self-quenching of micelle-solubilized pyrene through excimer formation. We consider the effect of random distribution of pyrene in micelles and the micellar size distribution. The measured average aggregation <n> _M is based on a new M-weighted raging similar to our exponential-weighted averaging in the transient decay method. We apply this method to study the effect of a large concentration of salt on the average aggregation behavior of sodium dodecyl sulfate (SDS) and cetyle tetraammonium bromide (CTAB). The sizes increase with increasing ionic concentrations. For SDS, we used the thermodynamic model developed by Missel et al. to calculate < n > _M which we compare with experimental results.     

A novel trilinear decomposition algorithm： Three-dimension non-negative matrix factorization

Non-negative matrix factorization(NMF)is a technique for dimensionality reduction by placing non-negativity constraints onthe matrix.Based on the PARAFAC model,NMF was extended for three-dimension data decomposition.The three-dimension non-negative matrix factorization(NMF3)algorithm,which was concise and easy to implement,was given in this paper.The NMF3algorithm implementation was based on elements but not on vectors.It could decompose a data array directly without unfolding,which was not similar to that the traditional algorithms do.It has been applied to the simulated data array decomposition andobtained reasonable results.It showed that NMF3 could be introduced for curve resolution in chemometrics.     

西印度蔗螟聚集信息素次要组份合成方法的改进

2-甲基-4-庚醇和2-甲基-4-辛醇是西印度蔗螟(Metamasiushemipterus)聚集信息素的次要组份，本文以天然产物(S)-亮氨酸为原料合成出了2-甲基-4-庚醇及2-甲基-4-辛醇的所有对映异构体，其关键步骤是由(2S)-4-甲基-1,2-戊二醇合成出(2S)和(2R)-4-甲基-1,2-环氧戊烷两种重要中间体，目标产物光学纯度可达95%以上。     

predForm-Site: Formylation site prediction by incorporating multiple features and resolving data imbalance

Formylation is one of the newly discovered post-translational modifications in lysine residue which is responsible for different kinds of diseases. In this work, a novel predictor, named predForm-Site, has been developed to predict formylation sites with higher accuracy. We have integrated multiple sequence features for developing a more informative representation of formylation sites. Moreover, decision function of the underlying classifier have been optimized on skewed formylation dataset during prediction model training for prediction quality improvement. On the dataset used by LFPred and Formator predictor, predForm-Site achieved 99.5% sensitivity, 99.8% specificity and 99.8% overall accuracy with AUC of 0.999 in the jackknife test. In the independent test, it has also achieved more than 97% sensitivity and 99% specificity. Similarly, in benchmarking with recent method CKSAAP_FormSite, the proposed predictor significantly outperformed in all the measures, particularly sensitivity by around 20%, specificity by nearly 30% and overall accuracy by more than 22%. These experimental results show that the proposed predForm-Site can be used as a complementary tool for the fast exploration of formylation sites. For convenience of the scientific community, predForm-Site has been deployed as an online tool, accessible at http://103.99.176.239:8080/predForm-Site.     

光解碎片平动谱中二级过程的运动学及化学动力学

本文发展了一套分析处理分子束光解反应实验中二级分解产物飞行谱的方法, 它改进了Kroger和Riley的最初讨论。本文表明许多重要的信息都可以从高度平均的实验数据中得出。这包括二级分解产物的平均平动能分布、空间各向异性参数、平行竞争通道间的反应比。模拟的结果可以表现二级分解反应的一些主要特征。     

Emissive Annular Digold(I) Compounds Containing Diphosphine and Dithiolate Ligands

Molecular structures of three emissive annular digold compounds [Au₂(dmpm)(dtc)]Cl (dmpm = Me₂PCH₂PMe_2,dtc = S₂CNEt₂), 1 , [Au₂(dppm)(dtc)]PF₆, (dppm = Ph₂PCH₂PPh₂),₂,and [Au₂(dppe)(dtc)]-(PF₂) (dppe = Ph₂P(CH₂)₂PPh₂), 3, were determined. All three compounds are dimetallacycles having two gold atoms bridged by a dithiolate ligand and a diphosphine ligand, the geometry around each gold atom being almost linear. All the dimetal lacy die rings are slightly distorted from planarity with intramolecular Au-Au distances shorter than 3.0 Å. Compound 1 forms a polymeric chain through intermolecular Au-Au contacts (3.061 ? 3.135 Å). Compound 2 forms a tetramer through intermolecular Au-Au interactions (Au-Au distances ranging from 3.086 to 3.222 ). Compound 3 is monomeric. All of the compounds luminesce at 77 K in the solid state. Emissions originating from ³LMCT from dtc ligand to Au excited states are assigned. The emission maxima of 1 ? 3 are at 541,535 and 520 nm respectively and are blue shifted as the number of Au-Au interactions is decreased.