1,8-萘酰亚胺衍生物的设计、合成及其对半胱氨酸的识别研究

巯基氨基酸水平异常与多种疾病相关,其检测仍存在一定的局限,研究检测巯基氨基酸的荧光探针具有一定的价值.以苊为原料合成了61个1,8-萘酰亚胺衍生物,研究了该类化合物的荧光性能及其作为半胱氨酸含量测定的荧光探针的可能性.紫外光谱分析表明1,8-萘酰亚胺衍生物上N-取代基对最大吸收波长无明显影响;荧光光谱(FL)的性能测试显示硝基萘酰亚胺衍生物N-甲基-4-硝基-1,8-萘二甲酰亚胺(4a)～4-硝基-N-间氟苯基-1,8-萘二甲酰亚胺(4s)无荧光,氨基萘酰亚胺衍生物N-甲基-4-氨基-1,8-萘二甲酰亚胺(5a)～4-氨基-N-间氟苯基-1,8-萘二甲酰亚胺(5s)有强烈黄色荧光,而马来酰亚胺萘酰亚胺衍生物N-甲基-4-(1H-吡咯-2,5-二酮-1-基)-1,8-萘二甲酰亚胺(6a)～4-(1H-吡咯-2,5-二酮-1-基)-N-(间氟苯基)-1,8-萘二甲酰亚胺(6s)有微弱蓝色荧光,其中7个马来酰亚胺萘酰亚胺衍生物探针对半胱氨酸(Cys)溶液有荧光点亮效应.对7个探针加入21种其它氨基酸作为干扰项的测试显示探针对半胱氨酸检测有良好的选择性.研究了不同pH值下荧光强度,检测探针与半...     

高效液相色谱法同时测定复杂食品基质中8种合成色素的含量北大核心CSCD

采用固相萃取-高效液相色谱法同时测定复杂食品基质中的柠檬黄、日落黄、苋菜红、胭脂红、诱惑红、酸性红、赤藓红、亮蓝等8种合成色素的含量。样品经乙醇-乙腈-甲醇-氨水(3+3+3+1)混合液超声提取3次后,提取液采用ProElut PWA-2固相萃取柱净化,净化液在Agilent Eclipse XDB-C_(18)色谱柱上分离,以乙腈-0.02mol·L^(-1)乙酸铵溶液为流动相进行梯度洗脱,采用二极管阵列检测器,检测波长为254nm。8种合成色素的峰面积与其质量浓度在1.0~50.0mg·L^(-1)内呈线性关系,检出限(3S/N)在0.25~0.80μg·kg^(-1)之间。加标回收率为84.6%~99.0%,测定值的相对标准偏差(n=6)在1.4%~2.5%之间。     

由4，4＇-联二吡啶桥联α,β-不饱和酸铜形成铜（II）的一维配位聚合物

A methanol solution of 4,4‘-bipyridine reacts with Cu2A4(H2O)2 to yield coordination polymers of general formula: [Cu2A4(bipy)]n [A: CH2=C(Me)CO2^- (1), CH2=CHCO2^- (2); bipy: 4,4‘-bipyridine]. They were characterized by elemental analyses, IR spectra and thermal analyses. The X-ray structure analyses of 1 show a one-dimensional chain structure where the binuclear structural units Cu2[CH2=C(Me)CO2]4 are bridged by 4,4‘-bipyridine molecules. Furthermore, the binuclear units between adjacent layers can form micropores. The temperature-dependent magnetic susceptibility of 1 indicates that the strong antiferromagnetic interaction exists between copper(Ⅱ) atoms in the binuclear units.     

因子分析-导数光度法同时测定苯酚、间苯二酚、对苯二酚混合体系的比较

同时采集多事体系的紫外基谱和一阶导数光谱数据,用因子分析技术地两套数据进行分析对比,结果表明一阶导数光谱数据经因子分析法同时测定混合多酚所得结果明显优于基本光谱数据经因子分析法所得结果,具有明显的消除背景干扰,提高灵敏度等优点。     

比值导数光谱法同时测定苯酚间苯二酚对苯二酚

以比值导数光谱法对苯酚、间苯二酚、对苯二酚的二组分和三组分混合体系进行了分析。方法以混合物的波谱除以干扰组分的波普得到比值波谱,再用“减（加）法技术”以比值波谱对波长求导得到比值导数波谱,方法兼具导数光谱能消除低频背景和高频噪声干扰的优点。由此得到的幽会导数波谱可完全消除干扰组分的吸光度的贡献,此法可很方便地对二组分体系进行测定。进一步以求得的比导数波谱对波长二次求导,可对三组分体系进行分析,用此     

属性约简在中医证候诊疗数据分析中的应用

针对中医诊疗数据和诊疗结果数据存在不确定性等特点,通过研究基于粗糙集的属性约简方法,引入属性作用集差异度概念,并定义基于属性作用集差异度的属性重要度的计算方法,提出基于属性作用集差异度的属性约简算法,并将其应用于中医证候数据约简中以实现中医证候诊疗症状关键因子提取的需要。通过实际中医证候诊疗数据集上测试及与其他属性约简算法的测试比较,结果表明所提出的属性约简算法是有效的。     

具脉冲效应和反馈控制的企业集群竞争模型的持久性分析

根据企业集群与生物种群有着一定的相似性,借鉴种群生态学中的种群竞争模型建立了网状型企业集群模式下企业间竞争关系的数学模型-一类具脉冲效应和反馈控制的非自治企业竞争模型系统,并通过脉冲微分方程的比较性定理,建立了该系统持久性生存的充分条件,并做经济学解释.     

Structural,electronic,and magnetic properties of vanadium atom-adsorbed MoSe_2 monolayer

Using the first-principles calculations, we study the structural, electronic, and magnetic properties of vanadium adsorbed MoSe_2 monolayer, and the magnetic couplings between the V adatoms at different adsorption concentrations. The calculations show that the V atom is chemically adsorbed on the MoSe_2 monolayer and prefers the location on the top of an Mo atom surrounded by three nearest-neighbor Se atoms. The interatomic electron transfer from the V to the nearestneighbor Se results in the polarized covalent bond with weak covalency, associated with the hybridizations of V with Se and Mo. The V adatom induces local impurity states in the middle of the band gap of pristine MoSe_2, and the peak of density of states right below the Fermi energy is associated with the V- dz~2 orbital. A single V adatom induces a magnetic moment of 5 μBthat mainly distributes on the V-3d and Mo-4d orbitals. The V adatom is in high-spin state, and its local magnetic moment is associated with the mid-gap impurity states that are mainly from the V-3d orbitals. In addition,the crystal field squashes a part of the V-4s electrons into the V-3d orbitals, which enhances the local magnetic moment.The magnetic ground states at different adsorption concentrations are calculated by generalized gradient approximations(GGA) and GGA+U with enhanced electron localization. In addition, the exchange integrals between the nearest-neighbor V adatoms at different adsorption concentrations are calculated by fitting the first-principle total energies of ferromagnetic(FM) and antiferromagnetic(AFM) states to the Heisenberg model. The calculations with GGA show that there is a transition from ferromagnetic to antiferromagnetic ground state with increasing the distance between the V adatoms. We propose an exchange mechanism based on the on-site exchange on Mo and the hybridization between Mo and V, to explain the strong ferromagnetic coupling at a short distance between the V adatoms. However, the ferromagnetic exchange mechanism is sensitive to both the increased inter-adatom distance at low concentration and the enhanced electron localization by GGA+U, which leads to antiferromagnetic ground state, where the antiferromagnetic superexchange is dominant.     

微晶硅薄膜的结构及光学性质的研究

借助RF-PECVD辅助RTP技术，采用高沉积气压的技术路线制备了优质的微晶硅薄膜，并利用拉曼光谱、反射谱和透射谱分别研究了微晶硅的晶化率和光学性质.实验中发现微晶硅的吸收边出现了相对红移，此相对红移可归结于薄膜晶化率的提高和带尾态密度的降低. 关键词： 微晶硅 拉曼光谱 快速热处理 红移     

WIMS多群截面库更新时NJOY输入参数研究

以最新的微观评价库CENDL-2.1为基础,用先进的群常数制作程序系统——NJOY来制作新的WIMS69群截面库,研究不同的 NJOY输入参数对 WIMS程序所计算的积分量的影响,并给出了详细的参数研究结果,同时还分析和讨论了计算结果与基准实验结果的比对.WIMS multi group constant library is the associated working library of WIMS/D4 lattice code, and it was created by using rather old and obsolete data based on ENDF/B3 (1972). Recently, the new evaluated data files such as ENDF/B 6.5, JEF 2.2, CENDL 2.1 and JENDL 3.2 were released. It s necessary to update the old library by the new evaluated data. The parameter study is performed to investigate the sensitivity of the integral parameters calculated with WIMS/D4 on the selection...