Sign Response Mechanism of TCA Self-assembled Fluorescence Probe for Cu~(2+) Detection: FRET Evidence by DFT

A new type of self-assembled molecule ON-OFF fluorescence probe for toxic transition metal ions, made up of thiacalix[4]arene, micelle and fluorescence group, has been studied by DFT/TDDFT method combined with experiment spectra. Since the mechanism of the optical quenching signal response of such self-assembled micelle probe has always been a controversial issue of uncertainty, the spatial construction and geometric structures of the functional units of probe in the Cu~(2+) ion detecting process were calculated and the mechanism was investigated by the molecular transition orbital pairs method to explore the origination of ON-OFF fluorescence sign response. The results presented that the signal response mechanism of the micelle probe is ascribed to F?rster resonance energy transfer(FRET) which provides new sights different from most of the conclusions by the related research work reported.     

水溶性苝系衍生物荧光探针识别金属离子的光物理机制计算研究

随着人们对荧光化合物电子光谱和光物理行为的深入研究,在利用荧光分子作为探针,检测各种不同体系的状态及其变化等方面都有了巨大的进展。其中,N,N′-二天冬氨酸铵盐-3,4,9,10-四羧酸二酰亚胺(PTCDA)是一种水体环境中选择性好灵敏度高的典型荧光分子探针。本文用密度泛函理论对PTCDA的光物理机制进行研究。计算了PTCDA分子在理想状态下的最优构型,电荷布居和激发光谱。根据计算结果,拟合此苝系衍生物激发态与Cu2+结合前后的吸收光谱,与Cu2+结合前后,吸收光谱峰形相似,加铜后整体吸收峰位发生了红移,有猝灭变色现象。通过与实验值的对比,计算所得分子构型合理有效,激发光谱谱峰位置切合实际。分析得出：PTCDA分子对二价铜离子有较好荧光探测活性,其光信号响应机制属于分子内电荷转移(ICT)机制。当分子接收二价铜离子时,吸收光谱谱峰位置红移,分子内电荷转移方向和强度均发生变化,既有猝灭信号,也有光的颜色变化信号,是一种具有猝灭与变色双信号的荧光探针材料,具有很大的开发潜力。所做工作只是用量子化学计算方法在分子荧光探针领域进行光物理响应机制分析的初步探索,可以为该领域提供系统而有价值的理论参考。     

铂电阻数字测温的研究

本文堤出一种连续式非线性Ａ／Ｄ转换器。其电路简单，线性比精度较高，用于铂 电阻温度传感器．在－２００℃到 ＋６５０℃的全温度范围内线性化误差为０．０５８％． 按上述原理．采用 ＣＭＯＳ大规模集成电路 Ａ／Ｄ转换器研制的铂电阻数字温度计， 在上述温度范围内．实测精度为０．１２％． 本文论述了电路最佳参数Ｉ．Ｋ的选泽方法．给出采用小型计算帆（ＰＣ－１５００） 求最佳参数 Ｉ．Ｋ的两个实用程序。可根据要求，在任意温度范围内．求出最佳的 Ｉ．Ｋ值和与之对应的误差．本文还提出进一步提高线性比精度的方法．以扩大应用 范围．     

Ir—C60配合物衍生结构三阶非线性光学性质的DFT计算研究

基于密度泛函理论（DFT）,利用高精度量子化学计算方法对配位铱原子的富勒烯衍生物分子Ir（η5C60Me5）（CO）2的非线性光学性质进行了计算研究,结果显示具有较高对称性的Ir（η5C60Me5）（CO）2衍生物分子,具有较高的三阶非线性光学响应．为了揭示Ir—Go的非线性光学响应的起源,研究了Ir（η5GoM60）（C0）2的电子结构性质,并且基于含时密度泛函理论（TDDFT）研究了Ir（η5C60Me5）（C0）2配合物的激发态性质,探讨了富d电子及d空轨道的重过渡金属铱与富“轨道及离域电子的富勒烯相互系统作用对体系三阶非线性光学性质的影响机制．     

新型荧光探针光猝灭的光物理机制含时密度泛函理论计算

3-羟基黄酮(3-HF)是二代新型荧光分子探针的典型代表,用高精度的量子化学计算方法—密度泛函理论对3-羟基黄酮的光物理机制进行研究。计算了3-羟基黄酮分子在理想状态下的最优构型,电荷布居和激发光谱。得到3-羟基黄酮荧光的发射光谱,从而分析出3-羟基黄酮分子内质子转移的光物理循环图,解释其光物理机制。通过与实验值的对比,计算所得分子构型合理有效,激发光谱谱峰位置切合实际。该工作只是用量子化学计算方法在分子荧光探针领域进行光物理响应机制分析的初步探索,可以为该领域提供有价值的理论参考。     

TDDFT Study on the Electronic Excitations and First Hyperpolarizabilities of Mixed-metal Carbonyl Clusters W2Ir2（μ-L）（CO）8（η^5-C5H4Me）2（L = dppe/dppf）

Mixed-metal carbonyl clusters of W2Ir2（CO）10（η^5-C5H4Me）2 1 and W2Ir2（μ-L）（CO）8（η^5-C5H4Me）2 （L = dppe 2, dppf 3） have been studied by TDDFT method focusing on their electronic and nonlinear optical properties. These three clusters exhibit the first static hyperpolarizabilities of medium magnitude （βtot-10×10^-30 esu）. The origin of β is discussed by the new proposed orbital-pair decomposition scheme by Barandes et al. The result suggests that the β values of the two clusters are mainly originated from d-d electron transition within the metal skeleton, and d-p （π＊） electron transition from metals to carbonyls and phenyl. The additional coordination by the electron donor group, ferrocene, makes cluster 3 own much larger β values, and the relatively longer range charge transfer from d orbitals of ferrocene to d orbirals of Ir and W is responsible for the enhanced β values.     

工程地质勘察中水文地质环节的深化研究

为了促进工程地质勘察系统的健全,提高工程建设的质量效率,我们要进行水文地质环节的深化,促进该系统内部相关环节的有效协调,促进其综合效益的提升,以满足实际工作的需要.为此我们要进行水文地质内容的深化,促进其对其性质原理的有效理解深入,促进对其岩石水理性质的深入,以有效避免其岩石工程的相关危害问题.     

Ligand-controlled First Hyperpolarizabilities of a Series of Tetrahedral Iridium Clusters Ir4（CO）9L： a TDDFT Study

A series of tetrahedral iridium carbonyl clusters coordinated by systematically varied series of ligands have been studied by TDDFT method focusing on their electronic and non- linear optical properties. The clusters of Ir4（CO）12 （1）, Ir4（μ-CO）3（CO）9 （2）, Ir4（μ-L）（CO）10 （L = dppm 3, dppe 4, （Ph2P）2CHMe 5, Ph2P（CH2）3PPh2 6） and Ir4（CO）10（phen） （phen = 1,10-phen- anthroline） （7） exhibit the first static hyperpolarizabilities of medium magnitude （βtot-10×10^-30 esu）. The second order nonlinear optical response of the seven clusters increase from 0 to 23 ×10^-30 esu; the high symmetric cluster Ir4（CO）12 debases its symmetry and presents the second order nonlinear optical behavior as the coordination style of some carbonyls changes to bridge style, and then the response increases regularly with the systematical variation of the ligands. The origination of the first hyperpolarizability is discussed by the expanded orbital decomposition scheme. The results suggest the d-d electron transition from the apical iridium atom to the other three Ir atoms inside the metal skeleton, and d-πelectron transitions from metals to carbonyls are responsible for the first hyperpolarizabilities. Particularly, for cluster 7, the charge transfer from d orbitals of iridium to π＊ orbirals of phenanthroline originates the first hyperpolarizabilities.     

安全管理学在实验室安全工作中的应用

运用事故致因理论分析实验室安全事故的原因,即:事故的发生是人的不安全行为和物的不安全状态两大因素综合作用的结果,而人和物的状态都是需要管理的。因此将安全管理学理论与实验室安全管理实际相结合,提出高校和科研院所实验室安全管理对策,如转变安全管理观念、建立安全激励机制和完善规章制度、形成多级安全培训体系、加强安全文化建设和加大安全科研投入等,方可实现真正"以人为本"的实验室安全管理。