Three-dimensional quantum dynamics study of vibrational predissociation of HeI2 van der Waals molecule for low vibrational excitation using the time-dependent wave packet method

Three-dimensional quantum mechanical calculations for vibrational predissociation of He1₂(B) van der Waals molecules are presented using the time-dependent wave packet technique within the golden rule approximation. The total and partial decay widths, lifetimes, rates and their dependence on initial vibrational states were obtained for HeI₂ at low initial vibrational excited levels. Our calculations show that the calculated total decay widths, lifetimes and rates agree well with those extrapolated from experimental data available. The predicted total decay widths as a function of initial vibrational states exhibit highly nonlinear behavior. The very short propagation time (less than 1 ps) required in the golden rule wave packet calculation is determined by the duration time of the final state interaction between the fragments on the vibrationally deexcited adiabatic potential surface. The final state interaction between the fragments is shown to play an important role in determining the final rotational distribution. This interpretation clearly explains the dynamical effect that the final rotational distribution shifts to the lower rotational energy levels as the initial vibrational quantum numberu increases.     

Four New Lanostane Triterpenoids from Euphorbia humifusa

Four new lanostane triterpenoids, namely (3β)‐3‐hydroxy‐24‐methylenelanost‐8‐ene‐7,11‐dione ( 1 ), (3β)‐3‐hydroxylanosta‐8,24‐diene‐7,11‐dione ( 2 ), (3β,7α)‐3,7‐dihydroxylanosta‐8,24‐dien‐11‐one ( 3 ), and (3β,11β)‐3,11‐dihydroxylanosta‐8,24‐dien‐7‐one ( 4 ) were isolated from Euphorbia humifusa, together with 2 known compounds. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with the related known compounds.     

In vivo therapeutic response monitoring by a self-reporting upconverting covalent organic framework nanoplatform

The real-time and in situ monitoring of reactive oxygen species (ROS) generation is critical for minimizing the nonspecific damage derived from the high doses of ROS required during the photodynamic therapy (PDT) process. However, phototherapeutic agents that can generate ROS-related imaging signals during PDT are rare, hampering the facile prediction of the future therapeutic outcome. Herein, we develop an upconverting covalent organic framework (COF) nanoplatform via a core-mediated strategy and further functionalized it with a singlet oxygen reporter for the efficient near-infrared activated and in situ self-reporting of PDT. In this work, the COF photodynamic efficacy is greatly improved (12.5 times that of irregular COFs) via tailoring the size. Furthermore, this nanoplatform is able to not only produce singlet oxygen for PDT, but it can also emit singlet oxygen-correlated luminescence, allowing the real-time and in situ monitoring of the therapeutic process for cancer cells or solid tumors in vivo via near-infrared luminescence imaging. Thus, our core-mediated synthetic and size-tailored strategy endows the upconverting COF nanoplatform with promising abilities for high-efficacy, deep-tissue, precise photodynamic treatment.

An upconverting covalent organic framework nanoplatform is designed for the first time for the near-infrared activated in situ self-reporting of photodynamic therapy in vivo.     

负载Fe3（CO）12催化剂的制备及合成氨的催化活性

以Ｆｅ_３（ＣＯ）_（１２）为母体，以活性氧化铝或活性炭为载体制备了负载型氨合成催化剂．在固定床管式流动反应系统中测定了催化活性，并与以Ｒｕ_３（ＣＯ）_（１２）和ＲｕＣｌ_３·ｘＨ_２Ｏ为母体的负载催化剂以及低温高活性氨合成工业催化剂的活性进行了对比。结果表明：以活性炭为载体的Ｆｅ_３（ＣＯ）_（１２）催化剂在１５ＭＰａ、４００℃以上表现出很高活性，且每克纯活性组分的催化活性在某些温度下比当前活性较高的工业熔铁催化剂的活性要高得多，但低温常压下几乎无活性。负载钉催化剂在低温常压下即显活性，且以ＲｕＣｌ_３·ｘＨ_２Ｏ为母体，比以Ｒｕ_３（ＣＯ）_（１２）为母体的负载钌催化剂活性高。     

Highly luminescence manganese doped carbon dots

Heteroatom doped carbon dots(CDs) with distinct merits are of great attractions in various fields such as solar cells, catalysis, trace element detection and photothermal therapy. In this work, we successfully synthesized blue-fluorescence and photostability manganese-doped carbon dots(Mn-CDs) with a quantum yield up to 7.5%, which was prepared by a facile one-step hydrothermal method with sodium citrate and manganese chloride. The Mn-CDs is the high mono-dispersity, uniform spherical nanoparticles. The Mn element plays a critical role in achieving a high quantum yield in synthesis of carbon dots, which was confirmed by the structure analysis using XPS and FTIR. Spectroscopic investigations proved that the decent PLQY and luminescence properties of Mn-CDs are due to the heteroatom doped, oxidized carbon-based surface passivation. In addition, the Mn-CDs are demonstrated as promising fluorescent sensors for iron ions with a linear range of 0–500 mmol/L and a detection limit of2.1 nmol/L(turn-off), indicating their great potential as a fluorescent probe for chemical sensing.     

不同结晶速率的PET薄膜在拉伸过程中的结晶与取向

用多种方法对两个结晶速率不同的PET样品在拉伸过程中的结晶和取向进行了研究。结果表明在同样的拉伸条件下,结晶速率较快的样品的结晶度和取向程度均比另一样品要高得多,这种结构变化上的差别说明把拉伸行为的差别归因于结晶速率的不同是合理的。     

阴离子在构筑吡啶酰胺－铜(II)配位超分子体系中的作用

Three complexes Cu（ppca）2（H2O）2（NO3）2 （1）, Cu2（μ-OH）2（ppca）2（H2O）4）·（ClO4）2 （2） and Cu2（μ-CH3COO）4（ppca）2（3） have been synthesized by the reaction of copper（Ⅱ） salts with N-phenyl-4-pyridinecarboxamide （ppca） and characterized. For anions, in complex 1, NO3^- coordinated with copper（Ⅱ）, in complex 2 perchlorate anion did not take part in coordination, the copper（Ⅱ） cations were connected by μ-OH to form a dinuclear unit, and complex 3 had a dimeric copper（Ⅱ） carboxylate paddle-wheel core. Noncovalent interactions linked these complexes to form supramolecular networks. Different coordinating modes of anions controlled modes of intennolecular interactions, which resulted in different final structures.     

INDO STUDIES ON THE ELECTRONIC STRUCTURE OF[Ln(CCl_3COO)_3·phen·C_2H_5OH]_2(Ln=Pr,Sm)

The electronic structure and chemical bonding of the title comp-lexes have been studied by an unrestricted INDO program made applicable forthe lanthanoid compounds.The results indicated:(1)In coordinated bonds O-Lnand N-Ln,5d orbitals of Ln have large contribution in all valence orbitalsof Ln and 4f orbitals have very small contribution.(2)The covalent chara-cter and ionic character are almost equal in the chemical bond which iscomparatively weak between phen,C_2H_5OH and Ln are mainly ionic with somecovalent character.     

Control of polymer topology by chain-walking catalysts

Chain-walking catalysts are demonstrated to control the branching topology of polyethylene by tuning the competition between monomer insertion and chain isomerization (walking). The topology of the polyethylene was controlled from linear with moderate branching to hyperbranched to dendritic. Although overall branching number and distribution of short chain branching are relatively constant, the topology of the polyethylene changes from linear polyethylene with moderate branches at high ethylene pressures to a dendritic polyethylene at low pressures. This provides a straightforward one-pot process for making polymers with a full range of tunable topologies.     

单级高压微流量电渗泵的研究

设计了一种高压微流量电渗泵。泵体主要由高压电源、电渗柱、毛细通道、导电空心电极以及气泡去除器、压力传感器等构成。单级电渗泵可以给出0～20MPa范围的输出压力和nL～μL级输出流量。输出压强和输出流量取决于电压、填充柱阻力和流体性质。