狭义相对论效应──运动时钟变慢的计算机模拟演示实验

利用精炼的C语言进行程序设计，定量模拟狭义相结论的运动时钟变慢，并对处于两种不同时空观的时钟运行进行对比，使得时间膨胀效应变得直观。     

Why is the partial molar volume of CO2 so small when dissolved in a room temperature ionic liquid? Structure and dynamics of CO2 dissolved in [Bmim+] [PF6(-)

When supercritical CO2 is dissolved in an ionic liquid, its partial molar volume is much smaller than that observed in most other solvents. In this article we explore in atomistic detail and explain in an intuitive way the peculiar volumetric behavior experimentally observed when supercritical CO2 is dissolved in 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim+] [PF6(-)]). We also provide physical insight into the structure and dynamics occurring across the boundary of the CO2 ionic liquid interface. We find that the liquid structure of [Bmim+] [PF6(-)] in the presence of CO2 is nearly identical to that in the neat ionic liquid (IL) even at fairly large mole fractions of CO2. Our simulations indicate, in agreement with experiments, that partial miscibilities of one fluid into the other are very unsymmetrical, CO2 being highly soluble in the ionic liquid phase while the ionic liquid is highly insoluble in the CO2 phase. We interpret our results in terms of the size and shape of spontaneously forming cavities in the ionic liquid phase, and we propose that CO2 occupies extremely well-defined locations in the IL. Even though our accurate prediction of cavity sizes in the neat IL indicates that these cavities are small compared with the van der Waals radius of a single carbon or oxygen atom, CO2 appears to occupy a space that was for the most part a priori "empty".     

活性炭纤维对氙的动态吸附性能研究

采用动态吸附实验装置，研究了吸附温度、原料气浓度和原料气流量对活性炭纤维动态吸附氙性能的影响。结果表明：在低温条件下（≤273K)，随着温度的升高，活性炭纤维对氙的平衡吸附量明显下降／同时，活性炭纤维对氙的平衡吸附量分别随着原料气浓度及原料气流量的增大而增大。     

铑配合物的抗肿瘤活性及其作用机制研究

自从Rosenberg等人发现顺铂具有抗肿瘤活性以来，金属配合物的抗肿瘤活性引起了人们的广泛关注。本文综述了近年来铑配合物抗肿瘤活性的研究进展，并对铑配合物的抗肿瘤机制和构效关系进行了探讨，为进一步寻找高效低毒和抗肿瘤谱广的新药物揭示了可循的途径。     

Construction of diverse peptide structural architectures via chemoselective peptide ligation

Herein, we report the development of a facile synthetic strategy for constructing diverse peptide structural architectures via chemoselective peptide ligation. The key advancement involved is to utilize the benzofuran moiety as the peptide salicylaldehyde ester surrogate, and Dap–Ser/Lys–Ser dipeptide as the hydroxyl amino functionality, which could be successfully introduced at the side chain of peptides enabling peptide ligation. With this method, the side chain-to-side chain cyclic peptide, branched/bridged peptides, tailed cyclic peptides and multi-cyclic peptides have been designed and successfully synthesized with native peptidic linkages at the ligation sites. This strategy has provided an alternative strategic opportunity for synthetic peptide development. It also serves as an inspiration for the structural design of PPI inhibitors with new modalities.

Methods of introducing peptide salicylaldehyde esters and hydroxyl amine functionality into the peptide side chain have been developed. Diverse peptide structural motifs were constructed via ligation with native amide linkages at the ligation sites.     

Drying and hydrophobic collapse of paraffin plates

We perform molecular dynamics simulations of the hydrophobic collapse of two paraffin plates to examine how the collapse is mediated by realistic paraffin-water attractive van der Waals forces. We explore several aspects of the drying transition between the plates, including the critical separation for drying and the critical size of the vapor bubble required for the nucleation of the drying event. We also investigate the kinetics of hydrophobic collapse and find that the hydrophobic collapse occurs in about 100 ps. We compare these results with the simulations with the plate-water van der Waals attractions turned off and with recent results on the hydrophobic collapse of multidomain proteins. Last, we discuss the relationship among the dewetting transition critical distance, van der Waals potential well depth, and water contact angle on solute surface using a simple macroscopic theory.     

A fast parallel clustering algorithm for molecular simulation trajectories

We implemented a GPU‐powered parallel k‐centers algorithm to perform clustering on the conformations of molecular dynamics (MD) simulations. The algorithm is up to two orders of magnitude faster than the CPU implementation. We tested our algorithm on four protein MD simulation datasets ranging from the small Alanine Dipeptide to a 370‐residue Maltose Binding Protein (MBP). It is capable of grouping 250,000 conformations of the MBP into 4000 clusters within 40 seconds. To achieve this, we effectively parallelized the code on the GPU and utilize the triangle inequality of metric spaces. Furthermore, the algorithm's running time is linear with respect to the number of cluster centers. In addition, we found the triangle inequality to be less effective in higher dimensions and provide a mathematical rationale. Finally, using Alanine Dipeptide as an example, we show a strong correlation between cluster populations resulting from the k‐centers algorithm and the underlying density. © 2012 Wiley Periodicals, Inc.     

Plutonium-239 sorption and transport on/in unsaturated sediments: comparison of batch and column experiments for determining sorption coefficients

Sorption (distribution) coefficients of plutonium were most often derived by static batch experiments. However, it is not clear how unsaturated flow conditions including moisture content and pore water velocity change the sorption coefficients. Transport experiments of plutonium through the unsaturated sediments packed into the columns were then performed in order to determine the sorption coefficients (column-K _ds). Static batch experiments were also conducted to obtain batch-K _ds and then compare the differences between batch-K _ds and column-K _ds. The results show that unsaturated flow conditions had no significant effect on column-K _ds, and the average column-K _d value was 1.74 ± 0.02 m³/kg. By comparison, batch-K _d values spanned several orders of magnitude, regardless of the specified liquid–solid conditions. Moreover, the batch-K _d (22.7 m³/kg) at the standard L/S (4 mL/g) recommended by ASTM D 4319 was over an order of magnitude larger than the average column-K _d.     

Adatom Defect Induced Spin Polarization of Asymmetric Structures

The spin polarization of carbon nanomaterials is crucial to design spintronic devices. In this paper, the first-principles is used to study the electronic properties of two defect asymmetric structures, Cap-(9, 0)-Def [6, 6] and Cap-(9, 0)-Def [5, 6]. We found that the ground state of Cap-(9, 0)-Def [6, 6] is sextet and the ground state of Cap-(9, 0)-Def [5, 6] is quartet, and the former has a lower energy. In addition, compared with Cap-(9, 0) CNTs, the C adatom on C₃₀ causes spin polarization phenomenon and Cap-(9, 0)-Def [6, 6] has more spin electrons than Cap-(9, 0)-Def [5, 6] structure. Moreover, different adsorb defects reveal different electron accumulation. This finding shows that spin polarization of the asymmetric structure can be adjusted by introducing adatom defects.