New European Union＇s Requirements and IFRS Practice Statement ＂Management Commentary＂： Does MD＆A Disclosure Quality Affect Analysts＇ Forecasts？

The Management Discussion and Analysis （MD＆A） is a mandatory document under the European Union＇s （EU） law. In 2003, the EU issued Directive 2003/51/EC, which broadened the information that firms have to provide in their MD＆A, and in 2010 the International Accounting Standards Board （IASB） issued the International Financial Reporting Standards （IFRS） Practice Statement ＂Management Commentary＂, a non-binding guidance for the presentation of this document. The aim of this paper is to examine the relationship between MD＆A disclosure quality and properties of analysts＇ forecasts. In fact, although most studies found that financial analysts mainly refer to financial statement data in forecasting earnings, there are few researches highlighting the importance of MD＆A disclosures for financial analysts. On this basis, Ramnath, Rock, and Shane （2008） called for researches in order to better understand the relationship between the information really used by analysts and their forecasts. To assess the quality of MD＆A disclosures, we developed a multidimensional measure on the basis of the EU requirements and the IFRS Practice Statement, and then we regressed this variable on both forecast accuracy and dispersion. The findings show that our measure of MD＆A disclosure quality is significantly and positively related to forecast accuracy. We conducted other analyses in order to better understand the previous relationship and we found that, if we analyze the different information contained in the MD＆A statement, financial analysts consider useful accounting and financial data in forecasting earnings. These results enhance our understanding of the role of MD＆A disclosures in the wide set of information that firms provide to financial statement users.

The Effect of Interatomic Potentials on the Molecular Dynamics Simulation of Nanometric Machining

One of the major tasks in a molecular dynamics （MD） simulation is the selection of adequate potential functions, from which forces are derived. If the potentials do not model the behaviour of the atoms correctly, the results produced from the simulation would be useless. Three popular potentials, namely, Lennard-Jones （L J）, Morse, and embedded-atom method （EAM） potentials, were employed to model copper workpiece and diamond tool in nanometric machining. From the simulation results and further analysis, the EAM potential was found to be the most suitable of the three potentials. This is because it best describes the metallic bonding of the copper atoms; it demonstrated the lowest cutting force variation, and the potential energy is most stable for the EAM.

Sea surface height variations in the Mindanao Dome region in response to the northern tropical Pacific winds

Sea surface height (SSH) variability in the Mindanao Dome (MD) region is found to be one of the strong variations in the northern Pacific. It is only weaker than that in the Kuroshio Extension area, and is comparable to that in the North Pacific Subtropical Countercurrent region. Based on a 1.5-layer reduced gravity model, we analyzed SSH variations in this region and their responses to northern tropical Pacific winds. The average SSH anomaly in the region varies mainly on a seasonal scale, with significant periods of 0.5 and 1 year, ENSO time scale2-7years, and time scale in excess of 8 years. Annual and long-term variabilities are comparably stronger. These variations are essentially a response to the northern tropical Pacific winds. On seasonal and ENSO time scales, they are mainly caused by wind anomalies east of the region, which generate westward-propagating, long Rossby waves. On time scales longer than 8 years, they are mostly induced by local Ekman pumping. Long-term SSH variations in the MD region and their responses to local winds are examined and discussed for the first time .

Advances in studies of the tribological behavior of molecular deposition films

An overview of the advances in studies on tribology of molecular deposition （MD） films is presented here to summarize the studies of nanofrictional properties, adhesion, wear and mechanical behavior, as well as the molecular dynamics simulation of nanotribological properties of the film in the last decade. Some key research topics which need to be investigate further are addressed.

Role of Residue 90 in Catalysis of Cytochrome P450 2C9

The cytochrome P450 mutant CYP2C9.13（L90P） shows a greatly impaired catalytic activity compared with the wild-type. We constructed the mutants by substitution at residue 90 of CYP2C9, expressed in COS-7 cells, assayed their thermal stability and catalysis activity and analyzed the mutants via molecular dynamic（MD） simulation and flexible docking. Mutant L90E exhibits a significantly lower catalytic activity than the wild-type for the hydroxylation of diclofenac, lornoxicam and luciferin and its molecular dynamics simulation results indicate that the size of the entrance of substrate access was reduced significantly. An increase or minor decrease of catalytic activity was observed for mutants L90Q, L90W, L90R, L90I and L90G, and the sizes of the entrances of substrate access and the active site cavities had a little change in those mutants. The thermal stability and the potential energy of the MD simulation of these mutants showed a similar tendency as the catalysis assays did. Flexible docking results show the fluctuation of interaction energy is due to the change of electrostatic potential distribution. All the above facts show that the changes in the catalysis activity of the mutants caused by the substitution at residue 90 are due to the changes in the size of entrance, the shape and size of active site cavity, electrostatic potential distribution and thermal stability. The residue 90 of CYP2C9 has an important effect on the enzyme catalytic activity.

Studies on the Structures and Hydrogen-bonding Interactions in Aqueous Glycine Solutions Using All-atom Molecular Dynamics Simulations and NMR Spectroscopy

All-atom molecular dynamics （MD） simulations and chemical shifts were used to study interactions and structures in the glycine-water system. Radial distribution functions and the hydrogen-bond network were applied in MD simulations. Aggregates in the aqueous glycine solution could be classified into different regions by analysis of the hydrogen-bonding network. Temperature-dependent NMR spectra and the viscosity of glycine in aqueous solutions were measured to compare with the results of MD simulations. The variation tendencies of the hydrogen atom chemical shifts and viscosity with concentration of glycine agree with the statistical results of hydrogen bonds in the MD simulations.

Wetting and coalescence of the liquid metal on the metal substrate

Molecular dynamics （MD） simulations are performed to investigate the wettability of liquid metal on the metal sub- strate. Results show that there exists different wettability on the different metal substrates, which is mainly determined by the interaction between the liquid and the substrate. The liquid metal is more likely to wet the same kind of metal substrate, which attracts the liquid metal to one side on the hybrid substrate. Exchanging the liquid metal and substrate metal has no effect on the wettability between these two metals. Moreover, the study of metal drop coalescing indicates that the metal substrate can significantly affect the coalescence behavior, in which the changeable wettability of liquid metal plays a predominant role. These studies demonstrate that the wetting behavior of liquid metal can be controlled by choosing the suitable metal substrate.

A note on hydrodynamics from dissipative particle dynamics

We calculate current correlation functions （CCFs） of dissipative particle dy- namics （DPD） and compare them with results of molecular dynamics （MD） and solutions of linearized hydrodynamic equations. In particular, we consider three versions of DPD, the empirical/classical DPD, coarse-grained （CG） DPD with radial-direction interactions only and full （radial, transversal, and rotational） interactions between particles. To fa- cilitate quantitative discussions, we consider specifically a star-polymer melt system at a moderate density. For bonded molecules, it is straightforward to define the CG variables and to further derive CG force fields for DPD within the framework of the Mori-Zwanzig formalism. For both transversal and longitudinal current correlation functions （TCCFs and LCCFs）, we observe that results of MD, DPD, and hydrodynamic solutions agree with each other at the continuum limit. Below the continuum limit to certain length scales, results of MD deviate significantly from hydrodynamic solutions, whereas results of both empirical and CG DPD resemble those of MD. This indicates that the DPD method with Markovian force laws possibly has a larger applicability than the continuum description of a Newtonian fluid. This is worth being explored further to represent gen- eralized hydrodynamics.

The effect of dislocations on the thermodynamic properties of Ta single crystal under high pressure by molecular dynamics simulation

The thermodynamic properties of Ta metal under high pressure are studied by molecular dynamics simulation. For dislocation-free Ta crystal, all the thermodynamic properties considered are in good agreement with the results from exper- iments or higher level calculations. If dislocations are included in the Ta crystal, it is found that as the dislocation density increases, the hydrostatic pressure at the phase transition point of bcc-＋hcp and hcp--＋fcc decreases, while the Hugoniot temperature increases. Meanwhile, the impact pressure at the elastic-plastic transition point is found to depend on the crys- tallographic orientation of the pressure. As the dislocation density increases, the pressure of the elastic-plastic transition point decreases rapidly at the initial stage, then gradually decreases with the increase of the dislocation density.

Theoretical studies and molecular dynamics simulations on ion transport properties in nanochannels and nanopores

Control of ion transport and fluid flow through nanofluidic devices is of primary importance for energy storage and conversion, drug delivery and a wide range of biological processes. Recent development of nanotechnology, synthesis techniques, purification technologies, and experiment have led to rapid advances in simulation and modeling studies on ion transport properties. In this review, the applications of Poisson-Nernst-Plank （PNP） equations in analyzing transport properties are presented. The molecular dynamics （MD） studies of transport properties of ion and fluidic flow through nanofluidic devices are reported as well.

Molecular Docking of 3-Methylindole-containing Drugs Binding into CYP3A4

Drugs SPD-304（6,7-dimethyl-3-{[methyl-（2-{methyl-[1-（3-trifluoromethyl-phenyl）-1H-indol-3-ylme thyl]-amino}-ethyl）-amino]-methyl}-chromen-4-one） and zafirlukast contain a common structural element of 3-substituted indole moiety which closely relates to a dehydrogenated reaction catalyzed by cytochrome P450s（CYPs）. It was reported that the dehydrogenation can produce a reactive electrophilic intermediate which cause toxicities and inactivate CYPs. Drug L-745,870（3-{[4-（4-chlorophenyl）piperazin-1-yl]-methyl}-1H-pyrrolo 2,3-β-pyridine） might have similar effect since it contains the same structural element. We used molecular docking approach combined with molecular dynamics（MD） simulation to model three-dimensional（3D） complex structures of SPD-304, zafirlukast and L-745,870 into CYP3A4, respectively. The results show that these three drugs can stably bind into the active site and the 3-methylene carbons of the drugs keep a reasonable reactive distance from the heme iron. The complex structure of SPD-304-CYP3A4 is in agreement with experimental data. For zafirlukast, the calcu lation results indicate that 3-methylene carbon might be the dehydrogenation reaction site. Docking model of L-745,870-CYP3A4 shows a potential possibility of L-745,870 dehydrogenated by CYP3A4 at 3-methylene carbon which is in agreement with experiment in vivo. In addition, residues in the phenylalanine cluster as well as S119 and R212 play a critical role in the ligands binding based on our calculations. The docking models could provide some clues to understand the metabolic mechanism of the drugs by CYP3A4.

Recommendation for and comparison of three types of dementia： Alzheimer’s disease, subcortical ischemic vascular dementia, and mixed dementia

With the progress in global demography of aging, dementia has become a great world health-care issue that require urgent attention and settlement. Demen-tia can arise from a variety of factors, such as neuronal degeneration for Alzheimer’s disease （AD）, vascular risk factors and multiple infarcts for vascular dementia （VaD）, and both degeneration and vascular factors for mixed de-mentia （MD）. Pathophysiology of AD includes the amy-loid and tau protein hypothesis, and infammation-related mechanisms are also widespread mentioned. Subcortical ischemic vascular dementia （SIVD）, a subtype of VaD, is commonly caused by complete or incomplete lacunar infarction of VaD pathology. MD involves both degenera-tion and vascular factors, and the interaction between the two results in the complication of the pathological mech-anism and clinical phenotype. The clinical manifestationsof AD are often divided into four stages according to the progress of the disease, while the phenotypes of SIVD usually has two categories. As for MD, the phenotypes are complex and diverse. Several clinical studies showedthat its symptoms and signs are more similar to SIVD than AD. This article aims to analyze and compare the differ-ent aspects of the three kinds of dementia.

电场环境下纳米通道内水分子传输行为的MD模拟研究

纳米通道内的水分子传输是近年来分子动力学(MD)模拟研究的热点之一。本文综述了电场对纳米通道中水分子传输行为影响的研究成果,主要介绍了三种施加电场的方法:在通道附近加电荷、在通道两侧的水相中加离子或带电荷的氨基酸以及对纳米通道直接施加电场。并报道了各类电场对纳米通道内水的填充平衡及相变行为、水分子偶极取向、水流量、水扩散速率等产生的影响,以及加电场的各种相关应用,如水流开关、信号传输、水泵及存储器等。最后,剖析了电场环境下MD模拟研究中尚待解决的问题。

How Mutations Affecting the Ligand-receptor Interactions： a Combined MD and QM/MM Calculation on CYP2E1 and Its Two Mutants

Cytochrome P450（CYP） 2El is a dual function monoxygenase with a crucial role in the metabolism of 6% of drugs on the market at present. The enzyme is of tremendous interest for its association with alcohol consumption, diabetes, obesity and fasting. Despite the abundant experimental mutagenesis data, the molecular origin and the structural motifs for the enzymatic activity deficiencies have not been rationalized at the atomic level. In this regard, we have investigated the effects of mutation on the structural and energetic characteristics upon single point mutations in CYP2E1, N219D and $366C. The molecular dynamics（MD） simulation combined with quantum mechanics/molecular mechanics（QM/MM） and noncovalent interaction（NCI） analysis was carried out on CYP2EI and its two mutants. The results highlight the critical role of Phe207, which is responsible for both structural flexibility and energetic variation, shortening the gap between the theory and the experimentally observed results of enzymatic activity decrease, The underlying molecular mechanism of the enzymatic activity deficiencies for mutants may be attributed to the changes of spatial position of Phe207 in the two mutants. This work provides particular explanations to how mutations affect ligand-receptor interactions based on combined MD and QM/MM calculations. Furthermore, the mutational effects on the activity of CYP2E1 obtained in the present study are beneficial to both the experimental and the computational works of CYPs and may allow researchers to achieve desirable changes in enzymatic activity.

Molecular dynamics study on the relationships of modeling,structural and energy properties with sensitivity for RDX-based PBXs

In this paper,a primary model is established for MD(molecular dynamics) simulation for the PBXs(polymer-bonded explosives) with RDX(cyclotrimethylene trinitramine) as base explosive and PS as polymer binder.A series of results from the MD simulation are compared between two PBX models,which are represented by PBX1 and PBX2,respectively,including one PS molecular chain having 46 repeating units and two PS molecular chains with each having 23 repeating units.It has been found that their structural,interaction energy and mechanical properties are basically consistent between the two models.A systematic MD study for the PBX2 is performed under NPT conditions at five different temperatures,i.e.,195 K,245 K,295 K,345 K,and 395 K.We have found that with the temperature increase,the maximum bond length(L max) of RDX N N trigger bond increases,and the interaction energy(E N-N) between two N atoms of the N-N trigger bond and the cohesive energy density(CED) decrease.These phenomena agree with the experimental fact that the PBX becomes more sensitive as the temperature increases.Therefore,we propose to use the maximum bond length L max of the trigger bond of the easily decomposed and exploded component and the interaction energy E N-N of the two relevant atoms as theoretical criteria to judge or predict the relative degree of heat and impact sensitivity for the energetic composites such as PBXs and solid propellants.

Theoretical and experimental study of the thermal conductivity of nanoporous media

The nanoparticle thermal conductivity and nanoscale thermal contact resistance were investigated by molecular dynamics(MD) simulations to further understand nanoscale porous media thermal conductivity.Macroscale porous media thermal conductivity models were then revised for nanoporous media.The effective thermal conductivities of two packed beds with nanoscale nickel particles and a packed bed with microscale nickel particles were then measured using the Hot Disk.The measured results show that the nano/microscale porous media thermal conductivities were much less than the thermal conductivities of the solid particles.Comparison of the measured and calculated results shows that the revised combined parallel-series model and the revised Hsu-Cheng model can accurately predict the effective thermal conductivities of micro-and nanoparticle packed beds.

Analysis on Dissociation of Pyramidal I Dislocation in Magnesium by Generalized-Stacking-Fault Energy

The generalized-stacking-fault energies are calculated to illustrate the dissociation of〈c＋a〉dislocation on pyramidal I plane in magnesium.The c surfaces of {1011} plane and its adjacent planes {3034} and {3032} are presented using Liu embedded-atom-method potential method,and one possible dissociation path of 1/3{1123} dislocation on {1011} plane with minimum energy is predicted.Meanwhile,another two reasonable dissociation paths of 1/3{1123} dislocation successively on {3034} and {3032} planes are also proposed.Moreover,based on molecular dynamics simulations of magnesium single crystals under c-axis compression,the possible slip path is further examined and discussed.

Molecular Dynamics Simulation for the Impact of External Electric Fields on CaCl2 Aqueous Solution

Non-equilibrium molecular dynamics（MD） simulations were performed according to the electronic anti-fouling technology, and some structural parameters and dynamic parameters of CaCl2 aqueous solution were taken as indicators to compare the different effect on the anti-fouling performance by applying different electric fields. The results show that electric fields can effectively decrease the viscosity of CaCl2 aqueous solution and enhance the ionic activity by enlarging the self-diffusion coefficient. In addition, with the same electric field strength, the electrostatic field is more effective at decreasing the viscosity of CaCI2 aqueous solution and increasing the self-diffusion coefficient of water molecules, while the alternating electric field is more effective at increasing the self-diffusion coefficient of Ca2＋. Furthermore, an alternating electric field with different frequencies was applied; the results show that an 800 kHz frequency is most effective to decrease the viscosity, and a 700 kHz frequency is most effective to en- hance the self-diffusion coefficient of water molecule. Otherwise, 400 kHz is most effective to enhance the self-diffusion coefficient of Ca2＋. Additionally, by studying the change of structure parameters, it was concluded that an external electric field can enhance the hydration between Ca2＋ and coordinated water molecules, and the alternating electric field is more effective in this respect.

Optimized multi-dimensional optical storage reading strategy

A novel multi-dimensional （MD） optical storage was presented, which was realized by utilizing the space between tracks. Based on scalar diffraction theory, the channel bits parameters of the multi-dimensional optical storage were optimized, and the linear and nonlinear signals were analyzed accurately. Therefore, the format of the multi-dimensional optical disc was obtained, which makes the detection of readout signal easier. With respect to servo, coding and readout physics parameter of channel, the multi-dimensional optical disc is compatible with traditional disc such as Blu-ray disc （BD）. Also, the novel multi-dimensional optical storage is able to achieve a doubled density and a ten-fold readout data rate compared with traditional optical discs.

Fault Diagnosis of Rolling Element Bearing Using Multi-Scale Lempel-Ziv Complexity and Mahalanobis Distance Criterion

A new fault diagnosis technique for rolling element bearing using multi-scale Lempel-Ziv complexity(LZC) and Mahalanobis distance(MD) criterion is proposed in this study. A multi-scale coarse-graining process is used to extract fault features for various bearing fault conditions to overcome the limitation of the single stage coarse-graining process in the LZC algorithm. This is followed by the application of MD criterion to calculate the accuracy rate of LZC at different scales, and the best scale corresponding to the maximum accuracy rate is identified for fault pattern recognition. A comparison analysis with Euclidean distance(ED) criterion is also presented to verify the superiority of the proposed method. The result confirms that the fault diagnosis technique using a multi-scale LZC and MD criterion is more effective in distinguishing various fault conditions of rolling element bearings.