Anisotropy of Thermal-expansion for β-Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine： Quantum Chemistry Calculation and Molecular Dynamics Simulation

Molecular dynamics simulations on octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine （HMX） at 303-383 K and atmospheric pressure are carried out under NPT ensemble and COMPASS force field, the equilibrium structures at elevated temperatures were obtained and showed that the stacking style of molecules don＇t change. The coefficient of thermal expansion （CTE） values were calculated by linear fitting method. The results show that the CTE values are close to the experimental results and show anisotropy. The total energies of HMX cells with separately increasing expansion rates （100%-105%） along each crystallographic axis was calculated by periodic density functional theory method, the results of the energy change rates are anisotropic, and the correlation equations of energy change-CTE values are established. Thus the hypostasis of the anisotropy of HMX crystal＇s thermal expansion, the determinate molecular packing style, is elucidated.

Similarity theory for the physical simulation of natural gas hydrate reservoir development

In order to apply physical simulation results to natural gas hydrate reservoir parameters to provide a theoretical framework for the design of a development plan,an analytical equation method was used to obtain the similarity criteria of natural gas hydrate reservoir development by physical simulation,based on a mathematical model of natural gas hydrate development.Given the approach of numerical simulation,a sensitivity analysis for all parameters was carried out,which specifically demonstrated that initial temperature is the most important parameter.Parameters of thermal conductivity coefficients are not necessary for conducting the NGH dissociation process,which will fundamentally simplify the design and establishment of the model.The analysis provides a sound theoretical basis and design principles for particular similarity.

Theoretical Investigation on the Absence of Spore Photoproduct Analogue at Cytosine-Thymine Site

As a well known DNA photolesion product, the special UV induced pyrimidine dimmer called spore photoproduct （SP）, has aroused strong research interests. The SP formation was reported solely between two adjacent thymidine residues. It remains unclear in pervious experimental observations why there is an absence of the cytosine-derived SP-like photoprod- uct formation at the cytosine containing DNA strand, although the cytosine residue holds great similarity to thymine in terms of molecular structure. From a theoretical perspec- tive, we have explored this issue in this work by means of density functional theory at the B3LYP/6-311＋＋G（d,p） //B3LYP/6-31G（d,p） level for the DNA dinucleotide fragment, cy- tosine phosphate thymine （CpT）. Key factors blocking the formation of the SP-like product between two adjacent cytosine and thymidine residues are revealed. Instead of undergoing photochemical SP reaction, a photophysical deactivation pathway back to the ground state turns out to be favorable for the CpT dinucleotide fragment.

Methodology Approach Using Harmonic Synthesis as Simulation Method for Investigation of Power Network with Non-Linear Loads

The paper deals with analysis and synthesis of non-harmonic and non-linear sources and appliances, and their interaction with harmonic power supply network. Basic idea is based on knowledge of harmonic spectrum of the sources and/or appliances, respectively. Obviously, one need to know voltage harmonic components of voltage sources （renewable with inverters,...）, and current harmonic components generated by non-linear appliances （rectifiers,...）. Method of investigation lies on decomposition of real electric circuit into n-harmonic separated equivalent schemes for each harmonic component. Then transient analysis will be done for each scheme separately using ＂impedance harmonic matrices＂. The important fact is that each equivalent scheme is now linearized and therefore easily calculated. Finally, the effects of each investigated schemes arc summed into resulting quantities of real non-linear electric circuit.

Simulation methodology development for rotating blade containment analysis

An experimental and numerical investigation on the aeroengine blade/case containment analysis is presented. Blade out containment capability analysis is an essential step in the new aeroengine design, but containment tests are time-consuming and incur significant costs; thus, developing a short-period and low-cost numerical method is warranted. Using explicit nonlinear dynamic finite element analysis software, the present study numerically investigated the high-speed impact process for simulated blade containment tests which were carried out on high-speed spin testing facility. A number of simulations were conducted using finite element models with different mesh sizes and different values of both the contact penalty factor and the friction coefficient. Detailed comparisons between the experimental and numerical results reveal that the mesh size and the friction coefficient have a considerable impact on the results produced. It is shown that a finer mesh will predict lower containment capability of the case, which is closer to the test data. A larger value of the friction coefficient also predicts lower containment capability. However, the contact penalty factor has little effect on the simulation results if it is large enough to avoid false penetration.

Copula-Based Monte Carlo Scenarios Generation Method for STOPF Problem

This paper introduces a Monte Carlo scenario generation method based on copula theory for the stochastic optimal power flow （STOPF） problem with wind power. By using copula theory, the scenarios are simulated from multivariable joint distribution but only from their dependency matrix. Hence, the scenarios generated by proposed method can contain flail statistical information of multivariate. Here, the details of simu- lating scenarios for multi-wind-farm are explained with four steps： determine margin of one wind farm, fit the copulas, choose optimal copulas and simulate scenarios by Mote Carlo. Moreover, the producing process of scenarios is demonstrated by two adjacent actual wind farms in China. With the scenarios, the STOPF is con- verted into the same amount deterministic sub OPF models which can be solved by available technology per- fectly. Results using copula theory are compared against results from history samples based on two designs： IEEE 30-bus and IEEE 118-bus systems. The comparison results prove the accuracy of the proposed methodology.