集束战斗部子弹药抛撒半径及母弹解爆高度确定方法

介绍了集束战斗部性能指标要求的论证方法 .分析了影响战斗部攻击效能的因素 .给出了集束战斗部子弹药抛撒半径及母弹解爆高度的确定方法 .

静态爆破在拉西瓦水电站孤石解爆中的应用

静态爆破具有无声、无振、无飞石、无毒气、无冲击波、无有毒有害残留物、无公害等特点。因此,在拉西瓦水电站孤石解爆中采用静态爆破的方式。通过施工现场生产性实验,确定了影响静态爆破施工效果的关键参数,避免了因飞石造成的人员伤害及施工间的相互干扰,加快了施工进度,保障了施工安全。

非线性热方程解的爆破定理

本文研究了非线性热方程具第二类边界条件的混合问题解的爆破,得到了几类非线性热方程解爆破的充分条件,推广和补充了文[1～5]的结果。

杀爆弹毁伤中心偏移问题分析

通过合理假设,在解爆坐标系下建立了杀爆弹解爆后抛出的球形杀伤元素——钢珠的运动参数计算模型,解算杀伤元素弹道获得落点坐标和毁伤中心坐标,绘制落点散布图,发现杀伤元素毁伤中心与目标瞄准点有明显偏移。通过绘制杀伤元素毁伤中心与目标瞄准点随杀爆弹解爆弹道倾角和爆高的变化图,分析得出弹道倾角和解爆高度对毁伤中心偏移量影响的一般规律,为进一步提高武器命中精度和毁伤效能奠定了良好的研究基础。

Blow-up of Solution for a Nonlinear Hyperbolic Equation

In this paper, the existence and uniqueness of the local generalized solution of the initial boundary value problem for a nonlinear hyperbolic equation are proved by the contraction mapping principle and the sufficient conditions of blow_up of the solution in finite time are given.

Blow-Up Rate for a Semilinear Parabolic System

This paper deals with the blow-up rate of positive solution for a semilinearparabolic system coupled in the equations and boundary condition. The upper and lower bounds ofblow-up rates are obtained.

Mitigation of blast loadings on structures by an anti-blast plastic water wall

Seven in-situ tests were carried out in far field to study the blast mitigation effect of a kind of water filled plastic wall. Test results show that the mitigation effect of water filled plastic wall is remarkable. The maximum reduction of peak reflected overpressure reaches up to 94.53%, as well as 36.3% of the minimum peak reflected overpressure reduction in the scaled distance ranging from 1.71 m/kg1/3 to 3.42 m/kg1/3. Parametric studies were also carried out. The effects of the scaled gauge height, water/charge scaled distance(the distance between the explosive charge and the water wall), water wall scaled height and water/structure scaled distance(the distance between the water wall and the structure) were systematically investigated and compared with the usual rigid anti-blast wall. It is concluded that these parameters affect the mitigation effects of plastic water wall on blast loadings significantly, which is basically consistent to the trend of usual rigid anti-blast wall. Some formulae are also derived based on the numerical and test results, providing a simple but reliable prediction model to evaluate the peak overpressure of mitigated blast loadings on the structures.

Introduction to Enhanced Protective Film Systems

An explosive blast mitigation alternative has increased the safety of structures by using " catcher" systems. These systems " catch" or repel the failure of the window or in-fill wall pro-tecting life and property from ballistic shards or fragments. They can be designed to be stand-alone in new construction and structural retrofits or used to augment structural hardening tech-niques. Cables, fabrics, and thin gauge sheet steel are examples of catcher systems used in the past. A new and evolving category of catcher systems are based on polymeric materials that can be used for both wall and window upgrades. These products are a proven blast mitigation concept and K&C Protective Technologies Pte Ltd (KCPT) together with Sherwin-Williams(SW) use KCPT′s blast engineering capacity and SW′s material engineering principles to create engineered systems for even greater in-use performance.

Theoretical Study on Vibrational Spectra, Detonation Properties and Pyrolysis Mechanism for Cyclic 2-Diazo-4,6-dinitrophenol

Based on the full optimized molecular geometrical structures at the DFT-B3LYP/6- 311＋G^＊＊ level, there exists intramolecular hydrogen bond interaction for cyclic 2-diazo- 4,6-dinitrophenol. The assigned infrared spectrum is obtained and used to compute the thermodynamic properties. The results show that there are four main characteristic regions in the calculated IR spectra of the title compound. The detonation velocities and pressures are also evaluated by using Kamlet-Jacobs equations based on the calculated density and condensed phase heat of formation. Thermal stability and the pyrolysis mechanism of 2- diazo-4,6-dinitrophenol are investigated by calculating the bond dissociation energies at the B3LYP/6-311＋G^＊＊ level.

Existence of Explosive Solutions for a Class of Nonlinear Elliptic Equations

By the subsuper solutions method, the explosive supersolutions and explosive subsol utions are obtained and the exsistence of explosive solutions is proved on a bounded domain for a class of nonlinear elliptic problems.Then, the exsitence of an entire large solution is proved by the perturbed method.

Suppressive Influence of Time- Space White Noise on the Explosion of Solutions of Stochastic Fokker- Planck Delay Differential Equations

It is generally known that the solutions of deterministic and stochastic differential equations （SDEs） usually grow linearly at such a rate that they may become unbounded after a small lapse of time and may eventually blow up or explode in finite time. If the drift and diffusion functions are globally Lipschitz, linear growth may still be experienced, as well as a possible blow-up of solutions in finite time. In this paper, a nonlinear scalar delay differential equation with a constant time lag is perturbed by a multiplicative Ito-type time - space white noise to form a stochastic Fokker-Planck delay differential equation. It is established that no explosion is possible in the presence of any intrinsically slow time - space white noise of Ito - type as manifested in the resulting stochastic Fokker- Planck delay differential equation. Time - space white noise has a role to play since the solution of the classical nonlinear equation without it still exhibits explosion.

dentification of blasting vibration and coal-roc fracturing microseismic signals

A new method based on variational mode decomposition （VMD） is proposed to distinguish between coal-rock fracturing and blasting vibration microseismic signals. First, the signals are decomposed to obtain the variational mode components, which are ranked by frequency in descending order. Second, each mode component is extracted to form the eigenvector of the energy of the original signal and calculate the center of gravity coefficient of the energy distribution plane. Finally, the coal-rock fracturing and blasting vibration signals are classified using a decision tree stump. Experimental results suggest that VMD can effectively separate the signal components into coal-rock fracturing and blasting vibration signals based on frequency. The contrast in the energy distribution center coefficient after the dimension reduction of the energy distribution eigenvector accurately identifies the two types of microseismic signals. The method is verified by comparing it to EMD and wavelet packet decomposition.

Study of the Effect of Different Solids Load on the Optimum pH during Enzymatic Hydrolysis of Steam Exploded Corn Stover

The understanding of enzymatic saccharification of pretreated lignocellulosic material is of great importance. There are several important commercially available enzymes in the market that are used for this purpose. The conditions of pH and temperature performance of any particular enzyme are very well defined and it is clearly indicated by its manufacturer and it depends on the type of enzyme or enzymes in the complex pool. It is well know that commercial cellulases work best at pH around 4.8-5.0 and as a consequence this is widely used in the industry and the literature. In this study it was found that optimum pH of cellulases is different than that recommended by its manufacturer at higher solids load saccharification. The optimum pH changes depending on the consistency or solids loads of the matrix where the enzyme is acting upon. Steam exploded corn stover was tested with cellulases and xylanases at different pH, consistencies and ionic strength. Results showed that the optimum pH at lower consistency （1% w/w） is the same as the one recommended by the manufacturer and in the literature; however at higher consistency the value obtained was higher （pH 5.5 to pH 6.5） instead ofpH 4.8. The difference could represent up to 30-50% higher yields and hence of great importance for the economics of second generation fuel production. An explanation of this behavior could be associated with the Donnan effect theory. This effect indicates that the presence of charged groups in the fiber matrix creates a pH gradient within the slurry. If the charged groups are negatively charged this would create a local or internal pH lower than the surrounding liquid pH. This could explain why by reducing the concentration of H^＋ higher enzymatic conversion yields were observed.

On a Class of Nonlinear Wave Equations

This paper investigated the asymptotic behavior of global weak solutions of the initial boundary value problem for a class of nonlinear wave equations. Moreover, blowup of this kind of equations was also disscussed.

Detonation initiated disintegration of coal particle due to the maxi- mum strain energy theory

Fragmentation behaviour of coal particles subjected to detonation wave is being studied. Detonation wave is initiated by a plasma cartridge at one end of a detonation tube. Coal particles are subjected to a shock whose temperature depends on the Mach number of the detonation wave. Temperature shock is found to generate thermal stresses which may fragment the coal particles. A non-dimensional mathematical model for the heat transfer process in the coal particle is proposed. Thermal stresses are calculated at various times and radii while maximum strain energy theory is used to understand the failure behavior viz., the time, temperature and location of fracture. A physical model for coal particle fragmentation when subjected to detonation wave is also proposed. The study suggests that detonation combustion of coal is qualitatively different from conventional method.

Detection of UXO magnetic anomaly in Jinshan area

Magnetic survey is one of the most successful techniques for locating buried unexploded ordnances( UXO). For the location and identification of buried UXO in Jinshan area,a total-field magnetic survey is applied. The analytic signal of magnetic field is widely used to outline the boundaries of geology bodies,slightly dependent on the magnetization direction. In order to locate the UXO position,the analytic signal is applied to process the magnetic UXO data,which performs better than the conventional magnetic data. Then a typical UXO anomaly is extracted from the original data to invert for its depth by an improved Euler method proposed.The calculated depth is close to the real buried depth.

Solutions to the Complex Korteweg-de Vries Equation: Blow-up Solutions and Non-Singular Solutions

In the paper two kinds of solutions are derived for the complex Korteweg-de Vries equation, includ- ing blow-up solutions and non-singular solutions. We derive blow-up solutions from known 1-soliton solution and a double-pole solution. There is a complex Miura transformation between the complex Korteweg-de Vries equation and a modified Kortcweg-de Vries equation. Using the transformation, solitons, breathers and rational solutions to the com- plex Korteweg-de Vries equation are obtained from those of the modified Korteweg-de Vries equation. Dynamics of the obtained solutions are illustrated.

Blow-up of p-Laplacian evolution equations with variable source power

We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous function defined in with 0 〈 q- infq（x） = q（x） 〈 ∞supq（x） = q＋ 〈 ∞. It is demonstrated that the equation with variable source power has much richer dynamics with interesting phenomena which depends on the interplay of q（x） and the structure of spatial domain Ω, compared with the case of constant source power. For the case that is a bounded domain, the exponent p - 1 plays a crucial role. If q＋ 〉 p - 1, there exist blow-up solutions, while if q＋ p - 1, all the solutions are global. If q-〉 p - 1, there exist global solutions, while for given q- 〈 p - 1 〈 q＋, there exist some function q（x） and such that all nontrivial solutions will blow up, which is called the Fujita phenomenon. For the case Ω = RN the Fujita phenomenon occurs if 1 q＋ q＋ ≤p--1＋p/N, while if q_ 〉 p -- 1 ＋p/N there exist global solutions.

Moving finite element methods for time fractional partial differential equations

With the aim of simulating the blow-up solutions, a moving finite element method, based on nonuni- form meshes both in time and in space, is proposed in this paper to solve time fractional partial differential equations （FPDEs）. The unconditional stability and convergence rates of 2 -a for time and r for space are proved when the method is used for the linear time FPDEs with a-th order time derivatives. Numerical exam-ples are provided to support the theoretical findings, and the blow-up solutions for the nonlinear FPDEs are simulated by the method.

BLOW-UP OF SOLUTIONS OF THE IGNITION MODEL

By use of maximum principle and auxiliary function method,the paper discusses the blow-up sets of the solutions of the ignition model in two cases,It is obtained that the solutions blow up in single point in nonsymmetric case and that the solutions blow up totally or at a couple of points in symmetric case.