Nonlinear dispersion equations: Smooth deformations,compactions, and extensions to higher orders

The third-order nonlinear dispersion PDE, as the key model,

Theoretical calculation of nitro-1-(2,4,6-trinitrophenyl)-1H-azoles energetic compounds

In order to study the properties of new energetic compounds formed by introducing nitroazoles into 2,4,6-trinitrobezene, the density, heat of formation and detonation properties of 36 nitro-1-(2,4,6-trinitrobenzene)-1H-azoles energetic compounds are studied by density functional theory, and their stability and melting point are predicted. The results show that most of target compounds have good detonation properties and stability. And it is found that nitro-1-(2,4,6-Trinitrophenyl)-1H-pyrrole compounds and nitro-1-(2,4,6-trinitrop-enyl)-1H-Imidazole compounds have good thermal stability, and their weakest bond is C NO₂ bond, the bond dissociation energy of the weakest bond is 222–238 kJ mol⁻¹ and close to 2,4,6-trinitrotoluene (235 kJ mol⁻¹). The weakest bond of the other compounds may be the C NO₂ bond or the N N bond, and the strength of the N N bond is related to the nitro group on azole ring.     

Determination of the Uranium(VI) and ‐(IV) Species in Uranium Ores

The determination of the two species of uranium(VI and IV) present in 6 uranium ores was studied in relation to the chemical and mineralogical composition, humidity, and pH of the samples taken over from the mine. X‐ray diffraction studies, performed on the uranium ores in powder form allowed to establish their mineralogical composition. Thechemical analysis pointed out the presence, besides the two uranium species, of some microelements able to influence the U^VI/U^IV ratio in minerals and to leach out U^VI as uranyl ions from the corresponding minerals.     

Local exposure of 849 MHz and 1763 MHz radiofrequency radiation to mouse heads does not induce cell death or cell proliferation in brain

Even though there is no direct evidence to prove the cellular and molecular changes induced by radiofrequency (RF) radiation itself, we cannot completely exclude the possibility of any biological effect of mobile phone frequency radiation. We established a carousel-type exposure chamber for 849 MHz or 1763 MHz of mobile phone RF radiation to expose RF to the heads of C57BL mice. In this chamber, animals were irradiated intermittently at 7.8 W/kg for a maximum of 12 months. During this period, the body weights of 3 groups-sham, 849 MHz RF, and 1763 MHz RF-did not show any differences between groups. The brain tissues were obtained from 3 groups at 6 months and 12 months to examine the differences in histology and cell proliferation between control and RF exposure groups, but we could not find any change upon RF radiation. Likewise, we could not find changes in the expression and distribution of NeuN and GFAP in hippocampus and cerebellum, or in cell death by TUNEL assay in RF exposure groups. From these data, we conclude that the chronic exposure to 849 MHz and 1763 MHz RF radiation at a 7.8 W/kg specific absorption rate (SAR) could not induce cellular alterations such as proliferation, death, and reactive gliosis.     

Communication games with partially soft power constraints

We consider a class of communication games which involves the transmission of a Gaussian random variable through a conditionally Gaussian memoryless channel in the presence of an intelligent jammer. The jammer is allowed to tap the channel and feed a correlated signal back into it. The transmitter-receiver pair is assumed to cooperate in minimizing some quadratic fidelity criterion while the jammer maximizes this same criterion. Security strategies which protect against irrational jammer behavior and which yield an upper bound on the cost are shown to exist for the transmitter-receiver pair over a class of fidelity criteria. Closed-form expressions for these strategies are provided in the paper, which are, in all cases but one, linear in the available information.This work was supported in part by the US Air Force under Grant No. AFOSR-84-0056 and in part by the Joint Services Electronics Program under Contract No. N00014-84-C-0149. An earlier version of this paper was presented at the 1986 IEEE Symposium on Information Theory, Ann Arbor, Michigan, 1986.     

Synthesis,crystal structure and thermal properties of an unsymmetrical 1,2,4,5‐tetrazine energetic derivative

A new unsymmetrical s‐tetrazine derivative, namely 4‐({2‐[6‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐1,2,4,5‐tetrazin‐3‐yl]hydrazin‐1‐ylidene}methyl)phenol (DPHM), C₁₄H₁₄N₈O, was synthesized based on 3‐(3,5‐dimethylpyrazol‐1‐yl)‐6‐hydrazinyl‐s‐tetrazine (DPHT). The structure was characterized by elemental analysis and single‐crystal X‐ray diffraction. Crystal structure determination shows that DPHM crystallizes in the monoclinic P2₁/c space group with high coplanarity and a zigzag layered structure. In addition, its thermal behaviour was investigated by DSC and TG–DTG methods. The thermal safety of DPHM was evaluated by self‐accelerating decomposition temperature (T_SADT), critical temperature of thermal explosion (T_b), entropy of activation (ΔS), enthalpy of activation (ΔH) and free energy of activation (ΔG). Meanwhile, the kinetic parameters and specific heat capacity of DPHM were also determined. The results show that DPHM has better stability and detonation properties than 3‐(2‐benzylidenehydrazin‐1‐yl)‐6‐(3,5‐dimethylpyrazol‐1‐yl)‐s‐tetrazine (DAHBTz), due to the introduction of a hydroxy group, which increases the number of hydrogen‐bond interactions and improves the stability and density of DPHM. This study demonstrates that the performance of an explosive can be optimized through structural modification.     

On localization of vorticity in Lorentz lattice gases

We study the generalized deterministic Lorentz lattice gases, in a fixed as well as in varying environments, in lattices with dimensionsd3. We show that bounded orbits (vortices) in these models are often contained in some lower dimensional subsets (vortex sheets) of these lattices.     

双目标消防救援站选址模型的元胞阴阳平衡优化算法

为衡量消防救援站在不同时间内提供的救援服务质量,基于火灾风险等级引入时效性评价函数,构建考虑时效性和经济性的双目标选址模型。针对新模型属于NP难问题特点,设计元胞阴阳平衡优化算法进行求解。寻优个体既在阴阳平衡优化算法搜索空间进行全局探索,又在元胞空间利用演化规则在邻居范围内进行局部开发。实验证明了新模型的可行性和有效性,与蝙蝠算法、蜂群算法、和声搜索算法、NGSA-Ⅱ和元胞蚁群优化算法的比较表明,新算法在非劣解集的收敛性、多样性、分布均匀性以及计算速度方面优势显著。     

Long-time tails in lattice Lorentz gases

We consider a Lorentz gas on a square lattice with a fraction c of scattering sites. The collision laws are deterministic (fixed mirror model) or stochastic (with transmission, reflection, and deflection probabilities ,, and respectively). If all mirrors are parallel, the mirror model is exactly solvable. For the general case a self-consistent ring kinetic equation is used to calculate the longtime tails of the velocity correlation function (0) (t) and the tensor correlation Q(0)Q(t) withQ= _{x y} . Both functions showt ^–2 tails, as opposed to the continuous Lorentz gas, where the tails are respectivelyt ^–2 andt ^–3. Inclusion of the self-consistent ring collisions increases the low-density coefficient of the tail in (0)(t) by 30–100% as compared to the simple ring collisions, depending on the model parameters.