Energetic nitrocellulose coating: effective way to decrease sensitivity and modify surface property of HMX particles

Modifying the surface properties of energetic materials has theoretical and practical significance in the field of their application. In this paper, irregular cyclotetramethylene tetranitramine (HMX) particles were successfully coated by energetic nitrocellulose (NC), leading to the uniform NC-coated HMX particles. As coating materials, energetic (NC was chosen to decrease the sensitivity and modify the surface property of HMX particles, in order to expand their application furthermore. Scanning electron microscopy, laser particle size analysis, energy dispersive spectrometer, and Fourier-transform infrared (FT-IR) spectra were utilized to investigate the morphology, size, and coating quality of NC-coated HMX particles. These results indicated the effective preparation of composites structure. Moreover, the thermal behaviors of NC-coated HMX particles were investigated by simultaneous thermogravimetric and differential scanning calorimetry analysis, coupled with FT-IR and mass spectroscopy. These results showed that NC did not induce chemical properties change of HMX, only physical hydrogen bond was formed in the coating process. Finally, the friction sensitivity, impact sensitivity, and surface properties NC-coated HMX were investigated, and the results suggested that NC-coated HMX particles had better safety and depicted stronger interaction with the binder matrix than original HMX, owing to the stability of NC on the outer layer.     

Evaluation of a new alkaline/microbe/polymer flooding system for enhancing heavy oil recovery

The new alkaline/microbe/polymer (AMP) flooding system was first constructed and evaluated for enhancing oil recovery. The system is composed of 0.3?wt% Na₂CO₃, 2?wt% microbial cultures and 0.2?wt% polymer. Compared with the conventional alkaline/surfactant/polymer (ASP) system, the AMP system exhibits identical displacement properties. Chromatography analysis reveals crude oil is not negatively affected by the microbes in AMP system. Further comparative core flooding experiments using the AMP and ASP systems demonstrate that the AMP system possesses greater potential for enhancing heavy oil recovery, which shows the characteristic of two-stage additional oil increment with total additional oil recovery of 17.11%–19.91%.     

Phragmites stimulation and natural attenuation of indigenous microbial community accelerated bioremediation of oil contaminated soil

Illumina high-throughput sequencing method was used to reflect fluctuation of indigenous microbial community during phragmites stimulation process in this study. Results showed Proteobacteria, Fimicutes, and Actinobacteria were most influential in process, Firmicutes and Deinococcus-Thermus were positively affected by nutrient amendment. Firmicutes can be seen as indicator of degradation rate. Dietzia, Salinimicrobium, and Halomonas were the most dominant genus in both Phragmites and Blank setups. These results indicated phragmites addition improved the efficiency of biodegradation and significantly regulated the microbial community structure and functions during remediation process.     

Hydrocarbon preservation and formation water geochemistry in abnormal pressure system in the Bawu area of Lishu depression,Songliao Basin,China

The hydrocarbon production in the Bawu area of Lishu Depression is high. However, the Bawu area has undergone three main tectonic movements, the strata were strongly uplifted and eroded, and the fractures were extremely developed. The conditions of hydrocarbon preservation have become intricate. In this study, by analyzing isotopes compositions and geochemical features of formation water, and the characteristics of formation pressure, the hydrocarbon preservation can be deduced. The subnormal and lower normal pressure zones (away from Xiaokuan Fault) of Yingcheng and Shahezi Formations are relatively closed and more conducive to hydrocarbon preservation.     

中间轨道计算的线性拟合方法

本文对现有的中间轨道法作了简要的介绍，通过分析与数据，说明Barrar对称中心法的压缩系数是可以加大并由此提高精度的。文中给出了一种中间轨道计算的新方法--线性拟合法，及多种线性拟合法的拟合系数。数字计算结果显示了线性拟合法的精确性。     

基于Petri网工作流网在舰载机出航准备建模中的应用

基于Petri网的工作流网的舰载机出航准备建模,将舰载机出航准备工作流网分为:与舰载机起飞降落紧密相关的活动、飞行甲板上的舰载机的活动和进入机库舰载机的活动.任何一架舰载机在航母降落,代表该舰载机的托肯会由C1库所进入工作流网,使整个工作流网启动.每个托肯根据航母指挥机构的命令选择不同流向,并向指挥机构显示舰载机出航准备状态.当舰载机接到起飞命令,升空作战时,流程结束.     

一种雷达网目标分配的数学模型研究

本文就雷达网防空中使用多程式雷达时的目标分配问题建立了数学模型.在此基础上,给出了目标分配数学优化算法,为雷达网防空指挥控制系统中的目标分配提供了新的理论方法.     

非充分灌溉条件下水稻需水量计算

本文提出了非充分灌溉条件下水稻不同生育阶段的需水量计算模型，并运用实测资料对模型进行了验证。     

用厂坝连接解决大坝深层抗滑稳定问题

本文以万家寨水电站为背景，研究了不同厂坝连接方式对坝体和厂房的应力、变形及深层抗滑稳定性的影响。研究结果表明，考虑混凝土重力坝与坝后式厂房的相互作用后，可以提高大坝抗滑稳定性，改善坝体应力状态，并能减小由于下游尾水过高引起厂房向上游的变形。     

寒冷地区拱坝苯板保温层的效果及计算方法

寒冷地区拱坝的温度应力比南方大得多，温度荷载的影响可能超过水荷载。本文提出在拱坝下游面用苯板作永久保护层，以降低温度荷载，减小拱坝厚度、还给出了相应的计算方法，响水拱坝加固采用了苯板保温方案。