Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In ...Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In order to obtain high-quality HMX@PDA-based PBX explosives with high sphericity and a narrow particle size distribution,composite microspheres were prepared using co-axial droplet microfluidic technology.The formation mechanism,thermal behavior,mechanical sensitivity,electrostatic spark sensitivity,compressive strength,and combustion performance of the microspheres were investigated.The results show that PDA can effectively enhance the interfacial interaction between the explosive particles and the binder under the synergistic effect of chemical bonds and the physical"mechanical interlocking"structure.Interface reinforcement causes the thermal decomposition temperature of the sample microspheres to move to a higher temperature,with the sensitivity to impact,friction,and electrostatic sparks(for S-1)increasing by 12.5%,31.3%,and 81.5%respectively,and the compressive strength also increased by 30.7%,effectively enhancing the safety performance of the microspheres.Therefore,this study provides an effective and universal strategy for preparing high-quality functional explosives,and also provides some reference for the safe use of energetic materials in practical applications.展开更多
Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not on...Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not only affects the engineering safety critically but also improves the maintenance costs. This paper takes the main rail roadway with severely deformation in China＇s Zaoquan coal mine as an example to study the long-term deformation tendency and damage zone by means of in-situ deformation monitoring and acoustic wave testing technique. A three-dimensional finite element model reflecting the engineering geological condition and initial design scheme is established by ABAQUS. Then, on the basis of field monitoring deformation data, the surrounding rock geotechnical and theological parameters of the roadway are obtained by back analysis. A combined supporting technology with U-shaped steel support and anchor-grouting is proposed for the surrounding soft rock. The numerical simulation of the combined supporting technology and in-situ deformation monitoring results show that the soft rock surrounding the roadway has been held effectively.展开更多
传统的数据清洗方法因需专家手动定义数据质量规则,不仅复杂且耗时巨大,且清洗后的数据可能不能被重复利用,降低了数据清洗的质量和效率.为此,提出基于双重深度Q网络的否定约束迁移(double deep Q-network for denial constraints trans...传统的数据清洗方法因需专家手动定义数据质量规则,不仅复杂且耗时巨大,且清洗后的数据可能不能被重复利用,降低了数据清洗的质量和效率.为此,提出基于双重深度Q网络的否定约束迁移(double deep Q-network for denial constraints transfer,DDQN-DCT)算法.该算法设计否定约束(denial constraint,DC)的相似性度量方法,并结合相似性和DC的简洁性和覆盖度,使用双重深度Q网络(double deep Q-network,DDQN)对DC规则中的谓词进行修改从而实现DC迁移,目标是使迁移后的规则与原规则具有最大的相似性,以保留原有规则的信息.基于DDQN-DCT进一步设计了DDQN-DCT+算法,把DDQN的动作选择策略划为增加和删除2个阶段,并通过对比实验证明DDQN-DCT+在DC简洁性上有更好的表现.通过与暴力依赖约束迁移(brute-force dependency constraint transfer,BFDC)、DDQN-DCT+和结构扩大/缩小(structure expansion/reduction,SER)方法进行对比实验,发现DDQN-DCT算法在规则相似度上相较于BFDC平均提升约10%,相较于DDQN-DCT+平均提升约10.6%,相较于SER平均提升约16.4%.DDQN-DCT能够有效地将源域的规则迁移到相似的目标域数据上.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22005275).
文摘Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In order to obtain high-quality HMX@PDA-based PBX explosives with high sphericity and a narrow particle size distribution,composite microspheres were prepared using co-axial droplet microfluidic technology.The formation mechanism,thermal behavior,mechanical sensitivity,electrostatic spark sensitivity,compressive strength,and combustion performance of the microspheres were investigated.The results show that PDA can effectively enhance the interfacial interaction between the explosive particles and the binder under the synergistic effect of chemical bonds and the physical"mechanical interlocking"structure.Interface reinforcement causes the thermal decomposition temperature of the sample microspheres to move to a higher temperature,with the sensitivity to impact,friction,and electrostatic sparks(for S-1)increasing by 12.5%,31.3%,and 81.5%respectively,and the compressive strength also increased by 30.7%,effectively enhancing the safety performance of the microspheres.Therefore,this study provides an effective and universal strategy for preparing high-quality functional explosives,and also provides some reference for the safe use of energetic materials in practical applications.
基金Projects(51409154,41772299)supported by the National Natural Science Foundation of ChinaProject(J16LG03)supported by the Shandong Province Higher Educational Science and Technology Program,China+1 种基金Projects(2015JQJH106,2014TDJH103)supported by the SDUST Research Fund,ChinaProject(201630576)supported by the Tai’an Scientific and Technologic Development Project,China
文摘Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not only affects the engineering safety critically but also improves the maintenance costs. This paper takes the main rail roadway with severely deformation in China＇s Zaoquan coal mine as an example to study the long-term deformation tendency and damage zone by means of in-situ deformation monitoring and acoustic wave testing technique. A three-dimensional finite element model reflecting the engineering geological condition and initial design scheme is established by ABAQUS. Then, on the basis of field monitoring deformation data, the surrounding rock geotechnical and theological parameters of the roadway are obtained by back analysis. A combined supporting technology with U-shaped steel support and anchor-grouting is proposed for the surrounding soft rock. The numerical simulation of the combined supporting technology and in-situ deformation monitoring results show that the soft rock surrounding the roadway has been held effectively.
文摘传统的数据清洗方法因需专家手动定义数据质量规则,不仅复杂且耗时巨大,且清洗后的数据可能不能被重复利用,降低了数据清洗的质量和效率.为此,提出基于双重深度Q网络的否定约束迁移(double deep Q-network for denial constraints transfer,DDQN-DCT)算法.该算法设计否定约束(denial constraint,DC)的相似性度量方法,并结合相似性和DC的简洁性和覆盖度,使用双重深度Q网络(double deep Q-network,DDQN)对DC规则中的谓词进行修改从而实现DC迁移,目标是使迁移后的规则与原规则具有最大的相似性,以保留原有规则的信息.基于DDQN-DCT进一步设计了DDQN-DCT+算法,把DDQN的动作选择策略划为增加和删除2个阶段,并通过对比实验证明DDQN-DCT+在DC简洁性上有更好的表现.通过与暴力依赖约束迁移(brute-force dependency constraint transfer,BFDC)、DDQN-DCT+和结构扩大/缩小(structure expansion/reduction,SER)方法进行对比实验,发现DDQN-DCT算法在规则相似度上相较于BFDC平均提升约10%,相较于DDQN-DCT+平均提升约10.6%,相较于SER平均提升约16.4%.DDQN-DCT能够有效地将源域的规则迁移到相似的目标域数据上.
