期刊文献+
共找到20,552篇文章
< 1 2 250 >
每页显示 20 50 100
铅酸蓄电池中硫化氢产生的分析研究 预览
1
作者 赵弟 宋志光 +4 位作者 宋艳龙 周胜文 陈志雪 赵凯 张文龙 《蓄电池》 2019年第5期216-221,228共7页
铅酸蓄电池在充电过程中可能会产生臭鸡蛋气味的、对人体有害的难闻气体。选择不同类型的免维护铅酸蓄电池对该气体的成分以及产生的原因进行研究。结果表明,该气体为硫化氢气体。它的产生受电化学反应、温度、电解液密度、电压和电流... 铅酸蓄电池在充电过程中可能会产生臭鸡蛋气味的、对人体有害的难闻气体。选择不同类型的免维护铅酸蓄电池对该气体的成分以及产生的原因进行研究。结果表明,该气体为硫化氢气体。它的产生受电化学反应、温度、电解液密度、电压和电流等共同影响。最后根据研究结果对其产生机理进行了推测。 展开更多
关键词 铅酸蓄电池 臭鸡蛋气味 硫化氢 充电 隔板 荷电状态 电解液密度 电池温度
在线阅读 下载PDF
混流云雾煤矿除尘装置研究与应用
2
作者 袁昌宇 《煤矿机械》 北大核心 2019年第5期124-126,共3页
针对煤矿开采工作面粉尘量大、除尘难度大、除尘效果不佳的问题,通过对荷电水雾降尘的技术方法研究,选取合适的荷电方式,设计混流云雾煤矿除尘装置。通过除尘装置,带电荷的小分子云雾颗粒与飘散的煤粉碰撞并凝聚成团聚物,团聚物不断变... 针对煤矿开采工作面粉尘量大、除尘难度大、除尘效果不佳的问题,通过对荷电水雾降尘的技术方法研究,选取合适的荷电方式,设计混流云雾煤矿除尘装置。通过除尘装置,带电荷的小分子云雾颗粒与飘散的煤粉碰撞并凝聚成团聚物,团聚物不断变大、变重后自然沉降,大大提高了煤矿除尘的效率。 展开更多
关键词 荷电 除尘装置 混流云雾
Parameter identification and state-of-charge estimation approach for enhanced lithium-ion battery equivalent circuit model considering influence of ambient temperatures
3
作者 庞辉 牟联晶 郭龙 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期562-570,共9页
It is widely accepted that the variation of ambient temperature has great influence on the battery model parameters and state-of-charge(SOC) estimation, and the accurate SOC estimation is a significant issue for devel... It is widely accepted that the variation of ambient temperature has great influence on the battery model parameters and state-of-charge(SOC) estimation, and the accurate SOC estimation is a significant issue for developing the battery management system in electric vehicles. To address this problem, in this paper we propose an enhanced equivalent circuit model(ECM) considering the influence of different ambient temperatures on the open-circuit voltage for a lithium-ion battery. Based on this model, the exponential-function fitting method is adopted to identify the battery parameters according to the test data collected from the experimental platform. And then, the extended Kalman filter(EKF) algorithm is employed to estimate the battery SOC of this battery ECM. The performance of the proposed ECM is verified by using the test profiles of hybrid pulse power characterization(HPPC) and the standard US06 driving cycles(US06) at various ambient temperatures, and by comparing with the common ECM with a second-order resistance capacitor. The simulation and experimental results show that the enhanced battery ECM can improve the battery SOC estimation accuracy under different operating conditions. 展开更多
关键词 LITHIUM-ION battery parameter identification state of CHARGE AMBIENT temperature
运动微粒导致间隙击穿的模拟研究
4
作者 徐翱 钟伟 +2 位作者 金大志 陈磊 谈效华 《真空科学与技术学报》 EI CAS CSCD 北大核心 2019年第8期637-643,共7页
当在充满气体的两电极平板间隙中,运动的带电微米级微粒由于外力作用运动到电极表面附近时,可能会引起微粒与电极间局部微放电,甚至在一定条件下可能会引发间隙气体击穿,这是一种非常特殊的击穿现象。因此,本文通过理论公式和静电场模拟... 当在充满气体的两电极平板间隙中,运动的带电微米级微粒由于外力作用运动到电极表面附近时,可能会引起微粒与电极间局部微放电,甚至在一定条件下可能会引发间隙气体击穿,这是一种非常特殊的击穿现象。因此,本文通过理论公式和静电场模拟,分析了不同大小的带电微粒距离阴极表面不同距离的电场畸变情况;接着基于二维轴对称网格粒子法耦合蒙特卡洛碰撞(PIC-MCC)算法,建立了带电微粒距离电极表面1μm处引发间隙气体击穿的仿真模型,并与不考虑微粒的仿真计算结果进行了对比,获得了电子、离子在不同情况下的时空分布演化过程,揭示了带电微粒接近导致阴极表面电场增强从而发射场致电子是引发间隙气体击穿的首要原因,并阐明了这些电子引发间隙击穿的物理机制。这为进一步深入理解运动微粒引发间隙击穿的物理机理奠定了基础。 展开更多
关键词 微粒 击穿 电荷 等离子体 模拟
火电厂磨煤机钢球装载量与电机电流的关系分析 预览
5
作者 王承亮 《华电技术》 CAS 2019年第5期34-39,45共7页
为确定火电厂钢球磨煤机正常运行中钢球添加依据,保证钢球磨煤机有相对稳定的制粉能力,降低制粉单耗和优化锅炉燃烧,通过试验手段研究钢球磨煤机钢球装载量与电机电流的关系,并通过试验数据分析确定了磨煤机电流与钢球装载量的预测关系... 为确定火电厂钢球磨煤机正常运行中钢球添加依据,保证钢球磨煤机有相对稳定的制粉能力,降低制粉单耗和优化锅炉燃烧,通过试验手段研究钢球磨煤机钢球装载量与电机电流的关系,并通过试验数据分析确定了磨煤机电流与钢球装载量的预测关系式和最佳钢球装载量,同时提出了磨煤机正常运行中钢球添加方式及添加量的指导建议。 展开更多
关键词 火电厂 锅炉 制粉系统 钢球磨煤机 电流 装载量 深度挖潜
在线阅读 下载PDF
Recent Progress in the Fabrication, Properties, and Devices of Heterostructures Based on 2D Materials 预览
6
作者 Yanping Liu Siyu Zhang +2 位作者 Jun He Zhiming M.Wang Zongwen Liu 《纳微快报:英文版》 CAS CSCD 2019年第1期217-240,共24页
With a large number of researches being conducted on two-dimensional(2D)materials,their unique properties in optics,electrics,mechanics,and magnetics have attracted increasing attention.Accordingly,the idea of combini... With a large number of researches being conducted on two-dimensional(2D)materials,their unique properties in optics,electrics,mechanics,and magnetics have attracted increasing attention.Accordingly,the idea of combining distinct functional 2D materials into heterostructures naturally emerged that provides unprecedented platforms for exploring new physics that are not accessible in a single 2D material or 3D heterostructures.Along with the rapid development of controllable,scalable,and programmed synthesis techniques of high-quality 2D heterostructures,various heterostructure devices with extraordinary performance have been designed and fabricated,including tunneling transistors,photodetectors,and spintronic devices.In this review,we present a summary of the latest progresses in fabrications,properties,and applications of different types of 2D heterostructures,followed by the discussions on present challenges and perspectives of further investigations. 展开更多
关键词 Two-dimensional(2D)materials 2D HETEROSTRUCTURES CHARGE and MAGNETOTRANSPORT Electronic and OPTOELECTRONIC DEVICES
在线阅读 免费下载
Efficient ternary organic solar cells based on a twin spiro-type non-fullerene acceptor
7
作者 Lirong Wu Lingchao Xie +7 位作者 Hanmin Tian Ruixiang Peng Jiaming Huang Billy Fanady Wei Song Songting Tan Wengang Bi Ziyi Ge 《科学通报:英文版》 SCIE EI CSCD 2019年第15期1087-1094,共8页
A novel small-molecule(SM) acceptor DTF-IC is designed and synthesized in this work. The power conversion efficiency(PCE) of ternary OSCs increased up to 12.14% from 10.90% by incorporating 10 wt% of DTF-IC as second ... A novel small-molecule(SM) acceptor DTF-IC is designed and synthesized in this work. The power conversion efficiency(PCE) of ternary OSCs increased up to 12.14% from 10.90% by incorporating 10 wt% of DTF-IC as second acceptors into the binary OSCs consisting of PBDB-T as donor and IT-M as acceptor. This was mainly due to the large increase in short-circuit current(Jsc) from 16.18 to 17.95 mA/cm~2, without any drop in the open-circuit voltage(Voc) and fill factor(FF). The addition of DTF-IC enabled the donor and acceptor to form a distinct complementary absorption profile in the visible-light region, which boosted the photon harvesting in the range of 730–800 nm and consequently increased the Jscof the ternary system by 11%. Moreover, there was an energy transfer between the two SM acceptors, favorable for enhancing charge separation and transfer as well as reducing charge recombination at PBDB-T:IT-M and PBDB-T:DTF-IC interface. Simultaneously, HOMO and LUMO energy levels of DTF-IC were lower than those of PBDB-T, but still higher than those of IT-M. Thus, DTF-IC is able to provide a cascading energy level with the host donor and acceptor which are beneficial for efficient charge transfer between the acceptors and facilitating exciton dissociation and carrier transport. Meanwhile, the highly crystalline DTF-IC as a third component can improve the crystallization process of the active layer while maintaining proper phase separation. This work proposes a novel idea for non-fullerene acceptors achieved via twin spiro-type structure modifying by indanone and provides a new direction for the selection of ternary solar cell materials. 展开更多
关键词 TERNARY organic solar cells High efficiency PHOTON HARVESTING Charge transport Energy transfer
Calibration of the DAMPE Plastic Scintillator Detector and its on-orbit performance
8
作者 Meng Dingx Ya-Peng Zhang +17 位作者 Yong-Jie Zhang Yuan-Peng Wang Tie-Kuang Dong Antonio De Benedittis Paolo Bernardini Fang Fang Yao Li Jie Liu Peng-Xiong Ma Zhi-Yu Sun Valentina Gallo Stefania Vitillo Zhao-Min Wang Yu-Hong Yu Chuan Yue Qiang Yucin Yong Zhou Yun-Long Zhang 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2019年第3期145-154,共10页
The DArk Matter Particle Explorer(DAMPE)is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons,γ-rays,protons and heavy ions.The Plastic Scintillator Detector(PSD)is the top-most sub-detect... The DArk Matter Particle Explorer(DAMPE)is a space-borne apparatus for detecting the highenergy cosmic-ray-like electrons,γ-rays,protons and heavy ions.The Plastic Scintillator Detector(PSD)is the top-most sub-detector of the DAMPE.The PSD is designed to measure the charge of incident highenergy particles and it also serves as a veto detector for discriminating γ-rays from charged particles.In this paper,a PSD on-orbit calibration procedure is described,which includes the five steps of pedestal,dynode correlation,response to minimum-ionizing particles,light attenuation function and energy reconstruction.A method for reconstructing the charge of incident high energy cosmic-ray particles is introduced.The detection efficiency of each PSD strip is verified to be above 99.5%;the total efficiency of the PSD for charged particles is above 99.99%. 展开更多
关键词 COSMIC RAY instrumentation: DAMPE charge measurement plastic scintillator detector CALIBRATION
Charge trapping memory device based on the Ga2O3 films as trapping and blocking layer
9
作者 白冰 王宏 +9 位作者 李岩 郝云霞 张博 王博平 王子航 杨红旗 高启航 吕超 张庆顺 闫小兵 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期101-104,共4页
We present a new charge trapping memory(CTM) device with the Au/Ga2O3/SiO2/Si structure, which is fabricated by using the magnetron sputtering, high-temperature annealing, and vacuum evaporation techniques. Transmissi... We present a new charge trapping memory(CTM) device with the Au/Ga2O3/SiO2/Si structure, which is fabricated by using the magnetron sputtering, high-temperature annealing, and vacuum evaporation techniques. Transmission electron microscopy diagrams show that the thickness of the SiO2 tunneling layer can be controlled by the annealing temperature.When the devices are annealed at 760℃, the measured C-V hysteresis curves exhibit a maximum 6 V memory window under a ±13 V sweeping voltage. In addition, a slight degradation of the device voltage and capacitance indicates the robust retention properties of flat-band voltage and high/low state capacitance. These distinctive advantages are attributed to oxygen vacancies and inter-diffusion layers, which play a critical role in the charge trapping process. 展开更多
关键词 CHARGE TRAPPING memory SiO2 TUNNELING layer ANNEALING temperature
批量压制装药的多通道自适应压力平衡原理与工装设计 预览
10
作者 喻晓彧 丁海港 +1 位作者 杨永林 刘永状 《兵器装备工程学报》 CAS 北大核心 2019年第10期181-184,共4页
提出了多通道自适应压力平衡原理,利用帕斯卡定律来保证多个通道输出的力基本相等,并根据该原理设计了弹药批量压制工装,建立了该工装的有限元模型,对关键部件进行了应力应变校核。该工装含有多个压头,可一次压制多个药柱,同时各压头能... 提出了多通道自适应压力平衡原理,利用帕斯卡定律来保证多个通道输出的力基本相等,并根据该原理设计了弹药批量压制工装,建立了该工装的有限元模型,对关键部件进行了应力应变校核。该工装含有多个压头,可一次压制多个药柱,同时各压头能够伸出不同的长度,以补偿压机的安装误差和药柱高度误差,保证批量压制的一致性。该研究为实现高精度的弹药批量压制提供了借鉴。 展开更多
关键词 装药 批量压制 压力平衡 工装设计 强度校核
在线阅读 免费下载
A theoretical study of step edge geometry on sapphire(0001) and its effect on ZnO nucleation
11
作者 Ping Yang Li-Xin Zhang 《物理学前沿:英文版》 SCIE CSCD 2019年第2期105-112,共8页
Step-edge-induced nucleation plays a key role in controlling the growth of novel nanostructures and low-dimensional mat erials. However, it is difficult to experimentally determine the step edge structures of complex ... Step-edge-induced nucleation plays a key role in controlling the growth of novel nanostructures and low-dimensional mat erials. However, it is difficult to experimentally determine the step edge structures of complex metal oxides. In this work, we present a detailed theoretical study of the stability of stoichiometTic steps on sapphire(OOOl). Based on first-principles calculations and excess charge computation by Finnis1 approach, a pair of non-polar step edges are determined to be the most stable. By studying the adsorption characteristics of ZnO and combining previous works, we successfully explained how growth temperature and deposition rate affect the in-plane orientation of ZnO grown on sapphire(OOOl). The knowledge on the step edge structures and nucleation patterns would benefit the study on step-edge-guided nanostruc ture grow th. 展开更多
关键词 stepped SAPPHIRE surface FIRST-PRINCIPLES EXCESS charge step-edge-induced NUCLEATION
固体推进剂装药枪击试验数值模拟与试验 预览
12
作者 李军强 申依欣 +5 位作者 刘春 张佳钰 张崇民 付小龙 樊学忠 张国防 《固体火箭技术》 EI CAS CSCD 北大核心 2019年第4期451-455,共5页
固体推进剂的枪击试验是评价固体推进剂及装药在受到枪击的情况下,是否发生燃烧、爆炸及爆轰等剧烈反应的重要试验方法。采用LS-Dyna有限元仿真软件研究了枪击试验推进剂的反应过程,并采用12.7 mm枪击试验验证了LS-Dyna的计算结果。结... 固体推进剂的枪击试验是评价固体推进剂及装药在受到枪击的情况下,是否发生燃烧、爆炸及爆轰等剧烈反应的重要试验方法。采用LS-Dyna有限元仿真软件研究了枪击试验推进剂的反应过程,并采用12.7 mm枪击试验验证了LS-Dyna的计算结果。结果表明,以点火增长模型、Johnson-Cook本构模型和Gruneisen状态方程分别赋予推进剂、子弹及推进剂壳体,计算结果表明,推进剂发生明显的燃烧反应,且推进剂燃烧在壳体内部产生的压力显著增大。采用12.7 mm枪击试验验证的试验结果表明,推进剂装药在12.7 mm子弹以约850 m/s速度撞击下,推进剂发生燃烧,此结果与模拟结果相一致。 展开更多
关键词 应用化学 固体推进剂 装药 数值模拟 枪击
在线阅读 下载PDF
Surface charge induced tuning of electrical properties of CVD assisted graphene and functionalized graphene sheets
13
作者 Manash Jyoti Deka Devasish Chowdhury 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第1期151-158,共8页
We demonstrate a new approach to tune the electrical properties of graphene and functionalized graphene. Graphene was synthesized using thermal chemical vapour deposition(TCVD) method on copper foil using precursor ga... We demonstrate a new approach to tune the electrical properties of graphene and functionalized graphene. Graphene was synthesized using thermal chemical vapour deposition(TCVD) method on copper foil using precursor gas acetylene and co-catalyst H2 gas. TCVD assisted graphene was successfully transferred onto a silicon wafer. Transferred graphene sheet was then functionalized to prepare graphene oxide(GO) and reduced graphene oxide(rGO). Different surface charge carbon nanoparticles, e.g. carbon nanoparticle with net positive charge and carbon nanoparticle with net negative charge were then immobilized on transferred graphene and functionalized graphene sheets. The functionalized graphene and charge mobilized functionalized graphene were characterized by Uv–vis spectroscopy,Fourier transformed infrared spectroscopy, scanning electron microscopy, and Raman spectroscopy. After immobilization of carbon nanomaterials, the ac electrical conductivity was found to increase due to enhancement of the surface charge, electron density, and mobility. It was observed that negative surface charge immobilized graphene and functionalized graphene show higher conductivity. Thus, the electrical property of graphene and functionalized graphene can be tuned by surface modification with different surface charge carbon nanomaterials. 展开更多
关键词 GRAPHENE Chemical VAPOUR DEPOSITION (CVD) Surface CHARGE
Evaluating the topological charge density with the symmetricmulti-probing method
14
作者 熊光仪 张剑波 邹优豪 《中国物理C:英文版》 SCIE CAS CSCD 2019年第3期29-36,共8页
We evaluate the topological charge density of SU(3) gauge fields on a lattice by calculating the trace of the overlap Dirac matrix employing the symmetric multi-probing(SMP) method in 3 modes. Since the topological ch... We evaluate the topological charge density of SU(3) gauge fields on a lattice by calculating the trace of the overlap Dirac matrix employing the symmetric multi-probing(SMP) method in 3 modes. Since the topological charge Q for a given lattice configuration must be an integer number, it is easy to estimate the systematic error(the deviation of Q to the nearest integer). The results demonstrate a high efficiency and accuracy in calculating the trace of the inverse of a large sparse matrix with locality by using the SMP sources when compared to using point sources.We also show the correlation between the errors and probing scheme parameter rmin, as well as lattice volume NL and lattice spacing a. It is found that the computational time for calculating the trace by employing the SMP sources is less dependent on NL than by using point sources. Therefore, the SMP method is very suitable for calculations on large lattices. 展开更多
关键词 lattice QCD TOPOLOGICAL charge PROBING METHOD large SPARSE matrix INVERSE trace
时域有限差分法配电线路耦合雷电过电压求解及空间变化特征分析 预览
15
作者 韩海安 《电测与仪表》 北大核心 2019年第11期37-40,共4页
电力系统中配电线路一般裸露在空气中,极易遭受雷电过电压侵害造成供电中断。针对配电线路耦合过电压的空间分布特征问题,采用时域有限差分方法(FDTD)对雷击点相对于配电线路中点、端点位置处的雷电感应过电压进行计算,从而对耦合的雷... 电力系统中配电线路一般裸露在空气中,极易遭受雷电过电压侵害造成供电中断。针对配电线路耦合过电压的空间分布特征问题,采用时域有限差分方法(FDTD)对雷击点相对于配电线路中点、端点位置处的雷电感应过电压进行计算,从而对耦合的雷电过电压峰值时间及空间变化趋势进行研究。仿真结果表明:雷击点处于配电线路中部时,产生峰值28.07kV的雷电过电压,且线路中点位置处束缚的感应电荷最多,随后由中点迅速地向线路两端移动。而雷击点处于线路两端时,产生峰值32.74kV的雷电感应过电压。 展开更多
关键词 配电线路 FDTD 过电压 电荷 空间
在线阅读 下载PDF
The impact of crystal defects towards oxide semiconductor photoanode for photoelectrochemical water splitting
16
作者 Qi-Tao Liu De-Yu Liu +1 位作者 Jian-Ming Li Yong-Bo Kuang 《物理学前沿:英文版》 CSCD 2019年第5期37-61,共25页
Photoelectrochemical (PEC) water oxidation for sustainable clean energy and fuel production is a potential solution to the demands of organic pollutant removal and growing energy consumption.Development of high perfor... Photoelectrochemical (PEC) water oxidation for sustainable clean energy and fuel production is a potential solution to the demands of organic pollutant removal and growing energy consumption.Development of high performance photoanodes,which is a key component in the system,is one of the central topics in the area.The crystal defect is an old concept but fruiting new understanding witli promotive impact to the development of high performance photoanodes.In this review,we elucidated the typical defects involved in the photoanode with the position where they play the roles in the structure and how the properties of photoanode are influenced.In addition,we summarized the feasible protocols to maximize the pros but reduce the cons brought by having defects to the photoanode performance based on recent most prominent researcli advancements in the field.Finally,we briefly sketched the future perspective with the challenges of this topic when in the scenario of possible developments into practical applications. 展开更多
关键词 PHOTOANODE DEFECT engineering OXIDE scinicoiuluctor water SPLITTING CHARGE transfer
Three-dimensional electric potential induced by a point singularity in a multilayered dielectric medium 预览
17
作者 Xu WANG P. SCHIAVONE 《应用数学和力学:英文版》 SCIE EI CSCD 2019年第9期1327-1334,共8页
A simple and effective method is proposed to derive the three-dimensional electric potential induced by a point singularity of any type in an N-phase dielectric medium composed of N-2 intermediate dielectric layers of... A simple and effective method is proposed to derive the three-dimensional electric potential induced by a point singularity of any type in an N-phase dielectric medium composed of N-2 intermediate dielectric layers of equal thickness encased in two semi-infinite dielectric media. The point singularity can include a point charge or a point electric dipole. The original boundary value problem for the N-phase medium is reduced to the determination of a single unknown three-dimensional harmonic function through satisfaction of the continuity conditions across all of the N-1 perfect planar interfaces. The single harmonic function can be completely determined after analytically solving the resulting linear recurrence relations, which are independent of the type and the specific location of the singularity. When the singularity is a point charge, we obtain the self-energy of the point charge expressed in terms of a single function and the Coulomb force on the point charge expressed in terms of the negative derivative of this function. 展开更多
关键词 MULTILAYERED dielectric medium POINT charge POINT electric DIPOLE linear RECURRENCE relation ANALYTICAL solution
在线阅读 下载PDF
Facile synthesis of Li3V2(PO4)3/C cathode material for lithium-ion battery via freeze-drying 预览
18
作者 Shuainan Guo Ying Bai +2 位作者 Zhenfeng Geng Feng Wu Chuan Wu 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第5期159-165,共7页
In this work, we report a facile route for the synthesis of Li3V2(PO4)3/C cathode material via freezedrying and then calcination. The effect of calcination temperature on the electrochemical properties of the Li3V2(PO... In this work, we report a facile route for the synthesis of Li3V2(PO4)3/C cathode material via freezedrying and then calcination. The effect of calcination temperature on the electrochemical properties of the Li3V2(PO4)3/C is also investigated. When used as a lithium-ion battery cathode, the optimized Li3V2(PO4)3/C (LVP-800) through calcination at 800 ℃ exhibits a high initial charge and discharge capacity. The excellent electrochemical performance of LVP-800 is attributed to the good crystallinity and uniform morphology of the electrode material. In addition, the residual carbon can also improve the conductivity and buffer the volume expansion during the Li-ion extraction/reinsertion. Meanwhile, charge compensation also plays an important role in excellent electrochemical performance. 展开更多
关键词 Li3V2(PO4)3/C FREEZE-DRYING Charge compensation LITHIUM-ION battery
在线阅读 下载PDF
光面爆破技术在大红山铁矿采切作业面的应用 预览
19
作者 杨小平 麦宗华 +1 位作者 程传钊 宗黎 《中国矿业》 北大核心 2019年第A01期209-211,共3页
针对大红山铁矿一期井下巷道施工成型质量差,巷道超挖现象严重,开挖巷道围岩受到破坏大,巷道后期顶板边帮管理困难大,支护工程量大,影响巷道的正常使用。根据现场实际情况,提出巷道拱部采用光面爆破施工,减小巷道顶板边帮危石,减小围岩... 针对大红山铁矿一期井下巷道施工成型质量差,巷道超挖现象严重,开挖巷道围岩受到破坏大,巷道后期顶板边帮管理困难大,支护工程量大,影响巷道的正常使用。根据现场实际情况,提出巷道拱部采用光面爆破施工,减小巷道顶板边帮危石,减小围岩的破坏,提高巷道的整体成型质量,减小顶板边帮的安全管理难度,提高巷道使用过程中的安全性。 展开更多
关键词 巷道 炮孔 装药 光面爆破 超挖
在线阅读 下载PDF
Effect of wave shaper on reactive materials jet formation and its penetration performance 预览
20
作者 Huan-guo Guo Yuan-feng Zheng +3 位作者 Le Tang Qing-bo Yu Chao Ge Hai-fu Wang 《Defence Technology(防务技术)》 CSCD 2019年第4期495-505,共11页
Wave shaper effect on formation behavior and penetration performance of reactive liner shaped charge(RLSC)are investigated by experiments and simulations.The reactive materials liner with a density of2.3 g/cm~3 is fab... Wave shaper effect on formation behavior and penetration performance of reactive liner shaped charge(RLSC)are investigated by experiments and simulations.The reactive materials liner with a density of2.3 g/cm~3 is fabricated by cold pressing at a pressure of 300 MPa and sintering at a temperature of 380℃.Experiments of the RLSC with and without wave shaper against steel plates are carried out at standoffs of0.5,1.0,and 1.5 CD(charge diameter),respectively.The experimental results show that the penetration depths and structural damage effects of steel plates decrease with increasing the standoff,while the penetration depths and the damage effects of RLSC without wave shaper are much greater than that with wave shaper at the same standoff.To understand the unusual experimental results,numerical simulations based on AUTODYN-2 D code are conducted to discuss the wave shaper effect,including the propagation behavior of detonation wave,the velocity and temperature distribution of reactive jet,and penetration depth of reactive jet.The simulations indicate that,compared with RLSC without wave shaper,there is a higher temperature produced inside reactive jet with wave shaper.This unusual temperature rise effects are likely to be an important mechanism to cause the initiation delay time of reactive jet to decline,which results in significantly decreasing its penetration performance. 展开更多
关键词 Shaped charge REACTIVE materials LINER Wave SHAPER REACTIVE JET PENETRATION PERFORMANCE
在线阅读 免费下载
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈