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Recent advances in the synthesis and energetic properties of potassium-based potential green primary explosives

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Defence Technology（防务技术） 2022年第11期18卷 1945-1959页

作者： Qamar-un-Nisa Tariq Saira manzoor maher-un-Nisa Tariq Wen-Li Cao jian-Guo Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Department of Chemistry University of OkaraOkara56300Pakistan

Primary explosives are utilized as a reliable initiator for secondary explosives in an extensive range of military and civilian operations. Heavy-metal-based primary explosives are moderate performing, more sensitive, and environmentally hazardous, posing a direct and indirect threat to health and ***, heavy-metal-based primaries have been replaced by environment-friendly metal-based primary explosives, such as potassium complexes. This review presents not only a summary of the current progress of new-generation potassium-based primary explosives and their methods of preparation, energetic properties, and applications, but also a further comparison with traditional primary explosives. In addition, this work discusses the necessity of heavy metal-free primary explosives and the major challenges faced in replacing traditional primary explosives.

关键词： Green primary explosives Heterocyclic compounds Synthesis Energetic properties

Spiking neural P systems with neuron division and budding

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Science China(Information Sciences) 2011年第8期54卷 1596-1607页

作者： P■un Gheorghe PREZ-jIMNEZ mario j. Department of Computer Science and Artificial Intelligence university of Sevilla Avda Reina Mercedes s/n 41012 Sevilla Spain Institute of mathematics of the Romanian Academy PO Box 1-764 014700 Bucuresti Romania

Spiking neural P systems are a class of distributed and parallel computing models inspired by spiking *** this work,the features of neuron division and neuron budding are introduced into the framework of spiking neural P systems,which are processes inspired by neural stem cell division. With neuron division and neuron budding,a spiking neural P system can generate exponential work space in polynomial time as the case for P systems with active *** this way,spiking neural P systems can efficiently solve computationally hard problems by means of a space-time tradeoff,which is illustrated with an efficient solution to SAT problem.

关键词： natural computing membrane computing spiking neural P system neuron division

Low-cost hybrid integrated 4 × 25.78 Gb/s CWDM TOSA for 10 km transmission using DFB-LDs and an arrayed waveguide grating multiplexer

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Photonics Research 2018年第11期6卷 1067-1073页

作者： j1un LIU QINGZHONG HUANG SHIQI TAO CHENG ZENG jINSONG xia Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

We have developed a cost-effective and highly compact 100-Gb/s coarse wavelength division multiplexing(CWDM) transmitter optical subassembly(TOSA) using lens-free hybrid integration. To achieve large alignment tolerances, distributed feedback laser diodes(DFB-LDs) are butt-coupled to a four-channel silica-based planar lightwave circuit(PLC) arrayed waveguide grating, with the silicon sub-mounts and PLC adhesively ***, a flexible printed circuit is employed to connect the internal DFB-LDs and the exterior of the TOSA package for radiofrequency signal transmission, eliminating the expensive ceramic feed-through. The packaged CWDM TOSA, which is 15.8 mm × 7.0 mm × 6.0 mm in size, shows a side-mode suppression ratio of>40 dB, a 3 dB bandwidth of >18 GHz, and error-free transmission with an average optical output power of >0 dBm and dynamic extinction ratio of >4.0 dB at 25.78125 Gb/s over a 10 km single-mode fiber for all four lanes.

关键词： DFB PLC AWG Figure Low-cost hybrid integrated 4

Bending properties of extruded AZ91–0.9Ca–0.6Y alloy and their improvement through precompression and annealing

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journal of magnesium and Alloys 2022年第8期10卷 2238-2251页

作者： jong un Lee Gyo Myeong Lee Sung Hyuk Park School of materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

In this study,an extruded Mg–9Al–1Zn–0.3Mn–0.9Ca–0.6Y(AZXW9110)alloy is subjected to precompression and subsequent annealing(PCA)treatment for improving its bending formability,and the three-point bending properties of the as-extruded material and the precompressed and subsequently annealed(PCAed)material at room temperature are *** bending,microcracks formed in undissolved Al2Ca,Al2Y,and Al8Mn4Y particles propagate along the grain boundaries or twin boundaries and consequently form a macrocrack in the tension zones of the bending samples of both the ***,the bending formability of the PCAed material is 75%higher than that of the as-extruded material owing to the promoted twinning and slip behaviors in the *** as-extruded material has a strong normal direction(ND)texture and a weak transverse direction(TD)texture,and the ND-and TD-oriented grains are unfavorable for both{10–12}twinning and basal slip in the tension zone of the bending sample of this material,which eventually results in its low bending *** PCAed material has a strong extrusion direction(ED)texture,weak TD texture,and spread ND *** bending,{10–12}twins are fully formed in the ED-oriented grains,and this{10–12}twinning effectively accommodates the plastic strain in the tension *** addition,the activation of basal slip in the ND-oriented grains of the PCAed material is promoted owing to the spread ND texture of this ***,this material exhibits substantially superior bending formability because of the vigorous{10–12}twinning in its ED-oriented grains and promoted basal slip in its ND-oriented grains.

关键词： magnesium Bending Formability Twinning Texture

Influence of Bi addition on dynamic recrystallization and precipitation behaviors during hot extrusion of pure Mg

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journal of materials Science & Technology 2020年第9期44卷 62-75页

作者： jongbin Go jong un Lee Hui Yu Sung Hyuk Park School of materials Science and Engineering Kyungpook National UniversityDaegu41566Republic of Korea School of materials Science and Engineering Hebei University of TechnologyTianjin300130China

Low material cost and high extrudability for ensuring price competitiveness with Al alloys,as well as excellent mechanical properties,are essential for expanding the application range of Mg *** is a promising alloying element for developing extruded Mg alloys that satisfy such *** is inexpensive,exhibits a high solubility limit,and forms a thermally stable Mg3Bi2 phase,which improves the commercial viability and enables the high-speed extrusion of Mg–Bi *** this study,the effects of Bi addition on the dynamic recrystallization(DRX)and dynamic precipitation behaviors during hot extrusion of a pure Mg and the resultant microstructure and mechanical properties of the extruded materials were *** addition of 6 wt%and 9 wt%Bi to a pure Mg yielded numerous fine Mg3Bi2 precipitates during the early stage of hot ***,the area fraction of dynamic recrystallized(DRXed)grains decreased because of DRX-behavior suppression by the Zener pinning ***,the DRXed grain size was substantially reduced through the grain-boundary pinning *** size and number of undissolved Mg3Bi2 particles in the homogenized billets increased when the Bi content was increased,which resulted in increased DRX fractions owing to the enhanced levels of particle stimulated *** addition yielded considerable strength improvement of the extruded pure ***,the extruded Mg–Bi binary materials were less ductile than the extruded pure Mg *** lower ductility resulted from the cracking at twins formed in the coarse unDRXed grains of the Mg-6Bi material and the cracking at large undissolved Mg3Bi2 particles in the Mg-9Bi material.

关键词： magnesium Bi addition Extrusion Recrystallization Precipitation

Effects of surface roughness on bending properties of rolled AZ31 alloy

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journal of magnesium and Alloys 2023年第4期11卷 1224-1235页

作者： Gyo Myeong Lee jong un Lee Sung Hyuk Park School of materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

This study investigated the effects of mechanical-polishing-induced surface roughness and the direction of polishing lines on the bending properties of a rolled AZ31 *** this end,three-point bending tests were performed on one sample without polishing lines(SS sample)and two samples with polishing lines—one in which the polishing lines were parallel to the rolling direction(RS-RD sample)and the other in which they were parallel to the transverse direction(RS-TD sample).In all three samples,macrocracks were formed in the width direction on the outer surface,where tensile stress was predominantly generated in the longitudinal ***,the macrocracks formed in the SS sample were curved because of the merging of uniformly formed fine microcracks,whereas those formed in the RS-TD sample were linear owing to the formation of relatively coarse microcracks along the polishing *** bendability of the samples was in the order of SS>RS-RD>RS-TD,and their limiting bending depths were 4.8,4.6,and 4.4 mm,*** the presence of mechanical-polishing-induced surface roughness,polishing lines perpendicular to the direction of the major stress(i.e.,tensile stress along the longitudinal direction)resulted in a greater degree of stress concentration on the outer surface of the bending *** higher stress concentration promoted the formation of undesirable{10–11}contraction and{10–11}–{10–12}double twins—which typically act as crack initiation sites—and thereby facilitated crack generation and ***,the surface roughness caused premature fracture during bending deformation,which,in turn,caused deterioration of the bendability of the rolled Mg alloy.

关键词： AZ31 alloy Bending Surface roughness Stress concentration Crack

Morphotaxonomy and seasonal distribution of planktonic and benthic Prorocentrales in Karachi waters,Pakistan Northern Arabian Sea

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Chinese journal of Oceanology and Limnology 2013年第2期31卷 267-281页

作者： Sonia MunIR Zaib-un-nisa BURHAN Tahira NAZ P.j.A.SIDDIQUI Steve L.MORTON Centre of Excellence in marine Biology University of Karachi-75270Pakistan National Oceanic and Atmospheric Administrations 219 Fort Johnson RoadCharleston SC29412USA

Morphotaxonomy and seasonal abundance of dinoflagellates of the genera Prorocentrum and Mesoporos （Prorocentrales） were studied from nutrient-rich waters, Karachi Harbor and the mouth of the manora Channel, Pakistan during may 2002-july 2003. Using both light and scanning electron microscopy, 13 species of Prorocentrales were identified according to cell shape, size, ornamentation of thecal plates, and architecture of apical platelets, apical pore area, marginal pores, and intercalary bands. P. sigmoides, P. arcuatum, P. scutellum, P. donghaiense, P. balticum, P. minimum, P. emarginatum, P. lima, P. faustiae, and Mesoporos perforatus constitute new records for sindh coast of Pakistan. The most abundant species were P. minimum/P, balticum （4.5x103 cells/L）, P. micans （1.1~103 cells/L）, P. gracile/P, sigmoides （2.5 x 102 cells/L） and P. donghaiense （6.6 x 103 cells/L） at temperatures of 29-31 ~C and salinities of 35-40. maximum abundance was observed in winter and lower abundance in summer. There was no significant change in the distribution of species between stations except for the benthic species which occurred close to Karachi Harbor waters. Significant positive correlations were observed between Prorocentrum spp. and temperature （R2=0.27） and negative correlations with salinity （R2=-0.32） except for P. minimum and P. emarginatum which has negative correlation with temperature （R2=-0.24） and positive with salinity （R2=0.08, 0.19）. The finding of potential okadaic-acid producing species of benthic Prorocentrum call for monitoring for possible human health problems in this region.

关键词： ecology morphology planktonic/benthic Prorocentrales harmful algae scanning electronaaicroscopy northern Arabian Sea

Numerical modeling of sedimentation control scenarios in the approach channel of the Nakdong River Estuary Barrage,South Korea

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International journal of Sediment Research 2016年第3期31卷 257-263页

作者： un ji Eun-Kyung jang Gwonhan Kim Hydro Science and Engineering Research Institute Korea Institute of Civil Engineering and Building Technology

The effects of sedimentation reduction at the Nakdong River Estuary Barrage(NREB) in Korea were quantitatively analyzed with respect to different sediment control methods using the calibrated and validated two-dimensional *** countermeasures of sediment dredging,sediment flushing,channel geometry change,and a combination of flushing and channel geometry change were examined for the approach channel of the *** flood event and channel geometries of the 3.8 km section upstream of the NREB surveyed before and after dredging in 2007 were used for modeling *** a result,the half of sediments dredged in 2007 could be eliminated naturally by floods without *** numerical simulation of sediment flushing indicated that the deposition height decreased in the entire simulation section with the minimum and maximum reductions from 0.3 in to1.3 m in deposition *** channel contraction method produced quantitatively the largest amount of sedimentation reduction and sediment flushing and dredging *** reduction by a combination of flushing and channel contraction was up 10%compared to the individual method of channel contraction.

关键词： Channel contraction Nakdong River Estuary Barrage Sediment dredging Sediment flushing Sedimentation reduction

Nitro-tetrazole based high performing explosives:Recent overview of synthesis and energetic properties

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Defence Technology（防务技术） 2021年第6期17卷 1995-2010页

作者： Saira manzoor Qamar-un-nisa Tariq Xin Yin jian-Guo Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

Heterocyclic skeleton(Azoles)and different energetic groups containing high performing explosives are highly emerged in recent years to meet the challenging requirements of energetic materials in both military and civilian applications with improved *** this purpose tetrazole(Azole)is identified as an attractive heterocyclic backbone with energetic functional groups nitro(-NO_(2)),nitrato(-ONO_(2)),nitrimino(-NNO_(2)),and nitramino(eNHeNO_(2))to replace the traditionally used high performing *** tetrazole based compounds having these energetic functional groups demonstrated advanced energetic performance(detonation velocity and pressure),densities,and heat of formation(HOF)and became a potential replacement of traditional energetic compounds such as *** review presents a summary of the recently reported nitro-tetrazole energetic compounds containing poly-nitro,di/mono-nitro,nitrato/nitramino/nitrimino,bridged/bis/di tetrazole and nitro functional groups,describing their preparation methods,advance energetic properties,and further applications as highperforming explosives,especially those reported in the last *** review aims to provide a fresh concept for designing nitro-tetrazole based high performing explosives together with major challenges and perspectives.

关键词： Tetrazole Energetic materials Functional groups Heterocyclic High-performing explosives