Detonation Propagation Characteristics of Superposition Explosive Materials

In order to investigate detonation propagation characteristics of different charge patterns,the detonation velocities of superposition strip shaped charges made up of a detonating cord and explosives were measured by a detonation velocity measuring instrument under conditions of different ignition.The experimental results and theoretical analysis show that the maximum detonation propagation velocity depends on the explosive materials with the maximum velocity among all the explosive materials.Using detonating cord in a superposition charge can shorten detonation propagation time and improve the efficiency of explosive energy.The measurement method of detonation propagation velocity and experimental results are presented and investigated.

Initiation behavior of covered explosive subjected to reactive fragment

Reactive fragment enhances lethality by incorporating the defeat mechanisms of kinetic energy and chemical energy into a unitary damage unit. Combined studies on the behavior of reactive fragment initiating covered explosive are performed theoretically and experimentally. The results in- dicate that the response of the covered explosive subjected to reactive fragment is not consistent with the classical shock initiation model. When impacting and penetrating into the covered explosive, the reactive fragment releases great amounts of thermo-chemical energy up to 5. 68 times of its kinetic energy into the explosive due to violent chemical reactions. This impact-induced chemical energy re- lease behavior of the reactive fragment significantly enhances the initiation capability and damage effects on the covered explosive.

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

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 performance.For 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 explosives.The 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 RDX.This 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 decade.This review aims to provide a fresh concept for designing nitro-tetrazole based high performing explosives together with major challenges and perspectives.

Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one

Study on energy release characteristics of reactive material casings under explosive loading

Reactive Materials(RMs),a new material with structural and energy release characteristics under shockinduced chemical reactions,are promising in extensive applications in national defense and military fields.They can increase the lethality of warheads due to their dual functionality.This paper focuses on the energy release characteristics of RM casings prepared by alloy melting and casting process under explosive loading.Explosion experiments of RM and conventional 2A12 aluminum alloy casings were conducted in free field to capture the explosive fireballs,temperature distribution,peak overpressure of the air shock wave and the fracture morphology of fragments of reactive material(RM)warhead casings by using high-speed camera,infrared thermal imager temperature and peak overpressure testing and scanning electron microscope.Results showed that an increase of both the fireball temperature and air shock wave were observed in all RM casings compared to conventional 2A12 aluminum ally casings.The RM casings can improve the peak overpressure of the air shock wave under explosion loading,though the results are different with different charge ratios.According to the energy release characteristics of the RM,increasing the thickness of RM casings will increase the peak overpressure of the near-field air shock wave,while reducing the thickness will increase the peak overpressure of the far-field air shock wave.

A Water-stable Metal-organic Framework for the Detection of Explosives and Antibiotics

A water-stable zinc-organic framework, Zn(bpda)(hip)·(DMF)(H2O)(1, H2bpda = N4,N4’-di(pyridin-4-yl)biphenyl-4,4’-dicarboxamide, H2 hip = 5-hydroxyisophthalic acid), has been synthesized via solvothermal reactions. Compound 1 exhibits strong fluorescence emission in water and can be used to detect various nitroaromatic explosives and antibiotics by means of fluorescence quenching in aqueous solution.

Fluorescent Silk Obtained by Feeding Silkworms with Fluorescent Materials

Comprehensive Summary Fluorescent silk has potential application in many fields such as bioimaging,tissue engineering scaffolds,luminescent marks,and dazzling fabrics.Among the methods to endow natural silk with fluorescent properties,feeding silkworms with fluorescent additives is facile,low-cost and environment friendly,which has the prospect of large-scale production.In this paper,we reviewed the research progress for this aim in the past ten years,and summarized the unified characteristics for the substances that can enter the silk gland by digestive tract of silkworms.The advantages and disadvantages of various fluorescent materials for this application are compared in detail.And the future research directions are suggested to overcome the shortcomings of the present research.

A Fluorescent In (Ⅲ) Metal-Organic Framework for Explosives Detection

Anovel metal-organic framework{[In_(3)(TATAT)_(2)]·3CH_(3)NH_(3)·7NMF·8H_(2)O}[JLU-MOF101,H_(6)TATAT=5,5′,5″-(1,3,5-triazine-2,4,6-triyl)tris-(azanediyl)triisophthalate,NMF=N-methyl-formamide]with cor topology has been synthesized under solvothermal conditions.The framework of JLU-MOF101 is constructed by{In(COO)_(4)}-nodes and a hexacarboxylic organic ligand.JLU-MOF101 exhibits excellent fluorescence properties in N,N-dimethylformamide(DMF)solution,and its emission spectrum can be greatly overlapped with the ultraviolet absorption spectra of trinitrophenol(TNP)and 2,4-dinitrophenol(2,4-DNP).As a result,JLU-MOF101 exhibits excellent performance of fluorescence quenching for TNP and 2,4-DNP.In addition,we demonstrate the selective detection capability of JLU-MOF101 through a large number of anti-interference tests.

Portable hydrogel-based tri-channel fluorescence sensor array for visual detection of multiple explosives

The identification and detection of various types of explosives are essential for human health and environmental monitoring.Array-based sensing approach offers significant advantages in detecting multi-analytes simultaneously,thereby holding great potential in identifying multiple explosives.Here,we report a tri-channel fluorescence array composed of three distinct fluorescence probes based on gold nanoclusters and nicotinamide adenine dinucleotide with well-separated emission colors.Through the specific interactions of explosives with different fluorescent probes and the yielded response patterns,seven explosives can be successfully distinguished with 100%accuracy.In particular,the sensor array exhibits excellent performance in the quantitative analysis of individual explosive and the differentiation of multiple explosive mixtures.To facilitate the field detection towards practical application,the tri-channel fluorescence array was further integrated with polymer hydrogels.The fabricated portable hydrogel-based array sensors can not only visually identify seven different explosives by their distinct fluorescence color change,but also enable quantitative detection based on linear discriminant analysis(LDA)together with a smartphone.This study illustrates the great potential of hydrogel-based fluorescence sensor array as robust sensors for explosives,which also holds significant promise for the development of portable explosive devices towards practical application.

A selective and stepwise aggregation of a new fluorescent probe for dinitrate explosive differentiation by self-adaptive host-guest interaction

Nitrate explosive is hard to detect due to lack of aromatic ring and weak interaction with fluorescence probe.More challenging is even to differentiate the dinitrates with multiple nitrate explosives based on photo induced electron transfer or aggregation caused fluorescence change mechanism.A highly selective dinitrate explosive probe was designed based on a new strategy-stepwise aggregation of multiple anchored fluorene dimer 8Py-2 F.Compared with its monomer counterpart 2Py-F,8Py-2 F showed a selective and stepwise fluorescence quenching to dinitrate explosives-ethylene glycol(EGDN)and triethylene glycol dinitrate(TEGDN).The limits of detection(LODs)are 2.72μM for TEGDN and 0.46μM for EGDN,which is three orders of magnitude lower than those of 2Py-F.The stepwise quenching process is well matched with the stepwise aggregation process as evidence by scanning electron microscopy(SEM).Nuclear magnetic resonance(NMR)and quantum chemical calculation proved the interaction force between the dinitrate and 8Py-2 F is hydron bonding interaction,and interaction distance is far less than that of the multiple nitrates coming from the flexibility of the chain and steric hinderance,which resulted in a self-adaptive interaction and higher selectivity.The new strategy is beneficial for the differentiation of the chemicals with similar energy level which is difficult to realize via other method,and the new method provides fluorometric probe for dinitrate explosive detection and makes it an ideal candidate for chemical detection and analysis in public safety and environmental monitoring.

Synthesis of novel thieno-[3,4-b]-pyrazine-cored molecules as red fluorescent materials

Two novel thieno-[3,4-b]-pyrazine-based molecules, TP-E and TP-O, were designed and synthesized for potential application as red fluorescent emitters. The bulky tetraphenylethylene groups were attached at the periphery of the thieno-[3,4-b]-pyrazine core to form the non-planar molecules, as efficient solid- state emitting materials. The peripheral groups were grafted to the emissive core through either a conjugated acetylene bond, or a non-conjugated ether bond. These molecules exhibit strnng red fluorescence in both dilute solutions and in thin films with large Stokes shifts of over 100 nm. The cyclic voltammetry measurements showed the reversible oxidation and reduction behavior for both compounds. All these properties indicate the two compounds are possible functional materials for use in ontoelectronic devices.

Pillararenes as Versatile Building Blocks for Fluorescent Materials

Fluorescent materials have received more and more attention in the past few decades because of their great potentials in the fields of luminescent devices,sensing,data storage,bioimaging,and other optical applications.Fluorescent materials comprising organic molecules are of broad interest owing to their highly tunable emission.Initial studies on organic fluorescent materials were mainly focused on the design and covalent modification of fluorophores in order to improve their photophysical properties at the molecular level,whereas in recent decades,many studies have revealed that the intermolecular or intramolecular noncovalent interactions also play a crucial role in luminescence.For example,the modulation of noncovalent interactions in aggregates and selfassemblies was proven to be capable of adjusting aggregation-induced emission(AIE)-active fluorophores by the restriction of intramolecular motions(RIM).In addition,in the crystalline state,intermolecular noncovalent interactions are able to promote phosphorescence by decreasing nonradiative decays.Introducing supramolecular macrocycles into organic fluorescent materials is an intriguing prospect because multiple noncovalent interactions are incorporated.On one hand,the photophysical properties of fluorophores can be changed upon inclusion within the macrocycles,providing unforeseen luminescence.On the other hand,the dynamic and reversible features of host−guest recognition endow the materials with controllability and stimuli-responsiveness,which is beneficial to the fabrication of smart materials.Among numerous supramolecular macrocycles,pillararenes are promising candidates that can be included in fluorescent materials.The advantages of pillararenes are their easy functionalization and planar chirality.After modification with proper substituents,pillararene derivatives possess high solubility and stability in both organic and aqueous media,and reversible guest binding remains.Such features make pillararenes versatile hosts in different environments.Additionally,pillararenes are planar chiral,and the interconversion between enantiomers can be adjusted with different-sized substituents and external stimuli,which are favorable to the construction of chiroptical materials.In this Account,we summarize research progress in the field of pillararene-based luminescent materials,which mainly includes the contributions made by our group.Using pillararenes as building blocks can facilitate the fabrication of high-performance fluorescent materials,in solution or the solid state,with different functions and mechanisms.Therefore,we categorize pillararene-based luminescent materials as those in solution or in the solid state.The applications and the advantages of pillararenes are discussed in detail.For example,in the solid state,pillararene-based host−guest complexation is capable of minimizing the aggregation-caused quenching(ACQ)of fluorophores.This broadens the application of fluorophores in crystalline materials.In solution,the host−guest complexes of pillararenes and fluorophores can self-assemble into well-defined nanostructures,which not only adjust the photophysical properties but also enable functions such as bioimaging.The remaining challenges and future perspectives are outlined at the end.It is expected that this Account will inspire new researchers in different fields and offer new opportunities for the construction of novel luminescent materials with pillararenes and other macrocycles.

Cooperative Supramolecular Polymerization of Propeller-Shaped Triphenylamine Cyanostilbenes for Explosive Detection

Self-assembly ofπ-conjugated compounds into supramolecular polymers has received considerable attention because of their intrinsic scientific interests and technological applications.As compared toπ-conjugated rods,discotics,and macrocycles,propeller-shapedπ-conjugated molecules have been less exploited to form long-range-ordered supramolecular polymers.Herein a novel type of supramolecular polymers has been constructed on the basis of propeller-shaped triphenylamine cyanostilbenes.The designed compound adopts nucleation-elongation cooperative mechanism for the supramolecular polymerization process,because of the participation of three-fold hydrogen bonds between the neighbouring monomers.The supramolecular polymeric state displays amplified chirality and enhanced emission than those in the monomeric state.The resulting supramolecular polymers exhibit severe emission quenching upon addition of 2,6-dinitrotoluene,ascribed to photoinduced electron transfer from the triphenylamine cyanostilbenes to the explosive analyte.The current study proves the feasibility to supramolecular polymerize propeller-likeπ-conjugated molecules,serving as a promising type of explosive sensor owing to their guest encapsulation and signal amplification capabilities.

Synthesis, Characterization of A Novel Polymeric Reaction Monomer for Preparing Highly Fluorescent Rare Earth Polymer Materials

A novel polymeric reaction monomer (NPRM) for preparing highly fluorescent rare earth polymer materials was synthesized via interface and coordinating reaction. The composition and structure of the NPRM and intermediate product (ligand) were characterized through the Fourier transform infrared spectroscopy (FT-IR), carbon-nuclear magnetic resonance spectrum (13CNMR), Mass spectra (MS), and element analysis data. The results showed that the composition and structure of NPRM agreed with that of anticipated product. The NPRM was composed of two important sections. Section 1 was able to provide excellent fluorescent properties for final rare earth polymer material through the effect energy transfer between ligand and rare earth ion; Section 2 would endow with the NPRM excellent polymeric active and form highly fluorescent rare earth polymer material. Fluorescent properties of the NPRM were also researched via a CARY ECLIPSE fluorescent spectrometer. The results showed that the NPRM possessed excellent luminescent properties. The corresponding emission peaks based on the 5D0→7F1(601.6 nm), 5D0→7F2(625.0 nm), 5D0→7F3(660.5 nm) and 5D0→7F4(706.3 nm) transitions for Eu3+ were observed. The strongest emission peak was at 625 nm, which belonged to 5D0→7F2 transition.

纳米铝粉在炸药中的应用研究进展及趋势

铝粉是火炸药行业中最常用的金属燃料。相比微米铝粉,纳米铝粉的比表面积、反应活性和反应完全性都高得多。因此,将纳米铝粉应用于炸药中,无疑将改善炸药的反应完全性,增加炸药威力,提高弹药的毁伤效能。本文系统综述了纳米铝粉对爆轰性能、安全性能、工艺性能等多种炸药性能的影响。就爆轰性能而言,纳米铝粉可以提高混合炸药几乎所有的爆轰参数,包括爆速、爆热、空中爆炸的冲击波超压峰值、水下爆炸的总能量、燃料空气炸药的爆炸压力峰值和爆炸压力上升速率、金属加速能力、纵火能力、作功能力及猛度等,可以全方位提高混合炸药的毁伤效果。但是,由于部分研究者选用的纳米铝粉有效铝含量差异较大,常常得出不同的结论。就安全性能而言,纳米铝粉的引入提高了混合炸药的撞击感度、摩擦感度、冲击波感度、热感度等,显著降低了炸药的点火能,并且对常用炸药(如TNT、RDX、HMX、CL-20、NG、TATB等)热分解有促进作用,导致纳米炸药的引入对混合炸药的安全性能有不利影响;就工艺性能而言,在浇注固体炸药体系中,纳米铝粉增加了浇注固体炸药体系的粘度,降低了压装炸药体系中炸药药柱的密度,纳米炸药的引入恶化了混合炸药的工艺性能。本文指出,由于纳米铝粉的比表面积大、反应活性高,从制备到储存的各个环节极易氧化,造成纳米铝粉的有效铝含量急剧降低,是部分研究者得到错误结论的一个重要原因。因此,应深入研究纳米铝粉的制备方法和存储条件,使纳米铝粉在炸药中充分发挥效能。

综合洗消体系对阻断非洲猪瘟病毒传入猪场的作用

切断非洲猪瘟病毒(ASFV)传播途径是防控非洲猪瘟的有效手段。本试验旨在通过在某种猪场建立综合洗消体系以阻断ASFV传入。对拟进入猪场的车辆在出发前和距猪场1 km处清洗和消毒,在猪场门口进行第3次消毒;人员进入猪场前洗澡和隔离,并将其衣物消毒;输入物资进场前消毒。通过实时荧光定量PCR检测经洗消的车辆、人员、物资和猪场内猪只携带ASFV核酸情况,酶联免疫吸附测定(ELISA)检测猪只的ASFV抗体水平。结果显示,2019、2020、2021和2022年,车辆ASFV检出率分别为2.6%、1.3%、0和0,人员ASFV检出率分别为3.0%、1.1%、0和0.9%,物资ASFV检出率分别为12.5%、0、5.9%和0;4年间,猪场内猪只的ASFV核酸和抗体检测均为阴性。结果表明,通过建立完善的洗消体系并开展ASFV检测,能有效阻断ASFV传入猪场。

我国民爆物品爆炸事故统计分析及防范对策

为分析我国民爆物品爆炸事故一般性规律与事故原因,对2006—2023年全国民爆物品爆炸事故的发生时间、地区分布、事故等级等维度进行事故统计与分析,使用层次分析法构建了包含人、机、环、制度4个一级指标和安全意识、技术培训、监管力度、安全教育、标准化作业、生产设备、生产工艺、天气气候、仓储条件、安全管理体制、应急管理制度共11个二级指标的层次结构模型,通过分析得到各指标权重进而对爆炸事故影响因素做出重要性排序。研究结果表明:爆炸事故发生次数逐年降低,安全形势转好,时间上集中于每年的第2、3季度,空间上以“南北高低交错”特征分布于各省份,事故等级中一般事故、较大事故占据主导地位;基于层次分析法得知一级指标中人是造成事故的最主要因素,二级指标中标准化作业、生产工艺、监管力度和安全管理体制是比较重要的几项因素,最后针对事故影响因素重要度提出了严格标准化作业、增加安全投入、加强监管力度和完善安全管理体制的预防措施。

荧光染色工艺研究进展

综述了荧光染色工艺近期的研究进展。介绍了黄色发光荧光染料、红色发光荧光染料和橙色发光荧光染料的分光光度颜色测量结果及其与EN471标准要求的匹配性以及荧光染料在材料涂料工业上的应用,以调整材料的表面性能。

静电组装低感度CL-20@GO核壳复合材料的制备及性能研究

为降低六硝基六氮杂异伍兹烷(CL-20)的机械感度,提高其综合性能,以3-氨丙基三乙氧基硅烷(APS)为改性剂对CL-20改性,以氧化石墨烯(GO)为包覆材料,利用静电自组装方法对改性CL-20炸药进行表面包覆,制备得到CL-20@GO核壳复合材料;采用水接触角测试、扫描电子显微镜(SEM)和X射线光电子能谱(XPS)等对样品进行形貌表征;利用差示扫描量热仪(DSC)测试其热性能,并测试了其机械感度。结果表明,经质量分数5%的APS溶液改性的CL-20成功引入氨基基团,亲水性效果最佳;GO层包覆改性CL-20完整,致密性强;与原料CL-20相比,CL-20@GO核壳复合材料的活化能提高了63.0kJ/mol,撞击感度(H 50)由13.0cm提升至23.5cm,摩擦感度由100%降至24%,表明采用静电自组装的GO涂层可以明显降低CL-20的感度。