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In this study, catalyst formation [Pb(H2O)6][ATZ]·H2O (ATZ = azo tetrazolium anion) was successfully synthesized originally; meanwhile, the single-crystal structure of the compound was cultivated and analyzed by diffraction single-crystal method. The influence of the compound in which [Pb(H2O)6][ATZ]·H2O was used as combustion catalyst on the decomposition temperature of potassium nitrate was studied by TG–DSC. The result proved that [Pb(H2O)6][ATZ]·H2O can effectively reduce the decomposition temperature. In other words, [Pb(H2O)6][ATZ]·H2O can reduce the decomposition temperature of potassium nitrate, so the addition of [Pb(H2O)6][ATZ]·H2O can make potassium nitrate better to be used in the fields of initiating explosive device and fire engineering.

A novel environmental-friendly unpacking powder for fireworks which has no sulfur, no magnesium, no aluminum or their alloys has been prepared in this study: potassium perchlorate (75%), potassium hydrogen terephthalate (13%), micronano porous silicon (9%), carbon (2%), ferrocene (1%). The PM2.5 and PM10 were collected by the ambient air particulate sampler, and the gas product was tested with a smoke analyzer and gas chromatograph to investigate its environmental-friendly performance. The detonation radius was measured by similar triangulation method, and p–t curves were measured in a closed bomb to investigate its practicality. The heat of combustion, sensitivity and hygroscopicity of the formula were measured according to China fireworks industry standard to verify the safety of the novel unpacking powder. The test results suggest that new unpacking powder using micronano porous silicon can effectively reduce the PM content and the product does not contain SO2, so it can be applied to export.

A quantitative feeding system of molten metal was designed based on a special vehicle cover, which achieved the quantitative transport of molten metal in a fully enclosed environment. There are lots of advantages of this novel device, such as improving the accuracy of the molten metal pouring, reducing the oxide inclusions defects, improving the quality of forming parts, etc. The numerical simulation of the casting process of filling mold was carried out based on the software ProCAST, which optimized the processing parameters of the quantitative feeding device. The result shows that the optimal movement speed of the punch piston is 0.08 m/s. The forming process of the aluminum alloy cover was designed and the process was conducted on the novel quantitative feeding device of molten metal. The structure and process performance of the forming parts were summarized and the defects were analyzed. The influence of technological parameters such as pouring temperature, filling speed, initial mold temperature, and feeding distance on the quality of forming parts was studied, which resulted in the optimum process parameters for the dosing device.

Gas generators are the functional materials producing gas by combustion. In situations such as pneumatics, fire extinguishing bomb, air bag, deep-water salvage, the gas generators can be ignited to provide power and energy through rapid release of gas. However, the research about gas generators with low water vapor is blank in world. The most widely used gas generators (such as nitroguanidine gas generators) produce a lot of water vapor through combustion, whose liquefaction will cause the reduction of gas pressure. This work selected 4,5-diazolyl-1,2,3-triazole (BTTZ) as gas-generating material. Two kinds of gas generator formulations based on BTTZ with common oxometallate (KNO3) and metal oxide (CuO) were designed. The properties of these gas generator formulations were studied by calculation and experiments. The gas production, gas production rate, water vapor content, compatibility and mechanical sensitivity were measured. The gas specific volume of the formulation 1 was 4.08 m3 kg−1. The clean harmless gas content reaches 93.55%. The water vapor content of the product was 6.08% (volume percentage), which is much lower than the nitroguanidine gas generators (53.47%). Therefore, formulation 1 is a low-water vapor environmental-friendly gas generator as a cleaner production material with practical value.

Black powder is often used as propellant in the fireworks industry, but the sulphur in the black powder will pose great risks to the environment and human health. Although there are sulphur-free propellant with metal powder and smokeless propellant prepared from expired military gunpowder to solve the problem, the high sensitivity and huge explosive power of the mental powder and instability of the expired military gunpowder lead to low security in actual application. Therefore, sulphur-free propellant which can replace black powder is urgently needed. In this study, a discharge height test was conducted for the sulphur-free environmental protection formulation [potassium perchlorate (70%), potassium hydrogen terephthalate (10%), carbon (11%), ferrocene (1%), phenolic resin (7%), calcium stearate (2%)] optimized by an orthogonal test. The thermal explosion in critical temperature was used to determine the thermal stability of sulphur-free propellant and black powder, then compared with combustion heat. The preesure-time test was used to compare the peak pressure of this two propellant. The impact, friction and flame sensitivity were also measured. It is thought that sulphur-free propellant can replace the black powder as the new environmental-friendly propellant in the fireworks industry with low sensitivity and excellent storage performance, and have great potential in application.

This work sets focus on producing hydrophobic silica and fire-extinguishing-composition solution into dry water extinguishant powder by high-speed shearing. The solid-to-liquid ratio, different stirring periods and rotational speed were taken into account to analyze their influence on the covering effect. The dry water extinguishants containing ammonium dihydrogen phosphate (ADP) and phosphoric acid are respectively produced added with gel. The jet apparatus is improved for the experiment. According to the results, the phosphoric acid gel dry water extinguishant works best to put out Type-A fire. The ADP dry water extinguishant excels in putting out Type-B fire, equivalent to superfine ABC dry powder extinguishant in terms of effectiveness but with a low cost. For this reason, dry water extinguishant has a broad prospect of application.

The normal pyrotechnically generated aerosol extinguishing agent is effective in extinguishing Class B fire, but have difficulty extinguishing the Class A wood-crib fire. To solve this problem, an experiment has been made in this paper to study the extinction effectiveness of a new type of pyrotechnically generated aerosol extinguishing agent in wood crib fire. Differing from the old ones, the new type of pyrotechnically generated aerosol extinguishing agent generates via combustion of aerosol forming agents containing a kind of phosphorus-containing compound named P90x, which is flammable and has been widely used as fire retardants in materials. P90x was added, for the first time, as a reducer into aerosol forming agents to improve the capabilities against the Class A wood-crib fire. Five aerosol forming agents with the different mass ratio of P90x and potassium nitrate were tested for fire extinguishing efficiency. The fire extinguishing efficiency increased as the amount of P90x increases. And the best fire extinguishing efficiency in this experiment was 20 g/m 3 for wood-crib fire. This new type of aerosol extinguishing agents can adhere to the surface of burning wood and react with it to extinguish fire efficiently. Therefore, the Class A fire (wood cribs) can be extinguished by pyrotechnically generated aerosol extinguishing agents for the first time from all over the world.

Up to now, the research studies about 5-aminotetrazole (5-AT) gas generators are still not complete. In this work, ten gas generators based on 5-AT with different ordinary oxidants were designed. A...

The Nalinggou–Daying uranium metallogenic belt is situated at the northern Ordos Basin, China. Petrographical, mineralogical and geochemical techniques were used to study the ore-bearing sandstones and host rocks in the Nalinggou–Daying uranium metallogenic belt. The present study shows that uranium minerals, i.e., coffinite, pitchblende, and brannerite, are mostly disseminated around pyrite and detrital particles. The ore-bearing sandstones are enriched in organic matter, with which this reductive environment influenced uranium leaching. The carbonate concentration of the uranium ores is markedly higher than that of the host rocks, and intense carbonatization occurs in the ore-bearing sandstones. In this case, the usage of the classical in-situ leach uranium mining technique by injecting H2SO4 + H2O2 solution produces calcium sulfate precipitate, which can lead to blocking of the ore-bearing strata. For this reason, laboratory and field uranium mining tests were conducted using CO2 + O2 in-situ leaching technology and were demonstrated to be successful, illustrating that this approach is technically feasible. Inhibiting ore bed blockage and increasing the amount of injected O2 are important for uranium leaching in this setting.

A cup burner was used to measure the minimum fire extinguishing concentrations for methane extinguishment by fine water mist with additives/air co-flow diffusion flames based on ultrasonic atomization. The comparison of the minimum fire extinguishing concentrations of pure and fine water mist revealed that the existence of additives could change the fire extinguishing efficiency of pure water, with their improvement effect ranked as KCl > KH 2 PO 4 > NH 4 H 2 PO 4 . A flame thermal balance equation was established, and a model for predicting the minimum fire extinguishing concentrations of different fire extinguishing agents was developed. A differential scanning calorimeter was used to measure solution heat capacity, and the physicochemical properties of different liquid extinguishers were predicted. When the mass fractions of the additives equated to 2%, the chemical fire extinguishing effect was superior. The influence of additives on fire extinguishing efficiency mainly involves an increase in chemical actions and a reduction in the competition between the evaporative capacities of pure water.

1,5-diaminotetrazolium chloride (DATC) and 1,5-diaminotetrazolium sulfate (DATS) were synthesized in this work. The structures of DATS and DATC were characterized. The single crystal of DATS was first cultured, and its structure was analyzed. The thermal behavior of DATS was investigated. The activation energy and pro-exponential factor were calculated, Ek = 120.86 KJ/mol, Ak = 1012.96 s−1. The density, heat of formation, detonation pressure, and detonation velocity of DATS were first calculated. The detonation pressure and detonation velocity of DATS are P = 11.877 GPa, D = 5.617 km s−1, which are smaller than those of 1,5-diaminotetrazolium nitrate (DATN) (P = 33.3GPa, D = 8.77 km s−1).

The synthesis mechanism of 3-nitro-4-(tetrazol-5-yl)furazan (NTZF) was calculated by Gaussian 09 for the first time, and NTZF was successfully synthesized based on the theoretical design. Its ionic salts (RbNTZF and CsNTZF) were synthesized and studied by single-crystal X-ray diffraction firstly. The thermal stability of NTZF was investigated by TG-DSC and the kinetic data of thermal decomposition were calculated. The sensitivity of NTZF was measured. The formation heat, detonation velocity (D) and detonation pressure (P) of NTZF were calculated. NTZF is insensitive to impact and friction (impact > 40 J, friction > 360 J) and has higher detonation velocity and pressure (D = 7.838 km s−1, P = 27.32 GPa) compared to TNT (D = 6881 m s−1, P = 19.5 GPa). NTZF has appropriate sensitivity and detonation performance, so it can be used as a low explosive and gas generant.

The synthesis and characterization of the 4,5-dicyano-2H-1,2,3-triazole anion in its 5-aminotetrazole, 1,5-diaminotetrazole, and 1,5-diamino-4-methyl-tetrazole salts are reported. All compounds were characterized by IR, 1H NMR, and 13C NMR spectroscopy, as well as elemental analyses. Their thermal decompositions were investigated by TG-DSC. The densities, combustion heats, and sensitivity properties were tested. Additionally, enthalpies of formation, detonation pressures, detonation velocities, and heats of detonation were calculated. The compounds have potential application in the energetic materials field.

The nitrogen content of tetrazolo[l,5-b][1,2,4]triazine is 68.9%. It has a good application prospect in energetic material field. The synthesis was carried out, and the single crystal was cultivated. The analysis showed that the two rings of tetrazolo[l,5-b][1,2,4]triazine are in the same flat, and the molecular accumulation displayed the net-like structure in the space. The thermal decomposition process was studied. The relationship between weight loss and temperature, and the thermal decomposition temperature were gained from thermogravimetry-differential thermogravimetry and differential scanning calorimetry. These provide the reference for its application in energetic material.

1,1′-diisopropylideneamino-5,5′-azotetrozole (DPrZT) was synthesized with 1-isopropylideneamino-5-aminotetrozole as the raw material and sodium urate isocyanide dichloride as oxidant. Three of the most important factors which affect the yield of DPrZT were gained from the single factor experiments. Based on the single factor experiments, the orthogonal experiments were carried out. The most optimal experimental condition was gained as follows: In the first stage, the reaction temperature was 30 °C, the reaction time was 20 min, and the dropping temperature was 30 °C; In the second stage, the reaction temperature was 30 °C, the reaction time was 20 min, and n(HAc):n(SDCI) was 0.5. The maximum yield was 89.6 % under the optimum reaction condition. The structure and performance of DPrZT were studied in detail in this paper. It showed good thermal stability and explosive performance. It exhibited prospective application in explosion field.

As a new azide-free gas generating pyrotechnic composition, the performance of four kinds of 5-aminotetrazole nitrate (5-ATN) gas generating compositions were investigated by hygroscopicity, compatibility, impact sensitivity, heat of combustion and burning temperature measurement. The advantages of the gas generant using KNO3 as an oxidizing agent include small hygroscopicity, better compatibility, lower impact sensitivity and proper burning temperature. The degree of water sorption in the mixed system with Sr (NO3)2 was much higher than that with KNO3. The participation of CuO can reduce the hygroscopicity of the system with Sr (NO3)2. As the oxidizing agent and catalyst, CuO can also decrease the impact sensitivity, heat of combustion and burning temperature of both systems. 5-ATN gas generant provides fair compatibility using 5-ATN as separate system.

An easy method to synthesize hollow carbon nanospheres (HCSs) with polystyrene as template and phenol as precursor is reported. The obtained HCSs have very thin shells and big hollow cores. The diffraction peaks of X-ray diffraction patterns located at about 2 θ = 22° and 43° are assigned to the (0 0 2) and (1 1 0) graphite plane of HCSs. Transmission electron microscopy shows every state in the synthesis process of HCSs.

Ventricular hypertrophy is a powerful and independent predictor of cardiovascular morbid events. The vascular properties of low-dose acetyl salicylic acid (aspirin) provide cardiovascular benefits through the irreversible inhibition of platelet cyclooxygenase 1; however, the possible anti-hypertrophic properties and potential mechanism of aspirin have not been investigated in detail. In this study, healthy wild-type male mice were randomly divided into three groups and subjected to transverse aortic constriction (TAC) or sham operation. The TAC-operated mice were treated with the human equivalent of low-dose aspirin (10 mg·kg(-1)·d(-1)); the remaining mice received an equal amount of phosphate buffered saline with 0.65% ethanol, which was used as a vehicle. A cardiomyocyte hypertrophy model induced by angiotensin II (10 nmol·L(-1)) was treated with the human equivalent of low (10 or 100 μmol·L(-1)) and high (1000 μmol·L(-1)) aspirin concentrations in plasma. Changes in the cardiac structure and function were assessed through echocardiography and transmission electron microscopy. Gene expression was determined through RT-PCR and western blot analysis. Results indicated that aspirin treatment abrogated the increased thickness of the left ventricular anterior and posterior walls, the swelling of mitochondria, and the increased surface area in in vivo and in vitro hypertrophy models. Aspirin also normalized the upregulated hypertrophic biomarkers, β-myosin heavy chain (β-MHC), atrial natriuretic peptide (ANP), and b-type natriuretic peptide (BNP). Aspirin efficiently reversed the upregulation of β-catenin and P-Akt expression and the TAC- or ANG II-induced downregulation of GSK-3β. Therefore, low-dose aspirin possesses significant anti-hypertrophic properties at clinically relevant concentrations for anti-thrombotic therapy. The downregulation of β-catenin and Akt may be the underlying signaling mechanism of the effects of aspirin.

1,1′-Diamino-5,5′-azotetrazole, which was obtained from the reaction of 1,5-diaminotetrazole with acetone, sodium dichloroisocyanurate and acetic acid respectively, was well characterized. Its structure was confirmed by X-ray crystallography and the thermal stability and explosive performance were also investigated.

In the crystal structure of the title compound, C7H10N6O3, there are N—H...O, N—H...N and C—H...O interactions, generating a three-dimensional supramolecular network structure. A short intermolecular O...C contact of 2.8994 (18) Å is alsopresent in the crystal structure, but no π–π contacts are observed.

The molecule of the title compound, C4H8N6, assumes an approximately planar structure, the methyl C atoms and the C atom to which they are bonded being out of the mean tetrazole ring plane by 0.108 and 0.139, and 0.144 Å, respectively. π–π stacking between parallel tetrazole rings [centroid–centroid distance = 3.4663 (11) Å] is observed in the crystal structure. Intermolecular N—H...N hydrogen bonding further helps to stabilize the crystal structure.