5-氨基四唑镍的合成及热分析研究

以5-氨基四唑和硝酸镍为原料,合成了5-氨基四唑镍。最佳反应条件为:温度60～70℃,反应物物质的量比为n(硝酸镍):n(5-氨基四唑)=0.2,反应时间3～4 h,pH值3～4。TG-DTA热分析表明,5-氨基四唑镍主要有两个吸热峰,第1个吸热峰在90℃左右,第2个吸热峰在210℃左右。     

唑、嗪和呋咱类富氮化合物热行为研究进展

综述了近年来国内外关于唑、嗪和呋咱类富氮化合物热行为的研究进展,分析总结了热行为研究的方法,得出了化合物结构和取代基团对化合物热稳定性的影响规律。研究表明,富氮化合物热稳定顺序为:呋咱类嗪类唑类;三唑四唑五唑;三嗪四嗪,这是由于含碳量、骨架张力和共平面等因素引起的。引入硝基、偶氮键、氰基和叠氮基等含氮基团会降低热稳定性,这是由于取代基团的吸电子效应引起的。富氮环之间的共轭效应可以有效增强分子化合物的热稳定性。指出将热分析与理论计算及气相色谱结合来推断反应机理是未来相关研究的一个方向。     

5-(4-叠氮呋咱基)-[1,2,3]三唑[4,5-c]并呋咱内盐的合成、晶体结构及性能

以3,4-二氨基呋咱为原料,经重氮化-叠氮化、氧化-环化等反应合成了一种新型无氢富氮含能材料5-(4-叠氮呋咱基)-[1,2,3]三唑[4,5-c]并呋咱内盐(AFTF);采用红外光谱、核磁共振、元素分析等方法表征了目标物的结构;获得了AFTF的单晶并进行了晶体结构解析;采用DSC方法研究了AFTF的热稳定性,初步探讨了氧化-环化反应机理;采用Gaussian 09程序CBS-QB3方法计算了AFTF的固相生成热,基于晶体密度和固相生成热,利用EXPLO5爆轰软件预估了AFTF的爆轰性能。结果表明,化合物AFTF晶体为正交晶系,空间群为P 2(1)2(1)2(1),晶胞参数为:a=8.1782(17),b=8.6446(18),c=11.521(2),V=814.5(3)3,Z=4,μ=0.151 mm^-1,F(000)=440;AFTF的熔点为101.02℃,热分解温度为186.39℃;AFTF晶体密度为1.795 g/cm 3(296 K),氮含量为63.6%,理论爆速为8.982 km/s,爆压为33.5 GPa,生成热为1178.9 kJ/mol,爆热为6450.8 kJ/kg,表明AFTF是一种爆轰性能优良的无氢富氮高能量密度化合物,有望应用于高能推进剂或气体发生剂领域;低熔点特性有望使其作为熔铸炸药载体使用。     

Above- and belowground litter stocks and decay at a multi-species afforestation site on arid,saline soil

We evaluated the annual stocks and decay rates of leaf litter, green foliage, and fine roots at a multiple-species afforestation site using the litterbag technique over 3 years. During the course of each year the decomposition of all residue types exhibited a pattern of initially rapid loss of mass over winter followed by decomposition rates that were effectively zero for the rest of the year. Depending on the year of measurement and tree species, decay constants defined by the asymptotic function (k _a ) for foliar materials ranged between 3 and 16 year^?1, with 55–74 % of the initial mass remaining after 1 year of field exposure. The greatest amount of mass remaining was observed in the third year when topsoil salinity increased to a point (11–18 dS m^?1) that it inhibited decomposition, superseding the influences of species characteristics and soil moisture. For foliar materials, the remaining stable fraction was smaller in Elaeagnus angustifolia that also showed a slower decay rate than other species. Fine roots (at a depth of 30 cm) degraded faster in all species, with 33–38 % of the initial mass remaining. The decay rates were lowest for Ulmus pumila roots, which were characterized by relatively dense tissue. The greater production and decomposition of nitrogen-rich residue might explain the superior performance of E. angustifolia in improving saline soil productivity. Irrespective of species, the carbon returns through the relatively fast decomposition of fine roots benefit soil fertility, whereas large inputs of slowly decomposing foliar residues represent carbon sequestration in the aboveground litter pool.     

450 kt/a合成氨装置在富氮天然气条件下运行讨论

以设计条件为比较基准,分析450 kt/a合成氨原料组分变化对其系统的影响;探讨合成氨装置在富氮天然气条件下性能表现,针对未来几年天然气供应计划,提出在该条件下合成氨的运行方案.     

富氮膜分离过程的理论分析和实验研究

本文对用中空纤维膜从空气中富集氮气的过程进行研究,较好地揭示了过程中各参数及膜性能与分离结果的关系.改变实验条件可得到浓度为85%～99.6%的富氮气体,回收率为78%～23%.实验对理论模型进行了验证,结果表明,在实验浓度范围内采用柱塞流逆流模型和全混柱塞流模型的计算值与实验值基本吻合,模型可以满足工业模拟和设计要求.     

Structural analysis of tars from fluidized-bed pyrolysis of coal. 1. Gas-liquid chromatography of aliphatic and aromatic subfractions

The effect of pyrolysing gas composition on the low-molecular-weight aliphatic and aromatic components of fluidized-bed tars has been investigated. Two tars from the rapid pyrolysis of coal in a fluidized-bed were solvent-fractionated into oils, asphaltenes and benzene-insoluble materials. The aliphatic and low-molecular-weight aromatic subfractions of the oils were then analysed by glass-capillary column gas-liquid chromatography. The results show that pyrolysis in a more active atmosphere of char gasification gases is ‘deeper’, and, to some extent, similar to hydrogen-assisted pyrolysis; the yield of tar is higher, and the product has higher aromaticity and average molecular weight compared with pyrolysis in nitrogen-rich flue gases.     

二硝甲基唑类含能化合物的研究进展

二硝甲基唑类化合物是一类结构新颖的多氮含能化合物。综述了二硝甲基唑类化合物的合成方法和反应性质,并对部分含能化合物的性质进行了介绍。结果表明,二硝甲基唑类化合物的密度较大,且具有较高的正生成焓,但自身热稳定性较差,以其为阴离子合成出的离子盐具有较好的热稳定性。目前,二硝甲基唑类化合物的合成方法较成熟,但理论方面的研究不够深入。     

含能黏合剂合成研究新进展

从热塑性含能黏合剂和热固性含能黏合剂两方面综述了国内外含能黏合剂近5年研究的最新进展,重点介绍了叠氮类、硝酸酯类、富氮含能类、聚磷氮烯类、改性端羟基聚丁二烯类热塑性含能黏合剂,GAP基ETPE、BAMO基ETPE、偕二硝基类热塑性含能黏合剂的合成及性能研究情况,对含能黏合剂研究的发展趋势进行了展望,附参考文献25篇.     

The synthesis of single phase WC nanoparticles/C composite by solid state reaction involving nitrogen-rich carbonized polyaniline

Single phase tungsten carbide nanoparticles (WC-NPs), (mean particle diameter 5.4 nm), distributed over carbonized polyaniline (C-PANI) nanotubes/nanosheets were synthesized by a solid state reaction between WO₃ and nitrogen-rich carbonized polyaniline at 1000 °C in a reducing atmosphere. The resulting composite was characterized by X-ray diffractometry, electron microscopy, thermogravimetry in oxidizing and reduction atmospheres and elemental analysis. We suggested that the synthesis of WC as a single phase was facilitated by reactive C atoms with dangling bonds, formed upon nitrogen removal.     

Impact of temporary nitrogen deprivation on tomato leaf phenolics

Reducing the use of pesticides represents a major challenge of modern agriculture. Plants synthesize secondary metabolites such as polyphenols that participate in the resistance to parasites. The aim of this study was to test: (1) the impact of nitrogen deficiency on tomato (Solanum lycopersicum) leaf composition and more particularly on two phenolic molecules (chlorogenic acid and rutin) as well as on the general plant biomass; and (2) whether this effect continued after a return to normal nitrogen nutrition. Our results showed that plants deprived of nitrogen for 10 or 19 days contained higher levels of chlorogenic acid and rutin than control plants. In addition, this difference persisted when the plants were once again cultivated on a nitrogen-rich medium. These findings offer interesting perspectives on the use of a short period of deprivation to modulate the levels of compounds of interest in a plant.     

Short-term induction of alkaloid production in lupines Differences between N2-fixing and nitrogen-limited plants

We used N₂-fixing and nonfixing lupines to examine the effects of plant nutrition on short-term alkaloid production in damaged leaves. Three different treatments were used: damaged leaves from N₂-fixing plants; undamaged leaves from these damaged, N₂-fixing plants; and damaged leaves on nitrogen-limited, nonfixing plants. Relative to controls, alkaloids increased in concentration more quickly in the N₂-fixing than in the nitrogen-limited plants. The magnitude of this increase in alkaloids was correlated with the initial alkaloid concentration. These results suggest that nitrogen-rich plants may benefit from faster and higher alkaloid induction than nitrogen-limited plants. In addition, the detailed dynamics of individual alkaloids are consistent with earlier proposals for the mechanism of lupine alkaloid induction.     

Inhibition of feeding by a generalist insect due to increased volatile leaf terpenes under nitrate-limiting conditions

Nitrogen-limited plants ofHeterotheca subaxillaris accumulate greater quantities of leaf volatile terpenes than do nitrogen-rich plants. A series of feeding trials were performed to determine if such nitrate-limited plants are better defended against generalist-feeding insect herbivores. Soybean looper (Pseudoplusia includens) larvae were fed leaves fromH. subaxillaris rosettes grown under high and low nitrate supply regimes. Larval consumption, growth, and survival declined as the leaf volatile terpene content increased. Larval consumption and growth were enhanced by higher plant nitrate supply and with increasing leafage. The results suggest that the higher quantity of volatile terpenes in the leaves of nitrate-limited plants may better defend these leaves against generalist-feeding insects.     

Investigation of nitrogen compounds in coal tar products. 1. Unfractionated materials

The direct application of gas chromatography (g.c.) with a nitrogen-selective alkali-flame detector (AFD) and mass spectrometry to the identification of nitrogen compounds in coal tar products without the need for prior separation of nitrogen-rich fractions is described. Accurate mass measurement has allowed the assignment of atomic compositions to many nitrogen heterocycles despite their presence as minor components in complex aromatic mixtures, but some interference from hydrocarbons was encountered. Boiling point characteristics were used to assist in distinguishing between the various possible isomeric compound types. The AFD was used successfully for the quantitative g.c. determination of a range of nitrogen heterocycles in the unfractionated samples.     

Polymers of phenylenediamines

The chemical or electrochemical oxidation of phenylenediamines in acidic aqueous media yields the corresponding oligomers or polymers. Their structures and properties are discussed in relation to a closely-related conducting polymer, polyaniline. Depending on the reaction conditions, polyphenylenediamines are produced as powders, colloidal dispersions, thin films, or composites. In contrast to polyaniline, polyphenylenediamines are rated as non-conductors and their conductivities are low. Similarly to polyaniline, these polymers display a salt–base transition and they are redox-active. They act as reductants of noble-metal compounds to the corresponding metals or as precursors in the carbonization to nitrogen-rich carbons. Applications proposed in the literature are outlined; they include the corrosion protection of metals, catalysis, electrorheology, sensors, energy-conversion devices, electrochromism, noble-metal recovery, and water treatment.     

Phase Relationships and Stability of α'-SiAlON

Phase diagrams on the α'-SiAlON plane have been investigated for ytterbium-, yttrium-, and neodymium-containing systems at different temperatures. Phase relationships between α'-SiAlON, β'-SiAlON, AlN polytypoids, and liquid/grain-boundary phases have been determined. The stability region of the α'-SiAlON phase increases as the temperature increases and the ionic size of the rare-earth cation decreases. Meanwhile, the solubility of aluminum and oxygen in β'-SiAlON varies with the solubility of aluminum and oxygen in α'-SiAlON, which causes migration of all the phase lines on the α'-plane toward the nitrogen-rich side at lower temperatures and with larger modifying cations. These systematic variations of the phase relationships fully explain the occurrence of α'→β' reverse transformations that are sometimes observed in this system.     

Carbon nanotubes/amorphous carbon composites as high-power negative electrodes in lithium ion capacitors

A nitrogen-rich carbon nanotubes/amorphous carbon (CNT/C) composite was prepared by carbonising a CNT/polyaniline (PANI) composite, and characterised. Scanning electron microscopy and X-ray photoelectron spectroscopy confirmed that the composite retained a mesoporous CNT structure as its backbone, whilst the nitrogen-rich PANI-derived carbon formed a thin amorphous coating on the CNT surface. Electrochemical characterisation of the CNT/C composite indicated that it had nearly double the reversible Li⁺ intercalation capacity (390 vs. 219 mAh g^?1) and 39 % less irreversible capacity (622 vs. 1,015 mAh g^?1) than the pristine CNT. The CNT/C composite showed exceptionally high rate capability with a de-intercalation capacity of 81 mAh g^?1 at a very high charge/discharge rate of 60 C (time taken for charge or discharge is 1 min) (1 C = 1 h charge or discharge), whereas the pristine CNT delivered 53 mAh g^?1 at this C-rate. By comparison, the rate capabilities of conventional graphite (N3 and SLP30) were very poor above 5 C (~17 mAh g^?1 at 5 C). Both the pristine CNT and CNT/C composite showed an excellent cyclability at 1 C charge/discharge over 600 cycles. The CNT/C composite maintained a fairly stable capacity of ~200 mAh g^?1 after 600 cycles, whilst the commercial graphite showed a steady and significant decrease in de-intercalation capacity; reaching <70 mAh g^?1 after 600 cycles.     

1,1′-二羟基-5,5′-联四唑二羟胺盐在火炸药中的应用研究进展

概括了1,1′-二羟基-5,5′-联四唑二羟胺盐(TKX-50)化合物的合成与制备、晶体特性和力学性能,总结了其在性能改进、相容性、能量、安全性等应用方面的研究现状。对比了TKX-50与传统中性有机硝铵类材料的不同,指出TKX-50是离子盐结构,无传统含能基团—NO₂,释能方式是以高能键断裂释放能量而不是氧化还原反应,使得计算得到的生成焓、爆热、燃烧热等能量特性与试验结果有巨大差异;最后归纳总结了TKX-50的应用优势和存在问题,并展望了其未来发展方向及研究重点,指出应充分挖掘以TKX-50为代表的富氮类含能离子盐能量特性,利用此类材料特有性质,扩大其在火炸药领域应用范围。     

4,5-二(1H-5-四唑基)-1,2,3-三唑及其含能盐的合成与表征

以4,5-二氰基-1,2,3-三唑为原料,经过重氮化偶联反应和[2+3]偶氮环加成反应合成了4,5-二(1H-5-四唑基)-1,2,3-三唑,并经过复分解反应合成了7种高氮含能盐。采用IR、~1 H NMR、~(13) C NMR对化合物的结构进行了表征;采用DSC法研究了它们的热行为;基于B3LYP/6-311G**方法计算了各化合物的理论密度、标准生成焓,并通过EXPLO5预估了各化合物的爆速和爆压。结果表明,8种化合物均具有较好的热稳定性;生成焓为647.4~1 579.4kJ/mol;爆速为7 652~8 389m/s;爆压除化合物2外均高于20GPa;除化合物1、7、8外,其他化合物标准状况下的气体产生量均大于800L/kg,是潜在的气体发生剂。