Catalyst Effects of Nanometer CuCr2O4 on the Thermal Decomposition of TEGDN Propellant

The catalyst effects of nanometer CuCr₂O₄ on the thermal decomposition of triethyleneglycol dinitrate (TEGDN) propellant were investigated using thermogravimetric analysis, differential scanning calorimetry, mass spectrometry, and Fourier transform infrared spectroscopy. The Ozawa equation and step integral equation were used to calculate the activation energy. The results showed that the thermal decomposition reaction of TEGDN propellant can be seen as two reactions. Nanometer CuCr₂O₄ added in TEGDN propellant reduced the activation energy of the second reaction step; therefore, the second reaction step was sped up. Mass spectrometry, Fourier transform infrared spectrometry and the combustion residue analysis results also supported this conclusion.     

Thermal Decomposition Behaviors and Burning Characteristics of AN/Nitramine-Based Composite Propellant

Ammonium nitrate (AN) has attracted much attention due to its clean burning nature as an oxidizer. However, an AN-based composite propellant has the disadvantages of low burning rate and poor ignitability. In this study, we added nitramine of cyclotrimethylene trinitramine (RDX) or cyclotetramethylene tetranitramine (HMX) as a high-energy material to AN propellants to overcome these disadvantages. The thermal decomposition and burning rate characteristics of the prepared propellants were examined as the ratio of AN and nitramine was varied. In the thermal decomposition process, AN/RDX propellants showed unique mass loss peaks in the lower temperature range that were not observed for AN or RDX propellants alone. AN and RDX decomposed continuously as an almost single oxidizer in the AN/RDX propellant. In contrast, AN/HMX propellants exhibited thermal decomposition characteristics similar to those of AN and HMX, which decomposed almost separately in the thermal decomposition of the AN/HMX propellant. The ignitability was improved and the burning rate increased by the addition of nitramine for both AN/RDX and AN/HMX propellants. The increased burning rates of AN/RDX propellants were greater than those of AN/HMX. The difference in the thermal decomposition and burning characteristics was caused by the interaction between AN and RDX.     

The Influence of Magnesium Hydride on the Thermal Decomposition Properties of Nitrocellulose

Magnesium hydride is a kind of attractive hydrogen storage material. In this article, the thermal decomposition characteristic of the pure nitrocellulose and the mixture of nitrocellulose with 5% MgH₂ was investigated using an accelerating rate calorimeter. The kinetic parameters such as activation energy, E_a; preexponential factor, A; and self-accelerating decomposition temperature, T_SADT, were also calculated. We easily showed that the decomposition reaction could be accelerated by adding MgH₂, which indicated that MgH₂ has an obvious catalytic influence on the decomposition of nitrocellulose. On the other hand, the calculated values of E_a and T_SADT showed a decrease in thermal sensitivity with the addition of MgH₂. These results were in accordance with our objectives. Therefore, MgH₂ is very likely to be an important additive in propellants.     

香豆胶衍生物的化学结构及稳定性研究

将市售商品溶于水,用异丙醇沉析提纯,溶于0.1 mol/L NaNO3纯水溶液中,经0.5μm滤膜过滤后用水相凝胶渗透色谱法(GPC)测定,测得香豆胶(FG)、羟丙基香豆胶(HPFG)、阳离子香豆胶(CFG)的数均、重均相对分子质量Mn、Mw分别为:1.19×105、3.36×105,8.52×104、2.85×105,9.33×104、2.87×105。用甘露聚糖链在碱性条件下醚化时发生降解,解释两种改性FG的相对分子质量较FG低而多分散性(Mw/Mn)较FG高的测试结果。认为商品FG的1%水溶液黏度(1300 mPa.s)高于商品HPFG和CFG(分别为705和610 mPa.s)的原因是前者相对分子质量较高且残渣含量也较高(~10%,后二者为1%~2%)。HPFG的取代度为0.12,根据文献发表的13C-NMR数据确认HPFG分子链上羟丙基取代位置为C6。讨论了香豆胶(半乳甘露聚糖)的化学结构。热重分析法测定的热稳定性,HPFG高于CFG,CFG又高于FG。图6表3参13。     

1-甲基-4,5-二硝基咪唑的工艺优化及热分解动力学研究

以甲基咪唑为原料,采用一步硝化法合成1 -甲基-4,5-二硝基咪唑,并通过元素分析、红外光谱以及核磁共振光谱、质谱对其结构进行了表征.通过正交试验考察了反应温度、反应时间及反应物物质的量比对产率的影响,得出最佳工艺条件为:反应温度80～85℃,反应时间2h,发烟硝酸与发烟硫酸的物质的量比1:2.在此条件下产品收率为74...     

基于BP神经网络的测井资料预测岩石热导率

为了获取无岩心深度段的岩石热导率,建立基于BP神经网络的热导率预测模型.根据声波、密度、中子、电阻率、自然伽马等5种测井响应预测岩石热导率,其模型计算所需时间较短,不需要岩性组分资料,比只考虑1种或其中几种物理参数影响的经验公式适用范围更广.对检验样本以及位于南海的1144A井、1146A井、1148A井等3口大洋科学...     

内焊余热和焊接热循环对螺旋埋弧预精焊管焊缝性能的影响

采用Charpy冲击、显微硬度和金相试验研究了内焊余热和焊接热循环对螺旋埋弧预精焊管焊缝韧性、显微硬度分布及微观组织的影响。结果表明,内焊余热和焊接热循环对焊缝及焊接热影响区(HAZ)韧性、硬度分布及微观组织形貌有较大影响。在内焊余热和焊接热循环作用下,焊缝及HAZ夏比冲击功均有明显降低,韧性呈现衰减趋势,显微硬度峰值均出现在焊缝中心附近,而微观组织则有不同程度长大。焊缝中心处主要由针状铁素体(AF)+少量准多边形铁素体(QPF)组成,HAZ则主要由尺寸粗大且均匀性差的粒状贝氏体组成。     

ZrO_2负载Ru─Fe双金属簇及其单金属簇上CO加氢反应及TPDE研究

测定了ＺｒＯ２负载的由不同前体得到的Ｒｕ－Ｆｅ双金属及其单金属催化剂的ＣＯ加Ｈ２反应活性。结果表明，ＺｒＯ２负载的由Ｒｕ２Ｆｅ（ＣＯ）１２或ＲｕＦｅ２（ＣＯ）１２获得的Ｒｕ－Ｆｅ双金属催化剂较负载Ｒｕ３（ＣＯ）１２、Ｆｅ２（ＣＯ）９及其混合簇催化剂以及由ＲｕＣｌ３、Ｆｅ（ＮＯ３）３制备的常规双金属催化剂具有高得多的ＣＯ加氢活性。用程序升温分解（ＴＰＤＥ）方法研究了ＺｒＯ２负载的Ｒｕ３（ＣＯ）１２，Ｆｅ２（ＣＯ）９及其混合簇催化剂的脱羰基过程。结果表明，除脱附作用外，负载络合物的羰基在Ａｒ中ＴＰＤＥ主要歧化生成ＣＯ２，在Ｈ２中ＴＰＤＥ主要加氢生成ＣＨ４。     

Ultraviolet and PAV aging procedures influence on rheological characteristics of Sasobit/SBS modified binder containing titanium dioxide nanoparticles

Abstract

The objective of this study is to evaluate the rheological properties of styrene-butadiene-styrene and Sasobit modified asphalt binder blended with various contents (0%, 1%, 3% and 5%) of nano-titanium dioxide (TiO₂) after Ultraviolet (UV) aging and PAV aging procedures. Rheological test results showed that nanoparticles generally had no effect on the complex modulus and phase angle of binders. UV aged binders showed better fatigue and cracking resistance than the PAV aged binders. Finally, compared to the control binder, the binder with nanoparticles had a higher fatigue resistance after UV aged, but worse fatigue resistance after PAV aged.     

三维非均质模型上聚合物及有机交联聚合物提高采收率研究

所用三维非均质物理模型高 10 0mm ,平面边长 5 0 0mm ,平面上一条对角线两端设注入井和产出井 ,沿对角线有渗透率约 3.0 μm2 的高渗条带 ,两侧为 0 .5 μm2 的低渗区。在平面内均匀布置 7排 7列共 49个测压点。驱替液有地层水 ;15 0 0mg/L聚合物溶液 (0 .3PV) ;15 0 0mg/L聚合物 +12 0 0mg/L酚醛树脂交联凝胶 (0 .2PV)。驱替温度 70℃。水驱、聚合物驱、交联聚合物驱的采出程度依次增大 ;聚合物驱、交联聚合物驱含水曲线上出现两个低谷区 ,曲线振荡明显 ,交联聚合物驱含水曲线振荡尤其剧烈。通过紧靠注入和产出井的 1点和 49点 ,主流线中间点 2 5点和非主流线上 38点 ,水驱死油区内 36点和 45点处压力变化曲线的对比 ,及聚合物和交联聚合物驱替液G′和G″曲线的对比 ,认为交联聚合物驱采收率高于聚合物驱采收率的原因 ,是具有更高弹性的交联聚合物驱替液改善油藏非均质性、扩大波及体积、提高后续注水冲刷效能、改善驱替效果的能力均更强。