REPORT ON ELECTROMAGNETIC METROLOGY IN CHINA DURING 1990-1992

ＲＥＰＯＲＴＯＮＥＬＥＣＴＲＯＭＡＧＮＥＴＩＣＭＥＴＲＯＬＯＧＹＩＮＣＨＩＮＡＤＵＲＩＮＧ１９９０－１９９２￥ＹａｎｇＸｉａｏｒｅｎ；ＲｅｎＤｉａｎｑｉｎｇ；ＬｉＺｉｚｈｏｎｇ（ＣｏｍｍｉｓｓｉｏｎＡ，ＣｏｍｍｉｔｔｅｅｆｏｒＣｈｉｎｅｓｅＵＲＳＩ）...     

含二氮杂萘结构聚醚砜酮酮的合成及表征

以１，４－二（４－氯代苯甲酰基）苯及４，４＇－二氯二苯砜单体与４－（４－羟基苯基）－２，３－二 氮杂萘－１－酮单体经来核取代反应，合成了一系列分子主链中含有Ｃ－Ｎ键的杂环聚醚砜酮酮三元共聚物 ＰＰＥＳＫＫ，用 ＦＴ－ＩＲ、１Ｈ－ＮＭＲ、ＤＳＣ、 ＴＧＡ、 Ｘ射线衍射等方法对共聚物进行了表征，结 果表明，ＰＰＥＳＫＫ为具有高热稳定性的可溶性无规共聚物，巨随着砜基比例的增加，共聚物玻璃化温度 逐渐升高     

聚醚型聚氨酯/乙烯基酯树脂互穿聚合物网络结构的研究

以聚氨酯（ＰＵ）为组分Ⅰ、乙烯基酯树脂（ＶＥＲ）为组分Ⅱ,采用二步法制备了聚氨酯／乙烯基酯树脂互穿聚合物网络（ＰＵ／ＶＥＲ－ＩＰＮ）,采用透射电镜（ＴＥＭ）和原子力显微镜观察了ＰＵ／ＶＥＲ－ＩＰＮ的微观形态,用调制ＤＳＣ（Ｍ－ＤＳＣＴＭ ）、动态力学分析方法（ＤＭＡ）研究了ＩＰＮ 的玻璃化转变行为及动态力学性能。结果表明,ＰＵ 网络与ＶＥＲ网络形成了多相微区结构,在界面处互穿和缠结,形成类似胞状的结构,ＰＵ 相为胞壁,ＶＥＲ为胞体。在ＰＵ 和ＶＥＲ之间,次级作用明显加强,出现氢键吸收峰,并且出现宽温度阻尼范围。当ＰＵ／ＶＥＲ＝ ４０／６０ 时,材料在宽温度范围的阻尼性能最好     

电影立体声制式的新发展

最近,杜比公司与卢卡斯电影公司共同开发了一种新的６．１立体声制式,名为“杜比数字环绕声ＥＸ”（ＤＯＬＢＹＤＩＧＩＴＡＬ－ＳＵＲＲＯＵＮＤＥＸ）。读到这个报导,不免引起笔者的一些思考,诸如：此制式与原有的杜比ＳＲ·Ｄ５．１立体声制式有什么不同？有些什么...     

苯乙烯—丙烯腈—N—苯基马来酰亚胺乳液共聚物的热分析表征

通过乳液聚合的方法制备了苯乙烯－丙烯腈－Ｎ－苯基马来酰亚胺三元共聚物，由ＤＳＣ、ＤＭＡ及ＴＧ热分析方法对共聚物的性能进行了对比表征。实验结果表明，ＤＭＡ方法能更好地表征Ｎ－ＰＭＩ组分对共聚物耐热性能的影响，它一方面可以确定玻璃化的变化，另一方面可以测定材料模量的变化情况。     

超高分子量聚乙烯热降解行为的研究

本文利用热重分析法（ＴＧ－ＤＴＧ），差热分析法（ＤＴＡ），粘度法研究了超高分子量聚乙烯（ＵＨＭＷＰＥ）在空气或Ｎ２气氛下的热降解行为，结果表明ＵＨＭＷＰＥ热降解过程符合自由基连锁反应机理，其热解行为或受空气或Ｎ２气氛，升温经和恒温时间的影响。     

浸渍—α—Ni（OH）稳定性的研究

通过Ｘ射线衍射分析证实含Ｂ添加剂的镍电极活性物质晶型结构为α型,差热－热重（ＤＴＡ－ＴＧ）分析则表明α－Ｎｉ（ＯＨ）２层间有结构水或化学吸附水存在。探讨了添加剂Ｂ分别与Ｎａ２Ｓ、Ｃａ（ＮＯ３）２共沉 镍电极性能。通过ＸＲＤ及５０多次大电流充放电循环表明,该电极仍具有     

超高取代度羧甲基纤维素的热分析

研究了氮气氨下对取代度在０．７９～２．５范围的羧甲基纤维素进行了ＴＧ,ＤＴＧ,ＤＴＡ热分析和裂解活化能的计算,结果表明,对于取代度大于１的羧甲基纤维素,随着取代度增大,其主要裂解开始温度Ｔ＾０１和主要裂解温度了升高,而主要裂解的温度范围（Ｔ＾０２－Ｔ＾０１）变窄和主要裂解温度范围内失重ＲＴ减少,因而其热稳定性有所提高。提高取代度（ＤＳ＝２．５０）的羧甲基纤维素裂解活化能也较高,羧甲基纤维素的ＤＴＧ     

动态硫化 EPDM／PP 共混物的动态力学性能

探讨了硫化剂用量、橡塑比对ＥＰＤＭ／ＰＰ共混物动态力学性能的影响。实验表明,在相同温度下,随着硫化剂用量增加,共混物的动态模量及ＥＰＤＭ的玻璃化温度（Ｔｇ）升高;随着树脂含量的增加,共混物的动态模量增大,ＥＰＤＭ的玻璃化温度降低。     

高温超高压处理HDPE的WAXD及FT—IR研究

用ＷＡＸＤ和ＦＴ－ＩＲ对高温超高压处理前后的ＨＤＰＥ进行了研究。发现经５．０ＧＰａ的高压处理或２００℃下４．０ＧＰａ的高压同时处理后的ＨＤＰＥ分子链的化学结构未发生变化。ＨＤＰＥ晶体中（２００）面与（１１０）面衍射峰的峰高比（γ）随着压力的升高而增大，表明ＨＤＰＥ分子链在超高压作用下发生了取向排列，且升高温度更有利于这种取向排列，且升高温度更有利于这种取向排列，但当压力增大至５．０ＧＰａ及温度升高     

水泥-沥青胶凝材料动态力学行为的初步研究

研究了不同沥青含量（A/C）的水泥-沥青复合胶凝材料7d龄期的动态黏弹性力学行为。选择3种温度环境（？25℃、25℃和75℃）,采用动态黏弹谱仪测试了3种不同A/C的水泥-沥青胶凝材料（简称为CAB）在频率范围0.1Hz~100Hz的动态力学性能,获得了不同温度下储存模量、损耗模量及损耗角随加载频率变化的基本规律。基于...     

老化对水泥乳化沥青胶结料动态力学性能的影响

基于分数导数修正Burgers模型,建立了水泥乳化沥青胶结料（简称复合胶结料）的本构方程。结合不同材料配比的复合胶结料的老化试验及频率扫描试验,分析了老化时间及材料配比等因素对复合胶结料黏弹性力学参数的影响。研究表明,复合胶结料的存储模量与损耗模量均随老化时间的增加而增大,在老化时间为0~8 h时,存储模量及损耗模量增加较快,当老化时间超过8 h后,其增长趋势减缓。对于乳化沥青与水泥的质量比（m_A/m_C）为1.2和1.4的复合胶结料,在不同的加载频率下,其相位角均随老化时间的增加而减小。对于m_A/m_C为1.0的复合胶结料,其相位角随着老化时间的增加呈现先增加后减小的变化规律。随着老化时间的增加,复合胶结料趋向于弹性材料的力学性质。分数导数修正Burgers模型可以较好的描述老化后复合胶结料的黏弹性动态力学行为,模型参数弹性模量E₁、黏度η₁和分数导数r可以描述老化情况下材料黏弹特性的变化规律。     

Characterization of polymorphic states in energetic samples of 1,3,5-trinitro-1,3,5-triazine (RDX) fabricated using drop-on-demand inkjet technology

The United States Army and the first responder community are evaluating optical detection systems for the trace detection of hazardous energetic materials. Fielded detection systems must be evaluated with the appropriate material concentrations to accurately identify the residue in theater. Trace levels of energetic materials have been observed in mutable polymorphic phases and, therefore, the systems being evaluated must be able to detect and accurately identify variant sample phases observed in spectral data. In this work, we report on the novel application of drop-on-demand technology for the fabrication of standardized trace 1,3,5-trinitro-1,3,5-triazine (RDX) samples. The drop-on-demand sample fabrication technique is compared both visually and spectrally to the more commonly used drop-and-dry technique. As the drop-on-demand technique allows for the fabrication of trace level hazard materials, concerted efforts focused on characterization of the polymorphic phase changes observed with low concentrations of RDX commonly used in drop-on-demand processing. This information is important when evaluating optical detection technologies using samples prepared with a drop-on-demand inkjet system, as the technology may be "trained" to detect the common bulk α phase of the explosive based on its spectral features but fall short in positively detecting a trace quantity of RDX (β-phase). We report the polymorphic shifts observed between α- and β-phases of this energetic material and discuss the conditions leading to the favoring of one phase over the other.     

聚乙烯/无机纳米复合材料的抗紫外老化性能

研究了茂金属聚乙烯（mPE）／纳米TiO2、线形低密度聚乙烯（LLDPE）／纳米ZnO、LLDPE／纳米CaCO3复合材料经过不同时间紫外辐照后的力学性能和热学性能,用傅立叶红外光谱测定了紫外辐照后的基团变化。结果表明,纳米TiO2和ZnO对聚乙烯抗紫外老化性能有比较明显的提升,为聚乙烯纳米复合材料的制备、加工和应用提供了理论依据。     

Effect of nitrate content on thermal decomposition of nitrocellulose

Data on the thermal stability of energetic materials such as nitrocellulose was required in order to obtain safety information for handling, storage and use. In the present study, the thermal stability of four nitrocellulose samples containing various amount of nitrate groups was determined by differential scanning calorimetery (DSC) and simultaneous thermogravimetery-differential thermal analysis (TG-DTA) techniques. The results of TG analysis revealed that the main thermal degradation for the nitrocellulose occurs in the temperature ranges of 192-209 degrees C. On the other hand, the TG-DTA analysis of compounds indicates that nitrate content of nitrocellulose could has affect on its thermal stability and its decomposition temperature decrease by increasing its nitrogen percent. The influence of the heating rate (5, 10, 15 and 20 degrees C/min) on the DSC behaviour of the nitrocellulose was verified. The results showed that, as the heating rate was increased, decomposition temperature of the compound was increased. Also, the kinetic parameters such as activation energy and frequency factor for the compound was obtained from the DSC data by non-isothermal methods proposed by ASTM E696 and Ozawa.     

Applicability of elastomer time-dependent behavior in dynamic mechanical damping systems

Dynamic thermomechanical analysis (DTMA) of unfilled as well as particle-filled poly(dimethylsiloxane) and poly(norbornene) was performed to compare their behavior as dampers. PDMS and PNB were filled with varying contents of spherical iron particles (aspect ratio of 1) and also different hardness formulations of the materials were characterized. The wicket-plot (tanδ vs. storage modulus) was considered therefore and all frequency- and temperature-dependent results were presented. Linear dependencies were observed for PDMS, even though the material did not reveal thermorheologically simple behavior. However, tanδ of PNB was a unique function of its storage modulus and so the material exhibited thermorheologically simple behavior. A linear shift factor over frequency–temperature and frequency–internal pressure (Fe-content) was found for PDMS. Master curves of PNB were constructed and reasonable results were achieved, which were due to their thermorheologically simple material behavior.     

RDX和NGU对叠氮硝胺发射药动态燃烧稳定性的影响

以30 mm高压模拟炮为试验平台,以单基发射药为参照,研究了3种典型叠氮硝胺(DIANP)发射药的动态燃烧稳定性,分析了配方组成对DIANP发射药起始燃烧特征、膛内压力上升过程及膛内压力波动的影响,探讨了DIANP发射药配方组成与其起始燃烧特征、膛内压力上升特点和压力波强度的相互关系。结果表明,在DIANP发射药配方中添加质量分数30%的固体组分黑索今(RDX)或硝基胍(NGU),发射药膛内动态燃烧稳定性增加,膛压-时间曲线波动减小,膛压从30 MPa增至50 MPa所需的时间分别增加了92%和78%,起始负压差从－40.7 MPa降低至－4.44 MPa和－10.66 MPa。在DIANP发射药体系引入高含量的固体组分RDX或NGU,由于低压下RDX分解前熔融吸热,而NGU火药燃烧表面存在坚实熔融层,均可有效减小DIANP发射药起始燃气的生成速率,降低发射装药起始燃气生成猛度,缓减起始阶段膛内压力的上升,提高药床起始燃烧一致性,减小膛内压力波强度。     

Molecular dynamics study of the structures and properties of RDX/GAP propellant

Molecular dynamics simulations have been performed to investigate well-known energetic material cyclotrimethylene trinitramine (RDX) crystal, glycidyl azide polymer (GAP) and RDX/GAP propellant. The results show that the binding energies on different crystalline surface of RDX change in the order of (0 1 0) > (1 0 0) > (0 0 1). The interactions between RDX and GAP have been analyzed by means of pair correlation functions. The mechanical properties of RDX/GAP propellant, i.e., elastic coefficients, modulus, Cauchy pressure, and Poisson's ratio, etc., have been obtained. It is found that mechanical properties are effectively improved by adding some amounts of GAP polymer, and the overall effect of GAP on three crystalline surfaces of RDX changes in the order of (1 0 0) > (0 1 0) > (0 0 1). The energetic properties of RDX/GAP propellant have also been calculated and the results show that compared with the pure RDX crystal, the standard theoretical specific impulse (I(sp)) of RDX/GAP propellant decrease, but they are still superior to those of double base propellant.     

高聚物材料动态模量测量与分析

高聚物材料具有良好的阻尼结构特性,因此在减振降噪中发挥很大作用。高聚物材料的模量是复数,并且随着系统的频率和环境温度呈非线性变化。将某高聚物材料在动态热机械分析仪上进行动态力学行为实验,并对实验结果采用分数导数维模型进行拟合。结果表明,分数导数维Maxwell模型可以同时精确的拟合高聚物材料的存储模量和损耗模量随频率变化的曲线,而且其形式简单,统一,计算所需参数较少,研究结果为实际应用提供了参考依据。     

温湿度和紫外老化对纸浆模塑材料性能的影响

目的 研究温度、湿度和紫外老化对脱木素和未脱木素纸浆模塑材料性能的影响,定量地对比不同因素作用下2种材料的力学性能差异。方法 以废纸浆为原料,经打浆、脱木素、湿成型、热压等工艺制得脱木素和未脱木素等2种纸浆模塑材料;模拟不同的温湿度和紫外老化环境,测试2种纸浆模塑材料物理力学性能的变化。结果 在同等条件下,脱木素材料的拉伸强度与弯曲强度均高于未脱木素材料;2种材料的拉伸强度、弹性模量和弯曲强度随着含水率升高而大幅降低;当温度为20 ℃、含水率为0~40%时,脱木素材料的拉伸强度下降了45 MPa,未脱木素材料的拉伸强度下降了35 MPa。当温度为0 ℃、含水率为0~40%时,脱木素材料的弯曲强度下降了70 MPa,未脱木素材料的弯曲强度降低了62 MPa;当含水率低于20%时,脱木素材料的拉伸性能和弯曲性能更易受到温度影响;虽然2种材料的拉伸性能和弯曲性能均随着紫外老化时间的延长而不断降低,但其影响程度远小于温湿度。结论 湿度对材料的力学性能影响最大,其次是温度和紫外老化;脱去木素有利于提高纸浆模塑材料的力学性能和抗紫外老化性能。