纳米RDX粉体的制备与撞击感度

将普通工业黑索今炸药溶解于混合溶剂中,通过喷雾干燥,制取纳米黑索今炸药粉体,得率达到50%以上,粒径为40～60nm。实验结果表明,随着粒径的减小,黑索今的机械撞击感度降低,纳米黑索今撞击感度的特性落高约为普通工业黑索今的两倍。     

大药片落锤撞击感度研究

设计建立了一种炸药大药片撞击感度试验方法,落锤质量为20 kg、落高度为0~15 m,对规格20 mm5 mm、重约2.8 g的大药片进行撞击感度测试。试验测试了两种典型炸药Tetryl和JOB-9003炸药的落锤撞击感度,落锤撞击Tetryl炸药和JOB-9003炸药的爆炸阈值落高分别约3.5 m和6.5 m。对落锤撞击JOB-9003炸药样品的过程进行了数值计算,计算结果与试验值相符。试验结果表明,该试验方法可以测量炸药的落锤撞击感度。     

GC/MS-衍生化法分析无机阴离子

研究了应用电子轰击电离源气相色谱/质谱法测定水中无机阴离子NO3-和SCN-。采用五氟苄基溴首先将NO3-和SCN-衍生化生成可挥发性化合物,然后用GC/MS法进行测定,检出限为10mg·L-1。应用该方法对水中硝酸根和硫氰根离子进行测定,取得满意的结果。     

高速逆流色谱法分离茶叶中的生物碱

以氯仿－甲醇－磷酸二氢钠缓冲液（２３ｍｍｏｌ／Ｌ,ｐＨ５．６）（体积比４∶３∶２）为溶剂系统,上相为固定相,下相为移动相,从茶叶的总生物碱中分离出三个成分,其中一个是咖啡碱,一个是茶碱,另一个待定。将分离结果与ＴＬＣ分离结果相比较,证实了高速逆流色谱法的有效及实用性。     

1,3,3-三硝基氮杂环丁烷的热安全性

借助不同加热速率(β)的非等温DSC曲线离开基线的初始温度(T₀)、onset温度(T_e)和峰顶温度(T_p), Kissinger法和Ozawa法求得的热分解反应的表观活化能(E_k和E_O)和指前因子(A_k), Hu-Zhao-Gao方程ln β_i＝ln[A₀/(b_{e0 or p0}G(α))]＋   b_{e0 or p0}T_{ei or pi}求得的b_{e0 or p0}, Zhao-Hu-Gao方程ln β_i＝ln[A₀/((a_{e0 or p0}＋1)G(α))]＋(a_{e0 or p0}＋1) ln T_{ei or pi}求得的a_{e0 or p0}, 微热量法确定的比热容(C_p), 以及密度(ρ)、热导率(λ)和分解热(Q_d, 取爆热之半)数据, Zhang-Hu-Xie-Li公式、Hu-Yang-Liang-Xie公式、Hu-Zhao-Gao公式、Zhao-Hu-Gao公式、Smith方程、Friedman公式和Bruckman-Guillet公式, 计算了TNAZ在β→0时的T₀, T_e和T_p值(T₀₀, T_eo和T_p0)、热爆炸临界温度(T_be和T_bp)、绝热至爆时间(t_Tlad)、撞击感度50%落高(H₅₀)和热点起爆临界温度(T_cr), 得到了评价TNAZ热安全性的结果: T_SADT＝T_e0＝485.81 K, T_p0＝497.38 K, T_beo＝499.50 K, T_bp0＝513.45 K, t_Tlad＝8.90 s (n＝0), t_Tlad＝8.96 s (n＝1), t_Tlad＝9.01 s (n＝2), H₅₀＝28.88 cm, T_cr＝641.46 K (T_room＝293.15 K), T_cr＝658.89 K (T_room＝300 K), 表明: (1) TNAZ对热是稳定的; (2)撞击感度好于环三亚甲基三硝胺(RDX); (3)热点起爆临界温度高于RDX, 而界于1,3,5-三氨基-2,4,6-三硝基苯(TATB)和六硝基茋(HNS)之间.     

固体氧化物燃料电池（SOFC）电池稳定性分析

固体氧化物燃料电池(SOFC)要长期可靠运行,必须具有较高的稳定性。本文从SOFC内阻的主要来源出发,详细分析了影响电池长期稳定性、特别是引起性能衰减的主要因素,并研究其衰减机理。通过对电解质、阴极、阳极及连接材料等关键材料的选择及性能稳定性进行分析,系统论述了阴极与其它材料的相互反应、阳极性能变化以及连接材料表面氧化层等诸多引起SOFC性能衰减的不利因素。在氧化、还原气氛和密封效果等方面对电池长期稳定性的影响也进行了阐述。通过对电池性能衰减的原因及其衰减机理进行分析,对于SOFC长期运行稳定性、进而商业化应用具有一定的理论和实际意义。     

两种离子化技术气相色谱-串联质谱法测定青菜与草莓中3种有机锡类农药残留

采用电子轰击(EI)和正化学(PCI)两种电离源技术,建立了气相色谱-串联质谱(GC-MS/MS)同时测定青菜和草莓中三环锡、三苯锡、苯丁锡农药残留的分析方法。样品经氢溴酸消解,丙酮-正己烷提取,经衍生后由Florisil固相萃取柱净化,分别采用EI和PCI两种电离源进行选择反应监测模式测定,采用基质匹配外标法定量。结果显示,在0.05~1.0 mg/L质量浓度范围内,3种有机锡农药呈良好线性,相关系数均大于0.998。两种方法中目标物的定量下限分别为0.019~0.042 mg/kg和0.009~0.042 mg/kg,均能满足国内外的限量要求。在0.05、0.10、0.20 mg/kg加标水平下,目标物的平均回收率为70.1%~93.9%,相对标准偏差(RSD)均小于10%。两种方法线性均较好,灵敏度较高,可用于水果蔬菜中有机锡农药的测定,且两种方法可实现互补,有助于提高定性和定量的可靠性。     

Estimation of the Annual Effective Dose Due to the Ingestion of 210Pb and 210Po in Crops from a Site of Coal Mining and Processing in Southwest China

The exploitation of mineral resources may cause the environmental release of radionuclides and their introduction in the human trophic chain, affecting public health in the short and long term. A case study of the environmental radiation impact from coal mining and germanium processing was carried out in southwest China. The coal mines contain germanium and uranium and have been exploited for more than 40 years. The farmlands around the site of the coal mining and germanium processing have been contaminated by the solid waste and mine water to some extent since then. Samples of crops were collected from contaminated farmlands in the research area. The research area covers a radius of 5 km, in which there are two coal mines. ²¹⁰Pb and ²¹⁰Po were analyzed as the key radionuclides during the monitoring program. The average activity concentrations of ²¹⁰Pb and ²¹⁰Po in the crops were 1.38 and 1.32 Bq/kg in cereals, 4.07 and 2.19 Bq/kg in leafy vegetables and 1.63 and 1.32 Bq/kg in root vegetables. The annual effective doses due to the ingestion of ²¹⁰Pb and ²¹⁰Po in consumed crops were estimated for adult residents living in the research area. The average annual effective dose was 0.336 mSv/a, the minimum was 0.171 mSv/a and the maximum was 0.948 mSv/a. The results show that the crops grown on contaminated farmland contained an enhanced level of radioactivity concentration. The ingestion doses of local residents in the research area were significantly higher than the average level of 0.112 mSv/a in China, and the world average level of 0.042 mSv/a through ²¹⁰Pb and ²¹⁰Po in crop intake, respectively.     

Intermolecular Phenolic Hydroxy Methylation Occurring between Chiral N,N＇-Bis（2-hydroxyphenyl）-2,2-dimethyl-1,3-dioxolane-4,5-dicarbamide and Co-crystallized Methanol under Electron Impact Ionization Conditions

An intermolecular phenolic hydroxy methylation occurring between chiral N,N‘-bis(2-hydroxyphenyl)-2,2-dimethyl-1,3-dioxolane-4,5-dicarbamide and co-crystallized methanol under electron impact ionization conditions was observed. The result was confirmed by X-ray diffraction structural ananlysis of a co-crystalline of(R,R)-enantiomer and methanol.