化学循环重整甲烷制合成气LaB03钙钛矿型氧载体研究

采用溶胶-凝胶法制备了不同B位可变价离子的La-B-O复合氧载体（B=Cr、Ni）,采用XRD、BET、FT-IR、H2-TPR及CH4-TPSR等进行了表征,并用于化学循环重整（CLR）CH4反应中.结果表明,LaNiO3氧化物更易于与CH4发生深度氧化和选择氧化,LaCrO3氧化物则利于CH4裂解,其氧物种氧化CH4的能力较弱.在连续流动CLR反应中,LaNiO3具有较高的供氧量和持续供氧能力,能将CH4选择氧化为H2/CO=1.45的合成气,其CH4转化率和CO选择性分别达到23.4%和86.9%,且其结构保持了较高的稳定性.     

气相色谱-三重四极杆串联质谱法测定白芍中99种农药残留

采用固相萃取技术(SPE)结合气相色谱-三重四极杆质谱(GC-MS/MS)建立了白芍中99种农药同时检测的分析方法。试样用乙酸乙酯提取,采用氨基固相萃取柱净化后,在GC-MS/MS多反应监测(MRM)模式下进行检测,基质匹配标准曲线内标法定量。结果表明,99种农药在0.001~0.25 mg/L范围内线性关系良好,相关系数(r²)大于0.99,方法定量限为0.001~0.050 mg/kg。加标水平为0.05、0.10和0.20 mg/kg时,99种农药的平均回收率为66.7%~128.0%,相对标准偏差(RSD, n=6)小于18.3%。对市售的13批样品进行测定,其中4批样品中检出微量的毒死蜱和p,p'-滴滴伊。实验证明,建立的SPE净化和GC-QqQ-MS相结合的检测方法具有准确可靠、灵敏度高等优点,适用于白芍中多农药残留的同时筛查测定。     

Problems caused by the activity of Al2O3-PLOT columns in the capillary gas chromatographic analysis of volatile organic compounds

Summary Al₂O₃-PLOT columns are used with great advantage for the analysis of volatiles, because of the increased capacity ratio and selectivity compared to WCOT-columns. Their applicability is limited to relatively non-polar components with relatively low boiling points i. e. eluting before n-decane.In the analysis of the halocarbons in stratospheric air, the decomposition of certain compounds was observed. In this study the stability of a number of volatile organic compounds was determined in function dependence of the column temperature using a two-dimensional GC-system.A possible reaction mechanism for the decomposition is proposed and confirmed for several chlorinated ethanes.     

快速溶剂萃取一气相色谱法测定土壤中多氯联苯Aroclor系列

建立了快速溶剂萃取、浓硫酸净化、气相色谱法测定土壤中多氯联苯Aroclor系列的方法.方法线性良好、灵敏度高、回收率在70%～110%之间、相对标准偏差RSD小于17%,并用于有证的标准土壤样品及环境实样的分析,结果满意.     

Integration of the equations of gas dynamics for 2.5-dimensional solutions

We integrate the equations of gas dynamics in finite form for the solutions in which the thermodynamic parameters depend only on one spatial variable. The corresponding motion of gas represents the nonlinear superposition of the one-dimensional gas motion corresponding to the invariant system and the two-dimensional motion determined by noninvariant functions. These motions are called 2.5-dimensional. We reduce the invariant system to a first-order implicit ordinary differential equation. We study various solutions of the latter. We construct some continuous and discontinuous solutions to the equations of gas dynamics and give their physical interpretation.     

毛细管气相色谱法测定热不稳定有机磷农药辛硫磷

The thermo-labile organophosphorous pesticide Phoxim was determined by capillary gas chromatographywith flame phototnetric detector. When high linear velocity H_2(>200cm/s) was used as carrier gas,the thermo-decomposition of Phoxim was considerably reduced.The most important gas chromatography conditions,injectortempereture and column head pressure,were studied.The thermo-decomposition preducts were identified by gaschromatography-mass spectrometry.     

Efficient Room‐Temperature,Au+‐Mediated Coupling of a Carbene Ligand with Methane To Generate C2Hx (x=4, 6)

The thermal reactions of the closed‐shell, “naked” gold–carbene complex [Au(CH₂)]⁺ with methane have been explored by using FTICR mass spectrometry complemented by quantum chemical (QC) calculations at the CCSD(T)//BMK level of theory. Mechanistic aspects for this unprecedentedly efficient carbene insertion in the C? H bond of methane have been addressed and the origin of the counterintuitive high reactivity of [Au(CH₂)]⁺ towards this most inert hydrocarbon is discussed.     

催化柴油中含氮化合物类型分布的气相色谱分析方法

建立了催化柴油馏分中各种含氮化合物类型分布的气相色谱-氮化学发光检测分析方法,考察了色谱条件对各种含氮化合物分离的影响。采用Al2O3柱富集催化柴油中的含氮化合物,辅以气相色谱-质谱检测器以及部分含氮化合物标准样品对某催化柴油中的80多个含氮化合物进行了定性(或归类)。以N,N-二甲基苯胺、三丁基胺、喹啉、吲哚、咔唑作为标准样品,考察了各种含氮化合物在氮化学发光检测器上的响应,以吲哚为参照,各含氮化合物的相对响应因子为0.97～1.07,表明含氮化合物的响应与其类型无关。氮的质量浓度在1.0～600 mg/L范围内,含氮化合物的峰面积与质量浓度有良好的线性响应,线性相关系数达0.998。催化柴油中几种含氮化合物(吲哚、C2-吲哚、咔唑、1-甲基咔唑、1,8-二甲基咔唑)含量测定值的相对标准偏差均小于8%。当信噪比(S/N)为3时,测得咔唑氮的检出限为1.0 mg/L。苯胺、喹啉、吲哚、咔唑等4种含氮化合物的加标回收率为89.5%～99.8%。该方法可用于不同来源和不同加工工艺的柴油馏分中各种含氮化合物类型分布的研究。     

Acid/base characterization of sepiolite by inverse gas chromatography

Summary The surface properties of sepiolite were investigated by inverse gas chromatography. It is shown that the value of the dispersive component change uniformly with temperature, while the values obtained for the parameters K_A and K_D indicate an acidic character for the sepiolite surface.     

钨合金柱形弹超高速撞击水泥砂浆靶的侵彻深度研究

为探索钨合金柱形弹超高速撞击水泥砂浆靶的侵彻深度随撞击速度变化规律,利用二级轻气炮开展了?3.45 mm×10.5 mm的克级93 W钨合金柱形弹以1.82~3.66 km/s的速度撞击水泥砂浆靶的实验,利用CT图像诊断技术获得了侵彻深度和残余弹长随撞击速度的变化规律,对超高速撞击过程进行了数值模拟,结合数值模拟结果进一步分析了超高速撞击物理过程。结果表明:(1)超高速撞击条件下成坑是弹坑+弹洞型;(2)侵深-速度曲线呈现先增大后减小的现象,在弹速2.6 km/s附近存在侵彻深度极大值,约为8.5倍弹长,相对于中低速侵彻的深度并没有显著优势。(3)通过基于数值模拟得到的弹靶界面压力时程曲线将侵彻过程分为4个阶段,其中准定常侵彻阶段和第三侵彻阶段是决定总侵深的主要阶段。(4)随撞击速度增加,弹体侵蚀逐渐剧烈,此时准定常侵彻阶段的侵深变化不大,而第三侵彻阶段中的刚体侵彻部分大幅降低,导致总侵深大幅降低,使总侵深曲线呈现先增大后减小的现象。