热稳定剂及与PVC混合物的热解反应研究

采用热分析方法对PVC加工成型中热稳定型的热解反应进行了研究，根据它们的热重曲线，分别求得热稳定剂及掺入热稳定剂后PVC混合物的热分解反应的各种特性参数，运用计算动力学参数的经验公式，求得热解活化能，定量地评价了热稳定剂及掺入热稳定剂后PVC混合物的热性能，并采用静态法测定了PVC混合物的热稳定时间。     

聚乙二醇蓄热调温性能及其在功能纺织品上的应用

对聚乙二醇(PEG)的自身交联及其与纤维素纤雏之间的交联反应进行了研究，探讨了交联前后PEG热活性的变化，并对PEG在焙烘交联时的受热稳定性以及分子量对热活性的影响进行了讨论。研究表明，PEG发生交联反应后，热性能参教产生偏移，热活性降低；热活性与分子量有直接关系；过高的焙烘温度将导致PEG氧化降解，热活性下降。在适宜的工艺条件下，纺织品经PEG后整理可获得热活性。     

氯化钙催化纤维素热裂解动力学研究

用差示热重分析仪对氯化钙纤维素热裂解动力学催化影响进行了研究。结果表明，氯化钙对焦炭的形成具有强烈的促进效果，使热裂解最终残留物产率从5％提升到10％以上，氯化钙的存在影响到热失重初始阶段活性纤维素的生成，使热重曲线向低温侧移动，并在低温段产生了小的失重速率峰。通过热重分析发现，氯化钙催化条件下纤维素热裂解动力学参数被分为了三段，分别对应于活性纤维素的生成、炭化和活性纤维素转化为挥发分产物三个区间，并依次成为整体失重过程的控制步骤。结合Broido-Shafizadeh机理分析以及与纯纤维素热裂解动力学参数的对比，氯化钙对这三个主要反应步骤都产生了促进效果，其中以催化焦炭的生成最为明显，在促进焦炭化的过程中，降低了气体产物的生成比率。     

具有苯烷基侧链的芳香液晶聚酯的合成及性质

以熔融缩聚方法全盛了具有苯烷基侧链取代的全芳香液晶聚酯，用TG，DSC，热台偏光显微镜研究了聚酯的热性能，并讨论了取代基对聚酯热性能的影响，所有合成的聚酯均为热致型液晶，且具有较低的相转变温度。特别是当聚对苯二甲酸对苯二酚酯的两个苯环上分别取代了叔丁基和苯烷基，或取代了两个苯烷基侧链后，聚酯的熔融温度下降到225℃以下，并可在室温下溶于普通的有机溶剂中。     

四元共聚物的热裂解色谱-质谱分析

报道了2－丁烯、甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸辛酯四元共聚物在不同裂解温度下的热裂解行为。用热裂解色谱－质谱分析方法，研究了裂解温度对裂解产物的影响，并讨论了四元共聚物的热裂解规律。     

60CrMnMo钢热疲劳裂纹生成与长大及稀土的作用

采用金相和扫描电镜等手段对６０ＣｒＭｎＭｏ钢热疲劳裂纹的萌生和长大规律进行了分析，并考查了稀土在钢中的作用。结果表明：热疲劳裂纹萌生于钢中夹杂物处，热疲劳裂纹的生长，不仅是裂纹自身发展的结果，更主要的是裂纹的相互联接。钢中加入稀土后，可以变质钢中夹杂物，从而抑制了热疲劳裂纹的生成与长大。     

酶促反应抑制动力学的微量热法研究——氟离子对漆树漆酶催化…

提出一个适合各类可逆性抑制的热动力学方程，并根据各量之间的关系提出了可逆竞争性抑制、非竞争抑制、反竞争性抑制的热动力学判据以及计算表观米氏常数Ｋｍ，ａｐｐ和抑制常数Ｋｉ等酶促反应生化常数的热动力学公式，并实验应用于ＮａＦ对漆树漆酶催化氧化邻苯二胺抑制向量热法温室，实验初步得出此抑制为非竞争性抑制，求出其Ｋｍ，ａｐｐ，Ｋｉ值。     

热重量法分析石墨成分

研究了用热重分析仪进行石墨成分分析的方法，摸索了仪器的适宜分析条件，并对试验结果进行了讨论。针对仪器系统误差对挥发分测定的影响，采用一无线性回归对测量数据进行了校正。方法的精密度和准确度试验证明，用热重量法可有效地应用于日常检验工作。     

苯并三呋咱氧化物中主要杂质对其热安定性的影响

根据苯并三呋咱氧化物（BTF）中主要杂质的种类，分别选择了三叠氮三硝基苯（TNTAB）、三氯三硝基苯（TCTNB）和叠氮化钠（NaN3)作为杂质研究对象，采用机械混合的方法制备了一系列不同配比的BTF混合物，再通过差热（DTA）、差示扫描量热（DSC）、真空安定性试验（VST）、布氏压力法、热失重、5s爆发点等热分析方法进行测试，结果表明TCTNB和NaN3对BTF热安定性影响较小，而TNTAB是影响BTF热安定性的主要因素。     

高温氧化铁脱硫剂还原硫化的热重热磁研究

以钢厂赤泥为主要原料制成四种高温煤气脱硫剂，用动态热重热磁天平对其还原和硫化行为进行了在位研究，未用Ｈ２还原的样品几乎无脱硫活性，经Ｈ２还原后有良好的脱硫性能。脱硫剂的还原和硫化性能与其物理化学性质密切相关，并对其影响进行了讨论。     

Characterization of aerosols generated by thermospray nebulization for atomic spectroscopy

The performance of an inductively coupled plasma (ICP) for atomic emission spectroscopy (AES) is strongly dependent upon the sample introduction system. The Thermospray Vaporizer has recently been shown to yield enhanced sensitivity compared to conventional pneumatic nebulizers when used as a sample introduction source for the ICP. This report is a study of the properties of the aerosols produced by the thermospray. Aerosol particle diameter distributions have been related to droplet size distribution and nebulization efficiencies as a function of the relevant variables of the nebulization system. The results help explain high emission intensities and lower detection limits achieved using the thermospray. The higher efficiencies with thermospray, compared to conventional pneumatic nebulization, also makes the thermospray a prime candidate for sample introduction into molecular gas ICPs.     

Use of a multi-tube Nafion® membrane dryer for desolvation with thermospray sample introduction to inductively coupled plasma-atomic emission spectrometry

A multi-tube Nafion^® membrane dryer used as a part of a desolvation system in conjunction with thermospray nebulization was optimized and characterized with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Either argon or nitrogen could be used as the sweep gas, and optimum conditions were found to be at low temperature and low sweep gas flow rate. Analyte sensitivity was not significantly affected by placing the membrane between the plasma and the nebulizer, although about 20% of the analyte entering the dryer is lost within the dryer. A dual role of the membrane dryer was demonstrated. As a secondary step within the desolvation system, it enabled a high desolvation efficiency of 99.94% for aerosols from 1% (v/v) nitric acid. Plasma solvent load could be reduced to 0.9 mg min⁻¹ with a tap water cooled condenser combined with the membrane dryer, compared to 21 mg min⁻¹ with the normal chilled condenser desolvation system. Meanwhile, the membrane was also found to act as a pulse dampener, eliminating the plasma pulsation in the central channel caused by thermospray nebulization and thus improving the analytical performance of the system. The average relative standard deviations (RSD) with the optimized membrane/thermospray system were 0.83% and 0.60% for the background and analyte signals, respectively, which were reduced by a factor of 1.9 and 2.7 for the background and analyte signals, respectively, compared to thermospray without the membrane desolvation, and were essentially identical to those obtained with pneumatic nebulization sample introduction. The improvements in detection limits with the membrane/thermospray system were 1.2–3.0 times with an average factor of 1.8 compared to thermospray without the membrane dryer, and 18–68 times with an average factor of 39 compared to the standard pneumatic nebulization sample introduction system without a desolvation unit. The detection limits for Mn, Mg, Cr and Cd with the present thermospray/membrane system were comparable to those reported for pneumatic nebulization ICP mass spectrometry.     

New developments in thermospray sample introduction for atomic spectrometry

The status of thermospray sample introduction for analytical atomic spectrometry was last reviewed in 1992. In this review, we summarize developments in this field since that time, including investigations of aerosol generation processes, noise diagnosis and control with inductively coupled plasma-atomic emission or mass spectrometry (ICP-AES/MS), high flow thermospray, the use of dual-stage desolvation systems based on membrane dryers, and the utilization of thermospray with axially viewed ICP-AES. Since a major advantage of methods based on thermospray is improved limits of detection, the emphasis for applications of thermospray with ICP spectrometries remains focused on environmental sample types, particularly with ICP-MS. Relatedly, the use of thermospray as a means for the direct speciation of Se is also under development.     

低功率微波热雾化器与同轴气动雾化器作为电感耦合等离子体发射光谱法进样装置的比较

对用低功率微波热雾化器(MWTN)和同轴气动雾化器(PN)作为电感耦合等离子体发射光谱仪(ICP-AES)进样装置时，仪器的操作条件(样品提升速率(Q1)、载气流速(Fc))进行了选择和比较。在选定的条件下，比较了两种雾化器的分析性能。发现HCI的浓度对两种雾化器的影响不同，对于MWTN，Cr、Cd、Co、Mn和Ls，谱线的发射强度随HCl浓度的增加而略有增加；而对于PN，谱线的发射强度随HCl浓度的增加而略有降低；MWTN对于上述5种元素的检出限均优于PN，而精密度则不如后者。     

用低功率微波热雾化器与十字交叉气动雾化器作为ICP-AES进样装置的比较

在 ICP- AES中 ,最常用来引入液体样品的方法是雾化法 .因此 ,雾化器雾化效率的高低直接影响到 ICP- AES的分析性能 [1,2 ] .目前 ,在 ICP- AES中最常用的雾化器是气动雾化器 (PN) .它的优点是简单、稳定性好 ;缺点是产生的雾滴的直径范围很宽 (一般为 1～ 50 μm) ,进样效率低 ,一般仅为 1 %～3% [3] .热雾化器是近年发展起来的一种雾化效率较高的雾化法 ,已被越来越多地用于 ICP- AES[4～ 7] .热雾化法的雾化原理与同轴气动雾化法类似 ,不同之处在于 :对于热雾化法来说 ,(1 )雾化所需的气体来自于液体样品本身而不是外加的惰性…     

等离子体原子光谱分析中溶液样品雾化进样方法的新进展

对近年来等离子体原子光谱分析中溶液样品引入方法的新进展作了综述，其中包括气动雾化法、超声雾化法、热雾化法、悬浆雾化法、高水压雾化法及电喷雾法等。文中还根据本课题组多年来的研究经验对每种方法的优缺点及其应用作了简要的介绍和评论。     

Thermospray nebulizer as sample introduction technique for microwave plasma torch atomic emission spectrometry

A thermospray nebulizer was used as a sample introduction device for microwave plasma torch (MPT) atomic emission spectrometry (AES). Experimental parameters, including the power supplied to the MPT, the flow rates of support and carrier gases, the observation height, the sample uptake rate, the thermospray working temperature, the temperature of the aerosol spray chamber and cooling water were optimized. Under optimum conditions, the relative standard deviation (RSD) of 10 measurements for 21 elements is in the range 0.3–2.0%. The detection limits were improved in comparison with the ultrasonic nebulizer as sample introduction technique for MPT–AES. The inclusion of 20% methanol into the MPT showed there is no effect on the stability of MPT discharge. The technique can thus be held to have the potential for interface to reverse-phase HPLC systems.     

Determination of trace amounts of cadmium, lead, copper and zinc in natural waters by inductively coupled plasma atomic emission spectrometry with thermospray nebulisation, after enrichment on Chelex-100

Enrichment on Chelex-100, followed by evaporation when necessary, was used for the pre-concentration of Cd, Pb, Cu and Zn from natural waters. The measurements were carried out with inductively coupled plasma atomic emission spectrometry using a thermospray nebulisation system to reach the required sensitivity. The detection limits corresponding to three times the standard deviation of the blank (in 1% v/v HNO3) after a 30-fold enrichment are 0.02 microgram l-1 for Cd, 0.33 microgram l-1 for Pb and 0.03 microgram l-1 for Cu and Zn. Matrix effects, which are fairly serious with thermospray nebulisation, were taken into account by using the standard additions method. Results obtained for several river water samples were compared with those found by analysis of the non-enriched sample with inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry. In all instances the agreement was satisfactory.     

Spectrochemical determination of trace As, Fe, Hg, Mn, and Pb by an argon-stabilized U-shaped DC arc

Argon-stabilized U-shaped DC arc with a system for aerosol introduction was used for the determination of As, Fe, Hg, Mn, and Pb. By applying a computer program performing a time integration of the registered signals and by optimizing the working conditions of an U-shaped arc plasma, the detection capability for As, Fe, Hg, Mn, and Pb was improved, which contributed to the lowering of the detection limits. The lowest detection limits for Fe, Mn, and Pb were achieved during an integration time of 20 s, and for As and Hg during an integration time of 30 s, and their values were 1.1, 0.1, 0.9, 15, and 2.6 ng/mL, respectively. The detection limits obtained by our method with optimal integration times were compared with the detection limits obtained using other methods: inductively coupled plasma-atomic emission spectrometry (ICP-AES), directly coupled plasma-atomic emission spectrometry (DCP-AES), microwave-induced plasma-atomic emission spectrometry (MIP-AES), inductively coupled plasma-mass spectrometry (ICP-MS), and an improved thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS). The text was submitted by the authors in English.     

Improvements in thermospray flame furnace atomic absorption spectrometry

In thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) a nickel atomization tube is placed in the acetylene/air flame on a holder built onto a standard AAS burner head. The liquid to be analyzed is transported by a low or high-pressure pump through a very hot, simple, inexpensive ceramic capillary tip acting as a flame-heated thermospray into the flame furnace. This results in complete sample introduction and increases the residence time of the sample in the absorption volume. This leads for 17 elements to a 3-110-fold improvement in the power of detection compared to conventional flame AAS. The absolute detection limits (3s values, N=25) lie between 0.2 μg l⁻¹ (Zn) and 310 μg l⁻¹ (Se) according to the element. The R.S.D. (N=15) is 1.4-5.5% according to the element and applied concentration. TS-FF-AAS can easily be incorporated on any standard flame AAS instrument and can be automated with a standard autosampler.