Evaluation of molybdate ester as a synergist for arylamine antioxidant in lubricants

An oil-soluble additive molybdate ester (ME) was synthesized. The antioxidation properties of p,p′-dioctyldiphenylamine (DODPA)- and ME-containing poly-α-olefin (PO)-derived lubricants were evaluated by differential scanning calorimetry (DSC) to measure and hot oil oxidation (HOO) tests. DSC test measures incipient oxidation temperature (IOT) and oxidation induction time (OIT) of the lubricant at high temperatures and the oxidation stability of oil viscosity increase is measured by HOO test. DSC test shows that IOT and OIT of DODPA-containing PO were improved significantly by ME addition. HOO test indicates that when combining with DODPA antioxidants, ME can also effectively reduce the increase in viscosity of the mineral oil 150 SN. These results suggest that the ME shows a good oxidative synergism with DODPA antioxidant. In addition, the changes occurring to DODPA in 150 SN oxidation with and without ME were observed by GC/MS analysis. The proposed mechanism of the inhibition involves a synergy between ME and DODPA.     

Study of the heating rate effect on the glass transition properties of (60 − x)V2O5–xSb2O3–40TeO2 oxide glasses using differential scanning calorimetry (DSC)

The glass-transition temperature (T_g) and crystallization temperature (T_Cr) have been determined for the system (60 − x)V₂O₅–xSb₂O₃–40TeO₂ with 0 < x < 10 (in mol%) using differential scanning calorimetry (DSC) at heating rates φ = 3, 6, 9 and 13 K/min. The effect of the heating rate and the Sb₂O₃ content on T_g is discussed. It was observed that the transition region shifts to higher temperatures when the measuring time is reduced (or, conversely, when the applied temperature rate is increased). Using differential scanning calorimetry, the compositional dependence of T_g has been determined and so, an empirical equation has been deduced which relates the glass-transition temperature with the Sb₂O₃ content.     

Evaluation of sodium acetylacetonate as a synergist for arylamine antioxidants in synthetic lubricants

Differential scanning calorimetry (DSC) was employed to evaluate the performance of an ester lubricant containing sodium acetylacetonate. In the isothermal DSC oxidation test, sodium acetylacetonate is an effective synergist for arylamine antioxidant p,p′-dioctyldiphenylamine (DODPA). When combining with arylamine antioxidants, sodium acetylacetonate can also effectively reduce the increases in viscosity and acid number of the ester oil in oxidation–corrosion test. The electron paramagnetic resonance (EPR) results indicated that sodium acetylacetonate can reduce the free radical contents in the oxidized oil with arylamine antioxidants present.     

差示扫描量热(DSC)图谱匹配识别法在鱼腥草产地快速鉴别中的应用

中药材的道地性鉴别研究是目前的一个难点。本研究探究了差示扫描量热(DSC)方法在鱼腥草产地鉴别中的应用。通过DSC测量方法的改进,测量参数的优化,得到了稳定、可重复、有辨识度的鱼腥草DSC谱图。研究发现鱼腥草样本在60℃~350℃区间内有两个明显的特征放热峰。不同产地样本的特征反应峰的起始温度、峰值温度、反应焓及DSC曲线的拓扑图形都有明显的差异,而且相同产地样本的DSC曲线具有良好的重复性。在此基础上,本研究将16个不同产地的鱼腥草样本DSC数据建成数据库,引入相似度匹配算法计算得到鱼腥草DSC谱图之间的相似度。通过相似度匹配可以实现鱼腥草产地的高效、精准鉴别,可为中药材产地的鉴别提供新的研究思路和方法。     

Fragility, DSC and elastic moduli studies on tellurite–vanadate glasses containing molybdenum

Ternary xMoO₃–40TeO₂–(60 − x)V₂O₅ glasses with 0 ? x ? 60 (in mol%) have been prepared by normal melt quenching method. DSC curves of these glasses have been investigated. The glass transition properties that have been measured and reported in this paper, include the glass transition temperature (T_g), glass transition width (ΔT_g), heat capacity change at glass transition (ΔC_P) and calculated fragility (F). Thermal stability, Poisson’s ratio, fragility and glass forming tendency of these glasses have been evaluated, to determine relationship between chemical composition and the thermal stability or to interpret the structure of glass. In addition, Makishima and Makenzie’s theory was applied for calculation of Young’s modulus, bulk modulus and shear modulus, indicating a strong relation between elastic properties and structure of glass. Generally, results of this work show that glass with x = 60 has the highest shear, bulk and Young’s moduli which make it as suitable candidate for the manufacture of strong glass fibers in technological applications; but it should be mentioned that glass with x = 20 has higher handling temperature and super resistance against thermal attack.     

DSC在Ti-Ni形状记忆合金相转变中的应用

论述了德国耐驰公司的差示扫描量热仪（DSC200PC）在研究Ti—Ni形状记忆合金相转变过程中的具体应用。结果表明：DSC200PC能够方便快捷的测定Ti—Ni形状记忆合金的相转变。为了节约测试成本，需要厂家对仪器冷却控制系统的电磁阀进行改进。同时，给出了Ti—Ni合金的马氏体起始温度Ms，马氏体结束温度Mf，奥氏体起始温凡和奥氏体结束温度Ar，并对其相变过程进行了判断。     

喷雾辅助激光解吸离子化质谱法用于奶制品快速鉴定

Spray-assisted laser desorption ionization mass spectrometry(SALDI-MS) was applied to rapid fingerprinting of dairy products for authentication. Unique SALDI-MS fingerprints of three famous Chinese dairy brands were obtained. Counterfeit samples could be rapidly distinguished from the authentic ones. We believe that this sample-preparation-free technique can be a very useful product screening tool in dairy industry because of its sensitivity, simplicity, and high throughput.     

Mixture of safflower oil and synthetic ester as a base stock for biodegradable lubricants

Biodegradable industrial lubricant applications are gaining popularity with growing environmental concern and stringent government regulations. Plant oils are major base stocks for eco‐friendly green lubricants. However, because of their poor oxidation stability, their applications are restricted to limited usages. Improvements of these plant oils can be made either by addition of functional additives or by chemical/genetic modifications. This paper evaluates the synergistic approach of phenolic and aminic antioxidants in safflower oil. Further, to enhance the oxidation properties of the plant oil, we incorporated and studied synthetic esters (SEs) for thermo‐oxidative stability by using rotating pressure vessel oxidation test and differential scanning calorimeter. The combination of phenolic and aminic antioxidants at a 2 : 1 ratio exhibited the best synergistic effect, when incorporated into a combination of plant oil and SE. In addition to thermo‐oxidative properties, the tribological properties of neat base stocks were also studied. A substitute of mineral oil‐based lubricants can be formulated cost effectively by using an appropriate mixture of plant oil and SE. Copyright © 2013 John Wiley & Sons, Ltd.     

含有乙炔基蒽的齐聚物的激光质谱表征

Different structural anthracene oligomers containing acetylene were characterized by laser desorption ionization time-of-flight mass spectrometry (LDI-TOF-MS). The samples were dissolved in chloroform and the data were recorded by positive ion mode. LDI-TOF-MS is very effective for the analysis of the novel meatl tetraazaporphrins including tetra-(naphthalene)-tetraazaporphyrin.     

碱金属盐化合物的抗氧作用机理

利用差示扫描量热法评价全氟丁酸钠在酯类油中的抗氧性能，试验表明，全氟丁酸钠与对对二异辛基二苯胺具有良好的抗氧协同作用利用质量色谱分析油品氧化前后ＤＯＤＰＡ的变化，以确定其抗氧机理。     

热脱附谱方法的脱附速率灵敏度与四极质谱仪参数关系的实验研究

为了获得热脱附谱（TDS）方法的脱附速率灵敏度与四极质谱仪（QMS）参数的关系,以优化TDS高灵敏度分析的条件和参数,采用一种特制的通导型校准漏孔,基于QMS对氢同位素释放速率的二次离子检测（SEM）模式,研究了QMS仪器参数对TDS氘气脱附速率灵敏度的影响规律。实验结果表明,QMS的参数对TDS的氘气脱附速率灵敏度具有明显的影响,获得了实现TDS高灵敏度分析的QMS参数范围：发射电流1 000~1 400 μA;离子能量（栅极电压）3~3.5 V;电子能量50~70 V;聚焦电压-100~-60 V;分辨率-5~+5。     

SNOM/SFM结合的近场光学探针

介绍了近年来近场光学探针技术的进展，特别是可与扫描力显徽镜结合的探针制备技术。     

光盘伺服槽道间距的一种间接检测方法

主要介绍了一种间接检测方法,该方法用于检测光盘刻槽机所刻母盘上伺服槽的道间距。该方法结合光盘刻槽机机械与电控系统的自身特点而进行设计,经应用取得良好效果。     

激光解吸/激光后电离质谱法快速检测黄酒中酪胺

黄酒是中国特有的酒类,营养丰富,酒曲中酶的作用可产生酪胺,人体中酪胺含量高低会影响神经传递过程。使用高效液相色谱-质谱法（HPLC/MS）分析黄酒中的酪胺,灵敏度高但需要复杂的样品前处理。本研究建立了激光解吸/激光后电离质谱法（解吸激光波长532 nm,后电离激光波长266 nm）快速检测黄酒体系中的酪胺,通过对梯度浓度的酪胺纯样进行分析,计算酪胺纯样的检出限。将该方法直接用于黄酒样品的快速分析,使用标准加入法测定黄酒中酪胺含量。本方法对酪胺纯样的检出限为32 μg/L,标准加入法测得的黄酒中酪胺含量约为68 mg/L,在安全食用范围内。该方法无需任何样品前处理,快捷省时,且谱图简单清晰,信噪比高,适用于实际样品中酪胺成分的选择性快速检测。     

星载差分吸收光谱仪摆镜控制系统设计

针对差分吸收光谱仪搭载于地球同步轨道卫星时对地成像的要求,设计了一种扫描摆镜转动控制系统。从摆镜控制结构设计、控制电路设计两个方面阐述了摆镜系统的方案。摆镜系统受载荷主控器控制,接收控制指令并回传当前摆镜位置状态,通过LMD18200驱动芯片进行功率输出,由步进电机和谐波减速器构成的驱动器驱动摆镜转动,编码器读取摆镜角度信息。给出了PWM(Pulse Width Modulation)波占空比的测定办法,并提出通过回转到成像起始点之前的方式,消除回程误差对成像区域步距不确定性的影响。实验结果表明该系统的步距角均值偏差小于1″,最大偏差小于5″,标准偏差小于2″。该光谱仪摆镜控制系统满足步距精度指标要求。     

利用PDSC考察环境友好润滑油基础油氧化安定性的研究

结合环境友好润滑油产品的开发工作,用加压差热扫描示量法(PDSC)研究了菜籽油、双酯、多元醇酯等几种基础油的氧化稳定性,并与旋转氧弹的结果进行了比较;对菜籽油在不同温度下的氧化反应特性进行了考察,并采用阿仑尼乌斯公式计算了菜籽油氧化反应的活化能,初步研究了其氧化反应机制。试验结果表明,PDSC可用于评价基础油的氧化安定性,合成酯的氧化安定性明显优于菜籽油,且多元醇酯的氧化安定性最好。     

国产X射线衍射仪变温样品室的温度校正

借助介电温谱、拉曼光谱、电子顺磁共振和差示扫描量热分析四项技术综合评价BaTiO3陶瓷的四方-立方相变点,即居里温度(Tc)。当采用国产X射线衍射仪变温样品室对BaTiO3陶瓷体进行变温XRD测量时,以BaTiO3陶瓷的Tc为依据,检测到变温样品室热电偶的监测温度与陶瓷体表面实际温度存在30℃的偏差,可对实际的陶瓷体表面温度进行校正。     

基质辅助激光解吸飞行时间质谱及毛细管电泳对基因工程产品─重组人表皮生长因子的质量控制研究

本文应用基质辅助激光解吸飞行时间质谱（ＭＡＬＤＩ－ＴＯＦ－ＭＳ）测定基因工程产品一重组人表皮生长因子（ｒｈＥＧＦ）的分子量，用毛细管电泳仪测定了其纯度，并得到用Ｇｌｕ－蛋白酶切后ｒｈＥＧＦ的质量肽图，其中８１％的肽段与理论值相符，无规则裂解只占８％。由此建立了一种对基因工程产品进行质量控制及研究蛋白质一级结构的新方法，此方法快速、简便，灵敏度极高，相对误差小于０．５％。     

多壁碳纳米管基质用于大气压基质辅助激光解吸电离质谱分析小分子化合物

以多壁碳纳米管(MWCNTs)为基质,考察了大气压基质辅助激光解吸电离质谱(AP-MALDI MS)分析氨基酸和生物碱等小分子化合物的效果.以脯氨酸、甲硫氨酸、异亮氨酸、组氨酸、谷氨酸、天冬氨酸、盐酸小檗碱、哈尔满碱、去甲哈尔满碱为样品,研究了激光能量、点样方法等实验条件对质谱信号强度和噪音的影响,比较了氧化、Fe3 ...