空气环境下PtO2分解实验的研究

标准铂电阻温度计的感温元件高纯铂丝的氧化是影响其测温性能的重要因素之一。利用差示量热扫描仪(DSC)和X射线光电子能谱技术(XPS),研究铂丝氧化的主要产物PtO2在不同温度下的生成产物,以及不同产物的生成和分解温度。结果表明:当温度在550～820 ℃范围内时,随着温度的升高,PtO2会逐渐分解生成PtO和Pt,且温度越高生成的Pt含量越多;当温度高于820 ℃时,PtO2会快速分解为Pt和O2。该研究结果对标准铂电阻温度计的制作技术和使用提供了理论支撑。     

提高铂电阻温度计测量准确度的实验方法研究

目前我国工业用A级铂电阻在0℃的最大允许误差为±0.15℃,为使铂电阻温度计误差小于0.1℃,提出了一种提高工业级铂电阻温度计准确度的方法。试验采用计算机温度自动检测系统,测温元件采用Pt100铂电阻,结果证明整个系统的测量误差在0.1℃以内,而且整体造价低,经济实用。此方法较好推广,可适用于热电阻温度计的温度测量。     

一种高精度薄膜铂电阻温度计测量迟滞性的研究

为了研究热迟滞性对工业铂电阻温度计测量不确定度的影响,选取了8支高精度铂电阻温度计进行实验。在-50～150℃内,选择3个温度区间,采用两种标准方法(IEC 60751,ASTM E644)测量水三相点(0.01℃)和所选温度范围内的中间点的迟滞性变化。实验结果表明:4支薄膜铂电阻温度计在两种标准方法测量下,随着温度区间跨度增大,热迟滞性影响增大,IEC 60751标准方法测量的热迟滞性最大值为14.2mK,ASTM E644标准方法测量的热迟滞性最大值为20.5mK;选取4支铂丝铂电阻温度计在温度范围为-50～150℃测量时,IEC 60751和ASTM E644标准方法测量的热迟滞性数据最大值分别为1.1mK和0.9mK;铂丝铂电阻温度计热迟滞性明显小于薄膜铂电阻温度计。     

基于标准铂电阻温度计的高精度测温仪的研制

标准铂电阻温度计是目前准确度最高的温度计．在-259．3567℃～961．78℃温度范围内．也是复现现行国际温标ITS-1990的标准仪器。在检定各种标准温度计和精密温度计量仪器时其作为标准器使用．也可以直接用于高精度测量。标准铂电阻温度计按工作等级划分为一等标准铂电阻温度计和二等标准铂电阻温度计。     

退火对标准铂电阻温度计性能影响的研究

退火是消除铂电阻温度计内部由于机械振动等因素带来应力的最有效手段,同时也可能改变铂电阻温度计内部铂丝的氧化状态。选用不同国家生产的4支标准铂电阻温度计,分别在600 ℃、500 ℃、450 ℃、420 ℃、350 ℃进行退火,研究铂电阻温度计退火后在室温下随时间的变化规律。结果表明,不同的退火温度对铂电阻温度计阻值产生不同影响,对应温度变化量可达1 mK,退火后在室温下0~6 h内变化显著,保持同一个热状态可有效提高铂电阻温度计的测量水平。     

-80～300℃铂电阻温度计在0℃的热迟滞性研究

针对两种不同类型的工业铂电阻温度计(IPRTs),使其在-80℃和300℃下恒温一定时间后再测量其0℃下的电阻偏移,由此来确定其在该温度下的热迟滞性。试验结果表明:薄膜型铂电阻温度计在0℃的热迟滞性远大于铂丝型铂电阻温度计,并且随着测量次数的增多,热迟滞性会逐渐减小。     

一种超长杆铂电阻温度计校准装置

核电站所用的铂电阻温度计总长度超过3m,温度计的感温元件长度接近3m,常规的校准系统不能用于此类超长杆温度计的性能评估。介绍了一种用于核电站的超长杆铂电阻温度计的校准实验装置,通过实验验证,该系统的温度稳定性优于±0.015℃,水平和垂直温度均匀性分别优于0.05℃和0.02℃,标准不确定度和扩展不确定度分别为0.016℃和0.032℃,该实验系统可有效地评估长杆铂电阻温度计的性能。     

高温铂电阻温度计

PtRh—Pt热电偶在+630℃～1063℃范围内测量温度其复现精度是±0.1K,这已达到它的测量极限。因此用铂电阻温度计作精密测温已越来越广泛,它不仅具有比热电偶有较高的精度和好的复现性,而且分辨率也比热电偶大得多。本文提出了一种新型的片状结构的支撑体,它由宝石和石英材料制成。同时还介绍了装配工艺,其中包括干燥空气的获得和填充,用氧—煤气火焰的焊接铂丝的方法。以及退火炉、退火过程、退火中温度计的放置方式等作了简要的叙述。文中还例举了各国高温铂电阻温度     

0～29.7646℃温区定点法分度精密铂电阻温度计外推使用的探讨

精密铂电阻温度计是介于标准铂电阻温度计与工业铂电阻温度计之间的测温传感器,利用ITS-90国际温标定义的固定点分度精密铂电阻温度计可以提高测温准确性和稳定性,但经常会出现超出内插方程所规定的温度范围以致无法用定点法分度的问题.本文对精密铂电阻温度计利用水三相点及镓熔点进行分度,调研了通过0～29.7646℃温区内插方程直接外推到70℃的可行性.实验以两支精密铂电阻温度计为对象,对定点法外推结果与直接比较法进行比较,结果显示:外推结果与标准值最大差值为1.5mK,表明精密铂电阻温度计利用水三相点及镓熔点进行分度并外推至70℃在一定的测量水平要求下是可行的.     

标准铂电阻温度计测量结果不确定度评定

本文以最常用的温度段（0-429．527）℃,以一等标准铂电阻温度计检定二等标准铂电阻温度计为例来分析标准铂电阻温度计的测量结果不确定度。     

The use of industrial-grade platinum resistance thermometers between 77 K and 273 K

The stability and interpolation characteristics of some industrial-grade platinum resistance thermometers have been investigated between 77 K and 273 K. Seven sensors were thermally cycled many times between 77 K and 373 K and were found to suffer reversible changes in ice-point resistance. After some tens of cycles between 77 K and 273 K the ice-point resistances of the thermometers stabilised to within a few milliohms, provided that the thermometers were not heated above 300 K. A two-point calibration method for these thermometers is described. Using resistance values at the ice-point and the oxygen boiling point, a measurement accuracy of 35 mK can be obtained over the range 77 K to 273 K. Interpolation data for 27 thermometers are given.     

高岭土在真空下的热分解行为

以含高岭石、一水硬铝石、黄铁矿的高岭土为原料,经过压块烘干后,在真空(15~50 Pa)、不同加热温度下,采用同步热分析仪(DSC-TGA)、X射线衍射(XRD)等分析手段对高岭土在真空下的热分解进行研究。DSC-TGA的结果与高岭石、一水硬铝石、黄铁矿三种矿物常压下的热力学计算出的分解温度相符。实验产物的XRD结果表明:在真空条件(15~50 Pa)下,一水硬铝石AlO(OH)在100~200℃之间脱水,300℃时脱水完全;黄铁矿FeS2在500~600℃分解,分解产物为FeS和S2,在700℃时,黄铁矿FeS2分解完全;高岭石Al2Si2O5(OH)4在实验煅烧过程中,在200~300℃之间脱水,生成非晶态的偏高岭石,比该矿在常压的脱水温度提前200℃左右。继而转变成A-lSi尖晶石,最后形成莫来石与方石英。实验结果与热力学计算符合,充分说明真空条件对高岭土中各种矿物分解产生气体的反应有较大的促进作用。在本实验三种矿物分解产生气体的过程中,先进行的反应对后一反应的发生影响不明显。     

Optothermal property and decomposition characteristics of PtO(x) ultrathin film sandwiched between ZnS-SiO2 for super-resolution near-field recording

We have investigated the optothermal property and decomposition characteristics of PtO(x) ultrathin film protected by ZnS-SiO2 layers and effects of the constituent phases of PtO(x) on super-resolution capability and read stability of the super-RENS disk. All the ZnS-SiO2/PtO(x)/ZnS-SiO2 multilayers exhibited a steep reflectivity drop at the temperature range between 265 and 350 degrees C, corresponding to the decomposition of PtO(x). The decomposition temperature of the 4-nm-thick PtO(x) ultrathin film protected by ZnS-SiO2 layers was much lower than those obtained in thick PtO(x) films without protection. The activation energy for thermal decomposition was approximately 1.3 eV. Both the decomposition temperature and activation energy for thermal decomposition were unaffected by the constituent phases of PtO(x). Carrier to noise ratios (CNR) of over 40 dB for mark size of 150 nm were achieved in all super-resolution near-field structure (super-RENS) disks, while the super-resolution readout was limited to 2.5 x 10(3) approximately 4.5 x 10(4) cycles. The effect of constituent phases of PtO(x) on the super-resolution capability of super-RENS disk with a PtO(x) mask layer was minimal. However, as the constituent phases of PtO(x) mask layer transformed from a mixture of Pt and PtO, to pure PtO, and then to a mixture of PtO and PtO2, the readout stability of super-RENS disk increased dramatically since less heat was absorbed by the PtO(x) mask layer composed of PtO and PtO2 during the readout process, prohibiting the diffusion of materials inside the bubble to the GeSbTe phase change layer.     

Pt/YSZ氧传感器的电极电阻和响应特性

应用两电极直流极化法测定了氧传感器在380～800℃中的Pt,空气／YSZ电极电阻,从交流低频阻抗测量外推法测得YSZ的体电阻,可以将YSZ的直流极化从电极的过电位中区分出来．Pt,空气｜（ZrO2）_0．93（Y₂O₃）_0．07｜空气,Pt,电池的直流极化1gI-η作图得出,电极电荷传递系数为2．YSZ体电阻、Pt,空气／YSZ电极电阻和电极交换电流对温度的Arrhenius图,在600℃和570℃附近存在着类似的活化能变化．测量表明;700℃时,氧传感器的测量响应时间≤2．5s．     

基于VBA的工业铂电阻半自动校准系统

介绍一种在Excel内嵌的VBA平台上开发的工业铂电阻半自动校准系统,对系统的工作原理及软件流程进行了论述,通过程序实现了判断恒温槽温场变化、自动记录铂电阻阻值数据、在校准(检定)完成后对铂电阻进行自动等级判定、自动生成原始记录和证书等功能,解决了以往工业铂电阻的校准(检定)工作中遇到的数据量大,后期处理繁琐的问题,具有推广价值。     

Corrosion‐Activated Chemotherapeutic Function of Nanoparticulate Platinum as a Cisplatin Resistance‐Overcoming Prodrug with Limited Autophagy Induction

Despite nanoparticulate platinum (nano‐Pt) has been validated to be acting as a platinum‐based prodrug for anticancer therapy, the key factor in controlling its cytotoxicity remains to be clarified. In this study, it is found that the corrosion susceptibility of nano‐Pt can be triggered by inducing the oxidization of superficial Pt atoms, which can kill both cisplatin‐sensitive/resistance cancer cells. Direct evidence in the oxidization of superficial Pt atoms is validated to observe the formation of platinum oxides by X‐ray absorption spectroscopy. The cytotoxicity is originated from the dissolution of nano‐Pt followed by the release of highly toxic Pt ions during the corrosion process. Additionally, the limiting autophagy induction by nano‐Pt might prevent cancer cells from acquiring autophagy‐related drug resistance. With such advantages, the possibility of further autophagy‐related drug resistance could be substantially reduced or even eliminated in cancer cells treated with nano‐Pt. Moreover, nano‐Pt is demonstrated to kill cisplatin‐resistant cancer cells not only by inducing apoptosis but also by inducing necrosis for pro‐inflammatory/inflammatory responses. Thus, nano‐Pt treatment might bring additional therapeutic benefits by regulating immunological responses in tumor microenvironment. These findings support the idea that utilizing nano‐Pt for its cytotoxic effects might potentially benefit patients with cisplatin resistance in clinical chemotherapy.