海水pH标准物质的研制

提出一种更适合于海水pH测量的海水pH标准物质,对小批量制备该标准物质的制备方法及其定值方法进行探索研究。采用分光光度测定法测定海水pH标准物质的pH值,对该批海水pH标准物质分别抽取一定数量的样品采用F检验法和t检验法进行了均匀性检验和稳定性考核。结果表明,该批以人工海水为介质的海水pH标准物质混合均匀,常温条件下保存六个月是稳定的。     

pH(酸度)计测量标准不确定度的评定

文章以JB pHB-Ⅱ型酸度检定仪为pH(酸度)计检定装置主标准器,依据JJG 119—2018《实验室pH(酸度)计检定规程》和JJF 1059.1—2012《7586测量不确定度评定与表示》,研究了pH(酸度)计测量标准不确定度的评定方法,并用传递比较法进行了验证,该方法科学有效。     

一级pH标准溶液pH_s值的电测定与一级pH标准物质的稳定性(英文)

中国计量科学研究院于1968年建立了(0～95)℃水溶液酸度(pH)标准测量装置,并鉴定了一批一级pH标准缓冲物质。为了保证pH标准测量的准确可靠和考察一级pH标准物质长时期保存的稳定性,对原pH标准测量装置进行了整顿,更新了主要测量设备,并在此基础上重新测定了0.05m磷苯二甲酸氢钾溶液、0.025m磷酸氢二钠和0.025m磷酸二氢钾溶液和0.01m硼砂溶液在25℃下的pH值。结果表明,对一级pH标准溶液的测定具有良好的重现性;对同一批号样品的多次测定和不同批号样品的测定,其pH值均不超出总不确定度范围。一级pH标准物质在普通实验室条件下密封存放16年后,其pH值未发生变化。     

有机物全熔点标准物质定值用毛细管熔点仪的研制

研制一种基于毛细管熔点原理的真空绝热杯式毛细管熔点仪,该装置消除了温场不均匀和温度计热滞后带来的系统误差,具有较高的测量精度.该装置用于月桂酸、联苯、咪唑、乙酰苯胺、非那西丁、对甲基苯甲酸、蒽和咔唑等8种有机物全熔点标准物质的定值,标准物质全熔点扩展不确定度为0.20℃和0.17℃(升温速率分别为1.0℃/min和0.5℃/min).标准物质定值结果与改进后的差示扫描量热仪结果一致,两者之间的差别不大于0.23℃,从而验证了该装置的准确性.     

基于重量稀释法的海水盐度测量标准不确定度研究

对基于重量稀释法的海水盐度测量标准进行了全面的不确定度分析研究,特别是对质量与盐度的传递关系,详细分析了过程引入的分量,为完善盐度标准量值溯源及传递体系,提供了技术参考。结果表明,基于重量稀释法配制的标准海水样品在盐度2～35范围内,其最大扩展不确定度与中国一级标准海水相当;并以8400B型实验室盐度计为被测对象,对配制的标准海水样品进行验证,测量结果完全满足盐度标准装置的性能要求。     

苯甲酸标准物质制备中区域熔融提纯装置的研制

阐述了中国计量科学研究院设计并研制的基于区域熔融原理的提纯装置,该装置用于制备一级热量标准物质苯甲酸。为了提高纯度,增加提纯后的产出量和效率,创新性地采用双加热炉进行同步加热,设计了角度调节器防止样品管的炸裂。提纯后的苯甲酸样品采用国家基准试剂纯度测定基准装置进行测定,测量结果为99.999%,扩展不确定度为 0.016%(k=2),从而验证了该装置满足标准物质的提纯要求。     

酸度(pH)国家计量基准

酸度（pH）国家计量基准是国家标准物质研究中心在60年代开始研究建立的,后经扩大量程,于1971年通过了中国计量科学研究院组织的成果鉴定,1978年获全国科学大会奖。1986年经原国家计量局批准为国家计量基准。酸度（pH）国家基准用于复现和保存水溶液pH标度的pH值。该基准采用红电极一银一氯化银电极无液接界电池电动势测量法,测量PH标准溶液的PHs值,根据能斯特公式进行计算。酸度（pH）基准由测量电池组、氢气发生器、电池电动势测量装置和精密恒温槽等装置以及一组（六种）pH一级标准物质配置的标准溶液组成,其测量范围是1－14p…     

一种数字多用表标准装置的不确定度评定

简述了以一种数字多用表测量标准装置的组成及原理,建立了标准的数学模型,分析了该装置测量标准的不确定度来源、计算方法及评定过程,并验证了该装置的评定结果。     

标准海水与包材的相容性试验研究

选择合适的包材,是标准物质生产的关键环节.本文以2类硼硅玻璃瓶、2类丁基胶塞为包材,采用正交设计试验冷封装制备标准海水,置于正常的保存环境,考察密封性、相容性.试验证明：硼硅玻璃瓶、丁基胶塞的组合密封效果良好;隔膜胶塞与标准海水是相容的,保存3年后盐度量值无明显变化,而镀膜胶塞影响海水盐度值.考虑到批量生产,确立中性硼硅玻璃瓶、隔膜胶塞作为包材.     

正交试验法在气体分析仪自动校准装置数据验证中的应用

以En值的绝对值为试验目标，采用正交试验法对气体分析仪自动校准装置进行了数据验证，验证结果表明，该装置输出的目标浓度值的气体和使用相同浓度的二级气体标准物质在各自的不确定度范围内等效一致，对数据进行了极差分析和方差分析，结果表明气体总流速及目标气体的组分数对输出量值的影响较大。     

Cyclic loading and marine environment effects on the properties of HDPE umbilical cables

This work presents a study of the effects of cyclic loading and marine environment on the mechanical properties of high-density polyethylene (HDPE) used in the external layer of submarine cables. Two different types of samples were tested. The first type was tested in the as-received condition whereas the second one was taken from the cyclic-loaded material. The cyclic-load test was carried out in a device, according to the API 17E standard (API 17E-98, Specification for sub sea production control umbilicas). These samples were submitted to a process of artificial aging. All the specimens were submitted to tensile test and the analysis and comparison of the results showed that HDPE suffered alterations in its mechanical behavior, especially the material submitted to cyclic loading. Both aged and as-received samples were observed by using scanning electron microscopy and their hardness was also measured. The results showed that the cyclic loading, the seawater and the ultraviolet radiations accelerated the degradation process of HDPE.     

An Earth‐Abundant Catalyst‐Based Seawater Photoelectrolysis System with 17.9% Solar‐to‐Hydrogen Efficiency

The implementation of water splitting systems, powered by sustainable energy resources, appears to be an attractive strategy for producing high‐purity H₂ in the absence of the release of carbon dioxide (CO₂). However, the high cost, impractical operating conditions, and unsatisfactory efficiency and stability of conventional methods restrain their large‐scale development. Seawater covers 70% of the Earth's surface and is one of the most abundant natural resources on the planet. New research is looking into the possibility of using seawater to produce hydrogen through electrolysis and will provide remarkable insight into sustainable H₂ production, if successful. Here, guided by density functional theory (DFT) calculations to predict the selectivity of gas‐evolving catalysts, a seawater‐splitting device equipped with affordable state‐of‐the‐art electrocatalysts composed of earth‐abundant elements (Fe, Co, Ni, and Mo) is demonstrated. This device shows excellent durability and specific selectivity toward the oxygen evolution reaction in seawater with near 100% Faradaic efficiency for the production of H₂ and O₂. Powered by a single commercial III–V triple‐junction photovoltaic cell, the integrated system achieves spontaneous and efficient generation of high‐purity H₂ and O₂ from seawater at neutral pH with a remarkable 17.9% solar‐to‐hydrogen efficiency.     

金属反射型保温材料导热系数的测定

根据稳态法测量导热系数原理,设计了一套稳态导热系数测量装置,利用自动控制技术实现实验过程的可控性。通过与导热系数参比块的测量校对,该装置测量结果的准确度达到标准要求。并利用此测量装置对压力容器金属反射型保温层试样的导热系数进行了测定,测定温度在80～220 ℃范围内,测量误差小于1.3%,导热系数值由0.040 W/(m·K)变化到0.053W/(m·K)。     

液氧密度标准计量装置

研制了一种液氧密度标准计量装置,介绍了其测量原理、装置流程及性能实验结果。分析了该装置的不确定度,并与国际水平进行了比较。     

由摩擦材料等同采用ISO标准引发的摩擦材料生产许可证工作的思考

随着我国的汽车工业进步,对汽车制动器衬片的质量和性能提出了更高的要求。而我国汽车制动器衬片生产企业的生产能力和水平与发达国家还有一定差距。目前我国汽车制动器衬片执行GB5763,摩擦材料标准化技术委员会正在试图等同采用更为先进的ISO15484体系。ISO15484对汽车制动器衬片产品的设计、研发、试生产到批量生产各个环节进行规定,在此过程中,台架试验成为非常重要的手段。新标准的等同采用将使生产许可证工作发生相应变化。作为强制的行政许可,适时的采用新标准作为企业取证的基本要求和产品检验依据,将促进行业的整体进步。而这一变化尚需时日,有待于新标准逐渐的被企业和行业所认同、接纳和采用。     

BFe10-1-1白铜和双相不锈钢在海水管路中应用的综合性能分析

根据舰船海水管路系统对材料的性能要求 ,从防污性能、成型性能、焊接性能、耐蚀性能等几个方面 ,对BFe1 0 1 1白铜和HDR双相不锈钢进行了综合分析。结论是 ,BFe1 0 1 1白铜目前仍是舰船海水管路系统的最佳选材 ,HDR双相不锈钢虽然具有优良的耐海水腐蚀性能 ,但不具有防污功能     

Determining subnanomolar iron concentrations in oceanic seawater using a siderophore-modified film analyzed by infrared spectroscopy

Iron is a bioactive trace element in seawater that regulates photosynthetic carbon dioxide drawdown and export from surface waters by phytoplankton in upward of 40% of the world's oceans. While autonomous sensor arrays are beginning to provide high-resolution data on temporal and spatial scales for some key oceanographic parameters, current analytical methods for iron are not amenable to autonomous platforms because of the need for user involvement and wet chemistry-based approaches. As a result, very large gaps remain in our understanding of iron distribution and chemistry in seawater. Here we present a straightforward nanostructure-based method to measure dissolved iron in natural seawater. The device comprises an iron-specific chelating biomolecule, desferrioxamine B (DFB), covalently immobilized on a mesoporous silica film. Changes in infrared spectral signatures of the immobilized DFB upon Fe(III) complexation provide an accurate and precise measure of iron on the surface of a chip exposed to seawater. The current system has a detection limit of approximately 50 pM for a 1-L sample at pH 1.7 and was used to measure dissolved iron in subarctic Pacific waters without interference from other elements in seawater. This technology provides a major step toward obtaining accurate iron measurements on autonomous research platforms.     

某海上油田海水系统青铜阀门腐蚀穿孔原因分析

某海上油田海水系统发生泄漏,经调查为某青铜截止阀腐蚀穿孔所致。针对此截止阀腐蚀失效开展了宏观分析、理化性能检验、扫描电镜(SEM)及能谱(EDS)分析、X射线衍射(XRD)分析等。结果表明:铸造加工缺陷导致材料耐蚀性降低是导致阀门腐蚀穿孔的主要原因;阀门穿孔位置遭受较严重冲刷腐蚀,是导致弯头腐蚀穿孔次要原因。建议今后对新购进青铜铸造构件加强质检,确保质量和耐蚀性合格,优化此类阀门结构设计,避免阀体局部遭受严重冲刷腐蚀。