液体饱和蒸气压测定实验装置的优化设计

介绍了对原有液体饱和蒸气压测定装置的改造设计思路和方案.经过改进的装置,克服了原装置平衡管内液体容易暴沸、空气容易倒灌以及原温度计给实验带来的读数复杂的缺点;同时使用该装置测定了环己烷在60～80 ℃ 内不同温度的饱和蒸气压值,并根据测定的数据计算得到了环己烷在这一温度范围内的平均摩尔汽化热.结果表明:新装置使实验操作易于控制,提高了测量精度,加快了实验速度,降低了实验失败率,同时也减少了实验室的环境污染.     

纯液体饱和蒸气压测定实验装置的改进

通过对纯液体饱和蒸气压测定原有实验装置的大胆改进,解决了长期以来该实验极难操作的诸多难题,大大提高了测定结果的精确度.     

低压无极灯汞蒸气压控制

汞蒸气压控制是无极灯的关键技术之一 ,通过对纯汞和汞齐的性能进行分析 ,指出汞齐的成分配比、用量和安放位置的确定是控制汞蒸气压达到最佳值的有效途径 .     

液体饱和蒸气压实验装置的改进

对液体饱和蒸气压测定实验在实验体系和装置上进行改进,改进后操作安全、方便、环保,试剂易得、价格与原试剂相差不多,实验效果较好.     

冷原子吸收汞蒸气发生器的改进及应用

介绍一种用于冷原子吸收光谱分析法测汞的新型的汞蒸气发生器，并探讨了将该发生器与测汞仪配合直接测定水中痕量汞的工作条件。采用该发生器比旧式汞反应瓶测汞操作简单、快速、灵敏度高。     

人体内汞分子形态的转化

利用气相色谱－原子吸收联用技术对人体内汞分子形态的转化进行了研究,其方法是收集长期接触汞蒸气的职业工人的尿样和血样,用联用系统进行测定。样品中的甲基汞和二甲汞都可被检出,这说明汞蒸气进入人体后可以发生分子形态的转化。为汞的毒性研究和临床治疗提供了重要依据。     

在线大气汞分析仪的开发及应用

作者基于金汞齐-冷原子荧光光谱法,自行开发用于分析环境空气中气态总汞(TGM)的在线监测仪器。该仪器操作时以净化后的环境空气作为载气,无需氩气或氮气。经测试:当采样流量为1L/min,采样时间为10min时,检测限能达到0.2ng/m3;0.1ng汞蒸气连续测定结果表明其相对标准偏差<1.4%;工作曲线线性良好,r=0.9995。运用该仪器,在北京大学对TGM进行了为期3周的连续观测,得到TGM平均浓度为7.8ng/m3。     

恒温热重法测定离子液体蒸气压和汽化焓

饱和蒸气压和汽化焓是离子液体科学研究和实际应用的不可或缺知识。然而,离子液体饱和蒸气压极低,常规测定蒸气压的方法基本不再适用.热重分析法是最近几年开发的直接实验测定离子液体饱和蒸气压新方法,它具有样品用量少,测量时间短,精度较高的优点.简要叙述了热重分析法测定离子液体蒸气压和蒸发焓原理;简述了基于统计热力学计算离子液体气相和液相热容差的Verevkin方法,应用这个热容差数据可将实验测定的平均温度汽化焓ΔglHom(Tav)转换成参考温度298 K的值ΔglHom(298);同时,根据Hildebrand溶解度参数理论,提出了利用汽化焓数据预测计离子液体极性的新方法.     

在线大气汞分析仪的开发及应用

作者基于金汞齐 冷原子荧光光谱法,自行开发用于分析环境空气中气态总汞（TGM）的在线监测仪器。该仪器操作时以净化后的环境空气作为载气,无需氩气或氮气。经测试：当采样流量为1L/min,采样时间为10min时,检测限能达到0.2ng/m³;0.1ng汞蒸气连续测定结果表明其相对标准偏差<1.4%;工作曲线线性良好,r=0.9995。运用该仪器,在北京大学对TGM进行了为期3周的连续观测,得到TGM平均浓度为7.8ng/m³。     

高碱度烧结矿的物理结构特征及测定

本文综述了研究炼铁原料物理结构的意义;介绍了用“汞压入法”测定原料物理结构的基本原理、装置以及作者所做的测定,并根据测定结果讨论了不同碱度,FeO含量以及加热条件对物理结构的影响。     

水蒸气在低膨胀率气流中的放热分析

在激波管内产生的低膨胀率蒸气膨胀气流中，探测记录了水蒸气凝结相变的过程及压力曲线在非等熵膨胀阶段出现的两次压力突跳，分析了产生两次突跳的原因及影响因素。并通过对比压力曲线和散射光功率曲线，指出，在低膨胀率状态下，最大过饱和度对应的Ｗｉｌｓｏｎ点并不是出现在按通常定义的散射光信号开始增大的时刻。     

内蒙古西部水汽总量与地面水汽压关系分析

根据2007-2008年内蒙古西部呼和浩特站,二连浩特站逐日08时地面及探空气象观测资料,计算得出两个站点全年水汽总量与地面水汽压值,对水汽总量与地面水汽压的特征及其关系进行了分析。在此基础上利用最小二乘原理对水汽总量与地面水汽压进行了回归分析,分别建立了两站的w-e回归方程,并对回归方程进行了检验。结果表明：水汽总量与地面水汽压之间存在着良好的线性关系,得出的w-e回归方程相关系数均趋近于1,拟合程度较高。此回归方程为不具有探空条件的气象站点提供了利用地面水汽压计算水汽总量的简便方法,具有良好的实际应用价值。     

Condensation of Water Vapor on Waterproof Breathable Fabrics

Condensation occurs when the local vapor pressure rises above the saturation vapor pressure at the local temperature in theory. A new measuring apparatus were made to obtain temperature and relative humidity simultaneously for the purpose of investigating the mechanism of condensation occurred on the fabrics. The experiment conducted at the standard condition of temperature of 20℃ and relative humidity of 65%. The result obtained from experiment showed that condensation could occur under the situation closed to saturation line as the temperature on fabric may be lower than dew point of water vapor in the measuring box depending on the experiment conducted at an ambient environment temperature of 20℃ The range of fabrics studied showed that PTFE laminated fabrics except nylon gingham PTFE laminated fabric facilitates the loss of water vapor and therefore prevent condensation. It is necessary to develop studies from a wide range of fabrics, especially breathable fabrics and under bad experiment conditio     

干燥操作必要条件的热力学分析

以化学势判据为依据,用热力学方法推导了干燥操作的必要条件。认为“物料表面水的蒸气压大于介质中水气分压是干燥操作必要条件”论点仅适用于物料温度与介质温度相同时,以熵判据为依据,用状态函数法推导出的结论更具有普遍意义。     

用水蒸汽吸附法测定毛细管压力

本文叙述了一种测定储集岩毛细管压力的新方法。选用某些无机盐的饱和溶液来控制平衡压力,在真空装置上,通过等温吸附实验,测定了两种天然岩心试样在低饱和度下的毛细管压力,结果与脱附法一致。在双对数坐标图上,毛细管压力与含水饱和度呈线性关系,但平衡时间大大缩短。     

SZ-8飞船用蛋白质结晶装置的研制

空间的微重力环境有助于改善蛋白质晶体的生长质量。为解析高分辨率的蛋白质分子结构和进一步的理性药物设计提供帮助。为利用德国提供的空间生物培养箱在我国的SZ—8飞船上实施空间蛋白质结晶实验,研制了新型实验装置。新装置具有120个结晶室单元,重0.11 kg,体积10-4m3,单个结晶室蛋白液用量可少至1μL。对汽相扩散和液-液扩散蛋白质结晶方法通用,而且不需要电力供应,没有运动部件。经火箭发射和飞船返回的力学环境模拟测试以及实际结晶实验验证,表明装置安全可靠,满足使用需求。     

汽—液平衡在混合溶剂盐效应研究中的应用——盐在醇—水混合溶剂中的溶剂化数及溶剂盐析盐溶的判断

在298.15K测定了甲醇—水—LiCl,乙醇—水—LiCl,丙酮—水—LiCl,丙酮—水—K_2CO_3四个体系在盐的物质之量分数保持在0.005左右时,不同溶剂组成的饱和蒸气压。数据首先用Barker法进行了关联,然后以盐在醇—水体系中非优先溶剂化的观点处理下,计算了各体系盐的溶剂化数。最后计算出溶剂组分自含盐体系转移到对应的不含盐的二元系过程中的自由能变化ΔGti,以此来作该溶剂盐析盐溶的判断。     

The seasonal cycle of interhemispheric oscillations in mass field of the global atmosphere

Using the daily and monthly data of surface air pressure, meridional wind, radiation and water vapor from NCEP/NCAR reanalysis for the period of 1979―2006, we have examined the seasonal variations of the interhemispheric oscillations (IHO) in mass field of the global atmosphere. Our results have demonstrated that IHO as observed in surface air pressure field shows the distinct seasonal cycle. This seasonal cycle has an interhemispheric seesaw structure with comparable annual ranges of surface air pressure in the Southern and Northern Hemispheres. Mass of water vapor changes out-of-phase between the Southern and Northern Hemispheres, showing clearly a seasonal cycle with its annual range almost equivalent to annual range of the IHO seasonal cycle. Amazingly, the cross-equatorial flow is found to be induced by annual changes in water vapor mass as a response of the atmosphere to seasonal cycle of forcing from hemispheric net surface short- and long-wave radiations. The IHO seasonality exhibits its larger variations in magnitude in mid-latitudes other than in other regions of the globe. Additionally, our results also show that the global air mass is redistributed seasonally not only between the Northern and Southern Hemispheres but also between land and sea. This land-sea air mass redis- tribution induces a zonal pattern of surface air pressure in the Northern Hemisphere but the meridional pattern in the Southern Hemisphere.     

GPS radio occultation: A potential new data source for improvement of antarctic pressure field

Radio occultation technique, first demonstrated by the GPS/MET experiment in 1995[1], has the potential to provide improved spatial and temporal resolution in the probing of the Earth's neutral atmosphere, including pressure,temperature and water vapor profiles, in addition to traditional measurements (e.g.,radiosonde, spaceborne radiometers) and ground-based GPS networks for precipitable water vapor (PWV) measurements. This paper provides an overview of the radio occultation concept and retrieval procedure and current technical limitations including lower troposphere inhomogeneities, signal penetration, multipath, and water vapor ambiguity. The current limitations using atmospheric model pressure fields (ECMWF and NCEP) for the modeling of atmospheric mass load over Antarctica, for its separation from climate sensitive signals observed by gravity mapping satellite,GRACE, are quantified. Atmospheric pressure fields over Antarctica are poorly known and higher temporal variability of pressure causes an "aliasing" error in GRACE-observed climate-sensitive signals such as hydrology, mass balance and oceanic mass variations. In particular, comparison of ECMWF 6-hour data with the Automatic Weather Station (AWS) in Antarctica indicates mean differences of 5 hPa,and rms of 1.7 hPa, exceeding the accuracy requirement for GRACE. Aliasing effec tmanifests as high-frequency errors in GRACE-observed gravity signals and are more pronounced over Antarctica. The possibility of using current operating satellite(SAC-C, CHAMP and GRACE) occultation data to improve Antarctic surface pressure fields is proposed. Preliminary results indicate that in the absence of water vapor over Antarctica, retrieved CHAMP pressure profile agrees well with radiosonde data from Neumayer station, and that occultation signals reach near the surface.     

改性聚酰亚胺膜的水蒸气渗透性和空气除湿性能

考察了改性聚酰亚胺(P I)膜的亲水性、水蒸气渗透性、制膜混合溶液的表观粘度。结果表明:随着季胺盐含量的增加,膜的亲水性增强,水分子的渗透系数增加,同时水分子的渗透受膜的厚度和相对湿度的影响,制膜混合溶液的表观粘度增大,出现了盐增粘现象。测试了一系列共混改性中空纤维膜组件的除湿性能,增大压力和增加吹扫气流量,对组件除湿十分有利,尽管在低吹扫气量的情况下,组件的除湿性能并不是一直随着膜的亲水性增强而提高,但是适当增加亲水性盐的含量,膜的除湿性能会得到有效改善。