电导法测定HCl在水和异丙醇混合溶剂中的活度系数

应用电导法测定了HCl在水和异丙醇混合溶剂中的活度系数,讨论了电解质溶液活度系数与温度和浓度的关系。     

盐酸-硫酸镍混合溶液热力学性质

在HCl-NiSO4-H2 O混合溶液中 ,以标准氢电极和银—氯化银电极组成无液接电池 ,恒定溶液总离子强度I和NiSO4在溶液中的离子强度分数yB 的条件下 ,在 2 78 1 5～ 3 2 3 1 5K温度范围内测定下列电池的电动势Pt,H2 ( 1 0 1 3 2 5kPa) |HCl(mA) ,NiSO4(mB) ,H2 O|AgCl-Ag由于体系存在硫酸的二级解离 ,应用数学迭代方法确定平衡体系氢离子的浓度 ,计算了混合溶液中HCl的活度系数γA,结果表明 ,在溶液总离子强度保持恒定时 ,HCl的活度系数服从Harned规则。在溶液组成恒定时 ,盐酸的活度系数logγA 对热力学温度l/T作图 ,是一条直线     

高低跟踪方式卫星重力观测的状态空间描述

当前的重力卫星任务除了本身特有的观测方式外，都采用了高低卫卫跟踪的观测方式。为研究高低卫卫跟踪观测系统的时变行为和获取重力场信息的能力，文中运用描述时变系统的状态空间模型方法，根据附加参数的类型，建立了3种状态空间模型，并对系统的可观测性从解析法的角度进行了分析。结果表明，对于单一的高低卫卫跟踪观测系统，引力系数的可观测性实际上是不成立的，根据一次任务只能建立引力系数的一组约束条件。     

Elementary Research on Activity Behavior of the Crust in Funan-Huoqiu Area, Southern Border of the North China Active Block Region

1.ESSENTIAL GEOLOGIC GEOMORPHIC CHARACTERIN THE STUDIDED REGIONThe studied region of the paper,the Funan-Huoqiu area,extends across the Jianghuai hills andHuaibei plain of Anhui Province,located in the south border area of the North China active blockregi…     

Dual-satellite crossover latitude-lumped coefficients, their use in geodesy and oceanography

Latitude-lumped coefficients (LLC) are defined, representing geopotential-orbit variations for dual-satellite crossovers (DSC). Formulae are derived for their standard errors from the covariances of geopotential field models. Numerical examples are presented for pairs of the altimeter-bearing satellites TOPEX/Poseidon, ERS 1, and Geosat, using the error matrices of recent gravity models. The DSC, connecting separate missions, will play an increasingly important role in oceanography spanning decades only when its nonoceanographic signals are thoroughly understood. In general, the content of even the long-term averaged DSC is more complex then their single satellite crossover (SSC) counterpart. The LLC, as the spatial spectra for the geopotential-caused crossover effects, discriminate these source-differences sharply. Thus, the zero-order LLC in DSC data contains zonal gravity information not present in SSC data. In addition, zero- and first-order LLC of DSC data can reveal a geocenter discrepancy between the orbit tracking of the separate satellite missions. For example, DSC analysis from orbits computed with JGM 2 show that the y-axis of the geocenter for Geosat in 1986–1988 is shifted with respect to T/P by 6–9 cm towards the eastern Pacific. Also, where the time-gap is necessarily large (as between, say, Geosat and T/P missions) oceanographic (sea-level) differences in DSC may corrupt the geopotential interpretation of the data. Most importantly, as we illustrate, media delays for the altimeter (from the ionosphere, wet troposphere and sea-state bias) are more likely sources of contamination across two missions than in SSC analyses. Again, the LLC of zero order best shows this contrast. Using the higher-order LLC of DSC for both Geosat-T/P and ERS 1-T/P as likely representation of geopotential-only error, we show by comparison with the predicted standard errors of JGM 2 that the latter's previously calibrated covariance matrix is generally valid. Received: 14 February 1996 / Accepted: 27 March 1997     

A thin film approach for producing mineral diffusion couples

Few diffusion coefficient values have been measured for silicate minerals at pertinent geologic conditions because of experimental restrictions. Until recently, analysis of diffusion couples was conducted principally with electron microprobes which have rather poor spatial resolution (micrometer scale). Ion microprobe analyses, however, eliminate many of the previous experimental restrictions; in depth profile mode they have excellent spatial resolution (tens of angstroms) and diffusion couples can be analyzed normal to the interface. Diffusion couples analyzed by ion microprobe must be well-defined and uniform; previous methods using solution precipitates to form the diffusion couples were heterogeneous and had limited success. A new approach, the thermal evaporation of²⁵MgO under high vacuum onto a crystalline substrate (oxide, silicate), produces a 1000 Å thick²⁵MgO _x (x<1) thin film. This method yields an excellent diffusion couple for low-temperature diffusion experiments. Diffusion anneal experiments using this approach for garnet provide a Mg self-diffusion coefficient ofD=0.60±0.09×10^–21 m²/s at 1000°C (logFO₂=–11.3,P=1 atm,X _Almandine=0.24).     

北天山活断层的初步研究

本文研究了北天山地区活断层的展布特征、活动时代、活动速率及其与地震活动的关系;描述了全新世活断层;估计了未来可能发生强震的危险区。     

地形图高程精度的估计方法

本文针对缺少野外检测资料情况提出了两图对照检测法;探讨了高程误差分布规律;并在此基础上,提出不等权逐步回归法答解科佩系数。理论研究和实例均证明了这种方法的可取性。     

安徽省山丘区匹配开发综合评价

安徽省山地丘陵区区域开发中存在区域开发方式与区域特征，人口数量、质量与土地承载力，经济发展与环境保护不匹配的问题。在制定区域匹配开发评价指标的基础上，通过环境指标、经济指标、社会指标的定量分析，获得不同类型区的匹配系数（Ｃ＿ｃ），根据匹配系数所揭示的问题，提出区域开发措施。     

Quantum yields for the photodissociation of acetone in air and an estimate for the life time of acetone in the lower troposphere

The room-temperature photodecomposition of acetone diluted with synthetic air was studied at nine wavelengths in the spectral region 250–330 nm. The quantum yields for the products CO₂ and CO indicated that it was not possible to suppress secondary reactions sufficiently, even with acetone/air mixing ratios as low as 150 ppmv, to derive from these data primary acetone photodissociation quantum yields. The behavior of CO₂ and CO formation nevertheless provides some insight into the mechanism of acetone photodecomposition. When small amounts of NO₂ are added to acetone/air mixtures, peroxyacetyl nitrate (PAN) is formed. Quantum yields for PAN are reported. They are better suited to represent primary quantum yields for acetone photodissociation, because PAN is a direct indicator for the formation of acetyl radicals. The data were combined with absorption cross-sections for acetone measured at wavelengths up to 360 nm to calculate photodissociation coefficients applicable to the ground-level atmosphere at 40° northern latitude. Comparison with the rates for the reaction of acetone with OH radicals shows that both processes contribute almost equally to the total acetone losses in the lower atmosphere. The resulting atmospheric life time at 40° northern latitude is 32 days, on average. This value must be considered an upper limit, since it does not take into account acetone losses due to the reaction of excited triplet acetone with oxygen.