东、黄海大气湿沉降中常量阴离子组分的研究

用离子色谱法分析了嵊泗群岛和千里岩岛两个观测站湿沉降样品中的F^-、NO3^-、Cl^-和SO4^2-等4种阴离子。结果表明，它们的月均浓度之间差别较大，季节性变化明显；与近岸城市相比，具有显的海洋性特征；对全年中酸雨的统计表明，两个观测站都受到了酸雨的影响，而嵊泗群岛更严重一些。     

合成铁氧化物矿物对苯酚的吸附实验研究

采用TEM、X射线衍射分析及BET比表面积测定等手段对合成的针铁矿、赤铁矿两种矿物进行表征,对此两种矿物对苯酚的吸附特性并批处理吸附实验研究结果表明,针铁矿对苯酚的吸附量大于赤铁矿的吸附量;针铁矿吸附苯酚的pH吸收边为峰型曲线,且峰值在pH 7～8。Langmuir方程拟合结果的吻合程度较之Henry线性方程与Freundlich方程高。实验中氧化铁矿物表面对苯酚的吸附则主要表现为表面分子吸附,可能存在表面疏水性作用,而静电离子交换和表面配合吸附模式不明显。     

光释光测年和孢粉分析揭示的晚冰期以来科尔沁沙地演化过程

利用光释光测年技术对科尔沁沙地的7个风成砂-砂质古土壤剖面进行年代测试,结合地层和孢粉分析得到晚冰期以来科尔沁沙地的演化过程如下:16~10 ka B.P.,风成砂出现,沙地活化;10~3 ka B.P.,砂质古土壤发育,沙地固定;约3 ka B.P.前后,风成砂出现,沙地活化;3 ka B.P.至今,多层弱发育砂质古土壤和风成砂的交替出现,指示晚全新世科尔沁沙地的多次固定与活化;从约4~2 ka B.P.,沙地环境由草甸草原逐渐退化为典型草原。分析表明,3 ka B.P.以前科尔沁沙地的演化完全受气候变化的控制,之后(尤其是辽代以后)人类活动的影响日益增强。     

大气CO2标准气浓度标定及采样瓶CO2浓度分析系统

对美国NOAA／CMDL开发的用于我国大气本底监测的非色散红外CO2瓶分析和标准气标定系统做了测试与讨论,并对在青海瓦里关、浙江临安、黑龙江龙凤山和北京上甸子所采集到的实验性空气样品中的CO2浓度进行了测量,与瓦里关在线连续测量结果进行了对比,结果均表明该系统具有较高的灵敏度、精确度和较好的稳定性,具备了从进样到数据处理等较为完整的自动化功能,具有简便易行、准确可靠等特点,可用于大气CO2标准气体的标定及采样瓶分析。测量和对比结果也表明,样瓶采样和分析系统可在一定程度上替代现场连续测量系统,在不同的地点进行采样并进行集中分析也是一种较为经济、实用的方法。     

Migration of Depocenters and Accumulation Centers and its Indication of Subsidence Centers in the Mesozoic Ordos Basin

Based on the integrated study of structure attributions and characteristics of the original basin in combination with lithology and lithofacies,sedimentary provenance analysis and thickness distribution of the Mesozoic Ordos Basin,it is demonstrated that the depocenters migrated counterclockwise from southeast to the north and then to the southwest from the Middle-Late Triassic to the Early Cretaceous.There were no unified and larger-scale accumulation centers except several small isolated accumulation c...     

WEIGHTED ANALYSIS OF PRINCIPAL COMPONENTS: TWO APPROXIMATIONS TO STATISTICAL WEIGHTS

Two approximate methods for weighted principal components analysis (WPCA) were devised and testedin numerical experiments using either empirical variances (obtained from replicated data) or assumedvariances (derived from unreplicated data). In the first ('spherical') approximation each data vector wasassigned a weight proportional to the geometrical mean of its variances in all dimensions. Thearithmetical mean of variances was used instead in the other approximation. Both the numericalexperiments with artificial data containing random errors of various kinds (constant, proportional,constant plus proportional, Poisson) and the analysis of two sets of Raman spectra clearly indicated thenecessity of introducing statistical weights. The spherical approximation was found to be slightly betterthan the arithmetical one. The application of statistical weighting was found to improve the performanceof PCA in estimation problems.     

IDENTIFICATION OF FINITE IMPULSE RESPONSE MODELS WITH CONTINUUM REGRESSION

The use of continuum regression(CR)for the identification of finite impulse response(FIR)dynamicmodels is investigated.CR encompasses the methods of principal component regression(PCR),partialleast squares(PLS)and multiple linear regression(MLR).PCR and MLR are at the two extremes of thecontinuum.In PCR and PLS,cross-validation is used to determine the optimum number of factors or‘latent variables’to retain in the regression model.CR allows one to vary the method in addition.Cross-validation then determines both the optimum method and the number of latent variables.The CR‘prediction error surface’—a function of the method and number of latent variables—is elucidated.Theoptimal model is defined as the minimum of this surface.Among the cases studied,the optimal modelusually comes from the region of the continuum between PCR and PLS.Few derive from the regionbetween PLS and MLR.It is also demonstrated that FIR models identified by CR have frequency domainproperties similar to those identified by PCR.     

Pt/十六烷基三甲基溴化铵纳米聚集体修饰玻碳电极促进析氢(英文)

A novel, cost-effective, and simple electrocatalyst based on a Pt-modified glassy carbon electrode(GCE), using cetyltrimethylammonium bromide(CTAB) as a cationic surfactant, is reported. Amphiphilic CTAB molecules were adsorbed on GCE by immersion in a CTAB solution. The positively charged hydrophilic layer, which consisted of small aggregates of average size less than 100 nm,was used for accumulation and complexation of [PtCl2. anions by immersing the electrode in Ksolution. The modified electrode was characterized using scanning electron microscopy,energy-dispersive X-ray spectroscopy, impedance spectroscopy, and electrochemical methods. The electrocatalytic activity of the Pt particles in the hydrogen evolution reaction(HER) was investigated.The results show that the CTAB surfactant enhances the electrocatalytic activity of the Pt particles in the HER in acidic solution.     

高纯度超细镍粉的除杂研究

工业湿法制备超细镍粉过程中，提高镍粉的纯度一直是困扰生产厂家的难题，为此，在研究黑镍除杂和用螯合剂水溶液超声波搅拌洗涤除杂的基础上，讨论温度，pH值，黑镍量，螯合剂，超声波的搅拌洗涤次数等因素对除杂效果的影响。通过实验找出湿法制备高纯度超细镍粉除杂的最佳工艺条件。     

四川平武绿柱石宝石成矿地质特征

四川平武产出世界上十分稀少和珍贵的无色透明扁平板状绿柱石宝石。在野外详细调研和系统分析、测试基础上，全国总结和介绍矿床成矿地质环境，绿柱石宝石产出特征，绿柱石宝石矿物学、化学成分、结晶习性及晶体化学、谱学特征、包裹体特征，花岗岩与Be及W,Sn矿化关系和成矿的物理、化学条件。从而，确认该矿床为岩浆期后气成-热液型绿柱石宝石矿床。