概括平差模型的解法探讨

分析了概括平差模型系数矩阵可能出现非列满秩情况的原因,研究了如何使系数矩阵为列满秩矩阵,避免了系数矩阵为非列满秩时的复杂解算过程。     

单柱离子色谱测定二氧化锰产品中无机阴离子杂质

采用了单柱离子色谱法测ＭｎＯ２产品中无机离子杂质；提出了消除干扰的可行途径，将Ｌａ（ＯＨ）３加入后能同时消除进样峰的干扰和溶剂峰的出现。选用１．７５ｍｍｏｌ／Ｌ邻苯二甲酸１．７５ｍｍｏｌ／Ｌ三羟甲基氨基甲烷为混合淋洗剂测定Ｆ＾－，Ｃｌ＾－，ＮＯ３＾和ＳＯ＾２－４，其标准加入回收率为９５％－１０５％；ＲＳＤ（ｎ＝７）为２．４７％－８．０８％。     

Identification and occurrence of novel C36–C54 3,4-dialkylthiophenes with an unusual carbon skeleton in immature sediments

A series of novel long-chain 3,4-dialkylthiophenes (C₃₆–C₅₄) was identified in a number of sediments ranging from Pleistocene to Cretaceous. The identifications were based on mass spectral characterisation, desulphurisation and mass spectral data of synthesised model compounds. These organic sulphur compounds are probably formed by sulphur incorporation into mid-chain dimethylalkadienes with two methylenic double bonds. These putative precursor lipids are unprecedented and may be considered rather unusual. The distribution of 3,4-dialkylthiophenes in sediments varies considerably with the depositional palaeoenvironment, indicating that these compounds have a potential as molecular markers reflecting changes in palaeoenvironment.     

Time effects on dynamic soil properties under random excitation conditions

Two types of clayey soils, a kaolinite and a bentonite, were tested using a resonant column apparatus under random excitation conditions. The concept of root mean square (rms) strain was utilized for the purpose of strain calculations during random loading. The conventional estimator of the transfer function was used for random vibration analysis. The effect of confinement duration (at a constant pressure) on dynamic soil properties, namely damping and shear modulus, was evaluated. The results indicate that for both cohesive soils, the effect of time was less pronounced during random vibration than sinusoidal loading at the same rms strain. This effect is however more pronounced when the peak shearing strain of sinusoidal loading is considered. Furthermore, time effects were more pronounced at low strain levels than at high strain levels.     

耗能-隔震柔性底层钢管混凝土-钢筋混凝土组合框架的实验研究

本文用钢管混凝土柱作为结构底层耗能柱、用承重墙和隔震器控制结构底层倒塌破坏,从而提出了一种新的耗能-隔震柔性底层结构体系。通过本文12根钢管混凝土柱和文献[7]中7根钢管混凝土柱的低周疲劳实验,初步确定了钢管混凝土柱地震损伤模型的参数;通过两个钢管混凝土-钢筋混凝土三层框架模型和一个纯钢筋混凝土三层框架模型的拟动力实验,研究和比较了两类结构体系的地震损伤。     

Investigation of NaCl deliquescence in porous substrates using RH-XRD

We report on the use of X-ray diffractometry under controlled conditions of temperature and relative humidity (RH-XRD) for the investigation of NaCl deliquescence in the pore space of glass filter frits, which were used as model substrates. The study confirms that RH-XRD is an appropriate experimental technique for the in situ observation of phase transformation in porous materials. It is used for an investigation of both the deliquescence kinetics and the deliquescence humidity within pores of different median pore diameter. Several major influences affecting deliquescence rates in the pore space close to the surface of a porous material are discussed. It appears that quite short-term variation of ambient relative humidity, e.g., typical daily fluctuations, might induce damaging deliquescence–crystallization cycles within the pore space of building materials. In agreement with theoretical considerations it was found that confinement of NaCl crystals in pores with median diameters in the range 1.4–70 μm does not affect the deliquescence humidity of the salt.     

散体材料桩复合地基极限承载力计算

以土力学及弹塑性理论为基础，分析了散体材料桩的塑性应力分布。推导出了单桩极限承载力和单桩复合地基的极限承载力计算公式。得出了提高桩体材料的内摩擦角和桩周土对桩的径向围限力是提高散体材料桩复合地基承载力的有效途径的结论。给出了工程实例，验证了文中计算公式的实用性。     

REMOTE SENSING OF THE SEASONAL VARIATION IN COLUMN ABUNDANCE OF ATMOSPHERIC CH4*

Infrared solar spectra on clear days were measured automatically by an infrared solar spectrometer(ISS) with 0.4 cm^-1 resolution developed by us.A line-by line(LBL) computation method was used to calculate theoretical atmospheric absorption.In the wavelength range of 3.410-3.438 μm.the absorption is mainly due to atmospheric methane and water vapor.Columnatmospheric methane was retrieved from the recorded infrared solar spectra.The seasonal variation of column atmospheric methane in Hefei has been obtained from the measuremental data of nearly 18 months since the April of 1997.and found that it is similar to that of background data.The instruments.principles of measurement and some of results were introduced,and the results are also discussed briefly in the paper.     

中高层钢筋混凝土异形柱框架结构弹塑性时程分析

用杆模型编制了钢筋混凝土异形柱框架结构的弹塑性时程分析程序FEANT。采用该程序对一中高层大开间钢筋混凝土异形柱框架结构振动台试验模型进行了计算分析，计算值与试验值吻合较好，能满足工程需要。     

珠江三角洲软土微结构的定量研究

对用不同长度的PVC管在珠海和广州两地采得的淤泥样柱施于一定荷载，然后在扫描电镜下研究软土受压后在样柱垂深方向上的微结构变化，并将样品的微结构照片扫描，在计算机内进行量化处理。结果表明，样品的孔隙分布分维差随着离施压点距离的增加而逐渐减小，从而得到两者的关系方程。据此，可了解在一定荷载下应力在软土层中向下的衰减趋势。文章还对软土的天然含水量和围压对压缩变形的影响作了初步的讨论。