紫外线辐射增加对大豆的影响及其估算

在田间及盆栽试验中观测到经超量紫外线（UV280～400 nm）辐射处理的大豆作物，其株型、生理活动及产量均受到不同程度的影响，其影响量随UV辐射强度，大豆品种以及环境条件不同而异。文章还给出了计算紫外线辐射对大豆影响程度的公式，该计算方法效果较好。     

Analysis of Physical and Chemical Parameters for Discrimination of Water Origin in a Hydroelectric Reservoir

Seventeen physical and chemical parameters were obtained from a hydroelectric reservoir located in a tropical region in the south of Brazil. Multivariate Principal Component Analysis (PCA) and Hierarchical Group Analysis (HGA) were used to identify the parameters discriminating the origin of water from the Tibagi and the Primeiro de Maio River, after it has passed the mixing region. The study was conducted during the dry and rainy seasons in July 2002 and February 2003 at three depths and three sampling sites located 0, 5, and 10 km away from the mixing region. The statistical methods showed to be appropriate for identifying the contribution of each tributary in the water mixing site of a complex water system. The most important discriminating parameter was the absorbance relation A(253 nm)/A(203 nm), followed by the concentrations of Fe(III), Mn(III), and Ni(II). An anthropogenic interference was found in the reservoir due to high Ni(II) and orthophosphate concentrations caused by a nearby town sewage discharge. The interference was more important during the dry periods due to the lower dispersion of the pollutants. Urgent initiatives should be taken from the state government to build treatment stations for the wastewater of the small cities around the Capivara hydroelectric reservoir to prevent the drinking water quality from deteriorating.     

作物冠层气孔阻力与土壤水势关系的研究

利用棉花观测资料分析了气孔阻力与土壤水势的关系，并根据气孔阻力在冠层内的垂直变化，建立棉花冠层内气孔阻力的一元回归方程。由此初步解决了花铃期棉花冠层中气孔阻力的计算问题，而且对于监测棉田土壤水分动态、调节灌溉、进而采限措施减少蕾铃脱落有重要意义。     

某铁路大桥钻孔灌注桩工程性状浅析

通过对某铁路特大桥钻孔灌注桩单桩竖向静载荷试验、桩身轴力测试，探讨钻孔灌注桩侧摩阻力发挥的影响因素及荷载传递中的工程性状，为钻孔灌注桩的设计、施工提供参考。     

常德市太阳山周围村镇建筑抗震性能调查

通过对常德市太阳山东西两则农村和集镇515栋房屋的32项建筑指标的调查,揭示了农村和集镇建筑抗震性能现状,分析了本区农村建筑抗震设防存在的问题和地震时可能造成的破坏,提出了相应的抗震措施.     

Calculation of the UV Absorption Spectra of As(III) Oxo- and Thio- Acids and Anions in Aqueous Solution and of PF3 in the Gas-phase

Changes in the UV spectra of As(OH)₃ solutions with variations in pH and temperature have recently been used to determine the temperature dependence of the pK_a of the acid. In previous studies I used quantum mechanical techniques to study changes in structure and vibrational spectra as a function of pH for arsenites and thioarsenites. I previously calculated UV spectra for ``molecular' minerals, like realgar As₄S₄. Here I use a number of different quantum mechanical methods, both Hartree-Fock and density functional theory based, to calculate the UV spectra for both a related simple well-characterized gas-phase molecule PF₃ and for As(OH)₃ and As(SH)₃ and their conjugate anions and some neutral and anionic oligomers in aqueous solution. For the monomeric species small numbers of water molecules have been explicitly included, in a supermolecule or microsolvation approach. I find that UV absorption energies accurate to a few tenths of an eV can be obtained both for gas- phase PF₃ and for neutral arsenious acid in aqueous solution, for which the UV absorption maximum is calculated to occur around 6.5 eV, consistent with experiment. Accurate calculation of the UV energies for arsenite anions in aqueous solution is much more difficult, since basis set size and solvation effects are considerably larger than for the neutral molecules, but fairly reliable results can still be obtained. Deprotonation is found to reduce the lowest calculated UV transition energy by about half an eV. Oligomerization also reduces the lowest calculated UV energy by at least half an eV. Replacement of one or all the –OH groups by –SH groups reduces the lowest calculated UV energies by about 2 eV. UV excitation energies have been calculated for oligomeric species as large as As₃E₃(EH)₃ and As₄E₆, where E = O, S, and may be useful for identifying such species in solution.     

Influence of Clouds on UV Irradiance at Ground Level and Backscattered Exittance

The influence of various cloud parameters and the interactions with the ground albedo and the solar zenith angle have been studied by means of model simulations. The radiative transfer model suitable for a cloudy atmosphere as well as for a clear atmosphere has been developed on the basis of the Discrete Ordinate Method. This study leads to a general understanding for cloudy atmospheres: in the presence of a uniform cloud, the cloud scattering is dominant to molecular and aerosol scattering, and it is also wavelength-independent; the ratio of transmitted irradiance in a cloudy atmosphere to that in the background clear atmosphere is independent of cloud height and solar zenith angle. That’s to say, the radiation downwelling out of a cloud is quite isotropic; it decreases approximately exponentially with the cloud optical depth at a rate related to the ground albedo; the reflected irradiance at the top of the atmosphere is dependent on cloud optical depth as well as on solar zenith angle, but not on ground albedo for clouds of not very thin optical depth.     

The NO2 absorption spectrum. III: The 200–300 nm region at ambient temperature

Absorption cross-section measurements of NO₂ performed in our laboratory have been extended to the 200–300 nm region at ambient temperature. Low pressures have been used, limiting the effects of the dimer N₂O₄ which has an absorption cross-section from one to two orders of magnitude larger than that of NO₂ in this region. The results have been compared to those of previous authors and are now available for atmospheric purposes at 0.01 nm intervals.Unité de Recherche Associée au CNRS.     

降雨对浅层水流阻力的影响

通过实验室人工降雨水槽试验,研究了降雨影响下浅层水流的阻力规律。根据试验中观察到的物理现象及对实测资料的分析,讨论了降雨对浅层水流特性的影响,提出了"伪层流"的概念,建立了不同流区的Darcy-Weisbach阻力系数∫的估算式。研究成果可用于坡面流计算及土壤侵蚀模拟等方面。     

“新编凯斯波动分析程序”的编制与应用

从提高动测桩的功能和精度,深入研究桩-土相互作用机理出发,作者开展了波动方程分析程序的编制和研究。作者采用了凯普威普(CAPWAP C)程序中的一些基本假设和基本模型,而在一些模型和方法上作了某些改进,在此基础上提出了“新编凯斯波动分析程序”。该程序可以解决一般凯斯法(Case method)不能解决的问题:变断面桩;桩身沿长度方向上材料不同的桩;桩身较长的桩(25m 以上)。可以提供较为深入的更全面的数据:单桩总静阻力;桩侧静摩阻力;桩端端承力;各土层的摩阻力,…,等。本文叙述了“新编凯斯波动分析程序”的编制目的,基本原理与模型,计算步骤。并提供了在某工程实例中的应用情况。