数字化地图印刷一种随机挂网计算模型

基于彩色图像像素3刺激值与相应网点面积率之间的α幂修正的Neugebauer方程,建立由常规的调幅网为基础的调频挂网计算模型,以此实现分色胶片随机挂网     

Al_2O_3-SiC-C砖渣静态侵蚀后的显微结构分析

铁水预处理用鱼雷罐、铁水罐的炉衬多为Ａｌ２Ｏ３ＳｉＣＣ砖,随着铁水脱硫量的加大,耐火材料的侵蚀也较严重。而现在由于市场需要钢水中的磷含量要求较低,脱磷处理过程中由于国外多采用氧化铁系脱磷剂,氧化亚铁对石墨的氧化很大,对炉衬侵蚀也大,这就要求对Ａｌ２Ｏ３ＳｉＣＣ砖的性能进行改进以适宜工艺需要。国内对脱磷的研究较少,实际生产对铁水进行脱磷处理的厂家也很少。为探讨脱硫、磷剂对耐火材料的影响,本文对不同脱硫、磷剂侵蚀Ａｌ２Ｏ３ＳｉＣＣ砖后的残砖的显微结构进行了分析,探讨了铝碳化硅碳砖的侵蚀原…     

A wavelet method for detecting S‐waves in seismic data

Seismic signals consist of several typically short energy bursts, called phases, exhibiting several patterns in terms of dominant frequency, amplitude and polarisation. We present a fast algorithm to detect the so‐called S‐phase in a three‐component seismic signal. This new approach combines traditional S‐phase detection methods and the discrete wavelet transform. This revised version was published online in July 2006 with corrections to the Cover Date.     

High temperature dehydroxylation of muscovite-2M1: a kinetic study by in situ XRPD

Muscovite-2M₁ shows a major phase transition at about 800°C, which is generally attributed in the literature to the structural dehydroxylation process, although a number of structural models have been proposed for the dehydroxylated phase, and different transformation mechanisms have also been put forward. The observed first order transformation involves an increase in the cell volume, and it is not clear to date how the cell expansion is related to the loss of hydroxyl groups. The phase change has been re-investigated here by in situ high temperature powder diffraction, both in non-isothermal and isothermal modes, to combine for the first time the structural and the kinetic interpretation of the transformation. The results unequivocally confirm that the reaction taking place in the temperature range 700–1000°C is truly a dehydroxylation process, involving the nucleation and growth of the high temperature dehydroxylated phase, having Al in 5-fold coordination. Structural simulations of the basal peaks of the powder diffraction patterns indicate that the model originally proposed by Udagawa et al. (1974) for the dehydroxylated phase correctly describes the high temperature phase. The kinetic analysis of the isothermal data using an Avrami-type model yields values for the reaction order compatible with a reaction mechanism limited by a monodimensional diffusion step. Apparent activation energy of the process in vacuum is about 251 kJ/mol. Experiments carried out at temperatures much higher than the onset temperature of the reaction show that the dehydroxylation reaction overlaps with the reaction of formation of mullite, the final product in the reaction pathway. Received: 24 April 1998 / Revised, accepted: 12 October 1998     

胜利油田边缘及外围找寻不同类型深部天然气的可能性

笔者依据对前人资料和本人研究成果的综合分析,提出在胜利油田的边部碱性橄榄玄武岩发育地带找寻无机成因二氧化碳气藏和在油田外围金伯利角砾岩筒或含地幔岩包体的碱性玄武岩火山口附近找寻地球深部来源烃类气藏的建议。     

Adsorption of Au(III) and Au(I) complexes on δ-MnO2

The sorption of AuCl₄ ⁻,AuCl₂ ⁻ and Au(S₂O₃)^3- on δ-MnO₂ was investigated at pH2–11.6, 0.01 mol/L and 0.1 mol/L NaNO₃ solutions. At pH 4 in two electrolyte strength solutions, Au sorption densities on δ-MnO₂ are 0.18–0.21 and 0.28μmoL/m² for AuCl₄ ⁻ and Au(S₂O₃)₂ ^3-, respectively, and the Au surface coverage is approximate to or lower than 1%. This adsorption of the two Au complexes decreases as the solution pH increases, which conforms to the sorption regularity of the anion on δ-MnO₂. The Au sorption decreases in the sequence of Au(S₂O₃)₂ ^3- >AuCl₄ ⁻ >AuC1₂ ⁻. The intrinsic equilibrium constants (logK ^int) of the three Au complexes are 1.17–2.7, much higher than those of Cu and Cd. The hydrolysis products of AuCl₄ ^- are preferentially adsorbed by δ-MnO₂ and the inner-sphere Au-surface complexes are formed on the surface. Project supported by the National Studying-abroad Foundation, the National Natural Science Foundation of China (Grant No. 49573200) and the Australian Mining Industry.     

数字地震仪(或雷达)的文件格式及其转换方法

详细介绍了ＳＥＧ新规定的ＳＥＧ－２标准及其文件结构,这一标准不但适用于数字地震仪,而且也适用于地质雷达等数字化记录设备。同时给出了一个在ＩＢＭ－ＰＣ环境不读取ＳＥＧ－２数据文件的Ｃ语言示范程序,根据这个示范程序,用户可以很方便地将ＳＥＧ－２数据文件转换成适用于特定应用软件的数据格式。     

青藏高原环境气象研究进展

近十年来,青藏高原环境气象研究进展迅速,无论是观测研究还是理论研究方面均有新的发现。周秀骥和邹捍等先后发现夏季青藏高原上空的臭氧低值中心并提出了产生这种低值中心的可能原因。高登义等利用１９７５年以来对珠穆朗玛峰北坡水环境的监测资料,分析研究后发现,１９９０￣１９９１年爆发的中东战争油田燃烧曾污染了珠峰地区的水环境,带来珠峰北坡绒布河水十三种化学元素含量的剧烈增加,比其前后各年增加了５￣７倍。     

Improved Method for Calculating Anthropogenic CO2 in the Upper Layer of the North Pacific Subtropical Gyre along 175°E

Seawater samples were collected in the North Pacific along 175°E during a cruise of the Northwest Pacific Carbon Cycle Study (NOPACCS) program in 1994. Many properties related to the carbonate system were analyzed. By using well-known ratios to correct for chemical changes in seawater, the CO₂ concentration at a given depth was back calculated to its initial concentration at the time when the water left the surface in winter. We estimated sea-surface CO₂ and titration alkalinity (TA) in present-day winter, from which we evaluated the degree of air-sea CO₂ disequilibrium in winter was. Using a correction factor for air-sea CO₂ disequilibrium in winter, we reconstructed sea-surface CO₂ in pre-industrial times. The difference between the back-calculated initial CO₂ and sea-surface CO₂ in pre-industrial times should correspond to anthropgenic CO₂ input. Although the mixing of different water masses may cause systematic error in the calculation, we found that the nonlinear effect induced by the mixing of different water masses was negligible in the upper layer of the North Pacific subtropical gyre along 175°E. The results of our improved method of assessing the distribution of anthropogenic CO₂ in that region show marked differences from those obtained using the previous back-calculation method.     

从正反两个角度探讨摆式波力电站的吸能机制

本文主要论述了摆式波力电站的吸能机制,提出了吸能原理,从力和作功的角度探讨了吸能的实质,分析比较了几种摆板运动方程形式之间的联系和区别。给出了波能转换效率的定义,并进一步分析了波能转换效率的组成和性质。