Discovery of a New Pulsating X-Ray Source with a 1549.1 Second Period, AX J183220-0840

A new pulsating X-ray source, AX J183220-0840, with a 1549.1 s period was discovered at R.A.=18h32m20s and decl.=-8&j0;40'30" (J2000, with an uncertainty of 0&farcm;6) during an ASCA observation on the Galactic plane. The source was observed two times, in 1997 and in 1999. A phase-averaged X-ray flux of 1.1x10-11 ergs cm-2 s-1 and a pulsation period of 1549.1+/-0.4 s were consistently obtained from these two observations. The X-ray spectrum was represented by a flat, absorbed power law with a photon index of Gamma approximately 0.8 and an absorption column density of NH approximately 1.3x1022 cm-2. Also, a signature of iron K-shell line emission with a centroid of 6.7 keV and an equivalent width of approximately 450 eV was detected. From the pulsation period and the iron-line feature, AX J183220-0840 is likely to be a magnetic white dwarf binary with a complexly absorbed thermal spectrum with a temperature of about 10 keV.     

Parameterization of the Absorption of the H2O Continuum, CO2, O2, and Other Trace Gases in the Fu-Liou Solar Radiation Program

The absorption properties of the water vapor continuum and a number of weak bands for H2O, O2, CO2, CO, N2O, CH4, and O3 in the solar spectrum are incorporated into the Fu-Liou radiation parameterization program by using the correlated k-distribution method (CKD) for the sorting of absorption lines. The overlap absorption of the H2O lines and the H2O continuum (2500-14500 cm^-1) are treated by taking the two gases as a single-mixture gas in transmittance calculations. Furthermore, in order to optimize the computation efforts, CO2 and CH4 in the spectral region 2850-5250 cm^-1 are taken as a new singlemixture gas as well. For overlap involving other absorption lines in the Fu-Liou spectral bands, the authors adopt the multiplication rule for transmittance computations under which the absorption spectra for two gases are assumed to be uncorrelated. Compared to the line-by-line (LBL) computation, it is shown that the errors in fluxes introduced by these two approaches within the context of the CKD method are small and less than 0.48% for the H20 line and continuum in the 2500-14500 cm^-1 solar spectral region, -1% for H2O (line) H2O (continuum) CO2 CH4 in the spectral region 2850-5250 cm^-1, and -1.5% for H2O (line) H2O (continuum) O2 in the 7700-14500 cm^-1 spectral region. Analysis also demonstrates that the multiplication rule over a spectral interval as wide as 6800 cm^-1 can produce acceptable errors with a maximum percentage value of about 2% in reference to the LBL calculation. Addition of the preceding gases increases the absorption of solar radiation under all sky conditions. For clear sky, the increase in instantaneous solar absorption is about 9%-13% (-12 W m^-2) among which the H20 continuum produces the largest increase, while the contributions from O2 and CO2 rank second and third, respectively. In cloudy sky, the addition of absorption amounts to about 6-9 W m^-2. The new, improved program with the incorporation of the preceding gases produces a smaller solar absorption in clouds due to the reduced solar flux reaching the cloud top.     

语音处理技术在110联动报修系统中的应用

介绍了语音压缩处理技术在武汉市供电局 1 1 0联动报修系统中的应用。该系统需要对大量用户电话进行录音和压缩存储 ,因而语音处理技术在该系统中占据重要地位     

惠陆低凸起东侧早文昌期源-汇系统分析与勘探实践

惠陆低凸起东侧为陆丰南富生烃洼陷,为厘清该低凸起东侧物源面貌及沉积储层分布规律,综合利用钻井和三维地震资料,恢复了古物源区面貌,描述了源-汇体系要素,预测了富砂沉积体平面分布,并探讨了砂体差异富集的控制因素。结果表明:惠陆低凸起发育完整的受古地貌控制的源-汇系统,研究区古近纪下文昌组进一步可划分为A—H共8个凸起群单元,在古地貌恢复的基础之上,8个凸起群单元共划分出17个由独立流域和对应沉积区组成的源-汇系统。惠陆低凸起东侧发育流域1—6组成的6个独立的源-汇系统,其中流域2、4和6剥蚀范围大,基底受剥蚀能力强,水系发育数量多且相对汇聚,是主要的优势物源供给区。2号流域(陆丰13东洼缓坡中部)大的剥蚀面积、花岗岩和喷出岩母岩为大型辫状河三角洲及优势储层发育提供了物质基础,多个水系和平面上的优势汇聚为优质的水下分流河道砂岩储层提供了良好的发育条件。     

准噶尔盆地南缘中段异常压力分布及影响因素

准噶尔盆地南缘地区盆地演化时间长, 近期构造活动剧烈, 构造应力场复杂, 地层异常压力高且分布极不规律, 对构造的形成演化及对油气的成藏过程影响极大.据实测资料和间接估算数据所展示的地层压力分布特征, 分析了砂砾岩地层和泥岩地层在压力成因和分布等方面的差异, 从不同渗透性地层内压力形成的机制和分布特征的角度讨论了控制和影响现今压力分布的地质因素.准噶尔盆地南缘存在的极高地层压力是在压实作用、构造挤压作用所形成的地层高压背景下, 叠加了近期因断裂活动和背斜构造快速形成所引起的他源高压而形成的.沉积相带分布、压实作用、构造应力、地层的形变和断裂的活动过程等都明显地影响了压力的演化和分布.      

基于Landsat TM/ETM数据的锡林河流域土地覆盖变化

根据1987年、1991年、1997年和2000年4期Landsat TM/ETM影像的土地利用/土地覆盖分类结果,运用地理信息系统空间分析方法,分析了内蒙古锡林河流域1987~2000年间各土地利用类型及草甸草原、典型草原、荒漠草原的数量变化和空间变化特征。分析结果显示,锡林河流域土地利用/土地覆盖变化的主要特征为草甸草原、典型草原面积的大幅减少和荒漠草原、农田和沙漠化土地面积的大幅增加及城镇的扩张。其中面积增加最大的是荒漠草原,增加了2328 km²;相当于1987年荒漠草原面积的56 %。农田和城镇面积逐年增大,分别从1987年的114.3 km²和25.2 km²增加到2000年的332.1 km²和43.6 km²。面积减少最多的是羊草＋丛生禾草、羊草＋杂类草等优良高产温带典型草原类型,共减少2040 km²。草甸草原面积亦呈逐年减少的趋势,从1987年的1103 km²减少到2000年375 km²,面积减少了65.9 %。农田、沙化地及城镇等非草原土地利用类型面积增加了62.5 %。     

冻融循环作用下黄土渗透性与其结构特征关系研究

在季节冻土区,周期性的冻融作用改变土体的内部结构,导致土体的渗透性发生变化。黄土渗透性变化的原因可以归结为两类:1黄土孔隙孔径大小的变化。2黄土颗粒粒径大小的变化.因为分形理论能够很好地估算土体的结构特征,所以本文基于分形理论探究冻融循环后黄土渗透性变化的原因。对经历过冻融循环的原状黄土和重塑黄土进行颗粒质量-粒径分布和孔隙体积-孔径分布分形计算,结果显示:原状黄土和重塑黄土的颗粒质量-粒径分形维数与渗透系数的拟合度R2分别为0.7509和0.8222,高于孔隙体积-孔径分形维数与渗透系数的拟合度0.467和0.4576。颗粒质量-粒径分形维数与渗透系数的拟合度比孔隙体积-孔径分形维数高,说明土颗粒粒径对渗透性的影响大于孔隙孔径,即土体渗透性与土颗粒粒径大小有高度相关性,而与孔隙孔径的关系弱于颗粒粒径。     

柴达木盆地盐湖物质来源识别

柴达木盆地是我国重要的盐矿资源战略基地,深入认识其物质来源具有重要的科学及社会意义。本研究根据柴达木盆地盐湖水、晶间卤水,以及格尔木河流域地表水、地下水化学组成,利用多元统计方法,探讨盆地区盐湖物质来源。结果显示:从山前到湖区,水体溶解性总固体逐渐增大,微量组分含量也逐渐升高,二者均表现为晶间卤水盐湖水格尔木河流域水体;阳离子变化趋势为:补给源头由昆仑山雪融水以Ca2+为主过渡到格尔木河流域以Na+为主;再到盐湖区以Mg2+为主;阴离子则从以HCO-3为主逐步过渡到以Cl-为主;盐湖水和晶间卤水的化学组成差异显著。因子分析表明,对于格尔木河流域河水和地下水,岩石风化淋滤是其化学组分的主要来源。而岩石风化淋滤来源和深部水来源对柴达木盆地不同盐湖区化学组成的贡献率差异很大,该差异取决于周围岩石的化学组成和深部水的存在及其化学组成,以及断层是否导通为深部水补给盐湖提供了通道。