PVC／蒙脱石（粘）土纳米复合材料研究进展及其应用

总结分析了PVC／蒙脱石（粘）土纳米复合材料的研究进展，并对其应用进行综述。采用熔融插层、悬浮聚合及乳液聚合等方法可以制备PVC／蒙脱石（粘）土纳米复合材料，并被应用到工程材料、阻隔性材料、功能性材料等领域。PVC／蒙脱石（粘）土纳米复合材料与传统的复合材料相比，表现出了更优越的综合性能，且比传统的复合材料轻，具有高强度、高模量、高耐热性、低吸湿性、高尺寸稳定性、阻隔性能好，性能全而超过了PVC树脂。PVC／蒙脱石（粘）土纳米复合材料不仅具有良好的加工性能，与普通的玻璃纤维增强和矿物增强PVC相比，具有密度低、耐磨性好、综合性能优等特性。     

Microphysical Effects of Cloud Seeding in Supercooled Stratiform Clouds Observed from NOAA Satellite

Based on the satellite retrieval methodology, the spectral characteristics and cloud microphysical properties were analyzed that included brightness temperatures of Channels 4 and 5, and their brightness temperature difference (BTD), the particle effective radius of seeded cloud track caused by an operational cloud seeding and the microphysical effects of cloud seeding were revealed by the comparisons of their differences inside and outside the seeded track. The cloud track was actually a cloud channel reaching 1.5-km deep and 14-km wide lasting for more than 80 min. The effective radius of ambient clouds was 10-15μm, while that within the cloud track ranged from 15 to 26μm. The ambient clouds were composed of supercooled droplets, and the composition of the cloud within the seeding track was ice. With respect to the rather stable reflectance of two ambient sides around the track, the visible spectral reflectance in the cloud track varied at least 10%, and reached a maximum of 35%, the reflectance of 3.7μm in the seeded track relatively decreased at least 10%. As cloud seeding advanced, the width and depth were gradually increased. Simultaneously the cloud top temperature within the track became progressively warmer with respect to the ambient clouds, and the maximum temperature differences reached 4.2 and 3.9℃at the first seeding position for Channels 4 and 5. In addition, the BTD in the track also increased steadily to a maximum of 1.4℃, compared with 0.2-0.4℃of the ambient clouds. The evidence that the seeded cloud became thinner comes from the visible image showing a channel, the warming of the cloud tops, and the increase of BTD in the seeded track. The seeded cloud became thinner mainly because the cloud top descended and it lost water to precipitation throughout its depth. For this cloud seeding case, the glaciation became apparent at cloud tops about 22 min after seeding. The formation of a cloud track in the supercooled stratiform clouds was mainly because that the seeded cloud volume glaciated into ice hydrometeors that precipitated and so lowered cloud top height. A thin line of new water clouds formed in the middle of the seeded track between 38 and 63 min after seeding, probably as a result of rising motion induced by the released latent heat of freezing. These clouds disappeared in the earlier segments of the seeded track, which suggested that the maturation of the seeding track was associated with its narrowing and eventual dissipation due to expansion of the tops of the ambient clouds from the sides inward.     

一次区域性暴雪天气成因分析

分析了2001年1月6日河南省中北部出现的区域性暴雪天气过程中天气系统的演变、物理量场,并对数值预报产品作出天气学解释。     

对GZRS房产测绘系统分摊模式的探讨

结合实际工作对广州市房产面积测算目前使用的GZRS绘图系统的分摊模式进行了详细的分析,说明了只有正确理解各个分摊模式的概念,才能使测量成果质量得到保证。     

SYNTHESIS AND PROPERTIES OF SULFHYDRYL CHITOSAN

A new adsorbent for heavy metal ions, sulfhydryl chitosan (S-chitosan), was produced by treatment of chitosan with sulhydryl acetic acid in the presence of sulfuric acid as a catalyst. Its structure was confrrmed by elemental analysis and FI‘-IR spectra analysis. The adsorption properties of sulthydryl chitosan for Cu(Ⅱ ), Cd(Ⅱ ), Pb(Ⅱ), Cr(Ⅲ) and Ni(Ⅱ) were investigated, and the effect of pH value on adsorption, adsorption kinetics, and selective adsorption was examined. It was shown that S-chitosan has good adsorption for Pb(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ) like chitosan, is also insoluble in acid solution; has good adsorption kinetic properties for heavy metal ions; and can be used in acid solution. The adsorption capacities of S-chitosan can be affected by media acidity. The adsorbed Cu(Ⅱ) Cd(Ⅱ) and Pb(Ⅱ) could be eluted by diluted chlorhydric acid.     

ANALYSIS ON SPATIAL DIFFERENCE OF LAND USECHANGE BASED ON PHYSICAL AND CULTURALLANDSCAPE ATTRIBUTES──A Case Study at Mongolian AutonomousCounty of Qian Gorlos, Jilin Province

Land use changes are regarded as landscapepattern change driven by many interactive natural andsocial-economic fact6apCQUES, 1999; JOHANN etal., 1999), and show the competition between land usetypes undet different conditions. Socio-economic attributely contribute to lands use/cover change in shortperiod(BENOIT et al., 1999; TURNER et al., 1995 ),whereas physical conditions constrain essential changetendency and change process. The spatial difference inland use dynamic in Mongolian A…     

Climato-hydrological environment inferred from Lake Baikal sediments based on an automatic orbitally tuned age model

We propose a new automatic orbital tuning algorithm to adjust climatic signals to insolation. This can tune two signals with periodicity only without shape similarity. A Genetic Algorithm (GA) is used as an optimizing method. The new age model for the Brunhes epoch in Lake Baikal core BDP98 defined climatic shifts at about 250 kyr B.P., 350 kyr B.P. and 700 kyr B.P. The sedimentation rate for the interval from 350 kyr B.P. to 700 kyr B.P. was comparatively low and stable. This new model also indicates that there was a stadial during the super interglacial period (MIS 11), and that the terrestrial response to climate change was complex in this period.     

江苏埤城岩群岩石物理性质

对ZK03孔岩芯物性测定,获得了埤城岩群密度、磁化率、剩余磁化强度和电阻率、极化率5项物性参数。埤城岩群有较高的密度,与围岩的密度差达0.15×10³ kg/m³,具有重力勘探的物性前提;埤城岩群有较高的电阻率,与部分围岩电阻率差异明显,可有条件的开展电阻率勘查工作;埤城岩群具低磁性和低电化学活动性,磁测和激电方法应慎用。     

淮北煤田松散层电性特征及富水性评价

根据淮北平原电测深资料结合钻探工作,评述了第四系松散层中砂质类和粘土类的电性特征及分布规律,对松散层中含水层各岩性的电性影响因素进行了分析,认为视电阻率与含砂量和颗粒度与正比,与矿化度成反比;介绍了含水层富水性特征参数的提取方法及电性参数与水文地质参数相关关系,认为视电阻率与含水层的渗透系数成正比.通过对电性资料的认识和区域水质资料的分析,获得了该区面积性水文地质参数.该区富水性评价成果已被实际水文地质资料验证.