In situ measurements of the physical characteristics of Titan's environment

On the basis of previous ground-based and fly-by information, we knew that Titan's atmosphere was mainly nitrogen, with some methane, but its temperature and pressure profiles were poorly constrained because of uncertainties in the detailed composition. The extent of atmospheric electricity ('lightning') was also hitherto unknown. Here we report the temperature and density profiles, as determined by the Huygens Atmospheric Structure Instrument (HASI), from an altitude of 1,400 km down to the surface. In the upper part of the atmosphere, the temperature and density were both higher than expected. There is a lower ionospheric layer between 140 km and 40 km, with electrical conductivity peaking near 60 km. We may also have seen the signature of lightning. At the surface, the temperature was 93.65 +/- 0.25 K, and the pressure was 1,467 +/- 1 hPa.     

Nd-Fe-Co-Al-B永磁合金性能研究

在(Nd,Fe)(76.5)Co_(15)Al_1B_(7.5)的基础上,研究丁Nd,Fe量变化对合金性能的影响,其形式为Nd_(18-x)Fe_(58.5+x)Co_(15)Al_1B_(7.5),x=1,2,3,4,结果合金最佳性能出现在Nd量为15—16at％之间。同时研究了用W,Mo,Zr,Nb替代Al的工作,其替代式为Nd_(16)Fe_(76.5)Co_(15)B_(7.5),M_1,M为W,Mo,Zr,Nb。W替代Al的合金有较好的磁性能和热稳定性能。     

Parental origin of chromosomes involved in the translocation t(9;22).

Functionally equivalent genetic maternal can be labelled by an epigenetic marking process and used differentially depending on whether its origin is maternal or paternal. This phenomenon is known as genomic imprinting and is manifested at either the chromosomal or gene level. Genomic imprinting seems to play an important role in cancer predisposition syndromes, and phenotypic consequences are evident in constitutional deletion syndromes and uniparental disomies. Moreover, there seems to be a preferential retention of paternal alleles in sporadic tumours such as Wilms' tumour, rhabdomyosarcoma, osteosarcoma and retinoblastoma. To investigate whether chromosomes involved in acquired abnormalities of haematologic neoplasms show a similar 'parent of origin' bias, we studied the inheritance of the translocated chromosomes 9 and 22 in cases of Philadelphia-chromosome-positive leukaemia, using unique specific chromosome band polymorphisms. Here we show that the translocated chromosome 9 was of paternal origin, whereas the translocated chromosomes 22 were derived exclusively from the maternal copy, in 11 cases with reliable polymorphisms. Our data therefore provide evidence that imprinting phenomena may play an important role in acquired tumour-specific chromosome rearrangements.     

氯乙酸异辛酯的测定

研究了皂化法测定氯乙酸异辛酯的含量．从反应原理、实验条件选择、结果计算等作了较深入的探讨．     

n次多项式f（x）＝x~n—α和Vandermonde行列式的应用

借助于ｎ次多项式ｆ（ｘ）＝ｘ~ｎ—α以及Ｖａｎｄｅｒｍｏｎｄｅ行列式探讨了某些特殊的ｎ阶行列式的计算方法．     

山东车前属（Plantago）花粉形态的研究及其分类学意义

首次报道了山东车前属６种、１变种的花粉形态及扫描电镜下的亚显微结构．结果表明花粉特征具明显的分类学意义．     

杂多酸催化合成甲基丙烯酸十八酯

求文研究以杂多酸（ＨＰＡ）取代甲醇镁和阳离子交换树脂作为催化剂，采用酯交换的方法合成甲基丙烯酸十八酯，具有催化剂活性高反应速率快（提高１～５倍），产率高（９０％以上），且无需外加阻聚剂的特点，根据乙烯基单体的易聚合的特点，我们应用杂多酸（ＨＰＡ）作催化剂的同时还兼有阻聚剂的作用，开拓丙烯酸酯合成的新工艺。     

合肥盆地东缘断裂的新活动性

合肥盆地四周被断裂分割和围限。属于典型的中新代断陷盆地，东缘断裂在其构造演化中起着主导作用。本文从构造地貌、沿程盆地特征、地震活动和断层泥等方面的研究，并应用测龄技术成果，论述它的新活动性。