光学CT技术的研究进展

介绍了光学CT技术发展的历史和现状，重点讨论了当前普通采用的重建算法的原理及公式，指出了影响图像重建精度的关键因素，在此基础上，预测了光学CT技术的未来发展趋势。     

基于多电极电磁流量计的流速场重建

多电极电磁流量计是传统电磁流量计与电磁层析成象技术的结合.利用多电极在多角度下的多个测量值,并应用层析成象技术可得到管道内流速场的重建图像.提出采用基于S-L滤波函数的滤波反投影算法及其简化算法,它可以获得管道内非轴对称流速场的重建图像.图像重建结果表明该算法明显优于简单反投影算法.同时也证明了该算法对轴对称流型的不可区分性.     

文蛤(Meretrix Meretrix)凝集素(MML)的初步研究——Ⅰ.MML在文蛤体内的分布及纯化

在文蛤(Meretrix Meretrix)体内具有血球凝集活性的凝集素(简称MML),经实验证实仅分布于文蛤外套腔液中。向外套腔液中加入固体硫酸铵达40％时,可使99％的MML沉淀。用不同饱和度的硫酸铵溶液依次对上述沉淀进行抽提,得到MML粗制品溶液,其比活比原始外套腔液提高了约9.95倍,总活力回收达48％。最后用自制的人血浆糖蛋白一Sepharose 4 B亲合层析柱可将上述MML粗制品的比活再提高400多倍。结果与原始外套腔液比较,MML终产品的比活总共提高了4313倍,总活力回收达44.8％,在电泳鉴定时显示出单一的区带。     

α—淀粉酶的纯化

枯草芽孢杆菌（Bacillus sublilis）BF7658产生的α－淀粉酶，经絮凝、流水 层析和DEAE－－纤维素层分析进行了提纯。提纯的酶活力为132413．8U／g，与业用酶相比，纯度提高19－22倍，为精酶。用聚丙烯酰胺凝胶电泳方法，图谱上只出现单一的区带。     

S—十烷基异硫脲盐酸盐反相纸层析分离金属离子的研究

以氯代十烷和硫脲为原料，在无水乙醇溶剂中，合成了Ｓ－十烷基异硫脲盐酸盐用经的乙醇溶液为固定相，以不同浓度的盐酸溶液为展开剂，对４４种金属离子进行了反相纸层析，并绘制了Ｒｆ图谱。结果表明选择适当的展开剂，能成功地用反相纸层析分离Ｍｏ－Ｗ，Ｌａ－Ｇｄ等金属离子。     

Morphology of polar ionospheric O^＋ ion upflow： FAST observations during quiet time

With energetic ion measurements on FAST satellite, the morphologic features of quiet-time ionospheric O ion upflowing at altitudes of 2000 to 4000 km are drawn out for the first time. The pre-noon cusp/cleft is the predominant region of upflowing occurrence for O with lower energy. Meanwhile the pre-dawn sector near the equatorward edge of the plasma convection dominates the occurrence for the higher energy O ions. No matter whether the energy is lower or higher, the upflows occur often over a wide MLT range of lower latitudes outside the auroral oval. The upflowing within the pre-midnight (21:00― 22:00 MLT) auroral oval carrys larger energy fluxes, with extremely large fluxes for higher energy O appearing near the polar cap boundary. For altitudes of 2000―4200 km under observation, the ion conics occur much more frequently than ion beams. Ion beams are rarely found below 3000 km, while the conics occur uniformly over the observed altitudes.     

Applying partial correlation method to analyzing the correlation between ionospheric NmF2 and height of isobaric level in the lower atmosphere

On the basis of a multiple linear regression model performed for ionospheric NmF2, partial correlation method is first applied to investigating the relation between NmF2 and h (the height of isobaric level) in the lower atmosphere over Wuhan, China during 1957―2004. The results show that partial correlation method can eliminate the influences of solar and geomagnetic activities as well as the seasonal varia- tion factors and reveal the true correlation between NmF2 and h in the lower atmosphere. A weak posi- tive correlation between NmF2 and h is found in the middle stratosphere. In addition, by comparing the partial correlation coefficients between NmF2 and its influence factors, we find that NmF2 is mainly affected by solar activity and the seasonal variation factors, and weakly affected by geomagnetic ac- tivity, but hardly affected by h in the lower atmosphere. The study suggests that partial correlation method is a helpful tool for investigating the correlation between ionospheric parameter and its influ- ence factors.     

重组抑肽酶的表达纯化和活性测定

抑肽酶是一种用途广泛的丝氨酸蛋白酶抑制剂.用基因重组技术将化学合成的抑肽酶基因插入表达载体pET28a,并转化至大肠杆菌Rosetta(DE3)中,经IPTG诱导后,表达产物以包涵体形式存在于菌体内包涵体纯化后经复性及CM-阳离子交换层析后,从每升培养液可获得2.4 mg抑肽酶,纯度可达90%.活性测定结果显示,重组抑肽酶可竞争性抑制纤溶酶对小分子底物S2251的水解活性.抑制常数(Ki)为(0.6±0.3)nmol/L,与天然抑肽酶的抑制活性相似.     

青稞中β-葡聚糖的水法提取及性质分析

以水法分离纯化藏青稞β—葡聚糖，探索了一种高效简便的β—葡聚糖提取方法以适应生产的需要．对所获多糖进行了相关的性质分析，纸层析、紫外吸收光谱分析的和红外光谱结果表明，该多糖为单一多糖，还由扫描电镜对其形态作了观测．     

1997 年11 月6 日大耀斑期间电离层TEC 的GPS 观测结果分析

利用 ＧＰＳ测量电离层 ＴＥＣ方法处理了１９９７年 １１月６日世界时１１：４９耀斑爆发期间地球向日面纬度范围在［Ｎ２８～Ｎ４５］,经度范围在［Ｗ９０～Ｅ７７］的１５个台站的ＧＰＳ观测数据,得到了耀斑期间电离层ＴＥＣ的变化结果．本次耀斑为本太阳活动周开始以来观测到的最强的一次,耀斑的Ｘ射线级别为Ｘ９．４．计算结果表明：在几分钟内耀斑引起了大空间范围的电离层ＴＥＣ增加,ＴＥＣ增加的最大幅度在２．５×１０~１６ｍ~－２以上,ＴＥＣ增幅的大小与星下点的地方时有直接的关系,但增幅并不与当地时１２点对称,地方时上午的电离层ＴＥＣ增幅要比下午的更大些．