双波长吸光光度法测定磷矿中氧化镁

以EGTA－Ba和SO4^2-为联合掩蔽体系，有效地消除因大量钙存在而产生的干扰。在PH10．2硼砂缓溶液中，镁与偶氮氯磷Ⅰ形成稳定络合物，用自制的双波长分光光度仪，在组合波长570nm和500nm下，用于磷矿中镁的测定。不需分离，方法简单，快速，结构满意。     

便携式病害猪肉速测仪的研制与应用

基于健康与病害猪肉中过氧化物酶(POD)的活性不同的原理,研制出便携式的病害猪肉速测仪,用于病害猪肉的检验与鉴别,以评判猪肉的品质。仪器的工作系统由检测系统和软件系统两部分组成。该检测仪具有操作简便,检测快速,可进行现场检测等优点。在对市场猪肉的检测中,利用测定体系与POD的反应动力学曲线,可快速准确地完成病害猪肉的鉴别,健康猪肉和病害猪肉的符合率分别为100%和96%。     

ON THE ABRUPT CHANGE IN SOUTH ASIAN SUMMER MONSOON CLIMATE AND ITS SYNCHRONISM WITH THE GLOBAL RAPID WARMING

This paper has analysed the major characteristics of long-term variation, of summermonsoon climate in South Asia since 1888. An abrupt enhancement of summer monsoon inthe 1920s and its synchronism with the global rapid warming have been detected by theMann-Kendall Rank Statistic test. Based on diagnostic analysis on the atmospheric circulationover the monsoon region and the thermal conditions of both ocean and land during theperiod of abrupt change, it is found that the warming over land was stronger and earlierthan that over the ocean, which would enhance the land-sea thermal contrast and thereforebe favorable to the development of monsoon low and the disturbance in the monsoon flow.This may be a direct factor for the abrupt enhancement of summer monsoon.     

CHROMATIN AND DNA OF YOLK GRANULES BENEATH "BLASTODERM REGION" OF UNFERTILIZED CHICKEN EGG

Electron microscopic study shows that the chromatin structure of yolk granules beneath the "blastoderm region" of the unfertilized chicken egg is identical to that of yolk granules beneath the blastoderm of the fertilized and unincubated chicken egg, and both chromatin structures are very similar to those of blastoderm nuclei. Furthermore the molecular shapes of DNA of both yolk granules are also very similar to those of the blastoderm nuclei, being all linear. Based on these observations, we have come to the conclusion that chromatin and DNA widely exist in the yolk when yolk granules have reached their development-specified competence. The results indicate further that the yolk granules are capable of synthesizing DNA, and provide the condition for the interaction of DNA with histones to form chromatin through self-organization.     

柴油中正构烷烃的高温气相色谱分析

利用高温气相色谱法对柴油中正构烷烃的碳数分布及含量进行了分析。同时根据所得数据计算出正构烷烃的平均相对分子质量及平均碳原子数。试验表明，气相色谱的最佳测定条件为：柱初温60℃，柱终温330℃，升温速率6℃／min，汽化室温度350℃。分析出吐哈两种柴油中C11～C19的正构烷烃均占分析总量的75％以上，吐哈0^#与-10^#柴油正构烷烃的平均相对分子质量、平均碳原子数分别为214．57、15．18和203．34、14．38。所得数据为设计研究针对吐哈原油有效降凝剂提供了参考数据。     

光学遥感大气气溶胶和水汽的研究

本文用研制的辐射计(0.5—1.06微米七个波段),在北京地区进行了一年的观测,从中分析了大气气溶胶的特性、气溶胶粒子浓度和谱分布的变化规律及其和气象条件的关系。根据遥感大气水汽含量,和探空资料进行比较,取得了一致的结果。文中还讨论了气溶胶和水汽对大气光学厚度的影响以及在水汽吸收带中,大气光学厚度和大气水汽含量的关系。     

ELECTRON MICROSCOPIC STUDIES ON THE CHROMATIN OF BLASTODERM NUCLEI AND YOLK GRANULES BENEATH BLASTODERM OF FERTILIZED AND UNINCUBATED CHICKEN EGGS

Chromatln prepared both from the yolk granules beneath the blastoderm and from the nuclei of the blastoderm cells of fertilized and unincubated chicken eggs was examined under electron microscope and its structure was compared. The results indicate that the above two kinds of chromatin fibers seem to have no apparent difference in structural relation and diameter. The electron microscopic appearances of the basic structures of both kinds of chromatin are all "beads-on-a-string"-shaped filaments.After the digestion of chromatin from both raw materials with DNase Ⅰ, the connecting strings of chromatin fibers were cut off, only the scattered beads could be observed under electron microscope. The diameter of the scattered beads is equal to that of the beads on the chromatin fibers, and most of them are 150 in diameter.     

氯代膦烯化合物与零价钯的氧化加成反应机理探讨

与氯代烯烃或芳烃相反, 氯代膦烯与零价钯的氧化加成反应可以在温和条件下进行. 提出了可能的反应机理. 起始卤代膦烯的结构决定了反应历程和最终产物的结构.     

初三学生化学三重表征转化的眼动实验研究

化学三重表征研究一直深受国内外学者的重视,目前,初级表征的研究已有一定的理论基础,但是,次级表征（即不同表征水平之间的转化）的研究仍是研究的弱点和难点。纸笔检测、口语报告研究方法都存在一定的局限。为了从信息加工过程研究三重表征间转化的基本特点,采用眼动分析法对12名初三学生进行3×3两因素混合实验。结果显示：（1）在初三上册期末,学优生基本可以进行三重表征之间的直接转化;（2）学中生符号表征较强且依赖于符号表征,表现出“双通道协同加工”现象,符号—宏观、微观转化水平较强,宏观—微观、符号和微观—符号、宏观转化水平较弱;（3）学困生普遍缺乏三重表征的思维和意识,三重表征间的转化水平较低,相比较而言,符号-宏观、微观表征转化稍强于宏观-微观、符号表征转化和微观-符号、宏观表征转化。     

提高气冷涡轮气热耦合计算精度的措施

温度场计算的准确性对气冷涡轮的设计影响极大.实际的气冷涡轮在运行状态下,存在多种物理现象:冷气带来的燃气组分变化、湍流、转捩、温度边界层的发展变化、热辐射等.而在数值计算中,计算结果也要受到网格质量的影响.采用自编程序、商业CFD软件对某两级气冷涡轮、C3X以及MARK Ⅱ叶片进行计算,分别描述冷气组分变化、计算网格、湍流模型以及转捩温度场模拟精度的影响;同时定性分析温度边界层复合性质与辐射换热对温度计算的影响.得出在气热耦合计算中,考虑上述因素的影响是很有必要的.