Suggestions for the quantitative X-ray microanalysis of thin sections of frozen-dried and embedded biological tissues

When a microregion in a thin section of frozen-dried and embedded tissue is analysed by the conventional electron-probe X-ray continuum-normalization method, the measured quantity is in mmol of element per kg of embedded specimen. As each microregion contains an unknown amount of embedding medium, this quantity generally lies indeterminately somewhere within the wide range between mmol of element per kg of hydrated tissue and mmol of element per kg of dehydrated tissue. However, if a ‘tag’ element is incorporated in the embedding medium, the contribution of the medium to the local continuum count in each probed field should be measurable, and the X-ray data may then unambiguously yield mmol of element per kg of dehydrated tissue. This result should not be affected by shrinkage on freeze-drying or by incomplete replacement of water by embedding medium. The same X-ray data can additionally provide estimates of mmol of element per unit volume, mmol of element per kg of hydrated tissue and local dry-mass fraction. However, these estimates are subject to errors due to tissue shrinkage, incomplete replacement of water and beam damage.     

浅谈克东县水土流失的成因及存在的问题

克东县属丘陵地带,土壤主要是黑土。近年来由于水土流失严重,对农业生产和农民生活带来了极大的不便。虽然采取治理与开发相结合的措施,取得了一定成绩,但目前的任务仍然艰巨。     

The influence of Mgon the formation of calcareous deposits on a freely corroding low carbon steel in seawater

The purpose of this study was to determine how magnesium in seawater influences the corrosion behaviour of freely corroding steel. This was done by studying if Mg(OH)₂ is formed and if calcite and aragonite differ in their protective properties. No Mg(OH)₂ was detected after immersion of steel in a Mg²⁺-containing artificial seawater. Magnesium seems to influence the corrosion behaviour of freely corroding steel by causing calcium carbonate to precipitate as aragonite. Aragonite is more effective in covering the surface than calcite and is therefore more functional in preventing oxygen from reaching the steel surface, thereby lowering the corrosion rate.     

关于从旋涡炉渣回收铜的研究

介绍了用自然澄清法降低、回收旋涡炉渣中的铜的方法。该方法工艺简单。操作方便，不仅降低冶炼成本，同时提高了经济效益。     

铀表面初始氧化行为的电子能量损失谱研究

利用俄歇电子能谱仪获取了表面清洁的铀及其在氧化过程中的电子能量损失谱(EELS)，研究这些电子能量损失谱线显示：清洁表面铀的等离子损失的实验值与理论值较为符合；随着氧化程度的加剧，体等离子体(BP)、表面等离子体(SP)以及价带间跃迁所造成的电子能量损失峰发生了明显的连续偏移和强度的变化，表明室温下清洁表面铀暴露微量纯氧后，在铀表面上发生了U→UO→UO2初始氧化过程。同时，又采用了俄歇电子能谱(AES)和X射线光电子谱(XPS)对照分析了铀的初始氧化过程。     

Data Squashing by Empirical Likelihood

Data squashing was introduced by W. DuMouchel, C. Volinsky, T. Johnson, C. Cortes, and D. Pregibon, in Proceedings of the 5th International Conference on KDD (1999). The idea is to scale data sets down to smaller representative samples instead of scaling up algorithms to very large data sets. They report success in learning model coefficients on squashed data. This paper presents a form of data squashing based on empirical likelihood. This method reweights a random sample of data to match certain expected values to the population. The computation required is a relatively easy convex optimization. There is also a theoretical basis to predict when it will and won't produce large gains. In a credit scoring example, empirical likelihood weighting also accelerates the rate at which coefficients are learned. We also investigate the extent to which these benefits translate into improved accuracy, and consider reweighting in conjunction with boosted decision trees.     

单分散六边形扁平溴碘化银微晶的结构与性能的研究

应用可控双注仪制备了一系列碘含量相同而碘在微晶中分布不同的单分散六边形扁平溴碘化银乳剂。用扫描电镜（ＳＴＥＭ）与Ｘ－射线能谱仪（ＥＤＳ）对单个微晶进行了微区分析，并用介电损耗，微波光导等方法研究了此类乳剂微晶的结构与性能的关系。结果表明：严格控制微晶成核、成熟、生长三个阶段的条件，可制得含六边形颗粒９２％以上的扁平溴碘化银乳剂，颗粒大小变化系数小于１２％。此外碘在微晶中的分布明显影响微晶的电性质和     

铁钴钒软磁合金损耗谱的分形结构

研究了铁钴钒软磁合金的铁芯损耗，发现铁芯损耗谱具有分形结构。讨论了带材厚度和磁感应强度对分形维数Ｄｆ的影响。     

Ion irradiation—induced structure damage to botanic samples using the ion transmission energy spectrum

1 INTRODUCTIONThe new aPplications of low energy heavy ion beam in irradi4ted botanical materialswere studied in recellt yeaxs. The beaminduced mutation effect on crop seeds has causedthe attention of physicist and biologists.[1l:] FOr examPle, 1ow energy ions can induceremarkable mutation to rice seeds.[3] There are many special phenomena when heavyions bombard botanic sW1e due to its special structure. Some studies showed that tllepenetration depths of some ions were far larger than t…     

长25-29井卡钻事故的处理

长２５－２９井在完井阶段通井过程中发生粘附卡钻事故，在处理卡钻过程中又发生卡套铣筒、井漏、溢流等事故及复杂情况。通过对井下情况的认真分析，采取先堵漏后循环再解卡的处理方案，顺利地解除了该次卡钻事故，大大地减少了经济损失。