Essentiality and injectivity relative to sequential purity of acts

For a class ℳ of monomorphisms of a category, mathematicians consider different types of essentiality, depending on ℳ. In this paper, considering the category of acts over a semigroup, we first briefly study the class ℳ _p of a certain kind of pure monomorphisms, in a manner borrowed from V. Gould, to be called sequentially pure. Then, we study in detail three kinds of essentiality with respect to this class, and give some useful criteria to get (internal) characterizations (in terms of elements) for essentialities. Finally, the relations between injectivity, essentiality, retractness, and injective hulls, all with respect to the class of sequentially pure monomorphisms, are investigated. The second author is thankful to Iran National Science Foundation (INSF) for their financial support.     

Vacuum solutions in the Neveu-Schwarz field theory of a fermionic string and the zero-curvature representation in graded spaces

We demonstrate that vacuum solutions in the Neveu-Schwarz field theory of a fermionic string incorporating the GSO(−) sector are naturally related to the zero-curvature representation in a graded space of special form. We use the same representation to describe the equivalence of the cubic and nonpolynomial theories with the GSO(−) sector also taken into account. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 159, No. 1, pp. 131–141, April, 2009.     

三能级混合态的量子几何相位

把三能级开放系统的密度矩阵按照Gellmann矩阵展开,然后将展开系数和Bloch球中的方位角对应, 从而获得了Poincaré球内部点和复三维Hilbert空间的非单位矢量即波函数的映射.进一步建议用该非单位矢量来定义混合态的量子几何相位.结果显示该几何相位仅仅与复Hilbert投影空间的几何结构有关, 与开放系统具体的演化路径无关;并且该混合态的几何相位依赖于开放系统的反转粒子数,也是描述开放系统混合度的单值光滑曲线,这个结果意味着混合态的演化的确按照几何相位保持其运动记忆.此外,在纯态的限制下,Berry相位是本文定义的几何相位极限情况.     

强流脉冲电子束诱发纯钛表面的微观结构及应力状态

利用强流脉冲电子束(HCPEB)装置对金属纯钛进行轰击,采用X射线衍射,扫描电子显微镜及透射电子显微镜技术详细分析了轰击样品表层的结构和缺陷. X射线衍射分析表明, HCPEB能够在材料表层诱发幅值为 GPa量级的压应力,并在(100), (102)和(103)晶面出现择优取向.表层微观结构的观察表明: HCPEB轰击后材料表层发生了马氏体相变,形成了大量的片状马氏体组织; 此外, HCPEB轰击还在辐照表面诱发了强烈的塑性变形,一次轰击后,晶粒内部的塑性变形以(100)晶面的位错滑移为主,位错密度显著提高;多次轰击后,样品变形结构发生变化,变形孪晶的数量明显增多. 这些变形微结构不仅影响表层的织构演化行为,而且还能细化晶粒,进而提高材料表面硬度, 为HCPEB技术进行纯钛表面强化提供了一条有效的途径.     

等离子发射光谱法测定精铟中的痕量杂质元素

研究了等离子发射光谱法对精铟中9种杂质元素的连续测定。以HCl-HNO3溶解样品,讨论了分析谱线及溶液酸度的选择,并用等效浓度差减法消除了基体的影响。对仪器的功率和工作气体流量等分析条件进行了优化。结果表明,杂质元素的检出限为0.0005~0.0107mg/L,相关系数r≥0.9994,回收率为96.45%~103.13%,相对标准偏差不大于2.05%。     

高纯纳米氧化钛的制备及催化活性

以工业级硫酸钛为原料,在酸性环境下以EDTA作为络合剂,采用控制沉淀法制备高纯度纳米TiO2。考察了pH值、反应温度、煅烧温度等工艺条件对TiO2颗粒晶型、大小和分布影响。利用TEM、XRD、ICP等手段对产物进行表征,TiO2纯度超过99.9%,粒径为10-20nm,分布均匀。经过对其光催化降解苯酚反应活性实验,结果表明样品具有较好的光催化活性。