Gram Matrices of Mixed-State Ensembles

International Journal of Theoretical Physics - Gram matrices arise naturally in the consideration of pair-wise overlap of a family of vectors or quantum pure states, and play an important role in...     

甲醇在超临界环已烷中形成簇团的Monte Carlo初探

用Ｍｏｎｔｅ Ｃａｒｌｏ方法研究了甲醇－环己烷体系的微观结构随压力（密度）的变化情况，结果表明，在临界区域甲醇分子的聚集最为明显，形成的甲醇团簇尺寸最大，溶剂分子在甲醇周围的局部密度则在低于临界区或亚临界区较大。     

用CuO／γ－Al2O3催化剂同时脱除烟气中的SO2和NO

 研究了用CuO／γ－Al2O3催化剂同时脱除烟气中的SO2和NO，并在固定床反应器中考察了反应条件对其催化活性的影响．结果表明，温度和SO2对CuO／γ－Al2O3的催化活性均具有双重影响．新鲜催化剂和硫化催化剂上最适宜的脱硝温度分别为250～300℃和300～450℃，最适宜的n（NH3）／n（NO）约为1．2．烟气中的氧可大大提高CuO／γ－Al2O3的脱硫脱硝活性．综合考虑吸附硫容和NO脱除率，CuO／γ－Al2O3同时脱硫脱硝的最适宜温度为350～450℃．温度和SO2在高温区对CuO／γ－Al2O3活性的影响源于两者对NH3氧化活性的改变，高温下CuO／γ－Al2O3的活性下降是因为NH3氧化加剧；SO2通过使催化剂硫化生成硫酸盐来抑制NH3氧化，从而提高CuO／γ－Al2O3的活性．吸硫饱和的催化剂可于5％NH3中还原再生，再生后其硫容较初始时降低，但其活性大幅度提高．     

The effect of ionic strength on the diffusion of 125I in Gaomiaozi bentonite

The diffusion of ¹²⁵I^? in compacted Gaomiaozi (GMZ) bentonite was investigated by capillary in-diffusion method. Apparent and effective diffusion coefficients and accessible porosity of iodide in GMZ bentonite were obtained, and the effect of ionic strength on diffusion parameters was studied. The apparent diffusion coefficients of iodide in compacted GMZ bentonite are in the range of 1.0–6.0 × 10^?10 m² s^?1 under the conditions of dry bulk density 1,500 kg m^?3 and temperature 298 K, and increase with increasing ionic strength. This effect was explained through the analysis of microscopic structure of compacted bentonite. The iodide can only diffuse in unbound interparticle pore solution of compacted bentonite. The apparent diffusion coefficient is a function of accessible porosity which is decided by the thickness of diffusion double layer, and the thickness is in turn controlled by ionic strength.     

Computer‐assisted design and synthesis of molecularly imprinted polymers for the simultaneous determination of six carbamate pesticides from environmental water

The computer‐assisted design and synthesis of molecularly imprinted polymers for the simultaneous capture of six carbamate pesticides from environmental water are reported in this work. The quantum mechanical computational approach was employed to design the molecularly imprinted polymers with carbofuran as template. The interaction energies between the template molecule and different functional monomers in various solvents were calculated to assist in the selection of the functional monomer and porogen. The optimised molecularly imprinted polymer was subsequently used as a class‐selective sorbent in solid‐phase extraction for pre‐concentration and determination of carbamates from environmental water. The parameters influencing the extraction efficiency of the molecularly imprinted solid‐phase extraction procedure were systematically investigated to facilitate the class‐selective extraction. For the proposed method, linearity was observed over the range of 2–500 ng/mL with the correlation coefficient ranging from 0.9760 to 1.000. The limits of detection ranged from 0.2 to 1.2 ng/mL, and the limit of quantification was 4 ng/mL. These results confirm that computer‐assisted design is an effective evaluation tool for molecularly imprinted polymers synthesis, and that molecularly imprinted solid‐phase extraction can be applied to the simultaneous analysis of carbamates in environmental water.     

核化学与放射化学的研究进展

在我国核能快速发展的新形势下,新型核能资源的开发、乏燃料后处理、放射性废物处理与处置等核燃料循环化学研究日益活跃。随着科学技术的不断发展,离子加速器、反应堆、各种类型的探测器和分析设备、以及计算机技术等的发展,核化学与放射化学研究的范围和成果在不断扩展和增加,如核安全、环境放射化学、放射分析化学、放射性药物与标记化合物等,研究成果对于国防建设、核能发展、核技术应用等方面具有重要支撑作用。本文综述了近年来国内在上述领域所取得的研究进展。共引用参考文献161篇。     

磁性碱木素胺稳定的Ru纳米粒子催化α-蒎烯加氢反应

通过Mannich反应在碱木素结构中引入胺源,再结合共沉淀法制备了包裹Fe₃O₄磁核的稳定金属粒子的碱木素胺载体,并进一步构建了催化可再生资源α-蒎烯加氢反应的Ru纳米粒子催化剂.通过元素分析、粉末X射线衍射、傅里叶变换红外光谱、电感耦合等离子体原子发射光谱、透射电子显微镜、热重分析和X射线光电子能谱等方法对该催化剂进行表征.结果表明,碱木素中的苯环和含氧基团均对金属粒子有稳定作用,但胺源的引入可更加有效地稳定金属粒子.经过对催化剂制备工艺、木质素类型、胺源类型和胺源含量的筛选,得到活性最优的催化剂Fe₃O₄@0.8ALN₁-Ru,Ru负载量为1.92 mmol/g,Ru粒子粒径为（2.1±0.5）nm.该催化剂在n（α-蒎烯）/n（Ru）=65.8,1 MPa H₂条件下70℃催化1 mL α-蒎烯加氢反应2 h,可获得99.64%的α-蒎烯转化率和96.52%的顺式蒎烷选择性,并表现出良好的重复使用稳定性.     

一类格序半群的同余

本文讨论了一类可换格序半群的同余性质。给出了这类格序半群同余的表示和同态分解定理。这个结论一般化了［１］和［２］中的结果。     

On Lattice-ordered Rees Matrix Semigroups

ＯｎＬａｔｔｉｃｅ－ｏｒｄｅｒｅｄＲｅｅｓＭａｔｒｉｘＳｅｍｉｇｒｏｕｐｓ￥（谢祥云）ＸｉｅＸｉａｎｇｙｕｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＬａｎｚｈｏｕＵｎｉｖｅｒｓｉｔｙ，Ｌａｎｚｈｏｕ，７３００００）Ａｂｓｔｒａｃｔ：Ｔｈｅｐ...