Controllable synthesis of composites of ZSM-5 and KIT-1 using an ionic liquid as template

ZSM-5/KIT-1 composites were synthesized using an ionic liquid as a template. The structures and morphologies of as-obtained products were characterized using an infrared spectroscopy, X-ray diffractometer, N₂ adsorption/desorption, scanning electron microscopy and transmission electron microscopy. The resultant zeolites show a fully crystalline microporous MFI zeolite framework and a three-dimensional network of short worm-like channels. Mesopores and microspores of 4.2 and 0.8 nm in diameter coexist in the zeolite composites. Moreover, the ratio of ZSM-5 and KIT-1 could be simply adjusted by controlling the pre-crystalline time. We believe that the strategy for fabricating ZSM-5/KIT-1 through a simple method could potentially promote the large-scale production of zeolite composites.     

氨基化多壁碳纳米管的制备与表征

以多壁碳纳米管(MWNTs)为原料,经自由基反应,制备了氰基改性的多壁碳纳米管,然后采用Al-NiCl2.6H2O-THF体系还原氰基得到了氨基化的碳纳米管。通过拉曼光谱仪、热重分析仪、X射线光电子能谱仪和透射电子显微镜对产物的结构与形貌进行了表征。结果表明:氨基通过共价键枝接在MWNTs的表面,氨基化多壁碳纳米管每1000个表面碳原子中有17.1个转化为氨基;该反应条件温和,反应时间短,且不破坏MWNTs的结构。     

被动调Q激光器优化的研究

被动调Q激光器以其结构简单、紧凑而获得了广泛的应用。为优化其性能参数,在总结近些年被动调Q基本理论基础上,对于具有能量上转换(Energy-transfer upconversion)的激光工作物质构成的被动调Q激光器,提出了可以将能量上转换引起的损耗归到线性损耗中进行优化设计的方法,并给出了输出镜的反射率和饱和吸收体的小信号透过率两者优化选择的直接关系图。根据被动调Q激光器的特有参数α,在总结提高调Q峰值功率的方法基础上,得出当α接近无穷大时,从被动调Q过渡到主动调Q,实现了被动调Q和主动调Q理论的统一。     

极大算子的加权BLO估计(英文)

引入加权BLO空间,得到了极大奇异积分算子和Hardy-Littlewood极大算子的加权BLO估计.     

非同构饱和正交设计的最小矩混杂优势准则

为了区分不同构的饱和正交设计, Fang 和 Zhang^[2]提出最小混杂优势准则区分不同构的对称饱和正交设计, 然而该方法不能区分非对称的情况. 为此, 该文考虑最小矩混杂优势准则及其性质并推广文献[2]的结果. 同时, 基于该准则, 给出一个新算法来检测对称或非对称设计的非同构性. 例子显示最小矩混杂优势准则可以有效的区分非同构饱和设计.     

CoMoSx/γ-Al2O3催化剂在还原脱硫中的吸附性能和催化活性

以等体积浸渍法与原位还原硫化法相结合制备了CoMoS_x/γ-Al_2O_3催化剂。采用X射线衍射(XRD)、扫面电子显微镜/能谱(SEM/EDS)、X射线光电子能谱(XPS)、程序升温脱附/程序升温还原/程序升温表面反应-质谱分析(TPD/TPR/TPSR-MS)对催化剂进行了表征,系统地研究了CoMoS_x/γ-Al_2O_3催化剂的结构、表面CO和SO_2的吸附-脱附行为及其表面反应特性。采用微型固定床反应器评价了CoMoS_x/γ-Al_2O_3催化剂的催化特性。研究表明,CoMoS_x/γ-Al_2O_3催化剂由γ-Al_2O_3和高分散的Co-Mo-S组成,预硫化过程中不会出现CoS_2和Co_9S_8等硫化物。γ-Al_2O_3几乎不会吸附CO,CoMoS_x对CO具有强吸附作用;而γ-Al_2O_3和CoMoS_x都可以吸附SO_2,但γ-Al_2O_3的吸附作用较弱,CoMoS_x的吸附作用较强。在γ-Al_2O_3上会吸附微量的COS,而CoMoS_x不会吸附COS。在SO_2与CO的表面反应中,吸附在CoMoS_x上的SO_2会与CO发生反应,而吸附在γ-Al_2O_3上的SO_2不会发生反应。在400℃时,SO_2的转化率和硫单质的选择性都接近100%。     

Simplified reproducing kernel method for fractional differential equations with delay

This paper is devoted to the numerical scheme for the delay initial value problems of a fractional order. The main idea of this method is to establish a novel reproducing kernel space that satisfies the initial conditions. Based on the properties of the new reproducing kernel space, the simplified reproducing kernel method (SRKM for short) is applied to obtain accurate approximation. The Schmidt orthogoralization process which requires a large number of calculation is less likely to be employed. Numerical experiments are provided to illustrate the performance of the method.     

亚纯函数涉及重值分担小函数的唯一性

本文研究了亚纯函数涉及重值分担小函数的唯一性问题, 通过构造辅助函数, 特别是通过深入分析计数函数, 我们得到一些结果, 所得结果推广了一些学者的已有成果.     

Highly strained metastable structures and selective area epitaxy of Ge-rich Ge1−xSix/Si(100) materials using nanoscale building blocks

Low-temperature heteroepitaxy (330 ^°C–430 ^°C) of Si_0.5Ge_0.5 and Si_0.25Ge_0.75 on Si(100) using single-source silyl-germanes [ SiH₃GeH₃,HSi(GeH₃)₃] produces monocrystalline structures, smooth and continuous surface morphologies and low defect densities. The metastable compressive strain in these films is dramatically enhanced relative to alternative growth methods. At such low temperatures the material grows seamlessly, conformally, and selectively in the “source/drain” regions of prototypical transistors. These results suggest that films grown via silyl-germanes could have applications in optoelectronics and as stressors for mobility enhancement in Si devices.     

Self-assembled supramolecular architecture with alternating porphyrin and phthalocyanine, bonded by hydrogen bonding and π–π stacking

5, 10, 15, 20-tetraphenyl porphyrinato manganese (III) (MnTPP) ligated by THF in opposite axial directions and a sixcoordinate phthalocyaninato cobalt (II) (CoPc) with 1-phenyl-1H-tetrazole-5-thiol (HL) molecules as axial ligands were self-assembled in a mixed solution of tetrahydrofuran and acetone (v/v = 1:1) to form a hydrogen bonding “polymer” alternated with porphyrin (Por) and phthalocyanine (Pc) molecules, MnTPP(THF)₂CoPc(L)₂(1). The hydrogen bonding interaction was contributed by nitrogen [in the axial ligand (L⁻) of phthalocyanine] and hydrogen atom (in a peripheral phenyl around the porphyrin ring). This hydrogen bonding “polymer” was also enhanced by π–π stacking of the tetrazole in L⁻ with both TPP and Pc macrocycles. These polymer chains were constructed into their three-dimension (3D) architecture only by Van der Waal’s attractions. Crystal data for 1 indicate a triclnic system of P-1. Unit cell: a = 11.3932(8) Å, b = 12.6462(9) Å, c = 14.4939(11) Å, α = 91.1970(10)°, β = 95.5050(10)°, γ = 90.7200(10)°, and with cell volume of 2078.0(3) ų.