Dependence of Crystal Quality and β Value on Synthesis Temperature in Growing Gem Diamond Crystals

High quality Ib gem diamond single crystals were synthesized in cubic anvil high-pressure apparatus （SPD- 6 × 1200） under 5.4GPa and 1230℃-1280℃. The （100） face of seed crystal was used as growth face, and Ni70Mn25Co5 alloy was used as solvent/catalyst. The dependence of crystal quality andβ value （the ratio of height to diameter of diamond crystal） on synthesis temperature was studied. When the synthesis temperature is between 1230℃ and 1280℃, theβ value of the synthetic high-quality gem diamond crystals is between 0.4 and 0.6. The results show that when theβ value is between 0.4 and O. 45, the synthetic diamonds are sheet-shape crystals; however, when theβ value is between 0.45 and 0.6, the synthetic diamonds are tower-shape crystals. In addition, when theβ value is less than 0.4, skeleton crystals will appear. When theβ value is more than 0.6, most of the synthetic diamond crystals are inferior crystals.     

Thermal stress reduction of GaAs epitaxial growth on V-groove patterned Si substrates

We investigate the thermal stresses for GaAs layers grown on V-groove patterned Si substrates by the finite-element method. The results show that the thermal stress distribution near the interface in a patterned substrate is nonuniform,which is far different from that in a planar substrate. Comparing with the planar substrate, the thermal stress is significantly reduced for the Ga As layer on the patterned substrate. The effects of the width of the V-groove, the thickness, and the width of the SiO₂ mask on the thermal stress are studied. It is found that the SiO₂ mask and V-groove play a crucial role in the stress of the Ga As layer on Si substrate. The results indicate that when the width of V-groove is 50 nm, the width and the thickness of the SiO₂ mask are both 100 nm, the Ga As layer is subjected to the minimum stress. Furthermore,Comparing with the planar substrate, the average stress of the Ga As epitaxial layer in the growth window region of the patterned substrate is reduced by 90%. These findings are useful in the optimal designing of growing high-quality Ga As films on patterned Si substrates.     

Thermal Entanglement Between Atoms in the Four-Cavity Linear Chain Coupled by Single-Mode Fibers

Natural thermal entanglement between atoms of a linear arranged four coupled cavities system is studied. The results show that there is no thermal pairwise entanglement between atoms if atom-field interaction strength f or fiber-cavity coupling constant J equals to zero, both f and J can induce thermal pairwise entanglement in a certain range. Numerical simulations show that the nearest neighbor concurrence C_AB is always greater than alternate concurrence C_AC in the same condition. In addition, the effect of temperature T on the entanglement of alternate qubits is much stronger than the nearest neighbor qubits.     

一类含氟芳基噁二唑化合物的合成及其光物理和电化学性质研究

合成和表征了一类苯环上含F和CF₃基团的1,3,4-噁二唑类化合物, 研究了它们的紫外-可见光谱、荧光光谱和电化学性质. 结果表明, 与不含氟的噁二唑化合物相比, 三氟甲基苯单元可降低化合物的LUMO能级, 而四氟苯单元则对化合物的光学和电化学性质无显著影响.     

两个由5-硝基间苯二甲酸和双咪唑基配体构筑的锰、钴配合物的合成及晶体结构

通过水热法合成了2个新的配合物[Mn(NIPH)(mbix)]_n (1)和[Co(NIPH)(mbix)(H₂O)₃]_2n·2nH₂O (2)(H₂NIPH=5-硝基间苯二甲酸,mbix=1,3-双(咪唑基-1-基)苯)。并对其进行了元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射测定。这两个配合物通过氢键和π-π相互作用形成了三维超分子网状结构。     

固态格点自旋体系中的量子关联

量子态的关联特性是量子通信和量子计算的重要资源。文章首先回顾了经典关联、量子关联的概念以及常用的度量方法,随后简要介绍了作者最近对固态格点自旋体系中量子关联的研究成果。最后对未来量子关联的研究指出了几个方向。     

1,8-萘酰亚胺衍生物的合成、表征及电存储性能

本文以三苯胺结构作为电子给体,与三种接有不同吸电子基团的1,8-萘酐反应合成了具有电子给-受体结构的N-(4-三苯胺)-1,8-萘酰亚胺(NA-ATPA)、N-(4-三苯胺)-(4-氰基)-1,8-萘酰亚胺(NA(CN)-ATPA)和N-(4-三苯胺)-(4-硝基)-1,8-萘酰亚胺(NA(NO_2)-ATPA),并对它们的结构进行了表征。利用紫外可见光谱、荧光发射光谱和循环伏安法对产物的光物理性能和电化学性能进行了测试,并测试了其存储行为,结果显示NA-ATPA表现出易失的静态随机存储行为(SRAM),NACN-ATPA表现出非易失的闪存型存储(Flash),NA(NO_2)-ATPA表现出非易失只读型存储(WORM)。三种萘酰亚胺对存储行为中高导态的维持能力逐渐增强,其原因是引入的吸电子基团的吸电子性越强,其LUMO值和能隙值降低的越多,越利于电荷转移,形成更稳定的电荷转移络合物。另外,本文还对原料和产物的电子结构、分子轨道和能级进行了分子模拟计算,研究了三种化合物基态和激发态的差别,并对其电子转移过程进行了理论分析。     

化学发光法测定甲萘威

在NaOH介质中,铁氰化钾氧化鲁米诺产生化学发光,甲萘威对该发光反应有较强的抑制作用且抑制发光强度与甲萘威的浓度呈较好的线性关系,基于此性质建立了测定甲萘威的新方法。在实验的优化条件下,测定甲萘威的检出限为5.5×10-11mol.L-1,线性范围为1.5×10-10—4.0×10-8mol.L-1,对5.0×10-9mol.L-1甲萘威进行了11次平行测定,其RSD为1.74%。该法用于合成样品中甲萘威的测定,结果令人满意。