Effects of initial conditions on the synchronization of the coupled memristor neural circuits

Nonlinear Dynamics - The fourth basic two-terminal circuit element has been called the memristor because its resistance (conductance) depends on the complete past history of the memristor current...     

A new highly sensitive and selective fluorescent probe for Hg2+ and its application in living cells

Abstract

A new coumarin-based probe (HgP) with two “S” groups was designed and synthesized The probe HgP exhibited a fast response time (<2?min) and high selectivity (DL, 2.2?×?10^?7?mol/L). Furthermore, its capability of biological application was stu died, and the results showed that it could be applied to recognize Hg²⁺ in living cells (HK2 cells).     

APPLICATIONS AND CHALLENGES OF STRUCTURAL OPTIMIZATION IN HIGH-SPEED AEROCRAFT 1)

高速飞行器是航空航天领域发展的重要方向,具有重大战略意义和重要经济社会价值。首先,对结构优化技术及其在飞行器零部件和全机结构概念设计中的应用进行综述;然后,根据典型使用环境和设计要求,总结高速飞行器结构设计中存在的主要问题和应用需求,着重介绍近年来在高速飞行器零部件和全机结构概念设计中应用结构优化技术的典型案例;最后,提出近期亟待突破或完善的结构优化技术。结构优化技术与设计经验相结合带来设计理念的变革,将成为先进飞行器设计的必备工具和标准流程。面向重大需求的结构优化理论研究与工程实践对提升我国航空航天核心竞争力具有重要价值。     

小流量条件下汽轮机多级三维粘性流场的数值分析

1绪言小流量条件下汽轮机内部流动具有比设计条件下更为复杂的特征，最突出的表现是随冲角的增大而出现的分离流、先速流。这种流态不仅影响汽轮机的运行效率，更重要的是它还与汽轮机的安全可靠性密切相关，它可能诱发叶片的失速颤振而使叶片断裂。虽然大的负攻角所引起的本级叶片的脱流现象已成共识，但对小流量条件下汽轮机内部流动的认识只有一些实验观测到的现象和二维的数值分析，并且只限于末级叶片。在文献＊中，我们对某一汽轮机低压缸末级和次末级叶片在0．35小流量工况下的两级流场进行了三维粘性数值分析，计算得到的分离流态同…     

Gr-凝聚环的小有限分次投射维数gr.fp.dimR

文 [1],[2 ]分别研究了Gr NoetherGr 局部 (半局部 )环的同调维数 ,本文主要进一步讨论Gr 凝聚Gr 半局部环的同调性质 .在§ 1中 ,主要刻画交换Gr 凝聚Gr 半局部环R的分次弱整体维数gr.gl.w .dimR ;在§ 2中 ,定义了分次环R的小有限分次投射维数gr.fp .dimR .刻画了gr.fp .dimR =gr .gl.w .dimR的Gr 凝聚环 .由于Gr Noether环是Gr 凝聚的 ,因而本文所得的结果对于Gr Noether环是自然成立的 .同时 ,本文所得的结果 ,也可视为文 [4 ]关于一般交换凝聚环相应结论的推广 .     

An Extra‐Large‐Pore Zeolite with 24×8×8‐Ring Channels Using a Structure‐Directing Agent Derived from Traditional Chinese Medicine

Extra‐large‐pore zeolites have attracted much interest because of their important applications for processing larger molecules. Although great progress has been made in academic science and industry, it is challenging to synthesize these materials. A new extra‐large‐pore zeolite SYSU‐3 (Sun Yat‐sen University no. 3) has been synthesized by using a novel sophoridine derivative as an organic structure‐directing agent (OSDA). The framework structure was solved and refined using continuous rotation electron diffraction (cRED) data from nanosized crystals. SYSU‐3 exhibits a new zeolite framework topology, which has the first 24×8×8‐ring extra‐large‐pore system and a framework density (FD) as low as 11.4 T/1000 ų. The unique skeleton of the OSDA plays an essential role in the formation of the distinctive zeolite structure. This work provides a new perspective for developing new zeolitic materials by using alkaloids as cost‐effective OSDAs.     

钴与5－Cl－PADAB反应机理及其应用的研究

对钴与４－［（５－氯－２－吡啶）偶氮］－１，３－二氨基苯（５－Ｃｌ－ＰＡＤＡＢ）形成络合物的吸收光谱进行探讨，结果表明：试剂及络合物在不同酸度条件下形成不同型体。在酸性条件下，络合物为大阳离子，钴离子以三价形式存在，钻与试剂的络合比为１：２。在强酸性介质中，将此络合物用于光度测定钻，方法选择性及稳定性好，且灵敏度极高。对水、粮食、土壤、茶叶及维生素Ｂ＿（１２）中微量钻进行直接测定，获得满意结果。     

Synthesis, crystal structure, and solid-state NMR spectroscopy of a new open-framework aluminophosphate (NH(4))(2)Al(4)(PO(4))(4)(HPO(4))xH(2)O

A new three-dimensional open-framework aluminophosphate (NH(4))(2)Al(4)(PO(4))(4)(HPO(4)).H(2)O (denoted AlPO-CJ19) with an Al/P ratio of 4/5 has been synthesized, using pyridine as the solvent and 2-aminopyridine as the structure-directing agent, under solvothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by solid-state NMR techniques. The alternation of the Al-centered polyhedra (including AlO(4), AlO(5), and AlO(6)) and the P-centered tetrahedra (including PO(4) and PO(3)OH) results in an interrupted open-framework structure with an eight-membered ring channel along the [100] direction. This is the first aluminophosphate containing three kinds of Al coordinations (AlO(4), AlO(5), and AlO(6)) with all oxygen vertexes connected to framework P atoms. (27)Al MAS NMR, (31)P MAS NMR, and (1)H --> (31)P CPMAS NMR characterizations show that the solid-state NMR techniques are an effective complement to XRD analysis for structure elucidation. Furthermore, all of the possible coordinations of Al and P in the aluminophosphates with an Al/P ratio of 4/5 are summarized. Crystal data: (NH(4))(2)Al(4)(PO(4))(4)(HPO(4))xH(2)O, monoclinic P2(1) (No. 4), a = 5.0568(3) A, b = 21.6211(18) A, c = 8.1724(4) A, beta = 91.361(4) degrees , V = 893.27(10) A(3), Z = 2, R(1) = 0.0456 (I > 2 sigma(I)), and wR(2) = 0.1051 (all data).