Persistent Current in a Mesoscopic Ring Side-Attached with a Quantum Dot

We theoretically investigate properties of the ground state of a closed dot-ring system with a magnetic flux in the Kondo regime by means of a tight-banding Anderson Hamiltonian, using the Slave-Boson mean-field approach. The persistent current shows interesting dependences on the parity and on the size of the system. The signature of Kondo resonance at ζk/L = 0.15 is expected to be observed experimentally in the future. With the intensity of the coupling tD changes from weak to strong, the properties of the system changes largely, which are different from the in-line one because of the attached dot.     

光氧化反应的研究——Ⅳ.联苯酰作用下的烯烃光氧化及[2+4]环加成反应

α-二酮可引起脂族、芳族烯烃的光氧化反应,为合成环氧化物提供了新的途径。Bartlett 认为这类反应可能经历自由基历程。sawaki 等进一步阐明,该反应经过酰氧自由     

MSTP的应用与发展

多业务传送平台(MSTP)和数据设备的关系是联合组网、长期并存的关系,运营商的运维体制必须改革,不能仍将传输设备和数据设备截然分开进行建设;互连互通涉及到业务层、封装层、数据处理层、SDH承载层、SDH线路侧,运营商应重点关注;MSTP的进一步发展是加载自动交换光网络(ASON)控制平面,但要注意在支持数据业务的情况下,传送平面和控制平面在带宽调整方面的协调性;MSTP将来可能有两种转向:逐步退出传送网络的核心层或演化成为事实上的以分组交换为核心的承载网设备.     

HCFC-141b大限迫近家电用发泡材料后市将如何更迭演进?

目前,我国家电用发泡剂行业主要活跃着HCFC-141b、环戊烷、HFC-245fa等品种,它们在冰箱、冷柜、热水器、小家电等家电产品中都有着重要应用。     

无线传输技术在通信机房动环监测中的应用

现阶段，通信机房动环监测能以多种方式进行数据传输，其中无线网络传输技术主要包括4G、5G等，实现了多种环境下的动环监测。为了能在通信网络中断的情况下正常使用网络，现阶段动环监测机房中仍有传统有线网络存在，有助于避免影响正常的传输工作，进一步提高通信机房动环监测的可靠性和故障处理效率。文中对通信机房动环监控系统的建立、开发与应用进行了分析，在此基础上，提出了通信机房动环监测中的无线传输应用关键技术，希望能促进通信机房动环监测的发展，为通信工作者提供参考。     

大学物理实验融入思政教育的实例探析

“课程思政”是高校实现立德树人根本任务的重要举措。《大学物理实验》课程是思政教育的良好载体。为了将思政教育思想更好地渗入到大学物理实验教学中，文章对《大学物理实验》进行了课程思政的总体教学设计，并以“牛顿环”课堂教学为例探讨如何将课程思政元素融入到大学物理实验教学的各个环节，给出学生评价，进行教学总结。     

One-dimensional Coordination Polymers of rctt-1,3-Diphenyl-2,4-bis [2-（5-phenyl）- oxazolyl]cyclobutane with CuCI2 and COCl2

The Cu（Ⅱ） and Co（Ⅱ） supramolecular coordination polymers, [CuCl2（DPO）- （CH3CN）0.5（CH2Cl2）0.5]n （CuDPO, DPO = rctt-1,3-diphenyl-2,4-bis[2-（5-phenyl）oxazolyl]cyclo- butane） and [CoCl2（DPO）]n （CoDPO）, were synthesized and characterized by single-crystal X-ray diffraction method. CuDPO crystallizes in monoclinic, space group P21/n, with a = 11.243（5）, b = 16.070（8）, c = 19.872（9） A, β = 95.678（10）°, Z = 4, V= 3573（3） A3, C35.50H28.50Cl3CuN2.50O2, Mr = 692.00, Dc = 1.287 g/cm3, p = 0.868 mm^-1, F（000） = 1420, S = 1.089, （△/σ）max = 0.069, the final R = 0.0682 and wR = 0.1749. CoDPO is of monoclinie, space group P21/n, with a = 11.396（4）, b = 15.151（5）, c = 17.673（6） A, β = 90.528（6）°, Z = 4, V = 3051.4（17） A3, C34H26Cl2CoN2O2, Mr = 624.40, Dc = 1.359 g/cm3, μ = 0.770 mm^-1, F（000） = 1284, S = 0.981, （△/σ）max = 0.001, the final R = 0.0471 and wR = 0.0961. In each case, the metal cation is coordinated by two C1 anions and two N atoms from oxazole ring of the ligands, which leads to the formation of a one-dimensional polymeric structure. It is found that the cyclobutane ring of coordinated DPO adopts a distorted conformation in the crystal, which is attributed to the increased steric effect between adjacent aryl substituents for the coordination of oxazole ring to metal cation. Thermal gravimetric analysis of the two complexes was also observed.