降雨背景下诱骗态协议最优平均光子数的变色龙自适应策略

为了应对降雨给采用诱骗态协议的量子通信系统带来的突发性干扰,根据降雨分布模型和退极化信道的特性,本文提出了基于变色龙算法的每脉冲最优平均光子数自适应策略;建立了降雨强度、链路距离与最优平均光子数之间的自适应关系;并对采用变色龙算法前后,系统的性能参数进行了比较.仿真结果表明,当降雨强度J为30 mm/24 h、链路距离L为30 km时,通过采用变色龙算法,系统的安全密钥生成率由2×10~(-4)提高到3.5×10~(-4);当J为60 mm/24 h,L为20 km时,系统的信道生存函数值由0.52提高到0.63;当要求生存函数不低于0.5时,系统能够应对的最大雨强由62 mm/24 h提高到74 mm/24 h.因此,根据降雨强度和链路距离,通过变色龙算法自适应地调整系统发送端信号脉冲所含的平均光子数,可以提高量子通信系统在降雨背景下的有效性和可靠性.     

一种基于分层的量子分组传输方案及性能分析

大规模量子通信网络中,采用量子分组传输技术能有效提升发送节点的吞吐量,提高网络中链路的利用率,增强通信的抗干扰性能.然而量子分组的快速传输与路由器性能息息相关.路由器性能瓶颈将严重影响网络的可扩展性和链路的传输效率.本文提出一种量子通信网络分层结构,并根据量子密集编码和量子隐形传态理论,给出一种基于分层的量子分组信息传输方案,实现端到端的量子信息传输.该方案先将量子分组按照目的地址进行聚类,再按聚类后的地址进行传输.仿真结果表明,基于分层的量子分组信息传输方案能够有效减少量子分组信息在量子通信网络中的传输时间,并且所减少的时间与量子路由器性能与发送的量子分组数量有关.因此,本文提出的量子分组信息传输方案适用于大规模量子通信网络的构建.     

Antibacterial Activity of a Promising Antibacterial Agent: 22-(4-(2-(4-Nitrophenyl-piperazin-1-yl)-acetyl)-piperazin-1-yl)-22-deoxypleuromutilin

A novel pleuromutilin derivative, 22-(4-(2-(4-nitrophenyl-piperazin-1-yl)-acetyl)-piperazin-1-yl)-22-deoxypleuromutilin (NPDM), was synthesized in our laboratory and proved excellent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). In this study, more methods were used to further study its preliminary pharmacological effect. The antibacterial efficacy and toxicity of NPDM were evaluated using tiamulin as the reference drug. The in vitro antibacterial activity study showed that NPDM is a potent bactericidal agent against MRSA that induced time-dependent growth inhibition and a concentration-dependent post-antibiotic effect (PAE). Toxicity determination showed that the cytotoxicity of NPDM was slightly higher than that of tiamulin, but the acute oral toxicity study proved that NPDM was a low-toxic compound. In an in vivo antibacterial effect study, NPDM exhibited a better therapeutic effect than tiamulin against MRSA in a mouse thigh infection model as well as a mouse systemic infection model with neutropenia. The 50% effective dose (ED₅₀) of NPDM in a Galleria mellonella infection model was 50.53 mg/kg. The pharmacokinetic properties of NPDM were also measured, which showed that NPDM was a rapid elimination drug in mice.     

In-situ fabrication of ZnO nanoparticles sensors based on gas-sensing electrode for ppb-level H_2S detection at room temperature

The zinc oxide(ZnO)nanoparticles(NPs)sensors were prepared in-situ on the gas-sensing electrodes by a one-step simple sol-gel method for the detection of hydrogen sulfide(H₂S)gas.The sphere-like ZnO NPs were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),x-ray diffraction(XRD),energy dispersive x-ray analysis(EDX),and their H₂S sensing performance were measured at room temperature.Testing results indicate that the ZnO NPs exhibit excellent response to H₂S gas at room temperature.The response value of the optimal sample to750 ppb H₂S is 73.3%,the detection limit reaches to 30 ppb,and the response value is 7.5%.Furthermore,the effects of the calcining time and thickness of the film on the gas-sensing performance were investigated.Both calcining time and film thickness show a negative correlation with the H₂S sensing performance.The corresponding reaction mechanism of H₂S detection was also discussed.     

Theoretical study of local lattice structure of Mn in perovskite fluorides A2MF4 (A=K, Rb; M=Mg, Zn, Cd) series

A theoretical method for investigating the inter-relation between the molecular structure and electronic structure has been established on the basis of the 252×252 complete energy matrices for a 3d⁵ configuration ion in a tetragonal ligand field. By means of this method, which is independent of the X-ray diffraction, the local structure of the paramagnetic Mn²⁺ ion in perovskite fluorides A₂MF₄ (A=K, Rb; M=Zn, Mg, Cd) are determined directly by analyzing the EPR spectrum of octahedral Mn²⁺ center in A₂MF₄ crystals and the optical absorption spectrum of the (MnF₆)⁴⁻ cluster. It is shown that, comparing with the octahedral cubic structure, the local micro-structure in the vicinity of Mn²⁺ displays an elongated distortion when and a compressed distortion when , and ΔR vs. as well as ΔR vs. in the distortion region is, respectively, approximately linear. Simultaneously, the theoretical zero-field-splitting parameters , and are in good agreement with the experimental values.     

两个基于羧基-水分子链构筑的超分子镉配合物的合成、晶体结构和荧光性质

以5-甲基-3-吡唑甲酸(H2MPCA)为主配体,在螯合配体菲咯琳(phen)或2,2′-联吡啶(2,2′-bpy)的存在条件下,与醋酸镉在常温下反应得到2个基于氢键构筑的羧基-水分子链的超分子化合物,[Cd(HMPCA)2(2,2′-bpy)]·2H2O(1)和[Cd(HMPCA)2(phen)]·2.5H2O(2),并通过元素分析、红外光谱、热重分析、X-射线衍射等对其结构进行了表征。结构分析表明,在化合物1和2中,单核镉的配合物和游离水分子通过氢键及π…π堆积作用形成了三维超分子结构,在此过程中,游离水和羧基构筑的链状水分子簇起着非常重要的作用。此外,我们还研究了化合物1和2的热重和荧光性质。     

Syntheses,crystal structures and properties of four metal coordination complexes constructed from aromatic carboxylate and benzimidazole-based ligands

Transition Metal Chemistry - Four metal–organic coordination complexes, namely {[Zn(SIP)(mbi)2]·(Hmbi)·(H2O)2}n (1), {[Cd3(SIP)2(bbhb)3(H2O)4]·(H2O)2}n (2),...     

以咪唑为配体的钴和镍的配合物的合成、晶体结构及电化学性质

合成了2种新颖的配合物[M(ImH)6](tfbdc)(M=Co,Ni;tfbdc=2,3,5,6-四氟对二苯甲酸根;ImH=咪唑),并通过元素分析,红外光谱,热重分析,循环伏安及X-射线单晶结构分析对其结构及性质进行了表征。2个配合物[Co(ImH)6](tfbdc)(1)和[Ni(ImH)6](tfbdc)(2)都属单斜晶系,空间群为P21/c,且Z=2。每1个金属离子与来自6个咪唑分子的6个氮原子配位,形成八面体配位构型。独立组分,[M(ImH)6]2+阳离子和四氟对二苯甲酸阴离子之间通过两种氢键(N-H…O和C-H…F)连接形成了一种三维的超分子网络结构。     

液相色谱-串联质谱法测定果蔬中4种新型卵菌纲杀菌剂残留

建立了蔬菜和水果中噻唑菌胺、苯噻菌胺、氟啶酰菌胺和双炔酰菌胺4种新型卵菌纲杀菌剂的分散固相萃取-液相色谱-串联质谱检测方法.样品经乙腈均质提取,混合使用乙二胺-N-丙基硅烷(PSA)和ODSC18-N两种基质分散净化剂净化,采用液相色谱-三重四级杆串联质谱(LC/MS/MS)检测.实验通过空白基质溶液稀释标准建立校正的...     

Synthesis and Crystal Structure of a Magnesium Metal-organic Framework

A magnesium metal organic framework, [NH2(CH3)2][N(CH3)4][Mg5(bpdc)3(O2CH)6]· 3H2O (1, bpdcH2 = 4,4′-biphenyldicarboxylic acid), has been solvothermally synthesized and structurally characterized. 1 crystallizes in the trigonal system, space group R-3, with a = 11.3427(3), c = 41.5662(18) , V = 4631.3(3) 3, Z = 3 and the final R = 0.0457. Its structure features a pillared-layered three-dimensional network with 8.21  cavities, in which cationic [NH2(CH3)2]+ or [N(CH3)4]+ and lattice water molecules are located. Thermal stability of the title compound has also been investigated.