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981.
Julio A. López-Saldívar Armando Figueroa Octavio Castaños Ramón López–Peña Margarita A. Man’ko Vladimir I. Man’ko 《Journal of Russian Laser Research》2016,37(4):313-327
We propose the discretization of the density matrix as a nonlinear positive map for systems with continuous variables. We use this procedure for calculating the entanglement between two modes through different criteria, such as Tsallis entropy, von Neumann entropy and linear entropy, and the logarithmic negativity. As an example, we study the dynamics of entanglement for the two-mode squeezed-vacuum state in the parametric amplifier and show good agreement with the analytic results. Also we address the loss of information on the system state due to the discretization of the density matrix. 相似文献
982.
On Multi‐component Ermakov Systems in a Two‐Layer Fluid: Integrable Hamiltonian Structures and Exact Vortex Solutions 下载免费PDF全文
By introducing an elliptic vortex ansatz, the 2+1‐dimensional two‐layer fluid system is reduced to a finite‐dimensional nonlinear dynamical system. Time‐modulated variables are then introduced and multicomponent Ermakov systems are isolated. The latter is shown to be also Hamiltonian, thereby admitting general solutions in terms of an elliptic integral representation. In particular, a subclass of vortex solutions is obtained and their behaviors are simulated. Such solutions have recently found applications in oceanic and atmospheric dynamics. Moreover, it is proved that the Hamiltonian system is equivalent to the stationary nonlinear cubic Schrödinger equations coupled with a Steen‐Ermakov‐Pinney equation. 相似文献
983.
Hong-ni?Teng Teng?Shen Yi-xiao?Hou Yong?ChenEmail author Xiao-yan?Kou Xiu-yun?Wang Man?Hai 《Colloid Journal》2016,78(5):690-697
Mesoporous silica materials were synthesized using tetraеthoxysilane as precursor and liquid crystals formed in aqueous mixtures of cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) as templates, without and with the addition of NaBr or Na2SO4. For this purpose, the formation of liquid crystals as a function of the ratio of CTAB and SDS under different conditions was studied. It was found that liquid crystals formed in the mixed system of CTAB and SDS at certain mixing ratios are well-structured templates for the synthesis of mesoporous silicas. The synthesized silica materials were characterized by transmission electron microscope and nitrogen adsorption/desorption analysis. The pore size of mesoporous silicas could be controlled between 3 to 6 nm by simply changing the concentration of NaBr in solution. The mesoporous silicas exhibited lamellar structure and the order of structural arrangement was promoted with addition of NaBr. However, addition of Na2SO4 led to ink-bottle type pores of mesoporous silica with a narrow pore size distribution of around 2 nm and a higher specific surface area of 610 m2 g–1. 相似文献
984.
Dr. Man‐Rong Li Maria Retuerto Prof. Peter W. Stephens Prof. Mark Croft Dr. Denis Sheptyakov Vladimir Pomjakushin Zheng Deng Dr. Hirofumi Akamatsu Venkatraman Gopalan Dr. Javier Sánchez‐Benítez Felix O. Saouma Prof. Joon I. Jang Prof. David Walker Prof. Martha Greenblatt 《Angewandte Chemie (International ed. in English)》2016,55(34):9862-9867
Cationic rearrangement is a compelling strategy for producing desirable physical properties by atomic‐scale manipulation. However, activating ionic diffusion typically requires high temperature, and in some cases also high pressure in bulk oxide materials. Herein, we present the cationic rearrangement in bulk Mn2FeMoO6 at unparalleled low temperatures of 150–300 oC. The irreversible ionic motion at ambient pressure, as evidenced by real‐time powder synchrotron X‐ray and neutron diffraction, and second harmonic generation, leads to a transition from a Ni3TeO6–type to an ordered‐ilmenite structure, and dramatic changes of the electrical and magnetic properties. This work demonstrates a remarkable cationic rearrangement, with corresponding large changes in the physical properties in a bulk oxide at unprecedented low temperatures. 相似文献
985.
Ying Li Siwei Xu Dr. Xianfa Zhang Yi Man Dr. Jing Zhang Guangming Zhang Dr. Shuo Chen Dr. Chunbo Duan Dr. Chunmiao Han Prof. Hui Xu 《Angewandte Chemie (International ed. in English)》2023,62(39):e202308410
Electroluminescent (EL) clusters emerged rapidly, owing to their organic–inorganic hybrid character useful for comprehensive performance integration and the potential for large-scale display and lighting applications. However, despite their good photoluminescent (PL) properties, until present, no efficient EL monodentate ligand-based clusters were reported due to structural variation during processing and excitation and exciton confinement on cluster-centered quenching states. Here we demonstrate an effective bulky passivation strategy for efficient cluster light-emitting diodes with a monophosphine Cu4I4 cube named [TMeOPP]4Cu4I4. With terminal pyridine groups, an active matrix named TmPyPB supports an effective host-cluster interplay for configuration fixation, structural stabilization, and exciton-confinement optimization. Compared to common inactive hosts, the passivation effects of TmPyPB markedly reduce trap-state densities by 24–40 % to suppress nonradiative decay, resulting in state-of-the-art PL and EL quantum yields reaching 99 % and 15.6 %, respectively, which are significantly improved by about 7-fold. TmPyPB simultaneously increases EL luminance to 104 nits, which is ≈100-fold that of the non-doped analogue. 相似文献
986.
Dr. Jiahui Zhou Dr. Yang Mei Prof. Feng Wu Dr. Yutong Hao Dr. Wenwen Ma Prof. Li Li Prof. Man Xie Prof. Renjie Chen 《Angewandte Chemie (International ed. in English)》2023,62(29):e202304454
Metallic Zinc (Zn) is considered as a remarkably promising anode for aqueous Zn-ion batteries due to its high volumetric capacity and low redox potential. Unfortunately, dendritic growth and severe side reactions destabilizes the electrode/electrolyte interface, and ultimately reduce the electrochemical performance. Here, an artificial protective layer (APL) with a regulated ion and electron-conducting interphase is constructed on the Zn-metal anode to provide excellent interfacial stability in high-rate cycling. The superior ionic and moderate electronic conductivity of the APL derives from the co-embedding of MXene and Zn(CF3SO3)2 salts into the polyvinyl alcohol hydrogel, which enables a synergistic effect of local current density reduction during plating and ion transport acceleration during stripping for Zn anode. Furthermore, the high Young's modulus of the protective layer and dendrite-free deposition morphology during cycling suppresses hydrogen evolution reactions (2.5 mmol h−1 cm−2) and passivation. As a result, in symmetrical cell tests, the modified battery presents a stable life of over 2000 cycles at ultra-high current density of 20 mA cm−2. This research presents a new insight into the formation and regulation of stable electrode-electrolyte interface for the Zn-metal anode. 相似文献
987.
Simon de Graaff Marcel Eilers Julia Buschermöhle Nina Bengen Dr. Anna Dierks Dr. Marc Schmidtmann Dr. Manfred Manßen Prof. Dr. Rüdiger Beckhaus 《欧洲无机化学杂志》2023,26(5):e202200637
Bis(η5:η1-(di-para-tolyl)pentafulvene)niobium chloride ( 1 ) reacts with methyl lithium via salt metathesis to the methylated bis(pentafulvene)niobium complex 2 , and with lithium 2,6-diisopropylanilide addition and subsequent N−H bond activation to the imido mono(pentafulvene)niobium complex 3 . Avoiding the competing protonation of the chloride, bis(pentafulvene)niobium complex 2 reacts with primary aromatic and aliphatic amines to form terminal niobocene imido complexes, and with water to form the analog terminal oxo complex. Secondary methyl amines undergo a simultaneous N−H and C−H activation to form niobaaziridines under mild conditions. In contrast to other reported examples, 3 can be employed to investigate the uncontested reactivity of mono(pentafulvene)niobium complexes. Reaction with 4-tert-butylphenol selectively yields a niobocene phenolate complex. Unprecedented for mono(pentafulvene)niobium complexes, treating 3 with multiple-bond-containing substrates (nitriles, isocyanates) smoothly results the insertion into the Nb-Cexo σ-bond, forming the corresponding alkylidene amido and imidato complexes. 相似文献
988.
A simple and fast method for the functionalisation of single-walled carbon nanotubes with carboxylic acid terminated molecules, at varying molar fractions, is presented. 相似文献
989.
Jens Casper Laura Nicolle Melanie Willimann Evrim Ümit Kuzucu Alan Tran Perrine Robin Pascal Detampel Hiu Man Grisch-Chan Beat Thöny Jörg Huwyler Sandrine Gerber-Lemaire 《Macromolecular bioscience》2023,23(1):2200314
The delivery of nucleic acids relies on vectors that condense and encapsulate their cargo. Especially nonviral gene delivery systems are of increasing interest. However, low transgene expression levels and limited tolerability of these systems remain a challenge. The improvement of nucleic acid delivery using depolymerized chitosan–polyethylenimine DNA complexes (dCS-PEI/DNA) is investigated. The secore complexes are further combined with chitosan-based shells and functionalized with polyethylene glycol (PEG) and cell penetrating peptides. This modular approach allows to evaluate the effect of functional shell components on physicochemical particle characteristics and biological effects. The optimized ternary complex combines a core-dCS-linear PEI/DNA complex with a shell consisting of dCS-PEG-COOH, which results in improved nucleic acid encapsulation, cellular uptake and transfection potency in human hepatoma HuH-7cells and murine primary hepatocytes. Effects on transgene expression are confirmed in wild-type mice following retrograde intrabiliary infusion. After administration of only 100 ng complexed DNA, ternary complexes induced a high reporter gene signal for three days. It is concluded that ternary coreshell structured nanoparticles comprising functionalized chitosan can be used for in vitro andin vivo gene delivery. 相似文献
990.
为探究土壤间各养分指标间的相互关系,选取了天津市宁河区不同区域的种植土壤,基于行业标准规定的检测方法,对主要养分指标进行了测定,并研究各指标间的相关性。结果表明,各区域土壤pH值变异系数最小,整体均呈碱性;有机质、全氮及速效钾变异系数属于中等;有效磷的变异系数最高。各研究区域土壤有机质含量与全氮含量呈显著正相关(P<0.01),与pH值呈显著负相关(P<0.01),而与其他指标间不具备普遍且显著的相关性。基于多元线性回归分析建立了土壤有机质与全氮及pH值之间的预测模型,通过模型计算出的预测值与实际测定值的拟合性较好;另取土壤样品进行验证表明,预测模型具有良好的可靠性和准确性。 相似文献