利用破坏对称性的超导人造原子制备χ型四比特纠缠态

提出了利用在一维传输线共振器中的破坏对称性的超导人造原子来制备χ型四比特纠缠态的方案. 方案中所用到的Δ型三能级人造原子不同于自然的原子, 它可以产生循环跃迁. 经过适当时间的相互作用和简单的操作, 可以得到想要制备的纠缠态. 由于人造原子的激发态和光子态被绝热消除, 所以该方案对于人造原子的自发辐射和传输线共振器的衰减是鲁棒的.     

多失效模式光电系统可靠性建模分析方法北大核心CSCD

系统可靠性建模分析是开展可靠性分配、预计、故障树分析及可靠性优化设计的基础。介绍了一种光电系统可靠性建模分析方法,针对光电系统中部分分系统具有多种失效模式且各失效模式均服从指数分布的特点,依据齐次马尔科夫理论,采用马尔科夫状态转移图方法建立了产品的可靠性模型,并给出解析表达式、数值计算方法和Monte Carlo仿真方法。最后,将其应用于某机载光电系统供电回路的实例分析中。采用两种计算方法及Monte Carlo仿真方法分别进行计算,并将结果进行对比分析,证明了该方法的正确性及可行性。     

第三族金属氧化物离子对二氧化碳转化的红外光谱研究

本文利用红外光解离光谱研究了第三族金属氧化物离子对二氧化碳分子的转化机制. 研究表明,对于[ScO(CO₂)_n]⁺体系,在n≤4时,形成了溶剂化结构;在n=5时,形成了碳酸盐结构,实现了二氧化碳的转化. 对于[YO(CO₂)_n]⁺体系,需要4个二氧化碳分子就可以实现二氧化碳的转化. 而在[YO(CO₂)_n]⁺体系中,只发现了溶剂化结构,没有观察到碳酸盐结构. 理论计算表明,[YO(CO₂)_n]⁺体系拥有最小的溶剂化结构向碳酸盐结构转化能垒,[LaO(CO₂)_n]⁺体系拥有最大的溶剂化结构向碳酸盐结构转化能垒. 本文从分子水平揭示了不同金属氧化物离子对二氧化碳分子转化的影响规律.     

800Hz Terfenol-D鱼唇式弯张换能器

本文研制了800Hz Terfenol-D鱼唇式弯张换能器，换能器设计中采用永磁偏磁场和能有效抑制涡流损耗的闭合磁路结构，最高声源级185dB，-3dB带宽180Hz,这种鱼唇工弯张换能器克服了连续直流提供偏磁场时发热强的缺点，并且仅需要普通的功率放大器，更适于长时间连续工作，使这一新型低频大功率水声换能器趋于实用化。     

Hollow Gaussian beams in strongly nonlocal nonlinear media

The propagation of hollow Gaussian beams in strongly nonlocal nonlinear media is studied in detail.Two analytical expressions are derived.For hollow Gaussian beams,the intensity distribution always evolves periodically.However the second-order moment beam width can keep invariant during propagation if the input power is equal to the critical power.The interaction of two hollow Gaussian beams and the vortical hollow Gaussian beams are also discussed.The vortical hollow Gaussian beams with an appropriate topological charge can keep their shapes invariant during propagation.     

Controlled decoherence of three-level rf-SQUID qubit with asymmetric potential

A scheme is proposed to controll the decoherence of three-level rf-SQUID qubit with asymmetric potential by designing an external electric circuit for superconductive flux qubit. The results show that it may not only raise the gate speed but also extend decoherence time for a three-level structure.     

Two-dimensional non-spatial filtering based on holographic Bragg gratings

The filter made up of two gratings performs as a two-dimensional non-spatial filtering. This paper reports that the volume Bragg gratings are fabricated by interfering two collimated coherent laser beams in photopolymer. Diffraction efficiency of a single grating is up to 78% in Bragg's condition, then a two-dimensional non-spatial filter, which consists of two volume Bragg gratings and a half-wave plate, enables the laser beam filtered in two dimensions with the diffraction efficiency of 54%. The Bragg's condition and effect of polarisation on performances of the two-dimension filter are also discussed.     

血液接触生物材料的血液相容性评价研究进展

生物材料的血液相容性是决定该材料能否在临床成功应用的重要标准之一.当材料与血液接触后,会引起溶血、凝血和免疫等一系列反应,机制复杂且受多种因素影响.因此,在材料临床应用前需根据ISO 10993-4进行生物相容性评价,血液相容性评价是其中重要部分,但目前尚未形成统一的评价标准与评价体系.本文总结了近年对血液相容性评价的...     

Dynamic synovial fibroblasts are modulated by NBCn1 as a potential target in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by aggressive fibroblast-like synoviocytes (FLSs) and pannus formation. Various therapeutic strategies have been developed against inflammatory cytokines in RA in recent decades. Based on the migratory features of FLSs, we examined whether modulation of the migratory module attenuates RA severity. In this study, inflamed synovial fluid-stimulated FLSs exhibited enhanced migration and migratory apparatus expression, and sodium bicarbonate cotransporter n1 (NBCn1) was identified in primary cultured RA-FLSs for the first time. The NBC inhibitor S0859 attenuated the migration of FLSs induced with synovial fluid from patients with RA or with TNF-α stimulation. Inhibition of NBCs with S0859 in a collagen-induced arthritis (CIA) mouse model reduced joint swelling and destruction without blood, hepatic, or renal toxicity. Primary FLSs isolated from the CIA-induced mouse model also showed reduced migration in the presence of S0859. Our results suggest that inflammatory mediators in synovial fluid, including TNF-α, recruit NBCn1 to the plasma membrane of FLSs to provide dynamic properties and that modulation of NBCn1 could be developed into a therapeutic strategy for RA.Subject terms: Chemotaxis, Bone, Ion channel signalling, Rheumatoid arthritis, Drug development     

Thermodynamic equilibrium between locally excited and charge-transfer states through thermally activated charge transfer in 1-(pyren-2′-yl)-o-carborane

Reversible conversion between excited-states plays an important role in many photophysical phenomena. Using 1-(pyren-2′-yl)-o-carborane as a model, we studied the photoinduced reversible charge-transfer (CT) process and the thermodynamic equilibrium between the locally-excited (LE) state and CT state, by combining steady state, time-resolved, and temperature-dependent fluorescence spectroscopy, fs- and ns-transient absorption, and DFT and LR-TDDFT calculations. Our results show that the energy gaps and energy barriers between the LE, CT, and a non-emissive ‘mixed’ state of 1-(pyren-2′-yl)-o-carborane are very small, and all three excited states are accessible at room temperature. The internal-conversion and reverse internal-conversion between LE and CT states are significantly faster than the radiative decay, and the two states have the same lifetimes and are in thermodynamic equilibrium.

Reversible conversion between excited-states is key to many photophysical phenomena. We studied the equilibrium between LE and CT states by time-resolved and temperature-dependent fluorescence, fs- and ns-transient absorption, and LR-TDDFT calculations.