摘要：The slow light propagation in a line waveguide in the two-dimensional triangular photonic crystal has been numerically studied, based on which a wideband photonic crystal waveguide with low group-velocity and low dispersion is proposed. The numerical simulation analysis shows that it is possible to maximize the group index and minimize the group-velocity dispersion in wide bandwidth by increasing the radius of the basic air hole and changing the position of the first two rows of air holes in photonic crystal waveguides. Such a photonic crystal waveguide exhibits low group velocity and low group-velocity dispersion over a broad wavelength range. A larger group index-bandwidth product is achieved in this type of waveguide structure. The numerically computed results present the normalized bandwidth as 0.32%, 0.48% and 0.642% corresponding to the group index of 85, 58 and 45, respectively.

摘要：Traditional tumor models do not tend to accurately simulate tumor growth in vitro or enable personalized treatment and are particularly unable to discover more beneficial targeted *** address this,this study describes the use of threedimensional(3D)bioprinting technology to construct a 3D model with human hepatocarcinoma SMMC-7721 cells(3DP-7721)by combining gelatin methacrylate(GelMA)and poly(ethylene oxide)(PEO)as two immiscible aqueous phases to form a bioink and innovatively applying fluorescent carbon quantum dots for long-term tracking of *** GelMA(10%,mass fraction)and PEO(1.6%,mass fraction)hydrogel with 3:1 volume ratio offered distinct pore-forming characteristics,satisfactorymechanical properties,and biocompatibility for the creation of the 3DP-7721 *** analysis and quantitative real-time fluorescence polymerase chain reaction(PCR)were used to evaluate the biological properties of the *** with the two-dimensional culture cell model(2D-7721)and the 3D mixed culture cell model(3DM-7721),3DP-7721 significantly improved the proliferation of cells and expression of tumor-related proteins and ***,we evaluated the differences between the three culture models and the effectiveness of antitumor drugs in the three models and discovered that the efficacy of antitumor drugs varied because of significant differences in resistance proteins and genes between the three *** addition,the comparison of tumor formation in the three models found that the cells cultured by the 3DP-7721 model had strong tumorigenicity in nude *** evaluation of the levels of biochemical indicators related to the formation of solid tumors showed that the 3DP-7721 model group exhibited pathological characteristics of malignant tumors,the generated solid tumors were similar to actual tumors,and the deterioration was *** research therefore acts as a foundation for the application of 3DP-7721 models in drug devel

摘要：化学取代是有效调节分子电导,产生多通道输运、量子干涉效应和其他机制的关键方法.但分子骨架和侧基之间存在复杂的相互作用,目前仍未被研究清楚.在本工作中,我们结合扫描隧道显微镜裂结实验技术和第一性原理计算方法,深入研究了具有不同σ和π侧基的分子电导.实验结果及理论分析表明,σ侧基的加入引起了分子前线轨道的对称性破缺并加剧了分子内散射,从而导致电导的降低.相反,π侧基引入了额外的电荷传输通道,实现了电荷传输的多通道效应,增加了分子的电导.这些发现为未来分子功能化和分子电子器件的设计提供了坚实的基础.

摘要：The use of a reconfigurable intelligent surface(RIS)in the enhancement of the rate performance is considered to involve the limitation of the RIS being a passive *** address this issue,we propose a RIS-aided amplify-and-forward(AF)relay network in this *** jointly optimizing the beamforming matrix at AF relay and the phase-shift matrices at RIS,two schemes are put forward to address a maximizing signal-to-noise ratio(SNR)***,aiming at achieving a high rate,a high-performance alternating optimization(AO)method based on Charnes–Cooper transformation and semidefinite programming(CCT-SDP)is proposed,where the optimization problem is decomposed into three subproblems solved using CCT-SDP,and rank-one solutions can be recovered using Gaussian ***,the optimization variables in the CCT-SDP method are matrices,leading to extremely high *** reduce the complexity,a low-complexity AO scheme based on Dinkelbachs transformation and successive convex approximation(DT-SCA)is proposed,where the variables are represented in vector form,and the three decoupling subproblems are solved using *** results verify that compared to three benchmarks(i.e.,a RIS-assisted AF relay network with random phase,an AF relay network without RIS,and a RIS-aided network without AF relay),the proposed CCT-SDP and DT-SCA schemes can harvest better rate ***,it is revealed that the rate of the low-complexity DT-SCA method is close to that of the CCT-SDP method.

摘要：We successfully designed and fabricated TES bolometers utilizing Al/Ti bilayer TESs as sensitive *** reduce the intrinsic noise level and tune the saturation power of a bolometer,the TES thermometer is placed on a suspended SiN platform which is thermally coupled to the heat bath by four long SiN beams with different *** measurement results show that the detectors have background limited noise performance,with a low noise equivalent power(NEP)on the order of10-17W/Hz1/2and have a saturation power of several tens pW at a bath temperature of 320 *** detectors are suitable for applications in ground-based astrophysics experiments by integrating absorbers for specific wavelengths.

摘要：We present a novel and simple design of an air-slot mode-gap photonic crystal(PC) nanocavity by introducing a linear air slot to the center of a line-defect waveguide in a two dimensional triangular-lattice silicon PC slab.A high quality factor(Q factor) of 8.42*105 and an ultrasmall mode volume of 0.998 cubic wavelength are achieved in an optimized air-slot nanocavity which is a suitable choice for the strong matter-field interaction in free *** high Q cavities with ultrasmall mode volume are important for applications such as quantum computation and nonlinear optics.

摘要：This work is about the development of a super low noise amplifier with minimum power consumption and high gain for several wireless *** amplifier operates at frequency bands of 0.9-2.4 GHz and can be used in many applications like Wireless local area network(WLAN),WiFi,Bluetooth,ZigBee and Global System for mobile communications(GSM).This new design can be employed for the IEEE 802.15.4 standard in industrial,scientific and medical(ISM) *** enhancement mode pseudomorphic high electron mobility transistor PHEMT is used here due to its high linearity,better performance and less noisy *** common source inductive degeneration method is employed here to enhance the gain of *** amplifier produces a gain of more than 17 dB and noise figure of about 0.5 *** lower values of S11 and S22 reflect the accuracy of impedance matching network placed at the input and output sides of *** Advance Design System(ADS) is used for the design and simulation *** the layout of design is developed on the FR4 substrate.

摘要：量子安全直接通信(QSDC)是通信双方不需要事先共享密钥,直接利用量子信道传输机密信息的一种新型保密通信模式.传统QSDC方案需要在量子信道中分发两轮光子.本文利用极化-空间超纠缠态设计了一种新型的一步QSDC方案,只需在量子信道中分发一轮光子.因此,该方案可简化实验操作并降低信息错误,实现双向通信,且在理论上具有绝对安全性.此外,通过分发一对超纠缠光子能传递2比特的信息,该方案具有较高的通信效率.在极化和空间自由度的纠缠保真度为0.98的情况下,该方案的最大通信距离约为216 ***也可用于远距离分发密钥,与传统的基于纠缠的量子密钥分发(QKD)方案相比,该方案在150 km的通信距离的密钥产生率约为QKD的2.5倍.而且,借助于未来的量子中继技术,采用该方案有望实现任意长距离的安全通信.

摘要：单极势垒异质结构可以选择性地降低暗电流,但不影响光电流,是一种构建高性能光电探测器的有效策略.特别地,具有可调谐能带结构和自钝化表面的二维(2D)材料不仅能满足能带匹配要求,而且避免了界面缺陷和晶格失配,有助于设计单极势垒异质结构.这里,我们展示了一种混合维度WS_(2)/WSe_(2)/p-Si单极势垒异质结光电探测器.其中,2D WS_(2)充当光子吸收体,原子级厚度的WSe_(2)充当单极势垒,3D p-Si充当光生载流子收集器.插入的WSe_(2)不仅减轻了有害的衬底效应,而且形成了高导带势垒,可以过滤掉若干暗电流分量,同时不影响光电流.在隧穿效应和载流子倍增效应的驱动下,该WS_(2)/WSe_(2)/p-Si器件表现出高于10~5的高开/关比、2.39×10^(12)Jones的高探测度和8.47/7.98毫秒的快速上升/衰减时间.这些优点显著优于传统的WS_(2)/p-Si器件,为设计高性能的光电器件开辟了一个新方案.

摘要：高性能赝电容的发展需要从电子转移、电解质离子吸附和扩散方面全面理解电极材料.本论文结合第一性原理与转移矩阵法,以TiO_(2)为原型,通过引入各种缺陷,即氧缺陷(V_(O))和共掺杂缺陷(V_(O)+N_(O)),在综合考虑以上因素后获得了较高的赝电容.与本征TiO_(2)(300 F g^(-1))相比,有缺陷的TiO_(2)产生的赝电容高达1700 F g^(-1).此外,缺陷会使得表面能带弯曲减小电子传输势垒,H离子在TiO_(2)-V_(O)中显示出比在TiO_(2)-V_(O)+N_(O)中高得多的势垒,表明在共掺杂体系中H扩散更容易.这项工作为电解质离子的吸附和扩散以及缺陷对电子传输的影响提供了见解,对于下一代超级电容器电极材料的设计和优化具有重要意义.