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：A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as *** hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a ***,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo ***,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular *** key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the *** and multiple tissue compartments with different geometries can be established using either straight or curved DTB *** effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor *** a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan ***,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.

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：随着对X射线成像,特别是对弯曲和不规则物体的三维成像的需求不断增加,高性能柔性闪烁膜的开发引起了人们的极大关注.镧系(Ⅲ)-有机闪烁体由于其在结构设计和光学可调谐方面的巨大灵活性,最近成为一类新的有前途的X射线闪烁体.然而,设计具有高光产额和良好溶液分散性的镧系元素(Ⅲ)-有机闪烁体仍然具有挑战性.本文报道了一种具有高效X射线激发发光(XEL)和良好溶液分散性的铕-钛氧簇合物(Eu-TiOCs)闪烁体.笼状镧-钛氧原子簇核作为X射线吸收剂,产生高能电子并引发二次电子热弛豫.有机配体作为能量转移桥和天线,通过级联能量转移来敏化Ln^(3+);离子的发光.Eu-TiOCs闪烁体表现出高的稳态X射线光产额(高达26,816±2000 photons MeV^(-1)).此外,EuTiOCs闪烁体和聚合物的羟基之间的弱氢键相互作用增强了Eu-TiOCs的溶液分散性,有利于制备低光散射和均匀闪烁膜.铕-钛氧簇与聚合物之间的通过无机簇笼和有机配体之间的协同作用,所得到的柔性闪烁膜对平面和非平面物体都表现出的高空间分辨率和低剂量X射线成像.本工作为进一步设计和制备高性能X射线闪烁体和高分辨率柔性闪烁膜提供了新思路.

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：针对非仿射离散非线性系统的带干扰轨迹跟踪问题,提出一种直接自适应模糊滑模控制设计。为了获得自适应特性及消除滑模控制抖振,通过使用一个动态模糊逻辑系统(Dynamic fuzzy logical system,DFLS)实现等价控制。DFLS的参数实行在线自调节。用Lyapunov分析方法验证了滑模控制的稳定性,结果表明,整个系统渐近稳定且具备自适应、消除抖振的特点。通过数值仿真和一个2自由度机械臂的应用设计仿真证明了所提出设计的良好性能。

摘要：An analysis illustrates the loop nonlinear performance in a bang-bang PLL. A third-order equivalent model is deduced to give an approximate evaluation of the loop parameters. The architecture of the proposed phase detector is composed of four master-slave DFFs and two XORs based on the current mode logic circuit. A no-load architecture is introduced in the XOR design. The oscillator is designed with an LC VCO implementation for the jitter requirement. A simple voltage-to-current converter is proposed to drive the loop filter. The loop filter design is described in detail, which is important to ensure the nonlinear loop stability. The chip is fabricated in a 0.18 μm CMOS technology. The experimental results show that it can achieve the frequency range of 2.995 to 3.35 GHz, and a phase noise of-118.38 dBc/Hz at 1 MHz offset. The frequency to voltage gain is 270 MHz/V. The chip consumes less than 81 mW with 1.8 V supply voltage, and it occupies a 0.5 mm2 area.

摘要：Recently the content centric networks(CCNs) have been advocated as a new solution to design future networks. In the CCNs, content and its interest are delivered over the content store and pending interest table, respectively, where both have limited capacities. Therefore, how to design the corresponding algorithms to efficiently deliver content and inertest over them becomes an important issue. In this paper, based on the analysis of content distribution, status of content store, and pending interest, we propose a novel caching algorithm with which the resources of content store and pending interest table can be efficiently used. Simulation results prove that the proposal can outperform the conventional methods.

摘要：Similarity measure construction has been proposed as fault detection of flight test method in order to obtain the primary control surface stuck and the combination stuck of primary *** measures were obtained through analyzing the certainty and uncertainty of fuzzy membership functions,which were designed based on well-known Hamming *** was applied to the fault detection of primary control surface stuck of uninhabited aerial vehicle(UAV).At post-failure control surface,if the UAV is controllable and trimmable using other control surfaces,the UAV is able to fly or return to the safety region through reconfiguration of flight control *** detect the fault,similarity measure computations were carried *** result could be applicable with the real-time parameter estimation *** monitoring the value of coefficients due to the control surface deviation,it becomes aware that the control surface fault occurs or *** control surface stuck position and value were separated by comparing the trim value with the reference *** is the advantage of increasing in reliability without adding sensors or with additional low cost.

摘要：Fractional order proportional-integral-derivative(FOPID) controller generalizes the standard PID controller. Compared to PID controller, FOPID controller has more parameters and the tuning of parameters is more complex. In this paper, an improved artificial bee colony algorithm, which combines cyclic exchange neighborhood with chaos(CNC-ABC), is proposed for the sake of tuning the parameters of FOPID controller. The characteristic of the proposed CNC-ABC exists in two folds: one is that it enlarges the search scope of the solution by utilizing cyclic exchange neighborhood techniques, speeds up the convergence of artificial bee colony algorithm(ABC). The other is that it has potential to get out of local optima by exploiting the ergodicity of chaos. The proposed CNC-ABC algorithm is used to optimize the parameters of the FOPID controller for an automatic voltage regulator(AVR) system. Numerical simulations show that the CNC-ABC FOPID controller has better performance than other FOPID and PID controllers.