Finite Horizon Maximum Likelihood Estimation for Integrated Navigation with RF Beacon Measurements

We develop a Finite Horizon Maximum Likelihood Estimator (FHMLE) that fuses Inertial Measurement Unit (IMU) and radio frequency (RF) measurements over a sliding window of finite length for three‐dimensional navigation. Available RF data includes pseudo–ranges, angles of transmission (AoT), and Doppler shift measurements. The navigation estimates are obtained by solving a finite‐dimensional nonlinear optimization using a primal‐dual interior point algorithm (PDIP). The benefits of the proposed estimation method are highlighted using simulations results comparing the FHMLE approach with an Unscented Kalman Filter (UKF), in a scenario where an aircraft approaches a carrier, with RF measurements from beacons aboard the carrier, and low‐cost IMU measurements aboard the aircraft. When the Geometric Dilution of Precision is large, we found that the FHMLE is able to achieve smaller estimation errors than the UKF, which tends to carry a bias throughout the trajectory.     

具有近室温磁热效应的Fe71Mo9P13C7块体非晶态合金

通过Fluxing提纯处理和J-Quenching快速凝固技术相结合的方法成功制备出临界尺寸为1.3 mm的Fe₇₁Mo₉P₁₃C₇块体非晶态合金棒,并对其热力学性能、磁性能和磁热性能进行了研究。结果显示,Fe₇₁Mo₉P₁₃C₇块体非晶态合金的饱和磁化强度为0.55 T;在5 T外加磁场下的最大等温磁熵变值为2.57 J/（kg·K）,制冷能力为305.57 J kg。重要的是Fe₇₁Mo₉P₁₃C₇块体非晶态合金的居里温度为355 K,接近室温,因此有望成为室温磁制冷工质的候选材料。     

Structural,Electrical and Photoresponse Properties of Si-based Diode with Organic Interfacial Layer Containing Novel Cyclotriphosphazene Compound

The electrical and photoresponse properties of Al/p-Si/organic layer/Al diode were investigated. Organic layer containing novel 2,2-bis[spiro(7,8-dioxy- 4-methylcoumarin)]-4,4,6,6-bis[spiro(2’,2”-dioxy-1’,1”- biphenylyl)]cyclotriphosphazene compound was coated by drop casting method on p-Si having ohmic contact. The structural characterization of novel cyclotriphosphazene compound was confirmed by using ¹H, ¹³C and ³¹P-NMR, elemental analysis and FT-IR spectroscopic techniques. The diode exhibits a photoconducting and photodiode behavior under solar light illumination. The electrical parameters such as ideality factor, barrier height and series resistance of the diode were determined from I-V characteristics. It is seen that the photocurrent of the diode under illumination is higher than dark current. Also, the frequency dependence of capacitance (C) and conductance (G) was explained on the basis of interface states. It is evaluated that the hybrid photodiode can be used as a photosensor in organic photodetector applications.     

Triboelectric charging of monodisperse particles in fluidized beds

To investigate the interplay between particle charging and hydrodynamics in fluidized beds, models for triboelectric charging and electrostatic forces were built into a computational fluid dynamics‐discrete element method model. Charge transfer was governed by the difference in effective work function between contacting materials as well as the electric field at the point of contact. Monodisperse particles were fluidized with an effective work function difference between the particles and the conducting walls. For smaller work function differences, hydrodynamics were not changed significantly as compared with an uncharged case. In these simulations, the average charge saturated at a value much lower than the value anticipated based on the work function difference, and a unimodal distribution of charges was observed. For larger work function differences, particles stuck to walls and bed height oscillations due to slugging were less pronounced. For these cases, a bimodal distribution of charges emerged due to effects from strong electric fields. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1872–1891, 2017     

The Impact of Sequential Fluorination of π‐Conjugated Polymers on Charge Generation in All‐Polymer Solar Cells

The performance of all‐polymer solar cells (all‐PSCs) is often limited by the poor exciton dissociation process. Here, the design of a series of polymer donors ( P1 – P3 ) with different numbers of fluorine atoms on their backbone is presented and the influence of fluorination on charge generation in all‐PSCs is investigated. Sequential fluorination of the polymer backbones increases the dipole moment difference between the ground and excited states (Δµ_ge) from P1 (18.40 D) to P2 (25.11 D) and to P3 (28.47 D). The large Δµ_ge of P3 leads to efficient exciton dissociation with greatly suppressed charge recombination in P3 ‐based all‐PSCs. Additionally, the fluorination lowers the highest occupied molecular orbital energy level of P3 and P2 , leading to higher open‐circuit voltage (V_OC). The power conversion efficiency of the P3 ‐based all‐PSCs (6.42%) outperforms those of the P2 and P1 (5.00% and 2.65%)‐based devices. The reduced charge recombination and the enhanced polymer exciton lifetime in P3 ‐based all‐PSCs are confirmed by the measurements of light‐intensity dependent short‐circuit current density (J_SC) and V_OC, and time‐resolved photoluminescence. The results provide reciprocal understanding of the charge generation process associated with Δµ_ge in all‐PSCs and suggest an effective strategy for designing π‐conjugated polymers for high performance all‐PSCs.     

Comparison of total‐etch,self‐etch,and selective etching techniques on class V composite restorations prepared by Er:YAG laser and bur: a scanning electron microscopy study

The purpose of this study was to compare total‐etch, self‐etch, and selective etching techniques on the marginal microleakage of Class V composite restorations prepared by Er:YAG laser and bur. Class V cavities prepared on both buccal and lingual surfaces of 30 premolars by Er:YAG laser or bur and divided into six groups. The occlusal margins were in enamel, and the cervical margins were in cementum. Group‐1: bur preparation(bp)+Adper Single Bond 2 (ASB)+Filtek Z550 (FZ); Group‐2: laser preparation(lp)+(ASB)+(FZ); Group‐3: bp + Clearfil S3 Bond Plus (CSBP)+(FZ); Group‐4: lp+(CSBP) (FZ); Group‐5: bp + acid etching+(CSBP)+(FZ); Group‐6: lp + acid etching+(CSBP)+(FZ). All teeth were stored in distilled water at 37°C for 24 hr, and then thermocycled 1000 times (5–55°C). Five teeth from each group were chosen for the microleakage investigation, and two teeth for the scanning electron microscope evaluation. Teeth which were prepared for the microleakage test were immersed in .5% methylene blue dye for 24 hr. After immersion, the teeth were sectioned and observed under a stereomicroscope for dye penetration. Data were analyzed using Kruskal–Wallis and Mann–Whitney U tests (p < .05). More microleakage was observed in the cervical regions compared to the occlusal regions in Groups 3, 5, and 6, respectively (p < .05). There is no statistically significant difference in Groups 1, 2, and 4, in terms of cervical regions versus occlusal regions (p > .05). No significant differences were observed among any groups in terms of occlusal and cervical surfaces, separately (p > .05). Different etching techniques did not influence microleakage of Class V restorations prepared by Er:YAG laser and bur.     

舰艇编队协同反导网络关键边评估

为评估构建的舰艇编队协同反导作战网络的各条边,设计一种改进的关键边度量方法。综合分析舰艇编队协同反导作战网络的拓扑结构,综合考虑边介数和边的2个端点对边的支撑作用,给出关键边评估模型及基本算法流程,并针对作战网络进行分析计算。结果表明:该方法克服了以边介数作为评估关键边的重要度指标的片面性,能提高网络的传输能力,增强网络重连能力,大大提高网络的鲁棒性和抗毁性。     

一株冬虫夏草菌的液态发酵条件研究

以菌丝体干质量、胞内多糖含量及腺苷含量为评价指标,研究了一株冬虫夏草菌的液态发酵条件。确定利用葡萄糖蛋白胨液体培养基发酵生产菌丝体、胞内多糖及腺苷的最佳条件为装液量100 mL/500 mL,接种量3%,温度24 ℃,培养时间4 d,摇床转速140 r/min;试验得菌丝体干质量为17.232 g/L;胞内多糖含量为78.34 mg/g;腺苷含量为633.7 μg/g。     

Lubrication of poly(vinyl alcohol) chain orientation by carbon nano‐chips in composite tapes

The extraordinary structural properties of graphene and carbon nanotube materials motivate the development of practical methods for their use in fabricating continuous, strong, and tough composite fibers. Poly(vinyl alcohol) (PVA)/carbon nano‐chip fiber (CNCF) composite tapes with 0.5 wt % loading show that Young's modulus, tensile strength, and toughness are increased by 585%, 653%, and 20%, respectively as compared to the control (PVA) tapes. Nano‐chips exfoliated from the CNCF during processing, lubricate polymer chain alignment, and orientation during drawing, where composite tapes could be drawn to higher draw ratios compared with the control tapes. As a result, the Herman's orientation factor (f) increased from 0.5 (control tape) to 0.8 (composite tape). Theoretical analysis shows ～ 16 vol % of the composite tapes consists of fully oriented PVA chains, which contributes to its exceptional mechanical performance. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013