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41.
王  赵文飞  滕克难  周璐  单鑫 《兵工学报》2022,43(11):2885-2896
针对海上要地防空作战中原火力分配方案可能被不确定因素打乱的问题,提出一种综合考虑目标拦截概率与防空武器射击稳定性的双目标动态火力分配(DWTA)模型。针对海上要地防空作战特点,给出3种不确定因素;构建DWTA双目标优化函数,并给出相关参数定义;接着给出双目标优化模型的求解步骤;结合算例对所提出的方法进行仿真验证。通过对仿真结果分析发现,所提模型能够给出防空武器射击稳定性高、目标拦截效率较高的火力分配方案;当有不确定因素时,该模型可以在一定时间内给出新的合理火力分配方案,对提高海上要地防空武器作战效率有一定参考价值。  相似文献   
42.
A polyacrylic acid(PAA)/gelatin(Gela)/polyvinyl alcohol(PVA)hydrogel was prepared by copolymerization,cooling,and freezing/thawing methods.This triplenetwork(TN)structure hydrogel displayed superior mechanical properties,low swelling ratio and self-healing properties,The superior mechanical properties are attributed to the triple helix association of Gela and PVA crystallites by reversible hydrogen bonding.The characterization results indicated that the fracture stress and the strain were 808 kPa and 370% respectively,while the compression strength could reach 4443 kPa and the compressive modulus was up to 39 MPa under the deformation of 90%.The hydrogen bonding in PVA contributed to maintain and improve the self-healing ability of hydrogels.Every type of hydrogels exhibited a higher swelling ratio under alkaline conditions,and the swelling ratios of PAA,PAA/PVA and PAA/Gela hydrogels were 27.71,12.30 and 9.09,respectively.The PAA/Gela/PVA TN hydrogel showed the lowest swelling ratio(6.57)among these hydrogels.These results indicate that the novel TN hydrogels possess good environmental adaptability and have potential applications in the biomedical engineering and sensor field.  相似文献   
43.
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.  相似文献   
44.
高梦琦  吴克楠  李强  霍军涛  穆保霞  马旭 《功能材料》2022,53(3):3158-3161+3166
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。  相似文献   
45.
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.  相似文献   
46.
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 (Δµge) from P1 (18.40 D) to P2 (25.11 D) and to P3 (28.47 D). The large Δµge 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 (VOC). 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 (JSC) and VOC, and time‐resolved photoluminescence. The results provide reciprocal understanding of the charge generation process associated with Δµge in all‐PSCs and suggest an effective strategy for designing π‐conjugated polymers for high performance all‐PSCs.  相似文献   
47.
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。  相似文献   
48.
本文提出一种新型水泥工业余热与生物质能互补发电系统,该系统采用水泥窑低温余热和生物质补燃有机结合的方式大幅提高水泥窑余热发电蒸汽参数与系统效率。来自水泥生产线窑头和窑尾的低温余热烟气全部用来加热工质水产生饱和蒸汽,饱和蒸汽进入生物质补燃系统中进行过热后送入汽轮发电机组中做功发电,补燃燃料为生物质气化燃气。本研究建立了单压和双压2种互补发电系统,分析了其热力学性能,结果表明:单压互补发电系统与传统单压纯低温发电系统相比,系统循环热效率和系统发电效率分别提高了1.63和1.92个百分点。双压互补发电系统与传统双压纯低温发电系统相比,系统循环热效率和系统发电效率分别提高了1.05和1.53个百分点。  相似文献   
49.
We have worked on the structural and magnetic properties of Zn0.99?xMn0.01Gd x O δ (for x = 0.02, 0.03, and 0.04) compounds prepared by using a sol–gel method. The x-ray diffraction, scanning electron microscopy, and energy dispersive x-ray spectroscopy were used to understand the structural properties of the samples. We observed that co-substitution of Mn (1 %) and Gd (2–4 %) into the ZnO does not change the hexagonal structure. Scanning electron microscope (SEM) images show us that the grain size decreases with the increasing amount of the Gd into the ZnO matrix. The magnetic properties of the samples have been investigated by using magnetic hysteresis and DC susceptibility measurements. The ZMG1 sample shows a weak ferromagnetic behavior at room temperature, whereas the ZMG2 and ZMG3 samples exhibit a paramagnetic nature. Furthermore, it is also found that the magnetizations of the samples decrease with increasing Gd content in the ZnMnO system due to the enhancing interaction between Gd 3+ ions. We summarize that the co-substitution of Mn and Gd into the ZnO generates a room-temperature ferromagnetism, but it still needs more work to obtain strong and high coercivity magnetic loops for applications.  相似文献   
50.
In response to rising energy costs and the impetus to reduce environmental impacts, upgrading the large building stock that is responsible for 40% of the total energy consumption to maximum energy efficiency is becoming an important task. Despite the many benefits associated with retrofit projects, they are still only slowly being implemented because of the many challenges that exist. One of these challenges is optimizing the decision between renovation scenarios based on economic and environmental goals, which can be made possible with an accurate pre-retrofit model. The intention of this paper is to introduce a pre-retrofit model that efficiently obtains and integrates multiple forms of building data as a critical step to develop a comprehensive understanding of a building to be renovated. Opportunities for utilizing building information modeling (BIM) and geographical information systems (GIS) for retrofitting projects were explored through the study of a historical campus building. With the use of as-is geometric data and as-is data, building data maps were obtained. The next step of this study is to use the model to conduct scenarios comparison and optimize renovation decision based on economic and environmental goals.  相似文献   
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