不同形貌α-Fe2O3的水热法制备及性能研究

以Fe(NO_3)_3·9H_2O为原料,聚乙烯吡咯烷酮作为表面活性剂,NaOH、Na_2CO_3、CH_3COONa为形貌改变剂,采用水热法制备出不同形貌的α-Fe_2O_3,并研究了不同因素对产物形貌的影响。利用SEM、EDS、XRD、FTIR等手段对其物相及微观形貌进行表征,并探讨其生长机理。通过光催化降解酸性大红模拟废水考察不同形貌α-Fe_2O_3的光催化性能,实验结果表明,类桑葚状α-Fe_2O_3对酸性大红模拟废水的降解效果最好,降解率高达99.01%,具有潜在的光催化应用前景。     

摄影作品在设计中的应用研究

目的探究摄影作品在艺术设计中的应用方式。方法结合艺术设计学、美术学、广告学、传播学理论知识,采用案例分析法、观察研究法、归纳法等方法,归纳艺术设计中摄影作品的具体处理手法。结论摄影与艺术设计的融合是现代艺术设计的创意灵魂,既符合消费者的审美求,又蕴藏有巨大的商业价值,对于现代艺术设计具有重要的指导意义。     

Ultrathin 2D Zirconium Metal–Organic Framework Nanosheets: Preparation and Application in Photocatalysis

Synthesizing ultrathin 2D metal–organic framework nanosheets in high yields has received increasing research interest but remains a great challenge. In this work, ultrathin zirconium‐porphyrinic metal–organic framework (MOF) nanosheets with thickness down to ≈1.5 nm are synthesized through a pseudoassembly–disassembly strategy. Owing to the their unique properties originating from their ultrathin thickness and highly exposed active sites, the as‐prepared ultrathin nanosheets exhibit far superior photocatalysis performance compared to the corresponding bulk MOF. This work highlights new opportunities in designing ultrathin MOF nanosheets and paves the way to expand the potential applications of MOFs.     

一种基于聚苯胺的鲜罗非鱼检测的可再生智能比色指示器

一种基于聚苯胺(PANI)开发可再生的指标,可应用于智能包装表明罗非鱼新鲜程度。从绿到蓝孔雀的聚苯胺膜显示的颜色变化,表现为挥发性盐基氮量即将达到临界值(20毫克/100克),该聚苯胺膜可以回收至少3次。这种指示器是环保的和可再生,有助于生产厂家降低成本。     

Fabrication of Titanium Aluminides via Powder-Cored Wire Arc Additive Manufacturing: Microstructural and Mechanical Characterization

Herein, an innovative powder-cored wire arc additive manufacturing (PC-WAAM) process is proposed to fabricate γ-TiAl thin-walled intermetallic alloy. The metallography, phase composition, and mechanical properties at different thin-wall locations are characterized. The results show that the alternatively distributed layer-like microstructure composed of α₂ (Ti₃Al) and γ (TiAl) phases is obtained along the building direction. The content of α₂ phase exhibits the tendency of decreasing from the bottom to top region. This unique microstructure characteristic is closely related to the typical thermal cycling history during deposition. Moreover, the tensile strength and microhardness of the top region are lower than the middle and bottom region. In general, the current PC-WAAM technique shows promising capability of fabricating γ-TiAl intermetallic alloy with low cost. This work becomes a valuable reference for understanding the evolution mechanism of microstructure and paves the way for the flexible and customized additive manufacturing of γ-TiAl alloy.     

Robust H-infinity control for uncertain discrete-time Markovian jump systems with actuator saturation

The design of robust H-infinity controller for uncertain discrete-time Markovian jump systems with actuator saturation is addressed in this paper. The parameter uncertainties are assumed to be norm-bounded. Linear matrix inequality (LMI) conditions are proposed to design a set of controllers in order to satisfy the closed-loop local stability and closed-loop H-infinity performance. Using an LMI approach, a set of state feedback gains is constructed such that the set of admissible initial conditions is enlarged and formulated through solving an optimization problem. A numerical example is given to illustrate the effectiveness of the proposed methods.     

基于照片的特定三维人脸建模方法

个性化的人脸模型在游戏娱乐、电影制作、聋哑人辅助教学等领域发挥着重要的作用.因此特定人脸建模越来越受人们重视.特定人脸建模是指利用具体的人脸信息建立具有不同特征的人脸模型.利用人脸的正面和侧面照片,首先对通用人脸模型进行几何信息的修改,使通用人脸模型的几何形状与特定的人脸模型一致;然后参考MPEG-4中的人脸定义标准,标识出人脸正面照片以及侧面照片中的特征点,使用克里金函数插值方法,通过对通用人脸模型进行纹理图像的变形,从而建立特定人脸模型.实验结果表明,克里金插值方法是一种光滑的内插方法,在数据点多时,其内插的结果可信度较高.     

多中继通信系统中量化误差补偿的MMSE中继预编码方案

为了补偿量化误差造成的系统性能的降级,文中提出将Grassmannian码本量化误差的统计特性引入多中继系统有限反馈中继预编码的设计,首先在QoS要求下的完全反馈中继预编码与接收均衡MMSE两步优化算法的基础上,给出了有限反馈下量化误差补偿的中继预编码与接收均衡MMSE两步优化方案,进而文中在中继和功率约束下,提出了一种有限反馈下量化误差补偿的中继预编码与接收均衡MMSE联合优化方案,并给出了中继预编码矩阵设计的闭合表达式.计算机仿真表明,文中提出的中继和功率约束下量化误差补偿的MMSE联合优化方案的系统性能优于QoS要求下量化误差补偿的MMSE两步优化方案,而且相比没有采用量化误差补偿的MMSE联合优化方案可以获得更低的误码率性能.