基于图形用户界面的循环式设计理念探寻及其哲思

图形用户界面(GUI,Graphic User Interface)已经大幅度渗入在用户的视觉领域中。图形用户界面是结合了美学、设计学、心理学、人机工程学等多学科背景而诞生的新的设计领域。新的审美理念也在科技和艺术深刻交融的当代诞生。文章通过对比分解方法研究全球最流行的图形用户界面的设计后,再次解读图形界面设计中的审美理念,探寻数字化世界的审美趋势,最终引发对循环设计理念和人性思考。     

A model based transformation paradigm for cross-language collaborations

Online collaboration is a big challenge in the field of international product development in a cross-language environment. It serves two purposes: cross-language translation and design requirement clarification. Though many approaches and tools are developed for each of the purposes, not a solution serves both of them well. Especially, the traditional statistical methods for cross-language translation cannot preserve the whole semantic information, which intend to incur misunderstanding and ineffective collaboration. This results in potential problems in clarifying the design requirements. In this paper, we proposed a method to online collaboration, named Cross-Language Transformation based on Recursive Object Model (CLT-ROM). The proposed method consists of two steps. Firstly, a natural language sentence is transformed into a source ROM diagram. Secondly, a corresponding target ROM diagram is generated by a transformation algorithm. The proposed method is a model-based communication tool which facilitates collaborations. Since the ROM has been proven effective in requirements clarification, some examples are given to illustrate that the CLT-ROM has a good capability of semantic preserving in requirement engineering for product development.     

干涉SAR阴影提取及相位补偿方法

针对阴影对干涉合成孔径雷达处理的不利影响,提出一种阴影提取方法和阴影区域相位补偿方法.用伪相关系数来锐化高相关区域和低相关区域边界,消除了地形变化对相关系数的影响,能较好地检测出阴影区城的边界.同时提出利用线性相位模型来补偿阴影区域的干涉相位,相位补偿后能够消除无效数据对相位展开过程的影响,从而提高生成的相位展开图精度.实测数据的处理结果表明,该方法能明显提高相位展开的可靠性.     

基于精细积分理论与算法体系的时变最优控制方案工程应用

以航天器的编队飞行控制为工程背景,利用PIMCSD工具箱设计了航天器远/近程逼近的时变控制方案,并在飞行控制仿真平台上通过了验证.仿真结果表明,相对于传统的定常控制器方案,新的时变控制器方案可以在更短的控制时间内,以更少的燃料消耗,达到更高的终端控制精度,从而验证了控制方案的可行性、有效性和先进性.同时,提出的时变控制器简化实现方案不仅可以保持良好的性能指标,也便于工程设计和实现.这些工作为航天器编队控制系统的工程设计提供了有益的参考.     

基于FPGA和TMS320DM642的CCD图像采集和处理系统硬件设计

为能高速、有效、实时采集CCD视频图像,提出了一种实时视频图像采集和处理系统设计方案.重点介绍其硬件设计原理、关键电路的设计,其主要功能是从CCD摄像头输出的模拟视频信号中提取实时图像,数字化后送入处理器作后期图像处理和分析.     

间歇精馏分离乙醇-DEM体系的研究

为除去DEM粗产品中的少量乙醇,获得高纯度DEM产品,测定乙醇-DEM体系的汽液平衡数据,采用间歇精馏法将体系分离精制.确定了精馏工艺条件,考查了原料组成、填料高度等因素对分离的影响,采用理论板数n≥28的填料蒸馏塔,当原料中乙醇含量等于2%时,产品DEM纯度町高于99.6%,回收率超过88%.为以后的工业装置设计及工业化生产提供了充足的实验依据.     

Versatile Hypoxic Extracellular Vesicles Laden in an Injectable and Bioactive Hydrogel for Accelerated Bone Regeneration

Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have emerged as an appealing alternative to cell therapy in regenerative medicine. Unlike bone marrow MSCs (BMSCs) cultured in vitro with normoxia, bone marrow in vivo is exposed to a hypoxic environment. To date, it remains unclear whether hypoxia preconditioning can improve the function of BMSC-derived EVs and be more conducive to bone repair. Herein, it is found that hypoxia preconditioned BMSCs secrete more biglycan (Bgn)-rich EVs via proteomics analysis, and these hypoxic EVs (Hypo-EVs) significantly promote osteoblast proliferation, migration, differentiation, and mineralization by activating the phosphatidylinositide 3-kinase/protein kinase B pathway. Subsequently, an injectable bioactive hydrogel composed of poly(ethylene glycol)/polypeptide copolymers is developed to improve the stability and retention of Hypo-EVs in vivo. The Hypo-EVs-laden hydrogel shows continuous liberation of Hypo-EVs for 3 weeks and substantially accelerates bone regeneration in 5-mm rat cranial defects. Finally, it is confirmed that Bgn in EVs is a pivotal protein regulating osteoblast differentiation and mineralization and exerts its effects through paracrine mechanisms. Therefore, this study shows that hypoxia stimulation is an effective approach to optimize the therapeutic effects of BMSC-derived EVs and that injectable hydrogel-based EVs delivery is a promising strategy for tissue regeneration.     

Self-Standing Covalent Organic Framework Membranes for H2/CO2 Separation

Covalent organic frameworks (COFs) are proposed as promising candidates for engineering advanced molecular sieving membranes due to their precise pore sizes, modifiable pore environment, and superior stability. However, COFs are insoluble in common solvents and do not melt at high temperatures, which presents a great challenge for the fabrication of COF-based membranes (COFMs). Herein, for the first time, a new synthetic strategy is reported to prepare continuous and intact self-standing COFMs, including 2D N-COF membrane and 3D COF-300 membrane. Both COFMs show excellent selectivity of H₂/CO₂ mixed gas (13.8 for N-COF membrane and 11 for COF-300 membrane), and especially ultrahigh H₂ permeance (4319 GPU for N-COF membrane and 5160 GPU for COF-300 membrane), which is superior to those of COFMs reported so far. It should be noted that the overall separation performance of self-standing COFMs exceeds the Robeson upper bound. Furthermore, a theoretical study based on Grand Canonical Monte Carlo (GCMC) simulation is performed to explain the excellent separation of H₂/CO₂ through COFMs. Thus, this facile preparation method will provide a broad prospect for the development of self-standing COFMs with highly efficient H₂ purification.     

Paving the Way for High-Performance UVB-LEDs Through Substrate-Dominated Strain-Modulation

AlGaN-based ultraviolet-B light-emitting diodes (UVB-LEDs) exhibit great potential in phototherapy, vitamin D3 synthesis promotion, plant growth regulation, and so on. However, subjected to the excess compressive strain induced by the large lattice mismatch between multiple quantum wells (MQWs) and AlN, UVB-LEDs that simultaneously satisfy the requirements of high light output power (LOP), low working voltage, and excellent stability are rarely reported. Here, a substrate-dominated strain-modulation strategy is proposed. By precisely manipulating the strain in AlN grown on nano-patterned sapphire substrate (NPSS) to a slightly tensile one, the compressive strain in the following Al_0.55Ga_0.45N underlayer and Al_0.28Ga_0.72N/Al_0.45Ga_0.55N MQWs is successfully suppressed. As a result, an outstanding UVB-LED with a peak wavelength at 303.6 nm is achieved. The 20 × 20 mil² UVB-LED chip shows a wall-plug efficiency (WPE) of 3.27% under a forward current of 20 mA and a high LOP of 57.2 mW with an extremely low voltage of 5.87 V under a forward current of 800 mA. It is more exciting that the LOP degradation is as low as 17% after 1000 h operation under a forward current density of 75 A cm⁻², showing excellent stability. The here-developed UVB-LED, with a high LOP and excellent reliability, will definitely promote the applications of AlGaN-based UVB-LEDs.