First principle investigation on hydrogen solid storage in Zr1-xNbxNiH3 (x = 0 and 0.1)

We study hydrogen storage properties of Nb doped ZrNiH₃ using the first-principles calculations based on density functional theory (DFT). To achieve such calculations, we used full potential linearized augmented plane waves (FP-LAPW) method implanted in WIEN2K code. Total energy and density of states (DOS) are computed for Zr_1-xNb_xNiH₃ (x = 0 and 0.1). It turns out that substituting 10% of zirconium by niobium in ZrNiH₃ matrix involves a destabilization of the system. This destabilization is induced by the formation of a new hybridization between niobium and hydrogen atoms. Furthermore, the thermodynamic stability in terms of its energy of formation, as well as the capacity of the material to store hydrogen are discussed. Noteworthy that from FP-LAPW we report that Nb doped ZrNiH₃ lower the desorption temperature to 305.77 K without significant reduction of the hydrogen storage capacity. This lowering of the temperature desorption makes the material very useful for hydrogen storage in solids.     

基于粗糙集理论的博物院文创产品开发导向研究

目的 为使博物院文创产品创新设计的决策过程充分考虑用户的需求偏好特征，对博物院文创产品设计的核心属性因素进行探究。方法 通过文化层次法提炼出博物院文创产品的设计要素，并运用粗糙集与语意差异法构建知识表达系统。然后通过属性约简和重要度计算，得出对感性意象语意影响较大的设计要素，进而定性与定量地获取博物馆文创产品的设计模式。以安徽博物院为例，提取出核心属性并筛选出最大程度影响用户感性意象简洁大方的设计要素为文化意象色彩，其次为文化情感属性，最后为文化象征意义与交互使用体验。结论 通过对博物院文创产品设计的用户需求关键因素进行分析与探究，提出了博物院文创产品的设计思路，进而为博物馆文创产品的设计、开发提供了参考依据。     

Improved photocatalytic hydrogen evolution by facet engineering of core-shell structural CdS@ZnO

The synthesis of photocatalysts with controlled facets has become an important approach to enhance the H₂ evolution activity. However, the relationship between different exposed facets of heterojunctions and photocatalytic performance still needs to be further investigated. In this study, three types of CdS@ZnO core-shell architectures with tunable heteroinnerfaces were fabricated. Hexagonal wurtzite ZnO samples with different percentages of exposed (001) facet showed up as rod-like, short rod-like and disk-like morphologies, respectively, subsequently, self-assembled flower-like CdS coated on the whole facet of ZnO, constructing a core-shell nanostructure with the corresponding tunable heterointerfaces. Under visible-light irradiation, it was discovered that the performance of hydrogen evolution is proportional to the ratio of (001) facet of ZnO in CdS@ZnO core-shell structures. Further photoelectric tests indicated that the (001) facet of ZnO by CdS modification can form a more perfect combination than that of (100) facet of ZnO, which exhibits higher electron conduction and separation performance.     

Correlation between crystal structure and enhanced microwave dielectric characteristics of wolframite-structure Mg0.5Zr0.5NbO4 ceramics

An effective and simple synthesis of high-performance materials exerts a significant influence on low-cost commercial production with high production efficiency. In the present work, the effects of intrinsic factors on the microwave dielectric properties of reaction-sintering Mg_0.5Zr_0.5NbO₄ ceramics were quantified through crystal chemistry, Raman analysis, and bond characteristics. Pure-phase and low-loss Mg_0.5Zr_0.5NbO₄ ceramics were synthesized with an effective and simple reaction-sintering procedure. Detailed Raman vibrations with complete mode assignments were firstly investigated to characterize the lattice vibration. Rietveld refinement and Raman analysis confirmed the formation of pure-phase MgZrNb₂O₈ ceramics even with the reaction-sintering process. Moreover, well-distributed microstructure with enhanced densification (nearly full density) was verified through SEM and element mapping. Through the chemical bond theory, the dielectric constant was dominated by the Nb–O bond ionicity (f_iNb-O). The Q × f was strongly related to the lattice energy (U_Nb–_O) and bond energy (E_Nb-O) of the Nb–O bond, while the τ_f value was influenced by the coefficient of thermal expansion of the Mg–O bond (α_Mg-O), providing guidance for performance modification of Mg_0.5Zr_0.5NbO₄ systems. Excellent microwave dielectric properties for the samples sintered at 1350 °C: ε_r = 28.6, Q × f = 82,000 GHz (7.1 GHz) and τ_f = ?47 ppm/°C were obtained via the reaction sintering process, exhibiting enormous potential for industrial production.     

Adaptive weight multi-channel center similar deep hashing

To increase the richness of the extracted text modality feature information and deeply explore the semantic similarity between the modalities. In this paper, we propose a novel method, named adaptive weight multi-channel center similar deep hashing (AMCDH). The algorithm first utilizes three channels with different configurations to extract feature information from the text modality; and then adds them according to the learned weight ratio to increase the richness of the information. We also introduce the Jaccard coefficient to measure the semantic similarity level between modalities from 0 to 1, and utilize it as the penalty coefficient of the cross-entropy loss function to increase its role in backpropagation. Besides, we propose a method of constructing center similarity, which makes the hash codes of similar data pairs close to the same center point, and dissimilar data pairs are scattered at different center points to generate high-quality hash codes. Extensive experimental evaluations on four benchmark datasets show that the performance of our proposed model AMCDH is significantly better than other competing baselines. The code can be obtained from https://github.com/DaveLiu6/AMCDH.git.     

用于密集烤房自动加煤除渣装置设计

根据现实生产中的需要和用户的要求,为了完善密集烤房生产工艺加工环节,运用CAD软件,设计出自动加煤和除渣装置.该装置主要功能是为密集烤房的加热室提供燃料,并去除已经燃烧完的煤渣,以便于继续添加新的燃料,整个运动过程是通过三菱PLC来实现控制,已经投入到实践生产过程中,从而减轻了操作人员的劳动强度.经使用证明该装置系统结构合理,性能稳定,有较强的可靠性和实用性,为今后产品功能完善提供了理论和实践基础.     

工程造价控制下的项目招标标段划分模型研究

从控制工程造价的角度出发,通过对标段划分过程中所涉及的生产成本与交易成本进行分析,建立不同的标段划分方案对应的工程造价计量模型,并引入一个实际案例对所建立的模型进行验证,从而得出科学结论,为业主或总承包方在标段划分的决策制定提供了量化依据。     

Novel red phosphors LaBSiO5 co-doped with Eu3+, Al3+ for near-UV light-emitting diodes

Red-emitting phosphors LaBSiO₅:Eu³⁺ and LaBSiO₅:Eu³⁺, Al³⁺ were synthesized by the conventional solid state method at 1100 °C. The structure and luminescent properties of these phosphors are investigated. LaBSiO₅:Eu³⁺ and LaBSiO₅:Eu³⁺, Al³⁺ could be efficiently excited by near ultraviolet light with the strongest excitation peak at 395 nm. The main emission peak is located at around 616 nm, which corresponds to the transition of ⁵D₀ → ⁷F₂ of Eu³⁺ ions. The emission intensity of LaBSiO₅:Eu³⁺ was enhanced by introducing Al³⁺ ions. Compared with Y₂O₂S:0.05Eu³⁺, the sample La_0.70B_0.75SiO₅:0.30Eu³⁺, 0.25Al³⁺ shares the intense red emission, and its emission intensity is about 3.8 times as strong as that of Y₂O₂S:0.05Eu³⁺ under 395 nm light excitation. Bright red light can be observed from the red LED based on La_0.70B_0.75SiO₅:0.30Eu³⁺, 0.25Al³⁺, hence La_0.70B_0.75SiO₅:0.30Eu³⁺, 0.25Al³⁺ maybe find application on near-UV InGaN-based white LEDs.     

基于无线信道状态信息的跌倒无源监测方法

针对传统基于视频或传感器的跌倒检测方法中环境依赖、空间受限等问题，提出了一种基于无线信道状态信息的跌倒无源检测方法Fallsense。该方法利用普适、低成本的商用WiFi设备，首先采集无线信道状态数据并对数据进行预处理，然后设计动作—信号分析模型，建立轻量级动态模板匹配算法以从时序信道数据中实时检测出承载真实跌倒事件的相关片段。大量实际环境下的实验表明，Fallsense可以实现较高的准确率以及较低的误报率，准确率达到95%，误报率为2.44%。与经典WiFall系统相比，Fallsense将时间复杂度从WiFall的O（mN log N）降低到O（N）（N是样本数，m是特征数），且准确率提高了2.69%，误报率下降了4.66%。实验结果表明，所提方法是一种快速高效的无源跌倒检测方法。