Lead-free sodium niobate nanowires with strong piezo-catalysis for dye wastewater degradation

In this work, the hydrothermally-synthesized sodium niobate nanowires were used to decompose Rhodamine B dye solution through the piezo-catalytic effect. With the sodium niobate catalyst, a high piezo-catalytic degradation ratio of ～80% was achieved under the excitation of vibration for the Rhodamine B dye solution (～5?mg/l). These active species in the catalytic process, hydroxyl radicals and superoxide radicals with the strong oxidation ability, were also observed, which confirmed the key role of piezoelectric effect for piezo-catalysis. The piezo-catalysis of sodium niobate nanowires provides a high-efficiency and reusable tool in application in depredating the dye wastewater.     

Xyloglucan Oligosaccharides Hydrolysis by Exo-Acting Glycoside Hydrolases from Hyperthermophilic Microorganism Saccharolobus solfataricus

In the field of biocatalysis and the development of a bio-based economy, hemicellulases have attracted great interest for various applications in industrial processes. However, the study of the catalytic activity of the lignocellulose-degrading enzymes needs to be improved to achieve the efficient hydrolysis of plant biomasses. In this framework, hemicellulases from hyperthermophilic archaea show interesting features as biocatalysts and provide many advantages in industrial applications thanks to their stability in the harsh conditions encountered during the pretreatment process. However, the hemicellulases from archaea are less studied compared to their bacterial counterpart, and the activity of most of them has been barely tested on natural substrates. Here, we investigated the hydrolysis of xyloglucan oligosaccharides from two different plants by using, both synergistically and individually, three glycoside hydrolases from Saccharolobus solfataricus: a GH1 β-gluco-/β-galactosidase, a α-fucosidase belonging to GH29, and a α-xylosidase from GH31. The results showed that the three enzymes were able to release monosaccharides from xyloglucan oligosaccharides after incubation at 65 °C. The concerted actions of β-gluco-/β-galactosidase and the α-xylosidase on both xyloglucan oligosaccharides have been observed, while the α-fucosidase was capable of releasing all α-linked fucose units from xyloglucan from apple pomace, representing the first GH29 enzyme belonging to subfamily A that is active on xyloglucan.     

Nanoporous copper sonocatalysts prepared by dealloying Cu–Al–Ti amorphous ribbons

ABSTRACT

Nanoporous copper (NPC) with a controllable ligament width was prepared by chemically dealloying Cu₄₅Al₄₅Ti₁₀ amorphous ribbons in dilute HCl solution. X-ray diffraction and scanning electron microscopy analysis confirmed the 3D, bicontinuous, nanoporous structure constituting fcc-Cu ligaments of 39–79?nm thickness. The coarsening of NPC ligaments increased significantly with an increase of HCl concentration, reaction temperature or time. The surface diffusivity and activation energy of NPC were also calculated. Finally, the catalytic activity of NPC was validated with the ultrasound and H₂O₂-assisted degradation of methyl orange (MO), where 99% MO was degraded within 15?min.     

Application of fuzzy image restoration in criminal investigation

The advancement of science and technology has a positive effect on the development of law disciplines. The development of algorithms and artificial intelligence also has a certain impact on judicial practice. Image restoration is a significant technique in image processing. It aims to objectively restore the content or quality of the original image from the degraded image. Image degradation is always generated in image transmission, such as distortion, blur. In modern video surveillance system, image restoration is significant for criminal investigation. However, image restoration based on conventional filter algorithms cannot achieve satisfactory performance. Thus, we first introduce the image restoration algorithms based on different degradation model. Then, we propose some applications of fuzzy image restoration in criminal investigation. We conduct experiments on both degraded images and videos and experimental results have shown the effectiveness of fuzzy image restoration applying to the criminal investigation.     

基于气动性能与刚度特性的风力机翼型优化设计

结合翼型泛函集成理论与叶片截面刚度矩阵数学计算模型,提出了风力机中等厚度翼型气动性能与结构刚度特性的一体化设计方法,实现了翼型气动性能与叶片截面刚度特性的同时提高。对考虑叶片截面铺层参数变化设计的WQ-B300翼型与DU97-W-300翼型进行了气动性能与结构刚度特性对比分析,结果表明:相比于DU97-W-300翼型,WQ-B300翼型的气动性能与叶片截面刚度性能均有显著提高,其挥舞刚度和摆振刚度分别提高了6.2%和8.4%,验证了该设计方法的可行性,给风力机中等厚度及大厚度翼型设计提供了一种思路。     

Implementation of ZnSnO3 nanosheets and their RE (Er,Eu, and Pr) materials: Enhanced photocatalytic activity

ZnSnO₃, ZnSnO₃@Er, ZnSnO₃@Eu, and ZnSnO₃@Pr materials were synthesized by a hydrothermal method, these active materials characterized by XRD, Raman, DRS-UV, FT-IR, BET surface areas and Scanning electron microscopy studies. The ZnSnO₃ nanosheets meta-stable form was confirmed by XRD. Here, addressing to the pure and doped materials functional groups were evaluated by FT-IR spectroscopy. ZnSnO₃, ZnSnO₃@Er, ZnSnO₃@Eu, and ZnSnO₃@Pr rotational vibrations frequency modes were predicted by the Raman spectroscopy. Our results are marvelously, the obtained bandgap energies at 3.5 eV for pure sample and ZnSnO₃@Er, ZnSnO₃@Eu and ZnSnO₃@Pr energies at 3.06 eV, 3.04 eV and 3.02 eV. The synthesized pure samples get a sheet-like morphology and doped for RE metals than morphology was changing for nanocubes. We assess for all samples that were focused on photocatalytic dye degradation for Methylene blue dye; hence, we are discussing these approaches, ZnSnO₃@Pr/Methylene blue sample was a great improvement and high decolorization efficiency compared with ZnSnO₃@Er, ZnSnO₃@Eu nanocubes. The ZnSnO₃@Pr sample surface area was investigated by BET analysis. In addition, we are testing the phenol degradation with wastewater. The ZnSnO₃@Er, ZnSnO₃@Eu catalysts were determined to the less efficiency when comparing to the ZnSnO₃@Pr material. The ZnSnO₃@Pr material results have more efficiency and a very good recyclable stability nature.     

考虑内外啮合相位差的行星轮系动态特性分析

对1.5MW级风电齿轮箱行星轮系统采用集中参数法建立行星轮系扭转动力学模型,运用Runge-Kutta法对所建立的扭转动力学模型进行求解,分别讨论了时变啮合刚度和相位差对行星轮系固有特性和稳态响应特性的影响。研究结果表明:时变啮合刚度导致系统各阶固有频率随时间周期性波动,而啮合相位差导致第1阶固有频率波动范围增大,其余4阶固有频率波动范围变小,且各阶固有频率间的变化步调存在相位差;是否考虑相位差对第3、4阶振型影响较为明显;对不同时刻的第3、4阶振型影响较大;考虑相位差时保持架、行星轮、太阳轮扭振角速度幅值均降低。     

响应曲面法优化电催化降解染料废水工艺的研究

采用中心复合设计的响应曲面法预测电催化降解染料废水的最优条件。具体以Ti/SnO₂-Sb 电极作为阳极，应用响应曲面法研究了pH、施加电压值、电极间距对亚甲基蓝溶液脱色效率的影响。研究结果表明模型拟合精度R²=0.9942，初始pH、施加电压值、电极间距及交互作用对脱色率响应值影响大。模型预测最佳反应条件pH为 6.98，施加电压6.0 V，电极间距为1.01 cm时，脱色效率预测值达到98.68%。采用实验进一步验证该模型，预测最佳条件下三次实验脱色率平均值98.47%。该方法可用于优化电催化降解染料废水的工艺参数，为实际废水处理提供优化方案。     

干熄炉斜道区莫来石-红柱石砖的损毁研究

测试并比较了使用4年后干熄炉斜道区莫来石-红柱石过梁砖不同部位(炉腔侧、风道侧和芯部)砖体的体积密度、显气孔率、耐压强度、化学组成,利用XRD和SEM分别分析了其物相组成和显微结构变化,并对其损毁机制进行了探讨。结果表明:1)莫来石-红柱石砖原始强度较低,易遭受炉体结构应力和热应力破坏;2)与砖体芯部相比,炉腔侧和风道侧受环境气氛影响更大,结构更为疏松,强度下降更明显;3)高温下红柱石莫来石化导致的体积膨胀、低熔点相侵入形成的新物相以及弱还原气氛下SiO2的分解破坏了材料的结合体系,造成了材料致密度的降低和强度大幅下降,是除了炉体结构应力、热应力等因素外,导致干熄炉斜道区莫来石-红柱石砖破坏的不可忽略的因素。