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328 results on '"Zhang, Qiyang"'

105. Molecularly Defined Approach for Preparation of Ultrasmall Pt-Sn Species for Efficient Dehydrogenation of Propane to Propene

Author

Kondratenko, Evgenii, primary, Li, Yuming, additional, Ma, Yingjie, additional, Zhang, Qiyang, additional, Kondratenko, Vita A., additional, Jiang, Guiling, additional, Sun, Huaqian, additional, Han, Shanlei, additional, Wang, Yajun, additional, Cui, Guoqing, additional, Zhou, Mingxia, additional, Huan, Qing, additional, Zhao, Zhen, additional, Xu, Chunming, additional, and Jiang, Guiyuan, additional

Published
2022
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117. Preparation of water polyacrylate coated trademark fabrics and its inkjet printing performance.

Author

Wang, Chenglong, Meng, Fan, Zhang, Qiyang, Zhu, Qing, Li, Hongyan, and Zheng, Jinhuan

Subjects
COATED textiles, TWO-dimensional bar codes, KAOLIN, EPSON printers, COATING processes, DIGITAL printing, NATURAL dyes & dyeing, ACRYLIC acid
Abstract

Trademark fabric was prepared with the water polyacrylate as a coating agent and a compound of kaolin and CaCO3 as filler to study the fabric's digital inkjet printing performance. Results showed that a 7:5 ratio of kaolin and CaCO3 in the fabric produced uneven pores; the best ink absorption, quick-drying performance and the best printing sharpness and the highest colourfastness to crocking. The coating slurry included 100 g water, 25 g EC-507 modified styrene acrylic emulsion, 75 g compound filler (kaolin and CaCO3 according to mass ratio 7:5), 1.5 g dispersant and 0.375 g crosslinking agent. The optimised coating process was a baking temperature of 150 °C and a baking time of 90 s. The fabric was printed upon using an Epson label printer, producing a printing pattern with good printing sharpness (e.g. lines had no bleeding phenomenon, text and patterns were clear, colours were better and printed two-dimensional codes were scannable). [ABSTRACT FROM AUTHOR]

Published
2022
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121. Effect of AlSiOxsupport modification by alkali or alkaline earth metals on propene formation in the metathesis of C2H4and 2-C4H8over MoOx-based catalystsElectronic supplementary information (ESI) available: Characterization and catalytic data. See DOI: https://doi.org/10.1039/d2cy01666d

Author

Zhang, Qiyang, Rabeah, Jabor, Vuong, Thanh Huyen, Otroshchenko, Tatiana, and Kondratenko, Evgenii V.

Abstract

The metathesis of ethylene with 2-butene to propene is currently applied for large-scale on-purpose production of this building block of the chemical industry. MoOx-based supported catalysts are promising alternatives to the industrially applied WOx-containing systems. The activity of such catalysts depends on the amount of active Mo–carbene (MoCHR) sites formed in situupon reaction of supported MoOxspecies with olefins. Herein, we demonstrate a way to control the ability of such species on the surface of AlSiOxto be transformed into Mo–carbenes by promoting the support with tiny amounts of alkali or alkaline earth metal (Li, Sr, Ca, Mg, Na, K, Ba, Rb, or Cs) oxides. The electrophilic properties of these additives were established to be relevant for in situtransformation of supported MoOxspecies into Mo–carbenes. The additive electronegativity (Pauling scale) affects olefin adsorption and therefore the formation of carbenes.

Published
2023
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123. Room-Temperature Metathesis of Ethylene with 2-Butene to Propene Over MoOx-Based Catalysts: Mixed Oxides as Perspective Support Materials.

Author

Otroshchenko, Tatiana, Zhang, Qiyang, and Kondratenko, Evgenii V.

Subjects
*MIXED oxide catalysts, *PROPENE, *METALLOCENE catalysts, *RUTHENIUM catalysts, *ETHYLENE, *CRYSTAL defects, *METATHESIS reactions
Abstract

We investigated the effect of supports based on ZrO2, TiO2, Al2O3, and SiO2 on the rate of propene formation in the metathesis of ethylene with 2-butene at 50 °C over Mo-containing catalysts possessing highly dispersed MoOx. Large improvements in this rate were achieved when using supports composed of mixed oxides (ZrO2–SiO2, ZrO2–PO4, TiO2–SiO2; Al2O3–SiO2) rather than of individual oxides (ZrO2, TiO2, Al2O3, SiO2). Although previous literature studies dealing with the metathesis reaction over Al2O3- or SiO2-suppported catalysts at higher temperatures suggest the importance of redox or acidic properties of supported MoOx species for catalyst activity, we were not able to establish any general direct correlation in this regard. Contrarily, the rate of propene formation can be significantly enhanced when promoting supports with an oxide promoter. We suggest that the created support lattice defects may facilitate the transformation of MoOx to Mo carbenes under reaction conditions or improve the intrinsic activity of the latter. [ABSTRACT FROM AUTHOR]

Published
2022
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127. LCPR-Net: low-count PET image reconstruction using the domain transform and cycle-consistent generative adversarial networks

Author

Xue, Hengzhi, primary, Zhang, Qiyang, additional, Zou, Sijuan, additional, Zhang, Weiguang, additional, Zhou, Chao, additional, Tie, Changjun, additional, Wan, Qian, additional, Teng, Yueyang, additional, Li, Yongchang, additional, Liang, Dong, additional, Liu, Xin, additional, Yang, Yongfeng, additional, Zheng, Hairong, additional, Zhu, Xiaohua, additional, and Hu, Zhanli, additional

Published
2021
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136. Evaluation of reconstruction algorithms for a stationary digital breast tomosynthesis system using a carbon nanotube X-ray source array

Author

Hu, Zhanli, primary, Chen, Zixiang, additional, Zhou, Chao, additional, Hong, Xuda, additional, Chen, Jianwei, additional, Zhang, Qiyang, additional, Jiang, Changhui, additional, Ge, Yongshuai, additional, Yang, Yongfeng, additional, Liu, Xin, additional, Zheng, Hairong, additional, Li, Zhicheng, additional, and Liang, Dong, additional

Published
2020
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147. Wasserstein generative adversarial networks for motion artifact removal in dental CT imaging

Author

Yongshuai Ge, Yang Yongfeng, Changhui Jiang, Zheng Hairong, Hu Zhanli, Zhang Qiyang, Liang Dong, and Liu Xin

Subjects
Artifact (error), Scanner, Mean squared error, Artificial neural network, Image quality, business.industry, Computer science, Deep learning, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Upsampling, Data acquisition, Computer vision, Artificial intelligence, business
Abstract

In dental computed tomography (CT) scanning, high-quality images are crucial for oral disease diagnosis and treatment. However, many artifacts, such as metal artifacts, downsampling artifacts and motion artifacts, can degrade the image quality in practice. The main purpose of this article is to reduce motion artifacts. Motion artifacts are caused by the movement of patients during data acquisition during the dental CT scanning process. To remove motion artifacts, the goal of this study was to develop a dental CT motion artifact-correction algorithm based on a deep learning approach. We used dental CT data with motion artifacts reconstructed by conventional filtered back-projection (FBP) as inputs to a deep neural network and used the corresponding high-quality CT data as labeled data during training. We proposed training a generative adversarial network (GAN) with Wasserstein distance and mean squared error (MSE) loss to remove motion artifacts and to obtain high-quality CT dental images. In our network, to improve the generator structure, the generator used a cascaded CNN-Net style network with residual blocks. To the best of our knowledge, this work describes the first deep learning architecture method used with a commercial cone-beam dental CT scanner. We compared the performance of a general GAN and the m-WGAN. The experimental results confirmed that the proposed algorithm effectively removes motion artifacts from dental CT scans. The proposed m-WGAN method resulted in a higher peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) and a lower root-mean-squared error (RMSE) than the general GAN method.

Published
2019

148. Stationary Digital Breast Tomosynthesis System that Uses a Carbon Nanotube X-ray Source Array: a Feasibility Study

Author

Dong Liang, Jiang Changhui, Shi Wei, Jun Li, Hong Xuda, Zhang Qiyang, Yang Yongfeng, Xin Liu, Hairong Zheng, Hu Zhanli, and Yongshuai Ge

Subjects
medicine.diagnostic_test, Image quality, business.industry, Computer science, Detector, Response time, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, 030220 oncology & carcinogenesis, Miniaturization, medicine, Mammography, Computer vision, Tomography, Artificial intelligence, Projection (set theory), business, Image resolution
Abstract

Breast cancer is the most common type of cancer in women. Mammography has been a good method of performing early screening to detect breast cancer. An alternative technique, digital breast tomosynthesis (DBT), which is based on limited-angle tomography, solves the overlapping problem associated with mammography but also has limitations. To decrease the limitations of motion artifacts and poor reconstructed image quality that are imposed by the use of a rotating anode with a single X-ray source in conventional DBT, we have developed and demonstrated a stationary DBT (s-DBT) system that uses a carbon nanotube (CNT) X-ray source array. This arc array consists of 9 X-ray-generating focal spots distributed across a 38.7° angle. Compared with a traditional thermal emission X-ray source, a CNT X-ray source has several desirable attributes, such as miniaturization, fast response time, efficient focusing and improved control of emitted electrons; as a result, the tested system can acquire projection images by electronically switching individual X-ray sources on and off conveniently without mechanical motion of either the X-ray source or the detector, leading to improved spatial resolution of acquired images and reduced radiation doses. The tested system was developed in an attempt to find a feasible method to avoid adverse effects and improve image quality relative to conventional DBT systems, and the results reconstructed using a modified form of FDK algorithm indicate the achievement of this objective.

Published
2018

149. 基于配准修复的双目显微相位恢复

Author

程鸿 Cheng Hong, 张齐杨 Zhang Qiyang, 沈川 Shen Chuan, 王丽 Wang Li, and 向昕宇 Xiang Xinyu

Subjects
Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials
Published
2021

150. Fundamentals and application potential of the synergy effect between ZnO and Mo/SiO2for propene production in the metathesis of ethylene and trans-2-buteneElectronic supplementary information (ESI) available: Characterization and catalytic data. See DOI: https://doi.org/10.1039/d2cy00895e

Author

Zhang, Qiyang, Otroshchenko, Tatiana, and Kondratenko, Evgenii V.

Abstract

The metathesis of ethylene with 2-butene to propene is a 100%-carbon-efficient process for on-purpose production of this important building block in the chemical industry. Herein, we demonstrate that the activity of Mo/SiO2can be increased up to 270-fold when using ZnO as a cocatalyst, which is inert for the target reaction. An intimate physical contact between ZnO and Mo/SiO2is required to efficiently use the enhancing effect of the cocatalyst. H/D isotopic exchange tests with 2-C4H8and 2-C4D8suggest that the enhancing effect depends on the ability of ZnO to activate 2-butene. A gas-phase promoter (not 1-butene but probably butene radical) formed in this reaction is suggested to contribute to the formation of catalytically active Mo–carbenes under reaction conditions and/or hinder their transformation into inactive ones. This fundamental knowledge opens the possibility for further improvements through catalyst or cocatalyst design and reactor operation. The obtained results are also attractive from a practical point of view. Both ZnO and Mo/SiO2can be regenerated without changing their initial performance as proven in several metathesis/regeneration cycles.

Published
2022
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