Research progress and the prospect of CO2 hydrogenation with dielectric barrier discharge plasma technology

Zhang Ziyi,Ding Honglei,Zhou Qi,Pan Weiguo,Qiu Kaina,Mu Xiaotian,Ma Junchi,Zhang Kai,Zhao Yuetong 한국탄소학회 2023 Carbon Letters Vol.33 No.4

In recent years, people are increasingly interested in CO2 hydrogenation to produce value-added chemicals and fuels (CH4, CH3OH, etc.). In the quest for an efficient treatment in CO2 methanation and methanolization, several technologies have been practiced, and DBD plasma technology gain attention due to its easily handling, mild operating conditions, strong activation ability, and high product selectivity. In addition, its reaction mechanism and the effect of packing materials and reaction parameters are still controversial. To address these problems efficiently, a summary of the reaction mechanism is presented. A discussion on plasma-catalyzed CO2 hydrogenation including packing materials, reaction parameters, and optimizing methods is addressed. In this review, the overall status and recent findings in DBD plasma-catalyzed CO2 hydrogenation are presented, and the possible directions of future development are discussed.

An Economic Elucidation of the Antidumping Issue

Zhang Shujuan,ang Xiaotian 조선대학교 지식경영연구원 2005 지역개발연구 Vol.10 No.1

The paper constructs simple models to analyze the players' actions and motivations in the antidumping issue. On the basis of it the study goes deep into the characteristics of foreign antidumping against China and their causes and draws some important conclusions. Not only is there defects in the conventional definition of dumping but also the definition of dumping in Antidumping Agreement of WTO is necessary to be improved. We must tune up the drawback policy of exported goods lest it should become the backing exporters' malign competition and the excuse of foreign antidumping. The same antidumping tax on our exporters enormously cools down their enthusiasm. The main cause of the characteristics of foreign antidumping against China lies in Foreign Discrimination against China, especially Non-Market Economy Country.

Experimental Investigation on the Properties of Sustainable Pervious Concrete with Different Aggregate Gradation

Junyu Zhang,Haoran Sun,Xiaotian Shui,Wenxuan Chen 한국콘크리트학회 2024 International Journal of Concrete Structures and M Vol.18 No.2

Pervious concrete (PC) as a green infrastructure material has been increasingly used due to its positive environmental impacts, such as controlling storm water runoff, removing water pollutants and reducing heat island effect. The aggregate gradation is a critical factor influencing the physical properties of PC. Therefore, this paper represents an attempt to determine the effects of aggregate gradation on the various physical properties of PC, and then to explore relationships between them. To this end, three aggregate gradations 4.75–9.5 mm, 9.5–19 mm and 19–31.5 mm were recombined with various proportions (20–80%) to obtain five different gradations named as A, B, C, D and E. PC mixtures were prepared with these five aggregate gradations. Then, physical and mechanical properties of PC including porosity, permeability, compressive strength and water stability were investigated, according to the available specification. The results suggested that it was feasible to use waste concrete for permeable pavement, because all the specimens provided required specification requirements. Different linear relationships were also found between the maximum aggregate size and porosity, permeability coefficient, compressive strength and its loss rate. That is, porosity and permeability increased with the proportion of larger size aggregate increased, however, compressive strength reduced. Thus the compressive strength had an inverse correlation with the porosity and water permeability. Among five different aggregate gradations, group C (20% of 4.75–9.5 mm aggregate, 50% of 9.5–19 mm aggregate and 30% of 19–31.5 mm aggregate) can be seen as the optimum gradation and is suitable for base layer materials of permeable pavements.

Oxytocin-induced endothelial nitric oxide dependent vasorelaxation and ERK1/2-mediated vasoconstriction in the rat aorta

Xu, Qian,Zhuo, Kunping,Zhang, Xiaotian,Zhang, Yaoxia,Xue, Jiaojiao,Zhou, Ming-Sheng The Korean Society of Pharmacology 2022 The Korean Journal of Physiology & Pharmacology Vol.26 No.4

Oxytocin is a neuropeptide produced primarily in the hypothalamus and plays an important role in the regulation of mammalian birth and lactation. It has been shown that oxytocin has important cardiovascular protective effects. Here we investigated the effects of oxytocin on vascular reactivity and underlying the mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and in rat aorta ex vivo. Oxytocin increased phospho-eNOS (Ser 1177) and phospho-Akt (Ser 473) expression in HUVECs in vitro and the aorta of rat ex vivo. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), inhibited oxytocin-induced Akt and eNOS phosphorylation. In the rat aortic rings, oxytocin induced a biphasic vascular reactivity: oxytocin at low dose (10^-9-10^-8 M) initiated a vasorelaxation followed by a vasoconstriction at high dose (10^-7 M). L-NAME (a nitric oxide synthase inhibitor), endothelium removal or wortmannin abolished oxytocin-induced vasorelaxation, and slightly enhanced oxytocin-induced vasoconstriction. Atosiban, an oxytocin/vasopressin 1a receptor inhibitor, totally blocked oxytocin-induced relaxation and vasoconstriction. PD98059 (ERK1/2 inhibitor) partially inhibited oxytocin-induced vasoconstriction. Oxytocin also increased aortic phospho-ERK1/2 expression, which was reduced by either atosiban or PD98059, suggesting that oxytocin-induced vasoconstriction was partially mediated by oxytocin/V1aR activation of ERK1/2. The present study demonstrates that oxytocin can activate different signaling pathways to cause vasorelaxation or vasoconstriction. Oxytocin stimulation of PI3K/eNOS-derived nitric oxide may participate in maintenance of cardiovascular homeostasis, and different vascular reactivities to low or high dose of oxytocin suggest that oxytocin may have different regulatory effects on vascular tone under physiological or pathophysiological conditions.

Spatio-Temporal Saliency Fusion Based Small Infrared Moving Target Detection Under Sea-Sky Background

Li Shaoyi,Wang Xiaotian,Zhang Kai,Niu Saisai,Zou Yijun 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

Small infrared moving target detection has an important role in the sea-based infrared search and tracking, maritime area surveillance and other applications. This method aims to detect the small infrared moving targets with the sea-sky background. The present study proposes a detection algorithm for small infrared targets based on the spatio-temporal saliency fusion. The contourlet analysis and edge extraction are carried out in the concurrent design. In order to effectively suppress the background and improve the target signal-clutter ratio, the spectral residual method is combined with the abovementioned methods to reconstruct the target fusion saliency image. Then the target motion region is estimated based on the optical flow method for the fusion saliency image and it is matched with the target area of interest to achieve the moving target detection. Moreover, the pipeline filtering is introduced to achieve the target confirmation by multi-frame judgment, reduce false alarm rate and complete the moving target detection for the infrared image sequence. Experimental results show that the proposed algorithm can achieve continuous target detection and have a higher detection precision via real long wave infrared image sequences.

Does Foreign Bank Entry Make Chinese Banks Stronger?

Yingkai Yin,Yahua Zhang,Xiaotian Tina Zhang,Fang Hu 연세대학교 동서문제연구원 2015 Global economic review Vol.44 No.3

China has encouraged its domestic banks to introduce foreign investment since the early 2000s. In the meantime, China has gradually fulfilled its World Trade Organisation (WTO) accession commitment to give foreign banks the same treatment as their Chinese counterparts in the last decade. This research has examined the effects of the two modes of foreign bank entry, namely, minority ownership participation, and setting up branches and subsidiaries, on the performance of Chinese banks. Our results suggest that there is no systematically significant impact of the minority ownership participation on the performance indicators of Chinese banks. However, it appears that the physical presence of foreign banks has been a significant driver for domestic banks to improve profitability and efficiency. Opening the country to foreign banks appears to have made Chinese banks stronger and more competitive.

Research on vibration of ceramic motorized spindle influenced by interference and thermal displacement

Zinan Wang,Ke Zhang,Zhan Wang,Xiaotian Bai,Qingyuan Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

The vibration of ceramic motorized spindle determines the machining quality of CNC machine tools. The dynamic characteristics of a motorized spindle were explored under the influence of interference fit and thermal displacement. Using heat transfer theory and bearing Harris theory, the temperature field model of motorized spindle was established, which aims to find the relationship of thermal displacement and interference. In addition, the dynamic and thermal factors were coupled to the dynamic model of the ceramic motorized spindle rotor system, of which the variation rules of bearing stiffness and rotor vibration characteristics were calculated and analyzed. The accuracy of the motorized spindle rotor system dynamic model was verified by experiments. The results show that the interference fit of shaft and bearing decreases with the rotating speed increase under the combined influence of centrifugal force, load and thermal displacement. The vibration was calculated by the dynamic model of motorized spindle rotor system considering dynamic and thermal factors. The maximum error was 3.9 %, which is well consistent with the experimental results. The dynamic characteristics of ceramic motorized spindle can be improved by appropriately increasing the degree of interference tightness at high speed.

A Study of Leveraging Memory Level Parallelism for DRAM System on Multi-Core Architecture

Yuxuan Wang,Yingping Zhang,Xiaotian Zhang,Jian Yin,Licheng Chen 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.4

DRAM system has been more and more critical on modern multi-core architecture where the Moore’s law has been made effect on increasing the number of cores integrated in a processor chip. The performance of DRAM system is usually measured in term of bandwidth and latency, which are regarded as inherently depending on Row Buffer Hit Rate (RBHR) according to previous studies. In this paper, we find that Memory Level Parallelism (MLP) exhibits a stronger correlation with the performance of DRAM system on multi-core/many-core architecture than RBHR, and promoting MLP significantly improves DRAM system performance. In order to exploit the MLP, we have evaluated various approaches including multi-bank, multi-row-buffers, multi-memory-controllers and the obsolete Virtual Channel Memory (VCM). The experimental results show that VCM is a better alternative to traditional DRAM chip on multicore/many-core architecture than the other three approaches because VCM has almost all the advantages of the others: 1) it can improve homogeneous workloads’ IPC by 2.21X on a 16-core system with 32 virtual channels due to leveraging unexploited MLP. 2) It can also promote Quality-of-Service (QoS) of DRAM system by removing unfairness while memory controllers serve memory requests. 3) It can save energy and has low area costs. Unfortunately, VCM, which was proposed in the late 1990s, faded away before multi-core/manycore became dominated. Therefore, we suggest memory chip vendors reconsider the VCM technology for multi-core architecture.

Differential Evolution Algorithm for Constraint Joint Replenishment Problem with Indirect Grouping Strategy

Li Chengyan,Gao Jun,Zhang Tianwei,Wang Xiaotian 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.5

The joint replenishment problem with deterministic resource restriction is considered. We present a differential evolution (DE) algorithm that uses indirect grouping strategy to solve constrained joint replenishment. The procedure and structure of the DE algorithm is proposed. Extensive computational experiments are performed to compare the performances of the DE algorithm with results of genetic algorithm (GA) and heuristic algorithm CRAND. The experimental results indicate that the DE algorithm performs relative to CRAND and superior to GA.

A Flattop Radiation Pattern Antenna with Special‑Shaped Array Placement for Stadium Communications

Bing Ma,Tao Zhang,Wenjun Gao,Xiaotian Wang,Zhijia Liu 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

A fattop radiation pattern antenna with special-shaped array placement for large-scale stadium communications is presented in this paper. The antenna array consists of only 16 electric dipoles, each of that is±45° linear polarizations, placed in three rings confguration above a ground plane. Under the ground plane two feeding networks with±45° linear polarizations, respectively are used to divide signals to the 16 electric dipoles to produce fattop radiation patterns. A prototype operated at 2300–2700 MHz for stadium wireless communications, such as 4G LTE, is manufactured and tested, and good agreements between simulation and measurement are demonstrated. The measured gain is above 12 dBi and the side-lobe levels are lower than −20 dB. The measured isolations between the two polarization ports are less than −30 dB within the operating band. A fast beam ramp of less than 20° from −3 to −20 dB is achieved.