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Efficient conversion of benzene and syngas to toluene and xylene over ZnO-ZrO_(2)&H-ZSM-5 bifunctional catalysts

Chinese Journal of Chemical Engineering 2022年第5期35卷 203-210页

作者： Xiao Zhao Xuan Shi Zhongshun Chen Long Xu chengyi dai Yazhou Zhang Xinwen Guo Dongyuan Yang Xiaoxun Ma School of Chemical Engineering Northwest UniversityXi’an 710069China International Science&Technology Cooperation Base for Clean Utilization of Hydrocarbon Resources Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiNorthwest UniversityXi’an 710069China School of Chemical Engineering Dalian University of TechnologyDalian 116024China Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China Shanxi yanchang Petroleum(Group)Corp.LtdXi’an 710000China

A series of ZnO-ZrO_(2) solid solutions with different Zn contents were synthesized by the urea coprecipitation method,which were coupled with H-ZSM-5 zeolite to form bifunctional *** a new benzene alkylation reagent,syngas was used instead of methanol to realize the efficient conversion of syngas and benzene into toluene and xylene.A suitable ratio of ZnO-ZrO_(2) led to the significant improvement in the catalytic performance,and a suitable amount of acid helped to increase the selectivity of toluene/xylene and reduce the selectivity of the by-products ethylbenzene and C^(9+) *** highest benzene conversion of 89.2%and toluene/xylene selectivity of 88.7%were achieved over 10%ZnO-ZrO_(2)&H-ZSM-5(Si/Al=23)at a pressure of 3 MPa and a temperature of 450℃.In addition,the effect of the zeolite framework structure on product distribution was *** to the molecular dynamics of aromatic hydrocarbons,H-ZSM-5 zeolites comprise 10-membered-ring pores,which are beneficial to the activation of benzene;hence,the conversion of benzene is higher.H-ZSM-35 and HMOR zeolites exhibited small eight-membered-ring channels,which were not conducive to the passage of benzene;hence,the by-product ethylbenzene exhibits a higher *** distance between the active centers of the bifunctional catalysts was the main factor affecting the catalytic performance,and the powder mixing method was more conducive to the conversion of syngas and benzene.

关键词： ZnO-ZrO_(2) Bifunctional catalysts Aromatics Alkylation of benzene Syngas

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Fluoride-mediated nano-sized high-silica ZSM-5 as an ultrastable catalyst for methanol conversion to propylene

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Journal of Energy Chemistry 2018年第4期27卷 1225-1230页

作者： Junjie Li Min Liu Xinwen Guo chengyi dai Chunshan Song State Key Laboratory of Fine Chemicals PSU-DUT Joint Centre for Energy Research School of Chemical Engineering Dalian University of Technology Department of Energy and Mineral Engineering EMS Energy Institute PSU-DUT Joint Centre for Energy Research Pennsylvania State University

Fluoride mediated nano-sized ZSM-5 （ZSM-5-F） with a high Si/AI ratio of 181 was fabricated using a seed-induction method and evaluated the catalysis of the methanol to propylene （MTP） reaction. High propylene selectivity （45%） was similar to ZSM-5-OH synthesized via a hydroxide route. However, ZSM- 5-F showed much longer lifetime （305 h） compared with ZSM-5-OH （157 h） in spite of similar crystal size and aluminum content. Characterization by NH3-TPD. Py-IR, OH-IR, SEM, TG-DTA, XRD and 1H MAS NMR techniques indicated that the enhanced catalytic performance of ZSM-S-F is attributed to the fewer structural defects in the form of internal silanol groups and silanol nests.

关键词： Fluoride route Nano-sized High Si/Al Structural defects MTP

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Confined space synthesis of Ni(OH)_(2)-impregnated three-dimensional ordered mesoporous carbon as a high-performance supercapacitor electrode

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Carbon Resources Conversion 2022年第2期5卷 101-110页

作者： Huiyong Chen Xin Yang Wencheng Yang Siyu Zhang Xingrui Wang Baoyu Liu chengyi dai Jianbo Zhang Xiaoxun Ma School of Chemical Engineering Northwest UniversityXi’anShaanxi 710069China International Science&Technology Cooperation Base for Clean Utilization of Hydrocarbon Resources Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiNorthwest UniversityXi’anShaanxi 710069China School of Cultural Heritage Northwest UniversityXi’anShaanxi 710069China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhouGuangdong 510006China

Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted *** forms of high-crystalline nanosheet-like Ni(OH)_(2) severally distribute within mesopores or over the outer surface of 3DOMC particles depending on the loading amount(3%^(−1)5%)of Ni(OH)_(2).Benefitted from the highly hybrid combination and efficient electrolyte diffusion,the obtained Ni(OH)_(2)/carbon nanocomposites exhibit an excellent electrochemical performance,and the optimal sample of 6%_Ni(OH)_(2)/3DOMC with confined extrasmall Ni(OH)_(2) nanosheets as dominant shows the highest specific capacitance of 552.5F.g^(−1) at 1.0A⋅g^(−1),which is 330%higher than the contrast sample by using actived carbon as the ***,the assembled hybrid supercapacitor by using 6%_Ni(OH)_(2)/3DOMC and 3DOMC as positive and negative electrodes displays an energy density of 11.7 ***^(−1) at 288.1 ***^(−1) and a superior charge/discharge *** is expected that the flexible component,well-defined structure,and superior electrochemical performance could promote a great application potential of Ni(OH)_(2)/3DOMC nanocomposites as supercapacitor electrodes and in other energy storage devices.

关键词： Composite electrodes Mesoporous carbon Ni(OH)_(2) Confined space synthesis Supercapacitors

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Spatial Heterogeneity of Embedded Water Consumption from the Perspective of Virtual Water Surplus and Deficit in the Yellow River Basin,China

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Chinese Geographical Science 2024年第2期34卷 311-326页

作者： MA Weijing LI Xiangjie KOU Jingwen LI chengyi College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China School of Economics and Management Ningxia UniversityYinchuan 750021China

Virtual water trade(VWT)provides a new perspective for alleviating water crisis and has thus attracted widespread ***,the heterogeneity of virtual water trade inside and outside the river basin and its influencing factors remains further *** this study,for better investigating the pattern and heterogeneity of virtual water trade inside and outside provincial regions along the Yellow River Basin in 2015 using the input-output model(MRIO),we proposed two new concepts,i.e.,virtual water surplus and virtual water deficit,and then used the Logarithmic Mean Divisia Index(LMDI)model to identify the inherent mechanism of the imbalance of virtual water trade between provincial regions along the Yellow River Basin and the other four regions in *** results show that:1)in provincial regions along the Yellow River Basin,the less developed the economy was,the larger the contribution of the agricultural sector in virtual water trade,while the smaller the contribution of the industrial sector.2)Due to the large output of agricultural products,the upstream and midstream provincial regions of the Yellow River Basin had a virtual water surplus,with a net outflow of virtual water of 2.7×10^(8) m^(3) and 0.9×10^(8) m^(3),respectively.3)provincial regions along the Yellow River Basin were in a virtual water deficit with the rest of China,and the decisive factor was the active degree of trade with the *** study would be beneficial to illuminate the trade-related water use issues in provincial regions along the Yellow River Basin,which has farreaching practical signific-ance for alleviating water scarcity.

关键词： virtual water trade(VWT) input-output model(MRIO) virtual water surplus virtual water deficit Yellow River Basin,China

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A ratiometric fluorescent probe for hypoxanthine detection in aquatic products based on the enzyme mimics and fluorescence of cobalt-doped carbon nitride

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Food Science and Human Wellness 2024年第2期13卷 879-884页

作者： Xin Wang chengyi Hong Zhengzhong Lin Zhiyong Huang College of Ocean Food and Biological Engineering Jimei UniversityXiamen 361021China

A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 *** the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by *** result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.

关键词： Co doped g-C_(3)N_(4) Ratiometric fluorescent probe Hypoxanthine Freshness Aquatic products

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Controlled direct synthesis of single-to multiple-layer MWW zeolite

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National Science Review 2021年第7期8卷 167-174页

作者： Jie-Qiong Chen Yu-Zhao Li Qing-Qing Hao Huiyong Chen Zhao-Tie Liu chengyi dai Jianbo Zhang Xiaoxun Ma Zhong-Wen Liu School of Chemical Engineering Northwest University Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei Energy International Science & Technology Cooperation Base of MOST for Clean Utilization of Hydrocarbon Resources Key Laboratory of Syngas Conversion of Shaanxi Province School of Chemistry & Chemical Engineering Shaanxi Normal University

The minimized diffusion limitation and completely exposed strong acid sites of the ultrathin zeolites make it an industrially important catalyst especially for converting bulky molecules. However, the structure-controlled and large-scale synthesis of the material is still a challenge. In this work, the direct synthesis of the single-layer MWW zeolite was demonstrated by using hexamethyleneimine and amphiphilic organosilane as structure-directing agents. Characterization results confirmed the formation of the single-layer MWW zeolite with high crystallinity and excellent thermal/hydrothermal stability. The formation mechanism was rigorously revealed as the balanced rates between the nucleation/growth of the MWW nanocrystals and the incorporation of the organosilane into the MWW unit cell, which is further supported by the formation of MWW nanosheets with tunable thickness via simply changing synthesis conditions. The commercially available reagents, well-controlled structure and the high catalytic stability for the alkylation of benzene with 1-dodecene make it an industrially important catalyst.

关键词： MWW 2D zeolite zeolite nanosheets amphiphilic organosilane alkylation

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Seismic performance evaluation of water supply pipes installed in a full-scale RC frame structure based on a shaking table test

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 163-178页

作者： Wu Houli Guo Endong Wang Jingyi dai Xin dai Chenxi Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

As an important part of nonstructural components,the seismic response of indoor water supply pipes deserves much *** paper presents shaking table test research on water supply pipes installed in a full-scale reinforced concrete(RC)frame *** material pipes and different methods for penetrating the reinforced concrete floors are combined to evaluate the difference in seismic *** response spectra and pipe acceleration amplification factors based on test data are discussed and compared with code provisions.A seismic fragility study of displacement demand is conducted based on numerical *** acceleration response and displacement response of different combinations are *** results show that the combination of different pipe materials and different passing-through methods can cause obvious differences in the seismic response of indoor riser pipes.

关键词： water supply pipe different materials shaking table test amplification factor seismic fragility

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Near-field wideband beam training for ELAA with uniform circular array

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Science China(Information Sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong dai Department of Electronic Engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

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Biohythane production from two-stage anaerobic digestion of food waste:A review

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Journal of Environmental Sciences 2024年第5期139卷 334-349页

作者： Xiaona An Ying Xu Xiaohu dai State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

The biotransformation of food waste(FW)to bioenergy has attracted considerable research attention as a means to address the energy crisis and waste disposal *** this end,a promising technique is two-stage anaerobic digestion(TSAD),in which the FW is transformed to biohythane,a gaseous mixture of biomethane and *** review summarises the main characteristics of FW and describes the basic principle of ***,the factors influencing the TSAD performance are identified,and an overview of the research status;economic aspects;and strategies such as pre-treatment,co-digestion,and regulation of microbial consortia to increase the biohythane yield from TSAD is ***,the challenges and future considerations associated with the treatment of FW by TSAD are *** paper can provide valuable reference for the improvement and widespread implementation of TSAD-based FW treatment.

关键词： Two-stage anaerobic digestion(TSAD) Food waste(FW) Methane production Hydrogen production

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State of the art of lightweight aggregates used in lightweight refractories for working lining of high-temperature furnaces

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1320-1343页

作者： Wei Zhang Wen-yong dai Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina Research and Development Department AGC Plibrico(Dalian)Industries Inc.Dalian 116600LiaoningChina

Lightweight refractories for the working lining of high-temperature furnaces play an important role in the smelting of advanced steels and *** prepare lightweight refractories for the working lining of high-temperature furnaces,the synthesis of lightweight aggregates is the ***,the research on the synthesis of lightweight aggregates with high service temperature,low thermal conductivity,high strength,and good slag resistance has received widespread *** available literature on the synthesis of lightweight aggregates was summarized,including corundum,mullite,mullite-corundum,spinel,corundum-spinel,cordierite,cordierite-mullite,calcium hexaluminate,corundum-calcium hexaluminate,bauxite,magnesia,magnesia-based,and forsterite-based ***,the future development trend of lightweight aggregates was proposed.

关键词： Lightweight aggregate Lightweight refractory Working lining Apparent porosity Closed porosity Thermal conductivity Pore-forming approach

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