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Thickness bound for nonlocal wide-field-of-view metalenses

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light(Science & Applications) 2022年第12期11卷 3018-3027页

作者： shiyu li Chia Wei Hsu Ming Hsieh Department of Electrical and Computer Engineering University of Southern CaliforniaLos AngelesCA 90089USA

Metalenses—flat lenses made with optical metasurfaces—promise to enable thinner,cheaper,and better imaging *** a sufficient angular field of view(FOV)is crucial toward that goal and requires a tailored incidentangle-dependent ***,we show that there is an intrinsic trade-off between achieving a desired broad-angle response and reducing the thickness of the *** the memory effect in disordered media,this thickness bound originates from the Fourier transform duality between space and *** can write down the transmission matrix describing the desired angle-dependent response,convert it to the spatial basis where its degree of nonlocality can be quantified through a lateral spreading,and determine the minimal device thickness based on such a required lateral *** approach is *** applied to wide-FOV lenses,it predicts the minimal thickness as a function of the FOV,lens diameter,and numerical *** bound is tight,as some inverse-designed multi-layer metasurfaces can approach the minimal thickness we *** work offers guidance for the design of nonlocal metasurfaces,proposes a new framework for establishing bounds,and reveals the relation between angular diversity and spatial footprint in multi-channel systems.

关键词： desired angular field

High-lattice-adapted surface modifying Na_(4)MnV(PO_(4))_(3) for better sodium storage

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Nano Research 2024年第4期17卷 2728-2735页

作者： Chongran Song shiyu li Ying Bai International Joint Research Laboratory of New Energy Materials and Devices of Henan Province School of Physics and ElectronicsAcademy for Advanced Interdisciplinary StudiesHenan UniversityKaifeng 475004China

Sodium-ion batteries(SIBs)are required to possess long cycle life when used for large-scale energy *** polyanionic Na_(4)MnV(PO_(4))_(3)(NMVP)reveals good cyclic stability due to its unique three-dimensional(3D)frame structure,but it still faces the challenge of interfacial degradation in practical *** this work,NASICON-type Na_(1.3)Al_(0.7)Ti_(1.3)(PO_(4))_(3)(NATP)was deposited on the surface of NMVP to promote interface stability by surface modification and gradient *** a result,the optimized NMVP@2%NATP released a capacity retention of 44.8%after 1000 cycles at 5 C,much higher than that of the initial NMVP(28.9%).The enhanced electrochemical performance was mainly attributed to NATP coating acting as a fast ion transport carrier and physical barrier,significantly facilitating the Na^(+)diffusion and isolating side reaction at the electrode/electrolyte *** the other hand,Ti_(4)^(+)and Al^(3+)cations from the NATP were partially doped inside the NMVP surface to boost the transport of Na^(+),and the perfect lattice matching of NVMP and NATP improved the interface and structural stability accompanying long *** work demonstrated the effectiveness of surface modification with high lattice match material and provided new perspectives for high energy density solid-state SIBs.

关键词： high-lattice-adapted cathode surface modification sodium-ion batteries

Process Optimization of Coke Oven Gas to Methanol Based on the Downgrade of By-Product Steam

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Transactions of Tianjin University 2019年第3期25卷 214-225页

作者： Qingjuan Zheng shiyu li School of Chemical Engineering and Technology Tianjin University

In the coke oven gas to methanol(CTM) process, boiling water(above 200 ℃) is generally used as the coolant in the methanol synthesis reactor, and thus, medium-pressure steam is generated as a by-product. In this paper, the influence of the coolant temperature on the CTM process is investigated from two aspects, which are the performance analyses of the reactor and the overall process and the energy integration of by-product steam. The results reveal that the coolant temperature plays a key role in the CTM process optimization. When the coolant temperature is reduced to 187 ℃, though low-pressure steam is generated, the techno-economic performance of the whole process is greatly improved: the energy/exergy efficiency is increased by 4-9%, energy cost is saved by 37.1%, income is increased by 5.4 M$/year, and the C02 emission is reduced by 21.3%.

关键词： Coke oven gas Methanol synthesis Process optimization Energy saving

Optimized Process and Design:Incomplete Combustion in FCC Regenerators to Produce CO

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China Petroleum Processing & Petrochemical Technology 2022年第4期24卷 64-75页

作者： Yi Cai li shiyu liu Zhiqiang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Ningxia Ruiyuan Petrochemical Co. LtdYinchuan 750004China

The catalyst regeneration process running under the partial oxidation mode in traditional fluid catalytic cracking(FCC)units needs a carbon monoxide(CO)boiler to burn the flue gas,resulting in a large volume of CO_(2) *** this study,the performance of a set of industrial serial-type FCC regenerators and the changes in flue gas composition were analyzed by establishing a model of the regenerators and the flue gas energy recovery *** the value of utilizing CO,based on the simulation,this paper proposes two schemes for maximizing CO content in the flue gas of *** two sets of optimal process operating parameters were obtained using a genetic *** with the original process,the CO contents of flue gas in the two optimized processes increased to 6.6%and 12.5%,CO_(2) emissions were reduced by 48.4%and 96.7%,and the costs of CO production were 0.57$/m^(3) and 0.84$/m^(3),respectively.

关键词： FCC regenerators rigorous process simulation CO production CO_(2)utilization

Mechanical strength and the degradation mechanism of metakaolin based geopolymer mixed with ordinary Portland cement and cured at high temperature and high relative humidity

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Chinese Journal of Chemical Engineering 2023年第8期60卷 118-130页

作者： Xia Miao Xiaofan Pang shiyu li Haoguang Wei Jianhao Yin Xiangming Kong State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing 100101China Sinopec Research Institute of Petroleum Engineering Co. LtdBeijing 100101China Department of Civil Engineering Tsinghua UniversityBeijing 100084China

Geopolymer is a new type of eco-friendly cementitious material, and its superior drying and high temperature resistance has been widely recognized. The service performance of geopolymer under 150 ℃ high-temperature hydrothermal conditions is still less discussed. In this paper, the mechanical strength of pure metakaolin system with low calcium content and metakaolin-cement system with high calcium content under hydrothermal and non-hydrothermal conditions were studied. The results show that under 150 ℃ hydrothermal conditions, the strength of pure metakaolin geopolymer sharply decreases by reduction rate of 81.8% compared to the sample under 150 ℃ drying conditions, while the strength of metakaolin-cement geopolymers is well retained with only a slight decrease of 14.4%. This is mainly because the predominantly hydration product sodium aluminosilicate(N-A-S-H) gel of pure metakaolin system undergoes the process of “dissociation–repolymerization–crystallization” under 150 ℃ hydrothermal conditions, resulting in the loss of cementation ability and obvious deterioration of mechanical strength. In the metakaolin-cement system, the high-calcium calcium silicate gel(C-A-S-H)gel maintains a stable structure, thereby maintaining the macroscopic strength of the material under the hydrothermal conditions.

关键词： Geopolymer Hydrothermal conditions Strength Degradation Crystallization Gels

Design and Optimization of Multiple Interconnected Utility Systems in An Integrated Refining and Petrochemical Complex

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China Petroleum Processing & Petrochemical Technology 2020年第4期22卷 126-136页

作者： Bai Haobo li shiyu Wang Xupeng liu Chang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350

In an integrated refining and petrochemical complex,a centralized utility system(CUS)is introduced to integrate the steam demands of production ***,two sub-utility systems(SUSs)located inside the alkene and refinery plants,respectively,can satisfy the shaft *** is difficult to determine the steam production of the CUS because the steam demands of the alkene and refinery plants also depend on the design and operation of the *** explore the complicated interaction between the CUS and SUSs,we proposed a mixed-integer nonlinear programming(MINLP)model for the design and optimization of multiple interconnected utility systems to minimize the total annualized cost(TAC).An extended superstructure was suggested to contain multiple inter-plant connected steam pipe alternatives between the CUS and SUSs.A more accurate model of the complex steam turbine was *** the proposed MINLP framework is applied to a new integrated refining and petrochemical *** scenarios are investigated in the case study to explore the effect of steam main temperatures on system configurations and operating *** optimizing the main temperatures,a TAC of$2.7 million can be *** from the results of the two scenarios,the feasibility and effectiveness of the proposed framework for the design and optimization of multiple interconnected utility systems have been demonstrated.

关键词： MINLP model multiple interconnected utility systems complex steam turbines steam main temperatures

Photosynthetic co-culture system of algae and human umbilical vein endothelial cells:The effect on alleviating hypoxia and hypoxia/reoxygenation injury

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Biosurface and Biotribology 2024年第2期10卷 76-88页

作者： Donghu lin Yuanyuan Chen Xinyu Tao Xin Che shiyu li shiyu Cheng Shuxin Qu Institute of Biomedical Engineering College of MedicineSouthwest Jiaotong UniversityChengduSichuanChina Key Laboratory of Advanced Technologies of Materials Ministry of Education School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuanChina School of life Science and Engineering Southwest Jiaotong UniversityChengduSichuanChina

It is a developed photosynthetic co-culture system to alleviate the hypoxia and hypoxia/reoxygenation(H/R)-injured human umbilical vein endothelial cells(HUVECs).The algae,Chlorella vulgaris,were encapsulated to slow their growth while not affecting the photosynthetic oxygen-producing capacity by Layer-by-layer(LbL)using gelatin and sodium alginate as the positive and negative charges materials,***,the photosynthetic co-culture system of HUVECs and self-oxygenating alginate hydrogel(Algae-gel)was constructed in which the optimal ratios between algae and HUVECs were 5:1 and 20:1 for a 2D or 3D co-cultured manner,*** indicated that the 3D cocultured manner of HUVECs needed more O_(2) by the production of algae than it did in a 2D co-cultured *** co-cultured Algae-gel could alleviate hypoxia and the oxidative stress injury of hypoxia and hypoxia/reoxygenation(H/R)-treated HUVECs in the proliferation,intracellular ROS and cellular migratory *** addition,the Algaegel could downregulate the expression of hypoxia-inducible factors 1α(HIF-1α)and vascular endothelial growth factor(VEGF)of hypoxia and H/R-injured HUVECs due to the improvement of hypoxia and H/R *** photosynthetic co-culture system could offer a promising approach for repairing hypoxia and H/R-injured cells or tissue by providing safe and stable O_(2).

关键词： biomaterials biomedical application bionic design regenerative medicine self-assembly tissue engineering

Hydroarylation of terminal alkynes with arylboronic acids catalyzed by low loadings of palladium

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Chinese Chemical Letters 2023年第2期34卷 165-169页

作者： Lei Xu shiyu li Qi Zhang Ning Deng Biao Zhang Huajian Xu School of Chemistry and Chemical Engineering School of Food and Biological EngineeringInstitute of Industry&Equipment TechnologyAnhui Province Key Laboratory of Advance Catalytic Materials and Reaction EngineeringHefei University of TechnologyHefei 230009China

The hydroarylation reaction of terminal alkynes with arylboronic acids catalyzed by low(400 ppm) loadings of palladium has been developed. The reaction is broad in scope and high-yielding, even on multigram scale. It is suitable for the synthesis of alkenes labeled with deuterium, and for the late-stage modification of bioactive molecules.

关键词： Hydroarylation Low loadings Terminal alkyne Deuterium-labeled Palladium

Dispersion-flattened Bragg photonic crystal fiber for large capacity optical communication system

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Frontiers of Optoelectronics 2009年第3期2卷 289-292页

作者： Wei CHEN shiyu li Peixiang LU Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology State Key Laboratory of Optical Communication Technologies and Networks Fiberhome Telecommunication Technologies Co.Ltd.

A novelty dispersion ultra-flattened Bragg photonic crystal fiber(PCF) has been fabricated in this paper. The fiber is composed of compound cores and periodical claddings with 11 coaxial rings. It has flattened dispersion of 8.5±1.3 ps·(nm·km)–1in the communication wavelength range of 1460–1625 nm. Its dispersion slope alters from – 0.0428 to 0.0392 ps·nm–2·km–1. The low attenuation of 0.52 d B/km and low bending loss of 0.09 d B at 1550 nm of the fiber are also achieved. The Bragg PCF has enormously potential application in the fields of dense wavelength division multiplexing systems because of its superior dispersion properties and easy splicing performances.

关键词： photonic crystal fiber (PCF) fabrication low dispersion communication optoelectronic devices