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Cross-subcarrier precoder design for massive MIMO-OFdM downlink with symplectic optimization

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Science China(Information Sciences) 2025年

作者： Yu-Xuan ZHANG An-An LU Xiang-Gen XIA Xi-Qi GAO National Mobile Communications research Laboratory Southeast University Purple Mountain Laboratories department of Electrical and Computer Engineering University of Delaware

We propose a cross-subcarrier precoder design(CSPd) for massive multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFdM) downlink. This work aims to significantly improve the channel estimation and signal detection performance by enhancing the smoothness of the frequency domain effective channel. This is accomplished by designing a few vectors known as the transform domain precoding vectors(TdPVs), which are then transformed into the frequency domain to generate the precoders for a set of subcarriers. To combat the effect of channel aging, the TdPVs are optimized under imperfect channel state information(CSI). The optimal precoder structure is derived by maximizing an upper bound of the ergodic weighted sum-rate(WSr) and utilizing the a posteriori beam-based statistical channel model(BSCM). To avoid the large-dimensional matrix inversion, we propose an algorithm with symplectic optimization. Simulation results indicate that the proposed cross-subcarrier precoder design significantly outperforms conventional methods.

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Synthetic control of chiral pore surfaces in covalent organic frameworks for enantioselective separation of chiral drugs

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Science China Chemistry 2025年

作者： Shiguo Fu Xiaofeng Zhang Kaixuan Wang Linfeng Chen Fan Xia Yong Cui Yan Liu School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Faculty of Materials Science and Chemistry China University of Geosciences

Enantioselective separations of racemates using porous materials are highly attractive and significant in both fundamental research and technological applications. However, achieving controlled chiral pore surfaces to create the necessary driving force for enantiomer discrimination poses a fundamental challenge. Herein, we demonstrate that chiral covalent organic frameworks(COFs) possess the essential characteristics for effective enantioseparations through synthetic control over pore surfaces. We synthesized three 3d chiral COFs (CCOFs) featuring abundant chiral recognition sites on the pore walls via the condensation of enantiopure dialdehyde of 2,2′-dihydroxy-1,1′-binaphthyl and tetraamine. All CCOFs with high stability exhibit an 11-fold interpenetrated framework with tubular open channels, decorated with dihydroxyl or diethoxyl groups. The CCOFs with dihydroxyl groups serve as solid adsorbents for the adsorptive separation and solid-phase extraction of various chiral 1-phenylethanol-derived enantiomers, particularly racemic drugs, achieving up to 98%enantiomeric excess. In contrast, the CCOF with diethoxy groups is unable to resolve the racemates. These CCOF materials can be recycled and reused without any apparent loss of performance. density functional theory (dFT) calculations reveal that the enantiospecific recognition arises from the well-organized chiral inner sphere and multiple chiral host-guest interactions.

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design high-performance narrowband emitters for blue light-emitting diodes through manipulating resonance structure of aromatic heterocycles

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Science China Chemistry 2025年

作者： Yue Yu Lei Xu Wenle Tan Yuyu Pan Jiyin Xiao Bohan Wang Guangjun Tian Yuguang Ma Lei Ying Institute of Polymer Optoelectronic Materials and devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials State Key Laboratory of Luminescent Materials and Devices South China University of Technology School of Petrochemical Engineering Shenyang University of Technology Key Laboratory for Microstructural Material Physics of Hebei Province School of Science Yanshan University

Narrowband light-emitting materials play critical roles in improving the color gamut and energy consumption of electroluminescence. Herein we demonstrated that by regulating the ground state resonance structure form of emitters with polycyclic aromatic heterocycles, the high-energy vibration of the C–C bond can be effectively suppressed, resulting in narrow emission like classical cyanine dyes. The designed compounds consist of twist and planar conformation, while having differences in the orientation of the positioning electron-donating(nitrogen) and electron-accepting(carbonyl) groups in the polycyclic aromatic hydrocarbon skeleton. The resulting compound Ac-Ph-Ac with a dominated zwitterionic resonance structure exhibits a relatively wide electroluminescent profile with the full width at half maximum(FWHM) of 42 nm and moderate device performance. In contrast, the “soliton transition” of 2AcPh based on the cyanine limit character effectively suppresses C–C stretching vibration in the polycyclic aromatic heterocycle skeleton, leading to a narrow electroluminescent profile with FWHM of 30 nm(0.16 eV)associated with an impressively high external quantum efficiency of 28.52%, which is among the highest efficiencies of so far reported non-sensitized organic light-emitting diodes.

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Self-assembled carbon monoxide nanoprodrug for chemiexcitationtriggered synergistic chemotherapy against breast cancer

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Science China Chemistry 2025年

作者： Shunfei Cui Yiyao Pan Chenzhe Ma Bin Qi Qingqiang Min Ming Li Huabing Chen Hengte Ke Xingyue Ji Jiangsu Province Engineering research Center of Precision diagnostics and Therapeutics development College of Pharmaceutical ScienceSoochow University

Carbon monoxide（CO） has recently been well-established as a promising therapeutic modality against cancer. The development of transition-metal-free and tumor-targeted delivery platforms for CO is highly demanded but remains very sporadic. Herein, we developed a polyprodrug system for the co-delivery of CO and a chemotherapeutic agent combretastin A-4（CA-4） to the tumor site based on a chemiexcitation mechanism. Such a poly-prodrug successfully achieved the co-activation of CO and CA-4 in response to H2O2at the tumor site both in vitro and in vivo. Importantly, a synergist effect between CO and CA-4 was observed in suppressing tumor growth in a mouse tumor model. It is anticipated that such a poly-prodrug system could be potentially adapted for the co-delivery of CO and another drug payload for combinational therapy for other indications.

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Numerical Study on the Impact of Ground Heating and Ambient Wind Speed on Flow Fields in Street Canyons

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Advances in Atmospheric Sciences 2012年第6期29卷 1227-1237页

作者：李磊杨琳张立杰江崟 shenzhen National Climate Observatory Meteorological Bureau of Shenzhen Municipality shenzhen Meteorological Service Center Meteorological Bureau of Shenzhen Municipality

The impact of ground heating on flow fields in street canyons under different ambient wind speed conditions was studied based on numerical methods. A series of numerical tests were performed, and three factors including height-to-width （H/W） ratio, ambient wind speed and ground heating intensity were taken into account. Three types of street canyon with H/W ratios of 0.5, 1.0 and 2.0, respectively, were used in the simulation and seven speed values ranging from 0.0 to 3.0 m s-1 were set for the ambient wind speed. The ground heating intensity, which was defined as the difference b-ween the ground temperature and air temperature, ranged from 10 to 40 K with an increase of 10 K in the tests. The results showed that under calm conditions, ground heating could induce circulation with a wind speed of around 1.0 m s-i, which is enough to disperse pollutants in a street canyon. It was also found that an ambient wind speed threshold may exist for street canyons with a fixed H/W ratio. When ambient wind speed was lower than the threshold identified in this study, the impact of the thermal effect on the flow field was obvious, and there existed a multi-vortex flow pattern in the street canyon. When the ambient wind speed was higher than the threshold, the circulation pattern was basically determined by dynamic effects. The tests on the impact of heating intensity showed that a higher ground heating intensity could strengthen the vortical flow within the street canyon, which would help improve pollutant diffusion capability in street canyons.

关键词： street canyon thermal effect ambient wind ground heating intensity computational fluid dynamics (CFd)

review of Ultraviolet Non-Line-of-Sight Communication

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China Communications 2016年第6期13卷 63-75页

作者： renzhi Yuan Jianshe Ma shenzhen Graduate School of Tsinghua University Shenzhen 518055China

With rapid advances of solar blind ultraviolet LEd and ultraviolet detecting technology in recent years, ultraviolet communication gradually becomes a research hotspot due to its inherent advantages: low solar background noise, non-line-of-sight(NLOS) and good secrecy. The strong scattering characteristics in atmospheric render ultraviolet waveband the ideal choice for achieving NLOS optical communication. This paper reviews the research history and status of ultraviolet communication both in China and abroad, and especially introduces three main issues of ultraviolet communication: channel model, system analysis and design, light sources and detectors. For each aspect, current open issues and prospective research directions are analyzed.

关键词： ultraviolet communication non-line-of-sight scattering model

A NUMErICAL STUdY ON THE INFLUENCES OF UrBAN PLANNING ANd CONSTrUCTION ON THE SUMMEr UrBAN HEAT ISLANd IN THE METrOPOLIS OF shenzhen

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Journal of Tropical Meteorology 2011年第4期17卷 392-398页

作者：张小丽李磊杜雁江崟房小怡力梅陈元昭白玉洁 Meteorological Bureau of shenzhen Municipality Urban Planning & design Institute of shenzhen Beijing Municipal Climate Center Guangdong Meteorological Training Centre

By means of the regional boundary layer model (rBLM),a study on the influences of the urban planning and construction on the summer urban heat island (UHI) in the metropolis of shenzhen is *** the study,the current summer UHI distribution,the influences of the increasing high-density construction and the energy consumption on the summer air temperature distribution,and the influences of the urban ventilation corridor on the summer air temperature distribution are numerically *** conclusions are drawn in the light of the study:(1) The summer UHI is more obvious in day time than that in night time in the summer of shenzhen,and the maximum values of UHI intensity in the day time appear in the areas with high-density construction,which are located in Nanshan,Futian and Luohu and western Bao'an districts.(2) The increase of construction density and energy consumption in the urban area will lead to the increase of temperature near the ground,and the increase of temperature at nighttime is more obvious than that at daytime.(3) The ventilation corridor can effectively reduce the UHI intensity and can be taken as a method to eliminate the negative climatic effect caused by the increase of high-density construction and energy consumption in the future.

关键词： urban heat island numerical simulation shenzhen

Observations of intracellular second-harmonic generation imaging in black phosphorus nanosheets

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Journal of Innovative Optical Health Sciences 2021年第2期4卷 11-18页

作者： Xiao Peng Yiwan Song Zheng Peng Kaixuan Nie Hao Liu Yingxin Zhou Feifan Zhou Yufeng Yuan Jun Song Junle Qu Center for Biomedical Optics and Photonics(CBOP)&College of Physics and Optoelectronic Engineering Key Laboratory of Optoelectronic devices and Systems of Ministry of Education and Guangdong Province shenzhen University Shenzhen 518060P.R.China

Functionalized black phosphorus(BP)nanosheets have been considered as promising nanoagents in cancer therapy due to their excellent photothermal conversion ***,it is still difficult to visually monitor the dynamic localization of BP nanoagents in cancer *** this paper,we systematically studied the second-harmonic generation(SHG)signals originating from exfoliated BP ***,under the excitation of a high frequency pulsed laser at 950 nm,the SHG signals of BP nanosheets in vitro are almost undetectable because of their poor ***,the intracellular SHG signals from BP nanosheets could be measured by in vivo optical imaging due to the efficient enrichment of living HeLa ***,the SHG signal intensity from BP nanosheets increases with the prolonged incubation *** can be expected that the BP nanosheets could be a promising intracellular SHG nanoprobe employed for visually in vivo biomedical imaging in practical cancer photothermal therapy(PIT).

关键词： Second harmonic generation nanoprobe black phosphorus nanosheets in vivo im-aging HeLa cells visual monitoring

Over 12%efficient kesterite solar cell via back interface engineering

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Journal of Energy Chemistry 2022年第12期75卷 321-329,I0008页

作者： Yunhai Zhao Zixuan Yu Juguang Hu Zhuanghao Zheng Hongli Ma Kaiwen Sun Xiaojing Hao Guangxing Liang Ping Fan Xianghua Zhang Zhenghua Su shenzhen Key Laboratory of Advanced Thin Films and Applications Key Laboratory of Optoelectronic Devices and SystemsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060GuangdongChina CNrS ISCR(Institut des Sciences Chimiques de Rennes)UMR 6226Univ RennesRennes F-35000France School of Photovoltaic and renewable Energy Engineering UNSW SydneySydney NSW 2052Australia shenzhen University Institute of Microscale Optoelectronics Shenzhen UniversityShenzhen 518060GuangdongChina

Kesterite Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)has attracted considerable attention as a non-toxic and earthabundant solar cell *** selenization of CZTSSe film at high temperature,the reaction between CZTSSe and Mo is one of the main reasons that result in unfavorable absorber and interface quality,which leads to large open circuit voltage deficit(VOC-def)and low fill factor(FF).Herein,a WO_(3)intermediate layer introduced at the back interface can effectually inhibit the unfavorable interface reaction between absorber and back electrode in the preliminary selenization progress;thus high-quality crystals are *** this back interface engineering,the traditional problems of phase segregation,voids in the absorber and over thick Mo(S,Se)_(2)at the back interface can be well solved,which greatly lessens the recombination in the bulk and at the *** increased minority carrier diffusion length,decreased barrier height at back interface contact and reduced deep acceptor defects give rise to systematic improvement in VOCand FF,finally a 12.66%conversion efficiency for CZTSSe solar cell has been *** work provides a simple way to fabricate highly efficient solar cells and promotes a deeper understanding of the function of intermediate layer at back interface in kesterite-based solar cells.

关键词： Cu_(2)ZnSn(S Se)_(4) WO_(3)intermediate layer Crystal growth Minority carrier diffusion length Interface contact quality