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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年第2期68卷 216-229页

作者： Yuxuan ZHANG An-An LU Xiang-Gen XIA Xiqi 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.

关键词： massive MIMO-OFDM cross subcarrier precoder design transform domain precoding vectors effective channel symplectic optimization

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Strategies for efficient enrichment of anaerobic ammonia oxidizing bacteria in activated sludge

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Journal of Environmental Sciences 2025年第5期151卷 703-713页

作者： Bin Tang Jin Wang xingdong gao Zhihua Li Key Laboratory of Northwest Water Resource Environmentand EcologyMOESchool of Environmental and Municipal EngineeringXi’an University of Architecture and TechnologyXi’an 710055China Xi’an Key Laboratory of Intelligent Equipment Technology for Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China

Anaerobic ammonia oxidation(Anammox)is an economical and sustainablewastewater nitrogen removal technology,and its application in the mainstream process is the inevitable trend of the development of ***,how to effectively enriching Anammox bacteria from the activated sludge remains challenging and restricts its extensive *** this study,the rapid and efficient enrichment of Anammox bacteriawas achieved by raising the reflux ratio and nitrogen loading rate(NLR)using conventional activated sludge as the *** the screening phase(days 1–90),the reflux ratio was increased to discharge partial floc sludge,resulting in the relative abundance of Candidatus Brocadiaceae increased from0.04%to 22.54%,which effectively reduced thematrix and spatial competition between other microorganisms and Anammox *** day 90,the stoichiometric ratio of the Anammox process closely approached the theoretical value of 1:1.32:0.26,indicating that the Anammox reaction was the primary nitrogen removal process in the *** the enrichment phase(days 91–238),the NLR increased from 0.43 to 1.20 kgN/(m^(3)·d)and removal efficiency was 71.89%,resulting in the relative abundance of Candidatus Brocadiaceae increased to 61.27%on day *** reactor operated steadily from days 444 to 498,maintaining the nitrogen removal rate(NRR)of 3.00 kgN/(m^(3)·d)and achieving successful sludge granulation with the particle size of 392.4μ*** short,this study provided a simple and efficient approach for enriching Anammox bacteria from the activated sludge,supporting to start an Anammox process efficiently.

关键词： Anammox Activated sludge Enrichment Nitrogen removal Strategy

MetaCoorNet: an improved generated residual network for grasping pose estimation

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Science China(Information Sciences) 2025年第03期68卷 242-257页

作者： Hejia gao Chuanfeng HE Junjie ZHAO Changyin SUN School of Artificial Intelligence Anhui University Engineering Research Center of Autonomous Unmanned System Technology Ministry of Education Anhui Provincial Key Laboratory of Security Artificial Intelligence Anhui University School of Automation Southeast University

Robotic grasping presents significant challenges due to variations in object properties, environmental complexities,and the demand for real-time operation. This study proposes the MetaCoorNet(MCN), which is a novel deep learning architecture specifically designed to address these challenges in robotic grasping pose estimation. By combining spatial and channel operators, the MetaCoor block is utilized to extract features efficiently. This architecture enhances feature selectivity by embedding location information into channel attention using a positional embedding technique within the coordinate attention mechanism. Consequently, the proposed MCN can focus on pertinent grasp-related regions. Furthermore, convolutional fusion blocks seamlessly integrate spatial and channel features, resulting in enhanced feature resolution and representation *** innovative design enables the proposed MCN to achieve state-of-the-art performance on the Cornell and Jacquard datasets,attaining accuracies of 98% and 91.2%, respectively. The effectiveness and robustness of MCN are further validated through real-world experiments conducted using a seven-degree-of-freedom Kinova manipulator.

关键词： generative ResNet meta light block coordinate attention feature resolution robot grasping

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Pronounced impact of size and shape effects on creep rupture life of a K439B superalloy combustion chamber casting simulator

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China Foundry 2025年

作者： Wen-tong Liu yi-dong Wu Lei gao Jing-yang Chen Cheng-bo Xiao Xi-dong Hui State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

The size and shape effect(SSE) of components has become a critical issue for mechanical properties, application reliability, and processing. In this study, the creep rupture life(CRL) of components with different wall thicknesses and positions in a combustion chamber casing simulator made of K439B superalloy was investigated. The intrinsic mechanisms of the SSE were explored from the dendrite structure, volume fraction and size of the γ' phase, and element segregation, etc. It is shown that this casting exhibits a strong SSE of creep rupture life, characterized by a significant difference in the CRL values up to 60% with the variation of wall thickness and position in the casing. In terms of casting technology, the influence of SSE on CRL is actually determined by the cooling rate. The SSE on the creep rupture life originates from the dendrite structure(such as the secondary dendrite arm spacing), volume fraction size of the γ' phase in the dendrite trunk, and elements segregation rate. This work may have implications for the design and application of engineering components with large sizes and complex structures.

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Anchoring thiol-rich traps in 1D channel wall of metal-organic framework for efficient removal of mercury ions

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Chinese Chemical Letters 2025年第2期36卷 432-435页

作者： Xudong Zhao Yuxuan Wang Xinxin gao Xinli gao Meihua Wang Hongliang Huang Baosheng Liu College of Chemical Engineering and Technology Taiyuan University of Science and Technology Instrumental Analysis Center Taiyuan University of Science and Technology State Key Laboratory of Separation Membranes and Membrane Processes School of Chemical Engineering and TechnologyTiangong University College of Materials Science and Engineering Taiyuan University of Science and Technology

Metal-organic frameworks （MOFs） attract broad interests in mercury （Hg） ion adsorption field,while unreasonable distribution of active groups commonly restricts their utilization *** this work,we constructed a new MOF （TYUST-6） with dense thiol-rich traps in the 1D pore *** accessible channel and rational distribution of thiols allow the smooth diffusion of Hg ions and thereby result in a high Langmuir adsorption capacity of 1347.6 mg/g,almost reaching the theoretical maximum （1444.3 mg/g）.Adsorption equilibrium needs 10 and 30 min at the initial concentrations of 10 and 100 mg/L,*** co-existing ions and solution pH show almost negligible interferences on the adsorption,and adsorbent regeneration can be well *** experimental characterizations and theoretical calculations,the thiol groups in the pore wall are proved to be the dominant interaction ***,this work reports a novel high-capacity adsorbent for Hg2+,and proposes a feasible guideline for designing effective adsorbents.

关键词： Adsorption Mercury ion Metal-organic frameworks Thiol groups Waste water treatment

Effects of probiotic treatment on the prognosis of patients with sepsis: a systematic review

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World Journal of Emergency Medicine 2025年第1期16卷 18-27页

作者： Chao Gong Shengyong Xu Youlong Pan Shigong Guo Joseph Harold Walline Xue Wang Xin Lu Shiyuan Yu Mubing Qin Huadong Zhu Yanxia gao yi Li Emergency Department the State Key Laboratory for ComplexSevere and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing 100730China Emergency Department Qinghai Cardio-cerebrovascular Specialty HospitalXining 810012China Department of Rehabilitation Medicine Southmead HospitalBristol BS105NBUK Department of Emergency Medicine Milton S.Hershey Medical Centerthe Pennsylvania State UniversityHershey 17033USA Department of Allergy&Clinical Immunology Peking Union Medical College HospitalPeking Union Medical College&Chinese Academy of Medical SciencesNational Clinical Research Center for Immunologic DiseasesBeijing 100730China Emergency Department the First Affi liated Hospital of Zhengzhou UniversityZhengzhou 450052China

BACKGROUND: Sepsis, a common acute and critical disease, leads to 11 million deaths annually worldwide. Probiotics are living microorganisms that are beneficial to the host and may benefit sepsis outcomes, but their effects are stil inconclusive. This study aimed to evaluate the overal eff ect of probiotics on the prognosis of patients with *** RESOURCES: We searched several sources for published/presented studies, including Pub Med, EMBASE, Web of Science, the Cochrane Library and the US National Library of Medicine Clinical Trials Register(***) updated through July 30, 2023, to identify all relevant randomized controlled trials(RCTs) or observational studies that assessed the effectiveness of probiotics or synbiotics in patients with sepsis and reported mortality. We focused primarily on mortality during the study period and analyzed secondary outcomes, including 28-day mortality, in-intensive care unit(ICU) mortality and other ***: Data from 405 patients in five RCTs and 108 patients in one cohort study were included in the analysis. The overall quality of the studies was satisfactory, but clinical heterogeneity existed. All adult studies reported a tendency for probiotics to reduce the mortality of patients with sepsis, and most studies reported a decreasing trend in the incidence of infectious complications, length of ICU stay and duration of antibiotic use. There was only one RCT involving ***: Probiotics show promise for improving the prognosis of patients with sepsis, including reducing mortality and the incidence of infectious complications, particularly in adult patients. Despite the limited number of studies, especially in children, these findings will be encouraging for clinical practice in the treatment of sepsis and suggest that gut microbiota-targeted therapy may improve the prognosis of patients with sepsis.

关键词： Sepsis Probiotics Synbiotics Mortality Gut microbiota

维普期刊数据库

One-dimensional wave theory analysis of factors and characteristics influencing errors in two-wave method data processing in SHPB

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Acta Mechanica Sinica 2025年第1期41卷 128-140页

作者： Minghui Ma Guangfa gao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China

A simplified calculation of the specimen’s stress-strain curve is generally conducted using the two-wave method by the split Hopkinson pressure bar(SHPB),which aligns the onset of the transmitted and reflected ***,this approach neglects the travel time of elastic waves within the *** the travel time of elastic waves,this study quantitatively investigates the error characteristics and patterns of stress,strain,and strain rate in the specimen under different conditions using the theoretical two-wave method,and compares the results with those obtained using the onset-aligned twowave *** study reveals that the stress-time curves derived from the theoretical two-wave method are lower than the actual stress curves,whereas those obtained from the onset-aligned two-wave method are consistently higher than the actual stress curves,with the stress deviation approximating a constant value when the dimensionless time exceeds *** starting point of the stress-strain curves obtained by the theoretical two-wave method is not zero but a point on the strain axis,whereas the onset-aligned two-wave method always starts at ***,the slopes of the stress-strain curves obtained by both methods differ from the actual Young’s modulus of the material,and functional relationships between the slopes and the actual Young’s modulus are *** research offers theoretical guidance for the refined design of SHPB experiments and the accurate processing of data.

关键词： SHPB Stress wave effect Assumption of stress uniformity Dynamic stress-strain curve

Catalytic atroposelective synthesis of indolyl quinazolinones bearing N-N/C-C diaxes

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Science China Chemistry 2025年

作者： Ning-yi Wang Shuo gao Zhu-Di Shu Bei-Bei Cheng Chun Ma Yu-Chen Zhang Feng Shi Research Center of Chiral Functional Heterocycles School of Chemistry and Materials Science Jiangsu Normal University School of Petrochemical Engineering Changzhou University School of Chemistry and Chemical Engineering Henan Normal University

The first catalytic atroposelective synthesis of indole derivatives bearing N-N/C-C diaxes has been established by the strategy of de novo ring formation. By this strategy, various indolyl quinazolinones bearing vicinal N-N/C-C diaxes were synthesized in high yields with overall good diastereoselectivities and excellent enantioselectivities via chiral phosphoric acid-catalyzed onepot asymmetric formal (5+1) cycloaddition/oxidation reaction. Moreover, such indolyl quinazolinones bearing vicinal N-N/CC diaxes have good configurational stability and could be converted into new chiral ligands with applications in asymmetric catalysis. Therefore, this work not only offered a new member for the family of diaxial atropisomers, but also provided a powerful strategy for catalytic asymmetric synthesis of atropisomers bearing N-N/C-C diaxes.

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Efficiency improvement for post-sulfurized CIGS solar cells enabled by in situ Na doping

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Journal of Energy Chemistry 2025年第2期101卷 324-332页

作者： Zeran gao Yuchen Xiong Jiawen Wang Shanshan Tian Wanlei Dai Haoyu Xu Xinzhan Wang Chao gao Yali Sun Wei Yu National-Local Joint Engineering Laboratory of New Energy Photovoltaic Devices Key Laboratory of Brain-like Neuromorphic Devices and Systems of Hebei Province Hebei University

Despite sulfurization offers the advantage of improving the photovoltaic performance in preparing Cu（In,Ga）Se2（CIGS） absorbers,deep level defects in the absorber and poor energy level alignment on the front surface are still main obstacles limiting the improvement of power co nversion efficiency（PCE） in sulfided CIGS solar ***,an in-situ Na doping strategy is proposed,in which the tailing effect of crystal growth is used to promote the sulfurization of CIGS *** is found that the grain growth is supported by Na incorporating due to the enrichment of NaSexnear the upper *** high soluble Na during grain growth can not only suppress intrinsic InCudonor defects in the absorber,but also tailor S distribution in bulk and the band alignment at the heterojunction,which are both beneficial for the effective electron ***,the Na aggregation near the bottom of the absorber also contributes to the crystalline quality increasing and favorable ultra-thin MoSe2formation at back contact,resulting in a reduced barrier height conducive to hole *** of the champion device is as high as 16.76% with a 28% *** research offers new insights into synthesizing CIGS solar cells and other chalcogenide solar cells with superior cell performance when using an intense sulfurization process.

关键词： CBO CIGS Defect In situ doping Sulfurization