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Solar trough receiver with V-grooved light traps for efficiency improvement

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Science China Technological Sciences 2025年第1期 146-156页

作者： Bin LIU Qing LI Yu qiu School of Energy Science and Engineering Central South University

Parabolic trough collector is a promising technology for both domestic and industrial heat supplies. To enhance the collector efficiency, a modified trough receiver with dozens of V-grooved light traps incorporated into its lower-half absorber was introduced. For assessing the performance of this receiver, a solar-thermal-stress coupled model was established. Using this model, firstly, the effects of the V-grooved light traps were investigated. The results reveal that, compared to the conventional trough receiver, the modified trough receivers equipped with different traps can reduce their optical losses by 81.9–138.0 Wm-1（i.e., 15.0%–25.2%）, improving their optical efficiencies by 1.60%–2.69%. However, these traps also result in increased thermal loss from the receiver. Therefore, there is no single optimal modified trough receiver that consistently outperforms all other receivers across all possible conditions. Nonetheless, the MTR30-3 and MTR60-3 receivers emerge as the optimized choices due to their better solar-thermal performance. Subsequently, performance evaluation reveals that the two optimized receivers can enhance the receiver efficiencies within the typical solar irradiance range by 0.02%–2.65% and 0.05%–1.70% when the inlet fluid temperatures are below 488 and 523 K, respectively. Consequently, the collector efficiencies can be improved by 0.02%–2.49% and 0.05%–1.60%, respectively. Additionally, thermal stress analysis verifies that the two optimized receivers remain within safe limits under all typical conditions. Given that the heating temperature of a typical solar collector for domestic or industrial heat supply is typically below 523 K, the integration of the two optimized receivers has the capability to effectively enhance the overall collector efficiency.

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高管限薪方式与国有企业高质量发展

经济问题 2025年第1期 70-78页

作者：吴秋生郑玥臻山西财经大学会计学院山西太原030012

2009年和2015年中华人民共和国人力资源和社会保障部和国务院国有资产监督管理委员会先后出台了国有企业高管限薪规定,采取了绝对限薪和相对限薪两种不同方式,因此,有必要明晰哪一种方式更有利于促进国有企业高质量发展。以2010—2023年... 详细信息

2009年和2015年中华人民共和国人力资源和社会保障部和国务院国有资产监督管理委员会先后出台了国有企业高管限薪规定,采取了绝对限薪和相对限薪两种不同方式,因此,有必要明晰哪一种方式更有利于促进国有企业高质量发展。以2010—2023年的A股国有企业为样本进行研究,结果表明:与绝对限薪相比,相对限薪更能够促进国有企业高质量发展,且相对限薪程度越高、内部控制质量越高,上述关系越明显。进一步研究发现,相对限薪促进国有企业发展质量提高是通过降低盈余管理、提高创新效率等路径实现的,且这种作用路径在产品市场竞争度高的国有企业和实体国有企业中更明显。研究结论对合理制定和有效实施限薪政策及提高企业内部控制质量,促进国有企业高质量发展具有启示意义。

关键词：绝对限薪相对限薪全要素生产率内部控制质量

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高速移动环境中的MIMO非相干高效通信

桂林电子科技大学学报 2020年第4期40卷 259-269页

作者：郑霖杨超汪震周广鹏陈建梅林梦莹王俊义邓小芳李晓记仇洪冰桂林电子科技大学广西无线宽带与信号处理重点实验室广西桂林541004

针对当前高速移动环境下MIMO通信的研究现状,重点对非相干MIMO的研究进展进行了概览。参考高速移动信道模型,对基于能量检测的空分复用MIMO技术,充分利用时、频、空维度,保证高速移动的双色散衰落环境下的调制可靠性和容量性能进行了探... 详细信息

针对当前高速移动环境下MIMO通信的研究现状,重点对非相干MIMO的研究进展进行了概览。参考高速移动信道模型,对基于能量检测的空分复用MIMO技术,充分利用时、频、空维度,保证高速移动的双色散衰落环境下的调制可靠性和容量性能进行了探讨,另外,分析了能量检测MIMO技术应用于下行多用户链路高速移动环境的基本原理,及与现有相干Massive-MIMO技术的兼容性。通过对团队近年来在非相干空分复用MIMO通信平台的理论、设计、实践工作展示,验证了在高速移动环境下MIMO高效可靠通信技术的可行性与有效性。

关键词：高速移动信道 MIMO通信非相干通信时频色散

东江河口典型河段溶解氧时空动态及低氧成因解析

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湖泊科学 2025年第1期37卷 112-121页

作者：黄广灵黄本胜刘达邱静黄国如华南理工大学土木与交通学院广州510640 广东省水利水电科学研究院广州510635 广东省流域水环境治理与水生态修复重点实验室广州510635 华南理工大学亚热带建筑与城市科学全国重点实验室广州510640

为解析东江南支流低氧现象的成因,并为水环境治理提供科学依据,本研究分别于2019年春季和夏季对该河流的主要断面进行了水质监测。监测结果显示,东江南支流的溶解氧(DO)水平从中游道滘镇的6.93 mg/L降至出海口处的4.08 mg/L。DO与影响... 详细信息

为解析东江南支流低氧现象的成因,并为水环境治理提供科学依据,本研究分别于2019年春季和夏季对该河流的主要断面进行了水质监测。监测结果显示,东江南支流的溶解氧(DO)水平从中游道滘镇的6.93 mg/L降至出海口处的4.08 mg/L。DO与影响因子的相关性分析显示,DO与水温呈显著负相关,与盐度呈正相关,而与氨氮和总磷等营养物质呈显著负相关。这些营养物质的增加与DO的降低在空间上呈显著重叠,特别是在夏季。研究结果表明,东江南支流低氧现象受物理、化学和生物因素的共同影响,其中温度升高和营养物质浓度增加使得中下游水体的氧气消耗加快,河道汇流处的断面缩窄和下游水体的透光性差引起DO补给不足,从而导致下游沙田泗盛断面经常性出现氧亏(低氧)现象。

关键词：东江南支流溶解氧低氧营养物珠江

融合注意力机制的YOLOv8-TS交通标志检测网络

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现代电子技术 2025年第1期48卷 179-186页

作者：黄智渊方遒郭星浩厦门理工学院机械与汽车工程学院福建厦门361024 厦门大学航空航天学院福建厦门361005

道路交通标志识别是自动驾驶、车联网的重要组成部分,为进一步提高交通标志检测的精度和速度,提出一种基于YOLOv8s改进的YOLOv8-TS道路交通标志检测网络。首先,对YOLOv8s进行了整体的轻量化设计,并设计了Conv-G7S和CSP-G7S模块,减少了... 详细信息

道路交通标志识别是自动驾驶、车联网的重要组成部分,为进一步提高交通标志检测的精度和速度,提出一种基于YOLOv8s改进的YOLOv8-TS道路交通标志检测网络。首先,对YOLOv8s进行了整体的轻量化设计,并设计了Conv-G7S和CSP-G7S模块,减少了网络的参数量;其次,设计了CSP-SwinTransformer模块,强化了模型利用窗口内的特征信息进行上下文感知和建模的能力;然后,在颈部网络融合了卷积注意力机制(CBAM),强化了模型对不同通道、空间权重信息的学习;最后,对损失函数进行了改进,提升了边界框回归性能。实验结果表明,在中国道路交通标志TT100K数据集上,精确率(Precision)、平均精度(mAP@0.5)分别提高了6.9%、3.7%,而改进后模型的参数量下降了75.4%,模型的大小仅为5.8 MB,平均精度(mAP@0.5)达到96.5%,检测速度由126.58 f/s提升至136.99 f/s。

关键词：交通标志检测 YOLOv8-TS 轻量化注意力机制 Conv-G7S WIoU

Henig Efficiency in Vector Optimization with Nearly Cone-subconvexlike Set-valued Functions

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Acta Mathematicae Applicatae Sinica 2007年第2期23卷 319-328页

作者： qiu-sheng qiu Department of Mathematics Zhejiang Normal University Jinhua 321004 China Department of Mathematics Shanghai University Shanghai 200436 China

In this paper, we study Henig efficiency in vector optimization with nearly cone-subconvexlike set-valued function. The existence of Henig efficient point is proved and characterization of Henig efficiency is established using the method of Lagrangian multiplier. As an interesting application of the results in this paper, we establish a Lagrange multiplier theorem for super efficiency in vector optimization with nearly conesubconvexlike set-valued function.

关键词： Set-valued function vector optimization Lagrangian multiplier theorem Henig efficiency nearly cone-subconvexlikeness

Corrosion behavior of three Ag–50Cu alloys prepared by different processes in NaCl solutions

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Rare Metals 2017年第1期36卷 61-68页

作者： Zhong-qiu Jia qiu-Ying Liang qiu-Yue Tian Zhong-qiu Cao Yan Wang College of Chemistry-and Chemical Engineering Shenyang Normal University Shenyang 110034 China

Corrosion behavior of two nanocrystalline bulk Ag–50Cu alloys and one coarse-grained counterpart prepared by liquid-phase reduction(LPR), mechanical alloying(MA) and powder metallurgy(PM) methods,respectively, were investigated in Na Cl solutions. They were finished by means of PARM273 A and M5210 electrochemical apparatus through potentiodynamic polarization method and electrochemical impedance spectroscopy(EIS) technique. The results show that corrosion rates of three Ag–50Cu alloys increase with the increment of Na Cl solution concentrations. Corrosion rates of LPRAg–50Cu alloy are a little higher than those of PMAg–50Cu alloy,but evidently lower than those of MAAg–50Cu alloy. The difference in corrosion rates is attributed to the large reduction in the grain size and homogeneous microstructure of nanocrystalline alloys. Passive current densities decrease and afterward increase for PMAg–50Cu alloy,decrease for MAAg–50Cu alloy, and increase for LPRAg–50Cu alloy with the increment of Na Cl solution concentrations. After the grain sizes are refined, passive current densities become lower.

关键词： Copper alloys Corrosion Corrosion rate Corrosive effects Electrochemical corrosion Electrochemical impedance spectroscopy Electrochemistry Grain size and shape Mechanical alloying Nanocrystals Powder metallurgy Reduction Silver Silver alloys

HERMITE WENO SCHEMES WITH LAX-WENDROFF TYPE TIME DISCRETIZATIONS FOR HAMILTON-JACOBI EQUATIONS

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Journal of Computational Mathematics 2007年第2期25卷 131-144页

作者： Jianxian qiu Department of Mathematics Nanjing University Nanjing 210093 China

In this paper, we use Hermite weighted essentially non-oscillatory （HWENO） schemes with a Lax-Wendroff time discretization procedure, termed HWENO-LW schemes, to solve Hamilton-Jacobi equations. The idea of the reconstruction in the HWENO schemes comes from the original WENO schemes, however both the function and its first derivative values are evolved in time and are used in the reconstruction. One major advantage of HWENO schemes is its compactness in the reconstruction. We explore the possibility in avoiding the nonlinear weights for part of the procedure, hence reducing the cost but still maintaining non-oscillatory properties for problems with strong discontinuous derivative. As a result, comparing with HWENO with Runge-Kutta time discretizations schemes （HWENO-RK） of qiu and Shu [19] for Hamilton-Jacobi equations, the major advantages of HWENO-LW schemes are their saving of computational cost and their compactness in the reconstruction. Extensive numerical experiments are performed to illustrate the capability of the method.

关键词： WENO scheme Hermite interpolation Hamilton-Jacobi equation Lax-Wendroff type time discretization High order accuracy.

Multiscale strain alleviation of Ni-rich cathode guided by in situ environmental transmission electron microscopy during the solid-state synthesis

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Journal of Energy Chemistry 2023年第9期84卷 467-475页

作者： Fengyu Zhang Yunna Guo Chenxi Li Tiening Tan Xuedong Zhang Jun Zhao Ping qiu hongbing Zhang Zhaoyu Rong Dingding Zhu Lei Deng Zhangran Ye Zhixuan Yu Peng Jia Xiang Liu Jianyu Huang Liqiang Zhang School of New Energy and Materials China University of Petroleum BeijingBeijing 102249China Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004HebeiChina School of Materials Science and Engineering Beihang UniversityBeijing 100191China Sichuan New Energy Vehicle Innovation Center Yibin 644000SichuanChina School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105HunanChina Peking University Institute of Advanced Agricultural Sciences Shandong Laboratory of Advanced Agricultural Sciences at WeifangWeifang 261000ShandongChina China Oil&Gas Pipeline Network Corporation Department of Engineering Beijing 100026China Hebei Key Laboratory of Applied Chemistry College of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004HebeiChina Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education School of Materials Science and EngineeringXiangtan UniversityXiangtan 411105HunanChina

Ni-rich layered oxides are one of the most promising cathode materials for Li-ion batteries due to their high energy ***,the chemomechanical breakdown and capacity degradation associated with the anisotropic lattice evolution during lithiation/delithiation hinders its practical ***,by utilizing the in situ environmental transmission electron microscopy(ETEM),we provide a real time nanoscale characterization of high temperature solid-state synthesis of LiNi_(0.8)CO_(0.1)Mn_(0.1)O_(2)(NCM811) cathode,and unprecedentedly reveal the strain/stress formation and morphological evolution mechanism of primary/second ary particles,as well as their influence on electrochemical *** show that stress inhomogeneity during solid-state synthesis will lead to both primary/secondary particle pulverization and new grain boundary initiation,which are detrimental to cathode cycling stability and rate *** to alleviate this multiscale strain during solid-state synthesis,we introduced a calcination scheme that effectively relieves the stress during the synthesis,thus mitigating the primary/secondary particle crack and the detrimental grain boundaries formation,which in turn improves the cathode structural integrity and Li-ion transport kinetics for long-life and high-rate electrochemical *** work remarkably advances the fundamental understanding on mechanochemical properties of transition metal oxide cathode with solid-state synthesis and provides a unified guide for optimization the Ni-rich oxide cathode.

关键词： Ni-rich cathode In situ ETEM Solid-state synthesis Multiscale strain alleviation