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Global Convergence of a Modified PRP Conjugate Gradient Method

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Journal of Mathematical Research and Exposition 2010年第1期30卷 141-148页

作者： Hai Dong HUANG Yan Jun li zeng xin WEI College of Mathematics and Information Science Guangxi University Guangxi 530004 P. R. China

In this paper, a modified formula for βk^PRP is proposed for the conjugate gradient method of solving unconstrained optimization problems. The value of βk^PRP keeps nonnegative independent of the line search. Under mild conditions, the global convergence of modified PRP method with the strong Wolfe-Powell line search is established. Preliminary numerical results show that the modified method is efficient.

关键词： unconstrained optimization conjugate gradient method global convergence.

P-μc-Si_(1-x)Ge_x:H thin film by VHF-PECVD

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Optoelectronics Letters 2008年第2期4卷 130-132页

作者： SHANG Ze-ren ZHANG Jian-jun ZHANG li-ping HU zeng-xin XUE Jun-ming ZHAO Ying GENG xin-hua Key Laboratory of Photo-Electronics Thin Film Devices and Technique of Tianjin Key Laboratory of OPtoelectronic Information Science and Technology of Education Ministry Institute of Photo-Electronics Thin Film Devices and Technology Nankai University Tianjin 300071 China

In this paper, a series of boron doped microcrystalline hydrogenated silicon-germanium （p-μc-Si1-xGex：H） was deposited by very high frequency plasma-enhanced chemical vapor deposition （VHF-PECVD） from SiH4 and GeF4 mixtures. The effect of GeF4 concentration on films＇ composition, structure and electrical properties was studied. The results show that with the increase of GeF4 concentration, the Ge fraction x increases. The dark conductivity and crystalline volume fraction increase first, and then decrease. When the GC is 4%, p-μc-Si1-xGex：H material with high conductivity, low activation energy （σ= 1.68 S/cm, E8=0.047 eV）, high crystalline volume fraction （60%） and with an average transmission coefficient over the long wave region reaching 0.9 at the thickness of 72 nm was achieved. The experimental results were discussed in detail.

关键词： VHF-PECVD 薄膜化学纤维光半导体

Regulating crystallization and retarding oxidation in Sn-Pb perovskite via 1D cation engineering for high performance all-perovskite tandem solar cells

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Journal of Energy Chemistry 2025年第1期100卷 646-652页

作者： Ranran liu xin Zheng Zaiwei Wang Miaomiao zeng Chunxiang Lan Shaomin Yang Shangzhi li Awen Wang Min li Jing Guo Xuefei Weng Yaoguang Rong Xiong li Michael Gr?tzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences School of Physics and Optoelectronic Engineering Hainan University Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) Chinese Academy of Sciences School of Chemistry Chemical Engineering and Life Sciences State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

All-perovskite tandem solar cells have the potential to surpass the theoretical efficiency limit of single junction solar cells by reducing thermalization ***,the challenges encompass the oxidation of Sn2+to Sn4+and uncontrolled crystallization kinetics in Sn-Pb perovskites,leading to nonradiative recombination and compositional heterogeneity to decrease photovoltaic efficiency and operational ***,we introduced an ionic liquid additive,1-ethyl-3-methylimidazolium iodide （EMIMI） into Sn-Pb perovskite precursor to form low-dimensional Sn-rich/pure-Sn perovskites at grain boundaries,which mitigates oxidation of Sn2+to Sn4+and regulates the film-forming dynamics of Sn/Pb-based perovskite *** optimized single-junction Sn-Pb perovskite devices incorporating EMIMI achieved a high efficiency of 22.87%.Furthermore,combined with wide-bandgap perovskite sub-cells in tandem device,we demonstrate 2-terminal all-perovskite tandem solar cells with a power conversion efficiency of 28.34%,achieving improved operational stability.

关键词： All-perovskite tandem solar cells Sn-Pb perovskite 1D Regulated crystallization Antioxidation

A Modified Conjugate Gradient Method with Global Convergence Property

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Journal of Mathematical Research and Exposition 2009年第1期29卷 65-75页

作者： HONG ling MO li liu WEI zeng xin College of Mathematics & Information Science Guangxi University Guangxi 530004 China

A new conjugate gradient method is proposed in this paper. For any （inexact） line search, our scheme satifies the sufficient descent property. The method is proved to be globally convergent if the restricted Wolfe-P... 详细信息

关键词： unconstrained optimization conjugate gradient method Wolfe-Powell line search global convergence.

基于ELES模型的湖南城乡居民消费结构差异研究

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消费经济 2006年第3期22卷 84-86页

作者：李增欣中南大学商学院长沙410083

ELES模型是当前国内外比较流行的研究消费结构的计量经济模型,它能较好地将经验研究与理论分析结合起来。本文运用ELES模型,对湖南城乡居民消费结构的时间序列数据进行了较为全面、深入的计量检验,分析了城乡居民消费结构差异的情况,并... 详细信息

ELES模型是当前国内外比较流行的研究消费结构的计量经济模型,它能较好地将经验研究与理论分析结合起来。本文运用ELES模型,对湖南城乡居民消费结构的时间序列数据进行了较为全面、深入的计量检验,分析了城乡居民消费结构差异的情况,并提出了相应的政策建议。

关键词：企业消费利益自然资源和生态环境的价值对策

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长江水患灾害成因及其防治途径

西北大学学报（自然科学版） 1999年第2期29卷 176-179页

作者：李增新水利部水电规划设计总院

分析了长江水患灾害发生的主要成因即降水量大而集中、森林破坏造成水土流失加剧、水利工程设防标准较低等及其有关区域因素，在此基础上，提出了恢复生态平衡，建立标本兼治的防洪体系的基本思路即改变传统的被动“治水”方式，积极重... 详细信息

分析了长江水患灾害发生的主要成因即降水量大而集中、森林破坏造成水土流失加剧、水利工程设防标准较低等及其有关区域因素，在此基础上，提出了恢复生态平衡，建立标本兼治的防洪体系的基本思路即改变传统的被动“治水”方式，积极重视“疏导”洪水，统筹规划、加大投入，开展全流域综合治理以及封山育林、限制采伐、退耕还林、涵养水土资源；积极适度退田还湖，加大调蓄干流洪水；加固加高长江干流干堤。

关键词：长江洪水成因治理防治水灾

Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

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Science China Earth Sciences 2025年第1期68卷 62-73页

作者： xin li Yibo ZHOU Tao ZHAO xingjian HE Yanhong PAN State Key Laboratory for Mineral Deposits Research Center for Critical Earth Material Cycling Centre for Research and Education on Biological Evolution and Environment and Frontiers Science School of Earth Sciences and Engineering Nanjing University Institute of Palaeontology Yunnan Key Laboratory of Earth System Science Yunnan Key Laboratory for PalaeobiologyYunnan University

Mammalian hair, as a key feature related to endothermy, physical protection, and camouflage, has a long geohistorical record that dates back even to the Mesozoic. However, the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep time. To address this, we conducted taphonomic experiments to simulate the transformation process of black hair. The changes in the morphological structure, microscopic characteristics, and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy, Fourier transform infrared(FTIR) spectroscopy, and Raman spectroscopy. Our results revealed that damage to the morphology of hair began at a mild temperature(150–175°C), and hair transformed into a fluid-like mass at a relatively high temperature(200°C). In addition, the morphological structure of melanosomes had relatively greater preservation potential than keratins did, and the microscopic features of melanosomes were persistently stable. The Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature increased. Although the chemical signals were not lost completely, the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200°C), whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable, even at high temperatures(>200°C). These results were confirmed by principal component analysis(PCA) and principal component analysis linear discriminant analysis(PCA–LDA). In addition, the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid), which suggested that Raman spectroscopy can be used to detect melanin in fossils.

关键词： Mammalian hair Melanin Keratin Fossilization Experimental taphonomy

High-throughput screening of CO_(2) cycloaddition MOF catalyst with an explainable machine learning model

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Green Energy & Environment 2025年第1期10卷 132-138页

作者： Xuefeng Bai Yi li Yabo Xie Qiancheng Chen xin Zhang Jian-Rong li Beijing Key Laboratory for Green Catalysis and Separation and Department of Chemical Engineering College of Materials Science&EngineeringBeijing University of TechnologyBeijing100124China

The high porosity and tunable chemical functionality of metal-organic frameworks(MOFs)make it a promising catalyst design ***-throughput screening of catalytic performance is feasible since the large MOF structure database is *** this study,we report a machine learning model for high-throughput screening of MOF catalysts for the CO_(2) cycloaddition *** descriptors for model training were judiciously chosen according to the reaction mechanism,which leads to high accuracy up to 97%for the 75%quantile of the training set as the classification *** feature contribution was further evaluated with SHAP and PDP analysis to provide a certain physical understanding.12,415 hypothetical MOF structures and 100 reported MOFs were evaluated under 100℃ and 1 bar within one day using the model,and 239 potentially efficient catalysts were *** them,MOF-76(Y)achieved the top performance experimentally among reported MOFs,in good agreement with the prediction.

关键词： Metal-organic frameworks High-throughput screening Machine learning Explainable model CO_(2)cycloaddition

Uniform measure attractors for non-autonomous stochastic evolution systems

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Acta Mathematica Sinica,English Series 2025年

作者： Dingshi li Ran li Tianhao zeng School of Mathematics Southwest Jiaotong University

This paper is concerned with uniform measure attractors for non-autonomous stochastic evolution systems. We first introduce the concept of uniform measure attractor and then provide a sufficient criterion for existence and uniqueness of such attractors. As an application, we prove the existence and uniqueness of uniform measure attractors for the stochastic Navier-Stokes equations with deterministic almost-periodic forcing and nonlinear diffusion terms.

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