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具有无穷边界值的二次非线性奇摄动边值问题的双边界层

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高校应用数学学报（A辑） 2016年第3期31卷 316-326页

作者：韩建邦沈启霞郑州科技学院基础部河南郑州450064

研究了具有无穷边界值的二次非线性奇摄动边值问题的双边界层,利用边界层校正函数,构造其渐近解,并利用微分不等式理论,给出了一致有效渐近估计.最后给出算例验证了相关结论的正确性.

关键词：无穷大边界值双边界层边界层校正微分不等式

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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线性模型回归参数极大似然估计的约束EM算法

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河南大学学报（自然科学版） 2008年第3期38卷 231-234页

作者：文生兰沈启霞信息工程大学理学院郑州450001 郑州科技职业学院郑州450000

提出了非线性不等式约束下线性模型回归系数渐进极大似然估计的EM算法,利用极大似然估计的渐近正态性质,将EM算法的M-步转化为随机优化问题,给出了该随机优化问题的极限问题,即利用更易求解的极限问题的最优解来代替原优化问题的最优解... 详细信息

提出了非线性不等式约束下线性模型回归系数渐进极大似然估计的EM算法,利用极大似然估计的渐近正态性质,将EM算法的M-步转化为随机优化问题,给出了该随机优化问题的极限问题,即利用更易求解的极限问题的最优解来代替原优化问题的最优解,并证明了原优化问题的最优解是依概率收敛于极限问题的最优解.

关键词：极大似然估计非线性不等式约束渐近性

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中国工业、环境和居民健康的相关性分析

数学的实践与认识 2017年第24期47卷 294-300页

作者：沈启霞宋延乐郑州科技学院基础部河南郑州450064

通过向量自回归模型(VAR模型)和分位数回归模型来定量地分析我国工业发展水平、环境和居民健康之间的动态影响过程.研究表明:工业发展水平对环境污染影响以及环境污染对健康的影响都是持续增长的,从侧面反映了我国工业的发展仍是以环境... 详细信息

通过向量自回归模型(VAR模型)和分位数回归模型来定量地分析我国工业发展水平、环境和居民健康之间的动态影响过程.研究表明:工业发展水平对环境污染影响以及环境污染对健康的影响都是持续增长的,从侧面反映了我国工业的发展仍是以环境污染为代价,并通过环境污染对居民健康造成了深远影响,最终导致居民死亡率的增加.

关键词：工业发展环境污染居民健康 VAR模型分位数回归

Metal nanoparticles decorated CoFe-(oxy)hydroxysulfides nanosheets fabricated by a general strategy for electrocatalytic water splitting

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Journal of Energy Chemistry 2025年第1期100卷 26-38页

作者： xiaodong Yang Haochen shen xiaoming xiao Zhichao Li qi Zhou Wei Yang Bin Jiang Yongli Sun Luhong Zhang Zhenhua Yan School of Chemical Engineering and Technology Tianjin University Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Nankai University

This study presents a novel method to fabricate metal-decorated,sulfur-doped layered double hydroxides （M/SLDH） through spontaneous redox and sulfurization *** developed Ag/SLDH and Pt/SLDH catalysts with abundant heterogeneous interfaces and hierarchical nanostructures demonstrated outstanding oxygen evolution reaction （OER） and hydrogen evolution reaction （HER） performance,achieving low overpotentials of 212 and 35 mV at 10 mA cm-2in 1 M KOH,*** both anode and cathode in water splitting,they required only 1.47 V to reach 10 mA cm-2and exhibited high structural robustness,maintaining stability at 1000 mA cm-2for 300 ***-situ Raman analysis revealed that the synergistic effects of metal nanoparticles and S doping significantly promote the transformation into the S-Co1-xFexOOH layer,which serves as the active phase for water ***,ultraviolet photoelectron spectroscopy （UPS） and density functional theory （DFT） analyses indicated that incorporating metal nanoparticles and S doping increase electron density near the Fermi level and reduce reaction energy barriers,thus enhancing intrinsic OER and HER *** study provides a scalable strategy for synthesizing high-performance electrocatalysts for water splitting,with promising potential for broader applications.

关键词： Ultraviolet photoelectron spectroscopy

Role of the globus pallidus in motor and non-motor symptoms of Parkinson's disease

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Neural Regeneration Research 2025年第6期20卷 1628-1643页

作者： Yimiao Jiang Zengxin qi Huixian Zhu Kangli shen Ruiqi Liu Chenxin Fang Weiwei Lou Yifan Jiang Wangrui Yuan Xin Cao Liang Chen qianxing Zhuang Department of Physiology School of MedicineNantong UniversityNantongJiangsu ProvinceChina Department of Neurosurgery Huashan HospitalShanghai Medical CollegeFudan UniversityShanghaiChina National Center for Neurological Disorders ShanghaiChina Shanghai Key Laboratory of Brain Function Restoration and Neural Regeneration ShanghaiChina State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science Institute of Brain ScienceFudan UniversityShanghaiChina

The globus pallidus plays a pivotal role in the basal ganglia circuit. Parkinson's disease is characterized by degeneration of dopamine-producing cells in the substantia nigra, which leads to dopamine deficiency in the brain that subsequently manifests as various motor and non-motor symptoms. This review aims to summarize the involvement of the globus pallidus in both motor and non-motor manifestations of Parkinson's disease. The firing activities of parvalbumin neurons in the medial globus pallidus, including both the firing rate and pattern, exhibit strong correlations with the bradykinesia and rigidity associated with Parkinson's disease. Increased beta oscillations, which are highly correlated with bradykinesia and rigidity, are regulated by the lateral globus pallidus. Furthermore,bradykinesia and rigidity are strongly linked to the loss of dopaminergic projections within the cortical-basal ganglia-thalamocortical loop. Resting tremors are attributed to the transmission of pathological signals from the basal ganglia through the motor cortex to the cerebellum-ventral intermediate nucleus circuit. The cortico–striato–pallidal loop is responsible for mediating pallidi-associated sleep disorders. Medication and deep brain stimulation are the primary therapeutic strategies addressing the globus pallidus in Parkinson's disease. Medication is the primary treatment for motor symptoms in the early stages of Parkinson's disease, while deep brain stimulation has been clinically proven to be effective in alleviating symptoms in patients with advanced Parkinson's disease,particularly for the movement disorders caused by levodopa. Deep brain stimulation targeting the globus pallidus internus can improve motor function in patients with tremordominant and non-tremor-dominant Parkinson's disease, while deep brain stimulation targeting the globus pallidus externus can alter the temporal pattern of neural activity throughout the basal ganglia–thalamus network. Therefore, the comp

关键词： anxiety basal ganglia bradykinesia deep brain stimulation depression globus pallidus externus globus pallidus internus lateral globus pallidus medial globus pallidus neural circuit Parkinson's disease

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三元Logit模型回归参数的M-H算法

齐齐哈尔大学学报（自然科学版） 2016年第3期32卷 69-72页

作者：沈启霞杨帆郑州科技学院基础部郑州450064

Markov链Monte Carlo(MCMC)方法是现代统计计算中最重要的算法之一,利用其中的随机游动Metropolis-Hastings(M-H)算法,给出了2n+2-参数三元Logit模型的参数估计问题,并给出了6个参数的模拟结果。

关键词：三元Logit模型 M—H算法参数估计

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常微分方程在数学建模中的应用

晋城职业技术学院学报 2011年第1期4卷 42-44页

作者：崔娜沈启霞晋城职业技术学院山西晋城048026 郑州科技学院郑州450064

随着应用微分方程的解法和理论的日臻完善,人们越来越关注用该理论建立数学模型解决实际问题。本文介绍了利用常微分方程理论建立生物种群数量模型、腐败分子人数预测模型的建立过程。

关键词：数学模型常微分方程生物种群数量模型腐败人数的预测模型

Evaluating the impacts of converting grain to vegetable fields on nitrate transport in the deep vadose zone of the North China Plain

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Journal of Geographical Sciences 2025年第1期35卷 189-212页

作者： LIU Meiying MIN Leilei WU Lin ZHANG Yucui qi Yongqing WANG Shiqin LIU Binbin GENG Di shen Yanjun Hebei Key Laboratory of Water-Saving Agriculture Key Laboratory of Agricultural Water ResourcesCenter for Agricultural Resources ResearchInstitute of Genetics and Developmental BiologyCAS School of Advanced Agricultural Sciences University of Chinese Academy of Sciences

Nitrate （NO3-） accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO3-content in intensive agricultural *** land-use change （ALUC）,typically accompanied by substantial alterations in nitrogen fertilizer application and irrigation practices,is an important influencing *** study evaluated the changes in NO3-accumulation and transport in the deep vadose zone （DVZ,below the root zone）,and the groundwater NO3-content associated with ALUC from grain to vegetable fields in the North China Plain （NCP）.The ALUC from grain to vegetable resulted in nitrate–nitrogen （NO3--N） accumulation in DVZ increased by 235.5 kg ha-1m-1（163.2%） in the piedmont plain and 224.9 kg ha-1m-1（102.7%） in the central plain,*** change accelerated downward transport velocity in the DVZ (from 0.81±0.47 to 0.89±0.55 m yr-1in the piedmont plain,and from 0.24±0.12 to 0.92±0.12 m yr-1in the central plain) and increased NO3-leaching *** transport velocity and leaching fluxes resulted in chemical N-fertilizer entering the aquifer in several areas in the piedmont *** impact of the agricultural activity intensity changes,accompanied by the ALUC,on groundwater quantity and quality should be considered in similar regions.

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