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Wavelet analysis of spring climate characteristics in arid aeolian area of agro-pastoral ecotone in China

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Water Science and Engineering 2012年第3期5卷 269-277页

作者： Chun-xia ZOU xiang-dong shen Hong-yun LI Xia-zi LI Zhang-jun LI College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University Hohhot 010018 P. R. China College of Ecology and Environmental Science Inner Mongolia Agricultural University Hohhot 010018 P. R. China Inner Mongolia Weather Bureau Hohhot 010051 P. R. China

The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time series of temperature and precipitation in spring when sandstorms often occur in the area. Based on meteorological data for a 46-year period from 1959 to 2004, multi-scale variations and abrupt changes in temperature and precipitation were analyzed with the Mexican hat function （MHF） wavelet method, showing the multi-scale variation characteristics of temperature and precipitation, as well as the periods and change points at different time scales. The relationship between temperature and precipitation was obtained using the wavelet analysis method. Obvious staggered features of the variations of spring temperature and precipitation were observed in this agro-pastoral ecotone. The strongest oscillation periods of spring temperature variations were 1 and 22 years, while for precipitation, the strongest oscillation periods of variations were 2, 8, and 22 years. In addition, lower spring temperature corresponded to lower precipitation, whereas higher temperature yielded higher precipitation rate.

关键词： spring temperature spring precipitation climate characteristics MHF waveletmethod," arid aeolian area," agro-pastoral ecotone

A Catalog and Statistical Analysis for Magnetic Stars

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Research in Astronomy and Astrophysics 2023年第9期23卷 264-308页

作者： Abdurepqet Rustem Guo-Liang Lü Jin-Zhong Liu Chun-Hua Zhu Yu Zhang dong-xiang shen Yu-Hao Zhang Xiao-Long He School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi830011China

Magnetic fields are significant in the structure and evolution of stars. We present a comprehensive catalog of 1784known magnetic stars, detailing their identifications, HD numbers, precise locations, spectral types and averaged quadratic effective magnetic fields among other important information. The group comprises 177 O-type stars, 551B-type stars, 520 A-type stars, 91 F-type stars, 53 G-type stars, 61 K-type stars, 31 M-type stars and an additional300 stars whose spectral classification remains indeterminate. Our analysis examines the statistical properties of these magnetic stars. The relative integrated distribution function and number distribution function for all magnetic stars of the same spectral type can be effectively approximated using an exponential function of the averaged quadratic effective magnetic field. The analysis further reveals that A and B-type stars possess the strongest mean magnetic fields, indicating an easier detection of their magnetic fields.

关键词： stars early-type-stars chemically peculiar-stars magnetic field-catalogs

Search for variable stars in the open cluster NGC 1245

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Research in Astronomy and Astrophysics 2021年第5期21卷 223-234页

作者： dong-xiang shen Yu Zhang Chun-Yan Li xiang-Yun Zeng Guo-Liang Lv Chun-Hua Zhu Qing-Shun Hu Jin-Zhong Liu School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory National Astronomical ObservatoriesChinese Academy of SciencesUrumqi 830000China University of Chinese Academy of Sciences Beijing 100049China

We used the Nanshan 1 m telescope of Xinjiang Astronomical Observatory to investigate variable stars in the region of NGC 1245. We detected 55 variable stars in the field of view, 42 of them are newly discovered: six binaries, 22 pulsating stars, 14 unclassified variables. We discussed the physical properties and classifications of the variable stars through their light curves. The cross-matching with the members catalog of NGC 1245 suggests that 10 variable stars are identified as probable cluster members, which including one EW type binary, eight δ Scuti stars, and an unknown type variable star. Since the difference of the members catalog of the cluster and the limitations of the instrument, there are some huge differences in the variable list of NGC 1245 compared with the previous work.

关键词： open clusters and associations:individual(NGC 1245) stars:variables:general stars:variables:delta Scuti binaries:eclipsing

Photometric Properties and Stellar Parameters of the Rapidly Rotating Magnetic Early-B Star HD 345439

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Research in Astronomy and Astrophysics 2023年第1期23卷 18-31页

作者： dong-xiang shen Jin-Zhong Liu Chun-Hua Zhu Guo-Liang Lü Yu Zhang Cheng-Long Lü Hao-Zhi Wang Lei Li Xi-Zhen Lu Jin-Long Yu Abdurepqet Rustem School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory National Astronomical ObservatoriesChinese Academy of SciencesUrumqi 830000China

We first present the multicolor photometry results of the rapidly rotating magnetic star HD 345439 using the Nanshan One-meter Wide-field *** the photometric observations,we derive a rotational period of 0.7699±0.0014 *** light curves of HD 345439 are dominated by the double asymmetric S-wave feature that arises from the magnetic *** behaviors are not observed in Sector 41 of the Transiting Exoplanet Survey *** evidence is found of the occurrence of centrifugal breakout events neither in the residual flux nor in the systematic variations at the extremum of the light *** on the hypothesis of the Rigidly Rotating Magnetosphere model,we restrict the magnetic obliquity angleβand the rotational inclination angle i so that they satisfy the approximate relationβ+i≈105°.The color excess,extinction,and luminosity are determined to be E_((B-V))=0.745±0.016 mag,A_(V)=2.31±0.05 mag,and log(L/L_(⊙))=3.82±0.1 dex,***,we derive the effective temperature as T_(eff)=22±1 kK and the surface gravity as log g=4.00±*** mass M=-7.24_(-1.24)^(+1.75)M_(⊙),radius R=4.44_(-1.93)^(+2.68)R_(⊙),and age τ_(age)=23.62_(-21.97)^(+4.24) Myr are estimated from the Hertzsprung-Russell diagram.

关键词： stars chemically peculiar-stars early-type-stars fundamental parameters-stars magnetic field

Eye detection and tracking using IR source

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Optoelectronics Letters 2006年第2期2卷 145-147页

作者： WU Lin-tuo XU xiang-dong shen Chong National Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China

A real-time prototype of drowsy driver monitoring system using infrared sources to detect and track the eyes is presented. A special hardware is designed for controlling the LEDs and real-time image acquisition. This method adopts the differential image to enhance the accuracy and robustness of eye detection. A Kalman filter is implemented to track the eyes. The experimental results are discussed. The system is non-invesive, fast and reasonably accurate.

关键词：视觉检测视觉跟踪 IR资源驱动检测系统

Expression and role of PAK6 after spinal cord injury in adult rat

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Chinese Journal of Traumatology 2011年第5期14卷 277-281页

作者： CHEN xiang-dong ZHAO Wei shen Ai-guo Department of Orthopedics Affiliated Hospital of Nantong University Nantong 226001 China

Objective： To observe p21-activated kinase 6 （PAK6） expression and its possible role after spinal cord injury （SCI） in adult ***： Sprague-Dawley rats were subjected to spinal cord injury. To explore the pathological and physiological significance of PAK6, the expression patterns and distribution of PAK6 were observed by Western blot, immunohistochemistry and ***： Western blot analysis showed PAK6 protein level was significantly up-regulated on day 2 and day 4,then reduced and had no up-regulation till day 14. Immunohistochemistry analysis showed that the expression of PAK6 was significantly increased on day 4 compared with the control group. Besides, double immunofluorescence staining showed PAK6 was primarily expressed in the neurons and astrocytes in the control group. While after injury, the expression of PAK6 was increased significantly in the astrocytes and neurons, and the astrocytes were largely proliferated. We also examined the expression of proliferating cell nuclear antigen （PCNA） and found its change was correlated with the expression of PAK6. Importantly, double immunofluorescence staining revealed that cell proliferation evaluated by PCNA appeared in many PAK6-expressing cells on day 4 after ***： The up-regulation of PAK6 in the injured spinal cord may be associated with glial proliferation.

关键词： PAK6 protein, human p21-activated kinases Spinal cord injury Astrocytes

Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 102-110页

作者： Qiang Liu xiang Li shen Du Ming Gao Yanbin Yin Jiongming Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the *** which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid *** contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive ***,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding *** results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles *** addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually *** one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the *** findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

关键词： mold flux low basicity bubbles three-dimensional X-ray microscope viscosity

Remaining Life Prediction Method for Photovoltaic Modules Based on Two-Stage Wiener Process

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Energy Engineering 2025年第1期122卷 331-347页

作者： Jie Lin Hongchi shen Tingting Pei Yan Wu School of Electrical Engineering and Information Engineering Lanzhou University of TechnologyLanzhou730050China

Photovoltaic (PV) modules, as essential components of solar power generation systems, significantly influence unitpower generation *** service life of these modules directly affects these costs. Over time, the performanceof PV modules gradually declines due to internal degradation and external environmental *** cumulativedegradation impacts the overall reliability of photovoltaic power generation. This study addresses the complexdegradation process of PV modules by developing a two-stage Wiener process model. This approach accountsfor the distinct phases of degradation resulting from module aging and environmental influences. A powerdegradation model based on the two-stage Wiener process is constructed to describe individual differences inmodule degradation processes. To estimate the model parameters, a combination of the Expectation-Maximization(EM) algorithm and the Bayesian method is employed. Furthermore, the Schwarz Information Criterion (SIC) isutilized to identify critical change points in PV module degradation trajectories. To validate the universality andeffectiveness of the proposed method, a comparative analysis is conducted against other established life predictiontechniques for PV modules.

关键词： Photovoltaic modules degradation stochastic processes lifetime prediction

Optimizing Fine-Tuning in Quantized Language Models:An In-Depth Analysis of Key Variables

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Computers, Materials & Continua 2025年第1期82卷 307-325页

作者： Ao shen Zhiquan Lai dongsheng Li Xiaoyu Hu National Key Laboratory of Parallel and Distributed Computing National University of Defense TechnologyChangsha410073China Strategic Assessments and Consultation Institute Academy of Military ScienceBeijing100091China

Large-scale Language Models(LLMs)have achieved significant breakthroughs in Natural Language Processing(NLP),driven by the pre-training and fine-tuning *** this approach allows models to specialize in specific tasks with reduced training costs,the substantial memory requirements during fine-tuning present a barrier to broader ***-Efficient Fine-Tuning(PEFT)techniques,such as Low-Rank Adaptation(LoRA),and parameter quantization methods have emerged as solutions to address these challenges by optimizing memory usage and computational *** these,QLoRA,which combines PEFT and quantization,has demonstrated notable success in reducing memory footprints during fine-tuning,prompting the development of various QLoRA *** these advancements,the quantitative impact of key variables on the fine-tuning performance of quantized LLMs remains *** study presents a comprehensive analysis of these key variables,focusing on their influence across different layer types and depths within LLM *** investigation uncovers several critical findings:(1)Larger layers,such as MLP layers,can maintain performance despite reductions in adapter rank,while smaller layers,like self-attention layers,aremore sensitive to such changes;(2)The effectiveness of balancing factors depends more on specific values rather than layer type or depth;(3)In quantization-aware fine-tuning,larger layers can effectively utilize smaller adapters,whereas smaller layers struggle to do *** insights suggest that layer type is a more significant determinant of fine-tuning success than layer depth when optimizing quantized ***,for the same discount of trainable parameters,reducing the trainable parameters in a larger layer is more effective in preserving fine-tuning accuracy than in a smaller *** study provides valuable guidance for more efficient fine-tuning strategies and opens avenues for further research into optimizing LLM

关键词： Large-scale Language Model Parameter-Efficient Fine-Tuning parameter quantization key variable trainable parameters experimental analysis