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Study on the phytoplankton community structure and its driving factors in Furong Creek during spring and autumn under the influence of cascade weirs
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作者 REN Jiangshan YU Jun +2 位作者 LI Jingjuan LYU Jianzhang WANG Xiaogang 《水利水电技术(中英文)》 北大核心 2025年第3期171-185,共15页
[Objective]The construction of weirs changes the hydraulic characteristics of rivers and affects the structure of phytoplankton communities and the health of aquatic ecosystems in the river.This study aims to explore ... [Objective]The construction of weirs changes the hydraulic characteristics of rivers and affects the structure of phytoplankton communities and the health of aquatic ecosystems in the river.This study aims to explore the nonlinear response relationship between phytoplankton community structure and its driving factors in spring and autumn in Furong Creek under the construction of cascade weirs.[Methods]The structure of phytoplankton communities and related environmental factors were investigated in Furong Creek from 2023 to 2024.This study focused on the analysis of the changes of nutrient concentrations and biomass of phytoplankton in autumn and spring within the same dry season in Furong Creek.Redundancy analysis was used to identify the key factors influencing the structure of phytoplankton communities.The MIKE 11 model was employed to simulate the hydrodynamic changes in the river.Combined with total nitrogen and permanganate index,a GAM model of phytoplankton diversity index and hydrodynamic factors was developed,and the change of phytoplankton diversity after the optimized layout of the cascade weirs was fitted.[Results]The result showed that the annual average value of Shannon-Wiener diversity index of phytoplankton in Furong Creek was 2.79,which was in a state of mild pollution.A total of 239 species from 95 genera in 8 phyla were identified.Among the phytoplankton,Chlorophyta was the dominant group throughout the year in Furong Creek,followed by Bacillariophyta and Cyanophyta.The cell abundance of phytoplankton ranged from 3.11 to 20.64 mg/L and from 0.23 to 6.31 mg/L in spring and autumn,which indicated a clear seasonal succession of phytoplankton community structure.Compared with autumn,the relative abundance of Cyanophyta significantly decreased in spring across the whole river section,while Chrysophyta and Dinophyta showed significant increase at some monitoring sites,leading to water bloom phenomenon and a noticeable decline in the diversity of phytoplankton.The dominant species in the water bodies throughout the year were Cyclotella catenata,Chlorella vulgaris,Scenedesmus bijuga,Scenedesmus quadricauda,Chroomonas acuta,Cryptomonas ovata,and Cryptomonas erosa.Redundancy analysis(RDA)showed that hydrodynamic factors(v,h)and water environmental factors(TN,COD_(Mn))were the main influencing factors of phytoplankton community structure.[Conclusion]The result show that the nutrient concentration,phytoplankton biomass,and density in Furong Creek in spring are significantly higher than in autumn.The GAM model,constructed by combining hydrodynamic and environmental factors,can effectively reflect the nonlinear relationship between phytoplankton diversity index and its driving factors.In spring,with an increase in nutrient concentration,the habitat conditions of low flow speed and high water depths formed by overflow weirs will lead to a decrease in the Shannon-Wiener index of phytoplankton and an intensified risk of eutrophication.However,a reasonable layout scheme of cascade weirs will improve the diversity of phytoplankton and reduce the risk of eutrophication in the river.The findings of this study can help deepen the understanding of the ecological and environmental effects of cascade weir construction in the river. 展开更多
关键词 cascade weirs MIKE 11 model redundancy analysis GAM model influencing factors
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Ecological environmental quality evaluation and driving factor analysis of the Lijiang River Basin,based on Google Earth Engine 被引量:2
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作者 WEI Xi YANG Dazhi +2 位作者 CAI Xiangwen SHAO Ya TANG Xiangling 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2024年第9期1592-1608,共17页
For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological... For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region. 展开更多
关键词 Ecological environmental quality Remote sensing ecological index Driving factor google Earth Engine Lijiang River Basin
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Expression of transcription factors in polycystic ovary syndrome
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作者 ZHANG Qi ZHU Shujuan JIANG Bin 《中南大学学报(医学版)》 北大核心 2025年第3期447-456,共10页
Objective:Polycystic ovary syndrome(PCOS)is a common endocrine disorder that affects women’s health.This study aims to investigate gene and transcription factor(TF)expression differences between PCOS patients and hea... Objective:Polycystic ovary syndrome(PCOS)is a common endocrine disorder that affects women’s health.This study aims to investigate gene and transcription factor(TF)expression differences between PCOS patients and healthy individuals using bioinformatics approaches,and to verify the function of key transcription factors,with the goal of providing new insights into the pathogenesis of PCOS.Methods:Differentially expressed genes(DEGs)and differentially expressed transcription factors(DETFs)between PCOS patients and controls were identified from the RNA sequencing dataset GSE168404 using bioinformatics methods.Functional enrichment analysis was performed using Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.The expression and function of core transcription factors were further validated in ovarian tissues of PCOS model mice and control mice using Western blotting and reverse transcription quantitative polymerase chain reaction(RTqPCR).Results:A total of 332 DEGs were identified between PCOS patients and controls,including 259 upregulated and 73 downregulated genes in the PCOS group.19 DETFs were further screened,of which 16 were upregulated and 3 were downregulated in PCOS.The upregulated DETFs(including TFCP2L1,DACH1,ESR2,AFF3,SMAD9,ZNF331,HOPX,ATOH8,HIF3α,DPF3,HOXC4,HES1,ID1,JDP2,SOX4,and ID3)were primarily associated with lipid metabolism,development,and cell adhesion.Protein and mRNA expression analysis in PCOS model mice revealed significantly decreased levels of hypoxia-inducible factor(HIF)1αand HIF2α,and significantly increased expression of HIF3αcompared to control mice(all P<0.001).Conclusion:Significant differences in gene and TF expression exist between PCOS patients and healthy individuals.HIF-3αmay play a crucial role in PCOS and could serve as a novel biomarker for diagnosis and a potential therapeutic target. 展开更多
关键词 polycystic ovary syndrome transcription factor hypoxia-inducible factors regulatory networks BIOINFORMATICS
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Current status and diversity of fish resources in the Pinglu Canal Century Project
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作者 LU Jia TANG Wei +3 位作者 WANG Li XU Shengxian ZHANG Peng YANG Shengfa 《水利水电技术(中英文)》 北大核心 2025年第4期131-144,共14页
[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of... [Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of fish resources and the characteristics of their diversity is crucial for the ecological management of the Pinglu Canal.[Methods]During the spring and autumn in 2021 and 2022,a survey of fish resources and species diversity in the Pinglu Canal was conducted using multi-mesh gill nets.A total of 125 fish species were collected,belonging to 10 orders,34 families,and 89 genera.[Results]The result showed that the Pinglu Canal contained three nationally protected Class II species,two endemic species of the Qinjiang River,three anadromous/migratory species,and eight invasive species,accounting for 2.4%,1.6%,2.4%,and 6.4%of the total species,respectively.The fish community primarily consisted of mid-and bottom-dwelling,adhesive-egg-laying,and omnivorous species.The Shannon-Wiener,Simpson,Margalef,and Pielou indices of the fish community in the Pinglu Canal ranged from 2.347 to 2.757,0.081 to 0.151,3.493 to 4.382,and 0.812 to 0.892,respectively.These indices showed relatively uniform distribution across different river reaches.[Conclusion]The result indicate that the fish community structure in the Pinglu Canal is relatively uniform.The reach from the Yujiang River to the Shaping River shows higher stability,while other river reaches experience moderate or severe disturbances.This study provides supplementary baseline data on the fish community structure in the Pinglu Canal and explores the potential impact of inter-basin connectivity on fish resources,aiming to provide a scientific basis for habitat restoration assessments after the channel straightening project. 展开更多
关键词 Pinglu Canal Project inter-basin connectivity fish resources community structure BIODIVERSITY influencing factors
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Defect Dipole Thermal-stability to the Electro-mechanical Properties of Fe Doped PZT Ceramics
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作者 SUN Yuxuan WANG Zheng +5 位作者 SHI Xue SHI Ying DU Wentong MAN Zhenyong ZHENG Liaoying LI Guorong 《无机材料学报》 北大核心 2025年第5期545-551,I0009-I0010,共9页
The accepted doping ion in Ti^(4+)-site of PbZr_(y)Ti_(1–y)O_(3)(PZT)-based piezoelectric ceramics is a well-known method to increase mechanical quality factor(Q_(m)),since the acceptor coupled by oxygen vacancy beco... The accepted doping ion in Ti^(4+)-site of PbZr_(y)Ti_(1–y)O_(3)(PZT)-based piezoelectric ceramics is a well-known method to increase mechanical quality factor(Q_(m)),since the acceptor coupled by oxygen vacancy becomes defect dipole,which prevents the domain rotation.In this field,a serious problem is that generally,Qm decreases as the temperature(T)increases,since the oxygen vacancies are decoupled from the defect dipoles.In this work,Q_(m) of Pb_(0.95)Sr_(0.05)(Zr_(0.53)Ti_(0.47))O_(3)(PSZT)ceramics doped by 0.40%Fe_(2)O_(3)(in mole)abnormally increases as T increases,of which the Qm and piezoelectric coefficient(d_(33))at room temperature and Curie temperature(TC)are 507,292 pC/N,and 345℃,respectively.The maximum Qm of 824 was achieved in the range of 120–160℃,which is 62.52%higher than that at room temperature,while the dynamic piezoelectric constant(d_(31))was just slightly decreased by 3.85%.X-ray diffraction(XRD)and piezoresponse force microscopy results show that the interplanar spacing and the fine domains form as temperature increases,and the thermally stimulated depolarization current shows that the defect dipoles are stable even the temperature up to 240℃.It can be deduced that the aggregation of oxygen vacancies near the fine domains and defect dipole can be stable up to 240℃,which pins domain rotation,resulting in the enhanced Q_(m) with the increasing temperature.These results give a potential path to design high Q_(m) at high temperature. 展开更多
关键词 defect dipole temperature characteristic oxygen vacancy electro-mechanical property mechanical quality factor hardening doping
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Basic theory of dust explosion of energetic materials: A review
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作者 Mengli Yin Chunyan Wang +4 位作者 Haoyang Guo Yuhuai Shi Shengnan Shi Wenhui Wang Xiong Cao 《Defence Technology(防务技术)》 2025年第6期48-66,共19页
Due to the presence of nitro groups, the dust generated during the production and utilization of energetic materials may potentially lead to dust explosion even under low-oxygen or anaerobic conditions.Considering the... Due to the presence of nitro groups, the dust generated during the production and utilization of energetic materials may potentially lead to dust explosion even under low-oxygen or anaerobic conditions.Considering the high energy density of energetic materials, dust explosion can cause serious production safety accidents. Therefore, it is necessary to understand the dust explosion characteristics of energetic materials and the mechanism of dust explosion. According to the literature review, among various influencing factors, the physical and chemical properties of dust are the decisive factors affecting the explosion characteristics of dust. In addition to experimental studies, numerical simulation is another important tool. However, it is subjected to certain limitations. Moreover, it is essential but challenging to fully understand the underlying mechanism. In addition, given the safety hazards posed by dust explosion, explosion suppression has attracted extensive attention for research. Depending on the medium used, there are different forms of suppression, including powder explosion suppression, water spray explosion suppression, inert gas explosion suppression, porous material explosion suppression, and vacuum chamber explosion suppression. As for the selection of explosion suppression agent, consideration must be given to the characteristics of the material. Furthermore, the above research has laid a foundation for discussing the future progress in studying dust explosion of energetic materials, with nano dust and the constraints of existing technology as the focal point. 展开更多
关键词 Energetic dust explosion Influencing factors CFD simulation Explosion mechanism Explosion suppression Nano dust
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Fusion of Dual-targeting Peptides with MAP30 Promotes the Apoptosis of MDA-MB-231 Breast Cancer Cells
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作者 YANG Yi-Xuan WANG Xin-Yi +5 位作者 CHEN Wei-Wei GAN Li SUN Yu LIN Tong ZHAO Wei-Chun ZHU Zhen-Hong 《中国生物化学与分子生物学报》 北大核心 2025年第2期260-272,共13页
Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ab... Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ability,the arginine-glycine-aspartic(RGD)peptide and the epidermal growth factor receptor interference(EGFRi)peptide were fused with MAP30,which was named ELRL-MAP30.The efficiency of targeted therapy for triple-negative breast cancer(TNBC)MDA-MB-231 cells,which lack the expression of estrogen receptor(ER),Progesterone receptor(PgR)and human epidermal growth factor receptor-2(HER2),is limited.In this study,we focus on exploring the effect and mechanism of ELRL-MAP30 on TNBC MDA-MB-231 cells.First,we discovered that ELRL-MAP30 significantly inhibited the migration and invasion of MDA-MB-231 cells and induced MDA-MB-231 cell apoptosis.Moreover,ELRL-MAP30 treatment resulted in a significant increase in Bax expression and a decrease in Bcl-2 expression.Furthermore,ELRL-MAP30 triggered apoptosis via the Fak/EGFR/Erk and Ilk/Akt signaling pathways.In addition,recombinant ELRL-MAP30 can inhibit chicken embryonic angiogenesis,and also inhibit the tube formation ability of human umbilical vein endothelial cells(HUVECs),indicating its potential therapeutic effects on tumor angiogenesis.Collectively,these results indicate that ELRL-MAP30 has significant tumor-targeting properties in MDA-MB-231 cancer cells and reveals potential therapeutic effects on angiogenesis.These findings indicate the potential role of ELRL-MAP30 in the targeted treatment of the TNBC cell line MDA-MB-231. 展开更多
关键词 arginine-glycine-aspartic peptide(RGD) epidermal growth factor receptor interference peptide(EGFRi) momordica antiviral protein(MAP30) MDA-MB-231 cell tumor targeting APOPTOSIS
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The Expression Characteristics,Clinical Relevance and Tumor Inhibition of KCNN3 in Gastric Adenocarcinoma
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作者 ZHAN Zi-Qing JIN Jia-Bei +3 位作者 LI Yu-Xuan SHI Jia-Xin YE Meng JIN Xiao-Feng 《中国生物化学与分子生物学报》 北大核心 2025年第4期560-575,I0003-I0006,共20页
Potassium-calcium activates channel subfamily N member 3(KCNN3/SK3/KCa2.3)is involved in regulating cellular calcium signaling,muscle contraction and neurotransmitter release.Dysregulation of the KCNN3 channel is asso... Potassium-calcium activates channel subfamily N member 3(KCNN3/SK3/KCa2.3)is involved in regulating cellular calcium signaling,muscle contraction and neurotransmitter release.Dysregulation of the KCNN3 channel is associated with the development of various tumors.We use bioinformatics analysis to identify whether KCNN3 regulates the occurrence and development of stomach adenocarcinoma(STAD)as a prognostic target.By analyzing the Human Protein Atlas(HPA)database and The Cancer Genome Atlas(TCGA)database,we found that the protein and mRNA levels of KCNN3 were dramatically reduced in STAD,and TCGA database showed that KCNN3 significantly correlated with the prognosis and clinical features of STAD.In addition,we found that high expression of KCNN3 in STAD reduced the IC 50 of several drugs in STAD cells,suggesting that high expression of KCNN3 correlated with the drug sensitivity of STAD.To investigate the underlying biological mechanism,we identified a potential KCNN3 interaction factor,tumor necrosis factor receptor superfamily member 7(CD27/TNFRSF7),which is expressed at low levels in STAD.RT-qPCR and Western blotting confirmed that KCNN3 and CD27 positively correlated with each other at protein and mRNA levels,and co-immunoprecipitation and immunofluorescence experiments confirmed that the two proteins interact and colocalize in the cytoplasm.Moreover,we confirmed the inhibitory effect of KCNN3 on the proliferation,migration and invasion of human STAD cells in vitro and in vivo through subcutaneous tumorigenesis and cellular experiments.Furthermore,GO/KEGG enrichment analysis showed that KCNN3 was enriched in signaling pathways regulating the immune response and calcium or metal ion transport.Lastly,we verified through cell co-culture,RT-qPCR and CCK8 assays that high expression of KCNN3 can promote the increase of T cell activating factor and the killing effect of T cells on STAD cells.Therefore,our results suggest that KCNN3 is a potential inhibitory factor affecting the occurrence and progression of STAD. 展开更多
关键词 stomach adenocarcinoma(STAD) potassium calcium-activated channel subfamily N member 3(KCNN3/SK3/KCa2.3) tumor necrosis factor receptor superfamily member 7(CD27/TNFRSF7) drug sensitivity bioinformatics analysis
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Molecular Cloning and Characterization of the Actin-depolymerizing Factor Gene in Gossypium barbadense
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作者 MA Zhi-ying,CHI Ji-na,WANG Xing-fen,ZHOU Hong-mei,ZHANG Gui-yin(Agricultural University of Hebei,Baoding,Hebei 071001,China) 《棉花学报》 CSCD 北大核心 2008年第S1期41-,共1页
Sea Island cotton(Gossypium barbadense L.) has been highly valued in Verticillium wilt resistance and many fiber qualities including fiber length,strength,and fineness.To identify whether
关键词 Molecular Cloning and Characterization of the Actin-depolymerizing factor Gene in gossypium barbadense GENE length
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基于改进CPD的RIS辅助毫米波OFDM系统信道估计算法 被引量:1
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作者 任进 李一博 +1 位作者 周培豫 李玉宇 《无线电通信技术》 北大核心 2025年第1期29-35,共7页
在无线通信领域,系统性能的优劣通常与无线信道的特性密切相关。精确掌握信道和信号参数对于提升信息传输的可靠性和效率至关重要,因此信道估计成为该领域的核心技术之一。由于无线信道的不可预测性以及信号在传输过程中涉及多个维度(... 在无线通信领域,系统性能的优劣通常与无线信道的特性密切相关。精确掌握信道和信号参数对于提升信息传输的可靠性和效率至关重要,因此信道估计成为该领域的核心技术之一。由于无线信道的不可预测性以及信号在传输过程中涉及多个维度(如空间、时间、频率等),使得信道估计方法的设计变得异常复杂。近期研究表明,通过将这些多维度信号转换为张量并进行分析,可以显著降低信道估计的技术难度。探讨了信道估计算法的改进方法,特别是引入中心化处理作为数据预处理的一部分。中心化处理通过调整数据的均值来减少低频噪声,从而提高信噪比(Signal-to-Noise Ratio,SNR)。这不仅提升了信道估计的准确性,还降低了算法实现的复杂度,加快了模型的训练速度并提高了收敛效率。此外,还采用了因子分解的方法对张量进行分解,进一步降低了计算复杂度并提高了估计精度。仿真实验结果表明,改进后的算法不仅具有更高的准确度,而且在低SNR环境下表现出更优越的性能。 展开更多
关键词 智能反射面辅助 正交频分复用技术 信道估计 张量 因子分解
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Jiles-Atherton磁滞模型的改进与非正弦激励下软磁材料复杂磁滞准确模拟 被引量:2
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作者 刘任 顾朝阳 +1 位作者 孙江东 唐波 《中国电机工程学报》 北大核心 2025年第5期2016-2026,I0034,共12页
原始J-A(Jiles-Atherton)模型及其现有改进模型均不能准确模拟软磁材料在非正弦激励下含偏置小磁滞回环的复杂磁滞回线,因此,提出一种通用改进J-A模型已成为国际电磁场领域研究的热点与难点。为此,该文首先分析J-A模型不能准确模拟不同... 原始J-A(Jiles-Atherton)模型及其现有改进模型均不能准确模拟软磁材料在非正弦激励下含偏置小磁滞回环的复杂磁滞回线,因此,提出一种通用改进J-A模型已成为国际电磁场领域研究的热点与难点。为此,该文首先分析J-A模型不能准确模拟不同类型磁滞回环的问题,得到其根本原因为J-A模型中的不可逆磁化分量变化率未进行矫正,由此引入2个比例因子,控制其不可逆磁化分量满足要求;其次,发现J-A模型的钉扎系数和磁畴内耦合平均场参数随磁滞回线磁密幅值大小而变化,进一步提出改进J-A模型;另外,提出该改进模型参数的更新方法,弥补了传统方法须预知磁滞回线下一转折点数据的缺陷,需要指出的是,所提改进J-A模型所有参数通过实测对称磁滞回线即可辨识;最后,利用所提改进J-A模型与现有2种改进J-A模型分别模拟软磁材料在不同磁密下的对称磁滞回线与含偏置小回环的复杂磁滞回线,并对比实测值,验证所提改进J-A模型具有更高精度。 展开更多
关键词 软磁材料 磁滞回线 Jiles-Atherton模型 非正弦激励 比例因子
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New weighting factors assignment of evidence theorybased one vidence distance 被引量:3
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作者 ChenLiangzhou ShiWenkang DuFeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第2期273-278,共6页
Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict ... Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict information exists. Based on the analysis of some modified methods, Assigning the weighting factors according to the intrinsic characteristics of the existing evidence sources is proposed, which is determined on the evidence distance theory. From the numerical examples, the proposed method provides a reasonable result with good convergence efficiency. In addition, the new rule retrieves to the Yager's formula when all the evidence sources contradict to each other completely. 展开更多
关键词 evidence theory rule of combination weighting factors evidence distance.
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Comprehensive safety factor of roof in goaf underdeep high stress 被引量:11
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作者 JIANG Li-chun JIAO Hua-zhe +1 位作者 WANG Yu-dan WANG Ge-ge 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期595-603,共9页
The safety factor of roof under deep high stress is a quantitative index for evaluating roof stability.Based on the failure mode of surrounding rock of stope roof,the mechanics model of goaf roof is constructed,and th... The safety factor of roof under deep high stress is a quantitative index for evaluating roof stability.Based on the failure mode of surrounding rock of stope roof,the mechanics model of goaf roof is constructed,and the internal force of roof is deduced by the theory of hingeless arch.The calculation method of roof safety factor(K)under the environment of deep mining is proposed in view of compression failure and shear failure of roof.The calculation formulas of shear safety factor(K1),compression safety factor(K2)and comprehensive safety factor(K)of roof are given.The influence of stope span and roof thickness on roof stability is considered in this paper.The results show that when the roof thickness remains constant,the roof safety factor decreases with the increasing of the stope span;when the stope span remains constant,the roof safety factor increases with the increasing of the roof thickness.The deep mining example shows that when the stope span is 30 m and the roof thickness is 10 m,the roof comprehensive safety factor is 1.12,which indicates the roof is in a stable state. 展开更多
关键词 deep mining high stress hingeless arch comprehensive safety factor stope span
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Protective role of FoxO transcription factors against oxidative stress-induced chondrocyte dysfunction:a new therapeutic target for osteoarthritis 被引量:1
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作者 Ri-kang WANG 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2017年第10期975-975,共1页
Chondrocyte dysfunction has been demonstrated to be a major inducer of osteoarthritis(OA).The pathological mechanism of chondrocyte dysfunction is definitely multifactoral,but oxidative stressis regarded as one of the... Chondrocyte dysfunction has been demonstrated to be a major inducer of osteoarthritis(OA).The pathological mechanism of chondrocyte dysfunction is definitely multifactoral,but oxidative stressis regarded as one of the leading causes of apoptosis,autophagy,senescence,and mitochondrial dysfunctionin chondrocytes.Strategies for arresting oxidative stress-induced chondrocyte dysfunction have been considered as potential therapeutic targets for OA.Recently,fork head box O(Fox O)transcription factors have been determined to play a protective role in chondrocytes through the regulation of autophagy and defense against oxidative stress;they also regulate growth,maturation,and matrix synthesis.To explore Fox O′s potential role in the treatment of OA,we first discussed the recent advances in the field of oxidative stress-induced chondrocyte dysfunction and then emphasized the protective role of fox otranscription factors as a potential molecular target for the treatment of OA.Understanding the function of fox otranscription factors will be important in designing next-generation therapies to prevent or reverse the development of OA. 展开更多
关键词 fox otranscription factors oxidative stress chondrocyte dysfunction OSTEOARTHRITIS
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Genome-wide identification of Gossypium INDETERMINATE DOMAIN genes and their expression profiles in ovule development and abiotic stress responses 被引量:7
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作者 ALI Faiza QANMBER Ghulam +5 位作者 LI Yonghui MA Shuya LU Lili YANG Zuoren WANG Zhi LI Fuguang 《Journal of Cotton Research》 2019年第1期1-16,共16页
Background:INDETERMINATE DOMAIN(IDD)transcription factors form one of the largest and most conserved gene families in plant kingdom and play important roles in various processes of plant growth and development,such as... Background:INDETERMINATE DOMAIN(IDD)transcription factors form one of the largest and most conserved gene families in plant kingdom and play important roles in various processes of plant growth and development,such as flower induction in term of flowering control.Till date,systematic and functional analysis of IDD genes remained infancy in cotton.Results:In this study,we identified total of 162 IDD genes from eight different plant species including 65 IDD genes in Gossypium hirsutum.Phylogenetic analysis divided IDDs genes into seven well distinct groups.The gene structures and conserved motifs of GhIDD genes depicted highly conserved exon-intron and protein motif distribution patterns.Gene duplication analysis revealed that among 142 orthologous gene pairs,54 pairs have been derived by segmental duplication events and four pairs by tandem duplication events.Further,Ka/Ks values of most of orthologous/paralogous gene pairs were less than one suggested the purifying selection pressure during evolution.Spatiotemporal expression pattern by qRT-PCR revealed that most of the investigated GhIDD genes showed higher transcript levels in ovule of seven days post anthesis,and upregulated response under the treatments of multiple abiotic stresses.Conclusions:Evolutionary analysis revealed that IDD gene family was highly conserved in plant during the rapid phase of evolution.Whole genome duplication,segmental as well as tandem duplication significantly contributed to the expansion of IDD gene family in upland cotton.Some distinct genes evolved into special subfamily and indicated potential role in the allotetraploidy Gossypium hisutum evolution and development High transcript levels of GhIDD genes in ovules illustrated their potential roles in seed and fiber development Further,upregulated responses of GhIDD genes under the treatments of various abiotic stresses suggested them as important genetic regulators to improve stress resistance in cotton breeding. 展开更多
关键词 UPLAND cotton IDD transcription factor Gene DUPLICATION COLLINEARITY Spatiotemporal expression Abiotic stresses
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TESTING THE VALIDITY OF Ar/Ar SINGLE-CRYSTAL WHITE MICA AGES FOR EROSION, EXHUMATION AND PROVENANCE STUDIES:RECENT SEDIMENTS FROM THE GANGA RIVER, NORTH INDIA 被引量:1
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作者 Nikki White 1, Malcolm Pringle 2, Yani Najman 3, Mike Bickle 1, Peter Friend 1, Judith Bunbury 1 2 Sco 《地学前缘》 EI CAS CSCD 2000年第S1期351-353,共3页
Detrital white mica single\|crystal Ar\|Ar ages from the Himalayan foreland sedimentary record are potentially a powerful tool in constraining source regions, tectonic evolution, and the timing and extent of exhumatio... Detrital white mica single\|crystal Ar\|Ar ages from the Himalayan foreland sedimentary record are potentially a powerful tool in constraining source regions, tectonic evolution, and the timing and extent of exhumation (Copeland 1990, Najman 1997, White 1999). However such studies require large numbers of analyses, and Ar/Ar total\|fusion of white mica grains is a very rapid and cost\|effective technique.Such analyses, however, do result in the sacrifice of internal consistency checks inherent in, for example, Ar/Ar step\|heating analysis. 展开更多
关键词 white MICA age TESTING sediment Ganga River North India
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Roles of NAC transcription factors in cotton
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作者 XU Yuewei ZHAO Yunlei +3 位作者 CHEN Wei SANG Xiaohui ZHAO Pei WANG Hongmei 《Journal of Cotton Research》 CAS 2024年第3期289-301,共13页
Climate deterioration,water shortages,and abiotic stress are the main threats worldwide that seriously affect cotton growth,yield,and fiber quality.Therefore,research on improving cotton yield and tolerance to biotic ... Climate deterioration,water shortages,and abiotic stress are the main threats worldwide that seriously affect cotton growth,yield,and fiber quality.Therefore,research on improving cotton yield and tolerance to biotic and abiotic stresses is of great importance.The NAC proteins are crucial and plant-specific transcription factors(TFs)that are involved in cotton growth,development,and stress responses.The comprehensive utilization of cotton NAC TFs in the improvement of cotton varieties through novel biotechnological methods is feasible.Based on cotton genomic data,genome-wide identification and analyses have revealed potential functions of cotton NAC genes.Here,we comprehensively summarize the recent progress in understanding cotton NAC TFs roles in regulating responses to drought,salt,and Verticillium wilt-related stresses,as well as leaf senescence and the development of fibers,xylem,and glands.The detailed regulatory network of NAC proteins in cotton is also elucidated.Cotton NAC TFs directly bind to the promoters of genes associated with ABA biosynthesis and secondary cell-wall formation,participate in several biological processes by interacting with related proteins,and regulate the expression of downstream genes.Studies have shown that the overexpression of NAC TF genes in cotton and other model plants improve their drought or salt tolerance.This review elucidates the latest findings on the functions and regulation of cotton NAC proteins,broadens our understanding of cotton NAC TFs,and lays a fundamental foundation for further molecular breeding research in cotton. 展开更多
关键词 COTTON NAC transcription factor STRESS Regulatory network
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Influencing factors analysis of hard limestone reformation and strength weakening under acidic effect
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作者 HOU Ming-xiao HUANG Bing-xiang +2 位作者 ZHAO Xing-long JIAO Xue-jie ZHENG Chen-yang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2446-2466,共21页
Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way t... Roof disaster has always been an important factor restricting coal mine safety production.Acidic effect can reform the rock mass structure to weaken the macroscopic strength characteristics,which is an effective way to control the hard limestone roof.In this study,the effects of various factors on the reaction characteristics and mechanical properties of limestone were analyzed.The results show that the acid with stronger hydrogen production capacity after ionization(pK_(a)<0)has more prominent damage to the mineral grains of limestone.When pKa increases from−8.00 to 15.70,uniaxial compressive strength and elastic modulus of limestone increase by 117.22%and 75.98%.The influence of acid concentration is manifested in the dissolution behavior of mineral crystals,the crystal defects caused by large-scale acid action will lead to the deterioration of limestone strength,and the strength after 15%concentration reformation can be reduced by 59.42%.The effect of acidification time on limestone has stages and is the most obvious in the initial metathesis reaction stage(within 60 min).The key to the strength damage of acidified limestone is the participation of hydrogen ions in the reaction system.Based on the analytic hierarchy process method,the influence weights of acid type,acid concentration and acidification time on strength are 24.30%,59.54% and 16.16%,respectively.The research results provide theoretical support for the acidification control of hard limestone roofs in coal mines. 展开更多
关键词 hard roof acidic effect structural reformation strength weakening influencing factors
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Controlling factors of high-quality volcanic reservoirs of Yingcheng Formation in the Songnan gas field 被引量:3
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作者 DU Shang SHAN Xuan-long +1 位作者 YI Jian LI Ji-yan 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第4期892-902,共11页
Predicting high-quality volcanic reservoirs is one of the key issues for oil and gas exploration in the Songnan gas field.Core,seismic,and measurement data were used to study the lithologies,facies,reservoir porosity,... Predicting high-quality volcanic reservoirs is one of the key issues for oil and gas exploration in the Songnan gas field.Core,seismic,and measurement data were used to study the lithologies,facies,reservoir porosity,and reservoir types of the volcanic rocks in the Songnan gas field.The primary controlling factors and characteristics of the high-quality volcanic reservoirs of the Yingcheng Formation in the Songnan gas field were investigated,including the volcanic eruptive stage,edifice,edifice facies,cooling unit,lithology,facies,and diagenesis.Stages with more volatile content can form more high-quality reservoirs.The effusive rhyolite,explosive tuff,and tuff lava that formed in the crater,near-crater,and proximal facies and in the high-volatility cooling units of large acidic-lava volcanic edifices are the most favorable locations for the development of the high-quality reservoirs in the Songnan gas field.Diagenesis dissolution,which is controlled by tectonic action,can increase the size of secondary pores in reservoirs.Studying the controlling factors of the high-quality reservoirs can provide a theoretical basis for the prediction and analysis of high-quality volcanic reservoirs. 展开更多
关键词 Songnan gas field Yingcheng Formation high-quality volcanic reservoir controlling factor
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Research on User Profile Construction Method Based on Improved TF-IDF Algorithm
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作者 SHAO Ze-ming LI Yu-ang +4 位作者 YANG Ke WANG Guo-peng LIU Xing-guo CHEN Han-ning SI Zhan-jun 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第6期110-116,共7页
In the data-driven era of the internet and business environments,constructing accurate user profiles is paramount for personalized user understanding and classification.The traditional TF-IDF algorithm has some limita... In the data-driven era of the internet and business environments,constructing accurate user profiles is paramount for personalized user understanding and classification.The traditional TF-IDF algorithm has some limitations when evaluating the impact of words on classification results.Consequently,an improved TF-IDF-K algorithm was introduced in this study,which included an equalization factor,aimed at constructing user profiles by processing and analyzing user search records.Through the training and prediction capabilities of a Support Vector Machine(SVM),it enabled the prediction of user demographic attributes.The experimental results demonstrated that the TF-IDF-K algorithm has achieved a significant improvement in classification accuracy and reliability. 展开更多
关键词 TF-IDF-K algorithm User profiling Equalization factor SVM
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