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珊瑚钨矿岩体质量分级与基于Hoek-Brown强度准则的岩体强度估计 被引量:2
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作者 雷显权 刘福春 +2 位作者 熊有为 张军 刘恩彦 《矿业研究与开发》 北大核心 2025年第1期158-164,共7页
岩体强度是矿山工程安全稳定性分析的关键力学参数。结合珊瑚钨矿小型机械化开采技术攻关项目,在对岩体结构面进行详细调查的基础上,采用BQ、Q和RMR等3种方法进行岩体质量分级与稳定性评价,然后基于定量GSI和Hoek-Brown准则估计岩体强度... 岩体强度是矿山工程安全稳定性分析的关键力学参数。结合珊瑚钨矿小型机械化开采技术攻关项目,在对岩体结构面进行详细调查的基础上,采用BQ、Q和RMR等3种方法进行岩体质量分级与稳定性评价,然后基于定量GSI和Hoek-Brown准则估计岩体强度,获得准确可靠的岩体强度参数。研究结果表明:(1)灰岩岩体的优势节理面走向为NNW-SSE或NW-SE,倾向为NE或SW,倾角较大,体积节理数Jv为7.07~9.88条/m^(3),完整性系数Kv为0.55~0.63,岩体总体较完整;(2)灰岩岩体的[BQ]值、Q值和RMR89值分别为380.96,5.58和59,岩体质量等级为Ⅲ级或一般;(3)根据BQ分级结果,当巷道或采场跨度小于5 m时,围岩可基本稳定;根据Q分级结果,巷道或采场的最大不支护跨度约为6.35 m;根据RMR分级结果,当巷道或采场跨度为5 m时,围岩平均自立稳定时间可达7 d;(4)基于定量GSI和Hoek-Brown准则估计岩体强度,获得了灰岩岩体的Hoek-Brown强度参数和等效Mohr-Coulomb强度参数,为采矿设计和岩体稳定性分析提供了准确可靠的力学参数。 展开更多
关键词 岩体质量分级 岩体强度 HOEK-brown强度准则 地质强度指标
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砂化白云岩Hoek-Brown准则参数取值方法研究及其岩体力学参数估算 被引量:1
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作者 莫云 胡新丽 +3 位作者 崔德山 顾东明 谢昭宇 杨勇 《岩土力学》 北大核心 2025年第1期257-265,共9页
武汉市碳酸盐岩天兴洲条带,发育一套巨厚层砂化白云岩,其岩体力学参数取值,目前尚无相关经验或建议。基于Hoek-Brown(简称H-B)准则及其Mohr-Coulomb(简称M-C)线性转换理论,归纳总结前人研究成果,在试验数据的基础上,研究了砂化白云岩的... 武汉市碳酸盐岩天兴洲条带,发育一套巨厚层砂化白云岩,其岩体力学参数取值,目前尚无相关经验或建议。基于Hoek-Brown(简称H-B)准则及其Mohr-Coulomb(简称M-C)线性转换理论,归纳总结前人研究成果,在试验数据的基础上,研究了砂化白云岩的H-B准则参数,提出一种基于静止侧压力系数k_(1)的最大围压上限σ_(3max)简化取值方法,估算其岩体力学参数并给出了取值建议。结果表明:基于k_(1)的σ_(3m)_(ax)简化取值方法,合理缩减了围压σ_(3)的取值区间,提高了计算精度;砂化白云岩的地质强度指数GSI与无侧限抗压强度σ_(ci)呈良好的线性关系,结合其砂化程度在岩体块度上的贴切表现,制作了针对砂化白云岩的改进GSI建议值表;岩体材料参数m_(i)的大小主要受控于岩石种类及细观颗粒的粗糙程度,其取值区间跨度小且对岩体力学参数影响较小,取用m_(i)=9;通过H-B准则与M-C准则的线性转换,建立了σ_(ci)与岩体抗剪强度之间的计算关系;各试验值、拟合值及理论计算值之间关系自洽、结果合理,有效解决了极破碎白云岩岩体力学参数的取值问题。上述基础性工作对H-B准则的应用起到了有益的补充,对武汉市类似岩层的岩体力学参数取值方法研究及运用具有重要借鉴意义。 展开更多
关键词 砂化白云岩 HOEK-brown强度准则 地质强度指数(GIS) 岩体力学参数
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基于非局部理论的Hoek-Brown软化塑性模型
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作者 周鑫 于佳佳 +2 位作者 吴文杰 路德春 杜修力 《防灾减灾工程学报》 北大核心 2025年第1期13-20,共8页
由于缺失材料特征长度,局部应变软化模型在模拟结构层面的失效破坏时,会出现网格依赖性问题,严重影响计算结果的准确性与可靠性。本研究提出了非局部的Hoek-Brown软化塑性模型,该模型基于光滑的Hoek-Brown强度准则构造屈服函数,并利用... 由于缺失材料特征长度,局部应变软化模型在模拟结构层面的失效破坏时,会出现网格依赖性问题,严重影响计算结果的准确性与可靠性。本研究提出了非局部的Hoek-Brown软化塑性模型,该模型基于光滑的Hoek-Brown强度准则构造屈服函数,并利用过非局部公式将等效塑性剪应变发展为非局部变量,有效规避了结构失效破坏模拟时的网格依赖性问题。利用隐式返回映射应力更新算法求解非局部塑性模型的微分方程组,详细介绍了该模型的有限元实现流程。最后,以经典的缺陷板受压破坏问题和条形基础承载力问题为例,对模型的有效性进行验证。结果表明,在网格细化过程中,非局部Hoek-Brown软化塑性模型的模拟结果对网格尺寸不敏感,预测的剪切带宽度和荷载位移曲线基本不随网格尺寸变化。所提模型可为岩石工程的失效破坏分析提供具有网格客观性的计算工具。 展开更多
关键词 非局部积分方法 软化塑性模型 HOEK-brown强度准则 应力更新算法
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基于一种改进的三维Hoek-Brown强度准则井壁稳定评价模型及应用
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作者 石祥超 张琴 +1 位作者 高雷雨 张豪 《石油科学通报》 2025年第4期762-777,共16页
在钻井工程中,井壁稳定性分析直接关系到井身结构设计、钻井液密度窗口设计及钻井施工安全。传统强度准则因大多为线性假设和忽略中间主应力效应,难以准确表征深部复杂地质条件下岩石的非线性破坏特征,所以选取适宜的强度准则是准确评... 在钻井工程中,井壁稳定性分析直接关系到井身结构设计、钻井液密度窗口设计及钻井施工安全。传统强度准则因大多为线性假设和忽略中间主应力效应,难以准确表征深部复杂地质条件下岩石的非线性破坏特征,所以选取适宜的强度准则是准确评价井壁稳定性的关键。本文使用了一种改进的三维Hoek-Brown强度准则,通过理论研究与模型应用相结合的方式,建立了更符合实际工况的井壁稳定性评价模型。研究结果表明:该准则不仅保留了Hoek-Brown强度准则在子午面内的非线性特征,还考虑了中间主应力对岩石强度的影响。改进的三维准则在主应力空间中的屈服面呈圆锥形曲面,屈服曲线满足外凸、光滑且封闭的性质。通过对六种不同岩石真三轴试验数据的对比分析,证明了该准则对各类岩石的良好适用性。将该准则应用于川东铜锣峡气田嘉陵江组灰岩地层的井壁稳定性分析,计算得到坍塌压力当量密度为1.16 g/cm3,在沿最大水平主应力方向钻进时,坍塌压力当量密度最低,符合实际工况,优于其他四种传统强度准则。改进的三维Hoek-Brown强度准则为井壁稳定性分析提供了一种更加精确且实用的方法。 展开更多
关键词 改进的三维Hoek-brown强度准则 屈服面 屈服曲线 井壁稳定 坍塌压力当量密度
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基于广义Hoek-Brown准则的地表移动变形规律
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作者 迟学海 《黑龙江科技大学学报》 2025年第3期423-428,441,共7页
针对万成矿业煤炭开采活动对地表移动变形产生影响的问题,基于广义Hoek-Brown准则确定该矿岩体力学参数,运用FLAC^(3D)软件建立开采数值模型,结合地表沉降观测数据和采动沉降规律,分析该矿10^(#)煤层开采活动和地表沉降的关系。结果表明... 针对万成矿业煤炭开采活动对地表移动变形产生影响的问题,基于广义Hoek-Brown准则确定该矿岩体力学参数,运用FLAC^(3D)软件建立开采数值模型,结合地表沉降观测数据和采动沉降规律,分析该矿10^(#)煤层开采活动和地表沉降的关系。结果表明,10^(#)煤层开采引起地表变形的下沉系数为0.81,水平移动系数为0.26,主要影响角正切值为2.07,开采影响传播角为79°。研究可为矿区开采条件相近煤矿的开采设计、保护煤柱留设、生产作业规程编制、地面建筑保护、生态修复及地质灾害治理等提供参考。 展开更多
关键词 煤炭开采 地表移动变形 广义Hoek-brown准则
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基于广义Hoek-Brown准则的圆形巷道围岩弹塑性解析
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作者 王红英 张强 +2 位作者 吴培楠 韩立军 韩贵雷 《采矿与安全工程学报》 北大核心 2025年第4期789-797,共9页
Hoek-Brown屈服准则广泛用于巷道围岩弹塑性分析,然而广义Hoek-Brown屈服准则为非线性函数,导致静水压力条件下圆形巷道围岩弹塑性位移的解析解无法获得。基于广义Hoek-Brown屈服准则和非关联流动法则,推导圆形巷道围岩应力理论解;利用... Hoek-Brown屈服准则广泛用于巷道围岩弹塑性分析,然而广义Hoek-Brown屈服准则为非线性函数,导致静水压力条件下圆形巷道围岩弹塑性位移的解析解无法获得。基于广义Hoek-Brown屈服准则和非关联流动法则,推导圆形巷道围岩应力理论解;利用变量代换方法,将巷道塑性区围岩位移解表达式中以对数函数为底数的指数积分项转化为幂函数与指数函数的乘积形式;进一步借助级数展开方法,将其转换为一系列幂函数之和的积分项,最终获得塑性区围岩径向位移的解析表达式。通过5种典型理想弹(脆)塑性岩石算例,将解析解与数值积分解、近似理论解进行对比,验证了文中解析解的正确性,可为广义Hoek-Brown屈服地层中圆形巷道的弹塑性分析提供理论基准。 展开更多
关键词 圆形巷道 解析解 弹塑性 屈服准则 HOEK-brown
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具有分数Brown运动的分数阶中立型随机微分方程解的存在唯一性
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作者 李国平 韩婷 《河南师范大学学报(自然科学版)》 北大核心 2025年第3期104-111,共8页
研究了一类在Hilbert空间中具有分数Brown运动的分数阶中立型随机微分方程,利用Picard逐步逼近法得到了其非Lipschitz条件和弱化的线性增长条件下粘性解的新的存在唯一性的充分条件.所提的研究方法使得先前一些研究结果得到了拓展.最后... 研究了一类在Hilbert空间中具有分数Brown运动的分数阶中立型随机微分方程,利用Picard逐步逼近法得到了其非Lipschitz条件和弱化的线性增长条件下粘性解的新的存在唯一性的充分条件.所提的研究方法使得先前一些研究结果得到了拓展.最后通过具有分数Brown运动的随机非线性波动方程验证了理论的有效性. 展开更多
关键词 分数阶随机微分方程 分数brown运动 粘性解 存在唯一性
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由分数Brown运动驱动的EGARCH模型
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作者 王玮莹 韩月才 《吉林大学学报(理学版)》 北大核心 2025年第1期41-46,共6页
针对传统EGARCH模型难以捕捉长记忆性的问题,通过引入分数Brown运动提出一个fBm-EGARCH模型,给出模型的二阶矩、四阶矩及协方差函数性质,并理论证明其长期记忆性.数值模拟结果表明,该模型不仅能准确捕捉短期波动,还能反映长期记忆性,从... 针对传统EGARCH模型难以捕捉长记忆性的问题,通过引入分数Brown运动提出一个fBm-EGARCH模型,给出模型的二阶矩、四阶矩及协方差函数性质,并理论证明其长期记忆性.数值模拟结果表明,该模型不仅能准确捕捉短期波动,还能反映长期记忆性,从而验证了模型的有效性. 展开更多
关键词 EGARCH模型 分数brown运动 长期记忆性 流动性
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基于广义Hoek-Brown准则的岩体力学参数确定及岩体质量评价
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作者 周帆 张佳男 +5 位作者 付学会 王万禄 刘通 王智能 吴浩 袁明礼 《有色金属(矿山部分)》 2025年第4期120-128,共9页
昆阳磷矿二矿地质条件极为复杂且普遍采用的钻爆施工方法对岩体扰动影响显著,如何科学可靠地评价矿山岩层岩体质量是保障矿山安全、高效、经济开采的关键。针对矿山开采技术条件,首先在井巷掘进过程中现场采集了各岩层岩块并制备了标准... 昆阳磷矿二矿地质条件极为复杂且普遍采用的钻爆施工方法对岩体扰动影响显著,如何科学可靠地评价矿山岩层岩体质量是保障矿山安全、高效、经济开采的关键。针对矿山开采技术条件,首先在井巷掘进过程中现场采集了各岩层岩块并制备了标准岩样,分别进行了单轴压缩实验、巴西劈裂实验和变角剪切实验等系列岩石物理力学实验;随后提出了一种基于广义Hoek-Brown准则的岩体力学参数折减方法和评价指标定量赋分的改进RMR岩体质量评价方法并在昆阳磷矿二矿进行了应用实践。研究结果表明,室内岩石物理力学实验获得了矿山五种岩石的常规物理力学参数,在此基础上得出粉砂质页岩、顶板白云岩、上矿体、下矿体和底板白云岩岩体质量等级分别为Ⅱ、Ⅲ、Ⅲ、Ⅲ和Ⅱ,同时进一步折减计算得出了矿山五个岩层岩体的单轴抗压强度、抗拉强度、弹性模量、内聚力和内摩擦角,为矿山岩体工程施工提供了基础数据。 展开更多
关键词 岩体力学参数 岩体质量 HOEK-brown准则 RMR 强度折减
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Hydroxy-α-sanshool-loaded adipose-targeted mesoporous silica nanoparticles induce white adipose browning and reduce obesity by activating TRPV1 被引量:1
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作者 Qing Zhang Chengxun He +5 位作者 Juan Guo Dandan Tang Die Qian Chuan Zheng Chunjie Wu Wei Peng 《Bio-Design and Manufacturing》 2025年第2期288-309,I0005-I0011,共29页
Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxy... Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxylum bungeanum,which promotes the management of obesity by triggering the browning of white adipose tissue(WAT)targeting the membrane receptor of transient receptor potential vanilloid 1(TRPV1).However,HAS easily undergoes configuration transformation and oxidative degradation.The short peptide CKGGRAKDC or adipose-targeting sequence(ATS)binds specifically to prohibitin on the surface of WAT cells and can be used as recognition assembly to enhance adipocyte targetability.Furthermore,mesoporous silica nanoparticles(MSNs)are widely used in drug delivery systems because of their large specific surface area and pore volume.Therefore,HAS-loaded adipose-targeted MSNs(MSNs-ATS)were developed to enhance the adipocyte targetability,safety,and efficacy of HAS,and tested on mature 3T3-L1 cells and obese mouse models.MSNs-ATS showed higher specificity for adipocyte targetability without obvious toxicity.HAS-loaded MSNs-ATS showed anti-obesity effects superior to those of HAS alone.In conclusion,we successfully developed adipocyte-targeted,HAS-loaded MSNs with good safety and anti-obesity effects. 展开更多
关键词 Hydroxy-α-sanshool Adipocyte targetability Mesoporous silica nanoparticles White adipose tissue browning OBESITY
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混合双分数Brown运动驱动的4/2-CIR模型及欧式期权定价
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作者 杨源 夏莉 《应用数学进展》 2025年第8期86-94,共9页
文章以资产价格的特征函数为研究工具,深入探讨了欧式期权的定价公式。在假定资产价格遵循混合双分数布朗运动驱动的4/2模型、随机利率遵循CIR模型以及随机波动率符合Heston模型的前提下,推导出了资产价格满足的广义特征函数的近似解析... 文章以资产价格的特征函数为研究工具,深入探讨了欧式期权的定价公式。在假定资产价格遵循混合双分数布朗运动驱动的4/2模型、随机利率遵循CIR模型以及随机波动率符合Heston模型的前提下,推导出了资产价格满足的广义特征函数的近似解析解表达式。进而,借助广义特征函数,巧妙运用傅里叶变换及其逆变换,成功构建出欧式看涨期权的定价公式,为欧式期权定价研究提供了新的分析思路。 展开更多
关键词 模板混合双分数brown运动 4/2模型 广义特征函数 傅里叶变换
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Research Progress and Challenges of Tobacco Brown Spot
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作者 Dongkun WANG Ping LYU +12 位作者 Bin WANG Jijun NIU Guohua ZONG Yongqing XU Hairong XU Xiaojie BAI Weina ZHANG Yushan ZHANG Hanyu WU Songwei LIU Xianzhi ZHU Feng LI Lei TIAN 《Plant Diseases and Pests》 2025年第2期1-7,共7页
This paper provide a comprehensive overview of research findings regarding the pathogen responsible for tobacco brown spot,its occurrence regularity,and integrated control strategies.Additionally,this study provide a ... This paper provide a comprehensive overview of research findings regarding the pathogen responsible for tobacco brown spot,its occurrence regularity,and integrated control strategies.Additionally,this study provide a brief analysis of the challenges encountered in the study of tobacco brown spot,which include the study of pathogenesis and virulence,the breeding of disease-resistant varieties,the screening of low-toxicity and high-efficiency agents,the development of biological control methods with more stable efficacy,and the necessity for accurate prediction and forecasting techniques. 展开更多
关键词 TOBACCO brown SPOT INTEGRATED control CHALLENGE
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Harnessing Advanced Genomic Approaches to Unveil and Enhance Brown Planthopper Resistance in Rice
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作者 Lakshmi V.G.ISHWARYA S.VANISRI +5 位作者 P.S.BASAVARAJ M.SREEDHAR Lakshmi V.JHANSI M.MUNTAZIR C.GIREESH S.N.C.V.L.PUSHPAVALLI 《Rice science》 2025年第3期339-352,共14页
Brown planthopper(BPH)is a highly destructive pest that presents a significant challenge to rice production,particularly in the Asia-Pacific region.Numerous BPH-resistant rice varieties have been successfully bred and... Brown planthopper(BPH)is a highly destructive pest that presents a significant challenge to rice production,particularly in the Asia-Pacific region.Numerous BPH-resistant rice varieties have been successfully bred and released for commercial cultivation across diverse rice-growing ecosystems.However,resistance breakdown in several varieties carrying major resistance genes has been reported,highlighting the urgent need for the development of novel,genetically diverse,and broad-spectrum resistant varieties.To date,more than 45 resistance loci have been identified and mapped from both cultivated and wild rice species.Among these,a subset of genes(including Bph1,Bph3,Bph6,Bph7,Bph9,Bph10,Bph14,Bph15,Bph18,Bph21,Bph26/2,bph29,Bph32,Bph37,and Bph30/Bph40)have been positionally cloned.Most of these genes encode coiled-coil nucleotide-binding leucine-rich repeat proteins,which are central to plant immune responses,along with a few signaling molecules playing pivotal roles.In addition to these core resistance genes,various other genetic components,including miRNAs,protein kinases,and transcription factors,have been functionally characterized for their roles in mediating BPH resistance.The advent of post-genomic tools such as RNA sequencing and single-cell sequencing,along with cutting-edge genomic technologies like CRISPR/Cas gene editing,has significantly accelerated resistance breeding programs.In this context,we provide an overview of genetics,mapping,isolation,and functional characterization of BPH resistance,along with strategies for incorporating resistance using advanced genomics-assisted breeding tools.Furthermore,we present a snapshot of how the integration of genomics and novel breeding technologies holds great promise for dissecting the genetic architecture of pest resistance and accelerating crop improvement. 展开更多
关键词 brown planthopper CLONING CRISPR/Cas GENOMICS mapping
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Cordycepin ameliorates brown adipose tissue whitening induced by long-term continuous light exposure via the AMPK/PGC-1α/UCP1 signaling pathway
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作者 Ruonan Zhang Li Zhang +6 位作者 Yuqing Jiang Zhiwei Zhao Guanyu Zhang Yongqiang Zhang Shuai Wu Xi Li Danfeng Yang 《Frigid Zone Medicine》 2025年第3期129-140,I0003,I0004,共14页
Background:Long-term exposure to light has emerged as a novel risk factor for metabolic diseases.The whitening of brown adipose tissue(BAT)may play an important role in metabolic disorders caused by long-term continuo... Background:Long-term exposure to light has emerged as a novel risk factor for metabolic diseases.The whitening of brown adipose tissue(BAT)may play an important role in metabolic disorders caused by long-term continuous light exposure.This study aimed to investigate the morphological and functional alterations in BAT under continuous light conditions and to identify traditional Chinese medicine compounds capable of reversing these changes.Methods:A metabolic disorder model was established by subjecting mice to continuous light exposure for 5 weeks.During this period,body weight,food intake,and body fat percentage were monitored.Serum levels of triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),and low density lipoprotein cholesterol(LDL-C)were measured to assess lipid metabolism.Histological changes in BAT were examined using H&E staining.The expression of the thermogenic marker uncoupling protein 1(UCP1)in BAT was determined by RT-qPCR and Western blot to evaluate thermogenic function.RNA sequencing(RNA-seq)was employed to identify differentially expressed genes(DEGs)involved in BAT whitening induced by prolonged continuous light exposure.DEGs were analyzed using the connectivity map(CMap)database to identify potential preventive and therapeutic compounds.The therapeutic efficacy of the selected compounds was subsequently evaluated using the above indicators,and key pathways were validated through western blot analysis.Results:After 5 weeks of continuous light exposure,mice exhibited increased body fat percentage and serum levels of TG,impaired mitochondrial function,reduced thermogenic capacity,and whitening of BAT.Gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment analyses indicated that BAT whitening was primarily associated with the adenosine 5'-monophosphate-activated protein kinase(AMPK)signaling pathway,fatty acid metabolism,and circadian rhythm.Ten hub genes identified using Cytoscape were mainly related to AMPK signaling and heat shock proteins.In vivo experiments showed that cordycepin significantly attenuated the increase in body fat percentage caused by prolonged light exposure.This effect was mediated by activation of the AMPK/PGC-1α/UCP1 signaling pathway,which restored the multilocular morphology and thermogenic function of BAT.Conclusion:Cordycepin mitigates continuous light-induced BAT whitening and metabolic disturbances by activating the AMPK signaling pathway. 展开更多
关键词 long-term continuous light brown adipose tissue WHITENING CORDYCEPIN AMPK
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Deficiency of circadian gene Per2 blocks luteolin-induced adipocyte browning in mice through weakening liver PPARα/RXRα/FGF21 pathway
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作者 Shanshan Shui Juan Chen +5 位作者 Yan Lin Jingjing Yuan Xin Wang Xian Zhang Jian Liu Lei Zheng 《Food Science and Human Wellness》 2025年第3期892-901,共10页
During the development of diet-induced obesity,the change of energy matebolism is closely related to the function of the circadian clock in mammals.Luteolin(LU),one of the most common natural flavonoids riched in many... During the development of diet-induced obesity,the change of energy matebolism is closely related to the function of the circadian clock in mammals.Luteolin(LU),one of the most common natural flavonoids riched in many edible plants,can ameliorate obesity by activating adipose tissue browning,but its effect on circadian clock in this process remains poorly understood.Here we found that dietary LU improved circadian misalignment of energy expenditure in high-fat diet(HFD)-fed wild-type(WT)mice.Moreover,dietary LU efficiently elevated uncoupling protein 1 levels in adipose tissue during the dark period,which was similar to the LU-increased hepatic PER2 expressions.Hepatic peroxisome proliferators-activated receptorsα(PPARα)/recombinant retinoid X receptorα(RXRα)/fibroblast growth factor 21(FGF21)pathway was rhythmically elevated by dietary LU in HFD-fed WT mice,whereas the promotion was inhibited in Per2^(-/-)mice.Meanwhile,Per2 deletion abolished the effects of dietary LU on adipose tissue browning in HFD-fed mice.Further,LU treatment directly activated PPARα/RXRα/FGF21 signaling in primary cultured hepatocytes from WT mice rather than Per2^(-/-)mice.Taken together,the deletion of the core clock component Per2 impedes LUinduced adipose tissue browning through weakening PPARα/RXRα/FGF21 pathway in mice,providing a new insight into the interplay of energy metabolism and circadian clock for the anti-obesity activity of LU. 展开更多
关键词 Obesity Circadian clock LUTEOLIN Per2 gene Adipose tissue browning
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Pomegranate peel polyphenols improves diet-induced obesity and promotes adipose browning development through gut microbiota in mice
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作者 Zhuoting Luo Xiaoyu Song +2 位作者 Mengting Li Jianke Li Chen Hou 《Food Science and Human Wellness》 2025年第2期605-616,共12页
Gut microbiota regulate the activation of adipose browning,which promote energy dissipation and combat diet-induced obesity.Pomegranate peel polyphenols(PPPs)have been shown to reduce obesity,regulate lipid metabolism... Gut microbiota regulate the activation of adipose browning,which promote energy dissipation and combat diet-induced obesity.Pomegranate peel polyphenols(PPPs)have been shown to reduce obesity,regulate lipid metabolism in adipose tissue,and modulate the composition of gut microbiota in animal fed high-fat diet(HFD).However,the role of gut microbiota in the improvement of obesity by PPPs has not been elucidated.In current study,we applied antibiotics to inhibit gut microbiota in mice fed HFD and treated with PPPs.The results showed that the inhibition of gut microbiota impair the effect of PPPs on reducing obesity and promoting adipose browning,and change the fecal metabolomic profiles in respond to PPPs.Moreover,the inhibition of gut microbiota supressed the promotive effects of PPPs on the levels of Akkermansia and microbiota-related metabolites,such as urolithin A,short-chain fatty acids(SCFAs),and bile acids(BAs),which were associated with activating adipose browning.Therefore,our results suggested that the presence of gut microbiota is essential for PPPs to ameliorate HFD-induced obesity.The related bacteria or metabolites generated by the interaction between PPPs and microbiota promote adipose browning and facilitate the beneficial effects of PPPs. 展开更多
关键词 Pomegranate peel polyphenols OBESITY Gut microbiota High-fat diet Adipose browning
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Research progress on secondary formation,photosensitive reaction mechanism and human health effects of chromophoric brown carbon
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作者 Baihang Chen Jiangyao Chen +1 位作者 Guiying Li Taicheng An 《Journal of Environmental Sciences》 2025年第5期310-330,共21页
Brown carbon(BrC)has attracted widespread attention because of its strong absorption of solar radiation in the ultraviolet-visible wavelength range,which causes adverse impacts on human health.Originally,BrC was a phy... Brown carbon(BrC)has attracted widespread attention because of its strong absorption of solar radiation in the ultraviolet-visible wavelength range,which causes adverse impacts on human health.Originally,BrC was a physically defined class of substances.However,current research has gradually shifted towards the identification of its chemical groups,because its light-absorbing capability,chemical properties and health effects mainly depend on the chemical composition of its chromophores.Therefore,this review mainly focuses on the chemical understanding of BrC based on chromophores,and the secondary formation mechanism of chromophores,photosensitized reactions,and human health effects of BrC were detailly summarized.Firstly,BrC chromophores are divided into five categories:nitrogen-heterocycles,nitrogen-chain,aromatic species,oligomers and sulfur-containing organic compounds.Different chromophore precursor species exhibit variations,and their formation mechanisms are also distinct.Secondly,BrC can trigger the production of secondary organic aerosol(SOA)precursors or cause SOA growth because BrC is an important component of light-absorbing particles formed during incomplete combustion of biomass and fossil fuels,potentially exerting adverse effects on human health.Finally,developing sufficiently separated methods for BrC and refining algorithms and machine learning can lead to a more effective understanding of the chemical composition of chromophores,thus enabling better evaluation of the atmospheric effects and health impacts of BrC.In all,this review provides new insights into the categories of BrC chromophores and new advance in secondary formation mechanisms,photosensitized reactions,and human health effects on the basis of chemical structures. 展开更多
关键词 brown carbon Constituent characteristics Secondary formation mechanism PHOTOSENSITIVE Human health effects
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Genome-Wide Association Study of Brown Rice Weight Identifies an RNA-Binding Protein Antagonistically Regulating Grain Weight and Panicle Number
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作者 ZHOU Lin JIANG Hong +11 位作者 HUANG Long LI Ziang YAO Zhonghao LI Linhan JI Kangwei LI Yijie TANG Haijuan CHENG Jinping BAO Yongmei HUANG Ji ZHANG Hongsheng CHEN Sunlu 《Rice science》 2025年第4期525-536,I0050-I0065,共28页
Rice grain yield is primarily determined by three key agronomic traits:panicle number,grain number per panicle,and grain weight(GW).However,the inherent tradeoffs among these yield components remain a persistent chall... Rice grain yield is primarily determined by three key agronomic traits:panicle number,grain number per panicle,and grain weight(GW).However,the inherent tradeoffs among these yield components remain a persistent challenge in rice breeding programs.Notably,compared with GW,brown rice weight(BRW)provides a more direct metric associated with actual grain yield potential.In this study,we conducted a two-year replicated genome-wide association study to elucidate the genetic architecture of BRW and identify new loci regulating GW.Among seven consistently detected loci across experimental replicates,four were not co-localized with previously reported genes associated with BRW or GW traits.BRW1.1,one of the four newly identified loci,was found to encode a novel RNA-binding protein.Functional characterization revealed that BRW1.1 acts as a negative regulator of BRW,potentially through modulating mRNA translation processes.Intriguingly,through integrated analysis of mutant phenotypes and haplotype variations,we demonstrated that BRW1.1 mediates the physiological tradeoff between GW and panicle number.This study not only delineates the genetic determinants of BRW but also identifies BRW1.1 as a promising molecular target for breaking the yield component tradeoff in precision rice breeding. 展开更多
关键词 genome-wide association study brown rice weight RNA-binding protein TRADEOFF grain weight panicle number grain number rice yield
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时变混合双分数Brown运动下的欧式期权定价
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作者 盛嘉卿 夏莉 张亚茹 《统计学与应用》 2025年第1期240-250,共11页
金融资产价格具有“尖峰厚尾”和长期记忆等分形特征,采用具有GARCH结构的时变混合双分数Brown运动可以描述其动态变化过程。首先,构建混合双分数Brown运动下的期权定价模型和时变参数模型;再选取上证50ETF指数、香港恒生指数、日本东... 金融资产价格具有“尖峰厚尾”和长期记忆等分形特征,采用具有GARCH结构的时变混合双分数Brown运动可以描述其动态变化过程。首先,构建混合双分数Brown运动下的期权定价模型和时变参数模型;再选取上证50ETF指数、香港恒生指数、日本东证指数的历史收盘价进行实证分析,并与传统的BS模型、混合双分数Brown运动定价等模型进行对比研究。结果发现:时变混合双分数Brown运动下的欧式期权定价模型在期权定价精度方面具有明显优势,特别是在发达证券市场上表现更好,同时具有较强的预测能力。对金融衍生品、风险管理、投资管理等方面都具有一定的参考意义和实用价值。Financial asset prices have fractal characteristics such as “sharp peaks and thick tails” and long-term memory, and its dynamic process can be described by the time-varying mixed double-fractional Brownian motion with GARCH structure. Firstly, the option pricing model and the time-varying parameter model are constructed under the hybrid two-fractional Brown’s motion;then, the historical closing prices of SSE 50 ETF index, Hong Kong Hang Seng index, and Japan TSE index are selected for the empirical analysis, and compared with the traditional BS model and the hybrid two-fractional Brown’s motion pricing model. The results show that the European option pricing model with time-varying hybrid bifractional Brownian motion has obvious advantages in terms of option pricing accuracy, especially in the developed stock markets, and has strong forecasting ability. It has certain reference significance and practical value for financial derivatives, risk management and investment management. 展开更多
关键词 混合双分数brown运动(bmFBM) 时变Hurst指数 GARCH模型 欧式期权定价
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Consecutive superior oblique palsy following surgical management of brown syndrome:case series
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作者 Hajar Farvardin Majid Farvardin 《International Journal of Ophthalmology(English edition)》 2025年第6期1178-1180,共3页
Dear Editor,Brown syndrome is an ocular motility disorder characterized by restriction of elevation in adduction combined with a positive forced duction test and minimal or no superior oblique(SO)overaction[1].Other f... Dear Editor,Brown syndrome is an ocular motility disorder characterized by restriction of elevation in adduction combined with a positive forced duction test and minimal or no superior oblique(SO)overaction[1].Other features include V-pattern horizontal deviation and palpebral fissure widening while adduction[1]. 展开更多
关键词 ocular motility disorder palpebral fissure ELEVATION positive forced duction test surgical management consecutive superior oblique palsy restriction elevation adduction brown syndrome
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