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Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease 被引量:1
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作者 Bo Li Yujie Chen +10 位作者 Yan Zhou Xuanran Feng Guojun Gu Shuang Han Nianhao Cheng Yawen Sun Yiming Zhang Jiahui Cheng Qi Zhang Wei Zhang Jianhui Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1593-1601,共9页
Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheime... Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis. 展开更多
关键词 Alzheimer’s disease mitochondrial biogenesis neural stem cell-derived exosome sIRT1-PGC1α regional brain distribution whole brain clearing and imaging
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Differential distribution of PINK1 and Parkin in the primate brain implies distinct roles
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作者 Yanting Liu Wei Huang +8 位作者 Jiayi Wen Xin Xiong Ting Xu Qi Wang Xiusheng Chen Xianxian Zhao Shihua Li Xiaojiang Li Weili Yang 《Neural Regeneration Research》 SCIE CAS 2025年第4期1124-1134,共11页
The vast majority of in vitro studies have demonstrated that PINK1 phosphorylates Parkin to work together in mitophagy to protect against neuronal degeneration.However,it remains largely unclear how PINK1 and Parkin a... The vast majority of in vitro studies have demonstrated that PINK1 phosphorylates Parkin to work together in mitophagy to protect against neuronal degeneration.However,it remains largely unclear how PINK1 and Parkin are expressed in mammalian brains.This has been difficult to address because of the intrinsically low levels of PINK1 and undetectable levels of phosphorylated Parkin in small animals.Understanding this issue is critical for elucidating the in vivo roles of PINK1 and Parkin.Recently,we showed that the PINK1 kinase is selectively expressed as a truncated form(PINK1–55)in the primate brain.In the present study,we used multiple antibodies,including our recently developed monoclonal anti-PINK1,to validate the selective expression of PINK1 in the primate brain.We found that PINK1 was stably expressed in the monkey brain at postnatal and adulthood stages,which is consistent with the findings that depleting PINK1 can cause neuronal loss in developing and adult monkey brains.PINK1 was enriched in the membrane-bound fractionations,whereas Parkin was soluble with a distinguishable distribution.Immunofluorescent double staining experiments showed that PINK1 and Parkin did not colocalize under physiological conditions in cultured monkey astrocytes,though they did colocalize on mitochondria when the cells were exposed to mitochondrial stress.These findings suggest that PINK1 and Parkin may have distinct roles beyond their well-known function in mitophagy during mitochondrial damage. 展开更多
关键词 NEURODEGENERATION PARKIN Parkinson’s disease PINK1 subcellular distribution
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Ambient noise tomography of a linear seismic array based on an improved Voronoi tessellation
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作者 Kun Wang Weitao Wang +4 位作者 Libo Han Tingzi Li Yuan Ling Jianchao Zhou Huaiyu Yuan 《Earthquake Science》 2023年第6期477-490,共14页
Ambient noise tomography,when applied to a dense linear seismic array,has the capability to provide detailed insights into the fine velocity structures across diverse tectonic settings.The linear station arrangement n... Ambient noise tomography,when applied to a dense linear seismic array,has the capability to provide detailed insights into the fine velocity structures across diverse tectonic settings.The linear station arrangement naturally generates parallel and concentrated ray paths along the array trend.This unique geometry requires specific optimization of the inversion methodology and model parameterization.The Bayesian-based transdimensional inversion method,characterized by its fully non-linear nature and high degree of freedom in parameter settings,offers a powerful tool for ambient noise inversion.To effectively adapt this method to a linear array layout,we propose a modification to the Voronoi cell tessellation built in the transdimensional method.By introducing spatial priority to the Voronoi kernels,we strategically increased the density of Voronoi cells along the direction of the array.We then applied the modified approach to a linear seismic array in the North China Craton and validated its robustness through phase velocity images and resolution tests.Our improved non-uniform sampling technique in the 2-D model space accelerates convergence while simultaneously enhancing model accuracy.Compared with the conventional damped leastsquares method,the proposed algorithm revealed a shear-wave velocity map with notable low-velocity anomalies situated in the middle and lower crust beneath the borders of the Ordos block and its surrounding orogenic belt.Aligned with the crustal structures revealed by receiver function and electrical imaging,our findings indicated that the western and eastern margins of the Ordos block had experienced intensive crustal wedge deformation and re-melting,respectively. 展开更多
关键词 Voronoi cell transdimensional Bayesian method ambient noise inversion s velocity North China Craton
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Numerical Study on the Duct Acoustic Mode Control of Turbine Interaction Noise with Serrated Configurations
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作者 Kangshen Xiang Weijie Chen +1 位作者 Jianxin Lian Weiyang Qiao 《Journal of Applied Mathematics and Physics》 2023年第8期2491-2502,共12页
Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation b... Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation but little study about the relation between serration and mode. Thus, taking axial single-turbine test bench NPU-Turb as object, the effect of Stator with Serrated Trailing-edge (Bionic S) and Rotor with Serrated Leading-edge (Bionic R) on duct acoustic modes of turbine turbulence interac-tion noise were studied in detail using DDES/AA hybrid model validated by acoustic experiment of NPU-Turb. Serval conclusions can be made here. First, for broadband noise, the effect of serrations on duct modes (increased or reduced of PWL<sub>mn</sub>) with the increasing frequency is more prominent. Second, the changing trend of ?PWL<sub>mn</sub> is something like Chinese character “人” with circumferential mode m and alternating with radial mode. Such distribution is more obvious at higher frequency. More theoretical and mechanistic research work needs to be carried out in depth in the future. . 展开更多
关键词 Turbine Interaction noise Duct Acoustic Mode NPU-Turb Bionic s Bionic R
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高压管汇材料疲劳性能测试及P-S-N模型曲线的拟合
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作者 黄艳娟 周思柱 李宁 《长江大学学报(自然科学版)》 2024年第3期55-61,共7页
高压管汇作为压裂设备中的主要易损件之一,其失效危害较大。它的失效原因主要是疲劳、冲蚀、腐蚀或者材料缺陷引起的刺漏和爆裂,其中尤以疲劳失效最不可预估。目前,对于高压管汇材料的疲劳性能研究不够深入,为解决高压管汇材料疲劳寿命... 高压管汇作为压裂设备中的主要易损件之一,其失效危害较大。它的失效原因主要是疲劳、冲蚀、腐蚀或者材料缺陷引起的刺漏和爆裂,其中尤以疲劳失效最不可预估。目前,对于高压管汇材料的疲劳性能研究不够深入,为解决高压管汇材料疲劳寿命的准确描述问题,以某国产高压管汇材料为例,进行了一系列疲劳试验,并基于试验数据,采用多种分布模型和不同S-N模型进行拟合分析,得出综合评价拟合能力最强的P-S-N模型。结果表明,该材料在中长疲劳寿命区,Weibull三参数模型在7级应力水平下综合评价能力最好;在存活率分别为50%、90%、99%、99.9%时,指数S-N模型的拟合系数均大于0.98,拟合能力最好。得出的P-S-N模型曲线可以为高压管汇的疲劳寿命以及安全设计提供依据。 展开更多
关键词 高压管汇材料 正态分布模型 Weibull分布模型 P-s-N模型 幂函数s-N模型 指数s-N模型
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采用非稳相偏振滤波的DAS-VSP数据P/S波分离方法及其应用
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作者 王腾飞 程玖兵 +3 位作者 孟涛 曹中林 胡善政 段鹏飞 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第7期2761-2772,共12页
分布式光纤声学传感(DAS)因成本低、易布设以及高密度采样等优势正成为重要的地震观测技术,尤其是越来越多地与垂直地震剖面(VSP)结合,用于主动地震勘探或被动地震监测.DAS传感器通过感知弹性波场产生的轴向应变或应变速率来观测地震波... 分布式光纤声学传感(DAS)因成本低、易布设以及高密度采样等优势正成为重要的地震观测技术,尤其是越来越多地与垂直地震剖面(VSP)结合,用于主动地震勘探或被动地震监测.DAS传感器通过感知弹性波场产生的轴向应变或应变速率来观测地震波场振动.然而,目前单分量DAS-VSP数据未完整地记录地下弹性波场的三维矢量振动信号,因此如何从中分离出P波或S波用于后续地震成像与参数反演是重要且很有挑战的课题.以弹性波传播理论为基础,本文根据P波和S波的频散关系估算接收点处各自的偏振方向,通过随频率和空间位置变化的偏振滤波实现DAS-VSP数据的P/S波分离.理论模型合成数据与东海实际DAS-VSP数据实验结果表明,该方法能有效地将P波和S波信号从单分量DAS-VSP数据中分离出来,可为后续纵横波速度反演、PP与PS波成像提供关键的数据预条件处理. 展开更多
关键词 分布式光纤声学传感(DAs) VsP P/s波分离 偏振投影 非稳相滤波
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宽负荷下切圆燃煤锅炉H_(2)S分布特性的数值模拟
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作者 邓磊 袁茂博 +3 位作者 杨家辉 韩磊 姜家豪 车得福 《煤炭学报》 EI CAS CSCD 北大核心 2024年第6期2887-2895,共9页
锅炉采用空气分级燃烧降低NO_(x)排放的同时也提高了主燃区H_(2)S体积分数。炉墙壁面过高的H_(2)S体积分数是加剧水冷壁高温腐蚀的重要因素。为保障新能源并网发电,大型燃煤机组灵活调峰的需求增加,不同负荷下的水冷壁近壁面H_(2)S分布... 锅炉采用空气分级燃烧降低NO_(x)排放的同时也提高了主燃区H_(2)S体积分数。炉墙壁面过高的H_(2)S体积分数是加剧水冷壁高温腐蚀的重要因素。为保障新能源并网发电,大型燃煤机组灵活调峰的需求增加,不同负荷下的水冷壁近壁面H_(2)S分布特性值得关注。通过正交试验分析了切圆燃煤锅炉运行参数对水冷壁近壁面H_(2)S体积分数分布的影响。选取一台超临界600 MW切圆燃煤锅炉建立数值模型,设计L_(16)(4^(5))正交工况,覆盖100%BMCR、75%THA,50%THA以及35%BMCR四种负荷。建立了自定义SO_(x)生成模型以确定燃料硫的析出和转化路径,模型包含多表面反应子模型以描述焦炭与O_(2)/CO_(2)/H_(2)O等3种气体的异相反应,并确定焦炭气化反应消耗量占总消耗量的比例,进而对炉膛H_(2)S空间分布进行了模拟计算。研究表明,近壁面高体积分数H_(2)S区域主要位于投运燃烧器层中最下层燃烧器以下以及最上层燃烧器以上至SOFA层之间,烟气切圆沿炉膛高度增加逐渐增大是造成后一区域H_(2)S体积分数较高的重要原因。35%BMCR负荷下水冷壁重点区域的H_(2)S平均体积分数为364μL/L,明显低于其他负荷。锅炉运行参数对重点区域H_(2)S体积分数影响程度的排序为:锅炉负荷>一次风率>主燃区空气过量系数>假想切圆直径>燃烧器竖直摆角。 展开更多
关键词 切圆燃煤锅炉 宽负荷 H2s分布 正交分析 数值模拟
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基于短周期密集台阵的广州—佛山地区地壳浅部三维S波速度结构研究
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作者 高占永 叶秀薇 +4 位作者 林吉焱 段永红 王力伟 周铭 刘巧霞 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第4期1454-1470,共17页
广州—佛山地区位于珠三角经济区的核心地带,三条区域性断裂从中交错穿过.广州—佛山地区精细的地壳浅部三维S波速度结构,对于研究区内的城市规划建设、地震灾害评估、强地面运动模拟等具有重要意义.本文利用布设于广州—佛山地区短周... 广州—佛山地区位于珠三角经济区的核心地带,三条区域性断裂从中交错穿过.广州—佛山地区精细的地壳浅部三维S波速度结构,对于研究区内的城市规划建设、地震灾害评估、强地面运动模拟等具有重要意义.本文利用布设于广州—佛山地区短周期密集地震台阵中的1104个台站记录到的连续波形数据,采用背景噪声互相关方法计算了台站对间的互相关函数并进一步提取到周期范围在0.1~5 s内的39488条高质量面波群速度频散曲线,然后通过基于射线追踪的面波直接反演方法计算得到了研究区内0.3~3 km深度的高分辨率三维S波速度结构.结果显示:研究区内地壳浅部S波速度横向差异显著,其中南部的珠江三角洲断陷盆地S波速度结构相对较为复杂,而北部的广花盆地内部S波速度结构则表现相对简单.研究区内的低速异常主要位于断裂附近,且大都位于断裂的下降盘.珠江三角洲内三水盆地东缘表现为马鞍状低速异常,向下最大延伸至2 km,低速体南北两侧边界与控盆断裂位置基本一致.广花盆地内部存在两个平行排列的高速异常,中间夹持一平行构造走向的低速异常,总体速度结构特征符合广花盆地为一复式向斜的地质构造背景.低速异常向下延伸至1.4 km深度处,可能指示了卷入向斜地层的最大埋深.沿广州—从化断裂发育条带状低速异常,与沿断裂形成的沉积地层有关.条带状异常在浅部分为两段,表明广州—从化断裂在历史上可能具有分段活动性.玉带公园周围被高速异常环绕,异常向上延伸至距地表约1.3 km处,结合研究区已有资料推测该高速异常可能为早期岩浆侵入在地壳浅部的反映. 展开更多
关键词 密集台阵 背景噪声成像 地壳浅部 s波速度结构 广州—佛山
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基于T-S模糊逻辑的混合储能孤岛直流微电网功率分配控制
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作者 张伟杰 顾吉鹏 +3 位作者 张有兵 杨晓东 娄伟 汪斌杰 《电力自动化设备》 EI CSCD 北大核心 2024年第6期135-144,共10页
在含混合储能的直流微电网中,传统阻容下垂控制无法解决由线路电阻和负荷功率波动导致的系统功率分配失衡问题。为此,提出一种基于Takagi-Sugeno(T-S)模糊逻辑的自适应阻容下垂控制方法以实现混合储能的分频分配。根据蓄电池和超级电容... 在含混合储能的直流微电网中,传统阻容下垂控制无法解决由线路电阻和负荷功率波动导致的系统功率分配失衡问题。为此,提出一种基于Takagi-Sugeno(T-S)模糊逻辑的自适应阻容下垂控制方法以实现混合储能的分频分配。根据蓄电池和超级电容的物理特性,建立单个蓄电池支路输出电压、蓄电池组间输出功率差额和阻性下垂系数之间的T-S模糊逻辑关系,以及单个超级电容支路输出功率及其变化率、超级电容组间功率差额和容性下垂系数之间的T-S模糊逻辑关系,并由此构建基于T-S模糊逻辑的阻容下垂控制器。推导含混合储能的直流微电网中各部分的平均阻抗模型,并采用阻抗比分析法对微电网的小信号稳定性进行研究。MATLAB/Simulink仿真结果表明,基于T-S模糊逻辑的阻容下垂控制可保证在线路电阻和负荷功率波动情况下系统功率的合理分配。 展开更多
关键词 直流微电网 混合储能 T-s模糊逻辑 功率分配 稳定性分析
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青藏高原东南缘三维S波速度和径向各向异性及泸定M_(S)6.8和芦山M_(S)7.0地震孕震环境探讨
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作者 孙回归 王兴臣 常利军 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第1期108-127,共20页
利用青藏高原东南缘布设的684个流动地震台和150个固定地震台的连续背景噪声波形数据,提取了周期5~50 s的Rayleigh波和Love波相速度频散,并反演获得了该区域下方0~70 km三维S波速度和径向各向异性结构.结果表明:(1)受川滇地块南部高速... 利用青藏高原东南缘布设的684个流动地震台和150个固定地震台的连续背景噪声波形数据,提取了周期5~50 s的Rayleigh波和Love波相速度频散,并反演获得了该区域下方0~70 km三维S波速度和径向各向异性结构.结果表明:(1)受川滇地块南部高速体的阻挡,东南缘中下地壳内存在两条空间分布独立的低速带.西侧(L1)从川滇地块北部向南延伸至滇西南地块,其中下地壳平均V_(S)小于3.4 km·s^(-1)并表现为正径向各向异性结构,反映了高原中下地壳可能存在部分熔融和韧性变形;东侧低速带(L2)沿着小江断层南北分布,受到红河断层的阻挡,弱物质不太可能进入滇西南地块,该区域下地壳和上地幔顶部均显示较强的正各向异性,推测其更可能是沿小江断层相互驱动的块体在横向挤压过程中引起的地壳部分熔融而导致.(2)芦山M_(S)7.0地震位于龙门山逆冲断层南段,泸定M_(S)6.8地震位于鲜水河走滑断层东南段,两者都发生在地壳浅层高低速异常过渡带上,但其深部孕震环境有所不同.芦山震区西北部中下地壳低速体为负各向异性,推测韧性物质沿着龙门山下方陡倾断层向上运移,上地壳积累应力并通过薄弱区域释放导致了芦山地震的发生;泸定震区为正各向异性的中下地壳韧性变形促进了川滇地块SE向的水平运动,受刚性的四川盆地阻挡,加剧了上地壳发震断层的滑动变形和应力积累,脆性上地壳突然破裂导致了泸定地震的发生. 展开更多
关键词 青藏高原东南缘 背景噪声成像 s波速度 径向各向异性 泸定M_(s)6.8地震 芦山M_(s)7.0地震
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基于CSLE的泛第三极地区土壤侵蚀强度空间分布特征
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作者 刘子玥 章文波 +4 位作者 殷兵 杨勤科 魏欣 刘宝元 殷水清 《水土保持研究》 CSCD 北大核心 2024年第3期1-9,共9页
[目的]定量评估泛第三极地区的土壤侵蚀状况,明确土壤侵蚀的分布特征,以期为土壤侵蚀的科学防治提供依据。[方法]基于分层不等概系统抽样方法,共布设31 406个调查单元。利用中国土壤流失方程CSLE计算泛第三极地区土壤侵蚀速率,并利用莫... [目的]定量评估泛第三极地区的土壤侵蚀状况,明确土壤侵蚀的分布特征,以期为土壤侵蚀的科学防治提供依据。[方法]基于分层不等概系统抽样方法,共布设31 406个调查单元。利用中国土壤流失方程CSLE计算泛第三极地区土壤侵蚀速率,并利用莫兰指数(I)探讨其分布特征。[结果](1)泛第三极地区平均土壤侵蚀速率为162.73 t/(km^(2)·a),水土流失面积比例为7.75%,土壤侵蚀速率超过500 t/(km^(2)·a)的地区主要位于西亚、东亚和南亚;(2)土壤侵蚀存在明显的空间聚集性(I=0.920 9),以高高型和低低型聚集为主,高高型聚集主要分布在西亚北部、南亚北部和西南部以及中国的东北、黄土高原和西藏南部;(3)草地、灌丛和耕地是土壤侵蚀较严重的土地利用类型,其中>1 000 m的草地、>500 m的灌丛和耕地的土壤侵蚀更严重,超过25%的土地都发生了水土流失,平均土壤侵蚀速率变化于426.85~683.72 t/(km^(2)·a)。[结论]海拔介于1 000~6 000 m的草地、500~4 000 m的灌丛以及1 000~4 000 m的耕地是泛第三极地区土壤侵蚀发生的重点区域,需特别关注。 展开更多
关键词 土壤侵蚀 泛第三极 空间分布 莫兰指数
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鄂北S井区盒8上亚段砂体叠置类型及其对气藏分布的影响
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作者 杜家满 赵永刚 +2 位作者 申荣荣 于明航 阴旭航 《录井工程》 2024年第1期119-126,共8页
为明确鄂北S井区盒8上亚段地层砂体叠置类型及其与气藏分布的关系,通过岩心观察、测井解释等方法对研究区盒8上亚段沉积微相类型、砂体的垂向叠置及侧向接触关系进行深入研究,再结合试气资料探讨不同砂体叠置类型的气藏分布特征。结果表... 为明确鄂北S井区盒8上亚段地层砂体叠置类型及其与气藏分布的关系,通过岩心观察、测井解释等方法对研究区盒8上亚段沉积微相类型、砂体的垂向叠置及侧向接触关系进行深入研究,再结合试气资料探讨不同砂体叠置类型的气藏分布特征。结果表明:鄂北S井区盒8上亚段为曲流河三角洲平原亚相,有利砂体对应的沉积微相类型为边滩与河道充填微相;砂体垂向叠置类型可划分为分离式、叠加式、切叠式、替代式,侧向接触关系可划分为间湾接触、堤岸接触、对接式、侧切式、替代式;鄂北S井区盒8上亚段砂体垂向叠置类型主要为侧向切叠式和替代式,增加了砂体在侧向上的连通性;盒8上亚段砂体侧向接触关系主要为侧切式,提升了砂体侧向上的连通程度,气藏储存关系较好;单一、孤立存在的砂体,其连通性较差,整体的含气性也较差。该研究对寻找低渗透背景下产能高、潜力大的砂体分布区具有重要指导意义。 展开更多
关键词 鄂北s井区 盒8上亚段 砂体垂向叠置 砂体侧向接触 气藏分布
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利用HVSR方法探测四川理县西山村滑坡速度结构
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作者 孙晓倩 储日升 +2 位作者 曾求 盛敏汉 危自根 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第4期1515-1526,共12页
HVSR(Horizontal-to-Vertical Spectral Ratio)是地震背景噪声水平分量与垂直分量的频谱比,常被用来探测起伏地形较小的浅地表速度结构.然而,高起伏地形下该方法的适用性还需要仔细研究.本文探讨利用HVSR方法探测四川理县西山村滑坡的... HVSR(Horizontal-to-Vertical Spectral Ratio)是地震背景噪声水平分量与垂直分量的频谱比,常被用来探测起伏地形较小的浅地表速度结构.然而,高起伏地形下该方法的适用性还需要仔细研究.本文探讨利用HVSR方法探测四川理县西山村滑坡的速度结构.我们首先将ENZ坐标系下三分量地震数据旋转到垂直于地形自由面的LQT坐标系,分别计算了两个坐标系下2 h地震背景噪声数据的HVSR曲线,对比结果发现,LQT坐标系下三分量数据的HVSR峰值频率更能反映地下结构信息.然后,本文反演了29个台站LQT坐标系的HVSR曲线,获得了滑坡体堆积物及基岩的一维S波速度结构.西山村滑坡体堆积物的S波速度范围为50~1000 m·s^(-1),滑坡厚度23~130 m.滑坡体西侧边缘地下40~120 m处存在10~20 m的低速层,表明该位置抗剪强度相对较弱,是潜在的滑动危险区域.对数据进行坐标系转换后,HVSR方法能够利用较短的观测数据获取可靠的滑坡体速度结构,为滑坡体积估算、脆弱位置识别、灾害评估提供重要信息. 展开更多
关键词 理县西山村滑坡 HVsR s波速度结构 地震背景噪声
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基于B/S架构的空调智能监控系统设计与实现
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作者 余秋亮 王少林 王泽宇 《软件导刊》 2024年第3期114-120,共7页
为解决空调系统设备种类众多、协议不统一的问题,针对空调系统的监控需求,设计了基于分布式监控与集中管理模式、B/S架构的空调智能监控系统。首先,在设备监控层利用多线程技术实现设备实时数据的采集处理,采用多协议转换技术进行统一... 为解决空调系统设备种类众多、协议不统一的问题,针对空调系统的监控需求,设计了基于分布式监控与集中管理模式、B/S架构的空调智能监控系统。首先,在设备监控层利用多线程技术实现设备实时数据的采集处理,采用多协议转换技术进行统一协议转换、封装,将多种协议数据上传存储到数据库服务器。然后,通过模糊自适应PID控制器对监测数据进行轮询计算,调节变频器实时控制空调系统温度。最后,通过Web服务端口访问数据库服务器,实现系统集成与数据交换,建立集中控制、管理、运维的集成平台,实现系统设备的统一监控和调度,系统的统一部署和高可用性,完成空调监控系统的界面可视化并提升空调系统智能化水平。实践表明,该系统运行稳定,能实时监控空调运行状况,且具有较高的扩展性与管理效率。 展开更多
关键词 空调监控系统 B/s架构 分布式 多协议转换 模糊自适应PID
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背景噪声频率-贝塞尔变换法研究厦门岛浅层S波速度结构
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作者 李海艳 陈晓非 +4 位作者 陈举庆 蔡辉腾 刘琦 冯旭平 张功恒 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第7期2654-2667,共14页
为获取厦门岛浅层三维速度结构,本文使用福建省地震局于2019年布设的50个流动地震台站组成的密集台阵所记录到的垂向分量波形数据,计算背景噪声互相关,利用频率-贝塞尔变换(F-J)法提取子台阵的瑞利波相速度频散曲线进行反演,获取子台阵... 为获取厦门岛浅层三维速度结构,本文使用福建省地震局于2019年布设的50个流动地震台站组成的密集台阵所记录到的垂向分量波形数据,计算背景噪声互相关,利用频率-贝塞尔变换(F-J)法提取子台阵的瑞利波相速度频散曲线进行反演,获取子台阵下方一维S波速度结构,并通过插值得到厦门岛4 km以内的三维S波速度模型.结果表明,整体上厦门岛S波速度随深度增加呈现递增趋势,在近地表处的横向不均匀性显著.0~1 km深度的S波速度大体上呈现“北高南低”的特征,与岩性分布有较好的对应关系.随着深度的递增,高低速特征分布逐渐呈现为连续性较好,近北东向展布的条带状.结合前人研究结果,本文推测这一现象与厦门岛岩层在不同时期受到挤压和拉张作用形成的褶皱和断裂相关,反映了厦门岛所经历的多次构造变动和岩浆侵入事件.垂向剖面的速度差明显区与研究区断裂带位置具有一定的对应关系.研究结果可为厦门岛的构造演化研究和地质灾害评估提供新的科学依据. 展开更多
关键词 背景噪声成像 频率-贝塞尔变换法 厦门岛 浅层s波速度结构
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基于S变换相关度的配电网单相接地自适应有源消弧法
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作者 李运旺 陈俊德 +2 位作者 张大平 桑云 韩晓蕾 《电气传动》 2024年第7期86-92,共7页
提出了基于S变换相关度的配电网单向接地自适应有源消弧法,有效消除了配电网单相接地故障电弧,提升了电力系统稳定性。采集配电网线路零序电流时序数据,经S变换获取零序电流时频信息矩阵后,计算并获取各线路间时频信息矩阵相关度矩阵,... 提出了基于S变换相关度的配电网单向接地自适应有源消弧法,有效消除了配电网单相接地故障电弧,提升了电力系统稳定性。采集配电网线路零序电流时序数据,经S变换获取零序电流时频信息矩阵后,计算并获取各线路间时频信息矩阵相关度矩阵,输入卷积神经网络模型,输出单相接地故障选线结果;在故障线路采用基于模糊准PR与PI控制的双闭环自适应控制方法,向配电网故障线路中性点注入零序电流,有效控制注入电流相位以及幅值,迫使配电网故障线路所在相的电压值为0,完成自适应有源消弧。实验结果表明:该方法可有效识别配电网单相接地故障线路,实现配电网单相接地自适应有源消弧,且可尽快完成单相接地自适应有源消弧工作,保证配电网安全稳定运行。 展开更多
关键词 s变换 相关度 配电网 单相接地故障 自适应 有源消弧
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Designing Bayesian Two-Sided Group Chain Sampling Plan for Gamma Prior Distribution
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作者 Waqar Hafeez Nazrina Aziz 《Computer Systems Science & Engineering》 SCIE EI 2023年第2期1069-1079,共11页
Acceptance sampling is used to decide either the whole lot will be accepted or rejected,based on inspection of randomly sampled items from the same lot.As an alternative to traditional sampling plans,it is possible to... Acceptance sampling is used to decide either the whole lot will be accepted or rejected,based on inspection of randomly sampled items from the same lot.As an alternative to traditional sampling plans,it is possible to use Baye-sian approaches using previous knowledge on process variation.This study pre-sents a Bayesian two-sided group chain sampling plan(BTSGChSP)by using various combinations of design parameters.In BTSGChSP,inspection is based on preceding as well as succeeding lots.Poisson function is used to derive the probability of lot acceptance based on defective and non-defective products.Gamma distribution is considered as a suitable prior for Poisson distribution.Four quality regions are found,namely:(i)quality decision region(QDR),(ii)probabil-istic quality region(PQR),(iii)limiting quality region(LQR)and(iv)indifference quality region(IQR).Producer’s risk and consumer’s risk are considered to esti-mate the quality regions,where acceptable quality level(AQL)is associated with producer’s risk and limiting quality level(LQL)is associated with consumer’s risk.Moreover,AQL and LQL are used in the selection of design parameters for BTSGChSP.The values based on all possible combinations of design parameters for BTSGChSP are presented and inflection points’values are found.Thefinding exposes that BTSGChSP is a better substitute for the existing plan for industrial practitioners. 展开更多
关键词 Bayesian acceptance sampling poisson distribution gamma distribution producer’s risk consumer’s risk
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Natural variations and geographical distributions of seed carotenoids and chlorophylls in 1167 Chinese soybean accessions
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作者 Berhane S.GEBREGZIABHER ZHANG Sheng-rui +7 位作者 Muhammad AZAM QI Jie Kwadwo G.AGYENIM-BOATENG FENG Yue LIU Yi-tian LI Jing LI Bin SUN Jun-ming 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第9期2632-2647,共16页
Understanding the composition and contents of carotenoids in various soybean seed accessions is important for their nutritional assessment.This study investigated the variability in the concentrations of carotenoids a... Understanding the composition and contents of carotenoids in various soybean seed accessions is important for their nutritional assessment.This study investigated the variability in the concentrations of carotenoids and chlorophylls and revealed their associations with other nutritional quality traits in a genetically diverse set of Chinese soybean accessions comprised of cultivars and landraces.Genotype,planting year,accession type,seed cotyledon color,and ecoregion of origin significantly influenced the accumulation of carotenoids and chlorophylls.The mean total carotenoid content was in the range of 8.15–14.72μg g–1 across the ecoregions.The total carotenoid content was 1.2-fold higher in the landraces than in the cultivars.Soybeans with green cotyledons had higher contents of carotenoids and chlorophylls than those with yellow cotyledons.Remarkably,lutein was the most abundant carotenoid in all the germplasms,ranging from 1.35–37.44μg g–1.Carotenoids and chlorophylls showed significant correlations with other quality traits,which will help to set breeding strategies for enhancing soybean carotenoids without affecting the other components.Collectively,our results demonstrate that carotenoids are adequately accumulated in soybean seeds,however,they are strongly influenced by genetic factors,accession type,and germplasm origin.We identified novel germplasms with the highest total carotenoid contents across the various ecoregions of China that could serve as the genetic materials for soybean carotenoid breeding programs,and thereby as the raw materials for food sectors,pharmaceuticals,and the cosmetic industry. 展开更多
关键词 accession type carotenoid CHLOROPHYLL ECOREGION geographical distribution Pearson’s correlation soybean(Glycine max L.Merrill)
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Diameter distributions in Pinus sylvestris L.stands:evaluating modelling approaches including a machine learning technique
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作者 Şükrü Teoman Güner Maria J.Diamantopoulou Ramazan Özçelik 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第6期1829-1842,共14页
The diameter distribution of trees in a stand provides the basis for determining the stand’s ecological and economic value,its structure and stability and appropriate management practices.Scots pine(Pinus sylvestris ... The diameter distribution of trees in a stand provides the basis for determining the stand’s ecological and economic value,its structure and stability and appropriate management practices.Scots pine(Pinus sylvestris L.)is one of the most common and important conifers in Turkey,so a well-planned management schedule is critical.Diameter distribution models to accurately describe the stand structure help improve management strategies,but developing reliable models requires a deep understanding of the growth,output and constraints of the forests.The most important information derived by diameter distribution models is primary data on horizontal stand structure for each diameter class of trees:basal area and volume per unit area.These predictions are required to estimate the range of products and predicted volume and yield from a forest stand.Here,to construct an accurate,reliable diameter distribution model for natural Scots pine stands in the Türkmen Mountain region,we used Johnson’s SBdistribution to represent the empirical diameter distributions of the stands using ground-based measurements from 55 sample plots that included1219 trees in natural distribution zones of the forests.As an alternative,nonparametric approach,which does not require any predefined function,an artificial intelligence model was constructed based on support vector machine methodology.An error index was calculated to evaluate the results.Overall,both Johnson’s SB probability density function with a three-parameter recovery approach and the support vector regression methodology provided reliable estimates of the diameter distribution of these stands. 展开更多
关键词 Diameter distribution Johnson’s s_(B) support vector regression scots pine Türkmen mountains
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Green's functions for uniformly distributed loads acting on an inclined line in a poroelastic layered site 被引量:15
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作者 梁建文 尤红兵 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2005年第2期233-241,共9页
Based on one type of practical Biot's equation and the dynamic-stiffness matrices ofa poroelastic soil layer and half-space, Green's functions were derived for unitformly distributed loads acting on an inclined line... Based on one type of practical Biot's equation and the dynamic-stiffness matrices ofa poroelastic soil layer and half-space, Green's functions were derived for unitformly distributed loads acting on an inclined line in a poroelastie layered site. This analysis overcomes significant problems in wave scattering due to local soil conditions and dynamic soil-structure interaction. The Green's functions can be reduced to the case of an elastic layered site developed by Wolf in 1985. Parametric studies are then carried out through two example problems. 展开更多
关键词 Green's function poroelastic layered site Biot's equation uniformly distributed load wave scattering
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