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基于全景展开图像的隧道围岩节理识别方法

长江科学院院报 2024年第5期41卷 116-123页

作者：方星桦阳军生黄定詹双桥张聪中南大学土木工程学院长沙410075 中南林业科技大学土木工程学院长沙410004 广西交通设计集团有限公司南宁530012 湖南省水利水电勘测设计规划研究总院有限公司长沙410007

为了解决目前节理信息识别方法仅适用于局部岩体图像的问题,采用全景展开图像方法,将采集到的局部洞壁围岩图像进行特征点提取、点云模型重建、矫正拼接处理,获得高分辨率的隧道洞壁围岩全景展开图像。通过图像预处理、小尺寸特征图片的... 详细信息

为了解决目前节理信息识别方法仅适用于局部岩体图像的问题,采用全景展开图像方法,将采集到的局部洞壁围岩图像进行特征点提取、点云模型重建、矫正拼接处理,获得高分辨率的隧道洞壁围岩全景展开图像。通过图像预处理、小尺寸特征图片的smaAt-Unet神经网络识别、小尺寸图片识别结果的融合拼接,对洞壁围岩全景展开图像的节理信息进行了区域粗略分割识别。采用Zhang-Suen算法和8邻域连通域分析方法,从骨架化与骨架线分离、毛刺剔除、骨架线连接方面进行了算法分析计算,完成了节理信息的细化提取。对体积节理数和节理空间产状信息进行了量化分析,最终建立了一种基于全景展开图像的隧道洞壁围岩节理信息识别方法。工程应用结果表明,洞壁围岩全景展开图像识别后,节理面空间方程的平均拟合误差为0.90,说明该识别方法能够较好地识别全景展开图像中的节理信息。另外,洞壁围岩图像采集具有时间短、易操作、灵活性较高的优点,对现场施工影响较小,该识别方法能够较为快速地完成节理信息识别,给现场施工与动态设计提供参考。

关键词：隧道洞壁围岩全景展开图像 smaAt-Unet神经网络节理识别

2021年西宁市宾馆、理发店空气中化学污染物状况及健康风险评估

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环境卫生学杂志 2024年第1期14卷 68-71,92页

作者：吉秀亮杨君胜谢晓媛郭学斌青海省疾病预防控制中心公共卫生科西宁810007

目的了解西宁市宾馆、理发店空气中苯、甲苯、二甲苯、氨及甲醛等化学污染物的污染状况及健康风险特征,识别可能存在有害物质,为西宁市公共场所卫生状况的改善与管理提供依据。方法2021年对西宁市18家宾馆、9家理发店空气中苯、甲苯、... 详细信息

目的了解西宁市宾馆、理发店空气中苯、甲苯、二甲苯、氨及甲醛等化学污染物的污染状况及健康风险特征,识别可能存在有害物质,为西宁市公共场所卫生状况的改善与管理提供依据。方法2021年对西宁市18家宾馆、9家理发店空气中苯、甲苯、二甲苯、氨及甲醛进行监测,采用健康风险评价方法评价宾馆、理发店空气中化学污染物对从业人员的非致癌和致癌风险。结果2021年西宁市宾馆、理发店空气中苯、甲苯、二甲苯、氨均未超标,慢性非致癌效应的危害系数(hazard quo-tient,HQ)均低于1。甲醛致癌风险值高于1×10^(-4),苯的致癌风险值略高于1×10^(-6)。结论西宁市宾馆、理发店空气中氨、苯、甲苯和二甲苯暴露量未超过不良反应阈值,非致癌风险较低;甲醛、苯对人群具有潜在的致癌风险。

关键词：公共场所化学污染物风险评估

2018—2020年西宁市城区PM_(2.5)对儿童呼吸系统门诊量影响的时间序列分析

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环境与健康杂志 2024年第1期41卷 32-35页

作者：吉秀亮杨君胜谢晓媛郭学斌青海省疾病预防控制中心公共卫生科青海西宁810007

目的探讨西宁市城区PM_(2.5)对儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量的影响。方法收集2018—2020年西宁市城区逐日气象资料、大气污染物数据、儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量并进行分析。... 详细信息

目的探讨西宁市城区PM_(2.5)对儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量的影响。方法收集2018—2020年西宁市城区逐日气象资料、大气污染物数据、儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量并进行分析。采用基于Quasi-Poisson回归的广义线性模型(GLM),控制时间的季节和长期趋势、气象因素、星期几效应后,分别开展PM_(2.5)与逐日儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量的单滞后效应(lag0~lag7)和累积滞后效应(lag01~lag07)分析,计算PM_(2.5)每升高10μg/m^(3)时儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病增加的超额危险度(ER)。结果2018—2020年西宁市城区PM_(2.5)浓度变化趋势与儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量呈现一致的月度特征,PM_(2.5)年平均浓度为32μg/m^(3),儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病日均门诊量依次为119、57、32例。PM_(2.5)浓度每升高10μg/m^(3),儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病门诊量分别在滞后日lag1 d、lag1 d、lag0 d到达最大值,就诊风险分别增加2.02%(95%CI:1.64%~2.41%),2.18%(95%CI:1.60%~2.77%),2.10%(95%CI:1.41%~2.81%),且存在累积滞后效应。结论西宁市城区PM_(2.5)对儿童呼吸系统疾病、上呼吸道感染和慢性下呼吸道疾病存在一定的急性效应。

关键词： PM_(2.5) 呼吸系统疾病儿童时间序列分析

Recent Advances in Deciphering the Mechanisms and Biological Functions of DNA Demethylation

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Chinese Journal of Chemistry 2024年第6期42卷 645-651页

作者： yang Feng sheng-jun Chen Bi-Feng Yuan Key Laboratory of Aquatic Product Processing Ministry of Agriculture and Rural AffairsNational R&D Center for Aquatic Product ProcessingSouth China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesGuangzhouGuangdong510300 China School of Public Health Research Center of Public HealthRenmin Hospital of Wuhan UniversityWuhan UniversityWuhanHubei430071 China

5-Methylcytosine (5mC) is a dynamic and reversible epigenetic modification in genomic DNA of higher *** has been well-established that the demethylation of 5mC occurs through the ten-eleven translocation (TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase (TDG)-initiated base excision repair (BER).Recent findings also have identified an alternative pathway of DNA *** this pathway,TET enzymes directly oxidize 5mC to form 5-formylcytosine (5fC) or 5-carboxylcytosine (5caC).These modified bases can undergo direct deformylation or decarboxylation,***,DNA demethylation can also occur through the deamination of 5mC and 5hmC,resulting in the production of thymine and 5-hydroxymethyluracil (5hmU),*** DNA demethylation pathways possess critical functional implications and roles in biological *** Recent Advances article will focus on the studies of mechanisms and biological functions of DNA demethylation,shedding light on the reversible nature of the epigenetic modification of 5mC.

关键词： Epigenetics DNA DNA methylation 5-Methylcytosine Demethylation Mechanisms Biological functions C—C bond cleavage Mass spectrometry

复杂环境下城际铁路大直径双模盾构选型技术及应用

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科学技术与工程 2024年第20期24卷 8699-8706页

作者：王振华彭勇王忠钊王少勇阳军生徐海龙汤冲中铁三局集团广东建设工程有限公司广州510000 中南大学土木工程学院长沙410075

为研究复杂地质环境下大直径双模盾构选型技术及应用效果,以深大城际机场东站—黄麻布站区间为依托,首先分析了该区段的工程重难点和施工风险,结果表明:该区间需穿越长距离硬岩地层和部分软土地层,下穿多处重要建构筑物和穿越多条构造... 详细信息

为研究复杂地质环境下大直径双模盾构选型技术及应用效果,以深大城际机场东站—黄麻布站区间为依托,首先分析了该区段的工程重难点和施工风险,结果表明:该区间需穿越长距离硬岩地层和部分软土地层,下穿多处重要建构筑物和穿越多条构造破碎带和节理密集带,施工风险高、难度大。因此,为兼顾盾构机在硬岩地层的掘进效率和软土及不良地质条件下的地层稳定,综合选用EPB(earth pressure balance)/TBM(tunnel boring machine)双模盾构机,并根据施工重难点对盾构机结构和功能系统进行了针对性设计。最终,对该盾构的现场工程应用进行了效果评价。结果表明:所选的EPB/TBM双模盾构能较好地满足工程需求,确保了盾构机掘进的安全性和高效性。研究成果可为其他类似条件下的双模盾构机选型提供参考和指导。

关键词：盾构选型 EPB/TBM双模工程应用效果评价

Two-Photon Absorption-Induced Emission Properties of Dye HMASPS Doped Polymer

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Chinese Physics Letters 2002年第2期19卷 208-210页

作者： Wang Dong Zhou Guang-Yong Ren Yan yang sheng-jun Xu Xin-Guang Shao Zong-Shu Jiang Min-Hua State Key Laboratory of Crystal Materials Shandong University Ji'nan 250100

The 0.01M two-photon absorption dye trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methyl-pyridinium p-toluene sulfonate (HMASPS) doped polymer has been prepared. When pumped by the picosecond pulse from the pulsed mode-locked Nd:YAG laser, the polymer emits more intense upconverted fluorescence and superradiance compared to the solution sample of the dye. The two-photon pumped lasing with oscillating pulses has also been obtained. Compared to the dye in its solution state, the emission spectra of the polymer are all blueshifted. The polymer has a long upconverted fluorescent lifetime of about 4.041±0.04ns.

关键词： Photons

Effect of Mg and Fe Doping on Optical Absorption of LiNbO3 Crystal through First Principles Calculations

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Chinese Physics Letters 2014年第3期31卷 125-128页

作者： HUANG Duo-Hui yang jun-sheng CAO Qi-Long WAN Ming-Jie LI Qiang SUN Liang WANd Fan- Hou Computational Physics Key Laboratory of Sichuan Province Yibin University Yibin 644007

Using first principles calculations, we investigate the structural, optical, and electronic properties of LiNbO3 （LN） and M doped LN （M=Mg, Fe）. The density of states are calculated to analyze the effect of doping Mg and Fe ions on the absorption spectra and electronic properties of LN. The results show an ultraviolet shift in the optical absorption edge of Mg-doped LN compared with that of intrinsic LN. On the contrary, the absorption edge of Fe-doped LN crystal reveals a red shift. The optical absorption spectra show an improved optical response in the visible range for Mg-doped LN, which significantly differs from that obtained for Fe-doped LN. The electronic excitations from the valence band to the conduction band of LN leads to an improved optical absorption response in the visible region as observed experimentally. The obvious changes of the doped LN crystal are found in some cases, which provide a helpful guide for preparing doped LN crystal.

关键词： Light absorption

Narrowband blue emitter based on fused nitrogen/carbonyl combination with external quantum efficiency approaching 30%

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Science China Chemistry 2024年第1期67卷 351-359页

作者： Long Chen Jia-Heng Cai You-jun Yu yang-Kun Qu sheng-Yi yang sheng-Nan Zou Rui-Hong Liu Dong-Ying Zhou Liang-sheng Liao Zuo-Quan Jiang Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China Macao Institute of Materials Science and Engineering Macao University of Science and TechnologyMacao 999078China

Multi-resonance thermally activated delayed fluorescence(MR-TADF)emitters can enable narrowband emission with high color purity and electroluminescence ***/carbonyl(N/C=O)system is receiving increasing attention while the nitrogen/boron(N/B)system has been widely *** decoration is an effective approach for N/B type MR-TADF system but always leads to broadening and red-shifting of the emission band in N/C=O MR-TADF *** attribute these unfavorable phenomena to the formation of intramolecular charge transfer between the MR-core and peripheral *** address this issue,we have developed a new strategy by decorating DMQAO(a fused N/C=O MR-core)with a triazine acceptor and a neutral terphenyl group to construct MTDMQAO and MBDMQAO,*** introduction of the triazine acceptor not only realizes efficient narrowband emission in MTDMQAO,but also accelerates the reverse intersystem crossing process through enhanced spin-orbital *** a result,MTDMQAO exhibits a significantly higher external quantum efficiency of 29.4%compared to the referent emitters,validating the rationality of our derivation *** study highlights the potential of the N/C=O system for MR-TADF emitters and provides important insights for understanding the difference between N/B and N/C=O systems.

关键词： carbonyl group narrowband acceptor decoration thermally activated delayed fluorescence OLEDs

Two-Photon-Absorption Induced Superradiance of a New Organic Dye PSPS

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Chinese Physics Letters 2002年第5期19卷 739-741页

作者： Zhou Guang-Yong Wang Dong Wang Xiao-Mei yang sheng-jun Xu Xin-Guang Zhao Xian Shao Zong-Shu Jiang Min-Hua State Key Laboratory of Crystal Materials Institute of Crystal Materials Shandong University Ji'nan 250100

The linear and nonlinear optical properties of a new two-photon absorption (TPA) dye, trans-4-(4'-pyrrolidinyl styryl)-N-methyl pyridinium methyl sulfate (abbreviated as PSPS) is reported. Intense red superradiance with a peak located at 625nm can be observed from PSPS solution in benzyl alcohol when pumped by a focused picosecond laser beam operated at 1064nm. The lifetimes of one-photon absorption (OPA) and TPA fluorescence were measured to be 370 and 384ps, respectively. The pulse widths of OPA and TPA superradiance were 60 and 58 ps, respectively. The highest net upconversion efficiency from the absorbed pump laser to the upconverted superradiance is 8.3% at the pump energy of 0.6 mJ.

关键词： Two photon processes