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Dust storms in northern China and their significance for the concept of the Anthropocene

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Science China Earth Sciences 2022年第5期65卷 921-933页

作者： Jianbao LIU Jie chen Shengqian chen Xinwei YAN Haoran DONG Fahu chen Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental ScienceLanzhou UniversityLanzhou 730000China Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

A key scientific issue in the study of the Anthropocene is the determination of the corresponding stratigraphic marker in geological *** arid and semi-arid regions of Asia are the second largest dust source on Earth,and their release,transport and deposition of dust affect global climate change,as well as marine and terrestrial biogeochemical *** the past~2000 years,human activity has outpaced natural climatic variability as the dominant control of dust storms in northern ***,exploring the potential of anthropogenic Asian dust as a marker of the Anthropocene and its impacts on lake ecosystems may contribute to an improved definition of the characteristics and timing of the *** this context,we measured spectrally-inferred chlorophyll a from the sediments of an undisturbed alpine lake in northern China,and compared the results with dust storm data from the same cores and with regional climatic *** dust is a widely distributed,globally significant signal of human activity,and it is also well preserved in various geological archives;hence,we propose anthropogenic dust can be considered as a potential marker of the *** dust signals in stratigraphic records during the past~2000 years differ substantially from those during the early and middle Holocene,which demonstrates that,at least since~2000 years ago,human activity has exceeded the natural forcing of dust transport in northern *** therefore propose that there are spatial and temporal differences in the onset of the Anthropocene,as defined by anthropogenic dust deposition,which is therefore *** spectrally-inferred chlorophyll a record is consistent with dust storm activity over the past~2000 years(except since the 1950s),suggesting that anthropogenic dust storms were the dominant control on lake primary *** to the 1950s the interactions of the East Asian summer monsoon(EASM),human activity,dust storms and lake ecos

关键词： Anthropocene Stratigraphic marker Dust storms Lake primary production Time-transgressive Great Acceleration

Amorphous Electrode:From Synthesis to Electrochemical Energy Storage

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Energy & Environmental Materials 2023年第6期6卷 113-140页

作者： Jiawei Zhang Yu Li Zhen chen Qian Liu Qingguo chen Minghua chen School of Electrical and Electronic Engineering Key Laboratory of Engineering Dielectric and Applications(Ministry of Education)Harbin University of Science and Technology52 Xuefu RoadHarbin 150080China

Electrochemical batteries and supercapacitors are considered ideal rechargeable technologies for next-generation energy storage *** key to further commercial applications of electrochemical energy storage devices is the design and investigation of electrode materials with high energy density and significant cycling ***,amorphous materials have attracted a lot of attention due to their more defects and structure flexibility,opening up a new way for electrochemical energy *** this perspective,we summarize the recent research regarding amorphous materials for electrochemical energy *** review covers the advantages and features of amorphous materials,the synthesis strategies to prepare amorphous materials,as well as the application and modification of amorphous electrodes in energy storage ***,the challenges and prospective remarks for future development in amorphous materials for electrochemical energy storage are concluded.

关键词： amorphous materials defective energy storage structure flexible

Identification and classification of traditional Chinese medicine syndrome types among senior patients with vascular mild cognitive impairment using latent tree analysis

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Journal of Integrative Medicine 2017年第3期15卷 186-200页

作者： chen Fu Nevin Lianwen Zhang Bao-xin chen Zhou Rong chen Xiang Lan Jin Rong-juan Guo Zhi-gang chen yun-ling Zhang Department of Neurology Dongfang HospitalBeijing University of Chinese Medicine Department of Computer Science and Engineering The Hong Kong University of Science and Technology

OBJECTIVE： To treat patients with vascular mild cognitive impairment （VMCI） using traditional Chinese medicine （TCM）, it is necessary to classify the patients into TCM syndrome types and to apply different treatments to different types. In this paper, we investigate how to properly carry out the classification for patients with VMCI aged 50 or above using a novel data-driven method known as latent tree analysis （LTA）. METHOD： A cross-sectional survey on VMCI was carried out in several regions in Northern China between February 2008 and February 2012 which resulted in a data set that involves 803 patients and 93 symptoms. LTA was performed on the data to reveal symptom co-occurrence patterns, and the patients were partitioned into clusters in multiple ways based on the patterns. The patient clusters were matched up with syndrome types, and population statistics of the clusters are used to quantify the syndrome types and to establish classification rules. RESULTS： Eight syndrome types are identified： Qi deficiency, Qi stagnation, Blood deficiency, Blood stasis, Phlegm-dampness, Fire-heat, Yang deficiency, and Yin deficiency. The prevalence and symptom occurrence characteristics of each syndrome type are determined. Quantitative classification rules are established for determining whether a patient belongs to each of the syndrome types. CONCLUSION： A solution for the TCM syndrome classification problem for patients with VMCI and aged 50 or above is established based on the LTA of unlabeled symptom survey data. The results can be used as a reference in clinic practice to improve the quality of syndrome differentiation and to reduce diagnosis variances across physicians. They can also be used for patient selection in research projects aimed at finding biomarkers for the syndrome types and in randomized control trials aimed at determining the efficacy of TCM treatments of VMCI.

关键词： vascular mild cognitive impairment medicine, Chinese traditional syndrome latent tree analysis

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利用地震面波频散重建川滇地区壳幔S波速度

地球物理学报 2008年第4期51卷 1114-1122页

作者：张智陈赟李飞桂林工学院广西地质工程中心重点实验室桂林工学院资源与环境工程系桂林541004 岩石圈演化国家重点实验室中国科学院地质与地球物理研究所北京100029

利用适配滤波频时分析技术分析覆盖川滇地区的长周期面波记录,计算了周期10～100 s内的面波群速度频散,对研究区进行划分尺度大小1.5°×1.5°分格后,采用射线追踪方法求取各分段射线的长度和时间,得到各个格子的纯路径频散.继而采用阻... 详细信息

利用适配滤波频时分析技术分析覆盖川滇地区的长周期面波记录,计算了周期10～100 s内的面波群速度频散,对研究区进行划分尺度大小1.5°×1.5°分格后,采用射线追踪方法求取各分段射线的长度和时间,得到各个格子的纯路径频散.继而采用阻尼最小二乘法求解,反演得到该研究区壳幔S波速度分布.研究结果表明,川滇地区表现出地壳增厚和缩短,在地壳和上地幔顶部,川滇菱形块体内部与其外部相比,虽然存在局部速度负异常,总体上呈相对高速,其周边的走滑断裂带呈现深至上地幔顶部的负速度异常,这有助于地壳块体沿断裂的侧向挤出;此外,云南西部和四川西部壳内和上地幔高导层的存在被认为是与部分熔融的物质或与滑脱构造相关联;从纬向剖面和经向剖面可以得到四川盆地莫霍面平均深度大约为45 km,云南地区莫霍面深度南北方向不一致,云南地区最北端深度达到49 km,南端莫霍面深度大约为36 km,这说明不同构造块体在构造运动过程中受到影响的程度不同.

关键词：频时分析面波频散壳幔结构地壳增厚 S波速度分布

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利用贝叶斯模型进行热参数估计

系统仿真学报 2006年第6期18卷 1462-1465页

作者：高思云杨晨重庆大学动力工程学院重庆400044

对利用Bayesian模型分析热传导反问题中的导热系数预测问题的方法进行了研究。导热系数反问题的解是其后验概率密度的数学期望,用MarkovchainMonteCarlo算法计算后验状态空间以得到未知导热系数的统计估计。方法中取导热系数的先验分布... 详细信息

对利用Bayesian模型分析热传导反问题中的导热系数预测问题的方法进行了研究。导热系数反问题的解是其后验概率密度的数学期望,用MarkovchainMonteCarlo算法计算后验状态空间以得到未知导热系数的统计估计。方法中取导热系数的先验分布满足正态分布,似然函数中的温度数据满足稳态零均值白噪声,先验分布与似然函数相乘得到后验概率密度函数。采用Metropolis-Hasting算法进行数据采样构造Markovchain,并截取收敛后的样本进行分析。

关键词：参数估计 Bayesian模型 Markov chain Monte Carlo Metropolis-Hasting算法

Demethylation of tumor necrosis factor-α converting enzyme promoter associated with high hepatitis B e antigen level in chronic hepatitis B

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World Journal of Gastroenterology 2015年第27期21卷 8382-8388页

作者： Zhen-Li Wang Shuai Gao Xin-You Li Feng-kai Sun Feng Li Yu-chen Fan kai Wang Department of Hepatology Qilu Hospital of Shandong University Institute of Hepatology Shandong University

AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-negative CHB, and 40 healthy controls(HCs) were randomly enrolled in this study. Genomic DNA was extracted from peripheral blood mononuclear cells and methylation status of TACE promoter was determined by methylation-specific polymerase chain reaction. The clinical and laboratory parameters were ***: One hundred and thirty of 160 patients with CHB(81.25%) and 38 of 40 HCs(95%) displayed TACE promoter methylation. The difference was significant(χ2 = 4.501, P 0.05). In the HBe Ag-positive group, TACE methylation frequency was significantly negatively correlated with HBe Ag(r =-0.602, P < 0.01), alanine aminotransferase(r =-0.461, P < 0.01) and aspartate aminotransferase(r =-0.329, P < 0.01). CONCLUSION: Patients with HBe Ag-positive CHB have aberrant demethylation of the TACE promoter, which may potentially serve as a biomarker for HBe Ag seroconversion.

关键词： Tumor necrosis factor-α converting enzyme Methylation Chronic hepatitis B Methylation-specificpolymerase chain reaction Biomarker

Biocatalytic stereoselective synthesis of methyl mandelates by engineering a cytochrome P450 hydroxylase

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Green Synthesis and Catalysis

Green Synthesis and Catalysis 2024年第2期5卷 88-93页

作者： Lingzhi Xie yun Zhang Ruyue Zhang Haibo Cui Baodong Cui Wenyong Han Nanwei Wan Zhi Li Yongzheng chen Key Laboratory of Biocatalysis&Chiral Drug Synthesis of Guizhou Province Generic Drug Research Center of Guizhou ProvinceGreen Pharmaceuticals Engineering Research Center of Guizhou ProvinceSchool of PharmacyZunyi Medical UniversityZunyi 563000China Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education Zunyi Medical UniversityZunyi 563000China Department of Chemical and Biomolecular Engineering National University of Singapore 4 Engineering Drive 4Singapore 117585Singapore

Chiral methyl mandelates are useful synthons in organic transformation and pharmaceutical *** synthesis of these valuable compounds by direct C–H activating oxidative hydroxylation has attracted keen *** herein is achieving the stereoselective and efficient bio-hydroxylation of methyl 2-phenylacetates to the chiral methyl mandelates by directed evolution of the cytochrome P450DA *** the present study,a new colorimetric high-throughput screening assay was successfully developed based on a dualenzyme cascade for the engineering of the P450DA's hydroxylation *** beneficial variants with enhanced bio-hydroxylation activity were created by combining random mutagenesis and site-saturated/directed mutagenesis ***-cell bio-hydroxylation of various methyl 2-phenylacetates using the best septupletmutant P450DA-11 yielded the corresponding chiral methyl mandelates in up to 92%isolated yields and>99%ee.

关键词： Bio-hydroxylation Directed evolution Cytochrome P450 High-throughput screening Methyl mandelates

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含复杂预应力圆薄板振动模态解析方法研究

船舶力学 2020年第8期24卷 1062-1071页

作者：陈炉云黄惜春上海交通大学海洋工程国家重点实验室上海200240 上海交通大学海洋智能装备与系统教育部重点实验室上海200240 中国舰船研究设计中心武汉430064

本文研究预应力对圆薄板结构动力响应的影响,解决圆薄板结构中非均匀分布预应力的动力响应问题。根据含预应力的薄板结构应力-应变方程,建立含预应力圆薄板结构的运动控制微分方程。将焊接残余应力定义为复杂预应力,提出一种适用于复杂... 详细信息

本文研究预应力对圆薄板结构动力响应的影响,解决圆薄板结构中非均匀分布预应力的动力响应问题。根据含预应力的薄板结构应力-应变方程,建立含预应力圆薄板结构的运动控制微分方程。将焊接残余应力定义为复杂预应力,提出一种适用于复杂预应力分布的圆薄板解析求解方法。以具有周边简支边界条件薄圆板结构为例,对比焊接残余应力的不同分布形式对薄圆板结构固有频率及振型的影响。最后,利用有限元法对文中所提方法有效性进行验证。

关键词：复杂预应力圆薄板解析解振型固有频率

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黑云母花岗岩全风化层工程地质特性研究

铁道工程学报 2016年第6期33卷 22-25,43页

作者：陈爱云中铁第四勘察设计院集团有限公司武汉430063

研究目的:华东、华南地区广泛分布有黑云母花岗岩,花岗岩全风化层厚度大,工程地质特性特殊。目前有多条高速铁路在华东、华南区域兴建,针对这种地层条件下的边坡处理以及路基填筑成为极为关键的问题。为全面了解华东、华南地区黑云母花... 详细信息

研究目的:华东、华南地区广泛分布有黑云母花岗岩,花岗岩全风化层厚度大,工程地质特性特殊。目前有多条高速铁路在华东、华南区域兴建,针对这种地层条件下的边坡处理以及路基填筑成为极为关键的问题。为全面了解华东、华南地区黑云母花岗岩的工程地质特性,在该区域多地取样进行室内试验,对风化层的矿物风化特征、物理特性、强度特性以及膨胀性进行系统的探讨,为该区域的铁路建设提供可靠的依据。研究结论:(1)华东、华南地区黑云母花岗岩的矿物成分主要是石英、长石和黑云母,发生风化蚀变的主要是长石和云母,长石风化蚀变成高岭石、伊利石或蒙脱石,黑云母蚀变为伊利石和铁锰质物;(2)华东、华南地区黑云母花岗岩全风化层结构疏松,泥质胶结为主,塑性指数在10%左右,属于粉质黏土的范畴;(3)黑云母花岗岩全风化层原状样的摩擦角在27°左右,粘聚力均小于100 kP a,粘聚力随具体地区相差较大;(4)黑云母花岗岩全风化层均不具有膨胀性;(5)该研究成果可为穿越花岗岩地区的铁路勘察设计提供参考与借鉴。

关键词：花岗岩全风化层矿物风化蚀变强度