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Sorption behavior of tetracyclines on suspended organic matters originating from swine wastewater

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Journal of Environmental Sciences 2018年第3期30卷 144-152页

作者： Yaoyin lou Zhi-long ye Shaohua Chen xin ye Yujun Deng Jianqiao Zhang Key laboratory of Urban Pollutant Conversion Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China University of Chinese Academy of Sciences Beijing 100049 China

Tetracyclines（TCs） discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic matters（SOMs） play vital roles in antibiotics transport and degradation. However, limited information has been reported in the relevant literature. This study investigated TCs sorption behavior on SOM, withdrawn from swine wastewater. High TCs sorption capacities were detected, with the maximum values ranging from 0.337 to 0.679 mg/g. Increasing p H and temperature led to the decline of sorption capacity. Results from three-dimensional excitation–emission matrix fluorescence spectroscopy and Fourier transform infrared spectrometry revealed that amide and carboxyl groups were the main functional groups for TCs adsorption. The interactions between SOM and TCs were clarified as predominated by hydrogen-bonding and cation-exchange in acid conditions, and electrostatic repulsion in neutral or alkaline conditions. Adsorption kinetics modeling was conducted, and a satisfactory fitting was achieved with the Freundlich equation. These results indicated that the adsorption process was a rather complex process, involving a combination of cation-exchange and hydrogen-bonding. The results will provide a better understanding of the capability of SOM for TCs transport and abatement in the wastewater treatment process.

关键词： Tetracycline Suspended organic matters Adsorption Swine wastewater

Precise Asymptotics in the Baum-Katz and Davis laws of large Numbers of ρ-mixing Sequences

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Acta Mathematica Sinica,English Series 2005年第5期21卷 1057-1070页

作者： Wei HUANG ye JIANG li xin ZHANG Department of Mathematics Zhejiang University Hangzhou 310028 P. R. China

let {X,Xn;n ≥ 1} be a strictly stationary sequence of ρ-mixing random variables with mean zeros and finite variances. Set Sn =∑k=1^n Xk, Mn=maxk≤n｜Sk｜,n≥*** limn→∞ESn^2/n=：σ^2〉0 and ∑n^∞=1 ρ^2/d（2^n）〈∞,where d=2 if 1≤r〈2 and d〉r if r≥*** prove that if E｜X｜^r 〈∞,for 1≤p〈2 and r〉p,then limε→0ε^2（r-p）/2-p ∑∞n=1 n^r/p-2 P{Mn≥εn^1/p}=2p/r-p ∑∞k=1（-1）^k/（2k＋1）^2（r-p）/（2-p）E｜Z｜^2（r-p）/2-p,where Z has a normal distribution with mean 0 and variance σ^2.

关键词： ρ-mixing random variable Tail probabilities Baum-Katz law Davis law

A peep into mitochondrial disorder： multifaceted from mitochondrial DNA mutations to nuclear gene modulation

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Protein & Cell 2015年第12期6卷 862-870页

作者： Chao Chen ye Chen Min-xin Guan School of Medicine Institute of Genetics Zhejiang University Hangzhou 310058 China Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases Zhejiang University Hangzhou 310058 China

Mitochondrial genome is responsible for multiple human diseases in a maternal inherited pattern, yet phenotypes of patients in a same pedigree frequently vary largely. Genes involving in epigenetic modification, RNA processing, and other biological pathways, rather than ＂threshold effect＂ and environmental factors, provide more specific explanation to the aberrant phenotype. Thus, the double hit theory, mutations both in mito- chondrial DNA and modifying genes aggravating the symptom, throws new light on mitochondrial dysfunc- tion processes. In addition, mitochondrial retrograde signaling pathway that leads to reconfiguration of cell metabolism to adapt defects in mitochondria may as well play an active role. Here we review selected examples of modifier genes and mitochondrial retrograde signaling in mitochondrial disorders, which refine our understanding and will guide the rational design of clinical therapies.

关键词： mitochondrial disorder mitochondrial DNAmutation nuclear modifier gene mitochondrial retrogradesignaling

Multi-arm covariate-adaptive randomization

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Science China Mathematics 2023年第1期66卷 163-190页

作者： Feifang Hu Xiaoqing ye li-xin Zhang Department of Statistics The George Washington UniversityWashingtonDC 20052USA Institute of Statistics and Big Data Renmin University of ChinaBeijing 100872China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

Simultaneously investigating multiple treatments in a single study achieves considerable efficiency in contrast to the traditional two-arm *** treatment allocation for influential covariates has become increasingly important in today’s clinical *** multi-arm covariate-adaptive randomized clinical trial is one of the most powerful tools to incorporate covariate information and multiple treatments in a single *** and Simon’s procedure has been extended to the multi-arm ***,the theoretical properties of multi-arm covariate-adaptive randomization have remained largely elusive for *** this paper,we propose a general framework for multi-arm covariate-adaptive designs which also includes the two-arm case,and establish the corresponding theory under widely satisfied *** theoretical results provide new insights into the balance properties of covariate-adaptive randomization procedures and make foundations for most existing statistical inferences under two-arm covariate-adaptive ***,these open a door to study the theoretical properties of statistical inferences for clinical trials based on multi-arm covariateadaptive randomization procedures.

关键词： multiple treatment balancing covariate clinical trial marginal balance Markov chain Hu and Hu’s general procedure Pocock and Simon’s procedure stratified permuted block design

Automatic mass segmentation on mammograms combining random walks and active contour

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第9期13卷 635-648页

作者： xin HAO ye SHEN Shun-ren XIA MOE Key laboratory of Biomedical Engineering Zhejiang UniversityHangzhou 310027China Department of Signal and lnformation Processing China Jiliang UniversityHangzhou 310018China

Accurate mass segmentation on mammograms is a critical step in computer-aided diagnosis (CAD) systems. It is also a challenging task since some of the mass lesions are embedded in normal tissues and possess poor contrast or ambiguous margins. Besides, the shapes and densities of masses in mammograms are various. In this paper, a hybrid method combining a random walks algorithm and Chan-Vese (CV) active contour is proposed for automatic mass segmentation on mammograms. The data set used in this study consists of 1095 mass regions of interest (ROIs). First, the original ROI is preprocessed to suppress noise and surrounding tissues. Based on the preprocessed ROI, a set of seed points is generated for initial random walks segmentation. Afterward, an initial contour of mass and two probability matrices are produced by the initial random walks segmentation. These two probability matrices are used to modify the energy function of the CV model for prevention of contour leaking. lastly, the final segmentation result is derived by the modified CV model, during which the probability matrices are updated by inserting several rounds of random walks. The proposed method is tested and compared with other four methods. The segmentation results are evaluated based on four evaluation metrics. Experimental results indicate that the proposed method produces more accurate mass segmentation results than the other four methods.

关键词： Active contour Random walks Mass segmentation Mammogram

Effects of boron content on environmental embrittlement of ordered Ni3Fe alloys

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Advances in Manufacturing 2019年第2期7卷 221-227页

作者： Tao Chen ye-xin Chen Biao Yang Teng Wang Institute of Materials School of Materials Science and Engineering Shanghai University Shanghai 200072 People's Republic of China laboratory for Microstructures Shanghai University Shanghai 200444 People's Republic of China

The effects of boron content (CB = 0-0.14%(mass fraction)) on the tensile properties and enviro mental embrittlement of ordered Ni-24%Fe (atom fraction)- B (Ni3Fe-B) alloys have been investigated using tensile tests in vacuum and under gaseous hydrogen. The results indicate that, when CB le strength and elongation of the alloys in vacuum and gaseous hydrogen increase as CB in the ordered Ni3Fe-B alloy increases. The tensile strength and elongation are maximum, and the hydrogen embrittlement factor (IH) is minimum for the ordered Ni3Fe-0.06%B (mass fraction) alloy. Compared with the ordered B-free Ni3Fe alloy,IH of the ordered Ni3Fe-0.06%B (mass fraction) alloy decreases by 98.1%, and the fracture morphology of the alloy changes from fully intergranular to fully transgranular, when tested in gaseous hydrogen. A critical level of boron segregation at the grain boundaries of ordered Ni3Fe-B alloys is observed. The hydrogen embrittlement of ordered Ni3Fe- B alloys in gaseous hydrogen can be completely suppressed by boron atoms when CB ≥ 0.06%(mass fraction).

关键词： Ordered Ni3Fe alloy Boron content Environmental embrittlement

Effect of internal defects on tensile strength in SlM additively-manufactured aluminum alloys by simulation

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Chinese Journal of Aeronautics 2023年第10期36卷 485-497页

作者： xin SONG Bowen FU xin CHEN Jiazhen ZHANG Tong lIU Chunpeng YANG Yifan ye School of Mechanical Power Engineering Harbin University of Science and TechnologyHarbin 150080China COMAC Beijing Aircraft Technology Research Institute Beijing 102211China

This research investigates the effect of internal defects on the tensile strength of Selective laser Melting(SlM)additively-manufactured aluminum alloy(AlSi10Mg)test parts used for civil aircraft light weight design.A Finite Element Analysis(FEA)model containing internal defects was established by combining test data and the stress concentration factor comparison *** effect of variation in the number,location and shape of defects on the finite element results was *** results show that it is reasonable to use spherical defect *** finite element modeling and analysis methods are also applied to the study of the effect of internal defects on tensile strength in additive manufacturing of other metallic *** to the FEA results of single defects at different scales,the formula for calculating the weakening degree of tensile strength applicable to the defective area of less than 15%was *** result of the procedure is reliable and *** research results can guide the selection of process parameters for the additive manufacturing of aluminum ***,the research results can promote the application of metal additive manufacturing in designing light-weight civil aircraft structures.

关键词： Additive manufacturing Internal defects Tensile strength Elasticity FEA Simulation experiments

The Extension Dimension of Subcategories and Recollements of Abelian Categories

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1042-1058页

作者： xin MA ye Yang PENG Zhao Yong HUANG College of Science Henan University of EngineeringZhengzhou 451191P.R.China Department of Mathematics Nanjing UniversityNanjing 210093P.R.China

We investigate the behavior of the extension dimension of subcategories of abelian categories under ***Λ',Λ,Λ"be art in algebras such that(modΛ',mod A,modΛ")is a recollement,and let D'and D"be subcategories of modΛand modΛ"*** any n,m≥0,under some conditions,we get dimΩ^(k)(D)≤dimΩ^(n)(D')+dimΩ^(m)(D")+1,where k=max{m,n}and D is the subcategory of modΛglued by D'and D";moreover,we give a sufficient condition such that the converse inequality holds *** applications,some results for Igusa-Todorov subcategories and syzygy finite sub categories are obtained.

关键词： Recollements extension dimension Igusa–Todorov subcategories syzygy finite subcategories

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采用小波变换的空间外差干涉图误差分析方法

光谱学与光谱分析 2025年第1期45卷 8-14页

作者：王方原李晓静叶松李树王新强桂林电子科技大学光电工程学院广西桂林541004 广西光电信息处理重点实验室广西桂林541004

空间外差光谱技术(SHS)是一种应用于微弱物质探测、行星勘探以及大气遥感等领域的超光谱分析技术。受实验环境复杂及被测目标信号微弱等因素的影响,空间外差光谱仪的测量结果易出现干涉条纹倾斜、干涉图有斑点噪声等情况,从而最终影响... 详细信息

空间外差光谱技术(SHS)是一种应用于微弱物质探测、行星勘探以及大气遥感等领域的超光谱分析技术。受实验环境复杂及被测目标信号微弱等因素的影响,空间外差光谱仪的测量结果易出现干涉条纹倾斜、干涉图有斑点噪声等情况,从而最终影响测量光谱的精度。为了尝试解决这些问题,提出了基于小波变换的干涉图误差分析方法,对干涉图的斑点噪声水平和条纹倾斜误差进行有效的评价,从而为后续误差校正提供理论基础。首先对无误差的钾灯仿真干涉图加入不同标准差的高斯噪声,利用小波分解提取复小波系数,采用三种噪声估计法对干涉图数据进行计算,结果表明空域相关小波变换法噪声估计结果与真实值偏差最小,而Donoho估计法在修正截距后与真实值具有更好的吻合度。随后采用Db2小波对噪声水平不同的仿真钾灯干涉图进行一层小波分解并提取水平、对角及垂直三个方向的细节系数,采用Donoho估计法对干涉图进行二维噪声分析,有效表征了三幅干涉图各方向上的噪声水平特征。最后对仿真连续光干涉图进行小波分解并提取系数分析,研究了干涉条纹倾斜角度与小波分解系数的关系。研究结果表明,三个方向的小波细节系数估值变化分别在分解到不同层数时具有相似的变化规律:小波细节系数估值与条纹倾斜方向和小波细节系数的所属方向的夹角成反比,条纹倾斜方向与该小波细节系数的方向夹角越小,估值越大,反之则越小,且水平方向分解到第一层、对角方向分解到第二层、垂直方向分解到第三层符合变化规律。该研究是利用小波分解进行空间外差光谱误差分析的有益尝试,也为后续干涉图条纹倾斜误差的校正提供了一种新途径。

关键词：空间外差光谱技术噪声标准差估计干涉图小波变换