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Surface properties of bacteria from activated sludge in relation to bioflocculation

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Journal of Environmental Sciences 2010年第12期22卷 1840-1845页

作者： bing xie Jidong Gu Jun Lu Key Laboratory of Urbanization and Ecological Restoration of Shanghai Department of Environmental Science & Technology East China Normal University Shanghai 200062 China Laboratory of Environmental Toxicology Department of Ecology & Biodiversity The University of Hong Kong Pokfulam Road Hong Kong SAR China Department of Interdisciplinary Studies Faculty of Health & Environmental Sciences Auckland University of Technology Auckland 1142 New Zealand School of Biological Sciences Faculty of Science University of Auckland Auckland 1142 New Zealand

Two bacterial stains were isolated from the activated sludge and identified as Leucobacter sp. and Alcaligenesfaecalis by 16S rDNA sequencing. Pure cultures of these two strains, representing well or poorly settled bacteria, were used to investigate the mechanism of bioflocculation in activated sludge. Based on the analyses of the characteristics of cells hydrophobicity, ζ-potential, flocculation ability and extracellular polymeric substance （EPS） composition under different growth stages, it was found that the ratio of cell EPS protein had the highly influence on ζ-potential and hydrophobicity, which were important factors to bioflocculation. Cellulase and Proteinase K could destroy the extracellular biopolymer and resulted in a decrease in the hydrophobicity and ζ-potential. However, in our study, the flocculation characteristics exhibited differently in relation to cellulase and Proteinase K. Flocculation of cells treated with cellulase and Proteinase K decreased sharply, and then recovered quickly in cellulase treatment, while cells treated with Proteinase K showed no sign of recovery. This reveals that the presence of protein in extracellular biopolymer plays an important role to the bioflocculation of cells.

关键词： activated sludge hydrophobicity ζ-potential bioflocculation pure culture

Mirror-assisted multi-view high-speed digital image correlation for dual-surface dynamic deformation measurement

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Science China(Technological Sciences) 2023年第3期66卷 807-820页

作者： xie RuiLi CHEN Bin PAN bing Institute of Solid Mechanics Beihang UniversityBeijing 100191China Department of Fiber and Polymer Technology KTH Royal Institute of TechnologyStockholm 10044Sweden

Based on the recently proposed mirror-assisted multi-view digital image correlation(MV-DIC),we establish a cost-effective and easy-to-implement mirror-assisted multi-view high-speed digital image correlation(MVHS-DIC)method and explore its applications for dual-surface full-field dynamic deformation *** contrast to the general requirement of four expensive high-speed cameras for dual-surface dynamic deformation field measurement,the established mirror-assisted MVHS-DIC halves the cost by involving only two synchronized high-speed cameras and two planar *** two synchronized high-speed cameras can dynamically measure the front and rear surfaces of a sheet sample simultaneously through the reflection of the two *** results on the two surfaces are then transformed into the same coordinate system,leading to the required dual-surface 3D dynamical deformation *** effectiveness and accuracy of the established system are validated through modal tests of a cantilever aluminum *** vibration measurement of a drum and dual-surface transient deformation measurement of a smartphone in the drop-collision process further prove its *** from the attractive advantages of multi-view dynamic deformation measurement in a cost-efficient way,the established mirror-assisted MVHS-DIC is expected to encourage more comprehensive dynamic mechanical behavior characterization of regular-sized materials and structures in vibration and impact engineering fields.

关键词： multi-view high-speed digital image correlation dual-surface dynamic deformation measurement

Aeroservoelastic stability analysis for flexible aircraft based on a nonlinear coupled dynamic model

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Chinese Journal of Aeronautics 2018年第12期31卷 2185-2198页

作者： yi LIU Changchuan xie Beijing Institute of Electrical and Mechanical Engineering Beijing 100074China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

A unified theoretical aeroservoelastic stability analysis framework for flexible aircraft is established in this paper. This linearized state space model for stability analysis is based on nonlinear coupled dynamic equations, in which rigid and elastic motions of aircraft are both *** common body coordinate system is utilized as the reference frame in the deduction of dynamic equations, and significant deformations of flexible aircraft are also fully concerned without any excessive assumptions. Therefore, the obtained nonlinear coupled dynamic models can well reflect the special dynamic coupling mechanics of flexible aircraft. For aeroservoelastic stability analysis,the coupled dynamic equations are linearized around the nonlinear equilibrium state and together with a control system model to establish a state space model in the time domain. The methodology in this paper can be easily integrated into the industrial design process and complex *** results for a complex flexible aircraft indicate the necessity to consider the nonlinear coupled dynamics and large deformation when dealing with aeroservoelastic stability for flexible aircraft.

关键词： Aeroservoelasticity Flexible aircraft Geometric nonlinearity Nonlinear coupled dynamics Stability control

Preface: Special topic on photocatalytic or electrocatalytic reduction of CO2

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Science China Chemistry 2020年第12期63卷 1703-1704页

作者： yi xie Hefei National Laboratory for Physical Sciences at the Microscale CAS Center for Excellence in NanoscienceiCHEMUniversity of Science and Technology of ChinaHefei 230026China

CO2 reduction technology, which converts greenhouse gases into industrial feedstock or liquid fuels using renewable electricity or solar energy, is considered a promising energy conversion technology. The reaction uses CO2 molecules as the raw material, which can effectively reduce the atmospheric CO2 content, thereby curbing the greenhouse ***, by designing rational catalysts, CO2 molecules can be directly converted into usable fuels, which effectively alleviate the global energy crisis.

关键词： effect. thereby rational

AZD1775 synergizes with SLC7A11 inhibition to promote ferroptosis

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Science China Life Sciences 2025年第1期 204-218页

作者： Chen Xiong Hong Ling yingdan Huang Hanzhi Dong Bangxiang xie Qian Hao Xiang Zhou Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences Fudan University Department of Oncology Shanghai Medical CollegeFudan University Department of Breast Surgery Fudan University Shanghai Cancer CenterFudan University Department of Oncology First Affiliated Hospital of Nanchang University Beijing Institute of Hepatology Beijing Youan HospitalCapital Medical University Beijing Engineering Research Center for Precision Medicine and Transformation of Hepatitis and Liver Cancer Key Laboratory of Breast Cancer in Shanghai Fudan University Shanghai Cancer CenterFudan University Shanghai Key Laboratory of Medical Epigenetics International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology)Institutes of Biomedical SciencesFudan University

Tumor suppressor p53-mediated cell cycle arrest and DNA damage repair may exert cytoprotective effects against cancer therapies, including WEE1 inhibition. Considering that p53 activation can also lead to multiple types of cell death, the role of this tumor suppressor in WEE1 inhibitor-based therapies remains disputed. In this study, we reported that nucleolar stress-mediated p53 activation enhanced the WEE1 inhibitor AZD1775-induced ferroptosis to suppress lung cancer growth. Our findings showed that AZD1775 promoted ferroptosis by blocking cystine uptake, an action similar to that of Erastin. Meanwhile, inhibition of WEE1 by the WEE1 inhibitors or si RNAs induced compensatory upregulation of SLC7A11, which conferred resistance to ferroptosis. Mechanistically, AZD1775 prevented the enrichment of H3K9me3, a histone marker of transcriptional repression, on the SLC7A11 promoter by repressing the expression of the histone methyltransferase SETDB1, thereby enhancing NRF2-mediated SLC7A11 transcription. This finding was also validated using the H3K9me3 inhibitor BRD4770. Remarkably, we found that the nucleolar stress-inducing agent Actinomycin D(Act. D) inhibited SLC7A11 expression by activating p53, thus augmenting AZD1775-induced ferroptosis. Moreover, the combination of AZD1775 and Act. D synergistically suppressed wild-type p53-harboring lung cancer cell growth both in vitro and in vivo. Altogether, our study demonstrates that AZD1775 promotes ferroptosis by targeting cystine uptake but also mediates the adaptive activation of SLC7A11 through the WEE1-SETDB1 cascade and NRF2-induced transcription, and inhibition of SLC7A11 by Act. D boosts the anti-tumor efficacy of AZD1775 by enhancing ferroptosis in cancers with wild-type p53.

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Testing Lorentz violation with binary pulsars:constraints on standard model extension

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Research in Astronomy and Astrophysics 2013年第1期13卷 1-4页

作者： yi xie Department of Astronomy Nanjing University Key Laboratory of Modern Astronomy and Astrophysics Nanjing University Ministry of Education

Under the standard model extension （SME） framework, Lorentz invariance is tested in five binary pulsars： PSR J0737-3039, PSR B 1534＋12, PSR J1756-2251, PSR B1913＋16 and PSR B2127＋11C. By analyzing the advance of periastron, we obtain the constraints on a dimensionless combination of SME parameters that is sen- sitive to timing observations. The results imply no evidence for the break of Lorentz invariance at the 10-l level, one order of magnitude larger than the previous estima- tion.

关键词： gravitation -- relativity -- pulsars: individual (PSR 0737-3039 PSRB1534+12 PSR J1756-2251 PSR B1913+16 PSR B2127+ 11C)

Adaptive Optimization with Periodic Dither Signals

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Journal of Systems Science & Complexity 2021年第5期34卷 1766-1781页

作者： xie Siyu WANG Le yi Department of Electrical and Computer Engineering Wayne State UniversityDetroitMichigan 48202USA

Optimization methods in cyber-physical systems do not involve parameter uncertainties in most existing *** paper considers adaptive optimization problems in which searching for optimal solutions and identifying unknown parameters must be performed *** to the dual roles of the input signals on achieving optimization and providing persistent excitation for identification,a fundamental conflict *** this paper,a method of adding a small deterministic periodic dither signal to the input is deployed to resolve this conflict and provide sufficient excitation for estimating the unknown *** designing principle of the dither is *** dithered inputs,the authors show that simultaneous convergence of parameter estimation and optimization can be *** properties and convergence rates of parameter estimation and optimization variable updates are presented under the scenarios of uncertainty-free observations and systems with noisy observation and unmodeled *** fundamental relationships and tradeoff among updating step sizes,dither magnitudes,parameter estimation errors,optimization accuracy,and convergence rates are further investigated.

关键词： Adaptive optimization cyber-physical system identification optimization parameter uncertainty periodic dither signal

Calculation method of quantum efficiency to TiO_2 nanocrystal photocatalysis reaction

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Journal of Environmental Sciences 2002年第1期14卷 70-75页

作者： xie yi bing, YUAN Chun wei (National Laboratory of Molecular & Biomolecular Electronics, Southeast University, Nanjing 210096, China.) National Laboratory of Molecular & Biomolecular Electronics Southeast University Nanjing 210096 Chin

The quantum yield is an important factor to evaluate the efficiency of photoreactor. This article gives an overall calculation method of the quantum efficiency( Φ ) and the apparent quantum efficiency( Φ a) to the TiO 2/UV photocatalysis system. Furthermore, for the immobility system (IS), the formulation of the faction of light absorbed by the TiO 2 thin film is proposed so as to calculate the quantum efficiency by using the measured value and theoretic calculated value of transmissivity (T). For the suspension system(SS), due to the difficulty to obtain the absorption coefficient ( α ) of TiO 2 particulates, the quantum efficiency is calculated by means of the relative photonic efficiency ( ζ r) and the standard quantum yield ( Φ standard ).

关键词： photodegradation reaction quantum efficiency apparent quantum efficiency photonic efficiency relative photonic efficiency absorption coefficient

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基于乐观阴影集的荧光分子断层成像优化策略

郑州大学学报（理学版） 2025年第1期57卷 40-45页

作者：张钦然国栋凯易黄建谢琼西北大学信息与科学技术学院陕西西安710127 湖南中医药大学第一附属医院湖南长沙410208

荧光分子断层成像(fluorescence molecular tomography,FMT)是一种很有潜力的光学分子影像技术,由于光在生物组织内传输时会产生大量随机的强散射,传播过程极其复杂,使得荧光分子断层成像重建具有高度的病态性。为了获得准确的重建结果... 详细信息

荧光分子断层成像(fluorescence molecular tomography,FMT)是一种很有潜力的光学分子影像技术,由于光在生物组织内传输时会产生大量随机的强散射,传播过程极其复杂,使得荧光分子断层成像重建具有高度的病态性。为了获得准确的重建结果,提出了一种基于乐观阴影集的FMT优化策略。首先,定义了一种基于阴影集的情绪决策—乐观决策和悲观决策。然后,提出了一种基于乐观决策的FMT优化策略,该策略将荧光产额信息转换为模糊信息样本,通过阴影集计算当前模糊信息样本的最佳阈值,对样本的划分采取乐观决策。最后,筛选出荧光目标的预测位置。实验结果表明,所提算法能够有效提高FMT重建的精度。

关键词：阴影集三支决策荧光分子断层成像乐观决策

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