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Unveiling the interaction mechanisms of key functional microorganisms in the partial denitrification-anammox process induced by COD

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环境科学与工程前沿(英文) 2023年第8期17卷 153-165页

作者： Guangjiao Chen Lan Lin Ying Wang Zikun zhang Wenzhi Cao Yanlong Zhang Key Laboratory of Marine Environmental Science College of the Environment and EcologyXiamen UniversityXiamen 361102China Fujian Key Laboratory of Coastal Pollution Prevention and Control College of Environment and EcologyXiamen UniversityXiamen 361102China Department of Civil and Environmental Engineering Graduate School of EngineeringTohoku UniversitySendaiMiyagi 980-8579Japan

Partial denitrification-anammox(PD-anammox)is an innovative process to remove nitrate(NO_(3)^(–)–N)and ammonia(NH4+–N)simultaneously from wastewater.Stable operation of the PD-anammox process relies on the synergy and competition between anammox bacteria and denitrifiers.However,the mechanism of metabolic between the functional bacteria in the PD-anammox system remains unclear,especially in the treatment of high-strength wastewater.The kinetics of nitrite(NO_(2)^–N)accumulation during denitrification was investigated using the Michaelis-Menten equation,and it was found that low concentrations of NO_(3)^–N had a more significant effect on the accumulation of NO_(2)^–N during denitrification.Organic matter was a key factor to regulate the synergy of anammox and denitrification,and altered the nitrogen removal pathways.The competition for NO_(2)^–N caused by high COD concentration was a crucial factor that affecting the system stability.Illumina sequencing techniques demonstrated that excess organic matter promoted the relative abundance of the Denitratesoma genus and the nitrite reductase gene nirS,causing the denitrifying bacteria Denitratisoma to compete with Cadidatus Kuenenia for NO_(2)^–N,thereby affecting the stability of the system.Synergistic carbon and nitrogen removal between partial denitrifiers and anammox bacteria can be effectively achieved by controlling the COD and COD/NO_(3)^(–)N.

关键词： PD-anammox process Nitrite accumulation COD Microbial interaction

Quadratic Finite Volume Element Schemes over Triangular Meshes for a Nonlinear Time-Fractional Rayleigh-Stokes Problem

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Computer Modeling in Engineering & Sciences 2021年第5期127卷 487-514页

作者： Yanlong Zhang Yanhui Zhou Jiming Wu Graduate School of China Academy of Engineering Physics Beijing100088China School of Data and Computer Science Sun Yat-Sen UniversityGuangzhou510275China Institute of Applied Physics and Computational Mathematics Beijing100088China

In this article,we study a 2D nonlinear time-fractional Rayleigh-Stokes problem,which has an anomalous subdiffusion term,on triangular meshes by quadratic finite volume element schemes.Time-fractional derivative,defined by Caputo fractional derivative,is discretized through L2−1σformula,and a two step scheme is used to approximate the time first-order derivative at time tn−α/2,where the nonlinear term is approximated by using a matching linearized difference scheme.A family of quadratic finite volume element schemes with two parameters are proposed for the spatial discretization,where the range of values for two parameters areβ1∈(0,1/2),β2∈(0,2/3).For testing the precision of numerical algorithms,we calculate some numerical examples which have known exact solution or unknown exact solution by several kinds of quadratic finite volume element schemes,and contrast with the results of an existing quadratic finite element scheme by drawing diversified comparison plots and showing the detailed data of L2 error results and convergence orders.Numerical results indicate that,L2 error estimate of one scheme with parameters β_(1)=(3−√3)/6,β2=(6+√3−√21+6√3)/9 is O(h^(3)+△t^(2)),and L^(2) error estimates of other schemes are O(h^(2)+△t^(2)),where h and △t denote the spatial and temporal discretization parameters,respectively.

关键词： Quadratic finite volume element schemes anomalous sub-diffusion term L2 error estimate quadratic finite element scheme

Integrative lipidomics profile uncovers the mechanisms underlying high-level α-linolenic acid accumulation in Paeonia rockii seeds

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Horticulture Research 2023年第7期10卷 152-164页

作者： Weizong Yang Ziwei Xin Lihang Xie Yuhui Zhai Yanlong Zhang Lixin Niu Qingyu zhang College of Landscape Architecture and Arts Northwest A&F UniversityYangling 712100ShaanxiChina Academy of Medical Sciences Zhengzhou UniversityZhengzhou 450000China

Tree peony(Paeonia rockii)is an excellent woody oilseed crop,known for its highα-linolenic acid(ALA,∼45%)content,which is of great value for human health.However,the mechanisms underlying this high-level ALA accumulation in tree peony seeds are poorly understood.In this study,we evaluated the dynamic changes in the lipidomic profile of P.rockii seeds during development.A total of 760 lipid molecules were identified in P.rockii seeds;triacylglycerol(TAG)lipid molecules showed the highest abundance and diversity,both increasing during seed development.Particularly,ALA was the predominant fatty acid at the TAG sn-3 position.We further characterized two diacylglycerol acyltransferase(DGAT)genes and three phospholipid:diacylglycerol acyltransferase(PDAT)genes involved in the transfer of fatty acids to the TAG sn-3 position.Gene expression and subcellular localization analyses suggested that PrDGATs and PrPDATs may function as endoplasmic reticulum-localized proteins in seed TAG biosynthesis.In vitro functional complementation analysis showed different substrate specificities,with PrPDAT2 having a specific preference for ALA.Multiple biological assays demonstrated that PrDGAT1,PrDGAT2,PrPDAT1-2,and PrPDAT2 promote oil synthesis.Specifically,PrPDAT2 leads to preferential ALA in the oil.Our findings provide novel functional evidence of the roles of PrDGAT1 and PrPDAT2,which are potential targets for increasing the ALA yield in tree peony and other oilseed crops.

关键词： synthesis. finding predominant

Nonparametric TOA estimators for low-resolution IR-UWB digital receiver

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Journal of Systems Engineering and Electronics 2015年第1期26卷 26-31页

作者： Yanlong Zhang Weidong Chen School of Electrical Science and Engineering University of Science and Technology of China

Nonparametric time-of-arrival（TOA） estimators for impulse radio ultra-wideband（IR-UWB） signals are proposed. Nonparametric detection is obviously useful in situations where detailed information about the statistics of the noise is unavailable or not accurate. Such TOA estimators are obtained based on conditional statistical tests with only a symmetry distribution assumption on the noise probability density function. The nonparametric estimators are attractive choices for low-resolution IR-UWB digital receivers which can be implemented by fast comparators or high sampling rate low resolution analog-to-digital converters（ADCs）,in place of high sampling rate high resolution ADCs which may not be available in practice. Simulation results demonstrate that nonparametric TOA estimators provide more effective and robust performance than typical energy detection（ED） based estimators.

关键词： conditional test nonparametric estimator time-of-arrival（TOA） low-resolution

System identification under saturated precise or set-valued measurements

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Science China(Information Sciences) 2023年第1期66卷 224-243页

作者： yanlong ZHAO Hang zhang Ting WANG Guolian KANG Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences Institute of Artificial Intelligence University of Science and Technology Beijing Department of Biostatistics St.Jude Children's Research Hospital

This paper considers the system identification problem based on saturated precise or set-valued measurements, which is widely used in various fields and has essential difficulties. Since existing methodologies cannot make full use of the mixed data, this paper is aiming to fill the gap and build a unified framework in dealing with such problems rigorously and comprehensively. New algorithms are introduced and their properties are established. Most significantly, the Cramécr-Rao(CR) lower bound based on the measurements is established, which consists of two parts with respect to the precise data and set-valued data, respectively. This prompts the idea of designing an estimation algorithm by grouping and combining the estimations under two classifications of data. As a result, a CR lower bound-based algorithm(CRBA) is constructed. The convergence properties are theoretically analyzed in terms of consistency and asymptotic efficiency under periodic inputs. For general inputs, an algorithm based on the CRBA that combines the expectation maximization(EM) algorithm for set-valued subsystems and the gradient descent algorithm for precise subsystems is proposed. Numerical simulations validate the superiority of the proposed algorithms.

关键词： system identification Cramér-Rao lower bound truncated data precise measurement set-valued measurement

Size effects in the uniaxial compressive properties of 3D printed models of rocks:an experimental investigation

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International Journal of Coal Science & Technology 2022年第6期9卷 1-12页

作者： Hao Wu Yang Ju Xin Han zhangyu Ren Yue Sun Yanlong Zhang Tianyi Han School of Mechanics&Civil Engineering China University of Mining&Technology(Beijing)Beijing 100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining&Technology(Beijing)Beijing 100083China School of Emergency Management and Safety Engineering China University of Mining&Technology(Beijing)Beijing 100083China

Transparent physical models of real rocks fabricated using three-dimensional(3D)printing technology are used in photoelas-tic experiments to quantify the evolution of the internal stress and deformation fields of rocks.Therefore,they are rendered as an emerging powerful technique to quantitatively reveal the intrinsic mechanisms of rock failure.The mechanical behav-ior of natural rocks exhibits a significant size effect;however,limited research has been conducted on whether transparent physical models observe similar size effects.In this study,to make the transparent printed models accurately demonstrate the mechanical behavior of natural rocks and reveal the internal mechanism of the size effect in rock mechanical behavior,the size effect in 3D printed models of fractured and porous rocks under uniaxial compressive loading was investigated.Transparent cylindrical models with different sizes that contained different fractured and porous structures were printed using the fracture and porous characteristics extracted from natural coal and sandstone.The variation in uniaxial compres-sive strength and elastic modulus of fractured and porous models for increasing model sizes were obtained through uniaxial compression experiments.Finally,the influence of internal discontinuous structural features,such as fractures and pores,on the size effect pertaining to the mechanical behavior of the model was analyzed and elaborated by comparing it with the mechanical properties of the continuous homogeneous model without fractures and pores.The findings provided support and reference to analyze the size effect of rock mechanical behavior and the effect of the internal discontinuous structure using 3D printed transparent models.

关键词： Size effect 3D printed model Rocks Mechanical property Fractures Pores

Stability analysis of a slope containing water-sensitive mudstone considering different rainfall conditions at an open-pit mine

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International Journal of Coal Science & Technology 2023年第4期10卷 233-253页

作者： Guoyu Yang yanlong Chen Xuanyu Liu Ri Yang Yafei zhang Jialong zhang State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China School of Mines China University of Mining and TechnologyXuzhou 221116China Harwusu Open-Pit Mine China Shenhua Energy Co.LtdOrdos 010300China China Energy Investment Beidian Shengli Energy Co. LtdXinlinhot 026000China School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China

Mudstone, as a typical soft rock with wide distribution, has been endangering the slopes containing mudstone by its watersensitivity of swelling and weakening strength when encountering water. To comprehensively understand the water-sensitivity of mudstone and reveal its infuence on slope stability, we took the working slope containing water-sensitive mudstone of Shengli No.1 open-pit coal mine in Xilinhot, Inner Mongolia, China, as an example. Mudstone samples taken from the working slope were remodeled and saturated, and then triaxial tested to obtain the efective cohesion and efective internal friction angle. The flter paper method was used to obtain the soil–water characteristic curve of unsaturated mudstone. The pore structure of mudstone samples with diferent water contents were analyzed using the mercury intrusion porosimetry tests combined with the fractal dimension. The total pore content of the mudstone sample with lower water content is greater than that of the mudstone sample with higher water content. The mesopores are more in the mudstone sample with lower water content, while the small pores are more in the mudstone sample with higher water content. The variation of water content will change the complexity of mudstone pore structure. The higher the water content, the simpler the mudstone pore structure and the smoother the pore surface. Numerical calculations were conducted on the stability of the working slope under diferent rainfall conditions. The efective saturation on the mudstone layer surface changed and the plastic strain all occurred on the mudstone steps under diferent rainfall conditions. The key to preventing landslide of the slope containing water-sensitive mudstone in Shengli No.1 open-pit coal mine is to control the deformation and sliding of the mudstone layer.

关键词： Water-sensitivity SWCC Pore structure Rainfall infltration Slope stability

Geochronology and Geochemistry of Late Devonian I- and A-Type Granites from the Xing’an Block,NE China:Implications for Slab Break-off during Subduction of the Hegenshan-Heihe Ocean

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Journal of Earth Science 2022年第1期33卷 150-160页

作者： Zheng Ji Wenchun Ge Hao Yang Yanlong Zhang Yu Dong Junhui Bi Xiwen Liu College of Earth Sciences Jilin UniversityChangchun 130061China Tianjin Center China Geological SurveyTianjin 300170China Jilin Provincial Water Resources and Hydropower Consultative Company Changchun 130021China

We present detailed geochronological,geochemical,and zircon Hf isotopic data for Late Paleozoic granitic rocks from Handagai and Zhonghe plutons in the Xing’an Block,NE China,aiming to provide constraints on their origin and tectonic implications.New zircon U-Pb ages indicate they were formed in the Late Devonian(ca.379 Ma) immediately after a striking 50 Ma magmatic lull(ca.430-380 Ma) in the Xing ’ an Block.Petrological and geochemical features suggest that the Handagai monzogranites and Zhonghe alkali-feldspar granites are I- and A-type granites,respectively,although both of them have high-K calc-alkaline features and positive zircon ε_(Hf)(t) values(+3.47 to +10.77).We infer that the Handagai monzogranites were produced by partial melting of juvenile basaltic crustal materials under a pressure of <8-10 kbar,whereas the Zhonghe alkali-feldspar granites were generated by partial melting of juvenile felsic crustal materials at shallower depths(P ≤ 4 kbar).Our results,together with published regional data,indicate their generation involves a subduction-related extensional setting.Slab break-off of the Hegenshan-Heihe oceanic plate may account for the subduction-related extensional setting,as well as the transformation of arc magmatism from the Early-Middle Devonian lull to the Late Devonian-Early Carboniferous flare-up in the Xing’an Block.

关键词： Late Devonian granitoids geochemistry slab break-off Hegenshan-Heihe Ocean Xing’an Block

System identification with binary-valued observations under both denial-of-service attacks and data tampering attacks:the optimality of attack strategy

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Control Theory and Technology 2022年第1期20卷 127-138页

作者： Jin Guo Xuebin Wang Yanling zhang Wenchao Xue yanlong Zhao School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of Knowledge Automation for Industrial Processes Ministry of EducationBeijing100083China Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China

With the development of wireless communication technology,cyber physical systems are applied in various fields such as industrial production and infrastructure,where lots of information exchange brings cyber security threats to the systems.From the perspective of system identification with binary-valued observations,we study the optimal attack problem when the system is subject to both denial of service attacks and data tampering attacks.The packet loss rate and the data tampering rate caused by the attack is given,and the estimation error is derived.Then the optimal attack strategy to maximize the identification error with the least energy is described as a min–max optimization problem with constraints.The explicit expression of the optimal attack strategy is obtained.Simulation examples are presented to verify the effectiveness of the main conclusions.

关键词： System identification Binary-valued observations Denial-of-service attacks Data tampering attacks

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