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Host plant traits play a crucial role in shaping the composition of epiphytic microbiota in the arid desert,Northwest China

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Journal of Arid Land 2024年第5期16卷 699-724页

作者： zhang Jun zhang Yuanming zhang qi State Key Laboratory of Desert and Oasis Ecology Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsXinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Biodiversity Conservation and Application in Arid Lands Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Xinjiang Field Scientific Observation Research Station of Tianshan Wild Fruit Forest Ecosystem Yili Botanical GardenXinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China College of Life Sciences Shihezi UniversityShihezi 832003China

Phyllosphere microorganisms are a crucial component of environmental microorganisms,highly influenced by host characteristics,and play a significant role in plant health and ***,the impact of host characteristics on shaping phyllosphere microbial communities of plants with different life forms remains *** high-throughput sequencing technology,this study analyzed the diversity and community composition of phyllosphere epiphytic microorganisms(e.g.,bacteria and fungi)of various plant life forms in the hinterland of the Gurbantunggut Desert,Northwest *** annotation of prokaryotic taxa(FAPROTAX)and fungi function guild(FUNGuild)were employed to assess the ecological functions of microorganisms and to investigate the role of stochastic and deterministic processes in shaping phyllosphere microbial *** showed a diverse array of phyllosphere epiphytic microorganisms in the desert plants,with Proteobacteria,Cyanobacteria,and Actinobacteriota dominating bacterial community,while Ascomycota and Basidiomycota were prevalent in fungal *** across different plant life forms highlighted distinct microbial communities,indicating strong filtering effects by plant *** prediction identified intracellular parasites(accounting for 27.44%of bacterial community abundance),chemoheterotrophy(10.12%),and phototrophy(17.41%)as the main functions of epiphytic bacteria on leaves of different life form *** prediction indicated that phyllosphere epiphytic fungi primarily served as Saprotrophs(81.77%),Pathotrophs(17.41%),and Symbiotrophs(0.82%).Co-occurrence network analysis demonstrated a predominance of positive correlations among different microbial ***-Crick dissimilarity index analysis revealed that deterministic processes predominantly influenced phyllosphere bacterial and fungal community *** partitioning analysis and random forest modeling suggested that pla

关键词： phyllosphere epiphytic bacteria phyllosphere epiphytic fungi community structure community diversity functional diversity plant life form plant functional traits

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On the M/G/1 queueing system with multiclass customers and fixed feedback

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The Journal of China Universities of Posts and Telecommunications 2008年第2期15卷 114-121页

作者： zhang qi-zhi School of Computer South China Normal University Guangzhou 510631China

The M/G/1 queueing system with multiclass customer arrivals, fixed feedback, and first come first served policy is considered, where different classes of customers have different arrival rates, service-time distributions, and feedback numbers. The joint probabifity generation function of queue size of each class and the Laplace-Stieltjes transform of the total sojourn time of a customer in each class are presented, which extended the results obtained by Choi B D. The mean queue size of each class and mean total sojourn time of a customer in each class are obtained with this result. The results can be used in computer and communication networks for their performance analysis.

关键词： M/G/1 queueing system feedback multiclasscustomers queue size sojourn time

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On overload control of parlay application server in next generation network

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The Journal of China Universities of Posts and Telecommunications 2008年第1期15卷 43-47,60页

作者： zhang qi-zhi School of Computer South China Normal University Guangzhou 510631 China

After analyzing the features of the Parlay application server（AS）, which provides many services with different time constraints in the next generation network（NGN）, a selfadapted overload control algorithm implemented in Parlay AS is proposed. In this algorithm, the service process module in parlay AS uses the earliest deadline first （EDF） serving rule to serve messages, and the overload control mechanism, using the Leaky Bucket algorithm to control message flows, is triggered by estimating the queue waiting time of a newly arriving message. By simulation it shows that this algorithm is a simple, easy-to-use, and available algorithm.

关键词： parlay application server overload control NGN,EDF

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Non-integer Quantum Transition, a True Non-perturbation Effect in Laser-Atom Interaction

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Communications in Theoretical Physics 2007年第6期47卷 1017-1023页

作者： zhang qi-Ren Department of Technical Physics Peking University Beijing 100871 China

We show that in the quantum transition of an atom interacting with an intense laser of circular frequency ω, the energy difference between the initial and the final states of the atom is not necessarily an integer multiple of the quantum energy hω. This kind of non-integer transition is a true non-perturbation effect in laser-atom interaction.

关键词： transitions induced by intense lasers non-perturbation effect violation of Bohr condition

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Alternative flexible correction forming of a blade: multipoint correction with surface measurement and deformation simulation

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Advances in Manufacturing 2023年第4期11卷 587-600页

作者： Da-Wei zhang Wen-Long Gao-zhang qi zhang Xi’an Key Laboratory of Intelligent Equipment and Control School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an710049People’s Republic of China

Distortion during the forging or machining processes of a blade causes problems in subsequent manufacturing. This paper proposes an alternative multipoint correction method integrated with blade measurement, determination of correcting parameters, and adjustment of the correcting die. An iterative algorithm for determining the correcting parameters is proposed. Measuring equipment combining a laser displacement sensor with multipoint flexible support is manufactured to measure the blade shape. Multipoint correcting equipment with an adaptive lower die and rapid adjustment is manufactured, and software is developed for data analysis and equipment control. The correction experiment for a rough-machined steam-turbine blade indicates that the correcting parameters can be determined after one modification based on numerical simulation, and that a rough blade that meets the allowance for finish machining can be obtained using the determined correction parameters.

关键词： Blade Surface measurement Numerical simulation Multipoint correction

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The Photoionization of Atomic Hydrogen in an Intense Circularly Polarized Laser Field

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Communications in Theoretical Physics 2001年第12期36卷 685-690页

作者： zhang Deng zhang qi-Ren Department of Technical Physics Peking University Beijing 100871 China Department of Technical Physics Peking University Beijing 100871 China

We calculate nonperturbatively the irfluence of a strong circularly polarized laser beam on the hydrogen atom energy levels by making use of the time-independent formalism proposed by one of us. The photoionization cross section of the hydrogen atom irradiated by this laser beam and the angular distribution of photoelectrons are also calculated. From the numerical results we clearly see the intensity dependence of the whole photoionization process,including the intensity dependence of the photoelectron energies.

关键词： intensity dependence of photoelectron energies, photoionization, atomic hydrogen

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Noise-Induced Entanglement Transition in One-Dimensional Random Quantum Circuits

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Chinese Physics Letters 2022年第5期39卷 10-15页

作者： qi zhang Guang-Ming zhang State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China Frontier Science Center for Quantum Information Beijing 100084China

A random quantum circuit is a minimally structured model to study entanglement dynamics of many-body quantum *** consider a one-dimensional quantum circuit with noisy Haar-random unitary gates using density matrix operator and tensor contraction *** is shown that the entanglement evolution of the random quantum circuits is properly characterized by the logarithmic entanglement *** performing exact numerical calculations,we find that,as the physical error rate is decreased below a critical value p;≈0.056,the logarithmic entanglement negativity changes from the area law to the volume law,giving rise to an entanglement *** critical exponent of the correlation length can be determined from the finite-size scaling analysis,revealing the universal dynamic property of the noisy intermediate-scale quantum devices.

关键词： transition quantum Transition

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Grant-Free Random Access in Pilot-Reused Multicell Massive MIMO Systems with Backoff Mechanisms

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China Communications 2023年第9期20卷 185-195页

作者： qi zhang Jun zhang Shi Jin Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and TelecommunicationsNanjing 210003China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China

Grant-free random access(RA)is attractive for future network due to the minimized access *** this paper,we investigate the grantfree RA in multicell massive multiple-input multipleoutput(MIMO)systems with pilot *** backoff mechanism,user equipments(UEs)in each cell are randomly activated,and active UEs randomly select orthogonal pilots from a predefined pilot pool,which results in a random pilot contamination among *** the help of indicators that capture the uncertainties of UE activation and pilot selection,we derive a closed-form approximation of the spectral efficiency per cell after averaging over the channel fading as well as UEs’random *** on the analysis,the optimal backoff parameter and pilot length that maximize the spectral efficiency can be *** find that the backoff mechanism is necessary for the system with large number of UEs,as it can bring significant gains on the spectral ***,as UE number grows,more backoff time is needed.

关键词： backoff mechanism grant-free RA multicell massive MIMO

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Friction of two-dimensional colloidal particles with magnetic dipole and Lennard–Jones interactions: A numerical study

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Friction 2020年第4期8卷 666-673页

作者： Zhongying zhang Cange WU qi zhang Yigang CAO School of Physics and Engineering Zhengzhou UniversityZhengzhou 450001China

We use Langevin simulations to study the sliding friction of two-dimensional colloidal particles on a substrate with randomly distributed point-like pinning centers. The colloidal particles are modeled to interact with each other through repulsive magnetic dipole and attractive Lennard–Jones potentials. The subsequent occurrence of superlubricity, wherein the average friction force equals to zero, is accompanied by the appearance of islands with clear boundaries in the microscopic colloidal structures for weak pinning substrates. Friction arises for strong pinning substrates, and the average friction force increases with the substrate pinning intensity, and further, the islands disperse into disordered plastic structures. Moreover, the average friction force decreases with the repulsion intensity between the colloidal particles, and superlubricity finally results when the repulsion becomes sufficiently strong. Superlubricity also occurs for sufficiently weak attraction between colloidal particles, with an increase in the attraction intensity between colloidal particles leading to a nonlinear increase in the average friction force. With increasing temperature, the average friction force firstly increases and subsequently decreases rapidly. The above results can provide a theoretical framework for biological self-organization via utilization of the friction properties of microscopic or mesoscopic colloidal systems.

关键词： friction sliding friction superlubricity self-assembly

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Identification of the Original Tectonic Setting for Oceanic Andesite Using Discrimination Diagrams:An Approach Based on Global Geochemical Data Synthesis

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Journal of Earth Science 2022年第3期33卷 696-705页

作者： Xinyu Liu qi zhang Chengli zhang State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an 710069China Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

Systematical analyses of data from GEOROC and PetDB database show that large amount of Cenozoic andesites occurred in the various oceanic environments such as mid-oceanic ridge,plumerelated island and oceanic *** this study,we employed the geochemical data of 351 mid-ocean ridge andesites(MORA),2539 plume-related andesites(PRA)and 3488 oceanic arc andesites(OAA)from the database to discuss the relationship between andesite tectonic settings and their geochemical features,thereby making an attempt to construct tectonic discrimination *** on the data-driven pattern,all available elements were employed to derive logratios for the possible coordinates,and the overlap-rate calculation was adopted to evaluate the discrimination effect of more than 330000 prospective ***,four tectonic discrimination diagrams have been successfully established to identify MORA,PRA and OAA,which can be utilized to identify the original settings of andesite with an age range from Cenozoic to Archean a certain *** these diagrams,PRA is mainly distinguished by high LREE/HREE ratio due to enriched mantle ***,OAA is mainly characterized by high LILE/HFSE ratio,which reveals that fluids derived from subducted slab play an important role in forming oceanic arc ***,the petrogenesis of andesites is closely related to their tectonic ***,it should be noted that those andesites formed in both continental and oceanic environments cannot be effectively distinguished using these *** strongly recommend integrating the discrimination diagrams result with other geological information to reach a comprehensive interpretation of evolution history with those ancient *** paper presents a case study which suggests that data-driven method is a powerful tool for solving geological problems in this’big data’era.

关键词： andesite oceanic arc plume-related island mid-oceanic ridge tectonic discrimination diagrams geochemical data data analysis big data

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