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Magnetic Force Transmission of a Reciprocating Motion

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Journal of Bionic Engineering 2008年第2期5卷 143-147页

作者： Qing-chang Tan Fu-sheng zheng Jian-gang li Institute of Mechanical Science and Engineering Jilin University Changchun 130022 P~ R. China

Magnetic force transmission of a reciprocating motion is studied by theoretical analysis and experiment. A mathematical model for calculating the magnetic force is derived using the theory of equivalent magnetic charges. An experimental rig is constructed to test the transmission and the model is verified by experiment. Effect of the transmission parameters on the magnetic force is analyzed theoretically from the model, and characteristic of the transmission is studied experimentally. Since the transmission is without direct contact between two elements, it is suitable for application in an organism.

关键词： reciprocating motion, magnetic force transmission

FLUID CHARACTERISTICS OF ROTARY WING HEAT METER WITH SINGLE-CHANNEL

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Journal of Hydrodynamics 2008年第1期20卷 101-107页

作者： Du Guang-sheng liu zheng-gang li li liU Yong-hui MA Yong-kun MENG liang School of Energy and Power Engineering Shandong University Jinan 250061China

Fluid characteristics of a rotary wing heat meter with single-channel were studied through theretical analysis, numerical simulation and experiments. The obtained results show that the number of vanes can obviously influence the heat meter, but the water temperature seldom influence the meter , and the optimal number of vane is 6-8.

关键词： heat meter numerical simulation meter

Using Improved Particle Swarm Optimization Algorithm for Location Problem of Drone Logistics Hub

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Computers, Materials & Continua 2024年第1期78卷 935-957页

作者： li zheng gang Xu Wenbin Chen School of Mathematics and Computer Sciences Nanchang UniversityNanchang330031China

Drone logistics is a novel method of distribution that will become *** advantageous location of the logistics hub enables quicker customer deliveries and lower fuel consumption,resulting in cost savings for the company’s transportation *** firms must discern the ideal location for establishing a logistics hub,which is challenging due to the simplicity of existing models and the intricate delivery *** simulate the drone logistics environment,this study presents a new mathematical *** model not only retains the aspects of the current models,but also considers the degree of transportation difficulty from the logistics hub to the village,the capacity of drones for transportation,and the distribution of logistics hub ***,this paper proposes an improved particle swarm optimization(PSO)algorithm which is a diversity-based hybrid PSO(DHPSO)algorithm to solve this *** DHPSO,the Gaussian random walk can enhance global search in the model space,while the bubble-net attacking strategy can speed ***,Archimedes spiral strategy is employed to overcome the local optima trap in the model and improve the exploitation of the *** maintains a balance between exploration and exploitation while better defining the distribution of logistics hub locations Numerical experiments show that the newly proposed model always achieves better locations than the current *** DHPSO with other state-of-the-art intelligent algorithms,the efficiency of the scheme can be improved by 42.58%.This means that logistics companies can reduce distribution costs and consumers can enjoy a more enjoyable shopping experience by using DHPSO’s location *** the results show the location of the drone logistics hub is solved by DHPSO effectively.

关键词： Drone logistics location problem mathematical model diversity particle swarm optimization

Optimal rejection of bounded perturbations in linear leader-following consensus protocol: invariant ellipsoid method

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Science China(Information Sciences) 2024年第8期67卷 24-34页

作者： Siyuan WANG Andrey POLYAKOV Min li gang zheng Driss BOUTAT INSA Centre Val de Loire INRIA

The objective of the invariant ellipsoid method is to minimize the smallest invariant and attractive set of a linear control system operating under the influence of bounded external disturbances. This study extends the application of this method to address the leader-following consensus problem. Initially, a linear control protocol is designed for the multi-agent system in the absence of disturbances. Subsequently, in the presence of bounded disturbances, by employing a similar linear control protocol, a necessary and sufficient condition is introduced to derive the optimal control parameters for the multi-agent system such that the state of followers converges to and remains in a minimal invariant ellipsoid around the state of the leader.

关键词： multi-agent system leader-following consensus invariant ellipsoid disturbance

Characterization of geological uncertainties from limited boreholes using copula-based coupled Markov chains for underground construction

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Underground Space 2024年第3期16卷 94-105页

作者： Fan Wang Heng li gang li zheng-Jun You Elton J.Chen National Center of Technology Innovation for Digital Construction Huazhong University of Science and TechnologyWuhan 430074China Department of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Building and Real Estate The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina Shanghai Tunnel Engineering Co. Ltd.Shanghai 200032China Wuhan Metro Group Co.Ltd. Wuhan 430070China

This paper proposes an efficient method for quantifying the stratigraphic uncertainties and modeling the geological formations based on *** Markov chains are used to describe the soil transitions along different directions,and the transition probability matrices(TPMs)of the Markov chains are analytically expressed by *** copula expression is efficient since it can represent a large TPM by a few unknown *** to the analytical expression of the TPMs,the likelihood function of the Markov chain model is given in an explicit *** estimation of the TPMs is then re-casted as a multi-objective constrained optimization problem that aims to maximize the likelihoods of two independent Markov chains subject to a set of parameter *** the method which determines the TPMs by counting the number of transitions between soil types,the proposed method is more statistically ***,a random path sampling method is presented to avoid the directional effect problem in *** soil type at a location is inferred from its nearest known neighbors along the cardinal directions.A general form of the conditional probability,based on Pickard’s theorem and Bayes rule,is presented for the soil type *** proposed stratigraphic characterization and simulation method is applied to real borehole data collected from a construction site in Wuhan,*** is illustrated that the proposed method is accurate in prediction and does not show an inclination during simulation.

关键词： Geological stratigraphy Markov chain Transition probability matrix Statistical method Copula

Method of composing two-dimensional scanned spectra observed by the New Vacuum Solar Telescope

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Research in Astronomy and Astrophysics 2018年第4期18卷 59-68页

作者： Yun-Fang Cai Zhi Xu Yu-Chao Chen Jun Xu zheng-gang li Yu Fu Kai-Fan Ji Yunnan Observatories Chinese Academy of Sciences Kunming 650011 China University of Chinese Academy of Sciences Beijing 100049 China

In this paper we illustrate the technique used by the New Vacuum Solar Telescope（NVST）to increase the spatial resolution of two-dimensional（2D）solar spectroscopy observations involving two dimensions of space and one of *** an image stabilizer at the NVST,large scale wobble motion is present during the spatial scanning,whose instantaneous amplitude can reach 1.3′′due to the Earth’s atmosphere and the precision of the telescope guiding system,and seriously decreases the spatial resolution of 2D spatial maps composed with scanned *** make the following effort to resolve this problem：the imaging system（e.g.,the Ti O-band）is used to record and detect the displacement vectors of solar image motion during the raster scan,in both the slit and scanning *** spectral data（e.g.,the Hαline）which are originally obtained in time sequence are corrected and re-arranged in space according to those displacement *** scans are carried out in several active regions with different seeing conditions（two rasters are illustrated in this paper）.Given a certain spatial sampling and temporal resolution,the spatial resolution of the composed 2D map could be close to that of the slit-jaw *** resulting quality after correction is quantitatively evaluated with two methods.A physical quantity,such as the line-of-sight velocities in multiple layers of the solar atmosphere,is also inferred from the re-arranged spectrum,demonstrating the advantage of this technique.

关键词： instrumentation spectrographs — Sun sunspots — techniques imaging spectroscopy — techniques image processing

Robotic vs laparoscopic abdominoperineal resection for rectal cancer:A propensity score matching cohort study and metaanalysis

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1280-1290页

作者： li Song Wen-Qiong Xu zheng-Qiang Wei gang Tang Department of Gastrointestinal Surgery Chengdu Fifth People's HospitalChengdu 610000Sichuan ProvinceChina Department of Nephrology Chengdu Fifth People's HospitalChengdu 610000Sichuan ProvinceChina Department of Gastrointestinal Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400000China Division of Biliary Tract Surgery Department of General SurgeryWest China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND Robotic surgery(RS)is gaining popularity;however,evidence for abdominoperineal resection(APR)of rectal cancer(RC)is *** To compare the efficacy of RS and laparoscopic surgery(LS)in APR for *** We retrospectively identified patients with RC who underwent APR by RS or LS from April 2016 to June *** regarding short-term surgical outcomes were compared between the two *** reduce the effect of potential confounding factors,propensity score matching was used,with a 1:1 ratio between the RS and LS groups.A meta-analysis of seven trials was performed to compare the efficacy of robotic and laparoscopic APR for RC *** Of 133 patients,after propensity score matching,there were 42 patients in each *** postoperative complication rate was significantly lower in the RS group(17/42,40.5%)than in the LS group(27/42,64.3%)(P=0.029).There wasno significant difference in operative time(P=0.564),intraoperative transfusion(P=0.314),reoperation rate(P=0.314),lymph nodes harvested(P=0.309),or circumferential resection margin(CRM)positive rate(P=0.314)between the two *** meta-analysis showed patients in the RS group had fewer positive CRMs(P=0.04),lesser estimated blood loss(Plications(P=0.002)than patients in the LS *** Our study shows that RS is a safe and effective approach for APR in RC and offers better short-term outcomes than LS.

关键词： Robotic surgery Laparoscopic surgery Abdominoperineal resection Postoperative complications Propensity score

Prediction and quantification of effective gas source rocks in a lacustrine basin: Western Depression in the liaohe Subbasin, China

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Petroleum Science 2024年第4期21卷 2218-2239页

作者： Si-Bo Yang Mei-Jun li Hong Xiao Fang-zheng Wang Guo-gang Cai Shuang-Quan Huang State Key Laboratory of Petroleum Resources and Prospecting College of Geosciences China University of Petroleum China University of Petroleum-Beijing at Karamay College of Petroleum Research Institute of Petroleum Exploration and Development Liaohe Oilfield Company PetroChina

Due to limited data on the geochemical properties of natural gas, estimations are needed for the effective gas source rock in evaluating gas potential. However, the pronounced heterogeneity of mudstones in lacustrine successions complicates the prediction of the presence and geochemical characteristics of gas source rocks. In this paper, the liaohe Subbasin of Northeast China is used as an example to construct a practical methodology for locating effective gas source rocks in typical lacustrine basins. Three types of gas source rocks, microbial, oil-type, and coal-type, were distinguished according to the different genetic types of their natural gas. A practical three-dimensional geological model was developed, refined, and applied to determine the spatial distribution of the mudstones in the Western Depression of the liaohe Subbasin and to describe the geochemical characteristics(the abundance, type, and maturation levels of the organic matter). Application of the model in the subbasin indicates that the sedimentary facies have led to heterogeneity in the mudstones, particularly with respect to organic matter types. The effective gas source rock model constructed for the Western Depression shows that the upper sequence(SQ2) of the Fourth member(Mbr 4) of the Eocene Shahejie Formation(Fm) and the lower and middle sequences(SQ3 and SQ4) of the Third member(Mbr 3) form the principal gas-generating interval. The total volume of effective gas source rocks is estimated to be 586 km3. The effective microbial, oil-type, and coal-type gas source rocks are primarily found in the shallow western slope, the central sags, and the eastern slope of the Western Depression, respectively. This study provides a practical approach for more accurately identifying the occurrence and geochemical characteristics of effective natural gas source rocks, enabling a precise quantitative estimation of natural gas reserves.

关键词： Effective gas source rock 3D geological modeling Spatial distribution Geochemical characteristics Lacustrine rift basin

Influences of clean fracturing fluid viscosity and horizontal in-situ stress difference on hydraulic fracture propagation and morphology in coal seam

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International Journal of Coal Science & Technology 2024年第3期11卷 159-175页

作者： gang Wang Shuxin Wang Yixin liu Qiming Huang Shengpeng li Shuliang Xie Jinye zheng Jiuyuan Fan College of Safety and Environmental Engineering Shandong University of Science and TechnologyQingdao266590China Mine Disaster Prevention and Control-Ministry of State Key Laboratory Breeding Base Shandong University of Science and TechnologyQingdao266590China

The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal samples for experiments, and clean fracturing fluid samples were prepared using CTAB surfactant. A series of hydraulic fracturing tests were conducted with an in-house developed triaxial hydraulic fracturing simulator and the fracturing process was monitored with an acoustic emission instrument to analyze the influences of fracturing fluid viscosity and horizontal in-situ stress difference on coal fracture propagation. The results show that the number of branched fractures decreased, the fracture pattern became simpler, the fractures width increased obviously, and the distribution of AE event points was concentrated with the increase of the fracturing fluid viscosity or the horizontal in-situ stress difference. The acoustic emission energy decreases with the increase of fracturing fluid viscosity and increases with the increase of horizontal in situ stress difference. The low viscosity clean fracturing fluid has strong elasticity and is easy to be compressed into the tip of fractures, resulting in complex fractures. The high viscosity clean fracturing fluids are the opposite. Our experimental results provide a reference and scientific basis for the design and optimization of field hydraulic fracturing parameters.

关键词： Clean fracturing fluid Hydraulic fracturing Viscosity Horizontal in-situ stress difference Hydraulic fracture morphology Acoustic emission