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On Disjoint Cycles of the Same Length in Tournaments

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 271-281页

作者： yun WANG JIN YAN SHUO zhu School of Mathematics Shandong UniversityJinan 250100China

A tournament is an orientation of the complete *** form perhaps the most interesting class of digraphs and it has a great potential for *** provide a model of the statistical technique called the method of paired comparisons and they have also been studied in connection with sociometric relations in small *** this paper,we investigate disjoint cycles of the same length in *** 2010,Lichiardopol conjectured that for given integers l≥3 and k≥1,any tournament with minimum out-degree at least(l-1)k-1 contains k disjoint l-cycles,where an l-cycle is a cycle of order ***-Jensen et *** the conjecture for l=3 and Ma et *** that it also holds for l≥*** paper provides a proof of the conjecture for the case of 9≥l≥4.

关键词： tournaments minimum out-degree disjoint cycles

Effects of rarefaction on the characteristics of micro gas journal bearings

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第1期11卷 43-49页

作者： hai-jun ZHANG Chang-sheng zhu Ming TANG College of Electrical Engineering Zhejiang University Hangzhou 310027 China College of Mechanical-Electrical Engineering Jiaxing University Jiaxing 314001 China

Given the definition of the reference Knudsen number for micro gas journal bearings,the range in the number is related to the viscosity of air at different temperatures. A modified Reynolds equation for micro gas journal bearings based on Burgdorfer's first-order slip boundary condition is proposed that takes into account the gas rarefaction effect. The finite difference method (FDM) is adopted to solve the modified Reynolds equation to obtain the pressure profiles,load capacities and attitude angles for micro gas journal bearings at different reference Knudsen numbers,bearing numbers and journal eccentricity ratios. Numerical analysis shows that pressure profiles and non-dimensional load capacities decrease markedly as gas rarefaction in-creases. Attitude angles change conversely,and when the eccentricity ratio is less than 0.6,the attitude angles rise slightly and the influence of the reference Knudsen number is not marked. In addition,the effect of gas rarefaction on the non-dimensional load capacity and attitude angle decreases with smaller bearing numbers.

关键词： Reference Knudsen number Rarefaction effect Reynolds equation Finite difference method (FDM)

New numerical solution for self-acting gas journal bearings

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第5期10卷 685-690页

作者： hai-jun ZHANG Chang-sheng zhu Qin YANG College of Electrical Engineering Zhejiang University Hangzhou 310027 China College of Mechanical and Electrical Engineering Jiaxing University Jiaxing 314001 China

Taking a small pressure change in the gas film of self-acting gas-lubricated journal bearings into account, the corresponding nonlinear Reynolds equation is linearized through appropriate approximation and a modified Reynolds equation is derived and solved by means of the finite difference method (FDM). The gas film pressure distribution of a self-acting gas-lubricated journal bearing is attained and the load capacity is calculated. The numerical solution has a better agreement with experimental data than a direct numerical solution for different values of the bearing number. It is of interest to note that the eccentricity ratio, at which the new numerical solution is in better agreement with experimental data, is different when the bearing number is changing. The new numerical solution is slightly larger when the eccentricity ratio is smaller, and becomes slightly smaller when the eccentricity ratio is larger.

关键词： Self-acting gas journal bearings Reynolds equation Nonlinearity Finite difference method (FDM)

Incidence,Survival Outcome,and Prognostic Nomogram of Patients with Angioimmunoblastic T-cell Lymphoma:a Population-based Analysis

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Current Medical Science 2022年第6期42卷 1220-1230页

作者： hai-zhu CHEN yun-xia TAO Yu ZHOU Qiao-feng ZHONG Li-qiang ZHOU Yuan-kai SHI Department of Medical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted DrugsBeijing100021China

Objective Due to the rarity of angioimmunoblastic T-cell lymphoma(AITL),very limited data concerning its incidence patterns and prognostic factors are *** study aimed to explore the incidence,characteristics,survival outcomes,and prognostic factors of *** Age-adjusted incidence and temporal trends were calculated based on 1247 AITL patients from the National Cancer Institute’s Surveillance,Epidemiology,and End Results(SEER)-13 database.A total of 1525 AITL patients from the SEER-18 database and 43 patients from our single center were included for survival analysis and nomogram *** The age-adjusted incidence for overall cohort was 0.123[95%confidence interval(CI),0.117–0.131)per 100000 during 1992–*** overall incidence increased steeply at the rate of 15.3%(95%CI 11.0%–19.8%,P<0.001)per year during 1992–2004,but remained stable during 2004–2017(P=0.200).Similar incidence trends were observed in age,sex,and stage *** final nomograms consisted of four variables:age at diagnosis,sex,Ann Arbor stage,and primary *** concordance index(C-index)of the nomogram for 5-year overall survival prediction was 0.717,0.690 and 0.820 in the training cohort,validation cohort-1 and cohort-2,*** the disease-specific survival(DSS),the nomogram also demonstrated a good discrimination level,with the C-index for predicting the probability of DSS at 5 years of 0.716,0.682 and 0.813 for the three cohorts,*** calibration displayed good concordance between the nomogram-predicted and actual observed *** The age-adjusted incidence for AITL was low during 1992–*** incidence continuously increased during 1992–2004,but remained stable during 2004–*** nomograms as proposed may provide a favorable and accurate prognostic survival prediction in AITL.

关键词： angioimmunoblastic T-cell lymphoma incidence prognosis nomogram SEER

Large-eddy simulation of suspended sediment transport in turbulent channel flow

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Journal of Hydrodynamics 2013年第1期25卷 48-55页

作者： zhu hai WANG Ling-ling TANG Hong-wu College of Water Conservancy and Hydropower Engineering Hohai University

The numerical simulation of the non-cohesive sediment transport in a turbulent channel flow with a high concentration is a challenging but practical task. A modified coherent dynamic eddy model of the Large Eddy Simulation （LES） with a pick-up function is used in the present study to simulate the sediment erosion and the deposition in a turbulent channel flow. The rough wall model is used instead of the LES with the near-wall resolution to obtain the reasonable turbulent flow characteristics while avoiding the high costs in the computation. Good results are obtained, and are used to analyze the sediment transport properties. The results show that the streamwise vortices play an important role in the riverbed erosion and the sediment pick-up, which may serve as guidelines for the sediment management and the water environment protection engineering.

关键词： Large Eddy Simulation (LES) sediment suspension pick-up function turbulent channel flow

Metastatic low-grade endometrial stromal sarcoma with variable morphologies in the ovaries and mesentery: A case report

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World Journal of Clinical Cases 2022年第23期10卷 8384-8391页

作者： hai-yun Yu Yu-Lan Jin Department of Pathology Beijing Obstetrics and Gynecology HospitalCapital Medical University.Beijing Maternal and Child Health Care HospitalBeijing 100003China

BACKGROUND Low-grade endometrial stromal sarcoma(LGESS)classically exhibits a proliferative ***,morphological variation of extrauterine tumors presents a diagnostic *** SUMMARY We report the case of a 76-year-old female patient with extensive extrauterine and abdominal neoplastic *** tomography showed massive pleural and ascitic fluid,and there was an increase in serum cancer antigen *** underwent bilateral adnexectomy and tumor *** right ovary had been replaced by a multinodular mass that was 8.5 cm×4.5 cm×3.5 cm in *** addition,there was a 24 cm×15 cm×13 cm mesenteric mass,which was also multinodular,with local invasion of the intestinal serosa and underlying *** the microscope,the tumors in different places exhibited two different patterns,thus presenting great challenges to diagnosis and *** pathological assessment eliminated all differential diagnoses in favor of metastatic LGESS derived from a 20-year-old primary tumor initially misdiagnosed as *** LGESS morphology varies according to tumor *** diagnosis is critical for appropriate treatment and improved prognosis and patient care.

关键词： Gastrointestinal stromal tumor Low-grade endometrial stromal sarcoma Mesentery Ovary Tumor Case report

Distributed H∞ filtering of nonlinear systems with random topology by an event-triggered protocol

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Science China(Information Sciences) 2021年第10期64卷 206-220页

作者： yun CHEN Mengze zhu Renquan LU Anke XUE Key Lab for IoT and Information Fusion Technology of Zhejiang Hangzhou Dianzi University School of Automation Guangdong University of Technology

Applying an event-triggered protocol, this paper proposes a distributed H∞filter design for nonlinear perturbed systems under fading measurements with random topology. Nonlinearities in this system obey the one-sided Lipschitz constraint, which embraces the conventional Lipschitz condition as a special *** sensor network allows random variations of the interconnection strengths between adjacent nodes, and the connection coefficient is determined as the product of a constant and a stochastic variable with a known probabilistic feature. To reduce the unnecessary data transmission and efficiently use the limited bandwidth,the transmissions are orchestrated by an event-triggered regulating strategy. A stochastic bounded real lemma is established for the resulting error dynamics. Based on the presented matrix decomposition, which removes the direct coupling between the statistical information of interconnection strengths and the filter gain, the distributed H∞filter gain can be explicitly expressed and easily solved. The usefulness of the theoretical method is demonstrated in a simulation study.

关键词： sensor network distributed $H_\infty$ filtering one-sided Lipschitz condition event-triggered protocol random topology

KINETICS OF ALUMINUM EXTRACTION WITH DI—2-ETHYLHEXYL PHOSPHORIC ACID

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Transactions of Nonferrous Metals Society of China 1992年第4期2卷 14-20页

作者： Ma yun zhu Tun Institute of Chemical Metallurgy Academia SinicaBeijing 100080China

The kinetics of *** of aluminum with di-2-ethylhexyl phosphoric acid(DEHPA)in n-heptane have been studied in a constant interfacial area cell.A HC1-KHC8H404(potassium ***)buffer solution was used to maintain a constant pH during *** effects of the concentration of aluminum,pH,the concentration of the extractant,the interfacial area and the temperature on the extraction rate were investigated.A method has been invented to determine amont of the extracted aluminum in the organic phase with *** on calculation of the coordination states of the aluminum ions and their contribution to the reaction rate,a raaction mechanism which includes two main reaction paths,has been proposed to describe the *** path starts from Al(H_(2)O)6^(+).and the other starts from Al(H_(2)O)6^(+).The reaction could take place both in the aqueous phase and at the *** main reaction region could be changed as the conditions of extraction were ***[HA]0.03 mol/L it was shifted to a homogeneous aqueous solution reaction.

关键词： aluminum solvent extraction kinetics constant interfacial area cell di-2-ethylliexyl phosphoric

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

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China Ocean Engineering 2024年第2期38卷 285-296页

作者： DU Zun-feng zhu hai-ming YU Jian-xing State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing