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Improved Identification Method and Fault Current Limiting Strategy for Commutation Failure in LCC-HVDC

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1761-1772页

作者： Jian Liu sheng lin Wenliang Zhong Lei Liu School of Electrical Engineering Southwest Jiaotong UniversityChengdu 610031China State Grid Sichuan Electric Power Research Institute Chengdu 610072China

line-commutated converter based high-voltage direct-current(LCC-HVDC)transmission systems are prone to subsequent commutation failure(SCF),which consequently leads to the forced blocking of HVDC links,affecting the operation of the power *** accurate commutation failure(CF)identification is fairly vital to the prevention of ***,the existing CF identification methods cause CF misjudge or detection lag,which can limit the effect of SCF mitigation *** addition,earlier approaches to suppress SCF do not clarify the key factor that determines the evolution of extinction angle during system recovery and neglect the ***,this paper firstly analyzes the normal commutation process and CF feature based on the evolution topology of converter valve conduction in ***,the energy in the leakage inductance of converter transformer is presented to characterize the commutation state of the *** a CF identification method is proposed utilizing the leakage inductance ***,taking the key variable which is crucial to the tendency of extinction angle during the recovery process into account,a fault current limiting strategy for SCF mitigation is put *** with the original methods,the proposed methods have a better performance in CF identification and mitigation in terms of detection accuracy and mitigation ***,case study on PSCAD/EMTDC validates the proposed methods.

关键词： line commutated converter based high-voltage direct current(LCC-HVDC)transmission commutation failure identification commutation failure mitigation HVDC transmission control

Ideality analysis and general laws of bubble swarm microflow for large-scale gas-liquid microreaction processes

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Chinese Journal of Chemical Engineering 2022年第10期50卷 56-65页

作者： lin sheng Yuchao Chen Jian Deng Guangsheng Luo The State Key Laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

The flow ideality of bubbly microflow remains unclear even though it is vital for the design of microreactors,especially the ideality of bubble swarm microflow for large-scale gas-liquid microreaction *** work is the first time to report the ideality analysis of the microbubble swarm in a relatively large *** bubble swarm microflow has undergone two conditions:quasihomogeneous plug flow and liquid phase/gas-liquid qua si-homogeneous phase two-phase laminar *** the deviations of void fraction and bubble velocity from the ideal plug flow can divide into two parts,and the two transition points simultaneously happen at the velocity ratio of *** exists a critical capillary number to maintain the quasi-homogeneous plug flow,which could be regarded as the general laws for the design of gas-liquid ***,a novel model is developed to predict the bubble *** work could be very helpful for the large-scale gas-liquid microreactors design.

关键词： Bubble swarm Flow ideality Viscous fluids Gas-liquid microreactor

Reliability analysis of torpedo loading based on fractional-order optimization model

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Journal of Systems Engineering and Electronics 2023年第3期34卷 798-803页

作者： YANG Cheng LIANG Qingwei HAO Xinyu lin sheng College of Marine Northwest Polytechnic UniversityXi’an 710072China

A fractional-order cumulative optimization GM(1,2)model based on grey theory is proposed to study the relationship between torpedo loading and working *** this model,the average relative error function related to order and background value is *** the average relative error function as the objective function,the optimal value of the two parameters is obtained through the optimization method,and the minimum value of the average relative error is *** calculation example shows that this method can greatly improve the accuracy of the model and more accurately reflect the relationship between torpedo loading and working reliabilities compared with the traditional GM(1,2)model.

关键词： torpedo loading reliability working reliability grey theory fractional-order

DNA methyltransferase 3B promoter polymorphism and its susceptibility to primary hepatocellular carcinoma in the Chinese Han nationality population:A case-control study

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World Journal of Gastroenterology 2007年第45期13卷 6082-6086页

作者： Ying Wu Ju-sheng lin Institute of Liver Diseases TongjiHospital Tongji Medical College Huazhong University ofScience and Technology Wuhan 430030 Hubei Province China

AIM： To investigate the correlation between C/T single nucleotide polymorphism （SNP） in the promoter of the DNA methyltransferase 3B （D/VMT3B） gene and risk for development and progression of primary hepatocellular carcinoma （HCC）. METHODS： One hundred case subjects were selected consecutively from Tongji Hospital （Wuhan, China）. from March to November 2006. They did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed HCC. One hundred and forty control subjects having no history of cancerous or genetic diseases were healthy volunteers to Wuhan Blood Center in the same period. Frequency was matched for sex, age, alcohol consumption and cigarette smoking status of the case subjects. C/T polymorphism of the DNMT3B promoter was analyzed using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and sequencing analysis. The association between genotypes of DNMT3B and clinicopathological parameters among cases was also studied. RESULTS： The CC genotype HCC patients and controls. was not detected in both In control subjects, the frequency of TT and CT genotypes was 99.3% and 0.7% respectively, and that of T and C alleles was 99.6% and 0.4% respectively. The frequency of CT genotype was higher in HCC （3.0%）. The frequency of T and C alleles was 98.5% and 1.5% respectively. However, the genotype and allelotype distribution in HCC patients was not significantly different from that in controls. CONCLUSION： C/T polymorphism is not associated with the increased risk of HCC. DNMT3B genetic polymorphism is variable in different races, ethnic groups or geographic areas. Further study is needed to clarify the role of DNMT3B SNP in the development of HCCamong other populations.

关键词： DNA methyltransferase Single nucleotidepolymorphism Susceptibility Primary hepatocellularcarcinoma

Flag-transitive point-primitive 2-(v,k,4) symmetric designs and two dimensional classical groups

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Applied Mathematics(A Journal of Chinese Universities) 2011年第3期26卷 334-341页

作者： ZHOU sheng-lin TIAN De-lu Department of Mathematics South China University of Technology Guangzhou 510640 China

Let D be a 2-（v, k, 4） symmetric design and G be a flag-transitive point-primitive automorphism group of D with X ≥G ≤Aut（X） where X ≌ PSL2（q）.Then D is a 2-（15,8,4） symmetric design with X = PSL2（9） and ... 详细信息

关键词： Symmetric design flag-transitive point-primitive two dimensional classical group.

Advances in Research on Hepatitis B Virus DNA Integration

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Virologica Sinica 2008年第2期23卷 93-99页

作者： Ju-sheng lin lin-lin GAO Institute of Liver Diseases Tongji Hospital Tongji Medical College Huazhong University of Science ＆Technology Wuhan 430030 China

Since HBV DNA integration was discovered for the first time in 1980, various methods have been used to detect and study it, such as Southern Blot, in situ hybridization, polymerase chain reaction and so on. HBV DNA integration is thought to be random on the whole although some hot spots of integration were described by some researchers, one of which might be the repetitive sequences of the genomic DNA. Besides, DNA damage, especially double-strand breaks could promote HBV DNA integration into host genome. HBV DNA integration into cells may damage the stability of the genome, cause DNA rearrangement, promote DNA deletion and induce the formation of HCC.

关键词： Hepatitis B virus Integration Hepatocellular carcinoma

Connes distance of 2D harmonic oscillators in quantum phase space

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Chinese Physics B 2021年第11期30卷 170-179页

作者： Bing-sheng lin Tai-Hua Heng School of Mathematics South China University of TechnologyGuangzhou 510641China Laboratory of Quantum Science and Engineering South China University of TechnologyGuangzhou 510641China School of Physics and Material Science Anhui UniversityHefei 230601China

We study the Connes distance of quantum states of two-dimensional(2D)harmonic oscillators in phase *** the Hilbert–Schmidt operatorial formulation,we construct a boson Fock space and a quantum Hilbert space,and obtain the Dirac operator and a spectral triple corresponding to a four-dimensional(4D)quantum phase *** on the ball condition,we obtain some constraint relations about the optimal *** construct the corresponding optimal elements and then derive the Connes distance between two arbitrary Fock states of 2D quantum harmonic *** prove that these two-dimensional distances satisfy the Pythagoras *** results are significant for the study of geometric structures of noncommutative spaces,and it can also help us to study the physical properties of quantum systems in some kinds of noncommutative spaces.

关键词： Connes distance noncommutative geometry harmonic oscillator

NewBalance: Efficient Data Space Management and Algorithmic Optimization for Large-Scale Storage Systems

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Chinese Journal of Electronics 2017年第3期26卷 493-501页

作者： XU Guangping lin sheng SHI Kai ZHANG Hua Tianjin Key Laboratory of Intelligence Computing and New Software Technology Computer and Communication Engineering School Tianjin University of Technology

Fragmentation usually occurs when data space of original storage nodes has to be reallocated to new added storage nodes during the scale-out evolution of the large-scale storage *** greatly influences its performance and becomes a challenge to manage the whole *** present an efficient space management framework,called New Balance,to reduce fragmentation with the minimum data movement while keeping the storage system load *** space management framework has two phases including the collection phase and the allocation *** the collection phase,we propose a novel algorithm,called the greedy bi-direction collector,which collects enough space for the new storage *** the allocation phase,we formally represent it as a variant of the bin packing problem and then utilize some bin packing heuristics including the first fitting and the best fitting to allocate collected intervals to new added storage *** experimental results show that the amount of intervals can be reduced by 20%;5%and our algorithmic optimization improves the data lookup performance by at least 10%and the scale-out performance by 2X;X.

关键词： Large-scale storage systems Space management Algorithmic optimization Performance evaluation

A Categorification of the Boson Oscillator

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Communications in Theoretical Physics 2012年第1期57卷 34-40页

作者： lin Bing-sheng WU Ke School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

In this paper,we investigate the categorical description of the boson *** on the categories constructed by Khovanov,we introduce a categorification of the Fock states and the corresponding inner product of these *** find that there are two different categorical definitions of the inner product of the Fock *** two definitions are consistent with each other,and the decategorification results also coincide with those in conventional quantum *** also find that there are some interesting properties of the 2-morphisms which relate to the inner product of the states.

关键词： categorification Boson oscillator Fock state Heisenberg algebra