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Finite p-Groups Whose Number of Subgroups of Each Order Is at most p^4

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Algebra Colloquium 2019年第3期26卷 411-424页

作者： Lifang Wang Mathematics Department Shanxi Normal UniversityLin fenShanxi 041004China

Assume G is a group of order p^n,where p is an odd prime.Let sk(G)denote the number of subgroups of order p^k of G.We give a criterion for a p-group to be with sk(G)≤p^4 for each integer k satisfying 1≤k≤n.Moreover... 详细信息

关键词： finite p-groups enumeration of subgroups type of regular p-groups

Prediction of the short-term and long-term mortality in difficult-to-wean patients by transthoracic echocardiography and diaphragm ultrasound

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Chinese Medical Journal 2022年第13期135卷 1604-1606页

作者： Ling Luo Yidan Li Lifang Wang Bing Sun Zhaohui Tong Department of Respiratory and Critical Care Medicine Beijing Jishuitan HospitalBeijing 100035China Department of Ultrasound Beijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China Epidemiology Research Center Beijing Jishuitan HospitalBeijing 100035China Department of Respiratory and Critical Care Medicine Beijing Institute of Respiratory MedicineBeijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China

High mortality rates of 25%to,50%were reported in patients with extubation failure.liExtubation failure or re-intubation was an independent risk factor for death after extubation,not the precise reason.Common reasons included primary respiratory failure,cardiac dysfunction,ineffective cough,excess secretions,upper airway obstruction,etc.Therefore,death after extubation should be related to these reasons above in theory.

关键词： patients mortality death

Representation of elliptic Ding-Iohara algebra

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Frontiers of Mathematics in China 2020年第1期15卷 155-166页

作者： Lifang Wang Ke WU Jie YANG Zifeng YANG School of Mathematics and Statistics Henan universityKaifeng 475004China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

We define a vector representation V(u)of elliptic Ding-Iohara algebra u(q,t,p).Furthermore,we construct the tensor products of the vector representations and the Fock modulesF(u)by taking the inductive limit of certai... 详细信息

关键词： Elliptic Ding-Iohara algebra vector representation partition

Fairness in Admission:Voices from Rural Chinese Female Students in Selective Universities in Chinese Mainland

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Frontiers of Education in China 2016年第1期11卷 44-73页

作者： Yingyi MA Lifang Wang Department of Sociology Maxwell School of Citizenship and Public AffairsSyracuse UniversitySyracuseNY 13244USA Cultural Foundations of Education School of EducationSyracuse UniversitySyracuseNY 13244USA

As the Chinese mainland has transitioned from elite to mass higher education,the race to attend university has escalated to become a race to attend selective universities.This study focuses on rural female university students and explores how they make sense of their higher education admission experiences.We rationalize that the inquiry into fairness is crystallized through examining rural female students’voices,which remain largely marginalized from the literature.Drawing from in-depth interviews with 22 rural female undergraduates from five selective universities in northern China,we focus on their perspectives towards three key issues in higher education admission:entrance exams,region-based quotas that put them at distinct disadvantages,and new reform initiatives.

关键词： Chinese higher education reform and fairness university admission well-roundedness rural female students

Atmospheric wet and dry deposition of dissolved inorganic nitrogen to the South China Sea

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Science China Earth Sciences 2020年第9期63卷 1339-1352页

作者： Ying GAO Lifang Wang Xianghui GUO Yi XU Li LUO State Key Laboratory of Marine Environmental Science Xiamen UniversityXiamen 361102China College of Ocean and Earth Sciences Xiamen UniversityXiamen 361102China Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies Xiamen UniversityXiamen 361102China Jiangxi Provincial Key Laboratory for Causes and Control of Atmospheric Pollution East China University of TechnologyNanchang 330013China

At the global scale,atmospheric inputs of nitrogen are an important source of the new nitrogen that supports new marine production,especially in oligotrophic open oceans and marginal seas.This study reports quantities of atmospheric deposition of dissolved inorganic nitrogen(DIN)to the largest marginal sea in the North Pacific(the oligotrophic South China Sea,SCS)based primarily on rainwater sampling in the open northwestern region(Yongxing Island)from 2013 to 2015,and aerosol sampling from the SCS basin in June 2017.Atmospheric wet and dry deposition of DIN and their potential contributions to productivity were estimated.The volume-weighted mean rainwater concentrations during the wet and dry seasons were 4.9 and 18.1μmol L-1 for N+N(NO3-+NO2-),and 5.7 and 4.0μmol L-1 for NH4+,respectively.Rainwater concentrations of DIN were lower in the marginal seas than in the open ocean.The aerosol NO3-concentration was 1.15±1.18μg m-3 during the wet season,which is slightly lower than reported for the East China Sea and East Sea,but higher than in the Arabian Sea.Monthly wet and dry deposition rates ranged from 0.4-3.9 and 0.4-1.2 mmol m-2 mon-1 for NO3-,and 0.2-1.3 and 0.01-0.02 mmol m-2 mon-1 for NH4+,respectively.The annual wet and dry deposition fluxes of DIN were estimated to be 16.8 and 10.1 mmol m-2yr-1,respectively.Compared to other marginal seas,the SCS receives less atmospheric NO3-inputs than the Yellow Sea,East China Sea,East Sea,and northeastern Mediterranean Sea.The total atmospheric DIN deposition may account for 1.8-11.1%of the nitrogen supporting new production and 0.7-1.8%of the nitrogen supporting primary production.

关键词： South China Sea Atmospheric deposition Wet deposition Dry deposition Nitrate NO3- Ammonium NH4+

Finite 2-Groups Whose Number of Subgroups of Each Order are at Most 2^(4)

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Communications in Mathematics and Statistics 2018年第2期6卷 207-226页

作者： Lifang Wang Mathematics Department Shanxi Normal UniversityLinfen 041004ShanxiChina

Assume G is a group of order 2^(n),n≥5.Let s_(k)(G)denote the number of subgroups of order 2^(k) of G.We classify finite 2-groups G with s k(G)≤2^(4),where 1≤k≤n.

关键词： Minimal nonabelian p-groups Subgroup’s enumeration Central extension

Elevated Ducts and Low Clouds over the Central Western Pacific Ocean in Winter Based on GPS Soundings and Satellite Observation

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Journal of Ocean University of China 2021年第2期20卷 244-256页

作者： LI Xiaodong SHENG lifang wang Wencai College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China Key Laboratory of Physical Oceanography Ocean University of ChinaQingdao 266100China

Both low clouds and elevated ducts are common phenomena in the oceanic atmosphere. Low clouds affect elevated ducts by changing the structure of atmospheric temperature and humidity. However, due to the limitation of met-ocean measurements, research on them is still scattered. This paper presents the distribution of elevated ducts and clouds over the central Western Pacific Ocean(WPO) based on Global Position System(GPS) sounding data and Himawari-8 satellite products from November 2015 to January 2016. Results show that the frequency of elevated ducts detected by ship-based GPS soundings was as high as 77% over the central WPO. The height and frequency of elevated ducts are closely related to the low clouds. If there are no clouds, the occurrence probability and mean base height of the elevated ducts are 14% and 730 m, respectively. By comparison, the occurrence probability and mean base height increase up to 24% and 1471 m, respectively, in the presence of cumulus(Cu) clouds, and 22% and 1511 m, respectively, in the presence of stratocumulus(Sc) clouds. Elevated ducts occur near the cloud top. The analysis of geopotential height and wind fields from the European Centre for Medium-Range Weather Forecasts(ECMWF) reanalysis dataset(ERA-interim) shows that the study area is covered by a strong and stable subtropical high, and slowly sinking dry air masses inside the subtropical high are above the moist boundary-layer air mass. The appearance and evolution of low clouds will adjust the temperature and humidity structure of the lower troposphere. If there are no clouds, the marine boundary layer(MBL) is the classic mixed boundary layer. Humidity gradient and subsidence inversion are formed atop the mixed layer. When low clouds are present, long wave radiation and entrainment atop clouds form a strong temperature inversion and humidity gradient, which strengthen elevated ducts. However, when Sc clouds are decoupled, a weaker temperature inversion and humidity gradient may occur between the surface mixed layer and subc

关键词： elevated duct cumulus cloud stratocumulus cloud marine boundary layer subtropical high

Time-history performance optimization of flapping wing motion using a deep learning based prediction model

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Chinese Journal of Aeronautics 2024年第5期37卷 317-331页

作者： Tianqi wang Liu LIU Jun LI lifang ZENG School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China Huanjiang Laboratory Zhuji 311800China

Flapping Wing Micro Aerial Vehicles(FWMAVs)have caused great concern in various fields because of their high efficiency and maneuverability.Flapping wing motion is a very important factor that affects the performance of the aircraft,and previous works have always focused on the time-averaged performance optimization.However,the time-history performance is equally important in the design of motion mechanism and flight control system.In this paper,a time-history performance optimization framework based on deep learning and multi-island genetic algorithm is presented,which is designed in order to obtain the optimal two-dimensional flapping wing motion.Firstly,the training dataset for deep learning neural network is constructed based on a validated computational fluid dynamics method.The aerodynamic surrogate model for flapping wing is obtained after the convergence of training.The surrogate model is tested and proved to be able to accurately and quickly predict the time-history curves of lift,thrust and moment.Secondly,the optimization framework is used to optimize the flapping wing motion in two specific cases,in which the optimized propulsive efficiencies have been improved by over 40%compared with the baselines.Thirdly,a dimensionless parameter C_(variation)is proposed to describe the variation of the time-history characteristics,and it is found that C_(variation)of lift varies significantly even under close time-averaged performances.Considering the importance of time-history performance in practical applications,the optimization that integrates the propulsion efficiency as well as C_(variation)is carried out.The final optimal flapping wing motion balances good time-averaged and time-history performance.

关键词： FWMAV Flapping wing motion Deep learning Unsteady aerodynamic performance Optimization Time-history curve

P-Rex1 Overexpression Results in Aberrant Neuronal Polarity and Psychosis-Related Behaviors

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Neuroscience Bulletin 2019年第6期35卷 1011-1023页

作者： Qiongwei Li Lifang Wang Yuanlin Ma Weihua Yue Dai Zhang Jun Li Peking University Institute of Mental Health Peking University Sixth HospitalBeijing 100191China National Health Center Key Laboratory of Mental Health(Peking University) Beijing 100191China National Clinical Research Center for Mental Disorders Peking University Sixth HospitalBeijing 100191China Peking-Tsinghua Center for Life Sciences Peking UniversityBeijing 100871China PKU-IDG/McGovem Institute for Brain Research Peking UniversityBeijing 100871China

Neuronal polarity is involved in multiple developmental stages, including cortical neuron migration,multipolar-to-bipolar transition, axon initiation, apical/basal dendrite differentiation, and spine formation. All of these processes are associated with the cytoskeleton and are regulated by precise timing and by controlling gene expression. The P-Rex1(phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1) gene for example, is known to be important for cytoskeletal reorganization, cell motility, and migration. Deficiency of P-Rex1 protein leads to abnormal neuronal migration and synaptic plasticity, as well as autism-related behaviors.Nonetheless, the effects of P-Rex1 overexpression on neuronal development and higher brain functions remain unclear. In the present study, we explored the effect of P-Rex1 overexpression on cerebral development and psychosis-related behaviors in mice. In utero electroporation at embryonic day 14.5 was used to assess the influence of P-Rex1 overexpression on cell polarity and migration.Primary neuron culture was used to explore the effects of P-Rex1 overexpression on neuritogenesis and spine morphology. In addition, P-Rex1 overexpression in the medial prefrontal cortex(m PFC) of mice was used to assess psychosis-related behaviors. We found that P-Rex1 overexpression led to aberrant polarity and inhibited the multipolar-to-bipolar transition, leading to abnormal neuronal migration. In addition, P-Rex1 overexpression affected the early development of neurons, manifested as abnormal neurite initiation with cytoskeleton change,reduced the axon length and dendritic complexity, and caused excessive lamellipodia in primary neuronal culture.Moreover, P-Rex1 overexpression decreased the density of spines with increased height, width, and head area in vitro and in vivo. Behavioral tests showed that P-Rex1 overexpression in the mouse m PFC caused anxiety-like behaviors and a sensorimotor gating deficit. The appropriate P-Rex1 level plays a critical role in the developing cereb

关键词： P-Rex1 Neurodevelopment Polarity Lamellipodia Psychosis-related behavior