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| 1 | Role of the Nocturnal Low-level Jet in the Formation of the Morning Precipitation Peak over the Dabie Mountains显示文摘The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is verified against surface rain-gauge observations. The observed morning precipitation peak on the windward(relative to the prevailing synoptic-scale wind) side of the DBM is reproduced with good spatial and temporal accuracy. The interaction between the DBM and a nocturnal boundary layer low-level jet(BLJ) due to the inertial oscillation mechanism is shown to be responsible for this precipitation peak. The BLJ is aligned with the lower-level southwesterly synoptic-scale flow that carries abundant moisture.The BLJ core is established at around 0200 LST upwind of the mountains. It moves towards the DBM and reaches maximum intensity at about 70 km ahead of the mountains. When the BLJ impinges upon the windward side of the DBM in the early morning, mechanical lifting of moist air leads to condensation and subsequent precipitation. | Peiling FU Kefeng ZHU Kun ZHAO Bowen ZHOU Ming XUE | 2019 | Advances in Atmospheric Sciences2019，36，1： | 11 |
| 2 | On the Key Dynamical Processes Supporting the 21.7 Zhengzhou Record-breaking Hourly Rainfall in China显示文摘An extremely heavy rainfall event occurred in Zhengzhou,China,on 20 July 2021 and produced an hourly rainfall rate of 201.9 mm,which broke the station record for China's Mainland.Based on radar observations and a convection-permitting simulation using the WRF-ARW model,this paper investigates the multiscale processes,especially those at the mesoscale,that support the extreme observed hourly rainfall.Results show that the extreme rainfall occurred in an environment characteristic of warm-sector heavy rainfall,with abundant warm moist air transported from the ocean by an abnormally northward-displaced western Pacific subtropical high and Typhoon In-Fa(2021).However,rather than through back building and echo training of convective cells often found in warm-sector heavy rainfall events,this extreme hourly rainfall event was caused by a single,quasi-stationary storm in Zhengzhou.Scale separation analysis reveals that the extreme-rainproducing storm was supported and maintained by the dynamic lifting of low-level converging flows from the north,south,and east of the storm.The low-level northerly flow originated from a mesoscale barrier jet on the eastern slope of the Taihang Mountain due to terrain blocking of large-scale easterly flows,which reached an overall balance with the southerly winds in association with a low-level meso-β-scale vortex located to the west of Zhengzhou.The large-scale easterly inflows that fed the deep convection via transport of thermodynamically unstable air into the storm prevented the eastward propagation of the weak,shallow cold pool.As a result,the convective storm was nearly stationary over Zhengzhou,resulting in record-breaking hourly precipitation. | Peng WEI Xin XU Ming XUE Chenyue ZHANG Yuan WANG Kun ZHAO Ang ZHOU Shushi ZHANG Kefeng ZHU | 2023 | Advances in Atmospheric Sciences2023，40，3： | 9 |
| 3 | Poly(methyl methacrylate) bone cement composited with mineralized collagen for osteoporotic vertebral compression fractures in extremely old patients显示文摘To examine the clinical effects of a new bone cement composed of poly(methyl methacrylate)(PMMA)and mineralized collagen(MC)compared with pure PMMA bone cement in treating osteoporotic vertebral compression fractures(OVCFs)in patients aged over 80.In all,32 cases using pure PMMA bone cement and 31 cases using MC-modified PMMA(MC-PMMA)bone cement for OVCFs between June 2014 and March 2016 were screened as PMMA group and MC-PMMA group,respectively,with an average age of over 80.The operation duration,intraoperative blood loss,hospital stay,oswestry disability index(ODI),visual analogue scale(VAS),anterior vertebral height(AVH),intermediate vertebral height(IVH)and posterior vertebral height(PVH)of injured vertebrae,vertebral computed tomography value,re-fracture rate of adjacent vertebrae,correction rate of spinal kyphotic angle and wedge-shaped vertebra angle and surgical complications were compared between the two groups.In the early post-operative period,the VAS,ODI,AVH and IVH in MC-PMMA group were comparable to those in the traditional PMMA group.Moreover,the MC-PMMA group showed better effects compared with the PMMA group 12months after surgery.Thus,this new bone cement has superior clinic effects in the long term. | Kefeng Luo Guoqiang Jiang Jinjin Zhu Bin Lu Jiye Lu Kai Zhang Xiumei Wang Fu-Zhai Cui | 2020 | Regenerative Biomaterials2020，7，1： | 8 |
| 4 | A Prototype Regional GSI-based EnKF-Variational Hybrid Data Assimilation System for the Rapid Refresh Forecasting System:Dual-Resolution Implementation and Testing Results显示文摘A dual-resolution(DR) version of a regional ensemble Kalman filter(EnKF)-3D ensemble variational(3DEnVar) coupled hybrid data assimilation system is implemented as a prototype for the operational Rapid Refresh forecasting system. The DR 3DEnVar system combines a high-resolution(HR) deterministic background forecast with lower-resolution(LR) EnKF ensemble perturbations used for flow-dependent background error covariance to produce a HR analysis. The computational cost is substantially reduced by running the ensemble forecasts and EnKF analyses at LR. The DR 3DEnVar system is tested with 3-h cycles over a 9-day period using a 40/13-km grid spacing combination. The HR forecasts from the DR hybrid analyses are compared with forecasts launched from HR Gridpoint Statistical Interpolation(GSI) 3D variational(3DVar)analyses, and single LR hybrid analyses interpolated to the HR grid. With the DR 3DEnVar system, a 90% weight for the ensemble covariance yields the lowest forecast errors and the DR hybrid system clearly outperforms the HR GSI 3DVar.Humidity and wind forecasts are also better than those launched from interpolated LR hybrid analyses, but the temperature forecasts are slightly worse. The humidity forecasts are improved most. For precipitation forecasts, the DR 3DEnVar always outperforms HR GSI 3DVar. It also outperforms the LR 3DEnVar, except for the initial forecast period and lower thresholds. | Yujie PAN Ming XUE Kefeng ZHU Mingjun WANG | 2018 | Advances in Atmospheric Sciences2018，35，5： | 7 |
| 5 | Evaluation of WRF-based Convection-Permitting Multi-Physics Ensemble Forecasts over China for an Extreme Rainfall Event on 21 July 2012 in Beijing显示文摘On 21 July 2012,an extreme rainfall event that recorded a maximum rainfall amount over 24 hours of 460 mm,occurred in Beijing,China. Most operational models failed to predict such an extreme amount. In this study,a convective-permitting ensemble forecast system(CEFS),at 4-km grid spacing,covering the entire mainland of China,is applied to this extreme rainfall case. CEFS consists of 22 members and uses multiple physics parameterizations. For the event,the predicted maximum is 415 mm d^(-1) in the probability-matched ensemble mean. The predicted high-probability heavy rain region is located in southwest Beijing,as was observed. Ensemble-based verification scores are then investigated. For a small verification domain covering Beijing and its surrounding areas,the precipitation rank histogram of CEFS is much flatter than that of a reference global ensemble. CEFS has a lower(higher) Brier score and a higher resolution than the global ensemble for precipitation,indicating more reliable probabilistic forecasting by CEFS. Additionally,forecasts of different ensemble members are compared and discussed. Most of the extreme rainfall comes from convection in the warm sector east of an approaching cold front. A few members of CEFS successfully reproduce such precipitation,and orographic lift of highly moist low-level flows with a significantly southeasterly component is suggested to have played important roles in producing the initial convection. Comparisons between good and bad forecast members indicate a strong sensitivity of the extreme rainfall to the mesoscale environmental conditions,and,to less of an extent,the model physics. | Kefeng ZHU Ming XUE | 2016 | Advances in Atmospheric Sciences2016，33，11： | 7 |
| 6 | Percentile-based Neighborhood Precipitation Verification and Its Application to a Landfalling Tropical Storm Case with Radar Data Assimilation显示文摘The traditional threat score based on fixed thresholds for precipitation verification is sensitive to intensity forecast bias.In this study, the neighborhood precipitation threat score is modified by defining the thresholds in terms of the percentiles of overall precipitation instead of fixed threshold values. The impact of intensity forecast bias on the calculated threat score is reduced. The method is tested with the forecasts of a tropical storm that re-intensified after making landfall and caused heavy flooding. The forecasts are produced with and without radar data assimilation. The forecast with assimilation of both radial velocity and reflectivity produce precipitation patterns that better match observations but have large positive intensity bias.When using fixed thresholds, the neighborhood threat scores fail to yield high scores for forecasts that have good pattern match with observations, due to large intensity bias. In contrast, the percentile-based neighborhood method yields the highest score for the forecast with the best pattern match and the smallest position error. The percentile-based method also yields scores that are more consistent with object-based verifications, which are less sensitive to intensity bias, demonstrating the potential value of percentile-based verification. | ZHU Kefeng YANG Yi Ming XUE | 2015 | Advances in Atmospheric Sciences2015，32，11： | 2 |
| 7 | A Case Study of the Initiation of Parallel Convective Lines Back-Building from the South Side of a Mei-yu Front over Complex Terrain显示文摘Parallel back-building convective lines are often observed extending to the southwest of some mesoscale convective systems(MCSs)embedded in the mei-yu front in China.The convective lines with echo training behavior can quickly develop into a stronger convective group of echoes,resulting in locally heavy rainfall within the mei-yu front rainband.The initiation mechanism of the back-building convective lines is still unclear and is studied based on high-resolution numerical simulation of a case that occurred during 27−28 June 2013.In the present case,the new convection along the convective lines was found to be forced by nonuniform interaction between the cold outflow associated with the mei-yu front MCSs and the warm southerly airflow on the south side of the mei-yu front,which both are modified by local terrain.The mei-yu front MCSs evolved from the western to the eastern side of a basin surrounded by several mesoscale mountains and induced cold outflow centered over the eastern part of the basin.The strong southwest airflow ahead of the mei-yu front passed the Nanling Mountains and impacted the cold outflow within the basin.The nonuniform interaction led to the first stage of parallel convective line formation,in which the low mountains along the boundary of the two airflows enhanced the heterogeneity of their interaction.Subsequently,the convective group quickly developed from the first stage convective lines resulted in apparent precipitation cooling that enhanced the cold outflow and made the cold outflow a sharp southward windshift.The enhanced cold outflow pushed the warm southerly airflow southward and impacted the mountains on the southeast side of the basin,where the roughly parallel mountain valleys or gaps play a controlling role in a second stage formation of parallel convective lines. | Qiwei WANG Yi ZHANG Kefeng ZHU Zhemin TAN Ming XUE | 2021 | Advances in Atmospheric Sciences2021，38，5： | 2 |
| 8 | Predictability and skill of convection-permitting ensemble forecast systems in predicting the record-breaking“21·7”extreme rainfall event in Henan Province,China显示文摘During 19–21 July 2021,an extreme rainfall event occurred in Henan Province,China,during which a recordbreaking maximum hourly rainfall of 201.9 mm was recorded in Zhengzhou at 09 UTC July 20.In this study,the predictability of this extreme rainfall event is investigated using two convection-permitting ensemble forecast systems(CEFSs):one initialized from NCEP GEFS(named CEFS_GEFS)and the other initialized from time-lagged ERA5 data(named CEFS_ERA).Both are able to reproduce the daily heavy rainfall along the Taihang Mountains,but most members have significant position biases for the extreme rainfall in Zhengzhou.For the hourly rainfall,a few members are able to capture the evolution and propagation of extreme rainfall.However,all ensemble members underestimate the extreme hourly rainfall and have position errors of a few tens to a few hundreds of kilometers.Such results suggest that the predictability of the extreme hourly rainfall at the accuracy of city scale in Zhengzhou is low,especially by deterministic forecasting models,and the occurrence of the extreme requires many favorable conditions to happen simultaneously.In terms of the Brier score,CEFS_GEFS performs better than CEFS_ERA.The latter lacks spread,especially in regions with scarce rain,resulting in less dispersion in precipitation distributions and larger probability forecast error.When a neighborhood is applied,the probability of precipitation(POP)is significantly increased over Zhengzhou.While the traditional POP shows almost no skill for hourly rainfall≥25 mm h-1,the neighborhood POP significantly improves the forecast skill score,for both daily and hourly rainfall,suggesting higher predictability when spatial error among the ensemble members is allowed. | Kefeng ZHU Chenyue ZHANG Ming XUE Nan YANG | 2022 | Science China Earth Sciences2022，65，10： | 1 |
| 9 | Construction and evaluation of a multistage Mycobacterium tuberculosis subunit vaccine candidate Mtb10.4–HspX显示文摘 | Hongxia Niu Lina Hu Qing Li Zejiao Da Bingxiang Wang Kefeng Tang Qi Xin Hongjuan Yu Ying Zhang Yong Wang Xingming Ma Bingdong Zhu | 2011 | Vaccine2011，，51： | 1 |
| 10 | MDG-1, a polysaccharide from Ophiopogon japonicus , prevents high fat diet-induced obesity and increases energy expenditure in mice显示文摘 | Yuan Wang Yunyun Zhu Kefeng Ruan Hai Wei Yi Feng | 2014 | Carbohydrate Polymers2014，，： | 1 |
| 11 | Ergodic Capacity of NOMA-Based Overlay Cognitive Integrated Satellite-UAVTerrestrial Networks显示文摘Satellite communication has become a popular study topic owing to its inherent advantages of high capacity,large coverage,and no terrain restrictions.Also,it can be combined with terrestrial communication to overcome the shortcomings of current wireless communication,such as limited coverage and high destructibility.In recent years,the integrated satellite-unmanned aerial vehicle-terrestrial networks(IS-UAV-TNs)have aroused tremendous interests to effectively reduce the transmission latency and enhance quality-of-service with improved spectrum efficiency.However,the rapidly growing access demands and conventional spectrum allocation scheme lead to the shortage of spectrum resources.To tackle the mentioned challenge,the non-orthogonal multiple access(NOMA)scheme and cognitive radio technique are utilized in IS-UAV-TN,which can improve spectrum utilization.In our paper,the transmission capacity of an NOMA-enabled IS-UAV-TN under overlay mode is discussed,specifically,we derive the closed-form expressions of ergodic capacity for both primary and secondary networks.Besides,simulation results are provided to demonstrate the validity of the mathematical derivations and indicate the influences of critical system parameters on transmission performance.Furthermore,the orthogonal multiple access(OMA)-based scheme is compared with our NOMA-based scheme as a benchmark,which illustrates that our proposed scheme has better performance. | GUO Kefeng LIU Rui DONG Chao AN Kang HUANG Yuzhen ZHU Shibing | 2023 | Chinese Journal of Electronics2023，32，2： | 1 |
| 12 | Dynamic Contrast-Enhanced CT Characterization of Xp11.2 Translocation/TFE3 Gene Fusions versus Papillary Renal Cell Carcinomas显示文摘 | Jian He Kefeng Zhou Bin Zhu Gutian Zhang Xiaogong Li Hongqian Guo Weidong Gan Zhengyang Zhou Tian Liu Yi-Xiang Wang | 2015 | BioMed Research International2015，，： | 1 |
| 13 | A Novel Spectrum Encoding MIMO Communication System显示文摘 | Kefeng Tan Jean H. Andrian Hao Zhu Frank M. Candocia Chi Zhou | 2010 | Wireless Personal Communications2010，，1： | 1 |
| 14 | Covert Communication in Integrated High Altitude Platform Station Terrestrial Networks显示文摘In recent years,Internet of Things(IoT)technology has emerged and gradually sprung up.As the needs of largescale IoT applications cannot be satisfied by the fifth generation(5G)network,wireless communication network needs to be developed into the sixth generation(6G)network.However,with the increasingly prominent security problems of wireless communication networks such as 6G,covert communication has been recognized as one of the most promising solutions.Covert communication can realize the transmission of hidden information between both sides of communication to a certain extent,which makes the transmission content and transmission behavior challenging to be detected by noncooperative eavesdroppers.In addition,the integrated high altitude platform station(HAPS)terrestrial network is considered a promising development direction because of its flexibility and scalability.Based on the above facts,this article investigates the covert communication in an integrated HAPS terrestrial network,where a constant power auxiliary node is utilized to send artificial noise(AN)to realize the covert communication.Specifically,the covert constraint relationship between the transmitting and auxiliary nodes is derived.Moreover,the closed-form expressions of outage probability(OP)and effective covert communication rate are obtained.Finally,numerical results are provided to verify our analysis and reveal the impacts of critical parameters on the system performance. | Zeke Wu Kefeng Guo Rui Liu Shibin Zhu | 2023 | Computer Modeling in Engineering & Sciences2023，，4： | 0 |
| 15 | The Impact of Satellite Radiance Data Assimilation within a Frequently Updated Regional Forecast System Using a GSI-based Ensemble Kalman Filter显示文摘A regional ensemble Kalman filter (EnKF) data assimilation (DA) and forecast system was recently established based on the Gridpoint Statistical Interpolation (GSI) analysis system. The EnKF DA system was tested with continuous threehourly updated cycles followed by 18-h deterministic forecasts from every three-hourly ensemble mean analysis. Initial tests showed negative to neutral impacts of assimilating satellite radiance data due to the improper bias correction procedure. In this study, two bias correction schemes within the established EnKF DA system are investigated and the impact of assimilating additional polar-orbiting satellite radiance is also investigated. Two group experiments are conducted. The purpose of the first group is to evaluate the bias correction procedure. Two online bias correction methods based on GSI 3DVar and EnKF algorithms are used to assimilate AMSU-A radiance data. Results show that both variational and EnKF-based bias correction procedures effectively reduce the observation and background radiance differences, achieving positive impacts on forecasts. With proper bias correction, we assimilate full radiance observations including AMSU-A, AMSU-B, AIRS, HIRS3/4, and MHS in the second group. The relative percentage improvements (RPIs) for all forecast variables compared to those without radiance data assimilation are mostly positive, with the RPI of upper-air relative humidity being the largest. Additionally, precipitation forecasts on a downscaled 13-km grid from 40-km EnKF analyses are also improved by radiance assimilation for almost all forecast hours. | Kefeng ZHU Ming XUE Yujie PAN Ming HU Stanley G. BENJAMIN Stephen S. WEYGANDT Haidao LIN | 2019 | Advances in Atmospheric Sciences2019，36，12： | 0 |
| 16 | Tolerance and acceptance of hepatic venous pressure gradient measurement in cirrhosis(CHESS1904):An international multicenter study显示文摘Aim:To determine the tolerance and acceptance of hepatic venous pressure gradient(HVPG)measurements in patients with liver cirrhosis.Methods:This prospective international multicenter study included 271 patients with cirrhosis who were scheduled to undergo HVPG measurement between October 2019 and June 2020.Data related to the tolerance and acceptance of HVPG measurements were collected using descriptive questionnaires.Results:HVPG measurements were technically successful in all 271 patients,with 141(52.0%)undergoing HVPG measurement alone.The complication rate was 0.4%.Postoperative pain was significantly lower than preoperative expected pain(p<0.001)and intraoperative pain(p<0.001),and intraoperative pain was also significantly lower than preoperative expected pain(p=0.036).No,mild,moderate,severe,and intolerable discomfort scores were reported by 36.9%,44.6%,11.1%,6.3%,and 0.4%of these patients,respectively,during HVPG measurement and by 54.6%32.5%,11.4%,1.5%,and 0%,respectively,after HVPG measurement.Of these patients,39.5%had little understanding and 10%had no understanding of the value of HVPG measurement,with 35.1%and 4.1%regarding HVPG measurements as being of little or no help,respectively.Most patients reported that they would definitely(15.5%),probably(46.9%),or possibly(29.9%)choose to undergo additional HVPG measurements again,and 62.7%regarded the cost of the procedure as acceptable.Conclusion:HVPG measurement was safe and well‐tolerated in patients with cirrhosis,but patient education and communication are warranted to improve the acceptance of this procedure. | Jun‐Hui Sun He Zhao Haijun Zhang Lei Li NecatiÖrmeci Zi‐Niu Yu Xun Li Shuangxi Li Xujun Yang Huaping Wei Xiaoliang Zhu Zhengcong Zhang Yajin Wang Zhongwei Zhao Jianting Mao Qiaohong Wu Xiaole Sun Huiling Xiang Kefeng Jia Chao Yang Wei Wu Xiuqing Lin Haixin Yao Changzeng Zuo Jitao Wang Bo Zhang Chunqing Zhang Xiaoling Wu Guangchuan Wang Shengjuan Yao Ruihang Wang Li Zhou Hui Huan Qingli Tu Xue Pu Feng Zhang Qin Yin Linpeng Zhang Ying Guo Jian Wang Kohei Kotani Sawako Uchida‐Kobayashi Norifumi Kawada He Zhu Li Li Wei Wang Guo Zhang Lei Yu Xudong Cui Qingliang Zhu Hailong Zhang Xiaoli Hu Rafael OXimenes Adriano Gonçalves de Araújo Giulliano Gardenghi Yubao Zheng Zebin Wu Mingsheng Huang Xiaoyong Chen Jun Wu Feng Xie Yang Bo Shengjuan Hu Linke Ma Xiao Li Xiaolong Qi | 2022 | Portal Hypertension & Cirrhosis2022，1，1： | 0 |
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