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| 1 | Surgical outcomes of mini-open Wiltse approach and conventional open approach in patients with single-segment thoracolumbar fractures without neurologic injury显示文摘This study aimed to introduce a novel mini-open pedicle screw fixation technique via Wiltse approach,and compared it with the traditional posterior open method.A total of 72 cases of single-segment thoracolumbar fractures without neurologic injury underwent pedicle screw fixation via two different approaches.Among them,37 patients were treated using posterior open surgery,and 35 patients received mini-open operation via Wiltse approach.Crew placement accuracy rate,operative time,blood loss,postoperative drainage,postoperative hospitalization time,radiation exposure time,postoperative improvement in R value,Cobb's angle and visual analog scale(VAS)scores of the two methods were compared.There were no significant differences in the accuracy rate of pedicle screw placement,radiation exposure and postoperative R value and Cobb's angle improvement between the two groups.However,the mini-open method had obvious advantages over the conventional open method in operative time,blood loss,postoperative drainage,postoperative hospitalization time,and postoperative improvement in VAS.The mini-open pedicle screw technique could be applied in treatment of single-segment thoracolumbar fracture without neurologic injury and had advantages of less tissue trauma,short operative and rehabilitative time on the premise of guaranteed accuracy rate and no increased radiation exposure. | Haijun Li Lei Yang Hao Xie Lipeng Yu Haifeng Wei Xiaojian Cao | 2015 | The Journal of Biomedical Research2015，29，1： | 43 |
| 2 | Parameters optimum matching of pure electric vehicle dual-mode coupling drive system显示文摘As an important development direction of pure electric vehicle drive system,the distributed drive system has the advantages of compact structure,high transmission efficiency,and flexible control,but there are some serious problems such as high performance requirements to the drive motors,complex control strategies,and poor reliability.To solve these problems,a two motors dual-mode coupling drive system has been developed at first,which not only has the capacity of two-speed gear shifting,but also can automatically switch between the distributed drive and the centralized drive by means of modes change control.So,the performance requirements to the drive motors can be reduced,the problem of abnormal running caused by the fault of unilateral distributed drive systems also can be resolved by replacing the drive mode with centralized drive.Then,the system parameters primary and the optimum matching under the principle of efficiency optimization have been carried out,which makes the drive system achieve predetermined functions and meet the actual demands of different operating statuses.At last,the economic comparison of a pure electric vehicle installation with a dual-mode coupling drive sytem,a single-motor centralized drive system or a dual-motor distributed drive system in the simulation conditions has been completed.Compared with other systems,the driving range of the electric vehicle driven by the designed system is significantly increased,which proves the better efficiency and application value of the system. | ZHANG LiPeng LI Liang QI BingNan WANG Chong ZHANG YaHui SONG Jian | 2014 | Science China(Technological Sciences)2014，57，11： | 22 |
| 3 | Interfacial Microstructure and Properties of a Vacuum Hot Roll-bonded Titanium-Stainless Steel Clad Plate with a Niobium Interlayer显示文摘Vacuum hot roll bonding(VHRB)was used to bond pure titanium(Ti)plate to a 304 stainless steel(SS)plate with a niobium(Nb)interlayer,with the aim of producing a high-quality Ti-SS clad plate.The roll-bonding process was performed at diferent temperatures in the range of 850–1000 C,followed by characterization of microstructure and mechanical properties.The study demonstrates that the interfaces are free from cracks and discontinuities,and interdifusion between the stainless steel and the titanium is efectively prevented by inserting a layer of pure Nb foil.No intermetallic reaction layer occurred at the Nb-Ti interface at any of the investigated temperatures.An intermetallic FeNb phase was formed at the Nb-SS interface when bonding was performed at 950 C and above.The presence of the FeNb layer was confirmed by x-ray difraction.The maximum shear strength of^396 MPa was obtained when bonding is carried out at 900 C.However,the formation of the FeNb layer at roll bonding temperature greater than 900 C led to decrease in shear strength.Ductile fracture occurred through the Ti-Nb interface for roll-bonded temperatures of up to 900 C.On the other hand,at temperature of 950 C and above,failure occurred through the Nb-SS interface,with brittle fracture characteristics. | Zongan LUO Guanglei WANG Guangming XIE Lipeng WANG Kun ZHAO | 2013 | Acta Metallurgica Sinica(English Letters)2013，26，6： | 18 |
| 4 | Electromechanical coupling driving control for single-shaft parallel hybrid powertrain显示文摘The single-shaft parallel hybrid powertrain with the automatic mechanical transmission(AMT)is an efficient hybrid driving system in the hybrid electric bus(HEB),while the electromechanical coupling driving control becomes a complicated question to find a transient optimal control method to distribute the power between the engine and the electric machine(EM).This paper proposes an innovative control method to deal with the complicated transient coupling driving process of the electromechanical coupling driving system,considering the accelerating condition and the cruising condition mostly in the city driving cycle of HEB.The EM might be operated at driving mode or generating mode to assist the diesel engine to work in its high-efficiency area.Therefore,the adaptive torque tracking controller has been brought forward to ensure that the EM implements the demand torque as well as compensate the torque fluctuation of diesel engine.The d?q axis mathematical model and back stepping method are employed to deduce the adaptive controller and its adaptive laws.Simulation results demonstrate that the proposed control scheme can make the output torque of two power sources respond rapidly to the demand torque from the powertrain in the given driving condition.The proposed method could be adopted in the real control of HEB to improve the efficiency of the hybrid driving system. | YANG Chao JIAO XiaoHong LI Liang ZHANG YaHui ZHANG LiPeng SONG Jian | 2014 | Science China(Technological Sciences)2014，57，3： | 17 |
| 5 | UAV Communications with Millimeter-Wave Beamforming:Potentials,Scenarios,and Challenges显示文摘Unmanned aerial vehicle(UAV)has been widely used in many fields and is arousing global attention.As the resolution of the equipped sensors in the UAV becomes higher and the tasks become more complicated,much higher data rate and longer communication range are required in the foreseeable future.As the millimeter-wave(mm Wave)band can provide more abundant frequency resources than the microwave band,much higher achievable rate can be guaranteed to support UAV services such as video surveillance,hotspot coverage,and emergency communications,etc.The flexible mm Wave beamforming can be used to overcome the high path loss caused by the long propagation distance.In this paper,we study three typical application scenarios for mm Wave-UAV communications,namely communication terminal,access point,and backbone link.We present several key enabling techniques for UAV communications,including beam tracking,multi-beam forming,joint Tx/Rx beam alignment,and full-duplex relay techniques.We show the coupling relation between mm Wave beamforming and UAV positioning for mm Wave-UAV communications.Lastly,we summarize the challenges and research directions of mm Wave-UAV communications in detail. | Zhenyu Xiao Lipeng Zhu Xiang-Gen Xia | 2020 | China Communications2020，17，9： | 17 |
| 6 | Adakitic rocks associated with the Shilu copper–molybdenum deposit in the Yangchun Basin,South China,and their tectonic implications显示文摘South China is famous for the extensive magmatism and polymetallic mineralization that took place there in the Mesozoic. Shilu is a large porphyry–skarn Cu–Mo deposit in the Yangchun Basin, South China. The lithology of the Shilu intrusion is granodiorite and quartz diorite, both of which are high-K calc-alkaline series, with high Sr([400 ppm) content along with low Y and Yb contents. Most of the samples have characteristics of adakite except for a few samples that have slightly higher Y and Yb contents, which may be plausibly explained by crustal contamination. Laser Ablation Inductively Coupled Plasma Mass Spectrometry zircon U–Pb dating revealed ages between 106.6 ± 1.3 and 103.9 ± 0.5 Ma, with multiple magmatic pulses. Molybdenite Re–Os isochron age of 102.2 ± 2.9 Ma(MSWD = 9.4) was determined, which is identical to the youngest zircon U–Pb age(103.9 ± 0.5 Ma) within error.The Shilu intrusion has high oxygen fugacity as indicated by high zircon Ce^(4+)/Ce^(3+) and Eu_N/Eu_N* ratios. Considering the geochemical characteristics(high Sr, and low Y and Yb contents), high oxygen fugacity, and copper mineralization of the Shilu intrusion, it was most likely formed by partial melting of a subducted young oceanic slab. Whole-rock Sr–Nd isotope-, zircon Hf isotope-, and whole-rock trace element analyses show that Shilu adakitic magmas may have interacted with type II enriched mantle and/or crustal materials during ascent. South China was affected by the Pacific tectonic regime to the east and the Neo-Tethys tectonic regime to the south in the Cretaceous. Based on the Pacific Plate drifting and rotation history, it is hard to explain how the Pacific Plate would have subducted and melted, forming adakitic rocks in the Shilu region. Considering the tectonic history of Southeast Asia and the South China Sea, the Neo-Tethys trench should have been much closer to the South China Block in the Cretaceous, and thus have had a greater impact on the South China Block. Based on the subduction direction, time of subduction,and distance between the Neo-Tethys subduction zone and the Shilu deposit, subduction of the Neo-Tethys ridge is the best mechanism for explaining the Shilu adakitic rocks and Cu–Mo mineralization. | Lipeng Zhang Yongbin Hu Jinlong Liang Trevor Ireland Youliang Chen Rongqing Zhang Saijun Sun Weidong Sun | 2017 | Acta Geochimica2017，36，2： | 15 |
| 7 | Comparison of the Global Energy Cycle between Chinese Reanalysis Interim and ECMWF Reanalysis显示文摘The global energy cycle is a diagnostic metric widely used to gauge the quality of datasets. In this paper, the 'Mixed Space-Time Domain' method for diagnosis of energy cycle is evaluated by using newly developed datasets-the Chinese Reanalysis Interim (CRAI) and ECMWF Reanalysis version 5 (ERA5), over a 7-yr period (2010-16) on seasonal and monthly timescales. The results show that the energy components calculated from the two reanalysis datasets are highly consistent;however, some components in the global energy integral from CRAI are slightly larger than those from ERA5. The main discrepancy in the energy components stems from the conversion of baroclinic process, whereas the dominant difference originates from the conversion from stationary eddy available potential energy to stationary eddy kinetic energy (CES), which is caused by systematic differences in the temperature and vertical velocity in low-mid latitudes of the Northern Hemisphere and near the Antarctic, where there exist complex terrains. Furthermore, the monthly analysis reveals that the general discrepancy in the temporal variation between the two datasets also lie mainly in the CES as well as corresponding generation and dissipation rates. | Bin ZHAO Bo ZHANG Chunxiang SHI Jingwei LIU Lipeng JIANG | 2019 | Journal of Meteorological Research2019，33，3： | 14 |
| 8 | Synthetic Evaluation of Steady-state Power Quality Based on Combination Weighting and Principal Component Projection Method显示文摘With integration of renewable energy and use of non-linear loads in power systems,the power quality problem is increasingly attracting attention of researchers.In China,standards for individual power quality indexes are set.However,when evaluating power quality in practice,individual indexes cannot directly reflect a comprehensive level of power quality.In this paper,a comprehensive analysis of various indexes is conducted to obtain a unified parameter for describing the characteristics of power quality from an overall perspective.First,weight values of power quality indexes are calculated by combining the subjective and objective weight.Then,based on the principal components of the projection method,projection values of boundary data and data to be evaluated are obtained.Finally,using these projection values,a grade range for power quality data is located.A practical case study is presented to show the validity of the proposed method for evaluating power quality. | Jidong Wang Wenjie Pang Lipeng Wang Xipin Pang Ryuichi Yokoyama | 2017 | CSEE Journal of Power and Energy Systems2017，3，2： | 11 |
| 9 | Numerical study of corner separation in a linear compressor cascade using various turbulence models显示文摘Three-dimensional corner separation is a common phenomenon that significantly affects compressor performance.Turbulence model is still a weakness for RANS method on predicting corner separation flow accurately.In the present study,numerical study of corner separation in a linear highly loaded prescribed velocity distribution(PVD) compressor cascade has been investigated using seven frequently used turbulence models.The seven turbulence models include Spalart–Allmaras model,standard k–e model,realizable k–e model,standard k–x model,shear stress transport k–x model,v^2–f model and Reynolds stress model.The results of these turbulence models have been compared and analyzed in detail with available experimental data.It is found the standard k–e model,realizable k–e model,v^2–f model and Reynolds stress model can provide reasonable results for predicting three dimensional corner separation in the compressor cascade.The Spalart–Allmaras model,standard k–x model and shear stress transport k–x model overestimate corner separation region at incidence of 0°.The turbulence characteristics are discussed and turbulence anisotropy is observed to be stronger in the corner separating region. | Liu Yangwei Yan Hao Liu Yingjie Lu Lipeng Li Qiushi | 2016 | Chinese Journal of Aeronautics2016，29，3： | 11 |
| 10 | Plate subduction, oxygen fugacity, and mineralization显示文摘Plate subduction is the largest natural factory that processes elements,which controls recycling and mineralization of a variety of elements.There are three major ore deposit belts in the world:the circumPacific,the centralAsian,and the Tethys belts.All the three belts are closely associated with plate subductions,the mechanism remains obscure.We approached this problem from systematic studies on the behaviours of elements during geologic processes.This contribution summaries the recent progress of our research group.Our results suggest that porphyry Cu deposits form through partial melting of subducted young oceanic crust under oxygen fugacities higher than AFMQ^+1.5,which is promoted after the elevation of atmospheric oxygen at ca.550 Ma.Tin deposits are associated with reducing magmatic rocks formed as a consequence of slab rollback.The Neo-Tethys tectonic regime hosts more than 60%of the world's total Sn reserves.This is due to the reducing environment formed during the subduction of organic rich sediments.For the same reason,porphyry Cu deposits formed in the late stages during the closure of the Neo-Tethys Ocean.Tungsten deposits are also controlled by slab rollback,but is not so sensitive to oxygen fugacity.Subduction related W/Sn deposits are mostly accompanied by abundant accessory fluorites due to the breakdown of phengite and apatite.Decomposition of phengite is also significant for hard rock lithium deposits,whereas orogenic belt resulted from plate subduction promote the formation of Li brine deposits.Cretaceous red bed basins near the Nanling region are favorable for Li brines.Both Mo and Re are enriched in the oxidationreduction cycle during surface processes,and may get further enriched once Mo-,Re-enriched sediments are subducted and involved in magmatism.During plate subduction,Mo and Re fractionate from each other.Molybdenum is mainly hosted in porphyry Mo deposits and to a less extent,porphyry Cu-Mo deposits,whereas Re is predominantly hosted in porphyry Cu-Mo deposits and sedimentary sulfide deposits. | LIU He LIAO Renqiang ZHANG Lipeng LI Congying SUN Weidong | 2020 | Journal of Oceanology and Limnology2020，38，1： | 10 |
| 11 | A study on turbulence transportation and modification of Spalart–Allmaras model for shock-wave/turbulent boundary layer interaction flow显示文摘It is of great significance to improve the accuracy of turbulence models in shock-wave/ boundary layer interaction flow. The relationship between the pressure gradient, as well as the shear layer, and the development of turbulent kinetic energy in impinging shock-wave/turbulent boundary layer interaction flow at Mach 2.25 is analyzed based on the data of direct numerical simulation(DNS). It is found that the turbulent kinetic energy is amplified by strong shear in the separation zone and the adverse pressure gradient near the separation point. The pressure gradient was non-dimensionalised with local density, velocity, and viscosity. Spalart–Allmaras(S–A) model is modified by introducing the non-dimensional pressure gradient into the production term of the eddy viscosity transportation equation. Simulation results show that the production and dissipation of eddy viscosity are strongly enhanced by the modification of S–A model. Compared with DNS and experimental data, the wall pressure and the wall skin friction coefficient as well as the velocity profile of the modified S–A model are obviously improved. Thus it can be concluded that the modification of S–A model with the pressure gradient can improve the predictive accuracy for simulating the shock-wave/turbulent boundary layer interaction. | Ma Li Lu Lipeng Fang Jian Wang Qiuhui | 2014 | Chinese Journal of Aeronautics2014，27，2： | 9 |
| 12 | Large-eddy simulation of shock-wave/turbulent boundary layer interaction with and without Spark Jet control显示文摘The efficiency and mechanism of an active control device ‘‘Spark Jet' and its application in shock-induced separation control are studied using large-eddy simulation in this paper.The base flow is the interaction of an oblique shock-wave generated by 8° wedge and a spatially-developing Ma = 2.3 turbulent boundary layer.The Reynolds number based on the incoming flow property and the boundary layer displacement thickness at the impinging point without shock-wave is20000.The detailed numerical approaches were presented.The inflow turbulence was generated using the digital filter method to avoid artificial temporal or streamwise periodicity.The numerical results including velocity profile,Reynolds stress profile,skin friction,and wall pressure were systematically validated against the available wind tunnel particle image velocimetry(PIV) measurements of the same flow condition.Further study on the control of flow separation due to the strong shock-viscous interaction using an active control actuator ‘‘Spark Jet' was conducted.The single-pulsed characteristic of the device was obtained and compared with the experiment.Both instantaneous and time-averaged flow fields have shown that the jet flow issuing from the actuator cavity enhances the flow mixing inside the boundary layer,making the boundary layer more resistant to flow separation.Skin friction coefficient distribution shows that the separation bubble length is reduced by about 35% with control exerted. | Yang Guang Yao Yufeng Fang Jian Gan Tian Li Qiushi Lu Lipeng | 2016 | Chinese Journal of Aeronautics2016，29，3： | 8 |
| 13 | Experimental Study of Corner Stall in a Linear Compressor Cascade显示文摘In order to gain a better knowledge of the mechanisms and to calibrate computational fluid dynamics (CFD) tools including both Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES),a detailed and accurate experimental study of corner stall in a linear compressor cascade has been carried out.Data are taken at a Reynolds number of 382 000 based on blade chord and inlet velocity.At first,inlet flow boundary layer is surveyed using hot-wire anemometry.Then in order to investigate the effects of incidence,measurements are acquired at five incidences,including static pressures on both blade and endwall surfaces measured by pressure taps and the total pressure losses of outlet flow measured by a five-hole pressure probe.The maximum losses as well as the extent of losses of the corner stall are presented as a function of the investigated incidences. | MA Wei OTTAVY Xavier LU Lipeng LEBOEUF Francis GAO Feng | 2011 | Chinese Journal of Aeronautics2011，24，3： | 8 |
| 14 | A Case of COVID-19 Detected in a Cargo Worker at Pudong Airport-Shanghai Municipality, China, November 8, 2020显示文摘On November 8,2020,a 51-year-old male went to the fever clinic of Shanghai Pudong New Area People’s Hospital for diagnosis and treatment of symptoms and was tested for coronavirus disease 2019(COVID-19).In the early hours of November 9,the municipal and district-level CDCs determined his nucleic acid test results were positive,and after consultation with experts,comprehensive clinical examination,and inspection of imaging results,the COVID-19 diagnosis was confirmed. | Fanghao Fang Yang Song Lipeng Hao Kai Nie Xiaodong Sun | 2020 | China CDC weekly2020，2，47： | 8 |
| 15 | Generalized Internal Model Robust Control for Active Front Steering Intervention显示文摘Because of the tire nonlinearity and vehicle's parameters'uncertainties,robust control methods based on the worst cases,such as H_∞,μsynthesis,have been widely used in active front steering control,however,in order to guarantee the stability of active front steering system(AFS)controller,the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control.In this paper,a generalized internal model robust control(GIMC)that can overcome the contradiction between performance and stability is used in the AFS control.In GIMC,the Youla parameterization is used in an improved way.And GIMC controller includes two sections:a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters'uncertainties and some external disturbances.Simulations of double lane change(DLC)maneuver and that of braking on split-μroad are conducted to compare the performance and stability of the GIMC control,the nominal performance PID controller and the H_∞controller.Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle's parameters variations,H_∞controller is conservative so that the performance is a little low,and only the GIMC controller overcomes the contradiction between performance and robustness,which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller.Therefore,the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system,that is,can solve the instability of PID or LQP control methods and the low performance of the standard H_∞controller. | WU Jian ZHAO Youqun JI Xuewu LIU Yahui ZHANG Lipeng | 2015 | Chinese Journal of Mechanical Engineering2015，28，2： | 7 |
| 16 | Powertrain design and energy management of a novel coaxial series-parallel plug-in hybrid electric vehicle显示文摘For a series plug-in hybrid electric vehicle,higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone.However,the overly complex structure will inevitably lead to a substantial increase in the development cost.To improve the system price-performance ratio,a new kind of series-parallel hybrid system evolved from the series plug-in hybrid system is designed.According to the technical parameters of the selected components,the system model is established,and the vehicle dynamic property and pure electric drive economy are evaluated.Based on the dynamic programming,the energy management strategy for the drive system under the city driving cycle is developed,and the superiority validation of the system is completed.For the studied vehicle driven by the designed series-parallel plug-in hybrid system,compared with the one driven by the described series plug-in hybrid system,the dynamic property is significantly improved because of the multi-power coupling,and the fuel consumption is reduced by 11.4%with 10 city driving cycles.In a word,with the flexible configuration of the designed hybrid system and the optimized control strategy of the energy management,the vehicle performance can be obviously improved. | ZHANG LiPeng QI BingNan ZHANG RunSheng LIU JingChao WANG LiQiang | 2016 | Science China(Technological Sciences)2016，59，4： | 7 |
| 17 | Applicability Assessment of the 1998–2018 CLDAS Multi-Source Precipitation Fusion Dataset over China显示文摘Traditional hourly rain gauges and automatic weather stations rarely measure solid precipitation, except for those stations with weighing-type precipitation sensors. Microwave remote sensing has only a low ability to retrieve solid precipitation. In addition, there are no long-term, high-quality precipitation data in China that can be used to drive land surface models. To address these issues, in the China Meteorological Administration(CMA) Land Data Assimilation System(CLDAS), we blended the Climate Prediction Center(CPC) morphing technique(CMORPH) and Modern-Era Retrospective analysis for Research and Applications version 2(MERRA2) precipitation datasets with observed temperature and precipitation data on various temporal scales using multigrid variational analysis and temporal downscaling to produce a multi-source precipitation fusion dataset for China(CLDAS-Prcp). This dataset covers all of China at a resolution of 6.25 km at hourly intervals from 1998 to 2018. We performed dependent and independent evaluations of the CLDAS-Prcp dataset from the perspectives of seasonal total precipitation and land surface model simulation. Our results show that the CLDAS-Prcp dataset represents reasonably the spatial distribution of precipitation in China. The dependent evaluation indicates that the CLDAS-Prcp performs better than the MERRA2 precipitation, CMORPH precipitation, Global Land Data Assimilation System version 2(GLDAS-V2.1) precipitation,and CLDAS-V2.0 winter precipitation, as compared to the meteorological observational precipitation. The independent evaluation indicates that the CLDAS-Prcp dataset performs better than the Global Precipitation Measurement(GPM) precipitation dataset and is similar to the CLDAS-V2.0 summer precipitation dataset based on the hydrological observational precipitation. The simulated soil moisture content driven by CLDAS-Prcp is slightly better than that driven by the CLDAS-V2.0 precipitation, whereas the snow depth simulation driven by CLDAS-Prcp is much better than that driven by the CLDAS-V2.0 precipitation. This is because the CLDAS-Prcp data have included solid precipitation. Overall, the CLDAS-Prcp dataset can meet the needs of land surface and hydrological modeling studies. | Shuai SUN Chunxiang SHI Yang PAN Lei BAI Bin XU Tao ZHANG Shuai HAN Lipeng JIANG | 2020 | Journal of Meteorological Research2020，34，4： | 7 |
| 18 | A new free-hand pedicle screw placement technique with reference to the supraspinal ligament显示文摘We sought to compare the safety and accuracy of a new free-hand pedicle screw placement technique to that of the conventional technique.One hundred fifty-three consecutive adult patients with simple fracture in the thoracic or/and lumbar spine were alternately assigned to either the new free-hand or the conventional group.In the new free-hand technique group,preoperative computerized tomography(CT) images were used to calculate the targeted medial-lateral angle of each pedicle trajectory and the pedicle screw was inserted perpendicular to the corresponding supraspinal ligament.In the conventional technique group,the medial-lateral and cranial-caudal angle of each pedicle trajectory was determined by intraoperatively under fluoroscopic guidance.The accuracy rate of pedicle screw placement,the time of intraoperative fluoroscopy,the operating time and the amount of blood loss during operation were respectively compared.All screws were analyzed by using intraoperative radiographs,intraoperative triggered electromyography(EMG) monitoring data,postoperative CT data and clinical outcomes.The accuracy rate of pedicle screw placement in the new free-hand technique group and the conventional technique group was 96.3% and 94.2%(P < 0.05),respectively.The intraoperative fluoroscopy time of the new technique group was less than that of the conventional technique group(5.37 seconds vs.8.79 seconds,P < 0.05).However,there was no statistical difference in the operating time and the amount of blood loss during operation(P > 0.05).Pedicle screw placement with the free-hand technique which keeps the screw perpendicular to the supraspinal ligament is an accurate,reliable and safe technique to treat simple fracture in the thoracic or lumbar spine. | Juming Li Hong Zhao Hao Xie Lipeng Yu Jifu Wei Min Zong Feng Chen Ziqiang Zhu Ning Zhang Xiaojian Cao | 2014 | The Journal of Biomedical Research2014，28，1： | 7 |
| 19 | Integration, Quality Assurance, and Usage of Global Aircraft Observations in CRA显示文摘This paper presents a detailed description of integration, quality assurance procedure, and usage of global aircraft observations for China's first generation global atmospheric reanalysis(CRA) product(1979–2018). An integration method named 'classified integration' is developed. Aircraft observations from nine different sources are integrated into the Integrated Global Meteorological Observation Archive from Aircraft(IGMOAA), a new dataset from the National Meteorological Information Center(NMIC) of the China Meteorological Administration(CMA). IGMOAA consists of global aircraft temperature, wind, and humidity data from the surface to 100 h Pa, extending from 1973 to the present. Compared with observations assimilated in the Climate Forecast System Reanalysis(CFSR) of NCEP,the observation number of IGMOAA increased by 12.9% between 2010 and 2014, mainly as a result of adding more Chinese Aircraft Meteorological Data Relay(AMDAR) data. Complex quality control procedures for aircraft observations of NCEP are applied to detect data errors. Observations are compared with ERA-Interim reanalysis from 1979 to 2018 to investigate data quality of different types and aircraft, and subsequently to develop the blacklists for CRA. IGMOAA data have been assimilated in CRA in 2018 and are real-time updated at the CMA Data-as-a-Service(CMADaa S) platform. For CRA, the fits to observations improve over time. From 1994 to 2018, root-meansquare error(RMSE) of observations relative to CRA background decreases from 1.8 to 1.0℃ for temperature above 300 h Pa, and from 4.5 to 3 m s^(-1) for zonal wind. The RMSE for humidity appears to exhibit an apparent seasonal variation with larger errors in summer and smaller ones in winter. | Jie LIAO Huiying WANG Zijiang ZHOU Zhiquan LIU Lipeng JIANG Fang YUAN | 2021 | Journal of Meteorological Research2021，35，1： | 6 |
| 20 | Tempo-spatial characteristics and influential factors of rockburst:a case study of transportation and drainage tunnels in Jinping Ⅱ hydropower station显示文摘Jinping Ⅱ hydropower station is located in a high in-situ stress region in Southwest China. During the excavations of the transportation and drainage tunnels, more than 460 rockburst events were recorded in the transportation tunnel and 110 in the drainage tunnel, which has a serious and negative influence on the tunnels' construction and the safety of staff and equipment. In the paper, the characters of rockburst patterns are analyzed for the transportation and drainage tunnels. The results are illustrated as follow: (1) Most of intensive rockbursts occur in the layer T2b, and continuous occurrences of rockbursts are more frequently observed than those in other layers. (2) The critical overburden depth of rockburst in the transportation tunnel is 600 m, and the length of the continuous occurrence section of rockburst is smaller than 25 m. The damaged depth of the rockburst has the tendency to increase with the increasing overburden depth, and the maximum damaged depth is over 3.5 m. (3) From east to west (west to east) in Jinping Ⅱ hydropower station, the rockburst usually takes place in the right (left) side of tunnel working face, and then the left (right) or roof of the tunnel. The total length of the continuous occurrence section of rockburst is 57.4%-62.2% of the overall rockburst length, followed by the rockbursts of flake-splitting type and other types. (4) Compared with the transportation tunnel, the intensity of rockburst in the drainage tunnel is higher while the length of the continuous occurrence section of rockburst is smaller. The rockburst section with length less than 10 m and depth of 1 m mainly occurs in the layer at a depth of 1 800-2 000 m. The influences of opening geometry and excavation method on the characteristics of the adjacent zone are great, but the influence of the stress among the tunnel group induced by excavation is relatively low. | Lipeng Liu1, 2, Xiaogang Wang1, Yizhong Zhang3, Zhixin Jia1, Qingwei Duan1 1 Department of Geotechnical Engineering, China Institute of Water Resources and Hydropower Research, Beijing, 100048, China 2 School of Engineering and Technology, China University of Geosciences, Beijing, 100083, China 3 Beijing Vibroflotation Engineering Co., Ltd., Beijing, 100102, China | 2011 | Journal of Rock Mechanics and Geotechnical Engineering2011，3，2： | 5 |
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