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| 1 | Orbit determination and time synchronization for a GEO/IGSO satellite navigation constellation with regional tracking network显示文摘Aiming at regional services,the space segment of COMPASS (Phase I) satellite navigation system is a constellation of Geostationary Earth Orbit (GEO),Inclined Geostationary Earth Orbit (IGSO) and Medium Earth Orbit (MEO) satellites.Precise orbit determination (POD) for the satellites is limited by the geographic distribution of regional tracking stations.Independent time synchronization (TS) system is developed to supplement the regional tracking network,and satellite clock errors and orbit data may be obtained by simultaneously processing both tracking data and TS data.Consequently,inconsistency between tracking system and TS system caused by remaining instrumental errors not calibrated may decrease navigation accuracy.On the other hand,POD for the mixed constellation of GEO/IGSO/MEO with the regional tracking network leads to parameter estimations that are highly correlated.Notorious example of correlation is found between GEO's orbital elements and its clock errors.We estimate orbital elements and clock errors for a 3GEO+2IGSO constellation in this study using a multi-satellite precise orbit determination (MPOD) strategy,with which clock error elimination algorithm is applied to separate orbital and clock estimates to improve numerical efficiency.Satellite Laser Ranging (SLR) data are used to evaluate User Ranging Error (URE),which is the orbital error projected on a receiver's line-of-sight direction.Two-way radio-wave time transfer measurements are used to evaluate clock errors.Experimenting with data from the regional tracking network,we conclude that the fitting of code data is better than 1 m in terms of Root-Mean-Square (RMS),and fitting of carrier phase is better than 1 cm.For orbital evaluation,difference between computed receiver-satellite ranging based on estimated orbits and SLR measurements is better than 1 m (RMS).For clock estimates evaluation,2-hour linear-fitting shows that the satellite clock rates are about 1.E-10 s/s,while receiver clock rates are about 1×10 13-1×10 12 s/s.For the 72-hour POD experiment,the average differences between POD satellite clock rates estimates and clock measurements based on TS system are about 1×10 13 s/s,and for receiver clock rates,the differences are about 1×10 15 s/s. | ZHOU ShanShi HU XiaoGong WU Bin LIU Li QU WeiJing GUO Rui HE Feng CAO YueLing Wu XiaoLi ZHU LingFeng SHI Xin TAN HongLi | 2011 | Science China(Physics,Mechanics & Astronomy)2011，54，6： | 44 |
| 2 | PlantcircBase: A Database for Plant Circular RNAs显示文摘 | Qinjie Chu Xingchen Zhang Xintian Zhu Chen Liu Lingfeng Mao Chuyu Ye Qian-Hao Zhu Longjiang Fan | 2017 | Molecular Plant2017，10，8： | 15 |
| 3 | Applications of two-way satellite time and frequency transfer in the BeiDou navigation satellite system显示文摘A two-way satellite time and frequency transfer(TWSTFT) device equipped in the BeiDou navigation satellite system(BDS)can calculate clock error between satellite and ground master clock. TWSTFT is a real-time method with high accuracy because most system errors such as orbital error, station position error, and tropospheric and ionospheric delay error can be eliminated by calculating the two-way pseudorange difference. Another method, the multi-satellite precision orbit determination(MPOD)method, can be applied to estimate satellite clock errors. By comparison with MPOD clock estimations, this paper discusses the applications of the BDS TWSTFT clock observations in satellite clock measurement, satellite clock prediction, navigation system time monitor, and satellite clock performance assessment in orbit. The results show that with TWSTFT clock observations, the accuracy of satellite clock prediction is higher than MPOD. Five continuous weeks of comparisons with three international GNSS Service(IGS) analysis centers(ACs) show that the reference time difference between BeiDou time(BDT) and golbal positoning system(GPS) time(GPST) realized IGS ACs is in the tens of nanoseconds. Applying the TWSTFT clock error observations may obtain more accurate satellite clock performance evaluation in the 104 s interval because the accuracy of the MPOD clock estimation is not sufficiently high. By comparing the BDS and GPS satellite clock performance, we found that the BDS clock stability at the 103 s interval is approximately 10.12, which is similar to the GPS IIR. | ShanShi Zhou XiaoGong Hu Li Liu Rui Guo LingFeng Zhu ZhiQiao Chang ChengPan Tang XiuQiang Gong Ran Li Yang Yu | 2016 | Science China(Physics,Mechanics & Astronomy)2016，59，10： | 6 |
| 4 | Biochemical Composition and Nutritional Value of Different Shell Color Strains of Pacific Oyster Crassostrea gigas显示文摘The shell color of Pacific oyster(Crassostrea gigas) is a desirable trait; but the nutritional studies on C. gigas with different shell colors have not been conducted. Through successive selective breeding, five shell color strains of black(B), purple(P), orange(O), golden(G) and white(W) C. gigas have been developed. The aim of this study was to evaluate the chemical composition and nutritional value of five shell color strains and one commercial population with a common color. The biochemical composition including moisture, total protein, glycogen, ash, total fat, fatty acids(FA), amino acids and minerals was detected. The results indicated that the protein(50.76%–56.57%) was the major component. The content of glycogen showed a significant difference between orange shell and golden shell strains, as well as between commercial population and golden shell strain. In addition, all shell color strains contained a large amount of essential amino acids(12.20–14.15 g(100 g)^(-1)), of them leucine(2.81–3.29 g(100 g)^(-1)) and lysine(2.79–3.28 g(100 g)^(-1)) were predominant. The oysters were rich in polyunsaturated fatty acids(42.26%–45.24% of total fatty acid) with high levels of DHA(18.53%–21.16% of total fatty acid) and EPA(17.23%–18.68% of total fatty acid). Significant differences of mineral contents(Mg, Zn, Fe and Cu) were identified among the six populations. These results indicated that C. gigas with different shell colors presented rich nutritional value with high protein, glycogen, essential amino acids and polyunsaturated fatty acids. The biochemical composition obtained in this study is useful for selective breeding of C. gigas with different shell colors. | ZHU Yijing LI Qi YU Hong KONG Lingfeng | 2018 | Journal of Ocean University of China2018，17，4： | 4 |
| 5 | The role of γ-aminobutyric acid in aluminum stress tolerance in a woody plant, Liriodendron chinense×tulipifera显示文摘The aluminum(Al)cation Al^(3+)in acidic soil shows severe rhizotoxicity that inhibits plant growth and development.Most woody plants adapted to acidic soils have evolved specific strategies against Al^(3+)toxicity,but the underlying mechanism remains elusive.The four-carbon amino acid gamma-aminobutyric acid(GABA)has been well studied in mammals as an inhibitory neurotransmitter;GABA also controls many physiological responses during environmental or biotic stress.The woody plant hybrid Liriodendron(L.chinense×tulipifera)is widely cultivated in China as a horticultural tree and provides high-quality timber;studying its adaptation to high Al stress is important for harnessing its ecological and economic potential.Here,we performed quantitative iTRAQ(isobaric tags for relative and absolute quantification)to study how protein expression is altered in hybrid Liriodendron leaves subjected to Al stress.Hybrid Liriodendron shows differential accumulation of several proteins related to cell wall biosynthesis,sugar and proline metabolism,antioxidant activity,cell autophagy,protein ubiquitination degradation,and anion transport in response to Al damage.We observed that Al stress upregulated glutamate decarboxylase(GAD)and its activity,leading to increased GABA biosynthesis.Additional GABA synergistically increased Al-induced antioxidant enzyme activity to efficiently scavenge ROS,enhanced proline biosynthesis,and upregulated the expression of MATE1/2,which subsequently promoted the efflux of citrate for chelation of Al^(3+).We also showed similar effects of GABA on enhanced Al^(3+)tolerance in Arabidopsis.Thus,our findings suggest a function of GABA signaling in enhancing hybrid Liriodendron tolerance to Al stress through promoting organic acid transport and sustaining the cellular redox and osmotic balance. | Pengkai Wang Yini Dong Liming Zhu Zhaodong Hao LingFeng Hu Xiangyang Hu Guibin Wang Tielong Cheng Jisen Shi Jinhui Chen | 2021 | Horticulture Research2021，8，1： | 3 |
| 6 | Periodic performance of the chaotic spread spectrum sequence on finite precision显示文摘It is well known that the periodic performance of spread spectrum sequence heavily affects the cor-relative and secure characteristics of communication systems.The chaotic binary sequence is paid more and more attention since it is one kind of applicable spread spectrum sequences.However,there are unavoidable short cyclic problems for chaotic binary sequences in finite precision.The chaotic binary sequence generating methods are studied first.Then the short cyclic behavior of the chaotic sequences is analyzed in detail,which are generated by quantification approaches with finite word-length.At the same time,a chaotic similar function is defined for presenting the cyclic characteristics of the sequences.Based on these efforts,an improved method with scrambling control for generating chaotic binary sequences is proposed.To quantitatively describe the improvement of periodic performance of the sequences,an orthogonal estimator is also defined.Some simulating results are provided.From the theoretical deduction and the experimental results,it is concluded that the proposed method can effectively increase the period and raise the complexity of the chaotic sequences to some extent. | Zhu Canyan Zhang Lihua Wang Yiming Liu Jiasheng Mao Lingfeng | 2008 | Journal of Systems Engineering and Electronics2008，19，4： | 3 |
| 7 | An Adaptive Time Delay Estimator Based on ETDE Algorithm with Noisy Measurements显示文摘We address the problem of adaptive time delay estimation with noisy measurements. We develop a computationally efficient adaptive time delay estimator based on Explicit time delay estimation(ETDE) algorithm,by applying the unbiased impulse response estimation approach. In this algorithm, a weighted error function is derived, and the time delay is explicitly parameterized in the filter coefficients and iteratively updated directly by utilizing the modified error function. Simulations validate the performance of the proposed algorithm for colored input and low signal-to-noise ratio scenarios. | XIA Wei JIANG Wenying ZHU Lingfeng | 2017 | Chinese Journal of Electronics2017，26，4： | 3 |
| 8 | The method and experiment analysis of two-way common-view satellite time transfer for compass system显示文摘Time synchronization between ground and satellites is a key technology for satellite navigation system. With dual-channel satellite, a method called Two-Way Common-View(TWCV) satellite time transfer for Compass system is proposed, which combines both characteristics of satellite common-view and two-way satellite-ground time transfer. By satellite-ground two-way pseudo-range differencing and two stations common-view differencing, this TWCV method can completely eliminate the influence of common errors, such as satellite clock offset, ephemeris errors, troposphere delay and station coordinates errors. At the same time, ionosphere delay related to signal frequency is also weakened significantly. So the precision of time transfer is improved much more greatly than before. In this paper, the basic principle is introduced in detail, the effect of major errors is analyzed and the practical calculation model in the Earth-fixed coordinate system for this new method is provided. Finally, experiment analysis is conducted with actual Compass observing data. The results show that the deviation and the stability of the satellite dual channel can be better than 0.1 ns, and the accuracy of the two-way common-view satellite time transfer can achieve 0.4 ns. All these results have verified the correctness of this TWCV method and model. In addition, we compare this TWCV satellite time transfer with the independent C-band TWSTFT(Two-Way Satellite Time and Frequency Transfer). It shows that the result of the TWCV satellite time transfer is in accordance with the C-band TWSTFT result, which further suggests that the TWCV method is a remote high precision time transfer technique. The research results in this paper are very important references for the development and application of Compass satellite navigation system. | LIU Li TANG GuiFen HAN ChunHao SHI Xin GUO Rui ZHU LingFeng | 2015 | Science China(Physics,Mechanics & Astronomy)2015，58，8： | 2 |
| 9 | Distributed adaptive direct position determination based on diffusion framework显示文摘The conventional direct position determination(DPD) algorithm processes all received signals on a single sensor.When sensors have limited computational capabilities or energy storage,it is desirable to distribute the computation among other sensors.A distributed adaptive DPD(DADPD)algorithm based on diffusion framework is proposed for emitter localization.Unlike the corresponding centralized adaptive DPD(CADPD) algorithm,all but one sensor in the proposed algorithm participate in processing the received signals and estimating the common emitter position,respectively.The computational load and energy consumption on a single sensor in the CADPD algorithm is distributed among other computing sensors in a balanced manner.Exactly the same iterative localization algorithm is carried out in each computing sensor,respectively,and the algorithm in each computing sensor exhibits quite similar convergence behavior.The difference of the localization and tracking performance between the proposed distributed algorithm and the corresponding CADPD algorithm is negligible through simulation evaluations. | Wei Xia Wei Liu Lingfeng Zhu | 2016 | Journal of Systems Engineering and Electronics2016，27，1： | 2 |
| 10 | Origin of High Efficiency and Long-Term Stability in Ionic Liquid Perovskite Photovoltaic显示文摘Environment-friendly protic amine carboxylic acid ionic liquids(ILs)as solvents is a significant breakthrough with respect to traditional highly coordinating and toxic solvents in achieving efficient and stable perovskite solar cells(PSCs)with a simple one-step air processing and without an antisolvent treatment approach.However,it remains mysterious for the improved efficiency and stability of PSCs without any passivation strategy.Here,we unambiguously demonstrate that the three functions of solvents,additive,and passivation are present for protic amine carboxylic acid ILs.We found that the ILs have the capability to dissolve a series of perovskite precursors,induce oriented crystallization,and chemically passivate the grain boundaries.This is attributed to the unique molecular structure of ILs with carbonyl and amine groups,allowing for strong interaction with perovskite precursors by forming C=O…Pb chelate bonds and N-H…I hydrogen bonds in both solution and film.This finding is generic in nature with extension to a wide range of IL-based perovskite optoelectronics. | Lingfeng Chao Tingting Niu Hao Gu Yingguo Yang Qi Wei Yingdong Xia Wei Hui Shouwei Zuo Zhaohua Zhu Chengjie Pei Xiaodong Li Jing Zhang Junfeng Fang Guichuan Xing Hai Li Xiao Huang Xingyu Gao Chenxin Ran Lin Song Li Fu Yonghua Chen Wei Huang | 2020 | Research2020，，1： | 2 |
| 11 | Multi-agent control system with information fusion based comfort model for smart buildings显示文摘 | Zhu Wang Lingfeng Wang Anastasios I. Dounis Rui Yang | 2012 | Applied Energy2012，，： | 1 |
| 12 | Wear mechanism and life prediction of the ripper in a 9-m-diameter shield machine tunneling project of the Beijing new airport line in a sand-pebble stratum显示文摘Tool wear is a noteworthy problem in the process of shield tunneling,and the degree of wear varies with stratum.The sand-pebble strata in Beijing are typically mechanically unstable.However,many subways are buried wholly or partially in sand-pebble strata.Taking the Beijing New Airport line tunneling project as research background,this study evaluated the wear characteristics of the multiconfiguration rippers of a 9-m-diameter spoke-type shield tunneling machine in a sand-pebble stratum.The wear values of five ripper teeth and ripper flanks were analyzed based on field-measured data from the Beijing New Airport line project.As the analytical results show,the wear value generally increases as the installation radius enlarges with the rise of cutting trace length.The wear of the 190-rippers was divided into five categories:pedestal wear,ripper teeth collapse,uniform wear,ripper teeth falling off and ripper flank wear.Uniform wear of the ripper teeth and ripper flank wear were the two abrasion types of the 190-rippers.The teeth of the 155-rippers mostly maintained their cutting capacity under the protection of the 190-rippers.A wear prediction model of linear fitting field data was developed for a 190-ripper face to obtain the optimum shield driving distance in the sand-pebble stratum.The average wear coefficients of the 190-ripper before and after replacement matched well,being 0.045 and 0.066 mm/km,respectively.The results of this study provide a theoretical reference for tool wear prediction in shield construction under similar geological conditions. | Hua Jiang Jiachen Zhu Xiaoyan Zhang Jinxun Zhang Hongliang Li Lingfeng Meng | 2022 | Deep Underground Science and Engineering2022，1，1： | 1 |
| 13 | Preparation and photo-catalytic activity of supported TiO2 composites显示文摘 | GAO Ruqin ZHU Lingfeng | 2010 | IEEE2010，，10： | 1 |
| 14 | Enhanced strength and toughness of high nitrogen stainless bearing steel by controlling interstitial partitioning via V-microalloying显示文摘High-nitrogen stainless bearing steel(HNSBS)with ultra-high tensile strength(∼2403 MPa)and good toughness(∼80.0 J)was obtained by V-microalloying,overcoming the strength-toughness trade-off of conventional V-free HNSBS.In this work,since V-microalloying facilitated the enrichment of interstitial atoms(C and N)in precipitates,the content of interstitial atoms in the matrix was reduced accordingly(i.e.,interstitial partitioning).On the one hand,V-microalloying reduced the substantial intergranular precipitates and transformed the precipitates from M_(23)C_(6)+M_(2)N into V-containing M_(23)C_(6)+M_(2)N+MN with multi-scale particle sizes,causing a coupling strengthening effect,which contributed to the toughness and additional strength increase.On the other hand,V-microalloying controlled interstitial partitioning,effectively refined coarse retained austenite(RA),increased the fraction of dislocation martensite,and reduced the fraction of twin martensite.The more film-like RA and dislocation martensite with high dislocation density coordinated plastic deformation and prevented crack propagation,thus obviously enhancing the strength and toughness of 0.2 V steel.This study provides a new route to develop high-performance HNSBS for aerospace applications. | Lingfeng Xia Huabing Li Hao Feng Zhouhua Jiang Hongchun Zhu Shucai Zhang Xiaodong Wang | 2023 | Journal of Materials Science & Technology2023，，20： | 1 |
| 15 | Investigation of pyrolysis kinetics of carboxymethyl hydroxypropyl sesbania gum显示文摘 | Wang Zhe Zhu Lingfeng Zhang Guobao | 1997 | Journal of Thermal Analysis1997，49，： | 1 |
| 16 | Intelligent multiagent control system for energy and comfort management in smart and sustainable buildings显示文摘 | WANG Lingfeng WANG Zhu YANG Rui | 2012 | IEEE Transactions on Smart Grid2012，3，2： | 1 |
| 17 | Preparation and photo-catalytic activity of supported TiO2 composites显示文摘 | GAO Ruqin ZHU Lingfeng | | 0，，10： | 1 |
| 18 | Electrosur- gieal enueleation versus bipolar transurethral resection for pros- tates larger than 70ml:a prospective, randomized trial with 5 - year follow up 显示文摘 | Lingfeng Zhu Shushang Chen Shunliang Yang | 2013 | J Urol2013，189，4： | 1 |
| 19 | Electro- surgical enucleation versus bipolar transurethral resection for pros- tates larger than 70 ml : a prospective, randomized trial with 5 - year followup 显示文摘 | ZHU Lingfeng CHEN Shushang YANG Shunliang | 2013 | The Journal of Urology2013，189，4： | 1 |
| 20 | Multi-agent control system with information fusion based comfort model for smart buildings显示文摘 | Zhu Wang Lingfeng Wang Anastasios I. Dounis Rui Yang | 2012 | Applied Energy2012，，： | 1 |
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