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35篇 您的检索式:作者名="Li Haochen"
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1A Model Output Machine Learning Method for Grid Temperature Forecasts in the Beijing Area显示文摘In this paper, the model output machine learning (MOML) method is proposed for simulating weather consultation, which can improve the forecast results of numerical weather prediction (NWP). During weather consultation, the forecasters obtain the final results by combining the observations with the NWP results and giving opinions based on their experience. It is obvious that using a suitable post-processing algorithm for simulating weather consultation is an interesting and important topic. MOML is a post-processing method based on machine learning, which matches NWP forecasts against observations through a regression function. By adopting different feature engineering of datasets and training periods, the observational and model data can be processed into the corresponding training set and test set. The MOML regression function uses an existing machine learning algorithm with the processed dataset to revise the output of NWP models combined with the observations, so as to improve the results of weather forecasts. To test the new approach for grid temperature forecasts, the 2-m surface air temperature in the Beijing area from the ECMWF model is used. MOML with different feature engineering is compared against the ECMWF model and modified model output statistics (MOS) method. MOML shows a better numerical performance than the ECMWF model and MOS, especially for winter. The results of MOML with a linear algorithm, running training period, and dataset using spatial interpolation ideas, are better than others when the forecast time is within a few days. The results of MOML with the Random Forest algorithm, year-round training period, and dataset containing surrounding gridpoint information, are better when the forecast time is longer.Haochen LI Chen YU Jiangjiang XIA Yingchun WANG Jiang ZHU Pingwen ZHANG 2019Advances in Atmospheric Sciences2019,36,10:9
2Review of low timing jitter mode-locked fiber lasers and applications in dual-comb absolute distance measurement显示文摘Passively mode-locked fiber lasers emit femtosecond pulse trains with excellent short-term stability. The quantum-limited timing jitter of a free running femtosecond erbium-doped fiber laser working at room temperature is considerably below one femtosecond at high Fourier frequency. The ultrashort pulse train with ultralow timing jitter enables absolute time-of-flight measurements based on a dual-comb implementation, which is typically composed of a pair of optical frequency combs generated by femtosecond lasers. Dead-zone-free absolute distance measurement with sub-micrometer precision and kHz update rate has been routinely achieved with a dual-comb configuration, which is promising for a number of precision manufacturing applications, from large step-structure measurements prevalent in microelectronic profilometry to three coordinate measurements in large-scale aerospace manufacturing and shipbuilding. In this paper, we first review the sub-femtosecond precision timing jitter characterization methods and approaches for ultralow timing jitter mode-locked fiber laser design. Then, we provide an overview of the state-of-the-art dual-comb absolute ranging technology in terms of working principles, experimental implementations, and measurement precisions. Finally, we discuss the impact of quantum-limited timing jitter on the dual-comb ranging precision at a high update rate. The route to highprecision dual-comb range finder design based on ultralow jitter femtosecond fiber lasers is proposed.Haosen Shi Youjian Song Runmin Li Yuepeng Li Hui Cao Haochen Tian Bowen Liu Lu Chai Minglie Hu 2018Nanotechnology and Precision Engineering2018,1,4:9
3Machine Learning−based Weather Support for the 2022 Winter Olympics显示文摘1.A key support for the 2022 Winter Olympics The XXIV Olympic Winter Games are scheduled to take place from 4 to 22 February 2022,followed by the Paralympic Games from 4 to 13 March,in Beijing and towns in the neighboring Hebei Province,China.Weather plays an extremely important role in the outcome of the games(Chen et al.,2018).It can not only cause a difference between a medal or not,but affect the safety of athletes.Success of the Winter Olympics will greatly depend on weather conditions at the outdoor competition venues,dealing with many weather elements including the snow surface temperature,apparent temperature,gust wind speed,snow,visibility,etc.To ensure that the scheduled games go smoothly,it is imperative to have hourly or even every 10-minutely forecasts as well as updated weather-related risk assessments at the venues for the next 240 hours.So far,the Beijing/Hebei Meteorological Observatory has already started intelligent weather forecasting at 3-km resolution based on the results of numerical weather prediction(NWP)models.However,these experiments have suggested that the current forecasting techniques are incapable of capturing the complex mountain weather variations around some venues.The forecasting capability of NWP is constrained partly by limited knowledge of the local weather mechanisms.Jiangjiang XIA Haochen LI Yanyan KANG Chen YU Lei JI Lve WU Xiao LOU Guangxiang ZHU Zaiwen Wang Zhongwei YAN Lizhi WANG Jiang ZHU Pingwen ZHANG Min CHEN Yingxin ZHANG Lihao GAO Jiarui HAN 2020Advances in Atmospheric Sciences2020,37,9:6
4Approach to General Data Model of GIS Symbol Library and Symbol Library Data Exchange XML Schema显示文摘标志描绘是 GIS 的重要功能。在不同 GIS 平台分享符号的信息为 GIS 应用程序和用户是必要的。这篇论文讨论必要性,可能性和在不同 GIS 平台分享一个标志图书馆的答案技术。线路地图如下被设计:首先,为标志图书馆当模特儿建立一个一般数据,然后格式化设计标准交换,并且最后格式化号召 GIS 制造商为标准交换为他们的标志图书馆提供交换工具。这篇论文分析 GIS 符号的图书馆的一般特征,给一个标志图书馆模型和 XML 的一篇草稿标志图书馆交换格式的纲要。LI Qingyuan SU Deguo LI Hongsheng LIU Haochen SUN Lijian 2009Geo-Spatial Information Science2009,12,4:4
5N-doped-carbon coated Ni2P-Ni sheets anchored on graphene with superior energy storage behavior显示文摘Transition metal phosphides (TMPs) have been widely studied as electrode materials for supercapacitors and lithium-ion batteries due to their high electrochemical reacti on activities. The practical applicati on of TMPs was gen erally hampered by their low con ductivity and large volume changes during electrochemical reactions. In this work, nitrogen-doped-carbon (NC) coated Ni2P-Ni hybrid sheets were fabricated and loaded into highly con ductive graphe ne n etwork, forming a Ni2P ?Ni@NC@G composite. The highly con ductive g raphe ne, the NC coati ng layer, and the decorated Ni nano particles in combi nation offer continu ous electro n tran sport cha nnels in the composite, resulti ng with facilitated electrode reaction kinetics and superior rate performance. Besides, the flexible graphene sheets and well-decorated Ni particles among Ni2P can effectively buffer the harmful stress during electrochemical reactions to maintain an integrated electrode structure. With these favorable features, the composite dem on strated superior capacitive and lithium storage behavior. As an electrode material for supercapacitors, the composite shows a remarkable capacitance of 2,335.5 F·g^-1 at 1 A·g^-1 and high capacitance retention of 86.4% after 2,000 cycles. Asymmetrical supercapacitors (ASCs) were also prepared with remarkable energy density of 53.125 Whk·g^-1 and power density of 3,750 Whk·g^-1. As an anode for lithium ion batteries, a high reversible capacity of 1,410 mAh·g^-1 can be delivered at 0.2 A·g^-1 after 200 cycles. Promising high rate capability was also demonstrated with a high discharge capacity of 750 mAh·g^-1 at 8 A·g^-1. This work shall pave the way for the production of other TMP materials for energy storage systems.Yuanxing Zhang Li Sun Liqi Bai Haochen Si Yu Zhang Yihe Zhang 2019Nano Research2019,12,3:3
6Improved peroxidase-mimic property: Sustainable, high- efficiency interfacial catalysis with H2O2 on the surface of vesicles of hexavanadate-organic hybrid surfactants显示文摘Kun Chen Aruuhan Bayaguud Hui Li Yang Chu Haochen Zhang Hongli Jia Baofang Zhang Zicheng Xiao Pingfan Wu Tianbo Liu Yongge wei 2018Nano Research2018,11,3:2
7A reactive oxygen species-responsive hydrogel encapsulated with bone marrow derived stem cells promotes repair and regeneration of spinal cord injury显示文摘Spinal cord injury(SCI)is an overwhelming and incurable disabling event accompanied by complicated inflammation-related pathological processes,such as excessive reactive oxygen species(ROS)produced by the infiltrated inflammatory immune cells and released to the extracellular microenvironment,leading to the widespread apoptosis of the neuron cells,glial and oligodendroctyes.In this study,a thioketal-containing and ROS-scavenging hydrogel was prepared for encapsulation of the bone marrow derived mesenchymal stem cells(BMSCs),which promoted the neurogenesis and axon regeneration by scavenging the overproduced ROS and re-building a regenerative microenvironment.The hydrogel could effectively encapsulate BMSCs,and played a remarkable neuroprotective role in vivo by reducing the production of endogenous ROS,attenuating ROS-mediated oxidative damage and downregulating the inflammatory cytokines such as interleukin-1 beta(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-alpha(TNF-α),resulting in a reduced cell apoptosis in the spinal cord tissue.The BMSCs-encapsulated ROS-scavenging hydrogel also reduced the scar formation,and improved the neurogenesis of the spinal cord tissue,and thus distinctly enhanced the motor functional recovery of SCI rats.Our work provides a combinational strategy against ROS-mediated oxidative stress,with potential applications not only in SCI,but also in other central nervous system diseases with similar pathological conditions.Ziming Li Tengfei Zhao Jie Ding Haochen Gu Qiaoxuan Wang Yifan Wang Deteng Zhang Changyou Gao 2023Bioactive Materials2023,,1:2
8Combined immunotherapy with dendritic cells and cytokine-induced killer cells for malignant tumors: A systematic review and meta-analysis显示文摘Ran Chen Xin Deng Haochen Wu Peichun Peng Bin Wen Fuyin Li Fenfen Li 2014International Immunopharmacology2014,,2:2
9Lysohexaenetides A and B,linear lipopeptides from Lysobacter sp.DSM 3655 identified by heterologous expression in Streptomyces显示文摘Lysobacter harbors a plethora of cryptic biosynthetic gene clusters(BGCs),albeit only a limited number have been analyzed to date.In this study,we described the activation of a cryptic polyketide synthase(PKS)/nonribosomal peptide synthetase(NRPS)gene cluster(lsh)in Lysobacter sp.DSM 3655 through promoter engineering and heterologous expression in Streptomyces sp.S001.As a result of this methodology,we were able to isolate two novel linear lipopeptides,lysohexaenetides A(1)and B(2),from the recombinant strain S001-lsh.Furthermore,we proposed the biosynthetic pathway for lysohexaenetides and identified LshA as another example of entirely iterative bacterial PKSs.This study highlights the potential of heterologous expression systems in uncovering cryptic biosynthetic pathways in Lysobacter genomes,particularly in the absence of genetic manipulation tools.XU Qiushuang ZOU Haochen PAN Chen WANG Haoxin SHEN Yuemao LI Yaoyao 2023Chinese Journal of Natural Medicines2023,21,6:1
10A SIXTH ORDER AVERAGED VECTOR FIELD METHOD显示文摘在这份报纸,基于生根的树和 B 系列的理论,我们为顺序 = 的树建议替换法律的具体公式 5。在新替换法律的帮助下,我们导出扩大平均向量地(AVF ) 方法让一般 Hamiltonian 系统更高订的一个 B 系列综合者。新综合者结果是六的顺序并且确切为 Hamiltonian 系统保存精力。数字实验被介绍表明精确性和第六个顺序 AVF 方法的保存精力的性质。[从作者抽象]Haochen Li Yushun Wang Mengzhao Qin 2016Journal of Computational Mathematics2016,34,5:1
11Multi-SymplecticMethod for the Zakharov-Kuznetsov Equation显示文摘A newscheme for the Zakharov-Kuznetsov(ZK)equationwith the accuracy order of O(△t^(2)+△x+△y^(2))is proposed.The multi-symplectic conservation property of the new scheme is proved.The backward error analysis of the newmulti-symplectic scheme is also implemented.The solitary wave evolution behaviors of the Zakharov-Kunetsov equation is investigated by the new multi-symplectic scheme.The accuracy of the scheme is analyzed.Haochen Li Jianqiang Sun Mengzhao Qin 2015Advances in Applied Mathematics and Mechanics2015,7,1:1
12Enhanced photon communication through Bayesian estimation with an SNSPD array显示文摘Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication based on the superconducting nanowire single-photon detector(SNSPD)is a new technology that addresses the current sensitivity limitations at the level of single photons in deep space communication.The communication’s bit error rate(BER)is limited by dark noise in the space environment and the photon number distribution with a traditional single-pixel SNSPD,which is unable to resolve the photon number distribution.In this work,an enhanced photon communication method was proposed based on the photon number resolving function of four-pixel array SNSPDs.A simulated picture transmission was carried out,and the error rate in this counting mode can be reduced by 2 orders of magnitude when compared with classical optical communication.However,in the communication mode using photon-enhanced counting,the four-pixel response amplitude for counting was found to restrain the communication rate,and this counting mode is extremely dependent on the incident light intensity through experiments,which limits the sensitivity and speed of the SNSPD array’s performance advantage.Therefore,a BER theoretical calculation model for laser communication was presented using the Bayesian estimation algorithm in order to analyze the selection of counting methods for information acquisition under different light intensities and to make better use of the SNSPD array’s high sensitivity and speed and thus to obtain a lower BER.The counting method and theoretical model proposed in this work refer to array SNSPDs in the deep space field.XIANG LI JINGROU TAN KAIMIN ZHENG LABAO ZHANG LIJIAN ZHANG WEIJI HE PENGWEI HUANG HAOCHEN LI BIAO ZHANG QI CHEN RUI GE SHUYA GUO TAO HUANG XIAOQING JIA QINGYUAN ZHAO XUECOU TU LIN KANG JIAN CHEN PEIHENG WU 2020Photonics Research2020,8,5:1
13Mechanically driven assembly of biomimetic 2D-material microtextures with bioinspired multifunctionality显示文摘Nature provides a wealth of bio-inspiration for advanced material research.Assembling various nanomaterials into biomimetic microtextures with bioinspired functionalities has spurred increasing research interests and facilitated technological advances in various applications.In recent years,two-dimensional materials(2DMs)have emerged as important building block units in the biomimicry field due to their distinct chemical,physical,electrical,electrochemical,and catalytic properties.In this review article,various mechanically driven assembly approaches are summarized to fabricate various genealogies of biomimetic 2DM microtextures with bio-inspired multifunctionality.First,sequential deformation strategies are discussed to programmably construct higher dimensional 2DM microtextures,ranging from wrinkles/crumples(one-time deformation)to multiscale hierarchies(multiple deformations).Next,the current progress using higher dimensional 2DM microtextures to imitate different biological structures and/or induce bio-inspired multifunctionality is systematically summarized.Four showcases of bio-inspiration and biomimicry using different 2DM nanosheets are highlighted:(1)wrinkle patterns of an earthworm that spur the design of strain sensors with programmable working ranges and sensitivities,(2)wrinkle appearance of a Shar-Pei dog that motivates the fabrication of stretchable energy storage devices,(3)hierarchical scale textures of a desert lizard that inspire cation-induced gelation platforms for 2DM aerogels,and(4)wrinkle skin of an elephant that influences the development of 2DM protective skin for soft robots.Finally,challenges and future opportunities of adopting 2DM nanosheets to assemble biomimetic microstructures with synergistic functionalities are discussed.Yang Li Lin Jing Joshua M.Little Haochen Yang Tsai-Chun Chung Po-Yen Chen 2024Nano Research2024,17,2:1
14Energy Sharing and Frequency Regulation in Energy Network via Mixed H_(2)/H_(∞) Control with Markovian Jump显示文摘In this paper,the problem of mixed optimization for energy sharing and frequency regulation in a typical energy network scenario where energy routers(ERs)interconnected AC microgrids(MGs)is investigated.Continuous-time Markov chains are introduced to describe the switching paths in the power dynamics of MGs.Such that the modelling of considered energy network system could be closer to the real-world engineering practice.Advanced parameter estimation techniques are integrated into the proposed method to achieve better modelling accuracy and controlling performance.Based on the parameters of MG power dynamics,the mixed H_(2)/H_(∞) controllers are obtained via stochastic control theory.The feasibility and efficacy of the proposed approach are evaluated in numerical examples.Haochen Hua Yuchao Qin Zicheng He Liuying Li Junwei Cao 2021CSEE Journal of Power and Energy Systems2021,7,6:1
15A Comprehensive Evaluation Framework of Water-Energy-Food System Coupling Coordination in the Yellow River Basin,China显示文摘For mankind’s survival and development,water,energy,and food(WEF)are essential material guarantees.In China,however,the spatial distribution of WEF is seriously unbalanced and mismatched.Here,a collaborative governance mechanism that aims at nexus security needs to be urgently established.In this paper,the Yellow River Basin in China with a representative WEF system,was selected as a case.Firstly,a comprehensive framework for WEF coupling coordination was constructed,and the relationship and mechanism between them were analyzed theoretically.Then,we investigated the spatiotemporal characteristics and driving mechanisms of the coupling coordination degree(CCD)with a composite evaluation method,coupling coordination degree model,spatial statistical analysis,and multiscale geographic weighted regression.Finally,policy implications were discussed to promote the coordinated development of the WEF system.The results showed that:1)WEF subsystems showed a significant imbalance of spatial pattern and diversity in temporal changes;2)the CCD for the WEF system varied little and remained at moderate coordination.Areas with moderate coordination have increased,while areas with superior coordination and mild disorder have decreased.In addition,the spatial clustering phenomenon of the CCD was significant and showed obvious characteristics of polarization;and 3)the action of each factor is self-differentiated and regionally variable.For different factors,GDP per capita was of particular importance,which contributed most to the regional development’s coupling coordination.For different regions,GDP per capita,average yearly precipitation,population density,and urbanization rate exhibited differences in geographical gradients in an east-west direction.The conclusion can provide references for regional resource allocation and sustainable development by enhancing WEF system utilization efficiency.YIN Dengyu YU Haochen LU Yanqi ZHANG Jian LI Gensheng LI Xiaoshun 2023Chinese Geographical Science2023,33,2:1
16A Deep Spatio-Temporal Forecasting Model for Multi-Site Weather Prediction Post-Processing显示文摘In this paper, we propose a deep spatio-temporal forecasting model (DeepSTF) for multi-site weather prediction post-processing by using both temporal andspatial information. In our proposed framework, the spatio-temporal information ismodeled by a CNN (convolutional neural network) module and an encoder-decoderstructure with the attention mechanism. The novelty of our work lies in that our modeltakes full account of temporal and spatial characteristics and obtain forecasts of multiple meteorological stations simultaneously by using the same framework. We applythe DeepSTF model to short-term weather prediction at 226 meteorological stations inBeijing. It significantly improves the short-term forecasts compared to other widelyused benchmark models including the Model Output Statistics method. In order toevaluate the uncertainty of the model parameters, we estimate the confidence intervals by bootstrapping. The results show that the prediction accuracy of the DeepSTFmodel has strong stability. Finally, we evaluate the impact of seasonal changes and topographical differences on the accuracy of the model predictions. The results indicatethat our proposed model has high prediction accuracy.Wenjia Kong Haochen Li Chen Yu Jiangjiang Xia Yanyan Kang Pingwen Zhang 2022Communications in Computational Physics2022,31,1:1
17Grayscale morphological filter tbr small target detection 显示文摘Zhu Zhenfu Li Zhongling Liang Haochen 2000Proceedings of SPIE-The International Society for Optical Engineering2000,,4130:1
18LaneDraw: Cascaded lane and its bifurcation detection with nested fusion显示文摘Lane and its bifurcation detection is a vital and active research topic in low cost camera-based autonomous driving and advanced driver assistance system(ADAS). The common lane detection pipeline usually predicts lane segmentation mask firstly, and then makes line fitting by parabola or spline post-processing. However, if the speed of the lane and its bifurcation detection is fast and robust enough, we think curve fitting is not a necessary step. The goal of this work is to get accurate lane segmentation,identification of every lane, adaptability of lane numbers and the right combination of lane bifurcation. In this work, we relabeled lane and its bifurcation with solid line if the image of Tu Simple dataset has both of them. In the data training process, we apply a data balance strategy for the heavily biased lane and non-lane data. In such a way, we develop a competitive cascaded instance lane detection model and propose a novel bifurcation pixel embedding nested fusion method based on full binary segmentation pixel embedding with self-grouping cluster, called Lane Draw. Our method discards curve fitting process, therefore it reduces the complexity of post-processing and increases detection speed at 35 fps. Moreover, the proposed method yields better performance and high accuracy on the relabeled Tu Simple dataset. To the best of our knowledge, this is the first attempt in 2 D lane and bifurcation detection, which more often happens in actual situations.REN KeYan HOU HaoChen LI SiYang YUE TianYi 2021Science China(Technological Sciences)2021,64,6:1
19Bimetallic NiCo2S4 Nanoneedles Anchored on Mesocarbon Microbeads as Advanced Electrodes for Asymmetric Supercapacitors显示文摘Bimetallic Ni–Co sulfides are outstanding pseudocapacitive materials with high electrochemical activity and excellent energy storage performance as electrodes for high-performance supercapacitors.In this study,a novel urchin-like NiCo2S4@mesocarbon microbead(NCS@MCMB) composite with a core–shell structure was prepared by a facile two-step hydrothermal method.The highly conductive MCMBs offered abundant adsorption sites for the growth of NCS nanoneedles,which allowed each nanoneedle to fully unfold without aggregation,resulting in improved NCS utilization and efficient electron/ion transferin the electrolyte.When applied as an electrode material for supercapacitors,the composite exhibited a maximum specific capacitance of 936 Fg-1 at 1 Ag-1 and a capacitance retention of 94% after 3000 cycles at 5 Ag-1,because of the synergistic effect of MCMB and NCS.Moreover,we fabricated an asymmetric supercapacitor based on the NCS@MCMB composite,which exhibited enlarged voltage windows and could power a light-emitting diode device for several minutes,further demonstrating the exceptional electrochemical performance of the NCS@MCMB composite.Yu Zhang Yihe Zhang Yuanxing Zhang Haochen Si Li Sun 2019Nano-Micro Letters2019,11,2:1
20A station-data-based model residual machine learning method for fine-grained meteorological grid prediction显示文摘Fine-grained weather forecasting data,i.e.,the grid data with high-resolution,have attracted increasing attention in recent years,especially for some specific applications such as the Winter Olympic Games.Although European Centre for Medium-Range Weather Forecasts(ECMWF)provides grid prediction up to 240 hours,the coarse data are unable to meet high requirements of these major events.In this paper,we propose a method,called model residual machine learning(MRML),to generate grid prediction with high-resolution based on high-precision stations forecasting.MRML applies model output machine learning(MOML)for stations forecasting.Subsequently,MRML utilizes these forecasts to improve the quality of the grid data by fitting a machine learning(ML)model to the residuals.We demonstrate that MRML achieves high capability at diverse meteorological elements,specifically,temperature,relative humidity,and wind speed.In addition,MRML could be easily extended to other post-processing methods by invoking different techniques.In our experiments,MRML outperforms the traditional downscaling methods such as piecewise linear interpolation(PLI)on the testing data.Chuansai ZHOU Haochen LI Chen YU Jiangjiang XIA Pingwen ZHANG 2022Applied Mathematics and Mechanics(English Edition)2022,43,2:0
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