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| 1 | A Deep Learning Method for Bias Correction of ECMWF 24–240 h Forecasts显示文摘Correcting the forecast bias of numerical weather prediction models is important for severe weather warnings.The refined grid forecast requires direct correction on gridded forecast products,as opposed to correcting forecast data only at individual weather stations.In this study,a deep learning method called CU-net is proposed to correct the gridded forecasts of four weather variables from the European Centre for Medium-Range Weather Forecast Integrated Forecasting System global model(ECMWF-IFS): 2-m temperature,2-m relative humidity,10-m wind speed,and 10-m wind direction,with a forecast lead time of 24 h to 240 h in North China.First,the forecast correction problem is transformed into an image-toimage translation problem in deep learning under the CU-net architecture,which is based on convolutional neural networks.Second,the ECMWF-IFS forecasts and ECMWF reanalysis data(ERA5) from 2005 to 2018 are used as training,validation,and testing datasets.The predictors and labels(ground truth) of the model are created using the ECMWF-IFS and ERA5,respectively.Finally,the correction performance of CU-net is compared with a conventional method,anomaly numerical correction with observations(ANO).Results show that forecasts from CU-net have lower root mean square error,bias,mean absolute error,and higher correlation coefficient than those from ANO for all forecast lead times from 24 h to 240 h.CU-net improves upon the ECMWF-IFS forecast for all four weather variables in terms of the above evaluation metrics,whereas ANO improves upon ECMWF-IFS performance only for 2-m temperature and relative humidity.For the correction of the 10-m wind direction forecast,which is often difficult to achieve,CU-net also improves the correction performance. | Lei HAN Mingxuan CHEN Kangkai CHEN Haonan CHEN Yanbiao ZHANG Bing LU Linye SONG Rui QIN | 2021 | Advances in Atmospheric Sciences2021，38，9： | 15 |
| 2 | Salient region detection and segmentation for general object recognition and image understanding显示文摘General object recognition and image understanding is recognized as a dramatic goal for computer vision and multimedia retrieval. In spite of the great efforts devoted in the last two decades, it still remains an open problem. In this paper, we propose a selective attention-driven model for general image understanding, named GORIUM (general object recognition and image understanding model). The key idea of our model is to discover recurring visual objects by selective attention modeling and pairwise local invariant features matching on a large image set in an unsupervised manner. Towards this end, it can be formulated as a four-layer bottom-up model, i.e., salient region detection, object segmentation, automatic object discovering and visual dictionary construction. By exploiting multi-task learning methods to model visual saliency simultaneously with the bottom-up and top-down factors, the lowest layer can effectively detect salient objects in an image. The second layer exploits a simple yet effective learning approach to generate two complementary maps from several raw saliency maps, which then can be utilized to segment the salient objects precisely from a complex scene. For the third layer, we have also implemented an unsupervised approach to automatically discover general objects from large image set by pairwise matching with local invariant features. Afterwards, visual dictionary construction can be implemented by using many state-of-the-art algorithms and tools available nowadays. | HUANG TieJun TIAN YongHong LI Jia YU HaoNan | 2011 | Science China(Information Sciences)2011，54，12： | 14 |
| 3 | Research on Formation Mechanisms of Hot Dry Rock Resources in China显示文摘As an important geothermal resource, hot dry rock(HDR) reserves have been studied in many countries. HDR resources in China have huge capacity and have become one of the most important resources for the potential replacement of fossil fuels. However, HDR resources are difficult to develop and utilise. Technologies for use with HDR, such as high–temperature drilling, reservoir characterisation, reservoir fracturing, microseismic monitoring and high–temperature power stations, originate from the field of oil and drilling. Addressing how to take advantage of these developed technologies is a key factor in the development of HDR reserves. Based on the thermal crustal structure in China, HDR resources can be divided into four types: high radioactive heat production, sedimentary basin, modern volcano and the inner–plate active tectonic belt. The prospective regions of HDR resources are located in South Tibet, West Yunnan, the southeast coast of China, Bohai Rim, Songliao Basin and Guanzhong Basin. The related essential technologies are relatively mature, and the prospect of HDR power generation is promising. Therefore, analysing the formation mechanisms of HDR resources and promoting the transformation of technological achievements, large–scale development and the utilisation of HDR resources can be achieved in China. | WANG Guiling LIN Wenjing ZHANG Wei LU Chuan MA Feng GAN Haonan | 2016 | Acta Geologica Sinica(English Edition)2016，90，4： | 14 |
| 4 | Phytophthora sojae Effector PsAvh240 Inhibits Host Aspartic Protease Secretion to Promote Infection显示文摘Plants secrete defense molecules into the extracellular space (the apoplast) to combat attacking microbes. However, the mechanisms by which successful pathogens subvert plant apoplastic immunity remain poorly understood. In this study, we show that PsAvh240, a membrane-localized effector of the soybean pathogen Phytophthora sojae, promotes P. sojae infection in soybean hairy roots. We found that PsAvh240 interacts with the soybean-resistant aspartic protease GmAP1 in planta and suppresses the secretion of GmAP1 into the apoplast. By solving its crystal structure we revealed that PsAvh240 contain six a helices and two WY motifs. The first two a helices of PsAvh240 are responsible for its plasma membrane-localization and are required for PsAvh240's interaction with GmAP1. The second WY motifs of two PsAvh240 molecules form a handshake arrangement resulting in a handshake-like dimer. This dimerization is required for the effector's repression of GmAP1 secretion. Taken together, these data reveal that PsAvh240 localizes at the plasma membrane to interfere with GmAP1 secretion, which represents an effective mechanism by which effector proteins suppress plant apoplastic immunity. | Baodian Guo Haonan Wang Bo Yang Wenjing Jiang Maofeng Jing Haiyang Li Yeqiang Xia Yuanpeng Xu Qinli Hu Fangfang Wang Feng Yu Yan Wang Wenwu Ye Suomeng Dong Weiman Xing Yuanchao Wang | 2019 | Molecular Plant2019，12，4： | 12 |
| 5 | A state-of-the-art review on passivation and biofouling of Ti and its alloys in marine environments显示文摘High strength-to-weight ratio, commendable biocompatibility and excellent corrosion resistance make Ti alloys widely applicable in aerospace, medical and marine industries. However, these alloys suffer from serious biofouling, and may become vulnerable to corrosion attack under some extreme marine conditions. The passivating and biofouling performance of Ti alloys can be attributed to their compact,stable and protective films. This paper comprehensively reviews the passivating and biofouling behavior,as well as their mechanisms, for typical Ti alloys in various marine environments. This review aims to help extend applications of Ti alloys in extremely harsh marine conditions. | Shaokun Yan Guang-Ling Song Zhengxian Li Haonan Wang Dajiang Zheng Fuyong Cao Miroslava Horynova Matthew S.Dargusch Lian Z-hou | 2018 | Journal of Materials Science & Technology2018，34，3： | 11 |
| 6 | Endothelial CDS2 deficiency causes VEGFA-mediated vascular regression and tumor inhibition显示文摘The response of endothelial cells to signaling stimulation is critical for vascular morphogenesis,homeostasis and function.Vascular endothelial growth factor-a(VEGFA)has been commonly recognized as a pro-angiogenic factor in vertebrate developmental,physiological and pathological conditions for decades.Here we report a novel finding that genetic ablation of CDP-diacylglycerol synthetase-2(CDS2),a metabolic enzyme that controls phosphoinositide recycling,switches the output of VEGFA signaling from promoting angiogenesis to unexpectedly inducing vessel regression.Live imaging analysis uncovered the presence of reverse migration of the angiogenic endothelium in cds2 mutant zebrafish upon VEGFA stimulation,and endothelium regression also occurred in postnatal retina and implanted tumor models in mice.In tumor models,CDS2 deficiency enhanced the level of tumorsecreted VEGFA,which in-turn trapped tumors into a VEGFA-induced vessel regression situation,leading to suppression of tumor growth.Mechanistically,VEGFA stimulation reduced phosphatidylinositol(4,5)-bisphosphate(PIP2)availability in the absence of CDS2-controlled-phosphoinositide metabolism,subsequently causing phosphatidylinositol(3,4,5)-triphosphate(PIP3)deficiency and F0X01 activation to trigger regression of CDS2-null endothelium.Thus,our data indicate that the effect of VEGFA on vasculature is context-dependent and can be converted from angiogenesis to vascular regression. | Wencao Zhao Le Cao Hanru Ying Wenjuan Zhang Dantong Li Xiaolong Ziiu Wenzhi Xue Shuang Wu Mengye Cao Cong Fu Haonan Qi Yimei Hao Yun-Chi Tang Jun Qin Tao PZhong Xiaoxi Lin Luyang Yu Xuri Li Lin Li Dianqing Wu Weijun Pan | 2019 | Cell Research2019，29，11： | 9 |
| 7 | Nonlinear aeroelastic analysis of the folding fin with freeplay under thermal environment显示文摘The nonlinear aeroelastic behavior of a folding fin in supersonic flow is investigated in this paper.The finite element model of the fin is established and the deployable hinges are represented by three torsion springs with the freeplay nonlinearity.The aerodynamic grid point is assumed to be at the center of each aerodynamic box for simplicity.The aerodynamic governing equation is given by using the infinite plate spline method and the modified linear piston theory.An improved fixed-interface modal synthesis method,which can reduce the rigid connections at the interface,is developed to save the problem size and computation time.The uniform temperature field is applied to create the thermal environment.For the linear flutter analyses,the flutter speed increases first and then decreases with the rise of the hinge stiffness due to the change of the flutter coupling mechanism.For the nonlinear analyses,a larger freeplay angle results in a higher vibration divergent speed.Two different types of limit cycle oscillations and a multiperiodic motion are observed in the wide range of airspeed under the linear flutter boundary.The linear flutter speed shows a slight descend in the thermal environment,but the effect of the temperature on the vibration divergent speed is different under different hinge stiffnesses when there exists freeplay. | Haonan HE Hong TANG Kaiping YU Jinze LI Ning YANG Xiaolei ZHANG | 2020 | Chinese Journal of Aeronautics2020，33，9： | 8 |
| 8 | Exosome-based small RNA delivery:Progress and prospects显示文摘RNA interfering(RNAi), mediated by small interfering RNAs and microRNAs, is currently one of the most promising tools of gene therapy. Small RNAs are capable of inducing specific post-transcriptional gene silencing, providing a potentially effective platform for the treatment of a wide array of diseases. However, similar to other nucleic acid-based drugs,the major hurdle of RNAi therapy is lack of efficient and non-immunogenic delivery vehicles. Currently, viruses, synthetic polymers, and lipid-based carriers are among the most widely studied vehicles for small RNA delivery. However, many drawbacks are reported to be associated with these delivery vehicles. There is a pressing need to replace them with more efficient and better-tolerated approaches. Exosomes secreted from the endocytic compartment of live cells, are a subtype of endogenous extracellular vesicles that transfer genetic and biochemical information among different cells, thus playing an important role in cellcell communication. Recently, accumulating attention has been focused on harnessing exosomes as nanaocarriers for small RNAs delivery. Due to their natural role in shuttling endogenous nucleic acid in our body, exosomes may exhibit higher delivery efficiency, lower immunogenicity, and better compatibility than existing foreign RNA carriers. Importantly,exosomes own intrinsic homing capacity that can guide small RNAs across natural membranous barriers. Moreover, such a capacity can be further improved by adding appropriate targeting moieties. In this manuscript, we briefly review the progress and challenges of RNAi therapy, and discuss the potential of exosomes' applications in small RNA delivery with focus on the most recent advances in exosome-based small RNA delivery for disease therapy. | Mei Lu Haonan Xing Zhe Xun Tianzhi Yang Pingtian Ding Cuifang Cai Dongkai Wang Xiaoyun Zhao | 2018 | Asian Journal of Pharmaceutical Sciences2018，13，1： | 8 |
| 9 | Characterization and properties of a Sr2Si5N8:Eu^2+-based light-conversion agricultural film显示文摘In this paper,the fracture surfaces of a light-conversion film were observed using a scanning electron microscope(SEM),and then,the fluorescence spectra and mechanical properties of the film were tested.The SEM results show that the average diameter of the light conversion agent is 500 nm.The results of the mechanical properties tests show that the tensile strengths of light-conversion film increase from9.86 to 12.16 MPa and that the strain at breakage increases from 2.37%to 2.75%.In addition,the application effects of the light-co nversion film were studied.The results indicate that plant height,length of the maximum leaf,width of the maximum leaf and breadth of the plants increase by 24.43%,15.30%,15.60%and 19.07%,respectively.The quality of Chinese flowering cabbages treated with the lightconversion film is superior,including a 9.09%increase in the soluble protein content,a 21.27%increase in the polyphenol content,and a 19.15%increase in the soluble sugar content.Based on these results,light-conversion films can be applied in agricultural production. | Weibin Wu Zhenbang Zhang Riyue Dong Gening Xie Jianxian Zhou Kejue Wu Haonan Zhang Qianpei Cai Bingfu Lei | 2020 | Journal of Rare Earths2020，38，5： | 7 |
| 10 | Modified Multi-Key Fully Homomorphic Encryption Based on NTRU Cryptosystem without Key-Switching显示文摘The Multi-Key Fully Homomorphic Encryption (MKFHE) based on the NTRU cryptosystem is an important alternative to the post-quantum cryptography due to its simple scheme form,high efficiency,and fewer ciphertexts and keys.In 2012,Lopez-Alt et al.proposed the first NTRU-type MKFHE scheme,the LTV12 scheme,using the key-switching and modulus-reduction techniques,whose security relies on two assumptions:the Ring Learning With Error (RLWE) assumption and the Decisional Small Polynomial Ratio (DSPR) assumption.However,the LTV12and subsequent NTRU-type schemes are restricted to the family of power-of-2 cyclotomic rings,which may affect the security in the case of subfield attacks.Moreover,the key-switching technique of the LTV12 scheme requires a circular application of evaluation keys,which causes rapid growth of the error and thus affects the circuit depth.In this paper,an NTRU-type MKFHE scheme over prime cyclotomic rings without key-switching is proposed,which has the potential to resist the subfield attack and decrease the error exponentially during the homomorphic evaluating process.First,based on the RLWE and DSPR assumptions over the prime cyclotomic rings,a detailed analysis of the factors affecting the error during the homomorphic evaluations in the LTV12 scheme is provided.Next,a Low Bit Discarded&Dimension Expansion of Ciphertexts (LBD&DEC) technique is proposed,and the inherent homomorphic multiplication decryption structure of the NTRU is proposed,which can eliminate the key-switching operation in the LTV12 scheme.Finally,a leveled NTRU-type MKFHE scheme is developed using the LBD&DEC and modulus-reduction techniques.The analysis shows that the proposed scheme compared to the LTV12 scheme can decrease the magnitude of the error exponentially and minimize the dimension of ciphertexts. | Xiaoliang Che Tanping Zhou Ningbo Li Haonan Zhou Zhenhua Chen Xiaoyuan Yang | 2020 | Tsinghua Science and Technology2020，25，5： | 6 |
| 11 | The Extremely Hot and Dry Climatic Events and Potash Enrichment in Salt Lakes of the Jiangling Depression, Jianghan Basin显示文摘Objective A total of 820 million tons of potash reserves are predicted to exist in the Palaeocene–Eocene of the Jianghan Basin.However,the basin history is still unclear concerning the potash enriching conditions and mechanism.The Well SKD1 is the first exploration well drilled in the Paleogene of Jianghan Basin with continuous coring,which was implemented in the | WANG Chunlian LIU Chenglin YU Xiaocan LI Haonan LIU Jinlei | 2016 | Acta Geologica Sinica(English Edition)2016，90，2： | 6 |
| 12 | Integrating deep learning to achieve phase compensation for free-space orbital-angular-momentum-encoded quantum key distribution under atmospheric turbulence显示文摘A high-dimensional quantum key distribution(QKD), which adopts degrees of freedom of the orbital angular momentum(OAM) states, is beneficial to realize secure and high-speed QKD. However, the helical phase of a vortex beam that carries OAM is sensitive to the atmospheric turbulence and easily distorted. In this paper, an adaptive compensation method using deep learning technology is developed to improve the performance of OAM-encoded QKD schemes. A convolutional neural network model is first trained to learn the mapping relationship of intensity profiles of inputs and the turbulent phase, and such mapping is used as feedback to control a spatial light modulator to generate a phase screen to correct the distorted vortex beam. Then an OAM-encoded QKD scheme with the capability of real-time phase correction is designed, in which the compensation module only needs to extract the intensity distributions of the Gaussian probe beam and thus ensures that the information encoded on OAM states would not be eavesdropped. The results show that our method can efficiently improve the mode purity of the encoded OAM states and extend the secure distance for the involved QKD protocols in the free-space channel, which is not limited to any specific QKD protocol. | XINGYU WANG TIANYI WU CHEN DONG HAONAN ZHU ZHUODAN ZHU SHANGHONG ZHAO | 2021 | Photonics Research2021，9，2： | 5 |
| 13 | Heat Aggregation Mechanisms of Hot Dry Rocks Resources in the Gonghe Basin, Northeastern Tibetan Plateau显示文摘Hot dry rock(HDR) is an important geothermal resource and clean energy source that may play an increasingly important role in future energy management. High-temperature HDR resources were recently detected in deep regions of the Gonghe Basin on the northeastern edge of the Tibetan Plateau, which led to a significant breakthrough in HDR resource exploration in China. This research analyzes the deep temperature distribution, radiogenic heat production, heat flow, and crustal thermal structure in the Qiaboqia Valley, Guide Plain, and Zhacanggou area of the Gonghe Basin based on geothermal exploration borehole logging data, rock thermophysical properties, and regional geophysical exploration data. The results are applied to discuss the heat accumulation mechanism of the HDR resources in the Gonghe Basin. The findings suggest that a low-velocity layer in the thickened crust of the Tibetan Plateau provides the most important source of constant intracrustal heat for the formation of HDR resources in the Gonghe Basin, whereas crustal thickening redistributes the concentrated layer of radioactive elements, which compensates for the relatively low heat production of the basal granite and serves as an important supplement to the heat of the HDR resources. The negative effect is that the downward curvature of the lithospheric upper mantle caused by crustal thickening leads to a small mantle heat flow component. As a result, the heat flows in the Qiaboqia Valley and Guide Plain of the Gonghe Basin are 106.2 and 77.6 m W/m2, respectively, in which the crust-mantle heat flow ratio of the former is 3.12:1, indicating a notably anomalous intracrustal thermal structure. In contrast, the crust-mantle heat flow ratio in the Guide Plain is 1.84:1, which reflects a typical hot crust-cold mantle thermal structure. The Guide Plain and Zhacanggou area show the same increasing temperature trend with depth, which reflects that their geothermal backgrounds and deep high-temperature environments are similar. These results provide important insight on the heat source mechanism of HDR resource formation in the Tibetan Plateau and useful guidance for future HDR resource exploration projects and target sites selection in similar areas. | LIN Wenjing WANG Guiling ZHANG Shengsheng ZHAO Zhen XING Linxiao GAN Haonan TAN Xianfeng | 2021 | Acta Geologica Sinica(English Edition)2021，95，6： | 5 |
| 14 | Advance in bioequivalence assessment of topica dermatological products显示文摘Bioequivalence(BE) assessment of topical dermatological products is a long standing challenge. The development of generic topical dermatological products has often been hampered due to the limited number of acceptable approaches, which are capable of determining the BE between generic products and reference list products. The aim of this manuscript is to review different BE assessment approaches of topical dermatological products. Besides, the advances in BE evaluation and biowaivers are also provided. Currently, except in the case of dermatological corticosteroids, the golden rule to establish the BE of most topical dermatological products still heavily relied on clinical endpoint trials,which are often unreliable, time-consuming and expensive. The regulatory agencies and pharmaceutical industries are forging ahead to the development of new surrogate BE assessment approaches for other topical dermatological products. These promising approaches include dermatopharmacokinetic study(DPK), dermal microdialysis(DMD), in vitro studies, pharmacokinetic study(PK), near-infrared spectrometry(NIR), and confocal Raman spectroscopy(CRS). In addition, the expansion of biowaivers for topical dermatological products has been explored by pharmaceutical scientists. In conclusion, to accelerate the development and approval of topical dermatological products, emphasis should be put on the following areas, i.e., optimizing and standardizing the existing BE assessment methods, exploring novel alternatives of BE assessment approaches, and expanding biowaivers for topical dermatological products. | Mei Lu Haonan Xing Xiao Chen Lei Xian Jingzheng Jiang Tianzhi Yang Pingtian Ding | 2016 | Asian Journal of Pharmaceutical Sciences2016，11，6： | 4 |
| 15 | Variability of microphysical characteristics in the “21·7” Henan extremely heavy rainfall event显示文摘In this study, significant rainfall microphysical variability is revealed for the extremely heavy rainfall event over Henan Province in July 2021(the “21·7” Henan EHR event) using a dense network of disdrometers and two polarimetric radars.The broad distributions of specific drop size distribution(DSD) parameters are identified in heavy rainfall from the disdrometer observations, indicating obvious microphysical variability on the surface. A K-means clustering algorithm is adopted to objectively classify the disdrometer datasets into separate groups, and distinct DSD characteristics are found among these heavy rainfall groups. Combined with the supporting microphysical structures obtained through radar observations, comprehensive microphysical features of the DSD groups are derived. An extreme rainfall group is dominantly formed in the deep convection over the plain regions, where the high number of concentrations and large mean sizes of surface raindrops are underpinned by both active ice-phase processes and efficient warm-rain collision-coalescence processes in the vertical direction. Convection located near orographic regions is characterized by restricted ice-phase processes and high coalescence efficiency of liquid hydrometeors, causing the dominant DSD group to comprise negligible large raindrops. Multiple DSD groups can coexist within certain precipitation episodes at the disdrometer stations, indicating the potential microphysical variability during the passage of convective system on the plain regions. | Gang CHEN Kun ZHAO Yinghui LU Yuanyuan ZHENG Ming XUE Zhe-Min TAN Xin XU Hao HUANG Haonan CHEN Fen XU Ji YANG Shushi ZHANG Xueqi FAN | 2022 | Science China Earth Sciences2022，65，10： | 4 |
| 16 | Impacts of land use and salinization on soil inorganic and organic carbon in the middle-lower Yellow River Delta显示文摘Soil inorganic carbon(SIC)is an important reservoir of carbon(C)in arid,semi-arid,and semi-humid regions.However,knowledge is incomplete on the dynamics of SIC and its relationship with soil organic C(SOC)under different land use types in the semi-humid region,particularly in coastal zones impacted by soil salinization.We collected 170 soil samples from 34 profiles across various land use types(maize-wheat,cotton,paddy,and reed)in the middle-lower Yellow River Delta(YRD),China.We measured soil pH,electrical conductivity(EC),water-soluble salts,and SOC and SIC contents.Our results showed significant differences in both SOC and SIC among land use types.The dry cropland(maize-wheat and cotton)soils had significantly higher SOC and SIC densities(4.71 and 15.46 kg C m^(-2),respectively)than the paddy soils(3.28 and 14.09 kg C m^(-2),respectively)in the 0–100 cm layer.Compared with paddy soils,reed soils contained significantly higher SOC(4.68 kg C m^(-2))and similar SIC(15.02 kg C m^(-2))densities.There was a significant positive correlation between SOC and SIC densities over a 0–100 cm soil depth in dry cropland soils,but a negative relationship in the paddy soils.On average,SOC and SIC densities under maize-wheat cropping were 15%and 4%lower,respectively,in the salt-affected soils in the middle-lower YRD than the upper YRD.This study indicated that land use types had great influences on both SOC and SIC and their relationship,and salinization had adverse effect on soil C storage in the YRD. | Yang GUO Xiujun WANG Xianglan LI Minggang XU Yuan LI Haonan ZHENG Yongming LUO Pete SMITH | 2021 | Pedosphere2021，31，6： | 4 |
| 17 | Insights into Convective-scale Predictability in East China: Error Growth Dynamics and Associated Impact on Precipitation of Warm-Season Convective Events显示文摘This study investigated the regime-dependent predictability using convective-scale ensemble forecasts initialized with different initial condition perturbations in the Yangtze and Huai River basin(YHRB)of East China.The scale-dependent error growth(ensemble variability)and associated impact on precipitation forecasts(precipitation uncertainties)were quantitatively explored for 13 warm-season convective events that were categorized in terms of strong forcing and weak forcing.The forecast error growth in the strong-forcing regime shows a stepwise increase with increasing spatial scale,while the error growth shows a larger temporal variability with an afternoon peak appearing at smaller scales under weak forcing.This leads to the dissimilarity of precipitation uncertainty and shows a strong correlation between error growth and precipitation across spatial scales.The lateral boundary condition errors exert a quasi-linear increase on error growth with time at the larger scale,suggesting that the large-scale flow could govern the magnitude of error growth and associated precipitation uncertainties,especially for the strong-forcing regime.Further comparisons between scale-based initial error sensitivity experiments show evident scale interaction including upscale transfer of small-scale errors and downscale cascade of larger-scale errors.Specifically,small-scale errors are found to be more sensitive in the weak-forcing regime than those under strong forcing.Meanwhile,larger-scale initial errors are responsible for the error growth after 4 h and produce the precipitation uncertainties at the meso-β-scale.Consequently,these results can be used to explain underdispersion issues in convective-scale ensemble forecasts and provide feedback for ensemble design over the YHRB. | Xiaoran ZHUANG Jinzhong MIN Liu ZHANG Shizhang WANG Naigeng WU Haonan ZHU | 2020 | Advances in Atmospheric Sciences2020，37，8： | 3 |
| 18 | Fracture behavior and self-sharpening mechanisms of polycrystalline cubic boron nitride in grinding based on cohesive element method显示文摘Unlike monocrystalline cubic boron nitride(CBN), polycrystalline CBN(PCBN) shows not only higher fracture resistance induced by tool-workpiece interaction but also better selfsharpening capability;therefore, efforts have been devoted to the study of PCBN applications in manufacturing engineering. Most of the studies, however, remain qualitative due to difficulties in experimental observations and theoretical modeling and provide limited in-depth understanding of the self-sharpening behavior/mechanism. To fill this research gap, the present study investigates the self-sharpening process of PCBN abrasives in grinding and analyzes the macro-scale fracture behavior and highly localized micro-scale crack propagation in detail. The widely employed finite element(FE) method, together with the classic Voronoi diagram and cohesive element technique,is used considering the pronounced success of FE applications in polycrystalline material modeling.Grinding trials with careful observation of the PCBN abrasive morphologies are performed to validate the proposed method. The self-sharpening details, including fracture morphology, grinding force, strain energy, and damage dissipation energy, are studied. The effects of maximum grain cut depths(MGCDs) and grinding speeds on the PCBN fracture behavior are discussed, and their optimum ranges for preferable PCBN self-sharpening performance are suggested. | Xin HUANG Haonan LI Zhiwen RAO Wenfeng DING | 2019 | Chinese Journal of Aeronautics2019，32，12： | 3 |
| 19 | Inverted decoupling and LMI-based controller design for a turboprop engine with actuator dynamics显示文摘The main objective of the turboprop engine control system is to ensure propeller absorbed power at a constant propeller speed by controlling fuel flow and blade angle. Since each input variable affects the selected output variables, there exist strong interactions between different control loops of a Two-Spool Turbo Prop Engine(TSTPE). Inverted decoupling is used to decouple the interactions and decompose the TSTPE into two independent single-input single-output systems. The multi-variable PI controller and two single-variable PI controllers are designed for the TSTPE with actuator dynamics based on Linear Matrix Inequality(LMI), respectively, which is derived from static output feedback and pole placement condition. The step responses show that due to the difference in the response times of the selected output variables, it is difficult to design an appropriate multi-variable PI controller. The designed single-variable PI controllers are tested on the TSTPE integrated model to illustrate the effectiveness of the proposed method, that is,the interactions are first decoupled and then the controllers are designed, and the resulting simulated responses show that compared with the controller designed without actuator dynamics, the gas-generator shaft speed and power turbine shaft speed can better track their respective commands under the action of the controller designed with actuator dynamics. | Huairong CHEN Xi WANG Haonan WANG Nannan GU Meiyin ZHU Shubo YANG | 2020 | Chinese Journal of Aeronautics2020，33，6： | 3 |
| 20 | Effects of Solvent Molecules on the Interlayer Spacing of Graphene Oxide显示文摘Graphene oxide(GO) contains numerous functional groups that facilitate the intercalation of polar solvents. The properties and applications of GO are closely related to its interlayer spacing. We report on the changes in the interlayer spacing of GO after the adsorption of water molecules and the polar organic solvents C_2H_6O_2(EG), C_3H_7NO(DMF), C_5H_9NO(NMP). Experiments were conducted to investigate the variations in the functional groups and structure of GO after solvent adsorption, and they play a vital role in modeling and verifying the results of molecular dynamics simulation. The most stable GO structures are obtained through molecular dynamics simulation. The expansion of the interlayer spacing of GO after the adsorption of monolayer solvent molecules corresponds to the minimum three-dimensional size of the solvent molecules. The spatial arrangement of solvent molecules also contributes to the changes in interlayer spacing. Most adsorbed molecules are oriented parallel to the carbon plane of GO. However, as additional molecules are adsorbed into the interlaminations of GO, the adsorbed molecules are oriented perpendicular to the carbon plane of GO, and a large space forms between two GO interlayers. In addition, the role of large molecules in increasing interlayer spacing becomes more crucial than that of water molecules in the adsorption of binary solvent systems by GO. | Liyan Liu Ruifeng Zhang Ying Liu Haonan Zhu Wei Tan Guorui Zhu Yang Wang | 2018 | Transactions of Tianjin University2018，24，6： | 3 |
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