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| 1 | Third generation of vortex identification methods:Omega and Liutex/Rortex based systems显示文摘A vortex is intuitively recognized as the rotational/swirling motion of fluids,but a rigorous and universally-accepted definition is still not available.Vorticity tube/filament has been regarded equivalent to a vortex since Helmholtz proposed the concepts of vorticity tube/filament in 1858 and the vorticity-based methods can be categorized as the first generation of vortex identification methods.During the last three decades,a lot of vortex identification methods,including 0,A,and Aci criteria,have been proposed to overcome the problems associated with the vorticity-based methods.Most of these criteria are based on the Cauchy-Stokes decomposition and/or eigenvalues of the velocity gradient tensor and can be considered as the second generation of vortex identification methods.Starting from 2014,the Vortex and Turbulence Research Team at the University of Texas at Arlington(the UTA team)focus on the development of a new generation of vortex identification methods.The first fruit of this effort,a new Omega(/2)vortex identification method,which defined a vortex as a connected region where the vorticity overtakes the deformation,was published in 2016.In 2017 and 2018,a Liutex(previously called Rortex)vector was proposed to provide a mathematical definition of the local rigid rotation part of the fluid motion,including both the local rotational axis and the rotational strength.Liutex/Rortex is a new physical quantity with scalar,vector and tensor forms exactly representing the local rigid rotation of fluids.Meanwhile,a decomposition of the vorticity to a rotational part namely Liutex/Rortex and an anti-symmetric shear part(RS decomposition)was introduced in 2018,and a universal decomposition of the velocity gradient tensor to a rotation part(7?)and a non-rotation part(NR、was also given in 2018 as a counterpart of the traditional Cauchy-Stokes decomposition.Later in early 2019,a Liutex/Rortex based Omega method called Omega-Liutex,which combines the respective advantages of both Liutex/Rortex and Omega methods,was developed.And a latest objective Omega method,which is still under development,is also briefly introduced.These advances are classified as the third generation of vortex identification methods in the current paper.To elaborate the advantages of the third-generation methods,six core issues for vortex definition and identification have been raised,including:(1)the absolute strength,(2)the relative strength,(3)the rotational axis,(4)the vortex core center location,(5)the vortex core size,(6)the vortex boundary.The new third generation of vortex identification methods can provide reasonable answers to these questions,while other vortex identification methods fail to answer all questions except for the approximation of vortex boundaries.The purpose of the current paper is to summarize the main ideas and methods of the third generation of vortex identification methods rather than to conduct a comprehensive review on the historical development of vortex identification methods. | Chaoqun Liu Yi-sheng Gao Xiang-rui Dong Yi-qian Wang Jian-ming Liu Yu-ning Zhang Xiao-shu Cai Nan Gui | 2019 | Journal of Hydrodynamics2019，31，2： | 82 |
| 2 | Hi-TOM: a platform for high-throughput tracking of mutations induced by CRISPR/Cas systems显示文摘The CRISPR/Cas system has been extensively applied to make precise genetic modifications in various organisms. Despite its importance and widespread use, large-scale mutation screening remains time-consuming, labour-intensive and costly. Here, we developed Hi-TOM(available at http://gffzz103f3ce5d9b14419huc5wuw0ffxpn69wn.ffgz.tsg.suse.edu.cn/hi-tom/), an online tool to track the mutations with precise percentage for multiple samples and multiple target sites. We also described a corresponding next-generation sequencing(NGS) library construction strategy by fixing the bridge sequences and barcoding primers. Analysis of the samples from rice, hexaploid wheat and human cells reveals that the Hi-TOM tool has high reliability and sensitivity in tracking various mutations, especially complex chimeric mutations frequently induced by genome editing. Hi-TOM does not require special design of barcode primers,cumbersome parameter configuration or additional data analysis. Thus, the streamlined NGS library construction and comprehensive result output make Hi-TOM particularly suitable for high-throughput identification of all types of mutations induced by CRISPR/Cas systems. | Qing Liu Chun Wang Xiaozhen Jiao Huawei Zhang Lili Song Yanxin Li Caixia Gao Kejian Wang | 2019 | Science China(Life Sciences)2019，62，1： | 37 |
| 3 | Assessment of candidate plant DNA barcodes using the Rutaceae family显示文摘DNA barcoding is a rapidly developing frontier technology that is gaining worldwide attention.Here,seven regions (psbA-trnH,matK,ycf5,rpoC1,rbcL,ITS2,and ITS) with potential for use as DNA barcodes were tested for their ability to identify 300 samples of 192 species from 72 genera of the family Rutaceae.To evaluate each barcode’s utility for species authentication,PCR amplification efficiency,genetic divergence,and barcoding gaps were assessed.We found that the ITS2 region exhibited the highest inter-specific divergence,and that this was significantly higher than the intra-specific variation in the 'DNA barcoding gap' assessment and Wilcoxon two-sample tests.The ITS2 locus had the highest identification efficiency among all tested regions.In a previous study,we found that ITS2 was able to discriminate a wide range of plant taxa,and here we confirmed that ITS2 was also able to discriminate a number of closely related species.Therefore,we propose that ITS2 is a promising candidate barcode for plant species identification. | LUO Kun1,2,CHEN ShiLin1,CHEN KeLi2,SONG JingYuan1,YAO Hui1,MA XinYe1,ZHU YingJie3,PANG XiaoHui1,YU Hua1,LI XiWen1,4 & LIU Zhen2 1Institute of Medicinal Plant Development,Peking Union Medical College,Chinese Academy of Medical Sciences,Beijing 100193,China 2College of Pharmacy,Hubei University of Chinese Medicine,Wuhan 430061,China 3School of Bioscience and Engineering,Southwest Jiaotong University,Chengdu 610031,China 4Department of Chemistry,Tsinghua University,Beijing 100084,China | 2010 | Science China(Life Sciences)2010，53，6： | 32 |
| 4 | Rapid Identification of Rice Samples Using an Electronic Nose显示文摘Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety ofrice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors.TheCyranose-320 was able to differentiate between varieties of rice.The chemical composition of the rice odors for differentiatingrice samples needs to be investigated.The optimum parameter settings should be considered during the Cyranose-320 trainingprocess especially for multiple samples,which are helpful for obtaining an accurate training model to improve identificationcapability.Further,it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy.A re-duced number of sensors could potentially shorten the data processing time,and could be used to establish an application pro-cedure and reduce the cost for a specific electronic nose.Further research is needed for developing analytical procedures thatadapt the Cyranose-320 as a tool for testing rice quality. | John Westbrook W.C.Hoffmann R.E.Lacey | 2009 | Journal of Bionic Engineering2009，6，3： | 28 |
| 5 | Improved Sobel algorithm for defect detection of rail surfaces with enhanced efficiency and accuracy显示文摘A more effective and accurate improved Sobel algorithm has been developed to detect surface defects on heavy rails. The proposed method can make up for the mere sensitivity to X and Y directions of the Sobel algorithm by adding six templates at different directions. Meanwhile, an experimental platform for detecting surface defects consisting of the bed-jig, image-forming system with CCD cameras and light sources, parallel computer system and cable system has been constructed. The detection results of the backfin defects show that the improved Sobel algorithm can achieve an accurate and efficient positioning with decreasing interference noises to the defect edge. It can also extract more precise features and characteristic parameters of the backfin defect. Furthermore, the BP neural network adopted for defects classification with the inputting characteristic parameters of improved Sobel algorithm can obtain the optimal training precision of 0.0095827 with 106 iterative steps and time of 3 s less than Sobel algorithm with 146 steps and 5 s. Finally, an enhanced identification rate of 10% for the defects is also confirmed after the Sobel algorithm is improved. | 石甜 孔建益 王兴东 刘钊 郑国 | 2016 | Journal of Central South University2016，23，11： | 23 |
| 6 | Liutex (vortex) core definition and automatic identification for turbulence vortex structures显示文摘As a milestone research in vortex identification(VI),the physical quantity of Liutex,including its forms of scalar,vector and tensor,was systematically explored and rigorously obtained as the third-generation(3G)of the vortex definition and identification methods distinguished from the first generation(1G)by vorticity and the second generation(2G)by the vortex identification(VI)criteria solely dependent on the velocity gradient tensor eigenvalues.Based on these findings,the vortex-core lines were abstracted from the well-defined Liutex,and for the first time,were automatically generated and massively visualized using computer.The distinctive characteristics of these vortex cores with the intriguing threshold-independency make them be the uniquely appropriate entity to represent and to depict the vortex structures in turbulence.The letter made use of the DNS data for the natural transition in a zero-pressure gradient flat-plate(Type-A turbulent boundary layer(TBL))and the fully-developed turbulence in a square annular duct(Type-B TBL)to demonstrate the vortex structure represented by the vortex-core lines.The 3G VI approach based on the vortex-core lines is capable of profoundly uncovering the vortex natures.Moreover,the capability of automatically identifying the vortex cores and massively visualizing the large number of vortex-core behaviors in a transient way will enable the fluid-mechanics and other related-science communities to step into a new era to explore the intrinsic natures of the centennial puzzle of turbulence and other vortex-related phenomena in future. | Hongyi Xu Xiao-shu Cai Chaoqun Liu | 2019 | Journal of Hydrodynamics2019，31，5： | 21 |
| 7 | Comprehensive geochemical identification of highly evolved marine carbonate rocks as hydrocarbon-source rocks as exemplified by the Ordos Basin显示文摘This study reversed the developing environments of hydrocarbon-source rocks in the Ordos Basin and evaluated carbonate rocks as hydrocarbon-source rocks and their distributions on account of the fact that China’s marine carbonate rocks as hydrocarbon-source rocks are character- ized by intensive thermal evolution and relatively low abundance of organic matter, by taking the Lower Paleozoic of the Ordos Basin for example and in light of the calculated enrichment coefficients of trace elements, the REE distribution patterns, the mathematical statistics analysis of elements and carbon isotopes and their three-dimensional diagrammatization in combination with the necessary organic parameters. As for the Ordos Basin, TOC=0.2% is an important boundary value. Studies have shown that in the strata where TOC is greater than 0.2%, Ba is highly enriched with positive δ 13Ccarb shifts and δ 13Corg less than ?28‰, reflecting a thigh paleo-productivity, high burial amounts of organic matter, relatively good hydrocarbon-generating potentiality and intensive REE fractionation. All these indicated that the settlement rates are low and the geological conditions are good for the preservation of organic matter, hence favoring the development of hydrocarbon-source rocks. The Klimory and Wulalik formations show certain regularities in those aspects and, therefore, they can be regarded as the potential effective hydrocarbon-source rocks. In the strata where total TOC is less than 0.2%, the contents of Ba are low, δ 13Ccarb values are mostly negative, and δ 13Corg values range from ?24‰― ?28‰, demonstrating low burial amounts of organic matter, poor potentialities of hydrocarbon gen- eration, weak REE fractionation and rapid settlement rates. These facts showed that most of the hy- drocarbon-source rocks were formed in shallow-water, high-energy oxidizing environments, thus un- favoring the development of hydrocarbon-source rocks. It is feasible to make use of the geochemical method to comprehensively assess the highly evolved marine carbonates rocks as potential hydro- carbon-source rocks and their distributions. | Tenger | 2006 | Science China Earth Sciences2006，49，4： | 20 |
| 8 | A Liutex based definition and identification of vortex core center lines显示文摘Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex boundary (Liu C. 2019). However, most of the currently popular vortex identification methods, including the Q criterion, the criterion and the Acj criterion etc., are Eulerian local region-type vortex identification criteria and can only approximately identify the vortex boundary by somewhat arbitrary threshold. On the other hand, the existing Eulerian local line-type methods, which seek to extract line-type features such as vortex core line, are not entirely satisfactory since most of these methods are based on vorticity or pressure minimum that will fail in many cases. The key issue is the lack of a reasonable mathematical definition for vortex core center. To address this issue, a Liutex (previously named Rortex) based definition of vortex core center is proposed in this paper. The vortex core center, also called vortex rotation axis line here, is defined as a line where the Liutex magnitude gradient vector is aligned with the Liutex vector, which mathematically implies that the cross product of the Liutex magnitude gradient vector and the Liutex vector on the line is equal to zero. Based on this definition, a novel three-step method for extracting vortex rotation axis lines is presented. Two test cases, namely the Burgers vortex and hairpin vortices, are examined to justify the proposed method. The results demonstrate that the proposed method can successfully identify vortex rotation axis lines without any user-specified threshold, so that the proposed method is very straightforward, robust and efficient. | Yi-sheng Gao Jian-ming Liu Yi-fei Yu Chaoqun Liu | 2019 | Journal of Hydrodynamics2019，31，3： | 19 |
| 9 | Research progress of disinfection and disinfection by-products in China显示文摘Disinfection is an indispensable water treatment process for killing harmful pathogens and protecting human health. However, the disinfection has caused significant public concern due to the formation of toxic disinfection by-products(DBPs). Lots of studies on disinfection and DBPs have been performed in the world since 1974. Although related studies in China started in1980 s, a great progress has been achieved during the last three decades. Therefore, this review summarized the main achievements on disinfection and DPBs studies in China, which included:(1) the occurrence of DBPs in water of China,(2) the identification and detection methods of DBPs,(3) the formation mechanisms of DBPs during disinfection process,(4) the toxicological effects and epidemiological surveys of DBPs,(5) the control and management countermeasures of DBPs in water disinfection, and(6) the challenges and chances of DBPs studies in future. It is expected that this review would provide useful information and reference for optimizing disinfection process, reducing DBPs formation and protecting human health. | Xuefeng Sun Miao Chen Dongbin Wei Yuguo Du | 2019 | Journal of Environmental Sciences2019，31，7： | 18 |
| 10 | Identification of fruit and branch in natural scenes for citrus harvesting robot using machine vision and support vector machine显示文摘With the decrease of agricultural labor and the increase of production cost,the researches on citrus harvesting robot(CHR)have received more and more attention in recent years.For the success of robotic harvesting and the safety of robot,the identification of mature citrus fruit and obstacle is the priority of robotic harvesting.In this work,a machine vision system,which consisted of a color CCD camera and a computer,was developed to achieve these tasks.Images of citrus trees were captured under sunny and cloudy conditions.Due to varying degrees of lightness and position randomness of fruits and branches,red,green,and blue values of objects in these images are changed dramatically.The traditional threshold segmentation is not efficient to solve these problems.Multi-class support vector machine(SVM),which succeeds by morphological operation,was used to simultaneously segment the fruits and branches in this study.The recognition rate of citrus fruit was 92.4%,and the branch of which diameter was more than 5 pixels,could be recognized.The results showed that the algorithm could be used to detect the fruits and branches for CHR. | Lü Qiang Cai Jianrong Liu Bin Deng Lie Zhang Yajing | 2014 | International Journal of Agricultural and Biological Engineering2014，7，2： | 17 |
| 11 | 传播学本土化的选择、现状及未来发展显示文摘本文对80年代初以来,国内传播学研究本土化的发展及趋势做了理论上的初步梳理,并对本土化的意义及目标,本土化所追求的学术个性等问题进行了探讨。作者坚持应该从学术对话的层面上,倡导本土化的实践;在辨识本土化的过程中,加强对西方传播学理论的深入研究,以养育我们化西方传播学理论的能力,从而建构一个带有自身学术个性的理论世界。 | 潇湘 | 1995 | 新闻与传播研究1995，2，4： | 16 |
| 12 | Identification of Lagrangian coherent structures in the turbulent boundary layer显示文摘Using Finite-Time Lyapunov Exponents (FTLE) method, Lagrangian coherent structures (LCSs) in a fully developed flat-plate turbulent boundary layer are successfully identified from a two-dimensional (2D) velocity field obtained by time-resolved 2D PIV measurement. The typical LCSs in the turbulent boundary layer are hairpin-like structures, which are characterized as legs of quasi-streamwise vor- tices extending deep into the near wall region with an inclination angle θ to the wall, and heads of the transverse vortex tube located in the outer region. Statistical analysis on the characteristic shape of typical LCS reveals that the probability density distribution of θ accords well with t-distribution in the near wall region, but presents a bimodal distribution with two peaks in the outer region, corresponding to the hairpin head and the hairpin neck, respectively. Spatial correlation analysis of FTLE field is im- plemented to get the ensemble-averaged inclination angle θ R of typical LCS. θ R first increases and then decreases along the wall-normal direction, similar to that of the mean value of θ. Moreover, the most probable value of θ saturates at y+=100 with the maximum value of about 24°, suggesting that the most likely position where hairpins transit from the neck to the head is located around y+=100. The ensem- ble-averaged convection velocity Uc of typical LCS is finally calculated from temporal-spatial correla- tion analysis of FTLE field. It is found that the wall-normal profile of the convection velocity Uc(y) ac- cords well with the local mean velocity profile U(y) beyond the buffer layer, evidencing that the down- stream convection of hairpins determines the transportation properties of the turbulent boundary layer in the log-region and beyond. | PAN Chong WANG JinJun ZHANG Cao | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，2： | 14 |
| 13 | Antioxidant and Anti-inflammatory Capacity of Ferulic Acid Released from Wheat Bran by Solid-state Fermentation of Aspergillus niger显示文摘Objective A strain of Aspergillus niger(A. niger), capable of releasing bound phenolic acids from wheat bran, was isolated. This strain was identified by gene sequence identification. The antioxidant and anti-inflammatory capacity of ferulic acid released from wheat bran by this A. niger strain(FA-WB) were evaluated. Methods Molecular identification techniques based on PCR analysis of specific genomic sequences were conducted; antioxidant ability was examined using oxygen radical absorbance capacity(ORAC), cellular antioxidant activity(CAA) assays, and erythrocyte hemolysis assays. RAW264.7 cells were used as a model to detect anti-inflammatory activity. Results The filamentous fungal isolate was identified to be A. niger. ORAC and CAA assay showed that FA-WB had better antioxidant activity than that of the ferulic acid standard. The erythrocyte hemolysis assay results suggested that FA-WB could attenuate AAPH-induced oxidative stress through inhibition of reactive oxy gen species(ROS) generation. FA-WB could significantly restore the AAPH-induced increase in intracellular antioxidant enzyme activities to normal levels as well as inhibit the intracellular malondialdehyde formation. TNF-?, IL-6, and NO levels indicated that FA-WB can inhibit the inflammation induced by lipopolysaccharide(LPS). Conclusion Ferulic acid released from wheat bran by a new strain of A. niger had good anti-inflammatory activity and better antioxidant ability than standard ferulic acid. | YIN Zhi Na WU Wen Jia SUN Chong Zhen LIU Hui Fan CHEN Wen Bo ZHAN Qi Ping LEI Zhuo Gui XIN Xuan MA Juan Juan YAO Kun MIN Tian ZHANG Meng Meng WU Hui | 2019 | Biomedical and Environmental Sciences2019，32，1： | 14 |
| 14 | “认同”:新修辞学重要术语identification中译名辩显示文摘围绕当代修辞理论'新修辞学'中的重要术语Identification及其'同一'和'认同'两个译文,从该术语所处的理论语境、与division的吊诡关系以及来自修辞学界的理论呼应与旁证等几方面进行分析,论证identification译为'认同',能够正确体现伯克的修辞思想和新修辞内涵,有助于在汉语语境中对汉语学术受众产生预期影响,是翻译作为一种修辞实践的成功范例。 | 陈小慰 | 2017 | 当代修辞学2017，，5： | 14 |
| 15 | Progress in miRNA target prediction and identification显示文摘Recently, the identification of miRNA targets has received much attention. The strategies to determine miRNA targets include bioinformatic prediction and experimental assays. The bioinformatic prediction methods are mainly based on the confirmed rules of interaction between miRNAs and their targets, and are carried out by programs, such as miRanda, TargetScan, TargetScanS, RNAhybrid, DIANA-microT, PicTar, RNA22 and FindTar, which follow well-known principles. The experimental assays to find miRNA targets employ immunoprecipitation of AGO proteins to identify interacting mRNAs, or the analysis of mRNA or protein levels to identify genes which can be regulated by miRNAs. The improvement of current bioinformatic and experimental assays and the development of novel assays will enable greater efficiency in the identification of miRNA targets and thus facilitate miRNA research. This paper describes progress in the prediction and identification of miRNA targets. | XIA Wei, CAO GuoJun & SHAO NingSheng· Beijing Institute of Basic Medical Sciences, Beijing 100850 | 2009 | Science China(Life Sciences)2009，52，12： | 13 |
| 16 | Isolation and identification of bacteria responsible for simultaneous anaerobic ammonium and sulfate removal显示文摘Sulfate-dependent anaerobic ammonium oxidation is a novel biological reaction,in which ammonium is oxidized with sulfate as the electron acceptor under anoxic conditions.Ammonium and sulfate are cosmopolitan chemical species which are an integral part of the global nitrogen and sulfur cycles.A detailed exploration of sulfate-dependent anaerobic ammonium oxidation is quite practical.In this work,a bacterial strain named ASR has been isolated from an anaerobic ammonia and sulfate removing reactor working under steady-state.On the basis of electron microscopy,physiological tests and 16S rDNA phylogenetic sequence analysis,the strain ASR is found to be related to Bacillus benzoevorans.According to the biological carbon source utilization test,the strain ASR could use many carbon sources.Its optimum pH value and temperature were 8.5 and 30 °C,respectively.The test proves that the strain ASR is able to use sulfate to oxidize ammonia anaerobically.The maximum ammonia and sulfate removal rates were 44.4% and 40.0%,respectively.The present study provided biological evidence for the confirmation and development of sulfate-dependent anaerobic ammonium oxidation and brought new insights into the global nitrogen and sulfur cycles. | Cai, Jing Jiang, Jian Xiang Zheng, Ping | 2010 | Science China Chemistry2010，53，3： | 12 |
| 17 | Impact of on-range choice feeding with black soldier fly larvae(Hermetia illucens)on flock performance,egg quality,and range use of free-range laying hens显示文摘Semi-intensive free-range farm systems are common in Australia, and these systems frequently practise on-range feeding. The objective of this study was to investigate the benefit of on-range choice feeding on flock performance, egg quality, and range use of free-range laying hens using black soldier fly larvae(Hermetia illucens, BSF). A total of 160 mature ISA brown laying hens, previously determined to range daily, were allocated to a control group(control) or a treatment group(BSF) with various replicates depending on the parameter investigated. All hens were fed ad libitum indoors with a wheat-soy based diet formulated according to breed requirements. Black soldier fly hens were offered dried BSF larvae ad libitum on the range. Body weight, feed intake, BSF intake, egg production, feed conversion ratio, internal and external egg quality parameters, and individual range use using radio-frequency identification(RFID)technology was evaluated. Black soldier fly hens consumed on average 15 ± 1.7 g BSF larvae/hen per day.There were no differences between BSF and control hens for any of the performance parameters obtained(P > 0.05). Egg weight, shell weight, and shell thickness of eggs from BSF hens were significantly lower(P = 0.003, P = 0.001, and P = 0.004, respectively) than those of eggs from control hens. Egg yolk colour was significantly paler in eggs from BSF hens(P < 0.001). No significant ranging differences between the BSF and control hens were observed(P > 0.05) except for BSF hens showing longer total maximum time for a single visit to the range(P = 0.011). In conclusion, the average intake of BSF larvae indicated a good level of acceptance. Feed formulation should be adjusted for the intake of the choice fed source. The impact of choice-feeding on range use was minor. | Isabelle Ruhnke Camille Normant Dana L.M.Campbell Zafar Iqbal Caroline Lee Geoff N.Hinch Julie Roberts | 2018 | Animal Nutrition2018，，4： | 12 |
| 18 | Cavitation vortex dynamics of unsteady sheet/cloud cavitating flows with shock wave using different vortex identification methods显示文摘Cavitation is a complex multiphase flow phenomenon with an abrupt transient phase change between the liquid and the vapor, including multiscale vortical motions. The transient cavitation dynamics is closely associated with the evolution of the cavitation vortex structures. The present paper investigates the cavitation vortex dynamics using different vortex identification methods, including the vorticity method, the Q criterion method, the Omega method (Ω), the method and the Rortex method. The Q criterion is an eigenvalue-based criterion, and in the Ω method, the parameter is normalized, is independent of the threshold value and in most conditions Ω= 0.52 . The Rortex method is based on an eigenvector-based criterion. Numerical simulations are conducted using the implemented compressible cavitation solver in the open source software OpenFOAM for the sheet/cloud cavitating flows around a NACA66 (mod) hydrofoil fixed at a = 6°,= 1.25 and Re = 7.96 × 10^5 . The flow is characterized by the alternate interactions of the re-entrant flow and the collapse induced shock wave. Results include the vapor structures and the vortex dynamics in the unsteady sheet/cloud cavitating flows, with emphasis on the vortex structures in thecavitation region, the cavity interface, the cavity closure, the cavity wakes, and the foil wakes with the shedding cavity. The comparisons of the various methods, including that the vorticity method, the Q criterion method, the Ω method, the λ2 method and the Rortex method, show the performances of different methods in identifying the cavitation vortex structures. Generally, during the attached cavity growth stage, the Q criteria can well predict the vortex structures in the cavitation region and at the foil trailing edge in the pure liquid region, while with the Ω method and the Rortex method, the vortex structures outside the attached cavity and on the foil pressure side can also be predicted. The λ2 method can well predict the vortex structures in the cavity closure region. During the re-entrant jet development stage, the vortex structures in the re-entrant jet region is weak. During the cavity cloud shedding stage, the vortex dynamics at the foil leading edge covered by newly grown cavity sheet is different from that during the attached cavity sheet growth stage. During the shock wave formation and propagation stage, strong vortex structures with both the size and the strength are observed owing to the cavity cloud shedding and collapse behavior. The influence of the small parameter ε in the Ω method on the cavitation vortex identification is discussed. | Chang-chang Wang Ying Liu Jie Chen Fu-yi Zhang Biao Huang Guo-yu Wang | 2019 | Journal of Hydrodynamics2019，31，3： | 12 |
| 19 | A Linear Domain System Identification for Small Unmanned Aerial Rotorcraft Based on Adaptive Genetic Algorithm显示文摘This paper proposes a new adaptive linear domain system identification method for small unmanned aerial rotorcraft.Byusing the flash memory integrated into the micro guide navigation control module, system records the data sequences of flighttests as inputs (control signals for servos) and outputs (aircraft’s attitude and velocity information).After data preprocessing, thesystem constructs the horizontal and vertical dynamic model for the small unmanned aerial rotorcraft using adaptive geneticalgorithm.The identified model is verified by a series of simulations and tests.Comparison between flight data and the one-stepprediction data obtained from the identification model shows that the dynamic model has a good estimation for real unmannedaerial rotorcraft system.Based on the proposed dynamic model, the small unmanned aerial rotorcraft can perform hovering,turning, and straight flight tasks in real flight tests. | Xusheng Lei,Yuhu Du School of the Instrumentation Science and Opto-Electronic Engineering,Beihang University,Beijing 100191,P.R.China | 2010 | Journal of Bionic Engineering2010，7，2： | 12 |
| 20 | 引起青海省马铃薯根腐类病害的镰刀菌种类鉴定显示文摘马铃薯是继水稻、小麦和玉米之后的第四大粮食作物[1],也是我国青海省主要的经济作物。马铃薯干腐病是镰刀菌根腐类病害中最重要的一种病害,其窖藏期发病率最高可达60%[2],根腐类病害已成为限制青海省马铃薯产业发展的重要因素。 | 杨波 王喜刚 郭成瑾 沈瑞清 | 2019 | 植物病理学报2019，49，3： | 12 |
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