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| 1 | All-optical active THz metasurfaces for ultrafast polarization switching and dynamic beam splitting显示文摘Miniaturized ultrafast switchable optical components with an extremely compact size and a high-speed response will be the core of next-generation all-optical devices instead of traditional integrated circuits,which are approaching the bottleneck of Moore’s Law.Metasurfaces have emerged as fascinating subwavelength flat optical components and devices for light focusing and holography applications.However,these devices exhibit a severe limitation due to their natural passive response.Here we introduce an active hybrid metasurface integrated with patterned semiconductor inclusions for all-optical active control of terahertz waves.Ultrafast modulation of polarization states and the beam splitting ratio are experimentally demonstrated on a time scale of 667 ps.This scheme of hybrid metasurfaces could also be extended to the design of various free-space all-optical active devices,such as varifocal planar lenses,switchable vector beam generators,and components for holography in ultrafast imaging,display,and high-fidelity terahertz wireless communication systems. | Longqing Cong Yogesh Kumar Srivastava Huifang Zhang Xueqian Zhang Jiaguang Han Ranjan Singh | 2018 | Light(Science & Applications)2018，7，1： | 15 |
| 2 | Liquefaction macrophenomena in the great Wenchuan earthquake显示文摘On May 12,2008 at 14:28,a catastrophic magnitude Ms 8.0 earthquake struck the Sichuan Province of China.The epicenter was located at Wenchuan(31.00oN,103.40oE).Liquefaction macrophenomena and corresponding destruction was observed throughout a vast area of 500 km long and 200 km wide following the earthquake.This paper illustrates the geographic distribution of the liquefaction and the relationship between liquefaction behavior and seismic intensity,and summarizes the liquefaction macrophenomena,including sandboils and waterspouts,ground subsidence,ground fi ssures etc.,and relevant liquefaction features.A brief summary of the structural damage caused by liquefaction is presented and discussed.Based on comparisons with liquefaction phenomena observed in the 1976 Tangshan and 1975 Haicheng earthquakes,preliminary analyses were performed,which revealed some new features of liquefaction behavior and associated issues arising from this event.The site investigation indicated that the spatial non-uniformity of liquefaction distribution was obvious and most of the liquefi ed sites were located in regions of seismic intensity VIII.However,liquefaction phenomena at ten different sites in regions of seismic intensity VI were also observed for the fi rst time in China mainland.Sandboils and waterspouts ranged from centimeters to tens of meters,with most between 1 m to 3 m.Dramatically high water/sand ejections,e.g.,more than 10 m,were observed at four different sites.The sand ejections included silty sand,fi ne sand,medium sand,course sand and gravel,but the ejected sand amount was less than that in the 1976 Tangshan earthquake.Possible liquefaction of natural gravel soils was observed for the fi rst time in China mainland. | Chen Longwei Yuan Xiaoming Cao Zhenzhong Hou Longqing Sun Rui Dong Lin Wang Weiming Meng Fanchao Chen Hongjuan | 2009 | Earthquake Engineering and Engineering Vibration2009，8，2： | 14 |
| 3 | Comprehensive evaluation of water-inrush risk from coal floors显示文摘Lower groups of coal seams are presently being mined in the Yanzhou coal mining area. We need to evaluate the risk from water-inrush from coal floors in order to have safe production in the lower groups of coal seams in mines. Based on a system-atic collection of hydrogeological data and some data from mined working faces in these lower groups, we evaluated the factors affecting water-inrush from coal floors of the area by a method of dimensionless analysis. We obtained the order of the factors af-fecting water-inrush from coal floors and recalculated data on depths of destroyed floors by multiple linear regression analysis and obtained new empirical formulas. We also analyzed the water-inrush coefficient of mined working faces of the lower groups of coal seams and improved the evaluation standard of the water-inrush coefficient method. Finally, we made a comprehensive evaluation of water-inrush risks from coal floors by using the water-inrush coefficient method and a fuzzy clustering method. The evaluation results provide a solid foundation for preventing and controlling the damage caused by water of an Ordovician limestone aquifer in the lower group of coal seams in the mines of Yanzhou. It provides also important guidelines for lower groups of coal seams in other coal mines. | WEI Jiuchuan LI Zhongjian SHI Longqing GUAN Yuanzhang YIN Huiyong | 2010 | Mining Science and Technology2010，20，1： | 9 |
| 4 | Electrically Programmable Terahertz Diatomic Metamolecules for Chiral Optical Control显示文摘Optical chirality is central to many industrial photonic technologies including enantiomer identifcation,ellipsometry-based tomography,and spin multiplexing in optical communications.However,a substantial chiral response requires a threedimensional constituent,thereby making the morphology highly complex to realize structural reconfguration.Moreover,an active reconfguration demands intense dosage of external stimuli that pose a major limitation for on-chip integration.Here,we report a low bias,electrically programmable synthetic chiral paradigm with a remarkable reconfguration among levorotatory,dextrorotatory,achiral,and racemic conformations.Te switchable optical activity induced by the chiral conformations enables a transmission-type duplex spatial light modulator for terahertz single pixel imaging.Te prototype delivers a new strategy towards reconfgurable stereoselective photonic applications and opens up avenues for on-chip programmable chiral devices with tremendous applications in biology,medicine,chemistry,and photonics. | Longqing Cong Prakash Pitchappa Nan Wang Ranjan Singh | 2019 | Research2019，，1： | 8 |
| 5 | Multi target pigs tracking loss correction algorithm based on Faster R-CNN显示文摘In order to solve the problem that target tracking frames are lost during the visual tracking of pigs,this research proposed an algorithm for multi target pigs tracking loss correction based on Faster R-CNN.The video of live pigs was processed by Faster R-CNN to get the object bounding box.Then,the SURF and background difference method were combined to predict whether the target pig will be occluded in the next frame.According to the occlusion condition,the maximum value of the horizontal and vertical coordinate offset of the bounding box in the adjacent two frames of the frame image in continuous N(N is the value of the video frame rate)were calculated.When bounding boxes in a video frame are merged into one bounding box,this maximum value was used to correct the current tracking frame offset in order to achieve the purpose of solving the tracking target loss problem.The experiment results showed that the success rate range of RP Faster-RCNN in the data set was 80%-97% while in term of Faster-RCNN was 40%-85%.And the average center point error of RP Faster-RCNN was 1.46 lower than Faster-RCNN which was about 2.60.The new algorithm was characterized by good robustness and adaptability,which could solve the problem of missing tracking target and accurately track multiple targets when the targets occlude each other. | Longqing Sun Yuanbing Zou Yan Li Zhengda Cai Yue Li Bing Luo Yan Liu Yiyang Li | 2018 | International Journal of Agricultural and Biological Engineering2018，11，5： | 7 |
| 6 | Individual pig object detection algorithm based on Gaussian mixture model显示文摘The background models are crucially important for the object extraction for moving objects detection in a video.The Gaussian mixture model(GMM)is one of popular methods in the background models.Gaussian mixture model which applied to the pig target detection has some shortcomings such as low efficiency of algorithm,misjudgment points and ghosts.This study proposed an improved algorithm based on adaptive Gaussian mixture model,to overcome the deficiencies of the traditional Gaussian mixture model in pig object detection.Based on Gaussian mixture background model,this paper introduced two new parameters of video frames m and T0.The Gaussian distribution was scanned once every m frames,the excessive Gaussian distribution was deleted to improve the convergence speed of the model.Meanwhile,using different learning rates to suppress ghosts,a higher decreasing learning rate was adopted to accelerate the background modeling before T_(0),the background model would become stable as the time continued and a smaller learning rate could be used.In order to maintain a stable background and reduce noise interference,a fixed learning rate after T_(0) was used.Results of experiments indicated that this algorithm could quickly build the initial background model,detect the moving target pigs,and extract the complete contours of the target pigs’.The algorithm is characterized by good robustness and adaptability. | Li Yiyang Sun Longqing Zou Yuanbing Li Yue | 2017 | International Journal of Agricultural and Biological Engineering2017，10，5： | 6 |
| 7 | Superconducting nanowire single-photon detection system and demonstration in quantum key distribution显示文摘We developed a superconducting nanowire single-photon detection(SNSPD) system based on Gifford-McMahon cryocooler for quantum communication applications.Environmental factors which may influence the system performance are intensively studied.Those factors include temperature fluctuations,the ambient magnetic field and the background radiation.By optimizing the bias circuit,the stability of SNSPD system to electrical noise and disturbance was effectively enhanced,thus making it more suitable for field application.A 4-channel SNSPD system with quantum efficiency higher than 4% at the dark count rate of 10 Hz for λ=1550 nm is integrated and applied into a quantum key distribution(QKD) experiment.QKD was successfully carried out over 100 km optical fiber with the final secure key rate of 1.6 kbps and the quantum bit error rate of less than 2%. | CHEN SiJing LIU DengKuan YOU LiXing WANG YongLiang QIU LongQing XIE XiaoMing JIANG MianHeng CHEN TengYun LIU Yang MIKI Shigehito WANG Zhen | 2013 | Chinese Science Bulletin2013，58，10： | 4 |
| 8 | High NO_2/NO_X emissions downstream of the catalytic diesel particulate filter:An influencing factor study显示文摘Diesel vehicles are responsible for most of the traffic-related nitrogen oxide(NO x) emissions,including nitric oxide(NO) and nitrogen dioxide(NO2). The use of after-treatment devices increases the risk of high NO2/NO x emissions from diesel engines. In order to investigate the factors influencing NO2/NO x emissions, an emission experiment was carried out on a high pressure common-rail, turbocharged diesel engine with a catalytic diesel particulate filter(CDPF). NO2 was measured by a non-dispersive ultraviolet analyzer with raw exhaust sampling. The experimental results show that the NO2/NO x ratios downstream of the CDPF range around 20%–83%, which are significantly higher than those upstream of the CDPF. The exhaust temperature is a decisive factor influencing the NO2/NO x emissions. The maximum NO2/NO x emission appears at the exhaust temperature of 350°C. The space velocity,engine-out PM/NO x ratio(mass based) and CO conversion ratio are secondary factors. At a constant exhaust temperature, the NO2/NO x emissions decreased with increasing space velocity and engine-out PM/NO x ratio. When the CO conversion ratios range from 80% to 90%,the NO2/NO x emissions remain at a high level. | Chao He Jiaqiang Li Zhilei Ma Jianwei Tan Longqing Zhao | 2015 | Journal of Environmental Sciences2015，27，9： | 4 |
| 9 | Water inrush evaluation of coal seam floor by integrating the water inrush coefficient and the information of water abundance显示文摘The method of singular coefficient of water inrush to achieve safety mining has limitation and one sidedness. Aiming at the problem above, large amounts of data about water inrush were collected. Then the data, including the maximum water inrush, water inrush coefficient and water abundance in aquifers of working face, were processed by the statistical analysis. The analysis results indicate that both water inrush coefficient and water abundance in aquifers should be taken into consideration when evaluating the danger of water inrush from coal seam floor. The prediction model of safe-mining evaluation grade was built by using the support vector machine, and the result shows that this model has high classification accuracy. A feasible classification system of water-inrush safety evaluation can be got by using the data visualization method which makes the implicit support vector machine models explicit. | Shi Longqing Qiu Mei Wei Wenxue Xu Dongjing Han Jin | 2014 | International Journal of Mining Science and Technology2014，24，5： | 3 |
| 10 | Tungsten-potassium:a promising plasma-facing material显示文摘Tungsten-potassium(potassium-doped tungsten or WK),initially known from the electric filament industry,is a promising plasma-facing material(PFM)in future fusion facilities like International Thermonuclear Experimental Reactor(ITER).However,the brittle nature of W and irradiation-induced defects of WK materials may result in a risk of deuterium-tritium reaction failure in fusion reactors.Previous studies revealed that advanced W with ultrafine grains and nanostructures might be able to address these problems.However,K-doped W,a rapidly developed material for PFMs,lacks a systematical sum-mary.In this review,we firstly describe the powder metallurgy and plastic deformation for the preparation of WK.Then,the mechanical properties of WK and thermal shock resistance results are reviewed.Important issues such as irradiation damages from neutron,heavy ion,and plasma(H isotope or He)irradiation are also discussed.Hitherto,WK under irradia-tions shows comparable or even better performances compared with other counterparts such as ITER grade pure tungsten.This review could be benefitial to the future efforts of improving the ductility and irradiation tolerance of WK materials. | Xiaoliang Yang Wenbin Qiu Longqing Chen Jun Tang | 2019 | Tungsten2019，1，2： | 3 |
| 11 | Pig target tracking algorithm based on multi-channel color feature fusion显示文摘In the process of tracking the target of the pig,with the change of the size of the tracking target in the video image,the estimated tracking target scale cannot be adaptively updated in real-time,resulting in the low accuracy of the tracking target.In this study,a multi-channel color feature adaptive fusion algorithm was proposed,and the target scale of the pig was updated in real-time by utilizing the contour information of the target pig.Experiments show that the proposed algorithm had a distance precision of 89.7%and an overlap precision of 87.5%,and the average running speed of this algorithm was 50.1 fps.The robustness of the proposed algorithm in tracking target deformation and scale variation were significantly improved,which satisfies the accuracy and real-time requirements of pig target tracking. | Longqing Sun Shuaihua Chen Ting Liu Chunhong Liu Yan Liu | 2020 | International Journal of Agricultural and Biological Engineering2020，13，3： | 2 |
| 12 | Paraffin section observation of flower bud differentiation of Chimonanthus praecox in Kunming and comparison of the differentiation processes in different regions,China显示文摘Chimonanthus praecox is an important ornamental plant and cut flower material in China.It blooms in the freezing winter and its flower emits charming fragrance.However,in different region the flowering time is variable.In order to understand the flowering mechanism of Ch.praecox in the winter,we studied the flower bud differentiation in Spring City-Kunming using paraffin sectioning method in the present study.Meanwhile we compared the differentiation process difference from different regions.It was found that the temperature is the key factor for its flower bud differentiation and blossom of Ch.praecox.In the process of bud differentiation,the temperature 20℃was the optimum for inducing changes from vegetative axillary buds to reproductive buds and subsequent morphological differentiation in Ch.praecox.Furthermore in the first three differentiation periods—tepal primordial stage,staminal primordial stage and pistil primordial stage,Kunming took the shortest time to finish the process due to very rapid temperature rise to 20℃,whereas,in Zhengzhou the time for these differentiations was the longest,which may be caused by the slow temperature rise.After May,the high temperature stress forced the flower buds into the first long dormant period in all regions except Kunming.In Kunming,the average temperature was only 20–25℃,so the flower bud continued to differentiate.In all regions,Kunming is the first to complete whole flower bud differentiation even on the early August,and started the second dormancy very early but very long.In the other regions,the plants went through a shorter dormancy and the low temperature broke the dormancy rapidly.Contrarily the plants of Kunming spent a longer period for the low temperature.Thus,the low temperature less than 10℃is a key factor to breaking the second dormancy.Surely the regular effects of temperature on flower bud differentiation and blossom is very helpful for florescence regulation of Ch.praecox. | Sijin Li Nan Yang Longqing Chen | 2022 | Horticultural Plant Journal2022，8，2： | 2 |
| 13 | Broadband terahertz rotator with an all-dielectric metasurface显示文摘Polarization manipulation is essential in developing cutting-edge photonic devices ranging from optical communication displays to solar energy harvesting. Most previous works for efficient polarization control cannot avoid utilizing metallic components that inevitably suffer from large ohmic loss and thus low operational efficiency.Replacing metallic components with Mie resonance-based dielectric resonators will largely suppress the ohmic loss toward high-efficiency metamaterial devices. Here, we propose an efficient approach for broadband, highquality polarization rotation operating in transmission mode with all-dielectric metamaterials in the terahertz regime. By separating the orthogonal polarization components in space, we obtain rotated output waves with a conversion efficiency of 67.5%. The proposed polarization manipulation strategy shows impressive robustness and flexibility in designing metadevices of both linear-and circular-polarization incidences. | QUANLONG YANG XIEYU CHEN QUAN XU CHUNXIU TIAN YUEHONG XU LONGQING CONG XUEQIAN ZHANG YANFENG LI CAIHONG ZHANG XIXIANG ZHANG JIAGUANG HAN WEILI ZHANG | 2018 | Photonics Research2018，，11： | 2 |
| 14 | Genomic Variations in the Tea Leafhopper Reveal the Basis of Its Adaptive Evolution显示文摘Tea green leafhopper(TGL),Empoasca onukii,is of biological and economic interest.Despite numerous studies,the mechanisms underlying its adaptation and evolution remain enigmatic.Here,we use previously untapped genome and population genetics approaches to examine how the pest adapted to different environmental variables and thus has expanded geographically.We complete a chromosome-level assembly and annotation of the E.onukii genome,showing notable expansions of gene families associated with adaptation to chemoreception and detoxification.Genomic signals indicating balancing selection highlight metabolic pathways involved in adaptation to a wide range of tea varieties grown across ecologically diverse regions.Patterns of genetic variations among 54 E.onukii samples unveil the population structure and evolutionary history across different tea-growing regions in China.Our results demonstrate that the genomic changes in key pathways,including those linked to metabolism,circadian rhythms,and immune system functions,may underlie the successful spread and adaptation of E.onukii.This work highlights the genetic and molecular basis underlying the evolutionary success of a species with broad economic impacts,and provides insights into insect adaptation to host plants,which will ultimately facilitate more sustainable pest management. | Qian Zhao Longqing Shi Weiyi He Jinyu Li Shijun You Shuai Chen Jing Lin Yibin Wang Liwen Zhang Guang Yang Liette Vasseur Minsheng You | 2022 | Genomics, Proteomics & Bioinformatics2022，20，6： | 1 |
| 15 | Computer simu- lation of asisotropic grain growth显示文摘 | Yang Wei Chen Longqing Gary L Messing | 1995 | Mater Sci Eng A1995，195，： | 1 |
| 16 | A phase field study of strain energy effects on solute-grain boundary interactions显示文摘 | Tae Wook Heo Saswata Bhattacharyy Chen Longqing | 2011 | Acta Mater2011，56，： | 1 |
| 17 | Effect of remineralization on the nanomechanical properties and microtribological behavior of acid-eroded human tooth enamel显示文摘 | Zheng Liang Zheng Jing Weng Longqing | 2011 | Wear2011，271，9： | 1 |
| 18 | Diffuseqnterface description of strain-dominated morphology of critical nuclei in phase transformations显示文摘 | Zhang Lei Chen Longqing | 2008 | Acta Mater2008，56，： | 1 |
| 19 | Feasibility design of derrick anchor pile piling position based on ANSYS optimization 显示文摘 | Zhu Juan Zou Longqing Fu Hailong | 2013 | Advanced Mate- rial Research2013，，： | 1 |
| 20 | Application of new geophysical technology in coalmine safety monitoring显示文摘 | Cheng Jiulong Li Li Shi Longqing | 2002 | Progress in safety science and Technology2002，，3： | 1 |
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