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| 1 | Deep learning based classification of rock structure of tunnel face显示文摘The automated interpretation of rock structure can improve the efficiency,accuracy,and consistency of the geological risk assessment of tunnel face.Because of the high uncertainties in the geological images as a result of different regional rock types,as well as in-situ conditions(e.g.,temperature,humidity,and construction procedure),previous automated methods have limited performance in classification of rock structure of tunnel face during construction.This paper presents a framework for classifying multiple rock structures based on the geological images of tunnel face using convolutional neural networks(CNN),namely Inception-ResNet-V2(IRV2).A prototype recognition system is implemented to classify 5 types of rock structures including mosaic,granular,layered,block,and fragmentation structures.The proposed IRV2 network is trained by over 35,000 out of 42,400 images extracted from over 150 sections of tunnel faces and tested by the remaining 7400 images.Furthermore,different hyperparameters of the CNN model are introduced to optimize the most efficient algorithm parameter.Among all the discussed models,i.e.,ResNet-50,ResNet-101,and Inception-v4,Inception-ResNet-V2 exhibits the best performance in terms of various indicators,such as precision,recall,F-score,and testing time per image.Meanwhile,the model trained by a large database can obtain the object features more comprehensively,leading to higher accuracy.Compared with the original image classification method,the sub-image method is closer to the reality considering both the accuracy and the perspective of error divergence.The experimental results reveal that the proposed method is optimal and efficient for automated classification of rock structure using the geological images of the tunnel face. | Jiayao Chen Tongjun Yang Dongming Zhang Hongwei Huang Yu Tian | 2021 | Geoscience Frontiers2021，12，1： | 13 |
| 2 | Elemental geochemical records of seafloor hydrothermal activities in the sediments from the Okinawa Trough显示文摘The major and minor element contents in the sediment core H9 from the hydrothermal fields of the Okinawa Trough show a sharp change at the depth of 80 cm. The elements enriched in the upper 80 cm core are those enriched in the hydrothermal deposits and in the surface sediments recovered from the hydrothermal fields in the trough, which indicates the input of hydrothermal materials. Comparing with other hydrothermal sediments from Mid-ocean Ridges or the Lau Basin, the degree of the enrichment of elements iron, copper,cobalt, and nickel is relatively low. However, the enrichment of elements manganese, lead, arsenic, antimony and mercury is remarkable. The average contents of these elements in the upper 80 cm core sediments are three to six times those in the lower section, and 3~12 times those in the surface sediments which are not influenced by hydrothermal activities. Hydrothermal activities have contributed significant manganese, lead, arsenic, antimony and mercury to the sediments, and these elements are distinct indicators for the hydrothermal activity in the Okinawa Trough. The significant enrichment of these elements in Core H9 upward from the depth 80 cm indicates the start or the significant enhancing of the hydrothermal activity in this area at about 5 740 aB.P. The average accumulation rate of manganese during this period is about 40 461 μg/(cm2·ka), which is similar to the hydrothermal sediments in the Lau Basin or the East Pacific Rise. | ZHAI Shikui YU Zenghui DU Tongjun | 2007 | Acta Oceanologica Sinica2007，26，4： | 6 |
| 3 | GaN-based substrates and optoelectronic materials and devices显示文摘In order to solve the problems of GaN heteroepitaxy on sapphire substrate,some techniques were explored.Freestanding GaN substrates have been made by hydride vapor phase epitaxy(HVPE),laser lift-off(LLO),and chemical mechanical polishing techniques.Wafer bending and cracking in the HVPE growth were partly settled by pulsed flow modulation method.High-crystal quality was established for 1.2 mm thick GaN substrate by X-ray diffraction measurement,in which the full width of half maximum values were 72,110 arcsec for(102),(002)peaks.A novel micro-size patterned sapphire substrate(PSS)and a nano PSS were also fabricated.High-power vertical structure light emitting diodes(VSLEDs)have been developed by Au–Sn eutectic wafer bonding,homemade micro-area LLO,and light extraction structure preparation.The high-injection-level active region with low temperature GaN sandwiched layers was used for lowefficiency droop.The light output power of VSLED was achieved as 400 mW driven at 350 mA,and the dominant wavelength is about 460 nm.The structures and properties of strain modulated superlattices(SLs)and quantum wells as well as advanced simulation of carriers transport across the electron blocking layer were investigated in laser diodes.The hole concentration was achieved as high as1.6 9 1018cm-3in AlGaN/GaN SLs:Mg by inserting an AlN layer.High-quality AlGaN epilayers and structures were grown by MOCVD.Some device structures of UV LEDs and detectors were demonstrated.The emission wavelength of 262 nm UV LED has been successfully fabricated.At last,high-quality InN and InGaN materials for solar cell were grown by boundary-temperature-controlled epitaxy and growth-temperature-controlled epitaxy.Hall-effect measurement showed a recorded electron mobility of 3,280 cm2/(V s)and a residual electron concentration of 1.47 9 1017cm-3at 300 K. | Guoyi Zhang Bo Shen Zhizhong Chen Xiaodong Hu Zhixin Qin Xinqiang Wang Jiejun Wu Tongjun Yu Xiangning Kang Xingxing Fu Wei Yang Zhijian Yang Zhizhao Gan | 2014 | Chinese Science Bulletin2014，59，12： | 4 |
| 4 | Luminescence Degradation of In GaN/GaN Violet LEDs显示文摘 | Tongjun Yu Shuping Shang Zhizhong Chen | 2007 | Journal of Luminescence2007，，： | 1 |
| 5 | 查看详情显示文摘 | Hao Long Yang Wei Yu Tongjun | | 0，，9： | 1 |
| 6 | Separate and concurrent use of 2-deoxy-D-glucose and 3-bromopyruvatein pancreatic cancer cells显示文摘 | Huijie Xiao Shasha Li Dapeng Zhang Tongjun Liu Ming Yu Feng Wang | 2013 | Oncology Reports2013，，1： | 1 |
| 7 | Fabrication of dodecagonal pyramid on nitrogen face GaN and its effect on the light extraction显示文摘Wet etching has been widely used in defect evaluation for Ga-face GaN and surface roughness for N-face GaN dodecagonal pyramids has been fabricated on laser-lift-off N-face GaN by hot phosphor acid etching.The dodecagonal pyramid shows twelve facets including six{20-2-3}and six{22-4-5}planes.From cross-sectional TEM image,it is shown that the pyramid corresponds to the top of the edge dislocation.Compared with hexagonal pyramid-surface light emitting diodes(LEDs)etched by commonly used photoelectrochemical(PEC)process in KOH aqueous,the dodecagonal pyramid-surface LEDs show improved light extraction efficiency because of more facets,which effectively reduces the total internal reflection. | QI ShengLi,CHEN ZhiZhong,SUN YongJian,FANG Hao,TAO YueBin,SANG LiWen,TIAN PengFei,DENG JunJing,ZHAO LuBing,YU TongJun,QIN ZhiXin&ZHANG GuoYi State Key Laboratory for Artificial Microstructure and Mesoscopic Physics,School of Physics,Peking University,Beijing 100871,China | 2010 | Science China(Technological Sciences)2010，53，3： | 0 |
| 8 | 6-26 Conceptual Design of a 3.6 T Curved Tilted Solenoid Superconducting Magnet显示文摘The type of tilted solenoid is a novel approach to be used in superconducting dipole magnet design. The dipolefield is obtained by using concentric pairs of helically-wound coils that are tilted at opposite angles; this effectivelycancels the solenoid component of the field and adds the dipole content of each layer. Fig. 1 shows a dipole magnetcomposed of a pair of coils.According to the principle of modulating the tilted solenoid, we proposed a conceptual design of curved superconductingmagnet. The magnet with 150 mm bore diameter is curved 60 ? at a radius of 833 mm. The magnetconsists of 10 layers and the thickness of each layer is 5 mm. It could be cooled by a GM refrigerator. The detailedparameters of magnet are showed in Table 1. | Liang Yu Wu Wei Yang Tongjun Chen Yuquan | 2014 | IMP & HIRFL Annual Report2014，，1： | 0 |
| 9 | Phase reaction of Au/Sn solder bonding for GaN-based vertical structure light emitting diodes显示文摘Au/Sn solder bonding on Si substrates was used to fabricate the GaN-based vertical structure light emitting diodes (VSLEDs). The phase reaction of Au/Sn solder under different bonding conditions was investigated by the measurement of electron back scattering diffraction (EBSD), and the characteristics of VSLED were analyzed by scanning acoustic microscope (SAM), Raman scattering, current-voltage (I-V) and light output-current (L-I) curves. After the bonding process, horizontal stripes of Au/Sn phase (δ phase) and Au5Sn phase (ζ phase) were redirected to vertical stripes, and δ phase tended to move to the solder joint. Sn interstitial diffusion led to the distribution of δ phase and voids in Au/Sn solder, which could be seen in SAM and SEM images. Vertical distribution of the δ phase and ζ phase with proper voids in the Au/Sn bonding layer showed the best bonding quality. Good bonding quality led to little shift of the E2-high mode of Raman spectra peak in GaN after laser lift off (LLO). It also caused more light extraction and forward bias reduction to 2.9 V at 20 mA. | TIAN PengFei, SUN YongJian, CHEN ZhiZhong, QI ShengLi, DENG JunJing, YU TongJun, QIN ZhiXin & ZHANG GuoYi State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China | 2010 | Science China(Technological Sciences)2010，53，2： | 0 |
| 10 | Batch synthesis of transfer-free graphene with wafer-scale uniformity显示文摘Scalable synthesis of transfer-free graphene over insulators offers exciting opportunity for next-generation electronics and optoelectronics.However,rational design of synthetic protocols to harvest wafer-scale production of directly grown graphene still remains a daunting challenge.Herein we explore a batch synthesis of large-area graphene with wafer-scale uniformity by virtue of direct chemical vapor deposition(CVD)on quartz.Such a controllable CVD approach allows to synthesize 30 pieces of 4-inch graphene wafers in one batch,affording a low fluctuation of optical and electrical properties.Computational fluid dynamics simulations reveal the mechanism of uniform growth,indicating thermal field and confined flow field play leading roles in attaining the batch uniformity.The resulting wafer-scale graphene enables the direct utilization as key components in optical elements.Our method is applicable to other types of insulating substrates(e.g.,sapphire,SiO2/Si,Si3N4),which may open a new avenue for direct manufacture of graphene wafers in an economic fashion. | Bei Jiang Qiyue Zhao Zhepeng Zhang Bingzhi Liu Jingyuan Shan Liang Zhao Mark H.Rümmeli Xuan Gao Yanfeng Zhang Tongjun Yu Jingyu Sun Zhongfan Liu | 2020 | Nano Research2020，13，6： | 0 |
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