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新疆南天山榆树沟含石榴夕线石泥质麻粒岩的超高温变质作用及其构造意义

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岩石学报 2025年第1期41卷 215-236页

作者：荆彦清仝来喜刘兆李超大陆动力学国家重点实验室西北大学地质学系西安710069

天山造山带是中亚造山带的重要组成部分,新疆南天山造山带出露有橄榄岩-麻粒岩地体,其北部榆树沟地区麻粒岩超高温变质作用的确定及P-T-t轨迹的建立为南天山造山带增生造山过程的研究提供了重要依据。本文主要以榆树沟地区3个含石榴夕... 详细信息

天山造山带是中亚造山带的重要组成部分,新疆南天山造山带出露有橄榄岩-麻粒岩地体,其北部榆树沟地区麻粒岩超高温变质作用的确定及P-T-t轨迹的建立为南天山造山带增生造山过程的研究提供了重要依据。本文主要以榆树沟地区3个含石榴夕线石泥质麻粒岩为研究对象,在详细岩相学研究的基础上进行了温压计算、相平衡模拟及锆石U-Pb年龄分析。结果显示其普遍保留了4个阶段的矿物组合:(1)峰前阶段(M1)主要是石榴子石核部与核部包裹体矿物Grt1+Bt1+Pl1+Ilm1+Rt1+Qz1±Ksp1;(2)峰期阶段(M2)由石榴子石幔部和基质矿物核部组成,Grt2+Sil2+Ksp2+Pl2+Ilm2+Rt2+Qz2+Liq2,其温压条件为910~973℃和0.90~1.09GPa;(3)高压麻粒岩相阶段(M3)主要是石榴子石内边部和边部包裹体及基质中矿物的边部,Grt3+Bt3+Sil3+Ksp3+Pl3+Ilm3+Rt3+Qz3+Liq3,其温压结果为845~869℃和1.01~1.14GPa;(4)角闪岩相退变质阶段(M4)以石榴子石的外边部及围绕石榴子石的矿物为代表,Grt4+Bt4+Sil4+Ksp4+Pl4+Ilm4+Qz4±Rt4,其温压条件为701~737℃和0.7~0.8GPa。温压结果指示泥质麻粒岩记录了一条逆时针P-T轨迹。锆石U-Pb年龄分析结果指示原岩沉积是在427Ma之后,超高温变质作用发生在397~409Ma,压力峰期变质作用年龄范围为381~395Ma,退变质年龄结果为355~387Ma。超高温变质作用的热源可能是泥盆纪弧岩浆侵入,随后麻粒岩及与之接触的橄榄岩被俯冲板片捕获并经历了高压变质作用,后期受挤压折返发生了退变质降压冷却。

关键词：泥质麻粒岩超高温变质作用 P-T轨迹榆树沟南天山

Real-time detection network for tiny traffic sign using multi-scale attention module

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Science China(Technological Sciences) 2022年第2期65卷 396-406页

作者： YANG TingTing tong chao School of Computer Science&Engineering Beihang UniversityBeijing 100191China

As one of the key technologies of intelligent vehicles, traffic sign detection is still a challenging task because of the tiny size of its target object. To address the challenge, we present a novel detection network improved from yolo-v3 for the tiny traffic sign with high precision in real-time. First, a visual multi-scale attention module(MSAM), a light-weight yet effective module, is devised to fuse the multi-scale feature maps with channel weights and spatial masks. It increases the representation power of the network by emphasizing useful features and suppressing unnecessary ones. Second, we exploit effectively fine-grained features about tiny objects from the shallower layers through modifying backbone Darknet-53 and adding one prediction head to yolo-v3. Finally, a receptive field block is added into the neck of the network to broaden the receptive field. Experiments prove the effectiveness of our network in both quantitative and qualitative aspects. The m AP@0.5 of our network reaches 0.965 and its detection speed is55.56 FPS for 512 × 512 images on the challenging Tsinghua-Tencent 100 k(TT100 k) dataset.

关键词： tiny object detection traffic sign detection multi-scale attention module real-time

Fragmentation for selection: how the deleterious mt DNA is removed in the female germline

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Science Bulletin 2019年第22期64卷 1646-1648页

作者： chao tong MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network Life Sciences Institute Zhejiang University The Second Affiliated Hospital School of Medicine Zhejiang University

Mitochondria are the energy factories and metabolic centers of cells,and their malfunction can lead to multiple human *** highly dynamic organelles,mitochondria undergo frequent fission and fusion processes[1].The fusion process enables the exchange of inner materials between individual *** materials from healthy mitochondria could potentially compensate for the defects found in the defective *** processes not only increase the mitochondrial number but also separate the damaged parts of mitochondria from the healthy ones,thus,facilitating the elimination of the defective mitochondria through a process known as *** fusion leads to extra connections and branching of the mitochondria,whereas extra fission results in fragmentation of *** fusion and fission processes are differently tuned in various tissues to adapt to different physiological requirements[2].

关键词： removed branching elimination

Recent progress in the study of methylated tumor suppressor genes in gastric cancer

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Chinese Journal of Cancer 2013年第1期32卷 31-41页

作者： Xiao-tong Hu chao He Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province Department of Colorectal Surgery Sir Run Run Shaw Hospital

Gastric cancer is one of the most common malignancies and a leading cause of cancer mortality *** pathogenesis mechanisms of gastric cancer are still not fully *** of tumor suppressor genes and activation of oncogenes caused by genetic and epigenetic alterations are known to play significant roles in *** evidence has shown that epigenetic silencing of the tumor suppressor genes,particularly caused by hypermethylation of CpG islands in promoters,is critical to carcinogenesis and ***,we review the recent progress in the study of methylations of tumor suppressor genes involved in the pathogenesis of gastric *** also briefly describe the mechanisms that induce tumor suppressor gene methylation and the status of translating these molecular mechanisms into clinical applications.

关键词：抑癌基因甲基化胃癌肿瘤抑制基因癌组织发病机制表观遗传恶性肿瘤

Global and Local Convergence of a New Affine Scaling Trust Region Algorithm for Linearly Constrained Optimization

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Acta Mathematica Sinica,English Series 2016年第10期32卷 1203-1213页

作者： chao GU De tong ZHU School of Mathematics and Information Shanghai LiXin University of Commerce Department of Mathematics Shanghai Normal University

Chen and Zhang [Sci. China, Set. A, 45, 1390-1397 （2002）] introduced an affine scaling trust region algorithm for linearly constrained optimization and analyzed its global convergence. In this paper, we derive a new affine scaling trust region algorithm with dwindling filter for linearly constrained optimization. Different from Chen and Zhang＇s work, the trial points generated by the new algorithm axe accepted if they improve the objective function or improve the first order necessary optimality conditions. Under mild conditions, we discuss both the global and local convergence of the new algorithm. Preliminary numerical results are reported.

关键词： Linearly constrained optimization affine scaling trust region dwindling filter~ conver-gence

Combating acoustic heterogeneity in photoacoustic computed tomography:A review

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Journal of Innovative Optical Health Sciences 2020年第3期3卷 32-47页

作者： tong Wang Wen Liu chao Tian Department of Optics and Optical Engineering University of Science and Technology of China Hefei Anhui 230026 P.R.China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei Anhui 230026P.R.China Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of China Hefei Anhui 230026P.R.China

Based on the energy conversion of light into sound,photoacoustic computed tomography(PACT)is an emerging biomedical imaging modality and has unique applications in a range of biomedical *** PACT,image formation relies on a process called acoustic inversion from received photoacoustic *** most PACT systems perform this inversion with a basic assumption that biological tissues are acoustically homogeneous,the community gradually rea-lizes that the intrinsic acoustic heterogeneity of tissues could pose distortions and artifacts to finally formed *** paper surveys the most recent research progress on acoustic het-erogeneity correction in *** major strategies are reviewed in detail,including half-time or partial-time reconstruction,autofocus reconstruction by optimizing sound speed maps,joint reconstruction of optical absorption and sound speed maps,and ultrasound computed tomog-raphy(USCT)enhanced *** correction of acoustic heterogeneity helps improve the imaging performance of PACT.

关键词： Photoacoustic computed tomography image reconstruction acoustic heterogeneity ultrasound computed tomography speed of sound

Measurement and characterization of bulk nanobubbles by nanoparticle tracking analysis method

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Journal of Hydrodynamics 2022年第6期34卷 1121-1133页

作者： Xiao-tong Ma Ming-bo Li chao Sun Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering of Ministry of EducationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing100084China

The size of the bulk nanobubbles(typically 100 nm-200 nm in diameter)is below the optical resolution of the typical microscopes,which makes it difficult to make a direct observation of them and differentiate between the nanoparticles and the *** this work,a nanoparticle tracking analysis(NTA)system is developed for tracking and sizing the bulk nanobubbles,and more broadly,the Brownian diffusing *** demonstrate the capabilities of the NTA in characterizing the nanoparticles through systematic validation of accuracy and *** particularly exhibit its unique advantages in detecting the polydisperse nanoparticle *** the nucleation and the thermodynamic stability of the bulk nanobubbles are systematically studied by the NTA *** bulk nanobubbles smaller than 600 nm in size are generated via the ultrasonication *** is shown that both the ultrasonic cavitation treatment time and amplitude,essentially,the energy input,favor the nucleation of the bulk nanobubbles with a more concentrated size distribution,a higher concentration,and a smaller hydrodynamic *** temperature dependence of the bulk nanobubbles over a wide range from 25°C to 70°C is *** is found that the nanobubble first shrinks in size significantly and then the size keeps approximately constant with the increasing temperature,showing a narrow size *** transition temperature is around 45°***,as an open system,the NTA is a potential tool in the study of the dynamic behavior of the bulk nanobubbles in situ,such as the coalescence and the collapse.

关键词： Nanoparticle tracking analysis bulk nanobubble light scattering hydrodynamic size number concentration

Effects of Pilot Fuel Ratio on Combustion Process:Flow Field Structure and Pollutant Emissions

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Journal of Thermal Science 2023年第6期32卷 2321-2335页

作者： ZONG chao JI Chenzhen CHENG Jiaying ZHU tong Postdoctoral Station of Mechanical Engineering Tongji UniversityShanghai201804China School of Mechanical Engineering Tongji UniversityShanghai201804China

As the only controllable means of a micro gas turbine(MGT)combustor during unit operation,pilot fuel ratio(PFR)is the key to achieving stable combustion and low pollutant *** paper discusses the influence of PFR on the inner flow field structure and pollutant *** steady-state three-dimensional RANS method with a 40-step reduced methane-air kinetics mechanism is used to study the reaction flow field and species field with PFR of 9.0%,12.7%,15.2%and 17.6%.Results show that,with the decrease in PFR,the axial velocity and temperature near the central axis of the combustion chamber show a tendency to decrease.A similar separation phenomenon occurred in the core pyrolysis reaction zone(measured by HCO)and oxidation zone(measured by OH),which is more conducive to promoting the oxidation of *** quantitative effect of the pilot flame on nitrogen oxides(NO_(x))was separated by using inert gas instead of nitrogen in combustion *** was found that the NOx produced by the pilot flame under the operation condition with a PFR of 9.0%was 3.2×10^(−6),accounting for 17.4%of the total NOx emission,which was twice that of PFR.

关键词： micro gas turbine pilot fuel ratio flow field structure carbon monoxide nitrogen oxide

Application of ensemble H-infinity filter in aquifer characterization andcomparison to ensemble Kalman filter

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Water Science and Engineering 2017年第1期10卷 25-35页

作者： tong-chao Nan Ji-chun Wu State Key Laboratory of Pollution Control and Resources Reuse Nanjing UniversityNanjing 210093China Department of Hydrosciences School of Earth Sciences and EngineeringNanjing UniversityNanjing 210093China

Though the ensemble Kalman filter （EnKF） has been successfully applied in many areas, it requires explicit and accurate model and measurement error information, leading to difficulties in practice when only limited information on error mechanisms of observational in-struments for subsurface systems is accessible. To handle the uncertain errors, we applied a robust data assimilation algorithm, the ensemble H-infinity filter （EnHF）, to estimation of aquifer hydraulic heads and conductivities in a flow model with uncertain/correlated observational errors. The impacts of spatial and temporal correlations in measurements were analyzed, and the performance of EnHF was compared with that of the EnKF. The results show that both EnHF and EnKF are able to estimate hydraulic conductivities properly when observations are free of error; EnHF can provide robust estimates of hydraulic conductivities even when no observational error information is provided. In contrast, the estimates of EnKF seem noticeably undermined because of correlated errors and inaccurate error statistics, and filter divergence was observed. It is concluded that EnHF is an efficient assimilation algorithm when observational errors are unknown or error statistics are inaccurate.

关键词： Data assimilation Hydraulic parameter estimation Ensemble H-Infinity filter Ensemble Kalman filter Hydraulic conductivity Robustness