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Experiment study on water-rock interaction about gold activation and migration in different solutions

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Journal of Central South University of Technology 2001年第2期8卷 105-107页

作者： DAI ta gen, gu Li, QIU Dong sheng, XIE Wen bing (College of Resources, Environment and Civil Engineering, Central South University, Changsha 410083, China) College of Resources Environment and Civil Engineering Central South University Changsha China

The interactions on gold active and migratory quantities and rates between tuffaceous slate and solu tions with different compositions were experimentally studied at 200 ℃, 20 MPa, in a high pressure apparatus. After reaction, tuffaceous slate became light colored and soft, and its mass density reduced. The amount of gold extracted from tuffaceous slate ranges widely, from 0 027 to 0 234 μg/g. Chlorine solution may activate appreciable amount of gold, and the gold migratory rate is high enough, from 50 70% to 92 30%, which reveals that sulphur and chlorine work together in solutions to accelerate gold activation and migration, and to realize gold mineralization in favorable places.

关键词： water rock interaction activation migration chlorine sulphur gold

Nonlinear inversion of ultrasonic guided waves for in vivo evaluation of cortical bone properties

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Chinese Physics B 2022年第7期31卷 371-378页

作者： Xiaojun Song Tii Fan Jundong Zeng Qin-Zhen Shi Qiong Huang Meilin gu Petro Moilanen Yi-Fang Li Dean ta Center for Biomedical Engineering Fudan UniversityShanghai 200433China College of Electronics and Information engineering Shanghai University of Electric PowerShanghai 200090China Department of Physics University of HelsinkiHelsinkiFinland Academy for Engineering and Technology Fudan UniversityShanghai 200433China

Ultrasonic guided waves(UGWs),which propagate throughout the entire thickness of cortical bone,are attractive for the early diagnosis of ***,this is challenging due to the impact of soft tissue and the inherent difficulties related to multiparametric inversion of cortical bone quality factors,such as cortical thickness and bulk wave ***,in this research,a UGW-based multi-parameter inversion algorithm is developed to predict strength-related *** simulation,a free plate(cortical bone)and a bilayer plate(soft tissue and cortical bone)are used to validate the proposed *** inversed cortical thickness(CTh),longitudinal velocity(V_(L))and transverse velocity(V_(T))are in accordance with the true *** four bovine cortical bone plates were used in in vitro *** with the reference values,the relative errors for cortical thickness were 3.96%,0.83%,2.87%,and 4.25%,*** the in vivo measurements,UGWs are collected from the tibias of 10 *** theoretical dispersion curves depicted by the estimated parameters(V_(T),V_(L),CTh)match well with the extracted experimental *** comparison with dual-energy x-ray absorptiometry,our results show that the estimated transverse velocity and cortical thickness are highly sensitive to ***,these two parameters(CTh and V_(T))of long bones have potential to be used for diagnosis of bone status in clinical applications.

关键词： ultrasonic guided waves inversion algorithm transverse velocity bone evaluation

Screening COVID-19 from chest X-ray images by an optical diffractive neural network with the optimized F number

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Photonics Research 2024年第7期12卷 1410-1426页

作者： JIALONG WANG SHOUYU CHAI WENTING gu BOYI LI XUE JIANG YUNXIANG ZHANG HONGEN LIAO XIN LIU DEAN ta Academy for Engineering and Technology Fudan UniversityShanghai 200433China Center for Biomedical Engineering Fudan UniversityShanghai 200433China Department of Chemistry Fudan UniversityShanghai 200433China Department of Biomedical Engineering School of MedicineTsinghua UniversityBeijing 100084China

The COVID-19 pandemic continues to significantly impact people's lives worldwide, emphasizing the critical need for effective detection methods. Many existing deep learning-based approaches for COVID-19 detection offer high accuracy but demand substantial computing resources, time, and energy. In this study, we introduce an optical diffractive neural network(ODNN-COVID), which is characterized by low power consumption, efficient parallelization, and fast computing speed for COVID-19 detection. In addition, we explore how the physical parameters of ODNN-COVID affect its diagnostic performance. We identify the F number as a key parameter for evaluating the overall detection capabilities. Through an assessment of the connectivity of the diffractive network, we established an optimized range of F number, offering guidance for constructing optical diffractive neural networks. In the numerical simulations, a three-layer system achieves an impressive overall accuracy of 92.64% and 88.89% in binary-and threeclassification diagnostic tasks. For a single-layer system, the simulation accuracy of 84.17% and the experimental accuracy of 80.83% can be obtained with the same configuration for the binary-classification task, and the simulation accuracy is 80.19% and the experimental accuracy is 74.44% for the three-classification task. Both simulations and experiments validate that the proposed optical diffractive neural network serves as a passive optical processor for effective COVID-19 diagnosis, featuring low power consumption, high parallelization, and fast computing capabilities. Furthermore, ODNN-COVID exhibits versatility, making it adaptable to various image analysis and object classification tasks related to medical fields owing to its general architecture.

关键词： neural network offering

Photodegradation of Hexafluoropropylene Oxide Trimer Acid under UV Irradiation

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Journal of Environmental Sciences 2020年第11期32卷 132-140页

作者： Chen Li Na Mi Zhanghao Chen Cheng gu State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China

As a novel alternative to traditional perfluoroalkyl substances(PFASs),including perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS),hexafluoroproplyene oxide trimer acid(HFPO-ta)has been detected worldwide in surface ***,recent researches have demonstrated that HFPO-ta has stronger bioaccumulation potential and higher hepatotoxicity than *** treat these contaminants *** and PFOS,some photochemical techniques by adding exogenous substances had been ***,there is still no report for the behavior of HFPO-ta itself under direct UV *** current study investigated the photo-transformation of HFPO-ta under UV irradiation in aqueous *** 72 hr photoreaction,75%degradation ratio and 25%defluorination ratio were achieved under ambient *** active species,i.e.,hydrated electrons and active hydrogen atoms,generated from water splitting played dominant roles in degradation of HFPO-ta,which was confirmed by different effects of reaction atmospheres and quenching experiments.A possible degradation pathway was proposed based on the products identification and theoretical *** general,HFPO-ta would be transformed into shorter-chain PFASs,including hexafluoropropylene oxide dimer acid(HFPODA),perfluoropropionic acid(PFA)and trifluoroacetate(TFA).This research provides basic information for HFPO-ta photodegradation process and is essential to develop novel remediation techniques for HFPO-ta and other alternatives with similar structures.

关键词： HFPO-ta Photo-reductive Hydrated electrons Active hydrogen atoms Degradation pathway

An Improved Sensor Fault Diagnosis Scheme Based on ta-LSSVM and ECOC-SVM

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Journal of Systems Science & Complexity 2018年第2期31卷 372-384页

作者： gu Xiaodan DENG Fang GAO Xin ZHOU Rui School of Automation Beijing Institute of Technology Beijing 100081 China Department of Information Equipment Equipment Institute of PLA Beijing 101416 China School of Automation Beijing Institute of Technology Beijing 100081 China.

Monitoring the operational state of sensors promptly and the accurate diagnosis of faults are essential. This paper proposes an improved fault diagnosis scheme for sensors, which includes both fault detection and fault identification. Firstly, trend analysis combined with least squares support vector machine（ta-LSSVM） method is proposed and implemented to detect faults. Secondly, an improved error correcting output coding-support vector machine（ECOC-SVM） based fault identification method is proposed to distinguish different sensor failure modes. To demonstrate the effectiveness of the proposed scheme, experiments are conducted with an MTi-series sensor, and some comparisons are made with other fault identification methods. The experimental results demonstrate that the proposed fault diagnosis scheme offers an essential improvement with detection real-time property and better identification accuracy.

关键词： ECOC fault detection, fault identification SVM ta.

Conditional privacy protection authentication scheme based on bilinear pairings for VANET

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The Journal of China Universities of Posts and Telecommunications 2020年第1期27卷 62-71页

作者： Song Cheng gu Xin'an Ping Yuan Zhang Yadong School of Computer Science and Technology Henan Polytechnic UniversityJiaozuo 454000China School of Information Engineering Xuchang UniversityXuchang 461000China

To solve the problem of security and efficiency of anonymous authentication in the vehicle Ad-hoc network(VANET), a conditional privacy protection authentication scheme for vehicular networks is proposed based on bilinear pairings. In this scheme, the tamper-proof device in the roadside unit(RSU) is used to complete the message signature and authentication process together with the vehicle, which makes it more secure to communicate between RSU and trusted authority(ta) and faster to update system parameters and revoke the vehicle. And this is also cheaper than installing tamper-proof devices in each vehicle unit. Moreover, the scheme provide provable security proof under random oracle model(ROM), which shows that the proposed scheme can meet the security requirements such as conditional privacy, unforgeability, traceability, etc. And the results of simulation experiment demonstrate that this scheme not only of achieves high efficiency, but also has low message loss rate.

关键词： VANET anonymous authentication bilinear pairings conditional privacy protection

Early Indosinian Weiya Gabbro in Eastern Tianshan, China: Elemental and Sr-Nd-O Isotopic Geochemistry, and Its Tectonic Implications

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Acta Geologica Sinica(English Edition) 2007年第3期81卷 424-432页

作者： ZHANG Zunzhong gu Lianxing WU Changzhi State Key Laboratory of Mineral Deposit Research （Nanjing University） Department of Earth Sciences Nanjing University Nanjing Jiangsu 210093 School of the Environment Nanjing University Nanjing Jiangsu 210093

The Weiya gabbro in eastern Tianshan was formed during the early Indosinian. This rock, with low ratios of Ce/Pb （5.74-10.16）, is notably characterized by enrichment in large ion lithophile elements （LILE）, such as Rb, K, Ba and Pb, and in high field strength elements （HSFE）, such as U and Th, but depletion in Nb and ta. All samples of the Weiya gabbro display similar chondrite-normalized patterns with moderate enrichment in LREE （72.58-135.61ppm）, moderate depletion in HREE （15.26-25.31ppm） and mild fractionation between LREE and HREE （L/ H=4.09-5.98）. The average initial Sr value of the rock is 0.7069, and δ18O values of the rock range from 5.67‰-8.04‰. In terms of Nd isotope ratios, the Weiya gabbro is characterized by positive eNd（t） values （0.52-0.76）. All these characteristics indicate that the source region of the Weiya gabbro was metasomatized by fluids released from subducted young continental crust, with limited crustal contamination during magma ascent and emplacement. Continental （A-type） subduction was induced by northward subduction of the Paleo-Tethyan oceanic plate during the latest Permian to Triassic. From this point of view, it is supposed that tectonic conversion from the Paleo-Asian to the Paleo-Tethys regime occurred during the latest Permian or earliest Triassic.

关键词： Weiya gabbro mantle metasomatism intra-continental subduction easternTianshan Xinjiang

Petrochemical Characteristics of the Mesozoic-Cenozoic Volcanic Rock in Huanghua Basin

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Journal of Central South University 2000年第2期12卷 75-80页

作者： gu Li 1,DAI ta gen 1,DENG Cai hua 1,FAN Wei ming 2 (1 College of Resources, Environment and Civil Engineering, Central South University of Technology, Changsha 410083, China 2 Changsha Institute of Geotectonics, Academia Sinica, Changsha 410 College of Resources Environment and Civil Engineering Central South University of Technology Changsha China Changsha Institute of Geotectonics Academia Sinica Changsha China

Based on the data from typical core sampling, combined with K Ar dating, petrochemistry ,trace elemental geochemistry and isotopic compositions of the Mesozoic Cenozoic volcanic rock in the Huanghua basin, Bohai region, the geochemical features of the volcanic rock were studied. The rocks fall into four groups: Cenozoic basalt,Mesozoic late Cretaceous basaltic trachy andesite, Mesozoic late Cretaceous trachy dacite and liparite,and Mesozoic early Triassic dacite. The distribution pattern of the main elemental abundance of late Mesozoic shows a typical ***,for the volcanic rock,the amount of SiO 2 decreases gradually,the contents of Fe 2O 3,FeO,CaO,MgO,TiO 2,P 2O 5 and MnO increase little by *** Cenozoic basalt is derived from the asthenospheric *** late Cretaceous basaltic trachy andesite is derived from the enriched lithospheric *** late Cretaceous and early Palaeogene,the felsic volcanic rock may be derived from fractional melting of the crust.

关键词： Mesozoic Cenozoic era volcanism petrochemistry Huanghua basin

Fabrication of monodispersed B,N co-doped hierarchical porous carbon nanocages through confined etching to boost electrocatalytic oxygen reduction

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Nano Research 2023年第1期16卷 290-298页

作者： Xuefei Wang Chao Han Haitao Li Panpan Su Na ta Yanfu Ma Zhenguo Huang Jian Liu School of Civil&Environmental Engineering University of Technology SydneySydneyNSW2007Australia State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China DICP-Surrey Joint Centre for Future Materials University of Surrey GuildfordSurreyGU27XHUK

Dual heteroatom-doped carbons have attracted widespread research attention as catalysts in the field of energy storage and conversion due to their unique electronic structures and chemical *** particular,boron and nitrogen co-doped carbon(B,N@C)has shown great potential for photo/electrocatalytic ***,more needs to be done for rational designing and regulating the structure of these materials to improve their catalytic ***,monodispersed hierarchical porous B,N@C nanocages were fabricated by pyrolyzing zeolite imidazole framework(ZIF)which was treated with ammonia borane or boric acid via an integrated double-solvent impregnation and nanocofined-etching *** treated ZIF-8 provided an essential structural template to achieve B,N co-doped hierarchical structures with micro/meso/macro multimodal pore size *** resultant B,N@C nanocages displayed high catalytic activities for electrochemical oxygen reduction reaction(ORR)in alkaline media,outperforming most carbon-based catalysts,particularly from the perspective of the half-wave *** high catalytic performance is due to the enhanced activity by the coexistence of B and N and the mass transfer promoted by the unique hierarchical porous structure.

关键词： heteroatom doping hierarchical porous carbon host-guest chemistry confined etching electrocatalysis mass transfer