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Natural radioactivity level of associated bone-coal mining area in Zhejiang Province

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Nuclear Science and Techniques 2005年第5期16卷 310-314页

作者： YE Ji-Da ZHENG Hui-Di SONG Wei-Li ZENG Guang-Jian WANG Sha-Ling wu zong-mei Environmental Radiation Monitoring Station of Zhejiang Province Hangzhou 310012

The geographic distribution, γ-radiation level and specific activity of radionuclides of the bone-coal mines in Zhejiang Province were reported. The weighted average of γ-radiation dose rate of the bone-coal mines is 566 nGy/h for 107 main bone-coal mines. The weighted mean activity of 238U, 226Ra, 232Th and 40K in the samples are 949, 918, 34 and 554 Bq/kg for 171 samples of bone-coal, respectively.

关键词：浙江放射性物质放射性污染骨煤海洋污染

Investigation on natural radionucildes levels in multiple media in bone-coal mine areas of five provinces

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Nuclear Science and Techniques 2005年第4期16卷 244-248页

作者： KONG Ling-Li ZHANG Liang LI Ying YE Ji-Da JIANG Shan SHI Jin-Hua wu zong-mei wuhan Academy of Environmental Science Wuhan 430015 Environmental Monitoring Center Station of Hunan Province Changsha 410004 Environmtental Monitoring Center Station of Jiangxi Province Nanchang 330029 Enviromnental Radiation Monitoring Station of Zhejiang Province Han gzhou 310012 Environmental Radiation Surveillance Station of Anhui Province Hefei 230061

This paper reports methods and results of the investigation of natural radionuclides levels in multiple me-dia in the bone-coal mine areas in Hubei, Hunan, Jiangxi, Zhejiang, and Anhui Provinces. In the studied bone-coal mine areas, the specific activities of 238U and 226Ra in the soil samples were 0.37 and 0.24 Bq/g, respectively; the spe-cific activities of 226Ra in the samples of bone-coal, bone-coal cinder and bone-coal cinder brick (BCCB) were 1.3, 1.4 and 0.9 Bq/g, respectively. In the water samples collected from the bone-coal mine areas, the average concentra-tions of natural uranium and 226Ra were 33μg/L and 58 mBq/L, respectively, while in the water samples collected from outside the bone-coal mine areas, they were 3.4μg/L and 45 mBq/L, respectively. In addition, the specific activi-ties of 238U and 226Ra in air aerosol samples from the bone-coal mine areas were 0.6 and 0.5 mBq/m3, respectively.

关键词：骨煤放射性等级 BCCB 环境影响

The collective dose equivalent in evaluated region of bone-coal power stations and bone-coal shafts

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Nuclear Science and Techniques 2005年第4期16卷 253-256页

作者： ZHANG Liang JIANG Shan KONG Ling-Li LI Ying YE Ji-Da SHI Jin-Hua wu zong-mei Environmental Monitoring Center Station of Hunan Province Changsha 410004 Environmental Radiation Surveillance Station of Anhui Province Hefei 230061 wuhan Academy of Environmental Science Wuhan 430015 Environmental Monitoring Center Station of Jiangxi Province Nanchang 330029 Environmental Radiation Monitoring Station of Zhejiang Province Hangzhou 310012

During 1991-1993, the radioactivity levels of the bone-coal mines were investigated in Hubei, Hunan, Ji-angxi, Zhejiang and Anhui Provinces, respectively, where the reserve of bone-coal is about 90% of our country’s total reserve. The annual additional collective dose equivalent within 80km evaluated region of bone-coal power stations in Nijiangkou and Anren is 1.7 and 1.9 man·mSv, respectively, and that of Zhuantanyan bone-coal shaft is 1.4 man·mSv. The collective dose equivalent caused by bone-coal cinder brick produced for 25 years in the five prov-inces is 1.6×105 man Sv.

关键词：骨煤环境影响环境保护放射性等级环境监测

Advances in self-assembly-based circularly polarized luminescent materials

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Science China Chemistry 2024年第10期67卷 3247-3257页

作者： Bing-Hao Liu Yang zong Na Liu zong-Quan wu State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China The School of Pharmaceutical Sciences Jilin UniversityChangchun 130021China

Circularly polarized luminescent(CPL)materials have garnered attention for their diverse applications,including three-dimensional(3D)imaging,bio-imaging,chiral sensing,and other emerging ***,the fabrication of CPL-activated materials required the use of chiral luminescent small *** introduction of the idea of self-assembly has transformed the production of CPL-activated materials,providing new and promising opportunities for their *** utilizing self-assembly,it is now feasible to produce chiral nano-assemblies with CPL activity not only from chiral molecules but also from non-chiral substances and inorganic *** addition,self-assembly routes provide a way to increase the asymmetry factor,creating possibilities for additional refinement and adjustment of CPL material *** review offers a summary of the current progress and developments in the self-assembly of small molecules and polymers,with a specific emphasis on their capacity to create or enhance CPL in different *** aim of this review is to inspire interest in optical materials that are based on the principles of self-assembly.

关键词： circularly polarized luminescence photochemistry self-assembly chiral materials

Formation of a trans-cycloadduct from the reaction of difluorocarbene with cis-difluorostilbene

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Chinese Journal of Chemistry 1987年第3期5卷 273-279页

作者： JI Guo-Zhen* CHEN Guo-Fei wu zong-mei JIANG Xi-Kui, Shanghai Institute of Organic Chemistry, Academia Sinica 345 Lingling Lu, Shanghai, China. Shanghai Institute of Organic Chemistry Academia Sinica 345 Lingling Lu Shanghai China

The photochemical isomerization of trans and cis-difluorostilbenes has been *** the presence of a photosensitizer (biacetyl, 0.05 mol·L-1) about 75％ of the trans form can beconverted into the crystalline cis form. The reactions of difluorocarbene （CF2） from the Seyferthreagent （PhHgCF3） with cis- and trans-stilbene obey the Skell rule, i. e., stereospecific ***, although the reaction of CF2with trans-1,2-difluorostilbene yields trans-1,2-diphenyl-perfluorocyclopropane （9） as the only isolable product, the reaction of CF2with cis-difluorostilbenealso gives the same trans-cycloadduct as the only isolable Product. A possible mechanistic path in-volving the homolytic cleavage of the highly activated cyclopropane C-C bond facing the CF2groupis discussed.

关键词： Formation of a trans-cycloadduct from the reaction of difluorocarbene with cis-difluorostilbene cis

Prediction of discharge in a tidal river using the LSTM-based sequence-to-sequence models

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Acta Oceanologica Sinica 2024年第7期43卷 40-51页

作者： Zhigao Chen Yan zong Zihao wu Zhiyu Kuang Shengping Wang Key Laboratory of Mine Environmental Monitoring and Improving around Poyang Lake of Ministry of Natural Resources East China University of TechnologyNanchang 330013China School of Surveying and Geoinformation Engineering East China University of TechnologyNanchang 330013China

The complexity of river-tide interaction poses a significant challenge in predicting discharge in tidal *** short-term memory(LSTM)networks excel in processing and predicting crucial events with extended intervals and time delays in time series ***,the sequence-to-sequence(Seq2Seq)model,known for handling temporal relationships,adapting to variable-length sequences,effectively capturing historical information,and accommodating various influencing factors,emerges as a robust and flexible tool in discharge *** this study,we introduce the application of LSTM-based Seq2Seq models for the first time in forecasting the discharge of a tidal reach of the Changjiang River(Yangtze River)*** study focuses on discharge forecasting using three key input characteristics:flow velocity,water level,and discharge,which means the structure of multiple input and single output is *** experiment used the discharge data of the whole year of 2020,of which the first 80%is used as the training set,and the last 20%is used as the test *** means that the data covers different tidal cycles,which helps to test the forecasting effect of different models in different tidal cycles and different *** experimental results indicate that the proposed models demonstrate advantages in long-term,mid-term,and short-term discharge *** Seq2Seq models improved by 6%-60%and 5%-20%of the relative standard deviation compared to the harmonic analysis models and improved back propagation neural network models in discharge prediction,*** addition,the relative accuracy of the Seq2Seq model is 1%to 3%higher than that of the LSTM *** assessment of the prediction errors shows that the Seq2Seq models are insensitive to the forecast lead time and they can capture characteristic values such as maximum flood tide flow and maximum ebb tide flow in the tidal cycle *** indicates the significance of the Seq2Seq models.

关键词： discharge prediction long short-term memory networks sequence-to-sequence(Seq2Seq)model tidal river back propagation neural network Changjiang River(Yangtze River)Estuary

Phase-field lattice-Boltzmann study on fully coupled thermal-solute-convection dendrite growth of Al-Cu alloy

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China Foundry 2024年第2期21卷 125-136页

作者： Yin-qi Qiu Meng-wu wu Xun-peng Qin Shou-mei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000HubeiChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

Dendrite growth is a complex liquid-solid phase transition process involving multiple physical factors.A phase-field lattice-Boltzmann method was developed to simulate the two-and three-dimension dendrite growth of Al-Cu *** effect of fully coupled thermal-solute-convection interaction on the dendrite growth was investigated by incorporating a parallel-adaptive mesh refinement algorithm into the numerical *** accurately reproducing the latent heat release,solute diffusion and convective transport behaviors at the liquidsolid interface,the interaction mechanism among thermal-solute-convection transport as well as their coupling effects on the dendrite growth dynamics were *** simulation results show that the release of latent heat slows down the dendrite growth rate,and both natural and forced convection disrupt the symmetrical growth of *** combination makes the growth of dendrites more complex,capturing important physical aspects such as recalescence,dendrite tip splitting,dendrite tilting,dendrite remelting,and solute plume in the simulation *** on the robustness and powerful ability of the numerical model,the formation mechanisms of these physical aspects were revealed.

关键词： simulation phase field dendrite growth thermal-solute-convection interaction

Environmental radioactivity level at a mantle factory in eastern Zhejiang

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Nuclear Science and Techniques 2003年第4期14卷 272-277页

作者： YE Ji-Da, ZENG Guang-Jian, wu zong-mei, LIU Hong-Shi, NI Shi-Ying (Zhejiang Province Environmental Radiation Monitoring Center, Hangzhou 310012) Zhejiang Province Environmental Radiation Monitoring Center Hangzhou 310012

The γ radiation level, alpha potential energy of thoron and alpha surface contamination level at amantle factory in the east of Zhejiang Province are reported. The measured results show that the additional annual ef-fective dose equivalent absorbed by the worker in some workshops of the factory was higher than 15mSv-management limit. The alpha surface contamination on the workers' hands in some workshops was 10 timesmore than the management limit of National Standard (0.04 Bq/cm2). The mantle factory's main danger to body wasinternal irradiation of α rays from thoron aerosol.

关键词：环境放射性浙江 α表面污染钍环境监测

Cosmological interpretation for the stochastic signal in pulsar timing arrays

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 43-50页

作者： Yu-mei wu Zu-Cheng Chen Qing-Guo Huang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Department of Physics and Synergistic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

The pulsar timing array(PTA)collaborations have recently reported compelling evidence for a stochastic signal consistent with a gravitational-wave *** this paper,we combine the latest data sets from NANOGrav,PPTA,and EPTA to explore cosmological interpretations for the PTA signal from first-order phase transitions,domain walls,and cosmic strings,*** find that the domain wall model is strongly disfavored with the Bayes factors compared with the first-order phase transitions and cosmic strings being 1/90 and 1/189,respectively,breaking the degeneracy among these models in individual data *** also find that:(1)a strong phase transition at temperatures below the electroweak scale is favored,and the bubble collisions make the dominant contribution to the energy density spectrum;(2)a small reconnection probability p<1.55×10^(-1)allowed by strings in(super)string theory is favored at the 95%confidence level,and ground-based detectors can further constrain the parameter space.

关键词： puslar timing arrays gravitational-wave background first-order phase transitions domain walls cosmic strings