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Prompt fission neutron uranium logging(Ⅱ):dead-time effect of the neutron time spectrum

Nuclear Science and Techniques 2025年第2期36卷 82-94页

作者： Yan Zhang Chi liu Shi-liang liu Hao-Ran Zhang Hai-Tao Wang Jin-Hui Qu Wen-Xing Hu Ren-Bo Wang Bin Tang National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing East China University of TechnologyNanchang 330013China Fundamental Science on Radioactive Geology and Exploration Technology Laboratory East China University of TechnologyNanchang 330013China

The acquisition of neutron time spectrum data plays a pivotal role in the precise quantification of uranium via prompt fission neutron uranium logging(PFNUL).However,the impact of the detector dead-time effect remains paramount in the accurate acquisition of the neutron time ***,it is imperative for neutron logging instruments to establish a dead-time correction method that is not only uncomplicated but also practical and caters to various logging *** study has formulated an innovative equation for determining dead time and introduced a dead-time correction method for the neutron time spectrum,called the“dual flux method.”Using this approach,a logging instrument captures two neutron time spectra under disparate neutron *** carefully selecting specific“windows”on the neutron time spectrum,the dead time can be accurately *** substantiate its efficacy and discern the influencing factors,experiments were conducted utilizing a deuterium-tritium(D-T)neutron source,a Helium-3(3He)detector,and polyethylene shielding to collate and analyze the neutron time spectrum under varying neutron fluxes(at high voltages).The findings underscore that the“height”and“spacing”of the two windows are the most pivotal influencing ***,the“height”(fd)should surpass 2,and the“spacing”twd should exceed 200μ*** dead time of the 3 He detector determined in the experiment was 7.35μ*** the dead-time correction,the deviation of the decay coefficients from the theoretical values for the neutron time spectrum under varying neutron fluxes decreased from 12.4%to within 5%.Similarly,for the PFNUL instrument,the deviation in the decay coefficients decreased from 22.94 to 0.49%after correcting for the dead-time *** results demonstrate the exceptional efficacy of the proposed method in ensuring precise uranium *** dual flux method was experimentally validated as a universal approach applicable to pulsed neutron logging instrumen

关键词： PFNUL Neutron time spectrum Dead time Pulsed source Correction method

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Facile synthesis of the dodecahydridododecaborate (B12H122-) from borane Lewis base adducts

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Science China Chemistry 2025年

作者： Yi Jing Xin-Ran liu Xing-Hua Wang Hui Han Sha-Sha liang Xi-Meng Chen dong-Hui Wei Lai-Sheng Wang Xue-Nian Chen College of Chemistry Zhengzhou University School of Chemistry and Chemical Engineering Henan Key Laboratory of Boron Chemistry and Advanced MaterialsHenan Normal University Department of Chemistry Brown University

Polyhedral boranes are a class of well-known boron molecular clusters widely used in energy,chemistry,medicine,and materials science because of their unique physical and chemical *** efforts have been made in the past decades to find more effective synthetic methods for this important class of boron ***,existing synthetic methods suffer from low efficiency and low ***,we report a facile one-pot synthesis of[（CH3）3S]2B12H12with moderate yields at mild *** mechanisms for the multi-step chemoselective synthesis of B12H122-without other by-products are elucidated based on theoretical results and our previous *** Lewis base used in B–H bond condensation reaction,which acts as a hydrogen or to balance the newly generated polyhedral borane charges,is proposed and studied in *** current study has led to a more effective and selective synthetic method for B12H122-and has also implicated the syntheses of other new polyhedral boranes.

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High-throughput screening and evaluation of double-linker metal–organic frameworks for CO_(2)/H_(2)adsorption and separation

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Chinese Physics B 2025年第2期34卷 408-417页

作者： Ji-Long Huang Xiu-Ying liu Hao Chen Xiao-dong Li Jing-Xin Yu School of Physics Henan University of TechnologyZhengzhou 450001China R&D Center for Advanced Energy Materials Henan University of TechnologyZhengzhou 450001China

The capture of CO_(2)from CO_(2)/H_(2)gas mixtures in syngas is a crucial issue for hydrogen production from steam methane reforming in industry,as the presence of CO_(2)directly affects the purity of H_(2).A combination of a high-throughput screening method and grand canonical Monte Carlo simulation was utilized to evaluate and screen 1725 metal–organic frameworks(MOFs)in detail as a means of determining their adsorption performance for CO_(2)/H_(2)gas *** adsorption and separation performance of double-linker MOFs was comprehensively evaluated using eight evaluation indicators,namely,the largest cavity diameter,accessible surface area,pore occupied accessible volume,porosity,adsorption selectivity,working capacity,adsorbent performance score and percent *** optimal performance frameworks were screened to further study their single-component adsorption and binary competitive adsorption of CO_(2)/H_(2)*** CO_(2)adsorption selectivity at different CO_(2)/H_(2)feed ratios was also evaluated,which indicated their excellent adsorption and separation *** microscopic adsorption mechanisms for CO_(2)and H_(2)at the molecular level were investigated by analyzing the radial distribution function and density *** study may provide directional guidance and reference for subsequent experiments on the adsorption and separation of CO_(2)/H_(2).

关键词： metal–organic framework adsorption separation high-throughput screening grand canonical Monte Carlo simulation

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A promising approach for quantifying focal stroke modeling and assessing stroke progression:optical resolution photoacoustic microscopy photothrombosis

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Neural Regeneration Research 2025年第7期20卷 2029-2037页

作者： Xiao liang Xingping Quan Xiaorui Geng Yujing Huang Yonghua Zhao Lei Xi Zhen Yuan Ping Wang Bin liu Faculty of Health Sciences University of MacaoMacao Special Administrative RegionChina Center for Cognitive and Brain Sciences University of MacaoMacao Special Administrative RegionChina Department of Biomedical Engineering Southern University of Science and TechnologyShenzhenGuangdong ProvinceChina State Key Laboratory of Quality Research in Chinese Medicine Institute of Chinese Medical SciencesUniversity of MacaoTaipaMacao Special Administrative RegionChina Department of Emergency Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina

To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral ***,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly *** this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed *** observed the molding process in mice of different ages and presented age-dependent vascular embolism ***,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a *** imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.

关键词： age-dependent cerebral cortex ischemic stroke mouse model optical coherence tomography angiography photoacoustic microscopy photothrombosis vascular imaging

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Zircon U-Pb dating of the Shazibu Pluton in the Guocheng gold belt, Jiaolai Basin, Shandong Province: Implications for metallogeny of the Jiaodong gold province

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China Geology 2025年第1期8卷 230-232页

作者： Yuan-yuan Feng Ya-dong Li An-kai Geng liu-an Duan Da-dou Li No.1 Geological Team of Shandong Province Bureau of Geology and Mineral Resources Jinan 250100China Yantai Geological Survey Center of Coastal Zone China Geological SurveyYantai 264004China

*** Three stages of Mesozoic magmatic activity have been identified in the Jiaodong area,namely early magmatic emplacement,the magmatic emplacement prior to mineralization,and magmatic activity post-mineralization,fro... 详细信息

关键词： dating belt mineralization

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Origin and Evolution Process of Overpressure in the Shahezi Formation of Xujiaweizi Fault Depression in the Northern Songliao Basin,NE China

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Acta Geologica Sinica(English Edition) 2025年第1期99卷 212-227页

作者： ZHANG Chengju JIANG Zhenxue LU Jiamin SHI Lidong BI Zhongyu SUN Lidong YANG liang LI Xiaomei liu Jiajun MIAO Huan National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing 102249China Unconventional Petroleum Research Institute China University of Petroleum(Beijing)Beijing 102249China Exploration and Development Research Institute of PetroChina Daqing Oilfield Company Limited DaqingHeilongjiang 163712China

It is of great significance for deep oil and gas exploration to understand the origin and evolution behind *** occurs in the deep Shahezi Formation of Xujiaweizi fault ***,due to limited degree of exploration,there are some problems in the study area,such as unclear understanding of the origin of overpressure and the vague investigation of overpressure *** clarify the impact of overpressure on oil and gas migration and accumulation in the study area,this study focuses on the research of the origin and evolution of overpressure in the Shahezi Formation of the study area,utilizing single well logging parameters and combining methods such as microthermometry of fluid inclusions,laser Raman spectrum,and basin *** results show that the overpressure of the Shahezi Formation in Xujiaweizi fault depression is primarily generated by hydrocarbon generation pressurization,and the evolution of overpressure is closely related to hydrocarbon *** development of overpressure can be divided into two evolutionary stages:early hydrocarbon generation pressurization and late uplift release,with slight variations in different *** glutenite gas reservoirs in the Shahezi Formation are characterized by continuous *** overall charging period ranges from the late Denglouku to the early Mingshui(110-67 Ma ago).There is an obvious paleo-overpressure during the gas reservoir formation *** gas generation period of source rocks occurred approximately 125-60 Ma ago,and the main gas generation period(112-67 Ma ago)highly coincides with the period of natural gas *** anomalously high pressure during the accumulation period is considered the significant driving force for natural gas *** addition,the sustained effect of overpressure provides better conditions for the preservation of tight gas reservoirs within the *** results of the study are of guiding significance for the in-depth expl

关键词： fluid inclusion laser Raman spectrum basin simulation overpressure genesis paleo-pressure recovery Shahezi Formation Xujiaweizi fault depression

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Hierarchically Porous Polypyrrole Foams Contained Ordered Polypyrrole Nanowire Arrays for Multifunctional Electromagnetic Interference Shielding and Dynamic Infrared Stealth

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Nano-Micro Letters 2025年第4期17卷 399-418页

作者： Yu-long liu Ting-yu Zhu Qin Wang Zi-jie Huang De-xiang Sun Jing-hui Yang Xiao-dong Qi Yong Wang School of Chemistry Key Laboratory of Advanced Technologies of Materials(Ministry of Education)Southwest Jiaotong UniversityChengdu 610031People’s Republic of China

As modern communication and detection technologies advance at a swift pace,multifunctional electromagnetic interference(EMI)shielding materials with active/positive infrared stealth,hydrophobicity,and electric-thermal conversion ability have received extensive *** the aforesaid requirements simultaneously remains a huge *** this research,the melamine foam(MF)/polypyrrole(PPy)nanowire arrays(MF@PPy)were fabricated via one-step electrochemical *** hierarchical MF@PPy foam was composed of three-dimensional PPy micro-skeleton and ordered PPy nanowire *** to the upwardly grown PPy nanowire arrays,the MF@PPy foam possessed good hydrophobicity ability with a water contact angle of 142.00°and outstanding stability under various harsh ***,the MF@PPy foam showed excellent thermal insulation property on account of the low thermal conductivity and elongated ligament characteristic of PPy nanowire ***,taking advantage of the high conductivity(128.2 S m^(-1)),the MF@PPy foam exhibited rapid Joule heating under 3 V,resulting in dynamic infrared stealth and thermal camouflage *** importantly,the MF@PPy foam exhibited remarkable EMI shielding effectiveness values of 55.77 dB and 19,928.57 dB cm^(2)g^(-1).Strong EMI shielding was put down to the hierarchically porous PPy structure,which offered outstanding impedance matching,conduction loss,and multiple *** innovative approach provides significant insights to the development of advanced multifunctional EMI shielding foams by constructing PPy nanowire arrays,showing great applications in both military and civilian fields.

关键词： Polypyrrole nanowire arrays Hierarchical foam Hydrophobicity Infrared stealth Electromagnetic interference shielding

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Alteration mechanism and classification and mechanical properties of altered granite

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Journal of Earth Science 2025年

作者： dong Jinyu SHI Shang liu Handong REN Minghao LI Jianyong North China University of Water Resources and Electric Power College of Geosciences and Engineering， North China University of Water Resources and Electric Power

Altered rock， often encountered in major engineering projects， can seriously affect the stability of rocks and slopes surrounding deeply buried tunnels. This study addressed the alteration mechanism， alteration degree classification， and mechanical parameters of altered rock in engineering project areas using field testing， thin slice identification， X-ray diffraction， and major element testing. Results showed that the altered rock types in the areas of the Pingjiang Pumped Storage Power Station (Hunan Province) and a diversion tunnel in northern Xinjiang include biotite granodiorite， biotite monzogranite， and cataclastic granite， and that the main alteration mechanisms are chloritization of biotite and clayization of feldspar minerals. The altered rocks were classified as slightly， moderately， or strongly altered according to their apparent characteristics， rebound value， longitudinal wave velocity， metamorphic mineral content， and porosity. The bulk density， elastic modulus， cohesion， and internal friction angle (Poisson’s ratio) of the altered rocks decreased (increased) with increase in the degree of alteration. Numerical simulations showed that in altered rock slope areas， the zone of strong rock alteration and the moderate–strong alteration contact zone exhibit locally large deformations that represent certain hazard to engineering projects. These results provide valuable guidance and support for major projects in altered rock areas.

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Effects of Paclobutrazol Seed Soaking on Non-Structural Carbohydrate and Grain Enrichment in Direct-Seeded Rice

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Phyton-International Journal of Experimental Botany 2025年第1期94卷 269-279页

作者： Qiang Zhang dongsheng Gai Yong liu Weiyang liu Pengcheng Fu Xiwen Shao Xuanhe liang Yanqiu Geng Liying Guo Agronomy College Jilin Agricultural UniversityChangchun130118China Jilin Academy of Agricultural Sciences Changchun130118China

The yield of direct-seeded rice(DSR)was constrained by inadequate grain *** studies have indicated that paclobutrazol application plays a significant role in enhancing crop agronomic traits and increasing *** study aimed to examine the effects of paclobutrazol seed soaking(PSS)on non-structural carbohydrate accumulation and grain enrichment in DSR,potentially providing a theoretical foundation for achieving high-yield DSR *** experiment utilized two rice varieties,Jiyujing(JYJ)and Jijing305(JJ305),with seeds soaked in paclobutrazol concentrations of 0 mg L−1 and 100 mg L−*** demonstrated increased chlorophyll content,net photosynthetic rate,and leaf area,as well as an extended photosynthetic function period during the filling *** also elevated soluble sugar and starch contents in the flag leaf(during the filling stage)and stem sheath(after heading),decreased starch content in the top panicle while increasing it in the middle and lower panicle during the filling stage,and enhanced spikelet per unit area and seed setting rate,thereby improving DSR *** conclusion,PSS enhanced the photosynthetic capacity of DSR during the filling stage,coordinated the filling process of superior and inferior grains,maintained source-sink balance,and facilitated stable and orderly filling,ultimately resulting in improved yield.

关键词： Paclobutrazol direct-seeded rice soluble sugar starch yield

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Toroidal torques due to n=1 magnetic perturbations in ITER baseline scenario

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Plasma Science and Technology 2025年第1期27卷 39-51页

作者： Jingwei LI Li LI Yueqiang liu Yunfeng liang Yanfei WANG Lu TIAN Zhongqing liu Fangchuan ZHONG College of Physics Donghua UniversityShanghai 201620People’s Republic of China Member of Magnetic Confinement Fusion Research Centre Ministry of EducationShanghai 201620People’s Republic of China General Atomics San Diego CA 92186-5608United States of America Institut für Energie-und Klimaforschung–Plasmaphysik Partner of the Trilateral Euregio Cluster(TEC)Forschungszentrum Juülich GmbHJülich 52425Germany

Toroidal torques,generated by the resonant magnetic perturbation(RMP)and acting on the plasma column,are numerically systematically investigated for an ITER baseline *** neoclassical toroidal viscosity(NTV),in particular the resonant portion,is found to provide the dominant contribution to the total toroidal torque under the slow plasma flow regime in *** the electromagnetic torque always opposes the plasma flow,the toroidal torque associated with the Reynolds stress enhances the plasma flow independent of the flow direction.A peculiar double-peak structure for the net NTV torque is robustly computed for ITER,as the toroidal rotation frequency is scanned near the zero *** structure is found to be ultimately due to a non-monotonic behavior of the wave-particle resonance integral(over the particle pitch angle)in the superbanana plateau NTV regime in *** findings are qualitatively insensitive to variations of a range of factors including the wall resistivity,the plasma pedestal flow and the assumed frequency of the rotating RMP field.

关键词： toroidal torques resonant magnetic perturbation fieds plasma flow ITER baseline scenario

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