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Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-13 tandem accelerator

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Nuclear Science and Techniques 2024年第4期35卷 136-143页

作者： Yang Zhang Sheng-Quan Yan Ming He Qing-Zhang Zhao Wen-Hui Zhang Chao-Xin Kan Jian-Ming Zhou Kang-Ning Li Xiao-fei wang Jian-Cheng Liu Zhao-Hua Peng Zhuo Liang Ai-ling Li Jian Zheng Qi-Wen Fan Yun-Ju Li You-Bao wang Zhi-Hong Li Yang-Ping Shen Ding Nan Wei Nan Yu-Qiang Zhang Jia-Ying-Hao Li Jun-Wen Tian Jiang-Lin hou Chang-Xin Guo Zhi-Cheng Zhang Ming-Hao Zhu Yu-Wen Chen Yu-Chen Jiang Tao Tian Jin-Long Ma Yi-Hui Liu Jing-Yu Dong Run-Long Liu Mei-Yue-Nan Ma Yong-Shou Chen Wei-Ping Liu Bing Guo China Institute of Atomic Energy P.O.Box 275(10)Beijing 102413China College of Science Southern University of Science and TechnologyShenzhen 518055China School of Physics Xi’an Jiaotong UniversityXi’an 710049China

The Moon provides a unique environment for investigating nearby astrophysical events such as *** samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)*** this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy *** particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the ***,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS *** results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)*** sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

关键词： Accelerator mass spectrometry Wien filter Isobar separation Supernovae Chang'e-5 lunar samples

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Expert consensus on irrigation and intracanal medication in root canal therapy

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International Journal of Oral Science 2024年第1期16卷 26-35页

作者： Xiaoying Zou Xin Zheng Yuhong Liang Chengfei Zhang Bing Fan Jingping Liang Junqi ling Zhuan Bian Qing Yu Benxiang hou Zhi Chen Xi Wei Lihong Qiu Wenxia Chen Wenxi He Xin Xu Liuyan Meng Chen Zhang Liming Chen Shuli Deng Yayan Lei Xiaoli Xie Xiaoyan wang Jinhua Yu Jin Zhao Song Shen Xuedong Zhou Lin Yue Department of Cariology and Endodontology Peking University School and Hospital of Stomatology&National Center of Stomatology&National Clinical Research Center for Oral Diseases&National Engineering Laboratory for Digital and Material Technology of Stomatology&Beijing Key Laboratory of Digital Stomatology&Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health&NMPA Key Laboratory for Dental MaterialsBeijingChina Center of Stomatology Peking University HospitalBeijingChina State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases&West China Hospital of Stomatology Sichuan UniversityChengduChina Department of Emergency Peking University School and Hospital of Stomatology&National Center of Stomatology&National Clinical Research Center for Oral Diseases&National Engineering Laboratory for Digital and Material Technology of Stomatology&Beijing Key Laboratory of Digital Stomatology&Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health&NMPA Key Laboratory for Dental MaterialsBeijingChina Restorative Dental Sciences EndodonticsFaculty of DentistryThe University of Hong KongPok Fu LamHong Kong SARChina State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei Key Laboratory of StomatologySchool&Hospital of StomatologyWuhan UniversityWuhanChina Department of Endodontics Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Clinical Research Center for Oral DiseasesNational Center for StomatologyShanghai Key Laboratory of StomatologyShanghaiChina Department of Operative Dentistry and Endodontics Hospital of StomatologyGuanghua School of StomatologySun Yat-Sen University&Guangdong Provincial Key Laboratory of StomatologyGuangzhouChina State Key Laboratory of Oral&Maxillofacial Reconstruction and R

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.

关键词： treatment irrigation Expert

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伸缩缝及支座病害对简支梁桥车致动力响应的影响研究

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振动工程学报 2024年第2期37卷 286-296页

作者：侯剑岭刘灵灵吴喜德许维炳陈彦江王瑾刘钧岩王博李岩张轩交通运输部水运科学研究所北京100088 北京工业大学城市建设学部北京100124 哈尔滨工业大学交通科学与工程学院黑龙江哈尔滨150090 中建二局第一建筑工程有限公司北京100176

中小跨径桥梁在中国公路桥梁中占比大,其伸缩缝服役环境恶劣,易发生损伤造成过往车辆剧烈振动、桥梁支座损伤等病害。为探明伸缩缝、支座参数对简支梁桥车致动力响应的影响,建立了车⁃伸缩缝⁃桥梁耦合动力响应(VBCV⁃J)数值分析方法,并通... 详细信息

中小跨径桥梁在中国公路桥梁中占比大,其伸缩缝服役环境恶劣,易发生损伤造成过往车辆剧烈振动、桥梁支座损伤等病害。为探明伸缩缝、支座参数对简支梁桥车致动力响应的影响,建立了车⁃伸缩缝⁃桥梁耦合动力响应(VBCV⁃J)数值分析方法,并通过实测数据验证了该方法,进而开展了伸缩缝、支座参数影响规律的研究。研究结果表明:车速与车辆的振动密切相关,在车速较高、路面状况“一般”时,伸缩缝、梁端的冲击效应会超出规范值。伸缩缝中梁高于路面会导致该部件的冲击效应增大明显,反之则有所减小;而伸缩缝中梁高于或低于路面,均会造成该桥梁端冲击效应增大。伸缩缝弹性支撑刚度的降低、主梁边支座脱空均会引起伸缩缝、主梁梁端的冲击效应增大。支座刚度降低则主要导致主梁整体的冲击效应增大。伸缩缝的破损不仅影响自身冲击效应,还会大幅增大简支梁桥梁端构件的冲击作用,在设计和养护中,应对伸缩缝及梁端构件给予足够的重视。

关键词：简支梁桥伸缩缝支座参数分析

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无机阴离子对低温拜耳法中脱硅产物析出的影响

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Transactions of Nonferrous Metals Society of China 2024年第4期34卷 1300-1310页

作者：刘吉龙潘晓林吴鸿飞侯宪林于海燕东北大学多金属共生矿生态化冶金教育部重点实验室沈阳110819 东北大学冶金学院沈阳110819 沈阳市有色金属资源循环利用重点实验室沈阳110819

利用XRD、FT-IR、SEM和PSD等手段系统研究无机阴离子对低温拜耳法过程中脱硅产物(DSPs)的组成、结构以及微观形貌的影响。当溶液中存在氯化物、硫酸盐和碳酸盐时,形成氯化物型方钠石、碳酸盐型方钠石和黝方石,部分铝酸盐离子被阴离子杂... 详细信息

利用XRD、FT-IR、SEM和PSD等手段系统研究无机阴离子对低温拜耳法过程中脱硅产物(DSPs)的组成、结构以及微观形貌的影响。当溶液中存在氯化物、硫酸盐和碳酸盐时,形成氯化物型方钠石、碳酸盐型方钠石和黝方石,部分铝酸盐离子被阴离子杂质取代。硫酸盐与DSPs的结合能力强于铝酸盐、氯化物和碳酸盐。随着阴离子浓度的增加,DSPs的粒径增大,且DSPs的团聚程度和圆形片层结构的厚度均有所增加。此外,阴离子杂质会促进沸石骨架的溶解和方钠石中四元环的形成,从而促进沸石向方钠石转化。

关键词：拜耳法水合铝硅酸钠无机阴离子脱硅晶体结构

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高铁有砟轨道路基注浆过程冒浆分析和控制

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吉林大学学报（工学版） 2024年第2期54卷 506-515页

作者：韩笑凌贤长田爽丛晟亦哈尔滨工业大学土木工程学院哈尔滨150090 哈尔滨工业大学重庆研究院重庆401135 黑龙江省寒区轨道交通工程技术研究中心哈尔滨150090

采用COMSOL Multiphysics有限元软件建立高铁有砟轨道路基三维注浆模型,以注浆压力、注浆深度、注浆下倾角度、注浆管间距为主要参数进行了数值模拟研究。研究结果表明:上表面通量可很好地表征冒浆情况,上表面通量与注浆压力具有显著正... 详细信息

采用COMSOL Multiphysics有限元软件建立高铁有砟轨道路基三维注浆模型,以注浆压力、注浆深度、注浆下倾角度、注浆管间距为主要参数进行了数值模拟研究。研究结果表明:上表面通量可很好地表征冒浆情况,上表面通量与注浆压力具有显著正相关性,注浆压力每增大0.1 MPa,通量线性增大约0.05 kg/m^(2)·s;注浆深度、注浆下倾角度、注浆管间距的增大会使表面通量减小;注浆压力对冒浆影响最为显著;采用袖阀管分段和施加上盖层的联合注浆方法能有效控制高铁路基注浆过程中的冒浆问题。

关键词：高速铁路有砟轨道冒浆有限元模拟施工优化

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The Nano Research Young Innovators Awards in bio-inspired nanomaterials

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Nano Research 2024年第2期17卷 417-425页

作者： Jun Chen Shuotao wang Department of Bioengineering University of CaliforniaLos AngelesLos AngelesCA 90095USA Key Laboratory of Bio-inspired Materials and Interfacial Science Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Nano Research Young Innovators(NR45)Awards are designed to acknowledge and celebrate the achievements of young researchers under 45 years of *** individuals have made significant contributions to the field of nanoscience and *** the inaugural NR45 Awards in 2018,the journal's editorial board has recognized over a hundred innovators specializing in nanobiotechnology,nano energy,two-dimensional materials,and *** focus of the 2023 NR45 Awards is on bioinspired nanomaterials,acknowledging thirty-three outstanding young innovators for their extraordinary contributions in developing these materials with applications spanning clean energy,human healthcare,monitoring,and disease treatments,as shown in *** extend our heartfelt congratulations to all the 33 NR45 Awardees in 2023!

关键词： journal materials contributions

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Fullerene bisadduct stabilizers:The effect of different addition positions on inhibiting the autocatalytic decomposition of nitrocellulose absorbed nitroglycerin

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Defence Technology（防务技术） 2021年第6期17卷 1944-1953页

作者： ling Liao Bo Jin Zhi-cheng Guo fei xian Chen-jie hou Ru-fang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologySichuanMianyang621010China

To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose(NC)/nitroglycerine(NG),we synthesized N-(4-methoxy)phenylpyrrolidine-C_(60) and four different of bis(N-(4-methoxy)phenylpyrrolidine)-C_(60) compounds through Prato *** structures were characterized by UVevis,^(1)H NMR,^(13)C NMR,high-resolution mass spectroscopy,and single-crystal X-ray *** stabilization effect to NC/NG were investigated using differential scanning calorimetry,methyl violet,vacuum stabilization effect,weight loss,and accelerating rate calorimeter *** results indicated these compounds had excellent stabilization effect to NC/*** stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C_(60).Moreover,the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different,and its stabilization effect to NC is also *** stabilization effect order of different bisadduct isomers to nitrocellulose is as follows:e-edge>trans-2>cis-2>*** paramagnetic resonance(EPR)and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/*** EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide,and their ability is better than that of the monoadduct and C_(60),which is consistent with the results of stabilization effect performance test.

关键词： Fulleropyrrolidine bisadducts Stabilization effect Nitrocellulose/nitroglycerine

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Konjac glucomannan/pectin/Ca-Mg hydrogel with self-releasing alkalinity to recover phosphate in aqueous solution

Konjac glucomannan/pectin/Ca-Mg hydrogel with self-releasing...

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2024第五届全国功能高分子材料学术研讨会

作者：吴兴玉 Xinyu Zhang Yumei xian Yan Liu ling Luo Lilin wang Chengyi Huang Chao Chen Jinsong He Yanzong Zhang

*** phosphorus for agricultural cultivation can prevent water pollution and alleviate the phosphorus *** polymer hydrogels are featured with low phosphate recovery and poor selectivity,and should be modified with metallic *** and Mg phosphorus recovery yields high-value recyclable products such as hydroxyapatite,struvite,or magnesium phosphate,and yet its effect is often affected by *** problem can be solved by pretreating the metal with alkali[1].However,most polysaccharides are not alkali resistant or have poor water resistance[2].Here,using konjac glucomannan （KGM） and pectin loaded with Ca and Mg for phosphate adsorption capacity,and its agricultural reuse potential were *** KGM/pectin/Ca-Mg composite hydrogel was prepared by alkali-heat *** was freeze-dried for phosphate *** phosphate adsorption properties of the adsorbent were tested by different initial phosphate solution pH,adsorption kinetics,isothermal adsorption lines and coexisting ***,SEM-EDS,XPS,XRD and zero point potential were used to analyze the adsorption ***,the hydrogel was applied back to the soil,and the germination of plant seeds and the growth of seedlings were *** and Mg synergistically promote phosphate adsorption and remain stable in the pH range of 4～*** results showed that the precipitated product was Mg（PO）·8HO and CaPO（OH）·***,the adsorption capacity was significantly inhibited when COor SOcoexist,and it needed a long time to reach ***,the adsorption capacity in livestock wastewater of 17.05 mg-P/L and 35.73 mg-P/L still reached 9.41 mg-P/g and 21.61 mg-P/***,it is unnecessary to separate the recovered phosphate from the hydrogel,and it increased germination rate by 10%and reduce seedling growth difference after ***/pectin/Ca-Mg （KPCM） composite hydrogels can recover phosphate from aqueous solution by self-releasing alkalin

关键词： Konjac glucomannan Pectin Hydrogel Synergistic adsorption Potential fertilizer

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Pb、Zn和Cd复合重金属潜在超富集植物的筛选与胁迫响应特征

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环境科学 2024年第8期45卷 4870-4882页

作者：范拴喜张楠孙旻涵侯宪东陕西地建西安交大土地工程与人居环境技术创新中心西安710049 宝鸡文理学院地理与环境学院宝鸡721013 陕西省灾害监测与机理模拟重点实验室宝鸡721013

为了筛选Pb、Zn和Cd复合重金属超富集植物,对宝鸡市典型铅锌矿和冶炼厂区优势植物进行调查、采样和分析,初步筛选出一种潜在的Pb、Zn和Cd复合重金属超富集植物,并采用土培盆栽试验观测其在Pb、Zn和Cd复合重金属胁迫下叶绿素(叶绿素a、... 详细信息

为了筛选Pb、Zn和Cd复合重金属超富集植物,对宝鸡市典型铅锌矿和冶炼厂区优势植物进行调查、采样和分析,初步筛选出一种潜在的Pb、Zn和Cd复合重金属超富集植物,并采用土培盆栽试验观测其在Pb、Zn和Cd复合重金属胁迫下叶绿素(叶绿素a、叶绿素b、类胡萝卜素、总叶绿素)、抗氧化酶(SOD、CAT、POD)和其他生理指标(MDA、脯氨酸)的响应特征,再通过大田试验,进一步验证并确定了其对Pb、Zn和Cd复合重金属的富集能力,以期为Pb、Zn和Cd复合重金属污染土壤修复提供科学依据和技术支撑.结果表明,野外调查发现聚合草对Pb、Zn和Cd的富集量、富集系数(BCF)和转移系数(TF)均满足国际上超富集植物指标限值要求,是一种潜在的Pb、Zn和Cd复合重金属超富集植物;土培盆栽试验显示,随着Pb、Zn和Cd复合重金属胁迫梯度的提高,聚合草叶片中叶绿素a、叶绿素b和总叶绿素含量逐渐降低,直至胁迫梯度大于等于Ⅳ时,导致植物光合系统紊乱;蓖麻叶片中的叶绿素含量呈现“低促高抑”现象,而胁迫过高则激发了自身其他保护系统使得毒害减轻而升高;另外,与CK相比,聚合草和蓖麻的叶绿素a、叶绿素b、类胡萝卜素和总叶绿素各自均存在显著性差异(P<0.05).聚合草和蓖麻叶片中的SOD酶活性均呈现先增加后降低再增加的趋势;聚合草叶片中CAT酶活性先升后降的趋势,呈现“低促高抑效应”,而蓖麻叶片中CAT酶活性呈现持续降低的趋势;聚合草叶片中POD酶活性总体呈现增加趋势,而蓖麻叶片中POD酶活性先升后降低再升高;聚合草叶片中MDA含量总体呈现下降趋势,而蓖麻叶片中MDA含量总体呈上升特征;此外,各胁迫梯度之间,聚合草和蓖麻的SOD、CAT、POD、MDA及脯氨酸均存在显著性差异(P<0.05).大田试验结果表明,聚合草对Pb、Zn和Cd的富集量、BCF和TF均可以达到超富集植物指标限值要求,是一种潜在的Pb、Zn和Cd复合重金属超富集植物种质资源,能作为Pb、Zn和Cd复合重金属污染土壤修复的优选植物.

关键词： Pb、Zn和Cd复合污染超富集植物生理特性植物修复聚合草蓖麻

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基于模糊C均值聚类的空—地—井垂直重力梯度数据反演方法

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石油地球物理勘探 2024年第3期59卷 629-639页

作者：张显侯振隆赵福权秦朋波赵信阳王家辉东北大学资源与土木工程学院辽宁沈阳110819 中国冶金地质总局青岛地质勘查院山东青岛266109 广州海洋地质调查局广东广州511458

通过重力梯度数据三维反演能够获得地下密度结构模型,用于地质资源勘探等领域。航空、地面和井中观测的重力梯度数据含有不同频率的信息,通过数据联合可以降低反演多解性,提高成像分辨率。对于具有复杂形态的地下异常体,目前这种多尺度... 详细信息

通过重力梯度数据三维反演能够获得地下密度结构模型,用于地质资源勘探等领域。航空、地面和井中观测的重力梯度数据含有不同频率的信息,通过数据联合可以降低反演多解性,提高成像分辨率。对于具有复杂形态的地下异常体,目前这种多尺度数据联合反演的纵向空间分辨率,尤其是异常体底部的成像分辨率有待提升。针对该问题,开展了航空—地面—井中垂直重力梯度数据的联合反演方法研究。首先,在正则化反演中引入模糊C均值聚类算法,通过在迭代过程中加入聚类约束降低多解性;其次,联合航空、地面和井中垂直重力梯度数据,提出一种联合反演方法,并使用GPU加速计算;然后,将反演应用于理论模型数据与美国文顿盐丘地区重力梯度数据,验证方法的效果,并讨论了井位置对结果的影响;最后,对基于GPU加速的并行反演方法进行性能分析。数据试验证明了模糊C均值聚类算法能够降低反演的多解性,通过联合反演能够获得准确的密度分布,该方法具有一定的抗噪能力;使用异常旁井和穿异常井数据的成像分辨率更高。计算的文顿盐丘地区密度分布与其他学者的结论相近,证明了方法是有效且可行的。试验还表明,GPU并行方法具有较高的加速比,提出的方法能够为地质找矿等研究提供技术支撑。

关键词：空—地—井垂直重力梯度密度反演模糊C均值聚类文顿盐丘 GPU加速

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