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^(99m)Tc-DTPA眼眶SPECT/CT对甲状腺相关性眼病泪腺炎症的评估价值 被引量:10
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作者 蒋承志 李新辉 +4 位作者 赵敏 邓豪余 黄金 刘丹 许雪亮 《中南大学学报(医学版)》 CAS CSCD 北大核心 2019年第3期322-328,共7页
目的:探讨^(99m)锝-二亚乙基三胺五乙酸(^(99m)Tc-diethylene triamine pentaacetic acid,^(99m)Tc-DTPA)单光子发射型计算机断层显像/计算机断层扫描(single photon emission computed tomography/computed tomography,SPECT/CT)在甲... 目的:探讨^(99m)锝-二亚乙基三胺五乙酸(^(99m)Tc-diethylene triamine pentaacetic acid,^(99m)Tc-DTPA)单光子发射型计算机断层显像/计算机断层扫描(single photon emission computed tomography/computed tomography,SPECT/CT)在甲状腺相关性眼病(thyroid associated ophthalmopathy,TAO)患者泪腺炎症中的应用价值。方法:回顾性分析58例TAO患者的临床资料,根据临床活动评分(clinical active score,CAS)标准分为活动期组和非活动期组,同时选取影像学表现阴性的12例为对照组。所有患者行^(99m)Tc-DTPA眼眶SPECT/CT,分别在横断面、冠状面图像上测量泪腺横径、长径、体积,勾画泪腺与枕叶脑组织的感兴趣区,测量放射性计数平均值,计算靶/非靶比值(target/non-target ratio,T/NT),比较3组间泪腺参数的差异,并评价各参数对TAO活动性的诊断效能。结果:与对照组比较,除TAO非活动期组冠状面长径和T/NT值外,TAO患者各泪腺参数均明显增长或增高(P<0.05);与非活动组比较,除横断面和冠状面长径外,活动期组其余参数均明显增长或增高(P<0.05);除冠状面长径外,TAO患者泪腺参数均与CAS呈正相关,以横断面T/NT最大值的诊断效能最优(曲线下面积为0.82,P<0.01)。结论:^(99m)Tc-DTPA眼眶SPECT/CT作为一种无创性影像学方法,有助于评估TAO患者泪腺炎症程度及临床活动期分期。 展开更多
关键词 甲状腺相关性眼病 泪腺 单光子发射型计算机断层显像/计算机断层扫描
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考虑真实接触微凸体的岩石节理三维粗糙度指标 被引量:9
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作者 班力壬 戚承志 +3 位作者 李晓照 靳天伟 李惊涛 姜宽 《煤炭学报》 EI CAS CSCD 北大核心 2020年第12期4052-4061,共10页
节理在压剪作用下,仅仅是一小部分较陡微凸体发生接触而相互作用。以往在描述粗糙度时是考虑整个形貌面微凸体的分布特点,这使得所得粗糙度指标弱化了较陡微凸体作用而强化了较平缓微凸体对剪切强度的作用(实际上大多平缓微凸体在剪切... 节理在压剪作用下,仅仅是一小部分较陡微凸体发生接触而相互作用。以往在描述粗糙度时是考虑整个形貌面微凸体的分布特点,这使得所得粗糙度指标弱化了较陡微凸体作用而强化了较平缓微凸体对剪切强度的作用(实际上大多平缓微凸体在剪切过程中未接触)。为考虑实际接触节理的粗糙度,基于Grasselli视倾角分布函数研究了不同视倾角的面积比含量,分析了较陡接触微凸体对节理抗剪强度的作用。对于完全耦合的并且没有填充物的节理,当承受法向荷载时,节理少部分接触微凸体会发生弹性变形,在最初接触的微凸体部分会发生屈服。随着法向应力继续增加,会有更多的微凸体相互接触并发生屈服,这一过程会连续发生直至相互接触的微凸体面积足够大能够承受给定法向荷载的作用。因此,所有接触微凸体中的最小倾角为在一定荷载作用下刚好屈服的微凸体的倾角。对于岩石节理在法向应力下的剪切问题,实际接触面积可以近似认为是作用在节理面上法向荷载除以岩石的单轴抗压强度。考虑实际接触部分节理微凸体分布特征,获取了实际接触节理微凸体平均有效视倾角,得到了合理的三维粗糙度指标。采用巴西劈裂试验方法获取岩石节理面,扫描并获取了节理形貌坐标数据,用以研究节理表面粗糙度。节理峰值剪胀角反映了在某一法向应力下节理的剪切性质,并且可以准确的反映节理峰值抗剪强度。对比分析了实际接触节理粗糙度与节理峰值剪胀角趋势变化,结果表明节理粗糙度新指标可以与节理峰值抗剪强度很好地联系起来。 展开更多
关键词 粗糙度指标 节理峰值抗剪强度 接触理论 节理形貌面 微凸体
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Single-shot spectral-volumetric compressed ultrafast photography 被引量:7
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作者 Pengpeng Ding Yunhua Yao +12 位作者 Dalong Qi Chengshuai Yang Fengyan Cao Yilin He Jiali Yao chengzhi jin Zhengqi Huang Li Deng Lianzhong Deng Tianqing Jia jinyang Liang Zhenrong Sun Shian Zhang 《Advanced Photonics》 EI CSCD 2021年第4期35-40,共6页
In ultrafast optical imaging,it is critical to obtain the spatial structure,temporal evolution,and spectral composition of the object with snapshots in order to better observe and understand unrepeatable or irreversib... In ultrafast optical imaging,it is critical to obtain the spatial structure,temporal evolution,and spectral composition of the object with snapshots in order to better observe and understand unrepeatable or irreversible dynamic scenes.However,so far,there are no ultrafast optical imaging techniques that can simultaneously capture the spatial–temporal–spectral five-dimensional(5D)information of dynamic scenes.To break the limitation of the existing techniques in imaging dimensions,we develop a spectral-volumetric compressed ultrafast photography(SV-CUP)technique.In our SV-CUP,the spatial resolutions in the x,y and z directions are,respectively,0.39,0.35,and 3 mm with an 8.8 mm×6.3 mm field of view,the temporal frame interval is 2 ps,and the spectral frame interval is 1.72 nm.To demonstrate the excellent performance of our SV-CUP in spatial–temporal–spectral 5D imaging,we successfully measure the spectrally resolved photoluminescent dynamics of a 3D mannequin coated with CdSe quantum dots.Our SV-CUP brings unprecedented detection capabilities to dynamic scenes,which has important application prospects in fundamental research and applied science. 展开更多
关键词 ultrafast optical imaging multi-dimensional imaging computational imaging compressed sensing image reconstruction
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^(99m)Tc-DTPA眼眶SPECT/CT显像非靶区及阈值的选择在甲状腺相关性眼病中的应用 被引量:7
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作者 蒋承志 李新辉 +4 位作者 邓豪余 刘进言 黄金 刘丹 许雪亮 《中南大学学报(医学版)》 CAS CSCD 北大核心 2018年第8期869-874,共6页
目的:比较4种靶/非靶比值(target-to-nontarget ratio,T/NT)的诊断价值,选择更佳评估甲状腺相关性眼病(thyroid associated ophthalmopathy,TAO)活动性的T/NT以及判断TAO炎性活动性的阈值。方法:回顾性分析初诊为TAO的患者29例(58只眼)... 目的:比较4种靶/非靶比值(target-to-nontarget ratio,T/NT)的诊断价值,选择更佳评估甲状腺相关性眼病(thyroid associated ophthalmopathy,TAO)活动性的T/NT以及判断TAO炎性活动性的阈值。方法:回顾性分析初诊为TAO的患者29例(58只眼),均行^(99m)Tc-DTPA眼眶单光子发射计算机断层显像/计算机断层扫描(single photon emission computed tomography/computed tomography,SPECT/CT),根据临床活动性评分(clinical activity score,CAS)分为活动期组18例(36只眼),非活动期组11例(22只眼);同时设置对照组9例(18只眼);分别计算每个眼眶的眼眶/枕叶脑组织放射性计数比值(T/NT1)、眼眶/枕骨放射性计数比值(T/NT2)、眼眶/丘脑放射性计数比值(T/NT3)和眼眶/小脑放射性计数比值(T/NT4),与CAS行Spearman秩相关分析和受试者工作特征(receiver operating characteristic,ROC)曲线分析。结果:T/NT1和T/NT2与CAS有相关性(r_1=0.873,r_2=0.527;P<0.001),T/NT1与CAS评分相关性更好;T/NT3和T/NT4与CAS之间无相关性(r_3=0.039,r_4=0.090;均P>0.05);T/NT1的ROC曲线下面积为0.860,T/NT2的ROC曲线下面积为0.581,故T/NT1对TAO活动性评估的准确性更高;T/NT1=9.74为判断TAO患者活动性的阈值。结论:T/NT1与CAS有更好的相关性,对于TAO活动性评估有更高的诊断价值,SPECT/CT同机融合显像解剖定位更为精确。 展开更多
关键词 甲状腺相关性眼病 靶/非靶比值 阈值 单光子发射计算机断层显像/计算机断层扫捕
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Evolution and Domestication Footprints Uncovered from the Genomes of Coix 被引量:7
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作者 Hongbing Liu Junpeng Shi +11 位作者 Zexi Cai Yumin Huang Menglu Lv Huilong Du Qiang Gao Yi Zuo Zhaobin Dong Wei Huang Rui Qin chengzhi Liang jinsheng Lai Weiwei jin 《Molecular Plant》 SCIE CAS CSCD 2020年第2期295-308,共14页
Coix lacryma-jobi,a plant species closely related to Zea and Sorghum,is an important food and medicinal crop in Asia.However,no reference genome of this species has been reported,and its exact phylogeny within the And... Coix lacryma-jobi,a plant species closely related to Zea and Sorghum,is an important food and medicinal crop in Asia.However,no reference genome of this species has been reported,and its exact phylogeny within the Andropogoneae remains unresolved.Here,we generated a high-quality genome assembly of coix comprising~1.73 Gb with 44485 predicted protein-coding genes.We found coix to be a typical diploid plant with an overall 1-to-1 syntenic relationship with the Sorghum genome,despite its drastic genome expansion(~2.3-fold)due mainly to the activity of transposable elements.Phylogenetic analysis revealed that coix diverged with sorghum~10.41 million years ago,which was~1.49 million years later than the divergence between sorghum and maize.Resequencing of 27 additional coix accessions revealed that they could be unambiguously separated into wild relatives and cultivars,and suggested that coix experienced a strong genetic bottleneck,resulting in the loss of about half of the genetic diversity during domestication,even though many traits have remained undomesticated.Our data not only provide novel comparative genomic and evolutionary insights into the Andropogoneae lineage,but also an important resource that will greatly benefit molecular breeding of this important crop. 展开更多
关键词 COIX lacryma-jobi L. GENOME comparative GENOMICS DOMESTICATION
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Remote sensing of quality traits in cereal and arable production systems:A review
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作者 Zhenhai Li chengzhi Fan +8 位作者 Yu Zhao Xiuliang jin Raffaele Casa Wenjiang Huang Xiaoyu Song Gerald Blasch Guijun Yang James Taylor Zhenhong Li 《The Crop Journal》 SCIE CSCD 2024年第1期45-57,共13页
Cereal is an essential source of calories and protein for the global population.Accurately predicting cereal quality before harvest is highly desirable in order to optimise management for farmers,grading harvest and c... Cereal is an essential source of calories and protein for the global population.Accurately predicting cereal quality before harvest is highly desirable in order to optimise management for farmers,grading harvest and categorised storage for enterprises,future trading prices,and policy planning.The use of remote sensing data with extensive spatial coverage demonstrates some potential in predicting crop quality traits.Many studies have also proposed models and methods for predicting such traits based on multiplatform remote sensing data.In this paper,the key quality traits that are of interest to producers and consumers are introduced.The literature related to grain quality prediction was analyzed in detail,and a review was conducted on remote sensing platforms,commonly used methods,potential gaps,and future trends in crop quality prediction.This review recommends new research directions that go beyond the traditional methods and discusses grain quality retrieval and the associated challenges from the perspective of remote sensing data. 展开更多
关键词 Remote sensing Quality traits Grain protein CEREAL
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不同养分环境下钙添加对柏木家系苗木生长和根系发育的影响 被引量:6
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作者 袁承志 陈坦 +4 位作者 张振 金国庆 丰忠平 周志春 郑一 《应用与环境生物学报》 CAS CSCD 北大核心 2020年第5期1161-1168,共8页
研究不同养分环境下钙添加对柏木家系苗木生长和根系发育的影响,为柏木造林地选择和施肥管理提供理论依据.以5个柏木家系的1年生容器苗为材料,进行一个生长季的钙添加盆栽实验.实验分别在肥沃(添加3 g/kg NPK控释肥)和贫瘠(未施肥)两种... 研究不同养分环境下钙添加对柏木家系苗木生长和根系发育的影响,为柏木造林地选择和施肥管理提供理论依据.以5个柏木家系的1年生容器苗为材料,进行一个生长季的钙添加盆栽实验.实验分别在肥沃(添加3 g/kg NPK控释肥)和贫瘠(未施肥)两种土壤养分环境下,模拟3种浓度(0 g/kg、3 g/kg和6 g/kg)的钙添加对柏木家系苗木生长及根系发育的影响.结果表明:(1)肥沃条件下,柏木的株高、地径、全株干物质量、根长、根表面积和根体积分别是贫瘠条件下的1.46、1.14、1.67、1.28、1.45和1.65倍.(2)在贫瘠条件中,添加3 g/kg钙提早并延长了苗木的速生期,其株高、地径和全株干物质量较对照分别增加8.42%、6.06%和10.74%,而添加6 g/kg钙显著降低了柏木的株高、地径,较对照分别减少3.37%和5.66%;在肥沃条件中,随钙浓度的增加,柏木苗高的速生期出现推迟并缩短的现象,但株高和地径在不同钙处理间差异不显著.(3)在两种养分条件下,外源钙对柏木苗木的根系参数均有抑制作用.贫瘠条件下,3 g/kg钙处理抑制作用最强,柏木的根系参数在添加3 g/kg钙后较对照降低了12.20%、18.13%和23.41%;肥沃条件下,6 g/kg钙处理抑制作用最强,柏木的根系参数在添加6 g/kg钙后较对照降低了19.82%、17.00%和14.38%.(4)柏木家系的生长及根系发育对钙添加的响应不同.在贫瘠条件下,柏木生长及根系发育在家系间差异不显著,但株高和地径存在显著的家系×钙互作效应;在肥沃条件下,柏木生长及根系发育在家系间差异显著或极显著,柏木家系的株高、地径、全株干物质量、根茎干物质量和根体积存在显著的家系×钙互作效应.本研究表明在生产上可通过添加适量的钙来增加柏木在贫瘠立地条件下的高生长和干物质量;在相对肥沃的养分条件下可通过优良家系选育应用于生产.(图5表3参37) 展开更多
关键词 柏木 家系 钙添加 生长 根系发育
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A chromosome-scale genome assembly of Dasypyrum villosum provides insights into its application as a broad-spectrum disease resistance resource for wheat improvement 被引量:2
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作者 Xu Zhang Haiyan Wang +13 位作者 Haojie Sun Yingbo Li Yilong Feng chengzhi Jiao Mengli Li Xinying Song Tong Wang Zongkuan Wang Chunxia Yuan Li Sun Ruju Lu Wenli Zhang jin Xiao Xiue Wang 《Molecular Plant》 SCIE CAS CSCD 2023年第2期432-451,共20页
Dasypyrum villosum is one of the most valuable gene resources in wheat improvement,especially for disease resistance.The mining of favorable genes from D.villosum is frustrated by the lack of a whole genome sequence.I... Dasypyrum villosum is one of the most valuable gene resources in wheat improvement,especially for disease resistance.The mining of favorable genes from D.villosum is frustrated by the lack of a whole genome sequence.In this study,we generated a doubled-haploid line,91C43^(DH),using microspore culture and obtained a 4.05-GB high-quality,chromosome-scale genome assembly for D.villosum.The assembly contains39727 high-confidence genes,and 85.31% of the sequences are repetitive.Two reciprocal translocation events were detected,and 7VS-4VL is a unique translocation in D.villosum.The prolamin seed storage protein-coding genes were found to be duplicated;in particular,the genes encoding low-molecular-weight glutenin at the Glu-V3 locus were significantly expanded.RNA sequencing(RNA-seq)analysis indicated that,after Blumeria graminearum f.sp tritici(Bgt)inoculation,there were more upregulated genes involved in the pattern-triggered immunity and effector-triggered immunity defense pathways in D.villosum than in Triticum urartu.MNase hypersensitive sequencing(MH-seq)identified two Bgt-inducible MH sites(MHSs),one in the promoter and one in the 3'terminal region of the powdery mildew resistance(Pm)gene NLR1-V.Each site had two subpeaks and they were termed MHS1(MHS1.1/1.2)and MHS2(MHS2.1/2.2).Bgt-inducible MHS2.2 was uniquely present in D.villosum,and MHS1.1 was more inducible in D.villosum than in wheat,suggesting that MHSs may be critical for regulation of NLR1-V expression and plant defense.In summary,this study provides a valuable genome resource for functional genomics studies and wheat-D.villosum introgression breeding.The identified regulatory mechanisms may also be exploited to develop new strategies for enhancing Pm resistance by optimizing gene expression in wheat. 展开更多
关键词 D.villosum genome crop wild relative genome evolution disease resistance RNA-seq MNase hy-persensitivityassay
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大模型时代下全文计量分析的应用与思考——2023全文本文献计量分析学术沙龙综述
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作者 周海晨 章成志 +3 位作者 胡志刚 徐硕 毛进 陈亮 《信息资源管理学报》 2024年第2期162-168,F0003,共8页
2023年9月14日—16日,由中国科学院成都文献情报中心主办、科技创新评价研究中心(SERC)承办的“第六届科学计量与科技评价天府论坛”在成都举办。由章成志、胡志刚、徐硕等人共同发起的第四届“全文本文献计量分析”沙龙作为其中的一项... 2023年9月14日—16日,由中国科学院成都文献情报中心主办、科技创新评价研究中心(SERC)承办的“第六届科学计量与科技评价天府论坛”在成都举办。由章成志、胡志刚、徐硕等人共同发起的第四届“全文本文献计量分析”沙龙作为其中的一项重要活动,吸引了八十余位专家学者的积极参与和深入交流。本文通过对沙龙嘉宾的发言与研讨内容进行梳理与总结,将沙龙的主要内容归纳为大语言模型与全文本计量分析、全文计量分析的应用场景等方面,以期介绍国内外全文本文献计量分析的研究现状和发展趋势。 展开更多
关键词 全文本计量 大语言模型 颠覆性技术 创新识别
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Faster structured illumination microscopy using complementary encoding-based compressive imaging
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作者 ZHENGQI HUANG YUNHUA YAO +8 位作者 YILIN HE YU HE chengzhi jin MENGDI GUO DALONG QI LIANZHONG DENG ZHENRONG SUN ZHIYONG WANG SHIAN ZHANG 《Photonics Research》 SCIE EI CAS CSCD 2024年第4期740-748,共9页
Structured illumination microscopy (SIM) has been widely applied to investigate intricate biological dynamics due to its outstanding super-resolution imaging speed. Incorporating compressive sensing into SIM brings th... Structured illumination microscopy (SIM) has been widely applied to investigate intricate biological dynamics due to its outstanding super-resolution imaging speed. Incorporating compressive sensing into SIM brings the possibility to further improve the super-resolution imaging speed. Nevertheless, the recovery of the superresolution information from the compressed measurement remains challenging in experiments. Here, we report structured illumination microscopy with complementary encoding-based compressive imaging (CECI-SIM) to realize faster super-resolution imaging. Compared to the nine measurements to obtain a super-resolution image in a conventional SIM, CECI-SIM can achieve a super-resolution image by three measurements;therefore, a threefold improvement in the imaging speed can be achieved. This faster imaging ability in CECI-SIM is experimentally verified by observing tubulin and actin in mouse embryonic fibroblast cells. This work provides a feasible solution for high-speed super-resolution imaging, which would bring significant applications in biomedical research. 展开更多
关键词 ILLUMINATION COMPLEMENTARY FASTER
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基于免训练自监督式神经网络算法实现压缩超快成像高保真图像重构
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作者 金诚挚 齐大龙 +13 位作者 何宇 姚佳丽 郭姿含 许宁 程龙 毛佳亿 姚志明 宋岩 姚云华 沈乐成 邓联忠 盛亮 孙真荣 张诗按 《科学通报》 EI CAS CSCD 北大核心 2024年第19期2765-2776,共12页
压缩超快成像(compressed ultrafast photography,CUP)是目前最快的被动式单次超快光学成像技术,它通过数据获取和图像重构两个步骤实现超快事件的捕捉,已发展为记录不可逆或难以重复超快事件的一种有力工具,且能够探测荧光动力学等自... 压缩超快成像(compressed ultrafast photography,CUP)是目前最快的被动式单次超快光学成像技术,它通过数据获取和图像重构两个步骤实现超快事件的捕捉,已发展为记录不可逆或难以重复超快事件的一种有力工具,且能够探测荧光动力学等自发光瞬态场景.然而,传统的迭代优化型算法在图像重构上的保真度较低,而端到端型深度学习算法则严重依赖训练数据,训练复杂度高、通用性不足,这限制了CUP对超快现象进行高空间分辨率的观测.为此,我们开发了一种新型的免训练自监督式神经网络算法,其通过即插即用框架(plug-and-play,PnP)与深度图像先验(deep image prior,DIP)的结合可实现CUP的低复杂度高保真图像重建,简称为PnP-DIP算法.PnP-DIP基于交替方向乘子法(alternating direction method of multipliers,ADMM),利用DIP和PnP去噪器解决图像恢复子问题,可以在防止数据过拟合和噪声累积的同时,显著提高图像重建的精度与收敛速度.通过数值模拟,我们理论上证明了PnP-DIP算法在重构原始动态信息方面相比传统ADMM算法具有更高的保真度.同时,我们分别利用PnPDIP对自主研制CUP系统观测的皮秒激光脉冲和X射线闪烁体的时空强度演化数据进行重构,实验上验证了其优越的图像重构性能.这一研究有望推动CUP在高时空分辨观测需求中的应用,并为超快动力学的实时探测作出重大贡献. 展开更多
关键词 压缩超快成像 图像重构 交替方向乘子法 即插即用 深度图像先验
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Neodymium cations Nd^(3+x) were transported to the interior of Euglena gracilis 277 被引量:2
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作者 KANG Lin, SHEN Zhiqiang & jin chengzhi Institute of Genetics, State key Laboratory of Genetic Engineering, Fudan University, Shanghai 200433, China Research Centre of Analysis and Measurement, Fudan University, Shanghai 200433, China Correspondence should be addressed to jin chengzhi 《Chinese Science Bulletin》 SCIE EI CAS 2000年第7期585-592,共8页
Euglena gracilis 277, a unicellular green alga, demonstrated remarkable ability to transport Nd3+ to the cell compartments. For a given amount of Nd3+ and cells, the results of ICP-AES indicated that the cellular upta... Euglena gracilis 277, a unicellular green alga, demonstrated remarkable ability to transport Nd3+ to the cell compartments. For a given amount of Nd3+ and cells, the results of ICP-AES indicated that the cellular uptake of Nd3+ was independent of Nd3+ concentration in thebulk solution. The average uptake of Nd3+ per celi (mMd) is proportional to a parameter ξ-theratio of neodymium content to the celi counts of the system. A novel approach for probing cellular neodymium by tetraiodotetra chlorofluorescein (I4TCF) has been devised. Data derived from the cryosections of !4TCF-Nd3+ stained cells and EDAX of the fast freezing ultrathin cryosections indicate that Nd3+ is distributed over the celi compartments. Chloroplasts are the major compartments as the residence of Nd3+ in the alga. The transport should be against a concentration gradient of Nd3+ on the order of five, even higher. it is proposed that a calcium ion channel would play an important role in the Nd3+ transportation. 展开更多
关键词 NEODYMIUM CATIONS (Nd3+) EUGLENA GRACILIS EDAX I4TCF.
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Downward shift of gas hydrate stability zone due to seafloor erosion in the eastern Dongsha Island,South China Sea 被引量:4
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作者 jin Jiapeng WANG Xiujuan +5 位作者 HE Min LI Jie YAN chengzhi LI Yuanping ZHOU Jilin QIAN jin 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2020年第4期1188-1200,共13页
New acquired and reprocessed three-dimensional(3D)seismic data were used to delineate the distribution and characterization of bottom simulating reflections(BSRs)in the Chaoshan Sag,in the eastern part of Dongsha Isla... New acquired and reprocessed three-dimensional(3D)seismic data were used to delineate the distribution and characterization of bottom simulating reflections(BSRs)in the Chaoshan Sag,in the eastern part of Dongsha Island,South China Sea.Three submarine canyons with different scales were interpreted from the 3D seismic data,displaying three stages of canyon development and are related with the variation of BSR.Abundant faults were identified from the coherence and ant-tracing attributions extracted from 3D seismic data,which provide the evidence for fluid migration from deeper sediments to the gas hydrate stability zone(GHSZ).The uplift of Dongsha Island created a large number of faults and leads to the increased seafloor erosion.The erosion caused the cooling of the seafloor sediments and deepening of the base of the gas hydrate stability zone,which is attributed to the presence of paleo-BSR and BSR downward shift in the study area.Hence,methane gas may be released during the BSR resetting and gas hydrate dissociation related with seafloor erosion. 展开更多
关键词 bottom simulating reflections(BSRs) downward shift seafloor erosion gas hydrate dissociation
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33年生马尾松木材力学性质种源变异研究 被引量:5
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作者 袁承志 张振 +4 位作者 郑一 金国庆 丰忠平 周志春 徐刚标 《中南林业科技大学学报》 CAS CSCD 北大核心 2021年第8期68-74,107,共8页
【目的】研究成熟期马尾松木材力学性质的种源变异规律,加深对马尾松群体遗传进化的理解,为马尾松木材材质遗传改良提供理论依据。【方法】以33年生马尾松种源试验林中具有代表性的20个种源为研究对象,按照国家标准测定参试材料的木材... 【目的】研究成熟期马尾松木材力学性质的种源变异规律,加深对马尾松群体遗传进化的理解,为马尾松木材材质遗传改良提供理论依据。【方法】以33年生马尾松种源试验林中具有代表性的20个种源为研究对象,按照国家标准测定参试材料的木材力学性质指标。采用SPSS软件,分析马尾松木材力学性质和生长性状的种源间差异显著性,探讨木材力学性质指标与生长性状指标、种源气候因子之间的相关性。采用隶属函数法,综合评价马尾松种源木材力学性质。【结果】马尾松不同种源木材力学性质差异极显著,各项力学性质指标变异系数的变异幅度为5.40%~21.04%。马尾松木材力学性质指标与种源地理经度、纬度相关性不显著,但与种源的气温和降水量呈显著负相关,这表明马尾松木材力学性质差异主要受种源水热资源影响。种源气温是马尾松种源木材力学性质表现的最佳预测因子,种源气温越低,其木材硬度和抗弯强度越高。马尾松木材力学性质指标与其胸径、材积呈显著负相关,但与高径比呈显著正相关,木材力学性质指标间呈显著正相关。隶属函数综合评价表明,马尾松木材力学性质隶属值排名前3位的种源分别是湖南安化、四川南江和贵州黎平。结合生长性状表现,综合排名前3位的马尾松种源分别是浙江庆元、湖南安化和贵州黎平。【结论】马尾松木材力学性质在种源间存在丰富的遗传变异,种源选择可望获得预期的马尾松材性遗传改良效果。初选出的木材力学性质和生长表现优良的马尾松种源,可为林业生产提供良种材料。 展开更多
关键词 马尾松 种源 木材力学性质 变异
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Temporal compressive super-resolution microscopy at frame rate of 1200 frames per second and spatial resolution of 100 nm 被引量:1
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作者 Yilin He Yunhua Yao +10 位作者 Dalong Qi Yu He Zhengqi Huang Pengpeng Ding chengzhi jin Chonglei Zhang Lianzhong Deng Kebin Shi Zhenrong Sun Xiaocong Yuan Shian Zhang 《Advanced Photonics》 SCIE EI CAS CSCD 2023年第2期54-61,共8页
Various super-resolution microscopy techniques have been presented to explore fine structures of biological specimens.However,the super-resolution capability is often achieved at the expense of reducing imaging speed ... Various super-resolution microscopy techniques have been presented to explore fine structures of biological specimens.However,the super-resolution capability is often achieved at the expense of reducing imaging speed by either point scanning or multiframe computation.The contradiction between spatial resolution and imaging speed seriously hampers the observation of high-speed dynamics of fine structures.To overcome this contradiction,here we propose and demonstrate a temporal compressive super-resolution microscopy(TCSRM)technique.This technique is to merge an enhanced temporal compressive microscopy and a deep-learning-based super-resolution image reconstruction,where the enhanced temporal compressive microscopy is utilized to improve the imaging speed,and the deep-learning-based super-resolution image reconstruction is used to realize the resolution enhancement.The high-speed super-resolution imaging ability of TCSRM with a frame rate of 1200 frames per second(fps)and spatial resolution of 100 nm is experimentally demonstrated by capturing the flowing fluorescent beads in microfluidic chip.Given the outstanding imaging performance with high-speed super-resolution,TCSRM provides a desired tool for the studies of high-speed dynamical behaviors in fine structures,especially in the biomedical field. 展开更多
关键词 super-resolution microscopy high-speed imaging compressive sensing deep learning image reconstruction.
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基于数字孪生的生产线监控系统研究 被引量:4
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作者 张晓萍 窦金生 +3 位作者 宋天麟 赵呈治 金晓东 范利辉 《包装与食品机械》 CAS 北大核心 2022年第4期73-78,共6页
针对目前灌装生产线监控系统的透明度低和缺乏模型等问题,对灌装生产线监控硬件平台、控制系统和数据处理方法进行研究,设计基于数字孪生技术的灌装生产线动态模型监控系统。首先对架构进行阐述,系统包括设备层、感知层、数据模型层和... 针对目前灌装生产线监控系统的透明度低和缺乏模型等问题,对灌装生产线监控硬件平台、控制系统和数据处理方法进行研究,设计基于数字孪生技术的灌装生产线动态模型监控系统。首先对架构进行阐述,系统包括设备层、感知层、数据模型层和应用层;然后进行产线监控系统的硬件设计;再搭建生产线的数字孪生模型;其次对生产线监控系统的软件进行设计,包括上位机监控软件和下位机现场控制程序;最后对生产线监控系统进行实例验证。研究结果表明:系统可实现理瓶、贴标、灌装、旋盖和仓储等生产环节的数据采集,后台数据模型可视度高,可对生产过程进行动态监控,并对生产线进行故障报警和故障分析等智能化管理。 展开更多
关键词 数字孪生 生产线监控系统 IFIX PAC
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固体氧化物电池Ni-YSZ燃料电极长期稳定性研究进展 被引量:4
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作者 邵晴 罗凌虹 +4 位作者 关成志 王建强 金盾 余剑峰 林囿辰 《陶瓷学报》 CAS 北大核心 2022年第5期759-779,共21页
在碳中和背景下,固体氧化物电池(SOCs, Solid Oxide Cells)是一种极具前途的能量转换技术。在SOCs中,尽管在开发混合离子电子导体复合电极和钙钛矿燃料电极方面取得了令人瞩目的进展,但Ni-YSZ由于同时具有SOFC模式下氢氧化反应(HOR)和S... 在碳中和背景下,固体氧化物电池(SOCs, Solid Oxide Cells)是一种极具前途的能量转换技术。在SOCs中,尽管在开发混合离子电子导体复合电极和钙钛矿燃料电极方面取得了令人瞩目的进展,但Ni-YSZ由于同时具有SOFC模式下氢氧化反应(HOR)和SOEC模式下析氢反应(HER)的优异催化活性,仍然是商业化燃料电极的最佳选择。然而,Ni-YSZ电极的衰减是制约SOCs发展的重要问题。简单介绍了Ni-YSZ电极材料,并总结了SOFC和SOEC模式下有关Ni-YSZ电极衰减的典型现象,重点关注了Ni-YSZ电极衰减的原因,并基于衰减机理提出了改进方案和思路。最后,对Ni-YSZ电极长期稳定性的优化策略提出了展望。 展开更多
关键词 固体氧化物电池 燃料电极 Ni-YSZ 长期稳定性
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Investigation on the physical mechanism of cavity percentage dependent shear strength for rock joints considering the real contact joint surface
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作者 Liren Ban Zefan Wang +3 位作者 Weisheng Du Yuhang Hou chengzhi Qi jin Yu 《Rock Mechanics Bulletin》 2023年第4期1-11,共11页
To explain the effect of joint roughness on joint peak shear strength(JPSS)and investigate the effect of different contact states of joint surface on JPSS,we try to clarify the physical mechanism of the effect of join... To explain the effect of joint roughness on joint peak shear strength(JPSS)and investigate the effect of different contact states of joint surface on JPSS,we try to clarify the physical mechanism of the effect of joint cavity percentage(JCP)on JPSS from the perspective of the three-dimensional(3D)distribution characteristics of the actual contact joint surface,and propose a JPSS model considering the JCP.Shear tests for red sandstone joints with three different surface morphologies and three different JCPs were performed under constant normal load condition.Based on test fitting results,the reduction effect of the JCP on JPSS is investigated,and a JPSS model for cavity-containing joints is obtained.However,the above model only considers the influence of JCP by fitting test data,and does not reveal the physical mechanism of JCP affecting the JPSS.Based on the peak dilation angle model for consideration of the actual contact joint morphology,and the influence of JCP on the roughness of the actual contact joint surface,a theoretical model of the JPSS considering the JCP is proposed.The derivation process does not depend on the test fitting,but is entirely based on the joint mechanical law,and its physical significance is clear.It is proposed that the essence of the influence of the JCP on JPSS is that the JCP first affects the normal stress of the actual contact joints,further affects the roughness of actual contact joints,and then affects the shear strength. 展开更多
关键词 ROUGHNESS Joint peak shear strength Joint shear test Surface morphology Cavity percentage
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燃气轮机动力涡轮转子动力学相似试验模型的设计方法研究
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作者 黄朝晖 袁奇 +2 位作者 余承智 高进 孔祥林 《西安交通大学学报》 EI CAS CSCD 北大核心 2023年第10期78-88,共11页
针对某实际燃气轮机动力涡轮转子因结构尺寸大、质量大等原因无法直接开展试验动力学研究,提出了一种由三维有限元仿真计算和试验相结合的动力学相似试验转子模型的设计方法。首先,利用动力相似原则建立原始涡轮转子的动力相似试验转子... 针对某实际燃气轮机动力涡轮转子因结构尺寸大、质量大等原因无法直接开展试验动力学研究,提出了一种由三维有限元仿真计算和试验相结合的动力学相似试验转子模型的设计方法。首先,利用动力相似原则建立原始涡轮转子的动力相似试验转子模型和相应转子试验台,确定了目标函数为临界转速和振型相似;然后,分别进行转子动力学相似模型的有限元仿真计算和动力学特性试验,所得临界转速最大相对误差为4.5%,API 612高速动平衡标准下的不平衡响应峰-峰值相对误差为1.5%,说明仿真和试验的结果可靠;最后,对动力相似试验转子模型的有效性进行验证,动力相似试验转子模型的临界转速仿真和试验结果均与原始涡轮转子模型的临界转速成2.05倍关系,符合动力相似准则,并且动力相似试验转子模型的应变能分布与原始转子模型相似,成功构建了原始涡轮转子模型的动力相似试验转子模型,对于叶盘-转子系统的稳定性分析和试验设计研究有很大的参考价值和现实意义。 展开更多
关键词 燃气轮机 动力涡轮 动力学相似 应变能 临界转速 叶盘-转子系统
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单曝光偏振映射超快成像
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作者 丁鹏鹏 齐大龙 +7 位作者 姚云华 何一林 姚佳丽 金诚挚 郭姿含 邓联忠 孙真荣 张诗按 《Science Bulletin》 SCIE EI CAS CSCD 2023年第5期473-476,M0003,共5页
单曝光超快光学成像可以捕捉发生在纳秒时间尺度内的瞬态场景,尤其是对于泵浦探测技术无能为力的不可逆或难以重复的场景更具优势.为了打破传统CCD或CMOS相机的数据读出速度限制,单曝光超快成像技术通常将时间信息转换到波长、空间或空... 单曝光超快光学成像可以捕捉发生在纳秒时间尺度内的瞬态场景,尤其是对于泵浦探测技术无能为力的不可逆或难以重复的场景更具优势.为了打破传统CCD或CMOS相机的数据读出速度限制,单曝光超快成像技术通常将时间信息转换到波长、空间或空间频域等来进行超快探测.本文作者开发了一种新型时间-偏振映射的超快成像技术(PUMP),首先利用石英旋光晶体产生具有时变偏振角的超短激光脉冲照明动态场景,然后通过偏振滤波阵列对不同时刻信息进行快照曝光,最后结合迭代去卷积算法,实现了将时域信息转换到偏振维度的超快成像.此外,作者利用该新型超快成像系统实时观测了氧化铟锡薄膜的超快激光烧蚀动力学过程,验证了其在超快探测中的出色性能.该技术的发展有望进一步推动超快光学成像在基础和应用科学研究领域的应用. 展开更多
关键词 速度限制 应用科学研究 信息转换 氧化铟锡薄膜 超短激光脉冲 CMOS相机 动态场景 数据读出
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