检索结果-南通市图书馆

Characterizing motion types of G-band bright points in the quiet Sun

Research in Astronomy and Astrophysics 2015年第4期15卷 569-582页

作者： Yun-Fei Yang hui-xue qu Kai-Fan Ji Song Feng hui Deng Jia-Ben Lin Feng Wang Faculty of Information Engineering and Automation / Yunnan Key Laboratory of Computer Technology Application Kunming University of Science and Technology Key Laboratory of Solar Activity National Astronomical ObservatoriesChinese Academy of Sciences Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityMinistry of Education Yunnan Observatories Chinese Academy of Sciences

We study the motion of G-band bright points （GBPs） in the quiet Sun to obtain the characteristics of different motion types. A high resolution image sequence taken with the Hinode/Solar Optical Telescope （SOT） is used, and GBPs are automat- ically tracked by segmenting 3D evolutional structures in a space-time cube. After putting the GBPs that do not move during their lifetimes aside, the non-stationary GBPs are categorized into three types based on an index of their motion type. Most GBPs that move in straight or nearly straight lines are categorized as a straight mo- tion type, a few moving in rotary paths into rotary motion, and the others fall into a motion type we called erratic. The mean horizontal velocities are 2.18±0.08 km s-1, 1.63±0.09km s^-1 and 1.33±0.07 km s^-1 for straight, erratic and rotary motion types, respectively. We find that a GBP drifts at a higher and constant velocity during its whole life if it moves in a straight line. However, it has a lower and variational velocity if it moves on a rotary path. The diffusive process is ballistic-, super- and sub-diffusion for straight, erratic and rotary motion types, respectively. The corresponding diffusion index （γ） and coefficients （K） are 2.13±0.09 and 850±37km^2 s^-1, 1.82±0.07 and 331 ±24 km^2 s^-1, and 0.73±0.19 and 13±9 km^2 s^-1. In terms of direction of motion, it is homogeneous and isotropic, and usually persists between neighboring frames, no matter what motion type a GBP is classified as.

关键词： techniques: image processing -- Sun: photosphere -- methods: dataanalysis -- methods: statistical

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In situ detection of tumor infiltrating lymphocytes expressing perforin and fas-ligand genes in human HCC

引用

World Journal of Gastroenterology 1999年第1期5卷 17-19页

作者： QIAN Qi Jun, xue hui Bin, qu Zeng Qiang, FANG Shi Gang, CAO hui Fang and WU Meng Chao

AIM To investigate the expression of perforin and fas ligand (fas L) of tumor infiltrating lymphocytes (TILs) in human hepatocellular carcinoma (HCC). METHODS By in situ hybridization and immunohistochemistry, the perforin and fas L gene expression of TILs was studied in 20 HCC cases. RESULTS Positive expression of perforin and fas L genes was detected in 16 HCC cases. One patient had expression of perforin and fas L genes in the majority of TILs and survived 1 5 years after tumor resection without HCC relapse. This seems that the presence of a large number of activated T cells might be beneficial for the antitumor immunity. In other cases, less than 10% of TILs were able to express perforin and fas L genes. CONCLUSION Although there were a number of T cells in HCC, only few of them were immunoactive and able to kill tumor cells. It seems important to promote further proliferation of these activated T cells in vitro or in vivo .

关键词： carcinoma, hepatocellular lymphocytes fas ligand genes perforin in situ hybridization liver neoplasms

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of wind speed,underlying surface,and seed morphological traits on the secondary seed dispersal in the Tengger Desert,China

引用

Journal of Arid Land 2024年第4期16卷 531-549页

作者： qu Wenjie ZHAO Wenzhi YANG Xinguo WANG Lei ZHANG xue qu Jianjun Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou 730000China Key Laboratory of Restoration and Reconstruction of Degraded Ecosystems in Northwestern China of Ministry of Education Ningxia UniversityYinchuan 750021China University of Chinese Academy of Sciences Beijing 100049China School of Ecology and Environment Ningxia UniversityYinchuan 750021China

The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key *** on field wind tunnel experiments using 11 common plant species on the southeastern edge of the Tengger Desert,China,we studied the secondary seed dispersal in the fixed and semi-fixed sand dunes as well as in the mobile dunes in order to understand the limitations of vegetation regeneration and the maintenance of its *** results indicated that there were significant variations among the selected 11 plant species in the threshold of wind speed(TWS).The TWS of Caragana korshinskii was the highest among the 11 plant species,whereas that of Echinops gmelinii was the *** morphological traits and underlying surface could generally explain the *** the secondary seed dispersal processes,the proportions of seeds that did not disperse(no dispersal)and only dispersed over short distance(short-distance dispersal within the wind tunnel test section)were significantly higher than those of seeds that were buried(including lost seeds)and dispersed over long distance(long-distance dispersal beyond the wind tunnel test section).Compared with other habitats,the mobile dunes were the most difficult places for secondary seed *** seeds were the easiest to be found in the semi-fixed sand dunes,whereas fixed sand dunes were the best sites for seeds that dispersed over long *** results of linear mixed models showed that after controlling the dispersal distance,smaller and rounder seeds dispersed *** index and wind speed were the two significant influencing factors on the burial of *** explanatory power of wind speed,underlying surface,and seed morphological traits on the seeds that did not disperse and dispersed over short distance was far greater than that on the seeds that were buried and dispersed over long distance,implying that the processes and mechanisms of burial and lo

关键词： seed dispersal seed morphological traits wind speed vegetation regeneration wind tunnel Tengger Desert

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fault Analysis on AES:A Property-Based Verification Perspective

引用

Tsinghua Science and Technology 2024年第2期29卷 576-588页

作者： Xiaojie Dai Xingxin Wang xue qu Baolei Mao Wei Hu School of Cybersecurity Northwestern Polytechnical UniversityXi’an 710072China School of Cyber Science and Engineering Zhengzhou UniversityZhengzhou 450001China

Fault analysis is a frequently used side-channel attack for ***,existing fault attack methods usually involve complex fault fusion analysis or computation-intensive statistical analysis of massive fault *** this work,we take a property-based formal verification approach to fault *** derive fine-grained formal models for automatic fault propagation and fusion,which establish a mathematical foundation for precise measurement and formal reasoning of fault *** extract the correlations in fault effects in order to create properties for fault *** further propose a method for key recovery,by formally checking when the extracted properties can be satisfied with partial keys as the search *** results using both unprotected and masked advanced encryption standard(AES)implementations show that our method has a key search complexity of 216,which only requires two correct and faulty ciphertext pairs to determine the secret key,and does not assume knowledge about fault location or pattern.

关键词： side-channel attack fault analysis fault propagation model property extraction fault verification

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Digitalizing river aquatic ecosystems

引用

Journal of Environmental Sciences 2024年第3期137卷 677-680页

作者： Yaohui Bai hui Lin Chenchen Wang Qiaojuan Wang Jiuhui qu Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China School of Environmental and Municipal Engineering Tianjin Chengjian UniversityTianjin 300384China Center for Water and Ecology Tsinghua UniversityBeijing 100084China

Traditional river health assessment relies on limited water quality indices and representative organism activity,but does not comprehensively obtain biotic and abiotic information of the ***,we propose a new approach to evaluate the ecological and health risks of river aquatic ***,detailed physicochemical and biological characterization of a river ecosystem can be obtained through pollutant determination(especially emerging pollutants)and DNA/RNA ***,supervised machine learning can be applied to perform classification analysis of characterization data and ascertain river ecosystem ecology and *** proposed methodology transforms river ecosystem health assessment and can be applied in river management.

关键词： Digitalizing River ecosystem health Emerging pollutants High throughput sequencing Machine learning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Single-Fluorophore Multicolor Molecular Sensor That Visually Identifies Organic Anions Including Phosphates

引用

CCS Chemistry 2024年第3期6卷 774-782页

作者： Zezhou Zong Qi Zhang Da-hui qu Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237

Developing fluorescent sensors for small-molecule phosphates offers opportunities in optically detecting biorelevant reactions and ***,it remains elusive how to identify phosphates from other anions,such as carboxylates and sulfates,because current synthetic phosphate receptors lack *** we report the construction of a multicolor fluorescent sensor that can identify phosphates from other analogous *** key design principle is to take advantage of the highly sensitive conformation-dependent emissive wavelength of diphenyl-9,14-dihydrodibenzo[a,c]phenazine fluorophores to sense the minor structural differences between phosphates and other anions,for example,sulfates and *** effect of structural factors such as spacer length and urea versus thiourea has been investigated by comparing the optical properties and binding affinities with the phosphate *** strategy provides a simple and robust fluorescent sensing solution to optically analyze small-molecule phosphates with antiinterference performance.

关键词： fluorescent sensors photoluminescence host-guest chemistry supramolecular chemistry noncovalent bonds

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Controlling molecular assembly on time scale:Time-dependent multicolor fluorescence for information encryption

引用

Chinese Chemical Letters 2024年第7期35卷 336-340页

作者： Zixi Zou Jingyuan Wang Yian Sun Qian Wang Da-hui qu Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Dynamic assembly on time scale is common in biological systems but rare for artificial materials,especially for smart luminescent *** molecular assembly in a spatio-temporal manner and resulting in white-light-including multicolor fluorescence with time-dynamic features remains ***,controlling molecular assembly on time scale is achieved by integrating a pH-responsive motif to a transient alkaline solution which is fabricated by activators(NaOH)and deactivators(esters),leading to automatic assembly on time scale and time-dependent multicolor fluorescence changing from blue to white and *** kinetics of the assembly process is dependent on the ester hydrolysis process,which can be controlled by varying ester concentrations,temperature,initial pH,stirring rate and ester *** dynamic fluorescent system can be further developed for intelligent fluorescent materials such as fluorescent ink,three-dimension(3D)codes and even four-dimension(4D)codes,exhibiting a promising potential for information encryption.

关键词： Supramolecular chemistry Multicolor fluorescence White light emission Time-dependent fluorescence Information encryption

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Solidification behaviour and hot cracking susceptibility of a novel Ni-based superalloy

引用

Journal of Iron and Steel Research International 2024年第4期31卷 956-966页

作者： Yue Chen Shao-min Lv Xing-fei Xie Xiao-can Wen Jng-long qu Jin-hui Du High-Temperature Materials Institute China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China Beijing GAONA Materials and Technology Co. Ltd.Beijing 100081China Sichuan CISRI-GAONA Forging Co. Ltd.Deyang 610000SichuanChina

A novel Ni-based superalloy GH4151,with a γ′ volume fraction of about 55%and a service temperature capability up to 8oo oC,was *** to the different cooling conditions of various regions during the solidification of ingots,significant cooling rate variations may lead to the occurrence of hot *** scanning laser microscope was utilised to investigate the solidification process and phase precipitation behaviour of the GH4151 under wide range cooling *** characteristics of L→γ transformation were analysed,and the growth rates of at each stage were *** segregation behaviour was predicted using the Scheil equation,and the predicted results match well with the experimental *** sensitivity coefficient for hot cracking was modified,and cracking sensitivity coefficient values for the alloy under different cooling rates were computed,revealing that the alloy is most susceptible to hot cracking at 10℃/min cooling ***,controlling the cooling rate can reduce the possibility of hot cracking in ingot.

关键词： Ni-based superalloy Solidification behaviour In-situ observation Clyne and Davies's criterion:Hot cracking susceptibility

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering the axial coordination of cobalt single atom catalysts for efficient photocatalytic hydrogen evolution

引用

Nano Research 2024年第6期17卷 5114-5121页

作者： Ning Kang Lingwen Liao xue Zhang Zhen He Binlu Yu Jiahong Wang Yongquan qu Paul KChu Seeram Ramakrishna xue-Feng Yu Xin Wang Licheng Bai Materials Interfaces Center Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences(CAS)Shenzhen 518055China Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsChinese Academy of SciencesHefei 230031China Department of Chemistry City University of Hong KongKowloonHong Kong 999077China Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM) City University of Hong KongKowloonHong Kong 999077China Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Department of Physics and Department of Materials Science and Engineering City University of Hong KongKowloonHong Kong 999077China National University of Singapore(NUS)Centre for Nanofibers and Nanotechnology Department of Mechanical EngineeringNational University of SingaporeSingapore 117542Singapore

Improving the catalytic activity of non-noble metal single atom catalysts(SACs)has attracted considerable attention in materials *** optimizing the local electronic structure of single atom can greatly improve their catalytic activity,it often involves in-plane modulation and requires high ***,we report a novel strategy to manipulate the local electronic structure of SACs via the modulation of axial Co-S bond anchored onto graphitic carbon nitride(C_(3)N_(4))at room temperature(RT).Each Co atom is bonded to four N atoms and one S atom(Co-(N,S)/C_(3)N_(4)).Owing to the greater electronegativity of S in the Co-S bond,the local electronic structure of the Co atoms is available to be controlled at a relatively moderate ***,when employed for the photocatalytic hydrogen evolution reaction,the adsorption energy of intermediate hydrogen(H*)on the Co atoms is remarkably *** the presence of the Co-(N,S)/C_(3)N_(4)SACs,the hydrogen evolution rates reach up to 10 mmol/(g·h),which is nearly 10 and 2.5 times greater than the rates in the presence of previously reported transition metal/C_(3)N_(4)and noble platinum nanoparticles(PtNPs)/C_(3)N_(4)catalysts,*** to the tailorable axial Co-S bond in the SAC,the local electronic structure of the Co atoms can be further optimized for other photocatalytic *** axial coordination engineering strategy is universal in catalyst designing and can be used for a variety of photocatalytic applications.

关键词： transition metal single-atom local electronic structure photocatalytic hydrogen evolution graphitic carbon nitride axial coordination environment

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Machine learning-based radiomics score improves prognostic prediction accuracy of stage II/III gastric cancer: A multi-cohort study

引用

World Journal of Gastrointestinal Surgery 2024年第2期16卷 345-356页

作者： Ying-Hao Xiang Huan Mou Bo qu hui-Rong Sun Department of General Surgery Lichuan People's HospitalEnshi 445400Hubei ProvinceChina

BACKGROUND Although accurately evaluating the overall survival(OS)of gastric cancer patients remains difficult,radiomics is considered an important option for studying *** To develop a robust and unbiased biomarker for predicting OS using machine learning and computed tomography(CT)image *** This study included 181 stage II/III gastric cancer patients,141 from Lichuan People's Hospital,and 40 from the Cancer Imaging Archive(TCIA).Primary tumors in the preoperative unenhanced CT images were outlined as regions of interest(ROI),and approximately 1700 radiomics features were extracted from each *** skeletal muscle index(SMI)and skeletal muscle density(SMD)were measured using CT images from the lower margin of the third lumbar *** the least absolute shrinkage and selection operator regression with 5-fold cross-validation,36 radiomics features were identified as important predictors,and the OS-associated CT image radiomics score(OACRS)was cal-culated for each patient using these important *** Patients with a high OACRS had a poorer prognosis than those with a low OACRS score(P<0.05)and those in the TCIA *** and multivariate analyses revealed that OACRS was a risk factor[RR=3.023(1.896-4.365),P<0.001]independent of SMI,SMD,and pathological ***,OACRS outperformed SMI and SMD and could improve OS prediction(P<0.05).CONCLUSION A novel biomarker based on machine learning and radiomics was developed that exhibited exceptional OS discrimination potential.

关键词： Radiomics Machine learning Gastric cancer Skeletal muscle density Skeletal muscle index

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：