检索结果-南通市图书馆

Simultaneous fluorescence and Compton scattering computed tomography based on linear polarization X-ray

NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-10页

作者： chi, zhi-jun Zhang, Hong-Ze Lin, Jin Zhang, Xuan-Qi Ding, Hao Tian, Qi-Li Zhang, zhi Du, Ying-Chao Huang, Wen-Hui Tang, Chuan-Xiang Beijing Normal Univ Sch Phys & Astron Minist Educ Key Lab Beam Technol Beijing 100875 Peoples R China Tsinghua Univ Minist Educ Dept Engn Phys Key Lab Particle & Radiat Imaging Beijing 100084 Peoples R China

PurposeTo propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized *** Carlo simulations were adopted to demonstrate the feasibility of the proposed method. In the simulations, the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum, water, and gold (Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%, and a parallel-hole collimator imaging geometry was adopted. The light source was modeled based on a Thomson scattering X-ray source. The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization *** the X-ray fluorescence computed tomography (XFCT) and Compton scattering computed tomography (CSCT) images of the phantom were accurately reconstructed. A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images. The interplay between XFCT and CSCT was analyzed, and the contrast-to-noise ratio (CNR) of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities. Compared with K-edge subtraction imaging, XFCT exhibits a CNR advantage for the *** XFCT and CSCT can be realized by using linearly polarized X-rays. The synergy between the two imaging modalities would have an important application in cancer radiation therapy

关键词： X-ray fluorescence computed tomography Compton scattering computed tomography Linear polarization Thomson scattering X-ray source Monte Carlo simulation DUAL-ENERGY CT NANOPARTICLE-LOADED OBJECTS ATTENUATION COEFFICIENTS XFCT PARAMETRIZATION FEASIBILITY ELEMENTS

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

A modern survey method for determining live loads based on multi-source and open-access data on the Internet

引用

Frontiers of Structural and Civil Engineering 2024年第8期18卷 1135-1147页

作者： chi XU jun CHEN Jie LI School of Civil Engineering Tongji UniversityShanghai 200092China The State Key Laboratory on Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

Sufficient survey data are required to describe the stochastic behaviors of live ***,due to manual and on-site operation required by traditional survey methods,traditional surveys face challenges like occupant resistance,high costs,and long implementation *** study proposes a new survey method to access live load data online and *** samples are acquired from multi-source,open-access and dynamically updated data on the *** change intervals,geometrical dimensions and object quantities are obtained from transaction information,building attributes and virtual reality models on real estate websites,*** object weights are collected from commodity information on e-commerce *** integration of the aforementioned data allows for the extraction of necessary statistics to describe a live load *** proposed method is applied to a live load survey in china,covering 20040 m^(2),with around 90000 samples acquired for object weights and load *** survey results reveal that about 70%−80%of the amplitude statistics are attributable to 1/6 of the total object types.

关键词： live load online survey method data acquisition data integration

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

Study of primordial deuterium abundance in Big Bang nucleosynthesis

引用

Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： zhi-Lin Shen Jian-jun He Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

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

Effect of Wave Nonlinearity on the Instantaneous Seabed Liquefaction

引用

china Ocean Engineering 2024年第1期38卷 93-103页

作者： WANG Zhao-jun SUI Ti-ti ZHANG chi PAN jun-ning Key Laboratory of Port Waterway and Sedimentation Engineering of the Ministry of TransportNanjing Hydraulic Research InstituteNanjing 210024China Key Laboratory of Coastal Disaster and Protection(Hohai University) Ministry of EducationNanjing 210098China The National Key Laboratory of Water Disaster Prevention Nanjing 210098China

The nonlinear variation of wave is commonly seen in nearshore area,and the resulting seabed response and liquefaction are of high concern to coastal *** this study,an analytical formula considering the nonlinear wave skewness and asymmetry is adopted to provide wave pressure on the seabed *** liquefaction depth attenuation coefficient and width growth coefficient are defined to quantitatively characterize the nonlinear effect of wave on seabed *** on the 2D full dynamic model of wave-induced seabed response,a detailed parametric study is carried out in order to evaluate the influence of the nonlinear variation of wave loadings on seabed ***,new empirical prediction formulas are proposed to fast predict the maximum liquefaction under nonlinear *** indicate that(1)Due to the influence of wave nonlinearity,the vertical transmission of negative pore water pressure in the seabed is hindered,and therefore,the amplitude decreases significantly.(2)In general,with the increase of wave nonlinearity,the liquefaction depth of seabed decreases *** under asymmetric and skewed wave loading,the attenuation of maximum seabed liquefaction depth is the most significant among all the nonlinear wave ***,highly skewed wave can cause the liquefaction depth of seabed greater than that under linear wave.(3)The asymmetry of wave pressure leads to the increase of liquefaction width,whereas the influence of skewedness is not significant.(4)Compared with the nonlinear waveform,seabed liquefaction is more sensitive to the variation of nonlinear degree of wave loading.

关键词： nonlinear wave seabed response seabed liquefaction numerical simulation liquefaction prediction

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

Equivalence between the internal observability and equation

引用

Applied Mathematics(A Journal of chinese Universities) 2024年第1期39卷 89-97页

作者： LIU Wen-jun TU zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

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

Causal roles of gut microbiota in cholangiocarcinoma etiology suggested by genetic study

引用

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1319-1333页

作者： zhi-Tao Chen Chen-Chen Ding Kai-Lei Chen Yang-jun Gu chi-Cheng Lu Qi-Yong Li Division of Hepatobiliary and Pancreatic Surgery Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical CollegeHangzhou 310000Zhejiang ProvinceChina Pediatric Psychology The Affiliated Mental Health Centre&Hangzhou Seventh People’s HospitalZhejiang University School of MedicineHangzhou 310000Zhejiang ProvinceChina School of Medicine Zhejiang Shuren UniversityHangzhou 310000Zhejiang ProvinceChina School of Medicine Zhejiang Chinese Medical University Zhejiang Shuren CollegeHangzhou 310000Zhejiang ProvinceChina

BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant biliary tract cancer with poor *** studies have implicated the gut microbiota in CCA,but evidence for causal mechanisms is *** To investigate the causal relationship between gut microbiota and CCA *** We performed a two-sample mendelian randomization study to evaluate potential causal associations between gut microbiota and CCA risk using genome-wide association study summary statistics for 196 gut microbial taxa and *** variants were used as instrumental *** sensitivity analyses assessed result *** Fifteen gut microbial taxa showed significant causal associations with CCA *** genetically predicted abundance of genus Eubacteriumnodatum group,genus Ruminococcustorques group,genus Coprococcus,genus Dorea,and phylum Actinobacteria were associated with reduced risk of gallbladder cancer and extrahepatic *** intrahepatic CCA risk was associated with higher abundance of family Veillonellaceae,genus Alistipes,order Enterobacteriales,and phylum *** effects against CCA were suggested for genus Collinsella,genus Eisenbergiella,genus Anaerostipes,genus Paraprevotella,genus Parasutterella,and phylum *** analyses indicated these findings were reliable without *** This pioneering study provides novel evidence that specific gut microbiota may play causal roles in CCA *** experimental validation of these candidate microbes is warranted to consolidate causality and mechanisms.

关键词： Cholangiocarcinoma Mendelian randomization Gut microbiota Instrumental variables Sensitivity analyses

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

Unlocking T cell exhaustion:Insights and implications for CAR-T cell therapy

引用

Acta Pharmaceutica Sinica B 2024年第8期14卷 3416-3431页

作者： Dian Xiong Haijun Yu zhi-jun Sun State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei Key Laboratory of StomatologySchool&Hospital of StomatologyFrontier Science Center for Immunology and MetabolismTaikang Center for Life and Medical ScienceWuhan UniversityWuhan 430079China Department of Radiation and Medical Oncology Hubei Province Cancer Clinical Study CenterHubei Key Laboratory of Tumor Biological BehaviorsZhongnan Hospital of Wuhan UniversityWuhan 430071China

chimeric antigen receptor T(CAR-T)cell therapy as a form of adoptive cell therapy(ACT)has shown significant promise in cancer treatment,demonstrated by the FDA-approved CAR-T cell therapies targeting CD19 or B cell maturation antigen(BCMA)for hematological malignancies,albeit with moderate outcomes in solid ***,despite these advancements,the efficacy of CAR-T therapy is often compromised by T cell exhaustion,a phenomenon that impedes the persistence and effector function of CAR-T cells,leading to a relapse rate of up to 75%in patients treated with CD19 or CD22 CAR-T cells for hematological *** to overcome CAR-T exhaustion employ state-of-the-art genomic engineering tools and single-cell sequencing *** this review,we provide a comprehensive understanding of the latest mechanistic insights into T cell exhaustion and their implications for the current efforts to optimize CAR-T cell *** insights,combined with lessons learned from benchmarking CAR-T based products in recent clinical trials,aim to address the challenges posed by T cell exhaustion,potentially setting the stage for the development of tailored next-generation approaches to cancer treatment.

关键词： Cancer immunotherapy CAR-T therapy T cell exhaustion Tumor immune microenvironment Spatial immune contexture Single-cell technologies CAR-T engineering Combination therapy

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

Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

引用

Defence Technology（防务技术） 2024年第1期31卷 58-72页

作者： Yong-Pan Duan Run-Qiang chi Bao-jun Pang Yuan Cai Hypervelocity Impact Research Center Harbin Institute of TechnologyHarbin150080China College of Science Heilongjiang University of Science and TechnologyHarbin 150022China

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris *** analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic *** proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal *** fragments of the catastrophically damaged COPVs were collected after the *** crack distribution and propagation process of the catastrophic ruptures of the COPVs were *** findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

关键词： Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms

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

Quasi-2D weak lensing cosmological constraints using the PDF-SYM method

引用

Science china(Physics,Mechanics & Astronomy) 2024年第7期67卷 44-58页

作者： Zhenjie Liu jun Zhang Hekun Li zhi Shen Cong Liu Department of Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai 200240China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

Cosmic shear statistics,such as the two-point correlation function(2PCF),can be evaluated with the PDF-SYM method instead of the traditional weighted-sum *** makes use of the full PDF information of the shear estimators,and does not require weightings on the shear estimators,which can in principle introduce additional systematic *** work presents our constraints on S8and?mfrom the shear-shear correlations using the PDF-SYM *** data we use is from the z-band images of the Dark Energy Camera Legacy Survey(DECa LS),which covers about 10000 deg2with more than 100 million *** shear catalog is produced by the Fourier Quad method,and well tested on the real data itself with the field-distortion *** main approach is called quasi-2D as we do use the photo-z information of each individual galaxy,but without dividing the galaxies into redshift *** mainly use galaxy pairs within the redshift interval between 0.2 and 1.3,and the angular range from 4.7 to 180 *** analysis yields S8=0.762±0.026 and?m=0.234±0.075,with the baryon effects and the intrinsic alignments *** results are robust against redshift *** check the consistency of our results by deriving the cosmological constraints from auto-correlations ofγ1andγ2separately,and find that they are consistent with each other,but the constraints from theγ1component are much weaker than that fromγ*** implies a much worse data quality ofγ1,which is likely due to additional shear uncertainties caused by CCD electronics(according to the survey strategy of DECa LS).We also perform a pure 2D analysis,which gives S8=0.81_(-0.04)^(+0.03)and?m=0.25_(-0.05)^(+0.06).Our findings demonstrate the potential of the PDF-SYM method for precision cosmology.

关键词： weak lensing shear-shear correlations cosmological parameters observations analysis

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

Special Issue:Dynamic Polymer Networks

引用

chinese Journal of Polymer Science 2024年第10期42卷 1401-1402页

作者： jun-Qi Sun zhi-Bo Li Tao Xie 不详

The ease of processing and light weight have made polymeric materials uniquely suited for numerous general ***,realization of their switchable chain configuration/mobility and molecular design versatility has pushed p... 详细信息

关键词： uniquely realization polymeric

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

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：