检索结果-南通市图书馆

Normalized glandular dose coefficients for digital breast tomosynthesis using detailed Chinese breast models

Nuclear Science and Techniques 2024年第5期35卷 42-59页

作者： Jia-Hao Wang Rui Qiu An-Kang Hu Ye-Qi Liu Zhen Wu Hui Zhang Jun-Li Li dep.rtment of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China Joint Institute of Tsinghua university Nuctech Company Limited BeijingBeijing 100084China

The rise in breast cancer diagnoses among Chinese women has necessitated the use of X-ray breast screening,which carries a radiation *** study aimed to provide a dosimetry protocol for the Chinese female population to replace the traditional standard that utilizes simplified breast models,for the accurate estimation of the mean glandular dose of a patient undergoing digital breast tomosynthesis(DBT).The first set of detailed Chinese female breast models and representative breast parameters was *** backscatter radiation and computational efficiency,we improved the combination of these models and the Chinese reference adult female whole-body voxel *** acquisition for four commercial DBT systems that are widely employed in China was simulated using the Monte Carlo method to obtain the normalized glandular dose coefficients of DBT(D_(gN)^(DBT))and the glandular dep.h dose(D_(g)^(dep.(z))for different breast characteristics and X-ray *** calculated a series of D_(gN)^(DBT) values for breasts with different percentage mass glandularities(5%,25%,50%,75%,and 100%)and compressed breast thicknesses(2,3,4,5,6,and 7 cm)at various tube potentials(25,28,30,32,35,and 49 kV)and target/filter combinations(W/Rh,W/Al,Mo/Mo,Rh/Rh,and Rh/Ag).The parameter dep.ndence of the breast characteristics and beam conditions on D_(gN)^(DBT) in detailed breast models was *** D_(gN)^(DBT) results were 14.6-51.0%lower than those of the traditional dosimetry standard in *** difference in D_(gN)^(DBT) was mainly due to a decrease in the dep.h of the main energy dep.sition area caused by the glandular distribution along the dep.h *** results obtained in this study may be used to improve breast dosimetry in China and provide more detailed information on risk assessment during DBT.

关键词： Digital breast tomosynthesis Normalized glandular dose coefficients Detailed breast model Monte Carlo simulation

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

Variations in Wear Resistance of a Novel Triboalloy Pseudoelastic TiNi Alloy-with Respect to its Pseudoelasticity and Hardness

引用

Journal of Materials Science & Technology 2001年第1期17卷 45-46页

作者： D.Y.Li and X.Ma dep.. of Chemical and Materials Engineering, university of Alberta, Edmonton, Alberta, Canada T6G 2G6 dep. of Chem. Univ. of Alberta Edmonton Canada

It has recently been found that TiNt shape memory alloy has another attractive property; high resistance to wear. The wear resistance of this alloy benefits from its pseudoelasticity (PE). It has, however, been noticed that other mechanical properties also affect the wear resistance, especially the hardness. Research was conducted to investigate the correlation between the wear resistance and both the PE and hardness. It has been demonstrated that when the PE is high, lower hardness leads to higher wear resistance.

关键词： TiNi Variations in Wear Resistance of a Novel Triboalloy Pseudoelastic TiNi Alloy-with Respect to its Pseudoelasticity and Hardness

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 Multi-Interface Remote Monitoring and Control System architecture Based on Embedded Server

引用

Journal of Harbin Institute of Technology(New Series) 2013年第6期20卷 67-76页

作者： He Liu Lei Wang Sheng-Peng Sun Ya-Dong Wang dep. of Biomedical Engineering Harbin Institute of Technology Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences dep. of Measurement-Control Technology Harbin University of Science and Technology

This paper presents a multi-interface embedded server architecture for remote real-time monitoring system and distributed monitoring applications. In the scheme,an embedded microprocessor( LPC3250 from NXP) is chosen as the CPU of the embedded server with a linux operation system( OS) environment. The embedded server provides multiple interfaces for supporting various application scenarios. The whole network is based on local area network and adopts the Browser / Server( B / S) model. The monitoring and control node is as a browser endpoint and the remote node with an embedded server is as a server endpoint. Users can easily acquire various sensors information through writing Internet protocol address of remote node on the computer browser. Compared with client / server( C / S) mode,B / S model needs less maintain and can be applicable to large user group. In addition,a simple network management protocol( SNMP) is used for management of devices in Internet protocol( IP) networks. The results of the demonstration experiment show that the proposed system gives good support to manage the network from different user terminals and allows the users to better interact with the ambient environment.

关键词： multi-interface remote monitoring and control embedded server simple network management protocol(SNMP

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 Semigroup Treatment to Viscosity Solutions of the Hanilton-Jacobi Fquation

引用

Chinese Quarterly Journal of Mathematics 1993年第2期8卷 94-101页

作者：宋清芳朱大新 dep. of Math. Henan University dep. of Math. Tianjin Unicersity

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

THE PERTURBATION SOLUTIONS OF THE FLOW IN A ROTATING CURVED ANNULAR PIPE

引用

Journal of Hydrodynamics 2001年第1期13卷 75-80页

作者： Zhang Ben-zhao, Chen Qian, Zhang Jin-suo, Cui Liang-chen dep.rtment of Mechanics, Zhejiang university, Hangzhou, 310027, China[WT5”HZ] dep. of Mechanics Zhejiang Univ. Hangzhou 310027 China

WT5”BZ]In this paper, the flow in a rotating curved annular pipe is examined by a perturbation method. A second order perturbation solution is presented. The characteristics of the secondary flow and the axial flow are studied in detail. The study indicates that the loops of the secondary flow are more complex than those in a curved annular pipe without rotation and its numbers dep.nd on the ratio of the Coriolis force to centrifugal force F. As F≈-1, the secondary flow has eight loops and its intensity reaches the minimum value, and the distribution of the axial flow is like that of the Poiseuille flow. The position of the maximum axial velocity is pushed to either outer bend or inner bend, which is also determined by F. [WT5”HZ]

关键词： rotating curved annular pipe secondary flow Coriolis force centrifugal force perturbation solution

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

Association between lifestyle factors and thyroid function in young euthyroid adults

引用

Food Science and Human Wellness 2024年第1期13卷 265-275页

作者： Elisa Merchan-Ramirez Guillermo Sanchez-Delgado Lucas Jurado-Fasoli Francisco M Acosta Manuel Munoz-Torres Jose M.Llamas-Elvira Jonatan R Ruiz Sport and Health university Research Institute(iMUDS) Faculty of Sports ScienceUniversity of GranadaGranada 18016Spain Pennington Biomedical Research Center Baton Rouge 70808USA Faculty of Medicine University of GranadaGranada 18071Spain Turku PET Centre University of TurkuTurku 20500Finland Turku PET Centre Turku University HospitalTurku 20520Finland Biosanitary Research Institute of Granada(Ibs.Granada) Granada 18012Spain CIBERFES Instituto de Salud CarlosⅢMadrid 28029Spain Endocrinology and Nutrition Service University Hospital San CecilioGranada 18016Spain Nuclear Medicine Service "Virgen de las Nieves"University HospitalGranada 18014Spain

Purpose:The present work examines the associations of dietary habits,sedentarism,physical activity(PA)levels and sleep habits,with thyroid function in young euthyroid ***:A total of 105 young euthyroid adults participated in this cross-sectional *** function was determined in fasting conditions(>6 h).Dietary habits were measured by a food frequency questionnaire and three non-consecutive 24 h recalls,and different dietary intake and patterns were then *** time spent in sedentary,PA levels and sleep habits were objectively measured using a wrist-worn ***:Energy and carbohydrate intake were positively associated with thyroid stimulating hormone(TSH)(β=0.222;R^(2)=0.102;P=0.022 andβ=0.425;R^(2)=0.129;P=0.007,respectively)whereas fat intake was negatively associated with TSH(β=-0.428;R^(2)=0.137;P=0.004).Energy intake was also positively associated with free triiodothyronine(β=0.277;R^(2)=0.137;P=0.004).Further,adherence to the Mediterranean diet was negatively related to TSH and free thyroxine(FT4)(β=-0.221;R^(2)=0.113;P=0.020 andβ=-0.268;R^(2)=0.071;P=0.007,respectively).Vigorous-intensity and overall PA were negatively associated with FT4(β=-0.227;R^(2)=0.052;P=0.022 andβ=-0.204;R^(2)=0.042;P=0.041,respectively).In contrast,no associations were found between sleep parameters and thyroid ***:Lifestyle factors such as dietary intake and PA levels seems to be related to thyroid function even in young euthyroid adults.

关键词： Thyroid hormones Dietary intake Sleep Physical activity Euthyroid

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

CHANGES OF MEAN VELOCITY PROFILES IN THE WAVE-CURRENT COMBINED FLOW

引用

Journal of Hydrodynamics 2001年第1期13卷 47-53页

作者： Wu, Y.S. Lian, J.J. Zhang, Q.H. Qin, C.R. dep. of Hydraulic Eng. Tsinghua Univ. Beijing 100084 China

A mathematical model is developed to simulate the change in mean velocity for the coexistent case of waves and current. The experimental results of mean velocity profile in a wave-current flume show the following features: Eulerian mean current profile for following current is more uniformly distributed than the corresponding pure current case, whereas , the case of an opposing current leads to the more straight profile. This model is based on Eulerian mean framework, and motions of wave and current are solved simultaneously. The comparisons of numerical results and experimental data show that the mathematical model presented in this paper is reasonable and feasible.

关键词： Computer simulation Hydrodynamics Mathematical models Sediment transport

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 Study on the Kinetics of the Catalytic Reforming Reaction of CH4 with CO2: Determination of the Reaction Order

引用

Journal of Natural Gas Chemistry 2003年第3期12卷 201-204页

作者： Chunyang Ji, Lihong Gong, Jiawei Zhang, Keying ShiChemistry dep.rtment of Harbin Normal university, Harbin 150080, China Chem. dep. Harbin Normal university Harbin 150080 China

The kinetics of the catalytic reforming reaction of methane with carbondioxide to produce synthesis gas on a Ni/α-Al_2O_3 and a HSD-2 type commercial catalyst has beenstudied. The results indicate that the reaction orders are one and zero for methane and carbondioxide, respectively, when the carbon dioxide partial pressure was about 12.5-30.0 kPa and thetemperature was at 1123-1173 K. However, when the carbon dioxide partial pressure was changed to30.0-45.0 kPa under the same temperature range of 1123-1173 K, the reaction orders of methane andcarbon dioxide are one. Furthermore, average rate constants at different temperatures weredetermined.

关键词： reforming methane carbon dioxide reaction order rate constant kinetics

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

Fatigue Behavior of Cemented Carbide Die in Cold Forging of Steel

引用

Journal of Materials Science & Technology 2001年第1期17卷 51-52页

作者： Z.Wang and K.Dohda dep.. of Mechanical System Engineering, Gifu university, Gifu, Japan dep. of Mech. Syst. Eng. Gifu Univ. Gifu Japan

The fatigue behavior of cemented carbide die under service load in the multistage cold forging of steel was investigated. It was found that the fatigue cracks do not initiate at the stress concentration position and the crack initiation position can be classified to three types. The crack initiation position can be predicted by FEM only when the plastic deformation of the die is considered.

关键词： Fatigue Behavior of Cemented Carbide Die in Cold Forging of Steel

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

Mechanism of the Forming of Nodular Graphite

引用

Journal of Materials Science & Technology 2000年第6期16卷 615-618页

作者： Shoukui ZHANG (dep.. of Materials Engineering, Dalian university of Technology, Dalian 116024, China) [Manuscript received September 6, 1999, in revised form January 21, 2000] dep. of Materials Eng. Dalian Univ. of Technol. Dalian 116024 China

This article presents a theory about the growth mechanism of bubble-screw dislocation of nodular graphite. Normally speaking, the crystallizing procedure of most nodular graphite is as follows: firstly, graphite generates nuclei on bubbles and fills them (mainly in the way of screw dislocation) forming the complete nuclei of nodular graphite-graphite bubble nuclei. Then, graphite grows up in the way of screw dislocation. Two important conditions concerning the production of nodular graphite are: (a) there is a relatively big interfacial energy between ferro liquid and graphite, and the one between ferro liquid and graphite prismatic plane is bigger than that between ferro liquid and graphite basal plane; (b) there are a certain amount of micro-bubbles in the melt.

关键词： Mechanism of the Forming of Nodular Graphite

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：