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期刊论文 42

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Current recommendations of managing HBV infection in preconception or pregnancy

null

《医学前沿(英文)》 2014年 第8卷 第2期   页码 158-165 doi: 10.1007/s11684-014-0340-4

摘要:

Hepatitis B remains a leading cause of cirrhosis, hepatocellular carcinoma and liver transplantation worldwide. Management of chronic hepatitis B during pregnancy is challenging. Transmission of hepatitis B to infants still occurs perinatally although immunoprophylaxis is widely available for infants born to mothers with chronic hepatitis B infection. The emerging data suggest that initiation of antiviral therapy in the beginning of the third trimester in highly viremic mothers can prevent immunoprophylaxis failure in their infants. The available drug safety data show that lamivudine, telbivudine and tenofovir are generally safe to be used during the pregnancy. In order to minimize the fetal exposure to the antiviral medication, antiviral therapy during the pregnancy should be limited to a selected group of patients with cirrhosis, high hepatitis B viral load, or prior history immunoprophylaxis failure. An elective Caesarean section may reduce the risk of perinatal transmission. For those females planning for pregnancy or in early stage of pregnancy, communication and follow-up among obstetrician, gastroenterologist, and primary care physician are important. In this article, we will review the features of hepatitis B infection before, during and after the pregnancy; the risk factors that increase mother-to-child transmission; safety data on antiviral drug use during pregnancy; and the potential role of Caesarean section in selected cases.

关键词: antiviral therapy     Caesarean section     cirrhosis     hepatitis B     immunoprophylaxis     mother-to-child transmission     pregnancy     prevention    

Introduction to the special section for ACMFMS 2010

Jinhao QIU

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 271-271 doi: 10.1007/s11465-011-0239-6

Effect of the new maternity insurance scheme on medical expenditures for caesarean delivery in Wuxi,

null

《医学前沿(英文)》 2016年 第10卷 第4期   页码 473-480 doi: 10.1007/s11684-016-0479-

摘要:

Aiming to control rising medical expenditures and help improve China’s healthcare systems, this study examined whether a cap-based medical insurance scheme with shared financial interest between the insurance and healthcare providers is effective in containing hospitals’ C-section medical expenditures. We used 6547 caesarean delivery case records from a teaching tertiary-level general public hospital located in Wuxi, China (2004–2013), and used the Chow test to investigate the possibility of significant variation in mean medical expenditures for caesarean deliveries pre- and post-reform. We also used paired sample t-tests and linear regression models to compare the mean medical expenditures between insured and uninsured women undergoing caesarean delivery during the post-reform period. After the scheme’s implementation, medical expenditures for caesarean deliveries declined and the medical expenditures of women covered by the scheme were significantly lower than those of uninsured patients. These findings indicated the scheme’s effectiveness in minimizing caesarean delivery expenditures. The cap-based medical insurance scheme with shared financial interest between insurance and healthcare providers would likely steer healthcare providers’ behaviors in a more cost-effective direction.

关键词: maternity insurance scheme     financial incentive     caesarean delivery     medical expenditure     China    

Study on shear resistance of aluminum alloy I-section members

DONG Zhen, ZHANG Qilin

《结构与土木工程前沿(英文)》 2008年 第2卷 第1期   页码 79-86 doi: 10.1007/s11709-008-0007-9

摘要: The design method for the shear resistance of aluminum alloy I-section members is presented, taking into consideration of the post-buckling strength of webs and the restraint effect of flanges, and the practical design formulas are proposed. The deflection of aluminum alloy I-section members under concentrated load is simulated by using the finite element method, and several design theories are discussed. The relation of shear resistance to the maximum web displacement reflects that the web of aluminum alloy I-section member is under fewer shears buckling force, while the whole member has higher shear resistance. However, the traditional design method is not able to give the real shear resistance of aluminum alloy I-section members. The proposed design formulas for the shear resistance of aluminum alloy I-section members is used to calculate accurately the post-buckling resistance of webs and the shear resistance contribution of flanges. The results are in a great agreement with the test data of Hamoodi M J, Burt C A, Evans H R and the results from Eurocode9 formulas.

关键词: formulas     displacement     deflection     relation     I-section member    

Introduction to the special section on the 12

Zhen-Min CHENG

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 1-1 doi: 10.1007/s11705-009-0003-1

Calculation of diagonal section and cross-section bending capacity for strengthening RC structure using

Shouping SHANG , Fangyuan ZHOU , Wei LIU ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 330-338 doi: 10.1007/s11709-009-0046-x

摘要: Because there is a great demand of reinforcement and retrofitting of aged structures nationwide, as well as the rapid development of innovative building materials, the adoption of strengthening RC structures using new inorganic materials has become possible. High-performance ferrocement laminate (HPFL) is an effective method of strengthening concrete structure. High-performance ferrocement laminate is a new type of inorganic material with the advantages such as high strength, small contraction, good bonding properties, etc. This paper introduces the formula of cross-section bending capacity for strengthening concrete beams with HPEL. A comparative analysis of experimental data, as well as the calculation of diagonal section bearing capacity of concrete members, is given.

关键词: RC beams     high-performance ferrocement laminate (HPFL)     inorganic material     reinforcement    

Torsional behavior of triangular web profile (TRIWP) steel section by experimental study

Fatimah DE’NAN,Hazwani HASAN,Mohd Hanim OSMAN,Sariffudin SAAD

《结构与土木工程前沿(英文)》 2016年 第10卷 第4期   页码 409-419 doi: 10.1007/s11709-016-0358-6

摘要: A triangular web profile (TriWP) is a modified section where the flanges are connected to a web plate of triangular profile. This study examined the torsional behavior of TriWP steel sections and compared to that of the flat web (FW) steel sections. Three types of specimen sizes were used: 180 mm × 75 mm × 5 mm × 2 mm, 200 mm × 100 mm × 8 mm × 6 mm, and 200 mm × 100 mm × 6 mm × 5 mm. All the specimens were loaded vertically until the maximum load was achieved and then the load was released. For both types of specimens, it was observed that the torsional rotation for bigger size [200 mm × 100 mm × 8 mm × 6 mm] were smaller than that of smaller size [180 mm × 75 mm × 5 mm × 2 mm] of the specimens. At the maximum torsional loading, the experimental result was compared to the theoretical calculation. The comparison showed that the percentage difference ranged from 1.10% to 16.80%. From the graph of torsional load versus rotational angle, the torsional rotation for all TriWP steel sections were smaller than that of the FW steel section under the same torsional loading i.e., 0.2 kNm and 1 kNm. The range between FW and TriWP were 3.74 to 71.83 at 0.2 kNm while 14.5 to 75.1 at 1.0 kNm. The findings were shown that the TriWP steel sections had better resistance against torsion in comparison to FW steel section.

关键词: corrugated web     i-beam     non uniform steel section     torsion resistance     torsion angle     triangular web profile steel section    

Introduction to the Special Section on Biomedical Devices for Personal Health Applications

I-Ming CHEN

《机械工程前沿(英文)》 2011年 第6卷 第1期   页码 1-2 doi: 10.1007/s11465-011-0210-6

Introduction to the special section on the Symposium on Computational Fluid Dynamics and Molecular Simulation

Tianwei TAN, Peiyong QIN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 241-241 doi: 10.1007/s11705-009-0285-3

Shear strength model of the reinforced concrete beams with embedded through-section strengthening bars

Linh Van Hong BUI; Phuoc Trong NGUYEN

《结构与土木工程前沿(英文)》 2022年 第16卷 第7期   页码 843-857 doi: 10.1007/s11709-022-0834-0

摘要: In this study, finite element (FE) analysis is utilized to investigate the shear capacity of reinforced concrete (RC) beams strengthened with embedded through-section (ETS) bars. Effects of critical variables on the beam shear strength, including the compressive strength of concrete, stiffness ratio between ETS bars and steel stirrups, and use of ETS strengthening system alone, are parametrically investigated. A promising method based on the bond mechanism between ETS strengthening and concrete is then proposed for predicting the shear resistance forces of the strengthened beams. An expression for the maximum bond stress of the ETS bars to concrete is developed. This new expression eliminates the difficulty in the search and selection of appropriate bond parameters from adhesion tests. The results obtained from the FE models and analytical models are validated by comparison with those measured from the experiments. Consequently, the model proposed in this study demonstrates better performance and more accuracy for prediction of the beam shear-carrying capacity than those of existing models. The results obtained from this study can also serve researchers and engineers in selection of the proper shear strength models for design of ETS-strengthened RC beams.

关键词: embedded through-section     strengthening     fiber-reinforced polymer     finite element     shear strength model     bond mechanism    

Improving retrieval precision of NO

Jinpeng YANG

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 92-96 doi: 10.1007/s11465-009-0001-5

摘要: The NO density error retrieved by the traditional method of differential optical absorption spectroscopy (DOAS) was analyzed. The technique for reducing the error is proposed and used to obtain the NO density of Chengdu through DOAS.

关键词: absorption structure     low-frequency structure     absorption cross-section     NO2 density    

Behavior of concrete-filled double skin steel tubular columns with octagon section under axial compression

YANG Junjie, PENG Guojun, XU Hanyong

《结构与土木工程前沿(英文)》 2008年 第2卷 第3期   页码 205-210 doi: 10.1007/s11709-008-0035-5

摘要: Based on some conclusions of two kinds of concrete-filled double skin steel tube (CFDSST) members with circular or square sections, a new kind of CFDSST with octagonal section, where the outer tube has an octagonal section and the inner tube has a circular section, is proposed in this paper. Behaviors of the CFDSST members with octagon section subjected to axial compression are investigated, and some curves of load-strain of steel tubes and confined concrete and the bearing capacity of members are obtained. It is indicated that the bearing capacity of the columns with octagonal section is larger than that with square section and is smaller than that with circular section, and the bearing capacity of members is related to the ratio of the straight side to the bevelled one. Based on the proper stress-strain relationship, a couple of numerical analyses are made using the finite element software named ANSYS. Finally, a simplified formula is proposed in the paper, and the numerical results agree well with the experimental results and the mathematical solutions. The results are valuable for engineers.

关键词: mathematical     numerical     compression     stress-strain relationship     straight    

Trial design of arch bridge of composite box section with steel web-concrete flange

Jiangang WEI, Qingwei HUANG, Baochun CHEN,

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 370-375 doi: 10.1007/s11709-010-0073-7

摘要: The concrete arch bridge is a natural and appropriate structural solution, aesthetically pleasing and easily integrated into the environment, especially in mountainous and island areas. However, construction difficulty and cost will increase with heavy self-weight when the span enlarges. A potential solution is to use a composite box arch ring with steel web-concrete flange. Taking Wanzhou Yangtze River Bridge (the longest concrete arch bridge in the world with a main span of 420 m) as a prototype, trial designs of a composite box arch with steel webs (including corrugated steel webs and plain steel webs) and concrete flanges were carried out. Comparison of quantities and structural behaviors of the prototype concrete arch with the two trial designed composite arch was presented. It is shown that the self-weight of the composite arch can reduce about 28% and the structures can meet the design requirements, therefore it is possible to use the two composite arches in long span arch bridges.

关键词: steel webs     concrete     box arch     trial design     structural behaviors     finite element method    

北京市剖宫产育龄妇女产后避孕意愿分析

沈洁,高丽丽,潘迎

《中国工程科学》 2014年 第16卷 第5期   页码 16-19

摘要:

为了了解北京市剖宫产术后妇女的避孕意愿及其影响因素,在北京市城、近、郊区采用分层整群抽样方法随机抽取2011 年7 月—2011 年12 月期间接受剖宫产手术的产妇364 名,进行问卷调查。采用卡方检验和多因素Logistic 回归方法对问卷调查结果进行分析。结果显示,被调查妇女平均年龄为(31±4.53)岁,剖宫产术后计划恢复性生活时间中位数为7 周。96.43 %的妇女对于产后可以采用的避孕方法并不清楚。仅有27.74 %的妇女表示产后会尽早或立即采取避孕措施,避孕套是妇女首选的产后避孕方法,占75.27 %。72.25 %的妇女没有避孕计划或要等到产后3 个月才开始避孕。62.64 %的妇女在剖宫产术后接受了避孕指导,医生推荐的产后避孕方法中避孕套占首位。医生强调剖宫产术后避孕的重要性、妇女具备正确产后避孕知识是妇女剖宫产术后尽早开始避孕的保护因素。剖宫产妇女对产后避孕服务有较高需求,希望在产前保健或产后访视时能得到专业人员的产后避孕咨询指导。剖宫产术后再次妊娠存在健康风险,剖宫产妇女产后尽早落实避孕措施应引起高度关注。建议尽快针对剖宫产妇女开展产后避孕服务,摸索适合北京的服务模式,以满足需求,减少产后非意愿妊娠的发生,降低剖宫产术后人工流产的风险。

关键词: 育龄妇女     剖宫产术后     产后服务     避孕    

水平管道淤积断面紊流的速度分布研究

王冬梅,张士林

《中国工程科学》 2005年 第7卷 第2期   页码 66-68

摘要:

对固定床水平管道断面的紊流速度分布进行研究。将整个断面分为弓形圆弧断面和渗流断面。弓形圆弧断面的速度分布研究基于圆形断面管道紊流理论,并且结合一定的假设数值模拟弓形圆弧断面管道的紊流速度分布规律;渗流断面的速度分布研究基于渗流理论。通过一定的边界条件将两部分断面速度分布组合成整个断面的速度分布。大量的实验证明本研究方法及程序较好地模拟了此断面的紊流速度分布。

关键词: 弓形圆弧断面     固定床     紊流速度     零剪力点     水力坡度    

标题 作者 时间 类型 操作

Current recommendations of managing HBV infection in preconception or pregnancy

null

期刊论文

Introduction to the special section for ACMFMS 2010

Jinhao QIU

期刊论文

Effect of the new maternity insurance scheme on medical expenditures for caesarean delivery in Wuxi,

null

期刊论文

Study on shear resistance of aluminum alloy I-section members

DONG Zhen, ZHANG Qilin

期刊论文

Introduction to the special section on the 12

Zhen-Min CHENG

期刊论文

Calculation of diagonal section and cross-section bending capacity for strengthening RC structure using

Shouping SHANG , Fangyuan ZHOU , Wei LIU ,

期刊论文

Torsional behavior of triangular web profile (TRIWP) steel section by experimental study

Fatimah DE’NAN,Hazwani HASAN,Mohd Hanim OSMAN,Sariffudin SAAD

期刊论文

Introduction to the Special Section on Biomedical Devices for Personal Health Applications

I-Ming CHEN

期刊论文

Introduction to the special section on the Symposium on Computational Fluid Dynamics and Molecular Simulation

Tianwei TAN, Peiyong QIN,

期刊论文

Shear strength model of the reinforced concrete beams with embedded through-section strengthening bars

Linh Van Hong BUI; Phuoc Trong NGUYEN

期刊论文

Improving retrieval precision of NO

Jinpeng YANG

期刊论文

Behavior of concrete-filled double skin steel tubular columns with octagon section under axial compression

YANG Junjie, PENG Guojun, XU Hanyong

期刊论文

Trial design of arch bridge of composite box section with steel web-concrete flange

Jiangang WEI, Qingwei HUANG, Baochun CHEN,

期刊论文

北京市剖宫产育龄妇女产后避孕意愿分析

沈洁,高丽丽,潘迎

期刊论文

水平管道淤积断面紊流的速度分布研究

王冬梅,张士林

期刊论文