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Early-life famine exposure, adulthood obesity patterns, and risk of low-energy fracture

《医学前沿(英文)》 2024年 第18卷 第1期   页码 192-203 doi: 10.1007/s11684-023-1023-9

摘要: Malnutrition in early life increases the risk of osteoporosis, but the association of early-life undernutrition combined with adulthood obesity patterns with low-energy fracture remains unknown. This study included 5323 community-dwelling subjects aged ≥40 years from China. Early-life famine exposure was identified based on the participants’ birth dates. General obesity was assessed using the body mass index (BMI), and abdominal obesity was evaluated with the waist-to-hip ratio (WHR). Low-energy fracture was defined as fracture occurring after the age of 40 typically caused by falls from standing height or lower. Compared to the nonexposed group, the group with fetal, childhood, and adolescence famine exposure was associated with an increased risk of fracture in women with odds ratios (ORs) and 95% confidence intervals (CIs) of 3.55 (1.57–8.05), 3.90 (1.57–9.71), and 3.53 (1.05–11.88), respectively, but not in men. Significant interactions were observed between fetal famine exposure and general obesity with fracture among women (P for interaction = 0.0008). Furthermore, compared with the groups with normal BMI and WHR, the group of women who underwent fetal famine exposure and had both general and abdominal obesity had the highest risk of fracture (OR, 95% CI: 3.32, 1.17–9.40). These results indicate that early-life famine exposure interacts with adulthood general obesity and significantly increases the risk of low-energy fracture later in life in women.

关键词: famine     obesity     body mass index     waist-to-hip ratio     low-energy fracture    

Regeneration of vernacular architecture: new rammed earth houses on the upper reaches of the Yangtze River

Jiaping LIU, Rongrong HU, Liu YANG, Runshan WANG,

《能源前沿(英文)》 2010年 第4卷 第1期   页码 93-99 doi: 10.1007/s11708-010-0002-4

摘要: In rural areas of western China, most of the vernacular architectures are made of earth. In the process of urbanization, few residents like to build their houses with earth because the old traditional earth house cannot meet their requirement for higher standard of living. As a result, much more energy will be consumed if industrial building materials are used instead of earth. The regeneration of the traditional earth house, therefore, becomes a challenge in new village construction. This paper briefly describes a project about creating a new prototype of earth house for the migrants along the upper reaches of the Yangtze River to shed light on finding an appropriate approach for regenerating the traditional earth houses with the concept of low-energy housing. It includes an investigation of the traditional earth house and the environment condition of the new settlement, the new house design process, and the quantitative evaluation of the living quality of the new house.

关键词: earth house     low-energy housing     upper reaches of the Yangtze River     passive solar technique    

Recent development in low-constraint fracture toughness testing for structural integrity assessment of

Jidong KANG, James A. GIANETTO, William R. TYSON

《机械工程前沿(英文)》 2018年 第13卷 第4期   页码 546-553 doi: 10.1007/s11465-018-0501-2

摘要:

Fracture toughness measurement is an integral part of structural integrity assessment of pipelines. Traditionally, a single-edge-notched bend (SE(B)) specimen with a deep crack is recommended in many existing pipeline structural integrity assessment procedures. Such a test provides high constraint and therefore conservative fracture toughness results. However, for girth welds in service, defects are usually subjected to primarily tensile loading where the constraint is usually much lower than in the three-point bend case. Moreover, there is increasing use of strain-based design of pipelines that allows applied strains above yield. Low-constraint toughness tests represent more realistic loading conditions for girth weld defects, and the corresponding increased toughness can minimize unnecessary conservatism in assessments. In this review, we present recent developments in low-constraint fracture toughness testing, specifically using single-edge-notched tension specimens, SENT or SE(T). We focus our review on the test procedure development and automation, round-robin test results and some common concerns such as the effect of crack tip, crack size monitoring techniques, and testing at low temperatures. Examples are also given of the integration of fracture toughness data from SE(T) tests into structural integrity assessment.

关键词: fracture toughness     constraint effect     single-edge-notched tension test     pipeline     structural integrity assessment    

Effect of fly ash replacement level on the fracture behavior of concrete

Mahdi AREZOUMANDI, Jeffery S. VOLZ

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 411-418 doi: 10.1007/s11709-013-0228-4

摘要: The production of portland cement–the key ingredient in concrete–generates a significant amount of carbon dioxide. However, due to its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete’s contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. ?This study presents the results of an experimental investigation that evaluates effect of fly ash replacement level on the fracture energy of concrete. This study includes four mixes with 0%, 30%, 50%, and 70% fly ash as a cement replacement. This experimental program consisted of 32 fracture beams to study the fracture behavior of concrete. The experimental fracture energies were compared with the fracture energy provisions of different design codes and also different analytical equations. Furthermore, statistical data analyses (parametric and non-parametric) were performed to evaluate whether or not there is any statistically significant difference between the experimental fracture energies of different mixes. Results of these statistical tests show that the mix with higher level of fly ash replacement level has higher fracture energy.

关键词: concrete     fracture energy     fly ash    

聚能效应在岩石定向断裂控制爆破中的研究

罗勇,沈兆武

《中国工程科学》 2006年 第8卷 第6期   页码 78-82

摘要:

针对目前石材开采面临的问题,对采用聚能药包岩石定向断裂控制爆破技术时的裂缝(纹)起裂和扩展的机理进行了探讨,同时对该法的爆破参数进行了设计;实验室和现场试验验证结果表明,由聚能射流形成的切缝有明显的定向作用,使爆生气体的能量沿预定方向集中,裂纹的定向断裂控制效果良好,表明该法是一种比较理想的断裂控制爆破技术;研究成果对相关理论研究和现场应用均有一定的指导意义,该法将会成为岩石定向断裂控制爆破发展的一个方向。

关键词: 聚能效应     定向断裂爆破     模型试验     药型罩     致裂    

Experimental investigations of internal energy dissipation during fracture of fiber-reinforced ultra-high-performance

Eric N. LANDIS, Roman KRAVCHUK, Dmitry LOSHKOV

《结构与土木工程前沿(英文)》 2019年 第13卷 第1期   页码 190-200 doi: 10.1007/s11709-018-0487-1

摘要: Split-cylinder fracture of fiber-reinforced ultra-high-performance concrete (UHPC) was examined using two complementary techniques: X-ray computed tomography (CT) and acoustic emission (AE). Fifty-mm-diameter specimens of two different fiber types were scanned both before and after load testing. From the CT images, fiber orientation was evaluated to establish optimum and pessimum specimen orientations, at which fibers would have maximum and minimum effect, respectively. As expected, fiber orientation affected both the peak load and the toughness of the specimen, with the optimum toughness being between 20% and 30% higher than the pessimum. Cumulative AE energy was also affected commensurately. Posttest CT scans of the specimens were used to measure internal damage. Damage was quantified in terms of internal energy dissipation due to both matrix cracking and fiber pullout by using calibration measurements for each. The results showed that fiber pullout was the dominant energy dissipation mechanism; however, the sum of the internal energy dissipation measured amounted to only 60% of the total energy dissipated by the specimens as measured by the net work of load. It is postulated that localized compaction of the UHPC matrix as well as internal friction between fractured fragments makes up the balance of internal energy dissipation.

关键词: ultra-high-performance concrete     concrete fracture     X-ray computed tomography     acoustic emission    

A new fracture criterion for peridynamic and dual-horizon peridynamics

Jinhai ZHAO, Hesheng TANG, Songtao XUE

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 629-641 doi: 10.1007/s11709-017-0447-1

摘要: A new fracture criterion based on the crack opening displacement for peridynamic (PD) and dual-horizon peridynamics (DH-PD) is proposed. When the relative deformation of the PD bond between the particles reaches the critical crack tip opening displacement of the fracture mechanics, we assume that the bond force vanishes. A new damage rule similar to the local damage rule in conventional PD is introduced to simulate fracture. The new formulation is developed for a linear elastic solid though the extension to nonlinear materials is straightforward. The performance of the new fracture criterion is demonstrated by four examples, i.e. a bilateral crack problem, double parallel crack, monoclinic crack and the double inclined crack. The results are compared to experimental data and the results obtained by other computational methods.

关键词: Castigliano’s theorem     breaking energy     critical extension     XFEM     COD     PD-COD    

Energy transition management towards a low-carbon world

《工程管理前沿(英文)》 2022年 第9卷 第3期   页码 499-503 doi: 10.1007/s42524-022-0201-9

关键词: energy transition     low-carbon technology     system modeling     transition path     emission reduction    

Correlation between carbon emissions and energy structure –Reliability analysis of low carbon target

Ben HUA

《能源前沿(英文)》 2011年 第5卷 第2期   页码 214-220 doi: 10.1007/s11708-010-0133-7

摘要: The influence of energy intensity on carbon intensity depends upon the fraction of energy mixes with high carbon emissions in the total energy mixes . The correlation of with a variety of primary energy mix fractions and technology advances such as CCS and CCHP is analyzed and deduced. Taking the long-term carbon reduction target in 2050 settled upon by the Copenhagen Agreement and the mid-term target suggested by the “450 Scenes Program” of the International Energy Agency (IEA) as constraints, the new pattern of the energy transition of the world in 2020, 2030, and 2050 are estimated and figured out. The peak value of energy consumption will lag behind the peak value of carbon emissions; the world energy structure shifting point will be in 2020–2025. Estimates show that China’s mid-2020 and long-term targets of energy-saving and emission reduction announced by the Chinese government might be achieved.

关键词: correlation     carbon emissions     energy consumption     high carbon emissions energy mix     target of emission reduction     reliability    

Practice on Ultra-low Emission and Energy Efficient Technologies in Coal-fired Power Plants

Yin-biao Chen,Yi Zhang,Wen Ling

《工程管理前沿(英文)》 2016年 第3卷 第4期   页码 377-383 doi: 10.15302/J-FEM-2016045

摘要: Restructuring of China’s energy mix is accelerating due to factors such as energy security, economic cost, climate change and environmental pressure. Efficient and clean utilization of coal-generated power therefore plays an increasingly important role in solving energy and environmental problems in China. Coal-fired power plants, with Shenhua Guohua Sanhe as one of the pioneers, followed trend of this era and adopted multiple ultra-low emission and energy efficient technologies, striving to be an industry leader in environmental protection, profitability and innovation. As a result, coal-fired power plants have seen ultra-low emissions of air pollutants and record-high energy efficiency, opening up a new era of more efficient and cleaner coal generation. By the end of 2015, Shenhua Group had had 45 ultra-low emission coal units, providing strong support for implementing of the national policy on ultra-low emission and energy efficient retrofit of coal-fired power plants across China.

关键词: coal     power generation     ultra-low emission     energy efficiency    

Fuel poverty and low carbon emissions: a comparative study of the feasibility of the hybrid renewableenergy systems incorporating combined heat and power technology

《能源前沿(英文)》 2022年 第16卷 第2期   页码 336-356 doi: 10.1007/s11708-021-0748-x

摘要: Fuel poverty is most prevalent in North East England with 14.4% of fuel poor households in Newcastle upon Tyne. The aim of this paper was to identify a grid connected renewable energy system coupled with natural gas reciprocating combined heat and power unit, that is cost-effective and technically feasible with a potential to generate a profit from selling energy excess to the grid to help alleviate fuel poverty. The system was also aimed at low carbon emissions. Fourteen models were designed and optimized with the aid of the HOMER Pro software. Models were compared with respect to their economic, technical, and environmental performance. A solution was proposed where restrictions were placed on the size of renewable energy components. This configuration consists of 150 kW CHP, 300 kW PV cells, and 30 kW wind turbines. The renewable fraction is 5.10% and the system yields a carbon saving of 7.9% in comparison with conventional systems. The initial capital investment is $1.24 million which enables the system to have grid sales of 582689 kWh/a. A conservative calculation determined that 40% of the sales can be used to reduce the energy cost of fuel poor households by $706 per annum. This solution has the potential to eliminate fuel poverty at the site analyzed.

关键词: greenhouse gas control     low carbon target     grid connected     renewable fraction     fuel poverty     combined heat and power     HOMER Pro    

Synergistic utilization of coal and other energy – Key to low carbon economy

Weidou NI, Zhen CHEN

《能源前沿(英文)》 2011年 第5卷 第1期   页码 1-19 doi: 10.1007/s11708-010-0136-4

摘要: In China, coal is a dominant component of energy mix, and it is expected to remain as such over the next 30 to 40 years. Coal is expected to be used even more in power generation. The direct combustion of coal already has been causing severe pollution and ecological degradation, and it is quite difficult to address the need to reduce greenhouse gas (GHG) given the direct combustion of coal. Therefore, the polygeneration system based on coal gasification, which is one of the major examples of synergistic utilization of coal, is proposed. It is a comprehensive solution to meet the energy challenges China is facing. Furthermore, the synergy of fossil fuels (especially coal) with renewable energy, the synergy of different kinds of energy for energy storage, the synergy of centralized and distributed supply of different kinds of energy, and the synergy of different kinds of energy in smart energy grid (power, gas, heat, and water) are the keys to making China a low-carbon economy. Carbon dioxide (CO ) mitigation in China should begin from the coal-chemical industry given their accumulated relevant experiences. The mitigation process should gradually be transformed into the “IGCC+ polygeneration+ CCUS”. The objectives of this paper are to describe the synergistic utilization of coal, and to analyze the synergy of coal with other energy resources, and to propose the scientific and technological problems to achieve these synergies.

关键词: synergy     clean and efficient utilization of coal     coal-based polygenration     CO2 mitigation     energy storage    

Tackling climate change and promoting the energy revolution

Xiangwan DU

《能源前沿(英文)》 2018年 第12卷 第3期   页码 338-343 doi: 10.1007/s11708-018-0535-5

摘要:

Following the Paris Agreement, green and low-carbon development has entered into a new stage. China’s international responsibility to combat climate change is consistent with the inherent sustainable development needs of the country. In this paper, the reasonability of China’s Intended Nationally Determined Contributions (INDC) is examined and the fact that low-carbon development can lead to modernization is demonstrated based on data analysis of energy economics from developed countries. Considering the fact that such an energy revolution forms the basis for China’s low-carbon transition, a roadmap of the China’s energy utilization is presented. Based on research results from the Chinese Academy of Engineering, the three historical stages of China’s energy structure reform are analyzed. Promoting a low-carbon transition through an energy revolution is a long-term and arduous process that requires a genuine transformation of development outlook and patterns. By empirically analyzing situations at home and abroad, a conclusion is made that economic development and a low-carbon transition can be achieved simultaneously; specifically, low-carbon development fosters new points of economic growth and gives rise to different development paths.

关键词: climate change     Paris Agreement     low-carbon transition     energy revolution    

大庆油田台肇地区低渗透储层裂缝及其开发对策研究

曾联波,刘洪涛,房宝才,邓海成

《中国工程科学》 2004年 第6卷 第11期   页码 73-79

摘要:

介绍了大庆油田外围典型的低渗透储层——台肇地区葡萄花油层中东西向、南北向、北西向和北东向4组高角度构造裂缝,其发育程度依次由强变弱。受现今地应力影响,近东西向裂缝连通性好,地下张开度和渗透率大,是该区主渗流方向;其次是北西向、北东向裂缝,近南北向裂缝渗透性较差,裂缝发育程度受岩性、层厚、断层、构造应力等因素影响。根据地质条件和油藏数值模拟,认为该区适应于用矩形井网和菱形井网开发,效果比反九点和五点井网好。低渗储层由于裂缝发育,降低了地层破裂压力,注入压力容易超过地层破裂压力,使注入水沿裂缝快速流动,引起水淹水窜,影响水驱效果,在油田注水开发中,应控制注水压力。人工裂缝的分布受现今地应力和天然裂缝控制、转为线性注水、开展动态调配水与脉冲式周期注水、进行注采系统和井网加密调整、选择压裂井与控制压裂规模等开发调整对策。

关键词: 裂缝     低渗透储层     开发对策    

微地震监测技术在低渗透油田裂缝研究中的应用——以大庆西部外围低渗透油田为例

赵玉武,曲瑛新,熊文平

《中国工程科学》 2012年 第14卷 第4期   页码 34-39

摘要:

微地震监测技术的现场应用是通过监测注水过程中产生的微震波,来确定出水驱前缘位置、优势注水方向、注水波及面积等资料,进而确定出裂缝分布的规律。在简要介绍无源微地震监测技术基本原理的基础上,结合地质动、静态资料,对微地震法在水驱前缘测试大庆西部外围低渗透油田的应用效果进行了分析。现场应用效果证明,微地震监测技术在低渗透油田裂缝研究领域具有良好的应用前景,对提高低渗透裂缝型油田开发效果具有十分重要的意义。

关键词: 无源微地震     裂缝     水驱前缘     注水开发    

标题 作者 时间 类型 操作

Early-life famine exposure, adulthood obesity patterns, and risk of low-energy fracture

期刊论文

Regeneration of vernacular architecture: new rammed earth houses on the upper reaches of the Yangtze River

Jiaping LIU, Rongrong HU, Liu YANG, Runshan WANG,

期刊论文

Recent development in low-constraint fracture toughness testing for structural integrity assessment of

Jidong KANG, James A. GIANETTO, William R. TYSON

期刊论文

Effect of fly ash replacement level on the fracture behavior of concrete

Mahdi AREZOUMANDI, Jeffery S. VOLZ

期刊论文

聚能效应在岩石定向断裂控制爆破中的研究

罗勇,沈兆武

期刊论文

Experimental investigations of internal energy dissipation during fracture of fiber-reinforced ultra-high-performance

Eric N. LANDIS, Roman KRAVCHUK, Dmitry LOSHKOV

期刊论文

A new fracture criterion for peridynamic and dual-horizon peridynamics

Jinhai ZHAO, Hesheng TANG, Songtao XUE

期刊论文

Energy transition management towards a low-carbon world

期刊论文

Correlation between carbon emissions and energy structure –Reliability analysis of low carbon target

Ben HUA

期刊论文

Practice on Ultra-low Emission and Energy Efficient Technologies in Coal-fired Power Plants

Yin-biao Chen,Yi Zhang,Wen Ling

期刊论文

Fuel poverty and low carbon emissions: a comparative study of the feasibility of the hybrid renewableenergy systems incorporating combined heat and power technology

期刊论文

Synergistic utilization of coal and other energy – Key to low carbon economy

Weidou NI, Zhen CHEN

期刊论文

Tackling climate change and promoting the energy revolution

Xiangwan DU

期刊论文

大庆油田台肇地区低渗透储层裂缝及其开发对策研究

曾联波,刘洪涛,房宝才,邓海成

期刊论文

微地震监测技术在低渗透油田裂缝研究中的应用——以大庆西部外围低渗透油田为例

赵玉武,曲瑛新,熊文平

期刊论文