Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 60

会议视频 1

年份

2023 2

2021 2

2020 2

2018 1

2017 3

2016 2

2015 2

2014 1

2013 9

2012 11

2011 5

2010 10

2009 4

2008 1

2007 1

2003 1

2001 2

1999 1

展开︾

关键词

三峡升船机 5

泰州大桥 4

三塔悬索桥 3

三峡工程 3

动力特性 3

施工技术 3

三塔两跨悬索桥 2

创新 2

升船机 2

升船机塔柱 2

塔柱 2

悬索桥 2

支撑系统 2

模型试验 2

横梁 2

海上风电场 2

混凝土 2

7种气态污染物 1

BNLAS 1

展开︾

检索范围：

排序：展示方式：

Optimization design of anti-seismic engineering measures for intake tower based on non-dominated sorting

《结构与土木工程前沿（英文）》页码 1428-1441 doi: 10.1007/s11709-023-0998-2

摘要： High-rise intake towers in high-intensity seismic areas are prone to structural safety problems under vibration. Therefore, effective and low-cost anti-seismic engineering measures must be designed for protection. An intake tower in northwest China was considered the research object, and its natural vibration characteristics and dynamic response were first analyzed using the mode decomposition response spectrum method based on a three-dimensional finite element model. The non-dominated sorting genetic algorithm-II (NSGA-II) was adopted to optimize the anti-seismic scheme combination by comprehensively considering the dynamic tower response and variable project cost. Finally, the rationality of the original intake tower antiseismic design scheme was evaluated according to the obtained optimal solution set, and recommendations for improvement were proposed. The method adopted in this study may provide significant references for designing anti-seismic measures for high-rise structures such as intake towers located in high-intensity earthquake areas.

关键词： intake tower NSGA-II mode decomposition response spectrum method anti-seismic engineering measures optimization design variable project cost

HTML PDF 收藏

J-shaped association between dietary zinc intake and new-onset hypertension: a nationwide cohort study

《医学前沿（英文）》 2023年第17卷第1期页码 156-164 doi: 10.1007/s11684-022-0932-3

摘要： We aimed to investigate the relationship of dietary zinc intake with new-onset hypertension among Chinese adults. A total of 12,177 participants who were free of hypertension at baseline from the China Health and Nutrition Survey were included. Dietary intake was assessed by three consecutive 24-h dietary recalls combined with a household food inventory. Participants with systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg or diagnosed by a physician or under antihypertensive treatment during the follow-up were defined as having new-onset hypertension. During a median follow-up duration of 6.1 years, 4269 participants developed new-onset hypertension. Overall, the association between dietary zinc intake and new-onset hypertension followed a J-shape (P for non-linearity < 0.001). The risk of new-onset hypertension significantly decreased with the increment of dietary zinc intake (per mg/day: hazard ratio (HR) 0.93; 95% confidence interval (CI) 0.88–0.98) in participants with zinc intake < 10.9 mg/day, and increased with the increment of zinc intake (per mg/day: HR 1.14; 95% CI 1.11–1.16) in participants with zinc intake ≥ 10.9 mg/day. In conclusion, there was a J-shaped association between dietary zinc intake and new-onset hypertension in general Chinese adults, with an inflection point at about 10.9 mg/day.

关键词： dietary zinc intake new-onset hypertension general population CHNS

HTML PDF 收藏

Water pumping analysis and experimental validation of beach well infiltration intake system in a seawater

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

《能源前沿（英文）》 2015年第9卷第3期页码 335-342 doi: 10.1007/s11708-015-0365-7

摘要： Based on energy conservation equation and Darcy’s law, a model of beach well infiltration intake system applied in a seawater source heat pump system was established. The model consists of the seawater seepage and the heat transfer process. A porous medium model in a software named FLUENT was applied to simulate the seepage and the heat transfer process. This model was also validated by field experiment conducted on the seashore in Tianjin, China. The maximum relative error between simulation results and experimental results was 2.1% (less than 5%), which was acceptable in engineering application. The porosity and coefficient of thermal conductivity of the aquifer soil were determined to be 0.49 W/(m·K) and 1.46 W/(m·K), respectively in the simulation. In addition, the influencing factors of pumping water of beach well were also analyzed. The pumping water was found to increase when the distance between the beach well and the impervious boundary becomes longer, when the distance between the beach well and the supplying water source shortens, when the diameter of the beach well enlarges, and the drawdown enlarges.

关键词： water pumping analysis experimental validation infiltration intake system seawater source heat pump

HTML PDF 收藏

Assessment on contaminations in sediments of an intake and the inflow canals in Taihu Lake, China

Xiaolong WANG,Shiming DING,Qi ZHANG,Weiping HU

《环境科学与工程前沿（英文）》 2015年第9卷第4期页码 665-674 doi: 10.1007/s11783-014-0701-x

摘要： As the second largest freshwater lake in China, Taihu Lake provides water supply to approximately 32 million inhabitants around the lake. However, dramatically increased pollution has threatened the safety of drinking water supply in recent years. In the present study, we investigated the contaminations of nutrients and heavy metals in the sediments of an intake and inflow canals in Gonghu Bay, Taihu Lake. Moreover, we also examined the impact of human activities on spatial distribution characteristics of contaminations. Our results showed that the intake presented relatively lower concentrations of phosphorus and nitrogen compared with inflow canals. However, the concentrations of Cr, Ni, Cu, Zn and Pb in the sediments of the intake exceeded the lowest effect level (LEL) values, indicating a potential risk to drinking water resource. In addition, the concentrations of Ni in the sediments of Tianji Canal and Jinshu Canal exceeded the severe effect level (SEL) value. More importantly, the concentrations of Cu in the sediments of Tianji Canal exceeded three times of the SEL value. Multivariate statistical analysis confirmed that the domestic sewage primarily contributed to the nutrient accumulation, and the leakage of electronic trash dominated the enrichment of metals in the sediments. Taken together, more effort should be made to ensure the security of water resources in Taihu Lake, especially for the treatment of domestic sewage and industrial wastewater.

关键词： drinking water resource nutrients heavy metals sediments Taihu Lake

HTML PDF 收藏

Safety and serviceability assessment for high-rise tower crane to turbulent winds

Zhi SUN, Nin HOU, Haifan XIANG

《结构与土木工程前沿（英文）》 2009年第3卷第1期页码 18-24 doi: 10.1007/s11709-009-0009-2

摘要： Tower cranes are commonly used facilities for the construction of high-rise structures. To ensure their workability, it is very important to analyze their response and evaluate their condition under extreme conditions. This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis. Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary, multivariate stochastic process according to some prescribed spectral density matrix. The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift, drag, and moment coefficients obtained from a CFD computation. Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response. Compared with structural on-site response measurement, the computed response using the proposed method has good precision. The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.

关键词： tower crane buffeting response wind velocity modeling

HTML PDF 收藏

c-Fos expression in rat brainstem following intake of sucrose or saccharin

Ke Chen, Jianqun Yan, Jinrong Li, Bo Lv, Xiaolin Zhao

《医学前沿（英文）》 2011年第5卷第3期页码 294-301 doi: 10.1007/s11684-011-0144-8

摘要： To examine whether the activation of brainstem neurons during intake of a sweet tastant is due to orosensory signals or post-ingestive factors, we compared the distribution of c-Fos-like immunoreactivity (c-FLI) in the nucleus of the solitary tract (NST) and parabrachial nucleus (PBN) of brainstem following ingestion of 0.25 M sucrose or 0.005 M saccharin solutions. Immunopositive neurons were localized mainly in the middle zone of the PBN and four rostral-caudal subregions of the NST. Intake of sucrose increased the number of FLI neurons in almost every subnucleus of the PBN (F = 7.610, = 0.023), in addition to the caudal NST at the level of the area postrema (F = 10.777, = 0.003) and the NST intermediate zone (F = 7.193, = 0.014). No significant increase in the number of c-Fos positive neurons was detected in response to saccharin ingestion, although there was a trend towards a modest increase in a few select NST and PBN nuclei. These results suggest that the PBN and NST may be involved in sweet taste perception and modulation of sweet tastant intake, but the significantly enhanced intensity of Fos expression induced by sucrose indicates that PBN/NST neuronal activity is driven by the integrated effects of sweet taste sensation and post-ingestive signals.

关键词： c-Fos parabrachial the nucleus of the solitary tract sweet tastant rat

HTML PDF 收藏

Association of maternal depression with dietary intake, growth, and development of preterm infants: a

Han Wang, Hong Zhou, Yan Zhang, Yan Wang, Jing Sun

《医学前沿（英文）》 2018年第12卷第5期页码 533-541 doi: 10.1007/s11684-017-0591-y

摘要：

This study aimed to explore the association of maternal depression with nutrient intake, growth, and development of preterm infants. A cohort study of 201 infants was conducted in Beijing. Based on the gestational age of an infant and status of the mother, the infants were divided into four groups: non-depression-fullterm (64), non-depression-preterm (70), depression-fullterm (36), and depression-preterm (31). Data on sociodemographic characteristics, nutritional intake, growth, and developmental status of children at 8 months (corrected ages) were collected using a quantitative questionnaire, a 24-Hour Dietary Recall, anthropometric measurements, and the Bayley-III scale. A multivariate analysis was used to evaluate the effects of maternal depression and preterm birth on infant growth and development. The energy, protein, and carbohydrate intake in the depression group was lower than the recommended amounts. The depression preterm groups indicated the lowest Z-scores for length and weight and the lowest Bayley-III scores. Preterm infants of depressed mothers are at high risks of poor growth and development delay.

关键词： maternal depression preterm infant nutrition growth development

HTML PDF 收藏

Practice and Experience of Canton Tower Project Management

Rong-hua Yi

《工程管理前沿（英文）》 2016年第3卷第1期页码 74-79 doi: 10.15302/J-FEM-2016013

摘要： This paper presents a brief introduction about the preliminary consulting and tender agent of Canton Tower, the basic situation of the whole-process supervision on the construction site, and a general summary of the Canton Tower project management. What’s more, the author suggests that some guidelines be formed for supervision enterprises involved in large-scale project management.

关键词： Canton Tower consultation tender agent whole-process supervision

HTML PDF 收藏

水电站叠梁门多层取水下泄水温公式

高学平,陈弘,宋慧芳

《中国工程科学》 2011年第13卷第12期页码 63-67

摘要：

对于温度成层型水库，水电站进水口分层取水方式通常被采用，目的是有选择地取用水库的不同层水体，减免下泄低温水对下游河流环境的负面影响。目前缺乏简单实用的分层取水下泄水温的预测公式。笔者针对糯扎渡水电站工程，试验模拟水库水温分布，量测下泄水温；依据大量的试验数据，建立下泄水温预测公式；所提出的公式得到了锦屏一级电站下泄水温试验数据的验证。

关键词：温度成层型水库水电站进水口叠梁门下泄水温公式模型试验

HTML PDF 收藏

Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

《机械工程前沿（英文）》 2017年第12卷第3期页码 321-332 doi: 10.1007/s11465-017-0434-1

摘要：

The magnitude and stability of power output are two key indices of wind turbines. This study investigates the effects of wind shear and tower shadow on power output in terms of power fluctuation and power loss to estimate the capacity and quality of the power generated by a wind turbine. First, wind speed models, particularly the wind shear model and the tower shadow model, are described in detail. The widely accepted tower shadow model is modified in view of the cone-shaped towers of modern large-scale wind turbines. Power fluctuation and power loss due to wind shear and tower shadow are analyzed by performing theoretical calculations and case analysis within the framework of a modified version of blade element momentum theory. Results indicate that power fluctuation is mainly caused by tower shadow, whereas power loss is primarily induced by wind shear. Under steady wind conditions, power loss can be divided into wind farm loss and rotor loss. Wind farm loss is constant at 3α(3α−1)R²/(8H²). By contrast, rotor loss is strongly influenced by the wind turbine control strategies and wind speed. That is, when the wind speed is measured in a region where a variable-speed controller works, the rotor loss stabilizes around zero, but when the wind speed is measured in a region where the blade pitch controller works, the rotor loss increases as the wind speed intensifies. The results of this study can serve as a reference for accurate power estimation and strategy development to mitigate the fluctuations in aerodynamic loads and power output due to wind shear and tower shadow.

关键词： wind turbine wind shear tower shadow power fluctuation power loss

HTML PDF 收藏

Impacts of solar multiple on the performance of direct steam generation solar power tower plant with

Yan LUO, Xiaoze DU, Lijun YANG, Chao XU, Muhammad AMJAD

《能源前沿（英文）》 2017年第11卷第4期页码 461-471 doi: 10.1007/s11708-017-0503-5

摘要： Solar multiple (SM) and thermal storage capacity are two key design parameters for revealing the performance of direct steam generation (DSG) solar power tower plant. In the case of settled land area, SM and thermal storage capacity can be optimized to obtain the minimum levelized cost of electricity (LCOE) by adjusting the power generation output. Taking the dual-receiver DSG solar power tower plant with a given size of solar field equivalent electricity of 100 MW in Sevilla as a reference case, the minimum LCOE is 21.77 ￠/kWh with an SM of 1.7 and a thermal storage capacity of 3 h. Besides Sevilla, two other sites are also introduced to discuss the influence of annual DNI. When compared with the case of Sevilla, the minimum LCOE and optimal SM of the San Jose site change just slightly, while the minimum LCOE of the Bishop site decreases by 32.8% and the optimal SM is reduced to 1.3. The influence of the size of solar field equivalent electricity is studied as well. The minimum LCOE decreases with the size of solar field, while the optimal SM and thermal storage capacity still remain unchanged. In addition, the sensitivity of different investment in sub-system is investigated. In terms of optimal SM and thermal storage capacity, they can decrease with the cost of thermal storage system but increase with the cost of power generation unit.

关键词： direct steam generation solar power tower solar multiple thermal energy storage capacity levelized cost of electricity (LCOE)

HTML PDF 收藏

泰州大桥——世界首座千米级三塔悬索桥

钟建驰

《中国工程科学》 2010年第12卷第4期页码 4-8

摘要：

2007年12月开工建设的泰州大桥位于江苏省中部，连接泰州与镇江，为世界首座千米级三塔连跨悬索桥，同时中塔采用世界首个纵向人字型钢塔，中塔基础采用世界上入土最深的水中沉井基础。为了建造这项宏伟的工程，针对众多技术挑战，建设者采取了一系列的创新技术：三塔悬索桥的设计技术，江中大型深井的定位着床、封底技术，人字型钢中塔的钢混结合连接技术、超厚钢板的焊接加工技术以及钢中塔异型节段的精确加工与控制技术等。

关键词：三塔悬索桥创新设计水中沉井人字型钢塔

HTML PDF 收藏

Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

《能源前沿（英文）》 2016年第10卷第2期页码 213-226 doi: 10.1007/s11708-016-0398-6

摘要： There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current (or voltage) source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词： grounding transmission line tower back flashover probability FDTD method

HTML PDF 收藏

螺旋结构冷却塔的塔板设计方法

黄锐

《中国工程科学》 2008年第10卷第11期页码 43-46

摘要：

针对冷却塔中螺旋结构类型的气液交换塔，提出其内部螺旋塔板形状的设计方法，包括塔壁上外螺旋线和塔中心轴管上内螺旋线的位置确定，以及两线之间螺旋曲面板在平面上的拓扑尺寸。通过塔的几何参数确定螺旋曲面板设计的关键参数，可实现扭曲状塔板与塔壁及内轴的准确配合。

关键词：冷却塔塔板设计螺旋曲面拓扑

HTML PDF 收藏

泰州大桥中间塔鞍座抗滑安全评估

阮欣,阮静,陈艾荣,郭济

《中国工程科学》 2012年第14卷第5期页码 71-74

摘要：

在分析鞍座抗滑机理的基础上，建立了基于最大静摩擦系数的三塔悬索桥中间塔鞍座抗滑基本评估模型,并发展了多种鞍座抗滑评估方法。包括基于目前使用的设计规范评估鞍座抗滑安全的确定性方法；基于静态车辆数据合成随机车流，并利用Rice公式外推其荷载效应极值，进而研究鞍座抗滑安全性能的评估方法；以及基于车辆荷载效应和抗力概率模型的鞍座抗滑概率评估方法。用上述三种方法分别对泰州大桥鞍座抗滑安全性进行全面评估，表明泰州大桥中塔鞍座抗滑安全可靠。

关键词：三塔两跨悬索桥中间塔鞍座确定性评估概率评估