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 438

会议视频 15

会议信息 1

年份

2024 1

2023 26

2022 34

2021 30

2020 22

2019 26

2018 24

2017 19

2016 22

2015 17

2014 14

2013 12

2012 34

2011 30

2010 49

2009 16

2008 17

2007 14

2006 7

2005 6

展开︾

关键词

天然气 11

能源 8

勘探开发 7

普光气田 7

页岩气 5

天然气水合物 4

温室气体 4

中国 3

采油工程 3

三相界面 2

中国近海 2

低碳 2

光声 2

关键技术 2

分布特征 2

南海 2

可持续发展 2

启示 2

大型化成藏 2

展开︾

检索范围：

排序：展示方式：

Numerical and experimental analyses of methane leakage in shield tunnel

《结构与土木工程前沿（英文）》页码 1011-1020 doi: 10.1007/s11709-023-0956-z

摘要： Tunnels constructed in gas-bearing strata are affected by the potential leakage of harmful gases, such as methane gas. Based on the basic principles of computational fluid dynamics, a numerical analysis was performed to simulate the ventilation and diffusion of harmful gases in a shield tunnel, and the effect of ventilation airflow speed on the diffusion of harmful gases was evaluated. As the airflow speed increased from 1.8 to 5.4 m/s, the methane emission was diluted, and the methane accumulation was only observed in the area near the methane leakage channels. The influence of increased ventilation airflow velocity was dominant for the ventilation modes with two and four fans. In addition, laboratory tests on methane leakage through segment joints were performed. The results show that the leakage process can be divided into “rapid leakage” and “slight leakage”, depending on the leakage pressure and the state of joint deformation. Based on the numerical and experimental analysis results, a relationship between the safety level and the joint deformation is established, which can be used as guidelines for maintaining utility tunnels.

关键词： shield tunnel harmful gas leakage numerical analysis laboratory test

HTML PDF 收藏

Assessment of pollution of potentially harmful elements in soils surrounding a municipal solid waste

Ying Han, Huiting Xie, Wenbin Liu, Haifeng Li, Mengjing Wang, Xuebin Chen, Xiao Liao, Nan Yan

《环境科学与工程前沿（英文）》 2016年第10卷第6期 doi: 10.1007/s11783-016-0873-7

摘要： Potentially harmful elements in ambient soil of a MSWI were assessed. Spatial distribution of potential ecological risk index was investigated. Health risk assessment of potentially harmful elements in soil was evaluated. Hg in the soil posed health hazards to the local population. We assessed the contamination levels of Mn, Zn, Cr, Cu, Ni, Pb, As and Hg and the risks posed by these potentially harmful elements in top-soils around a municipal solid waste incinerator (MSWI). We collected 20 soil samples, with an average pH of 8.1, and another fly ash sample emitted from the MSWI to investigate the concentrations of these elements in soils. We determined the concentrations of these elements by inductively coupled plasma–optical emission spectrometer (ICP-OES), except for Hg, which we measured by AF-610B atomic fluorescence spectrometer ( ). We assessed the risks of these elements through the use of geoaccumulation index ( ), potential ecological risk index ( ), hazard quotient ( ) and cancer risk ( ). The results showed that concentrations of potentially harmful elements in soil were influenced by the wind direction, and the concentrations of most elements were higher in the area northwest of the MSWI, compared with the area southeast of the incinerator, with the exception of As; these results were in accordance with those results acquired from our contour maps. According to the values, some soil samples were clearly polluted by Hg emissions. However, the health risk assessment indicated that the concentrations of Hg and other elements in soil did not pose non-carcinogenic risks to the local populations. This was also the case for the carcinogenic risks posed by As, Cr, and Ni. The carcinogenic risk posed by As was higher, in the range 6.49 × 10 –9.58 × 10 , but this was still considered to be an acceptable level of risk.

关键词： Soil Potentially harmful elements Contamination Kriging interpolation Risk assessment Wind direction

HTML PDF 收藏

Effects of leakage and friction on the miniaturization of a Wankel compressor

Yilin ZHANG, Wen WANG

《能源前沿（英文）》 2011年第5卷第1期页码 83-92 doi: 10.1007/s11708-010-0125-7

摘要： This paper presents a numerical simulation of the performance of a meso-scale Wankel compressor and discusses the factors affecting its miniaturization. The discussion is related to the effect of leakage and friction on the design limit (cooling capacity and dimension) of the meso Wankel compressor. In the simulation, the main leakage comes from the gaps between the rotor and the endplates as well as between the seal apex and the cylinder. The largest friction originates from the clearance among the end face of the eccentric shaft, the end faces of the rotor, and the endplates. The decreasing cooling capacity of the meso Wankel compressor increases the proportion of leakage to displacement and causes the coefficient of performance COP and the mechanical efficiency to decrease. The rational design cooling capacity limit for the meso-scale Wankel compressor is approximately 4 W.

关键词： meso-scale Wankel compressor leakage friction

HTML PDF 收藏

从大连输油管爆炸反思油气设备驱动方式——非能动控制驱动对油气储运的特殊意义

曾祥炜,陈崑,邱小平,曾小舸,向北平,臧红彬,石磊,龚伟

《中国工程科学》 2010年第12卷第9期页码 34-38

摘要：

通过分析大连输油管爆炸，对当今国内外油气储运设备驱动方式进行反思。提出非能动控制原理和方法，阐述非能动控制梭式核心元件的结构和原理；对非能动梭式控制管道爆破保护系统、巨型油罐梭式消防止回阀进行分析，得出非能动控制驱动对油气储运具有特殊意义。

关键词：非能动控制油气储运泄漏

HTML PDF 收藏

Cohesive zone model-based analyses of localized leakage of segmentally lined tunnels

《结构与土木工程前沿（英文）》 2023年第17卷第4期页码 503-521 doi: 10.1007/s11709-023-0927-4

摘要： This paper presents a novel approach for simulating the localized leakage behavior of segmentally lined tunnels based on a cohesive zone model. The proposed approach not only simulates localized leakage at the lining segment, but also captures the hydromechanically coupled seepage behavior at the segmental joints. It is first verified via a tunnel drainage experiment, which reveals its merits over the existing local hydraulic conductivity method. Subsequently, a parametric study is conducted to investigate the effects of the aperture size, stratum permeability, and spatial distribution of drainage holes on the leakage behavior, stratum seepage field, and leakage-induced mechanical response of the tunnel lining. The proposed approach yields more accurate results than the classical local hydraulic conductivity method. Moreover, it is both computationally efficient and stable. Localized leakage leads to reduced local ground pressure, which further induces outward deformation near the leakage point and slight inward deformation at its diametrically opposite side. A localized stress arch spanning across the leakage point is observed, which manifests as the rotation of the principal stresses in the adjacent area. The seepage field depends on both the number and location of the leakage zones. Pseudostatic seepage zones, in which the seepage rate is significantly lower than that of the adjacent area, appear when multiple seepage zones are considered. Finally, the importance of employing the hydromechanical coupled mechanism at the segment joints is highlighted by cases of shallowly buried tunnels subjected to surface loading and pressure tunnels while considering internal water pressure.

关键词： segmentally lined tunnel localized leakage cohesive element hydraulic behavior numerical modeling

HTML PDF 收藏

Long-term settlement behavior of ground around shield tunnel due to leakage of water in soft deposit

Huaina WU, Yeshuang XU, Shui-long SHEN, Jin-chun CHAI

《结构与土木工程前沿（英文）》 2011年第5卷第2期页码 194-198 doi: 10.1007/s11709-011-0105-y

摘要： The lining of shield tunnel is usually composed of segments, in which the joints, cracks, and the grouting holes (hereafter called lining deficit) exist. During the long-term running, soils and groundwater may leak from these kinds of lining deficit. The leaking of soil and groundwater causes the long-term ground loss around tunnel and thus results in the settlement of ground surface. This paper aims to analyze the impact of the leakage of groundwater through segments on the long-term settlement of ground surface. The adopted analytical method is based on the theory of groundwater seepage by using numerical simulation. The analyzed results show that settlement of ground surface increases gradually with the increase of the leaked volume of tunnel segments. When the leaked volume was unevenly distributed, differential settlement occurred locally. Comparative analysis by changing the leaked volume was conducted. The results reveal that there is a linear relationship between settlement and leaked volume when the leaked volume was controlled within the allowable limit.

关键词： lining deficit leakage of water shield tunnel settlement soft deposit

HTML PDF 收藏

A building unit decomposition model for energy leakage by infrared thermography image analysis

Yan SU, Fangjun HONG, Lianjie SHU

《能源前沿（英文）》 2020年第14卷第4期页码 901-921 doi: 10.1007/s11708-020-0679-y

摘要： A quantitative energy leakage model was developed based on the thermography image data measured for both external and internal building surfaces. The infrared thermography images of both surfaces of doors, windows, and walls of an office building in the Hengqin Campus of University of Macao were taken at various times in a day for four seasons. The transient heat ﬂux for sample units were obtained based on measurements of the seasonal transient local temperature differences and calculations of the effective thermal conductivity from the multiple-layer porous medium conduction model. Effects of construction unit types, orientations, and seasons were quantitatively investigated with unit transient orientation index factors. The corresponding electric energy consumption was calculated based on the air conditioning system coefficient of performance of heat pump and refrigerator cycles for different seasons. The model was validated by comparing to the electric meter records of energy consumption of the air conditioning system. The uncertainties of the predicted total building energy leakage are about 14.7%, 12.8%, 12.4%, and 15.8% for the four seasons, respectively. The differences between the predicted electric consumption and meter values are less than 13.4% and 5.4% for summer and winter, respectively. The typical daily thermal energy leakage value in winter is the highest among the four seasons. However, the daily electric energy consumption by the air conditioning system in summer and autumn is higher than that in winter. The present decomposition model for energy leakage is expected to provide a practical tool for quantitative analysis of energy leakage of buildings.

关键词： heat conductivity heat coefficient heat &fllig ux infrared thermography thermal image

HTML PDF 收藏

Bacteriophages in water pollution control: Advantages and limitations

《环境科学与工程前沿（英文）》 2021年第15卷第5期 doi: 10.1007/s11783-020-1378-y

摘要：

•Phages can be better indicators of enteric viruses than fecal indicator bacteria.

关键词： Phage Water pollution monitoring Harmful bacteria biocontrol Horizontal gene transfer Bacterial resistance

HTML PDF 收藏

国外网络空间不良信息管理与趋势

贾焰,李爱平,李欲晓、李树栋、田志宏、韩毅、时金桥、林彬

《中国工程科学》 2016年第18卷第6期页码 94-98 doi: 10.15302/J-SSCAE-2016.06.019

摘要：

针对网络空间内容安全中各种不良信息（包括恐怖、谣言、诈骗、暴力、色情和颠覆等）的治理需求，本文综述了国外网络空间不良信息的管理情况。首先，对国外网络空间不良信息进行了定义和分类；其次，梳理了国外网络空间不良信息监管的法律法规，阐述了一些国家在立法中普遍采取的做法；再次，从网络数据监听、网络不良信息过滤与舆论对抗入手，着重介绍了世界主要国家对网络不良信息的治理技术与手段；最后，总结了近年来全球范围内部分互联网不良信息治理专项行动等。

关键词：网络空间不良信息信息监管信息过滤舆论对抗

HTML PDF 收藏

Aggravation of membrane fouling and methane leakage by a three-phase separator in an external anaerobic

Chao Pang, Chunhua He, Zhenhu Hu, Shoujun Yuan, Wei Wang

《环境科学与工程前沿（英文）》 2019年第13卷第4期 doi: 10.1007/s11783-019-1131-6

摘要：

The existence of three-phase separator did not affect COD removal in the EAnCMBR.

The existence of three-phase separator aggravated methane leakage of EAnCMBR.

The existence of three-phase separator aggravated membrane fouling rate of EAnCMBR.

Start-up of EAnCMBR equipped three-phase separator was slightly delayed.

关键词： Anaerobic membrane bioreactor Three-phase separator Membrane fouling Methane leakage Sludge property

HTML PDF 收藏

在现场可编程门阵列中用于降低泄漏功率的动态电源门控 Research Article

Hadi JAHANIRAD

《信息与电子工程前沿（英文）》 2023年第24卷第4期页码 582-598 doi: 10.1631/FITEE.2200084

摘要：现场可编程门阵列（FPGA）器件由于其低设计成本和可重构性，在电子系统中得到广泛应用。在手持电子系统等电池受限的应用中，低功耗FGPA的需求很大。在现代集成电路技术中，泄漏功率几乎相当于动态功率，因此降低泄漏功率可以显著节省能耗。我们提出一种基于静态随机存取存储器（SRAM）的FPGA高效架构，其中每个模块定义了两种模式（活动模式和休眠模式）。在休眠模式下，模块消耗超低泄漏功率。当模块输出对新输入向量的评估时，模块模式由休眠模式动态改变为活动模式。在产生正确的输出后，该模块返回到休眠模式。所提电路设计在活动模式和休眠模式下都降低了泄漏功耗。通过在FPGA-SPICE软件上实现北卡罗来纳州微电子中心（MCNC）基准电路，将所提出的低泄漏FPGA体系结构与最先进的体系结构进行比较。仿真结果表明，休眠模式下泄漏功耗降低约95%。此外，与以往的最佳设计相比，总功耗（泄漏功耗+动态功耗）降低15%以上。平均面积开销（4.26%）小于其他电源门控设计。

关键词：现场可编程门阵列（FPGA）；泄漏功率；电源门控；晶体管级电路设计

HTML PDF 收藏

Leakage location system for oil pipeline on basis of stress wave detection

WANG Bangfeng, CHEN Renwen

《机械工程前沿（英文）》 2008年第3卷第3期页码 307-312 doi: 10.1007/s11465-008-0047-9

摘要： An online monitoring system was developed for rapidly determining the exact location of the holing position in an oil pipeline by monitoring and analyzing the characteristics of the strain wave caused by the hole. The system has a master-slaver computer structure based on a remote wireless network. The master system takes charge of managing and controlling the whole system, identifying the holing stress wave, and calculating the holing position. The slaver system is responsible for sampling the strain wave signal from the pipeline. The characteristics of the strain wave signal are extracted by a Hilbert-Huang transform based on a signal processing approach. The exact holing position can be obtained by a time delay locating method with stress wave characteristics. The experimental results of the in-service pipeline show that the average locating error of the system is less than 10 m, the accuracy ratio for the holing alarm is more than 90%, and the time that the system takes to respond to the leakage is less than 10 s.

HTML PDF 收藏

利用机器视觉技术对化工厂管道进行自动视觉泄漏检测与定位 Reiew

Mina Fahimipirehgalin, Emanuel Trunzer, Matthias Odenweller, Birgit Vogel-Heuser

《工程（英文）》 2021年第7卷第6期页码 758-776 doi: 10.1016/j.eng.2020.08.026

摘要：

在大型化工厂中，输送液体的管道的泄漏是一个重要的问题。管道的破损不仅会影响工厂的正常运行，同时也增加了维护成本。此外，还会使操作人员的生命安全受到威胁。因此，管道泄漏的检测与定位是维护和状态监测中的关键任务。近年来，大型工厂利用红外（IR）相机进行泄漏检测。红外相机可捕捉温度比周围环境温度高（或低）的液体泄漏。本文针对化工厂中的管道泄漏，提出了一种基于红外视频数据和机器视觉技术的检测与定位方法。由于所提出的方法是以视觉技术为基础，无需考虑泄漏液体的物理性质，因此其适用于任何类型的液体（水、油等）泄漏检测。在本方法中，首先对后续帧进行减影和分块处理，然后对每一分块进行主成分分析，提取特征；接着将分块内所有减影帧都转换为特征向量（作为块分类的依据），根据特征向量，采用k-最近邻算法将块分为正常（无泄漏）和异常（泄漏）两类；最后在各异常块上确定泄漏的位置。本文使用了两种不同格式的数据集（由红外相机拍摄的实验室工厂演示装置的视频图像组成）对上述方法进行评估。结果表明，本文提出的利用红外视频进行管道泄漏检测与定位的方法前景可观，具有较高的检测精度以及合理的检测时间。本文最后讨论了该方法在工厂进行实际推广的可能性及局限性。

关键词：泄漏检测与定位图像分析图像预处理主成分分析 k-最近邻分类

HTML PDF 收藏

Modeling and analysis of magnetic dipoles in weak magnetic field

WANG Zhaoxia, ZHANG Weimin, LIU Hongguang

《机械工程前沿（英文）》 2008年第3卷第2期页码 222-225 doi: 10.1007/s11465-008-0028-z

摘要： The magnetic leakage field distribution resulting from linear defects of a tube sample in the geomagnetic field is modeled according to the magnetic dipole theory. The formula to compute the normal component of the weak magnetic field is deduced based on the spatial distribution of the magnetic dipole. The shape and characteristics of the zero line (an important criterion for magnetic memory testing) of the normal field is analyzed under different longitudinal magnetizations. Results show that the characteristics of the zero line should be considered when the metal magnetic memory testing method is used to find and locate the defect.

关键词： geomagnetic theory important criterion magnetic leakage normal component

HTML PDF 收藏

CO, N, and CO/N mixed gas injection for enhanced shale gas recovery and CO geological storage

《能源前沿（英文）》 2023年第17卷第3期页码 428-445 doi: 10.1007/s11708-023-0865-9

摘要： In this work, using fractured shale cores, isothermal adsorption experiments and core flooding tests were conducted to investigate the performance of injecting different gases to enhance shale gas recovery and CO₂ geological storage efficiency under real reservoir conditions. The adsorption process of shale to different gases was in agreement with the extended-Langmuir model, and the adsorption capacity of CO₂ was the largest, followed by CH_4, and that of N₂ was the smallest of the three pure gases. In addition, when the CO₂ concentration in the mixed gas exceeded 50%, the adsorption capacity of the mixed gas was greater than that of CH₄, and had a strong competitive adsorption effect. For the core flooding tests, pure gas injection showed that the breakthrough time of CO₂ was longer than that of N₂, and the CH₄ recovery factor at the breakthrough time (

R C H 4

) was also higher than that of N₂. The

R C H 4

of CO₂ gas injection was approximately 44.09%, while the

R C H 4

of N₂ was only 31.63%. For CO₂/N₂ mixed gas injection, with the increase of CO₂ concentration, the

R C H 4

increased, and the

R C H 4

for mixed gas CO₂/N₂ = 8:2 was close to that of pure CO₂, about 40.24%. Moreover, the breakthrough time of N₂ in mixed gas was not much different from that when pure N₂ was injected, while the breakthrough time of CO₂ was prolonged, which indicated that with the increase of N₂ concentration in the mixed gas, the breakthrough time of CO₂ could be extended. Furthermore, an abnormal surge of N₂ concentration in the produced gas was observed after N₂ breakthrough. In regards to CO₂ storage efficiency (