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 21

年份

2021 2

2020 2

2019 1

2017 1

2012 1

2009 1

2008 3

2007 4

2006 2

2005 1

2003 1

2000 2

展开︾

关键词

可持续发展 2

GDP年增长率 1

Griewank；双尺度结构；多尺度量子谐振子算法；量子隧道效应 1

单位GDP环境负荷 1

单位GDP环境负荷的年下降率 1

单位GDP能耗 1

原代肝细胞 1

去分化 1

发展设想 1

土壤冲刷 1

增产 1

增加产量 1

多缝压裂 1

定向射孔 1

政策建议 1

武汉钢铁公司 1

沙尘暴 1

泄流体积 1

泛素化蛋白质组学 1

展开︾

检索范围：

排序：展示方式：

Zero increase in peak discharge for sustainable development

Xing Fang, Junqi Li, Yongwei Gong, Xiaoning Li

《环境科学与工程前沿（英文）》 2017年第11卷第4期 doi: 10.1007/s11783-017-0935-5

摘要： For urban land development, some or all natural land uses (primarily pervious) are converted into impervious areas which lead to increases of runoff volume and peak discharge. Most of the developed countries require a zero increase in peak discharge for any land development, and the policy has been implemented for several decades. The policy of zero increase in peak discharge can be considered as historical and early stage for the low impact development (LID) and sustainable development, which is to maintain natural hydrological conditions by storing a part or all of additional runoff due to the development on site. The paper will discuss the policy, the policy implementation for individual projects and their impact on regional hydrology. The design rainfalls for sizing LID facilities that are determined in 206 weather stations in USA are smaller than design rainfalls for sizing detention basins. The zero-increase policy links to financial responsibility and sustainability for construction of urban stormwater infrastructures and for reducing urban flooding. The policy was compared with current practices of urban development in China to shine the light for solving urban stormwater problems. The connections and differences among LID practices, the zero-increase policy, and the flood control infrastructure were discussed. We promote and advocate the zero-increase policy on peak discharge for comprehensive stormwater management in China in addition to LID.

关键词： Stormwater management Detention basin Zero increase Peak discharge Sustainable development Design rainfall

HTML PDF 收藏

Strength-increase mechanism and microstructural characteristics of a biotreated geomaterial

Chi LI, Siriguleng BAI, Tuanjie ZHOU, Hanlong LIU, Xiao QIN, Shihui LIU, Xiaoying LIU, Yang XIAO

《结构与土木工程前沿（英文）》 2020年第14卷第3期页码 599-608 doi: 10.1007/s11709-020-0606-7

摘要： Microbially induced calcite precipitation (MICP) is a recently proposed method that is environmentally friendly and has considerable potential applications in artificial biotreated geomaterials. New artificial biotreated geomaterials are produced based on the MICP technology for different parent soils. The purpose of this study is to explore the strength-increase mechanism and microstructural characteristics of the biotreated geomaterial through a series of experiments. The results show that longer mineralization time results in higher-strength biotreated geomaterial. The strength growth rate rapidly increases in the beginning and remains stable afterwards. The calcium ion content significantly increases with the extended mineralization time. When standard sand was used as a parent soil, the calcium ion content increased to a factor of 39 after 7 days. The bacterial cells with attached calcium ions serve as the nucleus of crystallization and fill the pore space. When fine sand was used as a parent soil, the calcium ion content increased to only a factor of 7 after 7 days of mineralization. The nucleus of crystallization could not normally grow because of the limited pore space. The porosity and variation in porosity are clearly affected by the parent soil. Therefore, the strength of the biotreated geomaterial is affected by the parent soil properties, mineralization time, and granular material pore space. This paper provides a basis for theory and experiments for biotreated geomaterials in future engineering practice.

关键词： biotreated geomaterial microbially induced calcite precipitation strength-increase mechanism microstructural characteristics

HTML PDF 收藏

The cavitation erosion damage process of dynamically loaded journal bearings

MA Yan-yan, CHENG Xian-hua

《机械工程前沿（英文）》 2006年第1卷第4期页码 461-464 doi: 10.1007/s11465-006-0059-2

摘要： The cavitation damage model was built using finite element analysis software MSC.Marc. This paper attempted to numerically analyze the action process based on damage mechanics when a jet created by bubble collapse acted on the bearing surface in the process of cavitation erosion. The numerical results show that the values of equivalent plastic strain and void volume fraction increase with time. The values of damage scalar are higher on the bearing surface and subsurface, and decrease when it approaches the interface of overlay and nickel layer. The strain history and damage evolvement of bearing material acted on by jet impact load can be calculated efficiently using the proposed method, which develops a new method of analyzing cavitation erosion failure of the bearing surface.

关键词： bearing fraction increase collapse process evolvement

HTML PDF 收藏

光子芯片——效率更高、能耗更低

Mitch Leslie

《工程（英文）》 2021年第7卷第9期页码 1195-1196 doi: 10.1016/j.eng.2021.07.005

HTML PDF 收藏

Significant increase of assimilable organic carbon (AOC) levels in MBR effluents followed by coagulation

Xiaojie Shi, Zhuo Chen, Yun Lu, Qi Shi, Yinhu Wu, Hong-Ying Hu

《环境科学与工程前沿（英文）》 2021年第15卷第4期 doi: 10.1007/s11783-020-1360-8

摘要： Abstract • Annual AOCs in MBR effluents were stable with small increase in warmer seasons. • Significant increase in AOC levels of tertiary effluents were observed. • Coagulation in prior to ozonation can reduce AOC formation in tertiary treatment. • ∆UV254 and SUVA can be surrogates to predict the AOC changes during ozonation. As water reuse development has increased, biological stability issues associated with reclaimed water have gained attention. This study evaluated assimilable organic carbon (AOC) in effluents from a full-scale membrane biological reactor (MBR) plant and found that they were generally stable over one year (125–216 µg/L), with slight increases in warmer seasons. After additional tertiary treatments, the largest increases in absolute and specific AOCs were detected during ozonation, followed by coagulation-ozonation and coagulation. Moreover, UV254 absorbance is known to be an effective surrogate to predict the AOC changes during ozonation. Applying coagulation prior to ozonation of MBR effluents for removal of large molecules was found to reduce the AOC formation compared with ozonation treatment alone. Finally, the results revealed that attention should be paid to seasonal variations in influent and organic fraction changes during treatment to enable sustainable water reuse.

关键词： Assimilable organic carbon (AOC) MBR effluents Tertiary treatments Coagulation Ozonation

HTML PDF 收藏

Direct synthesis of dimethyl carbonate over rare earth oxide supported catalyst

JIANG Qi, CHENG Jiye, GAO Zhiqin

《化学科学与工程前沿（英文）》 2007年第1卷第3期页码 300-303 doi: 10.1007/s11705-007-0055-z

摘要： Solid base catalysts for the direct synthesis of dimethyl carbonate (DMC) from carbon dioxide, methanol, and propylene oxide were prepared by loading KCl and KCO on the surface of LaO, YO, CeO and NdO. The catalysts were characterized by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. The catalytic activities were efficiently influenced by the preparation conditions. The optimal loading amount of KCO is 17.6% (mass) for KCl-KCO/YO and 22.2% for other catalysts. Supports affected the activity of catalyst. KCl-KCO/NdO exhibited the highest activity. The activity of KCl-KCO/YO increased with the increase of calcination temperature in the range of 800ºC–900ºC. The formation of KYO, YOCl or YO species probably promoted the catalysts.

关键词： thermogravimetric analysis increase KCl-KCO/NdO catalytic KCl-KCO/YO

HTML PDF 收藏

Dynamic fate modeling of γ-hexachlorocyclohexane in the lower reaches of the Liao River

LIU Zhenyu, YANG Fenglin, QUAN Xie, ZHANG Xiaohong

《环境科学与工程前沿（英文）》 2007年第1卷第2期页码 166-171 doi: 10.1007/s11783-007-0029-x

摘要： A QWASI model dependent on temperature is parameterized to describe the long-term fate of persistent organic pollutants (POPs) in the Liao River. The model parameters, namely fugacity capacity, degradation rate, and transfer coefficient, are profoundly affected by temperature. This model is used to simulate the fate of γ-hexachlorocyclohexane (γ-HCH) in the lower reaches of the Liao River from 1998 to 2008. Modeling results show that γ-HCH fugacity capacities in air, water, and sediment increase as temperature decreases, and the transfer and transformation rate coefficients increase as temperature increases. The variations of transfer and transformation parameter values depend on fugacity capacities, and transfer and transformation coefficients simultaneously. The performance of the model is evaluated by comparing the predicted and observed concentrations in the water and sediment of the Liao River. The predicted values agree well with the observed value in the order of magnitude, in most cases within the factor of 3. It is believed that the model is appropriate for simulating the long term fate of POPs in the Liao River.

关键词： coefficient POPs temperature sediment increase dependent

HTML PDF 收藏

Experimental research on self-stressing and self-compacting concrete filled steel tube columns subjected to eccentric load

Chengkui HUANG, Zuoqing SHANG, Peng ZHANG,

《结构与土木工程前沿（英文）》 2009年第3卷第4期页码 455-461 doi: 10.1007/s11709-009-0058-6

摘要： A total of fifteen self-stressing and self-compacting concrete (SSC) filled steel tube columns and three common self-compacting concrete filled steel tube (CFST) columns are tested under eccentric compression load to analyze the effect of initial self-stress on the compression behavior of CFSTs. The results show that the elastic working range of the columns is lengthened because of initial self-stress and it slightly decreases with the increase of load eccentricity ratio and slenderness ratio. Because of the initial self-stress, the concrete core is always under compression in three directions, so the compactness is enhanced and the ultimate bearing capacity obviously increases; but the initial self-stress hardly affects the failure mode of the columns.

关键词： increase capacity failure CFSTs CFST

HTML PDF 收藏

Effect of Fe content on FeMn catalysts for light alkenes synthesis

ZHOU Jun, CHU Wei, ZHANG Hui, XU Huiyuan, ZHANG Tao

《化学科学与工程前沿（英文）》 2008年第2卷第3期页码 315-318 doi: 10.1007/s11705-008-0050-z

摘要： The effect of Fe content on FeMn/MgO catalysts for light alkenes synthesis through CO hydrogenation was investigated. Catalysts were prepared by a conventional co-impregnation method, characterized using BET, X-ray powder diffraction (XRD) and Temperature-programmed reduction (H-TPR) techniques. High activity was obtained over the catalyst with 9 wt-% Fe content, over which CO conversion and the selectivity of C–C reached 91.36% and 58.48%, respectively. With the increase of Fe content, both the conversion and the selectivity were improved within a certain range and then decreased. The results show that the surface area of the catalyst played an important role in the catalytic reaction. With the increase of Fe loading, the interaction action between Fe and Mn was enhanced and FeMn solid solution was formed.

关键词： conventional co-impregnation increase conversion loading H-TPR

HTML PDF 收藏

Biaxial tensile-compressive experiment of concrete at high temperatures

SONG Yupu, ZHANG Zhong, QING Likun, YU Changjiang

《结构与土木工程前沿（英文）》 2007年第1卷第1期页码 94-98 doi: 10.1007/s11709-007-0009-z

摘要： Biaxial tension-compression experiments of concrete of five stress ratios at high temperatures were carried out using the large static-dynamic triaxial test system in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology. The stress ratios s1/s3 are 0, 0.1, 0.25, 0.50, and 0.75. The temperatures are 20vH, 200vH, 300vH, 500vH, 600vH. The mechanical behavior of concrete under biaxial tension-compression at high temperatures is analyzed. It is found that both the tensile strength and strain diminished with the increase in temperature under each stress ratio. Based on the test results, the relationship between tensile strengths and stress ratios and temperature is proposed. In addition, the failure criterion of concrete under biaxial stress state of tension-compression at high temperatures is established.

关键词： increase Offshore Engineering temperature relationship addition

HTML PDF 收藏

Growth and properties analysis of metal-organic chemical vapor deposited MgZnO films on -AlO substrates

SHI Zengliang, LIU Dali, YAN Xiaolong, GAO Zhongmin, BAI Shiying

《机械工程前沿（英文）》 2008年第3卷第3期页码 261-264 doi: 10.1007/s11465-008-0036-z

摘要： MgZnO (0 < ? 0.12) thin films with the wurtzite structure have been successfully grown on -AlO substrates by metal-organic chemical vapor deposition (MOCVD). X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), photoluminescence (PL) spectrometry, and transmission measurements are performed to study the characteristics of MgZnO thin films. Results show that with increasing Mg content, the diffraction peak of MgZnO thin films shifts towards a higher diffraction angle (the biggest shift is 0.22°), and the full width at half maximum (FWHM) of the diffraction peak is broadened. Meanwhile, a blue-shift occurs at the near-band-edge (NBE) emission peak and the largest blue-shift of the band gap of the MgZnO films is 113 meV with Mg content = 0.12. Therefore, the energy band gap of the MgZnO films is determined by Mg content in the thin films and the energy band gap increases with an increase of Mg content.

关键词： increase photoelectron spectroscopy transmission wurtzite structure MgZnO

HTML PDF 收藏

Aerodynamic performance of bowed compressor cascades with different camber angles

CHEN Shaowen, CHEN Fu, WANG Keli, GU Jun, WANG Zhongqi

《能源前沿（英文）》 2008年第2卷第3期页码 306-312 doi: 10.1007/s11708-008-0056-8

摘要： The effects of a positively bowed blade on the aerodynamic performance of annular compressor cascades with different camber angles were experimentally investigated. The distributions of the exit total pressure loss and secondary flow vectors of the compressor cascades were analyzed. The static pressure was measured by tapping on the cascade surfaces, and the ink-trace flow visualizations were conducted. The results show that the value of the optimum bowed angle and optimum bowed height decrease because of the increased losses at the mid-span with the increase of the camber angle. The C-shape static pressure distribution along the radial direction exists on the suction surface of the straight cascade with larger camber angles. When bowed blade is applied, the larger bowed angle and larger bowed height will further enhance the accumulation of the low-energy fluid at the mid-span, thus causing the flow behavior to deteriorate. Under 60° camber angle, flow behavior near the end-wall region of some bowed cascades even deteriorates instead of improving because the blockage of the separated flow near the mid-span keeps the low-energy fluid near the end-walls from moving towards the mid-span region. As a result, a rapid augmentation of the total loss can easily take place under a large bowed angle.

关键词： increase different blockage increased ink-trace

HTML PDF 收藏

Study of mechanism of activating flux increasing weld penetration of AC A-TIG welding for aluminum alloy

HUANG Yong, FAN Ding, FAN Qinghua

《机械工程前沿（英文）》 2007年第2卷第4期页码 442-447 doi: 10.1007/s11465-007-0076-9

摘要： When multi-component flux AF305 is used as surface activating flux for an aluminum alloy, the weld pene tration of activating flux-tungsten inert-gas (A-TIG) welding is over two times more than that of conventional TIG welding. Using A-TIG welding with the modes of alternating current (AC), direct current electrode negative (DCEN) and direct current electrode positive (DCEP), respectively, the flux differently affects weld penetration when the polarity is different. After studied the effect of compelled arc con striction on weld penetration of AC welding, it is believed that the constriction of the whole arc root is not the main mechanism that flux AF305 dramatically improves weld penetration. The penetration has a relationship with the separate distribution of slag on the weld surface. Then, an observation of scanning electron microscopy (SEM) and an electronic data systems (EDS) analysis of slag were performed respectively. The separate distribution of slag on the weld pool during welding and the great constriction of arc spots were confirmed by TIG welding with helium shielding gas. The relationship between slag distribution and weld penetration was studied by adding aluminum powder into flux AF305 to change the distribution of slag. During welding, the separate distribution of slag on the weld pool results in the great constriction of arc spots, an increase in arc spot force, and an increase in Lorentz force within the arc and weld pool. Finally, the weld penetration is increased.

关键词： A-TIG welding surface DCEN electrode negative increase

HTML PDF 收藏

定向射孔多缝压裂工艺案例分析

唐梅荣

《中国工程科学》 2012年第14卷第4期页码 105-112

摘要：

一种新型的压裂工艺在中国长庆油田试验成功，该工艺在层内压裂形成了2条独立裂缝，大幅增加了裂缝与油藏的接触面积，提高了产量。长庆油田开发的超低渗透油藏岩芯分析渗透率一般在0.5 mD以下，且受到储层条件、注采井网、压裂工艺等多重限制，常规压裂工艺改造难以实现该类油藏的有效开发。历经多年研究并结合自身实际，长庆油田于2006年提出了体积压裂的理念，通过在油层内造多缝扩大油藏的泄流体积以提高单井产量。室内物模试验研究射孔对压裂影响时观察到，当射孔方向与最大水平主应力方位存在夹角的情况下裂缝发生转向，即裂缝均先沿

关键词：定向射孔裂缝转向多缝压裂泄流体积增产