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 328

年份

2024 13

2023 23

2022 17

2021 19

2020 15

2019 13

2018 19

2017 14

2016 11

2015 9

2014 14

2013 16

2012 13

2011 14

2010 16

2009 23

2008 30

2007 21

2006 4

2005 2

展开︾

关键词

城市河流 2

微反应器 2

数值模拟 2

ADV 1

CBC－MAC模式 1

CCM模式 1

CCUS 1

CFD 1

CO₂利用 1

CTR模式 1

Cas12a 1

Chebyshev多项式 1

Colebrook隐式方程 1

HY-2 卫星 1

Matlab 1

PIV 1

PMAC模式 1

Preissmann格式 1

S 特性 1

展开︾

检索范围：

排序：展示方式：

Thermodynamic performance experiment and cooling number calculation of a counter-flow spray humidifier

WANG Yuzhang, LI Yixing, WENG Shilie, WANG Yonghong

《能源前沿（英文）》 2008年第2卷第1期页码 43-47 doi: 10.1007/s11708-008-0005-6

摘要： An experimental investigation of the thermodynamic performance of a counter-flow spray humidifier was conducted on the basis of theoretical analysis of the heat and mass transfer mechanism inside the humidifier. Critical parameters such as the temperature and relative humidity of air and the temperature of water at the inlet and outlet were measured. The influence of every measured parameter on the thermal performance of the humidifier was obtained under different experimental conditions. The cooling number, whose variation was also obtained, was calculated according to the measured data. The experimental results show that both the temperature and the temperature increment of outlet humid air and the temperature of outlet water increase with an increase of the water-gas ratio, whereas the cooling number decreases. Under all experimental conditions, the outlet humid air reaches or is close to the saturation level. The lower cooling number is favorable for the system, but it has an optimal value for a certain humidifier.

关键词： temperature increment counter-flow experimental investigation temperature water-gas

HTML PDF 收藏

Numerical analysis of 3-D unsteady flow in a vaneless counter-rotating turbine

ZHAO Qingjun, WANG Huishe, ZHAO Xiaolu, XU Jianzhong

《能源前沿（英文）》 2007年第1卷第3期页码 352-358 doi: 10.1007/s11708-007-0053-3

摘要： To reveal the unsteady flow characteristics of a vaneless counter-rotating turbine (VCRT), a three-dimensional, viscous, unsteady computational fluid dynamics (CFD) analysis was performed. The results show that unsteady simulation is superior to steady simulation because more flow characteristics can be obtained. The unsteady effects in upstream airfoil rows are weaker than those in downstream airfoil rows in the VCRT. The static pressure distribution along the span in the pressure surface of a high pressure turbine stator is more uniform than that in the suction surface. The static pressure distributions along the span in the pressure surfaces and the suction surfaces of a high pressure turbine rotor and a low pressure turbine rotor are all uneven. The numerical results also indicate that the load of a high pressure turbine rotor will increase with the increase of the span. The deviation is very big between the direction of air flow at the outlet of a high pressure turbine rotor and the axial direction. A similar result can also be obtained in the outlet of a low pressure turbine rotor. This means that the specific work of a high pressure turbine rotor and a low pressure turbine rotor is big enough to reach the design objectives.

关键词： unsteady flow three-dimensional pressure distribution similar result unsteady simulation

HTML PDF 收藏

Effect of counter current gas phase on liquid film

Shujuan LUO, Huaizhi LI, Weiyang FEI, Yundong WANG

《化学科学与工程前沿（英文）》 2009年第3卷第2期页码 135-137 doi: 10.1007/s11705-009-0129-1

摘要： Liquid film flow is very important in many industrial applications. However, there are few reports about its characteristics on structured packings. Therefore, in this paper, liquid film phenomena were investigated experimentally to exploit new approaches for intensifying the performance of the structured packings. All experiments were performed at room temperature. Water and air were the working fluids. The effect of counter current gas phase on the liquid film was taken into consideration. A high speed camera, a non-intrusive measurement technique, was used. It is shown that both liquid and gas phases have strong effects on film characteristics. In the present work, liquid film width increased by 57% because of increasing liquid flow rate, while it decreased by 25% resulting from the counter current gas phase.

关键词： counter current liquid film two phases structured packings

HTML PDF 收藏

Partial aging can counter-intuitively couple with sulfidation to improve the reactive durability of zerovalent

《环境科学与工程前沿（英文）》 2024年第18卷第2期 doi: 10.1007/s11783-024-1774-9

摘要：

● Partial aging of SZVI can enhance its reactive durability toward Cr(VI).

关键词： Zerovalent iron Sulfidation Partial aging Interface reconstruction Electron transfer

HTML PDF 收藏

Development of a cloud condensation nuclei (CCN) counter using a laser and charge-coupled device (CCD

Mikyung PARK, Jinkwan OH, Kihong PARK

《环境科学与工程前沿（英文）》 2011年第5卷第3期页码 313-319 doi: 10.1007/s11783-011-0346-y

摘要： A continuous flow streamwise thermal gradient cloud condensation nuclei (CCN) counter with an aerosol focusing and a laser-charge-coupled device (CCD) camera detector system was developed here. The counting performance of the laser-CCD camera detector system was evaluated by comparing its measured number concentrations with those measured with a condensation particle counter (CPC) using polystyrene latex (PSL) and NaCl particles of varying sizes. The CCD camera parameters (e.g. brightness, gain, gamma, and exposure time) were optimized to detect moving particles in the sensing volume and to provide the best image to count them. The CCN counter worked well in the particle number concentration range of 0.6–8000 #·cm and the minimum detectable size was found to be 0.5 μm. The supersaturation in the CCN counter with varying temperature difference was determined by using size-selected sodium chloride particles based on K?hler equation. The developed CCN counter was applied to investigate CCN activity of atmospheric ultrafine particles at 0.5% supersaturation. Data showed that CCN activity increased with increasing particle size and that the higher CCN activation for ultrafine particles occurred in the afternoon, suggesting the significant existence of hygroscopic or soluble species in photochemically-produced ultrafine particles.

关键词： aerosol cloud condensation nuclei (CCN) counter ultrafine particle

HTML PDF 收藏

Finite element modeling of counter-roller spinning for large-sized aluminum alloy cylindrical parts

Dawei ZHANG, Fan LI, Shuaipeng LI, Shengdun ZHAO

《机械工程前沿（英文）》 2019年第14卷第3期页码 351-357 doi: 10.1007/s11465-019-0528-z

摘要： Counter-roller spinning (CRS), where the mandrel is replaced by rollers, is an effective means of manufacturing large-sized, thin-walled, cylindrical parts with more than 2500 mm diameter. CRS is very complex because of multi-axis rotation, multi-local loading along the circumference, and radial-axial compound deformation. Analytical or experimental methods cannot fully understand CRS. Meanwhile, numerical simulation is an adequate approach to investigate CRS with comprehensive understanding and a low cost. Thus, a finite element (FE) model of CRS was developed with the FORGE code via meshing technology, material modeling, determining the friction condition, and so on. The local fine mesh moving with the roller is one of highlights of the model. The developed 3D-FE model was validated through a CRS experiment by using a tubular blank with a 720 mm outer diameter. The developed 3D-FE model of CRS can provide a basis for parameter optimization, process control, die design, and so on. The data on force and energy predicted by the 3D-FE model can offer reasonable suggestions for determining the main mechanical parameters of CRS machines and selecting the motors. With the predicted data, an all-electric servo-drive system/machine with distributed power was designed in this work for CRS with four pairs of rollers to manufacture a large-sized, thin-walled, cylindrical part with 6000 mm diameter.

关键词： large-sized cylindrical part counter-roller spinning aluminum alloy finite element method distributed power

HTML PDF 收藏

The Development Situation, Future and Counter Measures of Remanufacturing Industry in China

Wen-qiang Liu,Jun-yuan Mo,Cheng-kui Gu

《工程管理前沿（英文）》 2016年第3卷第2期页码 123-131 doi: 10.15302/J-FEM-2016021

摘要： Currently, resource supply and demand contradiction, and over-loaded environment capacity have become a bottleneck for sustainable economic development in China. Electro-mechanical products are approaching a peak of obsolescence, and massive abandoned electro-mechanical products are causing severe environmental pollution, huge waste of resources and potential safety hazard. Remanufacturing is repairing or modifying worn mechanical products using high-tech method, which buffers the contradiction between wasting and shortage of resources, and brings industry towards a comprehensive utilization of resource and environmental protection. As a new strategic industry, remanufacturing, which is highly coherent with the development strategy of the circular economy, is still in its infancy in China. This paper analyzes the developmental trends and problems of the remanufacturing industry in China, and proposes promoting measures based on the engineering practices of remanufacturing.

关键词： remanufacturing industry measures development

HTML PDF 收藏

Application of high-speed counter-current chromatography coupled with high performance liquid chromatography

Shengguo DENG, Zeyuan DENG, Yawei FAN, Jing LI, Rong LIU, Dongmei XIONG,

《化学科学与工程前沿（英文）》 2009年第3卷第4期页码 375-382 doi: 10.1007/s11705-009-0247-9

摘要： Quercetin-3--sambubioside Quercetin-3--β-D-xylopyranosyl (1→2)-β-D-glucopyranoside was separated and purified by semi-preparative high-speed counter-current chromatography (HSCCC) with a two-phase-solvent system composed of ethyl acetate-n-butanol–water (4∶1∶5, v/v) from the leaves of (Lotus). A total of 5.0mg of the targeted compound with a purity of 98.6% as determined by high performance liquid chromatography (HPLC) was obtained from 100m g of the crude extract cleaned up by AB-8 macroporous resin in a one-step separation. Quercetin-3--sambubioside was a novel flavonoid glycoside from the leaves of , and its chemical structure was identified by means of ESI-MS, 1D NMR and 2D NMR.

关键词： two-phase-solvent flavonoid glycoside high-speed counter-current macroporous counter-current chromatography

HTML PDF 收藏

用于图像融合基于混合全加器和计数器的高效华莱士树型乘法器 Research Articles

Ayoub SADEGHI, Nabiollah SHIRI, Mahmood RAFIEE, Mahsa TAHGHIGH

《信息与电子工程前沿（英文）》 2022年第23卷第6期页码 950-965 doi: 10.1631/FITEE.2100432

摘要：

提出一种新的基于计数器的华莱士树（CBW）8×8乘法器。乘法器的计数器使用基于传输门技术的新型混合全加器单元。所提全加器、基于传输门的与门和混合半加器生成M:3（4≤M≤7）数字计数器，能够节省至少50%的面积。通过90 nm技术仿真证明所提全加器和数字计数器在不同条件下均优于当前最先进设计。通过使用所提单元，CBW乘法器表现出高驱动、低功耗和高速性能。CBW乘法器在焊盘中的芯片面积为0.0147 mm2。后布局提取证明了实验的准确性。同时提出一种图像融合机制，其中MATLAB和HSPICE之间的直接接口用于在图像处理应用中评估所提CBW乘法器。峰值信噪比和结构相似性指数度量被用作图像质量参数，结果证实所提CBW乘法器可以替代文献中的设计。

关键词：全加器；传输门；计数器；乘法器；三维布局；图像融合

HTML PDF 收藏

基于量子点元胞自动机的低能耗、高速度和高效面积时序电路：T型锁存器和计数器研究 Research Article

Mohammad GHOLAMI1,Zaman AMIRZADEH2

《信息与电子工程前沿（英文）》 2023年第24卷第3期页码 457-469 doi: 10.1631/FITEE.2200361

摘要：量子点元胞自动机（QCA）是一种用于实现纳米数字电路的新型纳米技术。这种纳米技术在速度、面积和功耗方面都优于互补金属氧化物半导体（CMOS）技术，并且可以显著改善各种逻辑电路设计。本文提出一种在QCA技术中实现T型锁存器的新方法，该方法利用了QCA在时序和时钟相位上的固有特征，因此，所提单元结构与现有方法相比占用面积更少，功耗更低。与之前的最佳设计相比，该T型锁存器的占用面积减少6.45%，功耗降低44.49%。此外，本文首次设计了基于复位的T型锁存器和具有置位和复位功能的T型锁存器。基于所提T型锁存器，开发了一种新型3位计数器，与之前的最佳设计相比减少2.14%的单元数。在3位计数器的基础上，设计了4位计数器，与之前的设计相比，减少0.51%的单元数和4.16%的截面积。此外还引入两个选择性计数器，分别从0到5和从2到5进行计数。在相干矢量引擎模式下，使用QCADesigner和QCAPro软件进行模拟，并将所提电路与相关设计在延迟、单元数、面积和漏电功率方面进行了比较。

关键词：量子点元胞自动机（QCA）；量子点；T型锁存器；T型触发器；计数器；选择性计数器；QCADesigner软件；QCAPro软件

HTML PDF 收藏

Numerical study of internal flow field and flow passage improvement of an inlet particle separator

Florian PAOLI, Tong WANG

《能源前沿（英文）》 2011年第5卷第4期页码 386-397 doi: 10.1007/s11708-011-0156-8

摘要： By performing gas flow field numerical simulations for several inlet Reynolds numbers (from 2 × 10 to 9 × 10 ) and byflow ratios (from 10% to 20%), the present study has proposed to improve the flow passage of an inlet particle separator. An adjacent objective of the study is to lower pressure losses of the inlet particle separator (IPS). No particle has been included in the gas flow for a -epsilon turbulence model. The velocity distribution in different sections and the pressure coefficient along the duct have been analyzed, which indicates that there exist important low-velocity regions and vortices in the separation area. Therefore, the profile of streamlines along the original passage has been considered. This profile illustrated a vacuum region in the same area. All investigations suggest that the separation area is the most critical one for fulfilling the objective on pressure losses limitation. Then the flow passage improvement method has focused on the separation area. An improved shape has been designed in order to suit smoothly to the streamlines in this region. Similar numerical studies as those for the original shape have been conducted on this improved shape, confirming some considerable enhancements compared with the original shape. The significant vortices which appear in the original shape reduce in amount and size. Besides, pressure losses are greatly decreased in both outlets (up to 30% for high Reynolds number) and the flow is uniform at the main outlet. Subsequent engineering surveys could rely on expressions obtained for in both outlets which extend the pressure losses for a wide range of inlet Reynolds numbers. As a result, the numerical calculations demonstrate that the flow passage improvement method applied in this study has succeeded in designing a shape which enhances the flow behavior.

关键词： streamlines pressure losses flow passage improvement inlet particle separator (IPS)

HTML PDF 收藏

物质流分析的跟踪观察法

陆钟武

《中国工程科学》 2006年第8卷第1期页码 18-25

摘要：

流动，是物质（如铜、铝等）流动和流体流动二者所具有的基本特征，基于这个论点，简要地回顾了流体力学中研究流体流动的两种方法，即拉格朗日法和欧拉法；相应地提出了物质流分析的两种方法，即跟踪观察法和定点观察法。由于前者在文献中未见报道，因此对它进行了重点说明。强调了物质流的跟踪观察法既适用于稳态物质流（产品产量不变），也适用于非稳态物质流（产品产量增长或下降）。以钢铁产品生命周期的铁流图为例，说明了物质流的跟踪模型。在引入了物质流的非稳度后，提出了物质流各项指标的计算式，以及它们之间的相互关系。以瑞典铅酸电池系统为对象，计算了其中铅流的各项指标，并进行了必要的分析。

关键词：物质流的研究方法物质流的跟踪观察法物质流的基本公式物质流的非稳度

HTML PDF 收藏

Development of electrorheological chip and conducting polymer-based sensor

Xianzhou ZHANG, Weihua LI, Weijia WEN, Yanzhe WU, Gordon WALLACE,

《机械工程前沿（英文）》 2009年第4卷第4期页码 393-396 doi: 10.1007/s11465-009-0043-8

摘要： This paper presents the development of an integrated sensor using two types of smart materials: electrorheological (ER) fluids and conducting polymers (CPs). The developed ER chip worked as an actuator, and it was driven by different voltages and control frequencies. When the four electrodes are controlled synchronously, the diaphragm acts as a vibrator whose frequency can be adjusted in accordance with the frequency of the electrical signals. The response signals of the CP sensor were recorded, and its properties were analyzed. Experimental results show that the amplitude decreases monotonically when the frequency increases, owing to the time delay in the pressure buildup in the ER chip. However, the displacement fluctuation of the diaphragm below 20Hz can be detected clearly even if the value is very low. When the vibration frequency is larger than 20Hz, the CP sensor can hardly detect the displacement fluctuation. Thus, the upper limit frequency that the CP sensor can detect is about 20Hz. The practical applications of this microdevice are also discussed.

关键词： electrorheological (ER) fluids conducting polymer (CP) polydimethylsioxane (PDMS) driving frequency amplitude bubble counter

HTML PDF 收藏

面临挑战和机遇的中国花卉业

陈俊愉

《中国工程科学》 2002年第4卷第10期页码 17-20

摘要：

指出花卉业是朝阳产业，比较分析了我国花卉业与世界花卉业之特点与异同。以1999年我国首次举办’99昆明世界园艺博览会（园）为例，指出事实证明中国园林花卉业达到国际一流是可能的，但在“中华特色”上尚需大力加强。中国园林花卉业亟待加强领导、明确方向、扬长避短、全面复兴。剖析了中国花卉业“入世”后面临的严峻挑战，找到了“花卉新四化”的方向——认为这是顶着压力、抓住机遇的最佳对策。在五六十年内达到先进国家花卉业现有水平，是可能的，中国花卉业定要实现全面复兴，用几十年时间走完西方二三百年之路：即从世界园林之母的资源优势，达到并发挥全球花卉王国的生产与经营优势。

关键词：挑战机遇对策花卉花卉业前景

HTML PDF 收藏

UPFC setting to avoid active power flow loop considering wind power uncertainty

Shenghu LI, Ting WANG

《能源前沿（英文）》 2023年第17卷第1期页码 165-175 doi: 10.1007/s11708-020-0686-z

摘要： The active power loop flow (APLF) may be caused by impropriate network configuration, impropriate parameter settings, and/or stochastic bus powers. The power flow controllers, e.g., the unified power flow controller (UPFC), may be the reason and the solution to the loop flows. In this paper, the critical existence condition of the APLF is newly integrated into the simultaneous power flow model for the system and UPFC. Compared with the existing method of alternatively solving the simultaneous power flow and sensitivity-based approaching to the critical existing condition, the integrated power flow needs less iterations and calculation time. Besides, with wind power fluctuation, the interval power flow (IPF) is introduced into the integrated power flow, and solved with the affine Krawcyzk iteration to make sure that the range of active power setting of the UPFC not yielding the APLF. Compared with Monte Carlo simulation, the IPF has the similar accuracy but less time.

关键词： active power loop flow (APLF) unified power flow controller (UPFC) wind power uncertainty interval power flow (IPF)