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 208

年份

2023 23

2022 18

2021 18

2020 12

2019 8

2018 9

2017 16

2016 8

2015 3

2014 6

2013 4

2012 8

2011 11

2010 9

2009 13

2008 11

2007 4

2006 8

2005 1

2004 2

展开︾

关键词

三点弯曲梁 2

压力容器技术 2

双层辉光离子渗金属 2

双库协同机制 2

双目标渐进法 2

地震预测 2

抑爆抗爆 2

汶川地震 2

(GaxIn1−x)2O3薄膜；带隙可调谐；磁控溅射 1

12相整流 1

3D支架平台 1

4D打印 1

5G 1

CBC－MAC模式 1

CCM模式 1

CTR模式 1

Cuk矩阵变换器 1

Maradbcm算法 1

PMAC模式 1

展开︾

检索范围：

排序：展示方式：

Analysis of the double-layer α-Si:H emitter with different doping concentrations for α-Si:H/c-Si heterojunction

Haibin HUANG,Gangyu TIAN,Tao WANG,Chao GAO,Jiren YUAN,Zhihao YUE,Lang ZHOU

《能源前沿（英文）》 2017年第11卷第1期页码 92-95 doi: 10.1007/s11708-016-0432-8

摘要： Double-layer emitters with different doping concentrations (DLE) have been designed and prepared for amorphous silicon/crystalline silicon (α-Si:H/c-Si) heterojunction solar cells. Compared with the traditional single layer emitter, both the experiment and the simulation (AFORS-HET, http://www.paper.edu.cn/html/releasepaper/2014/04/282/) prove that the double-layer emitter increases the short circuit current of the cells significantly. Based on the quantum efficiency (QE) results and the current-voltage-temperature analysis, the mechanism for the experimental results above has been investigated. The possible reasons for the increased current include the enhancement of the QE in the short wavelength range, the increase of the tunneling probability of the current transport and the decrease of the activation energy of the emitter layers.

关键词： double-layer emitter α-Si:H/c-Si heterojunction solar cell short circuit current quantum efficiency current-voltage-temperature

HTML PDF 收藏

Optimal design of double-layer barrel vaults using genetic and pattern search algorithms and optimized

《结构与土木工程前沿（英文）》 2023年第17卷第3期页码 378-395 doi: 10.1007/s11709-022-0899-9

摘要： This paper presents a combined method based on optimized neural networks and optimization algorithms to solve structural optimization problems. The main idea is to utilize an optimized artificial neural network (OANN) as a surrogate model to reduce the number of computations for structural analysis. First, the OANN is trained appropriately. Subsequently, the main optimization problem is solved using the OANN and a population-based algorithm. The algorithms considered in this step are the arithmetic optimization algorithm (AOA) and genetic algorithm (GA). Finally, the abovementioned problem is solved using the optimal point obtained from the previous step and the pattern search (PS) algorithm. To evaluate the performance of the proposed method, two numerical examples are considered. In the first example, the performance of two algorithms, OANN + AOA + PS and OANN + GA + PS, is investigated. Using the GA reduces the elapsed time by approximately 50% compared with using the AOA. Results show that both the OANN + GA + PS and OANN + AOA + PS algorithms perform well in solving structural optimization problems and achieve the same optimal design. However, the OANN + GA + PS algorithm requires significantly fewer function evaluations to achieve the same accuracy as the OANN + AOA + PS algorithm.

关键词： optimization surrogate models artificial neural network SAP2000 genetic algorithm

HTML PDF 收藏

A Double-Layer Polysaccharide Hydrogel (DPH) for the Enhanced Intestine-Targeted Oral Delivery of Probiotics

Wen-Can Huang,Wenjie Wang,Wei Wang,Yanan Hao,Changhu Xue,Xiangzhao Mao,

《工程（英文）》 doi: 10.1016/j.eng.2023.05.024

摘要： Transplantation of probiotics to the intestine can positively regulate the gut microbiota, thereby promoting the immune system and treating various diseases. However, the harsh gastrointestinal environment and short retention time in the gastrointestinal tract significantly limit the bioavailability and intestinal colonization of probiotics. Herein, we present a double-layer polysaccharide hydrogel (DPH) in the form of a double-layer structure composed of a carboxymethyl cellulose (CMCL) supramolecular inner layer and a dialdehyde alginate (DAA) cross-linked carboxymethyl chitosan (CMCS) outer layer. This double-layer structure allows DPH to encapsulate and deliver probiotics in a targeted manner within the body. In the stomach, the cage structure of the DPH is closed, and the outer layer absorbs surrounding liquids to form a barrier to protect the probiotics from gastric fluids. In the intestine, the cage structure opens and disintegrates, releasing the probiotics. Thus, DPH endows probiotics with excellent intestine-targeted delivery, improved oral bioavailability, enhanced gastrointestinal tract tolerance, and robust mucoadhesion capacity. The encapsulated probiotics exhibit almost unchanged bioactivity in the gastrointestinal tract before release, as well as improved oral delivery. In particular, probiotics encapsulated by DPH exhibit 100.1 times higher bioavailability and 10.6 times higher mucoadhesion than free probiotics in an animal model 48 h post-treatment. In addition, with a remarkable ability to survive and be retained in the intestine, probiotics encapsulated by DPH show excellent in vitro and in vivo competition with pathogens. Notably, DAA-mediated dynamic crosslinking not only maintains the overall integrity of the hydrogels but also controls the release timing of the probiotics. Thus, it is expected that encapsulated substances (probiotics, proteins, etc.) can be delivered to specific sites of the intestinal tract by means of DPH, by controlling the dynamic covalent crosslinking.

关键词： Polysaccharides Chitosan Hydrogels Oral delivery Intestine-targeted

HTML PDF 收藏

大断面黄土隧道台阶法双层支护技术

李国良,宋冶,李雷,王新东,李波

《中国工程科学》 2014年第16卷第8期页码 54-63

摘要：

依托郑西高铁高桥隧道小角度下穿既有南同蒲铁路施工实践，通过试验研究取得大断面黄土隧道台阶法双层支护体系的力学特性及施工技术关键，在砂质新黄土条件下成功解决埋深仅11 m的下穿运营铁路的超大断面（171 m²）隧道施工，对类似工程的设计与施工具有重要参考价值。

关键词：大断面黄土隧道台阶法双层支护下穿

HTML PDF 收藏

NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

《化学科学与工程前沿（英文）》 2023年第17卷第4期页码 373-386 doi: 10.1007/s11705-022-2223-6

摘要： The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo₂O₄ nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo₂O₄ nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF∙cm^–2 at the current density of 1 mA∙cm^–2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW∙h∙cm^–3 at a power density of 180 mW∙cm^–3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA∙cm^–2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.

关键词： carbon cloth NiCo₂O₄ nanowires core−shell structure quinone-rich electric double layer capacitor

HTML PDF 收藏

Theoretical analysis and experimental study on the influence of electric double layer on thin film lubrication

WANG Xin-jie, BAI Shao-xian, HUANG Ping

《机械工程前沿（英文）》 2006年第1卷第3期页码 370-373 doi: 10.1007/s11465-006-0040-0

摘要： A new mathematical model for thin film lubrication is established by taking into account the effect of an electric double layer. In the present paper, experiments are carried out on a self-made tester. With a composite block and a

关键词： mathematical account electric composite lubrication

HTML PDF 收藏

基于双层多目标分割的超高速撞击航天器损伤红外检测算法 Research Article

杨晓1,殷春1,Sara DADRAS2,雷光钰1,谭旭彤1,邱根1

《信息与电子工程前沿（英文）》 2022年第23卷第4期页码 571-586 doi: 10.1631/FITEE.2000695

摘要：针对超高速撞击引起的航天器损伤检测，提出一种先进的基于红外成像检测的航天器缺陷提取算法。采用高速混合模型对红外视频流采样数据中的温度变化特征进行分类，并重构图像，得到反映缺陷特征的红外重构图像。设计的分割目标函数用于保证图像分割结果对噪声去除和细节保留的有效性，同时考虑到红外重构图像的复杂性，即所需权衡不同。因此，引入多目标优化算法以实现细节保留和噪声去除之间的平衡，并采用基于分解的多目标进化算法（MOEA/D）进行优化，以保证损伤分割的准确性。实验结果验证了所提算法的有效性。

关键词：超高速撞击损伤；缺陷检测；高斯混合模型；图像分割

HTML PDF 收藏

Stability analysis and optimization of excavation method of double-arch tunnel with an extra-large span

Yiguo XUE, Huimin GONG, Fanmeng KONG, Weimin YANG, Daohong QIU, Binghua ZHOU

《结构与土木工程前沿（英文）》 2021年第15卷第1期页码 136-146 doi: 10.1007/s11709-020-0710-8

摘要： The Xiamen Haicang double-arch tunnel has a maximum span of 45.73 m and a minimum burial depth of 5.8 m. A larger deformation or collapse of the tunnel is readily encountered during tunnel excavation. It is therefore necessary to select a construction approach that is suitable for double-arch tunnel projects with an extra-large span. In this study, three construction methods for double-arch tunnels with extra-large spans were numerically simulated. Subsequently, the deformation behavior and stress characteristics of the surrounding rock were obtained and compared. The results showed that the double-side-drift method with temporary vertical support achieves better adaptability in the construction of such tunnels, which can be observed from both the numerical results and monitoring data. In addition, the improved temporary support plays a critical role in controlling the surrounding rock deformation. In addition, the disturbance resulting from the excavation of adjacent drifts was obvious, particularly the disturbance of the surrounding rock caused by the excavation of the middle drift. The present findings can serve as the initial guidelines for the construction of ultra-shallowly buried double-arch tunnels with extra-large spans.

关键词： double-arch tunnel triple-layer composite liner system numerical modeling stress analysis settlement

HTML PDF 收藏

POCl₃ diffusion for industrial Si solar cell emitter formation

Hongzhao LI,Kyung KIM,Brett HALLAM,Bram HOEX,Stuart WENHAM,Malcolm ABBOTT

《能源前沿（英文）》 2017年第11卷第1期页码 42-51 doi: 10.1007/s11708-016-0433-7

摘要： POCl diffusion is currently the standard method for industrial n-type emitter fabrication. In this study, we present the impact of the following processing parameters on emitter formation and electrical performance: deposition gas flow ratio, drive-in temperature and duration, drive-in O flow rate, and thermal oxidation temperature. By showing their influence on the emitter doping profile and recombination activity, we provide an overall strategy for improving industrial POCl tube diffused emitters.

关键词： POCl₃ diffusion emitter recombination oxidation silicon

HTML PDF 收藏

Effect of Joule heating on electro-osmotic flow in a closed-end micro-channel with isothermal and convective boundary conditions

Liang ZHAO, Linhua LIU,

《能源前沿（英文）》 2009年第3卷第4期页码 381-388 doi: 10.1007/s11708-009-0057-2

摘要： The effect of Joule heating on the steady state electro-osmotic flow in a closed-end micro-channel is studied through numerical simulation with the finite volume method. The velocity field and the temperature field are described by a rigorous mathematical model. Thermophysical properties including viscosity and thermal conductivity are considered to be temperature-dependent. The simulations show that the presence of Joule heating causes an increase in temperature and a decrease in viscosity in the whole micro-channel, which, thereafter, induce a large velocity near the wall and an increase in fluid velocity at the central region in order to maintain a zero flow rate at the cross section of the micro-channel. The effect of Joule heating on the induced pressure gradient is also studied, which is very important for the application of the closed-end micro-channel as a micro-actuator. The results reveal that the induced pressure gradient, taking into consideration Joule heating, is significantly smaller than that without considering Joule heating when the wall temperature of the micro-channel is constant. The induced pressure gradient difference between considering Joule heating and without considering Joule heating is small under the convective boundary condition.

关键词： closed-end micro-channel electrical double layer electro-osmotic flow induced pressure gradient Joule heating

HTML PDF 收藏

基于时序优化长短期记忆和自适应阈值的高排放重型柴油车识别 Research Article

许镇义1,王仁军1,2,曹洋1,3,4,康宇1,3,4

《信息与电子工程前沿（英文）》 2023年第24卷第11期页码 1633-1646 doi: 10.1631/FITEE.2300005

摘要：在实际场景中，重型柴油车是城市氮氧化物的重要来源，其排放的氮氧化物（NOx）占车辆总排放量的80％以上，颗粒物（PM）占90％以上。检测和控制重型柴油车的排放对保护公众健康至关重要。目前，道路上的车辆必须每6个月或每年定期检测一次，在车辆检查站过滤出高排放的移动源。然而，由于年检间隔时间较长，很难及时有效地筛选出高排放车辆，而且固定的阈值不能适应车辆驾驶工况的动态变化。车载诊断设备（OBD）安装在车辆内部，可以连续跟踪和实时记录排放数据。本文提出一种时间优化长短期记忆（LSTM）和自适应动态阈值方法，使用OBD数据识别重型高排放车辆。首先，建立一个时间优化LSTM排放预测模型，以解决实际中大量OBD数据流造成的时间步注意力偏重问题。然后，利用灵活的阈值标准检测浓度预测误差序列，以区分异常排放情况，该阈值随驾驶条件变化自适应计算得到。最后，引入时间序列的相似性度量策略，以纠正一些假的异常结果。在3个真实OBD时间序列排放数据集上的实验表明，该方法得到优异的高排放源识别结果。

关键词：高排放识别；时序优化；车载诊断设备（OBD）；动态阈值

HTML PDF 收藏

Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

《结构与土木工程前沿（英文）》 2007年第1卷第4期页码 448-457 doi: 10.1007/s11709-007-0061-8

摘要： The double- fracture model can well describe the development of cracks undergoing during the entire fracture process in concrete. Therefore, it has been selected as the theoretical basis of the Norm for fracture test of

关键词： development concrete theoretical double- fracture

HTML PDF 收藏

Numerical study of thermal characteristics of double skin facade system with middle shade

Shaoning LIU, Xiangfei KONG, Hua YANG, Minchao FAN, Xin ZHAN

《能源前沿（英文）》 2021年第15卷第1期页码 222-234 doi: 10.1007/s11708-017-0480-8

摘要： Architectural shade is an effective method for improving building energy efficiency. A new shade combined with the double skin façade (DSF) system, called middle shade (MS), was introduced and developed for buildings. In this paper, a 3D dynamic simulation was conducted to analyze the influence of MS combined with DSF on the indoor thermal characteristics. The research on MS for DSF involves the temperature, the ventilation rate, the velocity distribution of the air flow duct, and the indoor temperature. The results show that the angle and position of the shade in the three seasons are different, and different conditions effectively enhance the indoor thermal characteristics. In summer, the appearance of MS in DSF makes the indoor temperature significantly lower. The indoor temperature is obviously lower than that of the air flow duct, and the temperature of the air flow duct is less affected by MS. The influence of the position of blinds on indoor temperature and ventilation rate is greater than the influence of the angle of blinds. According to the climate characteristics of winter and transition season, in winter, early spring, and late autumn, the indoor temperature decreases with the increase of the position of blinds at daytime, but the opposite is true at night. The results found in this paper can provide reference for the design and use of MS combined with DSF in hot summer and cold winter zone.

关键词： middle shade position thermal characteristics double skin facade

HTML PDF 收藏

Moment-curvature relationship of FRP-concrete-steel double-skin tubular members

Mingxue LIU, Jiaru QIAN

《结构与土木工程前沿（英文）》 2009年第3卷第1期页码 25-31 doi: 10.1007/s11709-009-0012-7

摘要： Tests were conducted on 3 specimens to study the flexural behavior of fiber reinforced polymer (FRP)-concrete-steel double-skin tubular members (DSTMs). The strip method was used to calculate the section moment-curvature curves of the 3 specimens and 12 models. A theoretical formula is presented for the flexural strength of DSTMs. The test results show that the tension zone of the specimen FRP tubes was in hoop compression while the compression zone was in hoop tension. The load-carrying capacity did not decrease even when the mid-span deflection reached about 1/24 of the span length. The tests, simulation and theoretical analysis resulted in a simplified formula for the flexural strength of DSTMs and a tri-linear moment-curvature model was expressed as a function of the section bending stiffness for DSTMs.

关键词： fiber reinforced polymer (FRP) concrete steel double-skin tubular members (DSTMs) moment-curvature curve flexural strength

HTML PDF 收藏

Enhancement of distillate output of double basin solar still with vacuum tubes

Hitesh N PANCHAL, P K SHAH

《能源前沿（英文）》 2014年第8卷第1期页码 101-109 doi: 10.1007/s11708-014-0299-5

摘要： The latent heat of condensation is lost to the atmosphere; hence it is not utilized to increase distillate output of single basin solar stills. This difficulty was overcome by attaching an additional basin to the main basin. The performance of the double basin solar still was also increased by attaching vacuum tubes to the lower basin; hence the lower basin possessed a higher temperature throughout the day. The latent heat of condensation of the bottom basin was also utilized to increase distillate. But the distillate output of the top basin was even lower compared with that of the bottom basin. This paper proposed a novel approach to increase the distillate output of the double basin solar still attached with vacuum tubes by introducing different sensible energy storage materials like pebbles, black granite gravel and calcium stones to increase the basin area. Experiments were conducted in climate conditions of Mehsana (23.6000° N, 72.4000° E) Gujarat from April to September 2013 with a constant water depth of 2 cm in the top basin with and without the use of basin materials. The results showed that the distillate output of basin material with calcium stones is greater (74%) compared with that of black granite gravel and pebbles. The integration of vacuum tubes with solar still greatly increases the distillate output of the solar still by providing hot water at the lower basin.

关键词： double basin solar still calcium stones pebbles granite gravel distillate output