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 148

会议视频 2

年份

2023 10

2022 12

2021 12

2020 4

2019 6

2018 15

2017 8

2016 5

2015 6

2014 5

2013 4

2012 9

2011 6

2010 6

2009 11

2008 9

2007 10

2006 2

2005 2

2004 3

展开︾

关键词

特征抽取 3

特征提取 3

人脸识别 2

微地震监测 2

提取 2

水驱前缘 2

注水开发 2

萃取 2

超超临界 2

7815 1

CECE-GC 1

DQP漂白 1

IKPCA 1

KPCA 1

KP法制浆 1

T试剂 1

主题提取；主题演化；评价方法 1

井底裂缝连通 1

产品制备 1

展开︾

检索范围：

排序：展示方式：

An extraction- assay system: Evaluation on flavonols in plant resistance to Pb and Cd by supercriticalextraction- gas chromatography

Xu Zhang, Huanhuan Yang, Xinlei Wang, Wen Song, Zhaojie Cui

《环境科学与工程前沿（英文）》 2018年第12卷第4期 doi: 10.1007/s11783-018-1059-2

摘要：

SFE-GC system is established for flavonols assessment.

Optimal parameters of SFE-GC are evaluated and determined.

Quercetin and kaempferol are detected in plant under heavy metal stress.

Gene expression analysis shows consistent regularity with content of flavonols.

ROS level is applied for elaborating the plant resistance status.

关键词： Flavonols Heavy metal Supercritical carbon dioxide extraction (SFE) GC Plant resistance

HTML PDF 收藏

Predicting the yield of pomegranate oil from supercritical extraction using artificial neural networks

J. Sargolzaei, A. Hedayati Moghaddam

《化学科学与工程前沿（英文）》 2013年第7卷第3期页码 357-365 doi: 10.1007/s11705-013-1336-3

摘要： Various simulation tools were used to develop an effective intelligent system to predict the effects of temperature and pressure on an oil extraction yield. Pomegranate oil was extracted using a supercritical CO (SC-CO ) process. Several simulation systems including a back-propagation neural network (BPNN), a radial basis function neural network (RBFNN) and an adaptive-network-based fuzzy inference system (ANFIS) were tested and their results were compared to determine the best predictive model. The performance of these networks was evaluated using the coefficient of determination ( ) and the mean square error (MSE). The best correlation between the predicted and the experimental data was achieved using the BPNN method with an of 0.9948.

关键词： oil recovery artificial intelligence extraction neural networks supercritical extraction

HTML PDF 收藏

Supercritical carbon dioxide extraction of CLA-ethyl ester

Yingdi CHEN, Peng XU, Jian CHENG

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 102-106 doi: 10.1007/s11705-010-0536-3

摘要： Supercritical carbon dioxide (SC-CO ) extraction of Conjugated linoleic acid (CLA) ethyl ester was investigated at pressures in the range of 9 to 10.5 MPa and temperature gradients ranging from 0°C to 21°C. The content of CLA-ethyl ester in the fraction was analyzed with gas chromatography (GC). The experimental results indicated that the rate of extraction would rise with the increase of pressure when temperature gradient was given. Moreover, the extraction pressure had insignificant influence on the selectivity of CLA-ethyl ester in SC-CO . When pressure was fixed, setting certain temperature gradient can improve the selectivity of CLA-ethyl ester in SC-CO , and CLA-ethyl ester can be concentrated more effectively than without a temperature gradient. The acid value and peroxide value of the fractions were reduced obviously, compared to the raw material. The optimal condition is pressure at 10 MPa and temperature gradient at 11°C.

关键词： supercritical carbon dioxide extraction CLA-ethyl ester temperature gradient

HTML PDF 收藏

Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Cunwen WANG, Lu CHEN, Bajpai RAKESH, Yuanhang QIN, Renliang LV

《能源前沿（英文）》 2012年第6卷第3期页码 266-274 doi: 10.1007/s11708-012-0193-y

摘要： Recently, biodiesel has received much more attention. Soybean oil, rapeseed oil, palm oil and corn oil are primary feedstock for biodiesel production. However, biodiesel production from these traditional oil-rich crops is limited by land availability, climate, and environmental and social issues regarding the use of feed and food crops for fuel. Oleaginous microorganisms, including microalgae, bacteria, yeast and fungi can be cultivated with high lipid contents and used as promising feedstock for biodiesel production. However, the high cost of biodiesel production using oil microorganisms has been the biggest obstacle for its industrialization. The process of biodiesel production from microorganisms involves many steps, of which the lipids extraction is the most important and costly. Therefore, searching for an effective and economical extraction system is critical. Various approaches of lipids extraction are discussed in this review, including traditional extraction procedures such as solvent extraction, pressing and solvent integrated extraction, as well as some new procedures.

关键词： oleaginous microorganisms biodiesel solvent extraction ultrasound-assisted extraction microwave-assisted extraction supercritical fluid extraction (SFE)

HTML PDF 收藏

Formation of coke in thermal cracking of jet fuel under supercritical conditions

ZHU Yuhong, YU Caixiang, LI Zimu, MI Zhentao, ZHANG Xiangwen

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 17-21 doi: 10.1007/s11705-008-0024-1

摘要： Continuous-flow reactor experiments were carried out to study coke formation from thermal cracking of home-made jet fuel RP-3 under supercritical conditions. The mechanism and precursor of coke forming were analyzed. The starting cracking temperature of RP-3 fuel was determined to be 471.8°C by differential scanning calorimetry (DSC). Temperature-programmed oxidation and scanning electron microscopy (SEM) characterizations of the stressed tubes showed that there are three different coke species including chemisorbed carbon, amorphous carbon and filamentous coke in the solid deposits. More than 90% of coke deposits are carried away by the supercritical fluid, which has strong capabilities of extraction for coke deposits and their precursors. There were 17.1 wt-% of iron and 11.1 wt-% of chromium found on the coke surface detected by energy dispersive spectroscopy (EDS) which suggests carburetion on alloy. RP-3 fuel and its cracking liquids were analyzed by GC-MS,which showed that the content of alkyl benzene and alkyl naphthalene increased evidently in cracking liquids.

关键词： dispersive spectroscopy different extraction calorimetry filamentous

HTML PDF 收藏

Calculation and analysis of sub/supercritical methanol preheating tube for continuous production of biodieselvia supercritical methanol transesterification

Wen CHEN, Weiyong YING, Cunwen WANG, Weiguo WANG, Yuanxin WU, Junfeng ZHANG,

《能源前沿（英文）》 2009年第3卷第4期页码 423-431 doi: 10.1007/s11708-009-0075-0

摘要： Biodiesel is an important renewable energy. Supercritical methanol transesterification for biodiesel has recently been concerned because of its obvious advantages. The tubular reactor is an ideal reactor for continuous preparation of biodiesel via supercritical methanol transesterification. A methanol preheating tube is necessary for the tubular reaction system because the reaction temperature for supercritical methanol transesterification is usually 520―600K. Therefore, in the range of 298―600K, changes of the density, isobaric capacity, viscosity and thermal conductivity of sub/supercritical methanol with temperature are first discussed. Then on the basis of these thermophysical properties, an integration method is adopted for the design of sub/supercritical methanol preheating tube when methanol is preheated from 298K to 600K at 16MPa and the influencing factors on the length of the preheating tube are also studied. The computational results show that the Reynolds number and the local convection heat-transfer coefficient of sub/supercritical methanol flowing in ф6mm×1.5mm preheating tube change drastically with temperature. For the local overall heat transfer coefficient and the average overall heat transfer coefficient , temperature also has an important influence on them when the inlet velocity of methanol is lower than 0.5m/s. But when the inlet velocity of methanol is higher than 0.5m/s, and almost keep invariable with temperature. Additionally, both the outlet temperature and the inlet velocity of methanol are the key affecting factors for the length of the preheating tube, especially when the outlet temperature is over the critical temperature of methanol. At the same time, the increase of tin bath’s temperature can shorten the required length of the preheating tube. At the inlet flow rate of 0.5m/s, the required length of the preheating tube is 2.0m when methanol is preheated from 298K to 590K at 16MPa with keeping the tin bath’s temperature 620K, which is in good agreement with the experimental results.

关键词： sub/supercritical methanol preheating tube integration method biodiesel

HTML PDF 收藏

Entity and relation extraction with rule-guided dictionary as domain knowledge

《工程管理前沿（英文）》页码 610-622 doi: 10.1007/s42524-022-0226-0

摘要： Entity and relation extraction is an indispensable part of domain knowledge graph construction, which can serve relevant knowledge needs in a specific domain, such as providing support for product research, sales, risk control, and domain hotspot analysis. The existing entity and relation extraction methods that depend on pretrained models have shown promising performance on open datasets. However, the performance of these methods degrades when they face domain-specific datasets. Entity extraction models treat characters as basic semantic units while ignoring known character dependency in specific domains. Relation extraction is based on the hypothesis that the relations hidden in sentences are unified, thereby neglecting that relations may be diverse in different entity tuples. To address the problems above, this paper first introduced prior knowledge composed of domain dictionaries to enhance characters’ dependence. Second, domain rules were built to eliminate noise in entity relations and promote potential entity relation extraction. Finally, experiments were designed to verify the effectiveness of our proposed methods. Experimental results on two domains, including laser industry and unmanned ship, showed the superiority of our methods. The F1 value on laser industry entity, unmanned ship entity, laser industry relation, and unmanned ship relation datasets is improved by +1%, +6%, +2%, and +1%, respectively. In addition, the extraction accuracy of entity relation triplet reaches 83% and 76% on laser industry entity pair and unmanned ship entity pair datasets, respectively.

关键词： entity extraction relation extraction prior knowledge domain rule

HTML PDF 收藏

A review on catalytic & non-catalytic bio-oil upgrading in supercritical fluids

Sainab Omar, Yang Yang, Jiawei Wang

《化学科学与工程前沿（英文）》 2021年第15卷第1期页码 4-17 doi: 10.1007/s11705-020-1933-x

摘要： This review article summarizes the key published research on the topic of bio-oil upgrading using catalytic and non-catalytic supercritical fluid (SCF) conditions. The precious metal catalysts Pd, Ru and Pt on various supports are frequently chosen for catalytic bio-oil upgrading in SCFs. This is reportedly due to their favourable catalytic activity during the process including hydrotreating, hydrocracking, and esterification, which leads to improvements in liquid yield, heating value, and pH of the upgraded bio-oil. Due to the costs associated with precious metal catalysts, some researchers have opted for non-precious metal catalysts such as acidic HZSM-5 which can promote esterification in supercritical ethanol. On the other hand, SCFs have been effectively used to upgrade crude bio-oil without a catalyst. Supercritical methanol, ethanol, and water are most commonly used and demonstrate catalyst like activities such as facilitating esterification reactions and reducing solid yield by alcoholysis and hydrolysis, respectively.

关键词： bio-oil upgrading supercritical review

HTML PDF 收藏

Polydimethylsiloxane assisted supercritical CO

Weixia Wang, Shuai Zhou, Zhong Xin, Yaoqi Shi, Shicheng Zhao

《化学科学与工程前沿（英文）》 2016年第10卷第3期页码 396-404 doi: 10.1007/s11705-016-1577-z

摘要： Foamable high melt strength polypropylene (HMSPP) was prepared by grafting styrene (St) onto polypropylene (PP) and simultaneously introducing polydimethylsiloxane (PDMS) through?a?one-step?melt extrusion process. The effect of PDMS viscosity on the foaming behavior of HMSPP was systematically investigated using supercritical CO as the foaming agent. The results show that the addition of PDMS has little effect on the grafting reaction of St and HMSPP exhibits enhanced elastic response and obvious strain hardening effect. Though the CO solubility of HMSPP with PDMS (PDMS-HMSPP) is lower than that of HMSPP without PDMS, especially for PDMS with low viscosity, the PDMS-HMSPP foams exhibit narrow cell size distribution and high cell density. The fracture morphology of PDMS-HMSPP shows that PDMS with low viscosity disperses more easily and uniformly in HMSPP matrix, leading to form small domains during the extrusion process. These small domains act as bubble nucleation sites and thus may be responsible for the improved foaming performance of HMSPP.

关键词： high melt strength polypropylene (HMSPP) polydimethylsiloxane (PDMS) supercritical CO₂ foaming behavior

HTML PDF 收藏

Corrosion mechanisms of candidate structural materials for supercritical water-cooled reactor

Lefu ZHANG, Fawen ZHU, Rui TANG

《能源前沿（英文）》 2009年第3卷第2期页码 233-240 doi: 10.1007/s11708-009-0024-y

摘要： Nickel-based alloys, austenitic stainless steel, ferritic/martensitic heat-resistant steels, and oxide dispersion strengthened steel are presently considered to be the candidate structural or fuel-cladding materials for supercritical water-cooled reactor (SCWR), one of the promising generation IV reactor for large-scale electric power production. However, corrosion and stress corrosion cracking of these candidate alloys still remain to be a major problem in the selection of nuclear fuel cladding and other structural materials, such as water rod. Survey of literature and experimental results reveal that the general corrosion mechanism of those candidate materials exhibits quite complicated mechanism in high-temperature and high-pressure supercritical water. Formation of a stable protective oxide film is the key to the best corrosion-resistant alloys. This paper focuses on the mechanism of corrosion oxide film breakdown for SCWR candidate materials.

关键词： supercritical water-cooled reactor general corrosion oxide film corrosion mechanism

HTML PDF 收藏

Development of a supercritical and an ultra-supercritical circulating fluidized bed boiler

Junfu LYU, Hairui YANG, Wen LING, Li NIE, Guangxi YUE, Ruixin LI, Ying CHEN, Shilong WANG

《能源前沿（英文）》 2019年第13卷第1期页码 114-119 doi: 10.1007/s11708-017-0512-4

摘要： The supercritical circulating fluidized bed (CFB) boiler, which combines the advantages of CFB combustion with low cost emission control and supercritical steam cycle with high efficiency of coal energy, is believed to be the future of CFB combustion technology. It is also of greatest importance for low rank coal utilization in China. Different from the supercritical pulverized coal boiler that has been developed more than 50 years, the supercritical CFB boiler is still a new one which requires further investigation. Without any precedentor engineering reference, Chinese researchers have conducted fundamental research, development, design of the supercritical CFB boilers independently. The design theory and key technology for supercritical CFB boiler were proposed. Key components and novel structures were invented. The first 600 MWe supercritical CFB boiler and its auxiliaries were successfully developed and demonstrated in Baima Power Plant, Shenhua Group as well as the simulator, control technology, installation technology, commissioning technology, system integration and operation technology. Compared with the 460 MWe supercritical CFB in Poland, developed in the same period and the only other supercritical one of commercial running in the word beside Baima, the 600 MWe one in Baima has a better performance. Besides, supercritical CFB boilers of 350 MWe have been developed and widely commercialized in China. In this paper, the updated progress of 660 MWe ultra-supercritical CFB boilers under development is introduced.

关键词： supercritical circulating fluidized bed boiler development demonstration

HTML PDF 收藏

Thermo-economic analysis of a direct supercritical CO electric power generation system using geothermal

《能源前沿（英文）》 2022年第16卷第2期页码 246-262 doi: 10.1007/s11708-021-0749-9

摘要： A comprehensive thermo-economic model combining a geothermal heat mining system and a direct supercritical CO₂ turbine expansion electric power generation system was proposed in this paper. Assisted by this integrated model, thermo-economic and optimization analyses for the key design parameters of the whole system including the geothermal well pattern and operational conditions were performed to obtain a minimal levelized cost of electricity (LCOE). Specifically, in geothermal heat extraction simulation, an integrated wellbore-reservoir system model (T2Well/ECO2N) was used to generate a database for creating a fast, predictive, and compatible geothermal heat mining model by employing a response surface methodology. A parametric study was conducted to demonstrate the impact of turbine discharge pressure, injection and production well distance, CO₂ injection flowrate, CO₂ injection temperature, and monitored production well bottom pressure on LCOE, system thermal efficiency, and capital cost. It was found that for a 100 MW_e power plant, a minimal LCOE of $0.177/kWh was achieved for a 20-year steady operation without considering CO₂ sequestration credit. In addition, when CO₂ sequestration credit is $1.00/t, an LCOE breakeven point compared to a conventional geothermal power plant is achieved and a breakpoint for generating electric power generation at no cost was achieved for a sequestration credit of $2.05/t.

关键词： geothermal heat mining supercritical CO₂ power generation thermo-economic analysis optimization

HTML PDF 收藏

Production of renewable fuels by blending bio-oil with alcohols and upgrading under supercritical conditions

Sainab Omar, Suzanne Alsamaq, Yang Yang, Jiawei Wang

《化学科学与工程前沿（英文）》 2019年第13卷第4期页码 702-717 doi: 10.1007/s11705-019-1861-9

摘要： The work studied a non-catalytic upgrading of fast pyrolysis bio-oil by blending under supercritical conditions using methanol, ethanol and isopropanol as solvent and hydrogen donor. Characterisation of the bio-oil and the upgraded bio-oils was carried out including moisture content, elemental content, pH, heating value, gas chromatography-mass spectrometry (GCMS), Fourier transform infrared radiation, C nuclear magnetic resonance spectroscopy, and thermogravimetric analysis to evaluate the effects of blending and supercritical reactions. The GCMS analysis indicated that the supercritical methanol reaction removed the acids in the bio-oil consequently the pH increased from 2.39 in the crude bio-oil to 4.04 after the supercritical methanol reaction. The ester contents increased by 87.49% after the supercritical methanol reaction indicating ester formation could be the major deacidification mechanism for reducing the acidity of the bio-oil and improving its pH value. Simply blending crude bio-oil with isopropanol was effective in increasing the C and H content, reducing the O content and increasing the heating value to 27.55 from 17.51 MJ·kg in the crude bio-oil. After the supercritical isopropanol reaction, the heating value of the liquid product slightly further increased to 28.85 MJ·kg .

关键词： bio-oil blending supercritical upgrading characterisation

HTML PDF 收藏

超临界化——优化我国火电结构应从这里起步

宋之平

《中国工程科学》 2002年第4卷第2期页码 22-27

摘要：

文章认为优化火电结构应放在超临界化上，使超临界机组和超超临界机组在我国火电中占据举足轻重的比例。而且这些机组的主要性能指标以及环保性能等应不逊于同类机组的国际水平。论述了超临界技术在优化火电结构的特殊作用，指出超临界化已被证明是改造和优化火电结构的一种成功的道路，阐明了我国实施这一发展道路的必要性和可能性。

关键词：火电结构超临界超超临界可持续发展战略

HTML PDF 收藏

Micronization of curcumin with biodegradable polymer by supercritical anti-solvent using micro swirl

Kimthet Chhouk, Wahyudiono, Hideki Kanda, Shin-Ichro Kawasaki, Motonobu Goto

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 184-193 doi: 10.1007/s11705-017-1678-3

摘要： Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and anti-microbial activity. In this work, a swirl mixer was employed to produce the micronized curcumin with polyvinylpyrrolidone (PVP) by the supercritical anti-solvent process to improve the bioavailability of curcumin. The effects of operating parameters such as curcumin/PVP ratio, feed concentration, temperature, pressure, and CO flow rate were investigated. The characterization and solubility of particles were determined by using scanning electron microscopy, Fourier Transform Infrared spectroscopy, and ultra-violet-visible spectroscopy. The result shows that the optimal condition for the production of curcumin/PVP particles is at curcumin/PVP ratio of 1:30, feed concentration of 5 mg·mL , temperature of 40 °C, pressure of 15 MPa, and CO flow rate of 15 mL·min . Moreover, the dissolution of curcumin/PVP particles is faster than that of raw curcumin.

关键词： micronization curcumin polyvinylpyrrolidone supercritical anti-solvent swirl mixer

HTML PDF 收藏

标题作者时间类型操作

An extraction- assay system: Evaluation on flavonols in plant resistance to Pb and Cd by supercriticalextraction- gas chromatography

Xu Zhang, Huanhuan Yang, Xinlei Wang, Wen Song, Zhaojie Cui

期刊论文

Predicting the yield of pomegranate oil from supercritical extraction using artificial neural networks

J. Sargolzaei, A. Hedayati Moghaddam

期刊论文

Supercritical carbon dioxide extraction of CLA-ethyl ester

Yingdi CHEN, Peng XU, Jian CHENG

期刊论文

Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Cunwen WANG, Lu CHEN, Bajpai RAKESH, Yuanhang QIN, Renliang LV

期刊论文

Formation of coke in thermal cracking of jet fuel under supercritical conditions

ZHU Yuhong, YU Caixiang, LI Zimu, MI Zhentao, ZHANG Xiangwen

期刊论文

Calculation and analysis of sub/supercritical methanol preheating tube for continuous production of biodieselvia supercritical methanol transesterification

Wen CHEN, Weiyong YING, Cunwen WANG, Weiguo WANG, Yuanxin WU, Junfeng ZHANG,

期刊论文

Entity and relation extraction with rule-guided dictionary as domain knowledge

期刊论文

A review on catalytic & non-catalytic bio-oil upgrading in supercritical fluids

Sainab Omar, Yang Yang, Jiawei Wang

期刊论文

Polydimethylsiloxane assisted supercritical CO

Weixia Wang, Shuai Zhou, Zhong Xin, Yaoqi Shi, Shicheng Zhao

期刊论文

Corrosion mechanisms of candidate structural materials for supercritical water-cooled reactor

Lefu ZHANG, Fawen ZHU, Rui TANG