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Study of simultaneous saccharification and fermentation for steam exploded wheat straw to ethanol

LUO Peng, YANG Chuanmin, LIU Zhong, WANG Gaosheng

《化学科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 447-451 doi: 10.1007/s11705-008-0069-1

摘要： Although simultaneous saccharification and fermentation (SSF) has been investigated extensively, the optimum condition for SSF of wheat straw has not yet been determined. Dilute sulfuric acid impregnated and steam explosion pretreated wheat straw was used as a substrate for the production of ethanol by SSF through orthogonal experiment design in this study. Cellulase mixture (Celluclast 1.5 l and -glucosidase Novozym 188) were adopted in combination with the yeast AS2.1. The effects of reaction temperature, substrate concentration, initial fermentation liquid pH value and enzyme loading were evaluated and the SSF conditions were optimized. The ranking, from high to low, of influential extent of the SSF affecting factors to ethanol concentration and yield was substrate concentration, enzyme loading, initial fermentation liquid pH value and reaction temperature, respectively. The optimal SSF conditions were: reaction temperature, 35°C; substrate concentration, 100 g·L; initial fermentation liquid pH, 5.0; enzyme loading, 30 FPU·g. Under these conditions, the ethanol concentration increased with reaction time, and after 72 h, ethanol was obtained in 65.8% yield with a concentration of 22.7 g·L.

关键词： optimal SSF     substrate concentration     optimum condition     enzyme loading     ethanol concentration    

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Study on the microwave-assisted extraction of polyphenols from tea

Liyun WANG, Peiyong QIN, Yan HU,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 307-313 doi: 10.1007/s11705-009-0282-6

摘要： This study demonstrated a promising method for quickly extracting tea polyphenol (TP) by microwave-assisted extraction (MAE) technology. Some influential parameters, including MAE temperature, microwave power, concentration of extraction solvent, MAE time and the solid/liquid ratio, were investigated. The optimum condition of MAE was obtained by dual extraction with 60% ethanol (v/v) and the solid/liquid ratio 1:12 g/mL at 80°C for 10 minutes under the microwave power 600 W. The yield of TP was 96.5% under the described condition. Compared with traditional methods, including hot reflux extraction (HRE), ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE), the extraction time was saved 8 times than that of HRE, and the yield was increased by 17.5%. The extraction time at comparable levels of production was saved 2 times, and the energy consumption was one fourth that of UAE. The extraction time was saved 5 times than that of SFE, and the yield of TP was increased by 40%. Moreover, compared with MAE of TP studied by others, it decreased the solid/liquid ratio from 1 ∶ 20 to 1 ∶ 12 g/mL without 90-min pre-leaching time, and the yield of TP was increased by 6%–40%.

关键词： energy consumption     microwave-assisted extraction     optimum condition     pre-leaching     concentration    

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旅客机环境控制系统优化研究

方林,王浚

《中国工程科学》 2006年 第8卷 第1期   页码 77-80

摘要：

为了选择经济高效的旅客机环境控制系统，对现役各种旅客机采用的环境控制系统方案进行了优化设计和比较，分别建立了二轮简单式低压除水系统、三轮升压式高压除水系统和四轮升压式高压除水系统（又称冷凝循环制冷系统）的优化设计数学模型，以起飞燃油质量代偿损失为目标函数，采用广义乘子法结合单纯形加速法求解，优化结果可作为设计研究旅客机环境控制系统的理论依据。

关键词： 旅客机     环境控制     优化设计    

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系统非优分析理论及方法

何平

《中国工程科学》 2003年 第5卷 第7期   页码 40-46

摘要：

对系统非优分析理论做了较为详细的论述。指出寻求不确定系统优化的主要问题，关键是缺少对系统的非优分析。在系统非优范畴的基础上建立了征兆群与经验分析，提出了系统非优度量以及从非优追踪到系统自组织等问题。

关键词： 系统非优范畴     非优征兆群     非优度量     系统自组织    

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Determining the optimum economic insulation thickness of double pipes buried in the soil for district

Fating LI, Pengfei JIE, Zhou FANG, Zhimei WEN

《能源前沿（英文）》 2021年 第15卷 第1期   页码 170-185 doi: 10.1007/s11708-020-0680-5

摘要： The insulation thickness (IT) of double pipes buried in the soil (DPBIS) for district heating (DH) systems was optimized to minimize the annual total cost of DPBIS for DH systems. An optimization model to obtain the optimum insulation thickness (OIT) and minimum annual total cost (MATC) of DPBIS for DH systems was established. The zero point theorem and fsolve function were used to solve the optimization model. Three types of heat sources, four operating strategies, three kinds of insulation materials, three buried depth (BD) values, and seven nominal pipe size (NPS) values were considered in the calculation of the OIT and MATC of DPBIS for DH systems, respectively. The optimization results for the above factors were compared. The results show that the OIT and MATC of DPBIS for DH systems can be obtained by using the optimization model. Sensitivity analysis was conducted to investigate the impact of some economic parameters, i.e., unit heating cost, insulation material price, interest rate, and insulation material lifetime, on optimization results. It is found out that the impact of sensitivity factors on the OIT and MATC of DPBIS for DH systems is different.

关键词： double pipes     optimization model     optimum insulation thickness     minimum annual total cost    

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Estimation of optimum design of structural systems via machine learning

《结构与土木工程前沿（英文）》 2021年 第15卷 第6期   页码 1441-1452 doi: 10.1007/s11709-021-0774-0

摘要： Three different structural engineering designs were investigated to determine optimum design variables, and then to estimate design parameters and the main objective function of designs directly, speedily, and effectively. Two different optimization operations were carried out: One used the harmony search (HS) algorithm, combining different ranges of both HS parameters and iteration with population numbers. The other used an estimation application that was done via artificial neural networks (ANN) to find out the estimated values of parameters. To explore the estimation success of ANN models, different test cases were proposed for the three structural designs. Outcomes of the study suggest that ANN estimation for structures is an effective, successful, and speedy tool to forecast and determine the real optimum results for any design model.

关键词： optimization     metaheuristic algorithms     harmony search     structural designs     machine learning     artificial neural networks    

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A review of condition-based maintenance: Its prognostic and operational aspects

Yanrong LI, Shizhe PENG, Yanting LI, Wei JIANG

《工程管理前沿（英文）》 2020年 第7卷 第3期   页码 323-334 doi: 10.1007/s42524-020-0121-5

摘要： Condition-based maintenance (CBM) detects early signs of failure and dictates when maintenance should be performed based on the actual condition of a system. In this paper, we first review some of the recent research on CBM under various physical structures and signal data. Then, we summarize several kinds of prognostic models that use monitoring information to estimate the reliability of complex systems or products. Monitoring information also facilitates operational decisions in production planning, spare parts management, reliability improvement, and prognostics and health management. Finally, we suggest some research opportunities for the reliability and operations management communities to fill the research gap between these two fields.

关键词： condition-based maintenance     prognostics     operational decision-making     reliability    

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Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要： Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词： water injection units     condition-based maintenance     trend prediction    

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Unified cycle model of a class of internal combustion engines and their optimum performance characteristics

Shiyan ZHENG

《能源前沿（英文）》 2011年 第5卷 第4期   页码 367-375 doi: 10.1007/s11708-011-0170-x

摘要： The unified cycle model of a class of internal combustion engines is presented, in which the influence of the multi-irreversibilities mainly resulting from the adiabatic processes, finite-time processes and heat leak loss through the cylinder wall on the performance of the cycle are taken into account. Based on the thermodynamic analysis method, the mathematical expressions of the power output and efficiency of the cycle are calculated and some important characteristic curves are given. The influence of the various design parameters such as the high-low pressure ratio, the high-low temperature ratio, the compression and expansion isentropic efficiencies etc. on the performance of the cycle is analyzed. The optimum criteria of some important parameters such as the power output, efficiency and pressure ratio are derived. The results obtained from this unified cycle model are very general and useful, from which the optimal performance of the Atkinson, Otto, Diesel, Dual and Miller heat engines and some new heat engines can be directly derived.

关键词： internal combustion engine     irreversibility     power output     efficiency     optimization    

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Real-time tool condition monitoring method based on temperature measurement and artificial neural network

《机械工程前沿（英文）》 doi: 10.1007/s11465-021-0661-3

摘要： Tool failures in machining processes often cause severe damages of workpieces and lead to large quantities of loss, making tool condition monitoring an important, urgent issue. However, problems such as practicability still remain in actual machining. Here, a real-time tool condition monitoring method integrated in an in situ fiber optic temperature measuring apparatus is proposed. A thermal simulation is conducted to investigate how the fluctuating cutting heats affect the measuring temperatures, and an intermittent cutting experiment is carried out, verifying that the apparatus can capture the rapid but slight temperature undulations. Fourier transform is carried out. The spectrum features are then selected and input into the artificial neural network for classification, and a caution is given if the tool is worn. A learning rate adaption algorithm is introduced, greatly reducing the dependence on initial parameters, making training convenient and flexible. The accuracy stays 90% and higher in variable argument processes. Furthermore, an application program with a graphical user interface is constructed to present real-time results, confirming the practicality.

关键词： tool condition monitoring     cutting temperature     neural network     learning rate adaption    

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Biological chip technology to quickly batch select optimum cryopreservation procedure

YU Lina, LIU Jing, ZHOU Yixin, HUA Zezhao

《能源前沿（英文）》 2007年 第1卷 第3期   页码 316-321 doi: 10.1007/s11708-007-0046-2

摘要： In the practices of cryobiology, selection of an optimum freeze/thawing program and an idealistic cryoprotective agent often requires rather tedious, time consuming and repetitive tests. Integrating the functions of sample preparation and viability detection, the concept of biochip technology was introduced to the field of cryopreservation, aiming at quickly finding an optimum freezing and thawing program. Prototype devices were fabricated and corresponding experimental tests were performed. It was shown that microflow-channel chip could not offer a high quality solution distribution. As an alternative, the spot-dropping chip proved to be an excellent way to load the sample quickly and reliably. Infrared thermal mapping on such a chip showed that it had a rather uniform heat transfer boundary. Applying the spot-dropping chip combined with the thermoelectric cooling device, the final output of cryopreservation of multiple samples was tested, and the optimal freeze/thawing program as well as the potentially best concentration of the cryoprotective agent was found by analyzing the results. Further, application of this technique to measure the thermo-physical properties of the cryo-protective agent was also investigated. The study demonstrated that a biochip with integrated automatic loading and inspection units opens the possibility of a massive optimization of the complex cryopreservation program in a quicker and more economical way.

关键词： idealistic cryoprotective     concentration     Prototype     technology     alternative    

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Implementation of an optimum algorithm for structural reliability analysis based on FEM

CHENG Ying, TU Hong-mao, FAN Hong-li

《机械工程前沿（英文）》 2006年 第1卷 第4期   页码 468-471 doi: 10.1007/s11465-006-0061-8

摘要： To analyze structural reliability by the stochastic FE (finite element) method rapidly and efficiently, a method combined with the FE method and gradient optimum algorithm based on ANSYS was presented when referring to the geometric interpretation of structural reliability index. ANSYS-based development was adopted to implement it. Results of an example demonstrate that the method requires fewer FE calculations compared with the design point method and Monte-Carlo simulation, and achieves satisfactory accuracy.

关键词： satisfactory     interpretation     algorithm     structural reliability     stochastic FE    

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Optimum design and preliminary experiments of a novel parallel end traction apparatus for upper-limb

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 726-746 doi: 10.1007/s11465-021-0651-5

摘要： Robot-assisted technology has been increasingly employed in the therapy of post stroke patients to deliver high-quality treatment and alleviate therapists’ burden. This paper introduces a novel parallel end traction apparatus (PETA) to supplement equipment selection. Considering the appearance and performance of the PETA, two types of special five-bar linkage mechanisms are selected as the potential configurations of the actuation execution unit because of their compact arrangement and parallel structure. Kinematic analysis of each mechanism, i.e., position solutions and Jacobian matrix, is carried out. Subsequently, a comparative study between the two mechanisms is conducted. In the established source of nondimensional parameter synthesis, the singularity, maximum continuous workspace, and performance variation trends are analyzed. Based on the evaluation results, the final scheme with determined configuration and corresponding near-optimized nondimensional parameters is obtained. Then, a prototype is constructed. By adding a lockable translational degree of freedom in the vertical direction, the PETA can provide 2D planar exercise and 3D spatial exercise. Finally, a control system is developed for passive exercise mode based on the derived inverse position solution, and preliminary experiments are performed to verify the applicability of the PETA.

关键词： parallel mechanism     upper-limb rehabilitation     singularity and workspace analyses     performance evaluation     optimum design    

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Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Amin Mohammad Mehdi,Bina Bijan,Majd Amir Masoud Samani,Pourzamani Hamidreza

《环境科学与工程前沿（英文）》 2014年 第8卷 第3期   页码 345-356 doi: 10.1007/s11783-013-0574-4

摘要： Benzene removal from aqueous solutions was evaluated using Fe O nano magnetic particles (NM) in continuous condition. A 4 factorial design including initial benzene concentration, NM dose, contact time and pH was investigated in 16 experiments (Taguchi OA design). The results indicated that all factors were significant and the optimum condition was: pH 8, NM dose of 2000 mg·L , benzene concentrations of 100 mg·L and contact time of 14 min. The maximum benzene uptake and distribution ratio in the optimum situation were 49.4 mg·g and 38.4 L·g , respectively. The nano particles were shown to capture 98.7% of the benzene in optimum batch condition and 94.5% in continuous condition. The isotherm data proved that the Brunauer-Emmett-Teller model fit more closely and produced an isotherm constant (b) less than one, indicating favorable adsorption. Regeneration studies verified that the benzene adsorbed by the NM could be easily desorbed by temperature, and thereby, NM can be employed repeatedly in water and wastewater management.

关键词： benzene     experimental design     Fe3O4     continues condition     thermal recycling    

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Optimum nitrogen fertilization of

Wentao ZOU,Ruifeng JIA,Jinchang YANG,Rongsheng LI,Guangtian YIN

《农业科学与工程前沿（英文）》 2016年 第3卷 第4期   页码 368-374 doi: 10.15302/J-FASE-2016120

摘要： A greenhouse pot experiment was conducted to study the effects of nitrogen fertilization on seedlings grown with 0, 50, 100, 150, 200, 300, 400 and 600 mg N per seedling according to exponential functions. Seedling height, root collar diameter, leaf area and total biomass increased with increasing fertilization from 0 to 200 mg N per seedling and decreased with further increase in fertilization from 300 to 600 mg N per seedling. The net photosynthetic rate, stomatal conductance, intercellular CO concentration and transpiration rate of seedlings showed a unimodal parabolic trend, with peak values of 7.29 mmol·m ·s , 0.071 mol·m ·s , 220 mmol·mol and 1.34 mmol·m ·s , respectively, when the rate of fertilization was 200 mg N per seedling. Photosynthetic gas exchange parameters were significantly different among nitrogen treatments. Based on the critical values of leaf N and P concentration and N/P ratio, the optimum amount of nitrogen of seedlings was 200–400 mg per seedling for leaf N and P concentration, and 100–400 mg per seedling for N/P ratio. It was concluded that 200–400 mg N per seedling was the most suitable nitrogen range for seedlings.

关键词： Calophyllum inophyllum     growth     nitrogen fertilization     nutrient status     photosynthesis    

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标题 作者 时间 类型 操作

Study of simultaneous saccharification and fermentation for steam exploded wheat straw to ethanol

LUO Peng, YANG Chuanmin, LIU Zhong, WANG Gaosheng

期刊论文

Study on the microwave-assisted extraction of polyphenols from tea

Liyun WANG, Peiyong QIN, Yan HU,

期刊论文

旅客机环境控制系统优化研究

方林,王浚

期刊论文

系统非优分析理论及方法

何平

期刊论文

Determining the optimum economic insulation thickness of double pipes buried in the soil for district

Fating LI, Pengfei JIE, Zhou FANG, Zhimei WEN

期刊论文

Estimation of optimum design of structural systems via machine learning

期刊论文

A review of condition-based maintenance: Its prognostic and operational aspects

Yanrong LI, Shizhe PENG, Yanting LI, Wei JIANG

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

Unified cycle model of a class of internal combustion engines and their optimum performance characteristics

Shiyan ZHENG

期刊论文

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

期刊论文

Biological chip technology to quickly batch select optimum cryopreservation procedure

YU Lina, LIU Jing, ZHOU Yixin, HUA Zezhao

期刊论文

Implementation of an optimum algorithm for structural reliability analysis based on FEM

CHENG Ying, TU Hong-mao, FAN Hong-li

期刊论文

Optimum design and preliminary experiments of a novel parallel end traction apparatus for upper-limb

期刊论文

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Amin Mohammad Mehdi,Bina Bijan,Majd Amir Masoud Samani,Pourzamani Hamidreza

期刊论文

Optimum nitrogen fertilization of

Wentao ZOU,Ruifeng JIA,Jinchang YANG,Rongsheng LI,Guangtian YIN

期刊论文