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Synthesis and characterization of castor oil-based polymeric surfactants

Xujuan HUANG,He LIU,Shibin SHANG,Zhaosheng CAI,Jie SONG,Zhanqian SONG

《农业科学与工程前沿（英文）》 2016年 第3卷 第1期   页码 46-54 doi: 10.15302/J-FASE-2016083

摘要： Dehydrated castor oil was epoxidized using phosphoric acid as a catalyst and acetic acid peroxide as an oxidant to produce epoxidized castor oil (ECO). Ring-opening polymerization with stannic chloride was used to produce polymerized ECO (PECO), and sodium hydroxide used to give hydrolyzed PECO (HPECO). The HPECO was characterized by Fourier transform infrared, H and C nuclear magnetic resonance spectroscopies, gel permeation chromatography, and differential scanning calorimetry. The weight-average molecular weight of soluble PECO and HPECO were 5026 and 2274 g·mol , respectively. PECO and HPECO exhibited glass transition. Through neutralizing the carboxylic acid of HPECO with different counterions, castor oil-based polymeric surfactants (HPECO-M, where M= Na , K or triethanolamine ion) exhibited high efficiency to reduce the surface tension of water. The critical micelle concentration (CMC) values of HPECO-M ranged from 0.042 to 0.098 g·L and the minimum equilibrium surface tensions at CMC ( ) of HPECO-M ranged from 25.6 to 30.0 mN·m . The water-hexadecane interfacial energy was calculated from measured surface tension using harmonic and geometric mean methods. Measured values of water-hexadecane interfacial tension agreed well with those calculated using the harmonic and geometric mean methods.

关键词： epoxidized vegetable oil     ring-opening polymerization     interfacial tension     polymeric surfactant    

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Preparation and properties of hollow fibre nanofiltration membrane with continuous coffee-ring structure

Xiuzhen Wei, Xufeng Xu, Yi Chen, Qian Zhang, Lu Liu, Ruiyuan Yang, Jinyuan Chen, Bosheng Lv

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 351-362 doi: 10.1007/s11705-020-1943-8

摘要： Polyamide (PA) hollow fibre composite nanofiltration (NF) membranes with a coffee-ring structure and beneficial properties were prepared by adding graphene oxide (GO) into the interfacial polymerization process. The presentation of the coffee-ring structure was attributed to the heterogeneous, finely dispersed multiphase reaction system and the “coffee-stain” effect of the GO solution. When the piperazine concentration was 0.4 wt-%, the trimesoyl chloride concentration was 0.3 wt-%, and the GO concentration was 0.025 wt-%, the prepared NF membranes showed the best separation properties. The permeate flux was 76 L·m ·h , and the rejection rate for MgSO was 98.6% at 0.4 MPa. Scanning electron microscopy, atomic force microscopy, and attenuated total reflectance-Fourier transform infrared spectroscopy were used to characterize the chemical structure and morphology of the PA/GO NF membrane. The results showed that GO was successfully entrapped into the PA functional layer. Under neutral operating conditions, the PA/GO membrane showed typical negatively charged NF membrane separation characteristics, and the rejection rate decreased in the order of Na SO >MgSO >MgCl >NaCl. The PA/GO NF membrane showed better antifouling performance than the PA membrane.

关键词： GO     PA     interfacial polymerization     hollow fibre NF membrane    

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Frequencies of circular plate with concentric ring and elastic edge support

null

《机械工程前沿（英文）》 2014年 第9卷 第2期   页码 168-176 doi: 10.1007/s11465-014-0299-5

摘要：

Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.

关键词： circular plate     frequency     elastic edge     rigid ring     mode switching    

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Liquid metal printing opening the way for energy conservation in semiconductor manufacturing industry

《能源前沿（英文）》 2022年 第16卷 第4期   页码 542-547 doi: 10.1007/s11708-022-0834-8

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Impacts of opening baffle of city road tunnels on natural ventilation performance

Weixiao YANG, Jincheng XING, Jianxing LI, Jihong LING, Haixian HAO, Zhiqiang YAN

《结构与土木工程前沿（英文）》 2013年 第7卷 第1期   页码 55-61 doi: 10.1007/s11709-013-0194-x

摘要： Based on the opening baffle mode for natural ventilation of city road tunnels, this paper studies the impacts of opening baffle on natural ventilation performance by verifying numerical simulation through model tests. By analyzing the impacts of installation angle, dimension, location, and quantity of opening baffle on ventilation performance, the paper reached the conclusions as follows: 1) When installation angle is larger than 45° and tunnel ventilation is well operated, the baffle exhaust could increase by at least 30% compared to when there is no baffle. 2) The baffle reaches its optimal performance when the length of the baffle is equal to the width of the city road tunnels. 3) Baffle exhaust could increase by 30% when it is installed in the downstream of openings. 4) The performance of a single baffle is better than that of multiple baffles.

关键词： city road tunnel     numerical simulation     baffle     top opening     natural ventilation    

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Fundamental buckling of circular plates with elastically restrained edges and resting on concentric rigid ring

Lokavarapu Bhaskara Rao, Chellapilla Kameswara Rao

《机械工程前沿（英文）》 2013年 第8卷 第3期   页码 291-297 doi: 10.1007/s11465-013-0255-9

摘要：

This work presents the existence of buckling mode switching with respect to the radius of concentric rigid ring support. The buckling mode may not be axisymmetric as previously assumed. In general, the plate may buckle in an axisymmetric mode but when the radius of the ring support becomes small, the plate may buckle in an asymmetric mode. The optimum radius of the concentric rigid ring support for maximum buckling load is also determined. Introducing internal rigid ring support, when placed at an optimal position increases the elastic buckling load capacity by 149.39 percent. The numerical results obtained are in good agreement with the previously published data.

关键词： buckling     circular plate     elastically restrained edge     rigid ring support     mode switching    

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Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 89-95 doi: 10.1007/s11705-010-0558-x

摘要： Although an important industrial catalyst for producing high density polyethylene, the SiO -supported organosilyl chromate UCC S-2 catalyst has not been fully investigated compared with the SiO -supported oxo chromium Phillips catalyst. In this work, gas phase ethylene polymerization by S-2 catalysts (Cat-1, Cat-2, and Cat-3) was carried out in a high-speed stirred-autoclave reactor. The effects of temperature, time, and pressure on kinetics, activity, and product properties were studied. All kinetics were typical built-up types with slow decay. Compared to the simple physical mixtures of Cat-1 and Cat-2, Cat-3 showed higher activity and its product had a broader molecular weight distribution, indicating new active species induced during blending of Cat-1 and Cat-2 in -hexane. The innovation by a simple catalyst technology created a new application to meet market demands.

关键词： UCC S-2 catalyst     Al-alkyl co-catalyst     gas-phase ethylene polymerization     high density polyethylene    

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Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 372-381 doi: 10.1007/s11705-010-0005-z

摘要： Thrombus formation and blood coagulation are serious problems associated with blood contacting products, such as catheters, vascular grafts, artificial hearts, and heart valves. Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper. Three approaches to modify biomaterial surfaces for improving the hemocompatibility, i.e., bioinert surfaces, immobilization of anticoagulative substances and biomimetic surfaces, are introduced. The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp (RGD) sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces. The RGD sequence can enhance adhesion and growth of endothelial cells (ECs) on material surfaces and increase the retention of ECs under flow shear stress conditions. This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.

关键词： biomimetic amphiphilic     amphiphilic phosphorylcholine     endothelial     functional     biomaterial    

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Synthesis and bulk polymerization kinetics of monomer dehydroabietic acid-(2-acryloyloxy-ethoxy)-ethyl

Haibo ZHANG,Yanping YANG,He LIU,Jie SONG,Shibin SHANG,Zhanqian SONG

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 97-105 doi: 10.15302/J-FASE-2016115

摘要： A bulk polymerization monomer dehydro- abietic acid-(2-acryloyloxy-ethoxy)-ethyl ester (DHA-DG-AC) was synthesized from dehydroabietic acid (DHA). The chemical structure of DHA-DG-AC was characterized by H NMR, C NMR, MS and FT-IR. The kinetics of the bulk polymerization of DHA-DG-AC was investigated by Differential Scanning Calorimeter (DSC). Two kinds of kinetic model (nth-order model and autocatalytic model) were used to investigate the polymerization process. The results showed that the experimental DSC curves were consistent with the computational data generated by the autocatalytic kinetic model, and the value of was 95.73 kJ·mol .

关键词： dehydroabietic acid     bulk polymerization     kinetics     autocatalytic kinetic model    

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Lateral-torsional buckling capacity assessment of web opening steel girders by artificial neural networks

Yasser SHARIFI,Sajjad TOHIDI

《结构与土木工程前沿（英文）》 2014年 第8卷 第2期   页码 167-177 doi: 10.1007/s11709-014-0236-z

摘要： Bridge girders exposed to aggressive environmental conditions are subject to time-variant changes in resistance. There is therefore a need for evaluation procedures that produce accurate predictions of the load-carrying capacity and reliability of bridge structures to allow rational decisions to be made about repair, rehabilitation and expected life-cycle costs. This study deals with the stability of damaged steel I-beams with web opening subjected to bending loads. A three-dimensional (3D) finite element (FE) model using ABAQUS for the elastic flexural torsional analysis of I-beams has been used to assess the effect of web opening on the lateral buckling moment capacity. Artificial neural network (ANN) approach has been also employed to derive empirical formulae for predicting the lateral-torsional buckling moment capacity of deteriorated steel I-beams with different sizes of rectangular web opening using obtained FE results. It is found out that the proposed formulae can accurately predict residual lateral buckling capacities of doubly-symmetric steel I-beams with rectangular web opening. Hence, the results of this study can be used for better prediction of buckling life of web opening of steel beams by practice engineers.

关键词： steel I-beams     lateral-torsional buckling     finite element (FE) method     artificial neural network (ANN) approach    

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A novel algorithm for frequency dependent modeling of ferrite ring and its optimum design to study VFTO

Mehrdad MAJIDI, Hamid JAVADI, Moein MANBACHI

《能源前沿（英文）》 2014年 第8卷 第1期   页码 90-100 doi: 10.1007/s11708-013-0286-2

摘要： One of the fundamental issues in gas insulated substations (GIS) which has destructive effects on GIS equipment is the very fast transient over-voltages (VFTOs). This paper models a 400/230 kV substation in order to study the effects of VFTO extensively implemented on EMTP-RV. In addition, the application of ferrite rings for suppressing VFTOs is assessed thoroughly. The main advantage of this paper is its new proposed algorithm according to the ferrite ring frequency dependent modeling that is validated with experimental results. This paper examines the effects of three compositions of the ferrite ring on VFTO suppression. Moreover, it estimates the dimension of the ferrite ring based on the SF6 gas insulation withstand and the maximum effect of ferrite rings on VFTO suppression constraint with the COMSOL multiphysics software. Furthermore, it gains VFTO attenuated percentages due to the installation of the ferrite ring in different GIS nodes. Finally, it analyzes the offered VFTO amendment technique in various GIS switching scenarios.

关键词： comsol multiphysics     EMTP-RV     ferrite ring     gas insulated substations (GIS)     transient over-voltage     insulation coordination    

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单向离合器外环应力计算的有限元方法研究

罗一新,吴波

《中国工程科学》 2004年 第6卷 第9期   页码 56-59

摘要：

单向离合器是一种常见的机械传动部件，其外环应力计算尚无理想的方法。文章以五滚柱式单向离合器为研究对象，根据外环的特点，采用有限元分析方法，分析了影响其计算精度的各种因素，计算出其外环的应力，并且将计算结果与曲梁计算法进行了比较。研究表明，有限元分析方法对于外环类零件的应力计算确是一种理想的方法。

关键词： 离合器     外环     应力     有限元    

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Improvement of part-load performance of gas turbine by adjusting compressor inlet air temperature and IGV opening

《能源前沿（英文）》 2022年 第16卷 第6期   页码 1000-1016 doi: 10.1007/s11708-021-0746-z

摘要： A novel adjusting method for improving gas turbine (GT) efficiency and surge margin (SM) under part-load conditions is proposed. This method adopts the inlet air heating technology, which uses the waste heat of low-grade heat source and the inlet guide vane (IGV) opening adjustment. Moreover, the regulation rules of the compressor inlet air temperature and the IGV opening are studied comprehensively to optimize GT performance. A model and calculation method for an equilibrium running line is adopted based on the characteristic curves of the compressor and turbine. The equilibrium running lines calculated through the calculation method involve three part-load conditions and three IGV openings with different inlet air temperatures. The results show that there is an optimal matching relationship between IGV opening and inlet air temperature. For the best GT performance of a given load, the IGV could be adjusted according to inlet air temperature. In addition, inlet air heating has a considerable potential for the improvement of part-load performance of GT due to the increase in compressor efficiency, combustion efficiency, and turbine efficiency as well as turbine inlet temperature, when inlet air temperature is lower than the optimal value with different IGV openings. Further, when the IGV is in a full opening state and an optimal inlet air temperature is achieved by using the inlet air heating technology, GT efficiency and SM can be obviously higher than other IGV openings. The IGV can be left unadjusted, even when the load is as low as 50%. These findings indicate that inlet air heating has a great potential to replace the IGV to regulate load because GT efficiency and SM can be remarkably improved, which is different from the traditional viewpoints.

关键词： inlet air temperature     inlet guide vane (IGV) opening     part-load     equilibrium running line     gas turbine (GT) efficiency     surge margin (SM)    

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Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

《能源前沿（英文）》 2012年 第6卷 第1期   页码 47-56 doi: 10.1007/s11708-011-0159-5

摘要： The advancement in power distribution system poses a great challenge to power engineering researchers on how to best monitor and estimate the state of the distribution network. This paper is executed in two stage processes. The first stage is to identify the optimal location for installation of monitoring instrument with minimal investment cost. The second stage is to estimate the bus voltage magnitude, where real time measurement is conducted and measured through identified meter location which is more essential for decision making in distribution supervisory control and data acquisition system (DSCADA). The hybrid intelligent technique is applied to execute the above two algorithms. The algorithms are tested with institute of electrical and electronics engineers (IEEE) and Tamil Nadu electricity board (TNEB) benchmark systems. The simulated results proves that the swarm tuned artificial neural network (ANN) estimator is best suited for accurate estimation of voltage with different noise levels.

关键词： artificial intelligence     power distribution control     state estimation    

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标题 作者 时间 类型 操作

Synthesis and characterization of castor oil-based polymeric surfactants

Xujuan HUANG,He LIU,Shibin SHANG,Zhaosheng CAI,Jie SONG,Zhanqian SONG

期刊论文

Preparation and properties of hollow fibre nanofiltration membrane with continuous coffee-ring structure

Xiuzhen Wei, Xufeng Xu, Yi Chen, Qian Zhang, Lu Liu, Ruiyuan Yang, Jinyuan Chen, Bosheng Lv

期刊论文

Frequencies of circular plate with concentric ring and elastic edge support

null

期刊论文

Liquid metal printing opening the way for energy conservation in semiconductor manufacturing industry

期刊论文

Impacts of opening baffle of city road tunnels on natural ventilation performance

Weixiao YANG, Jincheng XING, Jianxing LI, Jihong LING, Haixian HAO, Zhiqiang YAN

期刊论文

Fundamental buckling of circular plates with elastically restrained edges and resting on concentric rigid ring

Lokavarapu Bhaskara Rao, Chellapilla Kameswara Rao

期刊论文

Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

期刊论文

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

期刊论文

Synthesis and bulk polymerization kinetics of monomer dehydroabietic acid-(2-acryloyloxy-ethoxy)-ethyl

Haibo ZHANG,Yanping YANG,He LIU,Jie SONG,Shibin SHANG,Zhanqian SONG

期刊论文

Lateral-torsional buckling capacity assessment of web opening steel girders by artificial neural networks

Yasser SHARIFI,Sajjad TOHIDI

期刊论文

A novel algorithm for frequency dependent modeling of ferrite ring and its optimum design to study VFTO

Mehrdad MAJIDI, Hamid JAVADI, Moein MANBACHI

期刊论文

单向离合器外环应力计算的有限元方法研究

罗一新,吴波

期刊论文

Improvement of part-load performance of gas turbine by adjusting compressor inlet air temperature and IGV opening

期刊论文

Intelligent algorithm for optimal meter placement and bus voltage estimation in ring main distribution

L. RAMESH, N. CHAKRABORTY, S. P. CHOWDHURY

期刊论文

优秀论文尤须在权威刊物上发表——《中国工程科学》“学位论文精选”开栏寄语

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期刊论文