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期刊论文 20

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2023 4

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关键词

像融合;分数阶导数;直觉模糊集;多聚焦图像 1

多智能体;一致性;PID(Proportional-integral-derivative)控制;线性矩阵不等式 1

多期延迟付款 1

改进ROF去噪模型;时间分数阶导数;Caputo导数;图像去噪 1

残次品 1

深静水环境 1

白云岩 1

短缺 1

碱矿探边 1

网络空间;安全模型;安全能力;衍生风险 1

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重力二次导数 1

非衍生方法 1

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Self-extinguishing and transparent epoxy resin modified by a phosphine oxide-containing bio-based derivative

Gang Tang, Ruiqing Zhao, Dan Deng, Yadong Yang, Depeng Chen, Bing Zhang, Xinliang Liu, Xiuyu Liu

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1269-1280 doi: 10.1007/s11705-021-2042-1

摘要: A phosphine oxide-containing bio-based curing agent was synthesized by addition reaction between furan derivatives and diphenylphosphine oxide. The molecular structure of the as-prepared bio-based curing agent was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Dynamic mechanical analysis results indicated that with the increase of bio-based curing agent content, the glass transition temperature of epoxy/bio-based curing agent composites decreased, which was related to the steric effect of diphenylphosphine oxide species that possibly hinder the curing reaction as well as the reduction in the cross-linking density by mono-functional N H. By the addition of 7.5 wt-% bio-based curing agent, the resulting epoxy composite achieved UL-94 V-0 rating, in addition to limiting oxygen index of 32.0 vol-%. With the increase of content for the bio-based curing agent, the peak of heat release rate and total heat release of the composites gradually decreased. The bio-based curing agent promoted the carbonization of the epoxy matrix, leading to higher char yield with good thermal resistance. The high-quality char layer served as an effective barrier to retard the diffusion of decomposition volatiles and oxygen between molten polymers and the flame. This study provides a renewable strategy for fabricating flame retardant and transparent epoxy thermoset.

关键词: epoxy resin     flame retardant     furan derivative     diphenylphosphine oxide    

a catalyst for catalytic transfer hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 415-424 doi: 10.1007/s11705-022-2225-4

摘要: 2,5-bis(hydroxymethyl)furan (BHMF) is an important monomer of polyester. Its oxygen-containing rigid ring structure and symmetrical diol functional group establish it as an alternative to petroleum-based monomer with unique advantages for the prodution of the degradable bio-based polyester materials. Herein, we prepared a boehmite-supported copper-oxide catalyst for the selective hydrogenation of 5-hydroxymethylfurfural into BHMF via catalytic transfer hydrogenation (CTH). Further, ethanol successfully replaced conventional high-pressure hydrogen as the hydrogen donor, with up to 96.9% BHMF selectivity achieved under suitable conditions. Through characterization and factor investigations, it was noted that CuO is crucial for high BHMF selectivity. Furthermore, kinetic studies revealed a higher by-product activation energy compared to that of BHMF, which explained the influence of reaction temperature on product distribution. To establish the catalyst structure-activity correlation, a possible mechanism was proposed. The copper-oxide catalyst deactivated following CTH because ethanol reduced the CuO, which consequently decreased the active sites. Finally, calcination of the catalyst in air recovered its activity. These results will have a positive impact on hydrogenation processes in the biomass industry.

关键词: biomass     5-hydroxymethylfurfural     2     5-bis(hydroxymethyl)furan     transfer hydrogenation     catalysis    

Comparisons of bridges flutter derivatives and generalized ones

Fuyou XU , Zhe ZHANG , Cailiang HUANG , Airong CHEN ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 272-278 doi: 10.1007/s11709-009-0042-1

摘要: The causes of the nonlinearity of self-excited aerodynamic force of bridge are interpreted from such two aspects as amplitude and wind velocity. The concept of “generalized flutter derivative” is proposed, and its physical meaning is illustrated. The graphs of the generalized flutter derivatives of plate and Sutong Bridge section model are plotted. The characteristics of all generalized flutter derivatives are compared and analyzed, and their superiorities are verified. The results indicate that the physical meaning of generalized flutter derivatives are more explicit compared to the traditional ones. It is more convenient to understand the nonlinearity properties of self-excited aerodynamic force of bridge according to the generalized flutter derivatives graphs with the wind velocity as the horizontal coordinate.

关键词: bridge     flutter derivative     generalized flutter derivative     self-excited aerodynamic force     Sutong Bridge    

Online recognition of drainage type based on UV-vis spectra and derivative neural network algorithm

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1430-6

摘要:

• UV-vis absorption analyzer was applied in drainage type online recognition.

关键词: Drainage online recognition     UV-vis spectra     Derivative spectrum     Convolutional neural network    

A novel flavonol-based colorimetric and turn-on fluorescent probe for rapid determination of hydrazine in real water samples and its bioimaging and

《化学科学与工程前沿(英文)》 2023年 第17卷 第1期   页码 24-33 doi: 10.1007/s11705-022-2171-1

摘要: Hydrazine is extremely toxic and causes severe harm to human body. Herein, a novel fluorescent probe 4-oxo-2-styryl-4H-chromen-3-yl thiophene-2-carboxylate (FHT) was synthesized for detecting hydrazine by using natural cinnamaldehyde as starting material. This probe exhibited significantly enhanced fluorescence response towards hydrazine over various common metal ions, anions, and amine compounds. The detection limit of probe FHT for hydrazine was as low as 0.14 μmol·L–1, significantly lower than that of the threshold value of 0.312 μmol·L–1, imposed by the Environmental Protection Agency. Moreover, the proposed probe was able to detect hydrazine within wide pH (5–10) and linear detection ranges (0–110 μmol·L–1). This probe was employed for determining trace hydrazine in different environmental water samples. The probe FHT-loaded filter paper strips were able to conveniently detect hydrazine of low concentration through distinct naked-eye and fluorescent color changes. Importantly, the probe FHT with low cytotoxicity was successfully applied to visualize hydrazine in living Hela cells and zebrafish.

关键词: cinnamaldehyde     3-hydroxychromone derivative     hydrazine     fluorescent probe    

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1487-1499 doi: 10.1007/s11705-021-2085-3

摘要: Developing cost-effective electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is vital in energy conversion and storage applications. Herein, we report a simple method for the synthesis of graphene-reinforced CoS/C nanocomposites and the evaluation of their electrocatalytic performance for typical electrocatalytic reactions. Nanocomposites of CoS embedded in N, S co-doped porous carbon and graphene (CoS@C/Graphene) were generated via simultaneous sulfurization and carbonization of one-pot synthesized graphite oxide-ZIF-67 precursors. The obtained CoS@C/Graphene nanocomposites were characterized by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis-mass spectroscopy, scanning electronic microscopy, transmission electronic microscopy, X-ray photoelectron spectroscopy and gas sorption. It is found that CoS nanoparticles homogenously dispersed in the in situ formed N, S co-doped porous carbon/graphene matrix. The CoS@C/10Graphene composite not only shows excellent electrocatalytic activity toward ORR with high onset potential of 0.89 V, four-electron pathway and superior durability of maintaining 98% of current after continuously running for around 5 h, but also exhibits good performance for OER and HER, due to the improved electrical conductivity, increased catalytic active sites and connectivity between the electrocatalytic active CoS and the carbon matrix. This work offers a new approach for the development of novel multifunctional nanocomposites for the next generation of energy conversion and storage applications.

关键词: MOF derivative     graphene     electrocatalyst     oxygen reduction reaction     oxygen evolution reaction     hydrogen evolution reaction    

Synthesis of a cardanol-amine derivative using an ionic liquid catalyst

Atanu Biswas, Carlucio R. Alves, Maria T. S. Trevisan, Roseane L. E. da Silva, Roselayne F. Furtado, Zengshe Liu, H. N. Cheng

《化学科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 425-431 doi: 10.1007/s11705-016-1581-3

摘要: Cardanol is a biobased raw material derived from cashew nut shell liquid. In order to extend its utility, new derivatives and additional applications are useful. In this work cardanol was first epoxidized, and a novel aniline derivative prepared from it under mild reaction conditions with the help of an ionic liquid catalyst. The reaction chemistry was studied by using nuclear magnetic resonance. The resulting aminohydrin adduct showed antioxidant property and should also be a useful synthon for further reactions. As an example, the aminohydrin was shown to undergo a condensation reaction with formaldehyde to form a prepolymer, which could be further reacted to form thermosetting resins.

关键词: cardanol     epoxidation     aminohydrin     aniline     ionic liquid     aniline-formaldehyde    

Convergence performance comparisons of PID, MRAC, and PID+MRAC hybrid controller

Dan ZHANG,Bin WEI

《机械工程前沿(英文)》 2016年 第11卷 第2期   页码 213-217 doi: 10.1007/s11465-016-0386-x

摘要:

This study proposes a hybrid controller by combining a proportional-integral-derivative (PID) control and a model reference adaptive control (MRAC), which named as PID+MRAC controller. The convergence performances of the PID control, MRAC, and hybrid PID+MRAC are also compared. Through the simulation in Matlab, the results show that the convergence speed and performance of the MRAC and the PID+MRAC controller are better than those of the PID controller. In addition, the convergence performance of the hybrid control is better than that of the MRAC control.

关键词: proportional-integral-derivative (PID) control     model reference adaptive control     hybrid control     convergence speed     comparison    

Control algorithm of a servo platform

Shouyong XIE, Xiwen LI, Shuzi YANG, Mingjin YANG,

《机械工程前沿(英文)》 2010年 第5卷 第3期   页码 353-355 doi: 10.1007/s11465-010-0098-6

摘要: According to the characteristics of the movement of a special-purpose three-axis servo platform, this paper presents an improved grey prediction proportional integral derivative (PID) control algorithm. Different weights at different time are given to different sampling moments in the algorithm, and the time meanings of the sample data are paid more attention. Simulation results show that the performance of response and stability of the platform of the improved algorithm is better than that of the traditional one. The control algorithm meets all requirements of the control system of the special-purpose three-axis servo platform.

关键词: grey prediction     proportional integral derivative (PID) control     improved algorithm     weight     servo platform    

基于分数阶导数和直觉模糊集的多聚焦图像融合 Research Articles

张雪峰,闫慧,何昊

《信息与电子工程前沿(英文)》 2020年 第21卷 第6期   页码 809-962 doi: 10.1631/FITEE.1900737

摘要: 多聚焦图像融合在图像融合中日益重要,在图像处理中扮演着关键角色。本文提出一种基于分数阶导数和直觉模糊集的多聚焦图像融合方法。其将原始图像分解为基础层和细节层,建立一个新的分数阶空间频率来反映图像清晰度。采用分数阶空间频率作为细节层融合准则,并引入直觉模糊集对基础层进行融合。实验结果表明,该方法在多聚焦图像融合方面优于已有先进方法。

关键词: 像融合;分数阶导数;直觉模糊集;多聚焦图像    

基于时间分数阶导数的改进ROF去噪模型 Research Articles

廖星冉

《信息与电子工程前沿(英文)》 2020年 第21卷 第6期   页码 809-962 doi: 10.1631/FITEE.2000067

摘要: 本文主要讨论图像去噪和纹理保持问题。时间分数阶导数通常具有可调的分数阶控制扩散过程,应用于图像去噪时,其记忆效果能很好保留图像纹理。因此,在经典Rudin-Osher-Fatemi(ROF)模型基础上,设计一个新的时间分数阶导数ROF模型,空间上的离散化基于整数阶差分格式,时间上的离散化是Caputo导数的近似(即,用类Caputo差分法离散Caputo导数)。详细分析这种显式格式的稳定性和收敛性,证明该模型的数值解以阶数O(τ2−α+h2)收敛于精确解,其中τ,α和h分别为时间步长、分数阶和空间步长。最后,采用信噪比、特征相似度、直方图恢复度评价指标综合评价新模型性能。数值试验结果表明,改进的模型比现有模型具有更强去噪和纹理保持能力。

关键词: 改进ROF去噪模型;时间分数阶导数;Caputo导数;图像去噪    

多视角下的网络空间安全模型与体系化发展

孙帅 ,张蕾 ,胡春卉 ,傅首清 ,卿昱 ,崔勇

《中国工程科学》 2023年 第25卷 第6期   页码 116-125 doi: 10.15302/J-SSCAE-2023.06.009

摘要:

网络空间技术发展迅速,新应用、新技术衍生的网络空间安全风险趋于复杂化和隐蔽化;建立特有的网络空间安全模型是国内外应对复杂安全威胁的常规做法,但现有的网络空间安全模型存在未来发展方向不明确、新技术衍生风险分析能力不足、网络空间安全防御评估所需的安全能力缺失等问题。本文从技术、学科、产业等视角入手,开展了现有的网络空间安全模型评估,梳理了网络空间安全技术体系的自身特点及其发展脉络,阐明了网络安全应用存在的迫切问题;着重从网络空间安全技术视角出发,提出了一种基于技术要素的网络空间安全模型体系框架,并利用已有安全技术和新兴技术验证了体系框架的安全分析能力。从完善网络空间安全技术体系核心框架、促进网络空间安全领域“产学研”协同、推进网络空间安全核心技术标准制定、体系化解决人工智能安全威胁等方面提出了发展建议,以期高效应对网络空间安全威胁、提升我国网络空间安全保障能力。

关键词: 网络空间;安全模型;安全能力;衍生风险    

Nanopositioning and Nonlinearity Compensation for Step Imprint Lithography Tool

LU Bing-heng, LIU Hong-zhong, DING Yu-cheng, WANG Li, QIU Zhi-hui

《机械工程前沿(英文)》 2006年 第1卷 第1期   页码 6-13 doi: 10.1007/s11465-005-0003-x

摘要:

In this paper, the motion mode and nanopositioning accuracy in the step imprinting lithography process are presented, and the positioning errors different from the traditional errors, such as the gap error existing in the hinges of the stage structure and the random error produced during the process of the stage position adjustment, are analyzed. To avoid and eliminate these nonlinearity errors, radial basis function proportional integral derivative and position control algorithms are introduced into the macroand microdriving processes, respectively. The innovation of this driving method is that the motion locus is monotone, nonoscillatory, and a multistep approaching target, which eliminates the root of the random error by single direction driving mode and avoids the backlash error through preloading function. Driving experiments of different motion ranges prove that this nonlinearity compensation is very effective and the positioning accuracy during the step imprinting process can be improved up to 10 nm.

关键词: different     nonoscillatory     nonlinearity     integral derivative     positioning    

Probing the redox process of

Rui Lu, Wei Chen, Wen-Wei Li, Guo-Ping Sheng, Lian-Jun Wang, Han-Qing Yu

《环境科学与工程前沿(英文)》 2017年 第11卷 第1期 doi: 10.1007/s11783-017-0905-y

摘要: Fluorescece spectroelectrochemistry is used to probe redox process of benzoquinone. The benzoquinone reduction state has a lower fluorescence quantum efficiency. CVF and DCVF can reveal more information about benzoquinone redox reactions. This method can analyze compounds with fluorescence and electrochemical activities. Quinones are common organic compounds frequently used as model dissolved organic matters in water, and their redox properties are usually characterized by either electrochemical or spectroscopic methods separately. In this work, electrochemical methodology was combined with two fluorescence spectroelectrochemical techniques, cyclic volta- fluorescence spectrometry (CVF) and derivative cyclic volta- fluorescence spectrometry (DCVF), to determine the electrochemical properties of -benzoquinone in dimethyl sulfoxide, an aprotic solution. The CVF results show that the electrochemical reduction of -benzoquinone resulted in the formation of radical anion and dianion, which exhibited a lower fluorescence intensity and red-shift of the emission spectra compared to that of -benzoquinone. The fluorescence intensity was found to vary along with the electrochemical oxidation and reduction of -benzoquinone. The CVF and DCVF results were in good consistence. Thus, the combined method offers a powerful tool to investigate the electrochemical process of -benzoquinone and other natural organic compounds.

关键词: p-Benzoquinone     Electrochemistry     Fluorescence     Spectroelectrochemistry     Derivative cyclic volta fluorescence    

In-MOF-derived In2S3/Bi2S3 heterojunction for enhanced photocatalytic hydrogen production

《能源前沿(英文)》 2023年 第17卷 第5期   页码 654-663 doi: 10.1007/s11708-023-0885-5

摘要: Transition metal sulfides are commonly studied as photocatalysts for water splitting in solar-to-fuel conversion. However, the effectiveness of these photocatalysts is limited by the recombination and restricted light absorption capacity of carriers. In this paper, a broad spectrum responsive In2S3/Bi2S3 heterojunction is constructed by in-situ integrating Bi2S3 with the In2S3, derived from an In-MOF precursor, via the high-temperature sulfidation and solvothermal methods. Benefiting from the synergistic effect of wide-spectrum response, effective charge separation and transfer, and strong heterogeneous interfacial contacts, the In2S3/Bi2S3 heterojunction demonstrates a rate of 0.71 mmol/(g∙h), which is 2.2 and 1.7 times as much as those of In2S3 (0.32 mmol/(g∙h) and Bi2S3 (0.41 mmol/(g∙h)), respectively. This paper provides a novel idea for rationally designing innovative heterojunction photocatalysts of transition metal sulfides for photocatalytic hydrogen production.

关键词: photocatalytic hydrogen production     wide-spectrum response     metal sulfides     MOFs derivative     heterogeneous interfacial contact    

标题 作者 时间 类型 操作

Self-extinguishing and transparent epoxy resin modified by a phosphine oxide-containing bio-based derivative

Gang Tang, Ruiqing Zhao, Dan Deng, Yadong Yang, Depeng Chen, Bing Zhang, Xinliang Liu, Xiuyu Liu

期刊论文

a catalyst for catalytic transfer hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan

期刊论文

Comparisons of bridges flutter derivatives and generalized ones

Fuyou XU , Zhe ZHANG , Cailiang HUANG , Airong CHEN ,

期刊论文

Online recognition of drainage type based on UV-vis spectra and derivative neural network algorithm

期刊论文

A novel flavonol-based colorimetric and turn-on fluorescent probe for rapid determination of hydrazine in real water samples and its bioimaging and

期刊论文

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

期刊论文

Synthesis of a cardanol-amine derivative using an ionic liquid catalyst

Atanu Biswas, Carlucio R. Alves, Maria T. S. Trevisan, Roseane L. E. da Silva, Roselayne F. Furtado, Zengshe Liu, H. N. Cheng

期刊论文

Convergence performance comparisons of PID, MRAC, and PID+MRAC hybrid controller

Dan ZHANG,Bin WEI

期刊论文

Control algorithm of a servo platform

Shouyong XIE, Xiwen LI, Shuzi YANG, Mingjin YANG,

期刊论文

基于分数阶导数和直觉模糊集的多聚焦图像融合

张雪峰,闫慧,何昊

期刊论文

基于时间分数阶导数的改进ROF去噪模型

廖星冉

期刊论文

多视角下的网络空间安全模型与体系化发展

孙帅 ,张蕾 ,胡春卉 ,傅首清 ,卿昱 ,崔勇

期刊论文

Nanopositioning and Nonlinearity Compensation for Step Imprint Lithography Tool

LU Bing-heng, LIU Hong-zhong, DING Yu-cheng, WANG Li, QIU Zhi-hui

期刊论文

Probing the redox process of

Rui Lu, Wei Chen, Wen-Wei Li, Guo-Ping Sheng, Lian-Jun Wang, Han-Qing Yu

期刊论文

In-MOF-derived In2S3/Bi2S3 heterojunction for enhanced photocatalytic hydrogen production

期刊论文