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Influence of Fe on electrocatalytic activity of iron-nitrogen-doped carbon materials toward oxygen reduction reaction

Lin LI, Cehuang FU, Shuiyun SHEN, Fangling JIANG, Guanghua WEI, Junliang ZHANG

《能源前沿（英文）》 2022年第16卷第5期页码 812-821 doi: 10.1007/s11708-020-0669-0

摘要： The development of highly active nitrogen-doped carbon-based transition metal (M-N-C) compounds for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) greatly helps reduce fuel cell cost, thus rapidly promoting their commercial applications. Among different M-N-C electrocatalysts, the series of Fe-N-C materials are highly favored because of their high ORR activity. However, there remains a debate on the effect of Fe, and rare investigations focus on the influence of Fe addition in the second heat treatment usually performed after acid leaching in the catalyst synthesis. It is thus very critical to explore the influences of Fe on the ORR electrocatalytic activity, which will, in turn, guide the design of Fe-N-C materials with enhanced performance. Herein, a series of Fe-N-C electrocatalysts are synthesize and the influence of Fe on the ORR activity are speculated both experimentally and theoretically. It is deduced that the active site lies in the structure of Fe-N , accompanied with the addition of appropriate Fe, and the number of active sites increases without the occurrence of agglomeration particles. Moreover, it is speculated that Fe plays an important role in stabilizing N as well as constituting active sites in the second pyrolyzing process.

关键词： oxygen reduction reaction Fe-N-C active sites Fe addition second heat treatment

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Electrocoagulation process for the treatment of metal-plating wastewater: Kinetic modeling and energy

Fatih Ilhan, Kubra Ulucan-Altuntas, Yasar Avsar, Ugur Kurt, Arslan Saral

《环境科学与工程前沿（英文）》 2019年第13卷第5期 doi: 10.1007/s11783-019-1152-1

摘要： The wastewater from industrial area was treated by EC via Fe and Al electrodes. Cu, Ni, Cr and Zn were highly removed at the first minutes, simultaneously. Pseudo-2nd-order was found to be more suitable for kinetics. Adsorption capacities based on kinetic modeling were observed as Cr>Cu>Ni>Zn. The chemical cost in the case of pH adjustment after EC was less as 3.83 $/m3. It is known that wastewater produced by the metal-plating industry contains several heavy metals, which are acidic in nature and therefore toxic for the environment and for living creatures. In particular, heavy metals enter the food chain and accumulate in vital organs and cause serious illness. The precipitation of these metals is mostly achieved by pH adjustment, but as an alternative to this method, the electrocoagulation process has investigated in this study using iron and aluminum electrodes. The effects of the pH adjustment on removal before and after the electrocoagulation process were investigated, and cost analyses were also compared. It was observed that a high proportion of removal was obtained during the first minutes of the electrocoagulation process; thus, the current density did not have a great effect. In addition, the pH adjustment after the electrocoagulation process using iron electrodes, which are 10% more effective than aluminum electrodes, was found to be much more efficient than before the electrocoagulation process. In the process where kinetic modeling was applied, it was observed that the heavy metal removal mechanism was not solely due to the collapse of heavy metals at high pH values, and with this modeling, it was seen that this mechanism involved adsorption by iron and aluminum hydroxides formed during the electrocoagulation process. When comparing the ability of heavy metals to be adsorbed, the sequence was observed to be Cr>Cu>Ni>Zn, respectively.

关键词： Electrochemical treatment Heavy metals Kinetic modeling Pseudo first order kinetic Pseudo second order kinetic

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热处理数学模型与计算机模拟

潘健生,张伟民,田东,顾剑锋,胡明娟

《中国工程科学》 2003年第5卷第5期页码 47-54

摘要：

热处理计算机模拟是热处理智能化的基础。采用三维非线性有限元模型和界面条件突变的处理方法实现了几种复杂形状零件在复杂的淬火操作过程中温度场、相变、应力和应变的模拟，模拟结果与实测结果基本相符。将气体渗碳的计算机模拟与计算机控制技术相结合，研制成功智能型密封多用炉自动生产线，已处理渗碳件3 000炉次以上，全部合格。计算机模拟技术的应用明显提高渗碳和渗氮零件的承载能力和可靠性，减少热处理变形，缩短渗碳时间。建议将机械产品的CAD、选材与热处理的CAE和产品可靠性的动力评估技术相结合，进行高可靠而又无冗余的产品设计。

关键词：热处理数学模型计算机模拟智能化

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From plasma to plasmonics: toward sustainable and clean water production through membranes

《化学科学与工程前沿（英文）》 2023年第17卷第12期页码 1809-1836 doi: 10.1007/s11705-023-2339-3

摘要： The increasing demand for potable water is never-ending. Freshwater resources are scarce and stress is accumulating on other alternatives. Therefore, new technologies and novel optimization methods are developed for the existing processes. Membrane-based processes are among the most efficient methods for water treatment. Yet, membranes suffer from severe operational problems, namely fouling and temperature polarization. These effects can harm the membrane’s permeability, permeate recovery, and lifetime. To mitigate such effects, membranes can be treated through two techniques: plasma treatment (a surface modification technique), and treatment through the use of plasmonic materials (surface and bulk modification). This article showcases plasma- and plasmonic-based treatments in the context of water desalination/purification. It aims to offer a comprehensive review of the current developments in membrane-based water treatment technologies along with suggested directions to enhance its overall efficiency through careful selection of material and system design. Moreover, basic guidelines and strategies are outlined on the different membrane modification techniques to evaluate its prerequisites. Besides, we discuss the challenges and future developments about these membrane modification methods.

关键词： water treatment membrane-based process plasma treatment plasma polymerization plasmonic light-to-heat conversion

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可锻铸铁多段热处理工艺研究

邹安全,邓沛然,邓芬燕,邓俊彦,陈革英

《中国工程科学》 2005年第7卷第12期页码 74-77

摘要：

基于可锻铸铁的特点，成功开发了可锻铸铁多段加热热处理工艺。该工艺可使可锻铸铁铸件石墨化退火时间节约50%左右，获得了石墨核心多晶粒细小均匀分布，碳化物消除彻底的显微组织；产品综合力学性能超过了现行国际标准的性能指标，在现行国际及ISO5922－81《可锻铸铁》标准的基础上可增加KTH400－12和KTZ750－02两个牌号；经该工艺处理的线路工具、铁路管件、汽车发动机活塞等产品性能良好、质量可靠。

关键词：可锻铸铁渗碳体多段热处理石墨化退火

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UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTION

《农业科学与工程前沿（英文）》 2021年第8卷第2期

摘要：

Seedless fruits are desirable in the citrus fresh fruit market. Triploid production via diploid × tetraploid interploidy crosses is thought to be the most efficient and widely-used strategy for the breeding of seedless citrus. Although ‘Orah’ mandarin has desirable organoleptic qualities, seeds in the fruits weaken its market competitiveness. To produce new seedless cultivars that are similar to ‘Orah’ mandarin, we performed three 2x × 4x crosses using ‘Orah’ mandarin as the seed parent to regenerate triploid plantlets. A total of 182 triploid and 36 tetraploid plantlets were obtained. By analyzing their genetic origins using nine novel single nucleotide polymorphism (SNP) markers, all of the triploids and tetraploids derived from these three crosses were proven to be hybrids. Also, we demonstrated that 2n megagametophyte formation in ‘Orah’ mandarin result in tetraploid production in these three interploidy crosses. These tetraploid plantlets were genotyped using eight pericentromeric SNP markers and nine centromere distal SNP markers. Based on the genotypes of the 2n megagametophytes, the parental heterozygosity rates in 16 SNP loci and all 2n megagametophytes were less than 50%, indicating that second division restitution was the mechanism underlying 2n megagametophyte formation at both the population and individual levels. These triploid hybrids enrich the germplasm available for seedless breeding. Moreover, the tetraploid hybrids are valuable as parents for ploidy breeding for the production of seedless citrus fruits.

关键词： Citrus / 2n gamete / interploidy hybridization / pericentromeric SNP marker / second division restitution

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High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

《结构与土木工程前沿（英文）》 2019年第13卷第2期页码 406-416 doi: 10.1007/s11709-018-0475-5

摘要： We approximate the fracture surface energy functional based on phase-field method with smooth local maximum entropy (LME) and second-order maximum entropy (SME) approximants. The higher-order continuity of the meshfree methods such as LME and SME approximants allows to directly solve the fourth-order phase-field equations without splitting the fourth-order differential equation into two second-order differential equations. We will first show that the crack surface functional can be captured more accurately in the fourth-order model with smooth approximants such as LME, SME and B-spline. Furthermore, smaller length scale parameter is needed for the fourth-order model to approximate the energy functional. We also study SME approximants and drive the formulations. The proposed meshfree fourth-order phase-field formulation show more stable results for SME compared to LME meshfree methods.

关键词： second-order maximum entropy local maximum entropy second- and fourth-order phase-field models B-spline

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材料塑性成形与热处理一体化工程的理论基础

徐祖耀

《中国工程科学》 2004年第6卷第1期页码 16-21

摘要：

材料塑性成形与热处理一体化工程的理论基础，主要为应力—相变—形变间冶金交互作用和力学交互作用的机制、建模以及组织与性能变化的模拟。以钢为例，介绍了应力下铁素体、珠光体相变的文献工作，并提出0.38C-Cr-Mo钢在应力下铁素体形成和珠光体相变的动力学模型以及组织变化的计算机模拟；讨论了Scheil相加性原则的不足及其修正途径；略述应力对钢中贝氏体相变及马氏体相变的影响；简介相场理论及其应用。对材料在应力下相变理论、建模与组织模拟的后续研究工作提出了展望。

关键词：塑性成形—热处理应力下相变相变建模组织模拟 Scheil原则相场理论

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6016铝合金热处理工艺研究

张钧萍,金庆生,马鸣图

《中国工程科学》 2014年第16卷第1期页码 103-107

摘要：

通过硬度测试、力学性能测试和烘烤硬化性能测试，研究了6016 铝合金冷轧板材的热处理工艺，结果表明：合金的硬度随着固溶温度升高和固溶时间延长而增加；合金进行预时效处理时，随着预时效时间的增加硬度出现先降低后升高的现象，且预时效温度越高，硬度下降值越大；在本试验条件下，满足覆盖件性能要求的6016合金的热处理工艺为：540 ℃×20 min固溶水淬+120 ℃×10 min预时效处理。

关键词： 6016 合金固溶处理预时效处理烘烤硬化

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SARS分析、预测、防治决策支持系统探讨

周星宇,张江,刘扬,谢砚青,张然,赵阳,洪岳华,贺仲雄

《中国工程科学》 2005年第7卷第1期页码 69-75

摘要：

提出了一种防御SARS这样的突发疾病的智能决策支持系统。通过运用新的数据分析和决策支持理论，建立智能的决策支持系统，对现有的疫情进行数据噪声分析、灾变趋势预测以及提出科学决策。系统主要分噪声子系统、预测和模拟子系统、诊断子系统以及二次防御子系统4部分。其中预测子系统以FGR系统为原型，综合了传统微分方程的预测方法，以及基于数据的包括神经网络、支持向量机的方法和模糊推理方法的综合信息处理系统，经过该系统的预测分析和模拟可以对可变的突发疫情进行更科学的决策。

关键词： SARS 噪声分析 FGR预测诊治匹配二次防御

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Numerical simulation of sudden-expansion two-phase flows with two-scale second-order moment particle

ZENG Zhuoxiong, HAN Shoulei, ZHOU Lixing

《能源前沿（英文）》 2007年第1卷第2期页码 202-206 doi: 10.1007/s11708-007-0026-6

摘要： A two-scale second-order moment particle turbulence model is developed, based on the concept of particle large-scale fluctuation due to turbulence and particle small-scale fluctuation due to collision. The model is employed to simulate gas-particle flows in a sudden-expansion chamber. Simulation results are compared with the experimental results and with those obtained by the single-scale second-order moment two-phase turbulence model. It is shown that the two-scale model is with higher calculating accuracy than the single-scale model.

关键词： gas-particle single-scale second-order large-scale fluctuation second-order sudden-expansion

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UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTION

Qiangming XIA, Wei WANG, Kaidong XIE, Xiaomeng WU, Xiuxin DENG, Jude W. GROSSER, Wenwu GUO

《农业科学与工程前沿（英文）》页码 302-313 doi: 10.15302/J-FASE-2021385

摘要： Seedless fruits are desirable in the citrus fresh fruit market. Triploid production via diploid × tetraploid interploidy crosses is thought to be the most efficient and widely-used strategy for the breeding of seedless citrus. Although ‘Orah’ mandarin has desirable organoleptic qualities, seeds in the fruits weaken its market competitiveness. To produce new seedless cultivars that are similar to ‘Orah’ mandarin, we performed three 2x × 4x crosses using ‘Orah’ mandarin as the seed parent to regenerate triploid plantlets. A total of 182 triploid and 36 tetraploid plantlets were obtained. By analyzing their genetic origins using nine novel single nucleotide polymorphism (SNP) markers, all of the triploids and tetraploids derived from these three crosses were proven to be hybrids. Also, we demonstrated that 2n megagametophyte formation in ‘Orah’ mandarin result in tetraploid production in these three interploidy crosses. These tetraploid plantlets were genotyped using eight pericentromeric SNP markers and nine centromere distal SNP markers. Based on the genotypes of the 2n megagametophytes, the parental heterozygosity rates in 16 SNP loci and all 2n megagametophytes were less than 50%, indicating that second division restitution was the mechanism underlying 2n megagametophyte formation at both the population and individual levels. These triploid hybrids enrich the germplasm available for seedless breeding. Moreover, the tetraploid hybrids are valuable as parents for ploidy breeding for the production of seedless citrus fruits.

关键词： Citrus 2n gamete interploidy hybridization pericentromeric SNP marker second division restitution

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What should be done for the “second half” of China’s urbanization?

Chunfei WU, Xiaojiang LI, Pengfei LI

《工程管理前沿（英文）》 2018年第5卷第2期页码 276-277 doi: 10.15302/J-FEM-2017106

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Emissions analysis on second generation biodiesel

Yuvarajan Devarajan,Ravi kumar Jayabal,Devanathan Ragupathy,Harish Venu

《环境科学与工程前沿（英文）》 2017年第11卷第1期 doi: 10.1007/s11783-017-0891-0

摘要： CNSBD can be used as a fuel without any modification in existing CI engine. Pentanol reduces HC, CO, NO and Smoke emissions significantly. New and next generation alternative fuel is employed. Blending of CNSBD with pentanol resulted in no separation of phases and found miscible. This work investigates the effect of adding pentanol with biodiesel derived from cashew nut shell on its emissions characteristics is conducted in stationery diesel engine. The main purpose of this work is intended to reduce the emissions by fuelling biodiesel derived from cashew nut shell and the pentanol blends. Cashew nut shell biodiesel is prepared by transesterification process. Oxygenated additive used in the work is Pentanol. The experiment is conducted using four test fuels such as, biodiesel derived from cashew nut shell (CNSBD), a fuel containing 90% cashew nut shell biodiesel and 10% pentanol (CNSBD90P10), a fuel containing 80% cashew nut shell biodiesel and 20% pentanol (CNSBD80P20) and neat diesel. Experimental work concluded that by adding 10% of pentanol to cashew nut shell biodiesel 10.1%, 2.6%, 5.1% and 2.1%reduction in CO, HC, NO and Smoke emissions were observed respectively. Further by fueling with these blends, no modifications in engines were required.

关键词： Pentanol Biodiesel Emissions

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Absorption heat pump for waste heat reuse: current states and future development

Zhenyuan XU, Ruzhu WANG

《能源前沿（英文）》 2017年第11卷第4期页码 414-436 doi: 10.1007/s11708-017-0507-1

摘要： Absorption heat pump attracts increasing attention due to its advantages in low grade thermal energy utilization. It can be applied for waste heat reuse to save energy consumption, reduce environment pollution, and bring considerable economic benefit. In this paper, three important aspects for absorption heat pump for waste heat reuse are reviewed. In the first part, different absorption heat pump cycles are classified and introduced. Absorption heat pumps for heat amplification and absorption heat transformer for temperature upgrading are included. Both basic single effect cycles and advanced cycles for better performance are introduced. In the second part, different working pairs, including the water based working pairs, ammonia based working pairs, alcohol based working pairs, and halogenated hydrocarbon based working pairs, for absorption heat pump are classified based on the refrigerant. In the third part, the applications of the absorption heat pump and absorption heat transformer for waste heat reuse in different industries are introduced. Based on the reviews in the three aspects, essential summary and future perspective are presented at last.

关键词： absorption heat pump heat transformer waste heat working pair