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A pseudocapacitive molecule-induced strategy to construct flexible high-performance asymmetric supercapacitors

《化学科学与工程前沿（英文）》 2023年 第17卷 第9期   页码 1208-1220 doi: 10.1007/s11705-023-2304-1

摘要： The combination of high-voltage windows and bending stability remains a challenge for supercapacitors. Here, we present an “advantage-complementary strategy” using sodium lignosulfonate as a pseudocapacitive molecule to regulate the spatial stacking pattern of graphene oxide and the interfacial architectures of graphene oxide and polyaniline. Flexible and sustainable sodium lignosulfonate-based electrodes are successfully developed, showing perfect bending stability and high electronic conductivity and specific capacitance (521 F·g−1 at 0.5 A·g–1). Due to the resulting rational interfacial structure and stable ion-electron transport, the asymmetric supercapacitors provide a wide voltage window reaching 1.7 V, outstanding bending stability and high energy-power density of 83.87 Wh·kg–1 at 3.4 kW·kg–1. These properties are superior to other reported cases of asymmetric energy enrichment. The synergistic strategy of sodium lignosulfonate on graphene oxide and polyaniline is undoubtedly beneficial to advance the process for the construction of green flexible supercapacitors with remarkably wide voltage windows and excellent bending stability.

关键词： molecular synergy     pseudocapacitive lignosulfonate     flexible electronic devices     asymmetric supercapacitor     wide voltage windows    

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Tripotassium citrate monohydrate derived carbon nanosheets as a competent assistant to manganese dioxide with remarkable performance in the supercapacitor

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 420-432 doi: 10.1007/s11705-021-2065-7

摘要： Production cost, capacitance, and electrode materials safety are the key factors to be concerned about for supercapacitors. In this work, a type of carbon nanosheets was produced through the carbonization of tripotassium citrate monohydrate and nitric acidification. Subsequently, a well-designed manganese dioxide/carbon nanosheets composite was synthesized through hydrothermal treating. The carbon nanosheets served as the substrate for growing the manganese dioxide, regulating its distribution, and preventing it from inhomogeneous dimensions and severe agglomeration. Many manganese dioxide nanosheets grew vertically on the numerous functional groups generated on the surface of the carbon nanosheets during acidification. The synergistic combination of carbon nanosheets and manganese dioxide tailors the electrochemical performance of the composite, which benefits from the excellent conductivity and stability of carbon nanosheets. The carbon nanosheets derived from tripotassium citrate monohydrate are conducive to the remarkable performance of manganese dioxide/carbon nanosheets electrode. Finally, an asymmetric supercapacitor with active carbon as the cathode and manganese dioxide/carbon nanosheets as the anode was assembled, achieving an outstanding energy density of 54.68 Wh·kg–1 and remarkable power density of 6399.2 W·kg–1 superior to conventional lead-acid batteries. After 10000 charge-discharge cycles, the device retained 75.3% of the initial capacitance, showing good cycle stability. Two assembled asymmetric supercapacitors in series charged for 3 min could power a yellow light emitting diode with an operating voltage of 2 V for 2 min. This study may provide valuable insights for applying carbon materials and manganese dioxide in the energy storage field.

关键词： carbon nanosheets     manganese dioxide     asymmetric supercapacitors     energy density     power density    

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Numerical simulation and experimental research on heat transfer and flow resistance characteristics of asymmetric

Shaozhi ZHANG, Xiao NIU, Yang LI, Guangming CHEN, Xiangguo XU

《能源前沿（英文）》 2020年 第14卷 第2期   页码 267-282 doi: 10.1007/s11708-020-0662-7

摘要： The asymmetric plate heat exchanger (APHE) has the possibility of achieving balanced pressure drops on both hot and cold sides for situations with unbalanced flow, which may in turn enhance the heat transfer. In this paper, the single-phase water flow and heat transfer of an APHE consisted of two types of plates are numerically (400≤ ≤12000) and experimentally (400≤ ≤3400) investigated. The numerical model is verified by the experimental results. Simulations are conducted to study the effects of , an asymmetric index proposed to describe the geometry of APHEs. The correlations of the Nusselt number and friction factor in the APHEs are determined by taking and working fluids into account. It is found that an optimal exists where the pressure drops are balanced and the heat transfer area reaches the minimum. The comparison between heat transfer and flow characteristics of the APHEs and the conventional plate heat exchanger (CPHE) is made under various flow rate ratios of the hot side and the cold side and different allowable pressure drops. The situations under which APHE may perform better are identified based on a comprehensive index .

关键词： plate heat exchanger     asymmetric     simulation     correlation     heat transfer enhancement    

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nanofibers derived from bio-based phenolic resins as free-standing electrodes for high-performance supercapacitors

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 504-515 doi: 10.1007/s11705-022-2260-1

摘要： Phenolic resins were employed to prepare electrospun porous carbon nanofibers with a high specific surface area as free-standing electrodes for high-performance supercapacitors. However, the sustainable development of conventional phenolic resin has been challenged by petroleum-based phenol and formaldehyde. Lignin with abundant phenolic hydroxyl groups is the main non-petroleum resource that can provide renewable aromatic compounds. Hence, lignin, phenol, and furfural were used to synthesize bio-based phenolic resins, and the activated carbon nanofibers were obtained by electrospinning and one-step carbonization activation. Fourier transform infrared and differential scanning calorimetry were used to characterize the structural and thermal properties. The results reveal that the apparent activation energy of the curing reaction is 89.21 kJ·mol–1 and the reaction order is 0.78. The activated carbon nanofibers show a uniform diameter, specific surface area up to 1100 m2·g–1, and total pore volume of 0.62 cm3·g–1. The electrode demonstrates a specific capacitance of 238 F·g–1 (0.1 A·g–1) and good rate capability. The symmetric supercapacitor yields a high energy density of 26.39 W·h·kg–1 at 100 W·kg–1 and an excellent capacitance retention of 98% after 10000 cycles. These results confirm that the activated carbon nanofiber from bio-based phenolic resins can be applied as electrode material for high-performance supercapacitors.

关键词： lignin     bio-based phenolic resins     electrospinning     activated carbon nanofibers     supercapacitors    

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Synthesis of iron(II) complexes with asymmetric N

Wolfgang Bauer, Tanja Ossiander, Birgit Weber

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 400-408 doi: 10.1007/s11705-018-1753-4

摘要：

The synthesis of new Schiff base-like ligands with asymmetric substituents pattern and their iron complexes with pyridine as axial ligand is described. Two of the ligands and one of the iron(II) complexes were characterized by single crystal X-ray structure analysis. One of the the iron(II) complexes shows spin crossover behavior while the others remain in the high spin state. The influence of the reduced symmetry of the ligand on the properties of the complexes is discussed.

关键词： iron     Schiff base-like ligands     magnetism     spin crossover     X-ray structures    

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High-performance supercapacitors based on Ni

Yunrui Tian, Haishun Du, Shatila Sarwar, Wenjie Dong, Yayun Zheng, Shumin Wang, Qingping Guo, Jujie Luo, Xinyu Zhang

《化学科学与工程前沿（英文）》 2021年 第15卷 第4期   页码 1021-1032 doi: 10.1007/s11705-020-2006-x

摘要： We present a one-step route for the preparation of nickel phosphide/carbon nanotube (Ni P@CNT) nanocomposites for supercapacitor applications using a facile, ultrafast (90 s) microwave-based approach. Ni P nanoparticles could grow uniformly on the surface of CNTs under the optimized reaction conditions, namely, a feeding ratio of 30:50:25 for CNT, Ni(NO ) ·6H O, and red phosphorus and a microwave power of 1000 W for 90 s. Our study demonstrated that the single-step microwave synthesis process for creating metal phosphide nanoparticles was faster and simpler than all the other existing methods. Electrochemical results showed that the specific capacitance of the optimal Ni P@CNT-nanocomposite electrode displayed a high specific capacitance of 854 F·g at 1 A·g and a superior capacitance retention of 84% after 5000 cycles at 10 A·g . Finally, an asymmetric supercapacitor was assembled using the nanocomposite with activated carbon as one electrode (Ni P@CNT//AC), which showed a remarkable energy density of 33.5 W·h·kg and a power density of 387.5 W·kg . This work will pave the way for the microwave synthesis of other transition metal phosphide materials for use in energy storage systems.

关键词： Ni2P     CNT     supercapacitors     nanocomposites     microwave    

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Preparation of D-lysine by chemical reaction and microbial asymmetric transformation

LIU Yi, JIAO Qingcai, YIN Xiaoxing

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 40-43 doi: 10.1007/s11705-008-0023-2

摘要： The DL-lysine crystals from the racemization of L-lysine was treated as substrate with AS1.1009 intact cells as biocatalysts to produce crystalline D-lysine with a yield of 56.6% from the reaction mixture after simple purification. In the presence of 0.10 molar equivalent of salicylaldehyde, L-lysine racemization can be completed within 4 h in 1.0 mol/L of NaOH at 100°C. The activation energy of the processes was 62187.86 J/mol. The characteristics of AS1.1009 decarboxylase were studied. Under the conditions of pH 8.0, temperature 37°C, cell concentration 10 g/L, tween-80 0.5 g/L, substrate concentration 30 g/L, and the specific activity of up to 3840 U, L-lysine can be completely degraded by the decarboxylase for 12 h under the optimal conditions.

关键词： substrate     temperature     specific activity     presence     decarboxylase    

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Evaluation of a novel Asymmetric Genetic Algorithm to optimize the structural design of 3D regular and

Mohammad Sadegh ES-HAGHI, Aydin SHISHEGARAN, Timon RABCZUK

《结构与土木工程前沿（英文）》 2020年 第14卷 第5期   页码 1110-1130 doi: 10.1007/s11709-020-0643-2

摘要： We propose a new algorithm, named Asymmetric Genetic Algorithm (AGA), for solving optimization problems of steel frames. The AGA consists of a developed penalty function, which helps to find the best generation of the population. The objective function is to minimize the weight of the whole steel structure under the constraint of ultimate loads defined for structural steel buildings by the American Institute of Steel Construction (AISC). Design variables are the cross-sectional areas of elements (beams and columns) that are selected from the sets of side-flange shape steel sections provided by the AISC. The finite element method (FEM) is utilized for analyzing the behavior of steel frames. A 15-storey three-bay steel planar frame is optimized by AGA in this study, which was previously optimized by algorithms such as Particle Swarm Optimization (PSO), Particle Swarm Optimizer with Passive Congregation (PSOPC), Particle Swarm Ant Colony Optimization (HPSACO), Imperialist Competitive Algorithm (ICA), and Charged System Search (CSS). The results of AGA such as total weight of the structure and number of analyses are compared with the results of these algorithms. AGA performs better in comparison to these algorithms with respect to total weight and number of analyses. In addition, five numerical examples are optimized by AGA, Genetic Algorithm (GA), and optimization modules of SAP2000, and the results of them are compared. The results show that AGA can decrease the time of analyses, the number of analyses, and the total weight of the structure. AGA decreases the total weight of regular and irregular steel frame about 11.1% and 26.4% in comparing with the optimized results of SAP2000, respectively.

关键词： optimization     steel frame     Asymmetric Genetic Algorithm     constraints of ultimate load     constraints of serviceability limits     penalty function    

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nanoflake arrays on cellulose-derived carbon nanofibers as a freestanding electrode for high-performance supercapacitors

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 691-703 doi: 10.1007/s11705-022-2268-6

摘要： Cellulose has a wide range of applications in many fields due to their naturally degradable and low-cost characteristics, but few studies can achieve cellulose-nanofibers by conventional electrospinning. Herein, we demonstrate that the freestanding cellulose-based carbon nanofibers are successfully obtained by a special design of electrospinning firstly, pre-oxidation and high-temperature carbonization (1600 °C), which display a superior electrical conductivity of 31.2 S·cm–1 and larger specific surface area of 35.61 m2·g–1 than that of the polyacrylonitrile-based carbon nanofibers (electrical conductivity of 18.5 S·cm–1, specific surface area of 12 m2·g–1). The NiCo2O4 nanoflake arrays are grown uniformly on the cellulose-based carbon nanofibers successfully by a facile one-step solvothermal and calcination method. The as-prepared cellulose-based carbon nanofibers/NiCo2O4 nanoflake arrays are directly used as electrodes to achieve a high specific capacitance of 1010 F·g–1 at 1 A·g–1 and a good cycling stability with 90.84% capacitance retention after 3000 times at 10 A·g–1. Furthermore, the all-solid-state symmetric supercapacitors assembled from the cellulose-based carbon nanofibers/NiCo2O4 deliver a high energy density of 62 W·h·kg–1 at a power density of 1200 W·kg–1. Six all-solid-state symmetric supercapacitors in series can also power a ‘DHU’ logo consisted of 36 light emitting diodes, confirming that the cellulose-based carbon nanofiber is a promising carbon matrix material for energy storage devices.

关键词： cellulose     carbon nanofibers     NiCo2O4     supercapacitors    

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Preparation and characterization of asymmetric ultrafiltration membrane for effective recovery of proteases

Nora’aini ALI, Fadhilati HASSAN, Sofiah HAMZAH

《化学科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 184-191 doi: 10.1007/s11705-012-1288-z

摘要： The wash water generated from the surimi processing industry contains a large amount of proteases which are widely used in the food and biotechnology industries. Asymmetric polysulfone and polyethersulfone ultrafiltration (PSf-UF and PES-UF) membranes with three different polymer concentrations were screened for their abilities to recover proteases from surimi wash water. In-house fabricated membranes were prepared via a simple dry/wet phase inversion technique and were characterized in terms of permeability coefficient, membrane morphology and molecular weight cut-off (MWCO). The ability of the UF membranes to remove commercial proteases was tested at various pressures (up to 10 bars). The membrane with the best performance, 15 wt-% PSf-UF, was further tested with actual surimi wash water. The effect of the pH of the feed solution (4 to 8) in the pre-treatment stage was also evaluated to recover the highest amount of proteases. The highest retention of protease was 96% with a flux of 25.6 L/(m ·h) which was achieved with the 15 wt-% PSf-UF membrane.

关键词： membrane     ultrafiltration     proteases     surimi wash water    

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Size-controllable synthesis of monodispersed nitrogen-doped carbon nanospheres from polydopamine for high-rate supercapacitors

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1788-1800 doi: 10.1007/s11705-023-2326-8

摘要： Monodispersed nitrogen-doped carbon nanospheres with tunable particle size (100–230 nm) were synthesized via self-polymerization of biochemical dopamine in the presence of hexamethylenetetramine as a buffer and F127 as a size controlling agent. Hexamethylenetetramine can mildly release NH3, which in turn initiates the polymerization reaction of dopamine. The carbon nanospheres obtained exhibited a significant energy storage capability of 265 F·g–1 at 0.5 A·g–1 and high-rate performance of 82% in 6 mol·L–1 KOH (20 A·g–1), which could be attributed to the presence of abundant micro-mesoporous structure, doped nitrogen functional groups and the small particle size. Moreover, the fabricated symmetric supercapacitor device displayed a high stability of 94% after 5000 cycles, revealing the considerable potential of carbon nanospheres as electrode materials for energy storage.

关键词： carbon nanospheres     size-controlled     nitrogen-doped     high-rate     supercapacitors    

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Isolation of microbe for asymmetric reduction of prochiral aromatic ketone and its reaction characters

YANG Zhonghua, WANG Yu, WANG Guanghui, ZENG Rong, YAO Shanjing

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 416-420 doi: 10.1007/s11705-007-0076-7

摘要： The favorable microbes for the asymmetric reduction of prochiral aromatic ketones was isolated from soil using acetophenone as the sole carbon source, when the asymmetric reduction of acetophenone (ACP) to chiral ?-phenethyl alcohol (PEA) was chosen as the model reaction. Two microbe strains with excellent catalytic activity were obtained. They were and identified by bacteria identification. The product of the asymmetric reduction of ACP catalyzed by was mainly R-PEA and that by was mainly S-PEA. The yield and enantiomeric excesses (e.e.) could respectively reach 75% and 90% for , and 80% and 70% for , much higher than those catalyzed by baker s yeast.

关键词： excellent catalytic     prochiral aromatic     enantiomeric     -phenethyl     catalytic activity    

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大屯矿区深部软岩巷道非对称变形机理及控制对策研究

傅清国,邹朝阳

《中国工程科学》 2011年 第13卷 第11期   页码 102-106

摘要：

通过对孔庄矿工程地质情况调查与分析，结合室内岩石力学实验，运用三维数值模拟方法，研究巷道非对称变形时周围岩体的位移场分布规律，分析巷道推进到上部工作面下方时的应力分布规律。理论研究结果表明，孔庄矿－785 m水平轨道大巷非对称变形主要受其上部采空区煤柱的集中压力控制，黏土矿物遇水膨胀、岩层结构及高地应力作用进一步恶化了巷道围岩结构。该研究可为孔庄矿深部巷道非对称变形控制对策提供初步的理论依据。

关键词： 深部     软岩巷道     非对称变形     控制对策    

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Hierarchical porous carbon derived from one-step self-activation of zinc gluconate for symmetric supercapacitors

《化学科学与工程前沿（英文）》 2023年 第17卷 第4期   页码 387-394 doi: 10.1007/s11705-022-2250-3

摘要： Porous carbons with high specific area surfaces are promising electrode materials for supercapacitors. However, their production usually involves complex, time-consuming, and corrosive processes. Hence, a straightforward and effective strategy is presented for producing highly porous carbons via a self-activation procedure utilizing zinc gluconate as the precursor. The volatile nature of zinc at high temperatures gives the carbons a large specific surface area and an abundance of mesopores, which avoids the use of additional activators and templates. Consequently, the obtained porous carbon electrode delivers a satisfactory specific capacitance and outstanding cycling durability of 90.9% after 50000 cycles at 10 A∙g–1. The symmetric supercapacitors assembled by the optimal electrodes exhibit an acceptable rate capability and a distinguished cycling stability in both aqueous and ionic liquid electrolytes. Accordingly, capacitance retention rates of 77.8% and 85.7% are achieved after 50000 cycles in aqueous alkaline electrolyte and 10000 cycles in ionic liquid electrolyte. Moreover, the symmetric supercapacitors deliver high energy/power densities of 49.8 W∙h∙kg–1/2477.8 W∙kg–1 in the Et4NBF4 electrolyte, outperforming the majority of previously reported porous carbon-based symmetric supercapacitors in ionic liquid electrolytes.

关键词： self-activation     zinc organic salts     abundant mesopores     symmetric supercapacitor     liquid electrolyte    

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Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 251-255 doi: 10.1007/s11705-007-0045-1

摘要： A heterogeneous chiral catalyst Fe(III)-CS (chitosan) complex/mesoporous molecular sieve SBA-15 (Santa Barbara Amorphous) was prepared. The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor. Effects of Fe content in catalyst, reaction temperature, reaction time and promoter KOH concentration on the conversion of substrates and enantioselectivity were investigated. Fe-CS/SBA-15 with 2.2% mass fraction Fe exhibits considerable enantioselectivity and catalytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone. Under optimal reaction conditions: KOH concentration 0.03 mol/L, reaction temperature 70ºC and reaction time 4 h, enantiomer excess (ee) of ()-1-phenylethanol and conversion of acetophenone can reach 87.4% and 27.7%, respectively. Under the above KOH concentration and reaction temperature and reaction time of 8 h, the ee of ()-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2% and 25.5%, respectively.

关键词： asymmetric transfer     enantioselectivity     Fe-CS/SBA-15     aliphatic     aromatic    

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标题 作者 时间 类型 操作

A pseudocapacitive molecule-induced strategy to construct flexible high-performance asymmetric supercapacitors

期刊论文

Tripotassium citrate monohydrate derived carbon nanosheets as a competent assistant to manganese dioxide with remarkable performance in the supercapacitor

期刊论文

Numerical simulation and experimental research on heat transfer and flow resistance characteristics of asymmetric

Shaozhi ZHANG, Xiao NIU, Yang LI, Guangming CHEN, Xiangguo XU

期刊论文

nanofibers derived from bio-based phenolic resins as free-standing electrodes for high-performance supercapacitors

期刊论文

Synthesis of iron(II) complexes with asymmetric N

Wolfgang Bauer, Tanja Ossiander, Birgit Weber

期刊论文

High-performance supercapacitors based on Ni

Yunrui Tian, Haishun Du, Shatila Sarwar, Wenjie Dong, Yayun Zheng, Shumin Wang, Qingping Guo, Jujie Luo, Xinyu Zhang

期刊论文

Preparation of D-lysine by chemical reaction and microbial asymmetric transformation

LIU Yi, JIAO Qingcai, YIN Xiaoxing

期刊论文

Evaluation of a novel Asymmetric Genetic Algorithm to optimize the structural design of 3D regular and

Mohammad Sadegh ES-HAGHI, Aydin SHISHEGARAN, Timon RABCZUK

期刊论文

nanoflake arrays on cellulose-derived carbon nanofibers as a freestanding electrode for high-performance supercapacitors

期刊论文

Preparation and characterization of asymmetric ultrafiltration membrane for effective recovery of proteases

Nora’aini ALI, Fadhilati HASSAN, Sofiah HAMZAH

期刊论文

Size-controllable synthesis of monodispersed nitrogen-doped carbon nanospheres from polydopamine for high-rate supercapacitors

期刊论文

Isolation of microbe for asymmetric reduction of prochiral aromatic ketone and its reaction characters

YANG Zhonghua, WANG Yu, WANG Guanghui, ZENG Rong, YAO Shanjing

期刊论文

大屯矿区深部软岩巷道非对称变形机理及控制对策研究

傅清国,邹朝阳

期刊论文

Hierarchical porous carbon derived from one-step self-activation of zinc gluconate for symmetric supercapacitors

期刊论文

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

期刊论文