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Design, synthesis, biological activity and density function theory study of pyrazole derivatives containing

Xiaoming Ding, Zhiwen Zhai, Luping Lv, Zhaohui Sun, Xinghai Liu

《化学科学与工程前沿（英文）》 2017年 第11卷 第3期   页码 379-386 doi: 10.1007/s11705-017-1634-2

摘要： A variety of pyrazole derivatives containing 1,3,4-thiadiazole moiety were synthesized under microwave irradiation, and their structures were confirmed by H NMR and HRMS. They were evaluated for herbicidal and antifungal activities, and the results indicated that two compounds with a phenyl group ( ) and 4- -butylphenyl group ( ) possess good herbicidal activity for dicotyledon and with the inhibition of 90% for root and 80%–90% for stalk at 100 ppm respectively. The structure-activity relationship of compounds and was also studied by density function theory method.

关键词： pyrazole     1     3     4-thiadiazole     antifungal activity     herbicidal activity     density function theory    

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frameworks as highly active electrocatalysts for oxygen reduction and oxygen evolution reaction: a densityfunctional theory study

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 570-580 doi: 10.1007/s11705-022-2247-y

摘要： Recently, metal–organic frameworks are one of the potential catalytic materials for electrocatalytic applications. The oxygen reduction reaction and oxygen evolution reaction catalytic activities of heterometallic cluster-based organic frameworks are investigated using density functional theory. Firstly, the catalytic activities of heterometallic clusters are investigated. Among all heterometallic clusters, Fe2Mn–Mn has a minimum overpotential of 0.35 V for oxygen reduction reaction, and Fe2Co–Co possesses the smallest overpotential of 0.32 V for oxygen evolution reaction, respectively 100 and 50 mV lower than those of Pt(111) and RuO2(110) catalysts. The analysis of the potential gap of Fe2M clusters indicates that Fe2Mn, Fe2Co, and Fe2Ni clusters possess good bifunctional catalytic activity. Additionally, the catalytic activity of Fe2Mn and Fe2Co connected through 3,3′,5,5′-azobenzenetetracarboxylate linker to form Fe2M–PCN–Fe2M is explored. Compared with Fe2Mn–PCN–Fe2Mn, Fe2Co–PCN–Fe2Co, and isolated Fe2M clusters, the mixed-metal Fe2Co–PCN–Fe2Mn possesses excellent bifunctional catalytic activity, and the values of potential gap on the Mn and Co sites of Fe2Co–PCN–Fe2Mn are 0.69 and 0.70 V, respectively. Furthermore, the analysis of the electron structure indicates that constructing a mixed-metal cluster can efficiently enhance the electronic properties of the catalyst. In conclusion, the mixed-metal cluster strategy provides a new approach to further design and synthesize high-efficiency bifunctional electrocatalysts.

关键词： bimetallic metal–organic frameworks     bifunctional electrocatalyst     density functional theory     oxygen reduction reaction     oxygen evolution reaction    

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A density functional theory study on the mechanism of Dimethyl ether carbonylation over heteropolyacids

Kai Cai, Ying Li, Hongbao Shen, Zaizhe Cheng, Shouying Huang, Yue Wang, Xinbin Ma

《化学科学与工程前沿（英文）》 2021年 第15卷 第2期   页码 319-329 doi: 10.1007/s11705-020-1957-2

摘要： Dimethyl ether (DME) carbonylation is considered as a key step for a promising route to produce ethanol from syngas. Heteropolyacids (HPAs) are proved to be efficient catalysts for DME carbonylation. In this work, the reaction mechanism of DME carbonylation was studied theoretically by using density functional theory calculations on two typical HPA models (HPW, HSiW). The whole process consists of three stages: DME dissociative adsorption, insertion of CO into methoxyl group and formation of product methyl acetate. The activation barriers of all possible elementary steps, especially two possible paths for CO insertion were calculated to obtain the most favorable reaction mechanism and rate-limiting step. Furthermore, the effect of the acid strength of Brønsted acid sites on reactivity was studied by comparing the activation barriers over HPW and HSiW with different acid strength, which was determined by calculating the deprotonation energy, Mulliken population analyses and adsorption energies of pyridine.

关键词： dimethyl ether     carbonylation     mechanism     heteropolyacids     density functional theory    

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A density functional theory study of the adsorption of Hg and HgCl2 on a CaO(001) surface

GUO Xin, ZHENG Chuguang, LU Nanxia

《能源前沿（英文）》 2007年 第1卷 第1期   页码 101-104 doi: 10.1007/s11708-007-0011-0

摘要： The adsorption of mercury and mercury chloride on a CaO(001) surface was investigated by the density functional theory (DFT) by using CaO cluster embedded in an electrostatic field represented by 178 point charges at the crystal CaO lattice positions. For the mercury molecular axis normal to the surface, the mercury can only coordinate to the O anion and has a very weak binding energy of 19.649 kJ/mol. When the mercury chloride molecular axis is vertical to the surface, the Cl atom coordinates to the Ca cation and has a binding energy of 23.699 kJ/mol. When the mercury chloride molecular axis is parallel to the surface, the Hg atom coordinates to the O anion and has a binding energy of 87.829 kJ/mol, which means that the parallel geometry is more stable than the vertical one. The present calculations show that CaO injection could substantially reduce gaseous mercury chloride, but have no apparent effect on the mercury, which is compatible with the available experimental results. This research will provide valuable information for optimizing and selecting a sorbent for the trace element in flue gas.

关键词： mercury chloride     mercury molecular     surface     cluster     electrostatic    

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A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–H

《化学科学与工程前沿（英文）》 2022年 第16卷 第10期   页码 1485-1492 doi: 10.1007/s11705-022-2169-8

摘要： Methane activation is a pivotal step in the application of natural gas converting into high-value added chemicals via methane steam/dry reforming reactions. Ni element was found to be the most widely used catalyst. In present work, methane activation on MgO supported Ni–M (M = Fe, Co, Cu, Pd, Pt) cluster was explored through detailed density functional theory calculations, compared to pure Ni cluster. CH4 adsorption on Cu promoted Ni cluster requires overcoming an energy of 0.07 eV, indicating that it is slightly endothermic and unfavored to occur, while the adsorption energies of other promoters M (M = Fe, Co, Pd and Pt) are all higher than that of pure Ni cluster. The role of M on the first C–H bond cleavage of CH4 was investigated. Doping elements of the same period in Ni cluster, such as Fe, Co and Cu, for C–H bond activation follows the trend of the decrease of metal atom radius. As a result, Ni–Fe shows the best ability for C–H bond cleavage. In addition, doping the elements of the same family, like Pd and Pt, for CH4 activation is according to the increase of metal atom radius. Consequently, C–H bond activation demands a lower energy barrier on Ni–Pt cluster. To illustrate the adsorptive dissociation behaviors of CH4 at different Ni–M clusters, the Mulliken atomic charge was analyzed. In general, the electron gain of CH4 binding at different Ni–M clusters follows the sequence of Ni–Cu (–0.02 e) < Ni (–0.04 e) < Ni–Pd (–0.08 e) < Ni–Pt (–0.09 e) < Ni–Co (–0.10 e) < Ni–Fe (–0.12 e), and the binding strength between catalysts and CH 4 raises with the CH4 electron gain increasing. This work provides insights into understanding the role of promoter metal M on thermal-catalytic activation of CH4 over Ni/MgO catalysts, and is useful to interpret the reaction at an atomic scale.

关键词： CH4 dissociation     Ni–M     C–H bond activation     charge transfer    

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Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 334-346 doi: 10.1007/s11705-022-2209-4

摘要： The release and control of sulfur species in the pyrolysis of fossil fuels and solid wastes have attracted attention worldwide. Particularly, thiophene derivatives are important intermediates for the sulfur gas release from organic sulfur, but the underlying migration mechanisms remain unclear. Herein, the mechanism of sulfur migration during the release of sulfur-containing radicals in benzothiophene pyrolysis was explored through quantum chemistry modeling. The C1-to-C2 H-transfer has the lowest energy barrier of 269.9 kJ·mol–1 and the highest rate constant at low temperatures, while the elevated temperature is beneficial for C−S bond homolysis. 2-Ethynylbenzenethiol is the key intermediate for the formation of S and SH radicals with the overall energy barriers of 408.0 and 498.7 kJ·mol–1 in favorable pathways. The generation of CS radicals is relatively difficult because of the high energy barrier (551.8 kJ·mol–1). However, it can be significantly promoted by high temperatures, where the rate constant exceeds that for S radical generation above 930 °C. Consequently, the strong competitiveness of S and SH radicals results in abundant H2S during benzothiophene pyrolysis, and the high temperature is more beneficial for CS2 generation from CS radicals. This study lays a foundation for elucidating sulfur migration mechanisms and furthering the development of pyrolysis techniques.

关键词： benzothiophene     sulfur migration     pyrolysis     density functional theory    

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Robust isogeometric topology optimization for piezoelectric actuators with uniform manufacturability

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0683-5

摘要： Piezoelectric actuators have received substantial attention among the industry and academia due to quick responses, such as high output force, high stiffness, high accuracy, and precision. However, the design of piezoelectric actuators always suffers from the emergence of several localized hinges with only one-node connection, which have difficulty satisfying manufacturing and machining requirements (from the over- or under-etching devices). The main purpose of the current paper is to propose a robust isogeometric topology optimization (RITO) method for the design of piezoelectric actuators, which can effectively remove the critical issue induced by one-node connected hinges and simultaneously maintain uniform manufacturability in the optimized topologies. In RITO, the isogeometric analysis replacing the conventional finite element method is applied to compute the unknown electro elastic fields in piezoelectric materials, which can improve numerical accuracy and then enhance iterative stability. The erode–dilate operator is introduced in topology representation to construct the eroded, intermediate, and dilated density distribution functions by non-uniform rational B-splines. Finally, the RITO formulation for the design of piezoelectric materials is developed, and several numerical examples are performed to test the effectiveness and efficiency of the proposed RITO method.

关键词： piezoelectric actuator     isogeometric topology optimization     uniform manufacturability     robust formulation     density distribution function    

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A model for creep life prediction of thin tube using strain energy density as a function of stress triaxiality

Tahir MAHMOOD, Sangarapillai KANAPATHIPILLAI, Mahiuddin CHOWDHURY

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 181-186 doi: 10.1007/s11465-013-0257-7

摘要：

This paper demonstrates the application of a new multiaxial creep damage model developed by authors using stress traixiality to predict the failure time of a component made of 0.5%Cr-0.5%Mo-0.25%V low alloy steel. The model employs strain energy density and assumes that the uniaxial strain energy density of a component can be easily calculated and can be converted to multi-axial strain energy density by multiplying it to a function of stress trixiality which is a ratio of mean stress to equivalent stress. For comparison, an elastic-creep and elastic-plastic-creep finite element analysis (FEA) is performed to get multi-axial strain energy density of the component which is compared with the calculated strain energy density for both cases. The verification and application of the model are demonstrated by applying it to thin tube for which the experimental data are available. The predicted failure times by the model are compared with the experimental results. The results show that the proposed model is capable of predicting failure times of the component made of the above-mentioned material with an accuracy of 4.0%.

关键词： elastic-creep     elastic-plastic-creep     stress triaxiality     life prediction     pressure vessels     finite element analysis (FEA)    

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Role of oxygen vacancy inducer for graphene in graphene-containing anodes

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 326-333 doi: 10.1007/s11705-022-2213-8

摘要： Currently, graphene is only considered as a conductive additive and expansion inhibitor in oxides/graphene composite anodes. In this study, a new graphene role (oxygen vacancy inducer) in graphene/oxides composites anodes, which are treated at high-temperature, is proposed and verified using experiments and density functional theory calculations. During high-temperature processing, graphene forms carbon vacancies due to increased thermal vibration, and the carbon vacancies capture oxygen atoms, facilitating the formation of oxygen vacancies in oxides. Moreover, the induced oxygen vacancy concentrations can be regulated by sintering temperatures, and the behavior is unaffected by oxide crystal structures (crystalline and amorphous) and morphology (size and shape). According to density functional theory calculations and electrochemical measurements, the oxygen vacancies enhance the lithium-ion storage performance. The findings can result in a better understanding of graphene’s roles in graphene/oxide composite anodes, and provide a new method for designing high-performance oxide anodes.

关键词： oxide     oxygen vacancy     graphene     anode     density functional theory calculation    

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Mechanism insight into the formation of HS from thiophene pyrolysis: A theoretical study

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1404-8

摘要：

• Possible formation pathways of H2S were revealed in thiophene pyrolysis.

关键词： Density functional theory     Waste rubber     Thiophene     H2S     Pyrolysis    

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Phosphorus-doped Ni–Co sulfides connected by carbon nanotubes for flexible hybrid supercapacitor

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 491-503 doi: 10.1007/s11705-022-2257-9

摘要： As promising electrode materials for supercapacitors, nickel-cobalt bimetallic sulfides render the advantages of abundant redox reactions and inherently high conductivity. However, in general, unsatisfactory performance of low specific capacity, low rate capability, and fast capacity loss exist in Ni–Co sulfide electrodes. Herein, we rationally regulate phosphorus-doped nickel–cobalt sulfides (P-NCS) to enhance the electrochemical performance by gas–solid phosphorization. Moreover, carbon nanotubes (CNTs) as conductive additives are added to improve the cycle stability and conductivity and form the composite P-NCS/C/CNT. According to density functional theory, more electrons near the Fermi surface of P-NCS are demonstrated notionally than those of simple CoNi2S4. Electrochemical results manifest that P-NCS/C/CNT exhibits superior electrochemical performance, e.g., high specific capacity (932.0 C∙g‒1 at 1 A∙g‒1), remarkable rate capability (capacity retention ratio of 69.1% at 20 A∙g‒1), and lower charge transfer resistance. More importantly, the flexible hybrid asymmetric supercapacitor is assembled using P-NCS/C/CNT and activated carbon, which renders an energy density of 34.875 W·h∙kg‒1 at a power density of 375 W∙kg‒1. These results show that as-prepared P-NCS/C/CNT demonstrates incredible possibility as a battery-type electrode for high-performance supercapacitors.

关键词： cobalt nickel sulfide     phosphorus-doping     hybrid supercapacitor     carbon nanotube     density functional theory    

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Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0836-z

摘要： We studied the heterogeneous reaction mechanism of gaseous HNO with solid NaCl. HCl is released from heterogeneous reactions between gaseous HNO and solid NaCl. Water molecules induce surface reconstruction of NaCl to facilitate the reaction. Sea salt particles containing NaCl are among the most abundant particulate masses in coastal atmosphere. Reactions involving sea salt particles potentially generate Cl radicals, which are released into coastal atmosphere. Cl radicals play an important role in the nitrogen and O cycles, sulfur chemistry and particle formation in the troposphere of the polluted coastal regions. This paper aimed at the heterogeneous reaction between gaseous HNO and solid NaCl. The mechanism was investigated by density functional theory (DFT). The results imply that water molecules induce the surface reconstruction, which is essential for the heterogeneous reaction. The surface reconstruction on the defective (710) surface has a barrier of 10.24 kcal·mol and is endothermic by 9.69 kcal·mol , whereas the reconstruction on the clean (100) surface has a barrier of 18.46 kcal·mol and is endothermic by 12.96 kcal·mol . The surface reconstruction involved in water-adsorbed (710) surface is more energetically favorable. In comparison, water molecules adsorbed on NaCl (100) surface likely undergo water diffusion or desorption. Further, it reveals that the coordination number of the Cl is reduced after the surface reconstruction, which assists Cl to accept the proton from HNO . HCl is released from heterogeneous reactions between gaseous HNO and solid NaCl and can react with OH free radicals to produce atomic Cl radicals. The results will offer further insights into the impact of gaseous HNO on the air quality of the coastal areas.

关键词： Seasalt particles     NaCl     HNO3     Heterogeneous reaction     Reaction mechanism     Density functional theory    

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Regulation of radicals by hydrogen-donor solvent in direct coal liquefaction

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1689-1699 doi: 10.1007/s11705-022-2186-7

摘要： Radicals are important intermediates in direct coal liquefaction. Certain radicals can cause the cleavage of chemical bonds. At high temperatures, radical fragments can be produced by the splitting of large organic molecules, which can break strong chemical bonds through the induction pyrolysis of radicals. The reaction between the formation and annihilation of coal radical fragments and the effect of hydrogen-donor solvents on the radical fragments are discussed in lignite hydrogenolysis. Using the hydroxyl and ether bonds as indicators, the effects of different radicals on the cleavage of chemical bond were investigated employing density functional theory calculations and lignite hydrogenolysis experiments. Results showed that the adjustment of the coal radical fragments could be made by the addition of hydrogen-donor solvents. Results showed that the transition from coal radical fragment to H radical leads to the variation of product distribution. The synergistic mechanism of hydrogen supply and hydrogenolysis of hydrogen-donor solvent was proposed.

关键词： direct coal liquefaction     hydrogen-donor solvent     induced pyrolysis     radical mechanism     density functional theory calculations    

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Optimization of Land-use Based on the Theory of Cellular Automata and Value of Ecosystem Services

Lian-fu Jiang,Guo-xian Xu,Hao Jiang

《工程管理前沿（英文）》 2014年 第1卷 第4期   页码 395-401 doi: 10.15302/J-FEM-2014058

摘要： The main objective of the study was to confirm the location and configuration of “Habitat Conservation Area” in Dongguan City. The land utilization condition in the target city was simulated using Arc GIS and Geo SOS software basing on multi-criteria decision model of Cellular Automata (CA). Both the simulation result and accuracy satisfied well the basic requirements. In addition to multi-criteria decision model, space optimization technique was used as well in simulation experiments.

关键词： Ecosystem service function     optimization of land use     Cellular Automata (CA)    

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Robust control based on the Lyapunov theory of a grid-connected doubly fed induction generator

Ridha CHEIKH, Arezki MENACER, Said DRID

《能源前沿（英文）》 2013年 第7卷 第2期   页码 191-196 doi: 10.1007/s11708-013-0245-y

摘要： This paper discusses the robust control of a grid-connected doubly-fed induction generator (DFIG) controlled by vector control using a nonlinear feedback linearization strategy in order to ameliorate the performances of the control and to govern the developed stator active and reactive power in a linear and decoupled manner, in which an optimal operation of the DFIG in sub-synchronous operation is given, as well as the control stator power flow with the possibility of keeping stator power factor at a unity. The use of the state-all-flux induction machine model gives place to a simpler control model. So, to achieve this objective, the Lyapunov approach is used associated with a sliding mode control to guarantee the global asymptotical stability and the robustness of the parametric variations.

关键词： doubly fed induction generator (DFIG)     vector control     Lyapunov function     power factor unity     active power     reactive power    

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标题 作者 时间 类型 操作

Design, synthesis, biological activity and density function theory study of pyrazole derivatives containing

Xiaoming Ding, Zhiwen Zhai, Luping Lv, Zhaohui Sun, Xinghai Liu

期刊论文

frameworks as highly active electrocatalysts for oxygen reduction and oxygen evolution reaction: a densityfunctional theory study

期刊论文

A density functional theory study on the mechanism of Dimethyl ether carbonylation over heteropolyacids

Kai Cai, Ying Li, Hongbao Shen, Zaizhe Cheng, Shouying Huang, Yue Wang, Xinbin Ma

期刊论文

A density functional theory study of the adsorption of Hg and HgCl2 on a CaO(001) surface

GUO Xin, ZHENG Chuguang, LU Nanxia

期刊论文

A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–H

期刊论文

Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene

期刊论文

Robust isogeometric topology optimization for piezoelectric actuators with uniform manufacturability

期刊论文

A model for creep life prediction of thin tube using strain energy density as a function of stress triaxiality

Tahir MAHMOOD, Sangarapillai KANAPATHIPILLAI, Mahiuddin CHOWDHURY

期刊论文

Role of oxygen vacancy inducer for graphene in graphene-containing anodes

期刊论文

Mechanism insight into the formation of HS from thiophene pyrolysis: A theoretical study

期刊论文

Phosphorus-doped Ni–Co sulfides connected by carbon nanotubes for flexible hybrid supercapacitor

期刊论文

Heterogeneous reaction mechanism of gaseous HNO

Nan ZHAO,Qingzhu ZHANG,Wenxing WANG

期刊论文

Regulation of radicals by hydrogen-donor solvent in direct coal liquefaction

期刊论文

Optimization of Land-use Based on the Theory of Cellular Automata and Value of Ecosystem Services

Lian-fu Jiang,Guo-xian Xu,Hao Jiang

期刊论文

Robust control based on the Lyapunov theory of a grid-connected doubly fed induction generator

Ridha CHEIKH, Arezki MENACER, Said DRID

期刊论文