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Exact Fixed-node Quantum Monte Carlo: Self-optimizing Procedure

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Chinese Journal of Chemistry 2003年第9期21卷 1118-1122页

作者：黄宏新 college of Chemistry and chemical technology Hunan Normal University Changsha Hunan 410081 China

In this paper, a novel exact fixed-node quantum Monte Carlo (EFNQMC) algorithm was proposed, which is a self-optimizing and self-improving procedure. In contrast to the previous EFNQMC method, the importance function of this method is optimized synchronistically in the diffusion procedure, but not before beginning the EFNQMC computation. In order to optimize the importance function, the improved steepest descent technique is used, in which the step size is automatically adjustable. The procedure is quasi-Newton type and converges super linearly. The present method also uses a novel trial function, which has correct electron-electron and electron-nucleus cusp conditions. The novel EFNQMC algorithm and the novel trial function are employed to calculate the energies of 1 1A 1 state of CH 2, 1A g state of C 8 and the ground-states of H 2, LiH, Li 2 and H 2O.

关键词： exact fixed-node quantum Monte Carlo method electronic correlation energy self-optimizing procedure

2D SnOx/SnS2的异质结构的忆阻器用于神经形态计算（英文）

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Science China Materials 2025年

作者：吴扬武李思凡季云翁正进邢厚英 Lester Arauz Travis Hu 洪金华 Kah-Wee Ang 刘松 State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University Department of Electrical and Computer Engineering National University of Singapore Joint International Research Laboratory of Information Display and Visualization School of Electronic Science and Engineering Southeast University Department of Mechanical Engineering California State University Los Angeles 5151 State University Dr college of Materials Science and Engineering Hunan University Shenzhen Research Institute Hunan University

层状金属二硫化物（LMDs）神经形态忆阻器为解决传统冯·诺依曼架构在速度和能效上的限制,提供了一个有前景的替代方案.然而由于环境稳定性,晶体LMDs忆阻器的阻变行为和操作电压仍面临挑战,这阻碍了神经网络硬件的开发.在此,我们通过臭...

层状金属二硫化物（LMDs）神经形态忆阻器为解决传统冯·诺依曼架构在速度和能效上的限制,提供了一个有前景的替代方案.然而由于环境稳定性,晶体LMDs忆阻器的阻变行为和操作电压仍面临挑战,这阻碍了神经网络硬件的开发.在此,我们通过臭氧处理控制氧化制备了SnOx/SnS2阻变层,优化了其阻变操作特性.该忆阻器表现出低的开关电压（～1 V）、快的开关速度（～20 ns）、高的开关比（10～2）,并具备模拟突触权重可塑性的能力.通过截面透射电子显微镜和X射线光谱等手段的分析,探测到了阻变开关层中的缺陷和Ti导电丝,这有助于实现均匀开关并减少操作可变性.此外,SnOx/SnS2忆阻器在MNIST手写识别中实现了90%的准确率,并成功地实现了基于忆阻器的图像卷积,展示了SnOx/SnS2忆阻器在神经形态应用中的潜力.

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Properties of electrodeposited amorphous Fe-Ni-W alloy deposits

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Transactions of Nonferrous Metals Society of China 2006年第6期7卷 1289-1294页

作者：何凤姣王淼陆欣 college of Chemistry and chemical Engineering Hunan University Yingcai technology Co.Ltd

A new technique of electroplating amorphous Fe-Ni-W alloy deposits was *** structure and morphology o Fe-Ni-W alloy deposit were detected by XRD and *** friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium *** corrosion properties against 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide were also *** experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wea than hard chromium deposits under dry sliding *** oil sliding condition,except their better wear resistance,the deposits can protect their counterparts against *** deposits plated on brass and AISI 1045 steel show good behavior against corrosion o 5% sodium chloride,5% sulfuric acid and 5% sodium *** bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.

关键词： electrodeposition amorphous Fe-Ni-W alloy deposits wear resistance corrosion resistance

Synthesis and Characterization of a Novel Ionic Liquid Polymer: Poly(1-(3-aminobenzyl)-3-methylimidazolium chloride)

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Chinese Journal of Polymer Science 2014年第2期32卷 163-168页

作者：何德良 Fei Li San-bao Xia Fu-rong Liu Ying Xiong 张泉 college of Chemistry and chemical Engineering Hunan University college of Civil Engineering Hunan University

A new type of polymerizable ionic liquid （IL） 1-（3-aminobenzyl）-3-methylimidazolium chloride （AMIC） was synthesized to obtain a novel polymer salt poly（1-（3-aminobenzyl）-3-methylimidazolium chloride）（PAMIC）. The AMIC was structurally characterized by mass spectrometry and Fourier transform infrared spectrometry （FTIR）. The structure, morphology and properties of PAMIC were investigated by FTIR, ultraviolet visible absorption spectra （UV-Vis）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDX）, conductivity measurement and thermo- gravimetric analysis （TGA）. The PAMIC was spherulitic with an average diameter of about 50 nm and showed high conductivity and excellent thermal stability.

关键词： Ionic liquid 1-(3-Aminobenzyl)-3-methylimidazolium chloride Polymerization Poly(1-(3-aminobenzyl)-3- methylimidazolium chloride).

Method for triangular fuzzy multiple attribute decision making based on two-dimensional density operator method

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Journal of Systems Engineering and Electronics 2024年第1期35卷 178-185页

作者： LIN Youliang LI Wu LIU Gang HUANG Dong School of Economics and Management Hunan Institute of Science and TechnologyYueyang 414000China hunan vocational college for Nationalities Yueyang 414000China School of Information Science and Engineering Hunan Institute of Science and TechnologyYueyang 414000China

Aiming at the triangular fuzzy(TF)multi-attribute decision making(MADM)problem with a preference for the distribution density of attribute(DDA),a decision making method with TF number two-dimensional density(TFTD)operator is proposed based on the density operator theory for the decision maker(DM).Firstly,a simple TF vector clustering method is proposed,which considers the feature of TF number and the geometric distance of ***,the least deviation sum of squares method is used in the program model to obtain the density weight ***,two TFTD operators are defined,and the MADM method based on the TFTD operator is ***,a numerical example is given to illustrate the superiority of this method,which can not only solve the TF MADM problem with a preference for the DDA but also help the DM make an overall comparison.

关键词： fuzzy decision making clustering density operator multi-attribute decision making(MADM)

Preparation and photocatalytic performance of ZnO/ZnGa_2O_4 composite microspheres

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Journal of Central South University 2016年第12期23卷 3092-3099页

作者：张丽戴超华张秀秀刘又年阎建辉 college of Chemistry and chemical Engineering Hunan Institute of Science and Technology college of chemical Engineering Xiangtan University School of Chemistry and chemical Engineering Central South University

ZnO/ZnGa_2O_4 composite microspheres with heterojunction were successfully synthesized by one-pot hydrothermal *** samples were characterized by TG/DTA,XRD,TEM,HRTEM,UV-vis DRS,FL and BET *** results indicated the as-prepared samples showed better degree of crystalline and large specific surface *** photocatalytic activity was evaluated by degradation of methyl orange with the concentration of 50 mg/L under the irradiation of simulated *** effects of molar ratio of Zn to Ga and calcination temperature on the photocatalytic activity were investigated in *** results showed that the highest photocatalytic degradation efficiency was observed at the molar ratio of Zn to Ga of 1:0.5 in the starting materials and the calcination temperature of 400 °*** maximum photocatalytic degradation rate of MO was 97.1% within 60 min under the simulated sunlight irradiation,which is greatly higher than that of ZnO and ZnGa_2O_4.

关键词： ZnO/ZnGa2O4 photocatalytic performance microspheres simulated sunlight

Enantioselective extraction of clorprenaline enantiomers with hydrophilic selector of sulfobutylether-β-cyclodextrin by experiment and modeling

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Journal of Central South University 2014年第3期21卷 891-899页

作者：周丛山徐萍唐课文蒋新宇杨涛张盼良朱政 college of Chemistry and chemical Engineering Hunan Institute of Science and Technology college of Chemistry and chemical Engineering Central South University

Enantioselective extraction of hydrophobic clorprenaline （CPE） enantiomers from organic phase to aqueous phases with sulfobutylether-β-cyclodextrin （SBE-β-CD） as the selector was investigated with insight into a number of important process variables, such as the type of organic solvent, concentration of selector, pH, and temperature. Equilibrium of the extraction system was modeled using a reactive extraction modcl with a homogeneous aqueous phase reaction. The important parameters of this model were determined experimentally. The physical distribution coefficients for molecular and ionic CPE were determined as 0.3 and 8.93, respectively. The equilibrium constants of the complexation reaction with SBE-β-CD were determined as 152 and 110 L/mol for R- and S-CPE, respectively. Results show that the experimental data agree with the model predictions perfectly. Comprehensively considering the experiment and model, the extraction conditions are optimized and the best extraction conditions are： pH of 6.0, SBE-β-CD concentration of 0.04 tool/L, and temperature of 5 ℃, providing the enantioselectivity （a） of 1.25, the fraction of R-CPE （φR） in aqueous phase of 0.71 and performance factor （pf） of 0.025.

关键词： clorprenaline sulfobutylether-fl-cyclodextrin reactive extraction chiral recognition modeling

Mild and highly efficient transfer hydrogenation of aldehyde and ketone catalyzed by rubidium phosphate

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Journal of Central South University 2016年第7期23卷 1603-1610页

作者：黄云敬阳卫军秦明高赵昊良 college of Chemistry and chemical Engineering Hunan University

Rubidium phosphate can be more conveniently obtained by extracting trace Rb+ from the salt lake brine. Rb_3PO_4 was found to be an excellent heterogeneous catalyst for transfer hydrogenation. Rb_3PO_4 lost 70% of its active sites after adsorbing water, but the remaining was not affected. The reductions of aldehydes and ketones, when promoted by Rb_3PO_4, were allowed at room temperature. The activities of substrates at room temperature followed a descending order of 2,6-dichlorobenzaldehyde> 4-bromobenzaldehyde>benzaldehyde>acetophenone>anisaldehyde>butanone. A new catalytic cycle postulating a six-membered cyclic transition state for the reductions of aldehydes and ketones was proposed. These results exploited the catalytic usage of Rb_3PO_4 and worth in industrial application.

关键词： rubidium phosphate transfer hydrogenation heterogeneous catalysis cyclic transition state

Carbon-supported Fe/Co-N electrocatalysts synthesized through heat treatment of Fe/Co-doped polypyrrole-polyaniline composites for oxygen reduction reaction

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Science China Chemistry 2014年第5期57卷 739-747页

作者： YI QingFeng ZHANG YuHui LIU XiaoPing YANG YaHui School of Chemistry and chemical Engineering Hunan University of Science and Technology college of Resource and Environment Hunan Agricultural University

In this paper,we synthesized cathode catalysts(PANI-PPYR,Fe/PANI-PPYR,Co/PANI-PPYR and Fe-Co/PANI-PPYR)with high performance oxygen reduction by using a simple heat treatment *** catalysts were fabricated by directly calcining the Fe and/or Co doped polyaniline(PANI)-polypyrrole(PPYR)*** electrocatalytic activity for ORR both in acidic and in alkaline media was investigated by voltammetric *** the prepared catalysts,Co/PANI-PPYR presents the most positive ORR onset potential of 0.62 V(***)in 0.5 mol/L H2SO4 solution or?0.09 V(***)in 1 mol/L NaOH *** addition,the Co/PANI-PPYR catalyst shows the largest limiting-diffusion current density for ORR,which is 4.3 mA/cm2@0.2 V(***)in acidic and 2.3 mA/cm2@?0.3 V(***)in alkaline *** acidic media,a four-electron reaction of ORR on the Co/PANI-PPYR and Fe/PANI-PPYR catalysts is more dominant than a two-electron *** alkaline media,however,a four-electron and a two-electron mechanisms are co-present for the ORR on all the prepared ***/PANI-PPYR catalyst also presents good electrocatalytic activity stability for ORR both in acidic and in alkaline media.

关键词： oxygen reduction reaction polyaniline polypyrrole fuel cells