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Chemical constituents from the leaves of Cerbera manghas

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Asian Pacific Journal of Tropical Medicine 2010年第2期3卷 109-111页

作者： Zhang Xiao-po pei yue-hu Liu Ming-sheng Kang Sheng-li Zhang Jun-qing Department of Pharmacy Hainan Medical College School of Traditional Chinese Materia Media Shenyang Pharmaceutical University Hainan Provincial Institute of South China Medicine and Li Nationality Medicine

Objective:To study the chemical constituents in leaves of Cebera ***:Chemical constituents were isolated by using various column chromatography and tho structures were elucidated on basis of physicochemical constants and spectral data ***:Nine compounds were obtained including p-hydroxybenzaldehyde(1),benzamide(2),n-hexadecane acid monoglyceride(3),loliolide(4),β-sitosterol(5),cerberin(6),neriifolin(7),cerleaside A(8), daucosterol(9).Conclusions:Compounds 1-4 are obtained from this genus for the first time.

关键词： Cerbera manghas L. Li Nationality Medicine Chemical constituents

Modification of Carbon Nanotube Powder Microelectrode and Nitrite Reduction

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Chinese Chemical Letters 2002年第1期13卷 79-82页

作者： pei Fang LIU Jun Fu hu Department of Chemistry Wuhan UniversityWuhan 430072

The properties of the carbon nanotube powder microelectrodes (denoted CNTPME) are remarkably altered by anodic pretreatment and preadsorption of mediators. It seems that anodic pretreatment leads the long and tangled carbon nanotubes to be partially cut shorter, resulting in more openings as shown by TEM. Besides, the anodic pretreatment may adjust the hydrophobicity of nanotubes to match with that of Os(bpy)32+. As a result, the real surface area and the ability of adsorbing mediator Os(bpy)32+ of the nanotubes are markedly increased so as to effectively catalyze NO2- reduction in acidic solution.

关键词： Carbon nanotube powder microelectrode nitrite reduction modified electrode.

First principles study of Fenton reaction catalyzed by FeOCl:reaction mechanism and location of active site

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Rare Metals 2019年第8期38卷 783-792页

作者： Xuan-Xuan Ji Hai-Feng Wang pei-Jun hu Key Laboratory for Advanced Materials Research Institute of Industrial Catalysis and Centre for Computational Chemistry School of Chemical and Molecular Engineering East China University of Science and Technology Shanghai 200237 China School of Chemistry and Chemical Engineering The Queen’s University of Belfast Belfast BT9 5AZ UK

Fe-based solid catalysts in promoting Fenton reaction to generate ·OH radical has drawn much attention,and interestingly,FeOCl was reported to have superior activity compared with the traditional Fe2 O3 ***,the mechanism of Fenton reaction on FeOCl and the origin of high activity remain ***,by virtue of DFT+ U calculations,the H2 O2 decomposition and conversion mechanism on FeOCl(100)surface were systematically *** is found that on clean FeOCl(100)surface,the exposed[Fe^3+-Fe^3+]sites can hardly break O-O bond of H2 O2 into OH groups,but instead H2 O2 tends to dehydrogenate by the surface lattice O,resulting in a series of side reactions and final conversion into O2,while the left H atoms gradually saturate the surface lattice O and reduce Fe^3+ into Fe^2+.On fully H-covered FeOCl(100),H2O2 can efficiently dissociate at[Fe^2+-Fe^2+]sites into two OH,but OH binds with Fe^2+ so strongly that it cannot desorb as OH radical as easily as that on Fe^3+.Interestingly,FeOCl(100)tends to be partially protonated in the real acid solution,which,along with H2 O2 dehydrogenation,results in the formation of active unit [Fe^2+-Fe^3+].On[Fe^2+-Fe^3+]unit,H2 O2 can easily break its O-O bond and OH at Fe3+ can desorb as OH radical,while the other OH at Fe^2+ couples with the surface H into H2O and finish the catalytic *** comparison,Fe2 O3(012)cannot provide enough [Fe^2+-Fe^3+] active units due to the relative difficulty in H2 O2 dehydrogenation,which accounts for its inferior catalytic efficiency for Fenton reaction.

关键词： Fenton reaction FeOCl Density functional theory H2O2 Active site

Equitable Presentations for Multiparameter Quantum Groups

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Acta Mathematica Sinica,English Series 2021年第10期37卷 1560-1572页

作者： Nai Hong hu Yu Feng pei Jiao ZHANG School of Mathematical Sciences SKLPMMPEast China Normal UniversityShanghai 200241P.R.China Department of Mathematics Shanghai Normal UniversityShanghai 200234P.R.China Department of Mathematics Shanghai UniversityShanghai 200444P.R.China

In this paper, we give an equitable presentation for the multiparameter quantum group associated to a symmetrizable Kac–Moody Lie algebra, which can be regarded as a natural generalization of the Terwilliger's equita... 详细信息

关键词： Quantum groups equitable presentation Hopf algebras

Tf_2O-TMDS combination for the direct reductive transformation of secondary amides to aldimines,aldehydes, and/or amines

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Science China Chemistry 2016年第12期59卷 1638-1644页

作者： Qi-Wei Lang Xiu-Ning hu pei-Qiang huang Department of Chemistry Fujian Provincial Key Laboratory of Chemical Biology Collaborative Innovation Center of Chemistry for Energy Materials College of Chemistry and Chemical Engineering Xiamen University

The direct partial reduction of highly stable secondary amides to more reactive aldimines and aldehydes is a challenging yet highly demanding transformation. In this context, only three methods have been reported. We report herein an improved version of the Charette's method. Our protocol consists of activation of secondary amides with triflic anhydride/2-fluoropyridine,and partial reduction of the resulting intermediates with 1,1,3,3-tetramethyldisiloxane(TMDS), which delivered aldimines or aldehydes upon acidic hydrolysis. Aromatic amides were reduced to the corresponding aldimines in 85%–100% NMR yields,and yields(NMR) from aliphatic amides were 72%–86%. Acidic hydrolysis of the aldimine intermediates afforded, in one-pot,the corresponding aldehydes in 80%–96% yields. A simple protocol was established to isolate labile aldimines in pure form in92%–96% yields. The improved method gave generally higher yields as compared to the known ones, and features the use of cheaper and more atom-economical TMDS as a chemoselective reducing agent. In addition, a convenient extraction protocol has been established to allow the isolation of amines, which constitutes a mild method for the N-deacylation of amides, another highly desirable transformation. The extended method retains the advantages of the original method of Charette in terms of mild conditions, good functional group tolerance, and excellent chemoselectivity.

关键词： secondary amides amide activation partial reduction aldimines N-deacylation

Injury Morbidity between 2013 and 2018 in hunan Province,China

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Biomedical and Environmental Sciences 2022年第3期35卷 263-269页

作者： WANG Wan hui GAO De yue huA Jun Jie NING pei Shan SCHWEBEL David C hu Guo Qing Department of Epidemiology and Health Statistics Hunan Provincial Key Laboratory of Clinical EpidemiologyXiangya School of Public HealthCentral South UniversityChangsha 410083HunanChina Shanxi Bethune Hospital Taiyuan 030032ShanxiChina Department of Psychology University of Alabama at BirminghamBirminghamAlabama35294United States of America

Accurate and timely injury statistics are critical to assess the severity of public health *** statistics allow researchers,practitioners,and policymakers to determine morbidity and mortality rate disparities across s... 详细信息

关键词： hunan problems. policy

Electrochemical oxygen evolution reaction efficiently boosted by selective fluoridation of FeNi3 alloy/oxide hybrid

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Journal of Energy Chemistry 2020年第8期29卷 166-171,I0006页

作者： Meng Zha Chengang pei Quan Wang Guangzhi hu Ligang Feng Key Laboratory of Medicinal Chemistry for Natural Resource(Yunnan University) Ministry of EducationSchool of Chemical Science and EngineeringYunnan UniversityKunming 650091YunnanChina School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002JiangsuChina

Performance boosting of hybrid metal oxide and metal alloy catalyst is crucial to the water electrolysis for hydrogen generation. Herein, a novel concept of selective fluoridation of metal alloy/oxide hybrid is proposed to boost their catalytic performance for the oxygen evolution reaction(OER). A well-recognized OER catalyst system of FeNi3 alloy/oxide embedded in nitrogen-doped porous nanofibers(FeNiO/NCF) is employed as a proof of concept, and it is selectively fluoridated by transforming the metal oxide to metal fluoride(FeNiF/NCF). The crystal structure and surface chemical state transformation are well supported by the spectroscopic analysis and the improved electrochemical performance for OER can be well correlated to the phase and structure change. Specifically, FeNiF/NCF can drive the benchmark current density of 10 mA cm-2 at 260 mV with a Tafel slope of 67 mV dec-1, about 70 mV less than that of FeNiO/*** catalytic kinetics, rapid charge transfer ability, high catalytic efficiency and stability are also probed by electrochemical analysis. The high surface area and roughness are found mainly generated via the high-temperature annealing for the metal alloy/metal oxide formation, and the low-temperature fluoridation process intrinsically contributes to the active structure formation. It is an efficient and universal approach to increase the catalytic performance of metal alloy/oxide for energy-relevant catalytic reactions.

关键词： Oxygen evolution reaction Water splitting FeNi Metal oxide Metal fluoride

Privacy Preserving Algorithm for Spectrum Sensing in Cognitive Vehicle Networks

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Chinese Journal of Electronics 2024年第1期33卷 30-42页

作者： Hongning LI Tonghui hu Jiexiong CHEN Xiuqiang WU Qingqi pei Guangzhou Institute of Technology Xidian University Guangzhou CEPREI Shaanxi Key Laboratory of Blockchain and Secure Computing

The scarcity of spectrum resources fails to meet the increasing throughput demands of vehicular networks. There is an urgent need to maximize the utilization of spectrum bands in mobile networks. To ascertain the availability of spectrum bands, users should engage in wireless channel sensing and collaboration. However, spectrum sensing data always involves users’ privacy, such as their location. This paper first introduces sensing trajectory inference attack in cognitive vehicular networks and then proposes a data confusion-based privacy-preserving algorithm and a cryptonym array-based privacy-preserving aggregation scheme for spectrum sensing in cognitive vehicular networks. Unlike existing methods, the proposed schemes transmit confused data during the aggregation process. This deliberate obfuscation makes it almost impossible to infer users’ location from the transmitted data. The analysis demonstrates the resilience of the proposed schemes against sensing trajectory inference attack.

关键词： Privacy Data privacy Wireless sensor networks Authentication Data aggregation Throughput Inference algorithms

Influence of cutterhead opening ratio on soil arching effect and face stability during tunnelling through non-uniform soils

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Underground Space 2024年第4期17卷 45-59页

作者： Xue-Jian Chen pei-pei Fang Qiu-Nan Chen Jun hu Kai Yao Yong Liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China hubei Technology Innovation Center for Smart Hydropower Wuhan 430000China College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China School of Civil Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Civil and Architectural Engineering Hainan UniversityHaikou 570228China School of Qilu Transportation Shandong UniversityJinan 250002China

Tunnelling has increasingly become an essential tool in the exploration of underground space.A typical construction problem is the face instability during tunnelling,posing a great threat to associated *** face instability often occurs with the soil arching *** study investigates the combined effect of cutterhead opening ratio and soil non-uniformity on soil arching effect and face stability,via conducting random finite-element analysis coupled with Monte–Carlo *** results underscore that the face stability is strongly associated with the evolution of stress *** obtained stability factors in the uniform soils can serve as a reference for the design of support pressure in practical tunnelling *** addition,non-uniform soils exhibit a lower stability factor than uniform soils,which implies that the latter likely yields an underestimated probability of face *** tunnel face is found to have a probability of failure more than 50%if the spatial non-uniformity of soil is *** the end,a practical framework is established to determine factor of safety(FOS)corresponding to different levels of probability of face failure considering various opening ratios in non-uniform *** required FOS is 1.70 to limit the probability of face instability no more than 0.1%.Our findings can facilitate the prediction of probability of instability in the conventionally deterministic design of face pressure.

关键词： Tunnel Face stability Soil arching effect Cutterhead opening ratio Non-uniform soil Random field