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A New Triterpenoid Saponin: Se-saponin A

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Chinese Chemical Letters 2000年第4期11卷 333-336页

作者： Hui YANG~(1,2) Qin MU~1 yi neng he~1 Han Dong SUN~1 (1Laboratory of Phytochemistry, Kunming Institute of Botany, Chinese Academy of Sciences. Kunming 650204 (2Chemistry Department, College of Life Science and Chemistry, Yunnan University, Kunming 650091) Laboratory of Phytochemistry Kunming Institute of Botany Chinese Academy of Sciences Chemistry Department College of Life Science and Chemistry Yunnan University

A new triterpenoid saponin, se-saponin A, was isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Its structure was determined by spectral and chemical methods. Only one triterpenoid s... 详细信息

关键词： Clerodendrum serratum Verbenaceae triterpenoid saponin se-saponin A

Honeycomb-like biochar framework coupled with Fe_(3)O_(4)/FeS nanoparticles as efficient heterogeneous Fenton catalyst for phenol degradation

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Journal of Environmental Sciences 2024年第2期136卷 390-399页

作者： Aihua Cheng yi he Xiaohe Liu Chi he Department of Environmental Engineering College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of SciencesBeijing 101408China

Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater ***,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by *** prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the ***,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation ***,biochar can effectively promote cycling stability by limiting Fe *** work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.

关键词： Biomass Biochar Fenton reaction Fe_(3)O_(4)/FeS(Fe/S) Phenol degradation

Multiscale observation in wide-spatial radar surveillance based on coherent FDA design

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Science China(Information Sciences) 2024年第2期67卷 232-252页

作者： Lei YU Feng he yi SU College of Electronics Science National University of Defense Technology

Wide-spatial radar surveillance missions are challenging tasks, requiring an increased power budget and agility in transmission aimed at extracting information from multiple targets in different environments. These requirements necessitate high transmitting degrees of freedom(DOF) to achieve the objective of multiscale observation for specific tasks in specialized regions of interest. herein, we exploit the multiscale observation ability in wide-spatial radar surveillance based on frequency diverse array(FDA)radar. The proposed method facilitates spatial anisotropic control of multiple radar resources, including the transmitting waveforms, beampattern, and bandwidth. By utilizing a coherent FDA radar, we offer principles for the selection of baseband waveforms, in addition to the quantitative design of the beampattern gain and optimal bandwidth from the perspective of detection. The feasibility of the proposed method is validated through numerical experiments, thus indicating the potential in wide-spatial radar surveillance. Moreover,this work can be regarded as a preliminary attempt to gauge the efficacy of the computational array, a novel academic concept.

关键词： multi-scale observation wide-spatial surveillance frequency diverse array (FDA) beampattern synthesis frequency diversity gain computational array

Interaction of yttrium barrier and calcium-rich phase on production and properties of WC precursor powders and alloys

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Journal of Rare Earths 2024年第1期42卷 228-236,I0008页

作者： Wen he Dunqiang Tan Zhiqiang yi Zhiqiang Liu School of Materials Science and Engineering Nanchang UniversityNanchang330031China Instrumental Analysis Center of Nanchang Hangkong University Nanchang330063China

In order to reduce or eliminate the adverse effects of calcium impurity,the interaction of Ca and rare earth Y co-doping on the preparation of WC-Co cemented carbides was investigated.X-ray diffraction,scanning electron microscopy and transmission electron microscopy were employed to analyze the phase compositions,particle sizes and morphologies of them,*** results show that the second type of"yttrium barrier effect"is observed and the adverse influence of Ca-rich phase on tungsten powder can be eliminated by *** flexural strength and fracture toughness of YG6-0.01%Ca+0.09%Y alloy are 2199.5 MPa and 11.49 MPa·m^(1/2),showing improvement of 6.5% and 2.7% compared to YG6 alloy,*** evolutions of Ca-rich phase and Y-rich phase at the every alloy preparation stage of WO_(3),W,WC and cemented carbides are ***,the strengthening mechanism of WC-Co cemented carbide with co-addition of Ca and Y is proposed.

关键词： Yttrium barrier effect Ca-rich phase WC-Co cemented Carbide Microstructures Mechanisms Rare earths

Molecular evolution of Toll-like receptors in rodents

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Integrative Zoology 2024年第3期19卷 371-386页

作者： Qianqian SU yi CheN Hongxuan he College of Forestry Central South University of Forestry and TechnologyChangshaChina National Research Center for Wildlife-Borne Diseases Institute of ZoologyChinese Academy of SciencesBeijingChina

Toll-like receptors(TLRs),the key sensor molecules in vertebrates,trigger the innate immunity and prime the adaptive immune *** TLR family of rodents,the largest order of mammals,typically contains 13 TLR ***,a clear picture of the evolution of the rodent TLR family has not yet emerged and the TLR evolutionary patterns are unclear in rodent ***,we analyzed the natural variation and the evolutionary processes acting on the TLR family in rodents at both the interspecific and population *** results showed that rodent TLRs were dominated by purifying selection,but a series of positively selected sites(PSSs)primarily located in the ligand-binding domain was also *** numbers of PSSs differed among TLRs,and nonviralsensing TLRs had more PSSs than those in viral-sensing ***-conversion events were found between TLR1 and TLR6 in most rodent *** genetic analyses showed that TLR2,TLR8,and TLR12 were under positive selection in Rattus norvegicus and ***,whereas positive selection also acted on TLR5 and TLR9 in the former species,as well as TLR1 and TLR7 in the latter ***,we found that the proportion of polymorphisms with potentially functional change was much lower in viral-sensing TLRs than in nonviral-sensing TLRs in both of these rat *** findings revealed the first thorough insight into the evolution of the rodent TLR genetic variability and provided important novel insights into the evolutionary history of TLRs over long and short timescales.

关键词： adaptive evolution gene conversion positive selection rodents Toll-like receptors

Imaging of human parafoveal area with large field of view in adaptive optics line scanning ophthalmoscope

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Journal of Innovative Optical health Sciences 2024年第6期17卷 41-51页

作者： Wen Kong yiwei Chen Guohua Shi yi he Department of Biomedical Engineering University of Science and Technology of ChinaHefei 230041P.R.China Jiangsu Key Laboratory of Medical Optics Suzhou Institute of Biomedical Engineering and TechnologyChinese Academy of SciencesSuzhou 215163P.R.China Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of SciencesShanghai 200031P.R.China Key Laboratory of Myopia of State health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai 200003P.R.China

The parafoveal area,with its high concentration of photoreceptors andfine retinal capillaries,is crucial for central vision and often exhibits early signs of pathological *** current adaptive optics scanning laser ophthalmoscope(AOSLO)provides an excellent tool to acquire accurate and detailed information about the parafoveal area with cellular ***,limited by the scanning speed of two-dimensional scanning,thefield of view(FOV)in the AOSLO system was usually less than or equal to 2,and the stitching for the parafoveal area required dozens of images,which was time-consuming and ***,almost half of patients are unable to obtain stitched images because of their *** solve this problem,we integrate AO technology with the line-scan imaging method to build an adaptive optics line scanning ophthalmoscope(AOLSO)system with a larger *** the AOLSO,afocal spherical mirrors in pairs are nonplanar arranged and the distance and angle between optical elements are optimized to minimize the aberrations,two cylinder lenses are orthogonally placed before the imaging sensor to stretch the point spread function(PSF)for su±ciently digitizing light *** human retinal images show the whole parafoveal area with 55FOV,60 Hz frame rate and cellular *** advantage of the 5FOV of the AOLSO,only 9 frames of the retina are captured with several minutes to stitch a montage image with an FOV of 99,in which photoreceptor counting is performed within approximately 5*** AOLSO system not only provides cellular resolution but also has the capability to capture the parafoveal region in a single frame,which offers great potential for noninvasive studying of the parafoveal area.

关键词： Adaptive optics line scanning retinal imaging system parafoveal capillary vasculature.

Investigating the Effects of V2C MXene on Improving the Switching Stability and Reducing the Operation Voltages of TiO2-Based Memristors

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Chinese Journal of Electronics 2024年第5期33卷 1181-1187页

作者： Nan he Lei WANG yi TONG College of Electronic and Optical Engineering College of Flexible Electronics (Future Technology) and College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications Gusu Laboratory of Materials

Three-atoms-type V2C MXene, an emerging class of transition metal carbides, has attracted tremendous attention in the fabrication of advanced memristive devices due to its excellent electrochemical properties. However,the inserted effects and corresponding physical mechanisms of inserting V2C on traditional TiO2-based memristors have not been clearly explored. In this work, exhaustive electrical characterizations of the V2C/TiO2-based devices exhibit enhanced performance（e.g., improved switching stability and lower operating voltages） compared to the TiO2-based counterparts. In addition, the advantaged influences of the inserted V2C have also been studied by means of first-principles calculations, confirming that V2C MXene enables controllable internal ionic process and facilitated formation mechanism of the Ag conductive filaments. This work demonstrates a way to combine experimental and theoretical investigations to reveal the positive effects of introducing V2C MXene on memristor, which is beneficial for fabricating performance-enhanced memristors.

关键词： Performance evaluation Fabrication Memristors Process control Metals Switches Stability analysis Memristor V2C MXene First-principles calculation Switching stability Formation mechanism

Three New Styrylpyroncs from Goniothalamus leiocarpus

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Chinese Chemical Letters 1999年第2期10卷 135-138页

作者： Qing MU Chao Ming LI yi neng he Han Dong SUN Hui Lan ZheNG Yang LU Qi Tai ZheNG Nan WU Ren Wang JIANG(Phytochemistry Laboratory, Kunming Institute of Botany, the Chinese Acadmy of Sciences,Kunming 650204)(Institute of Meteria Medica. Chinese Academ Phytochemistry Laboratory Kunming Institute of Botany Chinese Acadmy of Sciences Kunming 650204 China Institute of Meteria Medica Chinese Academy of Medical Sciences Beijing 100050 China

Three new styrylpyrones. named 7-epi-goniodiol 1. leiocarpin B 2 and leiocarpin C *** isolated from the stem barks of Goniothalamus leiocarpus. Their structures were elucidated bymeans of spectral and chemical methods... 详细信息

关键词： Annonaceae Goniothalamus leiocarpus styrylpyrone 7-epi-goniodiol leiocarpin B leiocarpin C

New Dopamine Derivative from Lycium Barbarum

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Chinese Chemical Letters 1999年第2期10卷 131-132页

作者： Cheng ZOU Qing ZHAO Chang Xiang CheN yi neng he(Faculty of Pharmacy, Kunming Medical College, Kunming 650031)(Yunnan College of Traditional Chinese Medicine, Kunming 650200)(Laboratory of Phytochemistry, Kunming Institute of Botany, the Chinese Academy Faculty of Pharmacy Kunming Medical College Kunming 650031 China Yunnan Coll. Traditional Chinese M. Kunming 650200 China Laboratory of Phytochemistry Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China

A new dopamine derivative, lyciumide A, was isolated from the fruits of Lycium barbarum. Its structure was elucidated as p-methoxy-cis-cinnamoyl dopamine by spectral methods.

关键词： Lycium barbarum lyciumide A