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Effects of Exogenous Plant Hormones on Growth Status and Secondary Metabolism of Houttuynia cordata Thunb.

Medicinal Plant 2024年第1期15卷 1-7,12页

作者： xitao wang Kai YAN Tianhua YU Zhannan YANG Shiqiong LUO Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment of Guizhou Province/School of Life Sciences Guizhou Normal UniversityGuiyang 550081China Liupanshui Normal University Liupanshui 553004China

[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue culture method with Houttuynia cordata Thunb.as the research object.Different concentrations of 1-naphthalene acetic acid(NAA),auxin(indole-3-acetic acid,IAA)and gibberellin acid(GA_(3))were added to the group culture medium of H.cordata to investigate the effects of exogenous plant hormones on plant height,root length,fresh weight,morphological characteristics,four phenolics and 20 volatile compounds.[Results]The results showed that the exogenous plant hormone of 3 mg/L GA_(3)significantly increased plant height by 79.9%over the control;the exogenous plant hormone of 3 mg/L IAA significantly increased root length by 52.6%over the control;and the exogenous plant hormone of 1 mg/L GA_(3)significantly increased fresh weight of single plant by 458.2%over the control.In the treatment group of 1 mg/L NAA,chlorogenic acid content was significantly increased by 52.6%compared with the control;in the treatment group of 1 mg/L IAA,chlorogenic acid,rutin,isodendrin and quercetin content were significantly increased by 109.1%,100.6%,173.8%,and 198.7%compared with the control,respectively;in the treatment of 3 mg/L GA_(3),chlorogenic acid,rutin,isoquercitin,and quercitin content were significantly increased by 65.3%,104.9%,139.0%and 191.2%over the control.In addition,the content of volatile compounds was significantly higher in all H.cordata treated with exogenous plant hormones of 2 mg/L NAA,1 mg/L IAA,and 3 mg/L GA_(3);however,the content of volatile compounds was lower in all of the treatments with 2 mg/L GA_(3).[Conclusions]Different exogenous plant hormones have certain effects on the growth morphology and secondary metabolic content of H.cordata,which provides theoretical basis and technical support for the development and utilization of medicinal plants.

关键词： 1-Naphthaleneacetic acid(NAA) Auxin(IAA) Gibberellic Acid(GA_(3)) Phenols Volatiles

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Low cycle fatigue behavior of micro-grain casting K4169 superalloy at room temperature

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Progress in Natural Science:Materials International 2022年第6期32卷 693-699页

作者： Rui Liu xitao wang Pinpin Hu Chengbo Xiao Jinshan He Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Shandong Provincial Key Laboratory for High Strength Lightweight Metallic Materials Advanced Materials Institute Qilu University of Technology (Shandong Academy of Science) Science and Technology on Advanced High Temperature Structural Materials Laboratory AECC Beijing Institute of Aeronautical Materials

The strain-controlled low cycle fatigue tests were carried out at 298 K for the newly developed micro-grain casting K4169 superalloy,and the cyclic stress response,deformation and fracture behaviors of the alloy were studied.The results show that the fatigue life of the alloy was increased by more than two times compared with other casting K4169 alloys.This can be partly attributed to grain refinement impeding crack initiation and propagation.When the strain amplitude was in plastic range(Δεt/2≥ 0.5%),the alloy displayed a short period of initial cyclic stability followed by cyclic softening to fracture.By observing dislocation configurations,only a few dislocations moved around grain boundaries at initial cycles,leading to short cyclic stability.Afterwards,dislocations in the slip bands cut γ" phase continuously leading to cyclic softening.When the strain amplitude was in elastic range(Δεt/2 ≤ 0.4%),the alloy exhibited elastic deformation and the peak stress kept stable.In addition,the crack initiation site changed from the MC carbides to the persistent slip bands on surface with increasing strain amplitudes.

关键词： Micro-grain cast K4169 Low-cycle fatigue Cyclic softening Slip bands

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Comparison of the effects of pre-activators on morphology and corrosion resistance of phosphate conversion coating on magnesium alloy

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Journal of Magnesium and Alloys 2022年第12期10卷 3485-3494页

作者： Tao Li Zhongjun Leng Shifang wang xitao wang Reza Ghomashchi Yuansheng Yang Jixue Zhou Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan 250014China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Mechanical Engineering The University of AdelaideAdelaide SA 5005Australia

In this study, Mg–6.0Zn–3.0Sn–0.5Mn(ZTM630) magnesium alloy was pre-activated by colloidal Ti, oxalic acid, and phosphoric acid,and a phosphate conversion coating(PCC) was prepared on the alloy surface. The morphology and corrosion resistance of the prepared PCCs were investigated. Surface morphology studies showed that the phosphate crystals that formed the coating were the smallest for the sample pre-activated by phosphoric acid. The coating on the colloidal Ti and the phosphoric acid samples had the largest and the smallest thickness and surface roughness, respectively. The reason for the discrepancy was analyzed by comparing the surface morphologies of alloy samples immediately after the pre-activation treatment and various phosphating treatments. X-ray diffraction analysis revealed that all three PCCs contained the same compounds. The corrosion resistance time from the copper sulfate drop test and the electrochemical data from the potentiodynamic polarization curves showed that the coating pre-activated by phosphoric acid had the best corrosion resistance. Finally, the 1500 h neutral salt spray corrosion test confirmed that the phosphating treated magnesium alloy, which was pre-activated by phosphoric acid,exhibited excellent corrosion resistance and behavior.

关键词： Phosphate conversion coating Surface pre-activator Magnesium alloy Morphology Corrosion

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Effect of chromium interlayer thickness on interfacial thermal conductance across copper/diamond interface

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International Journal of Minerals,Metallurgy and Materials 2022年第11期29卷 2020-2031页

作者： Xiaoyan Liu Fangyuan Sun Wei wang Jie Zhao Luhua wang Zhanxun Che Guangzhu Bai xitao wang Jinguo wang Moon JKim Hailong Zhang State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Institute of Structure and Environment Engineering Beijing 100076China Department of Materials Science and Engineering University of Texas at DallasRichardsonTX 75080USA Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China Shandong Provincial Key Laboratory for High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan 250014China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China

The thermal conductivity of diamond particles reinforced copper matrix composite as an attractive thermal management material is significantly lowered by the non-wetting heterointerface.The paper investigates the heat transport behavior between a 200-nm Cu layer and a single-crystalline diamond substrate inserted by a chromium(Cr)interlayer having a series of thicknesses from 150 nm down to 5 nm.The purpose is to detect the impact of the modifying interlayer thickness on the interfacial thermal conductance(h)between Cu and diamond.The time-domain thermoreflectance measurements suggest that the introduction of Cr interlayer dramatically improves the h between Cu and diamond owing to the enhanced interfacial adhesion and bridged dissimilar phonon states between Cu and diamond.The h value exhibits a decreasing trend as the Cr interlayer becomes thicker because of the increase in thermal resistance of Cr interlayer.The high h values are observed for the Cr interlayer thicknesses below 21 nm since phononic transport channel dominates the thermal conduction in the ultrathin Cr layer.The findings provide a way to tune the thermal conduction across the metal/nonmetal heterogeneous interface,which plays a pivotal role in designing materials and devices for thermal management applications.

关键词： sputtering diamond metal/nonmetal interface interfacial thermal conductance time-domain thermoreflectance

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Synthesis of Bi-doped TiO2 Nanotubes and Enhanced Photo-catalytic Activity for Hydrogen Evolution from Glycerol Solution

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Chinese Journal of Chemistry 2013年第3期31卷 415-420页

作者： Wenxi Zhao xitao wang Huanxin Sang Kang wang Tianjin Key Laboratory of Applied Catalysis Science and Technology College of Chemical Engineering and Technology Tianjin University Tianjin 300072 China Tianjin Academy of Environmental Sciences Tianjin 300191 China

有可变 Bi/Ti 比率的做双性人的 TiO2 nanotubes 被热水的处理在 10 摩尔综合 ? 慮潮慰瑲捩敬吗？？

关键词：二氧化钛纳米管光催化活性铋掺杂合成析氢 TiO2纳米管油溶液 X射线光电子能谱

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Microstructure,Mechanical Properties and In Vitro Degradation Behavior of a Novel Biodegradable Mg-1.5Zn-0.6Zr-0.2Sc Alloy

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Journal of Materials Science & Technology 2015年第7期31卷 744-750页

作者： Tao Li Hailong Zhang Yong He Ning Wen xitao wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Institute of Stomatology General Hospital of Chinese People's Liberation Army

A novel Mg-1.5Zn-0.6Zr-0.2Sc （denoted as ZK21-0.2Sc） alloy was developed as potential biodegrad- able implant materials. The microstructure, mechanical properties, and in vitro degradation behavior of the as-cast ZK21-0.2Sc alloy were investigated and compared with ZK21 alloy and pure Mg. The ZK21 -0.2Sc alloy showed a single-phase structure with fine equiaxed grains. The alloy exhibited a good balance between strength and ductility. Both immersion tests and electrochemical tests showed that the ZK21-0.2Sc alloy had the lowest degradation rate in Hank＇s solution. The excellent degradation behavior of ZK21-0.2Sc alloy could be explained by the single-phase and fine grain structure, the more effective protection corrosion film, and the beneficial alloying effects of Zn, Zr and Sc.

关键词： Magnesium alloysScandiumBiomaterialsBiodegradableCorrosion

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Effect of grit blasting and subsequent heat treatment on stress rupture property of a Ni-based single-crystal superalloy SGX3

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Acta Metallurgica Sinica(English Letters) 2020年第12期33卷 1681-1688页

作者： Jinshan He Zhengrong Yu Longfei Li xitao wang Qiang Feng Beijing Advanced Innovation Center for Material Genome Engineering Collaborative Innovation Center of Steel TechnologyUniversity of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Material Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China Shandong Provincial Key Laboratory for High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan 250353China

In the present study,the effect of grit blasting and subsequent heat treatment on the stress rupture properties of a thirdgeneration nickel-based single-crystal superalloy SGX3 sheet was studied.It was found that the stress rupture life of alloy SGX3 sheet at 980℃/250 MPa was reduced by about 60%by only vacuum heat treatment at 1100℃ for 200 h and further reduced by 20%and 70%respectively with grit blasting of 0.3 MPa/1 min and 0.5 MPa/2 min before heat treatment.The microstructure analysis results indicated that the degradation of stress rupture life of alloy SGX3 sheet by vacuum heat treatment was mainly attributed to the variation ofγ/γ′microstructure,i.e.,the decrease inγ′volume fraction and the coarsening ofγ′precipitates.Furthermore,such degradation by grit blasting and subsequent vacuum heat treatment should be attributed to the formation of cellular recrystallization with different thicknesses at the surface of alloy SGX3 sheet,which not only acts as the vulnerable site for cracks to initiate and propagate but also reduces the effective loading area.

关键词： Ni-based single-crystal superalloy Creep life Degradation Recrystallization

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美军航天指挥控制系统发展现状

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火力与指挥控制 2024年第4期49卷 1-5,17页

作者：胡敏王阳张喜涛航天工程大学宇航科学与技术系北京101416

航天指挥控制系统是美军航天指挥的核心和枢纽。系统梳理了美军航天指挥控制系统早期发展、能力升级、实战转型、体系集成的发展脉络,结合60余年来美军各阶段的历史任务,总结美军航天指挥控制系统的主要特点,深入分析美军航天控制系统... 详细信息

航天指挥控制系统是美军航天指挥的核心和枢纽。系统梳理了美军航天指挥控制系统早期发展、能力升级、实战转型、体系集成的发展脉络,结合60余年来美军各阶段的历史任务,总结美军航天指挥控制系统的主要特点,深入分析美军航天控制系统的关键技术,研判系统未来的发展趋势。可以为相关指挥控制系统的研究提供新方法和新思路。

关键词：航天指挥控制系统太空防御作战中心联合太空作战中心任务系统企业级太空作战管理指挥控制系统

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Effect of Bi promoter on the performances of selective oxidation of isobutane to methacrolein over MoVO/AlPO_4 catalysts

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Journal of Natural Gas Chemistry 2012年第2期21卷 165-169页

作者： xitao wang Mei Li Fen wang Shunhe Zhong Shi Jiang Sihe wang Tianjin Key Laboratory of Applied Catalysis Science and Technology College of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Nature Gas Company Dagang Oil FieldTianjin 300280China

The effects of Bi on the catalytic performance of selective oxidation of isobutane to methacrolein over MoVO/AlPO4 catalyst were investigated by XRD, FT-Raman, XPS, UV-vis DRS techniques. The results show that the addition of Bi component into the MoVO/AlPO4 catalyst obviously improves the catalytic performance, and the selectivity to methacrolein can increase from 14.2% to 45.1% with the increase of Bi/V molar ratio from 0 to 1. Combining the characterization results with the reaction evaluation, it is concluded that the catalytic activities of the MoV0.3Bix/AlPO4 catalysts are related to the crystalline phase composition and the dispersion of molybdenum and vanadium oxides species in general, and also to the V5＋/V4＋ molar ratio on the surface in particular.

关键词： sol-gel method selective oxidation of isobutene methacrolein MoVBiO/AlPO4 catalyst

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Simple Preparation of Spherical Activated Carbon with Mesoporous Structure from Phenolic Resol and Associated Catalytic Performance in Isobutane Dehydrogenation

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Transactions of Tianjin University 2018年第4期24卷 351-360页

作者： xitao wang Chunyu Xin Chunjie Shi Anhua Dong Kang wang Collaborative Innovation Center of Chemical Science and Engineering School of Chemical Engineering and TechnologyTianjin University Tianjin Key Laboratory of Membrane Science and Desalination Technology Chemical Engineering Research CenterSchool of Chemical Engineering and TechnologyTianjin University

This study provides a detailed report on the synthesis of spherical activated carbon with mesoporous structure using a soluble low molecular weight phenolic resol precursor through an ammonium alginate assisted sol–gel method. The effects of calcinating temperature and the addition of CaCO_3 as a pore-enlarging agent on texture structure and catalytic performance in isobutane dehydrogenation to isobutene were investigated. Characterization of N_2 sorption,mechanical strength tests,and optical photographs confirmed that the obtained carbon materials had high mechanical strength,a good degree of sphericity,and a large surface area. Introducing CaCO_3 as a pore-enlarging agent during the preparation process promoted the formation of a mesoporous structure of carbon spheres and evidently increased the surface area and oxygen content,which can improve isobutane conversion and isobutene selectivity of these carbon spheres. The conversion of isobutane reached up to 28% for this spherical activated carbon,and the selectivity of isobutene reached up to 96%. Isobutane conversion increased with an increase in calcination temperature due to an increase in the oxygen content,whereas the selectivity of isobutene decreased due to the slight decrease in the specific surface area.

关键词： Spherical activated carbon Pore-enlarging agent Isobutane dehydrogenation Isobutene

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