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PtAu bimetallic nanocatalyst for selective hydrogenation of alkenes over aryl halides

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Nano Research 2019年第7期12卷 1659-1662页

作者： Le guo Junjie Mao shuangxi guo Qi Zhang Shuangfei Cai Wei He School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety Center of Materials Science and Optoelectronics EngineeringCAS center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyUniversity of Chinese Academy of SciencesBeijing 100190China Center of Single-Atom Clusters and Nanomaterials (CAN)Key Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Key Laboratory of Molecule-Based MaterialsCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China

Herein,we present a new strategy that for the first time achieved chemo- and enantio-selective hydrogenation of alkenes over arylhalides.Key to the success is that instead of using external poisons,we use the composition of the bimetallic nanocrystal catalysts to control chemoselectivity (hydrogenation of C=C bonds without cleavage of Ar-X bonds).We further show that this system combined with surface modifying chiral ligands can control the enantioselectivity.Thus,after synthesizing and screening a series of easily accessible MxAuy (M = Pd,Pt;x,y= 1,3,5) bimetallic nanocrystals (9-10 nm) supported on activated carbon,we identified that PtiAui/C is a recyclable and generally applicable catalyst for the chemoselective hydrogenation of alkenes without cleaving aryl halogen bonds.Furthermore,cinchonidine modified Pt,Aui/C is shown to be capable of enantioselective hydrogenation,as illustrated by the rapid and enantio-enriched synthesis of RIP1 inhibitor analogue 7-Br-O-Necl.

关键词： hydrogenation chemoselectivity enantioselectivity PtAu bimetallic

The Effect of Near-Wall Vortices on Wall Shear Stress in Turbulent Boundary Layers

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Engineering（科研） 2010年第3期2卷 190-196页

作者： shuangxi guo Wanping Li 不详

The objective of the present study is to explore the relation between the near-wall vortices and the shear stress on the wall in two-dimensional channel flows. A direct numerical simulation of an incompressible two-dimensional turbulent channel flow is performed with spectral method and the results are used to examine the relation between wall shear stress and near-wall vortices. The two-point correlation results indicate that the wall shear stress is associated with the vortices near the wall and the maximum correlation-value location of the near-wall vortices is obtained. The analysis of the instantaneous diagrams of fluctuation velocity vectors provides a further expression for the above conclusions. The results of this research provide a useful supplement for the control of turbulent boundary layers.

关键词： Spectral Methods Two-Dimensional Turbulence Wall Shear Stress Two-Point Correlation

Correlation between knowledge of prevention COVID-19 and depression of residents in Henan province,China

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中国研究型医院 2020年第2期7卷 21-26页

作者： Anna Ma Dongyang Wang Nannan Wang ShanShan Zhu Qiong Li shuangxi guo School of Nursing Xinxiang Medical UniversityXinxiangChina School of Nursing St.Paul UniversityManilaPhilippines School of Health Science Mae Fah Luang UniversityChiang RaiThailand Department of Neurology The First Affiliated Hospital of Xinxiang Medical UniversityXinxiangChina

Background:Coronavirus disease 2019(COVID-19) has shown explosive growth in cities in central China in recent days.Residents have the depression due to lack of corresponding prevention knowledge.Methods:A cross-sectional study was investigated 385 residents over 18 years of age.Structured questionnaire and DASS-21 scale used to explore the association between knowledge of prevention COVID-19 and depression among residents.Results:73 respondents (20.3%) suffered varying degrees of depression.The knowledge of the behavior of respondents most concerned (AOR 7.45,95%CI,1.87 ~ 29.77),the main symptoms of the COVID-19 (AOR 9.72,95%CI,1.19 ~ 79.12) and using special ambulances to transport patients or suspected patients (AOR 2.22,95%CI,1.07 ~ 4.62) was found to be significant related to depression.Conclusions:Although residents currently have a lower prevalence of depression,but there is a strong correlation between the knowledge and attitude of prevention COVID-19 and depression.Government agencies need to expand ways to spread the knowledge of prevention COVID-19.

关键词： Coronavirus disease 2019(COVID-19) Depression Resident

Strategies and prospects for melatonin to alleviate abiotic stress in horticultural plants

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Horticultural Plant Journal 2024年第3期10卷 601-614页

作者： Xiaoyun Wang Meng Cao Hongxin Li Ying Liu shuangxi Fan Na Zhang Yangdong guo College of Horticulture China Agricultural UniversityBeijing100193China College of Plant Science and Technology Beijing University of AgricultureBeijing102206China Beijing Bei Nong Enterprise Management Co. Ltd.Beijing102206China Sanya Institute of China Agricultural University SanyaHainan572000China

Melatonin is a conserved pleiotropic molecule in animals and plants.Melatonin is involved in many development processes and stress responses;thus,exploring its function in plants,particularly in horticultural plants,has become a rapidly developing field.Many studies have revealed that phytomelatonin acts as a plant biostimulant and increase its tolerance to various abiotic stressors,including extreme temperature,drought,osmotic disturbance,heavy metals,and ultraviolet(UV).Melatonin appears to have roles in the scavenging of reactive oxygen species(ROS)and other free radicals,affecting the primary and secondary metabolism of plants,regulating the transcripts of stress-related enzymes and transcription factors,and crosstalk with other hormones under different environmental conditions.This pleiotropy makes phytomelatonin an attractive regulator to improve resistance to abiotic stress in plants.The recent discovery of the potential phytomelatonin receptor CAND2/PMTR1 and the proposition of putative models related to the phytomelatonin signaling pathways makes phytomelatonin a new plant hormone.Based on relevant studies from our laboratory,this review summarizes the phytomelatonin biosynthetic and metabolic pathways in plants and the latest research progress on phytomelatonin in abiotic stress of horticultural plants.This study will provide a reference for elucidating the regulatory mechanism of phytomelatonin affecting the resistance to abiotic stress in plants.

关键词： Abiotic stress Biostimulant Horticultural plants Phytomelatonin

急性缺血性脑卒中患者血清NLRP3及诱导型一氧化氮合酶水平与卒中后抑郁的关系

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实用心脑肺血管病杂志 2024年第4期32卷 100-104页

作者：李月月王聪聪田小军苏洲郭双喜王玉梅新乡医学院第一附属医院神经内科河南省新乡市453100

目的探讨急性缺血性脑卒中(AIS)患者血清核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、诱导型一氧化氮合酶(iNOS)水平与卒中后抑郁(PSD)的关系。方法选取2022年8月—2023年8月新乡医学院第一附属医院神经内科收治的AIS患者,收集患者临床... 详细信息

目的探讨急性缺血性脑卒中(AIS)患者血清核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、诱导型一氧化氮合酶(iNOS)水平与卒中后抑郁(PSD)的关系。方法选取2022年8月—2023年8月新乡医学院第一附属医院神经内科收治的AIS患者,收集患者临床资料,随访1个月时采用汉密尔顿抑郁量表17项(HAMD-17)评估患者PSD发生情况,以HAMD-17评分≥8分为发生PSD,将发生PSD的患者纳入PSD组,其余患者纳入非PSD组;PSD组患者根据HAMD-17评分进一步分为轻度抑郁(8分≤HAMD-17评分<17分)和中-重度抑郁(HAMD-17评分≥17分)。采用Pearson相关分析探讨PSD组患者血清NLRP3、iNOS水平及HAMD-17评分间的相关性;采用多因素Logistic回归分析探讨AIS患者发生PSD的影响因素;采用ROC曲线分析血清NLRP3、iNOS水平及二者联合对AIS患者发生PSD的预测价值。结果本研究共纳入171例AIS患者,64例患者发生PSD,其中轻度抑郁34例、中-重度抑郁30例。PSD组患者美国国立卫生研究院卒中量表(NIHSS)评分、LDL-C及血清NLRP3、iNOS水平高于非PSD组(P<0.05)。中-重度抑郁患者血清NLRP3、iNOS水平高于轻度抑郁患者(P<0.05)。Pearson相关分析结果显示,PSD组患者血清NLRP3、iNOS水平与HAMD-17评分呈正相关(P<0.05),血清NLRP3水平与血清iNOS水平呈正相关(P<0.05)。多因素Logistic回归分析结果显示,NIHSS评分及血清NLRP3、iNOS水平是AIS患者发生PSD的独立影响因素(P<0.05)。ROC曲线分析结果显示,血清NLRP3、iNOS水平及二者联合预测AIS患者发生PSD的AUC分别为0.812、0.828、0.885。二者联合预测AIS患者发生PSD的AUC大于血清NLRP3、iNOS水平预测AIS患者发生PSD的AUC(P<0.05)。结论血清NLRP3、iNOS水平是AIS患者发生PSD的独立影响因素,并且与PSD严重程度相关。血清NLRP3水平联合血清iNOS水平对AIS患者发生PSD具有一定预测价值。

关键词：缺血性卒中卒中后抑郁核苷酸结合寡聚化结构域样受体蛋白3 诱导型一氧化氮合酶

Innovations in metallurgical and materials processes:advancing liquid theory and honoring Prof.Han-jie guo's contributions to physical chemistry in metallurgy

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Journal of Iron and Steel Research(International) 2024年第1期31卷 1-2页

作者： Shuai Liu Jing guo Han-jie guo School of Artificial Intelligence Beijing Technology and Business UniversityBeijing100048China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China

Spanning three decades,Prof.Han-jie guo's research group has dedicated itself to exploring the fundamental theories and practical applications of physical chemistry within the realm of metallurgy.Operating under the a... 详细信息

关键词： chemistry liquid complexes

Light People:Prof.Eric Mazur speaks about ultrafast optics and education

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Light(Science & Applications) 2024年第3期13卷 402-406页

作者： Chenzi guo Yang Li Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina State Key Laboratory of Precision Measurement Technology and Instrument Department of Precision InstrumentTsinghua UniversityBeijingChina

Prof.Eric Mazur is a great influencer over and beyond the optics community.As a physicist,he is a pioneer of ultrafast optics and was one of the inventors of colliding-pulse mode-locked laser.As an educator,he not only gave talks to thousands,but also revolutionized teaching with his globally renowned methodology“Peer Instruction”.As a leader and entrepreneur,he co-founded several companies and was President of Optica(formerly the Optical Society)and currently is the Chair of the Optica Foundation.Here,Light:Science&Applications talked with Prof.Eric Mazur about his opinions on research,education and industry.The full interview video can be found in the Supplementary File.

关键词： optics education companies

基于铺覆模拟的复合材料螺旋桨叶片分区域铺层优化

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宇航材料工艺 2022年第1期52卷 45-51页

作者：李雪芹郭双喜陈科先进复合材料重点实验室中国航空制造技术研究院复合材料技术中心北京101300 海军研究院北京100161

为了提高复合材料螺旋桨叶片的结构刚度,分区域优化设计了叶片复合材料结构的铺层角度。根据螺旋桨叶片的厚度和载荷条件,将其划分为4个区域。铺层优化以0°、45°、90°及-45°四个方向的铺覆在各个区域的模拟结果为基础。与初始的铺... 详细信息

为了提高复合材料螺旋桨叶片的结构刚度,分区域优化设计了叶片复合材料结构的铺层角度。根据螺旋桨叶片的厚度和载荷条件,将其划分为4个区域。铺层优化以0°、45°、90°及-45°四个方向的铺覆在各个区域的模拟结果为基础。与初始的铺层方案[0/45/0/-45]sn相比,优化后叶片的铺层方案能使铺层的主方向接近叶片各截面中心点的连线。优化后螺旋桨叶片的1阶和3阶频率提高超过了25%,2阶频率提高超过了5%;表面均布载荷下叶片变形减小了50%,热载荷下叶片变形减小了约25%;优化达到了提高叶片结构刚度的预期效果。分区域优化的方法既利用了复合材料的可设计性又提高了优化效率,适用于复杂复合材料结构的铺层优化。

关键词：铺层优化螺旋桨叶片复合材料铺覆模拟有限元分析

Emerging direct current triboelectric nanogenerator for high-entropy mechanical energy harvesting

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Science China(Technological Sciences) 2024年第5期67卷 1297-1316页

作者： CHEN Jie guo RuiLong guo HengYu College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Department of Applied Physics Chongqing UniversityChongqing 401331China

In the era of the Internet of Things(IoT),the provision of sustainable power to distributed,mobile,and low-power-consumption electronic devices is a critical challenge.To overcome this challenge,the triboelectric nanogenerator(TENG),a highly efficient high-entropy mechanical energy harvesting device,was developed in 2012.This device enables the direct conversion of irregular and low-frequency mechanical energy into pulsed alternating current(AC)signals.However,the incompatibility of most electronic devices with AC signals necessitates rectifier circuits or generators that deliver direct current(DC)signals.In recent years,DC-TENGs have undergone extensive development,achieving significant milestones in various application fields while also facing crucial challenges that require solutions.In this review,three categories of DC-TENG devices with distinct operating mechanisms are comprehensively explored:multiphase coupling,mechanical rectification,and air breakdown.Their typical structures and working mechanisms are thoroughly discussed,and specific output performance limitations,along with corresponding optimization strategies,are identified.Furthermore,the applications of DC-TENGs in various scenarios are summarized.Finally,the challenges faced by DC-TENGs and potential solutions are analyzed to guide further advancements in this technology.

关键词： TENG direct current working mechanisms output performance limitations optimization strategies