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Boekelheide(伯克海德)反应的研究进展

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当代化工研究 2024年第3期 12-14页

作者：谢子文刘继明罗文俊江西普正制药股份有限公司江西343000 浙江工业大学绿色制药协同创新中心浙江310014 赣南师范大学化学化工学院江西341000

2-羟甲基吡啶化合物是重要的有机合成中间体,广泛的存在于药物、天然产物结构中,同时也广泛的应用于各类有机转换。由于吡啶环的缺电子性,采用直接氧化法在其侧链引入羟基变得较为困难。相比较而言,采用伯克海德重排反应(Boekelheide Re... 详细信息

2-羟甲基吡啶化合物是重要的有机合成中间体,广泛的存在于药物、天然产物结构中,同时也广泛的应用于各类有机转换。由于吡啶环的缺电子性,采用直接氧化法在其侧链引入羟基变得较为困难。相比较而言,采用伯克海德重排反应(Boekelheide Reaction)则更具可行性,该方法成为目前研究者们制备2-羟甲基吡啶常用手段。由于反应条件温和、官能团容忍性好、区域选择性较高,该方法成为化学家们制备羟甲基吡啶化合物的首选手段之一。本文简单总结了Boekelheide反应的机理和研究进展。

关键词：伯克海德反应氮氧化吡啶 2-羟甲基吡啶

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Effects of Nursing Intervention Based on Transtheoretical Model of Behavioral Change on Disposal of Home Medical Waste in Diabetic Patients

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Medicinal Plant 2022年第3期13卷 71-74页

作者： ziwen xie Yan ZHAN Hao ZHANG Shuzhen ZHU Hubei University of Medicine Shiyan 442000 China Affiliated Taihe Hospital of Hubei University of Medicine Shiyan 442000 China First People's Hospital of Xiantao City Xiantao 433000 China

[Objectives]To explore the effects of nursing intervention on the disposal of home medical waste for diabetic patients.[Methods]A total of 118 diabetic patients with insulin injection at home who visited a community service center in Shiyan City during November 2020 and September 2021 were selected as the research objects to implement the intervention,and the medical waste knowledge,attitude scores and standardized medical waste disposal were compared before and after the intervention.[Results]After the intervention,the patient's medical waste knowledge score was significantly higher than that before the intervention,and the medical waste disposal attitude score was significantly higher than that before the intervention.[Conclusions]If the nursing intervention based on Transtheoretical Model(TTM)of Behavioral Change penetrates deep into patients'families and communities,it is helpful to improve the knowledge and attitude of diabetic patients on home medical waste disposal,and regulate their home medical waste disposal behavior.

关键词： Diabetic patients medical waste Disposal Intervention research

The Application of UAV-Based Hyperspectral Imaging to Estimate Crop Traits in Maize Inbred Lines

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Plant Phenomics 2021年第1期3卷 351-364页

作者： Meiyan Shu Mengyuan Shen Jinyu Zuo Pengfei Yin Min Wang ziwen xie Jihua Tang Ruili Wang Baoguo Li Xiaohong Yang Yuntao Ma College of Land Science and Technology China Agricultural UniversityBeijing 100193China State Key Laboratory of Plant Physiology and Biochemistry National Maize Improvement Center of ChinaChina Agricultural UniversityBeijing 100193China College of Agronomy Henan Agricultural UniversityZhengzhou 450002China Agricultural Artificial Intelligence and Crop Phenotype Engineering Research Center Inner Mongolia Institute of BiotechnologyHuhhot 010070China

Crop traits such as aboveground biomass(AGB),total leaf area(TLA),leaf chlorophyll content(LCC),and thousand kernel weight(TWK)are important indices in maize *** to extract multiple crop traits at the same time is helpful to improve the efficiency of *** with digital and multispectral images,the advantages of high spatial and spectral resolution of hyperspectral images derived from unmanned aerial vehicle(UAV)are expected to accurately estimate the similar traits among breeding *** study is aimed at exploring the feasibility of estimating AGB,TLA,SPAD value,and TWK using UAV hyperspectral images and at determining the optimal models for facilitating the process of selecting advanced *** successive projection algorithm(SPA)and competitive adaptive reweighted sampling(CARS)were used to screen sensitive bands for the maize *** least squares(PLS)and random forest(RF)algorithms were used to estimate the maize *** results can be summarized as follows:The sensitive bands for various traits were mainly concentrated in the near-red and red-edge *** sensitive bands screened by CARS were more abundant than those screened by *** AGB,TLA,and SPAD value,the optimal combination was the CARS-PLS *** the TWK,the optimal combination was the CARS-RF *** with the model built by RF,the model built by PLS was more *** study provides guiding significance and practical value for main trait estimation of maize inbred lines by UAV hyperspectral images at the plot level.

关键词： Crop breeding forest

Mass extinctions, their causes and consequences: an interview with Douglas *** and Shuzhong Shen

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National Science Review 2024年第1期11卷 66-70页

作者： Shucheng xie State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences at Wuhan

‘Mass extinctions’ have been a hot topic for several decades. What triggers a mass extinction? How does a mass extinction impact the evolution of life? How does our ecosystem recover after a mass extinction? These questions attracted the interest of both scientists and the public *** spoke to two renowned researchers in the field of mass extinctions: Prof. Douglas H. Erwin from the National Museum of Natural History of the USA, and Prof. Shuzhong Shen from Nanjing University, China.

关键词： Stratigraphy

Turbulence Statistics of Thermo-Buoyancy Supercritical Fuel Flow in a Regenerative Cooling Channel

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Journal of Thermal Science 2024年第1期33卷 126-137页

作者： SUN Feng xie Gongnan School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Department of Thermal Engineering Tsinghua UniversityBeijing 100084China

Active regenerative cooling with supercritical hydrocarbon fuel is considered as the most promising thermal protection *** existence of buoyancy force would lead to strongly anisotropic flow and thermal transport *** is closely related to the cooling performance of the *** elucidate the mechanisms of turbulent transport,the large eddy simulation(LES) was performed to assess turbulence statistics within different turbulence *** results indicated that the buoyancy and inertial force together dominated the change of turbulent ***,the spatial thermal buoyancy effect significantly suppressed the vertical velocity *** is due to the laminar motion caused by the buoyancy force,thereby weakening the thermal *** the statistics of velocity fluctuation,it was found that the buoyancy force and inertial force greatly weaken the vertical and streamwise velocity fluctuation,*** the statistics of thermal transport,the results pointed out that the near-wall heat transport characteristics need to be paid more *** thickness of the temperature mixing boundary layer led to the attenuation of vertical heat flux,which inhibited vertical temperature diffusion and predisposed to extreme conditions of heat transfer *** results can enhance the academic understanding of the heat transfer mechanism of supercritical fluids,and give guidance for further applications of thermal protection.

关键词： active regenerative cooling large eddy simulation(LES) buoyancy force turbulence statistics

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Output feedback stabilization of stochastic high-order planar nonlinear systems with stochastic inverse dynamics and output-constraint

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Science China(Information Sciences) 2024年第3期67卷 182-196页

作者： Ruiming xie Shengyuan XU Nanjing University of Science and Technology School of Automation

In this paper, we solve the output feedback control problem of stochastic high-order planar nonlinear systems with output constraint and stochastic integral input-to-state stability(SiISS) inverse dynamics. By employing a key coordinate transformation, a stochastic nonlinear system with output constraint and SiISS inverse dynamics is converted into an unconstrained system. By skillfully constructing an observer and adopting SiISS small-gain conditions, we develop a new output feedback control design and analysis method, and prove that all the closed-system signals are bounded almost surely, the output constraint is not violated almost surely, and the equilibrium point of the closed-loop system is stochastically asymptotically stable.

关键词： stochastic high-order planar nonlinear system outputconstraint stochastic inverse dynamics output feedbackstabilization stochastic integral input-to-state stability(SiISS)

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Fixed-time stabilization of output-constrained stochastic high-order nonlinear systems

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Science China(Information Sciences) 2024年第4期67卷 5-20页

作者： Ruiming xie Shengyuan XU Nanjing University of Science and Technology School of Automation

In this study, the fixed-time stabilization problem of stochastic high-order nonlinear systems with output constraint and high-order and low-order nonlinearities is addressed. A new coordinate transformation is employed to directly convert output-constrained stochastic systems into an equivalent unconstrained *** fully extracting the characteristics of system nonlinearities and using the stochastic fixed-time stability theorem, a new design and analysis method is constructed to guarantee that the trivial solution of the closed-loop system is stochastically fixed-time stable while fulfilling the output constraint.

关键词： stochastic high-order nonlinear system outputconstraint high-order and low-order nonlinearity fixed-timestabilization finite-time stabilization

Review of the research on the development and utilization of clay-type lithium resources

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Particuology 2024年第4期87卷 46-53页

作者： Ruiqi xie Zhihui Zhao Xiong Tong Xian xie Qiang Song Peiqiang Fan Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming650093China Yunnan Engineering Research Center for Metal Tailings Resource Utilization Kunming650093China

Since the demands for lithium have been in explosive growth recently and several great clay lithium resources were founded in China,the development and utilization of clay-type lithium resources become a hot *** order to provide a guidance for the concentration and extracting lithium of clay-type lithium resources,this review systematically summarized the main types and characteristics of clay-type lithium resources and the research status of lithium extraction from clay lithium ***,the flotation research status of the main mineral of clay lithium ore was also ***,we discussed the difficulties in the development and utilization of clay-type lithium ore and put forward the subsequent research *** paper can provide a guidance for the con-centration and extracting lithium of clay-type lithium resources in the future.

关键词： Clay lithium Clay mineral flotation Lithium extraction Leaching

Conductive and stable polyphenylene/CNT composite membrane for electrically enhanced membrane fouling mitigation

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Frontiers of Environmental Science & Engineering 2024年第1期18卷 35-47页

作者： Huijuan xie Haiguang Zhang Xu Wang Gaoliang Wei Shuo Chen xie Quan Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of Education) School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China

Nanocarbon-based conductive membranes, especially carbon nanotube (CNT)-based membranes, have tremendous potential for wastewater treatment and water purification because of their excellent water permeability and selectivity, as well as their electrochemically enhanced performance (e.g., improved antifouling ability). However, it remains challenging to prepare CNT membranes with high structural stability and high electrical conductivity. In this study, a highly electroconductive and structurally stable polyphenylene/CNT (PP/CNT) composite membrane was prepared by electropolymerizing biphenyl on a CNT hollow fiber membrane. The PP/CNT membrane showed 3.4 and 5.0 times higher electrical conductivity than pure CNT and poly(vinyl alcohol)/CNT (PVA/CNT) membranes, respectively. The structural stability of the membrane was superior to that of the pure CNT membrane and comparable to that of the PVA/CNT membrane. The membrane fouling was significantly alleviated under an electrical assistance of −2.0 V, with a flux loss of only 11.7% after 5 h filtration of humic acid, which is significantly lower than those of PP/CNT membranes without electro-assistance (56.8%) and commercial polyvinylidene fluoride (PVDF) membranes (64.1%). Additionally, the rejection of negatively charged pollutants (humic acid and sodium alginate) was improved by the enhanced electrostatic repulsion. After four consecutive filtration-cleaning cycle tests, the flux recovery rate after backwashing reached 97.2%, which was much higher than those of electricity-free PP/CNT membranes (67.0%) and commercial PVDF membranes (61.1%). This study offers insights into the preparation of stable conductive membranes for membrane fouling control in potential water treatment applications.

关键词： Polyphenylene CNTs Membrane Electro-assistance Membrane fouling mitigation