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Attractive natural products with strained cyclopropane and/or cyclobutane ring systems

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Science China Chemistry 2016年第9期59卷 1126-1141页

作者： Yao-yue Fan Xin-Hua Gao Jian-Min yue Shanghai Institute of Materia Medica Chinese Academy of Sciences

The strained cyclopropane and/or cyclobutane subunits occurred in many complex natural products including terpenoids, steroids and alkaloids. Natural products with cyclopropane and/or cyclobutane motifs not only furnished fascinating structures, but also exhibited versatile biological activities, such as cytotoxic, anti-HIM antimicrobial, antiviral, and immunosuppressive effects. This review covered a large array of structurally unique natural products with strained cyclopropane and/or cyclobutane motifs and summarized their structural features, distributions, biological activities, as well as biogenetic considerations.

关键词： natural products cyclopropane-containing cyclobutane-containing biological activity biosynthetic pathway

黄芪建中汤对老年脾胃虚寒型胃溃疡患者的临床疗效及血清EGF、TIMP-1及PGE2的影响

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中医药学报 2025年第1期53卷 93-97页

作者：高月李佳北京中医药大学孙思邈医院陕西铜川727000 神木市医院陕西神木719399

目的:评价黄芪建中汤对老年脾胃虚寒型胃溃疡患者的影响。方法:本研究纳入2021年7月-2023年5月在北京中医药大学孙思邈医院就诊的脾胃虚寒型胃溃疡患者84例,按随机数字表法分为西药组和联合组,每组42例。西药组常规西药治疗,联合组在西... 详细信息

目的:评价黄芪建中汤对老年脾胃虚寒型胃溃疡患者的影响。方法:本研究纳入2021年7月-2023年5月在北京中医药大学孙思邈医院就诊的脾胃虚寒型胃溃疡患者84例,按随机数字表法分为西药组和联合组,每组42例。西药组常规西药治疗,联合组在西药组的基础上加用黄芪建中汤治疗。分析两组患者治疗前后的溃疡愈合情况、肠道菌群分布情况,比较两组胃黏膜形态、胃黏膜功能指标、血清生物标志物以及不良反应发生率。结果:联合组患者的溃疡愈合率为92.86%(39/42)显著高于西药组的76.19%(32/42)(P0.05)。结论:黄芪建中汤治疗老年脾胃虚寒型胃溃疡患者,能有效提高溃疡愈合率,改善胃黏膜形态,调节胃黏膜功能指标及血清生物标志物水平,安全有效,值得临床进一步推广。

关键词：黄芪建中汤胃溃疡胃黏膜功能指标血清生物标志物脾胃虚寒

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提升薄煤层采煤机工作效率关键措施研究

煤矿机械 2025年第1期46卷 46-48页

作者：乐南更中煤科工集团上海有限公司上海200030 天地上海采掘装备科技有限公司上海201400

针对薄煤层工作面采煤机工作效率低的问题,提出了采煤机大功率化、合理确定滚筒大小、明确滚筒旋转方向、缩短检修维护时间的解决措施。研究表明,优选大功率薄煤层采煤机、合理选择滚筒直径,可显著提升采煤机工作效率;明确滚筒旋转方向... 详细信息

针对薄煤层工作面采煤机工作效率低的问题,提出了采煤机大功率化、合理确定滚筒大小、明确滚筒旋转方向、缩短检修维护时间的解决措施。研究表明,优选大功率薄煤层采煤机、合理选择滚筒直径,可显著提升采煤机工作效率;明确滚筒旋转方向为内旋,可降低采煤机运行阻力,有利于提升工作效率;开发基于自润滑技术的铰接轴套和轴承,可减少检修时间,提高采煤机开机率,提升工作效率。

关键词：薄煤层采煤机效率措施

Theoretical study on dynamic effective electroelastic properties of random piezoelectric composites with aligned inhomogeneities

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Applied Mathematics and Mechanics(English Edition) 2023年第4期44卷 525-546页

作者： Yanpeng yue Yongping WAN School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China

The closed-form solutions of the dynamic problem of heterogeneous piezoelectric materials are formulated by introducing polarizations into a reference medium and using the generalized reciprocity *** solutions can be reduced to the ones of an elastodynamic *** on the effective medium method,these closedform solutions can be used to establish the self-consistent equations about the frequencydependent effective parameters,which can be numerically solved by *** predictions are compared with the experimental results,and good agreement can be ***,the analyses on the effects of microstructure and wavelength on the effective properties,resonance frequencies,and attenuation are also presented,which may provide some guidance for the microstructure design and analysis of piezoelectric composites.

关键词： piezoelectric composite dynamic effective property self-consistent method resonance frequency wavelength

Livability assessment of 101,630 communities in China's major cities: A remote sensing perspective

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Science China Earth Sciences 2022年第6期65卷 1073-1087页

作者： Xin HUANG yue LIU School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China

Some of China's major cities have entered the middle and late stages of urbanization, and the development focus of these cities has gradually shifted from outward expansion to inward renewal. The community, as the basic unit of a city, is undoubtedly the main object of urban renewal. In order to efficiently and effectively address the problems in current community construction, it is necessary to conduct a large-scale in-depth assessment of the community livability, which can directly imply the satisfaction of residents with their quality of life. This study achieved the first comprehensive livability assessment at the individual community scale for 42 major cities of China from the perspective of remotely sensed and crowd-sourced geographic information. Specifically, we produced abundant fine-grained datasets for 42 cities, including high-resolution land cover maps interpreted from Ziyuan-3 satellites(ZY-3, 2.1 m), building height, point-of-interest, and boundaries of 101,630 *** designed in our proposed framework, the community livability was evaluated by 5 level-1 indicators, 27 level-2 indicators and an integrated community livability index(CLI). A number of interesting findings were obtained from this assessment:(1)According to the expert questionnaires, living comfort was considered as the most important livability factor for residents with the highest weight, while the building environment was rated the least. The negative factors(e.g., the factories around the community) impacted more on livability than the positive ones.(2) Most communities in major Chinese cities were characterized by dense buildings and sparse green spaces.(3) In these cities, community security construction was severely insufficient,particularly in less developed regions.(4) Imbalanced community livability development was prevalent across cities, and simultaneously, the CLI distribution within cities also exhibited significant spatial aggregation and heterogeneity. This resear

关键词： Community Livability Living comfort Building environment Security Remote sensing

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Interior-collapsing mechanism by hydrothermal process of the MgAl_(2)O_(4)/MgO porous ceramic

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Journal of Advanced Ceramics 2022年第5期11卷 814-824页

作者： Yao YAO yue ZHANG Key Laboratory of Aerospace Materials and Performance(Ministry of Education) School of Materials Science and EngineeringBeihang UniversityBeijing 100191China

Ceramic core is a critical component in the super-alloy turbine blade *** our previous work,a novel multi-phase MgAl_(2)O_(4)/MgO porous ceramic was prepared for this *** most important property was that it crumbled completely after hydrothermal treatment in just pure water,due to the hydration of *** this work,the hydration process of the MgO embedded in the inert matrix was investigated in *** collapse behaved as an interior destruction without any bulk expansion of the *** hydration percentage was the only factor related to the *** morphology of hydration product indicated that the reaction advanced in particular *** on the finite element analysis for the expansion effect on the porous structure,the interiorcollapsing mechanism was *** the hydration process,the MgO grains exerted pressure to the surrounding matrix and induced the collapse in the adjacent *** process took place throughout the ***,the sample crumbled completely to the *** bulk dilatation was detected before the powdering,indicating that the collapse process would not exert pressure *** the alloy blade would not be damaged during the removal of the ceramic *** was also predicted that the decrease in the MgO grain size was beneficial to the water-collapsibility.

关键词： ceramic cores porous structure MgO hydration interior-collapsing mechanism

Optimal Output Tracking Control and Stabilization of Networked Control Systems with Packet Losses

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Journal of Systems Science & Complexity 2021年第2期34卷 602-617页

作者： LIU yue HAN Chunyan School of Electrical Engineering University of JinanJinan 250022China

This paper studies the optimal output tracking control and stabilization for networked control systems with packet losses via output feedback *** finite-horizon and infinite-horizon cases are *** the finite-horizon case,the authors introduce an augmented system according to the state variable and the reference trajectory for the first *** on a set of difference Riccati equations,an optimal output feedback tracking controller is proposed by applying the stochastic maximum *** an optimal estimator is *** the infinite-horizon case,a necessary and sufficient condition for the stabilization of the system is *** an optimal output feedback stabilizing tracking controller is obtained by establishing a set of algebraic Riccati ***,numerical examples are given to verify the proposed results.

关键词： Networked control system output feedback control packet losses stabilization tracking control

8-Ranks of Class Groups of Quadratic Number Fields and Their Densities

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Acta Mathematica Sinica,English Series 2011年第7期27卷 1419-1434页

作者： Qin yue Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China

For F = Q（√εpq）, ε∈ {±1,±2}, primes -p ≡ q ≡ 1 mod 4, we give the necessary and sufficient conditions for 8-ranks of narrow class groups of F equal to 1 or 2 such that we can calculate their densities. All results are stated in terms of congruence relations of p, q modulo 2^n, the quartic residue symbol （1/q）4 and binary quadratic forms such as q^h（-2p）/^4 = x^2 ＋ 2py^2 where h（-2p） is the class number of Q（√-2p）. The results are very useful for numerical computations.

关键词： Class group unramified extension quartic residue

Constructing of highly porous thermoelectric structures with improved thermoelectric performance

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Nano Research 2021年第10期14卷 3608-3615页

作者： Peilei He yue Wu Department of Chemical and Biological Engineering Iowa State UniversityAmesIowa 50011USA

As more than 60%of worldwide consumed energy is unused and becomes waste heat every year,high-efficiency waste heat to power technologies are highly demanded for the conversion of wasted heat to *** which can convert the wasted heat directly into electricity represent a promising approach for energy *** technology has existed for several decades,but its usage has been limited due to low *** advances in nanotechnology have enabled the improving of thermoelectric properties which open up the thermoelectrics’feasibility in *** this paper,we present an overview of recent progress in increasing the porosity of thermoelectric materials from atomic scale to microscale,leading to the enhancement of figure of merit.

关键词： thermoelectrics semiconductors porous structures thermal conductivity