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Applied Mathematics and Mechanics(English Edition) 2015年第8期36卷 1017-1032页

作者： Demin ZHAO Jianlin LIU c.Q.wu Department of Mechanics College of Pipeline and Civil Engineering China University of Petroleum Department of Mechanical and Manufacturing Engineering University of Manitoba

The parametric excited vibration of a pipe under thermal loading may occur because the fluid is often transported heatedly. The effects of thermal loading on the pipe stability and local bifurcations have rarely been studied. The stability and the local bifurcations of the lateral parametric resonance of the pipe induced by the pulsating fluid velocity and the thermal loading are studied. A mathematical model for a simply supported pipe is developed according to the Hamilton principle. Two partial differential equations describing the lateral and longitudinal vibration are obtained. The singularity theory is utilized to anMyze the stability and the bifurcation of the system solutions. The transition sets and the bifurcation diagrams are obtained both in the unfolding parameter space and the physical parameter space, which can reveal the relationship between the thermal field parameter and the dynamic behaviors of the pipe. The frequency response and the relationship between the critical thermal rate and the pulsating fluid velocity are obtained. The numerical results demonstrate the accuracy of the single-mode expansion of the solution and the stability and local bifurcation analyses. It also confirms the existence of the chaos. The presented work can provide valuable information for the design of the pipeline and the controllers to prevent the structural instability.

关键词： thermal load parameter excited local bifurcation,unfolding parameterspace physical parameter space

基于固相萃取-高效液相色谱-串联质谱测定孕妇尿液中8种邻苯二甲酸酯代谢物及新生儿出生结局评价

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色谱 2025年第1期43卷 60-67页

作者：王梓皓徐梦菲李贝妮吴萍吴微湖北中医药大学检验学院湖北武汉430065

邻苯二甲酸酯(PAEs)是一种环境内分泌干扰物,广泛存在于日常生活中,并可通过多种途径进入机体。孕妇作为一类特殊人群,若暴露于PAEs,将会对子代的生长发育造成不良影响。研究建立了固相萃取-高效液相色谱-串联质谱(SPE-HPLc-MS/MS)同时... 详细信息

邻苯二甲酸酯(PAEs)是一种环境内分泌干扰物,广泛存在于日常生活中,并可通过多种途径进入机体。孕妇作为一类特殊人群,若暴露于PAEs,将会对子代的生长发育造成不良影响。研究建立了固相萃取-高效液相色谱-串联质谱(SPE-HPLc-MS/MS)同时检测孕妇尿液中8种PAEs代谢物(mPAEs)的分析方法。尿液样品经β-葡萄糖苷酶酶解后,采用Bond Elut Plexa固相萃取柱净化,样品经洗脱、浓缩、复溶后,进行HPLc-MS/MS分析。采用Agilent Eclipse Plus c18色谱柱(100 mm×3 mm,3.5μm)进行分离,以0.1%乙酸水溶液和0.1%乙酸乙腈作为流动相进行梯度洗脱,在多反应监测(MRM)模式下检测,内标法定量。结果表明,8种mPAEs在0.1~200 ng/mL范围内线性关系良好,检出限为0.015~0.048 ng/mL,定量限为0.050~0.160 ng/mL。在低、中、高3个加标水平(1、10、50 ng/mL)下,8种mPAEs的加标回收率为80.2%~99.7%。采用此方法对鄂州市妇幼保健院497名孕妇尿液中的8种mPAEs水平进行检测,结果表明,497名孕妇广泛暴露于PAEs,其中邻苯二甲酸单丁酯(MBP)的含量最高,中位数水平为104.46 ng/mL;邻苯二甲酸单苄酯(MBzP)的含量最低,中位数水平为0.22 ng/mL。同时,研究还对新生儿的出生结局进行了评估,线性回归模型表明,孕妇尿液中的邻苯二甲酸单乙酯(MEP)每增加一个自然对数(ln)水平,孕周减少0.11周(95%置信区间(cI):-0.18~-0.03);孕妇尿液中的邻苯二甲酸(2-乙基-5-氧己基)酯(MEOHP)和邻苯二甲酸单(2-乙基己基)酯(MEcPP)每增加一个ln水平,新生儿出生体重分别降低39.28 g(95%cI:-76.48~-2.09)和39.62 g(95%cI:-73.73~-5.52)。该方法操作简便,检出限低,具有较高的准确度和精密度,通过此方法测定了孕妇尿液中的8种mPAEs,并结合新生儿的出生结局发现,孕期PAEs暴露会影响新生儿的生长发育。

关键词：高效液相色谱-串联质谱邻苯二甲酸酯代谢物孕妇尿液出生结局

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省域高等教育分类发展的竞合逻辑与实践路径

高校教育管理 2025年第1期19卷 74-83页

作者：王丹吴立保南京信息工程大学高等教育研究所江苏南京210044 淮北师范大学教育学院安徽淮北235000

实现高等教育分类发展是建设教育强国的先决条件,省域高等教育分类发展对教育强国建设负有主体责任。本研究依托竞合理论,针对省域高等教育分类标准固化、合作联动不足和分类目标建设失衡、合作理念和行动不足等问题,提出竞合视角下省... 详细信息

实现高等教育分类发展是建设教育强国的先决条件,省域高等教育分类发展对教育强国建设负有主体责任。本研究依托竞合理论,针对省域高等教育分类标准固化、合作联动不足和分类目标建设失衡、合作理念和行动不足等问题,提出竞合视角下省域高等教育分类发展的实践路径,通过构建省域高等教育分类多主体竞合生态关系,建立互涉共生的省域高校分类发展主体,形成互补嵌入的结构化竞合和评价机制,分类引领确立互为目标的价值旨归以突破传统分类发展中的路径依赖和组织惯习影响,为建设中国特色、世界一流的高等教育贡献力量。

关键词：省域高等教育分类发展竞合理论生态关系实践路径

Sulfide elimination by intermittent nitrate dosing in sewer sediments

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Journal of Environmental Sciences 2015年第1期27卷 259-265页

作者： Yanchen Liu chen wu Xiaohong Zhou david Z.Zhu Hanchang Shi School of Environment Tsinghua University Department of civil and Environmental Engineering University of Alberta

The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation–reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S（nitrate/sulfide）ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.

关键词： Sewer system Sulfide elimination Sediment Optimal condition Intermittent nitrate dosing

comparative study of gut microbiota from captive and confiscatedrescued wild pangolins

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Journal of Genetics and Genomics 2021年第9期48卷 825-835页

作者： chunbing Liu Jingyang Hu Yajiang wu david M.Irwin wu chen Zhigang Zhang Li Yu State Key Laboratory for conservation and Utilization of Bio-Resources in Yunnan School of Life SciencesYunnan UniversityKunming 650091China Guangzhou Zoo&Guangzhou Wildlife Research center Guangzhou 510070China Department of Laboratory Medicine and Pathobiology University of TorontoTorontoOntario M5S 1A8Canada

Pangolins are among the most critically endangered animals due to widespread poaching and worldwide trafficking. captive breeding is considered to be one way to protect them and increase the sizes of their populations. However, comparative studies of captive and wild pangolins in the context of gut microbiota are rare. Here, the gut microbiome of captive and confiscated-rescued wild pangolins is compared, and the effects of different periods of captivity and captivity with and without antibiotic treatment are *** show that different diets and periods of captivity, as well as the application of antibiotic therapy, can alter gut community composition and abundance in pangolins. compared to wild pangolins, captive pangolins have an increased capacity for chitin and cellulose/hemicellulose degradation, fatty acid metabolism, and short-chain fatty acid synthesis, but a reduced ability to metabolize exogenous substances. In addition to increasing the ability of the gut microbiota to metabolize nutrients in captivity, captive breeding imposes some risks for survival by resulting in a greater abundance of antibiotic resistance genes and virulence factors in captive pangolins than in wild pangolins. Our study is important for the development of guidelines for pangolin conservation, including health assessment, disease prevention, and rehabilitation of wild pangolin populations.

关键词： Pangolin Gut microbiome captivity Antibiotic resistance genes Virulence factors

A modular hierarchical array camera

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Light(Science & Applications) 2021年第4期10卷 542-550页

作者： Xiaoyun Yuan Mengqi Ji Jiamin wu david JBrady Qionghai Dai Lu Fang Departm ent of Electronic Engineering Tsinghua UniversityBeijing 100084China Department of Automation Tsinghua UniversityBeijing 100084China college of Optical Sciences University of ArizonaTucsonAZ 85721USA lnstitute of Brain and cognitive Science Tsinghua UniversityBeijing 100084China Beijing National Research center for Information Science and Technology Beijing 100084China

Array cameras removed the optical limitations of a single camera and paved the way for high-performance imaging via the combination of micro-cameras and computation to fuse multiple aperture ***,existing solutions use dense arrays of cameras that require laborious calibration and lack flexibility and *** by the cognition function principle of the human brain,we develop an unstructured array camera system that adopts a hierarchical modular design with multiscale hybrid cameras composing different *** computations are designed to collaboratively operate along both intra-and intermodule *** system can adaptively allocate imagery resources to dramatically reduce the hardware cost and possesses unprecedented flexibility,robustness,and *** scenes of real-world data were acquired to perform human-centric studies for the assessment of human behaviours at the individual level and crowd behaviours at the population level requiring highresolution long-term monitoring of dynamic wide-area scenes.

关键词： camera system removed

Black Locust Transpiration Responses to Soil Water Availability as Affected by Meteorological Factors and Soil Texture

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Pedosphere 2015年第1期25卷 57-71页

作者： wu Yuan-Zhi HUANG Ming-Bin david N.WARRINGTON Shandong Provincial Key Laboratory of Water and Soil conservation and Environmental Protection Linyi University State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Northwest A&F University

On the Loess Plateau of china, a dry soil layer may form due to excess transpiration, leading to degradation of black locust(Robinia pseudoacacia) stands. In order to better manage projects involving black locust, this study was intended to investigate the response of black locust transpiration rate to soil water availability as affected by meteorological factors using two representative soils(loamy clay and sandy loam) on the Loess Plateau. Four soil water contents were maintained for black locust seedlings grown in pots initially outdoors and then in a climate-controlled chamber, by either drying or irrigating the pots. In both environments, daily transpiration rates were related by a power function to air temperature and by a logistic function to reference evapotranspiration(ET0). Transpiration rates were more susceptible to changes in the meteorological conditions in the sandy loam than in the loamy clay soil. The transpiration rate in the well-watered treatment was greater for black locust grown in the sandy loam than in the loamy clay soil. Normalized transpiration rates were unaffected by ET0 until a critical value of soil water content(θc) was attained; the θc value decreased significantly for the loamy clay soil but increased significantly for the sandy loam soil when ET0 increased. These suggested that the effect of the meteorological condition on the transpiration characteristics of black locust was dependent on soil texture.

关键词： dry soil layer evaporative demand loamy clay Loess Plateau reference evapotranspiration sandy loam temperature vapor pressure deficit

Exercise immunology:Novel insights

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Journal of Sport and Health Science 2024年第3期13卷 277-279,I0001页

作者： david c.Nieman Human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA

The coronavirus disease 2019(cOVID-19)pandemic heightened worldwide attention on the influence of exercise on the immune *** were raised about whether regular moderate-to-vigorous physical activity(MVPA)could help prevent cOVID-19 or mitigate symptoms when *** MVPA bolster immunity among those most prone to cOVID-19 including the elderly,obese,and immunocompromised patients?Does regular MVPA dampen systemic inflammation,thereby lessening the cOVID-19 cytokine storm?

关键词： immunity inflammation thereby

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science china chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-cheng Tang Ding-Kang chen Ming-Ming cao Yao-Wen chang Hong-Yu Tang chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of chinese Academy of Sciences Lab of computational chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at c-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

Laser additive manufacturing of biodegradable Mg-based alloys for biomedical applications: A review

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Journal of Magnesium and Alloys 2022年第4期10卷 915-937页

作者： c.L.wu W.J.Xie H.c.Man Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

Metallic implants are widely used in internal fixation of bone fracture in surgical *** are mainly used for providing mechanical support and stability during bone reunion,which usually takes a few months to *** implants made of stainless steels,Ti-based alloys and cocrMo alloys have been widely used for orthopedic reconstruction due to their high strength and high corrosion *** metallic implants will remain permanently inside the body after implantation,and a second surgery after bone healing is needed because the long-term presence of implant will lead to various *** implant removal surgery not only incurs expenditure,but also risk and psychological *** a consequence,studies on the development of biodegradable implants,which would degrade and disappear in vivo after bone reunion is completed,have drawn researchers’*** this connection,Mg-based alloys have shown great potentials as promising implant materials mainly due to their low density,inherent biocompatibility,biodegradability and mechanical properties close to those of ***,the high degradation rate of Mg-based implants in vivo is the biggest hurdle to *** from materials selection,a fixation implant is ideally tailor-made in size and shape for an individual case,for best surgical ***,laser additive manufacturing(LAM),with the advent of sophisticated laser systems and software,is an ideal process to solve these *** this paper,we reviewed the progress in LAM of biodegradable Mg-based alloys for biomedical *** effect of powder properties and laser processing parameter on the formability and quality was thoroughly *** microstructure,phase constituents and metallurgical defects formed in the LAMed samples were *** mechanical properties,corrosion resistance,biocompatibility and antibacterial properties of the LAMed samples were summarized and compared with samples fabricated by

关键词： Laser additive manufacturing Magnesium alloys Implant Biomedical applications Mechanical properties Biodegradability