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Behavior of Transversal Crack on Slab Corner During V-H Rolling Process

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Journal of Iron and Steel Research International 2006年第6期13卷 31-37页

作者： YU hai-liang liu Xiang-hua LI Chang-sheng Y. Kusaba State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Sumitomo Metal Industries Ltd Fuso-cho 660 AMAGASAKI Japan

The behavior of transversal cracks on the surface of the slab corner during vertical and horizontal （V-H） rolling process with flat vertical roll and groove vertical roll was simulated by explicit dynamic finite element method. The closure and growth of crack and the contact pressure on surfaces of the crack in contacting zone between slab and roll during rolling process were analyzed. The results showed that during vertical rolling process, when the groove vertical roll is used, the maximum contact pressure on surfaces of the crack is 115 MPa, and the closure of crack is stable when the flat vertical roll is used, the maximum contact pressure on surfaces of the crack is 70 MPa, and it fluctuates greatly. During horizontal rolling process, when groove vertical roll is used, the contact pressure becomes zero which may accelerate the growth of crack when flat vertical roll is used, there is still contact pressure. The cal culated results are in good agreement with the results of test.

关键词： slab crack V-H rolling process FEM

Asymmetric Synthesis of (3R,5R)-3-((tert-Butyldimethylsily)oxy)-5-((Z)-2-Bromovinyl)-Tetrahydro-Furan-2-one,an Intermediate for the Synthesis of Fostriecin

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Chinese Chemical Letters 2000年第11期11卷 957-960页

作者： Su Yun liu Dao Fei HUANG hai Hong HUANG liang HUANG Institute of Materia Medica Chinese Academy of Medical Science&Peking Union Medical CollegeBeijing 100050

(3R,5R)-3-((tert-Butyldimethylsily)oxy)-5-((Z)-2-bromovinyl)-tetrahydro-furan-2-one, an intermediate for the synthesis of Fostriecin was achieved by intramolecular asymmetric induction in propene addition of (-)-8-phenylmenthyl glyoxylate followed by inversion of C3-hydroxyl group and Sharpless asymmetric dihydroxylation with simultaneous cyclization to give lactone 5. Then protection of C3-hydroxyl group and oxidation of the C6-primary hydroxyl group which reacted with Wittig reagent to yield the target compound 4.

关键词： Fostriecin dihydroxylation (-)-8-phenylmenthol asymmetric synthes

Seasonal Variation of δ^13C of Four Tree Species： A Biological Integrator of Environmental Variables

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Journal of Integrative Plant Biology 2005年第12期47卷 1459-1469页

作者： hai-Tao LI Jun XIA Le XIANG Tao liang Qi-Jing liu Institute of Geographic Sciences and Natural Resources Research the Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research the Chinese Academy of Sciences Beijing 100101 China

Foliar δ^13C values, an indicator of long-term intercellular carbon dioxide concentration and, thus, of long-term water use efficiency （WUE） in plants, were measured for Pinus massoniana Lamb., P. elliottii Engelm., Cunninghamia laceolata （Lamb.） Hook., and Schima superba Gardn. et Champ. in a restored forest ecosystem in the Jiazhu River Basin. Seasonal variation and the relationship between the foliar δ^13C values of the four species and environmental factors （monthly total precipitation, monthly average air temperature, relative humidity, atmospheric pressure, and monthly total solar radiation and evaporation） were investigated. The monthly δ^13C values and WUE of the four species increased with increasing precipitation, air temperature, solar radiation, and evaporation, whereas δ^13C values of the four species decreased with increasing relative humidity and atmospheric pressure. Despite significant differences in δ^13C seasonal means for the four species, our results demonstrate a significant convergence in the responses of δ^13C values and WUE to seasonal variations in environmental factors among the species investigated and that the δ^13C signature for each species gives a strong indication of environmental variables.

关键词： δ^13C Cunninghamia laceolata Pinus elliottii Pinus massoniana Schima superba water use efficiency (WUE)

Mechanism of Effect of Microwave Modification on Pulverized Coal Combustion Properties

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Journal of Iron and Steel Research International 2014年第3期21卷 312-320页

作者： Qing-hai PANG Jian-liang ZHANG Rui MAO Zhe JIANG Tong liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Fushun Special Steel Shares Co. Ltd.

The mechanism of microwave modification or： facilitating the combustion properties of pulverized coal （PC） was investigated. Experimental researches on granularity and functional group as well as combustion properties of PC before and after modification were carried out. Micromorphology observation indicated that the size of PC par- ticles was relatively small, which was in accordance with the results of granularity analysis of PC. FT-IR （Fourier- transform infrared） spectra of two PCs indicated that the proportion of the functional groups with high activity in- creased after microwave irradiation. Furthermore, no valid effect of microwave was found on carbon matrix except small variations in PC particle size, which only led to subtle improvement in combustion of residual coke. Activation energies of Yungang and Yangquan PCs in temperature zone between 450--650 ℃ were reduced by 12.00% and 10.13%, respectively, which meant that microwave modification might effectively facilitate the combustion proper- ties of PC. Nevertheless, decrease in activation energies of residual cokes was 3.560% and 3.67% respectively, which was subtle and can be regarded as the result of smaller particle size produced by microwave irradiation.

关键词： pulverized coal injection combustion microwave modification

Analysis of Roll Gap Pressure in Sendzimir Mill by FEM

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Journal of Iron and Steel Research International 2008年第1期15卷 30-33页

作者： YU hai-liang liu Xiang-hua WANG Chao Park Hae-doo State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China Technical Research Laboratories POSCO Pohang 545-090 Korea

The acting force on the roll system of Sendzimir mill was analyzed using 3D *** roll gap pressure distribution and the acting force between rolls S and O,rolls O and I,rolls O and J,rolls I and A,rolls I and B,as well as rolls J and B were *** results showed that the roll gap pressure mainly affected the roll surface layer,50 mm for backup roll;the roll gap pressure distribution is of double peaks among the work roll,the 1st intermediate roll（IMR）,and the 2nd IMR;the maximum value of the roll gap pressure between the backup roll and the second IMR appears on the edge of the barrel of rolls;the component force presents the in-para-curve *** are important for reducing the wear of rolls and the break of the backup roll and guiding for production.

关键词： roll gap pressure Sendzimir mill FEM

The effects of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents:a meta-analysis

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Neural Regeneration Research 2025年第5期20卷 1513-1520页

作者： Xueyun Shao Longfei He Yangyang liu Physical Education School Shenzhen UniversityShenzhenGuangdong ProvinceChina Shenzhen Institute of Neuroscience ShenzhenGuangdong ProvinceChina

Brain-derived neurotrophic factor is a crucial neurotrophic factor that plays a significant role in brain health. Although the vast majority of meta-analyses have confirmed that exercise interventions can increase brain-derived neurotrophic factor levels in children and adolescents, the effects of specific types of exercise on brain-derived neurotrophic factor levels are still controversial. To address this issue, we used meta-analytic methods to quantitatively evaluate, analyze, and integrate relevant studies. Our goals were to formulate general conclusions regarding the use of exercise interventions, explore the physiological mechanisms by which exercise improves brain health and cognitive ability in children and adolescents, and provide a reliable foundation for follow-up research. We used the Pub Med, Web of Science, Science Direct, Springer, Wiley Online Library, Weipu, Wanfang, and China National Knowledge Infrastructure databases to search for randomized controlled trials examining the influences of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents. The extracted data were analyzed using Review Manager 5.3. According to the inclusion criteria, we assessed randomized controlled trials in which the samples were mainly children and adolescents, and the outcome indicators were measured before and after the intervention. We excluded animal experiments, studies that lacked a control group, and those that did not report quantitative results. The mean difference(MD;before versus after intervention) was used to evaluate the effect of exercise on brain-derived neurotrophic factor levels in children and adolescents. Overall, 531 participants(60 children and 471 adolescents, 10.9–16.1 years) were included from 13 randomized controlled trials. Heterogeneity was evaluated using the Q statistic and I^(2) test provided by Review Manager software. The meta-analysis showed that there was no heterogeneity among the studies(P = 0.67,

关键词： adolescents brain-derived neurotrophic factor children exercise meta-analysis randomized controlled trials

The role of axon guidance molecules in the pathogenesis of epilepsy

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Neural Regeneration Research 2025年第5期20卷 1244-1257页

作者： Zheng liu Chunhua Pan Hao Huang Department of Neurology Affiliated Hospital of Zunyi Medical UniversityZunyiGuizhou ProvinceChina

Current treatments for epilepsy can only manage the symptoms of the condition but cannot alter the initial onset or halt the progression of the disease. Consequently, it is crucial to identify drugs that can target novel cellular and molecular mechanisms and mechanisms of action. Increasing evidence suggests that axon guidance molecules play a role in the structural and functional modifications of neural networks and that the dysregulation of these molecules is associated with epilepsy susceptibility. In this review, we discuss the essential role of axon guidance molecules in neuronal activity in patients with epilepsy as well as the impact of these molecules on synaptic plasticity and brain tissue remodeling. Furthermore, we examine the relationship between axon guidance molecules and neuroinflammation, as well as the structural changes in specific brain regions that contribute to the development of epilepsy. Ample evidence indicates that axon guidance molecules, including semaphorins and ephrins, play a fundamental role in guiding axon growth and the establishment of synaptic connections. Deviations in their expression or function can disrupt neuronal connections, ultimately leading to epileptic seizures. The remodeling of neural networks is a significant characteristic of epilepsy, with axon guidance molecules playing a role in the dynamic reorganization of neural circuits. This, in turn, affects synapse formation and elimination. Dysregulation of these molecules can upset the delicate balance between excitation and inhibition within a neural network, thereby increasing the risk of overexcitation and the development of epilepsy. Inflammatory signals can regulate the expression and function of axon guidance molecules, thus influencing axonal growth, axon orientation, and synaptic plasticity. The dysregulation of neuroinflammation can intensify neuronal dysfunction and contribute to the occurrence of epilepsy. This review delves into the mechanisms associated with

关键词： axon guidance drug-resistant epilepsy epilepsy nerve regeneration nervous system diseases neural pathways neuroinflammatory diseases neuronal plasticity neurons synaptic remodeling

FoxO is required for optimal fitness of the migratory brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

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Insect Science 2023年第5期30卷 1352-1362页

作者： Jin-Li Zhang Ke-liang liu Xin-Yu Cai Xin-Yang liu hai-Jun Xu State Key Laboratory of Rice Biology Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang ProvinceInstitute of Insect SciencesCollege of Agriculture and BiotechnologyZhejiang UniversityHangzhouChina

The forkhead box O(FoxO)protein is the main transcriptional effector downstream of the insulin/insulin-like signaling pathway and regulates many developmental and physiological *** insects with loss-of-function mutations in FoxO exhibit phenotypes distinct from those of hemimetabolous insects in which RNA interference was *** the functional importance of FoxO,whether hemimetabolous insects share an evolutionally conserved function of FoxO with holometabolous insects remains to be *** used the clustered regularly interspaced short palindromic repeats/CRISPR-associated 9(CRISPR/Cas9)genome editing-system to establish a homozygous FoxO-null mutant(NlFoxO^(4E))of the wing-dimorphic brown planthopper(BPH)Nilaparvata lugens,an economically important insect pest of rice *** phenotypes of NlFoxO^(4E) mutants included extended nymphal duration,shortened lifespan,reduced reproduction,and decreased stress *** addition,depletion of NlFoxO promoted cell proliferation in wing buds and led to 100%long-winged morphs,in stark contrast to short-winged wild-type *** findings indicate that NlFoxO is highly functionally conserved with its counterpart in holometabolous insects,and is required for optimal fitness of *** insights from FoxO studies may facilitate the identification of potential target genes for BPH control applications.

关键词： cell proliferation CRISPR/Cas9 FoxO longevity planthopper reproduction

Investigation on Pulverized Coal Combustion Behavior by Non-Isothermic Integral Thermogravimetry Method

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Journal of Iron and Steel Research International 2011年第8期18卷 1-8页

作者： QI Cheng-lin ZHANG Jian-liang LIN Xiang-hai liu Qin-yuan WANG Xiao-liu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

The combustion process of pulverized coal was investigated by non-isothermic integral thermogravimetry. The thermogravimetry curves were fitted by the Coats-Redferm approximation function, and kinetic parameters and characteristic temperatures were obtained. The optimal mixing ratio and particle size can be ascertained. The characteristic temperature of pulverized coal can be obtained from the thermogravimetry curve, and the combustion of coal can be divided into homogeneous and heterogeneous combustion according to the differential thermal analysis curve. The activation energy of a single type of coal ranking from low to high is as follows： bituminous coal, meager-lean coal, and anthracite. In the first mixing method, with more low-price meager-lean coal B replacing high price anthracite A, the activation energy slightly decreases; with more bituminous coal replacing meager-lean coal, total tendency makes a declining of activation. In the later mixing method, with an increase in particle size, a declining activation energy can be seen in total tendency.

关键词： pulverized coal combustion themogravimetry kinetics mixed-coal granularity coal combustion