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Prediction Model of Abutment Pressure Affected by Far-Field Hard Stratum Based on Elastic Foundation Theory

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Computers, Materials & Continua 2021年第1期66卷 341-357页

作者： Zhimin zhang Tianhe kang Key Laboratory of In-situ Property-Improving Mining of Ministry of Education Taiyuan University of TechnologyTaiyuan030024China

In view of the three-dimensional dynamic abutment pressure,the influence of the far-field hard stratum(FHS)in deep,thick coal seams is *** on elastic foundation theory,a three-dimensional dynamic prediction model of the abutment pressure was *** this model,the dynamic change in the coal seam abutment pressure caused by the movement of the FHS was studied,and a method for determining the dynamic change range of the abutment pressure was *** results of the new prediction model of the abutment pressure are slightly higher than the measured values,with an error of 0.51%,which avoids the shortcomings of the results because the Winkler foundation model results are lower than the measured values and have an error of 9.98%.As time progresses,the abutment pressure and its distribution range are affected by the FHS movement,which has the characteristics of gradually increasing dynamic change until the FHS *** peak value of the abutment pressure increases linearly with time,and the influence range increases with time following a power function with an exponent of less than *** influence range of the FHS movement on the abutment pressure ahead of the working face,behind the working face,and along the working face is 10 times,25 times,and 17 times the mining thickness,*** to the actual geological parameters,the dynamic change range of the coal seam abutment pressure was determined by drawing an additional stress curve and by determining the threshold *** research results are of great significance to the partition optimization of the roadway support design of deep,thick coal seams.

关键词： Abutment pressure far-field hard stratum Kerr elastic foundation model dynamic change mechanical model influence range

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量子核判别分析算法

郑州大学学报（理学版） 2025年第1期57卷 61-66页

作者：康榕乘余凯张新林崧郭躬德福建师范大学计算机与网络空间安全学院福建福州350117 福建师范大学数字福建环境监测物联网实验室福建福州350117 福建师范大学数学与统计学院福建福州350117

核判别分析法通过核函数扩展了线性判别分析对非线性数据的处理能力,成为模式识别领域中一个重要的分支。然而,随着数据的指数增长,经典核判别分析算法在提取特征时会消耗大量计算资源。针对这一问题,利用量子叠加性和并行性提出了一种... 详细信息

核判别分析法通过核函数扩展了线性判别分析对非线性数据的处理能力,成为模式识别领域中一个重要的分支。然而,随着数据的指数增长,经典核判别分析算法在提取特征时会消耗大量计算资源。针对这一问题,利用量子叠加性和并行性提出了一种量子核判别分析算法。首先,借助量子随机存储器技术与控制旋转操作构造需要的类间矩阵和类内矩阵所对应的密度算子;然后,融入线性方程的求解思路并行获取特征态。理论分析表明,所提算法与经典算法相比具有指数级加速。

关键词：量子机器学习非线性判别分析核函数特征提取量子厄米特链积相位估计

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Study of Rotating Stall in a Centrifugal Compressor with Wide Vaneless Diffuser

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Journal of Thermal Science 2020年第3期29卷 743-752页

作者： zhang Lei ZHENG Zhi zhang Qian zhang Liang LI kang Department of Power Engineering North China Electric Power UniversityBaoding 071003China

To study the stall mechanism in a wide vaneless diffuser,a three-dimensional centrifugal compressor model was *** numerical simulation method was used to study the fluid characteristics in a centrifugal compressor with a wide vaneless diffuser under stall *** simulated results showed that the wide vaneless diffuser stall was related to the instability of the core *** to the influence of the reflow,the core flows moved between the hub and shroud side and the directions were not *** was called core flow distortion,which triggered the rotating *** reflow first appeared at the outlet boundary of the diffuser,and the reflux gradually expanded to the inside of the diffuser as the impeller ***,the reflux zones grew and merged,forming a stable low-speed fluid regiment,which produced a stall *** stall cells rotated around themselves with an opposite direction with impeller.

关键词： centrifugal compressor wide vaneless diffuser rotating stall numerical simulation

Radiological diagnosis of duodenocaval fistula:A case report and literature review

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World Journal of Gastroenterology 2010年第18期16卷 2314-2316页

作者： Guo, Yong zhang, Yan-qun Lin, Wei Gen Navy Hosp Dept Radiol Beijing 100048 Peoples R China

Duodenocaval fistula(DCF) is an uncommon but lethal clinical *** high mortality has been attributed to the difficulty of diagnosis before attempts at definitive *** this case report,we describe a patient with a series of computed tomography(CT) examinations over a 2-mo period in hospital.A low-density air bubble appeared in the inferior vena cava(IVC) on the second day in hospital and became clear on day 19,and gradually *** resonance imaging(MRI) also clearly demonstrated a high-signal enteric contrast medium or thrombus and signal-void air bubbles in the ***,cavography did not show the filling *** suggest that noninvasive CT and MRI should be chosen as a first-line investigation,and IVC,including the surrounding structures,should be carefully reviewed on images if DCF is clinically considered.

关键词： Duodenocaval fi stula Computed tomography Magnetic resonance imaging

Correlation of brain-derived neurotrophic factor to cognitive impairment following traumatic brain injury in rats

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Neural Regeneration Research 2008年第11期3卷 1161-1167页

作者： Dezhi kang zhang Guo Department of Neurosurgery First Affiliated Hospital Fujian Medical University Fuzhou 350005 Fujian Province China

BACKGROUND： In vitro and in vivo studies have confirmed that brain-derived neurotrophic factor （BDNF） can promote survival and differentiation of cholinergic, dopaminergic and motor neurons, and axonal regeneration. BDNF has neuroprotective effects on the nervous system. OBJECTIVE： To explore changes in BDNF expression and cognitive function in rats after brain injury. DESIGN, TIME AND SETTING： The neuropathology experiment was performed at the Second Research Room, Department of Neurosurgery, Fujian Medical University （China） from July 2007 to July 2008. MATERIALS： A total of 72 healthy, male, Sprague Dawley, rats were selected for this study. METHODS： Rat models of mild and moderate traumatic brain injury were created by percussion, according to Feeney＇s method （n = 24, each group）. A bone window was made in rats from the sham operation group （n = 24）, but no attack was conducted. MAIN OUTCOME MEASURES： At days 1, 2, 4 and 7 following injury, BDNF expression in the rat frontal lobe cortex, hippocampus and basal forebrain was examined by immunohistochemistry （streptavidin-biotin-peroxidase complex method）. Changes in rat cognitive function were assessed by the walking test, balance-beam test and memory function detection. RESULTS： Cognitive impairment was aggravated at day 2, and recovered to normal at days 3 and 7 in rats from the mild and moderate traumatic brain injury groups. BDNF expression in the rat frontal lobe cortex, hippocampus and basal forebrain was increased at 1 day, decreased at day 2, and then gradually increased in the mild and moderate traumatic brain injury groups. BDNF expression was greater in rats from the moderate traumatic brain injury group than in the sham operation and mild traumatic brain injury groups （P 〈 0.05）. CONCLUSION： BDNF expression in the rat frontal lobe cortex, hippocampus and basal forebrain is correlated to cognitive impairment after traumatic brain injury. BDNF has a protective effect on cognitive function in rats followi

关键词： brain-derived neurotrophic factor cognitive impairment traumatic brain injury

Global Exponential Projective Synchronization and Lag Synchronization of Hyperchaotic Lü System

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Communications in Theoretical Physics 2009年第4期51卷 679-683页

作者： zhang qun-Jiao LU Jun-An JIA Zhen College of Science Wuhan University of Science and Engineering Wuhan.430073 China School of Mathematics and Statistics Wuhan University Wuhan 430072 China Department of Mathematics and Physics Guilin University of Technology Guilin 541004 China

This paper investigates the projective synchronization and lag synchronization of a new hyperchaotic system[Physica A 364(2006)103].On the basis of Lyapunov stability theory,two novel nonlinear controllers are respectivelydesigned to guarantee the global exponential projective synchronization(including complete synchronization and anti-synchronization)and lag ***,numerical simulations are given to show the effectiveness of the mainresults.

关键词： hyperchaotic Lü system projective synchronization lag synchronization exponential

Downregulation of the nucleosome-binding protein 1 （NSBP1） gene can inhibit the in vitro and in vivo proliferation of prostate cancer cells

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Asian Journal of Andrology 2010年第5期12卷 709-717页

作者： Ning Jiang Li-qun Zhou Xiao-Yu zhang Department of Urology Peking University First Hospital Beijing 100034 China The Institute of Urology Peking University Beijing 100034 China National Urological Cancer Center Beijing 100034 China

This studay is to construct a lentiviral vector harbouring an RNA interference （RNAi） sequence that targets the gene encoding the human high-mobility group nucleosomal binding protein 1 （NSBP1）; to study its role in inducing G2/M phase arrest and apoptosis in prostate cancer （PCa） DU145 cells; and to assess the effect of its knockdown on cell proliferation in vitro and in vivo. RNAi was applied to knock down NSBP1 expression in the PCa cell line DU145 by lentiviral plasmids producing an NSBP1 small hairpin RNA. After NSBP1 knockdown in DU145 cells, the growth rate of cells was analyzed by MTT, and G2/M cell cycle arrest and apoptosis were assessed using a FAC- Scalibur flow cytometer. Tumour growth was assessed in nude mice. The mRNA and protein expression levels of NSBP1, cyclin B1 and Bcl-2 were analysed in vitro and in vivo by reverse-transcriptase polymerase chain reaction and Western blotting. Knockdown of NSBP1 resulted in a 22.6% decrease in the growth rate of cells compared with the PscNC lentivirus control cells at 96 h, decreased tumour growth in nude mice, and the induction of Gz/M cell cycle arrest （8.78%） and apoptosis （2.19-fold）. Consistent with the cell cycle arrest and apoptosis, the mRNA and protein expression levels of cyclin B 1 and Bcl-2 were decreased. In conclusion, knockdown of NSBP 1 causes a statistically significant inhibition of the in vitro and in vivo growth of the PCa cell line DU145. Growth suppression is at least partially due to NSBP1 knockdown-induced Gz/M cell cycle arrest and apoptosis. The present data provide the evidence that the NSBP1 knockdown-induced G2/M phase arrest and apoptosis may result from negative regulation of cyclin B 1 and Bcl-2 by NSBP1, with the resulting reduced expression of these proteins.

关键词： apoptosis NSBP 1 proliferation prostate cancer RNA interference

Effect of triple-phase contact line on contact angle hysteresis

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Science China(Physics,Mechanics & Astronomy) 2012年第6期55卷 1045-1050页

作者： YU Yang WU qun zhang Kai JI BaoHua Biomechanics and Biomaterials Laboratory Department of Applied Mechanics School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China Department of Engineering Mechanics Tsinghua University Beijing 100084 China

Recent studies have shown that the triple-phase contact line has critical effect on the contact angle hysteresis of *** this study,patterned surfaces with various surface structures of different area fractions were prepared by electron etching on a silicon *** advancing angle,receding angle and hysteresis angle of these surfaces were *** experimental results showed that while the geometry of microstructure and contact line have a minor effect on the advancing angle,they have a significant effect on the receding angle and thus the hysteresis *** have shown that the effect of microstructure and the contact line can be described by a quantitative parameter termed the triple-phase line *** theoretical predictions were in good agreement with our experimental results.

关键词： contact angle hysteresis receding angle surface microstructure area fraction contact line ratio wetting

Modeling the spatiotemporal dynamics of electric power consumption in China' Mainland using saturation-corrected DMSP/OLS nighttime stable light data

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International Journal of Digital Earth 2014年第12期7卷 993-1014页

作者： Chunyang He qun Ma Zhifeng Liu Qiaofeng zhang Center for Human-Environment System Sustainability(CHESS) State Key Laboratory of Earth Surface Processes and Resource EcologyBeijing Normal UniversityBeijingChina Department of Geosciences Murray State UniversityMurrayKYUSA

Obtaining timely and accurate data on the spatiotemporal dynamics of electric power consumption(EPC)is crucial for the effective utilization of electric power in *** Defense Meteorological Satellite Program’s Operational Linescan System(DMSP/OLS)nighttime stable light(NSL)data have good potential for estimating EPC effectively at large ***,saturated lighted pixels contained within the NSL data limit the accuracy of EPC *** developed a new method to correct the saturated lighted pixels,using the SPOT VEGETATION(SPOT/VGT)10-day synthesis product(S10)normalized differ-ence vegetation index(NDVI)data and then modeled the spatiotemporal dynamics of EPC in China' Mainland from 2000 to *** results demon-strated the reliability of our approach with an average Rvalue of 0.93(P<0.001)and an average relative error of-28.92%.EPC in China' Mainland showed an average annual growth rate of 13.46% during the study period from 1198.23 billion kWh in 2000 to 3290.51 billion kWh in *** in China' Mainland also showed clear regional *** coastal China and eastern coastal China consumed 37.61%of the total EPC in China' Mainland,with only 25.96% of the population and 6.11% of the area.

关键词： electric power consumption(EPC) DMSP/OLS nighttime stable light data saturation correction spatiotemporal dynamics China'Mainland