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X射线检查对小儿呼吸道合胞病毒肺炎的诊断效果及影像学分析

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中国医疗器械信息 2024年第14期30卷 133-135页

作者：刘倩雯连江县凤城镇社区卫生服务中心超声科福建福州350500

目的:研究小儿呼吸道合胞病毒肺炎应用X射线检查的效果。方法:研究对象为本社区卫生服务中心2020年1月~2023年12月收治的82例呼吸道合胞病毒肺炎患儿,所有患儿均进行X射线检查,观察呼吸道合胞病毒肺炎影像表现并详细记录检查结果。结果... 详细信息

目的:研究小儿呼吸道合胞病毒肺炎应用X射线检查的效果。方法:研究对象为本社区卫生服务中心2020年1月~2023年12月收治的82例呼吸道合胞病毒肺炎患儿,所有患儿均进行X射线检查,观察呼吸道合胞病毒肺炎影像表现并详细记录检查结果。结果:82例患儿的X射线检查结果显示:支气管炎23例(28.05%),肺内实质性病变59例(71.95%);54例(65.85%)患儿可见斑片状密度增高影沿支气管束走行,累及下肺野的病变共24例(29.27%),累及肺野内中带的病变共30例(36.59%);多灶性病变共38例(46.34%);实变较为少见共3例(3.66%),片状影融合表现为实变,主要在两下肺野、右上肺野分布,且其分布呈现出沿支气管束走行的特点;未观察到胸腔积液。32例患儿行X射线检查后在1周内进行复查,结果显示绝大多数患儿肺内病变均出现吸收,阅片结果与临床诊断的一致性较高(Kappa=0.786)。结论:X射线检查在小儿呼吸道合胞病毒肺炎的临床诊断中具有较高的应用价值,可有效检出肺内病变,明确病变分布,帮助临床上鉴别诊断该疾病。

关键词：呼吸道合胞病毒肺炎 X射线检查影像表现

数学教科书“旁白”中的“留白”探析——以人教A版高中数学教科书为例

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数学教育学报 2024年第4期33卷 20-25页

作者：韩粟刘倩雯汪晓勤华东师范大学数学科学学院上海200241

“旁白”是新世纪数学教科书的新增栏目之一.探析数学教科书旁白中的“留白”,旨在本土语境中重塑教科书旁白的教育价值,阐明其教学功能.教科书的整体定位转变、单元体例更新与意识形态变化,揭示了教科书旁白“留白有源”的理论背景.例... 详细信息

“旁白”是新世纪数学教科书的新增栏目之一.探析数学教科书旁白中的“留白”,旨在本土语境中重塑教科书旁白的教育价值,阐明其教学功能.教科书的整体定位转变、单元体例更新与意识形态变化,揭示了教科书旁白“留白有源”的理论背景.例析人教A版高中数学教科书,发现数学教科书在旁白中主要留有“论证之白”和“陈述之白”,其次留有“发现之白”和“方法之白”,极少留有“超越之白”,反映出教科书旁白“留白有形”的实然现状.未来可以从丰富教科书旁白的留白设计、实践基于教科书的“留白创造式”教学及拓展教科书旁白与留白的研究3个方面擘画和实现教科书旁白“留白有期”的美好蓝图.

关键词：数学教科书教科书旁白留白留白创造式教学

Unthermal Hawking Radiation from a General Stationary Black Hole

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Communications in Theoretical Physics 2008年第2期49卷 379-381页

作者： ZHANG Yong-Ping DAI qian liu wen-Biao Department of Physics Institute of Theoretical Physics Beijing Normal University Beijing 100875 China

Using Damour-Ruflini＇s method, Hawking radiation from a general stationary black hole is investigated again deeply. Considering the back reaction of the particle to the space-time and energy conservation, we find that the radiation is not exactly thermal and can take out information from the black hole. This can be used to explain the information loss paradox, and the result is consistent with the works finished before.

关键词： Hawking radiation stationary black hole back-reaction information loss paradox unitary theory

Synthesis and Crystal Structure of a Dinuclear Cu(Ⅱ) Complex Based on a Carboxyl-substituted 1H-1,2,3-Triazole and Its DNA Cleavage Activity

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Chinese Journal of Structural Chemistry 2015年第6期34卷 917-924页

作者： liu wen-qian ZHOU Shi-Lei FAN Ming-Zhu PAN Zhi-Quan CHEN Yun-Feng School of Chemistry and Environmental Engineering Wuhan Institute of Technology

The novel dinuclear copper complex [Cu2（H20）2（DMF）2（L）2] （1, H2L = 5-phenyl- 2H-1,2,3-triazole-4-carboxylic acid, DMF = N,N-dimethyl-formamide） has been synthesized and characterized by X-ray single-crystal diffraction. The compound crystallizes in triclinic system, space group P1 with a = 9.591, b = 10.508, c = 15.515A,β = 75.11°, V= 1446.2 A3, Z= 2, Mr = 683.62, Dc = 1.570 g/cm3, μ = 1.531 mm^-1, F（000） = 700, the final R = 0.0404 and wR = 0.1130 for 5327 observed reflections with I 〉 2σ（I）. In each unit of the complex, two Cu2＋ ions coordinated with two triazole ligands to form a dimeric [5,6,5] tricyclic structure. The central Cu atom is five-coordinated, and each copper atom shows a square pyramidal geometry. The crystal structure is stabilized by the inversion-related O-H…O hydrogen bond and C-H…O hydrogen bonding interactions to form a layer structure. Fluorescent spectra show an obvious quenching of fluorescence compared with free 1,2,3-triazole ligand. The results of agarose gel electrophoresis indicate that this complex can cleave the plasmid supercoiled DNA within shorter time in the 50-folds excess of ascorbate under physiological conditions, providing a new example in the research for artificial metal nucleic acid enzyme.

关键词： 1,2,3-triazole copper complex crystal structure fluorescent property DNA cleavage activity

Empirical Analysis on Influence Mechanism of Cohesiveness and Collective Efficacy of Virtual Community Based on Triadic Reciprocal Determinism

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China Communications 2014年第11期11卷 146-155页

作者： NING Lianju liu qian XIA wen School of Economics and Management Beijing University of Posts and Telecommunications Beijing 100876 China

The virtual community has become a new life style as for human,but the public's acceptance is relatively low at *** the research about the mechanism of the influence on the cohesiveness and the collective efficiency in virtual community has an important theoretical value and practical *** the paper,the key variables that affect virtual community cohesiveness are extracted from two aspects—self-perception of community members and community environment,and the influence mechanism model of virtual community cohesiveness and community collective efficiency is established based on Triadic Reciprocal *** means of the questionnaire on the community members and the empirical analysis,the key factors influencing cohesiveness of virtual community are brought up,as well as the mechanism that the four dimensions of cohesiveness work,on collective *** to the results,it is practically meaningful that the problems and insufficiency in the operation of existing virtual community are discovered,which guides the operating managers of the virtual community to formulate operation policy of the virtual community for operating managers to develop strategies.

关键词： virtual community cohesiveness collective efficacy environment variables self-cognition.

Tuning heterogeneous microstructures to enhance mechanical properties of nano-TiN particle reinforced Haynes 230 composites by laser powder bed fusion

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Rare Metals 2024年第9期43卷 4548-4565页

作者： wen-Jie liu Hui Li qian-Xing Yin He-Jun Du School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China The Institute of Technological Sciences Wuhan UniversityWuhan 430072China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

Laser powder bed fusion(LPBF)is considered to be one of the most promising additive manufacturing technologies for producing components with geometries and high geometrical precision that are unattainable by traditional *** superalloy exhibits exceptional mechanical and high-temperature performances,rendering it a prime candidate for advanced aero-engine *** the high demand for LPBF-manufactured superalloys,the superalloy is one of the materials manufactured difficultly by LPBF due to their large laser absorptivity fluctuation,poor molten pool stability and sharp temperature ***,superalloys are characterized by severe pores,undesirable coarse columnar grains and poor mechanical *** this work,the effect of nano-TiN particles on defects,molten pool characteristics and microstructure and performance of the composites were *** 4.5 wt%TiN/Haynes230 samples exhibited exceptional nanohardness and elastic modulus with maximum values reaching 5.53 GPa and 240.03 GPa,*** superior mechanical properties were attributed to the combined effects of spatter and gas pore inhibition,grain refinement and duplex nanophases ***,the stability of molten pool was enhanced,and spatter was effectively suppressed by adding nano-TiN particles,while grain refinement and columnar to equiaxed transitions were ***,the matrix exhibited a high dislocation density due to a significant hindrance of dislocation movement caused by massive nano-phases(e.g.,TiN and M_(23)C_(6)),resulting in the formation of extensive dislocation tangles and *** work offers novel insights into the role of nanoparticles reinforced superalloy composites by LPBF.

关键词： Composites Laser powder bed fusion Molten pool characteristics Microstructure Mechanical properties

Spatial pattern and utility of Populus euphratica seed rain:a simulation study combined with field investigations

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Forestry Studies in China 2012年第3期14卷 169-179页

作者： HAO Peng LI Jing-wen ZHOU Wei-lei liu qian-wen ZHANG Yu-bo Key Laboratory for Silviculture and Conservation of the Ministry of Education Beijing Forestry UniversityBeijing 100083E R.China Inner Mongolia Research Academy of Environmental Sciences Hohhot 010011P.R.China

Seed dispersal is a fundamental process affecting destinies of seeds and seedlings, as well as regeneration dynamics and distribution patterns of communities. Recently however, declining Populus euphratica forests have failed to regenerate by seeding, while the spatial pattern and utility of their seed rains are unclear. In this study, we designed a model to simulate seed rains based on field investigations by fitting our observations to a normal distribution and testing the model with data from three years, with ac- ceptable results. We examined the simulated results of dispersed seeds patterns on the classification of three factors, i.e., density of Sophora alopecuroides, surface soil moisture and surface soil salinity. The results of seed rain simulation show that over 70% of seeds were dispersed and confined to each of the three plots where their mother trees located. The proportion of 3：7 seeds dispersed inside and outside each plots remained largely unaltered. The differences in the amounts of dispersed seed among the different levels of each of the factors were not significant, although the distributing pattern of P. euphratica in each plot varied. Therefore, in P. eu- phratica communities, the amount of seed does not become a constraint in subsequent germination, although the surface environment does. We conclude that successful P. euphratica seed regeneration relies on less than 30% of seeds dispersed over longer distance to colonize favorable growth habitats.

关键词： Populus euphratica forest seed rain spatial pattern utility wind direction

A design of space robot multi-target capture algorithm based on DSP

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重庆邮电大学学报（自然科学版） 2009年第2期21卷 166-172页

作者： MA Xiao-na HU Bing-liang liu Xue-bin liu Hui liu qian-wen Laboratory of Spectral Imaging Technology Xi＇an Institute of Optics and Precision Mechanics of CAS Xi ＇ an 710119 P. R. China Graduate Institute of Chinese Academy of Sciences Beijing 100039 P. R. China

To correctly capture spatial targets from cluttered and motive celestial background,a new Multi-Target Capture algorithm was proposed,which is a comparative difference algorithm based on the combination of centroid extraction and despun registration of efficient ***,this algorithm was applied in an image processing system based on the DSP featuring high speed and high *** procedures of image processing are as follows:first,label efficient points in the frame and extract their centroids;second,make appropriate despun registration,according to the reference rotation angles provided by Space Robot position system;third,translate and register centroid coordinates of efficient points in reference frames and get the registration points according to the principle that there are the most same centroid coordinates of efficient points when completely registered;finally,eliminate the same background points by using comparative difference *** result shows that this image processing system can meet the needs of the whole system.

关键词：空间机器人捕获算法 DSP 多目标图像处理系统设计图像处理程序参考框架

Effect of stand age and individual growth on seed germination of Populus euphratica in the Ejina Oasis, China

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Forestry Studies in China 2011年第3期13卷 183-188页

作者： liu qian-wen HAO Peng LI Jing-wen TAN Zhi-gang Amugulang LUO Jing-yu College of Forestry Beijing Forestry University Beijing 100083 P. R. China Ejina Banner Forestry Bureau Inner Mongolia 735400 P. R. China

We conducted an investigation into the germination of seeds from individual Populus euphratica trees of different ages and growing conditions in order to discover the effect of intraspecific factors on their sexual reproduction in the Ejina Oasis, Inner Mongolia of China. By carrying out germination experiments of seeds collected at various seed dispersal periods, we found that P. euphratica seeds could be germinated intensively within 8 h from the start of the experiments, that the germination percentage decreased with the time of seed dispersal and that the germination percentage of seeds collected at the early stage of seed dispersal was 1.86 times greater than those collected at the final stage. There was no significant difference in the germination percentage or the germination index between seeds collected at the early and peak stages. The vitality of seeds from the mature forest was clearly higher than that of the half-mature and near-mature forests. The rate of branch dieback only affected seed germination at the final stage. Therefore, we conclude that the mature P. euphratica forest was the main contributor to reproduction. The results show that both the time of seed harvest and stand age were the main factors affecting the germination percentage of P. euphratica seeds.

关键词： sexual regeneration seed vitality Populus euphratica Ejina Oasis