小区间上的三素数定理(Ⅲ)

本文将证明:对充分大的奇数N,下面的方程有解...     

煤颗粒燃烧破碎特性及其分数维理论

本文采用激光衍射法和光学显微计算机图像系统及自行开发的软件,测量了三个典型煤在快速加热初期燃烧、等温加热燃烧和火焰燃烧方式的颗粒尺寸,运用分数维理论,建立了煤燃烧颗粒破碎理论,实验和理论研究揭示了煤燃烧中颗粒尺寸变化的本质,理论计算和实验结果符合良好。     

闭曲面上C0流有伪轨跟踪性质的条件

给出了闭曲面上奇点孤立的C⁰流有伪轨跟踪性质的充分必要条件     

农业供应链金融能有效缓解企业的融资约束？——涉农企业参与精准扶贫的实证研究

农业供应链金融为涉农企业融资难问题提供了新思路。本文以上市涉农上市企业2016~2018年的财务数据为样本,探讨了农业供应链金融对缓解企业融资约束的影响,以及涉农企业参与精准扶贫对缓解融资约束的调节作用。研究发现:涉农企业普遍面临融资约束问题,而农业供应链金融显著缓解了涉农企业的融资约束,且对参与精准扶贫企业的融资约束缓解更为显著。本文揭示了:农业供应链金融能有效缓解涉农企业的融资约束问题,再次证明了农业供应链金融缓解涉农企业融资约束的重要性和必要性,拓展了供应链金融研究的领域,同时对企业参与精准扶贫,响应新时期涉农企业社会责任的具体要求,形成政府、企业等共同承担社会责任的多元化减贫治理机制,助力乡村振兴提供相应借鉴。     

纳米氧化镱对熔融石英析晶动力学机制的影响

本文研究引入纳米氧化镱对熔融石英析晶机制及动力学过程的影响.通过X射线衍射仪(XRD)测试结果分析了纳米氧化镱的引入对熔融石英陶瓷析晶率的影响,采用动力学方法分析了纳米氧化镱的引入对熔融石英陶瓷析晶机制的影响,同时探讨了其等温析晶动力学过程.研究表明,熔融石英陶瓷的晶粒向二维兼有一维及三维的方式生长,引入纳米氧化镱的熔...     

退火温度对6H-SiC衬底上ZnO薄膜发光性质的影响

采用溶胶-凝胶方法,在6H-SiC衬底上制备ZnO薄膜.X射线衍射结果表明薄膜是c轴取向的,具有六方纤锌矿多晶结构.研究了退火温度对ZnO薄膜发光特性的影响.发现在650℃退火温度下,观察到近带边紫外发射和可见光发射并且紫外发光强度大于可见光发射.随着退火温度的提高,紫外峰强度减弱直至消失,而绿光发射强度先增加而后降低.对退火温度引起ZnO薄膜发光性质改变的机制进行了探讨.     

Determination of Acetonitrile Volume Fraction in Mobile Phase by HPLC

This paper reports the development and validation of an assay for the determination of acetonitrile in the recycled mobile phase using high performance liquid chromatography（HPLC）. The method is based on that the retention in reversed-phase liquid chromatography increases with decreasing concentration of organic phase in the mobile phase. The natural logarithm of the capacity ratio for a given solute is linearly related to the volume fraction of the organic modifier in the mobile phase. For dimethylphthalate and diethylphthalate, the linearity range is 30%--60%, and for biphenyl and terphenyl, the range is 60%--95%. Precision values（RSD） were both 〈1% and the accuracy（RE） was in the range of ±1%. The assay was successfully applied to the determination of acetonitrile concentration of recycled mobile phase after the distillation of the column eluent in our laboratory.     

576×6热像仪帧频提高方法

为了提高576×6红外热像仪的帧频,分析了扫描型焦平面探测器的扫描原理,提出了3种帧频提高方法:双向扫描成像;减少帧内无效扫描像元;缩短列周期时间.其中,双向扫描成像突破了当前通常只采用正程扫描时间成像的限制,扫描摆镜正程扫描时间和回扫时间均用来成像,提高了热像仪的成像效率;减少帧内无效扫描像元则推导出了标准输出格式下的探测器最小输出列数,减少甚至消除无效列数成像;缩短列周期则阐述了降低列周期方法以直接降低帧周期成像.分析表明,3种方法可以大幅度提高576×6热像仪帧频.     

A review of the metal stud stiffness on the sound insulation of gypsum-board partitions

For the sound insulation of a double-panel partition,the stud between two leaves creates a vibration transmission path,which can often be more critical and more important in the mid-frequency range than the airborne path through the cavity.Owing to the fact that partitions with light-weight steel studs are commonly used in building construction,studies on the sound insulation effect of such studs have been conducted.Especially,a model,initiated by Gu and Wang(1983),has been widely studied during the past decades.In the model,the steel stud is considered as an elastic spring with its cross-section stiffness in the sound insulation index prediction of such a partition.Experimental results of different stud profiles have been reported from different testing laboratories and more information has been gained to understand the stiffness effect of the stud on the sound insulation of the double-leaf partitions.In this paper,the authors have given this subject a thorough review and have concluded that a critical problem needs further investigation on the determination of the stiffness of the connecting elements in the double-leaf partitions.     

鲜红斑痣光动力治疗数学模型及临床验证

为了研究光动力治疗(PDT)中各个因素作用的规律,帮助临床采取有效的治疗方案,针对鲜红斑痣(PWS)组织特性,将光动力治疗中组织光分布、单线态氧产生、光敏剂漂白过程和光敏剂扩散过程结合起来,建立适合于光动力治疗鲜红斑痣病变的系统模型。利用建立的模型,对临床中出现的第二光斑治疗效果差的问题进行仿真研究,发现影响其治疗效果的因素,并通过仿真实验提出改进其治疗效果的新方案。通过临床实验,证明了新方案的有效性和模型的有效性。研究结果说明,针对特定的病例条件建立仿真模型,通过仿真实验可以为临床和理论研究提供一种有效的分析方法。