Zhejiang Daxue xuebao. Lixue banWe obtain the existence and multiplicity of positive solutions for a class of second-order discrete p-Laplace problems with Dirichlet boundary conditions by using the upper and lower solution method; The obtained results are then extended to the ...
仲海林(ZHONG Hailin) +1 more
doaj +1 more source
Research on the spectral attributes and spectral inversion algorithm of Ground Penetrating Radar signal [PDF]
, 2013 探地雷达(GPR)通过向地下发射高频率宽带电磁波来探测地下物体、地层界面以及地下介质属性和分布结构，被广泛应用于经济建设和军事各领域。由于雷达信号会受到各种电磁和背景噪声干扰，使得接收到的信号不能直接准确地反映地下介质信息，造成对目标检测和识别的困难。特别当目标体积较小或目标层厚度较薄时，目标的反射波很难被识别。在对路面、隧道以及地下污染物等检测时，遇到的地下介质多是层状分布的。人们不仅希望获得各层的深度和厚度，还希望得到各层介质的介电常数和电导率等参数。因此，本文将包含薄层的层状介质作为研究的对象 ...
黄忠来
core
A review of studies combining natural-source electromagnetic soundings and petrophysical experiments to constrain the volatile distribution in the deep earth [PDF]
Volatiles (such as H2O, CO2) are the crucial factors controlling the physical-chemical properties and dynamic processes of the multi-layer system within the Earth, and therein play an important role in plate tectonics, magmatic-mineral activities, and ...
Hongli Zhou +3 more
core +1 more source
Overview of Wire-driven Parallel Kinematic Manipulators for Aircraft Wind Tunnels [PDF]
, 2004 【中文文摘】首先概述了法国航空局SACSO项目关于绳牵引并联机构应用于飞行器风洞试验的研究工作,然后从六自由度绳牵引并联机构的结构设计、运动学及性能分析、工作空间的分析与综合、静刚度分析、运动控制和力控制等六方面,详细分析了六自由度绳牵引并联机构应用于飞行器风洞试验中的关键技术。分析结果表明:六自由度绳牵引并联机构必须根据飞行器的类型,以工作空间大小为依据进行构型设计;其运动控制方案可借用PID控制或自适应控制,其优点是便于动力学模型的线性化和解耦;其力控制方案可借用经典的阻抗控制和力/位置混合控制 ...
刘雄伟, 林麒, 郑亚青
core
Research on Seismic First Arrival Wave Traveltime Tomography [PDF]
, 2005 地震层析成像是一种利用观测到的穿过地球内部的地震波的运动学和动力学特征，获得地球内部介质物性信息的重要地球物理方法。随着相关理论方法以及工具设备的不断发展，这项技术已经广泛应用于工程和资源勘探等许多领域，并取得了可喜的成果。本论文以地震层析成像技术的一个重要分支——地震初至波走时层析成像方法为研究对象，深入探讨了走时层析成像过程中的两个核心步骤即正演模拟（射线追踪）与反演成像。首先，论文研究了地震射线追踪算法，对目前较为流行的几种地震初至波射线追踪算法进行了对比分析，指出其存在的问题 ...
谢华雯
core
Analysis of electrical resistivity and acoustic wave velocity characteristics in fault structures and their combined application in the detection process [PDF]
Finding out the specific location of the fault structure is of great significance for the engineering site selection and stability evaluation. Electrical resistivity tomography and acoustic logging are geophysical methods widely used in detecting ...
Chen YANG +5 more
core +1 more source
Research on Automobile Fault Diagnosis Expert System [PDF]
, 2005 专家系统是人工智能领域最为活跃和最富应用前景的一个分支，将专家系统应用于汽车故障诊断，它可以保存和利用专家的经验知识并结合有关汽车故障诊断方面的领域知识，提高故障诊断人员的经验水平，提高汽车故障诊断效率，适合于工程中这种多解性、创造性和复杂性问题的求解。特别是专家系统和面向对象方法的理论相结合而产生的新一代面向对象的专家系统，符合人类的思维习惯，方便对知识库的建立、维护和扩充，为专家系统的并行处理提供了基础，同时可以实现代码复用，缩短了专家系统的开发周期。本文通过以汽车故障诊断专家系统及其知识库 ...
邱忠民
core
Mechanisms controlling seasonal variations of hydrochemistry in a typical river of the Baiyangdian Basin [PDF]
To investigate the seasonal variation characteristics and controlling mechanism of the hydrochemistry of rivers that flow into the Baiyangdian Basin, the Angezhuang Reservoir—Zhongyishui River—Nanjuma River—Baigou Canal was selected to compare the ...
Rongtao MA +5 more
core +1 more source
Zhongguo shiyan zhenduanxue, 2016 Gorham-Stout综合征(Gorham-Stout syndrome,GSS)又称大块骨溶解症,是一种以特发性、进行性骨质溶解、吸收为特征的骨代谢疾病。GSS临床罕见,目前世界报道200余例,该病可发生于全身任何骨骼,多为单发,亦可多发,且症状多样,极易漏诊和误诊。GSS患者可有周围肌肉、结缔组织及脏器的受累,部分患者可合并胸腔或腹腔积液,病理学特点早期以骨小梁减少、髓腔扩大 ...
刘书中 +4 more
doaj
Research Progress on the Application of Strontium Isotope Analysis Techniques in Geology: A Review [PDF]
Strontium (Sr) isotopes have unique geochemical properties, such as time dependence and environmental sensitivity. With the development of testing technology and theoretical systems, using Sr isotopes has become a key technique in geoscience research ...
Chenghua YU +4 more
core +1 more source