It has been recognized that self-reliance and self-improvement of science and technology is a necessary choice of taking the independent innovation path with Chinese characteristics in the new era,which provides strategic support for the comprehensive con
The paper starts examining some ideas of Einstein and Rovelli about space and spacetime in the context of the general theory of relativity and identifying a connection among them.I continue drawing a parallel between those ideas in the field of physics an
Adi Nes(born in 1966)is a leading Israeli artist in the field of photography,with international recognition.Nes’photography is staged as theatre,with each detail carefully planned during the production process,after comprehensive visual and conceptual res
In the context of professional technical education,dual modality has been a commitment of the Chilean Ministry of Education to improve professional technical training in high school.The change has involved a curricular innovation around the development of
Ecological justice is a good state of symbiosis and sharing between man and nature on the basis of labor.Based on historical materialism,Marxs concept of ecological justice takes labor as the intermediary of the relationship between man and nature,and exp
This is a paper about semantic holism.Semantic holism is a doctrine about the philosophically indispensable circumstances for something to have meaning.We therefore instigate our argument by endeavoring to view semantic holism in its philosophical context
笔者等在野外调查的基础上,对出露于滇西临沧岩浆弧北部凤庆箐头山地区原1∶25万凤庆县幅划分的二叠纪糜棱岩化黑云二长花岗岩进行了系统的年代学、岩石学和地球化学研究。该花岗岩体中,锆石具典型的振荡环带,Th/U值均大于0.2,为岩浆成因,其LA-ICP-MS U-Pb年龄为213±5 Ma,应当为岩浆结晶年龄,表明该岩体形成于晚三叠世,而非前人认为的二叠纪。全岩主微量元素分析结果显示,箐头山花岗岩Na
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利用岩芯、薄片、扫描电镜和分析化验等资料,对南堡凹陷南部深层古近系沙一段(沙河街组一段)优质碎屑岩储层特征进行了分析并揭示其成因机制。研究表明:(1)南堡凹陷南部沙一段优质碎屑岩储层属于低孔中渗储层,发育原生孔隙、次生孔隙和微裂缝;(2)沙一段沉积期处于强水动力沉积环境,辫状河三角洲前缘水下分流河道砂体普遍发育,岩性主要为中粗砂岩、含砾砂岩和砂砾岩等粗岩性,岩石类型主要为岩屑长石砂岩,石英、岩浆岩岩屑等刚性组分含量高,储层在强压实作用下仍保留了局部原生残余粒间孔,部分刚性组分强压条件下形成微裂缝;(3)沙
针对电场积分法部分节点过于靠近导线、积分域划分不便于计算等问题,该文提出一种给定节点的Gauss型数值积分方法,从而降低非线性方程的求解难度,优化积分节点参数,提高电压测量精度。首先,结合空间电场数值积分法原型,建立给定节点的Gauss型积分方法计算模型,推导出含电场扰动因素的节点参数解析式;然后,利用Maxwell电磁仿真软件计算三相输电线路下方的电场分布情况,结合积分节点选取的限定因素,计算出节点坐标与对应权值;最后,搭建D-dot传感器测量实验平台检验所提出电压测量方法的有效性。根据5~20 kV电
土壤重金属污染对人类身体健康造成了严重威胁,作为快捷、高效、无损监测分析土壤重金属含量的方法之一,高光谱遥感反演土壤重金属含量的方法正逐步得到发展。本文以雄安新区西南部作为研究区,针对潜在生态风险最大且活性最强并易被植物吸收的重金属镉,开展高光谱反演研究。将采集来的426件土壤样品除杂、风干、过筛在实验室测得重金属含量,并用SVC便携式地面光谱仪测量样品350~2500 nm范围光谱。采用Savitzky—Golay卷积平滑方法进行光谱降噪平滑处理。由于粒径大小而不是化学成分差异可能会导致基线效应和漂移现