Results 91 to 100 of about 418,092 (185)

14MeV中子通量密度的测量

open access: yes四川大学学报. 自然科学版, 1986
精确测量14Mev中子通量密度,对基础研究、核参数测量以及核技术在工农医上的应用,具有重要意义.我们安装了一套测量系统,一年内的重复测量证明,本测量系统稳定、可靠。通量测量方法 测量14Mev中子通量用伴随粒子法,即通过测量T(d,n)4He反应中伴随中子产生的α粒子来确定中子通量的方法。在产生14Mev中子的T(d,n)4He反应中,
张增志   +6 more
doaj  

Land use overrides climatic controls on soil organic nitrogen transformations: Contrasting responsiveness between forest and cropland ecosystems

open access: yesFunctional Ecology, Volume 40, Issue 7, Page 2128-2142, July 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil organic nitrogen (SON) transformation is critical for global nutrient cycling and ecosystem productivity, yet how its responsiveness to climate change differs across diverse land use types remains poorly resolved.
Xinyi Yang   +10 more
wiley   +1 more source

驾驶分心的测量方法

open access: yes, 2007
驾驶分心是引起交通事故的一个重要原因。测量驾驶分心的方法可分为直接测量和间接测量,其中直接测量又包括眼动测量法和视觉遮挡测量法,间接测量包括外周视觉检测任务测量法。不同测量方法具有各自的特点 ...
刘宁, 张侃
core  

Complete elliptic Fourier descriptor normalization and its application in quantitative morphological analysis

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 7, Page 2123-2134, July 2026.
Abstract Elliptic Fourier analysis (EFA) is often employed in geometric morphometrics (GM), but the normalization of elliptic Fourier descriptor (EFD) has persistently posed challenges for obtaining unique and comparable results, especially in the application of outline‐based GM methods, which limits the implementation in automated analysis of numerous,
Hui Wu   +6 more
wiley   +1 more source

研究两相流流动特性的测量系统

open access: yes, 1992
一种在气-液两相流或液相流中流动特性的测量系统,其结构简单、操作方便、实用性强;它可以自动地移动测量探针、进行多通道的数据采集和对实测数据进行实时处理;采样频率可达几十万赫兹; 这个系统适用于处理各种仪表输出的模拟或数字信号。本文描述了测量气泡速度、气泡大小、含气率、混匀时间和剪切应力等的电位探针和电化学技术 ...
蔡志鹏   +4 more
core  

The underappreciated roles of fog and dew on vegetation and biocrusts

open access: yesNew Phytologist, Volume 251, Issue 1, Page 46-63, July 2026.
Summary Fog and dew represent minor components of ecosystem water budgets in most ecosystems. However, fog and dew can play an essential role in ecosystem dynamics and are particularly important for water‐limited systems. In addition to serving as direct water inputs, fog and dew can influence microclimate and water redistribution, thereby promoting ...
Lixin Wang, Yue Li, Mengyun Sun, Na Qiao
wiley   +1 more source

用涡轮流量计测量多相流流量

open access: yes, 2002
对涡轮流量传感器进行了理论分析,给出了涡轮流量计仪表常数的计算方法,讨论了获得较大固有仪表常数K_0时涡轮传感器结构参数(如叶片数、涡轮半径、口径等)的优化组合问题,通过多相流动实验,总结出K_0与流动密度之间的实验关系,由此给出用涡轮流量计测量多相流的半理论半经验公式,并在油井多相流量测量中得到了实际应用,符合较好。对涡轮流量传感器进行了理论分析,给出了涡轮流量计仪表常数的计算方法,讨论了获得较大固有仪表常数K_0时涡轮传感器结构参数(如叶片数、涡轮半径、口径等)的优化组合问题,通过多相流动实验 ...
田树祥   +4 more
core  

Simultaneous Generation of Topographic Models and Manning Roughness Coefficient Maps From Tri‐Stereoscopic Satellite Images: Application to the Huarmey River, Peru

open access: yesThe Photogrammetric Record, Volume 41, Issue 195, July/September 2026.
Tri‐stereoscopic PeruSat‐1 imagery enables the simultaneous generation of 0.70 m‐resolution topography and spatially distributed Manning roughness maps, achieving 0.434 m vertical accuracy. Integrated into HEC‐RAS, these products provide consistent, high‐resolution inputs that improve hydraulic modelling and flood risk assessment in data‐scarce river ...
Jorge L. Miranda‐Pita   +3 more
wiley   +1 more source

一种碘流量测量装置及其应用

open access: yes, 2010
一种碘流量测量装置,在所需测定碘流量的测试吸收池的一侧设置有光源,在光源的发射光路上、于测试吸收池左右两侧分别设置有对称的石英玻璃测试窗口,在测试窗口和光源之间设置有聚焦透镜,在测试吸收池的另一侧测试窗口外侧设置有分束片;光源的发射光经过测试吸收池后被分束片分成两部分光,透过分束片即为测试光,反射的即参考光;在分束片外侧的测试光路和参考光路上分别依次设置有聚焦透镜和带通干涉滤光片及硅探头;硅探头通过导线与计算机上的数据采集板连接,由计算机进行数据采集和处理。实验结果表明 ...
多丽萍   +4 more
core  

一种基于拉曼光谱测量的水面油膜厚度测量方法及装置

open access: yes, 2016
本发明公开一种基于拉曼光谱测量的水面油膜厚度测量方法,将水体和石油烃类污染物拉曼信号的峰高比作为油膜厚度计算因子,在一定的油膜厚度范围内,油膜厚度计算因子与油膜厚度呈线性关系;通过测量计算因子反演出水体表面油膜厚度。测量装置包括三维调整模块、三维调整支架和密封外壳,外壳内设置有光源控制电路、探测单元和信号处理传输单元;本发明的优点:可实现对水体油膜厚度的直接测量,检测速度快,避免繁琐的步骤,同时不需要化学试剂,对水质本身没有影响。探头内部设计有开关及透镜,可有效避免激光长期输出对人眼的伤害 ...
冯巍巍, 蔡宗岐
core  

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