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Weighing Leaves based on Physical Measurements and L-system Simulation
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作者 Xinyuan Gu 《International Journal of Technology Management》 2015年第4期113-115,共3页
In this paper, we revisit foundations of the applications of physical measurement and Lindenmayer system to the modeling of plants. The measurement is proposed to a formal procedure and measuring the mass of leaves on... In this paper, we revisit foundations of the applications of physical measurement and Lindenmayer system to the modeling of plants. The measurement is proposed to a formal procedure and measuring the mass of leaves on a tree, tailored to branching plant structures with Simpson' s rule and Monte Carlo Methods. L-system is possible to visualize mathematical models of biological structures and processes. The formalism is illustrated using theoretical branching systems, and applied to analyze total leaves number as well as total weight of them. 展开更多
关键词 Leaf Mass physical measurement L-SYSTEM FRACTAL
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Adherence to Physical Measures during the SARS-COV2 Pandemic by Haemodialysis Patients in a Burkina Faso Tertiary Hospital: A Cross-Sectional Survey
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作者 Bonzi Y. Juste Zoehinga Patrice +4 位作者 Sourabie Oumar Kabore D. Dieudonne Hien Siebou Sawadogo Amidou Coulibaly Gerard 《Open Journal of Nephrology》 2024年第3期375-385,共11页
Context: COVID-19 can spread rapidly in haemodialysis centres, leading to fatal outcomes. Implementing physical measures is crucial in limiting the spread of infection. Aims: To assess adherence to physical measures a... Context: COVID-19 can spread rapidly in haemodialysis centres, leading to fatal outcomes. Implementing physical measures is crucial in limiting the spread of infection. Aims: To assess adherence to physical measures against SARS-Cov2 in haemodialysis patients. Methods and Material: From 13 to 19 July 2021, we administered the questionnaire to haemodialysis patients during or immediately after the dialysis session. The dependent variables were adherence to wearing masks, hand washing outside the dialysis centre, social distancing of at least 1.5 meters, and cough and sneeze hygiene. Statistical Analysis Used: Data were analyzed using Epi info software;descriptive statistics were presented as mean, headcount, and percentage;related factors were determined by multi-logistic regression. The significance level was 5%. The Health Research Ethics Committee approved the research protocol. Results: 142 patients were included (mean age: 42.5 ± 14 years). Wearing masks, hand-washing, social distancing, and coughing and sneezing hygiene were observed by 88%, 75%, 47%, and 60% of patients, respectively. Conclusion: Wearing masks was the most respected physical measure, while social distancing was the least respected. 展开更多
关键词 physical Measures COVID-19 HAEMODIALYSIS SARS-COV2 Tertiary Hospital Sub-Saharan Africa
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MEASUREMENT METHOD AND PHYSICAL MODEL OF VSC CONDUCTIVITY AND ITS APPLICATIONS IN CONDUCTING POLYMERS
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作者 万梅香 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第4期330-339,共10页
Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC... Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail. 展开更多
关键词 VSC show measurement METHOD AND physical MODEL OF VSC CONDUCTIVITY AND ITS APPLICATIONS IN CONDUCTING POLYMERS
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Some considerations on the physical mea-sure of seismic intensity 被引量:1
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作者 郝敏 谢礼立 徐龙军 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第2期245-250,255,共7页
The study on seismic intensity can be traced prior to the time that modern seismology was established. In its early stage the seismic intensity was designed to serve as a measure in scaling the severity of earthquake ... The study on seismic intensity can be traced prior to the time that modern seismology was established. In its early stage the seismic intensity was designed to serve as a measure in scaling the severity of earthquake damage to civil engineering and environmental structures. Also the seismic intensity is usually assigned by engineers and seismologists with one or two characteristic parameters of earthquake ground motions to reflect earthquake damage potential so as to be able to serve as an input earthquake load for seismic design of structures. So choosing a proper parameter to reflect the action of seismic intensity is the main objective of the research on physical measure of seismic intensity. However, since various kinds of structures have quite different damage mechanisms, there will exist great differences in damages to different structures located at the same area during the same earthquake. Particularly, in some cases, quite different damages have happened even to the structures of same kind due to many other factors such as different construction materials, different configurations or on the different types of sites where structures located. In addition, the ground motion parameters, which result in damage to structures, are not the single peak value of ground motion. Hence, this paper emphasizes that the research on new physical measure of seismic intensity should not only consider the structural characteristics but also take into account other parameters such as duration, energy of ground motion and so on. In particular, as the physical measures of intensity, different ground motion parameter should be adopted for different structures. 展开更多
关键词 seismic intensity earthquake potential damage earthquake damage to structures physical measure of seismic intensity earthquake ground motion parameters
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Measurement of Electron-Drift Velocity in Ar+CH4 Mixtures Using Double-Grid Method 被引量:1
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作者 张家国 张国辉 陈金象 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第11期41-44,共4页
Based on analyzing the induced signals from the double-grids of an ionization chamber, the electron-drift time between the two grids is determined and the electron-drift velocity is derived. A waveform digitizer is em... Based on analyzing the induced signals from the double-grids of an ionization chamber, the electron-drift time between the two grids is determined and the electron-drift velocity is derived. A waveform digitizer is employed to record pulses from the two grids of the ionization chamber. The electron-drift velocity is measured as a function of the reduced electric field E/p for eight different ratios of Ar+CH4 mixtures. By analyzing the experimental data of this study, self-consistency of experimental data is achieved, and formulae for calculating electron-drift velocity in any ratio of Ar+CH4 mixtures are obtained. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement Plasma physics Particle physics and field theory
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Progress in AMS Measurement of 182Hf at CIAE
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作者 董克君 何明 +23 位作者 李振宇 王祥高 李朝历 游曲波 包轶文 武绍勇 沈洪涛 管永精 张伟 凡金龙 杨磊 孙宏清 丁有钱 贺国珠 李世琢 龚杰 何贤文 陆丽燕 王伟 胡跃明 袁坚 张生栋 常永福 姜山 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第11期27-30,共4页
Accelerator mass spectrometry (AMS) is one of the most promising methods to detect minute amounts of 182Hf. However, the sensitivity of 5×10^-11 for ^182Hf/180Hf obtained previously by the AMS method at China I... Accelerator mass spectrometry (AMS) is one of the most promising methods to detect minute amounts of 182Hf. However, the sensitivity of 5×10^-11 for ^182Hf/180Hf obtained previously by the AMS method at China Institute of Atomic Energy (CIAE) cannot meet the requirement of some applications. We present some new improvements of measurement method for AMS measurement of 182Hf at the CIAE HI?13 tandem accelerator system. As a result, a sensitivity of 1.0×10^-11 for 182Hf/180Hf is achieved. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement Particle physics and field theory
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Time-Resolved Measurement of Radiatively Heated Iron 2p-3d Transmission Spectra
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作者 赵阳 尚万里 +6 位作者 熊刚 靳奉涛 胡智民 韦敏习 杨国洪 张继彦 杨家敏 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第11期55-58,共4页
An experimental measurement of radiatively heated iron plasma transmission spectra was performed on Shenguang II laser facility. In the measurement, the self?emission spectrum, the backlighting spectrum, and the abso... An experimental measurement of radiatively heated iron plasma transmission spectra was performed on Shenguang II laser facility. In the measurement, the self?emission spectrum, the backlighting spectrum, and the absorption spectrum were imaged with a flat filed grating and recorded on a gated micro channel plate detector to obtain the time-resolved transmission spectra in the range 10-20 ? (approximately 0.6-1.3 keV). Experimental results are compared with the calculation results of an unsolved transition array (UTA) code. The time-dependent relative shift in the positions of the 2p-3d transmission array is interpreted in terms of the plasma temperature variations. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement Plasma physics Particle physics and field theory
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Reviving Direct Observation Methods for Physical Activity Behavior
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作者 Pedro Miguel Ribeiro da Silva Sérgio Hélder da Silva Soares Soares +2 位作者 Jorge Augusto Pinto Silva Mota Paula Maria Marques Moura Gomes Viana Pedro Miguel Machado Soares Carvalho 《Journal of Sports Science》 2021年第1期9-16,共8页
Purpose:Current Direct Observation(DO)methods are burdensome to the observer and relevant limitations can be identified on the outcome information.This study aims to characterize DO from the observers’point of view a... Purpose:Current Direct Observation(DO)methods are burdensome to the observer and relevant limitations can be identified on the outcome information.This study aims to characterize DO from the observers’point of view and to analyze the feasibility and usefulness of visual information in the form of video.Method:data collection was done with ten adult males,observed while performing different physical activities in an indoor court.Sessions were video recorded by two cameras.Three observers performed systematic observation,using SOPLAY,with different sampling rates.Inter observer’s agreement and with reference data was analyzed by Cohen’s Kappa statistic.Results:SOPLAY highest agreement between observers was 0.611 on vigorous category and walking category had the lowest 0.188.It doubles the time needed to annotate the video with pauses,but half of player’s behavior is preserved.Conclusion(s):using video to support DO permits to collect more accurate data and a more detailed behavior categorization is warranted.Developments in computer vision are expected to reduce the human efforts in DO methods. 展开更多
关键词 Measuring physical behavior systematic observation movement intensity video
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Quantum Theory of Consciousness
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作者 Gangsha Zhi Rulin Xiu 《Journal of Applied Mathematics and Physics》 2023年第9期2652-2670,共19页
Both consciousness and quantum phenomenon are subjective and indeterministic. In this paper, we propose consciousness is a quantum phenomenon. A quantum theory of consciousness (QTOC) is presented based on a new inter... Both consciousness and quantum phenomenon are subjective and indeterministic. In this paper, we propose consciousness is a quantum phenomenon. A quantum theory of consciousness (QTOC) is presented based on a new interpretation of quantum physics. We show that this QTOC can address the mind and body problem, the hard problem of consciousness. It also provides a physics foundation and mathematical formulation to study consciousness and neural network. We demonstrate how to apply it to develop and extend various models of consciousness. We show the predictions from this theory about the existence of a universal quantum vibrational field and the large-scale, nearly instantaneous synchrony of brainwaves among different parts of brain, body, people, and objects. The correlation between Schumann Resonances and some brainwaves is explained. Recent progress in quantum information theory, especially regarding quantum entanglement and quantum error correction code, is applied to study memory and shed new light in neuroscience. 展开更多
关键词 Quantum Theory of Consciousness Hard Problem of Consciousness measurement Problem of Quantum Physics Schumann Resonances and Brainwaves Quantum Information Theory Quantum Entanglement Large Scale Synchrony of Brainwaves
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A review of welding residual stress test methods 被引量:8
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作者 Gan Shiming Liu Huaying +1 位作者 Zhai Zhiping Han Yongquan 《China Welding》 CAS 2022年第2期45-55,共11页
Due to local uneven heating during the welding process,the residual stress of the structure after welding affects the reliability of it.In order to ensure the reliability,it is of great significance to test the residu... Due to local uneven heating during the welding process,the residual stress of the structure after welding affects the reliability of it.In order to ensure the reliability,it is of great significance to test the residual stress distribution of the welded joint.It has always been the focus to find a simple and feasible method for residual stress testing to quickly and accurately obtain the residual stress distribution of welded joints.The mechanical measurement method has high measurement accuracy,convenient and easy operation,but it will cause certain damage to the components.Physical measurement method can avoid damage to components,but its test cost is usually high,and its measurement accuracy can also be affected by the material microstructure characteristics of welded components.Based on the advantages and disadvantages of these two residual stress test methods,a modal test method is proposed.This method is a non-destructive measurement method.Based on the mathematical relationship between the residual stress of the welded structure and the natural frequency(mathematical model),the natural frequency is measured through the modal test to calculate the residual stress quickly.However,it is difficult to establish a mathematical model with this method,and it is not suitable for realization. 展开更多
关键词 welding residual stress mechanical measurement method physical measurement method modal test method
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Impact of Workspace Design in Indian Context on Occupant's Behavior, to Enhance Efficiency and Comfort
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作者 Pooja Mukund Pathak Alpana Rajendra Dongre 《Journal of Civil Engineering and Architecture》 2013年第3期310-322,共13页
The environmental psychology ofa workspace is a rich and diverse field of study that is growing fast and gaining popularity. The indoor environmental factors in workspaces should follow functional as well as behaviora... The environmental psychology ofa workspace is a rich and diverse field of study that is growing fast and gaining popularity. The indoor environmental factors in workspaces should follow functional as well as behavioral requirements as the spaces are designed as per the user's requirements, needs and aspirations. These play a major role in achieving behavioral impact on the user, as sense of well-being in the environment and physical comfort in the space enhances the productivity and efficiency of the user of the space. The slow and gradual importance of this issue in workspace design with Indian context, post occupancy evaluation can be adjudged as a permanent tool for improving indoor environment in buildings. Occupants should be used as a benchmark of evaluation, showing correlation of physical measurements and subjective parameters. It also suggests recommendations to improve quality of indoor environment in office buildings with analytical study, an important step in post occupancy evaluation. The objective of the paper is to inquire how people experience environmental psychology of the workspace as the determinants are efficiency, productivity and comfort. The success of any design depends upon the degree to which it creates an interface between the user and the environment. 展开更多
关键词 WORKSPACE physical measurements behavioral parameters EFFICIENCY COMFORT quantity quality
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Household and Community Assets and Farmers' Adaptation to Extreme Weather Event:the Case of Drought in China 被引量:17
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作者 WANG Yang-jie HUANG Ji-kun WANG Jin-xia 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第4期687-697,共11页
Under climate change, rising frequency and serious extreme weather events have challenged agricultural production. Designing appropriate adaptation measures to the extreme weather events require rigorous and empirical... Under climate change, rising frequency and serious extreme weather events have challenged agricultural production. Designing appropriate adaptation measures to the extreme weather events require rigorous and empirical analysis. The overall goals of this study are to understand physical adaptation measures taken by farmers and the impacts of household and community assets on farmers' adaptation when they face drought. The analyses are based on a unique data set collected from a household survey in three provinces in China. The survey results show that though not common on annual basis, some farmers did use physical adaptation measures to fight drought. Regression analysis reveals that both household and community assets significantly affect farmers' adaptation behaviors. Improving households' social capital and wealth, communities' network and access to government's anti-drought service can facilitate farmers' adaptation to drought. Results indicate that community's irrigation infrastructure and physical adaptation taken by farmers can substitute each other. Further analysis shows that the households taking adaptation measures have higher crop yields than those without taking these measures. The paper concludes with several policy implications. 展开更多
关键词 DROUGHT physical adaptation measure HOUSEHOLD community ASSET AGRICULTURE
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Theoretical Investigation of Femtosecond-Resolved Photoelectron Spectra of the Li2 Molecule 被引量:5
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作者 刘玉芳 刘瑞琼 丁俊霞 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第7期107-110,共4页
The time-dependent quantum wave packet method is used to investigate the dynamics for the Li2 molecule, and the time-resolved photoelectron spectra (TRPES) of the Li2 molecule are calculated. At the short delay time... The time-dependent quantum wave packet method is used to investigate the dynamics for the Li2 molecule, and the time-resolved photoelectron spectra (TRPES) of the Li2 molecule are calculated. At the short delay time, the particular phenomenon of TRPES with four peaks is qualitatively interpreted in a dressed state picture by analyzing wave packet motion on light-induced potential (LIP). The significant difference in the electronic structure of E1∑g^+ between the inner and outer turning points has an impact on the TRPES. The control for the first excited state A1∑u^+ of the initial wave packet is discussed. 展开更多
关键词 Atomic and molecular physics Instrumentation and measurement
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The chaotification of discrete Hopfield neural networks via impulsive control 被引量:2
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作者 刘娜 关治洪 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第7期55-57,共3页
The chaotification of discrete Hopfield neural networks is studied with impulsive control techniques. No matter whether the original systems are stable or not, chaotilication theorems for discrete Hopfield neural netw... The chaotification of discrete Hopfield neural networks is studied with impulsive control techniques. No matter whether the original systems are stable or not, chaotilication theorems for discrete Hopfield neural networks are derived, respectively. Finally, the effectiveness of the theoretical results is illustrated by some numerical examples. 展开更多
关键词 Instrumentation and measurement Statistical physics and nonlinear systems
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Information Feedback Strategies in a Signal Controlled Network with Overlapped Routes 被引量:2
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作者 田丽君 黄海军 刘天亮 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第7期388-391,共4页
We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers' route choice and the resultant system performance in a signal controlled network with overlapped rou... We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers' route choice and the resultant system performance in a signal controlled network with overlapped routes. Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers' travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity. 展开更多
关键词 Instrumentation and measurement Environmental and Earth science Statistical physics and nonlinear systems
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Theoretical Design of a 104MHz Ladder Type IH-RFQ Accelerator
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作者 聂元存 陆元荣 +5 位作者 陈佳洱 颜学庆 高淑丽 朱昆 刘克新 郭之虞 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第11期47-50,共4页
Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam ener... Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio (MWS). Tuning of the field flatness and frequency is investigated in principle. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement Particle physics and field theory
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High Power THz Undulator Radiation from Linear Accelerator
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作者 林栩凌 张建兵 +4 位作者 卢裕 雒峰 陆善良 俞铁民 戴志敏 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期107-109,共3页
A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the po... A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the power, frequency spectrum. First experiments show the averaged power at THz to be about 20mW. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement Particle physics and field theory
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Proton Ratio of HL-2A Bucket Ion Source
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作者 于利明 雷光玖 +10 位作者 曹建勇 杨立梅 姜韶风 韩小玉 张贤明 孙平 邹桂清 卢大伦 刘鹤 江涛 段旭如 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期75-78,共4页
For heating the tokamak plasma effectively, the ion source must be capable of producing ions with high proton ratio. The proton ratio, which is found to be more than 65.6% at the ion current of 19.6A with the extracti... For heating the tokamak plasma effectively, the ion source must be capable of producing ions with high proton ratio. The proton ratio, which is found to be more than 65.6% at the ion current of 19.6A with the extraction voltage of 39.6 k V, is measured with an image spectrograph by Doppler shift effect of Balmer-α-radiation spectrum emitted from fast hydrogen particles. The tendency of proton ratio with the ion density in experiment is almost the same as the mode devised by Zhang et al. Okumura et al. only gave the affection of the plasma volume and ion loss area on the proton ratio, but the relationship between the ion density in chamber and the proton ratio was not presented. We give the relationship. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement Plasma physics Particle physics and field theory
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A Field Assessment on Natural Ventilation and Thermal Comfort of Historical District--A Case of the Wugoushui Settlement in Taiwan
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作者 Yu-Chieh Chu Min-Fu Hsu Chun-Ming Hsieh 《Journal of Earth Science and Engineering》 2015年第8期463-472,共10页
Due to the urban and town development, it is common to see historical buildings and new buildings intermingled with one and another inside historical regions in Taiwan. With the increase of new buildings, natural vent... Due to the urban and town development, it is common to see historical buildings and new buildings intermingled with one and another inside historical regions in Taiwan. With the increase of new buildings, natural ventilation becomes harder, which leads to the impact on the preservation of historical building and the reduction of thermal comfort for residents. Besides, problems of new buildings' construction and design affect the developments of cities and towns in historical district, which has existed for hundreds of years. The Wugoushui Settlement is located in Pingtung County, the southernmost part of Taiwan, and its hot season of a year is pretty long and belongs to warm and humid tropical climate. In 2008, the Pingtung County Government officially registered and announced Wugoushui as traditional settlement and meanwhile, provided the maintenance and preservation for buildings in this region on government subsidies. This paper is based on one-year-long field experiments of Wugoushui Settlement. Residents in Wugoushui Settlement continue constructing new buildings near by the traditional buildings. With the fact that constructions of new buildings result in huge impact on the circumstances of natural ventilation and thermal comfort, which have been for hundreds of years, the simple weather station is set up to collect the data of local microclimate. In addition, four representative traditional architectures were selected to be measured their indoor and outdoor temperature, humidity, wind speed, wind direction and thermal radiation both in winter (December to February) and in summer (May to September). The measurement time of each building is one week and every data record is kept every minute. Besides, residents were asked to fill out the comfort survey. Based on these data, the distributions of indoor and outdoor thermal environment as well as the thermal comfort of living space under the condition of the natural ventilation are assessed. Finally, focused on the indoor living space of historical districts in southern Taiwan, there are two main suggestions given in the essay: first, a provisional comfort zone in summer is planned and proposed; second, the preliminary suggestions for the design and norms of new buildings in historical district are provided. 展开更多
关键词 Historical district historical settlement natural ventilation thermal comfort physical environment measurement PMV.
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The manufacture of a three-dimensional transducer used in laboratory
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作者 刘晓红 《Acta Seismologica Sinica(English Edition)》 CSCD 1996年第2期345-349,共5页
Since the development of ultrasonic pulse technique seismologists can study the seismic problems by simulation experiments in laboratries. In the 1950s Oliver (1954) conducted two-dimensional seismic model experimenta... Since the development of ultrasonic pulse technique seismologists can study the seismic problems by simulation experiments in laboratries. In the 1950s Oliver (1954) conducted two-dimensional seismic model experimental study. Henceforth geophysical model experiments have been conducted widly all over the world. In 1958 Zhao et al. of Peking University built the apparatures for seismic model experiments and did various model experiments (Zhao, 1986). In the 1960s, Birch (1960) measured the velocity of seismic waves in rocks under high pressure and first used the ultrasonic technique in the measurement of physical properties of rocks under high pressure. Since the end of the 1960s people paid attention to wave velocity anomaly as a seismic precursor, and simulation experiments of wave velocity anomoly have been developed (Nur, 1969; Liu and Lai, 1986; Liu, 1989). In the 1980s the developments of three-dimensional AE loation technique provided the conditions for study of seismic source mechanism in the laboratory (Kusunose, et al., 1981 ). All the experimental studies mentioned above used one-dimensional transducers. But the experiments require three-dimensional transducers with high precision to get accurate experimental data. We have manufactured three-dimensional transducers used in the laboratory,and they are able to stand high temperature and high pressure. By using the three-dimensional transducer in the laboratory the shape and the arrival times of longitudinal wave (P) and transverse wave in two polarization directions (S1, S2) can be measured simulataneously. Therefore, in the measurement of parameters of physical properties, the velocities, attenuation properties and frequency spectra of longitudinal wave (P) and transverse waves (S1, S2) can be measured with the same sample in the same experiemnt. Thus the problem caused by the difference in conditions of two experiments can be avoided. These trnasducers can also be used in model experiments and acoustic-wave position location, and under high temperature and high pressure conditions. 展开更多
关键词 seismic simulation experiment measurement of physical properties transducer.
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