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A Quasi-Linear Relationship between Planetary Outgoing Longwave Radiation and Surface Temperature in a Radiative-Convective-Transportive Climate Model of a Gray Atmosphere
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作者 Jie SUN Michael SECOR +1 位作者 Ming CAI Xiaoming HU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期8-18,共11页
In this study,we put forward a radiative-convective-transportive energy balance model of a gray atmosphere to examine individual roles of the greenhouse effect of water vapor,vertical convection,and atmospheric polewa... In this study,we put forward a radiative-convective-transportive energy balance model of a gray atmosphere to examine individual roles of the greenhouse effect of water vapor,vertical convection,and atmospheric poleward energy transport as well as their combined effects for a quasi-linear relationship between the outgoing longwave radiation(OLR)and surface temperature(T_(S)).The greenhouse effect of water vapor enhances the meridional gradient of surface temperature,thereby directly contributing to a quasi-linear OLR-T_(S) relationship.The atmospheric poleward energy transport decreases the meridional gradient of surface temperature.As a result of the poleward energy transport,tropical(high-latitude)atmosphere-surface columns emit less(more)OLR than the solar energy input at their respective locations,causing a substantial reduction of the meridional gradient of the OLR.The combined effect of reducing the meridional gradients of both OLR and surface temperature by the poleward energy transport also contributes to the quasi-linear OLR-T_(S) relationship.Vertical convective energy transport reduces the meridional gradient of surface temperature without affecting the meridional gradient of OLR,thereby suppressing part of the reduction to the increasing rate of OLR with surface temperature by the greenhouse effect of water vapor and poleward energy transport.Because of the nature of the energy balance in the climate system,such a quasi-linear relationship is also a good approximation for the relationship between the annual-mean net downward solar energy flux at the top of the atmosphere and surface temperature. 展开更多
关键词 outgoing longwave radiation greenhouse effect poleward energy transport
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追求卓越的早期教育质量--OECD早期保教质量调查报告“Starting StrongⅢ”述评 被引量:2
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作者 周玉娥 刘智成 《外国教育研究》 CSSCI 北大核心 2013年第6期11-16,共6页
早期教育质量的影响因素是多方面的,OECD成员国在提高早期教育质量方面作了许多积极探索,Starting StrongⅢ就是在广泛调研基础上形成的一份聚焦质量的报告。通过探讨Starting StrongⅢ的形成背景,进而分析其五个与早期教育质量密切相... 早期教育质量的影响因素是多方面的,OECD成员国在提高早期教育质量方面作了许多积极探索,Starting StrongⅢ就是在广泛调研基础上形成的一份聚焦质量的报告。通过探讨Starting StrongⅢ的形成背景,进而分析其五个与早期教育质量密切相关的重要政策杠杆,能为思考我国学前教育发展提供些许启示。 展开更多
关键词 早期教育和保育 质量 starting StrongⅢ
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制浆造纸翻译工作坊平台START翻译实训模式研究与实践
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作者 吕晶 赵丽娜 《造纸科学与技术》 2024年第8期157-160,共4页
制浆造纸专业英语翻译在当今全球化的经济环境中扮演着非常重要的角色,不仅是技术交流的工具,还是推动文化交流、学术研究以及国际贸易的重要力量。针对如今制浆造纸专业英语翻译教学存在的种种问题,提出基于翻译工作坊平台的START翻译... 制浆造纸专业英语翻译在当今全球化的经济环境中扮演着非常重要的角色,不仅是技术交流的工具,还是推动文化交流、学术研究以及国际贸易的重要力量。针对如今制浆造纸专业英语翻译教学存在的种种问题,提出基于翻译工作坊平台的START翻译实训模式。对此,对比分析了制浆造纸传统英语翻译教学与翻译工作坊教学的区别,探究了START翻译实训模式的构成与在制浆造纸专业英语翻译教学中的应用意义,并研究了基于翻译工作坊的制浆造纸专业英语START翻译实训模式的构建与实施策略,以期发挥START翻译实训的教学价值,提升制浆造纸专业英语翻译教学水平。 展开更多
关键词 制浆造纸 英语翻译 翻译工作坊平台 start翻译实训 实践
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Correlation Analysis of Persistent Heavy Rainfall Events in the Vicinity of the Yangtze River Valley and Global Outgoing Longwave Radiation in the Preceding Month 被引量:6
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作者 汤燕冰 赵璐 高坤 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2009年第6期1169-1180,共12页
Based on the National Oceanic and Atmospheric Administration (NOAA) daily satellite dataset of global outgoing longwave radiation (OLR) for the period of 1974-2004 and the NCEP-NCAR reanalysis for 1971- 2004, the ... Based on the National Oceanic and Atmospheric Administration (NOAA) daily satellite dataset of global outgoing longwave radiation (OLR) for the period of 1974-2004 and the NCEP-NCAR reanalysis for 1971- 2004, the linkage between persistent heavy rainfall (PHR) events in the vicinity of the Yangtze River valley and global OLR leading up to those events (with 1- to 3O-day lag) was investigated. The results reveal that there is a significant connection between the initiation of PHR events over the study area and anomalous convective activity over the tropical Indian Ocean, maritime continent, and tropical western Pacific Ocean. During the 30-day period prior to the onset of PHR events, the major significantly anomalous convective centers have an apparent dipole structure, always with enhanced convection in the west and suppressed convection in the east. This dipole structure continuously shifts eastward with time during the 30-day lead period. The influence of the anomalous convective activity over the tropical oceans on the initiation of PHR events over the study area is achieved via an interaction between tropical and extratropical latitudes. More specifically, anomalous convective activity weakens the Walker circulation cell over the tropical Indian Ocean first. This is followed by a weakening of the Indian summer monsoon background state and the excitation and dispersion of Rossby wave activity over Eurasia. Finally, a major modulation of the large scale background circulation occurs. As a result, the condition of a phase-lock among major large scale circulation features favoring PHR events is established over the study area. 展开更多
关键词 persistent heavy rainfall events global outgoing longwave radiation the Yangtze River valley
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Reconstruction of the starting time series of rainy season in Yunnan and the evolvement of summer monsoon during 1711-1982 被引量:2
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作者 YANG Yuda MAN Zhimin ZHENG Jingyun 《Journal of Geographical Sciences》 SCIE CSCD 2007年第2期212-220,共9页
According to the textual research into the historical documents dominated by archives yearly, as well as the verification with several other kinds of data, the later or earlier starting time of the rainy seasons in Yu... According to the textual research into the historical documents dominated by archives yearly, as well as the verification with several other kinds of data, the later or earlier starting time of the rainy seasons in Yunnan during 1711-1982 has been reconstructed. The analysis indicates that there are obvious fluctuations in the starting date of the rainy seasons in Yunnan in a year or years, and long fluctuation on the decadal scale. The rainy season comes earlier in the early 18th century, later in the 19th century and earlier again in the 20th century. This reflects to a certain degree the gradual change of the summer monsoon in Yunnan. There exists an obvious quasi-3 years cycle, which is related to EI-Nino's quasi-3 years cycle, and a 11.3-year cycle which is notably related to the 11-year cycle of the solar activity of starting date of the rainy seasons in Yunnan. Meanwhile, the dissertation finds that the EI-Nino is very important to the starting date of the rainy seasons in Yunnan. The starting date of the rainy seasons in Yunnan often comes later or normally in the year of EI-Nino. However, there is an obvious imperfect period in such influence, which in turn may mean that there is a certain fluctuation in the effect of ENSO on Asian summer monsoon. 展开更多
关键词 YUNNAN Qing Dynasty starting date of rainy season summer monsoon ENSO
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Retrieval of Outgoing Longwave Radiation from COMS Narrowband Infrared Imagery 被引量:1
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作者 Myung-Sook PARK Chang-Hoi HO +1 位作者 Heeje CHO Yong-Sang CHOI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第3期375-388,共14页
Hourly outgoing longwave radiation (OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite (COMS) has been retrieved since June 2010.The COMS OLR retrieval algorithms are based o... Hourly outgoing longwave radiation (OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite (COMS) has been retrieved since June 2010.The COMS OLR retrieval algorithms are based on regression analyses of radiative transfer simulations for spectral functions of COMS infrared channels.This study documents the accuracies of OLRs for future climate applications by making an intercomparison of four OLRs from one single-channel algorithm (OLR12.0 using the 12.0 μm channel) and three multiple-channel algorithms (OLR10.8+12.0 using the 10.8 and 12.0 pm channels; OLR6.7+10.8 using the 6.7 and 10.8 μm channels; and OLRAll using the 6.7,10.8,and 12.0 μm channels).The COMS OLRs from these algorithms were validated with direct measurements of OLR from a broadband radiometer of the Clouds and Earth's Radiant Energy System (CERES) over the full COMS field of view [roughly (50°S-50°N,70°-170°E)] during April 2011.Validation results show that the root-mean-square errors of COMS OLRs are 5-7 W m-2,which indicates good agreement with CERES OLR over the vast domain.OLR6.7+10.8 and OLRAll have much smaller errors (~ 6 W m-2) than OLR12.0 and OLR10.8+12.0 (~ 8 W m-2).Moreover,the small errors of OLR6.7+10.8 and OLRAll are systematic and can be readily reduced through additional mean bias correction and/or radiance calibration.These results indicate a noteworthy role of the 6.7 μm water vapor absorption channel in improving the accuracy of the OLRs.The dependence of the accuracy of COMS OLRs on various surface,atmospheric,and observational conditions is also discussed. 展开更多
关键词 outgoing longwave radiation Communication Oceanography and Meteorological Satellite Cloud and Earth's Radiant Energy System
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Starting flow in a rotating parallel plate channel 被引量:1
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作者 Chang Yi Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第5期1271-1276,共6页
The starting flow due to a suddenly applied pressure gradient in a parallel plate channel which is rotating as a system is studied. Exact analytic series solutions to the unsteady Navier-Stokes equations are found by ... The starting flow due to a suddenly applied pressure gradient in a parallel plate channel which is rotating as a system is studied. Exact analytic series solutions to the unsteady Navier-Stokes equations are found by both the Laplace transform method and the separation of parameters method, the latter is shown to be superior. Rotation not only induces a secondary transverse flow but also alters the character of the transient flow rate and velocity profiles. Back flow and inertial oscillations occur, especially at higher rota- tion rates. 展开更多
关键词 Rotating system Flow - starting
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Simulation study on starting of dual clutch transmission for tracked vehicles 被引量:1
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作者 张金乐 马彪 +1 位作者 张英锋 郑长松 《Journal of Beijing Institute of Technology》 EI CAS 2011年第1期77-83,共7页
In order to study the application of dual clutch transmission (DCT) on tracked vehicles, a simulation moclel and two control methods were performed for starting analysis. Based on a certain transmission of an existi... In order to study the application of dual clutch transmission (DCT) on tracked vehicles, a simulation moclel and two control methods were performed for starting analysis. Based on a certain transmission of an existing tracked vehicle, a DCT structure was proposed. Matlab/Simulink was a dopted as a platform to develop the simulation model. The engine speed was controlled to follow the target speed as a launch strategy. Two control methods, a proportional integral derivative ( PID ) control method and a fuzzy control method, were proposed to control the engine throttle and oil pressure in order to track the target engine speed. Simulation results show that either the PID control or fuzzy control method can improve the starting performance compared with no loop control meth od. Fuzzy control method can lead a better starting quality compared with PID control method. 展开更多
关键词 starting control dual clutch transmission proportional integral derivative (PID) fuzz y tracked vehicle
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Starting Characteristics of Motor in Inverter-Motor Drive System 被引量:1
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作者 Xi-jun Yang Xiang-jun Zhang You-min Gong 《Advances in Manufacturing》 2000年第2期140-144,共5页
When the induction motor is fed from the PWM VSI inverter, with and without torque enhancing function, the variations of the starting torque and the starting current versus the starting frequency are analyzed, base... When the induction motor is fed from the PWM VSI inverter, with and without torque enhancing function, the variations of the starting torque and the starting current versus the starting frequency are analyzed, based on the steady state equivalent circuit of the induction motor.The corresponding expressions are derived, and the corresponding curves are also drawn, from which the initial starting frequency range can be determined properly and easily. The initial starting frequency range is the common range, in which the starting torque should be high enough and the starting current low enough.Some other useful formulas are also derived.These results are significant for electrical drive designers to make the starting schemes. The effects of the increase of the stator and the rotor resistances on the starting torque and the initial starting frequency range are also discussed, which is caused by the skin effects of the high order harmonics present in the PWM inverter output voltage. 展开更多
关键词 inverter motor drive system starting characteristics skin effect
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Experimental study of the critical sand starting velocity of gas-watersand flow in an inclined pipe 被引量:2
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作者 Rui-Yao Zhang Jun Li +3 位作者 Hong-Wei Yang Geng Zhang Xi-Ning Hao Peng-Lin Liu 《Petroleum Science》 SCIE CAS CSCD 2022年第6期2981-2994,共14页
The purpose of this paper is to study the critical sand starting velocity and transformation law of flow pattern based on gas-water-sand three-phase flow in an inclined pipe.Firstly,the indoor simulation experiment sy... The purpose of this paper is to study the critical sand starting velocity and transformation law of flow pattern based on gas-water-sand three-phase flow in an inclined pipe.Firstly,the indoor simulation experiment system of gas-water-sand three-phase flow was used to test the conversion law of flow pattern based upon the different gas void fraction.Secondly,the influence of slug bubbles on sand migration was investigated according to distinctive hole deviation angles,gas void fraction and sand concentration.Finally,the critical sand starting velocity was tested based on dissimilar hole deviation angles,gas void fraction,sand concentration and sand particle size,and then the influence of the abovementioned key parameters on the sand starting velocity was debated based on the force analysis of the sand particles.The experimental results illustrated that when the gas void fraction was less than 5%,it was bubbly flow.When it increased from 5%to 30%,the bubbly flow and slug flow coexisted.When it was between 30%and 50%,the slug flow and agitated flow coexisted.When it reached 50%,it was agitated flow.Providing that the hole deviation angle was 90°,the phenomenon of overall migration and wavelike migration on the surface of sand bed was observed.On the contrary,the phenomenon of rolling and jumping migration was recognized.The critical sand starting velocity was positively correlated with the hole deviation angle and sand particle size,but negatively associated with the gas void fraction and sand concentration.This research can provide a certain reference for sand-starting production in the field of petroleum engineering. 展开更多
关键词 Three-phase flow Critical sand starting velocity Flow pattern Sand migration Gas void fraction Hole deviation angles Sand concentration
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Dynamics simulation of the belt conveyor possessing feedback loop during starting 被引量:1
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作者 席平原 张海涛 刘军 《Journal of Coal Science & Engineering(China)》 2005年第1期83-85,共3页
Synthesizing the mechanical models of the belt, the driver and the take-up device, the dynamics model was established on the longitudinal vibration of the overall belt conveyor system with finite elemental method, and... Synthesizing the mechanical models of the belt, the driver and the take-up device, the dynamics model was established on the longitudinal vibration of the overall belt conveyor system with finite elemental method, and S-function simulation block of asynchronous motor owing feedback function was built in Matlab/Simulink software, the simulation block indicates that motor rotation speed and its output moment vary with load and time, and the motor is a dynamic feedback system in working process. The state space block was adopted to express model of the belt. Thus it created simulation model of established dynamic model of overall belt conveyor system with Mat- lab/Simulink software, and simulates the course of starting by properly setting simulation parameters, and processes data for visualization. 展开更多
关键词 belt conveyor dynamics simulation starting process feedback loop
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Research on the Changes of Celestial Tide-generating Force and the Outgoing Long-wave Radiation before the Lushan (China) M_S7.0 Earthquake 被引量:1
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作者 Shi Haixia Ma Weiyu +1 位作者 Lu Xian Monika Joshi 《Earthquake Research in China》 CSCD 2015年第3期404-411,共8页
Calculation of tidal changes reveals that the MS 7. 0 Lushan County,Sichuan,China,earthquake of April 20,2013 occurred at the minimum phase point of tidal force. It indicates that the seismogenic fault on which the ti... Calculation of tidal changes reveals that the MS 7. 0 Lushan County,Sichuan,China,earthquake of April 20,2013 occurred at the minimum phase point of tidal force. It indicates that the seismogenic fault on which the tidal force acts on is of thrust type. The outgoing long-wave radiation( OLR) is the energy radiating from the Earth as infrared radiation at low energy to space. According to the tidal cycle,abnormal OLR change is analyzed based on NOAA satellite data around the whole of China before and after the earthquake. The result shows that the OLR changed evidently with the tide force change.Temporally,the change went through the course: initial OLR rise → s trengthening →reaching abnormal peak → a ttenuation → r eturning to normal; in space,the abnormal area was distributed along the Longmenshan fault and evolved as: scattering→ c onvergent→ s cattering. The process is similar to the change process of rock breaking under stress loading. It indicates that the celestial tidal force can trigger earthquakes when the tectonic stress reaches the critical break point of an active fault and the OLR anomaly is proportional to the seismic tectonic stress change. It is of practical value to combine OLR and tidal force anomaly with earthquake precursor studies. 展开更多
关键词 Celestial fide-generating force outgoing long-wave radiation Lushan earthquake CHANGES
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Analysis of Starting Performance of High PowerFactor Induction Motor with Floating Windingin Parallel Connection with Capacitors
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作者 ZHANG Qi XIE Guo dong (School of Automation, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第4期299-303,共5页
In this paper, by using a matrix technique, a dynamic model of high power factor induction motor with floating winding in parallel connection with capacitors is established. Then, the starting performance of this mot... In this paper, by using a matrix technique, a dynamic model of high power factor induction motor with floating winding in parallel connection with capacitors is established. Then, the starting performance of this motor is analyzed by computer simulation. By comparison of the tested and computed results, which are in good agreement, the dynamic model and simulative method are verified. 展开更多
关键词 high power factor starting performance computer simulation
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Starting of HPS lamps driven by electronic ballast
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作者 张伟强 王卫 徐殿国 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2001年第4期353-356,共4页
A complete research of two different starting techniques for HPS lamps driven by electronic ballast is presented while a traditional starting technique based on the series resonant theory which is used widely for fluo... A complete research of two different starting techniques for HPS lamps driven by electronic ballast is presented while a traditional starting technique based on the series resonant theory which is used widely for fluorescent lamps starting is analyzed in detail. An improved nth harmonic resonant technique is also simulated. Furthermore, a novel starting technique based on a pulse transformer is proposed, which still offer the automatic switch off capability. The differences between two starting techniques are explained. The experimental results from a lab prototype are used to verify the design. 展开更多
关键词 electronic ballast HPS lamp starting technique
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THE EVOLUTION OF STARTING VORTEX AND SECONDARY SEPARATION ON AN ELLIPTIC CYLINDER
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作者 Zhang Dieli (Institute of Mechanics,Academia Sinica) 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1989年第1期20-30,共11页
Flow visualization was used to investigate experimentally the evolution process from symmetrical shedding to staggered shedding of the starting vortex and the phenomenon of secondary separation on an elliptic cylinder... Flow visualization was used to investigate experimentally the evolution process from symmetrical shedding to staggered shedding of the starting vortex and the phenomenon of secondary separation on an elliptic cylinder at moderate Reynolds numbers.The vortex structure of the flow separation was studied.The temporal variation of separation angle and length of wake vortex were given. The photographs and experimental results provided basis for further investigation of the complicated feature of the starting process of unsteady separated flows around an elliptic cylinder. 展开更多
关键词 unsteady separated flows starting vortex secondary vortex secondary separation staggered shedding of vortex
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STUDY OF THE STARTING CURRENT AND FREQUENCY DEVIATION OF ELECTROSTATIC GYROMONOTRON
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作者 于善夫 徐晓曦 刘盛纲 《Journal of Electronics(China)》 1991年第2期169-174,共6页
From relativistic linear Vlasov-Maxwell equations,the expressions of the startingcurrent and frequency deviation of a electrostatic gyromonotron with a field distribution sin k‖zare derived and the numerical calculat... From relativistic linear Vlasov-Maxwell equations,the expressions of the startingcurrent and frequency deviation of a electrostatic gyromonotron with a field distribution sin k‖zare derived and the numerical calculation is carried out. 展开更多
关键词 ELECTROSTATIC ELECTRON CYCLOTRON RESONANCE MASER ELECTROSTATIC gyromonotron starting current Frequency deviation
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A Novel Part-Winding Starting Method for 4-Pole Squirrel Cage Induction Motor
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作者 Vadugapalayam Ponnuvel Sakthivel Ramachandran Bhuvaneswari Srikrishna Subramanian 《Engineering(科研)》 2010年第6期445-452,共8页
the paper has been removed due to the authors' personal reason.
关键词 INDUCTION Motor starting Part-Winding starting starting TORQUE starting Current
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Application of the Probability Model for Starting Period to Initiate to Take Palivizumab by Prefecture Using National Official Sentinel Surveillance in Japan
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作者 Junko Kurita Tamie Sugawara +1 位作者 Yasushi Ohkusa Michiko Nohara 《Journal of Biosciences and Medicines》 2020年第1期56-63,共8页
Background: Palivizumab were used for the premature infant or a high-risk infant with congenital heart disease. However, recently outbreak pattern of respiratory syncytial (RS) virus infection has been varying year by... Background: Palivizumab were used for the premature infant or a high-risk infant with congenital heart disease. However, recently outbreak pattern of respiratory syncytial (RS) virus infection has been varying year by year. Moreover, it also has some regional difference. Therefore, the object of the present study was to develop early detection of the timing of that outbreak had started in each prefecture. Method: We used data in National Official Sentinel Surveillance for Infectious Diseases (NOSSID). Study period was March 16th, 2011 to December 30th, 2018. We defined stating period to initiate to take palivizumab as 8 - 12 weeks before from the peak of outbreak. We estimated whether the week is included in starting period or not from April 1st to the peak of outbreak by the past number of patients of RS virus infection on week and its squared. Additionally, we have to take delay in NOSSID into consideration. Results: In nationwide, the last two seasons, the model predicted precisely the starting period. At prefectural level, the model predicted the starting period precisely in 16.6% of all year and prefectures pairs. When we consider the delay in NOSSID into consideration, the patients can start to take in 14.9% of all year and prefectures pairs. Discussion and Conclusion: The result of the probability model was not good, and thus we have to develop more sophisticated model for prediction at prefecture level. 展开更多
关键词 Respiratory Syncytial Virus Infection NATIONAL OFFICIAL SENTINEL Surveillance PALIVIZUMAB Probability Model starting PERIOD
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Effects of relaxation time on start-up time for starting flow of Maxwell fluid in a pipe
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作者 Zhen Li Keqin Zhu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第2期209-215,共7页
Although the analytical solution of the starting flow of Maxwell fluid in a pipe has been derived for a long time, the effect of relaxation time λ on start-up time ts of this flow is still not well understood. Especi... Although the analytical solution of the starting flow of Maxwell fluid in a pipe has been derived for a long time, the effect of relaxation time λ on start-up time ts of this flow is still not well understood. Especially, there exist a series of jumps on the ts-λ. curve. In this paper we introduce a normalized mechanical energy by mode decomposition and mathematical analogy to describe the start-up process. An improved definition of start-up time is presented based on the normalized mechanical energy. It is proved that the ts-λ. curve contains a series of jumps if λ is larger than a critical value. The exact positions of the jumps are determined and the physical reason of the jumps is discussed. 展开更多
关键词 Maxwell fluid starting flow·Relaxation time·start-up time·Mechanical energy
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Dose-response relationship of lung cancer to amount smoked, duration and age starting
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作者 John S Fry Peter N Lee +1 位作者 Barbara A Forey Katharine J Coombs 《World Journal of Meta-Analysis》 2013年第2期57-77,共21页
AIM: To quantify smoking/lung cancer relationships accurately using parametric modelling.METHODS: Using the International Epidemiological Studies on Smoking and Lung Cancer database of all epidemiological studies of... AIM: To quantify smoking/lung cancer relationships accurately using parametric modelling.METHODS: Using the International Epidemiological Studies on Smoking and Lung Cancer database of all epidemiological studies of 100+ lung cancer cases published before 2000, we analyzed 97 blocks of data for amount smoked, 35 for duration of smoking, and 27 for age started. Pseudo-numbers of cases and controls (or at risk) estimated from RRs by dose level formed the data modelled. We fitted various models relating loge RR to dose (d), including βd, βdY and βloge (1 + Wd), and investigated goodness-of-fit and heterogeneity between studies.0.833 loge [1 + (8.1c/10)] for cigarettes/d (c), 0.792 (y/10)0.74 for years smoked (y) and 0.176 [(70 - a)/10]1.44 for age of start (a). Each model fitted well overall, though some blocks misfitted. RRs rose from 3.86 to 22.31 between c = 10 and 50, from 2.21 to 13.54 be-tween y = 10 and 50, and from 3.66 to 8.94 between a = 30 and 12.5. Heterogeneity (P 〈 0.001) existed by continent for amount, RRs for 50 cigarettes/d being 7.23 (Asia), 26.36 (North America) and 22.16 (Europe). Little heterogeneity was seen for duration of smoking or age started.CONCLUSION: The models describe the dose-relation-ships well, though may be biased by factors including misclassification of smoking status and dose. 展开更多
关键词 SMOKING Lung neoplasms DOSE-RESPONSE Meta-analysis Review AMOUNT SMOKED DURATION of SMOKING Age at starting to smoke
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