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High Temperature Analysis and Warning in Nanxiong City during 1981-2017 预览
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作者 Wen Simei Zhu Zhen Huang Shunbang 《气象与环境研究:英文版》 CAS 2019年第2期61-63,共3页
Based on days of high temperature and extremely highest temperature data in Nanxiong City during 1981-2017,combining the Provisions on the Issuance of Early Warning Signals for Sudden Meteorological Disasters in Guang... Based on days of high temperature and extremely highest temperature data in Nanxiong City during 1981-2017,combining the Provisions on the Issuance of Early Warning Signals for Sudden Meteorological Disasters in Guangdong Province,days of high temperature,extreme temperature,characteristic of high temperature warning level in Nanxiong City in past 37 years were analyzed. The results showed that annual average days of high temperature in Nanxiong City was 31. 1 d,and annual average extremely highest temperature was 38. 0 ℃,while annual extremely highest temperature was 40. 4 ℃. High temperature occurred during May-September,and its main occurrence period was from July to August,accounting for 78%. Yellow high temperature weather was the most,followed by orange high temperature weather,and red high temperature weather was the least. High temperature warning concentrated during May-September,and orange and red warning mainly occurred in July-August. In the 21st century,high temperature warning at serious grade accounted for more than 70% of total disaster times. 展开更多
关键词 DAYS of HIGH TEMPERATURE EXTREMELY highest TEMPERATURE MONTHLY change Grade of HIGH TEMPERATURE HIGH TEMPERATURE WARNING
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温度参数对注塑成型的影响 预览
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作者 杨良波 欧相麟 +1 位作者 魏耀富 王大中 《广州化工》 CAS 2019年第10期137-139,共3页
塑料注塑件已经被广泛应用到汽车、家电、电子等国民经济的各个领域。热塑性聚合物的注塑成型可分为熔胶、充填、保压和冷却等阶段。合适的温度参数能保证在注塑过程中材料能充分干燥、熔体能良好塑化,从而顺利充模、冷却与定型,最终产... 塑料注塑件已经被广泛应用到汽车、家电、电子等国民经济的各个领域。热塑性聚合物的注塑成型可分为熔胶、充填、保压和冷却等阶段。合适的温度参数能保证在注塑过程中材料能充分干燥、熔体能良好塑化,从而顺利充模、冷却与定型,最终产生出合格的塑料产品。本文结合大量实例,分析了烘料温度、注塑机各段的温度、热流道的温度和模温等温度参数对注塑成型产品外观缺陷和性能的影响,为相关从业人员提供了新的思路。 展开更多
关键词 注塑 温度 烘料温度 喷嘴温度 模温
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温度对蔗螟天敌等腹黑卵蜂生长发育的影响 预览
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作者 潘雪红 商显坤 +1 位作者 魏吉利 黄诚华 《西南农业学报》 CSCD 北大核心 2019年第3期539-543,共5页
【目的】探明温度对广西蔗区甘蔗螟虫优势寄生性天敌等腹黑卵蜂生长发育的影响,为该天敌的室内人工饲养繁殖、田间保护及其对蔗螟的有效防控提供理论基础。【方法】测定了等腹黑卵蜂在17、20、23、26、29和32℃6个恒温条件下的世代发育... 【目的】探明温度对广西蔗区甘蔗螟虫优势寄生性天敌等腹黑卵蜂生长发育的影响,为该天敌的室内人工饲养繁殖、田间保护及其对蔗螟的有效防控提供理论基础。【方法】测定了等腹黑卵蜂在17、20、23、26、29和32℃6个恒温条件下的世代发育历期和发育速率,利用线性回归、S曲线回归和Logistic回归分析了温度与等腹黑卵蜂发育速率之间的关系,并用直接回归法和直接最优法2种方法比较了等腹黑卵蜂的发育起点温度和有效积温。【结果】等腹黑卵蜂在17~32℃范围内均能正常发育,发育历期随温度的升高而缩短,发育速率随温度的升高而加快。Logistic模型更能拟合等腹黑卵蜂发育速率与温度的关系,其回归方程为V=0.1755/(1+e^4.0166-0.1529T)。经Logistic模型计算出,等腹黑卵蜂的发育最适温度为26.27℃,相应发育历期为11.40d。利用直接最优法计算得出等腹黑卵蜂发育起点温度和有效积温分别为11.25℃和172.31d·℃。【结论】温度是影响等腹黑卵蜂生长发育的重要因素,本研究结果为今后等腹黑卵蜂的保护和甘蔗螟虫的天敌防治提供了科学依据。 展开更多
关键词 等腹黑卵蜂 温度 发育速率 发育起点温度 有效积温
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飞机制造过程中无线测温技术的探讨 预览
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作者 刘晓晗 《计量与测试技术》 2019年第4期80-84,共5页
计量在商用飞机制造领域中具有其特殊的定位和作用,本文就计量领域中的温度测试在商用飞机制造过程中的开展进行了阐述,着重探讨了无线测温技术的应用和意义,并对其未来发展方向进行了展望,对温度测试方法的改进具有一定的指导作用。
关键词 计量 飞机制造 温度 温度测试 无线测温
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温度对黄斑长翅卷叶蛾生长发育及繁殖的影响 预览
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作者 刘永华 刘娟 +1 位作者 阎雄飞 贺英 《森林与环境学报》 CSCD 北大核心 2019年第4期444-448,共5页
为明确温度对黄斑长翅卷叶蛾生长发育及繁殖的影响,测定了5个恒温(19、22、25、28和31℃)条件下黄斑长翅卷叶蛾各虫态的发育历期、卵孵化率、存活率、产卵量、成虫寿命等指标,计算出各个虫态的发育起点温度和有效积温。结果表明:在19~3... 为明确温度对黄斑长翅卷叶蛾生长发育及繁殖的影响,测定了5个恒温(19、22、25、28和31℃)条件下黄斑长翅卷叶蛾各虫态的发育历期、卵孵化率、存活率、产卵量、成虫寿命等指标,计算出各个虫态的发育起点温度和有效积温。结果表明:在19~31℃范围内,各虫态发育历期随着温度的升高而逐渐缩短。卵、幼虫、蛹、产卵前期和全世代的发育起点温度分别为(9.58±0.55)、(10.24±0.85)、(15.82±1.22)、(10.25±1.24)和(10.65±0.85)℃,有效积温分别为163.35、455.68、186.54、15.55和821.12d·℃。在22、25和28℃下,该虫的产卵量、卵孵化率以及幼虫和蛹存活率明显高于其它温度,成虫寿命和产卵期随温度升高逐渐缩短。总体上,22~28℃是该虫较为理想的生长发育和繁殖温度范围,研究结果为开展黄斑长翅卷叶蛾预测预报和综合防控提供了参考依据。 展开更多
关键词 黄斑长翅卷叶蛾 温度 生长 发育 繁殖 发育起点温度 有效积温
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Interpretation of 850 hPa of Temperature in Temperature Forecast 预览
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作者 Ma Ziping Lv Yan +2 位作者 Meng Lixia Hao Wenjin Gao Yuan 《气象与环境研究:英文版》 CAS 2019年第3期81-83,共3页
Special geographical location,topography and landform in Xinzhou region decide different climate characteristics in the area under its jurisdiction.Different change characteristics of temperature increase its forecast... Special geographical location,topography and landform in Xinzhou region decide different climate characteristics in the area under its jurisdiction.Different change characteristics of temperature increase its forecast difficulty.To understand occurrence time of daily highest and lowest temperature,Xinfu District was taken as research area,and actual lowest and highest temperature at automatic station of Xinfu District in 2014 was used.Analytic results showed that occurrence time of daily highest and lowest temperature was different in different seasons,and distribution characteristics of daily highest and lowest temperature were also different in each region.Moreover,forecast method and idea were proposed. 展开更多
关键词 TEMPERATURE FORECAST TEMPERATURE CHANGE CHARACTERISTICS TEMPERATURE distribution CHARACTERISTICS Xinzhou
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草地贪夜蛾的发育起点温度、有效积温和发育历期预测模型 预览 被引量:1
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作者 何莉梅 葛世帅 +3 位作者 陈玉超 吴秋琳 姜玉英 吴孔明 《植物保护》 CAS CSCD 北大核心 2019年第5期18-26,共9页
温度是影响草地贪夜蛾Spodoptera frugiperda生长发育、繁殖和分布地区的主要环境因素。本研究利用室内恒温饲养的方法,测定了草地贪夜蛾各发育阶段的发育起点温度、有效积温和生命表参数,并构建了发育历期的预测模型。研究结果表明,温... 温度是影响草地贪夜蛾Spodoptera frugiperda生长发育、繁殖和分布地区的主要环境因素。本研究利用室内恒温饲养的方法,测定了草地贪夜蛾各发育阶段的发育起点温度、有效积温和生命表参数,并构建了发育历期的预测模型。研究结果表明,温度对草地贪夜蛾各发育阶段的发育历期、化蛹率、蛹的存活率与羽化率以及成虫繁殖力有显著影响。各发育阶段的发育历期随温度的升高而缩短,15~35℃下幼虫的发育历期为55.26~9.58 d。20~30℃为种群生长发育的适宜温度,成虫繁殖的最适温度为20~25℃。卵、幼虫、蛹和卵到蛹的发育起点温度分别为10.27、11.10、12.20和11.34℃,有效积温分别为44.57、211.93、135.69和390.55日·度。本研究结果可为预测草地贪夜蛾的发育历期、发生区域、发生期和发生世代提供科学依据和技术支撑。 展开更多
关键词 草地贪夜蛾 温度 发育历期 发育起点温度 有效积温
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Clusters: Viscosity Cause? 预览
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作者 V. P. Malyshev A. M. Makasheva 《物理化学期刊(英文)》 2019年第3期107-125,共19页
The significance of the work is determined by the need to develop a cluster theory of the liquid state of a substance in order to more deeply substantiate the viscosity, which is still expressed by empirical parameter... The significance of the work is determined by the need to develop a cluster theory of the liquid state of a substance in order to more deeply substantiate the viscosity, which is still expressed by empirical parameters within the framework of ideal ideas about the stratified flow of a liquid. According to the reference data on the dynamic viscosity of the melts for chlorides of the first group of the Periodic System, the approximating dependences in the form of cluster-associate and Frenkel’s models were constructed at various temperatures. The first model is based on taking into account the share of particles that cannot overcome the thermal melting barrier and thus serve to form virtual clusters and associates while preserving the structural motifs of the solid phase. In the framework of the cluster-associate viscosity model developed by the authors, these formations determine the melt viscosity and serve as flow units to which the energy of fluid motion is applied. The Frenkel’s model allows us to estimate the activation energy of fluidity. Calculations show that by comparing this energy with the degree of cluster association obtained in the framework of the cluster-associate model, a fairly close linear correlation is obtained, and the proportionality coefficient has the meaning of the activation energy per cluster. This energy does not go beyond the van der Waals energy of the unsaturated intermolecular bond characteristic of the interaction of particles in a liquid. This confirms the earlier established by the authors a similar pattern for melts of simple substances, based on the understanding of fluidity as a consequence of the destruction of cluster associates while preserving the clusters themselves. 展开更多
关键词 Dynamic VISCOSITY CLUSTER ASSOCIATE Temperature FLUIDITY Activation Energy
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Increased Temperature and Entropy Production in the Earth’s Atmosphere: Effect on Wind, Precipitation, Chemical Reactions, Freezing and Melting of Ice and Electrical Activity 预览
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作者 Michael A. Pitt 《现代物理(英文)》 2019年第8期966-973,共8页
Since the late nineteenth century, until the present time, there has been an increase in the earth’s global mean surface temperature (GMST). This temperature increase has been calculated at 0.85&deg;C over the pe... Since the late nineteenth century, until the present time, there has been an increase in the earth’s global mean surface temperature (GMST). This temperature increase has been calculated at 0.85&deg;C over the period 1880-2012. The causes of this temperature increase include increased levels of greenhouse gases (GHG’s), variations in solar irradiance and changes in absorption and re-radiation of heat. Volcanic activity and orbital cycles work to cool the earth’s surface. A thermodynamic analysis is presented of the earth’s atmosphere. The analysis demonstrates an increase in entropy production as a result of increased GMST. An equation is derived expressing entropy production in the atmosphere based on atmospheric processes (wind, precipitation, chemical reactions, electrical activity and heat transfer). The effects of increased entropy production on wind, precipitation, freezing and melting of ice, chemical reactions and electrical activity are given showing an increase in the combination of the above phenomena. 展开更多
关键词 TEMPERATURE ENTROPY Earth’s Atmosphere
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长白山温带阔叶红松林对温湿环境的调节效应
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作者 王珮环 陈智 +3 位作者 于贵瑞 王秋凤 贾彦龙 韩士杰 《应用生态学报》 CAS CSCD 北大核心 2019年第5期1521-1528,共8页
森林具有改善气候、调节微环境的作用,森林小气候的研究对于揭示森林生态系统功能、评估森林生态环境效益具有重要意义.本研究以长白山阔叶红松林为例,基于2003—2014年林内通量塔气象资料及其附近气象站空旷地的同时段气象资料,对其最... 森林具有改善气候、调节微环境的作用,森林小气候的研究对于揭示森林生态系统功能、评估森林生态环境效益具有重要意义.本研究以长白山阔叶红松林为例,基于2003—2014年林内通量塔气象资料及其附近气象站空旷地的同时段气象资料,对其最高、最低和平均气温、相对湿度和表层土壤温度的日变化和季节变化进行对比分析.结果表明:林内气温和相对湿度分别呈现单峰型和U型日变化规律,日较差较林外低2.31℃和8.3%,表层土壤温度日变化趋于恒定,阔叶红松林减缓了温湿度的日变化.夏季主要为降温效应,冬季表现出显著的增温效应.夏季林内气温和土温比林外低1.30和3.91℃;冬季林内气温和土温比林外高2.06和5.44℃.森林对最高温和最低温的调节效应显著.在季节尺度上,夏季森林降低最高气温和土温1.80和5.45℃,冬季提高最低气温和土温3.69和7.92℃.在年尺度上,林内年最高气温和土温分别较林外低1.60和4.99℃,年最低气温和土温分别较林外高1.12和8.82℃.森林对土温的调节效应强于对气温的调节效应.气温和土温均以对低温的保温作用为主. 展开更多
关键词 气温 相对湿度 土壤温度 长白山 温带阔叶红松林 小气候
Physical Properties and Exchange System of Seawater in Royal Yacht Club Marina in the Northernmost Gulf of Aqaba 预览
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作者 Riyad Manasrah Thekrayat Al-Majali 《自然科学期刊(英文)》 2019年第4期106-121,共16页
This research was aimed at studying the general environmental status of the marina at Royal Yacht Club (RYC), which is located in the Jordanian Gulf of Aqaba. The physical properties (temperature, salinity and density... This research was aimed at studying the general environmental status of the marina at Royal Yacht Club (RYC), which is located in the Jordanian Gulf of Aqaba. The physical properties (temperature, salinity and density) were measured at surface and bottom water at 19 sites (T1 - T19). Total hydrocarbon was measured at surface at 12 sites (HC1-HC12). The water exchange and residence time were calculated using data of current speed and direction at 16 sites (C1 - C16). The mean values of temperature, salinity and density at surface and bottom waters in the RYC’s marina were 27.13°C ± 0.03°C, 40.51 ± 0.02 psu and 26.83 ± 0.02 kg&#183;m-3, respectively. The results of physical parameters revealed no significant differences among sites, which are all comparable with open waters. The measurements range of total hydrocarbon in the marina was 1.404 mg/l (at site HC11) to 98.56 mg/l (at HC9). In general, all the high values of total hydrocarbon were found at the corners of the marina and at areas with relatively intense boats’ movements. There was no correlation between distribution of total hydrocarbon and temperature (R2 = 0.048;p = 0.49) in the marina. Therefore, the major factors that influence the distribution of total hydrocarbon within the marina are the current system and boats’ movements as well as the location reference to the gate. The residence time of waters inside the marina was 1.32 days. This flushing time is acceptable to secure good environmental conditions inside the marine to avoid stagnant seawater. The mean value of current speed at the RYC’s marina gate with open water was 5.33 ± 2.63 cm/s, which is relatively comparable with current speed in vicinity of study area. In conclusions, the environmental condition of the RYC’s marina is acceptable in term of the residence time and exchange system with open water. Slightly high values of total hydrocarbon were detected, which can be solved by regular cleaning. 展开更多
关键词 Temperature Salinity Total Hydrocarbon FLUSHING Time MARINA ROYAL YACHT CLUB GULF of Aqaba
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Influence of Chicken Manure Amendment on the Thermal Properties of Selected Benchmark Soils in Zambia 预览
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作者 Mary Mwale Chishala Elijah Phiri Lydia M. Chabala 《土壤科学期刊(英文)》 2019年第2期35-46,共12页
Influence of Chicken Manure amendment on the thermal properties of selected Benchmark soils in Zambia was investigated in the laboratory under soil column experiments. Five benchmark soils were exerted to four chicken... Influence of Chicken Manure amendment on the thermal properties of selected Benchmark soils in Zambia was investigated in the laboratory under soil column experiments. Five benchmark soils were exerted to four chicken manure amendment rates of 0% (control), 2%, 4% and 6% on a weight basis. Soil temperature profiles were monitored in soil columns exerted to artificial heat source and generated data was used to compute the thermal properties of the soils. The effect of manure application on the soil thermal properties was strongly related to soil type and application rate. Significant differences (p ?3·c?1 (Mushemi series) to 8.62 MJ·m?3·c?1 (Makeni series) and attributed to differences in soil characteristics. Thermal diffusivity varied from 0.028 m2·s?1 (Makeni series) to 0.069 m2·s?1 (Mushemi series) a reverse trend to thermal conductivity. A similar trend was observed with damping depth however thermal conductivity was not significantly different among the benchmark soils. The studied soils showed significant differences (p λ), thermal diffusivity (Dh) and damping depth (d) decreased while volumetric heat capacity (Cv) increased with increased chicken manure addition. The differences in these thermal properties were attributed to differences in soil properties. These results suggest that chicken manure application can be an important intervention in regulation of the thermal properties of the soil and consequently the thermal regime of the soil. 展开更多
关键词 THERMAL REGIME CHICKEN MANURE BENCHMARK SOILS Climate Change Temperature
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Comparative Residual Stress Analysis in Welded Joints Using Both Experimental and Numerical Techniques 预览
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作者 Rajshekhar B. Aloor Ramakrishna H V Nagabhushana Musalammagri 《矿物质和材料特性和工程(英文)》 2019年第4期150-156,共7页
During cooling of the welds, the outer weld generally shrinks and the inner weld expands due to the differential cooling of outer and inner weld geometries. Due to this, tensile stresses can be observed in the inner w... During cooling of the welds, the outer weld generally shrinks and the inner weld expands due to the differential cooling of outer and inner weld geometries. Due to this, tensile stresses can be observed in the inner weld and compressive stresses can be observed on the outer weld which forms the residual stress formation in the joints. Life and the load carrying capacity of the structures are very much influenced by the extent of residual stress in the joints. Estimation of this stress helps in estimating the safety of the structure subjected to various types of loads. Especially the tensile stresses are the possible causes of reduction in strength as well as for fatigue fracture failures. X-ray diffraction technique (XRD), a non-destructive testing method, is used to find the residual stress in the present problem and the same problem is validated through finite element analysis. Comparison shows matching results between experimental and finite element analysis. The work is to show the efficiency of Finite element analysis as good alternative to the experimental techniques which are costly and need precise, costly equipment along with longer time for testing. XRD pattern was also represented to find the peaks in the XRD measurement. 展开更多
关键词 RESIDUAL Stress XRD Ansys Temperature
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Impact of Thickness of Polymer Electrolyte Membrane and Gas Diffusion Layer on Temperature Distributions in Polymer Electrolyte Fuel Cell Operated at Temperature around 90℃ 预览
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作者 Akira Nishimura Yusuke Sato +4 位作者 Satoru Kamiya Tatsuya Okado Kouhei Yamamoto Masafumi Hirota Eric Hu 《能源与动力工程:英文版》 2019年第3期97-115,共19页
Polymer Electrolyte Fuel Cell(PEFC)is desired to be operated at temperature around 90℃ for stationary applications during the period from 2020 to 2025 in Japan.It can be expected thinner polymer electrolyte membrane(... Polymer Electrolyte Fuel Cell(PEFC)is desired to be operated at temperature around 90℃ for stationary applications during the period from 2020 to 2025 in Japan.It can be expected thinner polymer electrolyte membrane(PEM)and gas diffusion layer(GDL)would promote the power generation performance of PEFC at this temperature.The aim of this study is to understand the impact of thickness of PEM and GDL on the temperature profile of interface between PEM and catalyst layer at the cathode(i.e.,the reaction surface)in a single PEFC with an initial operation temperature(Tini).An 1D multi-plate heat transfer model based on temperature data of separator measured using thermograph in power generation process was developed to evaluate temperature of the reaction surface(Treact).This study investigated the effect of Tini,flow rate and relative humidity of supply gas on Treact distribution.The study finds that when using thin GDL,the even distribution of Treact – Tini is obtained irrespective of thickness of PEM,Tini and relative humidity conditions.Treact – Tini using Nafion 115 is higher than the other thin PEMs irrespective of Tini and relative humidity conditions.It can be concluded that the even temperature distribution could be achieved by using thin PEM and GDL. 展开更多
关键词 PEFC heat transfer model TEMPERATURE distribution operation TEMPERATURE AROUND 90℃ thickness of PEM and GDL RELATIVE humidity condition.
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Quantifying and Validating Soybean Seed Emergence Model as a Function of Temperature 预览
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作者 Firas Ahmed Alsajri Chathurika Wijewardana +3 位作者 L. Jason Krutz J. Trenton Irby Bobby Golden K. Raja Reddy 《美国植物学期刊(英文)》 2019年第1期111-124,共14页
Developing a model for soybean seed emergence offers a tool producers could use for planting date options and in predicting seedling emergence. In this study, temperature effects on soybean seed emergence were quantif... Developing a model for soybean seed emergence offers a tool producers could use for planting date options and in predicting seedling emergence. In this study, temperature effects on soybean seed emergence were quantified, modeled, and validated. The data for seed emergence model development was generated at varying temperatures, 20&deg;C/12&deg;C, 25&deg;C/17&deg;C, 30&deg;C/22&deg;C, 35&deg;C/27&deg;C, and 40&deg;C/32&deg;C, on two soybean cultivars, Asgrow AG5332 and Progeny P 5333 RY. Time for 50% emergence (t50%) was recorded, and seed emergence rate (SER) was estimated as reciprocal to time at each temperature in both the cultivars. No differences were observed between the cultivars in their response to temperature. A quadratic model (QM) best described the relationship between t50% and SGR and temperature (R2 = 0.93). Two sets of experiments were conducted to validate the model. In Experiment 1, 17 time-series planting date studies with the same cultivars were used by utilizing diurnal and seasonal changes in temperature conditions. In the second experiment, sunlit growth chambers with 3 different day/night temperatures, low—20&deg;C/12&deg;C, optimum—30&deg;C/22&deg;C, and high—40&deg;C/32&deg;C, and 64 soybean cultivars belonging MG III, IV, and V, were used. Air temperature and t50 were recorded, and SGR was estimated in all experiments. No differences were recorded among the cultivars for t50% and SGR, but differences were observed among seeding date and temperature experiments. We tested QM and traditionally used Growing Degree Days models against the data collected in validation experiments. Both the model simulations predictions agreed closely with the observed data. Based on model statistics, R2, root mean square errors (RMSE), and comparison of observations and predictions to assess model performance, the QM model performed better than the GDD model for soybean seed emergence under a wide range of cultivars and environmental conditions. 展开更多
关键词 GROWING Degree DAYS MODEL SEED EMERGENCE Soybean TEMPERATURE
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Climate Trends of Temperature, Precipitation and River Discharge in the Abbay River Basin in Ethiopia 预览
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作者 Asaminew Abiyu Cherinet Denghua Yan +8 位作者 Hao Wang Xinshan Song Tianlin Qin Mulualem T. Kassa Abel Girma Batsuren Dorjsuren Mohammed Gedefaw Hejia Wang Otgonbayar Yadamjav 《水资源与保护(英文)》 2019年第10期1292-1311,共20页
Projecting future changes of streamflow in the Abby River Basin (ARB) is important for planning and proper management of the basin system. The current study conducted in five stations of the Abbay river basin, and inv... Projecting future changes of streamflow in the Abby River Basin (ARB) is important for planning and proper management of the basin system. The current study conducted in five stations of the Abbay river basin, and investigated the annual temperature, precipitation, and river discharge variability using the Innovative trend analysis method, Mann-Kendall, and Sen’s slope test estimator. The result showed a slightly increasing trend of annual precipitation in Assoa (Z = 0.71), Bahir Dar (Z = 0.13), and Gonder (Z = 0.26) stations, while a significant increasing trend was observed in Nedgo (Z = 2.45) and Motta (Z = 1.06) stations. Interestingly, the trend of annual temperature in Assosa (Z = 5.88), Bahir Dar (Z = 3.87), Gonder (Z = 4.38), Nedgo (Z = 4.77), and Motta (Z = 2.85) was abruptly increased. The average mean temperature has increased by 0.2°C in the past 36 years (1980 to 2016). The extreme high temperature was observed in the semi-dry zone of northern Ethiopia. During the study period, a significant declining trend of the river discharge was recorded, and the river discharge was sharply decreased from 1992 onwards. The results of the current study showed annual variability of river discharge, precipitation, and temperature of the study area of the basin that could be used as a basis for future studies. 展开更多
关键词 Abbay RIVER BASIN Climate Change Ethiopia PRECIPITATION RIVER DISCHARGE TEMPERATURE
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黄河三角州地区热量资源变化特征分析 预览
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作者 王峰 宗晓鸿 田世芹 《中国农业资源与区划》 CSSCI CSCD 北大核心 2019年第9期101-108,共8页
[目的]通过对黄河三角州地区热量指标分析,了解黄三角地区30年热量资源的变化特征。[方法]利用黄三角地区及周边共25个国家级气象站30年逐日气象数据,采用线性趋势估计法、Mann-Kendall突变分析、T滑动法、ARCGIS空间插值等方法,对黄三... [目的]通过对黄河三角州地区热量指标分析,了解黄三角地区30年热量资源的变化特征。[方法]利用黄三角地区及周边共25个国家级气象站30年逐日气象数据,采用线性趋势估计法、Mann-Kendall突变分析、T滑动法、ARCGIS空间插值等方法,对黄三角地区年平均气温、≥0℃积温、≥10℃积温、≥0℃、≥10℃初终日及持续日数等进行时间和空间分析。[结果](1)年平均气温、≥0℃、≥10℃积温均呈波动上升趋势,20世纪90年代增温最快,年平均气温、≥0℃积温在1996-1997年发生突变;季平均气温以冬季增温最为明显。(2)年平均气温、≥0℃、≥10℃积温空间分布基本一致,中西部地区,与纬度成反相关,经度成正相关。(3)≥0℃、≥10℃的初终间日数均呈上升趋势,其空间分布相似,中西部地区与纬度成反相关,经度成正相关。(4)≥0℃、≥10℃的初日为提前趋势,终日为推迟趋势,其空间分布特征中西部地区初日均与纬度成正相关,与经度相关程度不大;≥0℃终日与纬度成负相关,与经度成正相关,≥10℃终日与纬度相关程度不大,与经度成正相关。[结论]黄三角地区热量资源呈增加趋势。 展开更多
关键词 气温 积温 初终日数 特征分析 黄河三角洲
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模糊控制在射频消融温度与阻抗监测系统中的应用 预览
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作者 成志新 孟辉 +3 位作者 刘传永 王大鹏 金振华 李博 《生物医学工程研究》 2019年第2期201-205,共5页
为了提高射频消融系统中肿瘤组织温度和阻抗的控制精度,设计了基于模糊控制的温度与阻抗监测系统。系统采用光纤光栅温度传感器测量组织温度,运用电阻采样、互感器隔离的方式测量组织阻抗;选用模糊控制算法对温度和阻抗进行控制,并通过... 为了提高射频消融系统中肿瘤组织温度和阻抗的控制精度,设计了基于模糊控制的温度与阻抗监测系统。系统采用光纤光栅温度传感器测量组织温度,运用电阻采样、互感器隔离的方式测量组织阻抗;选用模糊控制算法对温度和阻抗进行控制,并通过建立分层多规则集结构模糊控制器,降低了控制复杂度。经过实验验证,治疗温度上升速度快、过渡时间短,最大超调量为1℃,稳态精度为±0.4℃,控制算法适应性强,可以实现对肿瘤组织均匀、平稳的加热治疗,对临床治疗肿瘤具有较高的实用价值。 展开更多
关键词 射频消融 温度 阻抗 模糊控制 光纤光栅温度传感器 分层多规则集结构
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Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings’ corticosterone metabolites of broilers 预览
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作者 ZHOU ying LI Xiu-mei +1 位作者 ZHANG Min-hong FENG Jing-hai 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第1期152-159,共8页
The present study aimed to investigate the effect of relative humidity (RH) at either acute or chronic moderate ambient temperature (Ta) on growth performance and droppings’ corticosterone metabolites of broilers. Tw... The present study aimed to investigate the effect of relative humidity (RH) at either acute or chronic moderate ambient temperature (Ta) on growth performance and droppings’ corticosterone metabolites of broilers. Two experiments were conducted: effect of RH (35, 60 or 85%) on average daily feed intake (ADFI) and droppings’ corticosterone metabolites at acute (1 d: 20–26 or 31–20°C, 26 or 31°C for 6 h d–1 at 10:00–16:00) moderate Ta (experiment 1) and effect of RH (35, 60 or 85%) on growth performance and droppings’ corticosterone metabolites at chronic (step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta (experiment 2). Droppings were collected at the 2, 4, 6, 8, and 22 h after Ta-RH controlled in experiment 1 and at the 2, 4, 6, and 22 h after Ta controlled to 32°C in experiment 2. The results showed that: 1) In experiment 1, 85% RH increased (P<0.05) the droppings’ corticosterone metabolites at the 2, 6, 8, and 22 h and 35% RH increased (P<0.05) it at the 2 and 22 h compared to the 60% RH. Moreover, 85% RH further increased (P<0.05) it compared to the 35% RH, however, no difference (P >0.05) was found in ADFI among the three RH groups at acute moderate 26°C;35 and 85% RH increased (P<0.05) droppings’ corticosterone metabolites at the 2, 6, 8 and 22 h and decreased (P<0.05) ADFI compared to the 60% RH, moreover, 85% RH further increased (P<0.05) droppings’ corticosterone metabolites and further decreased (P<0.05) ADFI compared to the 35% RH at acute moderate 31°C;and the average of droppings’ corticosterone metabolites in the whole period had a negative correlation (P<0.02) with the ADFI. 2) In experiment 2, 85% RH increased (P<0.01) droppings’ corticosterone metabolites only at the 2 h and decreased (P<0.02) ADFI and average daily gain (ADG) compared to the 60% RH, no difference (P >0.05) in droppings’ corticosterone metabolites was found between the 35 and 60% RH, however, 35% RH decreased (P<0.01) ADG compare 展开更多
关键词 broiler droppings’ CORTICOSTERONE METABOLITES relative humidity ACUTE MODERATE TEMPERATURE CHRONIC MODERATE TEMPERATURE
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灸热在人体穴位组织中传导机理研究
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作者 丁家峰 楚鑫 +8 位作者 常小荣 李新梅 曾尧 梁健 许雪梅 贲定严 刘密 戴国斌 洪珏 《针灸推拿医学:英文版》 CSCD 2019年第1期24-30,共7页
目的:通过温度采集技术和数值建模方法探讨艾灸生物传热的局部作用特点。方法:采用高精度温度测量阵列,实现对3cm灸距下艾灸温度的多点测量并获取艾灸温度场云图。运用有限元分析方法模拟出穴位组织温度三维动态分布模型。结果:通过数... 目的:通过温度采集技术和数值建模方法探讨艾灸生物传热的局部作用特点。方法:采用高精度温度测量阵列,实现对3cm灸距下艾灸温度的多点测量并获取艾灸温度场云图。运用有限元分析方法模拟出穴位组织温度三维动态分布模型。结果:通过数值分析,建立了人体穴位组织在施灸5min时温度分布的一维、二维及三维模型。结果表明灸热主要沿着组织表面至内部进行传导,随着组织深度的增加灸热的影响也越来越小。通过对5、10、15和20min不同时刻内穴位组织中温度场分析,表明随着施灸时间的增长,穴位组织的温度不断增加,灸热在穴位的传递深度进一步扩大。结论:运用有限元分析软件ANSYS14.0,结合人体组织的生物参数及实际测量的温度数值,建立了穴位组织温度场传播过程的三维动态模型,发现艾灸过程中热量在组织中的传播规律,揭示了艾灸传热(从近到远)、透热(由浅入深)的作用特点,为临床灸法的运用提供了理论和实验支持。 展开更多
关键词 灸法 艾条灸 足三里 有限元分析 温度 导热性 温度场 健康志愿者
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