期刊文献+
共找到961篇文章
< 1 2 49 >
每页显示 20 50 100
High Temperature Strain Structures and Quartz C-Axis Fabrics from Mylonitic Rocks in the Ailaoshan-Red River Shear Zone,Yunnan,and Their Tectonic Implication 被引量:12
1
作者 LIU Junlai TANG Yuan XIA Haoran GUO Qiang TRAN My Dung CAO Shuyun WU Hujun WU Wenbin ZHANG Zhaochong ZHAO Zhidan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2010年第6期1377-1390,共14页
The Ailaoshan-Red River(ASRR) shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed... The Ailaoshan-Red River(ASRR) shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed linearly along the shear zone,e.g.Xuelongshan,Diancangshan, Ailaoshan and Day Nui Con Voi from north to south.They bear a lot of lines of evidence for the tectonic evolution of the eastern Tibetan at different crustal levels in different tectonic stages.Controversy still exists on the deformation structures,microstructures and their relationship with metamorphisms along the ASRR.In this paper detailed microstructural and EBSD(Electron Backscattered Diffraction) fabric analysis of some highly sheared granitic rocks from different massifs along the ASRR are conducted.High temperature structures and microstructures are preserved in unsheared gneisses,in weakly sheared xenoliths or in some parts of the highly sheared rocks(mylonites).Several types of high temperature quartz c-axis fabrics show symmetrical patterns or transitions from symmetrical to asymmetrical patterns.The former are attributed to coaxial deformation during regional shortening in an early stage of the Indian-Eurasian tectonic interaction and the latter are related to the transitions from coaxial compression to noncoaxial shearing during the post-collisional ASRR left lateral shearing. 展开更多
关键词 high temperature deformation quartz fabrics shortening deformation Ailaoshan-Red River shear zone southeastern Tibet
下载PDF
Study of corrosion behavior of labeling medium on Fe-36%Ni cold-rolled strip used in LNG carriers in high-temperature and high-humidity environment
2
作者 WANG Xueting LV Jiansheng TIAN Yuxin 《Baosteel Technical Research》 CAS 2020年第1期39-43,共5页
To fulfill the high-quality surface requirements of the Fe-36% Ni cold-rolled strip used in liquid natural gas carriers,corrosion tests were conducted on alloy surfaces using ink media with different composition in hi... To fulfill the high-quality surface requirements of the Fe-36% Ni cold-rolled strip used in liquid natural gas carriers,corrosion tests were conducted on alloy surfaces using ink media with different composition in hightemperature and high-humidity conditions.The results show that the Cl^-content in ink is the main cause of surface corrosion of Fe-36%Ni alloy at 95%RH and 50℃ Cl^- penetrates the passivation film,causing pitting on the surface.This corrosive material primarily comprises elements Fe and O.After 120 h of high temperature and high humidity,pitting had occurred on the surface,which was characterized by irregularly distributed areas of bright red filamentous corrosion.With time,the corrosion gradually deepened and expanded to nearby areas.However,when the ink medium contained no Cl^-,no corrosion was found on the alloy surface.As such,during the production of Fe-36%Ni material and its application in LNG shipbuilding,care must be taken in the selection of the marker or medium that will come into contact with the strip surface to ensure that it contains no corrosive ions like Cl^-. 展开更多
关键词 corrosion Cl^- Fe-36%Ni high temperature and high humidity LNG
下载PDF
Impact of Relative Humidity of Supply Gas on Temperature Distributions in Single Cell of Polymer Electrolyte Fuel Cell When Operated at High Temperature 被引量:2
3
作者 Akira Nishimura Masato Yoshimura +2 位作者 Satoru Kamiya Masafumi Hirota Eric Hu 《Journal of Energy and Power Engineering》 2017年第11期706-718,共13页
For improving the performance of stationary PEFC (polymer electrolyte fuel cell) system, the cell operating temperature up to 90℃ will be preferred in Japan during the period from 2020 to 2030. To understand the op... For improving the performance of stationary PEFC (polymer electrolyte fuel cell) system, the cell operating temperature up to 90℃ will be preferred in Japan during the period from 2020 to 2030. To understand the operation of the PEFC system under relatively high temperature conditions, detail heat and mass transfer analysis is required. The purpose of this study is to analyze the impact of relative humidity of supply gas on temperature distribution on the backside of separator in single ceil of PEFC using Nation membrane at higher temperature e.g. 90℃. The in-plane temperature distribution when power was being generated was measured using thermograph with various relative humidity of supply gases. It was found that the in-plane temperature distribution at the anode was more even than that at the cathode irrespective of the relative humidity of supply gas at the anode and the cathode. The temperature elevated along gas flow through the gas channel at the cathode irrespective of relative humidity of supply gas at the anode and the cathode. The in-plane temperature distribution at the cathode was narrower with the increase in Tini irrespective of relative humidity of supply gas at the cathode, while it was not observed when changing the relative humidity of supply gas at the anode. When the relative humidity of supply gas at cathode decreased, the in-plane temperature distribution at the anode was wider compared to decreasing the relative humidity of supply gas at the anode. The study concluded that the impact of relative humidity of supply gas at both anode and cathode had little impact on the in-plane temperature distribution at the cathode. 展开更多
关键词 PEFC temperature distribution high temperature operation relative humidity.
下载PDF
Annual and seasonal changes of the air temperature with altitude in the Upper Dades valley, High Atlas, Morocco
4
作者 ŻMUDZKA Elwira DŁUŻEWSKI Maciej +2 位作者 DĄBSKI Maciej LEZIAK Kamil ROJAN Elżbieta 《Journal of Mountain Science》 SCIE CSCD 2022年第1期85-102,共18页
The purpose of this study is to determine the size of air temperature changes with altitude in the mountains of the arid zone, on the example of the Upper Dades valley(High Atlas, Morocco). The air temperature change ... The purpose of this study is to determine the size of air temperature changes with altitude in the mountains of the arid zone, on the example of the Upper Dades valley(High Atlas, Morocco). The air temperature change with altitude was determined on the basis of 5 years data from three meteorological stations. The analysis was carried out on an annual and seasonal basis. The annual and daily variations of thermal gradients between pairs of stations were also determined. It was found that the average thermal gradient in the Upper Dades valley was-1.02℃ per 100 m. The highest values of the thermal gradient occur in winter and the lowest in summer. In winter,the thermal gradient was characterized by the greatest variability. Minima of the daily variation of air temperature gradients were observed in early morning hours and maxima around midday. In the lower part of the valley, air temperature inversion frequently developed between 10 AM and 3 PM UTC.The obtained results show high thermal gradients in the mountains of the arid zone, with their annual amplitude increasing in the lower parts of the valley.The instantaneous values of the gradients were significantly modified by the supply of latent heat and the occurrence of dust storms. It has been shown that the advection factor plays an important role in shaping large gradient values. The study contains novel results of thermal gradient measurements in high mountains of arid zone. 展开更多
关键词 Air temperature gradient Thermal inversion Annual and seasonal variability Synoptic situation high mountains of arid zone high Atlas Mountains
下载PDF
Effects of high temperature and high relative humidity drying on moisture distribution,starch microstructure and cooking characteristics of extruded whole buckwheat noodles
5
作者 Linghan Meng Xuyang Sun +1 位作者 Yan Zhang Xiaozhi Tang 《Journal of Future Foods》 2024年第2期159-166,共8页
Drying is a key step in starch noodle production.The effects of high temperature(60,70,80°C)and high relative humidity(65%,75%,85%)drying(HTHD)on the moisture distribution,starch microstructure and cooking charac... Drying is a key step in starch noodle production.The effects of high temperature(60,70,80°C)and high relative humidity(65%,75%,85%)drying(HTHD)on the moisture distribution,starch microstructure and cooking characteristics of extruded whole buckwheat noodles were investigated.Compared to the conventional hot-air drying(CHAD)at 40°C,the increase in drying temperature(60–80°C)and the decrease in relative humidity(85%–65%)significantly improved drying efficiency of the extruded noodles.By adjusting drying temperature and relative humidity,the rate of moisture migration in noodles and phase transition of starch could be appropriately controlled.The optimum drying parameters(T70H75,70°C drying temperature and 75%relative humidity)showed smooth and dense network structure,resulting in the lowest cooking loss(6.61%),broken rate(0%),highest hardness(1695.17 g)and springiness(0.92).However,the total flavonoid content(TFC)and the total phenolic content(TPC)reduced by 6.81%–28.50%and 7.19%–53.23%in contrast to CHAD,and the color of buckwheat noodles became darker through HTHD.These findings showed the potential of HTHD for increasing drying efficiency and improving buckwheat noodle quality.The appropriate drying parameters could maintain a balanced relationship between moisture migration in noodles and phase transition of starch,which resulted in better cooking quality for extruded whole buckwheat noodles.Such a study is valuable for regulating the process conditions of buckwheat-based foods and promoting its commercial utilization. 展开更多
关键词 Extruded whole buckwheat noodle high temperature and high relative humidity drying Moisture distribution Starch microstructure Cooking characteristics
原文传递
The Influence of SST Warm-water Region and ITCZ in the North-West Pacific Ocean on the Northeast Cold Vortex and the Subtropical High
6
作者 梁红 马福全 +1 位作者 李大为 刘凯 《Meteorological and Environmental Research》 CAS 2010年第9期18-21,共4页
By using the monthly mean grid data of NCAR/NCEP reanalysis at 500 hPa geopotential height from 1958 to 1997,the relationship between the Northeast cold vortex and the western Pacific subtropical high was analyzed.The... By using the monthly mean grid data of NCAR/NCEP reanalysis at 500 hPa geopotential height from 1958 to 1997,the relationship between the Northeast cold vortex and the western Pacific subtropical high was analyzed.The influence of the sea surface temperature(SST) and outgoing longwave radiation(OLR) on the Northeast cold vortex and subtropical high was studied.As was shown in the results,in summer,there was a positive correlation between the Northeast cold vortex and the subtropical high,and an anti-phase relationship existed between the threshold characteristic line of GMS-SST=28 ℃ and the height index of the Northeast cold vortex and the subtropical high.With the gradual northward moving of the threshold characteristic line,the subtropical high was weakening,and the Northeast cold vortex was increasing and strengthening. 展开更多
关键词 Northeast cold vortex Subtropical high Sea surface temperature(SST) Intertropical convergence zone(ITCZ) China
下载PDF
Effects of Extreme Air Temperature and Humidity on the Insecticidal Expression Level of Bt Cotton 被引量:11
7
作者 CHENYuan WEN Yu-jin +5 位作者 CHEN Yuan John Tom Cothren ZHANG Xiang WANG Yong-hui WilliamA Payne CHEN De-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第11期1836-1844,共9页
The higher survival rates of Helicoverpa amigera larvae were usually observed after adverse climate which was related to extreme temperature (T) and relative humidity (RH) stresses in transgenic Bacillus thuringie... The higher survival rates of Helicoverpa amigera larvae were usually observed after adverse climate which was related to extreme temperature (T) and relative humidity (RH) stresses in transgenic Bacillus thuringiensis (Bt) cotton. The unstable resistance of Bt cotton to bollworms has been correlated with the reduced expression of CrylAc δ-endotoxin. The objective of this study was to investigate the effects of combined temperature and relative humidity stresses on the leaf CrylAc insecticidal protein expression during critical developmental stages. The study was undertaken on two transgenic cotton cultivars that share same parental background, Sikang 1 (a conventional cultivar) and Sikang 3 (a hybrid cultivar), during the 2007 and 2008 growing seasons at the Yangzhou University Farm, Yangzhou, China. The study was arranged with two factors that consisted of temperature (two levels) and relative humidity (three levels). The six T/RH treatments were 37℃/95%, 37℃/70%, 37℃/50%, 18℃/95%, 18℃/70%, and 18℃/50%. In 2007, the six treatments were imposed to the plants at peak flowering stage for 24 h; in 2008, the six treatments were applied to the plants at peak square, peak flowering, and peak boll stages for 48 h. The results of the study indicated that the leaf insecticidal protein expression in CrylAc was significantly affected by extreme temperature only at peak flowering stage, and by both extreme temperature and relative humidity during boll filling stage. The greatest reductions were observed when the stresses were applied at peak boll stage. In 2008, after 48 h stress treatment, the leaf Bt endotoxin expression reduced by 25.9-36.7 and 23.6-40.5% at peak boll stage, but only by 14.9-26.5 and 12.8-24.0% at peak flowering stage for Sikang 1 and Sikang 3, respectively. The greatest reduction was found under the low temperature combined with low relative humidity condition for both years. It is believed that the temperature and relative humidity stresses may be attributed to the reduced efficacy of Bt cotton in growing conditions in China, where extreme temperatures often increase up to 35-40℃ and/or decrease down to 15-20℃, and relative humidity may reach to 85-95% and/or reduce to 40-55% during the cotton growing season. 展开更多
关键词 Bt cotton high temperature low temperature relative humidity CryIAc protein
下载PDF
Microstructural analysis of the softened zone in the welding joint of 100 kg class hot-rolled extra-high-strength steel
8
作者 WANG Haitao QU Zhaoxia XU Lei 《Baosteel Technical Research》 CAS 2013年第3期10-13,共4页
Using the Gleeble 3500 thermal-mechanical system to simulate thermal cycles with different peak temperatures, the hardness and microstructure in the heat-affected zones of two kinds of 100 kg class hot-rolled extra-hi... Using the Gleeble 3500 thermal-mechanical system to simulate thermal cycles with different peak temperatures, the hardness and microstructure in the heat-affected zones of two kinds of 100 kg class hot-rolled extra-high-strength steel were compared. When the peak temperature of the thermal cycle was 800℃ ,incomplete transformation occurred during quenching in both steels, and massive martensite and bainite grains were formed. The hardness was determined by the composition and distribution of the microstructure. The concentration of massive martensite was low, and hence the hardness was low,in steel #1. Conversely,the massive martensite content in steel #2 was high and uniformly distributed,resulting in a high hardness. These findings can provide a reference for improving the mechanical properties in the softened zone. 展开更多
关键词 quenched and tempered extra-high-strength steel peak temperature softened zone HARDNESS massive martensite
下载PDF
A Large Ductile Sinistral Strike-Slip Shear Zone and Its Movement Timing in the South Qilian Mountains, Western China 被引量:5
9
作者 许志琴 李海兵 +4 位作者 陈文 吴才来 杨经绥 金小赤 陈方远 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2002年第2期183-193,共11页
There is a large ductile shear zone, 2 km wide and more than 350 km long, inthe South Qilian Mountains, western China. It is composed of volcanic, granitic and calcareousmylonites. The microstructures of the ductile s... There is a large ductile shear zone, 2 km wide and more than 350 km long, inthe South Qilian Mountains, western China. It is composed of volcanic, granitic and calcareousmylonites. The microstructures of the ductile shear zone show nearly E-W extending subverticalfoliation, horizontal and oblique stretching lineations, shearing sense from sinistral to obliquesinistral strike-slip from east to west, 'A' type folds and abundant granitic veins. Measuredlattice preferred orientations (LPOs) of the mylonitic and recrystallized quartz of the graniticmylonite in the west segment suggest a strong LPO characterized by the dominant slip systems (1010) formed at high temperature (>650 deg C). K-feldspar of the mylonite shows an ^(39)Ar/^(40)Arhigh-temperature plateau age of 243.3 +- 1.3 Ma, and biotite, 250.5 +- 0.5 Ma, which represent theformation age of the ductile shear zone. The ^(39)Ar/^(40)Ar plateau ages of 169.7 +- 0.3 Ma and160.6 +- 0.1 Ma and the ^(39)Ar/^(40)Ar isochron ages of 166.99 +- 2.37 Ma and 160.6 +- 0.1 Ma ofbiotites in the mylonite represent the subsequent deformation age. These ages indicate that thisductile shear zone is similar to the Altun and South Kunlun sinistral ductile shear zones in itsages of movement, formation, reactivation and duration. 展开更多
关键词 Early Triassic ductile sinistral shear zone high-temperature LPO SouthQilian
下载PDF
Influence Factors of Audible Noise Caused by Corona Discharge on UHVDC Transmission Lines Under High Altitude Condition 被引量:4
10
作者 TIAN Feng YU Zhanqing +3 位作者 ZENG Rong LIU Lei LI Min LI Ruihai 《高电压技术》 EI CAS CSCD 北大核心 2012年第12期3125-3132,共8页
关键词 高压直流输电线路 电晕放电 影响因素 噪声 高海拔 高压直流输电工程 绝对湿度 电压升高
下载PDF
New Zircon U-Pb Geochronology of the Post-kinematic Granitic Plutons in the Diancang Shan Metamorphic Massif along the Ailao Shan-Red River Shear Zone and Its Geological Implications 被引量:9
11
作者 CAO Shuyun LIU Junlai +1 位作者 Bemd LEISS ZHAO Chunqiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2010年第6期1474-1487,共14页
The Ailao Shan-Red River fault zone is the boundary between the Yangtze block to the northeast and the Indochina block to the southwest.It is an important tectonic zone due to its role in the southeastward extrusion o... The Ailao Shan-Red River fault zone is the boundary between the Yangtze block to the northeast and the Indochina block to the southwest.It is an important tectonic zone due to its role in the southeastward extrusion of the Indochina block during and subsequent to the Indian-Eurasian collision.Diancang Shan(DCS) high-grade metamorphic complex,located at the northwest extension along the Ailao Shan-Red River(ASRR) shear zone,is a representative metamorphic complex of the ASRR tectonic belt.Structural and microstructural analysis of sheared rocks in the high-grade metamorphic rocks reveals that they are coherent with solid-state high-temperature ductile deformation,which is attributed to left-lateral shearing along the ASRR shear zone.New LA-ICP-MS zircon U-Pb geochronological and microstructural studies of the post-kinematic granitic plutons provide a straightforward time constraint on the termination ductile left-lateral shearing and exhumation of the metamorphic massif in the ASRR shear zone.It is suggested that the left-lateral shearing along the ASRR shear zone ended at ca.21 Ma at relative lower-temperature or decreasing temperature conditions.During or after the emplacement of the young dikes at ca.21 Ma,rapid brittle deformation event occurred,which makes the DCS massif start fast uplift/exhumation and cooling to a shallow crustal level. 展开更多
关键词 high-temperature mylonites Diancang Shan metamorphic massif Ailao Shan-Red River shear zone timing of left-lateral ductile shearing GEOCHRONOLOGY
下载PDF
Numerical simulation of the mechanical behavior of superconducting tape in conductor on round core cable using the cohesive zone model 被引量:1
12
作者 Shengyi TANG Xubin PENG Huadong YONG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第9期1511-1532,共22页
Cables composed of rare-earth barium copper oxide(REBCO)tapes have been extensively used in various superconducting devices.In recent years,conductor on round core(CORC)cable has drawn the attention of researchers wit... Cables composed of rare-earth barium copper oxide(REBCO)tapes have been extensively used in various superconducting devices.In recent years,conductor on round core(CORC)cable has drawn the attention of researchers with its outstanding current-carrying capacity and mechanical properties.The REBCO tapes are wound spirally on the surface of CORC cable.Under extreme loadings,the REBCO tapes with layered composite structures are vulnerable,which can lead to degradation of critical current and even quenching of superconducting devices.In this paper,we simulate the deformation of CORC cable under external loads,and analyze the damage inside the tape with the cohesive zone model(CZM).Firstly,the fabrication and cabling of CORC are simulated,and the stresses and strains generated in the tape are extracted as the initial condition of the next step.Then,the tension and bending loads are applied to CORC cable,and the damage distribution inside the tape is presented.In addition,the effects of some parameters on the damage are discussed during the bending simulations. 展开更多
关键词 high temperature superconducting(HTS)tape superconducting cable finite element simulation cohesive zone model(CZM) damage
下载PDF
燃氢燃机高温高湿透平耦合传热和冷却特性
13
作者 任静 李雪英 +3 位作者 黄新宇 王文萍 孙鹏 李明飞 《动力工程学报》 CAS CSCD 北大核心 2024年第9期1416-1423,共8页
分析了燃氢燃机透平在导热/对流/辐射耦合作用下的流动传热和冷却特性,发展了能够计算高H_(2)O与CO_(2)分压比的灰气体加权和(WSGG)模型。结果表明:燃氢燃机工质中水蒸气含量增大导致金属壁面温度升高;加入辐射的影响后,H_(2)O和CO_(2)... 分析了燃氢燃机透平在导热/对流/辐射耦合作用下的流动传热和冷却特性,发展了能够计算高H_(2)O与CO_(2)分压比的灰气体加权和(WSGG)模型。结果表明:燃氢燃机工质中水蒸气含量增大导致金属壁面温度升高;加入辐射的影响后,H_(2)O和CO_(2)含量对传热的影响呈相反的结果,这主要是由于CO_(2)的对流传热能力强于H_(2)O,而H_(2)O的辐射能力强于CO_(2);在对流、导热、辐射3种传热方式都存在的燃氢透平冷却耦合系统中,气膜冷却的速度场几乎不受影响,而温度场则深受耦合及辐射的影响,所定义的耦合条件下气膜冷却效率能够表征燃氢条件下气膜的冷却性能,因此在燃氢燃机透平冷却的设计中,燃氢导致的热负荷恶化需纳入设计变量中。 展开更多
关键词 燃氢燃气轮机 透平 高温高湿 耦合传热 冷却特性 辐射
下载PDF
Early Mesozoic mantle-crust transitional zone in eastern Inner Mongolia: Evidence from measurements of compressional velocities of xenoliths at high pressure and high temperature 被引量:5
14
作者 邵济安 韩庆军 《Science China Earth Sciences》 SCIE EI CAS 2000年第S1期253-261,共9页
Compression wave velocity Vp has been measured on 10 representative rock samples from the Early Mesozoic granulite and mafic-ultramafic cumulate xenoliths population from the Harqin area of the Inner Mongolia Autonomo... Compression wave velocity Vp has been measured on 10 representative rock samples from the Early Mesozoic granulite and mafic-ultramafic cumulate xenoliths population from the Harqin area of the Inner Mongolia Autonomous Region (for short Inner Mongolia) as an aid to interpreting in-situ seismic velocity data and investigating velocity variation with depth in a mafic lower crust. The experiments have been carried out at constant confining pressures up to 1 000 MPa and temperatures ranging from 20 to around 1 300℃, using the ultrasonic transmission technique. After corrections for estimated in situ crustal pressures and temperatures, elastic wave velocities range from 6.5 to 7.4 km · s-1, indicating that they are components of the Early Mesozoic crust-mantle transitional zone. Combining with previous experimental data, we have also reestablished the Early-Mesozoic continental compression velocity profile and compared it with those of the present and of the different tectonic environments in the world. The result shows that it is similar to the velocity pattern of the extensional tectonic area, providing new clues to the Mesozoic continental structure of the North China Craton. 展开更多
关键词 EASTERN Inner Mongolia Early MESOZOIC CRUST-MANTLE transitional zone high temperature and high pressure congressional wave velocity.
原文传递
含界面过渡区随机分布多边形骨料沙漠砂混凝土高温后抗压强度研究
15
作者 刘海峰 陶仁光 吕晓晔 《混凝土》 CAS 北大核心 2024年第3期68-73,77,共7页
为研究试件尺寸、界面过渡区(ITZ)厚度及强度、沙漠砂替代率(DSRR)对沙漠砂混凝土(DSC)经历高温后抗压强度的影响,将DSC看作三相复合材料,建立含ITZ随机分布多边形骨料有限元模型,利用ANSYS对高温后DSC单轴受压破坏过程进行数值模拟。... 为研究试件尺寸、界面过渡区(ITZ)厚度及强度、沙漠砂替代率(DSRR)对沙漠砂混凝土(DSC)经历高温后抗压强度的影响,将DSC看作三相复合材料,建立含ITZ随机分布多边形骨料有限元模型,利用ANSYS对高温后DSC单轴受压破坏过程进行数值模拟。结果表明:模拟结果与试验结果误差在-2.59%~3.13%,吻合良好。高温后DSC抗压强度随试件尺寸增大而减小,强度下降范围为1.44%~4.13%;抗压强度随ITZ厚度增加呈逐渐减小趋势;随着ITZ强度增加,抗压强度基本呈线性增大趋势;抗压强度在DSRR为40%时最优,研究结果可为DSC工程应用提供理论依据。 展开更多
关键词 界面过渡区 沙漠砂混凝土 多边形骨料 高温 数值模拟
下载PDF
基于灾害风险理论的湖北水稻高温热害风险分析及区划 被引量:1
16
作者 李世刚 王东仙 +1 位作者 刘可群 刘志雄 《气象科技》 2024年第2期288-296,共9页
高温热害是长江流域最主要的气象灾害之一,科学评估热害风险是防灾减灾的基础。本文利用近60年气象观测资料,对湖北高温热害的时空分布特征进行了分析;基于自然灾害风险基本理论,建立了包括影响水稻结实率关键期的热害强度、灾害发生时... 高温热害是长江流域最主要的气象灾害之一,科学评估热害风险是防灾减灾的基础。本文利用近60年气象观测资料,对湖北高温热害的时空分布特征进行了分析;基于自然灾害风险基本理论,建立了包括影响水稻结实率关键期的热害强度、灾害发生时承灾体实际暴露度、灾害脆弱性等因素的高温热害风险评价模型,并进行了风险分析与区划。结果表明:高温天气出现概率高的时段是7月下旬,其中7月第6候为最高。从高温热害风险指数上来看,7月第3候抽穗开花水稻的热害风险最高,此后随时间的推移,热害风险降低;湖北现行的一季中稻抽穗开花期处于风险较高的时段,推迟5天其热害风险指数可下降20%左右;推迟15天以上热害风险指数将降低50%以上。江汉平原稻区是湖北高温热害风险低发地区,鄂东南及鄂西北地区是热害风险高发地区;针对各区热害特点提出了风险应对措施。 展开更多
关键词 水稻 高温热害 风险分析 区划
下载PDF
Low-temperature combined with high-humidity thawing improves the water-holding capacity and biochemical properties of Portunus trituberculatus protein
17
作者 Jiangang Ling Xiaoting Xuan +4 位作者 Zihan Xu Tian Ding Xudong Lin Yan Cui Donghong Liu 《Food Quality and Safety》 SCIE CSCD 2021年第2期152-160,共9页
This study compared the effects of conventional thawing methods(water immersion thawing(WIT,(25±1)℃),natural air thawing(AT,(25±1)℃,relative humidity(RH(65±2)per cent),refrigerator thawing(RT,4℃,RH(8... This study compared the effects of conventional thawing methods(water immersion thawing(WIT,(25±1)℃),natural air thawing(AT,(25±1)℃,relative humidity(RH(65±2)per cent),refrigerator thawing(RT,4℃,RH(80±2)per cent)and low-temperature(LT)combined with high-humidity thawing LT,-1℃to 1℃(LT-1-1),2-4℃(LT2-4),5-7℃(LT5-7)and 8-10℃(LT8-10),RH>95 per cent)on the water-holding capacity,lipid oxidation and biochemical properties of Portunus trituberculatus(P.trituberculatus)myofibrillar protein.The results showed that WIT and AT significantly decreased the water-holding capacity while dramatically increasing lipid oxidation,protein oxidation and degeneration,resulting in serious P.trituberculatus quality deterioration.High humidity was beneficial for P.trituberculatus\.ha\A/\ng.The thawing time of P.trituberculatus under the conditions of LT2-4 was only 39.39 per cent of that of conventional air thawing at 4℃(RT),and the LT2-4 samples not only maintained better water-holding capacity but also had an obviously reduced degree of lipid oxidation,protein oxidation and denaturation.Thawed samples LT2-4 and LT5-7 provided better maintenance of P.trituberculatus quality than the LT-1-1 and LT8-10 samples.The best quality was exhibited after thawing at 2-4℃.The levels of thiobarbituric acid reacting substances,carbonyl content and surface hydrophobicity observably decreased in these samples,while the total sulfhydryl contents dramatically increased compared to those of conventionally thawed samples,indicating lower lipid oxidation and protein oxidation.Moreover,the Ca2+-ATPase activity of the sample thawed at 2-4℃(2.06 μmol Pi/mg prot/h)was markedly higher than that of samples subjected to WIT and AT.The product qualities observed after thawing at-1℃to 1℃,5-7℃and 8-10℃under LT were comparable to that observed by RT.Considering its thawing efficiency and product quality,LT is a suitable method for the thawing of P.trituberculatus,and the ideal thawing conditions were LT at 2-4℃. 展开更多
关键词 Portunus trituberculatus- thawing low temperature combined with high humidity water-holding capacity lipid oxidation biochemical properties of myofibrillar protein
原文传递
高温高压实验揭示俯冲带蛇纹岩熔融行为与高镁岩浆成因
18
作者 胡佳森 张国良 《海洋地质与第四纪地质》 CAS CSCD 北大核心 2024年第2期157-170,共14页
近年来一些研究在岛弧岩浆中发现了蛇纹岩组分,这表明俯冲至弧下的蛇纹岩不仅为地幔楔提供流体,而且可以通过部分熔融参与岛弧岩浆形成。然而,蛇纹岩在地幔楔中的熔融行为及其在俯冲带物质循环中的作用仍未进行深入研究。因此,本研究选... 近年来一些研究在岛弧岩浆中发现了蛇纹岩组分,这表明俯冲至弧下的蛇纹岩不仅为地幔楔提供流体,而且可以通过部分熔融参与岛弧岩浆形成。然而,蛇纹岩在地幔楔中的熔融行为及其在俯冲带物质循环中的作用仍未进行深入研究。因此,本研究选择3种蛇纹岩样品:蚀变原岩分别为二辉橄榄岩(SE2)和方辉橄榄岩(SE3)的天然蛇纹岩,以及模拟含有大量滑石的合成蛇纹岩样品(SEQ),在700~1300℃和4 GPa的温度压力条件下进行了模拟实验,限定了蛇纹岩的熔融温度,分析了实验产生的熔体成分。研究发现,不同类型蛇纹岩的固相线存在显著差异,SE3、SEQ和SE2蛇纹岩的固相线分别为900~960℃、960~1100℃以及1150~1200℃。这3种蛇纹岩的固相线均高于俯冲板片上表面的温度,要求蛇纹岩通过底辟作用进入地幔楔以发生部分熔融。根据实验结果,本研究认为SE2和SEQ蛇纹岩可以在地幔楔底部相对较低的温度条件下(960~1100℃)即发生熔融,产生科马提质岩浆;而在上覆地幔楔更高温度条件下(>1200℃),SE2蛇纹岩可以发生更广泛、更高程度的部分熔融,产生玻安质岩浆。 展开更多
关键词 蛇纹岩 俯冲带 高温高压实验 高镁岩浆 科马提岩
下载PDF
夏季高温下支承层斜裂缝诱发纵连板上拱规律研究
19
作者 张雅琴 高亮 +2 位作者 钟阳龙 蒋函珂 黄伊琛 《铁道学报》 EI CAS CSCD 北大核心 2024年第3期165-175,共11页
在夏季高温作用下,支承层斜裂贯通缝可能导致结构上拱变形,衍生次生病害。基于内聚力和塑性损伤理论建立CRTSⅡ型板式无砟轨道结构有限元模型并与现场实测结果对比验证模型的有效性,分析夏季高温作用下支承层斜裂缝导致的结构上拱变形... 在夏季高温作用下,支承层斜裂贯通缝可能导致结构上拱变形,衍生次生病害。基于内聚力和塑性损伤理论建立CRTSⅡ型板式无砟轨道结构有限元模型并与现场实测结果对比验证模型的有效性,分析夏季高温作用下支承层斜裂缝导致的结构上拱变形、离缝、受力和伤损规律。结果表明,温度荷载作用下,斜裂缝一旦贯通,轨道结构变形急剧增大。随温度升高,支承层相互错动,CA砂浆层与支承层先离缝,随后轨道板与CA砂浆层离缝,轨道结构上拱变形。结构性能随温度演化过程可分为0~20℃的缓慢发展阶段、20~30℃的加速发展阶段和大于30℃的飞速破坏阶段。贯通斜裂缝位于板中,角度30°时,轨道结构变形达到最大值26 mm。建议温度大于30℃时,检修重点关注角度不大于45°的板中斜裂贯通缝。 展开更多
关键词 板式无砟轨道 内聚力模型 塑性损伤模型 高温 上拱变形
下载PDF
高温高湿环境下军事训练致新兵横纹肌溶解及相关脏器损伤的研究
20
作者 沈建 张昕 +6 位作者 刘赫男 周伯宁 李影 焦阳 刘冰 郑小来 付振虹 《陆军军医大学学报》 CAS CSCD 北大核心 2024年第10期1063-1067,共5页
目的通过比较不同训练环境对新兵实验室检测指标及心电图的影响,探讨新兵在高温高湿环境下出现横纹肌溶解和相关脏器损伤的可能性。方法选择两地新兵500名,均为男性,年龄(21.36±2.59)岁,按新兵所在环境分为常规环境组(北京某部,n=2... 目的通过比较不同训练环境对新兵实验室检测指标及心电图的影响,探讨新兵在高温高湿环境下出现横纹肌溶解和相关脏器损伤的可能性。方法选择两地新兵500名,均为男性,年龄(21.36±2.59)岁,按新兵所在环境分为常规环境组(北京某部,n=250)和高温高湿环境组(海南某部,n=250)。进行相同科目训练后4周,采集新兵的一般情况、训练前后血液及尿液学指标、心电图检查相关指标,并进行统计学分析。结果高温高湿环境组炎症反应、心肌损伤、肌肉损伤、肝损伤、肾损伤的发生率分别为45.76%、3.39%、12.71%、25.42%、12.71%,较常规环境组显著增加(P<0.05)。高温高湿环境组新兵窦性心动过缓、房性早搏、非特异ST-T变化、左室高电压、短PR间期的发生率分别为6.78%、5.93%、8.47%、6.78%、2.54%,显著高于常规环境组(P<0.05)。结论高温高湿环境下新兵军事训练后更易出现炎性反应、心肌损伤、肌肉损伤、肝损伤、肾损伤以及心电异常。 展开更多
关键词 军事训练 高温 高湿 横纹肌溶解 脏器损伤 心电图异常
下载PDF
上一页 1 2 49 下一页 到第
使用帮助 返回顶部