Spatial pattern recognition for near-surface high temperature increases in mountain areas using MODIS and SRTM DEM

Abrupt near-surface temperature changes in mountainous areas are a special component of the mountain climate system.Fast and accurate measurements of the locations,intensity,and width of the near-surface changes are necessary but highly difficult due to the complicated environmental conditions and instrumental issues.This paper develops a spatial pattern recognition method to measure the near-surface high temperature increase(NSHTI),one of the lesser-attended changes.First,raster window measurement was proposed to calculate the temperature lapse rate using MODIS land surface temperature and SRTM DEM data.It fully considers the terrain heights of two neighboring cells on opposite or adjacent slopes with a moving window of 3×3 cell size.Second,a threshold selection was performed to identify the NSHTI cells using a threshold of-0.65℃/100 m.Then,the NSHTI strips were parameterized through raster vectorization and spatial analysis.Taking Yunnan,a mountainous province in southwestern China,as the study area,the results indicate that the NSHTI cells concentrate in a strip-like pattern along the mountains and valleys,and the strips are almost parallel to the altitude contours with a slight northward uplift.Also,they are located mostly at a 3/5 height of high mountains or within 400 m from the valley floors,where the controlling topographic index is the altitude of the terrain trend surface but not the absolute elevation and the topographic uplift height and cutting depth.Additionally,the NSHTI intensity varies with the geographic locations and the proportions increase with an exponential trend,and the horizontal width has a mean of about 1000 m and a maximum of over 5000 m.The result demonstrates that the proposed method can effectively recognize NSHTI boundaries over mountains,providing support for the modeling of weather and climate systems and the development of mountain resources.

Distribution Characteristics of High Temperature Damage and Its Influence on the Rice Yield in the Area along Huaihe River

[Objective] The research aimed to study the distribution characteristics of high temperature damage and its influence on the rice yield in the area along Huaihe River.[Method] The meteorological data of 10 stations in the area along Huaihe River during 1965-2009 and the yield data of Anhui single-season middle rice during 1967-2006 were selected.The occurrence characteristic of summer high temperature weather and the intensity of high temperature damage in the area along Huaihe River were analyzed.Based on the previous high temperature damage index of rice,Changfeng County where was the typical rice planting zone in the area along Huaihe River was as the representation,and the yield damage loss rate risk of high temperature damage in Changfeng was analyzed by combining with the historical yield data.[Result] The high temperature weather in the area along Huaihe River frequently happened.The high temperature damage presented 'N' shape trend from west to east.The occurrence frequency of high temperature weather in Huainan and Bengbu where were in the middle area along Huaihe River was more and was less in Huoqiu and Shouxian where were near the south mountain area of Anhui.The occurrence time mainly focused from the middle and last dekads of July to the first dekad of August after the plum rain.At this time,it was the booting,heading and flowering periods of single-season middle rice,and the influence on the rice yield was obvious.The damage loss rate of single-season middle rice yield in Changfeng County along Huaihe River continued to increase as the increasing of high temperature damage duration.But the occurrence probability decreased.The intensity grade of high temperature damage disaster loss rate which happened frequently concentrated mainly in levels I and II.The longer the high temperature damage duration in the reproductive growth stage of rice was,the bigger the damage loss rate was.But the corresponding occurrence probability was small,and vice versa.[Conclusion] The research provided the reference for assessing the high temperature disaster risk.

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

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^-.

High Temperature-preventing Cultivation Technology of Single-season Middle Rice for High Yield and High Quality in Jianghuai Area

In recent years,with the global climate change,the frequency and duration of high temperature in summer and autumn have increased,causing high temperature heat damage to summer crops such as rice and maize.From the end of July to early August is the main period of high temperature occurrence,during which the daily average temperature above 30℃is a high probability event,and even the highest temperature is above 38℃,while this period coincides with the booting-blooming-filling stage of the single-season middle rice in Jianghuai,especially the middle-season indica rice,so it often leads to the degradation of rice spikelets,pollen abortion,difficulty in pollen dispersion,and even difficulty in heading,resulting in a serious decline in the seed setting rate and poor filling of grains,which finally affect the yield and quality.Based on the goal of high-yielding high-quality rice cultivation,this paper proposed targeted technical measures for single-season middle rice from the aspects of planting time sequence optimization,selection of high-temperature-resistant varieties,population construction,fertilizer and water management technology,and how to compensate for the occurrence of unexpected disasters to promote plant growth.This study provides technical support for high-yielding high-quality stress-resistant and disaster-reducing rice cultivation technology.

Characteristic Analysis and Forecast of Continuous High-temperature Weather in Xingtai Area of Hebei

Through the analysis of durative high-temperature weather process occurred in Xingtai area in June of 2010,and the statistics on relative humidity and 850 hPa of temperature on high temperature day in Xingtai area during 2001- 2010,it was concluded that 500 h Pa of stable warm high-pressure ridge situation and 850 hPa of strong warm air mass control were favorable circulation situations for the formation of high temperature;sinking and adiabatic warming of high-altitude air mass was an important cause of high temperature weather generation; ground humidity at 14： 00 was small,that is,the atmosphere was very dry,and it was sunny-cloudy（ high cirrus） weather,which was a necessary condition for the high temperature weather; westerly at some time was favorable condition for high temperature; 850 h Pa of temperature prediction at the station was the key.When the forecasted 850 h Pa of station temperature was 21 ℃ and above,it was reminded the forecasters in the high-temperature forecast process.

Impact of Relative Humidity of Supply Gas on Temperature Distributions in Single Cell of Polymer Electrolyte Fuel Cell When Operated at High Temperature

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.

Effects of Extreme Air Temperature and Humidity on the Insecticidal Expression Level of Bt Cotton

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.

Preparation of Zirconia-Ceria Powders with High Specific Surface Area

Zirconia-ceria mixed oxide powders were prepared by high temperature aging method.The effects of the temperature and the time of aging, cerium content and calcination on powder performance were studied.The result shows that high temperature aging is an efficient way of preparation of ZrO2-CeO2 mixed oxide powders with high specific surface area and good thermal stability, and that addition of a small amount of cerium to hydrous zirconia can promote the preparation of high specific surface area powders.

Effects of high temperature and high relative humidity drying on moisture distribution,starch microstructure and cooking characteristics of extruded whole buckwheat noodles

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.

Influence of welded pores on fatigue behavior of TC17 titanium alloy welded joints subjected to gigacycle regime at room and high temperatures

Welded structures in aero-engines commonly operate in high-temperature environments,making them susceptible to reduced fatigue life and premature failure due to welding defects within the structure.Thus,the gigacycle fatigue behaviors of titanium alloy welded joints at both room temperature(RT)and 400 ℃ were investigated,aiming to uncover the mechanism behind the formation of fine granular area(FGA)surrounding welded pores.The research findings demonstrate that the S-N curves of TC17 tita-nium alloy electron beam welded joint undergo a transition from a single linear decline at RT to a bilin-ear decline at 400 ℃.However,the fatigue failure mode remains unaffected by temperatures,and crack initiation is attributed to welded pores.By utilizing the Chapetti model curve to modify the Kitagawa-Takahashi(K-T)diagram,the lower threshold stress amplitude is introduced,enabling the determination of a safe size for welded pores at 400 ℃,which is calculated to be 11.3 μm.Additionally,the Gumbel probability distribution function is employed to assess the maximum size of welded pores.Finally,based on dislocation interactions,the formation mechanism of the FGA consisting of discontinuous nanograins with high-density dislocations is elucidated.

Low-temperature combined with high-humidity thawing improves the water-holding capacity and biochemical properties of Portunus trituberculatus protein

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℃.

功率器件芯片自发热对水汽入侵的抑制作用

为探究高温高湿环境中功率器件芯片自发热现象对水汽入侵的抑制作用机理及其对功率器件静态参数和封装可靠性的影响,将器件分成三组进行功率循环测试对比实验。第一组器件直接进行功率循环测试;第二组器件在60℃/85%RH环境储存1000 h再进行功率循环测试;第三组器件在60℃/85%RH环境储存1000 h期间导通电流,令芯片自发热模拟实际工况(芯片结温为120℃),然后进行功率循环测试。实验结果显示,水汽入侵会使功率器件的静态参数发生漂移,缩短器件功率循环寿命。器件功率循环寿命缩短的原因是水汽入侵腐蚀了器件键合线,影响了键合线可靠性。功率器件芯片自发热可以抑制水汽入侵,减小由水汽入侵导致的静态参数漂移及其对器件键合线的腐蚀作用。

High-temperature failure mechanism and defect sensitivity of TC17 titanium alloy in high cycle fatigue

Crack initiation is an essential stage of fatigue process due to its direct effect on fatigue failure.However,for titanium alloys in high-temperature high cycle fatigue(HCF),the crack initiation mechanisms remain unclear and the understanding for the defect sensitivity is also lacking.In this study,a series of fatigue tests and multi-scale microstructure characterizations were conducted to explore the high-temperature failure mechanism,and the coupled effect of temperature and defect on TC17 titanium alloy in HCF.It was found that an oxygen-rich layer(ORL)was produced at specimen surface at elevated temperatures,and brittle fracture of ORL at surface played a critical role for surface crack initiation in HCF.Besides,internal crack initiation with nanograins at high temperatures was a novel finding for the titanium alloy.Based on energy dispersive spectroscopy,electron backscatter diffraction and transmission electron microscope characterizations,the competition between surface and internal crack initiations at high temperatures was related to ORL at surface and dislocation resistance in inner microstructure.The fatigue strengths of smooth specimens decreased at elevated temperatures due to the lower dislocation resistance.While the fatigue strengths of the specimens with defect were not very sensitive to the temperatures.Finally,a fatigue strength model considering the coupled effect of temperature and defect was proposed for TC17titanium alloy.

基于Landsat的泰安市热岛效应研究

热岛效应对城市气候有非常重要的影响,文中利用美国Landsat数据对泰安市进行热岛效应研究,结果表明:高温区主要集中在南部、西部、东部建筑密集,人口稠密,林地面积稀少,工业化程度高的地区;泰山风景区、徂徕山风景区以及东平湖周围地区温度较低。

Ground Penetrating Radar Survey of Dam Structures of Kazakhstan on example of Aktobe and Karatomar Water Storage Basins

Ground penetrating radar surveys of technical condition of Karatomar and Aktobe water storage basins on the river Tobol are shown. In this article we have shown that dams have problems with cavities and identified longitudinal dimensions of anomalous zones of decompression.

Numerical Analysis of Temperature Distributions in Single Cell of PEFC by Heat Transfer Model Considering Vapor Transfer

Polymer Electrolyte Fuel Cell(PEFC)is required to be operated at temperature at 100℃ for fuel cell vehicle applications during the period from 2020 to 2025 in Japan.It is expected that micro porous layer(MPL)and thinner polymer electrolyte membrane(PEM)would enhance the power generation performance of PEFC at this temperature.The key objective of this study is to analyse the impact of MPL and thickness of PEM on the temperature distributions of interface between the PEM and catalyst layer at the cathode(i.e.,the reaction surface)in a single PEFC.A 1D multi-plate heat transfer model,considering vapor transfer,which is based on temperature data of separator measured using thermograph in power generation process.It is developed to evaluate temperature at the reaction surface.This study is investigated the effect of flow rate and relative humidity of supply gases on temperature distribution on reaction surface.The study reveals that the impact of flow rate of supply gas on temperature distribution on reaction surface is smaller with and without MPL.It is observed that the even temperature distribution on reaction surface as well as higher power generation performance can be obtained with MPL irrespective of thickness of PEM and relative humidity conditions.

燃氢燃机高温高湿透平耦合传热和冷却特性

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。

镁合金表面钼−钛−锰导电转化膜高温高湿条件下的失效分析

[目的]分析AZ91D镁合金表面Mo-Ti-Mn导电转化膜在“双85”(指温度85℃、相对湿度85%)湿热环境中的失效行为,为开发性能更好的导电膜层提供依据。[方法]研究了Mo-Ti-Mn转化膜在湿热试验不同时间后表面形貌、耐蚀性、表面接触电阻(ECR)及禁带宽度的变化情况。[结果]随着湿热试验时间的延长,Mo-Ti-Mn转化膜的颜色逐渐变浅,微裂纹变宽,耐蚀性变差,接触电阻和禁带宽度增大。[结论]在湿热环境下,水汽渗入膜层的微裂纹中,与膜层和镁合金基体发生电化学反应。随着时间的推移,原本致密的膜层开始变得疏松,电化学腐蚀反应加速,最终丧失导电性和防护性。

高温高湿隧道工人劳动强度和劳动时间研究

当隧道穿越高温热泉断层破碎带时,施工人员将面临高温高湿环境,而钻爆法隧道施工工序复杂,劳动强度大,高湿环境对隧道人员的影响巨大。为保障隧道施工人员的安全健康,本文基于能量代谢率变化规律得到高温高湿环境隧道施工人员劳动强度修正等级和人体预测热应激修正模型,给出了高温高湿环境下隧道施工人员安全连续劳动时间建议,并在高温隧道进行了现场测试。结果表明:当温度大于30℃,湿度大于70%时,温度每增加4℃,或相对湿度每上升10%,隧道施工人员劳动强度等级约增加一级;当温度超过38℃,相对湿度大于90%或温度超过40℃,相对湿度大于70%时,所施工人员均应停止作业,现场测试结果表明人体热应激修正模型误差小于5%。