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^-.

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 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.

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.

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。

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%。

基于神经网络的南方夏季蛋鸡舍环境与产蛋性能关系模型研究

为了解决南方地区夏季高温高湿蛋鸡舍环境质量难以精准评价与调控的问题,试验构建了基于神经网络的南方夏季蛋鸡舍环境与产蛋性能关系模型,将采集的蛋鸡舍多环境因子数据作为输入,将依据产蛋率划分的环境质量等级作为输出,对反向传播(BP)神经网络、径向基(RBF)神经网络和广义回归(GRNN)神经网络三种神经网络进行训练验证,得到蛋鸡舍环境质量初步评价结果,然后将归一化后神经网络组的输出作为改进D-S证据理论基本概率分配的输入,利用改进的D-S证据理论方法,融合计算得到蛋鸡舍环境质量的综合评价结果。结果表明:在神经网络初级融合评价有冲突的情况下,改进的D-S证据理论法对蛋鸡舍环境状态为差的支持率为0.796 4,而传统D-S证据理论方法、Murphy方法和邓勇方法对蛋鸡舍环境状态为差的支持率分别为0.698 7,0.687 8,0.694 0。说明试验构建的综合评价模型对蛋鸡舍环境的融合评价精度和准确率更高,可以有效解决融合决策失误问题,可用于南方夏季高温高湿蛋鸡舍环境的精准调控。

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

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。

高温高湿条件环己烷泄漏率法可行性研究

核设施通常采用碘吸附器净化放射性气态碘,环己烷泄漏率法可用于测试碘吸附器的泄漏率,但是高温、高湿的气流条件会造成环己烷气体在活性炭中过早解吸,可能导致无法辨别机械泄漏与解吸穿透,使得泄漏率试验失效。本试验采用环己烷气体动态解吸法测定了在气流温度为75℃、80℃、85℃,气流相对湿度为85%、90%、95%条件下,环己烷气体在与碘吸附器炭层等厚的活性炭试验床中的解吸穿透时间。结果表明,随着气流温度与湿度的上升,环己烷气体在活性炭床中的停留时段缩短,在最高试验温度(85℃)及试验气体相对湿度(95%)条件下,环己烷气体从活性炭床中的解吸穿透时间远大于工程实践中机械泄漏的判定时间。通过开展机械泄漏模拟试验,在试验炭床上分别设置多孔径泄漏点,测试了高温、高湿试验对应的气流条件下活性炭床的泄漏率。结果表明,高温高湿条件下,环己烷泄漏率法测试机械泄漏的灵敏度高,响应性好,具备用于碘吸附器的泄漏率测试的可行性。

毛椰子果不同温湿度贮藏条件下的品质变化

该研究采用三种不同温湿度贮藏条件对毛椰子果的品质变化进行分析。结果表明在25℃/70%贮藏条件下毛椰子果贮藏8 w后椰肉品质仍可接受,部分变质(坏果率24.07%),但部分出现无椰子水、椰肉干瘪现象;在35℃/80%条件下贮藏5 w后变质果已较多(坏果率59.26%);在45℃/90%条件下贮藏4 w后全部变质(坏果率100%)。变质后椰肉内表面出现变色、变软等现象。随着贮藏温湿度和贮藏时间的增加,毛椰子果的失重率明显增加,最高达到35.98%;椰肉油脂酸价也不断升高(由0.09 mg/g升至0.30 mg/g),变质果达到0.44 mg/g;总脂肪酸、饱和与不饱和脂肪酸都降低,总脂肪酸含量由733.66 mg/g最低降至25℃/70%贮藏8 w后的496.14 mg/g,变质果降低的更严重(200.08 mg/g)。随着贮藏时间的增加,椰子水可溶性固形物含量增加(由3.70°Brix增至7.00°Brix)。变质后pH值降低(低至4.22)、浑浊度增加(高达0.74)。综上所述,不同温湿度贮藏条件使毛椰子果品质发生了较大变化,该研究为毛椰子果贮藏过程中品质控制及变质果的筛选提供了一定的理论基础。

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℃.

低压静电场协同低温高湿解冻对牛肉嫩度和持水性的影响

为探究低压静电场协同低温高湿解冻对牛肉嫩度和持水性的影响,本研究以牛背最长肌为试验材料,分析了低压静电场解冻(电压2500 V,温度4℃,相对湿度50%)、低温高湿解冻(温度4℃,相对湿度98%)、低压静电场协同低温高湿解冻(电压2500 V,温度4℃,相对湿度98%)与低温解冻(温度4℃,相对湿度50%)四种解冻方式对冷冻牛肉剪切力、质构、水分分布、水分含量、持水性、感官评价的影响。结果表明:低压静电场协同低温高湿解冻的解冻时间最短(804 min),其中解冻损失(2.06%)、蒸煮损失(26.09%)与离心损失(15.00%)显著低于其余三种解冻方式(P<0.05),垂直肌纤维剪切力值(95.46 N)和平行肌纤维剪切力值(41.69 N)最低,自由水含量最低,水分迁移较少,水分含量(68.31%)最高,嫩度品质最优,该解冻方式样品的组织状态、气味、弹性及色泽均最优(总体可接受度最高);综上,低压静电场协同低温高湿解冻加快了牛肉解冻速率、减少了汁液流失,改善了牛肉持水性和嫩度,品质最佳。本研究结果将为低压静电场协同低温高湿解冻技术在冷冻牛肉解冻的产业应用提供理论依据。

南方夏季犊牛气喘病的病因探究及其防控策略

南方夏季高温高湿,新生犊牛呼吸道黏膜屏障与免疫机制不健全,以“气喘”和“高热”为主要临床症状的气喘病频发,救治不及时易造成患畜死亡。引起犊牛喘气病的因素颇多,其中包括环境、饲养管理、异物性肺炎及病原体感染等,严重困扰肉牛养殖业。文章总结了南方夏季犊牛喘气病的常见病因及其综合防控策略,以期为该病的临床诊疗及综合防控提供参考。

黄河口大闸蟹高温天气指数保险产品设计与研发

利用1981-2021年东营国家气象观测站逐日气温观测数据、2019-2021年黄河口农业水域小气候观测站逐日气温和水温观测数据以及2004-2021年东营市黄河口大闸蟹产量数据,采用滑动平均法分离气象产量后计算气象减产率,分析大闸蟹生长周期内温度和减产率的关系,筛选极显著相关的高温天气指标,构建高温指数-灾损模型,确定灾害损失阈值,设计研发黄河口大闸蟹高温天气指数保险产品。结果表明:随着生产技术的提高,黄河口大闸蟹增产明显;受不同年份气象条件差异影响,黄河口大闸蟹气象减产率波动明显,减产率与≥35℃有效积温日均值呈极显著正相关(P<0.01)。结合1981-2021年高温气象资料,确定≥35℃的有效积温日均值即高温指数达1.893℃·d,可导致大闸蟹减产12.4%;依高温指数-灾损模型可进一步将黄河口大闸蟹高温灾害分为轻度、较轻、中度、较重和重度五级,并取高温指数≥1.529℃·d作为理赔触发值计算可发生赔付年份的平均赔付金额为294.04元667m^(−2),赔付金额范围为58.59~651.00元667m^(−2);黄河口大闸蟹高温天气指数纯保险费率为6.61%,保费为43.03元667m^(−2)。

高干热现场环境下智能电能表可靠性验证方法

智能电能表通用技术规范要求电能表可靠寿命不低于16年,如何验证智能电能表可靠性不仅是行业亟需解决的现实问题,也是学术界面临的难点问题。文章在Weibull分布场合下给出了针对可靠寿命、平均寿命和失效率三项指标的可靠性验证抽样特性函数。结合高干热环境的加速效应,借助加速因子构建基于加速试验的电能表抽样特性函数,进而针对智能电能表的工程背景确定二参数抽样方案。在实验验证与分析中给出了高干热环境下智能电能表可靠性验证方案,在不同使用方风险、可接受的故障数条件下计算了试验样本容量与试验时间的组合,给出了表格和绘图,方便工程应用。对电力行业量测设备在高干热环境下开展可靠性验证具有示范作用。

不同造模方法建立高尿酸血症动物模型的述评

高尿酸血症(hyperuricemia,HUA)是体内嘌呤代谢紊乱引起的代谢性疾病,目前呈现总体患病率逐年增高、发病年轻化的趋势。该病是多种心血管危险事件及相关疾病的独立危险因素,然而其发病机制尚未完全阐明。建立可靠的HUA动物模型是研究其发病机制、相关并发症和治疗干预的基础。目前,HUA动物模型造模方法复杂多样,尚无统一标准。因此,本文从物种选择、评价方法、造模原理、制备方法展开讨论,对各造模方法的应用价值和潜在问题进行阐述,以期为建立及复制稳定可靠的HUA动物模型提供参考。

高温高湿环境与蛋白质补充对运动员能量代谢的影响

目的:探究高温高湿环境下递增负荷运动结合乳清蛋白补充对运动员静息代谢,运动时和运动后代谢气体中碳水化合物、脂肪代谢的影响。方法:招募8名一线男性现代五项运动员,分别按照常规环境-对照组、常规环境-乳清蛋白组、高温高湿环境-对照组、高温高湿环境-乳清蛋白组的干预顺序进行实验。测试当天进行静息代谢测试和体成分测试,在进入特殊环境测试前30 min补充或不补充乳清蛋白,随后进行递增负荷测试,结束后采集恢复10 min代谢气体,次日清晨再进行静息代谢测试。结果:在不同环境下急性递增负荷运动结合乳清蛋白补充干预次日的静息代谢率组间无显著性差异。高温高湿环境下的补充组和对照组的碳水化合物氧化率、供能率均显著提高(P<0.05)。递增负荷运动中各阶段碳水化合物氧化率,在高温高湿环境下4~8 km/h时补充与对照组均显著降低。在峰值运动负荷时和运动后的1~9 min内存在环境主效应显著性差异(P<0.05)。各阶段脂肪氧化率,在高温高湿环境下4~8 km/h阶段中补充与对照组均升高,存在补充主效应显著性差异(P<0.05)。在运动中的13~16 km/h时存在环境主效应显著性差异。结论:与常规环境相比,高温高湿环境急性递增负荷运动结合运动前乳清蛋白补充对运动员次日静息代谢、整个运动过程的碳水化合物氧化率和脂肪氧化率无影响。在较低运动强度下(4~8 km/h)补充乳清蛋白,可提高脂肪氧化率和降低碳水化合物氧化。

高温高湿贮藏对大豆及其加工产品品质影响研究进展

大豆作为一种优质的植物蛋白来源,近年来广泛应用于食品行业。大豆贮藏是大豆在收获后直至加工前的必要阶段,但贮藏过程中可能存在极端环境如高温、高湿及极低温等条件,会直接影响大豆原料的组分特性和结构,从而影响加工产品的品质。因此,研究大豆贮藏环境和产品品质变化至关重要。本文系统综述了国内外大豆贮藏过程中大豆及产品变化的相关研究进展,分析了不同贮藏条件下大豆原料的蛋白质、脂肪、碳水化合物等组分及其加工产品豆乳、豆腐的品质变化,重点分析高温高湿贮藏条件(极端环境)下大豆蛋白质等主要组分和豆腐品质的变化机制,为大豆长期贮运和豆制品产业发展提供参考。

高温高湿环境下大鼠肠道菌群与脑肠肽关联性分析

目的:探讨高温高湿环境下大鼠肠道菌群结构和功能表达,及其与血清脑肠肽指标间的相关性。方法:将16只成年SD雄性大鼠随机分成2组,常温常湿组和高温高湿组,每组8只。常温常湿组放置于温度(25±2)℃、湿度(50±5)%的恒温恒湿箱中,高温高湿组放置于温度(40±2)℃、湿度(70±5)%的恒温恒湿箱中,饲养7 d,期间正常喂食饮水。实验收集两组SD大鼠粪便样品于1.5 mL离心管,并通过腹主动脉采集血液样本。采用16S rDNA和宏基因组测序法对2组大鼠粪便样品进行分析,明确高温高湿环境对菌群结构和功能的影响。采用酶联免疫吸附测定法(ELISA)测定大鼠血清胆囊收缩素(CCK)水平;Spearman相关性分析菌群与脑肠肽间的相关性。结果:动物行为学观察表明高温高湿组大鼠躁动不安,随着时间延长出现大鼠前爪挠面部且精神差的情况,大鼠活动也逐渐减弱。16S rDNA和宏基因组测序结果显示,与常温常湿组相比,高温高湿环境能够显著降低肠道菌群的Alpha和Beta多样性,引起厚壁菌门/拟杆菌门的比值升高。物种差异分析获得核心差异菌群,其中上调菌群为棒状杆菌、另枝菌属,下调菌群为普雷沃氏菌、考拉杆菌、毛螺旋菌、瘤胃球菌;功能分析结果表明高温高湿主要影响精氨酸和脯氨酸代谢、卟啉代谢、视黄醇代谢等新陈代谢过程及生物合成,还涉及糖酵解/糖新生、ABC转运蛋白、核糖体等。ELISA测定结果显示高温高湿组SD大鼠血清CCK含量较常温常湿组显著降低,并与核心差异菌群呈现相关性。结论:高温高湿环境可引起大鼠肠道菌群结构和功能异常,进而通过核心差异菌群影响CCK水平变化,影响大鼠情绪的调控。功能富集分析表明,高温高湿环境下大鼠肠道差异菌与大鼠情绪变化具有相关性,提示与神经性疾病有重要的关系。该研究丰富了环境对肠道菌群影响的认识,同时对临床诊断和研究提供了支撑。