A Decadal Shift of Summer Surface Air Temperature over Northeast Asia around the Mid-1990s

This study identifies a decadal shift of summer surface air temperature （SAT） over Northeast Asia,including southeastern parts of Russia,Mongolia and northern China,around the mid-1990s.The results suggest that the SAT over the Northeast Asia experienced a significant warming after 1994 relative to that before 1993.This decadal shift also extends to northern China,and leads to a warmer summer over Northeast China and North China after the mid-1990s.The decadal warming over Northeast Asia is found to concur with the enhancement of South China rainfall around the mid-1990s.On the one hand,both the Northeast Asian SAT and South China rainfall exhibit this mid-1990s decadal shift only in summer,but not in other seasons.On the other hand,both the Northeast Asian SAT and South China rainfall exhibit this mid-1990s decadal shift not only in the summer seasonal mean,but also in each month of summer （June,July and August）.Furthermore,the decadal warming is found to result from an anticyclonic anomaly over Northeast Asia,which can be interpreted as the response to the increased precipitation over South China,according to previous numerical results.Thus,we conclude that the warming shift of summer Northeast Asian SAT around the mid-1990s was a remote response to the increased precipitation over South China.

Changes in the Covariability of Surface Air Temperature and Precipitation over East Asia Associated with Climate Shift in the Late 1970s

Variations in surface air temperature and precipitation are closely associated because of their thermodynamic relations. The climate shift in the late 1970s and associated changes in precipitation over East Asia have been well reported. However, how the covariability of surface air temperature and precipitation responds to the climate shift is not yet well understood. We used the observed mean（Tmean）, daily maximum（Tmax）, and minimum（Tmin） surface air temperatures and precipitation during the period of 1953–2000 to explore this issue. Results show that the covariability between Tmean and precipitation experienced remarkable changes over certain areas of East Asia after the climate shift with evident seasonal dependencies. In winter, after the climate shift significantly negative correlations occupied more areas over Mongolia and China. By contrast, in summer after the climate shift significantly negative correlations which existed over almost entire East Asia during the pre-shift period were mostly weakened with the exception of enhanced correlations over some small isolated areas. Changes in the covariability of Tmax and precipitation showed a similar spatial pattern to that of the Tmean, whereas the Tmin-precipitation covariability did not. In winter, after the climate shift positive correlations between Tmin and precipitation over southern China were largely weakened, while the areas with significantly negative correlations increased over Mongolia. In summer, changes in Tmin-precipitation covariability appeared to be a negative-positive-negative pattern from south to north over East Asia, with positive changes occurring in the Yangtze-Huai River valley and Korea and negative changes occurring over South China and Japan, and northern part of East Asia.

Preparation and High-Temperature Water-Gas Shift Catalytic Features of La_(1-x)Ce_x FeO_3 Perovskite

Based on water-gas shift reaction mechanism and perovskite compounds characteristics, La_(1- x )Ce_ x FeO_3 (.K) perovskite were designed and prepared as shift catalysts. DTA and XRD results reveal that La_(1- x )Ce_ x FeO_3 can be formed at 730～760 ℃ by mechanic-mix thermal decomposition method. Activity and heat-resisting tests show that La_(1- x )Ce_ x FeO_3 ((.K)) possess high thermal stability if x is less than or equals to 0.5. But when x is greater than 0.5, La_(1- x )Ce_ x FeO_3 (.K) will be converted into ceria and magnetite partially or completely under shift reaction conditions. In the case of x =0.5, the conversion of CO is about 68% at 530 ℃. Potassium can greatly improve the low temperature activity, but slightly reduces the high temperature activity, and has little impact on the thermal stability. La_(0.5)Ce_(0.5)FeO_3 (.K) is a promising chromium-free high temperature shift catalyst.

Observation of Temperature Induced Plasma Frequency Shift in an Extremely Large Magnetoresistance Compound LaSb

We report an optical spectroscopy study on LaSb, a compound recently identified to exhibit extremely large magnetoresistance. Our optieal measurement indicates that the material has a low carrier density. More inter- estingly, the study reveals that the plasma frequency increases with decreasing temperature. This phenomenon suggests either an increase of the conducting carrier density or/and a decrease of the effective mass of carriers with decreasing temperature. We attribute it primarily to the latter effect. Two possible scenarios on its physical origin are examined and discussed. The study offers new insight into the electronic structure of this compound.

An Abrupt Increase in the Summer High Temperature Extreme Days across China in the mid-1990s

Based on the daily maximum surface air temperature records from an updated homogenized temperature dataset for 549 Chinese stations during 1960-2008,we reveal that there is an abrupt increase in the number of days with high temperature extremes （HTEs,an HTE day is defined when the maximum temperature exceeds the 95th percentile of the daily maximum temperature distributions） across China in the mid-1990s.Before this regime shift,the average number of HTE days is about 2.9 d yr 1 during the period from the 1970s to the early 1990s,while it rocketed to about 7.2 d yr 1 after the mid-1990s.We show that the significant HTE day increase occurs uniformly across the whole of China after the regime shift.The observational evidence raises the possibility that this change in HTE days is associated with global-scale warming as well as circulation adjustment.Possible causes for the abrupt change in the HTE days are discussed,and the circulation adjustment is suggested to play a crucial role in the increase in HTE days in this region.

Variation in the distribution of wintering anchovy Engraulis japonicus and its relationship with water temperature in the central and southern Yellow Sea

In the present study,we investigated a shift in the spatial distribution of wintering anchovy(Engraulis japonicus)and its relationship with water temperature,using data collected by bottom trawl surveys and remote sensing in the central and southern Yellow Sea,during 2000–2015.Our results indicate that the latitudinal distribution of wintering anchovy varied between years,but there was no consistent pattern in the direction of change(north or south).Wintering anchovy did not move northward with increasing water temperature.However,the latitudinal distribution of wintering anchovy correlated well with 10°C and 11°C isotherms.The results of both a one-step and a two-step generalized additive model indicated that water temperature was associated with both presence and biomass of wintering anchovy.This paper is the fi rst to systematically examine the relationship between anchovy distribution and water temperature using a variety of techniques.All the fi ndings confi rm the impact of water temperature on wintering anchovy distribution,which has important implications for the continued management of the anchovy resource and the enhancement of marine fi shery resources in the Yellow Sea,especially as the climate changes.However water temperature only partly explains the species distribution of anchovy,and stock characteristics also aff ect fi shery distribution.Therefore,other factors should be considered in future research.

Extreme temperature increases the severity of intracerebral hemorrhage: An analysis based on the cold region of China

Objective:The purpose of this study was to find a suitable model to evaluate the relationship between temperature and intracerebral hemorrhage(ICH)and explore the effects of cold spells and heat waves on the clinicopathological parameters of ICH patients.Methods:We conducted a retrospective study based on the ICH admission in the First Affiliated Hospital of Harbin Medical University from 2015 to 2020(N=11124).The relationship between different seasons and the number of patients with ICH was explored.Poisson Akaike information criterion(AIC)was used to select the optimal model for temperature and ICH.Binary logistic regression analysis was used to investigate the association between extreme temperatures and clinicopathological features.Results:Hospital admissions for patients with ICH showed monthly changes.The optimal cold spell was defined as the daily average temperature<3rd percentile,lasting for five days,while the optimal heat wave was defined as the daily average temperature>97th percentile,lasting for three days.Based on the generalized extreme weather model,cold climate significantly increased the risk of hematoma volume expansion(OR 1.003;95%CI:1.000-1.005,P=0.047).In the optimal model,the occurrence of cold spells and heat waves increased the risk of midline shift in both conditions(OR 1.067;95%CI:1.021-1.115,P=0.004;OR 1.077;95%CI:1.030-1.127,P=0.001).Conclusion:Our study shows that seasonal cold spells and heat waves are essential factors affecting ICH severity,and targeted preventive measures should be taken to minimize the pathological impacts.

LED Applications in Railway Signals: Wavelength and Intensity vs Temperature Variation

In recent years, light emitting diodes (LEDs) have entered the lighting market, offering consumers performance and features exceeding those of traditional lighting technologies. LEDs (light-emitting diodes) are becoming more common in safety signals for railroad, highway, automotive, and many other applications. In addition to having a longer life and greater durability than incandescent bulbs, LEDs are much more energy efficient than their incandescent counterparts. Since the heat from the junction must be dissipated into the ambient somehow, changing the ambient temperature affects the junction temperature and hence the emitted light. When the LEDs are used in the railway or traffic signals, the optical proprieties of these have to maintain more rigorous specifications. Therefore the development of signals using LED as light source, able to respect intensity specifications, is not simple. In this paper, we describe problems of the temperature dependent changes of LED intensity and color shift. Besides we will introduce an innovative technique, that we have developed, to allow the use of the LEDs in applications with rigorous specifications.

叠合式有机朗肯循环的热力学分析

针对有机朗肯循环(ORC)中传热过程对循环性能的影响,该文提出一种既相似但又区别于混合工质,各工质独立运行的叠合式有机朗肯循环(AORC)。AORC中,各工质进行串/并联的叠合换热,可形成类似于非共沸混合工质的温度滑移。由于各工质独立运行,使得叠合工质的温度滑移量可进行调节,以减小与外界热/冷源的传热温差,提高传热匹配性以及循环性能。以两种工质叠合的AORC为例进行循环性能分析,并与常规ORC进行对比。结果表明,AORC并不是各工质基本ORC的简单线性叠加,而是一种优化叠加。相比常规ORC,AORC的净输出功率最大可提升34.48%。但当热源温度高于高温工质的热源转折温度时,AORC趋近于高温工质的基本ORC。

稻虾共作模式下土壤甲烷产生与氧化潜力及其对温度的响应特征

稻田是大气甲烷的重要人为排放源。为探讨不同稻田利用方式下甲烷产生和氧化潜力及其对温度的响应特征,以我国东南部地区常规稻田种植体系、由稻田转变来的稻虾种养结合体系和常规虾塘养殖体系为研究对象,分别采集位于江苏省句容市常规稻田(CR)、共作稻区(R-CR)和共作虾区(R-CC)以及常规虾塘(CC)土壤样品,在5℃、15℃、25℃和35℃条件下进行为期30 d的室内培养实验。结果表明:农业土地利用方式转变对甲烷产生和氧化潜力均有显著影响,甲烷产生潜力由大到小依次为:共作虾区、常规虾塘、共作稻区、常规稻田,分别为1.14、0.33、0.25和0.17μg·g^(-1)·d^(-1),甲烷氧化潜力从大到小依次为:常规稻田、常规虾塘、共作稻区、共作虾区,分别为1.38、1.01、1.00和0.71μg·g^(-1)·d^(-1)。由于水分管理差异以及饲料、氮肥投入导致底物和环境因子差异造成了产甲烷菌、甲烷氧化菌的活性差异,使得不同土地利用类型土壤呈现不同的甲烷产生和氧化潜力特征;甲烷产生潜力随培养温度的升高呈指数增长,在5℃、15℃、25℃和35℃时的平均值分别为0.13、0.26、0.55和0.95μg·g^(-1)·d^(-1)。而甲烷氧化潜力仅在低温时比较敏感,在15℃、25℃、35℃时与5℃下的甲烷氧化潜力存在显著差异,而三种培养温度之间无显著差异(甲烷氧化潜力在5℃、15℃、25℃和35℃时分别为0.71、1.14、1.14和1.11μg·g^(-1)·d^(-1))。总体上,甲烷产生潜力对温度的响应强于甲烷氧化潜力。此外,土壤甲烷产生和氧化潜力均受温度或土地利用类型单因素的显著影响(P<0.01),但两者的交互效应仅对土壤甲烷产生潜力存在显著影响,对甲烷氧化潜力并无显著影响。

2000—2018年长株潭城市群城市扩张及其热岛响应

城市热岛效应同城市居民福祉息息相关,特别是近20 a我国的中西部城市在快速城市化的背景下,城市扩张进程进一步加快,城市热岛效应的影响也随之不断增加。为探究城市及城市群扩张与城市热岛效应变化的关系,以长株潭城市群为研究区域,利用Boyce-Clark形状指数分析城市扩张进程及空间形态变化。首先,利用基于Google Earth Engine(GEE)平台的实用单通道算法进行温度反演;然后,使用均值-标准差法划分温度等级区并定义和提取城市热岛范围;最后,提取城市重心和热岛重心,采用重心迁移方法分析城市扩张与热岛效应之间的变化趋势。结果表明城市热岛变化与城市群城市扩张趋势一致,研究结论如下:①2015年后长株潭城市群进入高速发展关键时期;②城市扩张是热岛面积增加的主要原因;③城市热岛重心与城市重心迁移趋势基本一致,城市热岛范围增加的方向也同城市扩张方向基本一致。

2000-2021年乌鲁木齐河流域地表温度的时空变化特征分析

地表温度是影响生态变化的重要因素之一,地表温度可间接监测所在区域的生态环境状况.选取Landsat TM/OIL遥感影像为数据源,使用单窗算法定量反演2000,2005,2010,2015,2021年5期乌鲁木齐河流域地表温度,采用重心转移模型分析地表温度的空间转移特征,并结合土地利用数据分析不同土地利用类型的地表温度时空差异.结果表明:(1) 2000-2021年,乌鲁木齐河流域地表温度(Land Surface Temperature, LST)整体升高显著,22年间LST平均上升速率为0.44℃/a,在空间格局上,整个流域LST空间分布差异较大,温度主要以极高温、高温为主,其中,2021年高温区面积占流域面积的46%;(2) 2000-2021年各温区重心分布具有明显的方向性转移,各温区重心迁移轨迹明显向中游靠拢,建筑用地面积的增多是流域地表温度变化的主要因素;(3) 2000-2021年研究区地表热环境贡献从大到小依次为:草地、林地、水体、耕地、未利用地、建设用地,只有建设用地为正贡献.

时间-温度-应力等效原理在PET蠕变拉伸中的应用

为了研究时间-温度-应力等效原理在PET材料蠕变拉伸中的应用,预测PET材料的长期性能。对PET材料进行恒温度不同应力和恒应力不同温度下的短期拉伸蠕变试验,分析其蠕变行为。结果表明,在测试温度和测试应力范围内,PET材料表现出明显蠕变现象,且蠕变性能具有明显的温度相关性和应力水平相关性。不同温度和不同应力水平下的短期蠕变柔量曲线沿对数时间坐标轴可构建出宽广时域下温度应力耦合的蠕变柔量主曲线,所得温度应力耦合蠕变柔量主曲线基本一致,表明在试验温度和试验应力下,时间-温度-应力等效原理对PET材料有良好的适用性,可以用于PET材料的长期蠕变性能加速表征。此外,比较先温度后应力、先应力后温度和温度应力同时移位三种不同移位顺序下所获得的温度-移位联合移位因子,结果表明三种移位顺序下的联合移位因子近似相等,验证了联合移位因子分步获取的可行性。

差分式声表面波温度应变复合传感器

基于声表面波理论和微扰理论,提出了并研制由3个谐振器组成的差分式声表面波温度应变复合传感器。通过有限元分析软件对AT切和XY切的两种声表面波谐振器进行了仿真,根据其频率-应变响应和频率-温度响应,设计并研制了能够进行温度补偿和应力应变补偿的温度应变传感器,传感器的应力测量灵敏度为100 Hz/με,,温度测量灵敏度为80 kHz/℃。该传感器成功应用到了隔离开关的状态监测。现场测试表明,该传感器对隔离开关触指温度和应变的检测可实现对隔离开关工作状态的有效判别,在未来的电力系统设备在线检测中具有重要的应用前景。

嗜热链球菌grx02化学限定增殖培养基及变温培养策略的研究

文章研究了能够促进嗜热链球菌grx02生长的化学限定培养基成分、浓度及其变温培养方法。通过单一成分扣除实验确定化学限定培养基的碳源、氨基酸、维生素矿物质等营养成分的组成,进一步通过单因素实验,对化学限定培养基组分浓度、变温培养方法进行优化,以提高嗜热链球菌grx02的活菌数。结果表明,嗜热链球菌grx02化学限定增殖培养基由1种碳水化合物、16种氨基酸、6种维生素、3种矿物质、4种无机盐、2种有机盐组成;培养初始温度、延滞末期及对数末期温度分别为39、37、39℃。最终嗜热链球菌grx02生物量达到1.40,较优化前提高了1.63倍,活菌数达到9.04 log CFU/mL。可为嗜热链球菌生产及其代谢与功能研究提供参考。

变换单元高温冷凝液系统运行问题的分析与解决

针对中海石油华鹤煤化有限公司合成氨装置变换单元出现的高温冷凝液闪蒸槽压力低、高温冷凝液泵高频率运行、闪蒸气不能完全并入冷凝液汽提塔等问题,进行了原因分析,并结合运行情况,通过工艺操作调整和采取引高压氮气给闪蒸槽提压、优化冷凝液和闪蒸气管线伴热、直接向闪蒸气管线喷入低压蒸汽等技术改造措施,解决了高温冷凝液系统出现的问题。改造后,既节能降耗,又缩减了运行成本,降低装置运行风险。

Analysis of the blackbody-radiation shift in an ytterbium optical lattice clock

We accurately evaluate the blackbody-radiation shift in a171 Yb optical lattice clock by utilizing temperature measurement and numerical simulation. In this work. three main radiation sources are considered for the blackbody-radiation shift, including the heated atomic oven, the warm vacuum chamber, and the room-temperature vacuum windows. The temperatures on the outer surface of the vacuum chamber are measured during the clock operation period by utilizing seven calibrated temperature sensors. Then we infer the temperature distribution inside the vacuum chamber by numerical simulation according to the measured temperatures. Furthermore, we simulate the temperature variation around the cold atoms while the environmental temperature is fluctuating. Finally, we obtain that the total blackbody-radiation shift is -1.289（7）Hz with an uncertainty of 1.25×10;for our;Yb optical lattice clock. The presented method is quite suitable for accurately evaluating the blackbody-radiation shift of the optical lattice clock in the case of lacking the sensors inside the vacuum chamber.

ShiftMax208低温变换催化剂还原小结

对合成氨装置新更换的低变催化剂还原实际情况进行了总结,分析了催化剂在还原时的特点。

Distinct Global Patterns of Strong Positive and Negative Shifts of Seasons over the Last 6 Decades

Alterations of annual temperature cycles have profound implications on how the planet responds to global climate change. In this study, a high resolution global analysis of temperature cycle shifts and their development over time is presented. We show that over the last 63 years, phase shifts in the annual near surface temperature cycle exhibit large spatiotemporal variability. The calculated phase shifts comprise earlier onsets of seasons as well as delays with similar frequencies, depending on location. From 1978 to 2010 Eastern Europe experienced an advanced annual cycle of near-surface temperature of 3.2 days while Eastern Australia shows an opposite shift towards later seasons of 3.5 days in comparison to the preceding 30-year period from 1948 to 1977. The largest phase shifts of –5.5 days toward earlier seasons over land were found in Belarus and Northwest Russia. For the first time the developments of seasonal temperature shifts were generalized for large areas by using self-organizing feature map neural networks resulting into 4 significant global trends. The temperature phase shifts are also shown to have strong correlations with the timing of shrub foliation observed at 57 phenological stations across the USA. The findings have far-reaching, yet regionally distinct consequences on agriculture, animal life cycles, plant phenology, and regional weather phenomena that change with annual temperature cycles.

Preparation and Water-Gas Shift Catalytic Activities of the Perovskite Type Complex Oxide La_(1-x) Ce_xFeO_3

The perovskite type rare earth iron complex (REIC) oxide La 1-x Ce xFeO 3 is designed and prepared as water gas shift catalyst. Activity evaluation and heat resisting test show that the perovskite type compounds La 1-x Ce xFeO 3(·K) has a good thermal stability if x is less than or equal to 0.5 . But when x is greater than 0.5 , La 1-x Ce xFeO 3(·K) will turn out to be ceria and magnetite partially or completely at high temperature in the shift reaction atmosphere. In the case of x=0.5, the conversion of carbon monoxide is about 68% at 530 ℃. Potassium can greatly improve the low temperature activity, but slightly lower the high temperature activity, and has little impact on the thermal stability. La 0.5 Ce 0.5 FeO 3 (·K) is a promising chromium free high temperature shift catalyst.