Changes of heating and cooling degree days over China in response toglobal warming of 1.5℃, 2℃, 3℃ and 4℃

Future changes of heating degree days （HDD） and cooling degree days （CDD） in the 21st century with and without considering populationfactor are investigated based on four sets of climate change simulations over East Asia using the regional climate model version 4.4 （RegCM4.4）driven by the global models of CSIRO-Mk3-6-0, EC-EARTH, HadGEM2-ES, and MPI-ESM-MR. Under global warming of 1.5℃, 2℃, 3℃,and 4℃, significant decrease of HDD can be found over China without considering population factor, with greater decrease over high elevationand high latitude regions, including the Tibetan Plateau, the northern part of Northeast China, and Northwest China; while population-weightedHDD increased in areas where population will increase in the future, such as Beijing, Tianjin, parts of southern Hebei, northern Shandong andHenan provinces. Similarly, the CDD projections with and without considering population factor are largely different. Specifically, withoutconsidering population, increase of CDD were observed over most parts of China except the Tibetan Plateau where the CDD remained zerobecause of the cold climate even under global warming; while considering population factor, the future CDD decreases in South China andincreases in North China, the Sichuan Basin, and the southeastern coastal areas, which is directly related to the population changes. The differentfuture changes of HDD and CDD when considering and disregarding the effects of population show that population distribution plays animportant role in energy consumption, which should be considered in future research.

Impact of Thickness of Polymer Electrolyte Membrane and Gas Diffusion Layer on Temperature Distributions in Polymer Electrolyte Fuel Cell Operated at Temperature around 90℃

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.

Evolution of soil DOM during thermal remediation below 100℃:concentration,spectral characteristics and complexation ability

The impact of thermal remediation on soil function has drawn increasing attention.So far,as the most active fraction of soil organic matter,the evolution of dissolved organic matter(DOM)during the thermal remediation lacks in-depth investigation,especially for the temperatures value below 100℃.In this study,a series of soil thermal treatment experiments was conducted at 30,60,and 90℃ during a 90-d period,where soil DOM concentration increased with heating temperature and duration.The molecular weight,functional groups content and aromaticity of DOM all decreased during the thermal treatment.The excitation-emission matrices(EEM)results suggested that humic acid-like substances transformed into fulvic acid-like substances(FIII/FV increased from 0.27 to 0.44)during the heating process,and five DOM components were further identified by EEM-PARAFAC.The change of DOM structures and components indicated the decline of DOM stability and hydrophilicity,and can potentially change the bioavailability and mobility.Elevated temperature also resulted in the decline of DOM complexation ability,which may be caused by the loss of binding sites due to the decrease of polar function groups,aromatic structures and hydrophilic components.This study provides valuable information about the evolution of DOM during thermal remediation,which would potentially change the fate of metal ions and the effectiveness of the post-treatment technologies in the treated region.

加温后乳腺癌和正常乳腺细胞激光电泳行为的比较研究

应用激光多普勒电泳技术比较了在４２．５℃加温治疗后ＭＡ７３７乳腺癌和相应正常乳腺细胞的膜电荷效应，并观察了利多卡因对细胞膜热损伤的扩大作用。结果表明，肿瘤细胞随４２．５℃加温时间，从０’，３０’，６０’，９０’到１２０’的延长，ＥＰＭ值下降，分别为２．８３９，２．４６０，２．２６５，２．０７６和１．８７０μｍ／ｓｅｃ／ｖ／ｃｍ，而加温对正常细胞的表面电荷没有明显影响。表明肿瘤细胞比正常细胞有较高的热敏性。这两种细胞对温度反应的差异，与各自细胞膜治疗前的物理状态不同有关。局麻药利多卡因可进一步降低加温诱发的肿瘤细胞迁移速度的下降，其与肿瘤生长抑制关系作了初步分析。

Regional changes in extreme heat events in China under stabilized 1.5℃ and 2.0℃ global warming

Extreme heat events(EHEs)have a significant impact on the social economy and human health.China is a country with a large population and diverse terrain,and it is necessary to project future extreme heat changes in the sub-regions.This study used a specially designed dataset,the Community Earth System Model(CESM)simulations,namely CESM low-warming,to investigate the EHEs in China under 1.5℃ and 2.0℃ global warming.The results indicate that the regional mean warming over China will exceed the global average,about 1.63℃ and 2.24℃ in 1.5℃ and 2.0℃ warmer futures.Compared to the present-day(1976–2005),the frequency and duration of the EHEs in South China are projected to increase the most among the sub-regions.For example,the frequency of EHEs in South China at 1.5℃ and 2.0℃ warming will exceed 3 and 3.5 times the present-day level.However,when global warming rises from 1.5℃ to 2.0℃,the increased impacts relative to the 1.5℃ warming level will be the lowest in South China(less than 40%),and the highest increased impacts are projected to appear in Northeast China(53%-84%)and Northwest China(53%–107%).The main reason for this situation is that compared with the 1.5℃ scenario,the upper zonal westerly in northern China weakens and the continental high pressure enhances under the 2.0℃ scenario.Therefore,limiting global warming at 1.5℃ instead of 2.0℃ is beneficial for eliminating extreme heat events,especially for Northeast China and Northwest China.

Increased Tibetan Plateau vortex activities under 2℃warming compared to 1.5℃warming:NCAR CESM low-warming experiments

The Tibetan Plateau vortices(TPVs)are the major rain-producing systems over the Tibetan Plateau(TP).The activities of TPVs are closely related to TP's water source,which supplies fresh water to millions of people in Asia.Projection of the TPVs can increase understanding about the future of water supply in Asia under global warming.In this study,the possible activities of TPVs under 1.5℃and 2℃warming scenarios above the pre-industrial level are evaluated through the NCAR CESM(Community Earth System Model)Low-warming(CESM-LW)Experiments.The results show that the CESM-LW well reproduces the spatio-temporal characteristics of TPVs in the historical run from 1985 to 2000.The CESM-LW suggests TPVs in warm season(May-September)increase by 15%due to the additional 0.5℃warming by the end of this century(2071—2100).It implies the greater importance of TPVs to the precipitation over the TP in the future.The changes of TPVs are closely related to the large-scale circulations adjustments.The additional 0.5℃warming strengthens the temperature difference between the TP and its surrounding areas,which results in an enhanced convergence near the TP's surface and divergence in the upper troposphere by about-0.1×10^(-6)and 0.22×10^(6)s^(-1),respectively.The assessment of future TPVs provides a synoptic dynamic perspective on the climate change of precipitation and water resources.